version: bump snapshot

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

COPYING

@@ -1,338 +1,17 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 2, June 1991
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
 
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
 
-                            Preamble
-
-  The licenses for most software are designed to take away your
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-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
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-Foundation's software and to any other program whose authors commit to
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-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
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-                     END OF TERMS AND CONDITIONS
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-            How to Apply These Terms to Your New Programs
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-possible use to the public, the best way to achieve this is to make it
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-  To do so, attach the following notices to the program.  It is safest
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-    Copyright (C) <year>  <name of author>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License version 2
-    as published by the Free Software Foundation.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
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-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
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-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, the commands you use may
-be called something other than `show w' and `show c'; they could even be
-mouse-clicks or menu items--whatever suits your program.
-
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-  `Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -1,33 +1,19 @@
 PREFIX ?= /usr
 DESTDIR ?=
 BINDIR ?= $(PREFIX)/bin
-export GOPATH ?= $(CURDIR)/.gopath
 export GO111MODULE := on
 
 all: generate-version-and-build
 
-ifeq ($(shell go env GOOS)|$(wildcard .git),linux|)
-$(error Do not build this for Linux. Instead use the Linux kernel module. See wireguard.com/install/ for more info.)
-else
-ireallywantobuildon_linux.go:
-	@printf "WARNING: This software is meant for use on non-Linux\nsystems. For Linux, please use the kernel module\ninstead. See wireguard.com/install/ for more info.\n\n" >&2
-	@printf 'package main\nconst UseTheKernelModuleInstead = 0xdeadbabe\n' > "$@"
-clean-ireallywantobuildon_linux.go:
-	@rm -f ireallywantobuildon_linux.go
-.PHONY: clean-ireallywantobuildon_linux.go
-clean: clean-ireallywantobuildon_linux.go
-wireguard-go: ireallywantobuildon_linux.go
-endif
-
 MAKEFLAGS += --no-print-directory
 
 generate-version-and-build:
 	@export GIT_CEILING_DIRECTORIES="$(realpath $(CURDIR)/..)" && \
 	tag="$$(git describe --dirty 2>/dev/null)" && \
-	ver="$$(printf 'package main\nconst WireGuardGoVersion = "%s"\n' "$$tag")" && \
-	[ "$$(cat version.go 2>/dev/null)" != "$$ver" ] && \
-	echo "$$ver" > version.go && \
-	git update-index --assume-unchanged version.go || true
+	ver="$$(printf 'package device\nconst WireGuardGoVersion = "%s"\n' "$${tag#v}")" && \
+	[ "$$(cat device/version.go 2>/dev/null)" != "$$ver" ] && \
+	echo "$$ver" > device/version.go && \
+	git update-index --assume-unchanged device/version.go || true
 	@$(MAKE) wireguard-go
 
 wireguard-go: $(wildcard *.go) $(wildcard */*.go)
@@ -36,7 +22,10 @@ wireguard-go: $(wildcard *.go) $(wildcard */*.go)
 install: wireguard-go
 	@install -v -d "$(DESTDIR)$(BINDIR)" && install -v -m 0755 "$<" "$(DESTDIR)$(BINDIR)/wireguard-go"
 
+test:
+	go test -v ./...
+
 clean:
 	rm -f wireguard-go
 
-.PHONY: all clean install generate-version-and-build
+.PHONY: all clean test install generate-version-and-build

README.md

@@ -2,8 +2,6 @@
 
 This is an implementation of WireGuard in Go.
 
-***WARNING:*** This is a work in progress and not ready for prime time, with no official "releases" yet. It is extremely rough around the edges and leaves much to be desired. There are bugs and we are not yet in a position to make claims about its security. Beware.
-
 ## Usage
 
 Most Linux kernel WireGuard users are used to adding an interface with `ip link add wg0 type wireguard`. With wireguard-go, instead simply run:
@@ -20,7 +18,7 @@ To run wireguard-go without forking to the background, pass `-f` or `--foregroun
 $ wireguard-go -f wg0
 ```
 
-When an interface is running, you may use [`wg(8)`](https://git.zx2c4.com/WireGuard/about/src/tools/man/wg.8) to configure it, as well as the usual `ip(8)` and `ifconfig(8)` commands.
+When an interface is running, you may use [`wg(8)`](https://git.zx2c4.com/wireguard-tools/about/src/man/wg.8) to configure it, as well as the usual `ip(8)` and `ifconfig(8)` commands.
 
 To run with more logging you may set the environment variable `LOG_LEVEL=debug`.
 
@@ -28,7 +26,7 @@ To run with more logging you may set the environment variable `LOG_LEVEL=debug`.
 
 ### Linux
 
-This will run on Linux; however **YOU SHOULD NOT RUN THIS ON LINUX**. Instead use the kernel module; see the [installation page](https://www.wireguard.com/install/) for instructions.
+This will run on Linux; however you should instead use the kernel module, which is faster and better integrated into the OS. See the [installation page](https://www.wireguard.com/install/) for instructions.
 
 ### macOS
 
@@ -36,7 +34,7 @@ This runs on macOS using the utun driver. It does not yet support sticky sockets
 
 ### Windows
 
-It is currently a work in progress to strip out the beginnings of an experiment done with the OpenVPN tuntap driver and instead port to the new UWP APIs for tunnels. In other words, this does not *yet* work on Windows.
+This runs on Windows, but you should instead use it from the more [fully featured Windows app](https://git.zx2c4.com/wireguard-windows/about/), which uses this as a module.
 
 ### FreeBSD
 
@@ -48,7 +46,7 @@ This will run on OpenBSD. It does not yet support sticky sockets. Fwmark is mapp
 
 ## Building
 
-This requires an installation of [go](https://golang.org) ≥ 1.11.
+This requires an installation of [go](https://golang.org) ≥ 1.13.
 
 ```
 $ git clone https://git.zx2c4.com/wireguard-go
@@ -58,27 +56,22 @@ $ make
 
 ## License
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License version 2 as
-    published by the Free Software Foundation.
+    Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
     
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License along
-    with this program; if not, write to the Free Software Foundation, Inc.,
-    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-    ---------------------------------------------------------------------------
-    Additional Permissions For Submission to Apple App Store: Provided that you
-    are otherwise in compliance with the GPLv2 for each covered work you convey
-    (including without limitation making the Corresponding Source available in
-    compliance with Section 3 of the GPLv2), you are granted the additional
-    permission to convey through the Apple App Store non-source executable
-    versions of the Program as incorporated into each applicable covered work
-    as Executable Versions only under the Mozilla Public License version 2.0
-    (https://www.mozilla.org/en-US/MPL/2.0/).
+    Permission is hereby granted, free of charge, to any person obtaining a copy of
+    this software and associated documentation files (the "Software"), to deal in
+    the Software without restriction, including without limitation the rights to
+    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is furnished to do
+    so, subject to the following conditions:
     
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
     
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.

conn.go

@@ -1,180 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package main
-
-import (
-	"errors"
-	"golang.org/x/net/ipv4"
-	"golang.org/x/net/ipv6"
-	"net"
-)
-
-const (
-	ConnRoutineNumber = 2
-)
-
-/* A Bind handles listening on a port for both IPv6 and IPv4 UDP traffic
- */
-type Bind interface {
-	SetMark(value uint32) error
-	ReceiveIPv6(buff []byte) (int, Endpoint, error)
-	ReceiveIPv4(buff []byte) (int, Endpoint, error)
-	Send(buff []byte, end Endpoint) error
-	Close() error
-}
-
-/* An Endpoint maintains the source/destination caching for a peer
- *
- * dst : the remote address of a peer ("endpoint" in uapi terminology)
- * src : the local address from which datagrams originate going to the peer
- */
-type Endpoint interface {
-	ClearSrc()           // clears the source address
-	SrcToString() string // returns the local source address (ip:port)
-	DstToString() string // returns the destination address (ip:port)
-	DstToBytes() []byte  // used for mac2 cookie calculations
-	DstIP() net.IP
-	SrcIP() net.IP
-}
-
-func parseEndpoint(s string) (*net.UDPAddr, error) {
-
-	// ensure that the host is an IP address
-
-	host, _, err := net.SplitHostPort(s)
-	if err != nil {
-		return nil, err
-	}
-	if ip := net.ParseIP(host); ip == nil {
-		return nil, errors.New("Failed to parse IP address: " + host)
-	}
-
-	// parse address and port
-
-	addr, err := net.ResolveUDPAddr("udp", s)
-	if err != nil {
-		return nil, err
-	}
-	ip4 := addr.IP.To4()
-	if ip4 != nil {
-		addr.IP = ip4
-	}
-	return addr, err
-}
-
-func unsafeCloseBind(device *Device) error {
-	var err error
-	netc := &device.net
-	if netc.bind != nil {
-		err = netc.bind.Close()
-		netc.bind = nil
-	}
-	netc.stopping.Wait()
-	return err
-}
-
-func (device *Device) BindSetMark(mark uint32) error {
-
-	device.net.mutex.Lock()
-	defer device.net.mutex.Unlock()
-
-	// check if modified
-
-	if device.net.fwmark == mark {
-		return nil
-	}
-
-	// update fwmark on existing bind
-
-	device.net.fwmark = mark
-	if device.isUp.Get() && device.net.bind != nil {
-		if err := device.net.bind.SetMark(mark); err != nil {
-			return err
-		}
-	}
-
-	// clear cached source addresses
-
-	device.peers.mutex.RLock()
-	for _, peer := range device.peers.keyMap {
-		peer.mutex.Lock()
-		defer peer.mutex.Unlock()
-		if peer.endpoint != nil {
-			peer.endpoint.ClearSrc()
-		}
-	}
-	device.peers.mutex.RUnlock()
-
-	return nil
-}
-
-func (device *Device) BindUpdate() error {
-
-	device.net.mutex.Lock()
-	defer device.net.mutex.Unlock()
-
-	// close existing sockets
-
-	if err := unsafeCloseBind(device); err != nil {
-		return err
-	}
-
-	// open new sockets
-
-	if device.isUp.Get() {
-
-		// bind to new port
-
-		var err error
-		netc := &device.net
-		netc.bind, netc.port, err = CreateBind(netc.port, device)
-		if err != nil {
-			netc.bind = nil
-			netc.port = 0
-			return err
-		}
-
-		// set fwmark
-
-		if netc.fwmark != 0 {
-			err = netc.bind.SetMark(netc.fwmark)
-			if err != nil {
-				return err
-			}
-		}
-
-		// clear cached source addresses
-
-		device.peers.mutex.RLock()
-		for _, peer := range device.peers.keyMap {
-			peer.mutex.Lock()
-			defer peer.mutex.Unlock()
-			if peer.endpoint != nil {
-				peer.endpoint.ClearSrc()
-			}
-		}
-		device.peers.mutex.RUnlock()
-
-		// start receiving routines
-
-		device.net.starting.Add(ConnRoutineNumber)
-		device.net.stopping.Add(ConnRoutineNumber)
-		go device.RoutineReceiveIncoming(ipv4.Version, netc.bind)
-		go device.RoutineReceiveIncoming(ipv6.Version, netc.bind)
-		device.net.starting.Wait()
-
-		device.log.Debug.Println("UDP bind has been updated")
-	}
-
-	return nil
-}
-
-func (device *Device) BindClose() error {
-	device.net.mutex.Lock()
-	err := unsafeCloseBind(device)
-	device.net.mutex.Unlock()
-	return err
-}

conn/boundif_android.go

@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+func (bind *nativeBind) PeekLookAtSocketFd4() (fd int, err error) {
+	sysconn, err := bind.ipv4.SyscallConn()
+	if err != nil {
+		return -1, err
+	}
+	err = sysconn.Control(func(f uintptr) {
+		fd = int(f)
+	})
+	if err != nil {
+		return -1, err
+	}
+	return
+}
+
+func (bind *nativeBind) PeekLookAtSocketFd6() (fd int, err error) {
+	sysconn, err := bind.ipv6.SyscallConn()
+	if err != nil {
+		return -1, err
+	}
+	err = sysconn.Control(func(f uintptr) {
+		fd = int(f)
+	})
+	if err != nil {
+		return -1, err
+	}
+	return
+}

conn/boundif_windows.go

@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import (
+	"encoding/binary"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	sockoptIP_UNICAST_IF   = 31
+	sockoptIPV6_UNICAST_IF = 31
+)
+
+func (bind *nativeBind) BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error {
+	/* MSDN says for IPv4 this needs to be in net byte order, so that it's like an IP address with leading zeros. */
+	bytes := make([]byte, 4)
+	binary.BigEndian.PutUint32(bytes, interfaceIndex)
+	interfaceIndex = *(*uint32)(unsafe.Pointer(&bytes[0]))
+
+	sysconn, err := bind.ipv4.SyscallConn()
+	if err != nil {
+		return err
+	}
+	err2 := sysconn.Control(func(fd uintptr) {
+		err = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, sockoptIP_UNICAST_IF, int(interfaceIndex))
+	})
+	if err2 != nil {
+		return err2
+	}
+	if err != nil {
+		return err
+	}
+	bind.blackhole4 = blackhole
+	return nil
+}
+
+func (bind *nativeBind) BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error {
+	sysconn, err := bind.ipv6.SyscallConn()
+	if err != nil {
+		return err
+	}
+	err2 := sysconn.Control(func(fd uintptr) {
+		err = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, sockoptIPV6_UNICAST_IF, int(interfaceIndex))
+	})
+	if err2 != nil {
+		return err2
+	}
+	if err != nil {
+		return err
+	}
+	bind.blackhole6 = blackhole
+	return nil
+}

conn/conn.go

@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+// Package conn implements WireGuard's network connections.
+package conn
+
+import (
+	"errors"
+	"net"
+	"strings"
+)
+
+// A Bind listens on a port for both IPv6 and IPv4 UDP traffic.
+//
+// A Bind interface may also be a PeekLookAtSocketFd or BindSocketToInterface,
+// depending on the platform-specific implementation.
+type Bind interface {
+	// LastMark reports the last mark set for this Bind.
+	LastMark() uint32
+
+	// SetMark sets the mark for each packet sent through this Bind.
+	// This mark is passed to the kernel as the socket option SO_MARK.
+	SetMark(mark uint32) error
+
+	// ReceiveIPv6 reads an IPv6 UDP packet into b.
+	//
+	// It reports the number of bytes read, n,
+	// the packet source address ep,
+	// and any error.
+	ReceiveIPv6(buff []byte) (n int, ep Endpoint, err error)
+
+	// ReceiveIPv4 reads an IPv4 UDP packet into b.
+	//
+	// It reports the number of bytes read, n,
+	// the packet source address ep,
+	// and any error.
+	ReceiveIPv4(b []byte) (n int, ep Endpoint, err error)
+
+	// Send writes a packet b to address ep.
+	Send(b []byte, ep Endpoint) error
+
+	// Close closes the Bind connection.
+	Close() error
+}
+
+// CreateBind creates a Bind bound to a port.
+//
+// The value actualPort reports the actual port number the Bind
+// object gets bound to.
+func CreateBind(port uint16) (b Bind, actualPort uint16, err error) {
+	return createBind(port)
+}
+
+// BindSocketToInterface is implemented by Bind objects that support being
+// tied to a single network interface. Used by wireguard-windows.
+type BindSocketToInterface interface {
+	BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error
+	BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error
+}
+
+// PeekLookAtSocketFd is implemented by Bind objects that support having their
+// file descriptor peeked at. Used by wireguard-android.
+type PeekLookAtSocketFd interface {
+	PeekLookAtSocketFd4() (fd int, err error)
+	PeekLookAtSocketFd6() (fd int, err error)
+}
+
+// An Endpoint maintains the source/destination caching for a peer.
+//
+//	dst : the remote address of a peer ("endpoint" in uapi terminology)
+//	src : the local address from which datagrams originate going to the peer
+type Endpoint interface {
+	ClearSrc()           // clears the source address
+	SrcToString() string // returns the local source address (ip:port)
+	DstToString() string // returns the destination address (ip:port)
+	DstToBytes() []byte  // used for mac2 cookie calculations
+	DstIP() net.IP
+	SrcIP() net.IP
+}
+
+func parseEndpoint(s string) (*net.UDPAddr, error) {
+	// ensure that the host is an IP address
+
+	host, _, err := net.SplitHostPort(s)
+	if err != nil {
+		return nil, err
+	}
+	if i := strings.LastIndexByte(host, '%'); i > 0 && strings.IndexByte(host, ':') >= 0 {
+		// Remove the scope, if any. ResolveUDPAddr below will use it, but here we're just
+		// trying to make sure with a small sanity test that this is a real IP address and
+		// not something that's likely to incur DNS lookups.
+		host = host[:i]
+	}
+	if ip := net.ParseIP(host); ip == nil {
+		return nil, errors.New("Failed to parse IP address: " + host)
+	}
+
+	// parse address and port
+
+	addr, err := net.ResolveUDPAddr("udp", s)
+	if err != nil {
+		return nil, err
+	}
+	ip4 := addr.IP.To4()
+	if ip4 != nil {
+		addr.IP = ip4
+	}
+	return addr, err
+}

conn/conn_default.go

@@ -1,17 +1,15 @@
 // +build !linux android
 
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package conn
 
 import (
-	"golang.org/x/sys/unix"
 	"net"
 	"os"
-	"runtime"
 	"syscall"
 )
 
@@ -22,14 +20,16 @@ import (
  * See conn_linux.go for an implementation on the linux platform.
  */
 
-type NativeBind struct {
+type nativeBind struct {
 	ipv4       *net.UDPConn
 	ipv6       *net.UDPConn
+	blackhole4 bool
+	blackhole6 bool
 }
 
 type NativeEndpoint net.UDPAddr
 
-var _ Bind = (*NativeBind)(nil)
+var _ Bind = (*nativeBind)(nil)
 var _ Endpoint = (*NativeEndpoint)(nil)
 
 func CreateEndpoint(s string) (Endpoint, error) {
@@ -67,16 +67,12 @@ func (e *NativeEndpoint) SrcToString() string {
 }
 
 func listenNet(network string, port int) (*net.UDPConn, int, error) {
-
-	// listen
-
 	conn, err := net.ListenUDP(network, &net.UDPAddr{Port: port})
 	if err != nil {
 		return nil, 0, err
 	}
 
-	// retrieve port
-
+	// Retrieve port.
 	laddr := conn.LocalAddr()
 	uaddr, err := net.ResolveUDPAddr(
 		laddr.Network(),
@@ -100,9 +96,9 @@ func extractErrno(err error) error {
 	return syscallErr.Err
 }
 
-func CreateBind(uport uint16, device *Device) (Bind, uint16, error) {
+func createBind(uport uint16) (Bind, uint16, error) {
 	var err error
-	var bind NativeBind
+	var bind nativeBind
 
 	port := int(uport)
 
@@ -113,7 +109,6 @@ func CreateBind(uport uint16, device *Device) (Bind, uint16, error) {
 
 	bind.ipv6, port, err = listenNet("udp6", port)
 	if err != nil && extractErrno(err) != syscall.EAFNOSUPPORT {
-		return nil, 0, err
 		bind.ipv4.Close()
 		bind.ipv4 = nil
 		return nil, 0, err
@@ -122,7 +117,7 @@ func CreateBind(uport uint16, device *Device) (Bind, uint16, error) {
 	return &bind, uint16(port), nil
 }
 
-func (bind *NativeBind) Close() error {
+func (bind *nativeBind) Close() error {
 	var err1, err2 error
 	if bind.ipv4 != nil {
 		err1 = bind.ipv4.Close()
@@ -136,7 +131,9 @@ func (bind *NativeBind) Close() error {
 	return err2
 }
 
-func (bind *NativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
+func (bind *nativeBind) LastMark() uint32 { return 0 }
+
+func (bind *nativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
 	if bind.ipv4 == nil {
 		return 0, nil, syscall.EAFNOSUPPORT
 	}
@@ -147,7 +144,7 @@ func (bind *NativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
 	return n, (*NativeEndpoint)(endpoint), err
 }
 
-func (bind *NativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
+func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
 	if bind.ipv6 == nil {
 		return 0, nil, syscall.EAFNOSUPPORT
 	}
@@ -155,63 +152,25 @@ func (bind *NativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
 	return n, (*NativeEndpoint)(endpoint), err
 }
 
-func (bind *NativeBind) Send(buff []byte, endpoint Endpoint) error {
+func (bind *nativeBind) Send(buff []byte, endpoint Endpoint) error {
 	var err error
 	nend := endpoint.(*NativeEndpoint)
 	if nend.IP.To4() != nil {
 		if bind.ipv4 == nil {
 			return syscall.EAFNOSUPPORT
 		}
+		if bind.blackhole4 {
+			return nil
+		}
 		_, err = bind.ipv4.WriteToUDP(buff, (*net.UDPAddr)(nend))
 	} else {
 		if bind.ipv6 == nil {
 			return syscall.EAFNOSUPPORT
 		}
+		if bind.blackhole6 {
+			return nil
+		}
 		_, err = bind.ipv6.WriteToUDP(buff, (*net.UDPAddr)(nend))
 	}
 	return err
 }
-
-var fwmarkIoctl int
-
-func init() {
-	switch runtime.GOOS {
-	case "linux", "android":
-		fwmarkIoctl = 36 /* unix.SO_MARK */
-	case "freebsd":
-		fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
-	case "openbsd":
-		fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
-	}
-}
-
-func (bind *NativeBind) SetMark(mark uint32) error {
-	if fwmarkIoctl == 0 {
-		return nil
-	}
-	if bind.ipv4 != nil {
-		fd, err := bind.ipv4.SyscallConn()
-		if err != nil {
-			return err
-		}
-		err = fd.Control(func(fd uintptr) {
-			err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
-		})
-		if err != nil {
-			return err
-		}
-	}
-	if bind.ipv6 != nil {
-		fd, err := bind.ipv6.SyscallConn()
-		if err != nil {
-			return err
-		}
-		err = fd.Control(func(fd uintptr) {
-			err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
-		})
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}

conn/conn_linux.go

@@ -1,30 +1,21 @@
 // +build !android
 
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- *
- * This implements userspace semantics of "sticky sockets", modeled after
- * WireGuard's kernelspace implementation. This is more or less a straight port
- * of the sticky-sockets.c example code:
- * https://git.zx2c4.com/WireGuard/tree/contrib/examples/sticky-sockets/sticky-sockets.c
- *
- * Currently there is no way to achieve this within the net package:
- * See e.g. https://github.com/golang/go/issues/17930
- * So this code is remains platform dependent.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package conn
 
 import (
 	"errors"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/sys/unix"
 	"net"
 	"strconv"
 	"sync"
 	"syscall"
 	"unsafe"
+
+	"golang.org/x/sys/unix"
 )
 
 const (
@@ -32,8 +23,8 @@ const (
 )
 
 type IPv4Source struct {
-	src     [4]byte
-	ifindex int32
+	Src     [4]byte
+	Ifindex int32
 }
 
 type IPv6Source struct {
@@ -42,11 +33,16 @@ type IPv6Source struct {
 }
 
 type NativeEndpoint struct {
+	sync.Mutex
 	dst  [unsafe.Sizeof(unix.SockaddrInet6{})]byte
 	src  [unsafe.Sizeof(IPv6Source{})]byte
 	isV6 bool
 }
 
+func (endpoint *NativeEndpoint) Src4() *IPv4Source         { return endpoint.src4() }
+func (endpoint *NativeEndpoint) Dst4() *unix.SockaddrInet4 { return endpoint.dst4() }
+func (endpoint *NativeEndpoint) IsV6() bool                { return endpoint.isV6 }
+
 func (endpoint *NativeEndpoint) src4() *IPv4Source {
 	return (*IPv4Source)(unsafe.Pointer(&endpoint.src[0]))
 }
@@ -63,16 +59,14 @@ func (endpoint *NativeEndpoint) dst6() *unix.SockaddrInet6 {
 	return (*unix.SockaddrInet6)(unsafe.Pointer(&endpoint.dst[0]))
 }
 
-type NativeBind struct {
+type nativeBind struct {
 	sock4    int
 	sock6    int
-	netlinkSock   int
-	netlinkCancel *rwcancel.RWCancel
 	lastMark uint32
 }
 
 var _ Endpoint = (*NativeEndpoint)(nil)
-var _ Bind = (*NativeBind)(nil)
+var _ Bind = (*nativeBind)(nil)
 
 func CreateEndpoint(s string) (Endpoint, error) {
 	var end NativeEndpoint
@@ -109,59 +103,25 @@ func CreateEndpoint(s string) (Endpoint, error) {
 	return nil, errors.New("Invalid IP address")
 }
 
-func createNetlinkRouteSocket() (int, error) {
-	sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE)
-	if err != nil {
-		return -1, err
-	}
-	saddr := &unix.SockaddrNetlink{
-		Family: unix.AF_NETLINK,
-		Groups: uint32(1 << (unix.RTNLGRP_IPV4_ROUTE - 1)),
-	}
-	err = unix.Bind(sock, saddr)
-	if err != nil {
-		unix.Close(sock)
-		return -1, err
-	}
-	return sock, nil
-
-}
-
-func CreateBind(port uint16, device *Device) (*NativeBind, uint16, error) {
+func createBind(port uint16) (Bind, uint16, error) {
 	var err error
-	var bind NativeBind
+	var bind nativeBind
 	var newPort uint16
 
-	bind.netlinkSock, err = createNetlinkRouteSocket()
-	if err != nil {
-		return nil, 0, err
-	}
-	bind.netlinkCancel, err = rwcancel.NewRWCancel(bind.netlinkSock)
-	if err != nil {
-		unix.Close(bind.netlinkSock)
-		return nil, 0, err
-	}
-
-	go bind.routineRouteListener(device)
-
-	// attempt ipv6 bind, update port if succesful
-
+	// Attempt ipv6 bind, update port if successful.
 	bind.sock6, newPort, err = create6(port)
 	if err != nil {
 		if err != syscall.EAFNOSUPPORT {
-			bind.netlinkCancel.Cancel()
 			return nil, 0, err
 		}
 	} else {
 		port = newPort
 	}
 
-	// attempt ipv4 bind, update port if succesful
-
+	// Attempt ipv4 bind, update port if successful.
 	bind.sock4, newPort, err = create4(port)
 	if err != nil {
 		if err != syscall.EAFNOSUPPORT {
-			bind.netlinkCancel.Cancel()
 			unix.Close(bind.sock6)
 			return nil, 0, err
 		}
@@ -176,7 +136,11 @@ func CreateBind(port uint16, device *Device) (*NativeBind, uint16, error) {
 	return &bind, port, nil
 }
 
-func (bind *NativeBind) SetMark(value uint32) error {
+func (bind *nativeBind) LastMark() uint32 {
+	return bind.lastMark
+}
+
+func (bind *nativeBind) SetMark(value uint32) error {
 	if bind.sock6 != -1 {
 		err := unix.SetsockoptInt(
 			bind.sock6,
@@ -213,26 +177,22 @@ func closeUnblock(fd int) error {
 	return unix.Close(fd)
 }
 
-func (bind *NativeBind) Close() error {
-	var err1, err2, err3 error
+func (bind *nativeBind) Close() error {
+	var err1, err2 error
 	if bind.sock6 != -1 {
 		err1 = closeUnblock(bind.sock6)
 	}
 	if bind.sock4 != -1 {
 		err2 = closeUnblock(bind.sock4)
 	}
-	err3 = bind.netlinkCancel.Cancel()
 
 	if err1 != nil {
 		return err1
 	}
-	if err2 != nil {
 	return err2
-	}
-	return err3
 }
 
-func (bind *NativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
+func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
 	var end NativeEndpoint
 	if bind.sock6 == -1 {
 		return 0, nil, syscall.EAFNOSUPPORT
@@ -245,7 +205,7 @@ func (bind *NativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
 	return n, &end, err
 }
 
-func (bind *NativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
+func (bind *nativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
 	var end NativeEndpoint
 	if bind.sock4 == -1 {
 		return 0, nil, syscall.EAFNOSUPPORT
@@ -258,7 +218,7 @@ func (bind *NativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
 	return n, &end, err
 }
 
-func (bind *NativeBind) Send(buff []byte, end Endpoint) error {
+func (bind *nativeBind) Send(buff []byte, end Endpoint) error {
 	nend := end.(*NativeEndpoint)
 	if !nend.isV6 {
 		if bind.sock4 == -1 {
@@ -276,10 +236,10 @@ func (bind *NativeBind) Send(buff []byte, end Endpoint) error {
 func (end *NativeEndpoint) SrcIP() net.IP {
 	if !end.isV6 {
 		return net.IPv4(
-			end.src4().src[0],
-			end.src4().src[1],
-			end.src4().src[2],
-			end.src4().src[3],
+			end.src4().Src[0],
+			end.src4().Src[1],
+			end.src4().Src[2],
+			end.src4().Src[3],
 		)
 	} else {
 		return end.src6().src[:]
@@ -390,6 +350,11 @@ func create4(port uint16) (int, uint16, error) {
 		return FD_ERR, 0, err
 	}
 
+	sa, err := unix.Getsockname(fd)
+	if err == nil {
+		addr.Port = sa.(*unix.SockaddrInet4).Port
+	}
+
 	return fd, uint16(addr.Port), err
 }
 
@@ -449,6 +414,11 @@ func create6(port uint16) (int, uint16, error) {
 		return FD_ERR, 0, err
 	}
 
+	sa, err := unix.Getsockname(fd)
+	if err == nil {
+		addr.Port = sa.(*unix.SockaddrInet6).Port
+	}
+
 	return fd, uint16(addr.Port), err
 }
 
@@ -466,12 +436,14 @@ func send4(sock int, end *NativeEndpoint, buff []byte) error {
 			Len:   unix.SizeofInet4Pktinfo + unix.SizeofCmsghdr,
 		},
 		unix.Inet4Pktinfo{
-			Spec_dst: end.src4().src,
-			Ifindex:  end.src4().ifindex,
+			Spec_dst: end.src4().Src,
+			Ifindex:  end.src4().Ifindex,
 		},
 	}
 
+	end.Lock()
 	_, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0)
+	end.Unlock()
 
 	if err == nil {
 		return nil
@@ -482,7 +454,9 @@ func send4(sock int, end *NativeEndpoint, buff []byte) error {
 	if err == unix.EINVAL {
 		end.ClearSrc()
 		cmsg.pktinfo = unix.Inet4Pktinfo{}
+		end.Lock()
 		_, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0)
+		end.Unlock()
 	}
 
 	return err
@@ -511,7 +485,9 @@ func send6(sock int, end *NativeEndpoint, buff []byte) error {
 		cmsg.pktinfo.Ifindex = 0
 	}
 
+	end.Lock()
 	_, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0)
+	end.Unlock()
 
 	if err == nil {
 		return nil
@@ -522,7 +498,9 @@ func send6(sock int, end *NativeEndpoint, buff []byte) error {
 	if err == unix.EINVAL {
 		end.ClearSrc()
 		cmsg.pktinfo = unix.Inet6Pktinfo{}
+		end.Lock()
 		_, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0)
+		end.Unlock()
 	}
 
 	return err
@@ -530,7 +508,7 @@ func send6(sock int, end *NativeEndpoint, buff []byte) error {
 
 func receive4(sock int, buff []byte, end *NativeEndpoint) (int, error) {
 
-	// contruct message header
+	// construct message header
 
 	var cmsg struct {
 		cmsghdr unix.Cmsghdr
@@ -553,8 +531,8 @@ func receive4(sock int, buff []byte, end *NativeEndpoint) (int, error) {
 	if cmsg.cmsghdr.Level == unix.IPPROTO_IP &&
 		cmsg.cmsghdr.Type == unix.IP_PKTINFO &&
 		cmsg.cmsghdr.Len >= unix.SizeofInet4Pktinfo {
-		end.src4().src = cmsg.pktinfo.Spec_dst
-		end.src4().ifindex = cmsg.pktinfo.Ifindex
+		end.src4().Src = cmsg.pktinfo.Spec_dst
+		end.src4().Ifindex = cmsg.pktinfo.Ifindex
 	}
 
 	return size, nil
@@ -562,7 +540,7 @@ func receive4(sock int, buff []byte, end *NativeEndpoint) (int, error) {
 
 func receive6(sock int, buff []byte, end *NativeEndpoint) (int, error) {
 
-	// contruct message header
+	// construct message header
 
 	var cmsg struct {
 		cmsghdr unix.Cmsghdr
@@ -591,156 +569,3 @@ func receive6(sock int, buff []byte, end *NativeEndpoint) (int, error) {
 
 	return size, nil
 }
-
-func (bind *NativeBind) routineRouteListener(device *Device) {
-	type peerEndpointPtr struct {
-		peer     *Peer
-		endpoint *Endpoint
-	}
-	var reqPeer map[uint32]peerEndpointPtr
-	var reqPeerLock sync.Mutex
-
-	defer unix.Close(bind.netlinkSock)
-
-	for msg := make([]byte, 1<<16); ; {
-		var err error
-		var msgn int
-		for {
-			msgn, _, _, _, err = unix.Recvmsg(bind.netlinkSock, msg[:], nil, 0)
-			if err == nil || !rwcancel.RetryAfterError(err) {
-				break
-			}
-			if !bind.netlinkCancel.ReadyRead() {
-				return
-			}
-		}
-		if err != nil {
-			return
-		}
-
-		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
-
-			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
-
-			if uint(hdr.Len) > uint(len(remain)) {
-				break
-			}
-
-			switch hdr.Type {
-			case unix.RTM_NEWROUTE, unix.RTM_DELROUTE:
-				if hdr.Seq <= MaxPeers && hdr.Seq > 0 {
-					if uint(len(remain)) < uint(hdr.Len) {
-						break
-					}
-					if hdr.Len > unix.SizeofNlMsghdr+unix.SizeofRtMsg {
-						attr := remain[unix.SizeofNlMsghdr+unix.SizeofRtMsg:]
-						for {
-							if uint(len(attr)) < uint(unix.SizeofRtAttr) {
-								break
-							}
-							attrhdr := *(*unix.RtAttr)(unsafe.Pointer(&attr[0]))
-							if attrhdr.Len < unix.SizeofRtAttr || uint(len(attr)) < uint(attrhdr.Len) {
-								break
-							}
-							if attrhdr.Type == unix.RTA_OIF && attrhdr.Len == unix.SizeofRtAttr+4 {
-								ifidx := *(*uint32)(unsafe.Pointer(&attr[unix.SizeofRtAttr]))
-								reqPeerLock.Lock()
-								if reqPeer == nil {
-									reqPeerLock.Unlock()
-									break
-								}
-								pePtr, ok := reqPeer[hdr.Seq]
-								reqPeerLock.Unlock()
-								if !ok {
-									break
-								}
-								pePtr.peer.mutex.Lock()
-								if &pePtr.peer.endpoint != pePtr.endpoint {
-									pePtr.peer.mutex.Unlock()
-									break
-								}
-								if uint32(pePtr.peer.endpoint.(*NativeEndpoint).src4().ifindex) == ifidx {
-									pePtr.peer.mutex.Unlock()
-									break
-								}
-								pePtr.peer.endpoint.(*NativeEndpoint).ClearSrc()
-								pePtr.peer.mutex.Unlock()
-							}
-							attr = attr[attrhdr.Len:]
-						}
-					}
-					break
-				}
-				reqPeerLock.Lock()
-				reqPeer = make(map[uint32]peerEndpointPtr)
-				reqPeerLock.Unlock()
-				go func() {
-					device.peers.mutex.RLock()
-					i := uint32(1)
-					for _, peer := range device.peers.keyMap {
-						peer.mutex.RLock()
-						if peer.endpoint == nil || peer.endpoint.(*NativeEndpoint) == nil {
-							peer.mutex.RUnlock()
-							continue
-						}
-						if peer.endpoint.(*NativeEndpoint).isV6 || peer.endpoint.(*NativeEndpoint).src4().ifindex == 0 {
-							peer.mutex.RUnlock()
-							break
-						}
-						nlmsg := struct {
-							hdr     unix.NlMsghdr
-							msg     unix.RtMsg
-							dsthdr  unix.RtAttr
-							dst     [4]byte
-							srchdr  unix.RtAttr
-							src     [4]byte
-							markhdr unix.RtAttr
-							mark    uint32
-						}{
-							unix.NlMsghdr{
-								Type:  uint16(unix.RTM_GETROUTE),
-								Flags: unix.NLM_F_REQUEST,
-								Seq:   i,
-							},
-							unix.RtMsg{
-								Family:  unix.AF_INET,
-								Dst_len: 32,
-								Src_len: 32,
-							},
-							unix.RtAttr{
-								Len:  8,
-								Type: unix.RTA_DST,
-							},
-							peer.endpoint.(*NativeEndpoint).dst4().Addr,
-							unix.RtAttr{
-								Len:  8,
-								Type: unix.RTA_SRC,
-							},
-							peer.endpoint.(*NativeEndpoint).src4().src,
-							unix.RtAttr{
-								Len:  8,
-								Type: 0x10, //unix.RTA_MARK  TODO: add this to x/sys/unix
-							},
-							uint32(bind.lastMark),
-						}
-						nlmsg.hdr.Len = uint32(unsafe.Sizeof(nlmsg))
-						reqPeerLock.Lock()
-						reqPeer[i] = peerEndpointPtr{
-							peer:     peer,
-							endpoint: &peer.endpoint,
-						}
-						reqPeerLock.Unlock()
-						peer.mutex.RUnlock()
-						i++
-						_, err := bind.netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:])
-						if err != nil {
-							break
-						}
-					}
-					device.peers.mutex.RUnlock()
-				}()
-			}
-			remain = remain[hdr.Len:]
-		}
-	}
-}

conn/mark_default.go

@@ -0,0 +1,12 @@
+// +build !linux,!openbsd,!freebsd
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+func (bind *nativeBind) SetMark(mark uint32) error {
+	return nil
+}

conn/mark_unix.go

@@ -0,0 +1,65 @@
+// +build android openbsd freebsd
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import (
+	"runtime"
+
+	"golang.org/x/sys/unix"
+)
+
+var fwmarkIoctl int
+
+func init() {
+	switch runtime.GOOS {
+	case "linux", "android":
+		fwmarkIoctl = 36 /* unix.SO_MARK */
+	case "freebsd":
+		fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
+	case "openbsd":
+		fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
+	}
+}
+
+func (bind *nativeBind) SetMark(mark uint32) error {
+	var operr error
+	if fwmarkIoctl == 0 {
+		return nil
+	}
+	if bind.ipv4 != nil {
+		fd, err := bind.ipv4.SyscallConn()
+		if err != nil {
+			return err
+		}
+		err = fd.Control(func(fd uintptr) {
+			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
+		})
+		if err == nil {
+			err = operr
+		}
+		if err != nil {
+			return err
+		}
+	}
+	if bind.ipv6 != nil {
+		fd, err := bind.ipv6.SyscallConn()
+		if err != nil {
+			return err
+		}
+		err = fd.Control(func(fd uintptr) {
+			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
+		})
+		if err == nil {
+			err = operr
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

device/allowedips.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"errors"

device/allowedips_rand_test.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"math/rand"

device/allowedips_test.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"math/rand"

device/bind_test.go

@@ -1,15 +1,19 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
-import "errors"
+import (
+	"errors"
+
+	"golang.zx2c4.com/wireguard/conn"
+)
 
 type DummyDatagram struct {
 	msg      []byte
-	endpoint Endpoint
+	endpoint conn.Endpoint
 	world    bool // better type
 }
 
@@ -25,7 +29,7 @@ func (b *DummyBind) SetMark(v uint32) error {
 	return nil
 }
 
-func (b *DummyBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
+func (b *DummyBind) ReceiveIPv6(buff []byte) (int, conn.Endpoint, error) {
 	datagram, ok := <-b.in6
 	if !ok {
 		return 0, nil, errors.New("closed")
@@ -34,7 +38,7 @@ func (b *DummyBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
 	return len(datagram.msg), datagram.endpoint, nil
 }
 
-func (b *DummyBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
+func (b *DummyBind) ReceiveIPv4(buff []byte) (int, conn.Endpoint, error) {
 	datagram, ok := <-b.in4
 	if !ok {
 		return 0, nil, errors.New("closed")
@@ -50,6 +54,6 @@ func (b *DummyBind) Close() error {
 	return nil
 }
 
-func (b *DummyBind) Send(buff []byte, end Endpoint) error {
+func (b *DummyBind) Send(buff []byte, end conn.Endpoint) error {
 	return nil
 }

device/constants.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"time"
@@ -12,8 +12,8 @@ import (
 /* Specification constants */
 
 const (
-	RekeyAfterMessages      = (1 << 64) - (1 << 16) - 1
-	RejectAfterMessages     = (1 << 64) - (1 << 4) - 1
+	RekeyAfterMessages      = (1 << 60)
+	RejectAfterMessages     = (1 << 64) - (1 << 13) - 1
 	RekeyAfterTime          = time.Second * 120
 	RekeyAttemptTime        = time.Second * 90
 	RekeyTimeout            = time.Second * 5
@@ -22,7 +22,7 @@ const (
 	RejectAfterTime         = time.Second * 180
 	KeepaliveTimeout        = time.Second * 10
 	CookieRefreshTime       = time.Second * 120
-	HandshakeInitationRate  = time.Second / 20
+	HandshakeInitationRate  = time.Second / 50
 	PaddingMultiple         = 16
 )
 

device/cookie.go

@@ -1,22 +1,22 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"crypto/hmac"
 	"crypto/rand"
-	"git.zx2c4.com/wireguard-go/xchacha20poly1305"
-	"golang.org/x/crypto/blake2s"
-	"golang.org/x/crypto/chacha20poly1305"
 	"sync"
 	"time"
+
+	"golang.org/x/crypto/blake2s"
+	"golang.org/x/crypto/chacha20poly1305"
 )
 
 type CookieChecker struct {
-	mutex sync.RWMutex
+	sync.RWMutex
 	mac1 struct {
 		key [blake2s.Size]byte
 	}
@@ -28,7 +28,7 @@ type CookieChecker struct {
 }
 
 type CookieGenerator struct {
-	mutex sync.RWMutex
+	sync.RWMutex
 	mac1 struct {
 		key [blake2s.Size]byte
 	}
@@ -42,8 +42,8 @@ type CookieGenerator struct {
 }
 
 func (st *CookieChecker) Init(pk NoisePublicKey) {
-	st.mutex.Lock()
-	defer st.mutex.Unlock()
+	st.Lock()
+	defer st.Unlock()
 
 	// mac1 state
 
@@ -67,8 +67,8 @@ func (st *CookieChecker) Init(pk NoisePublicKey) {
 }
 
 func (st *CookieChecker) CheckMAC1(msg []byte) bool {
-	st.mutex.RLock()
-	defer st.mutex.RUnlock()
+	st.RLock()
+	defer st.RUnlock()
 
 	size := len(msg)
 	smac2 := size - blake2s.Size128
@@ -84,10 +84,10 @@ func (st *CookieChecker) CheckMAC1(msg []byte) bool {
 }
 
 func (st *CookieChecker) CheckMAC2(msg []byte, src []byte) bool {
-	st.mutex.RLock()
-	defer st.mutex.RUnlock()
+	st.RLock()
+	defer st.RUnlock()
 
-	if time.Now().Sub(st.mac2.secretSet) > CookieRefreshTime {
+	if time.Since(st.mac2.secretSet) > CookieRefreshTime {
 		return false
 	}
 
@@ -120,21 +120,21 @@ func (st *CookieChecker) CreateReply(
 	src []byte,
 ) (*MessageCookieReply, error) {
 
-	st.mutex.RLock()
+	st.RLock()
 
 	// refresh cookie secret
 
-	if time.Now().Sub(st.mac2.secretSet) > CookieRefreshTime {
-		st.mutex.RUnlock()
-		st.mutex.Lock()
+	if time.Since(st.mac2.secretSet) > CookieRefreshTime {
+		st.RUnlock()
+		st.Lock()
 		_, err := rand.Read(st.mac2.secret[:])
 		if err != nil {
-			st.mutex.Unlock()
+			st.Unlock()
 			return nil, err
 		}
 		st.mac2.secretSet = time.Now()
-		st.mutex.Unlock()
-		st.mutex.RLock()
+		st.Unlock()
+		st.RLock()
 	}
 
 	// derive cookie
@@ -159,26 +159,21 @@ func (st *CookieChecker) CreateReply(
 
 	_, err := rand.Read(reply.Nonce[:])
 	if err != nil {
-		st.mutex.RUnlock()
+		st.RUnlock()
 		return nil, err
 	}
 
-	xchacha20poly1305.Encrypt(
-		reply.Cookie[:0],
-		&reply.Nonce,
-		cookie[:],
-		msg[smac1:smac2],
-		&st.mac2.encryptionKey,
-	)
+	xchapoly, _ := chacha20poly1305.NewX(st.mac2.encryptionKey[:])
+	xchapoly.Seal(reply.Cookie[:0], reply.Nonce[:], cookie[:], msg[smac1:smac2])
 
-	st.mutex.RUnlock()
+	st.RUnlock()
 
 	return reply, nil
 }
 
 func (st *CookieGenerator) Init(pk NoisePublicKey) {
-	st.mutex.Lock()
-	defer st.mutex.Unlock()
+	st.Lock()
+	defer st.Unlock()
 
 	func() {
 		hash, _ := blake2s.New256(nil)
@@ -198,8 +193,8 @@ func (st *CookieGenerator) Init(pk NoisePublicKey) {
 }
 
 func (st *CookieGenerator) ConsumeReply(msg *MessageCookieReply) bool {
-	st.mutex.Lock()
-	defer st.mutex.Unlock()
+	st.Lock()
+	defer st.Unlock()
 
 	if !st.mac2.hasLastMAC1 {
 		return false
@@ -207,13 +202,8 @@ func (st *CookieGenerator) ConsumeReply(msg *MessageCookieReply) bool {
 
 	var cookie [blake2s.Size128]byte
 
-	_, err := xchacha20poly1305.Decrypt(
-		cookie[:0],
-		&msg.Nonce,
-		msg.Cookie[:],
-		st.mac2.lastMAC1[:],
-		&st.mac2.encryptionKey,
-	)
+	xchapoly, _ := chacha20poly1305.NewX(st.mac2.encryptionKey[:])
+	_, err := xchapoly.Open(cookie[:0], msg.Nonce[:], msg.Cookie[:], st.mac2.lastMAC1[:])
 
 	if err != nil {
 		return false
@@ -234,8 +224,8 @@ func (st *CookieGenerator) AddMacs(msg []byte) {
 	mac1 := msg[smac1:smac2]
 	mac2 := msg[smac2:]
 
-	st.mutex.Lock()
-	defer st.mutex.Unlock()
+	st.Lock()
+	defer st.Unlock()
 
 	// set mac1
 
@@ -249,7 +239,7 @@ func (st *CookieGenerator) AddMacs(msg []byte) {
 
 	// set mac2
 
-	if time.Now().Sub(st.mac2.cookieSet) > CookieRefreshTime {
+	if time.Since(st.mac2.cookieSet) > CookieRefreshTime {
 		return
 	}
 

device/cookie_test.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"testing"

device/device.go

@@ -1,22 +1,22 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
-	"git.zx2c4.com/wireguard-go/ratelimiter"
-	"git.zx2c4.com/wireguard-go/tun"
 	"runtime"
 	"sync"
 	"sync/atomic"
 	"time"
-)
 
-const (
-	DeviceRoutineNumberPerCPU     = 3
-	DeviceRoutineNumberAdditional = 2
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/ratelimiter"
+	"golang.zx2c4.com/wireguard/rwcancel"
+	"golang.zx2c4.com/wireguard/tun"
 )
 
 type Device struct {
@@ -29,7 +29,7 @@ type Device struct {
 	state struct {
 		starting sync.WaitGroup
 		stopping sync.WaitGroup
-		mutex    sync.Mutex
+		sync.Mutex
 		changing AtomicBool
 		current  bool
 	}
@@ -37,20 +37,21 @@ type Device struct {
 	net struct {
 		starting sync.WaitGroup
 		stopping sync.WaitGroup
-		mutex    sync.RWMutex
-		bind     Bind   // bind interface
+		sync.RWMutex
+		bind          conn.Bind // bind interface
+		netlinkCancel *rwcancel.RWCancel
 		port          uint16 // listening port
 		fwmark        uint32 // mark value (0 = disabled)
 	}
 
 	staticIdentity struct {
-		mutex      sync.RWMutex
+		sync.RWMutex
 		privateKey NoisePrivateKey
 		publicKey  NoisePublicKey
 	}
 
 	peers struct {
-		mutex  sync.RWMutex
+		sync.RWMutex
 		keyMap map[NoisePublicKey]*Peer
 	}
 
@@ -85,7 +86,7 @@ type Device struct {
 	}
 
 	tun struct {
-		device tun.TUNDevice
+		device tun.Device
 		mtu    int32
 	}
 }
@@ -93,7 +94,7 @@ type Device struct {
 /* Converts the peer into a "zombie", which remains in the peer map,
  * but processes no packets and does not exists in the routing table.
  *
- * Must hold device.peers.mutex.
+ * Must hold device.peers.Mutex
  */
 func unsafeRemovePeer(device *Device, peer *Peer, key NoisePublicKey) {
 
@@ -117,13 +118,13 @@ func deviceUpdateState(device *Device) {
 
 	// compare to current state of device
 
-	device.state.mutex.Lock()
+	device.state.Lock()
 
 	newIsUp := device.isUp.Get()
 
 	if newIsUp == device.state.current {
 		device.state.changing.Set(false)
-		device.state.mutex.Unlock()
+		device.state.Unlock()
 		return
 	}
 
@@ -132,29 +133,33 @@ func deviceUpdateState(device *Device) {
 	switch newIsUp {
 	case true:
 		if err := device.BindUpdate(); err != nil {
+			device.log.Error.Printf("Unable to update bind: %v\n", err)
 			device.isUp.Set(false)
 			break
 		}
-		device.peers.mutex.RLock()
+		device.peers.RLock()
 		for _, peer := range device.peers.keyMap {
 			peer.Start()
+			if peer.persistentKeepaliveInterval > 0 {
+				peer.SendKeepalive()
 			}
-		device.peers.mutex.RUnlock()
+		}
+		device.peers.RUnlock()
 
 	case false:
 		device.BindClose()
-		device.peers.mutex.RLock()
+		device.peers.RLock()
 		for _, peer := range device.peers.keyMap {
 			peer.Stop()
 		}
-		device.peers.mutex.RUnlock()
+		device.peers.RUnlock()
 	}
 
 	// update state variables
 
 	device.state.current = newIsUp
 	device.state.changing.Set(false)
-	device.state.mutex.Unlock()
+	device.state.Unlock()
 
 	// check for state change in the mean time
 
@@ -196,18 +201,22 @@ func (device *Device) IsUnderLoad() bool {
 }
 
 func (device *Device) SetPrivateKey(sk NoisePrivateKey) error {
-
 	// lock required resources
 
-	device.staticIdentity.mutex.Lock()
-	defer device.staticIdentity.mutex.Unlock()
+	device.staticIdentity.Lock()
+	defer device.staticIdentity.Unlock()
 
-	device.peers.mutex.Lock()
-	defer device.peers.mutex.Unlock()
+	if sk.Equals(device.staticIdentity.privateKey) {
+		return nil
+	}
 
+	device.peers.Lock()
+	defer device.peers.Unlock()
+
+	lockedPeers := make([]*Peer, 0, len(device.peers.keyMap))
 	for _, peer := range device.peers.keyMap {
 		peer.handshake.mutex.RLock()
-		defer peer.handshake.mutex.RUnlock()
+		lockedPeers = append(lockedPeers, peer)
 	}
 
 	// remove peers with matching public keys
@@ -227,27 +236,24 @@ func (device *Device) SetPrivateKey(sk NoisePrivateKey) error {
 
 	// do static-static DH pre-computations
 
-	rmKey := device.staticIdentity.privateKey.IsZero()
-
-	for key, peer := range device.peers.keyMap {
-
+	expiredPeers := make([]*Peer, 0, len(device.peers.keyMap))
+	for _, peer := range device.peers.keyMap {
 		handshake := &peer.handshake
-
-		if rmKey {
-			handshake.precomputedStaticStatic = [NoisePublicKeySize]byte{}
-		} else {
 		handshake.precomputedStaticStatic = device.staticIdentity.privateKey.sharedSecret(handshake.remoteStatic)
+		expiredPeers = append(expiredPeers, peer)
 	}
 
-		if isZero(handshake.precomputedStaticStatic[:]) {
-			unsafeRemovePeer(device, peer, key)
+	for _, peer := range lockedPeers {
+		peer.handshake.mutex.RUnlock()
 	}
+	for _, peer := range expiredPeers {
+		peer.ExpireCurrentKeypairs()
 	}
 
 	return nil
 }
 
-func NewDevice(tunDevice tun.TUNDevice, logger *Logger) *Device {
+func NewDevice(tunDevice tun.Device, logger *Logger) *Device {
 	device := new(Device)
 
 	device.isUp.Set(false)
@@ -293,14 +299,16 @@ func NewDevice(tunDevice tun.TUNDevice, logger *Logger) *Device {
 	cpus := runtime.NumCPU()
 	device.state.starting.Wait()
 	device.state.stopping.Wait()
-	device.state.stopping.Add(DeviceRoutineNumberPerCPU*cpus + DeviceRoutineNumberAdditional)
-	device.state.starting.Add(DeviceRoutineNumberPerCPU*cpus + DeviceRoutineNumberAdditional)
 	for i := 0; i < cpus; i += 1 {
+		device.state.starting.Add(3)
+		device.state.stopping.Add(3)
 		go device.RoutineEncryption()
 		go device.RoutineDecryption()
 		go device.RoutineHandshake()
 	}
 
+	device.state.starting.Add(2)
+	device.state.stopping.Add(2)
 	go device.RoutineReadFromTUN()
 	go device.RoutineTUNEventReader()
 
@@ -310,16 +318,15 @@ func NewDevice(tunDevice tun.TUNDevice, logger *Logger) *Device {
 }
 
 func (device *Device) LookupPeer(pk NoisePublicKey) *Peer {
-	device.peers.mutex.RLock()
-	defer device.peers.mutex.RUnlock()
+	device.peers.RLock()
+	defer device.peers.RUnlock()
 
 	return device.peers.keyMap[pk]
 }
 
 func (device *Device) RemovePeer(key NoisePublicKey) {
-	device.peers.mutex.Lock()
-	defer device.peers.mutex.Unlock()
-
+	device.peers.Lock()
+	defer device.peers.Unlock()
 	// stop peer and remove from routing
 
 	peer, ok := device.peers.keyMap[key]
@@ -329,8 +336,8 @@ func (device *Device) RemovePeer(key NoisePublicKey) {
 }
 
 func (device *Device) RemoveAllPeers() {
-	device.peers.mutex.Lock()
-	defer device.peers.mutex.Unlock()
+	device.peers.Lock()
+	defer device.peers.Unlock()
 
 	for key, peer := range device.peers.keyMap {
 		unsafeRemovePeer(device, peer, key)
@@ -367,8 +374,8 @@ func (device *Device) Close() {
 
 	device.log.Info.Println("Device closing")
 	device.state.changing.Set(true)
-	device.state.mutex.Lock()
-	defer device.state.mutex.Unlock()
+	device.state.Lock()
+	defer device.state.Unlock()
 
 	device.tun.device.Close()
 	device.BindClose()
@@ -376,10 +383,10 @@ func (device *Device) Close() {
 	device.isUp.Set(false)
 
 	close(device.signals.stop)
+	device.state.stopping.Wait()
 
 	device.RemoveAllPeers()
 
-	device.state.stopping.Wait()
 	device.FlushPacketQueues()
 
 	device.rate.limiter.Close()
@@ -391,3 +398,150 @@ func (device *Device) Close() {
 func (device *Device) Wait() chan struct{} {
 	return device.signals.stop
 }
+
+func (device *Device) SendKeepalivesToPeersWithCurrentKeypair() {
+	if device.isClosed.Get() {
+		return
+	}
+
+	device.peers.RLock()
+	for _, peer := range device.peers.keyMap {
+		peer.keypairs.RLock()
+		sendKeepalive := peer.keypairs.current != nil && !peer.keypairs.current.created.Add(RejectAfterTime).Before(time.Now())
+		peer.keypairs.RUnlock()
+		if sendKeepalive {
+			peer.SendKeepalive()
+		}
+	}
+	device.peers.RUnlock()
+}
+
+func unsafeCloseBind(device *Device) error {
+	var err error
+	netc := &device.net
+	if netc.netlinkCancel != nil {
+		netc.netlinkCancel.Cancel()
+	}
+	if netc.bind != nil {
+		err = netc.bind.Close()
+		netc.bind = nil
+	}
+	netc.stopping.Wait()
+	return err
+}
+
+func (device *Device) Bind() conn.Bind {
+	device.net.Lock()
+	defer device.net.Unlock()
+	return device.net.bind
+}
+
+func (device *Device) BindSetMark(mark uint32) error {
+
+	device.net.Lock()
+	defer device.net.Unlock()
+
+	// check if modified
+
+	if device.net.fwmark == mark {
+		return nil
+	}
+
+	// update fwmark on existing bind
+
+	device.net.fwmark = mark
+	if device.isUp.Get() && device.net.bind != nil {
+		if err := device.net.bind.SetMark(mark); err != nil {
+			return err
+		}
+	}
+
+	// clear cached source addresses
+
+	device.peers.RLock()
+	for _, peer := range device.peers.keyMap {
+		peer.Lock()
+		defer peer.Unlock()
+		if peer.endpoint != nil {
+			peer.endpoint.ClearSrc()
+		}
+	}
+	device.peers.RUnlock()
+
+	return nil
+}
+
+func (device *Device) BindUpdate() error {
+
+	device.net.Lock()
+	defer device.net.Unlock()
+
+	// close existing sockets
+
+	if err := unsafeCloseBind(device); err != nil {
+		return err
+	}
+
+	// open new sockets
+
+	if device.isUp.Get() {
+
+		// bind to new port
+
+		var err error
+		netc := &device.net
+		netc.bind, netc.port, err = conn.CreateBind(netc.port)
+		if err != nil {
+			netc.bind = nil
+			netc.port = 0
+			return err
+		}
+		netc.netlinkCancel, err = device.startRouteListener(netc.bind)
+		if err != nil {
+			netc.bind.Close()
+			netc.bind = nil
+			netc.port = 0
+			return err
+		}
+
+		// set fwmark
+
+		if netc.fwmark != 0 {
+			err = netc.bind.SetMark(netc.fwmark)
+			if err != nil {
+				return err
+			}
+		}
+
+		// clear cached source addresses
+
+		device.peers.RLock()
+		for _, peer := range device.peers.keyMap {
+			peer.Lock()
+			defer peer.Unlock()
+			if peer.endpoint != nil {
+				peer.endpoint.ClearSrc()
+			}
+		}
+		device.peers.RUnlock()
+
+		// start receiving routines
+
+		device.net.starting.Add(2)
+		device.net.stopping.Add(2)
+		go device.RoutineReceiveIncoming(ipv4.Version, netc.bind)
+		go device.RoutineReceiveIncoming(ipv6.Version, netc.bind)
+		device.net.starting.Wait()
+
+		device.log.Debug.Println("UDP bind has been updated")
+	}
+
+	return nil
+}
+
+func (device *Device) BindClose() error {
+	device.net.Lock()
+	err := unsafeCloseBind(device)
+	device.net.Unlock()
+	return err
+}

device/device_test.go

@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"net"
+	"strings"
+	"testing"
+	"time"
+
+	"golang.zx2c4.com/wireguard/tun/tuntest"
+)
+
+func getFreePort(t *testing.T) string {
+	l, err := net.ListenPacket("udp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+	return fmt.Sprintf("%d", l.LocalAddr().(*net.UDPAddr).Port)
+}
+
+func TestTwoDevicePing(t *testing.T) {
+	port1 := getFreePort(t)
+	port2 := getFreePort(t)
+
+	cfg1 := `private_key=481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58
+listen_port={{PORT1}}
+replace_peers=true
+public_key=f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725
+protocol_version=1
+replace_allowed_ips=true
+allowed_ip=1.0.0.2/32
+endpoint=127.0.0.1:{{PORT2}}`
+	cfg1 = strings.ReplaceAll(cfg1, "{{PORT1}}", port1)
+	cfg1 = strings.ReplaceAll(cfg1, "{{PORT2}}", port2)
+
+	tun1 := tuntest.NewChannelTUN()
+	dev1 := NewDevice(tun1.TUN(), NewLogger(LogLevelDebug, "dev1: "))
+	dev1.Up()
+	defer dev1.Close()
+	if err := dev1.IpcSetOperation(bufio.NewReader(strings.NewReader(cfg1))); err != nil {
+		t.Fatal(err)
+	}
+
+	cfg2 := `private_key=98c7989b1661a0d64fd6af3502000f87716b7c4bbcf00d04fc6073aa7b539768
+listen_port={{PORT2}}
+replace_peers=true
+public_key=49e80929259cebdda4f322d6d2b1a6fad819d603acd26fd5d845e7a123036427
+protocol_version=1
+replace_allowed_ips=true
+allowed_ip=1.0.0.1/32
+endpoint=127.0.0.1:{{PORT1}}`
+	cfg2 = strings.ReplaceAll(cfg2, "{{PORT1}}", port1)
+	cfg2 = strings.ReplaceAll(cfg2, "{{PORT2}}", port2)
+
+	tun2 := tuntest.NewChannelTUN()
+	dev2 := NewDevice(tun2.TUN(), NewLogger(LogLevelDebug, "dev2: "))
+	dev2.Up()
+	defer dev2.Close()
+	if err := dev2.IpcSetOperation(bufio.NewReader(strings.NewReader(cfg2))); err != nil {
+		t.Fatal(err)
+	}
+
+	t.Run("ping 1.0.0.1", func(t *testing.T) {
+		msg2to1 := tuntest.Ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2"))
+		tun2.Outbound <- msg2to1
+		select {
+		case msgRecv := <-tun1.Inbound:
+			if !bytes.Equal(msg2to1, msgRecv) {
+				t.Error("ping did not transit correctly")
+			}
+		case <-time.After(300 * time.Millisecond):
+			t.Error("ping did not transit")
+		}
+	})
+
+	t.Run("ping 1.0.0.2", func(t *testing.T) {
+		msg1to2 := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
+		tun1.Outbound <- msg1to2
+		select {
+		case msgRecv := <-tun2.Inbound:
+			if !bytes.Equal(msg1to2, msgRecv) {
+				t.Error("return ping did not transit correctly")
+			}
+		case <-time.After(300 * time.Millisecond):
+			t.Error("return ping did not transit")
+		}
+	})
+}
+
+func assertNil(t *testing.T, err error) {
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func assertEqual(t *testing.T, a, b []byte) {
+	if !bytes.Equal(a, b) {
+		t.Fatal(a, "!=", b)
+	}
+}
+
+func randDevice(t *testing.T) *Device {
+	sk, err := newPrivateKey()
+	if err != nil {
+		t.Fatal(err)
+	}
+	tun := newDummyTUN("dummy")
+	logger := NewLogger(LogLevelError, "")
+	device := NewDevice(tun, logger)
+	device.SetPrivateKey(sk)
+	return device
+}

device/endpoint_test.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"math/rand"

device/indextable.go

@@ -1,14 +1,14 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"crypto/rand"
+	"encoding/binary"
 	"sync"
-	"unsafe"
 )
 
 type IndexTableEntry struct {
@@ -18,31 +18,32 @@ type IndexTableEntry struct {
 }
 
 type IndexTable struct {
-	mutex sync.RWMutex
+	sync.RWMutex
 	table map[uint32]IndexTableEntry
 }
 
 func randUint32() (uint32, error) {
 	var integer [4]byte
 	_, err := rand.Read(integer[:])
-	return *(*uint32)(unsafe.Pointer(&integer[0])), err
+	// Arbitrary endianness; both are intrinsified by the Go compiler.
+	return binary.LittleEndian.Uint32(integer[:]), err
 }
 
 func (table *IndexTable) Init() {
-	table.mutex.Lock()
-	defer table.mutex.Unlock()
+	table.Lock()
+	defer table.Unlock()
 	table.table = make(map[uint32]IndexTableEntry)
 }
 
 func (table *IndexTable) Delete(index uint32) {
-	table.mutex.Lock()
-	defer table.mutex.Unlock()
+	table.Lock()
+	defer table.Unlock()
 	delete(table.table, index)
 }
 
 func (table *IndexTable) SwapIndexForKeypair(index uint32, keypair *Keypair) {
-	table.mutex.Lock()
-	defer table.mutex.Unlock()
+	table.Lock()
+	defer table.Unlock()
 	entry, ok := table.table[index]
 	if !ok {
 		return
@@ -65,19 +66,19 @@ func (table *IndexTable) NewIndexForHandshake(peer *Peer, handshake *Handshake)
 
 		// check if index used
 
-		table.mutex.RLock()
+		table.RLock()
 		_, ok := table.table[index]
-		table.mutex.RUnlock()
+		table.RUnlock()
 		if ok {
 			continue
 		}
 
 		// check again while locked
 
-		table.mutex.Lock()
+		table.Lock()
 		_, found := table.table[index]
 		if found {
-			table.mutex.Unlock()
+			table.Unlock()
 			continue
 		}
 		table.table[index] = IndexTableEntry{
@@ -85,13 +86,13 @@ func (table *IndexTable) NewIndexForHandshake(peer *Peer, handshake *Handshake)
 			handshake: handshake,
 			keypair:   nil,
 		}
-		table.mutex.Unlock()
+		table.Unlock()
 		return index, nil
 	}
 }
 
 func (table *IndexTable) Lookup(id uint32) IndexTableEntry {
-	table.mutex.RLock()
-	defer table.mutex.RUnlock()
+	table.RLock()
+	defer table.RUnlock()
 	return table.table[id]
 }

device/ip.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"net"

device/kdf_test.go

@@ -1,14 +1,15 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"encoding/hex"
-	"golang.org/x/crypto/blake2s"
 	"testing"
+
+	"golang.org/x/crypto/blake2s"
 )
 
 type KDFTest struct {

device/keypair.go

@@ -1,15 +1,18 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"crypto/cipher"
-	"git.zx2c4.com/wireguard-go/replay"
 	"sync"
+	"sync/atomic"
 	"time"
+	"unsafe"
+
+	"golang.zx2c4.com/wireguard/replay"
 )
 
 /* Due to limitations in Go and /x/crypto there is currently
@@ -23,7 +26,7 @@ type Keypair struct {
 	sendNonce    uint64
 	send         cipher.AEAD
 	receive      cipher.AEAD
-	replayFilter replay.ReplayFilter
+	replayFilter replay.Filter
 	isInitiator  bool
 	created      time.Time
 	localIndex   uint32
@@ -31,15 +34,23 @@ type Keypair struct {
 }
 
 type Keypairs struct {
-	mutex    sync.RWMutex
+	sync.RWMutex
 	current  *Keypair
 	previous *Keypair
 	next     *Keypair
 }
 
+func (kp *Keypairs) storeNext(next *Keypair) {
+	atomic.StorePointer((*unsafe.Pointer)((unsafe.Pointer)(&kp.next)), (unsafe.Pointer)(next))
+}
+
+func (kp *Keypairs) loadNext() *Keypair {
+	return (*Keypair)(atomic.LoadPointer((*unsafe.Pointer)((unsafe.Pointer)(&kp.next))))
+}
+
 func (kp *Keypairs) Current() *Keypair {
-	kp.mutex.RLock()
-	defer kp.mutex.RUnlock()
+	kp.RLock()
+	defer kp.RUnlock()
 	return kp.current
 }
 

device/logger.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"io"

device/misc.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"sync/atomic"
@@ -17,11 +17,11 @@ const (
 )
 
 type AtomicBool struct {
-	flag int32
+	int32
 }
 
 func (a *AtomicBool) Get() bool {
-	return atomic.LoadInt32(&a.flag) == AtomicTrue
+	return atomic.LoadInt32(&a.int32) == AtomicTrue
 }
 
 func (a *AtomicBool) Swap(val bool) bool {
@@ -29,7 +29,7 @@ func (a *AtomicBool) Swap(val bool) bool {
 	if val {
 		flag = AtomicTrue
 	}
-	return atomic.SwapInt32(&a.flag, flag) == AtomicTrue
+	return atomic.SwapInt32(&a.int32, flag) == AtomicTrue
 }
 
 func (a *AtomicBool) Set(val bool) {
@@ -37,7 +37,7 @@ func (a *AtomicBool) Set(val bool) {
 	if val {
 		flag = AtomicTrue
 	}
-	atomic.StoreInt32(&a.flag, flag)
+	atomic.StoreInt32(&a.int32, flag)
 }
 
 func min(a, b uint) uint {

device/mobilequirks.go

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+func (device *Device) DisableSomeRoamingForBrokenMobileSemantics() {
+	device.peers.RLock()
+	for _, peer := range device.peers.keyMap {
+		peer.Lock()
+		defer peer.Unlock()
+		peer.disableRoaming = peer.endpoint != nil
+	}
+	device.peers.RUnlock()
+}

device/noise-helpers.go

@@ -1,17 +1,18 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"crypto/hmac"
 	"crypto/rand"
 	"crypto/subtle"
+	"hash"
+
 	"golang.org/x/crypto/blake2s"
 	"golang.org/x/crypto/curve25519"
-	"hash"
 )
 
 /* KDF related functions.
@@ -41,7 +42,6 @@ func HMAC2(sum *[blake2s.Size]byte, key, in0, in1 []byte) {
 func KDF1(t0 *[blake2s.Size]byte, key, input []byte) {
 	HMAC1(t0, key, input)
 	HMAC1(t0, t0[:], []byte{0x1})
-	return
 }
 
 func KDF2(t0, t1 *[blake2s.Size]byte, key, input []byte) {
@@ -50,7 +50,6 @@ func KDF2(t0, t1 *[blake2s.Size]byte, key, input []byte) {
 	HMAC1(t0, prk[:], []byte{0x1})
 	HMAC2(t1, prk[:], t0[:], []byte{0x2})
 	setZero(prk[:])
-	return
 }
 
 func KDF3(t0, t1, t2 *[blake2s.Size]byte, key, input []byte) {
@@ -60,7 +59,6 @@ func KDF3(t0, t1, t2 *[blake2s.Size]byte, key, input []byte) {
 	HMAC2(t1, prk[:], t0[:], []byte{0x2})
 	HMAC2(t2, prk[:], t1[:], []byte{0x3})
 	setZero(prk[:])
-	return
 }
 
 func isZero(val []byte) bool {
@@ -78,12 +76,14 @@ func setZero(arr []byte) {
 	}
 }
 
-func newPrivateKey() (sk NoisePrivateKey, err error) {
-	// clamping: https://cr.yp.to/ecdh.html
-	_, err = rand.Read(sk[:])
+func (sk *NoisePrivateKey) clamp() {
 	sk[0] &= 248
-	sk[31] &= 127
-	sk[31] |= 64
+	sk[31] = (sk[31] & 127) | 64
+}
+
+func newPrivateKey() (sk NoisePrivateKey, err error) {
+	_, err = rand.Read(sk[:])
+	sk.clamp()
 	return
 }
 

device/noise-protocol.go

@@ -1,28 +1,51 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"errors"
-	"git.zx2c4.com/wireguard-go/tai64n"
+	"fmt"
+	"sync"
+	"time"
+
 	"golang.org/x/crypto/blake2s"
 	"golang.org/x/crypto/chacha20poly1305"
 	"golang.org/x/crypto/poly1305"
-	"sync"
-	"time"
+
+	"golang.zx2c4.com/wireguard/tai64n"
 )
 
+type handshakeState int
+
+// TODO(crawshaw): add commentary describing each state and the transitions
 const (
-	HandshakeZeroed = iota
-	HandshakeInitiationCreated
-	HandshakeInitiationConsumed
-	HandshakeResponseCreated
-	HandshakeResponseConsumed
+	handshakeZeroed = handshakeState(iota)
+	handshakeInitiationCreated
+	handshakeInitiationConsumed
+	handshakeResponseCreated
+	handshakeResponseConsumed
 )
 
+func (hs handshakeState) String() string {
+	switch hs {
+	case handshakeZeroed:
+		return "handshakeZeroed"
+	case handshakeInitiationCreated:
+		return "handshakeInitiationCreated"
+	case handshakeInitiationConsumed:
+		return "handshakeInitiationConsumed"
+	case handshakeResponseCreated:
+		return "handshakeResponseCreated"
+	case handshakeResponseConsumed:
+		return "handshakeResponseConsumed"
+	default:
+		return fmt.Sprintf("Handshake(UNKNOWN:%d)", int(hs))
+	}
+}
+
 const (
 	NoiseConstruction = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s"
 	WGIdentifier      = "WireGuard v1 zx2c4 Jason@zx2c4.com"
@@ -38,13 +61,13 @@ const (
 )
 
 const (
-	MessageInitiationSize      = 148                                           // size of handshake initation message
+	MessageInitiationSize      = 148                                           // size of handshake initiation message
 	MessageResponseSize        = 92                                            // size of response message
 	MessageCookieReplySize     = 64                                            // size of cookie reply message
-	MessageTransportHeaderSize = 16                                            // size of data preceeding content in transport message
+	MessageTransportHeaderSize = 16                                            // size of data preceding content in transport message
 	MessageTransportSize       = MessageTransportHeaderSize + poly1305.TagSize // size of empty transport
 	MessageKeepaliveSize       = MessageTransportSize                          // size of keepalive
-	MessageHandshakeSize       = MessageInitiationSize                         // size of largest handshake releated message
+	MessageHandshakeSize       = MessageInitiationSize                         // size of largest handshake related message
 )
 
 const (
@@ -89,12 +112,12 @@ type MessageTransport struct {
 type MessageCookieReply struct {
 	Type     uint32
 	Receiver uint32
-	Nonce    [24]byte
+	Nonce    [chacha20poly1305.NonceSizeX]byte
 	Cookie   [blake2s.Size128 + poly1305.TagSize]byte
 }
 
 type Handshake struct {
-	state                     int
+	state                     handshakeState
 	mutex                     sync.RWMutex
 	hash                      [blake2s.Size]byte       // hash value
 	chainKey                  [blake2s.Size]byte       // chain key
@@ -134,7 +157,7 @@ func (h *Handshake) Clear() {
 	setZero(h.chainKey[:])
 	setZero(h.hash[:])
 	h.localIndex = 0
-	h.state = HandshakeZeroed
+	h.state = handshakeZeroed
 }
 
 func (h *Handshake) mixHash(data []byte) {
@@ -153,20 +176,16 @@ func init() {
 }
 
 func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, error) {
+	var errZeroECDHResult = errors.New("ECDH returned all zeros")
 
-	device.staticIdentity.mutex.RLock()
-	defer device.staticIdentity.mutex.RUnlock()
+	device.staticIdentity.RLock()
+	defer device.staticIdentity.RUnlock()
 
 	handshake := &peer.handshake
 	handshake.mutex.Lock()
 	defer handshake.mutex.Unlock()
 
-	if isZero(handshake.precomputedStaticStatic[:]) {
-		return nil, errors.New("static shared secret is zero")
-	}
-
 	// create ephemeral key
-
 	var err error
 	handshake.hash = InitialHash
 	handshake.chainKey = InitialChainKey
@@ -175,31 +194,22 @@ func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, e
 		return nil, err
 	}
 
-	// assign index
-
-	device.indexTable.Delete(handshake.localIndex)
-	handshake.localIndex, err = device.indexTable.NewIndexForHandshake(peer, handshake)
-
-	if err != nil {
-		return nil, err
-	}
-
 	handshake.mixHash(handshake.remoteStatic[:])
 
 	msg := MessageInitiation{
 		Type:      MessageInitiationType,
 		Ephemeral: handshake.localEphemeral.publicKey(),
-		Sender:    handshake.localIndex,
 	}
 
 	handshake.mixKey(msg.Ephemeral[:])
 	handshake.mixHash(msg.Ephemeral[:])
 
 	// encrypt static key
-
-	func() {
-		var key [chacha20poly1305.KeySize]byte
 	ss := handshake.localEphemeral.sharedSecret(handshake.remoteStatic)
+	if isZero(ss[:]) {
+		return nil, errZeroECDHResult
+	}
+	var key [chacha20poly1305.KeySize]byte
 	KDF2(
 		&handshake.chainKey,
 		&key,
@@ -208,26 +218,32 @@ func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, e
 	)
 	aead, _ := chacha20poly1305.New(key[:])
 	aead.Seal(msg.Static[:0], ZeroNonce[:], device.staticIdentity.publicKey[:], handshake.hash[:])
-	}()
 	handshake.mixHash(msg.Static[:])
 
 	// encrypt timestamp
-
-	timestamp := tai64n.Now()
-	func() {
-		var key [chacha20poly1305.KeySize]byte
+	if isZero(handshake.precomputedStaticStatic[:]) {
+		return nil, errZeroECDHResult
+	}
 	KDF2(
 		&handshake.chainKey,
 		&key,
 		handshake.chainKey[:],
 		handshake.precomputedStaticStatic[:],
 	)
-		aead, _ := chacha20poly1305.New(key[:])
+	timestamp := tai64n.Now()
+	aead, _ = chacha20poly1305.New(key[:])
 	aead.Seal(msg.Timestamp[:0], ZeroNonce[:], timestamp[:], handshake.hash[:])
-	}()
+
+	// assign index
+	device.indexTable.Delete(handshake.localIndex)
+	msg.Sender, err = device.indexTable.NewIndexForHandshake(peer, handshake)
+	if err != nil {
+		return nil, err
+	}
+	handshake.localIndex = msg.Sender
 
 	handshake.mixHash(msg.Timestamp[:])
-	handshake.state = HandshakeInitiationCreated
+	handshake.state = handshakeInitiationCreated
 	return &msg, nil
 }
 
@@ -241,24 +257,24 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 		return nil
 	}
 
-	device.staticIdentity.mutex.RLock()
-	defer device.staticIdentity.mutex.RUnlock()
+	device.staticIdentity.RLock()
+	defer device.staticIdentity.RUnlock()
 
 	mixHash(&hash, &InitialHash, device.staticIdentity.publicKey[:])
 	mixHash(&hash, &hash, msg.Ephemeral[:])
 	mixKey(&chainKey, &InitialChainKey, msg.Ephemeral[:])
 
 	// decrypt static key
-
 	var err error
 	var peerPK NoisePublicKey
-	func() {
 	var key [chacha20poly1305.KeySize]byte
 	ss := device.staticIdentity.privateKey.sharedSecret(msg.Ephemeral)
+	if isZero(ss[:]) {
+		return nil
+	}
 	KDF2(&chainKey, &key, chainKey[:], ss[:])
 	aead, _ := chacha20poly1305.New(key[:])
 	_, err = aead.Open(peerPK[:0], ZeroNonce[:], msg.Static[:], hash[:])
-	}()
 	if err != nil {
 		return nil
 	}
@@ -272,23 +288,24 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 	}
 
 	handshake := &peer.handshake
-	if isZero(handshake.precomputedStaticStatic[:]) {
-		return nil
-	}
 
 	// verify identity
 
 	var timestamp tai64n.Timestamp
-	var key [chacha20poly1305.KeySize]byte
 
 	handshake.mutex.RLock()
+
+	if isZero(handshake.precomputedStaticStatic[:]) {
+		handshake.mutex.RUnlock()
+		return nil
+	}
 	KDF2(
 		&chainKey,
 		&key,
 		chainKey[:],
 		handshake.precomputedStaticStatic[:],
 	)
-	aead, _ := chacha20poly1305.New(key[:])
+	aead, _ = chacha20poly1305.New(key[:])
 	_, err = aead.Open(timestamp[:0], ZeroNonce[:], msg.Timestamp[:], hash[:])
 	if err != nil {
 		handshake.mutex.RUnlock()
@@ -298,11 +315,15 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 
 	// protect against replay & flood
 
-	var ok bool
-	ok = timestamp.After(handshake.lastTimestamp)
-	ok = ok && time.Now().Sub(handshake.lastInitiationConsumption) > HandshakeInitationRate
+	replay := !timestamp.After(handshake.lastTimestamp)
+	flood := time.Since(handshake.lastInitiationConsumption) <= HandshakeInitationRate
 	handshake.mutex.RUnlock()
-	if !ok {
+	if replay {
+		device.log.Debug.Printf("%v - ConsumeMessageInitiation: handshake replay @ %v\n", peer, timestamp)
+		return nil
+	}
+	if flood {
+		device.log.Debug.Printf("%v - ConsumeMessageInitiation: handshake flood\n", peer)
 		return nil
 	}
 
@@ -314,9 +335,14 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 	handshake.chainKey = chainKey
 	handshake.remoteIndex = msg.Sender
 	handshake.remoteEphemeral = msg.Ephemeral
+	if timestamp.After(handshake.lastTimestamp) {
 		handshake.lastTimestamp = timestamp
-	handshake.lastInitiationConsumption = time.Now()
-	handshake.state = HandshakeInitiationConsumed
+	}
+	now := time.Now()
+	if now.After(handshake.lastInitiationConsumption) {
+		handshake.lastInitiationConsumption = now
+	}
+	handshake.state = handshakeInitiationConsumed
 
 	handshake.mutex.Unlock()
 
@@ -331,7 +357,7 @@ func (device *Device) CreateMessageResponse(peer *Peer) (*MessageResponse, error
 	handshake.mutex.Lock()
 	defer handshake.mutex.Unlock()
 
-	if handshake.state != HandshakeInitiationConsumed {
+	if handshake.state != handshakeInitiationConsumed {
 		return nil, errors.New("handshake initiation must be consumed first")
 	}
 
@@ -387,7 +413,7 @@ func (device *Device) CreateMessageResponse(peer *Peer) (*MessageResponse, error
 		handshake.mixHash(msg.Empty[:])
 	}()
 
-	handshake.state = HandshakeResponseCreated
+	handshake.state = handshakeResponseCreated
 
 	return &msg, nil
 }
@@ -417,14 +443,14 @@ func (device *Device) ConsumeMessageResponse(msg *MessageResponse) *Peer {
 		handshake.mutex.RLock()
 		defer handshake.mutex.RUnlock()
 
-		if handshake.state != HandshakeInitiationCreated {
+		if handshake.state != handshakeInitiationCreated {
 			return false
 		}
 
 		// lock private key for reading
 
-		device.staticIdentity.mutex.RLock()
-		defer device.staticIdentity.mutex.RUnlock()
+		device.staticIdentity.RLock()
+		defer device.staticIdentity.RUnlock()
 
 		// finish 3-way DH
 
@@ -478,7 +504,7 @@ func (device *Device) ConsumeMessageResponse(msg *MessageResponse) *Peer {
 	handshake.hash = hash
 	handshake.chainKey = chainKey
 	handshake.remoteIndex = msg.Sender
-	handshake.state = HandshakeResponseConsumed
+	handshake.state = handshakeResponseConsumed
 
 	handshake.mutex.Unlock()
 
@@ -503,7 +529,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 	var sendKey [chacha20poly1305.KeySize]byte
 	var recvKey [chacha20poly1305.KeySize]byte
 
-	if handshake.state == HandshakeResponseConsumed {
+	if handshake.state == handshakeResponseConsumed {
 		KDF2(
 			&sendKey,
 			&recvKey,
@@ -511,7 +537,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 			nil,
 		)
 		isInitiator = true
-	} else if handshake.state == HandshakeResponseCreated {
+	} else if handshake.state == handshakeResponseCreated {
 		KDF2(
 			&recvKey,
 			&sendKey,
@@ -520,7 +546,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 		)
 		isInitiator = false
 	} else {
-		return errors.New("invalid state for keypair derivation")
+		return fmt.Errorf("invalid state for keypair derivation: %v", handshake.state)
 	}
 
 	// zero handshake
@@ -528,7 +554,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 	setZero(handshake.chainKey[:])
 	setZero(handshake.hash[:]) // Doesn't necessarily need to be zeroed. Could be used for something interesting down the line.
 	setZero(handshake.localEphemeral[:])
-	peer.handshake.state = HandshakeZeroed
+	peer.handshake.state = handshakeZeroed
 
 	// create AEAD instances
 
@@ -541,7 +567,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 
 	keypair.created = time.Now()
 	keypair.sendNonce = 0
-	keypair.replayFilter.Init()
+	keypair.replayFilter.Reset()
 	keypair.isInitiator = isInitiator
 	keypair.localIndex = peer.handshake.localIndex
 	keypair.remoteIndex = peer.handshake.remoteIndex
@@ -554,16 +580,16 @@ func (peer *Peer) BeginSymmetricSession() error {
 	// rotate key pairs
 
 	keypairs := &peer.keypairs
-	keypairs.mutex.Lock()
-	defer keypairs.mutex.Unlock()
+	keypairs.Lock()
+	defer keypairs.Unlock()
 
 	previous := keypairs.previous
-	next := keypairs.next
+	next := keypairs.loadNext()
 	current := keypairs.current
 
 	if isInitiator {
 		if next != nil {
-			keypairs.next = nil
+			keypairs.storeNext(nil)
 			keypairs.previous = next
 			device.DeleteKeypair(current)
 		} else {
@@ -572,7 +598,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 		device.DeleteKeypair(previous)
 		keypairs.current = keypair
 	} else {
-		keypairs.next = keypair
+		keypairs.storeNext(keypair)
 		device.DeleteKeypair(next)
 		keypairs.previous = nil
 		device.DeleteKeypair(previous)
@@ -583,18 +609,19 @@ func (peer *Peer) BeginSymmetricSession() error {
 
 func (peer *Peer) ReceivedWithKeypair(receivedKeypair *Keypair) bool {
 	keypairs := &peer.keypairs
-	if keypairs.next != receivedKeypair {
+
+	if keypairs.loadNext() != receivedKeypair {
 		return false
 	}
-	keypairs.mutex.Lock()
-	defer keypairs.mutex.Unlock()
-	if keypairs.next != receivedKeypair {
+	keypairs.Lock()
+	defer keypairs.Unlock()
+	if keypairs.loadNext() != receivedKeypair {
 		return false
 	}
 	old := keypairs.previous
 	keypairs.previous = keypairs.current
 	peer.device.DeleteKeypair(old)
-	keypairs.current = keypairs.next
-	keypairs.next = nil
+	keypairs.current = keypairs.loadNext()
+	keypairs.storeNext(nil)
 	return true
 }

device/noise-types.go

@@ -1,14 +1,15 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"crypto/subtle"
 	"encoding/hex"
 	"errors"
+
 	"golang.org/x/crypto/chacha20poly1305"
 )
 
@@ -45,8 +46,19 @@ func (key NoisePrivateKey) Equals(tar NoisePrivateKey) bool {
 	return subtle.ConstantTimeCompare(key[:], tar[:]) == 1
 }
 
-func (key *NoisePrivateKey) FromHex(src string) error {
-	return loadExactHex(key[:], src)
+func (key *NoisePrivateKey) FromHex(src string) (err error) {
+	err = loadExactHex(key[:], src)
+	key.clamp()
+	return
+}
+
+func (key *NoisePrivateKey) FromMaybeZeroHex(src string) (err error) {
+	err = loadExactHex(key[:], src)
+	if key.IsZero() {
+		return
+	}
+	key.clamp()
+	return
 }
 
 func (key NoisePrivateKey) ToHex() string {

device/noise_test.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"bytes"
@@ -113,7 +113,7 @@ func TestNoiseHandshake(t *testing.T) {
 		t.Fatal("failed to derive keypair for peer 2", err)
 	}
 
-	key1 := peer1.keypairs.next
+	key1 := peer1.keypairs.loadNext()
 	key2 := peer2.keypairs.current
 
 	// encrypting / decryption test

device/peer.go

@@ -1,16 +1,19 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"encoding/base64"
 	"errors"
 	"fmt"
 	"sync"
+	"sync/atomic"
 	"time"
+
+	"golang.zx2c4.com/wireguard/conn"
 )
 
 const (
@@ -19,14 +22,19 @@ const (
 
 type Peer struct {
 	isRunning                   AtomicBool
-	mutex                       sync.RWMutex // Mostly protects endpoint, but is generally taken whenever we modify peer
+	sync.RWMutex                // Mostly protects endpoint, but is generally taken whenever we modify peer
 	keypairs                    Keypairs
 	handshake                   Handshake
 	device                      *Device
-	endpoint                    Endpoint
+	endpoint                    conn.Endpoint
 	persistentKeepaliveInterval uint16
+	disableRoaming              bool
 
-	// This must be 64-bit aligned, so make sure the above members come out to even alignment and pad accordingly
+	// These fields are accessed with atomic operations, which must be
+	// 64-bit aligned even on 32-bit platforms. Go guarantees that an
+	// allocated struct will be 64-bit aligned. So we place
+	// atomically-accessed fields up front, so that they can share in
+	// this alignment before smaller fields throw it off.
 	stats struct {
 		txBytes           uint64 // bytes send to peer (endpoint)
 		rxBytes           uint64 // bytes received from peer
@@ -50,6 +58,7 @@ type Peer struct {
 	}
 
 	queue struct {
+		sync.RWMutex
 		nonce                           chan *QueueOutboundElement // nonce / pre-handshake queue
 		outbound                        chan *QueueOutboundElement // sequential ordering of work
 		inbound                         chan *QueueInboundElement  // sequential ordering of work
@@ -57,7 +66,7 @@ type Peer struct {
 	}
 
 	routines struct {
-		mutex    sync.Mutex     // held when stopping / starting routines
+		sync.Mutex                // held when stopping / starting routines
 		starting   sync.WaitGroup // routines pending start
 		stopping   sync.WaitGroup // routines pending stop
 		stop       chan struct{}  // size 0, stop all go routines in peer
@@ -67,18 +76,17 @@ type Peer struct {
 }
 
 func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
-
 	if device.isClosed.Get() {
 		return nil, errors.New("device closed")
 	}
 
 	// lock resources
 
-	device.staticIdentity.mutex.RLock()
-	defer device.staticIdentity.mutex.RUnlock()
+	device.staticIdentity.RLock()
+	defer device.staticIdentity.RUnlock()
 
-	device.peers.mutex.Lock()
-	defer device.peers.mutex.Unlock()
+	device.peers.Lock()
+	defer device.peers.Unlock()
 
 	// check if over limit
 
@@ -89,8 +97,8 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 	// create peer
 
 	peer := new(Peer)
-	peer.mutex.Lock()
-	defer peer.mutex.Unlock()
+	peer.Lock()
+	defer peer.Unlock()
 
 	peer.cookieGenerator.Init(pk)
 	peer.device = device
@@ -102,20 +110,23 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 	if ok {
 		return nil, errors.New("adding existing peer")
 	}
-	device.peers.keyMap[pk] = peer
 
 	// pre-compute DH
 
 	handshake := &peer.handshake
 	handshake.mutex.Lock()
-	handshake.remoteStatic = pk
 	handshake.precomputedStaticStatic = device.staticIdentity.privateKey.sharedSecret(pk)
+	handshake.remoteStatic = pk
 	handshake.mutex.Unlock()
 
 	// reset endpoint
 
 	peer.endpoint = nil
 
+	// add
+
+	device.peers.keyMap[pk] = peer
+
 	// start peer
 
 	if peer.device.isUp.Get() {
@@ -126,21 +137,25 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 }
 
 func (peer *Peer) SendBuffer(buffer []byte) error {
-	peer.device.net.mutex.RLock()
-	defer peer.device.net.mutex.RUnlock()
+	peer.device.net.RLock()
+	defer peer.device.net.RUnlock()
 
 	if peer.device.net.bind == nil {
 		return errors.New("no bind")
 	}
 
-	peer.mutex.RLock()
-	defer peer.mutex.RUnlock()
+	peer.RLock()
+	defer peer.RUnlock()
 
 	if peer.endpoint == nil {
 		return errors.New("no known endpoint for peer")
 	}
 
-	return peer.device.net.bind.Send(buffer, peer.endpoint)
+	err := peer.device.net.bind.Send(buffer, peer.endpoint)
+	if err == nil {
+		atomic.AddUint64(&peer.stats.txBytes, uint64(len(buffer)))
+	}
+	return err
 }
 
 func (peer *Peer) String() string {
@@ -162,8 +177,8 @@ func (peer *Peer) Start() {
 
 	// prevent simultaneous start/stop operations
 
-	peer.routines.mutex.Lock()
-	defer peer.routines.mutex.Unlock()
+	peer.routines.Lock()
+	defer peer.routines.Unlock()
 
 	if peer.isRunning.Get() {
 		return
@@ -181,10 +196,11 @@ func (peer *Peer) Start() {
 	peer.routines.stopping.Add(PeerRoutineNumber)
 
 	// prepare queues
-
+	peer.queue.Lock()
 	peer.queue.nonce = make(chan *QueueOutboundElement, QueueOutboundSize)
 	peer.queue.outbound = make(chan *QueueOutboundElement, QueueOutboundSize)
 	peer.queue.inbound = make(chan *QueueInboundElement, QueueInboundSize)
+	peer.queue.Unlock()
 
 	peer.timersInit()
 	peer.handshake.lastSentHandshake = time.Now().Add(-(RekeyTimeout + time.Second))
@@ -207,14 +223,14 @@ func (peer *Peer) ZeroAndFlushAll() {
 	// clear key pairs
 
 	keypairs := &peer.keypairs
-	keypairs.mutex.Lock()
+	keypairs.Lock()
 	device.DeleteKeypair(keypairs.previous)
 	device.DeleteKeypair(keypairs.current)
-	device.DeleteKeypair(keypairs.next)
+	device.DeleteKeypair(keypairs.loadNext())
 	keypairs.previous = nil
 	keypairs.current = nil
-	keypairs.next = nil
-	keypairs.mutex.Unlock()
+	keypairs.storeNext(nil)
+	keypairs.Unlock()
 
 	// clear handshake state
 
@@ -227,6 +243,25 @@ func (peer *Peer) ZeroAndFlushAll() {
 	peer.FlushNonceQueue()
 }
 
+func (peer *Peer) ExpireCurrentKeypairs() {
+	handshake := &peer.handshake
+	handshake.mutex.Lock()
+	peer.device.indexTable.Delete(handshake.localIndex)
+	handshake.Clear()
+	handshake.mutex.Unlock()
+	peer.handshake.lastSentHandshake = time.Now().Add(-(RekeyTimeout + time.Second))
+
+	keypairs := &peer.keypairs
+	keypairs.Lock()
+	if keypairs.current != nil {
+		keypairs.current.sendNonce = RejectAfterMessages
+	}
+	if keypairs.next != nil {
+		keypairs.loadNext().sendNonce = RejectAfterMessages
+	}
+	keypairs.Unlock()
+}
+
 func (peer *Peer) Stop() {
 
 	// prevent simultaneous start/stop operations
@@ -237,8 +272,8 @@ func (peer *Peer) Stop() {
 
 	peer.routines.starting.Wait()
 
-	peer.routines.mutex.Lock()
-	defer peer.routines.mutex.Unlock()
+	peer.routines.Lock()
+	defer peer.routines.Unlock()
 
 	peer.device.log.Debug.Println(peer, "- Stopping...")
 
@@ -251,20 +286,20 @@ func (peer *Peer) Stop() {
 
 	// close queues
 
+	peer.queue.Lock()
 	close(peer.queue.nonce)
 	close(peer.queue.outbound)
 	close(peer.queue.inbound)
+	peer.queue.Unlock()
 
 	peer.ZeroAndFlushAll()
 }
 
-var roamingDisabled bool
-
-func (peer *Peer) SetEndpointFromPacket(endpoint Endpoint) {
-	if roamingDisabled {
+func (peer *Peer) SetEndpointFromPacket(endpoint conn.Endpoint) {
+	if peer.disableRoaming {
 		return
 	}
-	peer.mutex.Lock()
+	peer.Lock()
 	peer.endpoint = endpoint
-	peer.mutex.Unlock()
+	peer.Unlock()
 }

device/peer_test.go

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"reflect"
+	"testing"
+	"unsafe"
+)
+
+func checkAlignment(t *testing.T, name string, offset uintptr) {
+	t.Helper()
+	if offset%8 != 0 {
+		t.Errorf("offset of %q within struct is %d bytes, which does not align to 64-bit word boundaries (missing %d bytes). Atomic operations will crash on 32-bit systems.", name, offset, 8-(offset%8))
+	}
+}
+
+// TestPeerAlignment checks that atomically-accessed fields are
+// aligned to 64-bit boundaries, as required by the atomic package.
+//
+// Unfortunately, violating this rule on 32-bit platforms results in a
+// hard segfault at runtime.
+func TestPeerAlignment(t *testing.T) {
+	var p Peer
+
+	typ := reflect.TypeOf(p)
+	t.Logf("Peer type size: %d, with fields:", typ.Size())
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		t.Logf("\t%30s\toffset=%3v\t(type size=%3d, align=%d)",
+			field.Name,
+			field.Offset,
+			field.Type.Size(),
+			field.Type.Align(),
+		)
+	}
+
+	checkAlignment(t, "Peer.stats", unsafe.Offsetof(p.stats))
+	checkAlignment(t, "Peer.isRunning", unsafe.Offsetof(p.isRunning))
+}

device/pools.go

@@ -1,9 +1,9 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import "sync"
 

device/queueconstants_android.go

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+/* Reduce memory consumption for Android */
+
+const (
+	QueueOutboundSize          = 1024
+	QueueInboundSize           = 1024
+	QueueHandshakeSize         = 1024
+	MaxSegmentSize             = 2200
+	PreallocatedBuffersPerPool = 4096
+)

device/queueconstants_default.go

@@ -1,11 +1,11 @@
-/* SPDX-License-Identifier: GPL-2.0
+// +build !android,!ios
+
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
-
-/* Implementation specific constants */
+package device
 
 const (
 	QueueOutboundSize          = 1024

device/queueconstants_ios.go

@@ -0,0 +1,18 @@
+// +build ios
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+/* Fit within memory limits for iOS's Network Extension API, which has stricter requirements */
+
+const (
+	QueueOutboundSize          = 1024
+	QueueInboundSize           = 1024
+	QueueHandshakeSize         = 1024
+	MaxSegmentSize             = 1700
+	PreallocatedBuffersPerPool = 1024
+)

device/receive.go

@@ -1,38 +1,40 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"bytes"
 	"encoding/binary"
-	"golang.org/x/crypto/chacha20poly1305"
-	"golang.org/x/net/ipv4"
-	"golang.org/x/net/ipv6"
 	"net"
 	"strconv"
 	"sync"
 	"sync/atomic"
 	"time"
+
+	"golang.org/x/crypto/chacha20poly1305"
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+	"golang.zx2c4.com/wireguard/conn"
 )
 
 type QueueHandshakeElement struct {
 	msgType  uint32
 	packet   []byte
-	endpoint Endpoint
+	endpoint conn.Endpoint
 	buffer   *[MaxMessageSize]byte
 }
 
 type QueueInboundElement struct {
 	dropped int32
-	mutex    sync.Mutex
+	sync.Mutex
 	buffer   *[MaxMessageSize]byte
 	packet   []byte
 	counter  uint64
 	keypair  *Keypair
-	endpoint Endpoint
+	endpoint conn.Endpoint
 }
 
 func (elem *QueueInboundElement) Drop() {
@@ -51,7 +53,7 @@ func (device *Device) addToInboundAndDecryptionQueues(inboundQueue chan *QueueIn
 			return true
 		default:
 			element.Drop()
-			element.mutex.Unlock()
+			element.Unlock()
 			return false
 		}
 	default:
@@ -78,7 +80,7 @@ func (peer *Peer) keepKeyFreshReceiving() {
 		return
 	}
 	keypair := peer.keypairs.Current()
-	if keypair != nil && keypair.isInitiator && time.Now().Sub(keypair.created) > (RejectAfterTime-KeepaliveTimeout-RekeyTimeout) {
+	if keypair != nil && keypair.isInitiator && time.Since(keypair.created) > (RejectAfterTime-KeepaliveTimeout-RekeyTimeout) {
 		peer.timers.sentLastMinuteHandshake.Set(true)
 		peer.SendHandshakeInitiation(false)
 	}
@@ -89,7 +91,7 @@ func (peer *Peer) keepKeyFreshReceiving() {
  * Every time the bind is updated a new routine is started for
  * IPv4 and IPv6 (separately)
  */
-func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
+func (device *Device) RoutineReceiveIncoming(IP int, bind conn.Bind) {
 
 	logDebug := device.log.Debug
 	defer func() {
@@ -97,7 +99,7 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 		device.net.stopping.Done()
 	}()
 
-	logDebug.Println("Routine: receive incoming IPv" + strconv.Itoa(IP) + " - starting")
+	logDebug.Println("Routine: receive incoming IPv" + strconv.Itoa(IP) + " - started")
 	device.net.starting.Done()
 
 	// receive datagrams until conn is closed
@@ -107,7 +109,7 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 	var (
 		err      error
 		size     int
-		endpoint Endpoint
+		endpoint conn.Endpoint
 	)
 
 	for {
@@ -177,16 +179,18 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 			elem.dropped = AtomicFalse
 			elem.endpoint = endpoint
 			elem.counter = 0
-			elem.mutex = sync.Mutex{}
-			elem.mutex.Lock()
+			elem.Mutex = sync.Mutex{}
+			elem.Lock()
 
 			// add to decryption queues
 
+			peer.queue.RLock()
 			if peer.isRunning.Get() {
 				if device.addToInboundAndDecryptionQueues(peer.queue.inbound, device.queue.decryption, elem) {
 					buffer = device.GetMessageBuffer()
 				}
 			}
+			peer.queue.RUnlock()
 
 			continue
 
@@ -281,7 +285,7 @@ func (device *Device) RoutineDecryption() {
 				elem.Drop()
 				device.PutMessageBuffer(elem.buffer)
 			}
-			elem.mutex.Unlock()
+			elem.Unlock()
 		}
 	}
 }
@@ -351,7 +355,10 @@ func (device *Device) RoutineHandshake() {
 			// consume reply
 
 			if peer := entry.peer; peer.isRunning.Get() {
-				peer.cookieGenerator.ConsumeReply(&reply)
+				logDebug.Println("Receiving cookie response from ", elem.endpoint.DstToString())
+				if !peer.cookieGenerator.ConsumeReply(&reply) {
+					logDebug.Println("Could not decrypt invalid cookie response")
+				}
 			}
 
 			continue
@@ -423,6 +430,7 @@ func (device *Device) RoutineHandshake() {
 			peer.SetEndpointFromPacket(elem.endpoint)
 
 			logDebug.Println(peer, "- Received handshake initiation")
+			atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)))
 
 			peer.SendHandshakeResponse()
 
@@ -453,6 +461,7 @@ func (device *Device) RoutineHandshake() {
 			peer.SetEndpointFromPacket(elem.endpoint)
 
 			logDebug.Println(peer, "- Received handshake response")
+			atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)))
 
 			// update timers
 
@@ -487,7 +496,6 @@ func (peer *Peer) RoutineSequentialReceiver() {
 	logDebug := device.log.Debug
 
 	var elem *QueueInboundElement
-	var ok bool
 
 	defer func() {
 		logDebug.Println(peer, "- Routine: sequential receiver - stopped")
@@ -513,20 +521,19 @@ func (peer *Peer) RoutineSequentialReceiver() {
 			elem = nil
 		}
 
+		var elemOk bool
 		select {
-
 		case <-peer.routines.stop:
 			return
-
-		case elem, ok = <-peer.queue.inbound:
-
-			if !ok {
+		case elem, elemOk = <-peer.queue.inbound:
+			if !elemOk {
 				return
 			}
+		}
 
 		// wait for decryption
 
-			elem.mutex.Lock()
+		elem.Lock()
 
 		if elem.IsDropped() {
 			continue
@@ -553,6 +560,7 @@ func (peer *Peer) RoutineSequentialReceiver() {
 		peer.keepKeyFreshReceiving()
 		peer.timersAnyAuthenticatedPacketTraversal()
 		peer.timersAnyAuthenticatedPacketReceived()
+		atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)+MinMessageSize))
 
 		// check for keepalive
 
@@ -614,8 +622,8 @@ func (peer *Peer) RoutineSequentialReceiver() {
 			src := elem.packet[IPv6offsetSrc : IPv6offsetSrc+net.IPv6len]
 			if device.allowedips.LookupIPv6(src) != peer {
 				logInfo.Println(
+					"IPv6 packet with disallowed source address from",
 					peer,
-						"sent packet with disallowed IPv6 source",
 				)
 				continue
 			}
@@ -628,11 +636,15 @@ func (peer *Peer) RoutineSequentialReceiver() {
 		// write to tun device
 
 		offset := MessageTransportOffsetContent
-			atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)))
 		_, err := device.tun.device.Write(elem.buffer[:offset+len(elem.packet)], offset)
+		if len(peer.queue.inbound) == 0 {
+			err = device.tun.device.Flush()
 			if err != nil {
+				peer.device.log.Error.Printf("Unable to flush packets: %v", err)
+			}
+		}
+		if err != nil && !device.isClosed.Get() {
 			logError.Println("Failed to write packet to TUN device:", err)
 		}
 	}
-	}
 }

device/send.go

@@ -1,20 +1,21 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"bytes"
 	"encoding/binary"
-	"golang.org/x/crypto/chacha20poly1305"
-	"golang.org/x/net/ipv4"
-	"golang.org/x/net/ipv6"
 	"net"
 	"sync"
 	"sync/atomic"
 	"time"
+
+	"golang.org/x/crypto/chacha20poly1305"
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
 )
 
 /* Outbound flow
@@ -43,7 +44,7 @@ import (
 
 type QueueOutboundElement struct {
 	dropped int32
-	mutex   sync.Mutex
+	sync.Mutex
 	buffer  *[MaxMessageSize]byte // slice holding the packet data
 	packet  []byte                // slice of "buffer" (always!)
 	nonce   uint64                // nonce for encryption
@@ -55,7 +56,7 @@ func (device *Device) NewOutboundElement() *QueueOutboundElement {
 	elem := device.GetOutboundElement()
 	elem.dropped = AtomicFalse
 	elem.buffer = device.GetMessageBuffer()
-	elem.mutex = sync.Mutex{}
+	elem.Mutex = sync.Mutex{}
 	elem.nonce = 0
 	elem.keypair = nil
 	elem.peer = nil
@@ -95,7 +96,7 @@ func addToOutboundAndEncryptionQueues(outboundQueue chan *QueueOutboundElement,
 		default:
 			element.Drop()
 			element.peer.device.PutMessageBuffer(element.buffer)
-			element.mutex.Unlock()
+			element.Unlock()
 		}
 	default:
 		element.peer.device.PutMessageBuffer(element.buffer)
@@ -106,6 +107,8 @@ func addToOutboundAndEncryptionQueues(outboundQueue chan *QueueOutboundElement,
 /* Queues a keepalive if no packets are queued for peer
  */
 func (peer *Peer) SendKeepalive() bool {
+	peer.queue.RLock()
+	defer peer.queue.RUnlock()
 	if len(peer.queue.nonce) != 0 || peer.queue.packetInNonceQueueIsAwaitingKey.Get() || !peer.isRunning.Get() {
 		return false
 	}
@@ -128,14 +131,14 @@ func (peer *Peer) SendHandshakeInitiation(isRetry bool) error {
 	}
 
 	peer.handshake.mutex.RLock()
-	if time.Now().Sub(peer.handshake.lastSentHandshake) < RekeyTimeout {
+	if time.Since(peer.handshake.lastSentHandshake) < RekeyTimeout {
 		peer.handshake.mutex.RUnlock()
 		return nil
 	}
 	peer.handshake.mutex.RUnlock()
 
 	peer.handshake.mutex.Lock()
-	if time.Now().Sub(peer.handshake.lastSentHandshake) < RekeyTimeout {
+	if time.Since(peer.handshake.lastSentHandshake) < RekeyTimeout {
 		peer.handshake.mutex.Unlock()
 		return nil
 	}
@@ -206,7 +209,7 @@ func (peer *Peer) SendHandshakeResponse() error {
 
 func (device *Device) SendHandshakeCookie(initiatingElem *QueueHandshakeElement) error {
 
-	device.log.Debug.Println("Sending cookie reply to:", initiatingElem.endpoint.DstToString())
+	device.log.Debug.Println("Sending cookie response for denied handshake message for", initiatingElem.endpoint.DstToString())
 
 	sender := binary.LittleEndian.Uint32(initiatingElem.packet[4:8])
 	reply, err := device.cookieChecker.CreateReply(initiatingElem.packet, sender, initiatingElem.endpoint.DstToBytes())
@@ -219,10 +222,7 @@ func (device *Device) SendHandshakeCookie(initiatingElem *QueueHandshakeElement)
 	writer := bytes.NewBuffer(buff[:0])
 	binary.Write(writer, binary.LittleEndian, reply)
 	device.net.bind.Send(writer.Bytes(), initiatingElem.endpoint)
-	if err != nil {
-		device.log.Error.Println("Failed to send cookie reply:", err)
-	}
-	return err
+	return nil
 }
 
 func (peer *Peer) keepKeyFreshSending() {
@@ -231,7 +231,7 @@ func (peer *Peer) keepKeyFreshSending() {
 		return
 	}
 	nonce := atomic.LoadUint64(&keypair.sendNonce)
-	if nonce > RekeyAfterMessages || (keypair.isInitiator && time.Now().Sub(keypair.created) > RekeyAfterTime) {
+	if nonce > RekeyAfterMessages || (keypair.isInitiator && time.Since(keypair.created) > RekeyAfterTime) {
 		peer.SendHandshakeInitiation(false)
 	}
 }
@@ -312,6 +312,7 @@ func (device *Device) RoutineReadFromTUN() {
 
 		// insert into nonce/pre-handshake queue
 
+		peer.queue.RLock()
 		if peer.isRunning.Get() {
 			if peer.queue.packetInNonceQueueIsAwaitingKey.Get() {
 				peer.SendHandshakeInitiation(false)
@@ -319,6 +320,7 @@ func (device *Device) RoutineReadFromTUN() {
 			addToNonceQueue(peer.queue.nonce, elem, device)
 			elem = nil
 		}
+		peer.queue.RUnlock()
 	}
 }
 
@@ -389,7 +391,7 @@ func (peer *Peer) RoutineNonce() {
 
 				keypair = peer.keypairs.Current()
 				if keypair != nil && keypair.sendNonce < RejectAfterMessages {
-					if time.Now().Sub(keypair.created) < RejectAfterTime {
+					if time.Since(keypair.created) < RejectAfterTime {
 						break
 					}
 				}
@@ -442,7 +444,7 @@ func (peer *Peer) RoutineNonce() {
 
 			elem.keypair = keypair
 			elem.dropped = AtomicFalse
-			elem.mutex.Lock()
+			elem.Lock()
 
 			// add to parallel and sequential queue
 			addToOutboundAndEncryptionQueues(peer.queue.outbound, device.queue.encryption, elem)
@@ -450,6 +452,21 @@ func (peer *Peer) RoutineNonce() {
 	}
 }
 
+func calculatePaddingSize(packetSize, mtu int) int {
+	lastUnit := packetSize
+	if mtu == 0 {
+		return ((lastUnit + PaddingMultiple - 1) & ^(PaddingMultiple - 1)) - lastUnit
+	}
+	if lastUnit > mtu {
+		lastUnit %= mtu
+	}
+	paddedSize := ((lastUnit + PaddingMultiple - 1) & ^(PaddingMultiple - 1))
+	if paddedSize > mtu {
+		paddedSize = mtu
+	}
+	return paddedSize - lastUnit
+}
+
 /* Encrypts the elements in the queue
  * and marks them for sequential consumption (by releasing the mutex)
  *
@@ -468,7 +485,7 @@ func (device *Device) RoutineEncryption() {
 				if ok && !elem.IsDropped() {
 					elem.Drop()
 					device.PutMessageBuffer(elem.buffer)
-					elem.mutex.Unlock()
+					elem.Unlock()
 				}
 			default:
 				goto out
@@ -516,13 +533,8 @@ func (device *Device) RoutineEncryption() {
 
 			// pad content to multiple of 16
 
-			mtu := int(atomic.LoadInt32(&device.tun.mtu))
-			lastUnit := len(elem.packet) % mtu
-			paddedSize := (lastUnit + PaddingMultiple - 1) & ^(PaddingMultiple - 1)
-			if paddedSize > mtu {
-				paddedSize = mtu
-			}
-			for i := len(elem.packet); i < paddedSize; i++ {
+			paddingSize := calculatePaddingSize(len(elem.packet), int(atomic.LoadInt32(&device.tun.mtu)))
+			for i := 0; i < paddingSize; i++ {
 				elem.packet = append(elem.packet, 0)
 			}
 
@@ -535,7 +547,7 @@ func (device *Device) RoutineEncryption() {
 				elem.packet,
 				nil,
 			)
-			elem.mutex.Unlock()
+			elem.Unlock()
 		}
 	}
 }
@@ -562,7 +574,6 @@ func (peer *Peer) RoutineSequentialSender() {
 						elem.Drop()
 					}
 					device.PutOutboundElement(elem)
-					elem.mutex.Unlock()
 				}
 			default:
 				goto out
@@ -589,7 +600,7 @@ func (peer *Peer) RoutineSequentialSender() {
 				return
 			}
 
-			elem.mutex.Lock()
+			elem.Lock()
 			if elem.IsDropped() {
 				device.PutOutboundElement(elem)
 				continue
@@ -600,19 +611,17 @@ func (peer *Peer) RoutineSequentialSender() {
 
 			// send message and return buffer to pool
 
-			length := uint64(len(elem.packet))
 			err := peer.SendBuffer(elem.packet)
+			if len(elem.packet) != MessageKeepaliveSize {
+				peer.timersDataSent()
+			}
 			device.PutMessageBuffer(elem.buffer)
 			device.PutOutboundElement(elem)
 			if err != nil {
 				logError.Println(peer, "- Failed to send data packet", err)
 				continue
 			}
-			atomic.AddUint64(&peer.stats.txBytes, length)
 
-			if len(elem.packet) != MessageKeepaliveSize {
-				peer.timersDataSent()
-			}
 			peer.keepKeyFreshSending()
 		}
 	}

device/sticky_default.go

@@ -0,0 +1,12 @@
+// +build !linux android
+
+package device
+
+import (
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/rwcancel"
+)
+
+func (device *Device) startRouteListener(bind conn.Bind) (*rwcancel.RWCancel, error) {
+	return nil, nil
+}

device/sticky_linux.go

@@ -0,0 +1,217 @@
+// +build !android
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ *
+ * This implements userspace semantics of "sticky sockets", modeled after
+ * WireGuard's kernelspace implementation. This is more or less a straight port
+ * of the sticky-sockets.c example code:
+ * https://git.zx2c4.com/WireGuard/tree/contrib/examples/sticky-sockets/sticky-sockets.c
+ *
+ * Currently there is no way to achieve this within the net package:
+ * See e.g. https://github.com/golang/go/issues/17930
+ * So this code is remains platform dependent.
+ */
+
+package device
+
+import (
+	"sync"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/rwcancel"
+)
+
+func (device *Device) startRouteListener(bind conn.Bind) (*rwcancel.RWCancel, error) {
+	netlinkSock, err := createNetlinkRouteSocket()
+	if err != nil {
+		return nil, err
+	}
+	netlinkCancel, err := rwcancel.NewRWCancel(netlinkSock)
+	if err != nil {
+		unix.Close(netlinkSock)
+		return nil, err
+	}
+
+	go device.routineRouteListener(bind, netlinkSock, netlinkCancel)
+
+	return netlinkCancel, nil
+}
+
+func (device *Device) routineRouteListener(bind conn.Bind, netlinkSock int, netlinkCancel *rwcancel.RWCancel) {
+	type peerEndpointPtr struct {
+		peer     *Peer
+		endpoint *conn.Endpoint
+	}
+	var reqPeer map[uint32]peerEndpointPtr
+	var reqPeerLock sync.Mutex
+
+	defer unix.Close(netlinkSock)
+
+	for msg := make([]byte, 1<<16); ; {
+		var err error
+		var msgn int
+		for {
+			msgn, _, _, _, err = unix.Recvmsg(netlinkSock, msg[:], nil, 0)
+			if err == nil || !rwcancel.RetryAfterError(err) {
+				break
+			}
+			if !netlinkCancel.ReadyRead() {
+				return
+			}
+		}
+		if err != nil {
+			return
+		}
+
+		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
+
+			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
+
+			if uint(hdr.Len) > uint(len(remain)) {
+				break
+			}
+
+			switch hdr.Type {
+			case unix.RTM_NEWROUTE, unix.RTM_DELROUTE:
+				if hdr.Seq <= MaxPeers && hdr.Seq > 0 {
+					if uint(len(remain)) < uint(hdr.Len) {
+						break
+					}
+					if hdr.Len > unix.SizeofNlMsghdr+unix.SizeofRtMsg {
+						attr := remain[unix.SizeofNlMsghdr+unix.SizeofRtMsg:]
+						for {
+							if uint(len(attr)) < uint(unix.SizeofRtAttr) {
+								break
+							}
+							attrhdr := *(*unix.RtAttr)(unsafe.Pointer(&attr[0]))
+							if attrhdr.Len < unix.SizeofRtAttr || uint(len(attr)) < uint(attrhdr.Len) {
+								break
+							}
+							if attrhdr.Type == unix.RTA_OIF && attrhdr.Len == unix.SizeofRtAttr+4 {
+								ifidx := *(*uint32)(unsafe.Pointer(&attr[unix.SizeofRtAttr]))
+								reqPeerLock.Lock()
+								if reqPeer == nil {
+									reqPeerLock.Unlock()
+									break
+								}
+								pePtr, ok := reqPeer[hdr.Seq]
+								reqPeerLock.Unlock()
+								if !ok {
+									break
+								}
+								pePtr.peer.Lock()
+								if &pePtr.peer.endpoint != pePtr.endpoint {
+									pePtr.peer.Unlock()
+									break
+								}
+								if uint32(pePtr.peer.endpoint.(*conn.NativeEndpoint).Src4().Ifindex) == ifidx {
+									pePtr.peer.Unlock()
+									break
+								}
+								pePtr.peer.endpoint.(*conn.NativeEndpoint).ClearSrc()
+								pePtr.peer.Unlock()
+							}
+							attr = attr[attrhdr.Len:]
+						}
+					}
+					break
+				}
+				reqPeerLock.Lock()
+				reqPeer = make(map[uint32]peerEndpointPtr)
+				reqPeerLock.Unlock()
+				go func() {
+					device.peers.RLock()
+					i := uint32(1)
+					for _, peer := range device.peers.keyMap {
+						peer.RLock()
+						if peer.endpoint == nil {
+							peer.RUnlock()
+							continue
+						}
+						nativeEP, _ := peer.endpoint.(*conn.NativeEndpoint)
+						if nativeEP == nil {
+							peer.RUnlock()
+							continue
+						}
+						if nativeEP.IsV6() || nativeEP.Src4().Ifindex == 0 {
+							peer.RUnlock()
+							break
+						}
+						nlmsg := struct {
+							hdr     unix.NlMsghdr
+							msg     unix.RtMsg
+							dsthdr  unix.RtAttr
+							dst     [4]byte
+							srchdr  unix.RtAttr
+							src     [4]byte
+							markhdr unix.RtAttr
+							mark    uint32
+						}{
+							unix.NlMsghdr{
+								Type:  uint16(unix.RTM_GETROUTE),
+								Flags: unix.NLM_F_REQUEST,
+								Seq:   i,
+							},
+							unix.RtMsg{
+								Family:  unix.AF_INET,
+								Dst_len: 32,
+								Src_len: 32,
+							},
+							unix.RtAttr{
+								Len:  8,
+								Type: unix.RTA_DST,
+							},
+							nativeEP.Dst4().Addr,
+							unix.RtAttr{
+								Len:  8,
+								Type: unix.RTA_SRC,
+							},
+							nativeEP.Src4().Src,
+							unix.RtAttr{
+								Len:  8,
+								Type: unix.RTA_MARK,
+							},
+							uint32(bind.LastMark()),
+						}
+						nlmsg.hdr.Len = uint32(unsafe.Sizeof(nlmsg))
+						reqPeerLock.Lock()
+						reqPeer[i] = peerEndpointPtr{
+							peer:     peer,
+							endpoint: &peer.endpoint,
+						}
+						reqPeerLock.Unlock()
+						peer.RUnlock()
+						i++
+						_, err := netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:])
+						if err != nil {
+							break
+						}
+					}
+					device.peers.RUnlock()
+				}()
+			}
+			remain = remain[hdr.Len:]
+		}
+	}
+}
+
+func createNetlinkRouteSocket() (int, error) {
+	sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE)
+	if err != nil {
+		return -1, err
+	}
+	saddr := &unix.SockaddrNetlink{
+		Family: unix.AF_NETLINK,
+		Groups: unix.RTMGRP_IPV4_ROUTE,
+	}
+	err = unix.Bind(sock, saddr)
+	if err != nil {
+		unix.Close(sock)
+		return -1, err
+	}
+	return sock, nil
+}

device/timers.go

@@ -1,11 +1,11 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  *
  * This is based heavily on timers.c from the kernel implementation.
  */
 
-package main
+package device
 
 import (
 	"math/rand"
@@ -19,7 +19,7 @@ import (
  */
 
 type Timer struct {
-	timer         *time.Timer
+	*time.Timer
 	modifyingLock sync.RWMutex
 	runningLock   sync.Mutex
 	isPending     bool
@@ -27,7 +27,7 @@ type Timer struct {
 
 func (peer *Peer) NewTimer(expirationFunction func(*Peer)) *Timer {
 	timer := &Timer{}
-	timer.timer = time.AfterFunc(time.Hour, func() {
+	timer.Timer = time.AfterFunc(time.Hour, func() {
 		timer.runningLock.Lock()
 
 		timer.modifyingLock.Lock()
@@ -42,21 +42,21 @@ func (peer *Peer) NewTimer(expirationFunction func(*Peer)) *Timer {
 		expirationFunction(peer)
 		timer.runningLock.Unlock()
 	})
-	timer.timer.Stop()
+	timer.Stop()
 	return timer
 }
 
 func (timer *Timer) Mod(d time.Duration) {
 	timer.modifyingLock.Lock()
 	timer.isPending = true
-	timer.timer.Reset(d)
+	timer.Reset(d)
 	timer.modifyingLock.Unlock()
 }
 
 func (timer *Timer) Del() {
 	timer.modifyingLock.Lock()
 	timer.isPending = false
-	timer.timer.Stop()
+	timer.Stop()
 	timer.modifyingLock.Unlock()
 }
 
@@ -79,7 +79,7 @@ func (peer *Peer) timersActive() bool {
 
 func expiredRetransmitHandshake(peer *Peer) {
 	if atomic.LoadUint32(&peer.timers.handshakeAttempts) > MaxTimerHandshakes {
-		peer.device.log.Debug.Printf("%s: Handshake did not complete after %d attempts, giving up\n", peer, MaxTimerHandshakes+2)
+		peer.device.log.Debug.Printf("%s - Handshake did not complete after %d attempts, giving up\n", peer, MaxTimerHandshakes+2)
 
 		if peer.timersActive() {
 			peer.timers.sendKeepalive.Del()
@@ -98,14 +98,14 @@ func expiredRetransmitHandshake(peer *Peer) {
 		}
 	} else {
 		atomic.AddUint32(&peer.timers.handshakeAttempts, 1)
-		peer.device.log.Debug.Printf("%s: Handshake did not complete after %d seconds, retrying (try %d)\n", peer, int(RekeyTimeout.Seconds()), atomic.LoadUint32(&peer.timers.handshakeAttempts)+1)
+		peer.device.log.Debug.Printf("%s - Handshake did not complete after %d seconds, retrying (try %d)\n", peer, int(RekeyTimeout.Seconds()), atomic.LoadUint32(&peer.timers.handshakeAttempts)+1)
 
 		/* We clear the endpoint address src address, in case this is the cause of trouble. */
-		peer.mutex.Lock()
+		peer.Lock()
 		if peer.endpoint != nil {
 			peer.endpoint.ClearSrc()
 		}
-		peer.mutex.Unlock()
+		peer.Unlock()
 
 		peer.SendHandshakeInitiation(true)
 	}
@@ -122,19 +122,19 @@ func expiredSendKeepalive(peer *Peer) {
 }
 
 func expiredNewHandshake(peer *Peer) {
-	peer.device.log.Debug.Printf("%s: Retrying handshake because we stopped hearing back after %d seconds\n", peer, int((KeepaliveTimeout + RekeyTimeout).Seconds()))
+	peer.device.log.Debug.Printf("%s - Retrying handshake because we stopped hearing back after %d seconds\n", peer, int((KeepaliveTimeout + RekeyTimeout).Seconds()))
 	/* We clear the endpoint address src address, in case this is the cause of trouble. */
-	peer.mutex.Lock()
+	peer.Lock()
 	if peer.endpoint != nil {
 		peer.endpoint.ClearSrc()
 	}
-	peer.mutex.Unlock()
+	peer.Unlock()
 	peer.SendHandshakeInitiation(false)
 
 }
 
 func expiredZeroKeyMaterial(peer *Peer) {
-	peer.device.log.Debug.Printf("%s: Removing all keys, since we haven't received a new one in %d seconds\n", peer, int((RejectAfterTime * 3).Seconds()))
+	peer.device.log.Debug.Printf("%s - Removing all keys, since we haven't received a new one in %d seconds\n", peer, int((RejectAfterTime * 3).Seconds()))
 	peer.ZeroAndFlushAll()
 }
 
@@ -147,7 +147,7 @@ func expiredPersistentKeepalive(peer *Peer) {
 /* Should be called after an authenticated data packet is sent. */
 func (peer *Peer) timersDataSent() {
 	if peer.timersActive() && !peer.timers.newHandshake.IsPending() {
-		peer.timers.newHandshake.Mod(KeepaliveTimeout + RekeyTimeout)
+		peer.timers.newHandshake.Mod(KeepaliveTimeout + RekeyTimeout + time.Millisecond*time.Duration(rand.Int31n(RekeyTimeoutJitterMaxMs)))
 	}
 }
 

device/tun.go

@@ -1,13 +1,14 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
-	"git.zx2c4.com/wireguard-go/tun"
 	"sync/atomic"
+
+	"golang.zx2c4.com/wireguard/tun"
 )
 
 const DefaultMTU = 1420
@@ -22,7 +23,7 @@ func (device *Device) RoutineTUNEventReader() {
 	device.state.starting.Done()
 
 	for event := range device.tun.device.Events() {
-		if event&tun.TUNEventMTUUpdate != 0 {
+		if event&tun.EventMTUUpdate != 0 {
 			mtu, err := device.tun.device.MTU()
 			old := atomic.LoadInt32(&device.tun.mtu)
 			if err != nil {
@@ -37,13 +38,13 @@ func (device *Device) RoutineTUNEventReader() {
 			}
 		}
 
-		if event&tun.TUNEventUp != 0 && !setUp {
+		if event&tun.EventUp != 0 && !setUp {
 			logInfo.Println("Interface set up")
 			setUp = true
 			device.Up()
 		}
 
-		if event&tun.TUNEventDown != 0 && setUp {
+		if event&tun.EventDown != 0 && setUp {
 			logInfo.Println("Interface set down")
 			setUp = false
 			device.Down()

device/tun_test.go

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"errors"
+	"os"
+
+	"golang.zx2c4.com/wireguard/tun"
+)
+
+// newDummyTUN creates a dummy TUN device with the specified name.
+func newDummyTUN(name string) tun.Device {
+	return &dummyTUN{
+		name:    name,
+		packets: make(chan []byte, 100),
+		events:  make(chan tun.Event, 10),
+	}
+}
+
+// A dummyTUN is a tun.Device which is used in unit tests.
+type dummyTUN struct {
+	name    string
+	mtu     int
+	packets chan []byte
+	events  chan tun.Event
+}
+
+func (d *dummyTUN) Events() chan tun.Event { return d.events }
+func (*dummyTUN) File() *os.File           { return nil }
+func (*dummyTUN) Flush() error             { return nil }
+func (d *dummyTUN) MTU() (int, error)      { return d.mtu, nil }
+func (d *dummyTUN) Name() (string, error)  { return d.name, nil }
+
+func (d *dummyTUN) Close() error {
+	close(d.events)
+	close(d.packets)
+	return nil
+}
+
+func (d *dummyTUN) Read(b []byte, offset int) (int, error) {
+	buf, ok := <-d.packets
+	if !ok {
+		return 0, errors.New("device closed")
+	}
+	copy(b[offset:], buf)
+	return len(buf), nil
+}
+
+func (d *dummyTUN) Write(b []byte, offset int) (int, error) {
+	d.packets <- b[offset:]
+	return len(b), nil
+}

device/uapi.go

@@ -1,12 +1,13 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package device
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -14,26 +15,24 @@ import (
 	"strings"
 	"sync/atomic"
 	"time"
+
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/ipc"
 )
 
 type IPCError struct {
-	Code int64
+	int64
 }
 
-func (s *IPCError) Error() string {
-	return fmt.Sprintf("IPC error: %d", s.Code)
+func (s IPCError) Error() string {
+	return fmt.Sprintf("IPC error: %d", s.int64)
 }
 
-func (s *IPCError) ErrorCode() int64 {
-	return s.Code
+func (s IPCError) ErrorCode() int64 {
+	return s.int64
 }
 
-func ipcGetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
-
-	device.log.Debug.Println("UAPI: Processing get operation")
-
-	// create lines
-
+func (device *Device) IpcGetOperation(socket *bufio.Writer) error {
 	lines := make([]string, 0, 100)
 	send := func(line string) {
 		lines = append(lines, line)
@@ -43,14 +42,14 @@ func ipcGetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 		// lock required resources
 
-		device.net.mutex.RLock()
-		defer device.net.mutex.RUnlock()
+		device.net.RLock()
+		defer device.net.RUnlock()
 
-		device.staticIdentity.mutex.RLock()
-		defer device.staticIdentity.mutex.RUnlock()
+		device.staticIdentity.RLock()
+		defer device.staticIdentity.RUnlock()
 
-		device.peers.mutex.RLock()
-		defer device.peers.mutex.RUnlock()
+		device.peers.RLock()
+		defer device.peers.RUnlock()
 
 		// serialize device related values
 
@@ -69,8 +68,8 @@ func ipcGetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 		// serialize each peer state
 
 		for _, peer := range device.peers.keyMap {
-			peer.mutex.RLock()
-			defer peer.mutex.RUnlock()
+			peer.RLock()
+			defer peer.RUnlock()
 
 			send("public_key=" + peer.handshake.remoteStatic.ToHex())
 			send("preshared_key=" + peer.handshake.presharedKey.ToHex())
@@ -101,16 +100,14 @@ func ipcGetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 	for _, line := range lines {
 		_, err := socket.WriteString(line + "\n")
 		if err != nil {
-			return &IPCError{
-				Code: ipcErrorIO,
-			}
+			return &IPCError{ipc.IpcErrorIO}
 		}
 	}
 
 	return nil
 }
 
-func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
+func (device *Device) IpcSetOperation(socket *bufio.Reader) error {
 	scanner := bufio.NewScanner(socket)
 	logError := device.log.Error
 	logDebug := device.log.Debug
@@ -118,6 +115,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 	var peer *Peer
 
 	dummy := false
+	createdNewPeer := false
 	deviceConfig := true
 
 	for scanner.Scan() {
@@ -130,7 +128,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 		}
 		parts := strings.Split(line, "=")
 		if len(parts) != 2 {
-			return &IPCError{Code: ipcErrorProtocol}
+			return &IPCError{ipc.IpcErrorProtocol}
 		}
 		key := parts[0]
 		value := parts[1]
@@ -142,10 +140,10 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 			switch key {
 			case "private_key":
 				var sk NoisePrivateKey
-				err := sk.FromHex(value)
+				err := sk.FromMaybeZeroHex(value)
 				if err != nil {
 					logError.Println("Failed to set private_key:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 				logDebug.Println("UAPI: Updating private key")
 				device.SetPrivateKey(sk)
@@ -157,20 +155,20 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				port, err := strconv.ParseUint(value, 10, 16)
 				if err != nil {
 					logError.Println("Failed to parse listen_port:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				// update port and rebind
 
 				logDebug.Println("UAPI: Updating listen port")
 
-				device.net.mutex.Lock()
+				device.net.Lock()
 				device.net.port = uint16(port)
-				device.net.mutex.Unlock()
+				device.net.Unlock()
 
 				if err := device.BindUpdate(); err != nil {
 					logError.Println("Failed to set listen_port:", err)
-					return &IPCError{Code: ipcErrorPortInUse}
+					return &IPCError{ipc.IpcErrorPortInUse}
 				}
 
 			case "fwmark":
@@ -187,14 +185,14 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				if err != nil {
 					logError.Println("Invalid fwmark", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				logDebug.Println("UAPI: Updating fwmark")
 
 				if err := device.BindSetMark(uint32(fwmark)); err != nil {
 					logError.Println("Failed to update fwmark:", err)
-					return &IPCError{Code: ipcErrorPortInUse}
+					return &IPCError{ipc.IpcErrorPortInUse}
 				}
 
 			case "public_key":
@@ -205,14 +203,14 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 			case "replace_peers":
 				if value != "true" {
 					logError.Println("Failed to set replace_peers, invalid value:", value)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 				logDebug.Println("UAPI: Removing all peers")
 				device.RemoveAllPeers()
 
 			default:
 				logError.Println("Invalid UAPI device key:", key)
-				return &IPCError{Code: ipcErrorInvalid}
+				return &IPCError{ipc.IpcErrorInvalid}
 			}
 		}
 
@@ -227,14 +225,14 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				err := publicKey.FromHex(value)
 				if err != nil {
 					logError.Println("Failed to get peer by public key:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				// ignore peer with public key of device
 
-				device.staticIdentity.mutex.RLock()
+				device.staticIdentity.RLock()
 				dummy = device.staticIdentity.publicKey.Equals(publicKey)
-				device.staticIdentity.mutex.RUnlock()
+				device.staticIdentity.RUnlock()
 
 				if dummy {
 					peer = &Peer{}
@@ -242,14 +240,34 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 					peer = device.LookupPeer(publicKey)
 				}
 
-				if peer == nil {
+				createdNewPeer = peer == nil
+				if createdNewPeer {
 					peer, err = device.NewPeer(publicKey)
 					if err != nil {
 						logError.Println("Failed to create new peer:", err)
-						return &IPCError{Code: ipcErrorInvalid}
+						return &IPCError{ipc.IpcErrorInvalid}
 					}
+					if peer == nil {
+						dummy = true
+						peer = &Peer{}
+					} else {
 						logDebug.Println(peer, "- UAPI: Created")
 					}
+				}
+
+			case "update_only":
+
+				// allow disabling of creation
+
+				if value != "true" {
+					logError.Println("Failed to set update only, invalid value:", value)
+					return &IPCError{ipc.IpcErrorInvalid}
+				}
+				if createdNewPeer && !dummy {
+					device.RemovePeer(peer.handshake.remoteStatic)
+					peer = &Peer{}
+					dummy = true
+				}
 
 			case "remove":
 
@@ -257,7 +275,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				if value != "true" {
 					logError.Println("Failed to set remove, invalid value:", value)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 				if !dummy {
 					logDebug.Println(peer, "- UAPI: Removing")
@@ -278,7 +296,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				if err != nil {
 					logError.Println("Failed to set preshared key:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 			case "endpoint":
@@ -288,9 +306,9 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				logDebug.Println(peer, "- UAPI: Updating endpoint")
 
 				err := func() error {
-					peer.mutex.Lock()
-					defer peer.mutex.Unlock()
-					endpoint, err := CreateEndpoint(value)
+					peer.Lock()
+					defer peer.Unlock()
+					endpoint, err := conn.CreateEndpoint(value)
 					if err != nil {
 						return err
 					}
@@ -299,20 +317,20 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				}()
 
 				if err != nil {
-					logError.Println("Failed to set endpoint:", value)
-					return &IPCError{Code: ipcErrorInvalid}
+					logError.Println("Failed to set endpoint:", err, ":", value)
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 			case "persistent_keepalive_interval":
 
 				// update persistent keepalive interval
 
-				logDebug.Println(peer, "- UAPI: Updating persistent keepalive interva")
+				logDebug.Println(peer, "- UAPI: Updating persistent keepalive interval")
 
 				secs, err := strconv.ParseUint(value, 10, 16)
 				if err != nil {
 					logError.Println("Failed to set persistent keepalive interval:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				old := peer.persistentKeepaliveInterval
@@ -323,7 +341,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				if old == 0 && secs != 0 {
 					if err != nil {
 						logError.Println("Failed to get tun device status:", err)
-						return &IPCError{Code: ipcErrorIO}
+						return &IPCError{ipc.IpcErrorIO}
 					}
 					if device.isUp.Get() && !dummy {
 						peer.SendKeepalive()
@@ -336,7 +354,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				if value != "true" {
 					logError.Println("Failed to replace allowedips, invalid value:", value)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				if dummy {
@@ -352,7 +370,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				_, network, err := net.ParseCIDR(value)
 				if err != nil {
 					logError.Println("Failed to set allowed ip:", err)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 				if dummy {
@@ -366,12 +384,12 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				if value != "1" {
 					logError.Println("Invalid protocol version:", value)
-					return &IPCError{Code: ipcErrorInvalid}
+					return &IPCError{ipc.IpcErrorInvalid}
 				}
 
 			default:
 				logError.Println("Invalid UAPI peer key:", key)
-				return &IPCError{Code: ipcErrorInvalid}
+				return &IPCError{ipc.IpcErrorInvalid}
 			}
 		}
 	}
@@ -379,7 +397,7 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 	return nil
 }
 
-func ipcHandle(device *Device, socket net.Conn) {
+func (device *Device) IpcHandle(socket net.Conn) {
 
 	// create buffered read/writer
 
@@ -404,12 +422,20 @@ func ipcHandle(device *Device, socket net.Conn) {
 
 	switch op {
 	case "set=1\n":
-		device.log.Debug.Println("UAPI: Set operation")
-		status = ipcSetOperation(device, buffered)
+		err = device.IpcSetOperation(buffered.Reader)
+		if err != nil && !errors.As(err, &status) {
+			// should never happen
+			device.log.Error.Println("Invalid UAPI error:", err)
+			status = &IPCError{1}
+		}
 
 	case "get=1\n":
-		device.log.Debug.Println("UAPI: Get operation")
-		status = ipcGetOperation(device, buffered)
+		err = device.IpcGetOperation(buffered.Writer)
+		if err != nil && !errors.As(err, &status) {
+			// should never happen
+			device.log.Error.Println("Invalid UAPI error:", err)
+			status = &IPCError{1}
+		}
 
 	default:
 		device.log.Error.Println("Invalid UAPI operation:", op)

device/version.go

@@ -0,0 +1,3 @@
+package device
+
+const WireGuardGoVersion = "0.0.20201118"

device_test.go

@@ -1,48 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package main
-
-/* Create two device instances and simulate full WireGuard interaction
- * without network dependencies
- */
-
-import "testing"
-
-func TestDevice(t *testing.T) {
-
-	// prepare tun devices for generating traffic
-
-	tun1, err := CreateDummyTUN("tun1")
-	if err != nil {
-		t.Error("failed to create tun:", err.Error())
-	}
-
-	tun2, err := CreateDummyTUN("tun2")
-	if err != nil {
-		t.Error("failed to create tun:", err.Error())
-	}
-
-	_ = tun1
-	_ = tun2
-
-	// prepare endpoints
-
-	end1, err := CreateDummyEndpoint()
-	if err != nil {
-		t.Error("failed to create endpoint:", err.Error())
-	}
-
-	end2, err := CreateDummyEndpoint()
-	if err != nil {
-		t.Error("failed to create endpoint:", err.Error())
-	}
-
-	_ = end1
-	_ = end2
-
-	// create binds
-
-}

donotuseon_linux.go

@@ -1,15 +0,0 @@
-// +build !android
-
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package main
-
-const DoNotUseThisProgramOnLinux = UseTheKernelModuleInstead
-
-// --------------------------------------------------------
-// Do not use this on Linux. Instead use the kernel module.
-// See wireguard.com/install for more information.
-// --------------------------------------------------------

go.mod

@@ -1,7 +1,9 @@
-module git.zx2c4.com/wireguard-go
+module golang.zx2c4.com/wireguard
+
+go 1.13
 
 require (
-	golang.org/x/crypto v0.0.0-20181001203147-e3636079e1a4
-	golang.org/x/net v0.0.0-20181005035420-146acd28ed58
-	golang.org/x/sys v0.0.0-20181005133103-4497e2df6f9e
+	golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9
+	golang.org/x/net v0.0.0-20201110031124-69a78807bb2b
+	golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7
 )

go.sum

@@ -1,6 +1,17 @@
-golang.org/x/crypto v0.0.0-20181001203147-e3636079e1a4 h1:Vk3wNqEZwyGyei9yq5ekj7frek2u7HUfffJ1/opblzc=
-golang.org/x/crypto v0.0.0-20181001203147-e3636079e1a4/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/net v0.0.0-20181005035420-146acd28ed58 h1:otZG8yDCO4LVps5+9bxOeNiCvgmOyt96J3roHTYs7oE=
-golang.org/x/net v0.0.0-20181005035420-146acd28ed58/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/sys v0.0.0-20181005133103-4497e2df6f9e h1:EfdBzeKbFSvOjoIqSZcfS8wp0FBLokGBEs9lz1OtSg0=
-golang.org/x/sys v0.0.0-20181005133103-4497e2df6f9e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9 h1:phUcVbl53swtrUN8kQEXFhUxPlIlWyBfKmidCu7P95o=
+golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b h1:uwuIcX0g4Yl1NC5XAz37xsr2lTtcqevgzYNVt49waME=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7 h1:s330+6z/Ko3J0o6rvOcwXe5nzs7UT9tLKHoOXYn6uE0=
+golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

helper_test.go

@@ -1,92 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package main
-
-import (
-	"bytes"
-	"errors"
-	"git.zx2c4.com/wireguard-go/tun"
-	"os"
-	"testing"
-)
-
-/* Helpers for writing unit tests
- */
-
-type DummyTUN struct {
-	name    string
-	mtu     int
-	packets chan []byte
-	events  chan tun.TUNEvent
-}
-
-func (tun *DummyTUN) File() *os.File {
-	return nil
-}
-
-func (tun *DummyTUN) Name() (string, error) {
-	return tun.name, nil
-}
-
-func (tun *DummyTUN) MTU() (int, error) {
-	return tun.mtu, nil
-}
-
-func (tun *DummyTUN) Write(d []byte, offset int) (int, error) {
-	tun.packets <- d[offset:]
-	return len(d), nil
-}
-
-func (tun *DummyTUN) Close() error {
-	close(tun.events)
-	close(tun.packets)
-	return nil
-}
-
-func (tun *DummyTUN) Events() chan tun.TUNEvent {
-	return tun.events
-}
-
-func (tun *DummyTUN) Read(d []byte, offset int) (int, error) {
-	t, ok := <-tun.packets
-	if !ok {
-		return 0, errors.New("device closed")
-	}
-	copy(d[offset:], t)
-	return len(t), nil
-}
-
-func CreateDummyTUN(name string) (tun.TUNDevice, error) {
-	var dummy DummyTUN
-	dummy.mtu = 0
-	dummy.packets = make(chan []byte, 100)
-	dummy.events = make(chan tun.TUNEvent, 10)
-	return &dummy, nil
-}
-
-func assertNil(t *testing.T, err error) {
-	if err != nil {
-		t.Fatal(err)
-	}
-}
-
-func assertEqual(t *testing.T, a []byte, b []byte) {
-	if bytes.Compare(a, b) != 0 {
-		t.Fatal(a, "!=", b)
-	}
-}
-
-func randDevice(t *testing.T) *Device {
-	sk, err := newPrivateKey()
-	if err != nil {
-		t.Fatal(err)
-	}
-	tun, _ := CreateDummyTUN("dummy")
-	logger := NewLogger(LogLevelError, "")
-	device := NewDevice(tun, logger)
-	device.SetPrivateKey(sk)
-	return device
-}

ipc/uapi_bsd.go

@@ -1,30 +1,19 @@
 // +build darwin freebsd openbsd
 
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package ipc
 
 import (
 	"errors"
-	"fmt"
-	"golang.org/x/sys/unix"
 	"net"
 	"os"
-	"path"
 	"unsafe"
-)
 
-var socketDirectory = "/var/run/wireguard"
-
-const (
-	ipcErrorIO        = -int64(unix.EIO)
-	ipcErrorProtocol  = -int64(unix.EPROTO)
-	ipcErrorInvalid   = -int64(unix.EINVAL)
-	ipcErrorPortInUse = -int64(unix.EADDRINUSE)
-	socketName        = "%s.sock"
+	"golang.org/x/sys/unix"
 )
 
 type UAPIListener struct {
@@ -83,10 +72,7 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 		unixListener.SetUnlinkOnClose(true)
 	}
 
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
+	socketPath := sockPath(name)
 
 	// watch for deletion of socket
 
@@ -145,58 +131,3 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 
 	return uapi, nil
 }
-
-func UAPIOpen(name string) (*os.File, error) {
-
-	// check if path exist
-
-	err := os.MkdirAll(socketDirectory, 0755)
-	if err != nil && !os.IsExist(err) {
-		return nil, err
-	}
-
-	// open UNIX socket
-
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
-
-	addr, err := net.ResolveUnixAddr("unix", socketPath)
-	if err != nil {
-		return nil, err
-	}
-
-	oldUmask := unix.Umask(0077)
-	listener, err := func() (*net.UnixListener, error) {
-
-		// initial connection attempt
-
-		listener, err := net.ListenUnix("unix", addr)
-		if err == nil {
-			return listener, nil
-		}
-
-		// check if socket already active
-
-		_, err = net.Dial("unix", socketPath)
-		if err == nil {
-			return nil, errors.New("unix socket in use")
-		}
-
-		// cleanup & attempt again
-
-		err = os.Remove(socketPath)
-		if err != nil {
-			return nil, err
-		}
-		return net.ListenUnix("unix", addr)
-	}()
-	unix.Umask(oldUmask)
-
-	if err != nil {
-		return nil, err
-	}
-
-	return listener.File()
-}

ipc/uapi_linux.go

@@ -1,28 +1,16 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package main
+package ipc
 
 import (
-	"errors"
-	"fmt"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/sys/unix"
 	"net"
 	"os"
-	"path"
-)
 
-var socketDirectory = "/var/run/wireguard"
-
-const (
-	ipcErrorIO        = -int64(unix.EIO)
-	ipcErrorProtocol  = -int64(unix.EPROTO)
-	ipcErrorInvalid   = -int64(unix.EINVAL)
-	ipcErrorPortInUse = -int64(unix.EADDRINUSE)
-	socketName        = "%s.sock"
+	"golang.org/x/sys/unix"
+	"golang.zx2c4.com/wireguard/rwcancel"
 )
 
 type UAPIListener struct {
@@ -83,10 +71,7 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 
 	// watch for deletion of socket
 
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
+	socketPath := sockPath(name)
 
 	uapi.inotifyFd, err = unix.InotifyInit()
 	if err != nil {
@@ -142,58 +127,3 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 
 	return uapi, nil
 }
-
-func UAPIOpen(name string) (*os.File, error) {
-
-	// check if path exist
-
-	err := os.MkdirAll(socketDirectory, 0755)
-	if err != nil && !os.IsExist(err) {
-		return nil, err
-	}
-
-	// open UNIX socket
-
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
-
-	addr, err := net.ResolveUnixAddr("unix", socketPath)
-	if err != nil {
-		return nil, err
-	}
-
-	oldUmask := unix.Umask(0077)
-	listener, err := func() (*net.UnixListener, error) {
-
-		// initial connection attempt
-
-		listener, err := net.ListenUnix("unix", addr)
-		if err == nil {
-			return listener, nil
-		}
-
-		// check if socket already active
-
-		_, err = net.Dial("unix", socketPath)
-		if err == nil {
-			return nil, errors.New("unix socket in use")
-		}
-
-		// cleanup & attempt again
-
-		err = os.Remove(socketPath)
-		if err != nil {
-			return nil, err
-		}
-		return net.ListenUnix("unix", addr)
-	}()
-	unix.Umask(oldUmask)
-
-	if err != nil {
-		return nil, err
-	}
-
-	return listener.File()
-}

ipc/uapi_unix.go

@@ -0,0 +1,65 @@
+// +build linux darwin freebsd openbsd
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package ipc
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	IpcErrorIO        = -int64(unix.EIO)
+	IpcErrorProtocol  = -int64(unix.EPROTO)
+	IpcErrorInvalid   = -int64(unix.EINVAL)
+	IpcErrorPortInUse = -int64(unix.EADDRINUSE)
+)
+
+// socketDirectory is variable because it is modified by a linker
+// flag in wireguard-android.
+var socketDirectory = "/var/run/wireguard"
+
+func sockPath(iface string) string {
+	return fmt.Sprintf("%s/%s.sock", socketDirectory, iface)
+}
+
+func UAPIOpen(name string) (*os.File, error) {
+	if err := os.MkdirAll(socketDirectory, 0755); err != nil {
+		return nil, err
+	}
+
+	socketPath := sockPath(name)
+	addr, err := net.ResolveUnixAddr("unix", socketPath)
+	if err != nil {
+		return nil, err
+	}
+
+	oldUmask := unix.Umask(0077)
+	defer unix.Umask(oldUmask)
+
+	listener, err := net.ListenUnix("unix", addr)
+	if err == nil {
+		return listener.File()
+	}
+
+	// Test socket, if not in use cleanup and try again.
+	if _, err := net.Dial("unix", socketPath); err == nil {
+		return nil, errors.New("unix socket in use")
+	}
+	if err := os.Remove(socketPath); err != nil {
+		return nil, err
+	}
+	listener, err = net.ListenUnix("unix", addr)
+	if err != nil {
+		return nil, err
+	}
+	return listener.File()
+}

ipc/uapi_windows.go

@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package ipc
+
+import (
+	"net"
+
+	"golang.org/x/sys/windows"
+
+	"golang.zx2c4.com/wireguard/ipc/winpipe"
+)
+
+// TODO: replace these with actual standard windows error numbers from the win package
+const (
+	IpcErrorIO        = -int64(5)
+	IpcErrorProtocol  = -int64(71)
+	IpcErrorInvalid   = -int64(22)
+	IpcErrorPortInUse = -int64(98)
+)
+
+type UAPIListener struct {
+	listener net.Listener // unix socket listener
+	connNew  chan net.Conn
+	connErr  chan error
+	kqueueFd int
+	keventFd int
+}
+
+func (l *UAPIListener) Accept() (net.Conn, error) {
+	for {
+		select {
+		case conn := <-l.connNew:
+			return conn, nil
+
+		case err := <-l.connErr:
+			return nil, err
+		}
+	}
+}
+
+func (l *UAPIListener) Close() error {
+	return l.listener.Close()
+}
+
+func (l *UAPIListener) Addr() net.Addr {
+	return l.listener.Addr()
+}
+
+var UAPISecurityDescriptor *windows.SECURITY_DESCRIPTOR
+
+func init() {
+	var err error
+	/* SDDL_DEVOBJ_SYS_ALL from the WDK */
+	UAPISecurityDescriptor, err = windows.SecurityDescriptorFromString("O:SYD:P(A;;GA;;;SY)")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func UAPIListen(name string) (net.Listener, error) {
+	config := winpipe.PipeConfig{
+		SecurityDescriptor: UAPISecurityDescriptor,
+	}
+	listener, err := winpipe.ListenPipe(`\\.\pipe\ProtectedPrefix\Administrators\WireGuard\`+name, &config)
+	if err != nil {
+		return nil, err
+	}
+
+	uapi := &UAPIListener{
+		listener: listener,
+		connNew:  make(chan net.Conn, 1),
+		connErr:  make(chan error, 1),
+	}
+
+	go func(l *UAPIListener) {
+		for {
+			conn, err := l.listener.Accept()
+			if err != nil {
+				l.connErr <- err
+				break
+			}
+			l.connNew <- conn
+		}
+	}(uapi)
+
+	return uapi, nil
+}

ipc/winpipe/file.go

@@ -0,0 +1,323 @@
+// +build windows
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2005 Microsoft
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+package winpipe
+
+import (
+	"errors"
+	"io"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"golang.org/x/sys/windows"
+)
+
+//sys cancelIoEx(file windows.Handle, o *windows.Overlapped) (err error) = CancelIoEx
+//sys createIoCompletionPort(file windows.Handle, port windows.Handle, key uintptr, threadCount uint32) (newport windows.Handle, err error) = CreateIoCompletionPort
+//sys getQueuedCompletionStatus(port windows.Handle, bytes *uint32, key *uintptr, o **ioOperation, timeout uint32) (err error) = GetQueuedCompletionStatus
+//sys setFileCompletionNotificationModes(h windows.Handle, flags uint8) (err error) = SetFileCompletionNotificationModes
+//sys wsaGetOverlappedResult(h windows.Handle, o *windows.Overlapped, bytes *uint32, wait bool, flags *uint32) (err error) = ws2_32.WSAGetOverlappedResult
+
+type atomicBool int32
+
+func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
+func (b *atomicBool) setFalse()   { atomic.StoreInt32((*int32)(b), 0) }
+func (b *atomicBool) setTrue()    { atomic.StoreInt32((*int32)(b), 1) }
+func (b *atomicBool) swap(new bool) bool {
+	var newInt int32
+	if new {
+		newInt = 1
+	}
+	return atomic.SwapInt32((*int32)(b), newInt) == 1
+}
+
+const (
+	cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 1
+	cFILE_SKIP_SET_EVENT_ON_HANDLE        = 2
+)
+
+var (
+	ErrFileClosed = errors.New("file has already been closed")
+	ErrTimeout    = &timeoutError{}
+)
+
+type timeoutError struct{}
+
+func (e *timeoutError) Error() string   { return "i/o timeout" }
+func (e *timeoutError) Timeout() bool   { return true }
+func (e *timeoutError) Temporary() bool { return true }
+
+type timeoutChan chan struct{}
+
+var ioInitOnce sync.Once
+var ioCompletionPort windows.Handle
+
+// ioResult contains the result of an asynchronous IO operation
+type ioResult struct {
+	bytes uint32
+	err   error
+}
+
+// ioOperation represents an outstanding asynchronous Win32 IO
+type ioOperation struct {
+	o  windows.Overlapped
+	ch chan ioResult
+}
+
+func initIo() {
+	h, err := createIoCompletionPort(windows.InvalidHandle, 0, 0, 0xffffffff)
+	if err != nil {
+		panic(err)
+	}
+	ioCompletionPort = h
+	go ioCompletionProcessor(h)
+}
+
+// win32File implements Reader, Writer, and Closer on a Win32 handle without blocking in a syscall.
+// It takes ownership of this handle and will close it if it is garbage collected.
+type win32File struct {
+	handle        windows.Handle
+	wg            sync.WaitGroup
+	wgLock        sync.RWMutex
+	closing       atomicBool
+	socket        bool
+	readDeadline  deadlineHandler
+	writeDeadline deadlineHandler
+}
+
+type deadlineHandler struct {
+	setLock     sync.Mutex
+	channel     timeoutChan
+	channelLock sync.RWMutex
+	timer       *time.Timer
+	timedout    atomicBool
+}
+
+// makeWin32File makes a new win32File from an existing file handle
+func makeWin32File(h windows.Handle) (*win32File, error) {
+	f := &win32File{handle: h}
+	ioInitOnce.Do(initIo)
+	_, err := createIoCompletionPort(h, ioCompletionPort, 0, 0xffffffff)
+	if err != nil {
+		return nil, err
+	}
+	err = setFileCompletionNotificationModes(h, cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS|cFILE_SKIP_SET_EVENT_ON_HANDLE)
+	if err != nil {
+		return nil, err
+	}
+	f.readDeadline.channel = make(timeoutChan)
+	f.writeDeadline.channel = make(timeoutChan)
+	return f, nil
+}
+
+func MakeOpenFile(h windows.Handle) (io.ReadWriteCloser, error) {
+	return makeWin32File(h)
+}
+
+// closeHandle closes the resources associated with a Win32 handle
+func (f *win32File) closeHandle() {
+	f.wgLock.Lock()
+	// Atomically set that we are closing, releasing the resources only once.
+	if !f.closing.swap(true) {
+		f.wgLock.Unlock()
+		// cancel all IO and wait for it to complete
+		cancelIoEx(f.handle, nil)
+		f.wg.Wait()
+		// at this point, no new IO can start
+		windows.Close(f.handle)
+		f.handle = 0
+	} else {
+		f.wgLock.Unlock()
+	}
+}
+
+// Close closes a win32File.
+func (f *win32File) Close() error {
+	f.closeHandle()
+	return nil
+}
+
+// prepareIo prepares for a new IO operation.
+// The caller must call f.wg.Done() when the IO is finished, prior to Close() returning.
+func (f *win32File) prepareIo() (*ioOperation, error) {
+	f.wgLock.RLock()
+	if f.closing.isSet() {
+		f.wgLock.RUnlock()
+		return nil, ErrFileClosed
+	}
+	f.wg.Add(1)
+	f.wgLock.RUnlock()
+	c := &ioOperation{}
+	c.ch = make(chan ioResult)
+	return c, nil
+}
+
+// ioCompletionProcessor processes completed async IOs forever
+func ioCompletionProcessor(h windows.Handle) {
+	for {
+		var bytes uint32
+		var key uintptr
+		var op *ioOperation
+		err := getQueuedCompletionStatus(h, &bytes, &key, &op, windows.INFINITE)
+		if op == nil {
+			panic(err)
+		}
+		op.ch <- ioResult{bytes, err}
+	}
+}
+
+// asyncIo processes the return value from ReadFile or WriteFile, blocking until
+// the operation has actually completed.
+func (f *win32File) asyncIo(c *ioOperation, d *deadlineHandler, bytes uint32, err error) (int, error) {
+	if err != windows.ERROR_IO_PENDING {
+		return int(bytes), err
+	}
+
+	if f.closing.isSet() {
+		cancelIoEx(f.handle, &c.o)
+	}
+
+	var timeout timeoutChan
+	if d != nil {
+		d.channelLock.Lock()
+		timeout = d.channel
+		d.channelLock.Unlock()
+	}
+
+	var r ioResult
+	select {
+	case r = <-c.ch:
+		err = r.err
+		if err == windows.ERROR_OPERATION_ABORTED {
+			if f.closing.isSet() {
+				err = ErrFileClosed
+			}
+		} else if err != nil && f.socket {
+			// err is from Win32. Query the overlapped structure to get the winsock error.
+			var bytes, flags uint32
+			err = wsaGetOverlappedResult(f.handle, &c.o, &bytes, false, &flags)
+		}
+	case <-timeout:
+		cancelIoEx(f.handle, &c.o)
+		r = <-c.ch
+		err = r.err
+		if err == windows.ERROR_OPERATION_ABORTED {
+			err = ErrTimeout
+		}
+	}
+
+	// runtime.KeepAlive is needed, as c is passed via native
+	// code to ioCompletionProcessor, c must remain alive
+	// until the channel read is complete.
+	runtime.KeepAlive(c)
+	return int(r.bytes), err
+}
+
+// Read reads from a file handle.
+func (f *win32File) Read(b []byte) (int, error) {
+	c, err := f.prepareIo()
+	if err != nil {
+		return 0, err
+	}
+	defer f.wg.Done()
+
+	if f.readDeadline.timedout.isSet() {
+		return 0, ErrTimeout
+	}
+
+	var bytes uint32
+	err = windows.ReadFile(f.handle, b, &bytes, &c.o)
+	n, err := f.asyncIo(c, &f.readDeadline, bytes, err)
+	runtime.KeepAlive(b)
+
+	// Handle EOF conditions.
+	if err == nil && n == 0 && len(b) != 0 {
+		return 0, io.EOF
+	} else if err == windows.ERROR_BROKEN_PIPE {
+		return 0, io.EOF
+	} else {
+		return n, err
+	}
+}
+
+// Write writes to a file handle.
+func (f *win32File) Write(b []byte) (int, error) {
+	c, err := f.prepareIo()
+	if err != nil {
+		return 0, err
+	}
+	defer f.wg.Done()
+
+	if f.writeDeadline.timedout.isSet() {
+		return 0, ErrTimeout
+	}
+
+	var bytes uint32
+	err = windows.WriteFile(f.handle, b, &bytes, &c.o)
+	n, err := f.asyncIo(c, &f.writeDeadline, bytes, err)
+	runtime.KeepAlive(b)
+	return n, err
+}
+
+func (f *win32File) SetReadDeadline(deadline time.Time) error {
+	return f.readDeadline.set(deadline)
+}
+
+func (f *win32File) SetWriteDeadline(deadline time.Time) error {
+	return f.writeDeadline.set(deadline)
+}
+
+func (f *win32File) Flush() error {
+	return windows.FlushFileBuffers(f.handle)
+}
+
+func (f *win32File) Fd() uintptr {
+	return uintptr(f.handle)
+}
+
+func (d *deadlineHandler) set(deadline time.Time) error {
+	d.setLock.Lock()
+	defer d.setLock.Unlock()
+
+	if d.timer != nil {
+		if !d.timer.Stop() {
+			<-d.channel
+		}
+		d.timer = nil
+	}
+	d.timedout.setFalse()
+
+	select {
+	case <-d.channel:
+		d.channelLock.Lock()
+		d.channel = make(chan struct{})
+		d.channelLock.Unlock()
+	default:
+	}
+
+	if deadline.IsZero() {
+		return nil
+	}
+
+	timeoutIO := func() {
+		d.timedout.setTrue()
+		close(d.channel)
+	}
+
+	now := time.Now()
+	duration := deadline.Sub(now)
+	if deadline.After(now) {
+		// Deadline is in the future, set a timer to wait
+		d.timer = time.AfterFunc(duration, timeoutIO)
+	} else {
+		// Deadline is in the past. Cancel all pending IO now.
+		timeoutIO()
+	}
+	return nil
+}

ipc/winpipe/mksyscall.go

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2005 Microsoft
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package winpipe
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go pipe.go file.go

ipc/winpipe/pipe.go

@@ -0,0 +1,509 @@
+// +build windows
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2005 Microsoft
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package winpipe
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"runtime"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+//sys connectNamedPipe(pipe windows.Handle, o *windows.Overlapped) (err error) = ConnectNamedPipe
+//sys createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *windows.SecurityAttributes) (handle windows.Handle, err error)  [failretval==windows.InvalidHandle] = CreateNamedPipeW
+//sys createFile(name string, access uint32, mode uint32, sa *windows.SecurityAttributes, createmode uint32, attrs uint32, templatefile windows.Handle) (handle windows.Handle, err error) [failretval==windows.InvalidHandle] = CreateFileW
+//sys getNamedPipeInfo(pipe windows.Handle, flags *uint32, outSize *uint32, inSize *uint32, maxInstances *uint32) (err error) = GetNamedPipeInfo
+//sys getNamedPipeHandleState(pipe windows.Handle, state *uint32, curInstances *uint32, maxCollectionCount *uint32, collectDataTimeout *uint32, userName *uint16, maxUserNameSize uint32) (err error) = GetNamedPipeHandleStateW
+//sys localAlloc(uFlags uint32, length uint32) (ptr uintptr) = LocalAlloc
+//sys ntCreateNamedPipeFile(pipe *windows.Handle, access uint32, oa *objectAttributes, iosb *ioStatusBlock, share uint32, disposition uint32, options uint32, typ uint32, readMode uint32, completionMode uint32, maxInstances uint32, inboundQuota uint32, outputQuota uint32, timeout *int64) (status ntstatus) = ntdll.NtCreateNamedPipeFile
+//sys rtlNtStatusToDosError(status ntstatus) (winerr error) = ntdll.RtlNtStatusToDosErrorNoTeb
+//sys rtlDosPathNameToNtPathName(name *uint16, ntName *unicodeString, filePart uintptr, reserved uintptr) (status ntstatus) = ntdll.RtlDosPathNameToNtPathName_U
+//sys rtlDefaultNpAcl(dacl *uintptr) (status ntstatus) = ntdll.RtlDefaultNpAcl
+
+type ioStatusBlock struct {
+	Status, Information uintptr
+}
+
+type objectAttributes struct {
+	Length             uintptr
+	RootDirectory      uintptr
+	ObjectName         *unicodeString
+	Attributes         uintptr
+	SecurityDescriptor *windows.SECURITY_DESCRIPTOR
+	SecurityQoS        uintptr
+}
+
+type unicodeString struct {
+	Length        uint16
+	MaximumLength uint16
+	Buffer        uintptr
+}
+
+type ntstatus int32
+
+func (status ntstatus) Err() error {
+	if status >= 0 {
+		return nil
+	}
+	return rtlNtStatusToDosError(status)
+}
+
+const (
+	cSECURITY_SQOS_PRESENT = 0x100000
+	cSECURITY_ANONYMOUS    = 0
+
+	cPIPE_TYPE_MESSAGE = 4
+
+	cPIPE_READMODE_MESSAGE = 2
+
+	cFILE_OPEN   = 1
+	cFILE_CREATE = 2
+
+	cFILE_PIPE_MESSAGE_TYPE          = 1
+	cFILE_PIPE_REJECT_REMOTE_CLIENTS = 2
+)
+
+var (
+	// ErrPipeListenerClosed is returned for pipe operations on listeners that have been closed.
+	// This error should match net.errClosing since docker takes a dependency on its text.
+	ErrPipeListenerClosed = errors.New("use of closed network connection")
+
+	errPipeWriteClosed = errors.New("pipe has been closed for write")
+)
+
+type win32Pipe struct {
+	*win32File
+	path string
+}
+
+type win32MessageBytePipe struct {
+	win32Pipe
+	writeClosed bool
+	readEOF     bool
+}
+
+type pipeAddress string
+
+func (f *win32Pipe) LocalAddr() net.Addr {
+	return pipeAddress(f.path)
+}
+
+func (f *win32Pipe) RemoteAddr() net.Addr {
+	return pipeAddress(f.path)
+}
+
+func (f *win32Pipe) SetDeadline(t time.Time) error {
+	f.SetReadDeadline(t)
+	f.SetWriteDeadline(t)
+	return nil
+}
+
+// CloseWrite closes the write side of a message pipe in byte mode.
+func (f *win32MessageBytePipe) CloseWrite() error {
+	if f.writeClosed {
+		return errPipeWriteClosed
+	}
+	err := f.win32File.Flush()
+	if err != nil {
+		return err
+	}
+	_, err = f.win32File.Write(nil)
+	if err != nil {
+		return err
+	}
+	f.writeClosed = true
+	return nil
+}
+
+// Write writes bytes to a message pipe in byte mode. Zero-byte writes are ignored, since
+// they are used to implement CloseWrite().
+func (f *win32MessageBytePipe) Write(b []byte) (int, error) {
+	if f.writeClosed {
+		return 0, errPipeWriteClosed
+	}
+	if len(b) == 0 {
+		return 0, nil
+	}
+	return f.win32File.Write(b)
+}
+
+// Read reads bytes from a message pipe in byte mode. A read of a zero-byte message on a message
+// mode pipe will return io.EOF, as will all subsequent reads.
+func (f *win32MessageBytePipe) Read(b []byte) (int, error) {
+	if f.readEOF {
+		return 0, io.EOF
+	}
+	n, err := f.win32File.Read(b)
+	if err == io.EOF {
+		// If this was the result of a zero-byte read, then
+		// it is possible that the read was due to a zero-size
+		// message. Since we are simulating CloseWrite with a
+		// zero-byte message, ensure that all future Read() calls
+		// also return EOF.
+		f.readEOF = true
+	} else if err == windows.ERROR_MORE_DATA {
+		// ERROR_MORE_DATA indicates that the pipe's read mode is message mode
+		// and the message still has more bytes. Treat this as a success, since
+		// this package presents all named pipes as byte streams.
+		err = nil
+	}
+	return n, err
+}
+
+func (s pipeAddress) Network() string {
+	return "pipe"
+}
+
+func (s pipeAddress) String() string {
+	return string(s)
+}
+
+// tryDialPipe attempts to dial the pipe at `path` until `ctx` cancellation or timeout.
+func tryDialPipe(ctx context.Context, path *string) (windows.Handle, error) {
+	for {
+		select {
+		case <-ctx.Done():
+			return windows.Handle(0), ctx.Err()
+		default:
+			h, err := createFile(*path, windows.GENERIC_READ|windows.GENERIC_WRITE, 0, nil, windows.OPEN_EXISTING, windows.FILE_FLAG_OVERLAPPED|cSECURITY_SQOS_PRESENT|cSECURITY_ANONYMOUS, 0)
+			if err == nil {
+				return h, nil
+			}
+			if err != windows.ERROR_PIPE_BUSY {
+				return h, &os.PathError{Err: err, Op: "open", Path: *path}
+			}
+			// Wait 10 msec and try again. This is a rather simplistic
+			// view, as we always try each 10 milliseconds.
+			time.Sleep(time.Millisecond * 10)
+		}
+	}
+}
+
+// DialPipe connects to a named pipe by path, timing out if the connection
+// takes longer than the specified duration. If timeout is nil, then we use
+// a default timeout of 2 seconds.  (We do not use WaitNamedPipe.)
+func DialPipe(path string, timeout *time.Duration, expectedOwner *windows.SID) (net.Conn, error) {
+	var absTimeout time.Time
+	if timeout != nil {
+		absTimeout = time.Now().Add(*timeout)
+	} else {
+		absTimeout = time.Now().Add(time.Second * 2)
+	}
+	ctx, _ := context.WithDeadline(context.Background(), absTimeout)
+	conn, err := DialPipeContext(ctx, path, expectedOwner)
+	if err == context.DeadlineExceeded {
+		return nil, ErrTimeout
+	}
+	return conn, err
+}
+
+// DialPipeContext attempts to connect to a named pipe by `path` until `ctx`
+// cancellation or timeout.
+func DialPipeContext(ctx context.Context, path string, expectedOwner *windows.SID) (net.Conn, error) {
+	var err error
+	var h windows.Handle
+	h, err = tryDialPipe(ctx, &path)
+	if err != nil {
+		return nil, err
+	}
+
+	if expectedOwner != nil {
+		sd, err := windows.GetSecurityInfo(h, windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+		if err != nil {
+			windows.Close(h)
+			return nil, err
+		}
+		realOwner, _, err := sd.Owner()
+		if err != nil {
+			windows.Close(h)
+			return nil, err
+		}
+		if !realOwner.Equals(expectedOwner) {
+			windows.Close(h)
+			return nil, windows.ERROR_ACCESS_DENIED
+		}
+	}
+
+	var flags uint32
+	err = getNamedPipeInfo(h, &flags, nil, nil, nil)
+	if err != nil {
+		windows.Close(h)
+		return nil, err
+	}
+
+	f, err := makeWin32File(h)
+	if err != nil {
+		windows.Close(h)
+		return nil, err
+	}
+
+	// If the pipe is in message mode, return a message byte pipe, which
+	// supports CloseWrite().
+	if flags&cPIPE_TYPE_MESSAGE != 0 {
+		return &win32MessageBytePipe{
+			win32Pipe: win32Pipe{win32File: f, path: path},
+		}, nil
+	}
+	return &win32Pipe{win32File: f, path: path}, nil
+}
+
+type acceptResponse struct {
+	f   *win32File
+	err error
+}
+
+type win32PipeListener struct {
+	firstHandle windows.Handle
+	path        string
+	config      PipeConfig
+	acceptCh    chan (chan acceptResponse)
+	closeCh     chan int
+	doneCh      chan int
+}
+
+func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *PipeConfig, first bool) (windows.Handle, error) {
+	path16, err := windows.UTF16FromString(path)
+	if err != nil {
+		return 0, &os.PathError{Op: "open", Path: path, Err: err}
+	}
+
+	var oa objectAttributes
+	oa.Length = unsafe.Sizeof(oa)
+
+	var ntPath unicodeString
+	if err := rtlDosPathNameToNtPathName(&path16[0], &ntPath, 0, 0).Err(); err != nil {
+		return 0, &os.PathError{Op: "open", Path: path, Err: err}
+	}
+	defer windows.LocalFree(windows.Handle(ntPath.Buffer))
+	oa.ObjectName = &ntPath
+
+	// The security descriptor is only needed for the first pipe.
+	if first {
+		if sd != nil {
+			oa.SecurityDescriptor = sd
+		} else {
+			// Construct the default named pipe security descriptor.
+			var dacl uintptr
+			if err := rtlDefaultNpAcl(&dacl).Err(); err != nil {
+				return 0, fmt.Errorf("getting default named pipe ACL: %s", err)
+			}
+			defer windows.LocalFree(windows.Handle(dacl))
+			sd, err := windows.NewSecurityDescriptor()
+			if err != nil {
+				return 0, fmt.Errorf("creating new security descriptor: %s", err)
+			}
+			if err = sd.SetDACL((*windows.ACL)(unsafe.Pointer(dacl)), true, false); err != nil {
+				return 0, fmt.Errorf("assigning dacl: %s", err)
+			}
+			sd, err = sd.ToSelfRelative()
+			if err != nil {
+				return 0, fmt.Errorf("converting to self-relative: %s", err)
+			}
+			oa.SecurityDescriptor = sd
+		}
+	}
+
+	typ := uint32(cFILE_PIPE_REJECT_REMOTE_CLIENTS)
+	if c.MessageMode {
+		typ |= cFILE_PIPE_MESSAGE_TYPE
+	}
+
+	disposition := uint32(cFILE_OPEN)
+	access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE | windows.SYNCHRONIZE)
+	if first {
+		disposition = cFILE_CREATE
+		// By not asking for read or write access, the named pipe file system
+		// will put this pipe into an initially disconnected state, blocking
+		// client connections until the next call with first == false.
+		access = windows.SYNCHRONIZE
+	}
+
+	timeout := int64(-50 * 10000) // 50ms
+
+	var (
+		h    windows.Handle
+		iosb ioStatusBlock
+	)
+	err = ntCreateNamedPipeFile(&h, access, &oa, &iosb, windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE, disposition, 0, typ, 0, 0, 0xffffffff, uint32(c.InputBufferSize), uint32(c.OutputBufferSize), &timeout).Err()
+	if err != nil {
+		return 0, &os.PathError{Op: "open", Path: path, Err: err}
+	}
+
+	runtime.KeepAlive(ntPath)
+	return h, nil
+}
+
+func (l *win32PipeListener) makeServerPipe() (*win32File, error) {
+	h, err := makeServerPipeHandle(l.path, nil, &l.config, false)
+	if err != nil {
+		return nil, err
+	}
+	f, err := makeWin32File(h)
+	if err != nil {
+		windows.Close(h)
+		return nil, err
+	}
+	return f, nil
+}
+
+func (l *win32PipeListener) makeConnectedServerPipe() (*win32File, error) {
+	p, err := l.makeServerPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	// Wait for the client to connect.
+	ch := make(chan error)
+	go func(p *win32File) {
+		ch <- connectPipe(p)
+	}(p)
+
+	select {
+	case err = <-ch:
+		if err != nil {
+			p.Close()
+			p = nil
+		}
+	case <-l.closeCh:
+		// Abort the connect request by closing the handle.
+		p.Close()
+		p = nil
+		err = <-ch
+		if err == nil || err == ErrFileClosed {
+			err = ErrPipeListenerClosed
+		}
+	}
+	return p, err
+}
+
+func (l *win32PipeListener) listenerRoutine() {
+	closed := false
+	for !closed {
+		select {
+		case <-l.closeCh:
+			closed = true
+		case responseCh := <-l.acceptCh:
+			var (
+				p   *win32File
+				err error
+			)
+			for {
+				p, err = l.makeConnectedServerPipe()
+				// If the connection was immediately closed by the client, try
+				// again.
+				if err != windows.ERROR_NO_DATA {
+					break
+				}
+			}
+			responseCh <- acceptResponse{p, err}
+			closed = err == ErrPipeListenerClosed
+		}
+	}
+	windows.Close(l.firstHandle)
+	l.firstHandle = 0
+	// Notify Close() and Accept() callers that the handle has been closed.
+	close(l.doneCh)
+}
+
+// PipeConfig contain configuration for the pipe listener.
+type PipeConfig struct {
+	// SecurityDescriptor contains a Windows security descriptor.
+	SecurityDescriptor *windows.SECURITY_DESCRIPTOR
+
+	// MessageMode determines whether the pipe is in byte or message mode. In either
+	// case the pipe is read in byte mode by default. The only practical difference in
+	// this implementation is that CloseWrite() is only supported for message mode pipes;
+	// CloseWrite() is implemented as a zero-byte write, but zero-byte writes are only
+	// transferred to the reader (and returned as io.EOF in this implementation)
+	// when the pipe is in message mode.
+	MessageMode bool
+
+	// InputBufferSize specifies the size the input buffer, in bytes.
+	InputBufferSize int32
+
+	// OutputBufferSize specifies the size the input buffer, in bytes.
+	OutputBufferSize int32
+}
+
+// ListenPipe creates a listener on a Windows named pipe path, e.g. \\.\pipe\mypipe.
+// The pipe must not already exist.
+func ListenPipe(path string, c *PipeConfig) (net.Listener, error) {
+	if c == nil {
+		c = &PipeConfig{}
+	}
+	h, err := makeServerPipeHandle(path, c.SecurityDescriptor, c, true)
+	if err != nil {
+		return nil, err
+	}
+	l := &win32PipeListener{
+		firstHandle: h,
+		path:        path,
+		config:      *c,
+		acceptCh:    make(chan (chan acceptResponse)),
+		closeCh:     make(chan int),
+		doneCh:      make(chan int),
+	}
+	go l.listenerRoutine()
+	return l, nil
+}
+
+func connectPipe(p *win32File) error {
+	c, err := p.prepareIo()
+	if err != nil {
+		return err
+	}
+	defer p.wg.Done()
+
+	err = connectNamedPipe(p.handle, &c.o)
+	_, err = p.asyncIo(c, nil, 0, err)
+	if err != nil && err != windows.ERROR_PIPE_CONNECTED {
+		return err
+	}
+	return nil
+}
+
+func (l *win32PipeListener) Accept() (net.Conn, error) {
+	ch := make(chan acceptResponse)
+	select {
+	case l.acceptCh <- ch:
+		response := <-ch
+		err := response.err
+		if err != nil {
+			return nil, err
+		}
+		if l.config.MessageMode {
+			return &win32MessageBytePipe{
+				win32Pipe: win32Pipe{win32File: response.f, path: l.path},
+			}, nil
+		}
+		return &win32Pipe{win32File: response.f, path: l.path}, nil
+	case <-l.doneCh:
+		return nil, ErrPipeListenerClosed
+	}
+}
+
+func (l *win32PipeListener) Close() error {
+	select {
+	case l.closeCh <- 1:
+		<-l.doneCh
+	case <-l.doneCh:
+	}
+	return nil
+}
+
+func (l *win32PipeListener) Addr() net.Addr {
+	return pipeAddress(l.path)
+}

ipc/winpipe/zsyscall_windows.go

@@ -0,0 +1,238 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package winpipe
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return nil
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+	modntdll    = windows.NewLazySystemDLL("ntdll.dll")
+	modws2_32   = windows.NewLazySystemDLL("ws2_32.dll")
+
+	procConnectNamedPipe                   = modkernel32.NewProc("ConnectNamedPipe")
+	procCreateNamedPipeW                   = modkernel32.NewProc("CreateNamedPipeW")
+	procCreateFileW                        = modkernel32.NewProc("CreateFileW")
+	procGetNamedPipeInfo                   = modkernel32.NewProc("GetNamedPipeInfo")
+	procGetNamedPipeHandleStateW           = modkernel32.NewProc("GetNamedPipeHandleStateW")
+	procLocalAlloc                         = modkernel32.NewProc("LocalAlloc")
+	procNtCreateNamedPipeFile              = modntdll.NewProc("NtCreateNamedPipeFile")
+	procRtlNtStatusToDosErrorNoTeb         = modntdll.NewProc("RtlNtStatusToDosErrorNoTeb")
+	procRtlDosPathNameToNtPathName_U       = modntdll.NewProc("RtlDosPathNameToNtPathName_U")
+	procRtlDefaultNpAcl                    = modntdll.NewProc("RtlDefaultNpAcl")
+	procCancelIoEx                         = modkernel32.NewProc("CancelIoEx")
+	procCreateIoCompletionPort             = modkernel32.NewProc("CreateIoCompletionPort")
+	procGetQueuedCompletionStatus          = modkernel32.NewProc("GetQueuedCompletionStatus")
+	procSetFileCompletionNotificationModes = modkernel32.NewProc("SetFileCompletionNotificationModes")
+	procWSAGetOverlappedResult             = modws2_32.NewProc("WSAGetOverlappedResult")
+)
+
+func connectNamedPipe(pipe windows.Handle, o *windows.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall(procConnectNamedPipe.Addr(), 2, uintptr(pipe), uintptr(unsafe.Pointer(o)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *windows.SecurityAttributes) (handle windows.Handle, err error) {
+	var _p0 *uint16
+	_p0, err = syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return
+	}
+	return _createNamedPipe(_p0, flags, pipeMode, maxInstances, outSize, inSize, defaultTimeout, sa)
+}
+
+func _createNamedPipe(name *uint16, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *windows.SecurityAttributes) (handle windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall9(procCreateNamedPipeW.Addr(), 8, uintptr(unsafe.Pointer(name)), uintptr(flags), uintptr(pipeMode), uintptr(maxInstances), uintptr(outSize), uintptr(inSize), uintptr(defaultTimeout), uintptr(unsafe.Pointer(sa)), 0)
+	handle = windows.Handle(r0)
+	if handle == windows.InvalidHandle {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func createFile(name string, access uint32, mode uint32, sa *windows.SecurityAttributes, createmode uint32, attrs uint32, templatefile windows.Handle) (handle windows.Handle, err error) {
+	var _p0 *uint16
+	_p0, err = syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return
+	}
+	return _createFile(_p0, access, mode, sa, createmode, attrs, templatefile)
+}
+
+func _createFile(name *uint16, access uint32, mode uint32, sa *windows.SecurityAttributes, createmode uint32, attrs uint32, templatefile windows.Handle) (handle windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall9(procCreateFileW.Addr(), 7, uintptr(unsafe.Pointer(name)), uintptr(access), uintptr(mode), uintptr(unsafe.Pointer(sa)), uintptr(createmode), uintptr(attrs), uintptr(templatefile), 0, 0)
+	handle = windows.Handle(r0)
+	if handle == windows.InvalidHandle {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func getNamedPipeInfo(pipe windows.Handle, flags *uint32, outSize *uint32, inSize *uint32, maxInstances *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procGetNamedPipeInfo.Addr(), 5, uintptr(pipe), uintptr(unsafe.Pointer(flags)), uintptr(unsafe.Pointer(outSize)), uintptr(unsafe.Pointer(inSize)), uintptr(unsafe.Pointer(maxInstances)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func getNamedPipeHandleState(pipe windows.Handle, state *uint32, curInstances *uint32, maxCollectionCount *uint32, collectDataTimeout *uint32, userName *uint16, maxUserNameSize uint32) (err error) {
+	r1, _, e1 := syscall.Syscall9(procGetNamedPipeHandleStateW.Addr(), 7, uintptr(pipe), uintptr(unsafe.Pointer(state)), uintptr(unsafe.Pointer(curInstances)), uintptr(unsafe.Pointer(maxCollectionCount)), uintptr(unsafe.Pointer(collectDataTimeout)), uintptr(unsafe.Pointer(userName)), uintptr(maxUserNameSize), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func localAlloc(uFlags uint32, length uint32) (ptr uintptr) {
+	r0, _, _ := syscall.Syscall(procLocalAlloc.Addr(), 2, uintptr(uFlags), uintptr(length), 0)
+	ptr = uintptr(r0)
+	return
+}
+
+func ntCreateNamedPipeFile(pipe *windows.Handle, access uint32, oa *objectAttributes, iosb *ioStatusBlock, share uint32, disposition uint32, options uint32, typ uint32, readMode uint32, completionMode uint32, maxInstances uint32, inboundQuota uint32, outputQuota uint32, timeout *int64) (status ntstatus) {
+	r0, _, _ := syscall.Syscall15(procNtCreateNamedPipeFile.Addr(), 14, uintptr(unsafe.Pointer(pipe)), uintptr(access), uintptr(unsafe.Pointer(oa)), uintptr(unsafe.Pointer(iosb)), uintptr(share), uintptr(disposition), uintptr(options), uintptr(typ), uintptr(readMode), uintptr(completionMode), uintptr(maxInstances), uintptr(inboundQuota), uintptr(outputQuota), uintptr(unsafe.Pointer(timeout)), 0)
+	status = ntstatus(r0)
+	return
+}
+
+func rtlNtStatusToDosError(status ntstatus) (winerr error) {
+	r0, _, _ := syscall.Syscall(procRtlNtStatusToDosErrorNoTeb.Addr(), 1, uintptr(status), 0, 0)
+	if r0 != 0 {
+		winerr = syscall.Errno(r0)
+	}
+	return
+}
+
+func rtlDosPathNameToNtPathName(name *uint16, ntName *unicodeString, filePart uintptr, reserved uintptr) (status ntstatus) {
+	r0, _, _ := syscall.Syscall6(procRtlDosPathNameToNtPathName_U.Addr(), 4, uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(ntName)), uintptr(filePart), uintptr(reserved), 0, 0)
+	status = ntstatus(r0)
+	return
+}
+
+func rtlDefaultNpAcl(dacl *uintptr) (status ntstatus) {
+	r0, _, _ := syscall.Syscall(procRtlDefaultNpAcl.Addr(), 1, uintptr(unsafe.Pointer(dacl)), 0, 0)
+	status = ntstatus(r0)
+	return
+}
+
+func cancelIoEx(file windows.Handle, o *windows.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall(procCancelIoEx.Addr(), 2, uintptr(file), uintptr(unsafe.Pointer(o)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func createIoCompletionPort(file windows.Handle, port windows.Handle, key uintptr, threadCount uint32) (newport windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall6(procCreateIoCompletionPort.Addr(), 4, uintptr(file), uintptr(port), uintptr(key), uintptr(threadCount), 0, 0)
+	newport = windows.Handle(r0)
+	if newport == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func getQueuedCompletionStatus(port windows.Handle, bytes *uint32, key *uintptr, o **ioOperation, timeout uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procGetQueuedCompletionStatus.Addr(), 5, uintptr(port), uintptr(unsafe.Pointer(bytes)), uintptr(unsafe.Pointer(key)), uintptr(unsafe.Pointer(o)), uintptr(timeout), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func setFileCompletionNotificationModes(h windows.Handle, flags uint8) (err error) {
+	r1, _, e1 := syscall.Syscall(procSetFileCompletionNotificationModes.Addr(), 2, uintptr(h), uintptr(flags), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func wsaGetOverlappedResult(h windows.Handle, o *windows.Overlapped, bytes *uint32, wait bool, flags *uint32) (err error) {
+	var _p0 uint32
+	if wait {
+		_p0 = 1
+	} else {
+		_p0 = 0
+	}
+	r1, _, e1 := syscall.Syscall6(procWSAGetOverlappedResult.Addr(), 5, uintptr(h), uintptr(unsafe.Pointer(o)), uintptr(unsafe.Pointer(bytes)), uintptr(_p0), uintptr(unsafe.Pointer(flags)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}

main.go

@@ -1,18 +1,23 @@
-/* SPDX-License-Identifier: GPL-2.0
+// +build !windows
+
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package main
 
 import (
 	"fmt"
-	"git.zx2c4.com/wireguard-go/tun"
 	"os"
 	"os/signal"
 	"runtime"
 	"strconv"
 	"syscall"
+
+	"golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/ipc"
+	"golang.zx2c4.com/wireguard/tun"
 )
 
 const (
@@ -32,56 +37,30 @@ func printUsage() {
 }
 
 func warning() {
-	if os.Getenv(ENV_WG_PROCESS_FOREGROUND) == "1" {
+	if runtime.GOOS != "linux" || os.Getenv(ENV_WG_PROCESS_FOREGROUND) == "1" {
 		return
 	}
 
-	shouldQuit := false
-
-	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
-	fmt.Fprintln(os.Stderr, "W                                                     G")
-	fmt.Fprintln(os.Stderr, "W   This is alpha software. It will very likely not   G")
-	fmt.Fprintln(os.Stderr, "W   do what it is supposed to do, and things may go   G")
-	fmt.Fprintln(os.Stderr, "W   horribly wrong. You have been warned. Proceed     G")
-	fmt.Fprintln(os.Stderr, "W   at your own risk.                                 G")
-	if runtime.GOOS == "linux" {
-		shouldQuit = os.Getenv("WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD") != "1"
-
-		fmt.Fprintln(os.Stderr, "W                                                     G")
-		fmt.Fprintln(os.Stderr, "W   Furthermore, you are running this software on a   G")
-		fmt.Fprintln(os.Stderr, "W   Linux kernel, which is probably unnecessary and   G")
-		fmt.Fprintln(os.Stderr, "W   foolish. This is because the Linux kernel has     G")
-		fmt.Fprintln(os.Stderr, "W   built-in first class support for WireGuard, and   G")
-		fmt.Fprintln(os.Stderr, "W   this support is much more refined than this       G")
-		fmt.Fprintln(os.Stderr, "W   program. For more information on installing the   G")
-		fmt.Fprintln(os.Stderr, "W   kernel module, please visit:                      G")
-		fmt.Fprintln(os.Stderr, "W           https://www.wireguard.com/install         G")
-		if shouldQuit {
-			fmt.Fprintln(os.Stderr, "W                                                     G")
-			fmt.Fprintln(os.Stderr, "W   If you still want to use this program, against    G")
-			fmt.Fprintln(os.Stderr, "W   the sage advice here, please first export this    G")
-			fmt.Fprintln(os.Stderr, "W   environment variable:                             G")
-			fmt.Fprintln(os.Stderr, "W   WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD=1    G")
-		}
-	}
-	fmt.Fprintln(os.Stderr, "W                                                     G")
-	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
-
-	if shouldQuit {
-		os.Exit(1)
-	}
+	fmt.Fprintln(os.Stderr, "┌───────────────────────────────────────────────────┐")
+	fmt.Fprintln(os.Stderr, "│                                                   │")
+	fmt.Fprintln(os.Stderr, "│   Running this software on Linux is unnecessary,  │")
+	fmt.Fprintln(os.Stderr, "│   because the Linux kernel has built-in first     │")
+	fmt.Fprintln(os.Stderr, "│   class support for WireGuard, which will be      │")
+	fmt.Fprintln(os.Stderr, "│   faster, slicker, and better integrated. For     │")
+	fmt.Fprintln(os.Stderr, "│   information on installing the kernel module,    │")
+	fmt.Fprintln(os.Stderr, "│   please visit: <https://wireguard.com/install>.  │")
+	fmt.Fprintln(os.Stderr, "│                                                   │")
+	fmt.Fprintln(os.Stderr, "└───────────────────────────────────────────────────┘")
 }
 
 func main() {
 	if len(os.Args) == 2 && os.Args[1] == "--version" {
-		fmt.Printf("wireguard-go v%s\n\nUserspace WireGuard daemon for %s-%s.\nInformation available at https://www.wireguard.com.\nCopyright (C) Jason A. Donenfeld <Jason@zx2c4.com>.\n", WireGuardGoVersion, runtime.GOOS, runtime.GOARCH)
+		fmt.Printf("wireguard-go v%s\n\nUserspace WireGuard daemon for %s-%s.\nInformation available at https://www.wireguard.com.\nCopyright (C) Jason A. Donenfeld <Jason@zx2c4.com>.\n", device.WireGuardGoVersion, runtime.GOOS, runtime.GOARCH)
 		return
 	}
 
 	warning()
 
-	// parse arguments
-
 	var foreground bool
 	var interfaceName string
 	if len(os.Args) < 2 || len(os.Args) > 3 {
@@ -117,23 +96,23 @@ func main() {
 	logLevel := func() int {
 		switch os.Getenv("LOG_LEVEL") {
 		case "debug":
-			return LogLevelDebug
+			return device.LogLevelDebug
 		case "info":
-			return LogLevelInfo
+			return device.LogLevelInfo
 		case "error":
-			return LogLevelError
+			return device.LogLevelError
 		case "silent":
-			return LogLevelSilent
+			return device.LogLevelSilent
 		}
-		return LogLevelInfo
+		return device.LogLevelInfo
 	}()
 
 	// open TUN device (or use supplied fd)
 
-	tun, err := func() (tun.TUNDevice, error) {
+	tun, err := func() (tun.Device, error) {
 		tunFdStr := os.Getenv(ENV_WG_TUN_FD)
 		if tunFdStr == "" {
-			return tun.CreateTUN(interfaceName, DefaultMTU)
+			return tun.CreateTUN(interfaceName, device.DefaultMTU)
 		}
 
 		// construct tun device from supplied fd
@@ -143,8 +122,13 @@ func main() {
 			return nil, err
 		}
 
+		err = syscall.SetNonblock(int(fd), true)
+		if err != nil {
+			return nil, err
+		}
+
 		file := os.NewFile(uintptr(fd), "")
-		return tun.CreateTUNFromFile(file, DefaultMTU)
+		return tun.CreateTUNFromFile(file, device.DefaultMTU)
 	}()
 
 	if err == nil {
@@ -154,12 +138,12 @@ func main() {
 		}
 	}
 
-	logger := NewLogger(
+	logger := device.NewLogger(
 		logLevel,
 		fmt.Sprintf("(%s) ", interfaceName),
 	)
 
-	logger.Info.Println("Starting wireguard-go version", WireGuardGoVersion)
+	logger.Info.Println("Starting wireguard-go version", device.WireGuardGoVersion)
 
 	logger.Debug.Println("Debug log enabled")
 
@@ -173,7 +157,7 @@ func main() {
 	fileUAPI, err := func() (*os.File, error) {
 		uapiFdStr := os.Getenv(ENV_WG_UAPI_FD)
 		if uapiFdStr == "" {
-			return UAPIOpen(interfaceName)
+			return ipc.UAPIOpen(interfaceName)
 		}
 
 		// use supplied fd
@@ -199,7 +183,7 @@ func main() {
 		env = append(env, fmt.Sprintf("%s=4", ENV_WG_UAPI_FD))
 		env = append(env, fmt.Sprintf("%s=1", ENV_WG_PROCESS_FOREGROUND))
 		files := [3]*os.File{}
-		if os.Getenv("LOG_LEVEL") != "" && logLevel != LogLevelSilent {
+		if os.Getenv("LOG_LEVEL") != "" && logLevel != device.LogLevelSilent {
 			files[0], _ = os.Open(os.DevNull)
 			files[1] = os.Stdout
 			files[2] = os.Stderr
@@ -239,14 +223,14 @@ func main() {
 		return
 	}
 
-	device := NewDevice(tun, logger)
+	device := device.NewDevice(tun, logger)
 
 	logger.Info.Println("Device started")
 
 	errs := make(chan error)
 	term := make(chan os.Signal, 1)
 
-	uapi, err := UAPIListen(interfaceName, fileUAPI)
+	uapi, err := ipc.UAPIListen(interfaceName, fileUAPI)
 	if err != nil {
 		logger.Error.Println("Failed to listen on uapi socket:", err)
 		os.Exit(ExitSetupFailed)
@@ -259,7 +243,7 @@ func main() {
 				errs <- err
 				return
 			}
-			go ipcHandle(device, conn)
+			go device.IpcHandle(conn)
 		}
 	}()
 

main_windows.go

@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/ipc"
+
+	"golang.zx2c4.com/wireguard/tun"
+)
+
+const (
+	ExitSetupSuccess = 0
+	ExitSetupFailed  = 1
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		os.Exit(ExitSetupFailed)
+	}
+	interfaceName := os.Args[1]
+
+	fmt.Fprintln(os.Stderr, "Warning: this is a test program for Windows, mainly used for debugging this Go package. For a real WireGuard for Windows client, the repo you want is <https://git.zx2c4.com/wireguard-windows/>, which includes this code as a module.")
+
+	logger := device.NewLogger(
+		device.LogLevelDebug,
+		fmt.Sprintf("(%s) ", interfaceName),
+	)
+	logger.Info.Println("Starting wireguard-go version", device.WireGuardGoVersion)
+	logger.Debug.Println("Debug log enabled")
+
+	tun, err := tun.CreateTUN(interfaceName, 0)
+	if err == nil {
+		realInterfaceName, err2 := tun.Name()
+		if err2 == nil {
+			interfaceName = realInterfaceName
+		}
+	} else {
+		logger.Error.Println("Failed to create TUN device:", err)
+		os.Exit(ExitSetupFailed)
+	}
+
+	device := device.NewDevice(tun, logger)
+	device.Up()
+	logger.Info.Println("Device started")
+
+	uapi, err := ipc.UAPIListen(interfaceName)
+	if err != nil {
+		logger.Error.Println("Failed to listen on uapi socket:", err)
+		os.Exit(ExitSetupFailed)
+	}
+
+	errs := make(chan error)
+	term := make(chan os.Signal, 1)
+
+	go func() {
+		for {
+			conn, err := uapi.Accept()
+			if err != nil {
+				errs <- err
+				return
+			}
+			go device.IpcHandle(conn)
+		}
+	}()
+	logger.Info.Println("UAPI listener started")
+
+	// wait for program to terminate
+
+	signal.Notify(term, os.Interrupt)
+	signal.Notify(term, os.Kill)
+	signal.Notify(term, syscall.SIGTERM)
+
+	select {
+	case <-term:
+	case <-errs:
+	case <-device.Wait():
+	}
+
+	// clean up
+
+	uapi.Close()
+	device.Close()
+
+	logger.Info.Println("Shutting down")
+}

ratelimiter/ratelimiter.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ratelimiter
@@ -20,21 +20,23 @@ const (
 )
 
 type RatelimiterEntry struct {
-	mutex    sync.Mutex
+	mu       sync.Mutex
 	lastTime time.Time
 	tokens   int64
 }
 
 type Ratelimiter struct {
-	mutex     sync.RWMutex
-	stopReset chan struct{}
+	mu      sync.RWMutex
+	timeNow func() time.Time
+
+	stopReset chan struct{} // send to reset, close to stop
 	tableIPv4 map[[net.IPv4len]byte]*RatelimiterEntry
 	tableIPv6 map[[net.IPv6len]byte]*RatelimiterEntry
 }
 
 func (rate *Ratelimiter) Close() {
-	rate.mutex.Lock()
-	defer rate.mutex.Unlock()
+	rate.mu.Lock()
+	defer rate.mu.Unlock()
 
 	if rate.stopReset != nil {
 		close(rate.stopReset)
@@ -42,11 +44,14 @@ func (rate *Ratelimiter) Close() {
 }
 
 func (rate *Ratelimiter) Init() {
-	rate.mutex.Lock()
-	defer rate.mutex.Unlock()
+	rate.mu.Lock()
+	defer rate.mu.Unlock()
+
+	if rate.timeNow == nil {
+		rate.timeNow = time.Now
+	}
 
 	// stop any ongoing garbage collection routine
-
 	if rate.stopReset != nil {
 		close(rate.stopReset)
 	}
@@ -55,48 +60,50 @@ func (rate *Ratelimiter) Init() {
 	rate.tableIPv4 = make(map[[net.IPv4len]byte]*RatelimiterEntry)
 	rate.tableIPv6 = make(map[[net.IPv6len]byte]*RatelimiterEntry)
 
-	// start garbage collection routine
+	stopReset := rate.stopReset // store in case Init is called again.
 
+	// Start garbage collection routine.
 	go func() {
 		ticker := time.NewTicker(time.Second)
 		ticker.Stop()
 		for {
 			select {
-			case _, ok := <-rate.stopReset:
+			case _, ok := <-stopReset:
 				ticker.Stop()
-				if ok {
-					ticker = time.NewTicker(time.Second)
-				} else {
+				if !ok {
 					return
 				}
+				ticker = time.NewTicker(time.Second)
 			case <-ticker.C:
-				func() {
-					rate.mutex.Lock()
-					defer rate.mutex.Unlock()
+				if rate.cleanup() {
+					ticker.Stop()
+				}
+			}
+		}
+	}()
+}
+
+func (rate *Ratelimiter) cleanup() (empty bool) {
+	rate.mu.Lock()
+	defer rate.mu.Unlock()
 
 	for key, entry := range rate.tableIPv4 {
-						entry.mutex.Lock()
-						if time.Now().Sub(entry.lastTime) > garbageCollectTime {
+		entry.mu.Lock()
+		if rate.timeNow().Sub(entry.lastTime) > garbageCollectTime {
 			delete(rate.tableIPv4, key)
 		}
-						entry.mutex.Unlock()
+		entry.mu.Unlock()
 	}
 
 	for key, entry := range rate.tableIPv6 {
-						entry.mutex.Lock()
-						if time.Now().Sub(entry.lastTime) > garbageCollectTime {
+		entry.mu.Lock()
+		if rate.timeNow().Sub(entry.lastTime) > garbageCollectTime {
 			delete(rate.tableIPv6, key)
 		}
-						entry.mutex.Unlock()
+		entry.mu.Unlock()
 	}
 
-					if len(rate.tableIPv4) == 0 && len(rate.tableIPv6) == 0 {
-						ticker.Stop()
-					}
-				}()
-			}
-		}
-	}()
+	return len(rate.tableIPv4) == 0 && len(rate.tableIPv6) == 0
 }
 
 func (rate *Ratelimiter) Allow(ip net.IP) bool {
@@ -109,7 +116,7 @@ func (rate *Ratelimiter) Allow(ip net.IP) bool {
 	IPv4 := ip.To4()
 	IPv6 := ip.To16()
 
-	rate.mutex.RLock()
+	rate.mu.RLock()
 
 	if IPv4 != nil {
 		copy(keyIPv4[:], IPv4)
@@ -119,15 +126,15 @@ func (rate *Ratelimiter) Allow(ip net.IP) bool {
 		entry = rate.tableIPv6[keyIPv6]
 	}
 
-	rate.mutex.RUnlock()
+	rate.mu.RUnlock()
 
 	// make new entry if not found
 
 	if entry == nil {
 		entry = new(RatelimiterEntry)
 		entry.tokens = maxTokens - packetCost
-		entry.lastTime = time.Now()
-		rate.mutex.Lock()
+		entry.lastTime = rate.timeNow()
+		rate.mu.Lock()
 		if IPv4 != nil {
 			rate.tableIPv4[keyIPv4] = entry
 			if len(rate.tableIPv4) == 1 && len(rate.tableIPv6) == 0 {
@@ -139,14 +146,14 @@ func (rate *Ratelimiter) Allow(ip net.IP) bool {
 				rate.stopReset <- struct{}{}
 			}
 		}
-		rate.mutex.Unlock()
+		rate.mu.Unlock()
 		return true
 	}
 
 	// add tokens to entry
 
-	entry.mutex.Lock()
-	now := time.Now()
+	entry.mu.Lock()
+	now := rate.timeNow()
 	entry.tokens += now.Sub(entry.lastTime).Nanoseconds()
 	entry.lastTime = now
 	if entry.tokens > maxTokens {
@@ -157,9 +164,9 @@ func (rate *Ratelimiter) Allow(ip net.IP) bool {
 
 	if entry.tokens > packetCost {
 		entry.tokens -= packetCost
-		entry.mutex.Unlock()
+		entry.mu.Unlock()
 		return true
 	}
-	entry.mutex.Unlock()
+	entry.mu.Unlock()
 	return false
 }

ratelimiter/ratelimiter_test.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ratelimiter
@@ -11,22 +11,21 @@ import (
 	"time"
 )
 
-type RatelimiterResult struct {
+type result struct {
 	allowed bool
 	text    string
 	wait    time.Duration
 }
 
 func TestRatelimiter(t *testing.T) {
+	var rate Ratelimiter
+	var expectedResults []result
 
-	var ratelimiter Ratelimiter
-	var expectedResults []RatelimiterResult
-
-	Nano := func(nano int64) time.Duration {
+	nano := func(nano int64) time.Duration {
 		return time.Nanosecond * time.Duration(nano)
 	}
 
-	Add := func(res RatelimiterResult) {
+	add := func(res result) {
 		expectedResults = append(
 			expectedResults,
 			res,
@@ -34,40 +33,40 @@ func TestRatelimiter(t *testing.T) {
 	}
 
 	for i := 0; i < packetsBurstable; i++ {
-		Add(RatelimiterResult{
+		add(result{
 			allowed: true,
-			text:    "inital burst",
+			text:    "initial burst",
 		})
 	}
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: false,
 		text:    "after burst",
 	})
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: true,
-		wait:    Nano(time.Second.Nanoseconds() / packetsPerSecond),
+		wait:    nano(time.Second.Nanoseconds() / packetsPerSecond),
 		text:    "filling tokens for single packet",
 	})
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: false,
 		text:    "not having refilled enough",
 	})
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: true,
-		wait:    2 * (Nano(time.Second.Nanoseconds() / packetsPerSecond)),
+		wait:    2 * (nano(time.Second.Nanoseconds() / packetsPerSecond)),
 		text:    "filling tokens for two packet burst",
 	})
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: true,
 		text:    "second packet in 2 packet burst",
 	})
 
-	Add(RatelimiterResult{
+	add(result{
 		allowed: false,
 		text:    "packet following 2 packet burst",
 	})
@@ -89,14 +88,31 @@ func TestRatelimiter(t *testing.T) {
 		net.ParseIP("3f0e:54a2:f5b4:cd19:a21d:58e1:3746:84c4"),
 	}
 
-	ratelimiter.Init()
+	now := time.Now()
+	rate.timeNow = func() time.Time {
+		return now
+	}
+	defer func() {
+		// Lock to avoid data race with cleanup goroutine from Init.
+		rate.mu.Lock()
+		defer rate.mu.Unlock()
+
+		rate.timeNow = time.Now
+	}()
+	timeSleep := func(d time.Duration) {
+		now = now.Add(d + 1)
+		rate.cleanup()
+	}
+
+	rate.Init()
+	defer rate.Close()
 
 	for i, res := range expectedResults {
-		time.Sleep(res.wait)
+		timeSleep(res.wait)
 		for _, ip := range ips {
-			allowed := ratelimiter.Allow(ip)
+			allowed := rate.Allow(ip)
 			if allowed != res.allowed {
-				t.Fatal("Test failed for", ip.String(), ", on:", i, "(", res.text, ")", "expected:", res.allowed, "got:", allowed)
+				t.Fatalf("%d: %s: rate.Allow(%q)=%v, want %v", i, res.text, ip, allowed, res.allowed)
 			}
 		}
 	}

replay/replay.go

@@ -1,83 +1,62 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
+// Package replay implements an efficient anti-replay algorithm as specified in RFC 6479.
 package replay
 
-/* Implementation of RFC6479
- * https://tools.ietf.org/html/rfc6479
- *
- * The implementation is not safe for concurrent use!
- */
+type block uint64
 
 const (
-	// See: https://golang.org/src/math/big/arith.go
-	_Wordm       = ^uintptr(0)
-	_WordLogSize = _Wordm>>8&1 + _Wordm>>16&1 + _Wordm>>32&1
-	_WordSize    = 1 << _WordLogSize
+	blockBitLog = 6                // 1<<6 == 64 bits
+	blockBits   = 1 << blockBitLog // must be power of 2
+	ringBlocks  = 1 << 7           // must be power of 2
+	windowSize  = (ringBlocks - 1) * blockBits
+	blockMask   = ringBlocks - 1
+	bitMask     = blockBits - 1
 )
 
-const (
-	CounterRedundantBitsLog = _WordLogSize + 3
-	CounterRedundantBits    = _WordSize * 8
-	CounterBitsTotal        = 2048
-	CounterWindowSize       = uint64(CounterBitsTotal - CounterRedundantBits)
-)
-
-const (
-	BacktrackWords = CounterBitsTotal / _WordSize
-)
-
-func minUint64(a uint64, b uint64) uint64 {
-	if a > b {
-		return b
-	}
-	return a
+// A Filter rejects replayed messages by checking if message counter value is
+// within a sliding window of previously received messages.
+// The zero value for Filter is an empty filter ready to use.
+// Filters are unsafe for concurrent use.
+type Filter struct {
+	last uint64
+	ring [ringBlocks]block
 }
 
-type ReplayFilter struct {
-	counter   uint64
-	backtrack [BacktrackWords]uintptr
+// Reset resets the filter to empty state.
+func (f *Filter) Reset() {
+	f.last = 0
+	f.ring[0] = 0
 }
 
-func (filter *ReplayFilter) Init() {
-	filter.counter = 0
-	filter.backtrack[0] = 0
-}
-
-func (filter *ReplayFilter) ValidateCounter(counter uint64, limit uint64) bool {
+// ValidateCounter checks if the counter should be accepted.
+// Overlimit counters (>= limit) are always rejected.
+func (f *Filter) ValidateCounter(counter uint64, limit uint64) bool {
 	if counter >= limit {
 		return false
 	}
-
-	indexWord := counter >> CounterRedundantBitsLog
-
-	if counter > filter.counter {
-
-		// move window forward
-
-		current := filter.counter >> CounterRedundantBitsLog
-		diff := minUint64(indexWord-current, BacktrackWords)
-		for i := uint64(1); i <= diff; i++ {
-			filter.backtrack[(current+i)%BacktrackWords] = 0
+	indexBlock := counter >> blockBitLog
+	if counter > f.last { // move window forward
+		current := f.last >> blockBitLog
+		diff := indexBlock - current
+		if diff > ringBlocks {
+			diff = ringBlocks // cap diff to clear the whole ring
 		}
-		filter.counter = counter
-
-	} else if filter.counter-counter > CounterWindowSize {
-
-		// behind current window
-
+		for i := current + 1; i <= current+diff; i++ {
+			f.ring[i&blockMask] = 0
+		}
+		f.last = counter
+	} else if f.last-counter > windowSize { // behind current window
 		return false
 	}
-
-	indexWord %= BacktrackWords
-	indexBit := counter & uint64(CounterRedundantBits-1)
-
 	// check and set bit
-
-	oldValue := filter.backtrack[indexWord]
-	newValue := oldValue | (1 << indexBit)
-	filter.backtrack[indexWord] = newValue
-	return oldValue != newValue
+	indexBlock &= blockMask
+	indexBit := counter & bitMask
+	old := f.ring[indexBlock]
+	new := old | 1<<indexBit
+	f.ring[indexBlock] = new
+	return old != new
 }

replay/replay_test.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package replay
@@ -14,22 +14,22 @@ import (
  *
  */
 
-const RejectAfterMessages = (1 << 64) - (1 << 4) - 1
+const RejectAfterMessages = 1<<64 - 1<<13 - 1
 
 func TestReplay(t *testing.T) {
-	var filter ReplayFilter
+	var filter Filter
 
-	T_LIM := CounterWindowSize + 1
+	const T_LIM = windowSize + 1
 
 	testNumber := 0
-	T := func(n uint64, v bool) {
+	T := func(n uint64, expected bool) {
 		testNumber++
-		if filter.ValidateCounter(n, RejectAfterMessages) != v {
-			t.Fatal("Test", testNumber, "failed", n, v)
+		if filter.ValidateCounter(n, RejectAfterMessages) != expected {
+			t.Fatal("Test", testNumber, "failed", n, expected)
 		}
 	}
 
-	filter.Init()
+	filter.Reset()
 
 	T(0, true)                      /*  1 */
 	T(1, true)                      /*  2 */
@@ -67,53 +67,53 @@ func TestReplay(t *testing.T) {
 	T(0, false)                     /* 34 */
 
 	t.Log("Bulk test 1")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := uint64(1); i <= CounterWindowSize; i++ {
+	for i := uint64(1); i <= windowSize; i++ {
 		T(i, true)
 	}
 	T(0, true)
 	T(0, false)
 
 	t.Log("Bulk test 2")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := uint64(2); i <= CounterWindowSize+1; i++ {
+	for i := uint64(2); i <= windowSize+1; i++ {
 		T(i, true)
 	}
 	T(1, true)
 	T(0, false)
 
 	t.Log("Bulk test 3")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := CounterWindowSize + 1; i > 0; i-- {
+	for i := uint64(windowSize + 1); i > 0; i-- {
 		T(i, true)
 	}
 
 	t.Log("Bulk test 4")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := CounterWindowSize + 2; i > 1; i-- {
+	for i := uint64(windowSize + 2); i > 1; i-- {
 		T(i, true)
 	}
 	T(0, false)
 
 	t.Log("Bulk test 5")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := CounterWindowSize; i > 0; i-- {
+	for i := uint64(windowSize); i > 0; i-- {
 		T(i, true)
 	}
-	T(CounterWindowSize+1, true)
+	T(windowSize+1, true)
 	T(0, false)
 
 	t.Log("Bulk test 6")
-	filter.Init()
+	filter.Reset()
 	testNumber = 0
-	for i := CounterWindowSize; i > 0; i-- {
+	for i := uint64(windowSize); i > 0; i-- {
 		T(i, true)
 	}
 	T(0, true)
-	T(CounterWindowSize+1, true)
+	T(windowSize+1, true)
 }

rwcancel/fdset.go

@@ -0,0 +1,24 @@
+// +build !windows
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package rwcancel
+
+import "golang.org/x/sys/unix"
+
+type fdSet struct {
+	unix.FdSet
+}
+
+func (fdset *fdSet) set(i int) {
+	bits := 32 << (^uint(0) >> 63)
+	fdset.Bits[i/bits] |= 1 << uint(i%bits)
+}
+
+func (fdset *fdSet) check(i int) bool {
+	bits := 32 << (^uint(0) >> 63)
+	return (fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
+}

rwcancel/fdset_default.go

@@ -1,24 +0,0 @@
-// +build !freebsd
-
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package rwcancel
-
-import "golang.org/x/sys/unix"
-
-type fdSet struct {
-	fdset unix.FdSet
-}
-
-func (fdset *fdSet) set(i int) {
-	bits := 32 << (^uint(0) >> 63)
-	fdset.fdset.Bits[i/bits] |= 1 << uint(i%bits)
-}
-
-func (fdset *fdSet) check(i int) bool {
-	bits := 32 << (^uint(0) >> 63)
-	return (fdset.fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
-}

rwcancel/fdset_freebsd.go

@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
- */
-
-package rwcancel
-
-import "golang.org/x/sys/unix"
-
-type fdSet struct {
-	fdset unix.FdSet
-}
-
-func (fdset *fdSet) set(i int) {
-	bits := 32 << (^uint(0) >> 63)
-	fdset.fdset.X__fds_bits[i/bits] |= 1 << uint(i%bits)
-}
-
-func (fdset *fdSet) check(i int) bool {
-	bits := 32 << (^uint(0) >> 63)
-	return (fdset.fdset.X__fds_bits[i/bits] & (1 << uint(i%bits))) != 0
-}

rwcancel/rwcancel.go

@@ -1,15 +1,20 @@
-/* SPDX-License-Identifier: GPL-2.0
+// +build !windows
+
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
+// Package rwcancel implements cancelable read/write operations on
+// a file descriptor.
 package rwcancel
 
 import (
 	"errors"
-	"golang.org/x/sys/unix"
 	"os"
 	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 func max(a, b int) int {
@@ -59,7 +64,13 @@ func (rw *RWCancel) ReadyRead() bool {
 	fdset := fdSet{}
 	fdset.set(rw.fd)
 	fdset.set(closeFd)
-	err := unixSelect(max(rw.fd, closeFd)+1, &fdset.fdset, nil, nil, nil)
+	var err error
+	for {
+		err = unixSelect(max(rw.fd, closeFd)+1, &fdset.FdSet, nil, nil, nil)
+		if err == nil || !RetryAfterError(err) {
+			break
+		}
+	}
 	if err != nil {
 		return false
 	}
@@ -74,7 +85,13 @@ func (rw *RWCancel) ReadyWrite() bool {
 	fdset := fdSet{}
 	fdset.set(rw.fd)
 	fdset.set(closeFd)
-	err := unixSelect(max(rw.fd, closeFd)+1, nil, &fdset.fdset, nil, nil)
+	var err error
+	for {
+		err = unixSelect(max(rw.fd, closeFd)+1, nil, &fdset.FdSet, nil, nil)
+		if err == nil || !RetryAfterError(err) {
+			break
+		}
+	}
 	if err != nil {
 		return false
 	}

rwcancel/rwcancel_windows.go

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: MIT
+
+package rwcancel
+
+type RWCancel struct {
+}
+
+func (*RWCancel) Cancel() {}

rwcancel/select_default.go

@@ -1,8 +1,8 @@
-// +build !linux
+// +build !linux,!windows
 
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package rwcancel
@@ -10,5 +10,6 @@ package rwcancel
 import "golang.org/x/sys/unix"
 
 func unixSelect(nfd int, r *unix.FdSet, w *unix.FdSet, e *unix.FdSet, timeout *unix.Timeval) error {
-	return unix.Select(nfd, r, w, e, timeout)
+	_, err := unix.Select(nfd, r, w, e, timeout)
+	return err
 }

rwcancel/select_linux.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package rwcancel

tai64n/tai64n.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tai64n
@@ -12,20 +12,24 @@ import (
 )
 
 const TimestampSize = 12
-const base = uint64(4611686018427387914)
+const base = uint64(0x400000000000000a)
+const whitenerMask = uint32(0x1000000 - 1)
 
 type Timestamp [TimestampSize]byte
 
-func Now() Timestamp {
+func stamp(t time.Time) Timestamp {
 	var tai64n Timestamp
-	now := time.Now()
-	secs := base + uint64(now.Unix())
-	nano := uint32(now.UnixNano())
+	secs := base + uint64(t.Unix())
+	nano := uint32(t.Nanosecond()) &^ whitenerMask
 	binary.BigEndian.PutUint64(tai64n[:], secs)
 	binary.BigEndian.PutUint32(tai64n[8:], nano)
 	return tai64n
 }
 
+func Now() Timestamp {
+	return stamp(time.Now())
+}
+
 func (t1 Timestamp) After(t2 Timestamp) bool {
 	return bytes.Compare(t1[:], t2[:]) > 0
 }

tai64n/tai64n_test.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tai64n
@@ -10,17 +10,31 @@ import (
 	"time"
 )
 
-/* Testing the essential property of the timestamp
- * as used by WireGuard.
- */
+// Test that timestamps are monotonic as required by Wireguard and that
+// nanosecond-level information is whitened to prevent side channel attacks.
 func TestMonotonic(t *testing.T) {
-	old := Now()
-	for i := 0; i < 10000; i++ {
-		time.Sleep(time.Nanosecond)
-		next := Now()
-		if !next.After(old) {
-			t.Error("TAI64N, not monotonically increasing on nano-second scale")
+	startTime := time.Unix(0, 123456789) // a nontrivial bit pattern
+	// Whitening should reduce timestamp granularity
+	// to more than 10 but fewer than 20 milliseconds.
+	tests := []struct {
+		name      string
+		t1, t2    time.Time
+		wantAfter bool
+	}{
+		{"after_10_ns", startTime, startTime.Add(10 * time.Nanosecond), false},
+		{"after_10_us", startTime, startTime.Add(10 * time.Microsecond), false},
+		{"after_1_ms", startTime, startTime.Add(time.Millisecond), false},
+		{"after_10_ms", startTime, startTime.Add(10 * time.Millisecond), false},
+		{"after_20_ms", startTime, startTime.Add(20 * time.Millisecond), true},
 	}
-		old = next
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ts1, ts2 := stamp(tt.t1), stamp(tt.t2)
+			got := ts2.After(ts1)
+			if got != tt.wantAfter {
+				t.Errorf("after = %v; want %v", got, tt.wantAfter)
+			}
+		})
 	}
 }

tun/operateonfd.go

@@ -0,0 +1,24 @@
+// +build !windows
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package tun
+
+import (
+	"fmt"
+)
+
+func (tun *NativeTun) operateOnFd(fn func(fd uintptr)) {
+	sysconn, err := tun.tunFile.SyscallConn()
+	if err != nil {
+		tun.errors <- fmt.Errorf("unable to find sysconn for tunfile: %s", err.Error())
+		return
+	}
+	err = sysconn.Control(fn)
+	if err != nil {
+		tun.errors <- fmt.Errorf("unable to control sysconn for tunfile: %s", err.Error())
+	}
+}

tun/tun.go

@@ -1,26 +1,29 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
 
-import "os"
-
-type TUNEvent int
-
-const (
-	TUNEventUp = 1 << iota
-	TUNEventDown
-	TUNEventMTUUpdate
+import (
+	"os"
 )
 
-type TUNDevice interface {
+type Event int
+
+const (
+	EventUp = 1 << iota
+	EventDown
+	EventMTUUpdate
+)
+
+type Device interface {
 	File() *os.File                 // returns the file descriptor of the device
 	Read([]byte, int) (int, error)  // read a packet from the device (without any additional headers)
 	Write([]byte, int) (int, error) // writes a packet to the device (without any additional headers)
+	Flush() error                   // flush all previous writes to the device
 	MTU() (int, error)              // returns the MTU of the device
 	Name() (string, error)          // fetches and returns the current name
-	Events() chan TUNEvent          // returns a constant channel of events related to the device
+	Events() chan Event             // returns a constant channel of events related to the device
 	Close() error                   // stops the device and closes the event channel
 }

tun/tun_darwin.go

@@ -1,53 +1,50 @@
-// +build !ios
-
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
 
 import (
-	"errors"
 	"fmt"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
 	"io/ioutil"
 	"net"
 	"os"
 	"syscall"
+	"time"
 	"unsafe"
+
+	"golang.org/x/net/ipv6"
+	"golang.org/x/sys/unix"
 )
 
 const utunControlName = "com.apple.net.utun_control"
 
-// _CTLIOCGINFO value derived from /usr/include/sys/{kern_control,ioccom}.h
-const _CTLIOCGINFO = (0x40000000 | 0x80000000) | ((100 & 0x1fff) << 16) | uint32(byte('N'))<<8 | 3
-
-// sockaddr_ctl specifeid in /usr/include/sys/kern_control.h
-type sockaddrCtl struct {
-	scLen      uint8
-	scFamily   uint8
-	ssSysaddr  uint16
-	scID       uint32
-	scUnit     uint32
-	scReserved [5]uint32
-}
-
-type nativeTun struct {
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
-	fd          uintptr
-	rwcancel    *rwcancel.RWCancel
-	events      chan TUNEvent
+	events      chan Event
 	errors      chan error
 	routeSocket int
 }
 
-var sockaddrCtlSize uintptr = 32
+func retryInterfaceByIndex(index int) (iface *net.Interface, err error) {
+	for i := 0; i < 20; i++ {
+		iface, err = net.InterfaceByIndex(index)
+		if err != nil {
+			if opErr, ok := err.(*net.OpError); ok {
+				if syscallErr, ok := opErr.Err.(*os.SyscallError); ok && syscallErr.Err == syscall.ENOMEM {
+					time.Sleep(time.Duration(i) * time.Second / 3)
+					continue
+				}
+			}
+		}
+		return iface, err
+	}
+	return nil, err
+}
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -79,7 +76,7 @@ func (tun *nativeTun) routineRouteListener(tunIfindex int) {
 			continue
 		}
 
-		iface, err := net.InterfaceByIndex(ifindex)
+		iface, err := retryInterfaceByIndex(ifindex)
 		if err != nil {
 			tun.errors <- err
 			return
@@ -88,22 +85,22 @@ func (tun *nativeTun) routineRouteListener(tunIfindex int) {
 		// Up / Down event
 		up := (iface.Flags & net.FlagUp) != 0
 		if up != statusUp && up {
-			tun.events <- TUNEventUp
+			tun.events <- EventUp
 		}
 		if up != statusUp && !up {
-			tun.events <- TUNEventDown
+			tun.events <- EventDown
 		}
 		statusUp = up
 
 		// MTU changes
 		if iface.MTU != statusMTU {
-			tun.events <- TUNEventMTUUpdate
+			tun.events <- EventMTUUpdate
 		}
 		statusMTU = iface.MTU
 	}
 }
 
-func CreateTUN(name string, mtu int) (TUNDevice, error) {
+func CreateTUN(name string, mtu int) (Device, error) {
 	ifIndex := -1
 	if name != "utun" {
 		_, err := fmt.Sscanf(name, "utun%d", &ifIndex)
@@ -118,64 +115,44 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 		return nil, err
 	}
 
-	var ctlInfo = &struct {
-		ctlID   uint32
-		ctlName [96]byte
-	}{}
-
-	copy(ctlInfo.ctlName[:], []byte(utunControlName))
-
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(_CTLIOCGINFO),
-		uintptr(unsafe.Pointer(ctlInfo)),
-	)
-
-	if errno != 0 {
-		return nil, fmt.Errorf("_CTLIOCGINFO: %v", errno)
+	ctlInfo := &unix.CtlInfo{}
+	copy(ctlInfo.Name[:], []byte(utunControlName))
+	err = unix.IoctlCtlInfo(fd, ctlInfo)
+	if err != nil {
+		return nil, fmt.Errorf("IoctlGetCtlInfo: %w", err)
 	}
 
-	sc := sockaddrCtl{
-		scLen:     uint8(sockaddrCtlSize),
-		scFamily:  unix.AF_SYSTEM,
-		ssSysaddr: 2,
-		scID:      ctlInfo.ctlID,
-		scUnit:    uint32(ifIndex) + 1,
+	sc := &unix.SockaddrCtl{
+		ID:   ctlInfo.Id,
+		Unit: uint32(ifIndex) + 1,
 	}
 
-	scPointer := unsafe.Pointer(&sc)
-
-	_, _, errno = unix.RawSyscall(
-		unix.SYS_CONNECT,
-		uintptr(fd),
-		uintptr(scPointer),
-		uintptr(sockaddrCtlSize),
-	)
-
-	if errno != 0 {
-		return nil, fmt.Errorf("SYS_CONNECT: %v", errno)
+	err = unix.Connect(fd, sc)
+	if err != nil {
+		return nil, err
 	}
 
+	err = syscall.SetNonblock(fd, true)
+	if err != nil {
+		return nil, err
+	}
 	tun, err := CreateTUNFromFile(os.NewFile(uintptr(fd), ""), mtu)
 
 	if err == nil && name == "utun" {
 		fname := os.Getenv("WG_TUN_NAME_FILE")
 		if fname != "" {
-			ioutil.WriteFile(fname, []byte(tun.(*nativeTun).name+"\n"), 0400)
+			ioutil.WriteFile(fname, []byte(tun.(*NativeTun).name+"\n"), 0400)
 		}
 	}
 
 	return tun, err
 }
 
-func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
-
-	tun := &nativeTun{
+func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
+	tun := &NativeTun{
 		tunFile: file,
-		fd:      file.Fd(),
-		events:  make(chan TUNEvent, 10),
-		errors:  make(chan error, 1),
+		events:  make(chan Event, 10),
+		errors:  make(chan error, 5),
 	}
 
 	name, err := tun.Name()
@@ -196,12 +173,6 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 		return nil, err
 	}
 
-	tun.rwcancel, err = rwcancel.NewRWCancel(int(tun.fd))
-	if err != nil {
-		tun.tunFile.Close()
-		return nil, err
-	}
-
 	tun.routeSocket, err = unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {
 		tun.tunFile.Close()
@@ -210,47 +181,43 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 
 	go tun.routineRouteListener(tunIfindex)
 
+	if mtu > 0 {
 		err = tun.setMTU(mtu)
 		if err != nil {
 			tun.Close()
 			return nil, err
 		}
+	}
 
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
-
-	var ifName struct {
-		name [16]byte
-	}
-	ifNameSize := uintptr(16)
-
-	_, _, errno := unix.Syscall6(
-		unix.SYS_GETSOCKOPT,
-		uintptr(tun.fd),
+func (tun *NativeTun) Name() (string, error) {
+	var err error
+	tun.operateOnFd(func(fd uintptr) {
+		tun.name, err = unix.GetsockoptString(
+			int(fd),
 			2, /* #define SYSPROTO_CONTROL 2 */
 			2, /* #define UTUN_OPT_IFNAME 2 */
-		uintptr(unsafe.Pointer(&ifName)),
-		uintptr(unsafe.Pointer(&ifNameSize)), 0)
+		)
+	})
 
-	if errno != 0 {
-		return "", fmt.Errorf("SYS_GETSOCKOPT: %v", errno)
+	if err != nil {
+		return "", fmt.Errorf("GetSockoptString: %w", err)
 	}
 
-	tun.name = string(ifName.name[:ifNameSize-1])
 	return tun.name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan Event {
 	return tun.events
 }
 
-func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -264,19 +231,7 @@ func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
-	for {
-		n, err := tun.doRead(buff, offset)
-		if err == nil || !rwcancel.RetryAfterError(err) {
-			return n, err
-		}
-		if !tun.rwcancel.ReadyRead() {
-			return 0, errors.New("tun device closed")
-		}
-	}
-}
-
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -299,32 +254,27 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
-	var err3 error
-	err1 := tun.rwcancel.Cancel()
-	err2 := tun.tunFile.Close()
+func (tun *NativeTun) Flush() error {
+	// TODO: can flushing be implemented by buffering and using sendmmsg?
+	return nil
+}
+
+func (tun *NativeTun) Close() error {
+	var err2 error
+	err1 := tun.tunFile.Close()
 	if tun.routeSocket != -1 {
 		unix.Shutdown(tun.routeSocket, unix.SHUT_RDWR)
-		err3 = unix.Close(tun.routeSocket)
-		tun.routeSocket = -1
+		err2 = unix.Close(tun.routeSocket)
 	} else if tun.events != nil {
 		close(tun.events)
 	}
 	if err1 != nil {
 		return err1
 	}
-	if err2 != nil {
 	return err2
-	}
-	return err3
 }
 
-func (tun *nativeTun) setMTU(n int) error {
-
-	// open datagram socket
-
-	var fd int
-
+func (tun *NativeTun) setMTU(n int) error {
 	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
@@ -337,29 +287,18 @@ func (tun *nativeTun) setMTU(n int) error {
 
 	defer unix.Close(fd)
 
-	// do ioctl call
-
-	var ifr [32]byte
-	copy(ifr[:], tun.name)
-	*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])) = uint32(n)
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCSIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return fmt.Errorf("failed to set MTU on %s", tun.name)
+	var ifr unix.IfreqMTU
+	copy(ifr.Name[:], tun.name)
+	ifr.MTU = int32(n)
+	err = unix.IoctlSetIfreqMTU(fd, &ifr)
+	if err != nil {
+		return fmt.Errorf("failed to set MTU on %s: %w", tun.name, err)
 	}
 
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
-
-	// open datagram socket
-
+func (tun *NativeTun) MTU() (int, error) {
 	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
@@ -372,19 +311,10 @@ func (tun *nativeTun) MTU() (int, error) {
 
 	defer unix.Close(fd)
 
-	// do ioctl call
-
-	var ifr [64]byte
-	copy(ifr[:], tun.name)
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCGIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-	if errno != 0 {
-		return 0, fmt.Errorf("failed to get MTU on %s", tun.name)
+	ifr, err := unix.IoctlGetIfreqMTU(fd, tun.name)
+	if err != nil {
+		return 0, fmt.Errorf("failed to get MTU on %s: %w", tun.name, err)
 	}
 
-	return int(*(*int32)(unsafe.Pointer(&ifr[16]))), nil
+	return int(ifr.MTU), nil
 }

tun/tun_freebsd.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -9,20 +9,30 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
 	"net"
 	"os"
 	"syscall"
 	"unsafe"
+
+	"golang.org/x/net/ipv6"
+	"golang.org/x/sys/unix"
 )
 
 // _TUNSIFHEAD, value derived from sys/net/{if_tun,ioccom}.h
 // const _TUNSIFHEAD = ((0x80000000) | (((4) & ((1 << 13) - 1) ) << 16) | (uint32(byte('t')) << 8) | (96))
-const _TUNSIFHEAD = 0x80047460
-const _TUNSIFMODE = 0x8004745e
-const _TUNSIFPID = 0x2000745f
+const (
+	_TUNSIFHEAD = 0x80047460
+	_TUNSIFMODE = 0x8004745e
+	_TUNSIFPID  = 0x2000745f
+)
+
+// TODO: move into x/sys/unix
+const (
+	SIOCGIFINFO_IN6        = 0xc048696c
+	SIOCSIFINFO_IN6        = 0xc048696d
+	ND6_IFF_AUTO_LINKLOCAL = 0x20
+	ND6_IFF_NO_DAD         = 0x100
+)
 
 // Iface status string max len
 const _IFSTATMAX = 800
@@ -33,7 +43,7 @@ const SIZEOF_UINTPTR = 4 << (^uintptr(0) >> 32 & 1)
 type ifreq_ptr struct {
 	Name [unix.IFNAMSIZ]byte
 	Data uintptr
-	Pad0 [24 - SIZEOF_UINTPTR]byte
+	Pad0 [16 - SIZEOF_UINTPTR]byte
 }
 
 // Structure for iface mtu get/set ioctls
@@ -49,17 +59,32 @@ type ifstat struct {
 	Ascii   [_IFSTATMAX]byte
 }
 
-type nativeTun struct {
+// Structures for nd6 flag manipulation
+type in6_ndireq struct {
+	Name          [unix.IFNAMSIZ]byte
+	Linkmtu       uint32
+	Maxmtu        uint32
+	Basereachable uint32
+	Reachable     uint32
+	Retrans       uint32
+	Flags         uint32
+	Recalctm      int
+	Chlim         uint8
+	Initialized   uint8
+	Randomseed0   [8]byte
+	Randomseed1   [8]byte
+	Randomid      [8]byte
+}
+
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
-	fd          uintptr
-	rwcancel    *rwcancel.RWCancel
-	events      chan TUNEvent
+	events      chan Event
 	errors      chan error
 	routeSocket int
 }
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -100,16 +125,16 @@ func (tun *nativeTun) routineRouteListener(tunIfindex int) {
 		// Up / Down event
 		up := (iface.Flags & net.FlagUp) != 0
 		if up != statusUp && up {
-			tun.events <- TUNEventUp
+			tun.events <- EventUp
 		}
 		if up != statusUp && !up {
-			tun.events <- TUNEventDown
+			tun.events <- EventDown
 		}
 		statusUp = up
 
 		// MTU changes
 		if iface.MTU != statusMTU {
-			tun.events <- TUNEventMTUUpdate
+			tun.events <- EventMTUUpdate
 		}
 		statusMTU = iface.MTU
 	}
@@ -194,23 +219,18 @@ func tunName(fd uintptr) (string, error) {
 
 // Destroy a named system interface
 func tunDestroy(name string) error {
-	// open control socket
+	// Open control socket.
 	var fd int
-
 	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
 		0,
 	)
-
 	if err != nil {
 		return err
 	}
-
 	defer unix.Close(fd)
 
-	// do ioctl call
-
 	var ifr [32]byte
 	copy(ifr[:], name)
 	_, _, errno := unix.Syscall(
@@ -219,7 +239,6 @@ func tunDestroy(name string) error {
 		uintptr(unix.SIOCIFDESTROY),
 		uintptr(unsafe.Pointer(&ifr[0])),
 	)
-
 	if errno != 0 {
 		return fmt.Errorf("failed to destroy interface %s: %s", name, errno.Error())
 	}
@@ -227,7 +246,7 @@ func tunDestroy(name string) error {
 	return nil
 }
 
-func CreateTUN(name string, mtu int) (TUNDevice, error) {
+func CreateTUN(name string, mtu int) (Device, error) {
 	if len(name) > unix.IFNAMSIZ-1 {
 		return nil, errors.New("interface name too long")
 	}
@@ -239,12 +258,15 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 	}
 
 	tunFile, err := os.OpenFile("/dev/tun", unix.O_RDWR, 0)
-
 	if err != nil {
 		return nil, err
 	}
-	tunfd := tunFile.Fd()
-	assignedName, err := tunName(tunfd)
+
+	tun := NativeTun{tunFile: tunFile}
+	var assignedName string
+	tun.operateOnFd(func(fd uintptr) {
+		assignedName, err = tunName(fd)
+	})
 	if err != nil {
 		tunFile.Close()
 		return nil, err
@@ -252,41 +274,82 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 
 	// Enable ifhead mode, otherwise tun will complain if it gets a non-AF_INET packet
 	ifheadmode := 1
-	_, _, errno := unix.Syscall(
+	var errno syscall.Errno
+	tun.operateOnFd(func(fd uintptr) {
+		_, _, errno = unix.Syscall(
 			unix.SYS_IOCTL,
-		uintptr(tunfd),
+			fd,
 			uintptr(_TUNSIFHEAD),
 			uintptr(unsafe.Pointer(&ifheadmode)),
 		)
+	})
 
 	if errno != 0 {
-		return nil, fmt.Errorf("error %s", errno.Error())
+		tunFile.Close()
+		tunDestroy(assignedName)
+		return nil, fmt.Errorf("Unable to put into IFHEAD mode: %w", errno)
 	}
 
-	// Rename tun interface
-
-	// Open control socket
+	// Open control sockets
 	confd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
 		0,
 	)
-
 	if err != nil {
+		tunFile.Close()
+		tunDestroy(assignedName)
 		return nil, err
 	}
-
 	defer unix.Close(confd)
+	confd6, err := unix.Socket(
+		unix.AF_INET6,
+		unix.SOCK_DGRAM,
+		0,
+	)
+	if err != nil {
+		tunFile.Close()
+		tunDestroy(assignedName)
+		return nil, err
+	}
+	defer unix.Close(confd6)
 
-	// set up struct for iface rename
+	// Disable link-local v6, not just because WireGuard doesn't do that anyway, but
+	// also because there are serious races with attaching and detaching LLv6 addresses
+	// in relation to interface lifetime within the FreeBSD kernel.
+	var ndireq in6_ndireq
+	copy(ndireq.Name[:], assignedName)
+	_, _, errno = unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(confd6),
+		uintptr(SIOCGIFINFO_IN6),
+		uintptr(unsafe.Pointer(&ndireq)),
+	)
+	if errno != 0 {
+		tunFile.Close()
+		tunDestroy(assignedName)
+		return nil, fmt.Errorf("Unable to get nd6 flags for %s: %w", assignedName, errno)
+	}
+	ndireq.Flags = ndireq.Flags &^ ND6_IFF_AUTO_LINKLOCAL
+	ndireq.Flags = ndireq.Flags | ND6_IFF_NO_DAD
+	_, _, errno = unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(confd6),
+		uintptr(SIOCSIFINFO_IN6),
+		uintptr(unsafe.Pointer(&ndireq)),
+	)
+	if errno != 0 {
+		tunFile.Close()
+		tunDestroy(assignedName)
+		return nil, fmt.Errorf("Unable to set nd6 flags for %s: %w", assignedName, errno)
+	}
+
+	// Rename the interface
 	var newnp [unix.IFNAMSIZ]byte
 	copy(newnp[:], name)
-
 	var ifr ifreq_ptr
 	copy(ifr.Name[:], assignedName)
 	ifr.Data = uintptr(unsafe.Pointer(&newnp[0]))
-
-	//do actual ioctl to rename iface
 	_, _, errno = unix.Syscall(
 		unix.SYS_IOCTL,
 		uintptr(confd),
@@ -295,19 +358,18 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 	)
 	if errno != 0 {
 		tunFile.Close()
-		tunDestroy(name)
-		return nil, fmt.Errorf("failed to rename %s to %s: %s", assignedName, name, errno.Error())
+		tunDestroy(assignedName)
+		return nil, fmt.Errorf("Failed to rename %s to %s: %w", assignedName, name, errno)
 	}
 
 	return CreateTUNFromFile(tunFile, mtu)
 }
 
-func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
+func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
 
-	tun := &nativeTun{
+	tun := &NativeTun{
 		tunFile: file,
-		fd:      file.Fd(),
-		events:  make(chan TUNEvent, 10),
+		events:  make(chan Event, 10),
 		errors:  make(chan error, 1),
 	}
 
@@ -329,12 +391,6 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 		return nil, err
 	}
 
-	tun.rwcancel, err = rwcancel.NewRWCancel(int(tun.fd))
-	if err != nil {
-		tun.tunFile.Close()
-		return nil, err
-	}
-
 	tun.routeSocket, err = unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {
 		tun.tunFile.Close()
@@ -352,8 +408,12 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
-	name, err := tunName(tun.fd)
+func (tun *NativeTun) Name() (string, error) {
+	var name string
+	var err error
+	tun.operateOnFd(func(fd uintptr) {
+		name, err = tunName(fd)
+	})
 	if err != nil {
 		return "", err
 	}
@@ -361,15 +421,15 @@ func (tun *nativeTun) Name() (string, error) {
 	return name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan Event {
 	return tun.events
 }
 
-func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -383,19 +443,7 @@ func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
-	for {
-		n, err := tun.doRead(buff, offset)
-		if err == nil || !rwcancel.RetryAfterError(err) {
-			return n, err
-		}
-		if !tun.rwcancel.ReadyRead() {
-			return 0, errors.New("tun device closed")
-		}
-	}
-}
-
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -418,14 +466,18 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
-	var err4 error
-	err1 := tun.rwcancel.Cancel()
-	err2 := tun.tunFile.Close()
-	err3 := tunDestroy(tun.name)
+func (tun *NativeTun) Flush() error {
+	// TODO: can flushing be implemented by buffering and using sendmmsg?
+	return nil
+}
+
+func (tun *NativeTun) Close() error {
+	var err3 error
+	err1 := tun.tunFile.Close()
+	err2 := tunDestroy(tun.name)
 	if tun.routeSocket != -1 {
 		unix.Shutdown(tun.routeSocket, unix.SHUT_RDWR)
-		err4 = unix.Close(tun.routeSocket)
+		err3 = unix.Close(tun.routeSocket)
 		tun.routeSocket = -1
 	} else if tun.events != nil {
 		close(tun.events)
@@ -436,13 +488,10 @@ func (tun *nativeTun) Close() error {
 	if err2 != nil {
 		return err2
 	}
-	if err3 != nil {
 	return err3
-	}
-	return err4
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 	// open datagram socket
 
 	var fd int
@@ -479,7 +528,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	// open datagram socket
 
 	fd, err := unix.Socket(

tun/tun_linux.go

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -12,15 +12,15 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
-	"net"
 	"os"
-	"strconv"
 	"sync"
+	"syscall"
 	"time"
 	"unsafe"
+
+	"golang.org/x/net/ipv6"
+	"golang.org/x/sys/unix"
+	"golang.zx2c4.com/wireguard/rwcancel"
 )
 
 const (
@@ -28,43 +28,57 @@ const (
 	ifReqSize       = unix.IFNAMSIZ + 64
 )
 
-type nativeTun struct {
+type NativeTun struct {
 	tunFile                 *os.File
-	fd                      uintptr
-	fdCancel                *rwcancel.RWCancel
 	index                   int32      // if index
-	name                    string        // name of interface
 	errors                  chan error // async error handling
-	events                  chan TUNEvent // device related events
-	nopi                    bool          // the device was pased IFF_NO_PI
+	events                  chan Event // device related events
+	nopi                    bool       // the device was passed IFF_NO_PI
 	netlinkSock             int
 	netlinkCancel           *rwcancel.RWCancel
 	hackListenerClosed      sync.Mutex
 	statusListenersShutdown chan struct{}
+
+	nameOnce  sync.Once // guards calling initNameCache, which sets following fields
+	nameCache string    // name of interface
+	nameErr   error
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) routineHackListener() {
+func (tun *NativeTun) routineHackListener() {
 	defer tun.hackListenerClosed.Unlock()
 	/* This is needed for the detection to work across network namespaces
 	 * If you are reading this and know a better method, please get in touch.
 	 */
-	fd := int(tun.fd)
 	for {
-		_, err := unix.Write(fd, nil)
+		sysconn, err := tun.tunFile.SyscallConn()
+		if err != nil {
+			return
+		}
+		err2 := sysconn.Control(func(fd uintptr) {
+			_, err = unix.Write(int(fd), nil)
+		})
+		if err2 != nil {
+			return
+		}
 		switch err {
 		case unix.EINVAL:
-			tun.events <- TUNEventUp
+			// If the tunnel is up, it reports that write() is
+			// allowed but we provided invalid data.
+			tun.events <- EventUp
 		case unix.EIO:
-			tun.events <- TUNEventDown
+			// If the tunnel is down, it reports that no I/O
+			// is possible, without checking our provided data.
+			tun.events <- EventDown
 		default:
 			return
 		}
 		select {
 		case <-time.After(time.Second):
+			// nothing
 		case <-tun.statusListenersShutdown:
 			return
 		}
@@ -78,7 +92,7 @@ func createNetlinkSocket() (int, error) {
 	}
 	saddr := &unix.SockaddrNetlink{
 		Family: unix.AF_NETLINK,
-		Groups: uint32((1 << (unix.RTNLGRP_LINK - 1)) | (1 << (unix.RTNLGRP_IPV4_IFADDR - 1)) | (1 << (unix.RTNLGRP_IPV6_IFADDR - 1))),
+		Groups: unix.RTMGRP_LINK | unix.RTMGRP_IPV4_IFADDR | unix.RTMGRP_IPV6_IFADDR,
 	}
 	err = unix.Bind(sock, saddr)
 	if err != nil {
@@ -87,7 +101,7 @@ func createNetlinkSocket() (int, error) {
 	return sock, nil
 }
 
-func (tun *nativeTun) routineNetlinkListener() {
+func (tun *NativeTun) routineNetlinkListener() {
 	defer func() {
 		unix.Close(tun.netlinkSock)
 		tun.hackListenerClosed.Lock()
@@ -119,6 +133,7 @@ func (tun *nativeTun) routineNetlinkListener() {
 		default:
 		}
 
+		wasEverUp := false
 		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
 
 			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
@@ -141,14 +156,20 @@ func (tun *nativeTun) routineNetlinkListener() {
 				}
 
 				if info.Flags&unix.IFF_RUNNING != 0 {
-					tun.events <- TUNEventUp
+					tun.events <- EventUp
+					wasEverUp = true
 				}
 
 				if info.Flags&unix.IFF_RUNNING == 0 {
-					tun.events <- TUNEventDown
+					// Don't emit EventDown before we've ever emitted EventUp.
+					// This avoids a startup race with HackListener, which
+					// might detect Up before we have finished reporting Down.
+					if wasEverUp {
+						tun.events <- EventDown
+					}
 				}
 
-				tun.events <- TUNEventMTUUpdate
+				tun.events <- EventMTUUpdate
 
 			default:
 				remain = remain[hdr.Len:]
@@ -157,21 +178,12 @@ func (tun *nativeTun) routineNetlinkListener() {
 	}
 }
 
-func (tun *nativeTun) isUp() (bool, error) {
-	inter, err := net.InterfaceByName(tun.name)
-	return inter.Flags&net.FlagUp != 0, err
-}
-
-func getDummySock() (int, error) {
-	return unix.Socket(
+func getIFIndex(name string) (int32, error) {
+	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
 		0,
 	)
-}
-
-func getIFIndex(name string) (int32, error) {
-	fd, err := getDummySock()
 	if err != nil {
 		return 0, err
 	}
@@ -194,10 +206,13 @@ func getIFIndex(name string) (int32, error) {
 	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), nil
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
+	name, err := tun.Name()
+	if err != nil {
+		return err
+	}
 
 	// open datagram socket
-
 	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
@@ -211,9 +226,8 @@ func (tun *nativeTun) setMTU(n int) error {
 	defer unix.Close(fd)
 
 	// do ioctl call
-
 	var ifr [ifReqSize]byte
-	copy(ifr[:], tun.name)
+	copy(ifr[:], name)
 	*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])) = uint32(n)
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
@@ -229,10 +243,13 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
+	name, err := tun.Name()
+	if err != nil {
+		return 0, err
+	}
 
 	// open datagram socket
-
 	fd, err := unix.Socket(
 		unix.AF_INET,
 		unix.SOCK_DGRAM,
@@ -248,7 +265,7 @@ func (tun *nativeTun) MTU() (int, error) {
 	// do ioctl call
 
 	var ifr [ifReqSize]byte
-	copy(ifr[:], tun.name)
+	copy(ifr[:], name)
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
 		uintptr(fd),
@@ -256,34 +273,50 @@ func (tun *nativeTun) MTU() (int, error) {
 		uintptr(unsafe.Pointer(&ifr[0])),
 	)
 	if errno != 0 {
-		return 0, errors.New("failed to get MTU of TUN device: " + strconv.FormatInt(int64(errno), 10))
+		return 0, errors.New("failed to get MTU of TUN device: " + errno.Error())
 	}
 
 	return int(*(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
+	tun.nameOnce.Do(tun.initNameCache)
+	return tun.nameCache, tun.nameErr
+}
 
+func (tun *NativeTun) initNameCache() {
+	tun.nameCache, tun.nameErr = tun.nameSlow()
+}
+
+func (tun *NativeTun) nameSlow() (string, error) {
+	sysconn, err := tun.tunFile.SyscallConn()
+	if err != nil {
+		return "", err
+	}
 	var ifr [ifReqSize]byte
-	_, _, errno := unix.Syscall(
+	var errno syscall.Errno
+	err = sysconn.Control(func(fd uintptr) {
+		_, _, errno = unix.Syscall(
 			unix.SYS_IOCTL,
-		tun.fd,
+			fd,
 			uintptr(unix.TUNGETIFF),
 			uintptr(unsafe.Pointer(&ifr[0])),
 		)
+	})
+	if err != nil {
+		return "", errors.New("failed to get name of TUN device: " + err.Error())
+	}
 	if errno != 0 {
-		return "", errors.New("failed to get name of TUN device: " + strconv.FormatInt(int64(errno), 10))
+		return "", errors.New("failed to get name of TUN device: " + errno.Error())
 	}
-	nullStr := ifr[:]
-	i := bytes.IndexByte(nullStr, 0)
-	if i != -1 {
-		nullStr = nullStr[:i]
+	name := ifr[:]
+	if i := bytes.IndexByte(name, 0); i != -1 {
+		name = name[:i]
 	}
-	tun.name = string(nullStr)
-	return tun.name, nil
+	return string(name), nil
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	if tun.nopi {
 		buff = buff[offset:]
@@ -311,7 +344,12 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Flush() error {
+	// TODO: can flushing be implemented by buffering and using sendmmsg?
+	return nil
+}
+
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -329,23 +367,11 @@ func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
-	for {
-		n, err := tun.doRead(buff, offset)
-		if err == nil || !rwcancel.RetryAfterError(err) {
-			return n, err
-		}
-		if !tun.fdCancel.ReadyRead() {
-			return 0, errors.New("tun device closed")
-		}
-	}
-}
-
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan Event {
 	return tun.events
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	var err1 error
 	if tun.statusListenersShutdown != nil {
 		close(tun.statusListenersShutdown)
@@ -356,40 +382,22 @@ func (tun *nativeTun) Close() error {
 		close(tun.events)
 	}
 	err2 := tun.tunFile.Close()
-	err3 := tun.fdCancel.Cancel()
 
 	if err1 != nil {
 		return err1
 	}
-	if err2 != nil {
 	return err2
-	}
-	return err3
 }
 
-func CreateTUN(name string, mtu int) (TUNDevice, error) {
-
-	// open clone device
-
-	// HACK: we open it as a raw Fd first, so that f.nonblock=false
-	// when we make it into a file object.
+func CreateTUN(name string, mtu int) (Device, error) {
 	nfd, err := unix.Open(cloneDevicePath, os.O_RDWR, 0)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, fmt.Errorf("CreateTUN(%q) failed; %s does not exist", name, cloneDevicePath)
+		}
 		return nil, err
 	}
 
-	err = unix.SetNonblock(nfd, true)
-	if err != nil {
-		return nil, err
-	}
-
-	fd := os.NewFile(uintptr(nfd), cloneDevicePath)
-	if err != nil {
-		return nil, err
-	}
-
-	// create new device
-
 	var ifr [ifReqSize]byte
 	var flags uint16 = unix.IFF_TUN // | unix.IFF_NO_PI (disabled for TUN status hack)
 	nameBytes := []byte(name)
@@ -401,55 +409,53 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
-		fd.Fd(),
+		uintptr(nfd),
 		uintptr(unix.TUNSETIFF),
 		uintptr(unsafe.Pointer(&ifr[0])),
 	)
 	if errno != 0 {
 		return nil, errno
 	}
+	err = unix.SetNonblock(nfd, true)
+
+	// Note that the above -- open,ioctl,nonblock -- must happen prior to handing it to netpoll as below this line.
+
+	fd := os.NewFile(uintptr(nfd), cloneDevicePath)
+	if err != nil {
+		return nil, err
+	}
 
 	return CreateTUNFromFile(fd, mtu)
 }
 
-func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
-	tun := &nativeTun{
+func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
+	tun := &NativeTun{
 		tunFile:                 file,
-		fd:                      file.Fd(),
-		events:                  make(chan TUNEvent, 5),
+		events:                  make(chan Event, 5),
 		errors:                  make(chan error, 5),
 		statusListenersShutdown: make(chan struct{}),
 		nopi:                    false,
 	}
-	var err error
 
-	tun.fdCancel, err = rwcancel.NewRWCancel(int(tun.fd))
+	name, err := tun.Name()
 	if err != nil {
-		tun.tunFile.Close()
-		return nil, err
-	}
-
-	_, err = tun.Name()
-	if err != nil {
-		tun.tunFile.Close()
 		return nil, err
 	}
 
 	// start event listener
 
-	tun.index, err = getIFIndex(tun.name)
+	tun.index, err = getIFIndex(name)
 	if err != nil {
 		return nil, err
 	}
 
 	tun.netlinkSock, err = createNetlinkSocket()
 	if err != nil {
-		tun.tunFile.Close()
 		return nil, err
 	}
 	tun.netlinkCancel, err = rwcancel.NewRWCancel(tun.netlinkSock)
 	if err != nil {
-		tun.tunFile.Close()
+		unix.Close(tun.netlinkSock)
 		return nil, err
 	}
 
@@ -459,9 +465,28 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 
 	err = tun.setMTU(mtu)
 	if err != nil {
-		tun.Close()
+		unix.Close(tun.netlinkSock)
 		return nil, err
 	}
 
 	return tun, nil
 }
+
+func CreateUnmonitoredTUNFromFD(fd int) (Device, string, error) {
+	err := unix.SetNonblock(fd, true)
+	if err != nil {
+		return nil, "", err
+	}
+	file := os.NewFile(uintptr(fd), "/dev/tun")
+	tun := &NativeTun{
+		tunFile: file,
+		events:  make(chan Event, 5),
+		errors:  make(chan error, 5),
+		nopi:    true,
+	}
+	name, err := tun.Name()
+	if err != nil {
+		return nil, "", err
+	}
+	return tun, name, nil
+}

tun/tun_openbsd.go

@@ -1,21 +1,20 @@
-/* SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2018 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
 
 import (
-	"errors"
 	"fmt"
-	"git.zx2c4.com/wireguard-go/rwcancel"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
 	"io/ioutil"
 	"net"
 	"os"
 	"syscall"
 	"unsafe"
+
+	"golang.org/x/net/ipv6"
+	"golang.org/x/sys/unix"
 )
 
 // Structure for iface mtu get/set ioctls
@@ -27,16 +26,15 @@ type ifreq_mtu struct {
 
 const _TUNSIFMODE = 0x8004745d
 
-type nativeTun struct {
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
-	rwcancel    *rwcancel.RWCancel
-	events      chan TUNEvent
+	events      chan Event
 	errors      chan error
 	routeSocket int
 }
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -44,13 +42,41 @@ func (tun *nativeTun) routineRouteListener(tunIfindex int) {
 
 	defer close(tun.events)
 
+	check := func() bool {
+		iface, err := net.InterfaceByIndex(tunIfindex)
+		if err != nil {
+			tun.errors <- err
+			return true
+		}
+
+		// Up / Down event
+		up := (iface.Flags & net.FlagUp) != 0
+		if up != statusUp && up {
+			tun.events <- EventUp
+		}
+		if up != statusUp && !up {
+			tun.events <- EventDown
+		}
+		statusUp = up
+
+		// MTU changes
+		if iface.MTU != statusMTU {
+			tun.events <- EventMTUUpdate
+		}
+		statusMTU = iface.MTU
+		return false
+	}
+
+	if check() {
+		return
+	}
+
 	data := make([]byte, os.Getpagesize())
 	for {
-	retry:
 		n, err := unix.Read(tun.routeSocket, data)
 		if err != nil {
 			if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINTR {
-				goto retry
+				continue
 			}
 			tun.errors <- err
 			return
@@ -67,28 +93,9 @@ func (tun *nativeTun) routineRouteListener(tunIfindex int) {
 		if ifindex != tunIfindex {
 			continue
 		}
-
-		iface, err := net.InterfaceByIndex(ifindex)
-		if err != nil {
-			tun.errors <- err
+		if check() {
 			return
 		}
-
-		// Up / Down event
-		up := (iface.Flags & net.FlagUp) != 0
-		if up != statusUp && up {
-			tun.events <- TUNEventUp
-		}
-		if up != statusUp && !up {
-			tun.events <- TUNEventDown
-		}
-		statusUp = up
-
-		// MTU changes
-		if iface.MTU != statusMTU {
-			tun.events <- TUNEventMTUUpdate
-		}
-		statusMTU = iface.MTU
 	}
 }
 
@@ -102,7 +109,7 @@ func errorIsEBUSY(err error) bool {
 	return false
 }
 
-func CreateTUN(name string, mtu int) (TUNDevice, error) {
+func CreateTUN(name string, mtu int) (Device, error) {
 	ifIndex := -1
 	if name != "tun" {
 		_, err := fmt.Sscanf(name, "tun%d", &ifIndex)
@@ -134,18 +141,17 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 	if err == nil && name == "tun" {
 		fname := os.Getenv("WG_TUN_NAME_FILE")
 		if fname != "" {
-			ioutil.WriteFile(fname, []byte(tun.(*nativeTun).name+"\n"), 0400)
+			ioutil.WriteFile(fname, []byte(tun.(*NativeTun).name+"\n"), 0400)
 		}
 	}
 
 	return tun, err
 }
 
-func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
-
-	tun := &nativeTun{
+func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
+	tun := &NativeTun{
 		tunFile: file,
-		events:  make(chan TUNEvent, 10),
+		events:  make(chan Event, 10),
 		errors:  make(chan error, 1),
 	}
 
@@ -167,12 +173,6 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 		return nil, err
 	}
 
-	tun.rwcancel, err = rwcancel.NewRWCancel(int(file.Fd()))
-	if err != nil {
-		tun.tunFile.Close()
-		return nil, err
-	}
-
 	tun.routeSocket, err = unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {
 		tun.tunFile.Close()
@@ -181,16 +181,19 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 
 	go tun.routineRouteListener(tunIfindex)
 
+	currentMTU, err := tun.MTU()
+	if err != nil || currentMTU != mtu {
 		err = tun.setMTU(mtu)
 		if err != nil {
 			tun.Close()
 			return nil, err
 		}
+	}
 
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	gostat, err := tun.tunFile.Stat()
 	if err != nil {
 		tun.name = ""
@@ -201,15 +204,15 @@ func (tun *nativeTun) Name() (string, error) {
 	return tun.name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan Event {
 	return tun.events
 }
 
-func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -223,19 +226,7 @@ func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
-	for {
-		n, err := tun.doRead(buff, offset)
-		if err == nil || !rwcancel.RetryAfterError(err) {
-			return n, err
-		}
-		if !tun.rwcancel.ReadyRead() {
-			return 0, errors.New("tun device closed")
-		}
-	}
-}
-
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -258,13 +249,17 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
-	var err3 error
-	err1 := tun.rwcancel.Cancel()
-	err2 := tun.tunFile.Close()
+func (tun *NativeTun) Flush() error {
+	// TODO: can flushing be implemented by buffering and using sendmmsg?
+	return nil
+}
+
+func (tun *NativeTun) Close() error {
+	var err2 error
+	err1 := tun.tunFile.Close()
 	if tun.routeSocket != -1 {
 		unix.Shutdown(tun.routeSocket, unix.SHUT_RDWR)
-		err3 = unix.Close(tun.routeSocket)
+		err2 = unix.Close(tun.routeSocket)
 		tun.routeSocket = -1
 	} else if tun.events != nil {
 		close(tun.events)
@@ -272,13 +267,10 @@ func (tun *nativeTun) Close() error {
 	if err1 != nil {
 		return err1
 	}
-	if err2 != nil {
 	return err2
-	}
-	return err3
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 	// open datagram socket
 
 	var fd int
@@ -315,7 +307,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	// open datagram socket
 
 	fd, err := unix.Socket(

tun/tun_windows.go

@@ -0,0 +1,236 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2018-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package tun
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"sync/atomic"
+	"time"
+	_ "unsafe"
+
+	"golang.org/x/sys/windows"
+
+	"golang.zx2c4.com/wireguard/tun/wintun"
+)
+
+const (
+	rateMeasurementGranularity = uint64((time.Second / 2) / time.Nanosecond)
+	spinloopRateThreshold      = 800000000 / 8                                   // 800mbps
+	spinloopDuration           = uint64(time.Millisecond / 80 / time.Nanosecond) // ~1gbit/s
+)
+
+type rateJuggler struct {
+	current       uint64
+	nextByteCount uint64
+	nextStartTime int64
+	changing      int32
+}
+
+type NativeTun struct {
+	wt        *wintun.Adapter
+	handle    windows.Handle
+	close     bool
+	events    chan Event
+	errors    chan error
+	forcedMTU int
+	rate      rateJuggler
+	session   wintun.Session
+	readWait  windows.Handle
+}
+
+var WintunPool *wintun.Pool
+
+func init() {
+	var err error
+	WintunPool, err = wintun.MakePool("WireGuard")
+	if err != nil {
+		panic(fmt.Errorf("Failed to make pool: %w", err))
+	}
+}
+
+//go:linkname procyield runtime.procyield
+func procyield(cycles uint32)
+
+//go:linkname nanotime runtime.nanotime
+func nanotime() int64
+
+//
+// CreateTUN creates a Wintun interface with the given name. Should a Wintun
+// interface with the same name exist, it is reused.
+//
+func CreateTUN(ifname string, mtu int) (Device, error) {
+	return CreateTUNWithRequestedGUID(ifname, nil, mtu)
+}
+
+//
+// CreateTUNWithRequestedGUID creates a Wintun interface with the given name and
+// a requested GUID. Should a Wintun interface with the same name exist, it is reused.
+//
+func CreateTUNWithRequestedGUID(ifname string, requestedGUID *windows.GUID, mtu int) (Device, error) {
+	var err error
+	var wt *wintun.Adapter
+
+	// Does an interface with this name already exist?
+	wt, err = WintunPool.OpenAdapter(ifname)
+	if err == nil {
+		// If so, we delete it, in case it has weird residual configuration.
+		_, err = wt.Delete(true)
+		if err != nil {
+			return nil, fmt.Errorf("Error deleting already existing interface: %w", err)
+		}
+	}
+	wt, _, err = WintunPool.CreateAdapter(ifname, requestedGUID)
+	if err != nil {
+		return nil, fmt.Errorf("Error creating interface: %w", err)
+	}
+
+	forcedMTU := 1420
+	if mtu > 0 {
+		forcedMTU = mtu
+	}
+
+	tun := &NativeTun{
+		wt:        wt,
+		handle:    windows.InvalidHandle,
+		events:    make(chan Event, 10),
+		errors:    make(chan error, 1),
+		forcedMTU: forcedMTU,
+	}
+
+	tun.session, err = wt.StartSession(0x800000) // Ring capacity, 8 MiB
+	if err != nil {
+		_, err = tun.wt.Delete(false)
+		close(tun.events)
+		return nil, fmt.Errorf("Error starting session: %w", err)
+	}
+	tun.readWait = tun.session.ReadWaitEvent()
+	return tun, nil
+}
+
+func (tun *NativeTun) Name() (string, error) {
+	return tun.wt.Name()
+}
+
+func (tun *NativeTun) File() *os.File {
+	return nil
+}
+
+func (tun *NativeTun) Events() chan Event {
+	return tun.events
+}
+
+func (tun *NativeTun) Close() error {
+	tun.close = true
+	tun.session.End()
+	var err error
+	if tun.wt != nil {
+		_, err = tun.wt.Delete(false)
+	}
+	close(tun.events)
+	return err
+}
+
+func (tun *NativeTun) MTU() (int, error) {
+	return tun.forcedMTU, nil
+}
+
+// TODO: This is a temporary hack. We really need to be monitoring the interface in real time and adapting to MTU changes.
+func (tun *NativeTun) ForceMTU(mtu int) {
+	tun.forcedMTU = mtu
+}
+
+// Note: Read() and Write() assume the caller comes only from a single thread; there's no locking.
+
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
+retry:
+	select {
+	case err := <-tun.errors:
+		return 0, err
+	default:
+	}
+	start := nanotime()
+	shouldSpin := atomic.LoadUint64(&tun.rate.current) >= spinloopRateThreshold && uint64(start-atomic.LoadInt64(&tun.rate.nextStartTime)) <= rateMeasurementGranularity*2
+	for {
+		if tun.close {
+			return 0, os.ErrClosed
+		}
+		packet, err := tun.session.ReceivePacket()
+		switch err {
+		case nil:
+			packetSize := len(packet)
+			copy(buff[offset:], packet)
+			tun.session.ReleaseReceivePacket(packet)
+			tun.rate.update(uint64(packetSize))
+			return packetSize, nil
+		case windows.ERROR_NO_MORE_ITEMS:
+			if !shouldSpin || uint64(nanotime()-start) >= spinloopDuration {
+				windows.WaitForSingleObject(tun.readWait, windows.INFINITE)
+				goto retry
+			}
+			procyield(1)
+			continue
+		case windows.ERROR_HANDLE_EOF:
+			return 0, os.ErrClosed
+		case windows.ERROR_INVALID_DATA:
+			return 0, errors.New("Send ring corrupt")
+		}
+		return 0, fmt.Errorf("Read failed: %w", err)
+	}
+}
+
+func (tun *NativeTun) Flush() error {
+	return nil
+}
+
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
+	if tun.close {
+		return 0, os.ErrClosed
+	}
+
+	packetSize := len(buff) - offset
+	tun.rate.update(uint64(packetSize))
+
+	packet, err := tun.session.AllocateSendPacket(packetSize)
+	if err == nil {
+		copy(packet, buff[offset:])
+		tun.session.SendPacket(packet)
+		return packetSize, nil
+	}
+	switch err {
+	case windows.ERROR_HANDLE_EOF:
+		return 0, os.ErrClosed
+	case windows.ERROR_BUFFER_OVERFLOW:
+		return 0, nil // Dropping when ring is full.
+	}
+	return 0, fmt.Errorf("Write failed: %w", err)
+}
+
+// LUID returns Windows interface instance ID.
+func (tun *NativeTun) LUID() uint64 {
+	return tun.wt.LUID()
+}
+
+// RunningVersion returns the running version of the Wintun driver.
+func (tun *NativeTun) RunningVersion() (version uint32, err error) {
+	return wintun.RunningVersion()
+}
+
+func (rate *rateJuggler) update(packetLen uint64) {
+	now := nanotime()
+	total := atomic.AddUint64(&rate.nextByteCount, packetLen)
+	period := uint64(now - atomic.LoadInt64(&rate.nextStartTime))
+	if period >= rateMeasurementGranularity {
+		if !atomic.CompareAndSwapInt32(&rate.changing, 0, 1) {
+			return
+		}
+		atomic.StoreInt64(&rate.nextStartTime, now)
+		atomic.StoreUint64(&rate.current, total*uint64(time.Second/time.Nanosecond)/period)
+		atomic.StoreUint64(&rate.nextByteCount, 0)
+		atomic.StoreInt32(&rate.changing, 0)
+	}
+}

tun/tuntest/tuntest.go

@@ -0,0 +1,150 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package tuntest
+
+import (
+	"encoding/binary"
+	"io"
+	"net"
+	"os"
+
+	"golang.zx2c4.com/wireguard/tun"
+)
+
+func Ping(dst, src net.IP) []byte {
+	localPort := uint16(1337)
+	seq := uint16(0)
+
+	payload := make([]byte, 4)
+	binary.BigEndian.PutUint16(payload[0:], localPort)
+	binary.BigEndian.PutUint16(payload[2:], seq)
+
+	return genICMPv4(payload, dst, src)
+}
+
+// Checksum is the "internet checksum" from https://tools.ietf.org/html/rfc1071.
+func checksum(buf []byte, initial uint16) uint16 {
+	v := uint32(initial)
+	for i := 0; i < len(buf)-1; i += 2 {
+		v += uint32(binary.BigEndian.Uint16(buf[i:]))
+	}
+	if len(buf)%2 == 1 {
+		v += uint32(buf[len(buf)-1]) << 8
+	}
+	for v > 0xffff {
+		v = (v >> 16) + (v & 0xffff)
+	}
+	return ^uint16(v)
+}
+
+func genICMPv4(payload []byte, dst, src net.IP) []byte {
+	const (
+		icmpv4ProtocolNumber = 1
+		icmpv4Echo           = 8
+		icmpv4ChecksumOffset = 2
+		icmpv4Size           = 8
+		ipv4Size             = 20
+		ipv4TotalLenOffset   = 2
+		ipv4ChecksumOffset   = 10
+		ttl                  = 65
+	)
+
+	hdr := make([]byte, ipv4Size+icmpv4Size)
+
+	ip := hdr[0:ipv4Size]
+	icmpv4 := hdr[ipv4Size : ipv4Size+icmpv4Size]
+
+	// https://tools.ietf.org/html/rfc792
+	icmpv4[0] = icmpv4Echo // type
+	icmpv4[1] = 0          // code
+	chksum := ^checksum(icmpv4, checksum(payload, 0))
+	binary.BigEndian.PutUint16(icmpv4[icmpv4ChecksumOffset:], chksum)
+
+	// https://tools.ietf.org/html/rfc760 section 3.1
+	length := uint16(len(hdr) + len(payload))
+	ip[0] = (4 << 4) | (ipv4Size / 4)
+	binary.BigEndian.PutUint16(ip[ipv4TotalLenOffset:], length)
+	ip[8] = ttl
+	ip[9] = icmpv4ProtocolNumber
+	copy(ip[12:], src.To4())
+	copy(ip[16:], dst.To4())
+	chksum = ^checksum(ip[:], 0)
+	binary.BigEndian.PutUint16(ip[ipv4ChecksumOffset:], chksum)
+
+	var v []byte
+	v = append(v, hdr...)
+	v = append(v, payload...)
+	return []byte(v)
+}
+
+// TODO(crawshaw): find a reusable home for this. package devicetest?
+type ChannelTUN struct {
+	Inbound  chan []byte // incoming packets, closed on TUN close
+	Outbound chan []byte // outbound packets, blocks forever on TUN close
+
+	closed chan struct{}
+	events chan tun.Event
+	tun    chTun
+}
+
+func NewChannelTUN() *ChannelTUN {
+	c := &ChannelTUN{
+		Inbound:  make(chan []byte),
+		Outbound: make(chan []byte),
+		closed:   make(chan struct{}),
+		events:   make(chan tun.Event, 1),
+	}
+	c.tun.c = c
+	c.events <- tun.EventUp
+	return c
+}
+
+func (c *ChannelTUN) TUN() tun.Device {
+	return &c.tun
+}
+
+type chTun struct {
+	c *ChannelTUN
+}
+
+func (t *chTun) File() *os.File { return nil }
+
+func (t *chTun) Read(data []byte, offset int) (int, error) {
+	select {
+	case <-t.c.closed:
+		return 0, io.EOF // TODO(crawshaw): what is the correct error value?
+	case msg := <-t.c.Outbound:
+		return copy(data[offset:], msg), nil
+	}
+}
+
+// Write is called by the wireguard device to deliver a packet for routing.
+func (t *chTun) Write(data []byte, offset int) (int, error) {
+	if offset == -1 {
+		close(t.c.closed)
+		close(t.c.events)
+		return 0, io.EOF
+	}
+	msg := make([]byte, len(data)-offset)
+	copy(msg, data[offset:])
+	select {
+	case <-t.c.closed:
+		return 0, io.EOF // TODO(crawshaw): what is the correct error value?
+	case t.c.Inbound <- msg:
+		return len(data) - offset, nil
+	}
+}
+
+const DefaultMTU = 1420
+
+func (t *chTun) Flush() error           { return nil }
+func (t *chTun) MTU() (int, error)      { return DefaultMTU, nil }
+func (t *chTun) Name() (string, error)  { return "loopbackTun1", nil }
+func (t *chTun) Events() chan tun.Event { return t.c.events }
+func (t *chTun) Close() error {
+	t.Write(nil, -1)
+	return nil
+}

tun/wintun/dll_fromfile_windows.go

@@ -0,0 +1,50 @@
+// +build !load_wintun_from_rsrc
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package wintun
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+type lazyDLL struct {
+	Name   string
+	mu     sync.Mutex
+	module windows.Handle
+}
+
+func (d *lazyDLL) Load() error {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.module))) != nil {
+		return nil
+	}
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.module != 0 {
+		return nil
+	}
+
+	const (
+		LOAD_LIBRARY_SEARCH_APPLICATION_DIR = 0x00000200
+		LOAD_LIBRARY_SEARCH_SYSTEM32        = 0x00000800
+	)
+	module, err := windows.LoadLibraryEx(d.Name, 0, LOAD_LIBRARY_SEARCH_APPLICATION_DIR|LOAD_LIBRARY_SEARCH_SYSTEM32)
+	if err != nil {
+		return fmt.Errorf("Unable to load library: %w", err)
+	}
+
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
+	return nil
+}
+
+func (p *lazyProc) nameToAddr() (uintptr, error) {
+	return windows.GetProcAddress(p.dll.module, p.Name)
+}

tun/wintun/dll_fromrsrc_windows.go

@@ -0,0 +1,58 @@
+// +build load_wintun_from_rsrc
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package wintun
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+
+	"golang.zx2c4.com/wireguard/tun/wintun/memmod"
+	"golang.zx2c4.com/wireguard/tun/wintun/resource"
+)
+
+type lazyDLL struct {
+	Name   string
+	mu     sync.Mutex
+	module *memmod.Module
+}
+
+func (d *lazyDLL) Load() error {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.module))) != nil {
+		return nil
+	}
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.module != nil {
+		return nil
+	}
+
+	const ourModule windows.Handle = 0
+	resInfo, err := resource.FindByName(ourModule, d.Name, resource.RT_RCDATA)
+	if err != nil {
+		return fmt.Errorf("Unable to find \"%v\" RCDATA resource: %w", d.Name, err)
+	}
+	data, err := resource.Load(ourModule, resInfo)
+	if err != nil {
+		return fmt.Errorf("Unable to load resource: %w", err)
+	}
+	module, err := memmod.LoadLibrary(data)
+	if err != nil {
+		return fmt.Errorf("Unable to load library: %w", err)
+	}
+
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
+	return nil
+}
+
+func (p *lazyProc) nameToAddr() (uintptr, error) {
+	return p.dll.module.ProcAddressByName(p.Name)
+}

tun/wintun/dll_windows.go

@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package wintun
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+)
+
+func newLazyDLL(name string) *lazyDLL {
+	return &lazyDLL{Name: name}
+}
+
+func (d *lazyDLL) NewProc(name string) *lazyProc {
+	return &lazyProc{dll: d, Name: name}
+}
+
+type lazyProc struct {
+	Name string
+	mu   sync.Mutex
+	dll  *lazyDLL
+	addr uintptr
+}
+
+func (p *lazyProc) Find() error {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr))) != nil {
+		return nil
+	}
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.addr != 0 {
+		return nil
+	}
+
+	err := p.dll.Load()
+	if err != nil {
+		return fmt.Errorf("Error loading %v DLL: %w", p.dll.Name, err)
+	}
+	addr, err := p.nameToAddr()
+	if err != nil {
+		return fmt.Errorf("Error getting %v address: %w", p.Name, err)
+	}
+
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr)), unsafe.Pointer(addr))
+	return nil
+}
+
+func (p *lazyProc) Addr() uintptr {
+	err := p.Find()
+	if err != nil {
+		panic(err)
+	}
+	return p.addr
+}

tun/wintun/memmod/memmod_windows.go

@@ -0,0 +1,620 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import (
+	"errors"
+	"fmt"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+type addressList struct {
+	next    *addressList
+	address uintptr
+}
+
+func (head *addressList) free() {
+	for node := head; node != nil; node = node.next {
+		windows.VirtualFree(node.address, 0, windows.MEM_RELEASE)
+	}
+}
+
+type Module struct {
+	headers       *IMAGE_NT_HEADERS
+	codeBase      uintptr
+	modules       []windows.Handle
+	initialized   bool
+	isDLL         bool
+	isRelocated   bool
+	nameExports   map[string]uint16
+	entry         uintptr
+	blockedMemory *addressList
+}
+
+func (module *Module) headerDirectory(idx int) *IMAGE_DATA_DIRECTORY {
+	return &module.headers.OptionalHeader.DataDirectory[idx]
+}
+
+func (module *Module) copySections(address uintptr, size uintptr, old_headers *IMAGE_NT_HEADERS) error {
+	sections := module.headers.Sections()
+	for i := range sections {
+		if sections[i].SizeOfRawData == 0 {
+			// Section doesn't contain data in the dll itself, but may define uninitialized data.
+			sectionSize := old_headers.OptionalHeader.SectionAlignment
+			if sectionSize == 0 {
+				continue
+			}
+			dest, err := windows.VirtualAlloc(module.codeBase+uintptr(sections[i].VirtualAddress),
+				uintptr(sectionSize),
+				windows.MEM_COMMIT,
+				windows.PAGE_READWRITE)
+			if err != nil {
+				return fmt.Errorf("Error allocating section: %w", err)
+			}
+
+			// Always use position from file to support alignments smaller than page size (allocation above will align to page size).
+			dest = module.codeBase + uintptr(sections[i].VirtualAddress)
+			// NOTE: On 64bit systems we truncate to 32bit here but expand again later when "PhysicalAddress" is used.
+			sections[i].SetPhysicalAddress((uint32)(dest & 0xffffffff))
+			var dst []byte
+			unsafeSlice(unsafe.Pointer(&dst), a2p(dest), int(sectionSize))
+			for j := range dst {
+				dst[j] = 0
+			}
+			continue
+		}
+
+		if size < uintptr(sections[i].PointerToRawData+sections[i].SizeOfRawData) {
+			return errors.New("Incomplete section")
+		}
+
+		// Commit memory block and copy data from dll.
+		dest, err := windows.VirtualAlloc(module.codeBase+uintptr(sections[i].VirtualAddress),
+			uintptr(sections[i].SizeOfRawData),
+			windows.MEM_COMMIT,
+			windows.PAGE_READWRITE)
+		if err != nil {
+			return fmt.Errorf("Error allocating memory block: %w", err)
+		}
+
+		// Always use position from file to support alignments smaller than page size (allocation above will align to page size).
+		memcpy(
+			module.codeBase+uintptr(sections[i].VirtualAddress),
+			address+uintptr(sections[i].PointerToRawData),
+			uintptr(sections[i].SizeOfRawData))
+		// NOTE: On 64bit systems we truncate to 32bit here but expand again later when "PhysicalAddress" is used.
+		sections[i].SetPhysicalAddress((uint32)(dest & 0xffffffff))
+	}
+
+	return nil
+}
+
+func (module *Module) realSectionSize(section *IMAGE_SECTION_HEADER) uintptr {
+	size := section.SizeOfRawData
+	if size != 0 {
+		return uintptr(size)
+	}
+	if (section.Characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA) != 0 {
+		return uintptr(module.headers.OptionalHeader.SizeOfInitializedData)
+	}
+	if (section.Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA) != 0 {
+		return uintptr(module.headers.OptionalHeader.SizeOfUninitializedData)
+	}
+	return 0
+}
+
+type sectionFinalizeData struct {
+	address         uintptr
+	alignedAddress  uintptr
+	size            uintptr
+	characteristics uint32
+	last            bool
+}
+
+func (module *Module) finalizeSection(sectionData *sectionFinalizeData) error {
+	if sectionData.size == 0 {
+		return nil
+	}
+
+	if (sectionData.characteristics & IMAGE_SCN_MEM_DISCARDABLE) != 0 {
+		// Section is not needed any more and can safely be freed.
+		if sectionData.address == sectionData.alignedAddress &&
+			(sectionData.last ||
+				(sectionData.size%uintptr(module.headers.OptionalHeader.SectionAlignment)) == 0) {
+			// Only allowed to decommit whole pages.
+			windows.VirtualFree(sectionData.address, sectionData.size, windows.MEM_DECOMMIT)
+		}
+		return nil
+	}
+
+	// determine protection flags based on characteristics
+	var ProtectionFlags = [8]uint32{
+		windows.PAGE_NOACCESS,          // not writeable, not readable, not executable
+		windows.PAGE_EXECUTE,           // not writeable, not readable, executable
+		windows.PAGE_READONLY,          // not writeable, readable, not executable
+		windows.PAGE_EXECUTE_READ,      // not writeable, readable, executable
+		windows.PAGE_WRITECOPY,         // writeable, not readable, not executable
+		windows.PAGE_EXECUTE_WRITECOPY, // writeable, not readable, executable
+		windows.PAGE_READWRITE,         // writeable, readable, not executable
+		windows.PAGE_EXECUTE_READWRITE, // writeable, readable, executable
+	}
+	protect := ProtectionFlags[sectionData.characteristics>>29]
+	if (sectionData.characteristics & IMAGE_SCN_MEM_NOT_CACHED) != 0 {
+		protect |= windows.PAGE_NOCACHE
+	}
+
+	// Change memory access flags.
+	var oldProtect uint32
+	err := windows.VirtualProtect(sectionData.address, sectionData.size, protect, &oldProtect)
+	if err != nil {
+		return fmt.Errorf("Error protecting memory page: %w", err)
+	}
+
+	return nil
+}
+
+func (module *Module) finalizeSections() error {
+	sections := module.headers.Sections()
+	imageOffset := module.headers.OptionalHeader.imageOffset()
+	sectionData := sectionFinalizeData{}
+	sectionData.address = uintptr(sections[0].PhysicalAddress()) | imageOffset
+	sectionData.alignedAddress = alignDown(sectionData.address, uintptr(module.headers.OptionalHeader.SectionAlignment))
+	sectionData.size = module.realSectionSize(&sections[0])
+	sectionData.characteristics = sections[0].Characteristics
+
+	// Loop through all sections and change access flags.
+	for i := uint16(1); i < module.headers.FileHeader.NumberOfSections; i++ {
+		sectionAddress := uintptr(sections[i].PhysicalAddress()) | imageOffset
+		alignedAddress := alignDown(sectionAddress, uintptr(module.headers.OptionalHeader.SectionAlignment))
+		sectionSize := module.realSectionSize(&sections[i])
+		// Combine access flags of all sections that share a page.
+		// TODO: We currently share flags of a trailing large section with the page of a first small section. This should be optimized.
+		if sectionData.alignedAddress == alignedAddress || sectionData.address+sectionData.size > alignedAddress {
+			// Section shares page with previous.
+			if (sections[i].Characteristics&IMAGE_SCN_MEM_DISCARDABLE) == 0 || (sectionData.characteristics&IMAGE_SCN_MEM_DISCARDABLE) == 0 {
+				sectionData.characteristics = (sectionData.characteristics | sections[i].Characteristics) &^ IMAGE_SCN_MEM_DISCARDABLE
+			} else {
+				sectionData.characteristics |= sections[i].Characteristics
+			}
+			sectionData.size = sectionAddress + sectionSize - sectionData.address
+			continue
+		}
+
+		err := module.finalizeSection(&sectionData)
+		if err != nil {
+			return fmt.Errorf("Error finalizing section: %w", err)
+		}
+		sectionData.address = sectionAddress
+		sectionData.alignedAddress = alignedAddress
+		sectionData.size = sectionSize
+		sectionData.characteristics = sections[i].Characteristics
+	}
+	sectionData.last = true
+	err := module.finalizeSection(&sectionData)
+	if err != nil {
+		return fmt.Errorf("Error finalizing section: %w", err)
+	}
+	return nil
+}
+
+func (module *Module) executeTLS() {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_TLS)
+	if directory.VirtualAddress == 0 {
+		return
+	}
+
+	tls := (*IMAGE_TLS_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	callback := tls.AddressOfCallbacks
+	if callback != 0 {
+		for {
+			f := *(*uintptr)(a2p(callback))
+			if f == 0 {
+				break
+			}
+			syscall.Syscall(f, 3, module.codeBase, uintptr(DLL_PROCESS_ATTACH), uintptr(0))
+			callback += unsafe.Sizeof(f)
+		}
+	}
+}
+
+func (module *Module) performBaseRelocation(delta uintptr) (relocated bool, err error) {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_BASERELOC)
+	if directory.Size == 0 {
+		return delta == 0, nil
+	}
+
+	relocationHdr := (*IMAGE_BASE_RELOCATION)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	for relocationHdr.VirtualAddress > 0 {
+		dest := module.codeBase + uintptr(relocationHdr.VirtualAddress)
+
+		var relInfos []uint16
+		unsafeSlice(
+			unsafe.Pointer(&relInfos),
+			a2p(uintptr(unsafe.Pointer(relocationHdr))+unsafe.Sizeof(*relocationHdr)),
+			int((uintptr(relocationHdr.SizeOfBlock)-unsafe.Sizeof(*relocationHdr))/unsafe.Sizeof(relInfos[0])))
+		for _, relInfo := range relInfos {
+			// The upper 4 bits define the type of relocation.
+			relType := relInfo >> 12
+			// The lower 12 bits define the offset.
+			relOffset := uintptr(relInfo & 0xfff)
+
+			switch relType {
+			case IMAGE_REL_BASED_ABSOLUTE:
+				// Skip relocation.
+
+			case IMAGE_REL_BASED_LOW:
+				*(*uint16)(a2p(dest + relOffset)) += uint16(delta & 0xffff)
+				break
+
+			case IMAGE_REL_BASED_HIGH:
+				*(*uint16)(a2p(dest + relOffset)) += uint16(uint32(delta) >> 16)
+				break
+
+			case IMAGE_REL_BASED_HIGHLOW:
+				*(*uint32)(a2p(dest + relOffset)) += uint32(delta)
+
+			case IMAGE_REL_BASED_DIR64:
+				*(*uint64)(a2p(dest + relOffset)) += uint64(delta)
+
+			case IMAGE_REL_BASED_THUMB_MOV32:
+				inst := *(*uint32)(a2p(dest + relOffset))
+				imm16 := ((inst << 1) & 0x0800) + ((inst << 12) & 0xf000) +
+					((inst >> 20) & 0x0700) + ((inst >> 16) & 0x00ff)
+				if (inst & 0x8000fbf0) != 0x0000f240 {
+					return false, fmt.Errorf("Wrong Thumb2 instruction %08x, expected MOVW", inst)
+				}
+				imm16 += uint32(delta) & 0xffff
+				hiDelta := (uint32(delta&0xffff0000) >> 16) + ((imm16 & 0xffff0000) >> 16)
+				*(*uint32)(a2p(dest + relOffset)) = (inst & 0x8f00fbf0) + ((imm16 >> 1) & 0x0400) +
+					((imm16 >> 12) & 0x000f) +
+					((imm16 << 20) & 0x70000000) +
+					((imm16 << 16) & 0xff0000)
+				if hiDelta != 0 {
+					inst = *(*uint32)(a2p(dest + relOffset + 4))
+					imm16 = ((inst << 1) & 0x0800) + ((inst << 12) & 0xf000) +
+						((inst >> 20) & 0x0700) + ((inst >> 16) & 0x00ff)
+					if (inst & 0x8000fbf0) != 0x0000f2c0 {
+						return false, fmt.Errorf("Wrong Thumb2 instruction %08x, expected MOVT", inst)
+					}
+					imm16 += hiDelta
+					if imm16 > 0xffff {
+						return false, fmt.Errorf("Resulting immediate value won't fit: %08x", imm16)
+					}
+					*(*uint32)(a2p(dest + relOffset + 4)) = (inst & 0x8f00fbf0) +
+						((imm16 >> 1) & 0x0400) +
+						((imm16 >> 12) & 0x000f) +
+						((imm16 << 20) & 0x70000000) +
+						((imm16 << 16) & 0xff0000)
+				}
+
+			default:
+				return false, fmt.Errorf("Unsupported relocation: %w", relType)
+			}
+		}
+
+		// Advance to next relocation block.
+		relocationHdr = (*IMAGE_BASE_RELOCATION)(a2p(uintptr(unsafe.Pointer(relocationHdr)) + uintptr(relocationHdr.SizeOfBlock)))
+	}
+	return true, nil
+}
+
+func (module *Module) buildImportTable() error {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_IMPORT)
+	if directory.Size == 0 {
+		return nil
+	}
+
+	module.modules = make([]windows.Handle, 0, 16)
+	importDesc := (*IMAGE_IMPORT_DESCRIPTOR)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	for !isBadReadPtr(uintptr(unsafe.Pointer(importDesc)), unsafe.Sizeof(*importDesc)) && importDesc.Name != 0 {
+		handle, err := loadLibraryA((*byte)(a2p(module.codeBase + uintptr(importDesc.Name))))
+		if err != nil {
+			return fmt.Errorf("Error loading module: %w", err)
+		}
+		var thunkRef, funcRef *uintptr
+		if importDesc.OriginalFirstThunk() != 0 {
+			thunkRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.OriginalFirstThunk())))
+			funcRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+		} else {
+			// No hint table.
+			thunkRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+			funcRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+		}
+		for *thunkRef != 0 {
+			if IMAGE_SNAP_BY_ORDINAL(*thunkRef) {
+				*funcRef, err = getProcAddress(handle, (*byte)(a2p(IMAGE_ORDINAL(*thunkRef))))
+			} else {
+				thunkData := (*IMAGE_IMPORT_BY_NAME)(a2p(module.codeBase + *thunkRef))
+				*funcRef, err = getProcAddress(handle, &thunkData.Name[0])
+			}
+			if err != nil {
+				windows.FreeLibrary(handle)
+				return fmt.Errorf("Error getting function address: %w", err)
+			}
+			thunkRef = (*uintptr)(a2p(uintptr(unsafe.Pointer(thunkRef)) + unsafe.Sizeof(*thunkRef)))
+			funcRef = (*uintptr)(a2p(uintptr(unsafe.Pointer(funcRef)) + unsafe.Sizeof(*funcRef)))
+		}
+		module.modules = append(module.modules, handle)
+		importDesc = (*IMAGE_IMPORT_DESCRIPTOR)(a2p(uintptr(unsafe.Pointer(importDesc)) + unsafe.Sizeof(*importDesc)))
+	}
+	return nil
+}
+
+func (module *Module) buildNameExports() error {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+	if directory.Size == 0 {
+		return errors.New("No export table found")
+	}
+	exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	if exports.NumberOfNames == 0 || exports.NumberOfFunctions == 0 {
+		return errors.New("No functions exported")
+	}
+	if exports.NumberOfNames == 0 {
+		return errors.New("No functions exported by name")
+	}
+	var nameRefs []uint32
+	unsafeSlice(unsafe.Pointer(&nameRefs), a2p(module.codeBase+uintptr(exports.AddressOfNames)), int(exports.NumberOfNames))
+	var ordinals []uint16
+	unsafeSlice(unsafe.Pointer(&ordinals), a2p(module.codeBase+uintptr(exports.AddressOfNameOrdinals)), int(exports.NumberOfNames))
+	module.nameExports = make(map[string]uint16)
+	for i := range nameRefs {
+		nameArray := windows.BytePtrToString((*byte)(a2p(module.codeBase + uintptr(nameRefs[i]))))
+		module.nameExports[nameArray] = ordinals[i]
+	}
+	return nil
+}
+
+// LoadLibrary loads module image to memory.
+func LoadLibrary(data []byte) (module *Module, err error) {
+	addr := uintptr(unsafe.Pointer(&data[0]))
+	size := uintptr(len(data))
+	if size < unsafe.Sizeof(IMAGE_DOS_HEADER{}) {
+		return nil, errors.New("Incomplete IMAGE_DOS_HEADER")
+	}
+	dosHeader := (*IMAGE_DOS_HEADER)(a2p(addr))
+	if dosHeader.E_magic != IMAGE_DOS_SIGNATURE {
+		return nil, fmt.Errorf("Not an MS-DOS binary (provided: %x, expected: %x)", dosHeader.E_magic, IMAGE_DOS_SIGNATURE)
+	}
+	if (size < uintptr(dosHeader.E_lfanew)+unsafe.Sizeof(IMAGE_NT_HEADERS{})) {
+		return nil, errors.New("Incomplete IMAGE_NT_HEADERS")
+	}
+	oldHeader := (*IMAGE_NT_HEADERS)(a2p(addr + uintptr(dosHeader.E_lfanew)))
+	if oldHeader.Signature != IMAGE_NT_SIGNATURE {
+		return nil, fmt.Errorf("Not an NT binary (provided: %x, expected: %x)", oldHeader.Signature, IMAGE_NT_SIGNATURE)
+	}
+	if oldHeader.FileHeader.Machine != imageFileProcess {
+		return nil, fmt.Errorf("Foreign platform (provided: %x, expected: %x)", oldHeader.FileHeader.Machine, imageFileProcess)
+	}
+	if (oldHeader.OptionalHeader.SectionAlignment & 1) != 0 {
+		return nil, errors.New("Unaligned section")
+	}
+	lastSectionEnd := uintptr(0)
+	sections := oldHeader.Sections()
+	optionalSectionSize := oldHeader.OptionalHeader.SectionAlignment
+	for i := range sections {
+		var endOfSection uintptr
+		if sections[i].SizeOfRawData == 0 {
+			// Section without data in the DLL
+			endOfSection = uintptr(sections[i].VirtualAddress) + uintptr(optionalSectionSize)
+		} else {
+			endOfSection = uintptr(sections[i].VirtualAddress) + uintptr(sections[i].SizeOfRawData)
+		}
+		if endOfSection > lastSectionEnd {
+			lastSectionEnd = endOfSection
+		}
+	}
+	alignedImageSize := alignUp(uintptr(oldHeader.OptionalHeader.SizeOfImage), uintptr(oldHeader.OptionalHeader.SectionAlignment))
+	if alignedImageSize != alignUp(lastSectionEnd, uintptr(oldHeader.OptionalHeader.SectionAlignment)) {
+		return nil, errors.New("Section is not page-aligned")
+	}
+
+	module = &Module{isDLL: (oldHeader.FileHeader.Characteristics & IMAGE_FILE_DLL) != 0}
+	defer func() {
+		if err != nil {
+			module.Free()
+			module = nil
+		}
+	}()
+
+	// Reserve memory for image of library.
+	// TODO: Is it correct to commit the complete memory region at once? Calling DllEntry raises an exception if we don't.
+	module.codeBase, err = windows.VirtualAlloc(oldHeader.OptionalHeader.ImageBase,
+		alignedImageSize,
+		windows.MEM_RESERVE|windows.MEM_COMMIT,
+		windows.PAGE_READWRITE)
+	if err != nil {
+		// Try to allocate memory at arbitrary position.
+		module.codeBase, err = windows.VirtualAlloc(0,
+			alignedImageSize,
+			windows.MEM_RESERVE|windows.MEM_COMMIT,
+			windows.PAGE_READWRITE)
+		if err != nil {
+			err = fmt.Errorf("Error allocating code: %w", err)
+			return
+		}
+	}
+	err = module.check4GBBoundaries(alignedImageSize)
+	if err != nil {
+		err = fmt.Errorf("Error reallocating code: %w", err)
+		return
+	}
+
+	if size < uintptr(oldHeader.OptionalHeader.SizeOfHeaders) {
+		err = errors.New("Incomplete headers")
+		return
+	}
+	// Commit memory for headers.
+	headers, err := windows.VirtualAlloc(module.codeBase,
+		uintptr(oldHeader.OptionalHeader.SizeOfHeaders),
+		windows.MEM_COMMIT,
+		windows.PAGE_READWRITE)
+	if err != nil {
+		err = fmt.Errorf("Error allocating headers: %w", err)
+		return
+	}
+	// Copy PE header to code.
+	memcpy(headers, addr, uintptr(oldHeader.OptionalHeader.SizeOfHeaders))
+	module.headers = (*IMAGE_NT_HEADERS)(a2p(headers + uintptr(dosHeader.E_lfanew)))
+
+	// Update position.
+	module.headers.OptionalHeader.ImageBase = module.codeBase
+
+	// Copy sections from DLL file block to new memory location.
+	err = module.copySections(addr, size, oldHeader)
+	if err != nil {
+		err = fmt.Errorf("Error copying sections: %w", err)
+		return
+	}
+
+	// Adjust base address of imported data.
+	locationDelta := module.headers.OptionalHeader.ImageBase - oldHeader.OptionalHeader.ImageBase
+	if locationDelta != 0 {
+		module.isRelocated, err = module.performBaseRelocation(locationDelta)
+		if err != nil {
+			err = fmt.Errorf("Error relocating module: %w", err)
+			return
+		}
+	} else {
+		module.isRelocated = true
+	}
+
+	// Load required dlls and adjust function table of imports.
+	err = module.buildImportTable()
+	if err != nil {
+		err = fmt.Errorf("Error building import table: %w", err)
+		return
+	}
+
+	// Mark memory pages depending on section headers and release sections that are marked as "discardable".
+	err = module.finalizeSections()
+	if err != nil {
+		err = fmt.Errorf("Error finalizing sections: %w", err)
+		return
+	}
+
+	// TLS callbacks are executed BEFORE the main loading.
+	module.executeTLS()
+
+	// Get entry point of loaded module.
+	if module.headers.OptionalHeader.AddressOfEntryPoint != 0 {
+		module.entry = module.codeBase + uintptr(module.headers.OptionalHeader.AddressOfEntryPoint)
+		if module.isDLL {
+			// Notify library about attaching to process.
+			r0, _, _ := syscall.Syscall(module.entry, 3, module.codeBase, uintptr(DLL_PROCESS_ATTACH), 0)
+			successful := r0 != 0
+			if !successful {
+				err = windows.ERROR_DLL_INIT_FAILED
+				return
+			}
+			module.initialized = true
+		}
+	}
+
+	module.buildNameExports()
+	return
+}
+
+// Free releases module resources and unloads it.
+func (module *Module) Free() {
+	if module.initialized {
+		// Notify library about detaching from process.
+		syscall.Syscall(module.entry, 3, module.codeBase, uintptr(DLL_PROCESS_DETACH), 0)
+		module.initialized = false
+	}
+	if module.modules != nil {
+		// Free previously opened libraries.
+		for _, handle := range module.modules {
+			windows.FreeLibrary(handle)
+		}
+		module.modules = nil
+	}
+	if module.codeBase != 0 {
+		windows.VirtualFree(module.codeBase, 0, windows.MEM_RELEASE)
+		module.codeBase = 0
+	}
+	if module.blockedMemory != nil {
+		module.blockedMemory.free()
+		module.blockedMemory = nil
+	}
+}
+
+// ProcAddressByName returns function address by exported name.
+func (module *Module) ProcAddressByName(name string) (uintptr, error) {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+	if directory.Size == 0 {
+		return 0, errors.New("No export table found")
+	}
+	exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	if module.nameExports == nil {
+		return 0, errors.New("No functions exported by name")
+	}
+	if idx, ok := module.nameExports[name]; ok {
+		if uint32(idx) > exports.NumberOfFunctions {
+			return 0, errors.New("Ordinal number too high")
+		}
+		// AddressOfFunctions contains the RVAs to the "real" functions.
+		return module.codeBase + uintptr(*(*uint32)(a2p(module.codeBase + uintptr(exports.AddressOfFunctions) + uintptr(idx)*4))), nil
+	}
+	return 0, errors.New("Function not found by name")
+}
+
+// ProcAddressByOrdinal returns function address by exported ordinal.
+func (module *Module) ProcAddressByOrdinal(ordinal uint16) (uintptr, error) {
+	directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+	if directory.Size == 0 {
+		return 0, errors.New("No export table found")
+	}
+	exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+	if uint32(ordinal) < exports.Base {
+		return 0, errors.New("Ordinal number too low")
+	}
+	idx := ordinal - uint16(exports.Base)
+	if uint32(idx) > exports.NumberOfFunctions {
+		return 0, errors.New("Ordinal number too high")
+	}
+	// AddressOfFunctions contains the RVAs to the "real" functions.
+	return module.codeBase + uintptr(*(*uint32)(a2p(module.codeBase + uintptr(exports.AddressOfFunctions) + uintptr(idx)*4))), nil
+}
+
+func alignDown(value, alignment uintptr) uintptr {
+	return value & ^(alignment - 1)
+}
+
+func alignUp(value, alignment uintptr) uintptr {
+	return (value + alignment - 1) & ^(alignment - 1)
+}
+
+func a2p(addr uintptr) unsafe.Pointer {
+	return unsafe.Pointer(addr)
+}
+
+func memcpy(dst, src, size uintptr) {
+	var d, s []byte
+	unsafeSlice(unsafe.Pointer(&d), a2p(dst), int(size))
+	unsafeSlice(unsafe.Pointer(&s), a2p(src), int(size))
+	copy(d, s)
+}
+
+// unsafeSlice updates the slice slicePtr to be a slice
+// referencing the provided data with its length & capacity set to
+// lenCap.
+//
+// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
+// update callers to use unsafe.Slice instead of this.
+func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
+	type sliceHeader struct {
+		Data unsafe.Pointer
+		Len  int
+		Cap  int
+	}
+	h := (*sliceHeader)(slicePtr)
+	h.Data = data
+	h.Len = lenCap
+	h.Cap = lenCap
+}

tun/wintun/memmod/memmod_windows_32.go

@@ -0,0 +1,16 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+	return 0
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+	return
+}

tun/wintun/memmod/memmod_windows_386.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_I386

tun/wintun/memmod/memmod_windows_64.go

@@ -0,0 +1,36 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows"
+)
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+	return uintptr(opthdr.ImageBase & 0xffffffff00000000)
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+	for (module.codeBase >> 32) < ((module.codeBase + alignedImageSize) >> 32) {
+		node := &addressList{
+			next:    module.blockedMemory,
+			address: module.codeBase,
+		}
+		module.blockedMemory = node
+		module.codeBase, err = windows.VirtualAlloc(0,
+			alignedImageSize,
+			windows.MEM_RESERVE|windows.MEM_COMMIT,
+			windows.PAGE_READWRITE)
+		if err != nil {
+			return fmt.Errorf("Error allocating memory block: %w", err)
+		}
+	}
+	return
+}

tun/wintun/memmod/memmod_windows_amd64.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_AMD64

tun/wintun/memmod/memmod_windows_arm.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARMNT

tun/wintun/memmod/memmod_windows_arm64.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARM64

tun/wintun/memmod/mksyscall.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go syscall_windows.go

tun/wintun/memmod/syscall_windows.go

@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import "unsafe"
+
+const (
+	IMAGE_DOS_SIGNATURE    = 0x5A4D     // MZ
+	IMAGE_OS2_SIGNATURE    = 0x454E     // NE
+	IMAGE_OS2_SIGNATURE_LE = 0x454C     // LE
+	IMAGE_VXD_SIGNATURE    = 0x454C     // LE
+	IMAGE_NT_SIGNATURE     = 0x00004550 // PE00
+)
+
+// DOS .EXE header
+type IMAGE_DOS_HEADER struct {
+	E_magic    uint16     // Magic number
+	E_cblp     uint16     // Bytes on last page of file
+	E_cp       uint16     // Pages in file
+	E_crlc     uint16     // Relocations
+	E_cparhdr  uint16     // Size of header in paragraphs
+	E_minalloc uint16     // Minimum extra paragraphs needed
+	E_maxalloc uint16     // Maximum extra paragraphs needed
+	E_ss       uint16     // Initial (relative) SS value
+	E_sp       uint16     // Initial SP value
+	E_csum     uint16     // Checksum
+	E_ip       uint16     // Initial IP value
+	E_cs       uint16     // Initial (relative) CS value
+	E_lfarlc   uint16     // File address of relocation table
+	E_ovno     uint16     // Overlay number
+	E_res      [4]uint16  // Reserved words
+	E_oemid    uint16     // OEM identifier (for e_oeminfo)
+	E_oeminfo  uint16     // OEM information; e_oemid specific
+	E_res2     [10]uint16 // Reserved words
+	E_lfanew   int32      // File address of new exe header
+}
+
+// File header format
+type IMAGE_FILE_HEADER struct {
+	Machine              uint16
+	NumberOfSections     uint16
+	TimeDateStamp        uint32
+	PointerToSymbolTable uint32
+	NumberOfSymbols      uint32
+	SizeOfOptionalHeader uint16
+	Characteristics      uint16
+}
+
+const (
+	IMAGE_SIZEOF_FILE_HEADER = 20
+
+	IMAGE_FILE_RELOCS_STRIPPED         = 0x0001 // Relocation info stripped from file.
+	IMAGE_FILE_EXECUTABLE_IMAGE        = 0x0002 // File is executable  (i.e. no unresolved external references).
+	IMAGE_FILE_LINE_NUMS_STRIPPED      = 0x0004 // Line nunbers stripped from file.
+	IMAGE_FILE_LOCAL_SYMS_STRIPPED     = 0x0008 // Local symbols stripped from file.
+	IMAGE_FILE_AGGRESIVE_WS_TRIM       = 0x0010 // Aggressively trim working set
+	IMAGE_FILE_LARGE_ADDRESS_AWARE     = 0x0020 // App can handle >2gb addresses
+	IMAGE_FILE_BYTES_REVERSED_LO       = 0x0080 // Bytes of machine word are reversed.
+	IMAGE_FILE_32BIT_MACHINE           = 0x0100 // 32 bit word machine.
+	IMAGE_FILE_DEBUG_STRIPPED          = 0x0200 // Debugging info stripped from file in .DBG file
+	IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP = 0x0400 // If Image is on removable media, copy and run from the swap file.
+	IMAGE_FILE_NET_RUN_FROM_SWAP       = 0x0800 // If Image is on Net, copy and run from the swap file.
+	IMAGE_FILE_SYSTEM                  = 0x1000 // System File.
+	IMAGE_FILE_DLL                     = 0x2000 // File is a DLL.
+	IMAGE_FILE_UP_SYSTEM_ONLY          = 0x4000 // File should only be run on a UP machine
+	IMAGE_FILE_BYTES_REVERSED_HI       = 0x8000 // Bytes of machine word are reversed.
+
+	IMAGE_FILE_MACHINE_UNKNOWN     = 0
+	IMAGE_FILE_MACHINE_TARGET_HOST = 0x0001 // Useful for indicating we want to interact with the host and not a WoW guest.
+	IMAGE_FILE_MACHINE_I386        = 0x014c // Intel 386.
+	IMAGE_FILE_MACHINE_R3000       = 0x0162 // MIPS little-endian, 0x160 big-endian
+	IMAGE_FILE_MACHINE_R4000       = 0x0166 // MIPS little-endian
+	IMAGE_FILE_MACHINE_R10000      = 0x0168 // MIPS little-endian
+	IMAGE_FILE_MACHINE_WCEMIPSV2   = 0x0169 // MIPS little-endian WCE v2
+	IMAGE_FILE_MACHINE_ALPHA       = 0x0184 // Alpha_AXP
+	IMAGE_FILE_MACHINE_SH3         = 0x01a2 // SH3 little-endian
+	IMAGE_FILE_MACHINE_SH3DSP      = 0x01a3
+	IMAGE_FILE_MACHINE_SH3E        = 0x01a4 // SH3E little-endian
+	IMAGE_FILE_MACHINE_SH4         = 0x01a6 // SH4 little-endian
+	IMAGE_FILE_MACHINE_SH5         = 0x01a8 // SH5
+	IMAGE_FILE_MACHINE_ARM         = 0x01c0 // ARM Little-Endian
+	IMAGE_FILE_MACHINE_THUMB       = 0x01c2 // ARM Thumb/Thumb-2 Little-Endian
+	IMAGE_FILE_MACHINE_ARMNT       = 0x01c4 // ARM Thumb-2 Little-Endian
+	IMAGE_FILE_MACHINE_AM33        = 0x01d3
+	IMAGE_FILE_MACHINE_POWERPC     = 0x01F0 // IBM PowerPC Little-Endian
+	IMAGE_FILE_MACHINE_POWERPCFP   = 0x01f1
+	IMAGE_FILE_MACHINE_IA64        = 0x0200 // Intel 64
+	IMAGE_FILE_MACHINE_MIPS16      = 0x0266 // MIPS
+	IMAGE_FILE_MACHINE_ALPHA64     = 0x0284 // ALPHA64
+	IMAGE_FILE_MACHINE_MIPSFPU     = 0x0366 // MIPS
+	IMAGE_FILE_MACHINE_MIPSFPU16   = 0x0466 // MIPS
+	IMAGE_FILE_MACHINE_AXP64       = IMAGE_FILE_MACHINE_ALPHA64
+	IMAGE_FILE_MACHINE_TRICORE     = 0x0520 // Infineon
+	IMAGE_FILE_MACHINE_CEF         = 0x0CEF
+	IMAGE_FILE_MACHINE_EBC         = 0x0EBC // EFI Byte Code
+	IMAGE_FILE_MACHINE_AMD64       = 0x8664 // AMD64 (K8)
+	IMAGE_FILE_MACHINE_M32R        = 0x9041 // M32R little-endian
+	IMAGE_FILE_MACHINE_ARM64       = 0xAA64 // ARM64 Little-Endian
+	IMAGE_FILE_MACHINE_CEE         = 0xC0EE
+)
+
+// Directory format
+type IMAGE_DATA_DIRECTORY struct {
+	VirtualAddress uint32
+	Size           uint32
+}
+
+const IMAGE_NUMBEROF_DIRECTORY_ENTRIES = 16
+
+type IMAGE_NT_HEADERS struct {
+	Signature      uint32
+	FileHeader     IMAGE_FILE_HEADER
+	OptionalHeader IMAGE_OPTIONAL_HEADER
+}
+
+func (ntheader *IMAGE_NT_HEADERS) Sections() []IMAGE_SECTION_HEADER {
+	return (*[0xffff]IMAGE_SECTION_HEADER)(unsafe.Pointer(
+		(uintptr)(unsafe.Pointer(ntheader)) +
+			unsafe.Offsetof(ntheader.OptionalHeader) +
+			uintptr(ntheader.FileHeader.SizeOfOptionalHeader)))[:ntheader.FileHeader.NumberOfSections]
+}
+
+const (
+	IMAGE_DIRECTORY_ENTRY_EXPORT         = 0  // Export Directory
+	IMAGE_DIRECTORY_ENTRY_IMPORT         = 1  // Import Directory
+	IMAGE_DIRECTORY_ENTRY_RESOURCE       = 2  // Resource Directory
+	IMAGE_DIRECTORY_ENTRY_EXCEPTION      = 3  // Exception Directory
+	IMAGE_DIRECTORY_ENTRY_SECURITY       = 4  // Security Directory
+	IMAGE_DIRECTORY_ENTRY_BASERELOC      = 5  // Base Relocation Table
+	IMAGE_DIRECTORY_ENTRY_DEBUG          = 6  // Debug Directory
+	IMAGE_DIRECTORY_ENTRY_COPYRIGHT      = 7  // (X86 usage)
+	IMAGE_DIRECTORY_ENTRY_ARCHITECTURE   = 7  // Architecture Specific Data
+	IMAGE_DIRECTORY_ENTRY_GLOBALPTR      = 8  // RVA of GP
+	IMAGE_DIRECTORY_ENTRY_TLS            = 9  // TLS Directory
+	IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG    = 10 // Load Configuration Directory
+	IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT   = 11 // Bound Import Directory in headers
+	IMAGE_DIRECTORY_ENTRY_IAT            = 12 // Import Address Table
+	IMAGE_DIRECTORY_ENTRY_DELAY_IMPORT   = 13 // Delay Load Import Descriptors
+	IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR = 14 // COM Runtime descriptor
+)
+
+const IMAGE_SIZEOF_SHORT_NAME = 8
+
+// Section header format
+type IMAGE_SECTION_HEADER struct {
+	Name                         [IMAGE_SIZEOF_SHORT_NAME]byte
+	physicalAddressOrVirtualSize uint32
+	VirtualAddress               uint32
+	SizeOfRawData                uint32
+	PointerToRawData             uint32
+	PointerToRelocations         uint32
+	PointerToLinenumbers         uint32
+	NumberOfRelocations          uint16
+	NumberOfLinenumbers          uint16
+	Characteristics              uint32
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) PhysicalAddress() uint32 {
+	return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetPhysicalAddress(addr uint32) {
+	ishdr.physicalAddressOrVirtualSize = addr
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) VirtualSize() uint32 {
+	return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetVirtualSize(addr uint32) {
+	ishdr.physicalAddressOrVirtualSize = addr
+}
+
+const (
+	// Section characteristics.
+	IMAGE_SCN_TYPE_REG    = 0x00000000 // Reserved.
+	IMAGE_SCN_TYPE_DSECT  = 0x00000001 // Reserved.
+	IMAGE_SCN_TYPE_NOLOAD = 0x00000002 // Reserved.
+	IMAGE_SCN_TYPE_GROUP  = 0x00000004 // Reserved.
+	IMAGE_SCN_TYPE_NO_PAD = 0x00000008 // Reserved.
+	IMAGE_SCN_TYPE_COPY   = 0x00000010 // Reserved.
+
+	IMAGE_SCN_CNT_CODE               = 0x00000020 // Section contains code.
+	IMAGE_SCN_CNT_INITIALIZED_DATA   = 0x00000040 // Section contains initialized data.
+	IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 // Section contains uninitialized data.
+
+	IMAGE_SCN_LNK_OTHER         = 0x00000100 // Reserved.
+	IMAGE_SCN_LNK_INFO          = 0x00000200 // Section contains comments or some other type of information.
+	IMAGE_SCN_TYPE_OVER         = 0x00000400 // Reserved.
+	IMAGE_SCN_LNK_REMOVE        = 0x00000800 // Section contents will not become part of image.
+	IMAGE_SCN_LNK_COMDAT        = 0x00001000 // Section contents comdat.
+	IMAGE_SCN_MEM_PROTECTED     = 0x00004000 // Obsolete.
+	IMAGE_SCN_NO_DEFER_SPEC_EXC = 0x00004000 // Reset speculative exceptions handling bits in the TLB entries for this section.
+	IMAGE_SCN_GPREL             = 0x00008000 // Section content can be accessed relative to GP
+	IMAGE_SCN_MEM_FARDATA       = 0x00008000
+	IMAGE_SCN_MEM_SYSHEAP       = 0x00010000 // Obsolete.
+	IMAGE_SCN_MEM_PURGEABLE     = 0x00020000
+	IMAGE_SCN_MEM_16BIT         = 0x00020000
+	IMAGE_SCN_MEM_LOCKED        = 0x00040000
+	IMAGE_SCN_MEM_PRELOAD       = 0x00080000
+
+	IMAGE_SCN_ALIGN_1BYTES    = 0x00100000 //
+	IMAGE_SCN_ALIGN_2BYTES    = 0x00200000 //
+	IMAGE_SCN_ALIGN_4BYTES    = 0x00300000 //
+	IMAGE_SCN_ALIGN_8BYTES    = 0x00400000 //
+	IMAGE_SCN_ALIGN_16BYTES   = 0x00500000 // Default alignment if no others are specified.
+	IMAGE_SCN_ALIGN_32BYTES   = 0x00600000 //
+	IMAGE_SCN_ALIGN_64BYTES   = 0x00700000 //
+	IMAGE_SCN_ALIGN_128BYTES  = 0x00800000 //
+	IMAGE_SCN_ALIGN_256BYTES  = 0x00900000 //
+	IMAGE_SCN_ALIGN_512BYTES  = 0x00A00000 //
+	IMAGE_SCN_ALIGN_1024BYTES = 0x00B00000 //
+	IMAGE_SCN_ALIGN_2048BYTES = 0x00C00000 //
+	IMAGE_SCN_ALIGN_4096BYTES = 0x00D00000 //
+	IMAGE_SCN_ALIGN_8192BYTES = 0x00E00000 //
+	IMAGE_SCN_ALIGN_MASK      = 0x00F00000
+
+	IMAGE_SCN_LNK_NRELOC_OVFL = 0x01000000 // Section contains extended relocations.
+	IMAGE_SCN_MEM_DISCARDABLE = 0x02000000 // Section can be discarded.
+	IMAGE_SCN_MEM_NOT_CACHED  = 0x04000000 // Section is not cachable.
+	IMAGE_SCN_MEM_NOT_PAGED   = 0x08000000 // Section is not pageable.
+	IMAGE_SCN_MEM_SHARED      = 0x10000000 // Section is shareable.
+	IMAGE_SCN_MEM_EXECUTE     = 0x20000000 // Section is executable.
+	IMAGE_SCN_MEM_READ        = 0x40000000 // Section is readable.
+	IMAGE_SCN_MEM_WRITE       = 0x80000000 // Section is writeable.
+
+	// TLS Characteristic Flags
+	IMAGE_SCN_SCALE_INDEX = 0x00000001 // Tls index is scaled.
+)
+
+// Based relocation format
+type IMAGE_BASE_RELOCATION struct {
+	VirtualAddress uint32
+	SizeOfBlock    uint32
+}
+
+const (
+	IMAGE_REL_BASED_ABSOLUTE           = 0
+	IMAGE_REL_BASED_HIGH               = 1
+	IMAGE_REL_BASED_LOW                = 2
+	IMAGE_REL_BASED_HIGHLOW            = 3
+	IMAGE_REL_BASED_HIGHADJ            = 4
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_5 = 5
+	IMAGE_REL_BASED_RESERVED           = 6
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_7 = 7
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_8 = 8
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_9 = 9
+	IMAGE_REL_BASED_DIR64              = 10
+
+	IMAGE_REL_BASED_IA64_IMM64 = 9
+
+	IMAGE_REL_BASED_MIPS_JMPADDR   = 5
+	IMAGE_REL_BASED_MIPS_JMPADDR16 = 9
+
+	IMAGE_REL_BASED_ARM_MOV32   = 5
+	IMAGE_REL_BASED_THUMB_MOV32 = 7
+)
+
+// Export Format
+type IMAGE_EXPORT_DIRECTORY struct {
+	Characteristics       uint32
+	TimeDateStamp         uint32
+	MajorVersion          uint16
+	MinorVersion          uint16
+	Name                  uint32
+	Base                  uint32
+	NumberOfFunctions     uint32
+	NumberOfNames         uint32
+	AddressOfFunctions    uint32 // RVA from base of image
+	AddressOfNames        uint32 // RVA from base of image
+	AddressOfNameOrdinals uint32 // RVA from base of image
+}
+
+type IMAGE_IMPORT_BY_NAME struct {
+	Hint uint16
+	Name [1]byte
+}
+
+func IMAGE_ORDINAL(ordinal uintptr) uintptr {
+	return ordinal & 0xffff
+}
+
+func IMAGE_SNAP_BY_ORDINAL(ordinal uintptr) bool {
+	return (ordinal & IMAGE_ORDINAL_FLAG) != 0
+}
+
+// Thread Local Storage
+type IMAGE_TLS_DIRECTORY struct {
+	StartAddressOfRawData uintptr
+	EndAddressOfRawData   uintptr
+	AddressOfIndex        uintptr // PDWORD
+	AddressOfCallbacks    uintptr // PIMAGE_TLS_CALLBACK *;
+	SizeOfZeroFill        uint32
+	Characteristics       uint32
+}
+
+type IMAGE_IMPORT_DESCRIPTOR struct {
+	characteristicsOrOriginalFirstThunk uint32 // 0 for terminating null import descriptor
+	// RVA to original unbound IAT (PIMAGE_THUNK_DATA)
+	TimeDateStamp uint32 // 0 if not bound,
+	// -1 if bound, and real date\time stamp
+	//     in IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT (new BIND)
+	// O.W. date/time stamp of DLL bound to (Old BIND)
+	ForwarderChain uint32 // -1 if no forwarders
+	Name           uint32
+	FirstThunk     uint32 // RVA to IAT (if bound this IAT has actual addresses)
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) Characteristics() uint32 {
+	return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) OriginalFirstThunk() uint32 {
+	return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+const (
+	DLL_PROCESS_ATTACH = 1
+	DLL_THREAD_ATTACH  = 2
+	DLL_THREAD_DETACH  = 3
+	DLL_PROCESS_DETACH = 0
+)
+
+//sys	loadLibraryA(libFileName *byte) (module windows.Handle, err error) = kernel32.LoadLibraryA
+//sys	getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) = kernel32.GetProcAddress
+//sys	isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) = kernel32.IsBadReadPtr
+
+type SYSTEM_INFO struct {
+	ProcessorArchitecture     uint16
+	Reserved                  uint16
+	PageSize                  uint32
+	MinimumApplicationAddress uintptr
+	MaximumApplicationAddress uintptr
+	ActiveProcessorMask       uintptr
+	NumberOfProcessors        uint32
+	ProcessorType             uint32
+	AllocationGranularity     uint32
+	ProcessorLevel            uint16
+	ProcessorRevision         uint16
+}

tun/wintun/memmod/syscall_windows_32.go

@@ -0,0 +1,45 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	BaseOfData                  uint32
+	ImageBase                   uintptr
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uintptr
+	SizeOfStackCommit           uintptr
+	SizeOfHeapReserve           uintptr
+	SizeOfHeapCommit            uintptr
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x80000000

tun/wintun/memmod/syscall_windows_64.go

@@ -0,0 +1,44 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	ImageBase                   uintptr
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uintptr
+	SizeOfStackCommit           uintptr
+	SizeOfHeapReserve           uintptr
+	SizeOfHeapCommit            uintptr
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x8000000000000000

tun/wintun/memmod/zsyscall_windows.go

@@ -0,0 +1,70 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package memmod
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+	procGetProcAddress = modkernel32.NewProc("GetProcAddress")
+	procIsBadReadPtr   = modkernel32.NewProc("IsBadReadPtr")
+	procLoadLibraryA   = modkernel32.NewProc("LoadLibraryA")
+)
+
+func getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) {
+	r0, _, e1 := syscall.Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(procName)), 0)
+	addr = uintptr(r0)
+	if addr == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) {
+	r0, _, _ := syscall.Syscall(procIsBadReadPtr.Addr(), 2, uintptr(addr), uintptr(ucb), 0)
+	ret = r0 != 0
+	return
+}
+
+func loadLibraryA(libFileName *byte) (module windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procLoadLibraryA.Addr(), 1, uintptr(unsafe.Pointer(libFileName)), 0, 0)
+	module = windows.Handle(r0)
+	if module == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

tun/wintun/resource/mksyscall.go

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go resource_windows.go

tun/wintun/resource/resource_windows.go

@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func MAKEINTRESOURCE(i uint16) *uint16 {
+	return (*uint16)(unsafe.Pointer(uintptr(i)))
+}
+
+// Predefined Resource Types
+var (
+	VS_VERSION_INFO uint16 = 1
+
+	RT_CURSOR                                          = MAKEINTRESOURCE(1)
+	RT_BITMAP                                          = MAKEINTRESOURCE(2)
+	RT_ICON                                            = MAKEINTRESOURCE(3)
+	RT_MENU                                            = MAKEINTRESOURCE(4)
+	RT_DIALOG                                          = MAKEINTRESOURCE(5)
+	RT_STRING                                          = MAKEINTRESOURCE(6)
+	RT_FONTDIR                                         = MAKEINTRESOURCE(7)
+	RT_FONT                                            = MAKEINTRESOURCE(8)
+	RT_ACCELERATOR                                     = MAKEINTRESOURCE(9)
+	RT_RCDATA                                          = MAKEINTRESOURCE(10)
+	RT_MESSAGETABLE                                    = MAKEINTRESOURCE(11)
+	RT_GROUP_CURSOR                                    = MAKEINTRESOURCE(12)
+	RT_GROUP_ICON                                      = MAKEINTRESOURCE(14)
+	RT_VERSION                                         = MAKEINTRESOURCE(16)
+	RT_DLGINCLUDE                                      = MAKEINTRESOURCE(17)
+	RT_PLUGPLAY                                        = MAKEINTRESOURCE(19)
+	RT_VXD                                             = MAKEINTRESOURCE(20)
+	RT_ANICURSOR                                       = MAKEINTRESOURCE(21)
+	RT_ANIICON                                         = MAKEINTRESOURCE(22)
+	RT_HTML                                            = MAKEINTRESOURCE(23)
+	RT_MANIFEST                                        = MAKEINTRESOURCE(24)
+	CREATEPROCESS_MANIFEST_RESOURCE_ID                 = MAKEINTRESOURCE(1)
+	ISOLATIONAWARE_MANIFEST_RESOURCE_ID                = MAKEINTRESOURCE(2)
+	ISOLATIONAWARE_NOSTATICIMPORT_MANIFEST_RESOURCE_ID = MAKEINTRESOURCE(3)
+	ISOLATIONPOLICY_MANIFEST_RESOURCE_ID               = MAKEINTRESOURCE(4)
+	ISOLATIONPOLICY_BROWSER_MANIFEST_RESOURCE_ID       = MAKEINTRESOURCE(5)
+	MINIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(1 /*inclusive*/)
+	MAXIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(16 /*inclusive*/)
+)
+
+//sys	findResource(module windows.Handle, name *uint16, resType *uint16) (resInfo windows.Handle, err error) = kernel32.FindResourceW
+
+func FindByID(module windows.Handle, id uint16, resType *uint16) (resInfo windows.Handle, err error) {
+	return findResource(module, MAKEINTRESOURCE(id), resType)
+}
+
+func FindByName(module windows.Handle, name string, resType *uint16) (resInfo windows.Handle, err error) {
+	var name16 *uint16
+	name16, err = windows.UTF16PtrFromString(name)
+	if err != nil {
+		return
+	}
+	resInfo, err = findResource(module, name16, resType)
+	return
+}
+
+//sys	sizeofResource(module windows.Handle, resInfo windows.Handle) (size uint32, err error) = kernel32.SizeofResource
+//sys	loadResource(module windows.Handle, resInfo windows.Handle) (resData windows.Handle, err error) = kernel32.LoadResource
+//sys	lockResource(resData windows.Handle) (addr uintptr, err error) = kernel32.LockResource
+
+func Load(module, resInfo windows.Handle) (data []byte, err error) {
+	size, err := sizeofResource(module, resInfo)
+	if err != nil {
+		err = fmt.Errorf("Unable to size resource: %w", err)
+		return
+	}
+	resData, err := loadResource(module, resInfo)
+	if err != nil {
+		err = fmt.Errorf("Unable to load resource: %w", err)
+		return
+	}
+	ptr, err := lockResource(resData)
+	if err != nil {
+		err = fmt.Errorf("Unable to lock resource: %w", err)
+		return
+	}
+	unsafeSlice(unsafe.Pointer(&data), unsafe.Pointer(ptr), int(size))
+	return
+}
+
+type VS_FIXEDFILEINFO struct {
+	Signature        uint32
+	StrucVersion     uint32
+	FileVersionMS    uint32
+	FileVersionLS    uint32
+	ProductVersionMS uint32
+	ProductVersionLS uint32
+	FileFlagsMask    uint32
+	FileFlags        uint32
+	FileOS           uint32
+	FileType         uint32
+	FileSubtype      uint32
+	FileDateMS       uint32
+	FileDateLS       uint32
+}
+
+//sys	verQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) = version.VerQueryValueW
+
+func VerQueryRootValue(block []byte) (ffi *VS_FIXEDFILEINFO, err error) {
+	var data *byte
+	var size uint32
+	err = verQueryValue(&block[0], windows.StringToUTF16Ptr("\\"), &data, &size)
+	if err != nil {
+		return
+	}
+	if uintptr(size) < unsafe.Sizeof(VS_FIXEDFILEINFO{}) {
+		err = errors.New("Incomplete VS_FIXEDFILEINFO")
+		return
+	}
+	ffi = (*VS_FIXEDFILEINFO)(unsafe.Pointer(data))
+	return
+}
+
+// unsafeSlice updates the slice slicePtr to be a slice
+// referencing the provided data with its length & capacity set to
+// lenCap.
+//
+// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
+// update callers to use unsafe.Slice instead of this.
+func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
+	type sliceHeader struct {
+		Data unsafe.Pointer
+		Len  int
+		Cap  int
+	}
+	h := (*sliceHeader)(slicePtr)
+	h.Data = data
+	h.Len = lenCap
+	h.Cap = lenCap
+}