version: bump snapshot

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

Makefile

@@ -22,7 +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

@@ -26,7 +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
 
@@ -46,7 +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) ≥ 1.12.
+This requires an installation of [go](https://golang.org) ≥ 1.13.
 
 ```
 $ git clone https://git.zx2c4.com/wireguard-go
@@ -56,7 +56,7 @@ $ make
 
 ## License
 
-    Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+    Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
     
     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

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

@@ -1,13 +1,12 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package device
+package conn
 
 import (
 	"encoding/binary"
-	"errors"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
@@ -18,17 +17,13 @@ const (
 	sockoptIPV6_UNICAST_IF = 31
 )
 
-func (device *Device) BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error {
+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]))
 
-	if device.net.bind == nil {
-		return errors.New("Bind is not yet initialized")
-	}
-
-	sysconn, err := device.net.bind.(*nativeBind).ipv4.SyscallConn()
+	sysconn, err := bind.ipv4.SyscallConn()
 	if err != nil {
 		return err
 	}
@@ -41,12 +36,12 @@ func (device *Device) BindSocketToInterface4(interfaceIndex uint32, blackhole bo
 	if err != nil {
 		return err
 	}
-	device.net.bind.(*nativeBind).blackhole4 = blackhole
+	bind.blackhole4 = blackhole
 	return nil
 }
 
-func (device *Device) BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error {
-	sysconn, err := device.net.bind.(*nativeBind).ipv6.SyscallConn()
+func (bind *nativeBind) BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error {
+	sysconn, err := bind.ipv6.SyscallConn()
 	if err != nil {
 		return err
 	}
@@ -59,6 +54,6 @@ func (device *Device) BindSocketToInterface6(interfaceIndex uint32, blackhole bo
 	if err != nil {
 		return err
 	}
-	device.net.bind.(*nativeBind).blackhole6 = blackhole
+	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

@@ -2,10 +2,10 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package device
+package conn
 
 import (
 	"net"
@@ -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(),
@@ -100,7 +96,7 @@ 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
 
@@ -135,6 +131,8 @@ func (bind *nativeBind) Close() error {
 	return err2
 }
 
+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

conn/conn_linux.go

@@ -2,19 +2,10 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 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-tools/tree/contrib/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 device
+package conn
 
 import (
 	"errors"
@@ -25,7 +16,6 @@ import (
 	"unsafe"
 
 	"golang.org/x/sys/unix"
-	"golang.zx2c4.com/wireguard/rwcancel"
 )
 
 const (
@@ -33,8 +23,8 @@ const (
 )
 
 type IPv4Source struct {
-	src     [4]byte
-	ifindex int32
+	Src     [4]byte
+	Ifindex int32
 }
 
 type IPv6Source struct {
@@ -49,6 +39,10 @@ type NativeEndpoint struct {
 	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]))
 }
@@ -68,8 +62,6 @@ func (endpoint *NativeEndpoint) dst6() *unix.SockaddrInet6 {
 type nativeBind struct {
 	sock4    int
 	sock6    int
-	netlinkSock   int
-	netlinkCancel *rwcancel.RWCancel
 	lastMark uint32
 }
 
@@ -111,59 +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 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 successful
-
+	// 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 successful
-
+	// 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
 		}
@@ -178,6 +136,10 @@ func CreateBind(port uint16, device *Device) (*nativeBind, uint16, error) {
 	return &bind, port, nil
 }
 
+func (bind *nativeBind) LastMark() uint32 {
+	return bind.lastMark
+}
+
 func (bind *nativeBind) SetMark(value uint32) error {
 	if bind.sock6 != -1 {
 		err := unix.SetsockoptInt(
@@ -216,22 +178,18 @@ func closeUnblock(fd int) error {
 }
 
 func (bind *nativeBind) Close() error {
-	var err1, err2, err3 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) {
@@ -278,10 +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[:]
@@ -478,8 +436,8 @@ 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,
 		},
 	}
 
@@ -573,8 +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
@@ -611,156 +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.Lock()
-								if &pePtr.peer.endpoint != pePtr.endpoint {
-									pePtr.peer.Unlock()
-									break
-								}
-								if uint32(pePtr.peer.endpoint.(*NativeEndpoint).src4().ifindex) == ifidx {
-									pePtr.peer.Unlock()
-									break
-								}
-								pePtr.peer.endpoint.(*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.endpoint.(*NativeEndpoint) == nil {
-							peer.RUnlock()
-							continue
-						}
-						if peer.endpoint.(*NativeEndpoint).isV6 || peer.endpoint.(*NativeEndpoint).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,
-							},
-							peer.endpoint.(*NativeEndpoint).dst4().Addr,
-							unix.RtAttr{
-								Len:  8,
-								Type: unix.RTA_SRC,
-							},
-							peer.endpoint.(*NativeEndpoint).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 := bind.netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:])
-						if err != nil {
-							break
-						}
-					}
-					device.peers.RUnlock()
-				}()
-			}
-			remain = remain[hdr.Len:]
-		}
-	}
-}

conn/mark_default.go

@@ -2,10 +2,10 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package device
+package conn
 
 func (bind *nativeBind) SetMark(mark uint32) error {
 	return nil

conn/mark_unix.go

@@ -2,10 +2,10 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
-package device
+package conn
 
 import (
 	"runtime"

device/allowedips.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/allowedips_rand_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/allowedips_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/bind_test.go

@@ -1,15 +1,19 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 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/boundif_android.go

@@ -1,44 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
- */
-
-package device
-
-import "errors"
-
-func (device *Device) PeekLookAtSocketFd4() (fd int, err error) {
-	nb, ok := device.net.bind.(*nativeBind)
-	if !ok {
-		return 0, errors.New("no socket exists")
-	}
-	sysconn, err := nb.ipv4.SyscallConn()
-	if err != nil {
-		return
-	}
-	err = sysconn.Control(func(f uintptr) {
-		fd = int(f)
-	})
-	if err != nil {
-		return
-	}
-	return
-}
-
-func (device *Device) PeekLookAtSocketFd6() (fd int, err error) {
-	nb, ok := device.net.bind.(*nativeBind)
-	if !ok {
-		return 0, errors.New("no socket exists")
-	}
-	sysconn, err := nb.ipv6.SyscallConn()
-	if err != nil {
-		return
-	}
-	err = sysconn.Control(func(f uintptr) {
-		fd = int(f)
-	})
-	if err != nil {
-		return
-	}
-	return
-}

device/conn.go

@@ -1,187 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
- */
-
-package device
-
-import (
-	"errors"
-	"net"
-	"strings"
-
-	"golang.org/x/net/ipv4"
-	"golang.org/x/net/ipv6"
-)
-
-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 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
-}
-
-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.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 = 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.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(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.Lock()
-	err := unsafeCloseBind(device)
-	device.net.Unlock()
-	return err
-}

device/constants.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -13,7 +13,7 @@ import (
 
 const (
 	RekeyAfterMessages      = (1 << 60)
-	RejectAfterMessages     = (1 << 64) - (1 << 4) - 1
+	RejectAfterMessages     = (1 << 64) - (1 << 13) - 1
 	RekeyAfterTime          = time.Second * 120
 	RekeyAttemptTime        = time.Second * 90
 	RekeyTimeout            = time.Second * 5

device/cookie.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/cookie_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/device.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -11,15 +11,14 @@ import (
 	"sync/atomic"
 	"time"
 
+	"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"
 )
 
-const (
-	DeviceRoutineNumberPerCPU     = 3
-	DeviceRoutineNumberAdditional = 2
-)
-
 type Device struct {
 	isUp     AtomicBool // device is (going) up
 	isClosed AtomicBool // device is closed? (acting as guard)
@@ -39,7 +38,8 @@ type Device struct {
 		starting sync.WaitGroup
 		stopping sync.WaitGroup
 		sync.RWMutex
-		bind   Bind   // bind interface
+		bind          conn.Bind // bind interface
+		netlinkCancel *rwcancel.RWCancel
 		port          uint16 // listening port
 		fwmark        uint32 // mark value (0 = disabled)
 	}
@@ -236,24 +236,12 @@ func (device *Device) SetPrivateKey(sk NoisePrivateKey) error {
 
 	// do static-static DH pre-computations
 
-	rmKey := device.staticIdentity.privateKey.IsZero()
-
 	expiredPeers := make([]*Peer, 0, len(device.peers.keyMap))
-	for key, peer := range 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)
-		}
-
-		if isZero(handshake.precomputedStaticStatic[:]) {
-			unsafeRemovePeer(device, peer, key)
-		} else {
 		expiredPeers = append(expiredPeers, peer)
 	}
-	}
 
 	for _, peer := range lockedPeers {
 		peer.handshake.mutex.RUnlock()
@@ -311,14 +299,16 @@ func NewDevice(tunDevice tun.Device, 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()
 
@@ -393,10 +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()
@@ -425,3 +415,133 @@ func (device *Device) SendKeepalivesToPeersWithCurrentKeypair() {
 	}
 	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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -8,28 +8,40 @@ package device
 import (
 	"bufio"
 	"bytes"
-	"encoding/binary"
-	"io"
+	"fmt"
 	"net"
-	"os"
 	"strings"
 	"testing"
 	"time"
 
-	"golang.zx2c4.com/wireguard/tun"
+	"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) {
-	// TODO(crawshaw): pick unused ports on localhost
+	port1 := getFreePort(t)
+	port2 := getFreePort(t)
+
 	cfg1 := `private_key=481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58
-listen_port=53511
+listen_port={{PORT1}}
 replace_peers=true
 public_key=f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725
 protocol_version=1
 replace_allowed_ips=true
 allowed_ip=1.0.0.2/32
-endpoint=127.0.0.1:53512`
-	tun1 := NewChannelTUN()
+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()
@@ -38,14 +50,17 @@ endpoint=127.0.0.1:53512`
 	}
 
 	cfg2 := `private_key=98c7989b1661a0d64fd6af3502000f87716b7c4bbcf00d04fc6073aa7b539768
-listen_port=53512
+listen_port={{PORT2}}
 replace_peers=true
 public_key=49e80929259cebdda4f322d6d2b1a6fad819d603acd26fd5d845e7a123036427
 protocol_version=1
 replace_allowed_ips=true
 allowed_ip=1.0.0.1/32
-endpoint=127.0.0.1:53511`
-	tun2 := NewChannelTUN()
+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()
@@ -54,7 +69,7 @@ endpoint=127.0.0.1:53511`
 	}
 
 	t.Run("ping 1.0.0.1", func(t *testing.T) {
-		msg2to1 := ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2"))
+		msg2to1 := tuntest.Ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2"))
 		tun2.Outbound <- msg2to1
 		select {
 		case msgRecv := <-tun1.Inbound:
@@ -67,7 +82,7 @@ endpoint=127.0.0.1:53511`
 	})
 
 	t.Run("ping 1.0.0.2", func(t *testing.T) {
-		msg1to2 := ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
+		msg1to2 := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
 		tun1.Outbound <- msg1to2
 		select {
 		case msgRecv := <-tun2.Inbound:
@@ -80,139 +95,6 @@ endpoint=127.0.0.1:53511`
 	})
 }
 
-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
-	}
-}
-
-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
-}
-
 func assertNil(t *testing.T, err error) {
 	if err != nil {
 		t.Fatal(err)

device/endpoint_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/indextable.go

@@ -1,14 +1,14 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
 
 import (
 	"crypto/rand"
+	"encoding/binary"
 	"sync"
-	"unsafe"
 )
 
 type IndexTableEntry struct {
@@ -25,7 +25,8 @@ type IndexTable struct {
 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() {

device/ip.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/kdf_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/keypair.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -8,7 +8,9 @@ package device
 import (
 	"crypto/cipher"
 	"sync"
+	"sync/atomic"
 	"time"
+	"unsafe"
 
 	"golang.zx2c4.com/wireguard/replay"
 )
@@ -24,7 +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
@@ -38,6 +40,14 @@ type Keypairs struct {
 	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.RLock()
 	defer kp.RUnlock()

device/logger.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/misc.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/noise-protocol.go

@@ -1,29 +1,51 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
 
 import (
 	"errors"
+	"fmt"
 	"sync"
 	"time"
 
 	"golang.org/x/crypto/blake2s"
 	"golang.org/x/crypto/chacha20poly1305"
 	"golang.org/x/crypto/poly1305"
+
 	"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"
@@ -95,7 +117,7 @@ type MessageCookieReply struct {
 }
 
 type Handshake struct {
-	state                     int
+	state                     handshakeState
 	mutex                     sync.RWMutex
 	hash                      [blake2s.Size]byte       // hash value
 	chainKey                  [blake2s.Size]byte       // chain key
@@ -135,7 +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) {
@@ -154,6 +176,7 @@ func init() {
 }
 
 func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, error) {
+	var errZeroECDHResult = errors.New("ECDH returned all zeros")
 
 	device.staticIdentity.RLock()
 	defer device.staticIdentity.RUnlock()
@@ -162,12 +185,7 @@ func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, e
 	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
@@ -176,31 +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,
@@ -209,26 +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
 }
 
@@ -250,16 +265,16 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 	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
 	}
@@ -273,23 +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()
@@ -299,11 +315,15 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 
 	// protect against replay & flood
 
-	var ok bool
-	ok = timestamp.After(handshake.lastTimestamp)
-	ok = ok && time.Since(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
 	}
 
@@ -322,7 +342,7 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
 	if now.After(handshake.lastInitiationConsumption) {
 		handshake.lastInitiationConsumption = now
 	}
-	handshake.state = HandshakeInitiationConsumed
+	handshake.state = handshakeInitiationConsumed
 
 	handshake.mutex.Unlock()
 
@@ -337,7 +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")
 	}
 
@@ -393,7 +413,7 @@ func (device *Device) CreateMessageResponse(peer *Peer) (*MessageResponse, error
 		handshake.mixHash(msg.Empty[:])
 	}()
 
-	handshake.state = HandshakeResponseCreated
+	handshake.state = handshakeResponseCreated
 
 	return &msg, nil
 }
@@ -423,7 +443,7 @@ func (device *Device) ConsumeMessageResponse(msg *MessageResponse) *Peer {
 		handshake.mutex.RLock()
 		defer handshake.mutex.RUnlock()
 
-		if handshake.state != HandshakeInitiationCreated {
+		if handshake.state != handshakeInitiationCreated {
 			return false
 		}
 
@@ -484,7 +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()
 
@@ -509,7 +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,
@@ -517,7 +537,7 @@ func (peer *Peer) BeginSymmetricSession() error {
 			nil,
 		)
 		isInitiator = true
-	} else if handshake.state == HandshakeResponseCreated {
+	} else if handshake.state == handshakeResponseCreated {
 		KDF2(
 			&recvKey,
 			&sendKey,
@@ -526,7 +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
@@ -534,7 +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
 
@@ -547,7 +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
@@ -564,12 +584,12 @@ func (peer *Peer) BeginSymmetricSession() error {
 	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 {
@@ -578,7 +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)
@@ -589,18 +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.Lock()
 	defer keypairs.Unlock()
-	if keypairs.next != receivedKeypair {
+	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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -52,6 +52,15 @@ func (key *NoisePrivateKey) FromHex(src string) (err error) {
 	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 {
 	return hex.EncodeToString(key[:])
 }

device/noise_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -12,6 +12,8 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+
+	"golang.zx2c4.com/wireguard/conn"
 )
 
 const (
@@ -24,10 +26,15 @@ type Peer struct {
 	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
@@ -51,6 +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
@@ -108,7 +116,6 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 	handshake := &peer.handshake
 	handshake.mutex.Lock()
 	handshake.precomputedStaticStatic = device.staticIdentity.privateKey.sharedSecret(pk)
-	ssIsZero := isZero(handshake.precomputedStaticStatic[:])
 	handshake.remoteStatic = pk
 	handshake.mutex.Unlock()
 
@@ -116,13 +123,9 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 
 	peer.endpoint = nil
 
-	// conditionally add
+	// add
 
-	if !ssIsZero {
 	device.peers.keyMap[pk] = peer
-	} else {
-		return nil, nil
-	}
 
 	// start peer
 
@@ -193,10 +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))
@@ -222,10 +226,10 @@ func (peer *Peer) ZeroAndFlushAll() {
 	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.storeNext(nil)
 	keypairs.Unlock()
 
 	// clear handshake state
@@ -253,7 +257,7 @@ func (peer *Peer) ExpireCurrentKeypairs() {
 		keypairs.current.sendNonce = RejectAfterMessages
 	}
 	if keypairs.next != nil {
-		keypairs.next.sendNonce = RejectAfterMessages
+		keypairs.loadNext().sendNonce = RejectAfterMessages
 	}
 	keypairs.Unlock()
 }
@@ -282,17 +286,17 @@ 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.Lock()

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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/queueconstants_android.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/queueconstants_default.go

@@ -2,7 +2,7 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/queueconstants_ios.go

@@ -2,7 +2,7 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/receive.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -17,12 +17,13 @@ import (
 	"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
 }
 
@@ -33,7 +34,7 @@ type QueueInboundElement struct {
 	packet   []byte
 	counter  uint64
 	keypair  *Keypair
-	endpoint Endpoint
+	endpoint conn.Endpoint
 }
 
 func (elem *QueueInboundElement) Drop() {
@@ -90,7 +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() {
@@ -108,7 +109,7 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 	var (
 		err      error
 		size     int
-		endpoint Endpoint
+		endpoint conn.Endpoint
 	)
 
 	for {
@@ -183,11 +184,13 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 
 			// 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
 

device/send.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
@@ -107,6 +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
 	}
@@ -310,6 +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)
@@ -317,6 +320,7 @@ func (device *Device) RoutineReadFromTUN() {
 			addToNonceQueue(peer.queue.nonce, elem, device)
 			elem = nil
 		}
+		peer.queue.RUnlock()
 	}
 }
 
@@ -448,6 +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)
  *
@@ -514,13 +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)
 			}
 

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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 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.
  */

device/tun.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/tun_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device

device/uapi.go

@@ -1,12 +1,13 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package device
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -15,6 +16,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"golang.zx2c4.com/wireguard/conn"
 	"golang.zx2c4.com/wireguard/ipc"
 )
 
@@ -30,7 +32,7 @@ func (s IPCError) ErrorCode() int64 {
 	return s.int64
 }
 
-func (device *Device) IpcGetOperation(socket *bufio.Writer) *IPCError {
+func (device *Device) IpcGetOperation(socket *bufio.Writer) error {
 	lines := make([]string, 0, 100)
 	send := func(line string) {
 		lines = append(lines, line)
@@ -105,7 +107,7 @@ func (device *Device) IpcGetOperation(socket *bufio.Writer) *IPCError {
 	return nil
 }
 
-func (device *Device) IpcSetOperation(socket *bufio.Reader) *IPCError {
+func (device *Device) IpcSetOperation(socket *bufio.Reader) error {
 	scanner := bufio.NewScanner(socket)
 	logError := device.log.Error
 	logDebug := device.log.Debug
@@ -138,7 +140,7 @@ func (device *Device) IpcSetOperation(socket *bufio.Reader) *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{ipc.IpcErrorInvalid}
@@ -306,7 +308,7 @@ func (device *Device) IpcSetOperation(socket *bufio.Reader) *IPCError {
 				err := func() error {
 					peer.Lock()
 					defer peer.Unlock()
-					endpoint, err := CreateEndpoint(value)
+					endpoint, err := conn.CreateEndpoint(value)
 					if err != nil {
 						return err
 					}
@@ -420,10 +422,20 @@ func (device *Device) IpcHandle(socket net.Conn) {
 
 	switch op {
 	case "set=1\n":
-		status = device.IpcSetOperation(buffered.Reader)
+		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":
-		status = device.IpcGetOperation(buffered.Writer)
+		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

@@ -1,3 +1,3 @@
 package device
 
-const WireGuardGoVersion = "0.0.20200121"
+const WireGuardGoVersion = "0.0.20201118"

go.mod

@@ -1,10 +1,9 @@
 module golang.zx2c4.com/wireguard
 
-go 1.12
+go 1.13
 
 require (
-	golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc
-	golang.org/x/net v0.0.0-20191003171128-d98b1b443823
-	golang.org/x/sys v0.0.0-20191003212358-c178f38b412c
-	golang.org/x/text v0.3.2
+	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

@@ -1,14 +1,17 @@
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc h1:c0o/qxkaO2LF5t6fQrT4b5hzyggAkLLlCUjqfRxd8Q4=
-golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+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 v0.0.0-20191003171128-d98b1b443823 h1:Ypyv6BNJh07T1pUSrehkLemqPKXhus2MkfktJ91kRh4=
-golang.org/x/net v0.0.0-20191003171128-d98b1b443823/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+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 v0.0.0-20191003212358-c178f38b412c h1:6Zx7DRlKXf79yfxuQ/7GqV3w2y7aDsk6bGg0MzF5RVU=
-golang.org/x/sys v0.0.0-20191003212358-c178f38b412c/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 v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
-golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+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=

ipc/uapi_bsd.go

@@ -2,32 +2,20 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ipc
 
 import (
 	"errors"
-	"fmt"
 	"net"
 	"os"
-	"path"
 	"unsafe"
 
 	"golang.org/x/sys/unix"
 )
 
-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"
-)
-
 type UAPIListener struct {
 	listener net.Listener // unix socket listener
 	connNew  chan net.Conn
@@ -84,10 +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
 
@@ -146,58 +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

@@ -1,31 +1,18 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ipc
 
 import (
-	"errors"
-	"fmt"
 	"net"
 	"os"
-	"path"
 
 	"golang.org/x/sys/unix"
 	"golang.zx2c4.com/wireguard/rwcancel"
 )
 
-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"
-)
-
 type UAPIListener struct {
 	listener        net.Listener // unix socket listener
 	connNew         chan net.Conn
@@ -84,10 +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 {
@@ -143,58 +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

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ipc

ipc/winpipe/file.go

@@ -3,7 +3,7 @@
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2005 Microsoft
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 package winpipe
 

ipc/winpipe/mksyscall.go

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2005 Microsoft
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package winpipe

ipc/winpipe/pipe.go

@@ -3,7 +3,7 @@
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2005 Microsoft
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package winpipe

main.go

@@ -2,7 +2,7 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package main
@@ -41,18 +41,16 @@ func warning() {
 		return
 	}
 
-	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
-	fmt.Fprintln(os.Stderr, "W                                                     G")
-	fmt.Fprintln(os.Stderr, "W   You are running this software on a Linux kernel,  G")
-	fmt.Fprintln(os.Stderr, "W   which is probably unnecessary and misguided. This G")
-	fmt.Fprintln(os.Stderr, "W   is because the Linux kernel has built-in first    G")
-	fmt.Fprintln(os.Stderr, "W   class support for WireGuard, and this support is  G")
-	fmt.Fprintln(os.Stderr, "W   much more refined than this slower userspace      G")
-	fmt.Fprintln(os.Stderr, "W   implementation. For more information on           G")
-	fmt.Fprintln(os.Stderr, "W   installing the kernel module, please visit:       G")
-	fmt.Fprintln(os.Stderr, "W           https://www.wireguard.com/install         G")
-	fmt.Fprintln(os.Stderr, "W                                                     G")
-	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+	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() {

main_windows.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package main

ratelimiter/ratelimiter.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package ratelimiter
@@ -20,21 +20,23 @@ const (
 )
 
 type RatelimiterEntry struct {
-	sync.Mutex
+	mu       sync.Mutex
 	lastTime time.Time
 	tokens   int64
 }
 
 type Ratelimiter struct {
-	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.Lock()
-	defer rate.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.Lock()
-	defer rate.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.Lock()
-					defer rate.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.Lock()
-						if time.Since(entry.lastTime) > garbageCollectTime {
+		entry.mu.Lock()
+		if rate.timeNow().Sub(entry.lastTime) > garbageCollectTime {
 			delete(rate.tableIPv4, key)
 		}
-						entry.Unlock()
+		entry.mu.Unlock()
 	}
 
 	for key, entry := range rate.tableIPv6 {
-						entry.Lock()
-						if time.Since(entry.lastTime) > garbageCollectTime {
+		entry.mu.Lock()
+		if rate.timeNow().Sub(entry.lastTime) > garbageCollectTime {
 			delete(rate.tableIPv6, key)
 		}
-						entry.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.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.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.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.Unlock()
+		rate.mu.Unlock()
 		return true
 	}
 
 	// add tokens to entry
 
-	entry.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.Unlock()
+		entry.mu.Unlock()
 		return true
 	}
-	entry.Unlock()
+	entry.mu.Unlock()
 	return false
 }

ratelimiter/ratelimiter_test.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 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:    "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: MIT
  *
- * Copyright (C) 2017-2019 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: MIT
  *
- * Copyright (C) 2017-2019 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

@@ -1,6 +1,8 @@
+// +build !windows
+
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package rwcancel

rwcancel/rwcancel.go

@@ -1,8 +1,12 @@
+// +build !windows
+
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 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 (

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: MIT
  *
- * Copyright (C) 2017-2019 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: MIT
  *
- * Copyright (C) 2017-2019 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: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tai64n
@@ -17,16 +17,19 @@ 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.Nanosecond()) &^ whitenerMask
+	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: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tai64n
@@ -10,21 +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 < 50; i++ {
-		next := Now()
-		if next.After(old) {
-			t.Error("Whitening insufficient")
+	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},
 	}
-		time.Sleep(time.Duration(whitenerMask)/time.Nanosecond + 1)
-		next = Now()
-		if !next.After(old) {
-			t.Error("Not monotonically increasing on whitened nano-second scale")
+
+	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)
 			}
-		old = next
+		})
 	}
 }

tun/operateonfd.go

@@ -2,7 +2,7 @@
 
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun

tun/tun.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun

tun/tun_darwin.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -20,19 +20,6 @@ import (
 
 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 {
 	name        string
 	tunFile     *os.File
@@ -41,8 +28,6 @@ type NativeTun struct {
 	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)
@@ -130,43 +115,21 @@ func CreateTUN(name string, mtu int) (Device, 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)
@@ -230,27 +193,19 @@ func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
 }
 
 func (tun *NativeTun) Name() (string, error) {
-	var ifName struct {
-		name [16]byte
-	}
-	ifNameSize := uintptr(16)
-
-	var errno syscall.Errno
+	var err error
 	tun.operateOnFd(func(fd uintptr) {
-		_, _, errno = unix.Syscall6(
-			unix.SYS_GETSOCKOPT,
-			fd,
+		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
 }
 
@@ -320,11 +275,6 @@ func (tun *NativeTun) Close() error {
 }
 
 func (tun *NativeTun) setMTU(n int) error {
-
-	// open datagram socket
-
-	var fd int
-
 	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
-
 	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: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -287,7 +287,7 @@ func CreateTUN(name string, mtu int) (Device, error) {
 	if errno != 0 {
 		tunFile.Close()
 		tunDestroy(assignedName)
-		return nil, fmt.Errorf("Unable to put into IFHEAD mode: %v", errno)
+		return nil, fmt.Errorf("Unable to put into IFHEAD mode: %w", errno)
 	}
 
 	// Open control sockets
@@ -328,7 +328,7 @@ func CreateTUN(name string, mtu int) (Device, error) {
 	if errno != 0 {
 		tunFile.Close()
 		tunDestroy(assignedName)
-		return nil, fmt.Errorf("Unable to get nd6 flags for %s: %v", assignedName, errno)
+		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
@@ -341,7 +341,7 @@ func CreateTUN(name string, mtu int) (Device, error) {
 	if errno != 0 {
 		tunFile.Close()
 		tunDestroy(assignedName)
-		return nil, fmt.Errorf("Unable to set nd6 flags for %s: %v", assignedName, errno)
+		return nil, fmt.Errorf("Unable to set nd6 flags for %s: %w", assignedName, errno)
 	}
 
 	// Rename the interface
@@ -359,7 +359,7 @@ func CreateTUN(name string, mtu int) (Device, error) {
 	if errno != 0 {
 		tunFile.Close()
 		tunDestroy(assignedName)
-		return nil, fmt.Errorf("Failed to rename %s to %s: %v", assignedName, name, errno)
+		return nil, fmt.Errorf("Failed to rename %s to %s: %w", assignedName, name, errno)
 	}
 
 	return CreateTUNFromFile(tunFile, mtu)

tun/tun_linux.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -12,7 +12,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"net"
 	"os"
 	"sync"
 	"syscall"
@@ -32,7 +31,6 @@ const (
 type NativeTun struct {
 	tunFile                 *os.File
 	index                   int32      // if index
-	name                    string     // name of interface
 	errors                  chan error // async error handling
 	events                  chan Event // device related events
 	nopi                    bool       // the device was passed IFF_NO_PI
@@ -40,6 +38,10 @@ type NativeTun struct {
 	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 {
@@ -64,14 +66,19 @@ func (tun *NativeTun) routineHackListener() {
 		}
 		switch err {
 		case unix.EINVAL:
+			// If the tunnel is up, it reports that write() is
+			// allowed but we provided invalid data.
 			tun.events <- EventUp
 		case unix.EIO:
+			// 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
 		}
@@ -85,7 +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 {
@@ -126,6 +133,7 @@ func (tun *NativeTun) routineNetlinkListener() {
 		default:
 		}
 
+		wasEverUp := false
 		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
 
 			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
@@ -149,11 +157,17 @@ func (tun *NativeTun) routineNetlinkListener() {
 
 				if info.Flags&unix.IFF_RUNNING != 0 {
 					tun.events <- EventUp
+					wasEverUp = true
 				}
 
 				if info.Flags&unix.IFF_RUNNING == 0 {
+					// 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 <- EventMTUUpdate
 
@@ -164,11 +178,6 @@ func (tun *NativeTun) routineNetlinkListener() {
 	}
 }
 
-func (tun *NativeTun) isUp() (bool, error) {
-	inter, err := net.InterfaceByName(tun.name)
-	return inter.Flags&net.FlagUp != 0, err
-}
-
 func getIFIndex(name string) (int32, error) {
 	fd, err := unix.Socket(
 		unix.AF_INET,
@@ -198,6 +207,11 @@ func getIFIndex(name string) (int32, 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,
@@ -212,9 +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,
@@ -231,6 +244,11 @@ func (tun *NativeTun) setMTU(n 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,
@@ -247,7 +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),
@@ -262,6 +280,15 @@ func (tun *NativeTun) MTU() (int, 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
@@ -282,13 +309,11 @@ func (tun *NativeTun) Name() (string, error) {
 	if errno != 0 {
 		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) {
@@ -367,6 +392,9 @@ func (tun *NativeTun) Close() error {
 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
 	}
 
@@ -408,16 +436,15 @@ func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
 		statusListenersShutdown: make(chan struct{}),
 		nopi:                    false,
 	}
-	var err error
 
-	_, err = tun.Name()
+	name, err := tun.Name()
 	if err != nil {
 		return nil, err
 	}
 
 	// start event listener
 
-	tun.index, err = getIFIndex(tun.name)
+	tun.index, err = getIFIndex(name)
 	if err != nil {
 		return nil, err
 	}

tun/tun_openbsd.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun

tun/tun_windows.go

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2018-2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2018-2020 WireGuard LLC. All Rights Reserved.
  */
 
 package tun
@@ -9,10 +9,9 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"sync"
 	"sync/atomic"
 	"time"
-	"unsafe"
+	_ "unsafe"
 
 	"golang.org/x/sys/windows"
 
@@ -33,18 +32,26 @@ type rateJuggler struct {
 }
 
 type NativeTun struct {
-	wt        *wintun.Interface
+	wt        *wintun.Adapter
 	handle    windows.Handle
 	close     bool
 	events    chan Event
 	errors    chan error
 	forcedMTU int
 	rate      rateJuggler
-	rings     *wintun.RingDescriptor
-	writeLock sync.Mutex
+	session   wintun.Session
+	readWait  windows.Handle
 }
 
-const WintunPool = wintun.Pool("WireGuard")
+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)
@@ -66,20 +73,20 @@ func CreateTUN(ifname string, mtu int) (Device, error) {
 //
 func CreateTUNWithRequestedGUID(ifname string, requestedGUID *windows.GUID, mtu int) (Device, error) {
 	var err error
-	var wt *wintun.Interface
+	var wt *wintun.Adapter
 
 	// Does an interface with this name already exist?
-	wt, err = WintunPool.GetInterface(ifname)
+	wt, err = WintunPool.OpenAdapter(ifname)
 	if err == nil {
 		// If so, we delete it, in case it has weird residual configuration.
-		_, err = wt.DeleteInterface()
+		_, err = wt.Delete(true)
 		if err != nil {
-			return nil, fmt.Errorf("Error deleting already existing interface: %v", err)
+			return nil, fmt.Errorf("Error deleting already existing interface: %w", err)
 		}
 	}
-	wt, _, err = WintunPool.CreateInterface(ifname, requestedGUID)
+	wt, _, err = WintunPool.CreateAdapter(ifname, requestedGUID)
 	if err != nil {
-		return nil, fmt.Errorf("Error creating interface: %v", err)
+		return nil, fmt.Errorf("Error creating interface: %w", err)
 	}
 
 	forcedMTU := 1420
@@ -95,17 +102,13 @@ func CreateTUNWithRequestedGUID(ifname string, requestedGUID *windows.GUID, mtu
 		forcedMTU: forcedMTU,
 	}
 
-	tun.rings, err = wintun.NewRingDescriptor()
+	tun.session, err = wt.StartSession(0x800000) // Ring capacity, 8 MiB
 	if err != nil {
-		tun.Close()
-		return nil, fmt.Errorf("Error creating events: %v", err)
-	}
-
-	tun.handle, err = tun.wt.Register(tun.rings)
-	if err != nil {
-		tun.Close()
-		return nil, fmt.Errorf("Error registering rings: %v", err)
+		_, 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
 }
 
@@ -123,16 +126,10 @@ func (tun *NativeTun) Events() chan Event {
 
 func (tun *NativeTun) Close() error {
 	tun.close = true
-	if tun.rings.Send.TailMoved != 0 {
-		windows.SetEvent(tun.rings.Send.TailMoved) // wake the reader if it's sleeping
-	}
-	if tun.handle != windows.InvalidHandle {
-		windows.CloseHandle(tun.handle)
-	}
-	tun.rings.Close()
+	tun.session.End()
 	var err error
 	if tun.wt != nil {
-		_, err = tun.wt.DeleteInterface()
+		_, err = tun.wt.Delete(false)
 	}
 	close(tun.events)
 	return err
@@ -156,56 +153,34 @@ retry:
 		return 0, err
 	default:
 	}
-	if tun.close {
-		return 0, os.ErrClosed
-	}
-
-	buffHead := atomic.LoadUint32(&tun.rings.Send.Ring.Head)
-	if buffHead >= wintun.PacketCapacity {
-		return 0, os.ErrClosed
-	}
-
 	start := nanotime()
 	shouldSpin := atomic.LoadUint64(&tun.rate.current) >= spinloopRateThreshold && uint64(start-atomic.LoadInt64(&tun.rate.nextStartTime)) <= rateMeasurementGranularity*2
-	var buffTail uint32
 	for {
-		buffTail = atomic.LoadUint32(&tun.rings.Send.Ring.Tail)
-		if buffHead != buffTail {
-			break
-		}
 		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.rings.Send.TailMoved, windows.INFINITE)
+				windows.WaitForSingleObject(tun.readWait, windows.INFINITE)
 				goto retry
 			}
 			procyield(1)
-	}
-	if buffTail >= wintun.PacketCapacity {
+			continue
+		case windows.ERROR_HANDLE_EOF:
 			return 0, os.ErrClosed
+		case windows.ERROR_INVALID_DATA:
+			return 0, errors.New("Send ring corrupt")
 		}
-
-	buffContent := tun.rings.Send.Ring.Wrap(buffTail - buffHead)
-	if buffContent < uint32(unsafe.Sizeof(wintun.PacketHeader{})) {
-		return 0, errors.New("incomplete packet header in send ring")
+		return 0, fmt.Errorf("Read failed: %w", err)
 	}
-
-	packet := (*wintun.Packet)(unsafe.Pointer(&tun.rings.Send.Ring.Data[buffHead]))
-	if packet.Size > wintun.PacketSizeMax {
-		return 0, errors.New("packet too big in send ring")
-	}
-
-	alignedPacketSize := wintun.PacketAlign(uint32(unsafe.Sizeof(wintun.PacketHeader{})) + packet.Size)
-	if alignedPacketSize > buffContent {
-		return 0, errors.New("incomplete packet in send ring")
-	}
-
-	copy(buff[offset:], packet.Data[:packet.Size])
-	buffHead = tun.rings.Send.Ring.Wrap(buffHead + alignedPacketSize)
-	atomic.StoreUint32(&tun.rings.Send.Ring.Head, buffHead)
-	tun.rate.update(uint64(packet.Size))
-	return int(packet.Size), nil
 }
 
 func (tun *NativeTun) Flush() error {
@@ -217,36 +192,22 @@ func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 		return 0, os.ErrClosed
 	}
 
-	packetSize := uint32(len(buff) - offset)
+	packetSize := len(buff) - offset
 	tun.rate.update(uint64(packetSize))
-	alignedPacketSize := wintun.PacketAlign(uint32(unsafe.Sizeof(wintun.PacketHeader{})) + packetSize)
 
-	tun.writeLock.Lock()
-	defer tun.writeLock.Unlock()
-
-	buffHead := atomic.LoadUint32(&tun.rings.Receive.Ring.Head)
-	if buffHead >= wintun.PacketCapacity {
-		return 0, os.ErrClosed
+	packet, err := tun.session.AllocateSendPacket(packetSize)
+	if err == nil {
+		copy(packet, buff[offset:])
+		tun.session.SendPacket(packet)
+		return packetSize, nil
 	}
-
-	buffTail := atomic.LoadUint32(&tun.rings.Receive.Ring.Tail)
-	if buffTail >= wintun.PacketCapacity {
+	switch err {
+	case windows.ERROR_HANDLE_EOF:
 		return 0, os.ErrClosed
-	}
-
-	buffSpace := tun.rings.Receive.Ring.Wrap(buffHead - buffTail - wintun.PacketAlignment)
-	if alignedPacketSize > buffSpace {
+	case windows.ERROR_BUFFER_OVERFLOW:
 		return 0, nil // Dropping when ring is full.
 	}
-
-	packet := (*wintun.Packet)(unsafe.Pointer(&tun.rings.Receive.Ring.Data[buffTail]))
-	packet.Size = packetSize
-	copy(packet.Data[:packetSize], buff[offset:])
-	atomic.StoreUint32(&tun.rings.Receive.Ring.Tail, tun.rings.Receive.Ring.Wrap(buffTail+alignedPacketSize))
-	if atomic.LoadInt32(&tun.rings.Receive.Ring.Alertable) != 0 {
-		windows.SetEvent(tun.rings.Receive.TailMoved)
-	}
-	return int(packetSize), nil
+	return 0, fmt.Errorf("Write failed: %w", err)
 }
 
 // LUID returns Windows interface instance ID.
@@ -254,9 +215,9 @@ func (tun *NativeTun) LUID() uint64 {
 	return tun.wt.LUID()
 }
 
-// Version returns the version of the Wintun driver and NDIS system currently loaded.
-func (tun *NativeTun) Version() (driverVersion string, ndisVersion string, err error) {
-	return tun.wt.Version()
+// 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) {

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/iphlpapi/conversion_windows.go

@@ -1,25 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package iphlpapi
-
-import "golang.org/x/sys/windows"
-
-//sys	convertInterfaceLUIDToGUID(interfaceLUID *uint64, interfaceGUID *windows.GUID) (ret error) = iphlpapi.ConvertInterfaceLuidToGuid
-//sys	convertInterfaceAliasToLUID(interfaceAlias *uint16, interfaceLUID *uint64) (ret error) = iphlpapi.ConvertInterfaceAliasToLuid
-
-func InterfaceGUIDFromAlias(alias string) (*windows.GUID, error) {
-	var luid uint64
-	var guid windows.GUID
-	err := convertInterfaceAliasToLUID(windows.StringToUTF16Ptr(alias), &luid)
-	if err != nil {
-		return nil, err
-	}
-	err = convertInterfaceLUIDToGUID(&luid, &guid)
-	if err != nil {
-		return nil, err
-	}
-	return &guid, nil
-}

tun/wintun/iphlpapi/mksyscall.go

@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package iphlpapi
-
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go conversion_windows.go

tun/wintun/iphlpapi/zsyscall_windows.go

@@ -1,60 +0,0 @@
-// Code generated by 'go generate'; DO NOT EDIT.
-
-package iphlpapi
-
-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 (
-	modiphlpapi = windows.NewLazySystemDLL("iphlpapi.dll")
-
-	procConvertInterfaceLuidToGuid  = modiphlpapi.NewProc("ConvertInterfaceLuidToGuid")
-	procConvertInterfaceAliasToLuid = modiphlpapi.NewProc("ConvertInterfaceAliasToLuid")
-)
-
-func convertInterfaceLUIDToGUID(interfaceLUID *uint64, interfaceGUID *windows.GUID) (ret error) {
-	r0, _, _ := syscall.Syscall(procConvertInterfaceLuidToGuid.Addr(), 2, uintptr(unsafe.Pointer(interfaceLUID)), uintptr(unsafe.Pointer(interfaceGUID)), 0)
-	if r0 != 0 {
-		ret = syscall.Errno(r0)
-	}
-	return
-}
-
-func convertInterfaceAliasToLUID(interfaceAlias *uint16, interfaceLUID *uint64) (ret error) {
-	r0, _, _ := syscall.Syscall(procConvertInterfaceAliasToLuid.Addr(), 2, uintptr(unsafe.Pointer(interfaceAlias)), uintptr(unsafe.Pointer(interfaceLUID)), 0)
-	if r0 != 0 {
-		ret = syscall.Errno(r0)
-	}
-	return
-}

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/namespace_windows.go

@@ -1,98 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package wintun
-
-import (
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"sync"
-	"unsafe"
-
-	"golang.org/x/crypto/blake2s"
-	"golang.org/x/sys/windows"
-	"golang.org/x/text/unicode/norm"
-
-	"golang.zx2c4.com/wireguard/tun/wintun/namespaceapi"
-)
-
-var (
-	wintunObjectSecurityAttributes *windows.SecurityAttributes
-	hasInitializedNamespace        bool
-	initializingNamespace          sync.Mutex
-)
-
-func initializeNamespace() error {
-	initializingNamespace.Lock()
-	defer initializingNamespace.Unlock()
-	if hasInitializedNamespace {
-		return nil
-	}
-	sd, err := windows.SecurityDescriptorFromString("O:SYD:P(A;;GA;;;SY)")
-	if err != nil {
-		return fmt.Errorf("SddlToSecurityDescriptor failed: %v", err)
-	}
-	wintunObjectSecurityAttributes = &windows.SecurityAttributes{
-		Length:             uint32(unsafe.Sizeof(windows.SecurityAttributes{})),
-		SecurityDescriptor: sd,
-	}
-	sid, err := windows.CreateWellKnownSid(windows.WinLocalSystemSid)
-	if err != nil {
-		return fmt.Errorf("CreateWellKnownSid(LOCAL_SYSTEM) failed: %v", err)
-	}
-
-	boundary, err := namespaceapi.CreateBoundaryDescriptor("Wintun")
-	if err != nil {
-		return fmt.Errorf("CreateBoundaryDescriptor failed: %v", err)
-	}
-	err = boundary.AddSid(sid)
-	if err != nil {
-		return fmt.Errorf("AddSIDToBoundaryDescriptor failed: %v", err)
-	}
-	for {
-		_, err = namespaceapi.CreatePrivateNamespace(wintunObjectSecurityAttributes, boundary, "Wintun")
-		if err == windows.ERROR_ALREADY_EXISTS {
-			_, err = namespaceapi.OpenPrivateNamespace(boundary, "Wintun")
-			if err == windows.ERROR_PATH_NOT_FOUND {
-				continue
-			}
-		}
-		if err != nil {
-			return fmt.Errorf("Create/OpenPrivateNamespace failed: %v", err)
-		}
-		break
-	}
-	hasInitializedNamespace = true
-	return nil
-}
-
-func (pool Pool) takeNameMutex() (windows.Handle, error) {
-	err := initializeNamespace()
-	if err != nil {
-		return 0, err
-	}
-
-	const mutexLabel = "WireGuard Adapter Name Mutex Stable Suffix v1 jason@zx2c4.com"
-	b2, _ := blake2s.New256(nil)
-	b2.Write([]byte(mutexLabel))
-	b2.Write(norm.NFC.Bytes([]byte(string(pool))))
-	mutexName := `Wintun\Wintun-Name-Mutex-` + hex.EncodeToString(b2.Sum(nil))
-	mutex, err := windows.CreateMutex(wintunObjectSecurityAttributes, false, windows.StringToUTF16Ptr(mutexName))
-	if err != nil {
-		err = fmt.Errorf("Error creating name mutex: %v", err)
-		return 0, err
-	}
-	event, err := windows.WaitForSingleObject(mutex, windows.INFINITE)
-	if err != nil {
-		windows.CloseHandle(mutex)
-		return 0, fmt.Errorf("Error waiting on name mutex: %v", err)
-	}
-	if event != windows.WAIT_OBJECT_0 && event != windows.WAIT_ABANDONED {
-		windows.CloseHandle(mutex)
-		return 0, errors.New("Error with event trigger of name mutex")
-	}
-	return mutex, nil
-}

tun/wintun/namespaceapi/mksyscall.go

@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package namespaceapi
-
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go namespaceapi_windows.go

tun/wintun/namespaceapi/namespaceapi_windows.go

@@ -1,83 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package namespaceapi
-
-import "golang.org/x/sys/windows"
-
-//sys	createBoundaryDescriptor(name *uint16, flags uint32) (handle windows.Handle, err error) = kernel32.CreateBoundaryDescriptorW
-//sys	deleteBoundaryDescriptor(boundaryDescriptor windows.Handle) = kernel32.DeleteBoundaryDescriptor
-//sys	addSIDToBoundaryDescriptor(boundaryDescriptor *windows.Handle, requiredSid *windows.SID) (err error) = kernel32.AddSIDToBoundaryDescriptor
-//sys	createPrivateNamespace(privateNamespaceAttributes *windows.SecurityAttributes, boundaryDescriptor windows.Handle, aliasPrefix *uint16) (handle windows.Handle, err error) = kernel32.CreatePrivateNamespaceW
-//sys	openPrivateNamespace(boundaryDescriptor windows.Handle, aliasPrefix *uint16) (handle windows.Handle, err error) = kernel32.OpenPrivateNamespaceW
-//sys	closePrivateNamespace(handle windows.Handle, flags uint32) (err error) = kernel32.ClosePrivateNamespace
-
-// BoundaryDescriptor represents a boundary that defines how the objects in the namespace are to be isolated.
-type BoundaryDescriptor windows.Handle
-
-// CreateBoundaryDescriptor creates a boundary descriptor.
-func CreateBoundaryDescriptor(name string) (BoundaryDescriptor, error) {
-	name16, err := windows.UTF16PtrFromString(name)
-	if err != nil {
-		return 0, err
-	}
-	handle, err := createBoundaryDescriptor(name16, 0)
-	if err != nil {
-		return 0, err
-	}
-	return BoundaryDescriptor(handle), nil
-}
-
-// Delete deletes the specified boundary descriptor.
-func (bd BoundaryDescriptor) Delete() {
-	deleteBoundaryDescriptor(windows.Handle(bd))
-}
-
-// AddSid adds a security identifier (SID) to the specified boundary descriptor.
-func (bd *BoundaryDescriptor) AddSid(requiredSid *windows.SID) error {
-	return addSIDToBoundaryDescriptor((*windows.Handle)(bd), requiredSid)
-}
-
-// PrivateNamespace represents a private namespace.
-type PrivateNamespace windows.Handle
-
-// CreatePrivateNamespace creates a private namespace.
-func CreatePrivateNamespace(privateNamespaceAttributes *windows.SecurityAttributes, boundaryDescriptor BoundaryDescriptor, aliasPrefix string) (PrivateNamespace, error) {
-	aliasPrefix16, err := windows.UTF16PtrFromString(aliasPrefix)
-	if err != nil {
-		return 0, err
-	}
-	handle, err := createPrivateNamespace(privateNamespaceAttributes, windows.Handle(boundaryDescriptor), aliasPrefix16)
-	if err != nil {
-		return 0, err
-	}
-	return PrivateNamespace(handle), nil
-}
-
-// OpenPrivateNamespace opens a private namespace.
-func OpenPrivateNamespace(boundaryDescriptor BoundaryDescriptor, aliasPrefix string) (PrivateNamespace, error) {
-	aliasPrefix16, err := windows.UTF16PtrFromString(aliasPrefix)
-	if err != nil {
-		return 0, err
-	}
-	handle, err := openPrivateNamespace(windows.Handle(boundaryDescriptor), aliasPrefix16)
-	if err != nil {
-		return 0, err
-	}
-	return PrivateNamespace(handle), nil
-}
-
-// ClosePrivateNamespaceFlags describes flags that are used by PrivateNamespace's Close() method.
-type ClosePrivateNamespaceFlags uint32
-
-const (
-	// PrivateNamespaceFlagDestroy makes the close to destroy the namespace.
-	PrivateNamespaceFlagDestroy = ClosePrivateNamespaceFlags(0x1)
-)
-
-// Close closes an open namespace handle.
-func (pns PrivateNamespace) Close(flags ClosePrivateNamespaceFlags) error {
-	return closePrivateNamespace(windows.Handle(pns), uint32(flags))
-}

tun/wintun/namespaceapi/zsyscall_windows.go

@@ -1,116 +0,0 @@
-// Code generated by 'go generate'; DO NOT EDIT.
-
-package namespaceapi
-
-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")
-
-	procCreateBoundaryDescriptorW  = modkernel32.NewProc("CreateBoundaryDescriptorW")
-	procDeleteBoundaryDescriptor   = modkernel32.NewProc("DeleteBoundaryDescriptor")
-	procAddSIDToBoundaryDescriptor = modkernel32.NewProc("AddSIDToBoundaryDescriptor")
-	procCreatePrivateNamespaceW    = modkernel32.NewProc("CreatePrivateNamespaceW")
-	procOpenPrivateNamespaceW      = modkernel32.NewProc("OpenPrivateNamespaceW")
-	procClosePrivateNamespace      = modkernel32.NewProc("ClosePrivateNamespace")
-)
-
-func createBoundaryDescriptor(name *uint16, flags uint32) (handle windows.Handle, err error) {
-	r0, _, e1 := syscall.Syscall(procCreateBoundaryDescriptorW.Addr(), 2, uintptr(unsafe.Pointer(name)), uintptr(flags), 0)
-	handle = windows.Handle(r0)
-	if handle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func deleteBoundaryDescriptor(boundaryDescriptor windows.Handle) {
-	syscall.Syscall(procDeleteBoundaryDescriptor.Addr(), 1, uintptr(boundaryDescriptor), 0, 0)
-	return
-}
-
-func addSIDToBoundaryDescriptor(boundaryDescriptor *windows.Handle, requiredSid *windows.SID) (err error) {
-	r1, _, e1 := syscall.Syscall(procAddSIDToBoundaryDescriptor.Addr(), 2, uintptr(unsafe.Pointer(boundaryDescriptor)), uintptr(unsafe.Pointer(requiredSid)), 0)
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func createPrivateNamespace(privateNamespaceAttributes *windows.SecurityAttributes, boundaryDescriptor windows.Handle, aliasPrefix *uint16) (handle windows.Handle, err error) {
-	r0, _, e1 := syscall.Syscall(procCreatePrivateNamespaceW.Addr(), 3, uintptr(unsafe.Pointer(privateNamespaceAttributes)), uintptr(boundaryDescriptor), uintptr(unsafe.Pointer(aliasPrefix)))
-	handle = windows.Handle(r0)
-	if handle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func openPrivateNamespace(boundaryDescriptor windows.Handle, aliasPrefix *uint16) (handle windows.Handle, err error) {
-	r0, _, e1 := syscall.Syscall(procOpenPrivateNamespaceW.Addr(), 2, uintptr(boundaryDescriptor), uintptr(unsafe.Pointer(aliasPrefix)), 0)
-	handle = windows.Handle(r0)
-	if handle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func closePrivateNamespace(handle windows.Handle, flags uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procClosePrivateNamespace.Addr(), 2, uintptr(handle), uintptr(flags), 0)
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}

tun/wintun/nci/mksyscall.go

@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package nci
-
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go nci_windows.go