conn: introduce new package that splits out the Bind and Endpoint types

The sticky socket code stays in the device package for now,
as it reaches deeply into the peer list.

This is the first step in an effort to split some code out of
the very busy device package.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
This commit is contained in:
David Crawshaw
2019-11-07 11:13:05 -05:00
committed by Jason A. Donenfeld
parent 6aefb61355
commit 203554620d
15 changed files with 562 additions and 452 deletions

59
conn/boundif_windows.go Normal file
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@@ -0,0 +1,59 @@
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"encoding/binary"
"unsafe"
"golang.org/x/sys/windows"
)
const (
sockoptIP_UNICAST_IF = 31
sockoptIPV6_UNICAST_IF = 31
)
func (bind *nativeBind) BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error {
/* MSDN says for IPv4 this needs to be in net byte order, so that it's like an IP address with leading zeros. */
bytes := make([]byte, 4)
binary.BigEndian.PutUint32(bytes, interfaceIndex)
interfaceIndex = *(*uint32)(unsafe.Pointer(&bytes[0]))
sysconn, err := bind.ipv4.SyscallConn()
if err != nil {
return err
}
err2 := sysconn.Control(func(fd uintptr) {
err = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, sockoptIP_UNICAST_IF, int(interfaceIndex))
})
if err2 != nil {
return err2
}
if err != nil {
return err
}
bind.blackhole4 = blackhole
return nil
}
func (bind *nativeBind) BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error {
sysconn, err := bind.ipv6.SyscallConn()
if err != nil {
return err
}
err2 := sysconn.Control(func(fd uintptr) {
err = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, sockoptIPV6_UNICAST_IF, int(interfaceIndex))
})
if err2 != nil {
return err2
}
if err != nil {
return err
}
bind.blackhole6 = blackhole
return nil
}

101
conn/conn.go Normal file
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@@ -0,0 +1,101 @@
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 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.
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)
}
// BindToInterface is implemented by Bind objects that support being
// tied to a single network interface.
type BindToInterface interface {
BindToInterface4(interfaceIndex uint32, blackhole bool) error
BindToInterface6(interfaceIndex uint32, blackhole bool) 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
}

177
conn/conn_default.go Normal file
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// +build !linux android
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"net"
"os"
"syscall"
)
/* This code is meant to be a temporary solution
* on platforms for which the sticky socket / source caching behavior
* has not yet been implemented.
*
* See conn_linux.go for an implementation on the linux platform.
*/
type nativeBind struct {
ipv4 *net.UDPConn
ipv6 *net.UDPConn
blackhole4 bool
blackhole6 bool
}
type NativeEndpoint net.UDPAddr
var _ Bind = (*nativeBind)(nil)
var _ Endpoint = (*NativeEndpoint)(nil)
func CreateEndpoint(s string) (Endpoint, error) {
addr, err := parseEndpoint(s)
return (*NativeEndpoint)(addr), err
}
func (_ *NativeEndpoint) ClearSrc() {}
func (e *NativeEndpoint) DstIP() net.IP {
return (*net.UDPAddr)(e).IP
}
func (e *NativeEndpoint) SrcIP() net.IP {
return nil // not supported
}
func (e *NativeEndpoint) DstToBytes() []byte {
addr := (*net.UDPAddr)(e)
out := addr.IP.To4()
if out == nil {
out = addr.IP
}
out = append(out, byte(addr.Port&0xff))
out = append(out, byte((addr.Port>>8)&0xff))
return out
}
func (e *NativeEndpoint) DstToString() string {
return (*net.UDPAddr)(e).String()
}
func (e *NativeEndpoint) SrcToString() string {
return ""
}
func listenNet(network string, port int) (*net.UDPConn, int, error) {
conn, err := net.ListenUDP(network, &net.UDPAddr{Port: port})
if err != nil {
return nil, 0, err
}
// Retrieve port.
// TODO(crawshaw): under what circumstances is this necessary?
laddr := conn.LocalAddr()
uaddr, err := net.ResolveUDPAddr(
laddr.Network(),
laddr.String(),
)
if err != nil {
return nil, 0, err
}
return conn, uaddr.Port, nil
}
func extractErrno(err error) error {
opErr, ok := err.(*net.OpError)
if !ok {
return nil
}
syscallErr, ok := opErr.Err.(*os.SyscallError)
if !ok {
return nil
}
return syscallErr.Err
}
func createBind(uport uint16) (Bind, uint16, error) {
var err error
var bind nativeBind
port := int(uport)
bind.ipv4, port, err = listenNet("udp4", port)
if err != nil && extractErrno(err) != syscall.EAFNOSUPPORT {
return nil, 0, err
}
bind.ipv6, port, err = listenNet("udp6", port)
if err != nil && extractErrno(err) != syscall.EAFNOSUPPORT {
bind.ipv4.Close()
bind.ipv4 = nil
return nil, 0, err
}
return &bind, uint16(port), nil
}
func (bind *nativeBind) Close() error {
var err1, err2 error
if bind.ipv4 != nil {
err1 = bind.ipv4.Close()
}
if bind.ipv6 != nil {
err2 = bind.ipv6.Close()
}
if err1 != nil {
return err1
}
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
}
n, endpoint, err := bind.ipv4.ReadFromUDP(buff)
if endpoint != nil {
endpoint.IP = endpoint.IP.To4()
}
return n, (*NativeEndpoint)(endpoint), err
}
func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
if bind.ipv6 == nil {
return 0, nil, syscall.EAFNOSUPPORT
}
n, endpoint, err := bind.ipv6.ReadFromUDP(buff)
return n, (*NativeEndpoint)(endpoint), err
}
func (bind *nativeBind) Send(buff []byte, endpoint Endpoint) error {
var err error
nend := endpoint.(*NativeEndpoint)
if nend.IP.To4() != nil {
if bind.ipv4 == nil {
return syscall.EAFNOSUPPORT
}
if bind.blackhole4 {
return nil
}
_, err = bind.ipv4.WriteToUDP(buff, (*net.UDPAddr)(nend))
} else {
if bind.ipv6 == nil {
return syscall.EAFNOSUPPORT
}
if bind.blackhole6 {
return nil
}
_, err = bind.ipv6.WriteToUDP(buff, (*net.UDPAddr)(nend))
}
return err
}

571
conn/conn_linux.go Normal file
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@@ -0,0 +1,571 @@
// +build !android
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"errors"
"net"
"strconv"
"sync"
"syscall"
"unsafe"
"golang.org/x/sys/unix"
)
const (
FD_ERR = -1
)
type IPv4Source struct {
Src [4]byte
Ifindex int32
}
type IPv6Source struct {
src [16]byte
//ifindex belongs in dst.ZoneId
}
type NativeEndpoint struct {
sync.Mutex
dst [unsafe.Sizeof(unix.SockaddrInet6{})]byte
src [unsafe.Sizeof(IPv6Source{})]byte
isV6 bool
}
func (endpoint *NativeEndpoint) Src4() *IPv4Source { return endpoint.src4() }
func (endpoint *NativeEndpoint) Dst4() *unix.SockaddrInet4 { return endpoint.dst4() }
func (endpoint *NativeEndpoint) IsV6() bool { return endpoint.isV6 }
func (endpoint *NativeEndpoint) src4() *IPv4Source {
return (*IPv4Source)(unsafe.Pointer(&endpoint.src[0]))
}
func (endpoint *NativeEndpoint) src6() *IPv6Source {
return (*IPv6Source)(unsafe.Pointer(&endpoint.src[0]))
}
func (endpoint *NativeEndpoint) dst4() *unix.SockaddrInet4 {
return (*unix.SockaddrInet4)(unsafe.Pointer(&endpoint.dst[0]))
}
func (endpoint *NativeEndpoint) dst6() *unix.SockaddrInet6 {
return (*unix.SockaddrInet6)(unsafe.Pointer(&endpoint.dst[0]))
}
type nativeBind struct {
sock4 int
sock6 int
lastMark uint32
}
var _ Endpoint = (*NativeEndpoint)(nil)
var _ Bind = (*nativeBind)(nil)
func CreateEndpoint(s string) (Endpoint, error) {
var end NativeEndpoint
addr, err := parseEndpoint(s)
if err != nil {
return nil, err
}
ipv4 := addr.IP.To4()
if ipv4 != nil {
dst := end.dst4()
end.isV6 = false
dst.Port = addr.Port
copy(dst.Addr[:], ipv4)
end.ClearSrc()
return &end, nil
}
ipv6 := addr.IP.To16()
if ipv6 != nil {
zone, err := zoneToUint32(addr.Zone)
if err != nil {
return nil, err
}
dst := end.dst6()
end.isV6 = true
dst.Port = addr.Port
dst.ZoneId = zone
copy(dst.Addr[:], ipv6[:])
end.ClearSrc()
return &end, nil
}
return nil, errors.New("Invalid IP address")
}
func createBind(port uint16) (Bind, uint16, error) {
var err error
var bind nativeBind
var newPort uint16
// Attempt ipv6 bind, update port if successful.
bind.sock6, newPort, err = create6(port)
if err != nil {
if err != syscall.EAFNOSUPPORT {
return nil, 0, err
}
} else {
port = newPort
}
// Attempt ipv4 bind, update port if successful.
bind.sock4, newPort, err = create4(port)
if err != nil {
if err != syscall.EAFNOSUPPORT {
unix.Close(bind.sock6)
return nil, 0, err
}
} else {
port = newPort
}
if bind.sock4 == FD_ERR && bind.sock6 == FD_ERR {
return nil, 0, errors.New("ipv4 and ipv6 not supported")
}
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(
bind.sock6,
unix.SOL_SOCKET,
unix.SO_MARK,
int(value),
)
if err != nil {
return err
}
}
if bind.sock4 != -1 {
err := unix.SetsockoptInt(
bind.sock4,
unix.SOL_SOCKET,
unix.SO_MARK,
int(value),
)
if err != nil {
return err
}
}
bind.lastMark = value
return nil
}
func closeUnblock(fd int) error {
// shutdown to unblock readers and writers
unix.Shutdown(fd, unix.SHUT_RDWR)
return unix.Close(fd)
}
func (bind *nativeBind) Close() error {
var err1, err2 error
if bind.sock6 != -1 {
err1 = closeUnblock(bind.sock6)
}
if bind.sock4 != -1 {
err2 = closeUnblock(bind.sock4)
}
if err1 != nil {
return err1
}
return err2
}
func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
var end NativeEndpoint
if bind.sock6 == -1 {
return 0, nil, syscall.EAFNOSUPPORT
}
n, err := receive6(
bind.sock6,
buff,
&end,
)
return n, &end, err
}
func (bind *nativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
var end NativeEndpoint
if bind.sock4 == -1 {
return 0, nil, syscall.EAFNOSUPPORT
}
n, err := receive4(
bind.sock4,
buff,
&end,
)
return n, &end, err
}
func (bind *nativeBind) Send(buff []byte, end Endpoint) error {
nend := end.(*NativeEndpoint)
if !nend.isV6 {
if bind.sock4 == -1 {
return syscall.EAFNOSUPPORT
}
return send4(bind.sock4, nend, buff)
} else {
if bind.sock6 == -1 {
return syscall.EAFNOSUPPORT
}
return send6(bind.sock6, nend, buff)
}
}
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],
)
} else {
return end.src6().src[:]
}
}
func (end *NativeEndpoint) DstIP() net.IP {
if !end.isV6 {
return net.IPv4(
end.dst4().Addr[0],
end.dst4().Addr[1],
end.dst4().Addr[2],
end.dst4().Addr[3],
)
} else {
return end.dst6().Addr[:]
}
}
func (end *NativeEndpoint) DstToBytes() []byte {
if !end.isV6 {
return (*[unsafe.Offsetof(end.dst4().Addr) + unsafe.Sizeof(end.dst4().Addr)]byte)(unsafe.Pointer(end.dst4()))[:]
} else {
return (*[unsafe.Offsetof(end.dst6().Addr) + unsafe.Sizeof(end.dst6().Addr)]byte)(unsafe.Pointer(end.dst6()))[:]
}
}
func (end *NativeEndpoint) SrcToString() string {
return end.SrcIP().String()
}
func (end *NativeEndpoint) DstToString() string {
var udpAddr net.UDPAddr
udpAddr.IP = end.DstIP()
if !end.isV6 {
udpAddr.Port = end.dst4().Port
} else {
udpAddr.Port = end.dst6().Port
}
return udpAddr.String()
}
func (end *NativeEndpoint) ClearDst() {
for i := range end.dst {
end.dst[i] = 0
}
}
func (end *NativeEndpoint) ClearSrc() {
for i := range end.src {
end.src[i] = 0
}
}
func zoneToUint32(zone string) (uint32, error) {
if zone == "" {
return 0, nil
}
if intr, err := net.InterfaceByName(zone); err == nil {
return uint32(intr.Index), nil
}
n, err := strconv.ParseUint(zone, 10, 32)
return uint32(n), err
}
func create4(port uint16) (int, uint16, error) {
// create socket
fd, err := unix.Socket(
unix.AF_INET,
unix.SOCK_DGRAM,
0,
)
if err != nil {
return FD_ERR, 0, err
}
addr := unix.SockaddrInet4{
Port: int(port),
}
// set sockopts and bind
if err := func() error {
if err := unix.SetsockoptInt(
fd,
unix.SOL_SOCKET,
unix.SO_REUSEADDR,
1,
); err != nil {
return err
}
if err := unix.SetsockoptInt(
fd,
unix.IPPROTO_IP,
unix.IP_PKTINFO,
1,
); err != nil {
return err
}
return unix.Bind(fd, &addr)
}(); err != nil {
unix.Close(fd)
return FD_ERR, 0, err
}
sa, err := unix.Getsockname(fd)
if err == nil {
addr.Port = sa.(*unix.SockaddrInet4).Port
}
return fd, uint16(addr.Port), err
}
func create6(port uint16) (int, uint16, error) {
// create socket
fd, err := unix.Socket(
unix.AF_INET6,
unix.SOCK_DGRAM,
0,
)
if err != nil {
return FD_ERR, 0, err
}
// set sockopts and bind
addr := unix.SockaddrInet6{
Port: int(port),
}
if err := func() error {
if err := unix.SetsockoptInt(
fd,
unix.SOL_SOCKET,
unix.SO_REUSEADDR,
1,
); err != nil {
return err
}
if err := unix.SetsockoptInt(
fd,
unix.IPPROTO_IPV6,
unix.IPV6_RECVPKTINFO,
1,
); err != nil {
return err
}
if err := unix.SetsockoptInt(
fd,
unix.IPPROTO_IPV6,
unix.IPV6_V6ONLY,
1,
); err != nil {
return err
}
return unix.Bind(fd, &addr)
}(); err != nil {
unix.Close(fd)
return FD_ERR, 0, err
}
sa, err := unix.Getsockname(fd)
if err == nil {
addr.Port = sa.(*unix.SockaddrInet6).Port
}
return fd, uint16(addr.Port), err
}
func send4(sock int, end *NativeEndpoint, buff []byte) error {
// construct message header
cmsg := struct {
cmsghdr unix.Cmsghdr
pktinfo unix.Inet4Pktinfo
}{
unix.Cmsghdr{
Level: unix.IPPROTO_IP,
Type: unix.IP_PKTINFO,
Len: unix.SizeofInet4Pktinfo + unix.SizeofCmsghdr,
},
unix.Inet4Pktinfo{
Spec_dst: end.src4().Src,
Ifindex: end.src4().Ifindex,
},
}
end.Lock()
_, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0)
end.Unlock()
if err == nil {
return nil
}
// clear src and retry
if err == unix.EINVAL {
end.ClearSrc()
cmsg.pktinfo = unix.Inet4Pktinfo{}
end.Lock()
_, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0)
end.Unlock()
}
return err
}
func send6(sock int, end *NativeEndpoint, buff []byte) error {
// construct message header
cmsg := struct {
cmsghdr unix.Cmsghdr
pktinfo unix.Inet6Pktinfo
}{
unix.Cmsghdr{
Level: unix.IPPROTO_IPV6,
Type: unix.IPV6_PKTINFO,
Len: unix.SizeofInet6Pktinfo + unix.SizeofCmsghdr,
},
unix.Inet6Pktinfo{
Addr: end.src6().src,
Ifindex: end.dst6().ZoneId,
},
}
if cmsg.pktinfo.Addr == [16]byte{} {
cmsg.pktinfo.Ifindex = 0
}
end.Lock()
_, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0)
end.Unlock()
if err == nil {
return nil
}
// clear src and retry
if err == unix.EINVAL {
end.ClearSrc()
cmsg.pktinfo = unix.Inet6Pktinfo{}
end.Lock()
_, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0)
end.Unlock()
}
return err
}
func receive4(sock int, buff []byte, end *NativeEndpoint) (int, error) {
// construct message header
var cmsg struct {
cmsghdr unix.Cmsghdr
pktinfo unix.Inet4Pktinfo
}
size, _, _, newDst, err := unix.Recvmsg(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], 0)
if err != nil {
return 0, err
}
end.isV6 = false
if newDst4, ok := newDst.(*unix.SockaddrInet4); ok {
*end.dst4() = *newDst4
}
// update source cache
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
}
return size, nil
}
func receive6(sock int, buff []byte, end *NativeEndpoint) (int, error) {
// construct message header
var cmsg struct {
cmsghdr unix.Cmsghdr
pktinfo unix.Inet6Pktinfo
}
size, _, _, newDst, err := unix.Recvmsg(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], 0)
if err != nil {
return 0, err
}
end.isV6 = true
if newDst6, ok := newDst.(*unix.SockaddrInet6); ok {
*end.dst6() = *newDst6
}
// update source cache
if cmsg.cmsghdr.Level == unix.IPPROTO_IPV6 &&
cmsg.cmsghdr.Type == unix.IPV6_PKTINFO &&
cmsg.cmsghdr.Len >= unix.SizeofInet6Pktinfo {
end.src6().src = cmsg.pktinfo.Addr
end.dst6().ZoneId = cmsg.pktinfo.Ifindex
}
return size, nil
}

12
conn/mark_default.go Normal file
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@@ -0,0 +1,12 @@
// +build !linux,!openbsd,!freebsd
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package conn
func (bind *nativeBind) SetMark(mark uint32) error {
return nil
}

65
conn/mark_unix.go Normal file
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@@ -0,0 +1,65 @@
// +build android openbsd freebsd
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"runtime"
"golang.org/x/sys/unix"
)
var fwmarkIoctl int
func init() {
switch runtime.GOOS {
case "linux", "android":
fwmarkIoctl = 36 /* unix.SO_MARK */
case "freebsd":
fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
case "openbsd":
fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
}
}
func (bind *nativeBind) SetMark(mark uint32) error {
var operr error
if fwmarkIoctl == 0 {
return nil
}
if bind.ipv4 != nil {
fd, err := bind.ipv4.SyscallConn()
if err != nil {
return err
}
err = fd.Control(func(fd uintptr) {
operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
})
if err == nil {
err = operr
}
if err != nil {
return err
}
}
if bind.ipv6 != nil {
fd, err := bind.ipv6.SyscallConn()
if err != nil {
return err
}
err = fd.Control(func(fd uintptr) {
operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
})
if err == nil {
err = operr
}
if err != nil {
return err
}
}
return nil
}