mirror of
https://github.com/e1732a364fed/v2ray_simple.git
synced 2025-12-24 13:27:56 +08:00
279 lines
7.1 KiB
Go
279 lines
7.1 KiB
Go
/*
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Packages tun provides utilities for tun.
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tun包提供 创建tun设备的方法，以及监听tun，将数据解析为tcp/udp数据的方法。
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tun 工作在第三层 IP层上。
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我们基本上抄了 xjasonlyu/tun2socks, 因此把GPL证书放在了本包的文件夹中
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本来最好是直接import的，但是目前（22.12.18）tun2socks的最新代码还没有打tag，而老代码又不可用，所以只能先复制过来。
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windows中,
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需要从 https://www.wintun.net/ 下载 wintun.dll 放到vs可执行文件旁边
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*/
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package tun
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import (
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"errors"
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"io"
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"log"
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"net"
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"strconv"
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"time"
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"github.com/e1732a364fed/v2ray_simple/netLayer"
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"github.com/e1732a364fed/v2ray_simple/netLayer/tun/device"
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"github.com/e1732a364fed/v2ray_simple/netLayer/tun/device/fdbased"
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"github.com/e1732a364fed/v2ray_simple/netLayer/tun/device/tun"
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"github.com/e1732a364fed/v2ray_simple/netLayer/tun/option"
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"github.com/e1732a364fed/v2ray_simple/utils"
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"gvisor.dev/gvisor/pkg/tcpip"
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"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
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"gvisor.dev/gvisor/pkg/tcpip/header"
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"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
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"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
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"gvisor.dev/gvisor/pkg/tcpip/stack"
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"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
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"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
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"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
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"gvisor.dev/gvisor/pkg/waiter"
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)
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// 若name为空则会返回错误. 若name可转换为数字，则会将其解析为fd 号
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func Open(name string) (device.Device, error) {
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if name == "" {
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return nil, errors.New("tun: dev name can't be empty")
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}
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_, err := strconv.Atoi(name)
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if err == nil {
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return fdbased.Open(name, uint32(utils.MTU))
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}
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return tun.Open(name, uint32(utils.MTU))
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}
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type StackCloser struct {
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*stack.Stack
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}
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func (sc *StackCloser) Close() error {
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sc.Stack.Close()
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//sc.Stack.Wait() //这个会卡住; 经测试，不调用它也不影响什么
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return nil
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}
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// 非阻塞
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func Listen(dev device.Device, tcpFunc func(netLayer.TCPRequestInfo), udpFunc func(netLayer.UDPRequestInfo)) (closer io.Closer, err error) {
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s := stack.New(stack.Options{
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NetworkProtocols: []stack.NetworkProtocolFactory{
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ipv4.NewProtocol,
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ipv6.NewProtocol,
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},
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TransportProtocols: []stack.TransportProtocolFactory{
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tcp.NewProtocol,
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udp.NewProtocol,
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icmp.NewProtocol4,
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icmp.NewProtocol6,
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},
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})
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closer = &StackCloser{Stack: s}
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opts := []option.Option{option.WithDefault()}
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for _, opt := range opts {
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if err = opt(s); err != nil {
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return
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}
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}
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nicID := tcpip.NICID(s.UniqueID())
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if ex := s.CreateNICWithOptions(nicID, dev,
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stack.NICOptions{
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Disabled: false,
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// If no queueing discipline was specified
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// provide a stub implementation that just
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// delegates to the lower link endpoint.
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QDisc: nil,
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}); ex != nil {
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err = utils.ErrInErr{ErrDesc: ex.String()}
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return
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}
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const defaultWndSize = 0
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const maxConnAttempts int = 2048
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tcpForwarder := tcp.NewForwarder(s, defaultWndSize, maxConnAttempts, func(r *tcp.ForwarderRequest) {
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var (
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wq waiter.Queue
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ep tcpip.Endpoint
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err tcpip.Error
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id = r.ID()
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)
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// Perform a TCP three-way handshake.
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ep, err = r.CreateEndpoint(&wq)
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if err != nil {
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// RST: prevent potential half-open TCP connection leak.
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r.Complete(true)
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return
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}
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setSocketOptions(s, ep)
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tcpConn := gonet.NewTCPConn(&wq, ep)
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info := netLayer.TCPRequestInfo{
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Conn: tcpConn,
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//比较反直觉
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Target: netLayer.Addr{
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Network: "tcp",
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IP: net.IP(id.LocalAddress),
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Port: int(id.LocalPort),
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},
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}
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// log.Printf("forward tcp request %s:%d->%s:%d\n",
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// id.RemoteAddress, id.RemotePort, id.LocalAddress, id.LocalPort)
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go tcpFunc(info)
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r.Complete(false)
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})
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s.SetTransportProtocolHandler(tcp.ProtocolNumber, tcpForwarder.HandlePacket)
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udpForwarder := udp.NewForwarder(s, func(r *udp.ForwarderRequest) {
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var (
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wq waiter.Queue
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id = r.ID()
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)
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ep, err := r.CreateEndpoint(&wq)
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if err != nil {
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log.Printf("tun Err, udp forwarder request %s:%d->%s:%d: %\n",
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id.RemoteAddress, id.RemotePort, id.LocalAddress, id.LocalPort, err)
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return
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}
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udpConn := gonet.NewUDPConn(s, &wq, ep)
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ad := netLayer.Addr{
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Network: "udp",
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IP: net.IP(id.LocalAddress),
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Port: int(id.LocalPort),
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}
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info := netLayer.UDPRequestInfo{
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MsgConn: &UdpMsgConn{
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PacketConn: udpConn,
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RealTarget: ad,
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},
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Target: ad,
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}
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go udpFunc(info)
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})
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s.SetTransportProtocolHandler(udp.ProtocolNumber, udpForwarder.HandlePacket)
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s.SetPromiscuousMode(nicID, true) //必须调用这个,否则tun什么也收不到
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s.SetSpoofing(nicID, true)
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s.SetRouteTable([]tcpip.Route{
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{
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Destination: header.IPv4EmptySubnet,
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NIC: nicID,
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},
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{
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Destination: header.IPv6EmptySubnet,
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NIC: nicID,
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},
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})
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return
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}
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func setSocketOptions(s *stack.Stack, ep tcpip.Endpoint) tcpip.Error {
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{ /* TCP keepalive options */
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ep.SocketOptions().SetKeepAlive(true)
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const tcpKeepaliveIdle time.Duration = time.Minute
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idle := tcpip.KeepaliveIdleOption(tcpKeepaliveIdle)
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if err := ep.SetSockOpt(&idle); err != nil {
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return err
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}
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const tcpKeepaliveInterval time.Duration = 30 * time.Second
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interval := tcpip.KeepaliveIntervalOption(tcpKeepaliveInterval)
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if err := ep.SetSockOpt(&interval); err != nil {
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return err
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}
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const tcpKeepaliveCount int = 9
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if err := ep.SetSockOptInt(tcpip.KeepaliveCountOption, tcpKeepaliveCount); err != nil {
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return err
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}
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}
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{ /* TCP recv/send buffer size */
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var ss tcpip.TCPSendBufferSizeRangeOption
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if err := s.TransportProtocolOption(header.TCPProtocolNumber, &ss); err == nil {
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ep.SocketOptions().SetReceiveBufferSize(int64(ss.Default), false)
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}
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var rs tcpip.TCPReceiveBufferSizeRangeOption
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if err := s.TransportProtocolOption(header.TCPProtocolNumber, &rs); err == nil {
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ep.SocketOptions().SetReceiveBufferSize(int64(rs.Default), false)
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}
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}
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return nil
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}
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// Wraps net.PacketConn and implements MsgConn
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type UdpMsgConn struct {
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net.PacketConn
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RealTarget netLayer.Addr
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tunSrcAddr net.Addr
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}
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func (mc *UdpMsgConn) ReadMsg() ([]byte, netLayer.Addr, error) {
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bs := utils.GetPacket()
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n, ad, err := mc.ReadFrom(bs)
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if err != nil {
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return nil, mc.RealTarget, err
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}
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mc.tunSrcAddr = ad
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return bs[:n], mc.RealTarget, nil
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}
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func (mc *UdpMsgConn) WriteMsg(p []byte, peera netLayer.Addr) error {
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//这里的peera是 远程地址，不是我们要写向的地址。在tun中我们要发向之前的tun的地址
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//笔记：那么在哪里传回远程地址的信息呢，如果不设该信息，不就无法进行fullcone了吗？
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//根据下面讨论，果然，这样不行。
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//https://github.com/xjasonlyu/tun2socks/issues/112
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// 看来似乎不应该采用tun2socks目前重构后的方法而应该用它在2.4.0之前的旧方法
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// 然而旧方法所使用的 gvisor包已经过时了。我尝试了一次，失败了，代码放在 tun_failed中备用。
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_, err := mc.WriteTo(p, mc.tunSrcAddr)
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return err
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}
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func (mc *UdpMsgConn) CloseConnWithRaddr(raddr netLayer.Addr) error {
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return mc.PacketConn.Close()
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}
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func (mc *UdpMsgConn) Close() error {
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return mc.PacketConn.Close()
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}
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func (mc *UdpMsgConn) Fullcone() bool {
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return false
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}
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