add vtun listener and handler

This commit is contained in:
ginuerzh
2025-07-23 21:30:21 +08:00
parent afcf4a5252
commit acae52ab89
20 changed files with 1157 additions and 85 deletions
+161
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@@ -0,0 +1,161 @@
// Package iobased provides the implementation of io.ReadWriter
// based data-link layer endpoints.
package tun
import (
"context"
"errors"
"io"
"sync"
"github.com/go-gost/core/logger"
"gvisor.dev/gvisor/pkg/buffer"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
"gvisor.dev/gvisor/pkg/tcpip/stack"
)
const (
// Queue length for outbound packet, arriving for read. Overflow
// causes packet drops.
defaultOutQueueLen = 1 << 10
)
// Endpoint implements the interface of stack.LinkEndpoint from io.ReadWriter.
type Endpoint struct {
*channel.Endpoint
// rw is the io.ReadWriter for reading and writing packets.
rw io.ReadWriter
// mtu (maximum transmission unit) is the maximum size of a packet.
mtu uint32
// offset can be useful when perform TUN device I/O with TUN_PI enabled.
offset int
// once is used to perform the init action once when attaching.
once sync.Once
// wg keeps track of running goroutines.
wg sync.WaitGroup
log logger.Logger
}
// New returns stack.LinkEndpoint(.*Endpoint) and error.
func newEndpoint(rw io.ReadWriter, mtu uint32, offset int, log logger.Logger) (*Endpoint, error) {
if mtu == 0 {
return nil, errors.New("MTU size is zero")
}
if rw == nil {
return nil, errors.New("RW interface is nil")
}
if offset < 0 {
return nil, errors.New("offset must be non-negative")
}
return &Endpoint{
Endpoint: channel.New(defaultOutQueueLen, mtu, ""),
rw: rw,
mtu: mtu,
offset: offset,
log: log,
}, nil
}
// Attach launches the goroutine that reads packets from io.Reader and
// dispatches them via the provided dispatcher.
func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher) {
e.Endpoint.Attach(dispatcher)
e.once.Do(func() {
ctx, cancel := context.WithCancel(context.Background())
e.wg.Add(2)
go func() {
e.outboundLoop(ctx)
e.wg.Done()
}()
go func() {
e.dispatchLoop(cancel)
e.wg.Done()
}()
})
}
func (e *Endpoint) Wait() {
e.wg.Wait()
}
// dispatchLoop dispatches packets to upper layer.
func (e *Endpoint) dispatchLoop(cancel context.CancelFunc) {
// Call cancel() to ensure (*Endpoint).outboundLoop(context.Context) exits
// gracefully after (*Endpoint).dispatchLoop(context.CancelFunc) returns.
defer cancel()
offset, mtu := e.offset, int(e.mtu)
for {
data := make([]byte, offset+mtu)
n, err := e.rw.Read(data)
if err != nil {
e.log.Error(err)
break
}
e.log.Debugf("read tun: (%d) % x", n, data[:n])
if n == 0 || n > mtu {
continue
}
if !e.IsAttached() {
continue /* unattached, drop packet */
}
pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
Payload: buffer.MakeWithData(data[offset : offset+n]),
})
switch header.IPVersion(data[offset:]) {
case header.IPv4Version:
e.InjectInbound(header.IPv4ProtocolNumber, pkt)
case header.IPv6Version:
e.InjectInbound(header.IPv6ProtocolNumber, pkt)
}
pkt.DecRef()
}
}
// outboundLoop reads outbound packets from channel, and then it calls
// writePacket to send those packets back to lower layer.
func (e *Endpoint) outboundLoop(ctx context.Context) {
for {
pkt := e.ReadContext(ctx)
if pkt == nil {
break
}
e.writePacket(pkt)
}
}
// writePacket writes outbound packets to the io.Writer.
func (e *Endpoint) writePacket(pkt *stack.PacketBuffer) tcpip.Error {
defer pkt.DecRef()
buf := pkt.ToBuffer()
defer buf.Release()
if e.offset != 0 {
v := buffer.NewViewWithData(make([]byte, e.offset))
_ = buf.Prepend(v)
}
if _, err := e.rw.Write(buf.Flatten()); err != nil {
return &tcpip.ErrInvalidEndpointState{}
}
return nil
}
+84
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package tun
import (
"context"
"net"
"time"
"github.com/go-gost/core/handler"
md "github.com/go-gost/core/metadata"
ctxvalue "github.com/go-gost/x/ctx"
"github.com/go-gost/x/registry"
"github.com/xjasonlyu/tun2socks/v2/core"
)
func init() {
registry.HandlerRegistry().Register("vtun", NewHandler)
}
type tunHandler struct {
options handler.Options
}
func NewHandler(opts ...handler.Option) handler.Handler {
options := handler.Options{}
for _, opt := range opts {
opt(&options)
}
return &tunHandler{
options: options,
}
}
func (h *tunHandler) Init(md md.Metadata) (err error) {
if err = h.parseMetadata(md); err != nil {
return
}
return
}
func (h *tunHandler) Handle(ctx context.Context, conn net.Conn, opts ...handler.HandleOption) error {
defer conn.Close()
log := h.options.Logger
start := time.Now()
log = log.WithFields(map[string]any{
"remote": conn.RemoteAddr().String(),
"local": conn.LocalAddr().String(),
"sid": ctxvalue.SidFromContext(ctx),
})
log.Infof("%s <> %s", conn.RemoteAddr(), conn.LocalAddr())
defer func() {
log.WithFields(map[string]any{
"duration": time.Since(start),
}).Infof("%s >< %s", conn.RemoteAddr(), conn.LocalAddr())
}()
ep, err := newEndpoint(conn, 1420, 0, log)
if err != nil {
return err
}
th := newTransportHandler(log)
th.ProcessAsync()
defer th.Close()
stack, err := core.CreateStack(&core.Config{
LinkEndpoint: ep,
TransportHandler: th,
})
if err != nil {
return err
}
defer stack.Close()
log.Debugf("is attached: %v", ep.IsAttached())
<-ctx.Done()
return nil
}
+12
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package tun
import (
mdata "github.com/go-gost/core/metadata"
)
type metadata struct {
}
func (h *tunHandler) parseMetadata(md mdata.Metadata) (err error) {
return
}
+105
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@@ -0,0 +1,105 @@
package tun
import (
"context"
"net/netip"
"sync"
"time"
"github.com/go-gost/core/logger"
"github.com/xjasonlyu/tun2socks/v2/core/adapter"
"go.uber.org/atomic"
)
const (
// tcpConnectTimeout is the default timeout for TCP handshakes.
tcpConnectTimeout = 5 * time.Second
// tcpWaitTimeout implements a TCP half-close timeout.
tcpWaitTimeout = 60 * time.Second
// udpSessionTimeout is the default timeout for UDP sessions.
udpSessionTimeout = 60 * time.Second
)
var _ adapter.TransportHandler = (*transportHandler)(nil)
type transportHandler struct {
// Unbuffered TCP/UDP queues.
tcpQueue chan adapter.TCPConn
udpQueue chan adapter.UDPConn
// UDP session timeout.
udpTimeout *atomic.Duration
procOnce sync.Once
procCancel context.CancelFunc
log logger.Logger
}
func newTransportHandler(log logger.Logger) *transportHandler {
return &transportHandler{
tcpQueue: make(chan adapter.TCPConn),
udpQueue: make(chan adapter.UDPConn),
udpTimeout: atomic.NewDuration(udpSessionTimeout),
procCancel: func() { /* nop */ },
log: log,
}
}
func (t *transportHandler) HandleTCP(conn adapter.TCPConn) {
t.tcpQueue <- conn
}
func (t *transportHandler) HandleUDP(conn adapter.UDPConn) {
t.udpQueue <- conn
}
func (t *transportHandler) process(ctx context.Context) {
for {
select {
case conn := <-t.tcpQueue:
go t.handleTCPConn(conn)
case conn := <-t.udpQueue:
go t.handleUDPConn(conn)
case <-ctx.Done():
return
}
}
}
// ProcessAsync can be safely called multiple times, but will only be effective once.
func (t *transportHandler) ProcessAsync() {
t.procOnce.Do(func() {
ctx, cancel := context.WithCancel(context.Background())
t.procCancel = cancel
go t.process(ctx)
})
}
// Close closes the Tunnel and releases its resources.
func (t *transportHandler) Close() {
t.procCancel()
}
func (t *transportHandler) SetUDPTimeout(timeout time.Duration) {
t.udpTimeout.Store(timeout)
}
func (t *transportHandler) handleTCPConn(originConn adapter.TCPConn) {
defer originConn.Close()
id := originConn.ID()
srcIP, _ := netip.AddrFromSlice(id.RemoteAddress.AsSlice())
dstIP, _ := netip.AddrFromSlice(id.LocalAddress.AsSlice())
raddr := netip.AddrPortFrom(srcIP, id.RemotePort)
laddr := netip.AddrPortFrom(dstIP, id.LocalPort)
t.log.Debugf("[TCP] %s <-> %s", raddr.String(), laddr.String())
}
// TODO: Port Restricted NAT support.
func (t *transportHandler) handleUDPConn(uc adapter.UDPConn) {
defer uc.Close()
}