332 lines
7.0 KiB
Go
332 lines
7.0 KiB
Go
package tap
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"io"
|
|
"net"
|
|
"os"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/go-gost/gost/pkg/bypass"
|
|
"github.com/go-gost/gost/pkg/chain"
|
|
"github.com/go-gost/gost/pkg/common/bufpool"
|
|
"github.com/go-gost/gost/pkg/handler"
|
|
tap_util "github.com/go-gost/gost/pkg/internal/util/tap"
|
|
"github.com/go-gost/gost/pkg/logger"
|
|
md "github.com/go-gost/gost/pkg/metadata"
|
|
"github.com/go-gost/gost/pkg/registry"
|
|
"github.com/shadowsocks/go-shadowsocks2/shadowaead"
|
|
"github.com/songgao/water/waterutil"
|
|
"github.com/xtaci/tcpraw"
|
|
)
|
|
|
|
func init() {
|
|
registry.RegisterHandler("tap", NewHandler)
|
|
}
|
|
|
|
type tapHandler struct {
|
|
group *chain.NodeGroup
|
|
chain *chain.Chain
|
|
bypass bypass.Bypass
|
|
routes sync.Map
|
|
exit chan struct{}
|
|
logger logger.Logger
|
|
md metadata
|
|
}
|
|
|
|
func NewHandler(opts ...handler.Option) handler.Handler {
|
|
options := &handler.Options{}
|
|
for _, opt := range opts {
|
|
opt(options)
|
|
}
|
|
|
|
return &tapHandler{
|
|
bypass: options.Bypass,
|
|
exit: make(chan struct{}, 1),
|
|
logger: options.Logger,
|
|
}
|
|
}
|
|
|
|
func (h *tapHandler) Init(md md.Metadata) (err error) {
|
|
return h.parseMetadata(md)
|
|
}
|
|
|
|
// implements chain.Chainable interface
|
|
func (h *tapHandler) WithChain(chain *chain.Chain) {
|
|
h.chain = chain
|
|
}
|
|
|
|
// Forward implements handler.Forwarder.
|
|
func (h *tapHandler) Forward(group *chain.NodeGroup) {
|
|
h.group = group
|
|
}
|
|
|
|
func (h *tapHandler) Handle(ctx context.Context, conn net.Conn) {
|
|
defer os.Exit(0)
|
|
defer conn.Close()
|
|
|
|
cc, ok := conn.(*tap_util.Conn)
|
|
if !ok || cc.Config() == nil {
|
|
h.logger.Error("invalid connection")
|
|
return
|
|
}
|
|
|
|
start := time.Now()
|
|
h.logger = h.logger.WithFields(map[string]interface{}{
|
|
"remote": conn.RemoteAddr().String(),
|
|
"local": conn.LocalAddr().String(),
|
|
})
|
|
|
|
h.logger.Infof("%s <> %s", conn.RemoteAddr(), conn.LocalAddr())
|
|
defer func() {
|
|
h.logger.WithFields(map[string]interface{}{
|
|
"duration": time.Since(start),
|
|
}).Infof("%s >< %s", conn.RemoteAddr(), conn.LocalAddr())
|
|
}()
|
|
|
|
network := "udp"
|
|
var raddr net.Addr
|
|
var err error
|
|
|
|
target := h.group.Next()
|
|
if target != nil {
|
|
raddr, err = net.ResolveUDPAddr(network, target.Addr())
|
|
if err != nil {
|
|
h.logger.Error(err)
|
|
return
|
|
}
|
|
h.logger = h.logger.WithFields(map[string]interface{}{
|
|
"dst": fmt.Sprintf("%s/%s", raddr.String(), raddr.Network()),
|
|
})
|
|
h.logger.Infof("%s >> %s", conn.RemoteAddr(), target.Addr())
|
|
}
|
|
|
|
h.handleLoop(ctx, conn, raddr, cc.Config())
|
|
}
|
|
|
|
func (h *tapHandler) handleLoop(ctx context.Context, conn net.Conn, addr net.Addr, config *tap_util.Config) {
|
|
var tempDelay time.Duration
|
|
for {
|
|
err := func() error {
|
|
var err error
|
|
var pc net.PacketConn
|
|
// fake tcp mode will be ignored when the client specifies a chain.
|
|
if addr != nil && !h.chain.IsEmpty() {
|
|
r := (&chain.Router{}).
|
|
WithChain(h.chain).
|
|
WithRetry(h.md.retryCount).
|
|
WithLogger(h.logger)
|
|
cc, err := r.Dial(ctx, addr.Network(), addr.String())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
pc = &packetConn{cc}
|
|
} else {
|
|
if h.md.tcpMode {
|
|
if addr != nil {
|
|
pc, err = tcpraw.Dial("tcp", addr.String())
|
|
} else {
|
|
pc, err = tcpraw.Listen("tcp", conn.LocalAddr().String())
|
|
}
|
|
} else {
|
|
laddr, _ := net.ResolveUDPAddr("udp", conn.LocalAddr().String())
|
|
pc, err = net.ListenUDP("udp", laddr)
|
|
}
|
|
}
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if h.md.cipher != nil {
|
|
pc = h.md.cipher.PacketConn(pc)
|
|
}
|
|
|
|
return h.transport(conn, pc, addr)
|
|
}()
|
|
if err != nil {
|
|
h.logger.Error(err)
|
|
}
|
|
|
|
select {
|
|
case <-h.exit:
|
|
return
|
|
default:
|
|
}
|
|
|
|
if err != nil {
|
|
if tempDelay == 0 {
|
|
tempDelay = 1000 * time.Millisecond
|
|
} else {
|
|
tempDelay *= 2
|
|
}
|
|
if max := 6 * time.Second; tempDelay > max {
|
|
tempDelay = max
|
|
}
|
|
time.Sleep(tempDelay)
|
|
continue
|
|
}
|
|
tempDelay = 0
|
|
}
|
|
|
|
}
|
|
|
|
func (h *tapHandler) transport(tap net.Conn, conn net.PacketConn, raddr net.Addr) error {
|
|
errc := make(chan error, 1)
|
|
|
|
go func() {
|
|
for {
|
|
err := func() error {
|
|
b := bufpool.Get(h.md.bufferSize)
|
|
defer bufpool.Put(b)
|
|
|
|
n, err := tap.Read(b)
|
|
if err != nil {
|
|
select {
|
|
case h.exit <- struct{}{}:
|
|
default:
|
|
}
|
|
return err
|
|
}
|
|
|
|
src := waterutil.MACSource(b[:n])
|
|
dst := waterutil.MACDestination(b[:n])
|
|
eType := etherType(waterutil.MACEthertype(b[:n]))
|
|
|
|
h.logger.Debugf("%s >> %s %s %d", src, dst, eType, n)
|
|
|
|
// client side, deliver frame directly.
|
|
if raddr != nil {
|
|
_, err := conn.WriteTo(b[:n], raddr)
|
|
return err
|
|
}
|
|
|
|
// server side, broadcast.
|
|
if waterutil.IsBroadcast(dst) {
|
|
go h.routes.Range(func(k, v interface{}) bool {
|
|
conn.WriteTo(b[:n], v.(net.Addr))
|
|
return true
|
|
})
|
|
return nil
|
|
}
|
|
|
|
var addr net.Addr
|
|
if v, ok := h.routes.Load(hwAddrToTapRouteKey(dst)); ok {
|
|
addr = v.(net.Addr)
|
|
}
|
|
if addr == nil {
|
|
h.logger.Warnf("no route for %s -> %s %s %d", src, dst, eType, n)
|
|
return nil
|
|
}
|
|
|
|
if _, err := conn.WriteTo(b[:n], addr); err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}()
|
|
|
|
if err != nil {
|
|
errc <- err
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
go func() {
|
|
for {
|
|
err := func() error {
|
|
b := bufpool.Get(h.md.bufferSize)
|
|
defer bufpool.Put(b)
|
|
|
|
n, addr, err := conn.ReadFrom(b)
|
|
if err != nil &&
|
|
err != shadowaead.ErrShortPacket {
|
|
return err
|
|
}
|
|
|
|
src := waterutil.MACSource(b[:n])
|
|
dst := waterutil.MACDestination(b[:n])
|
|
eType := etherType(waterutil.MACEthertype(b[:n]))
|
|
|
|
h.logger.Debugf("%s >> %s %s %d", src, dst, eType, n)
|
|
|
|
// client side, deliver frame to tap device.
|
|
if raddr != nil {
|
|
_, err := tap.Write(b[:n])
|
|
return err
|
|
}
|
|
|
|
// server side, record route.
|
|
rkey := hwAddrToTapRouteKey(src)
|
|
if actual, loaded := h.routes.LoadOrStore(rkey, addr); loaded {
|
|
if actual.(net.Addr).String() != addr.String() {
|
|
h.logger.Debugf("update route: %s -> %s (old %s)",
|
|
src, addr, actual.(net.Addr))
|
|
h.routes.Store(rkey, addr)
|
|
}
|
|
} else {
|
|
h.logger.Debugf("new route: %s -> %s", src, addr)
|
|
}
|
|
|
|
if waterutil.IsBroadcast(dst) {
|
|
go h.routes.Range(func(k, v interface{}) bool {
|
|
if k.(tapRouteKey) != rkey {
|
|
conn.WriteTo(b[:n], v.(net.Addr))
|
|
}
|
|
return true
|
|
})
|
|
}
|
|
|
|
if v, ok := h.routes.Load(hwAddrToTapRouteKey(dst)); ok {
|
|
h.logger.Debugf("find route: %s -> %s", dst, v)
|
|
_, err := conn.WriteTo(b[:n], v.(net.Addr))
|
|
return err
|
|
}
|
|
|
|
if _, err := tap.Write(b[:n]); err != nil {
|
|
select {
|
|
case h.exit <- struct{}{}:
|
|
default:
|
|
}
|
|
return err
|
|
}
|
|
return nil
|
|
}()
|
|
|
|
if err != nil {
|
|
errc <- err
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
err := <-errc
|
|
if err != nil && err == io.EOF {
|
|
err = nil
|
|
}
|
|
return err
|
|
}
|
|
|
|
var mEtherTypes = map[waterutil.Ethertype]string{
|
|
waterutil.IPv4: "ip",
|
|
waterutil.ARP: "arp",
|
|
waterutil.RARP: "rarp",
|
|
waterutil.IPv6: "ip6",
|
|
}
|
|
|
|
func etherType(et waterutil.Ethertype) string {
|
|
if s, ok := mEtherTypes[et]; ok {
|
|
return s
|
|
}
|
|
return fmt.Sprintf("unknown(%v)", et)
|
|
}
|
|
|
|
type tapRouteKey [6]byte
|
|
|
|
func hwAddrToTapRouteKey(addr net.HardwareAddr) (key tapRouteKey) {
|
|
copy(key[:], addr)
|
|
return
|
|
}
|