ginuerzh
d5fd62aa47
Translate all Chinese comments in the relay handler package to English: handler.go, connect.go, bind.go, forward.go, conn.go, entrypoint.go, observe.go, metadata.go. All inline and doc comments are now in English. Also set a persistent preference: all future code comments must be written in English only.
305 lines
9.6 KiB
Go
305 lines
9.6 KiB
Go
package relay
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"net"
|
|
"strconv"
|
|
"time"
|
|
|
|
"github.com/go-gost/core/auth"
|
|
"github.com/go-gost/core/handler"
|
|
"github.com/go-gost/core/hop"
|
|
"github.com/go-gost/core/limiter"
|
|
"github.com/go-gost/core/limiter/traffic"
|
|
md "github.com/go-gost/core/metadata"
|
|
"github.com/go-gost/core/observer/stats"
|
|
"github.com/go-gost/core/recorder"
|
|
"github.com/go-gost/relay"
|
|
xctx "github.com/go-gost/x/ctx"
|
|
stats_util "github.com/go-gost/x/internal/util/stats"
|
|
tls_util "github.com/go-gost/x/internal/util/tls"
|
|
rate_limiter "github.com/go-gost/x/limiter/rate"
|
|
cache_limiter "github.com/go-gost/x/limiter/traffic/cache"
|
|
xstats "github.com/go-gost/x/observer/stats"
|
|
stats_wrapper "github.com/go-gost/x/observer/stats/wrapper"
|
|
xrecorder "github.com/go-gost/x/recorder"
|
|
"github.com/go-gost/x/registry"
|
|
)
|
|
|
|
var (
|
|
ErrBadVersion = errors.New("relay: bad version")
|
|
ErrUnknownCmd = errors.New("relay: unknown command")
|
|
ErrUnauthorized = errors.New("relay: unauthorized")
|
|
)
|
|
|
|
func init() {
|
|
registry.HandlerRegistry().Register("relay", NewHandler)
|
|
}
|
|
|
|
// relayHandler is the GOST relay protocol server handler.
|
|
//
|
|
// The GOST relay protocol is a custom multiplexed transport supporting three modes:
|
|
// 1. Connect — the client requests a connection to a target address.
|
|
// The handler dials via the configured Router and pipes data bidirectionally.
|
|
// - Direct: handleConnect(), target address from the relay request.
|
|
// - Forward: handleForward(), target from hop selector (load balancing).
|
|
// 2. Bind — the client asks the handler to listen on a local port and forward
|
|
// incoming connections back through a mux session. Used for reverse proxying.
|
|
// 3. Forward — when a hop is set, the target is selected by the hop's strategy
|
|
// rather than specified by the client.
|
|
//
|
|
// Data flow:
|
|
//
|
|
// ┌─────────────────────────────────────────────────────────┐
|
|
// │ Handle() → parse relay.Request │
|
|
// │ ├─ extract auth (UserAuthFeature) → authenticate │
|
|
// │ ├─ extract target address (AddrFeature) │
|
|
// │ └─ extract network type (NetworkFeature) │
|
|
// │ │
|
|
// │ ┌── hop set? ──→ handleForward() │
|
|
// │ │ ├─ hop.Select() pick target node │
|
|
// │ │ └─ Router.Dial() → Pipe bidir copy │
|
|
// │ │
|
|
// │ └── no hop, dispatch by command: │
|
|
// │ ├─ CmdConnect → handleConnect() │
|
|
// │ │ ├─ bypass check │
|
|
// │ │ ├─ consistent-hashing │
|
|
// │ │ ├─ Router.Dial() / net.Dial() / serial.Open │
|
|
// │ │ ├─ send response header (noDelay) │
|
|
// │ │ ├─ optional protocol sniffing (HTTP/TLS MITM) │
|
|
// │ │ └─ Pipe bidir data copy │
|
|
// │ └─ CmdBind → handleBind() │
|
|
// │ ├─ bindTCP: net.Listen → mux session → tcpHandler │
|
|
// │ └─ bindUDP: net.ListenPacket → udp.Relay │
|
|
// └─────────────────────────────────────────────────────────┘
|
|
type relayHandler struct {
|
|
hop hop.Hop
|
|
md metadata
|
|
options handler.Options
|
|
stats *stats_util.HandlerStats
|
|
limiter traffic.TrafficLimiter
|
|
cancel context.CancelFunc
|
|
recorder recorder.RecorderObject
|
|
certPool tls_util.CertPool
|
|
}
|
|
|
|
func NewHandler(opts ...handler.Option) handler.Handler {
|
|
options := handler.Options{}
|
|
for _, opt := range opts {
|
|
opt(&options)
|
|
}
|
|
|
|
return &relayHandler{
|
|
options: options,
|
|
}
|
|
}
|
|
|
|
// Init 初始化 relay handler。在 handler 被注册到 service 后调用。
|
|
//
|
|
// 初始化流程：
|
|
// 1. 解析元数据配置（超时、嗅探、mux、MITM 等）
|
|
// 2. 如果配置了 Observer，创建 stats 统计器并启动后台轮询协程
|
|
// 3. 如果配置了 TrafficLimiter，创建带缓存的流量限制器
|
|
// 4. 从 Recorders 列表中选取 ServiceHandler 类型的 recorder
|
|
// 5. 如果配置了 MITM 证书，创建内存证书池
|
|
func (h *relayHandler) Init(md md.Metadata) (err error) {
|
|
if err := h.parseMetadata(md); err != nil {
|
|
return err
|
|
}
|
|
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
h.cancel = cancel
|
|
|
|
if h.options.Observer != nil {
|
|
h.stats = stats_util.NewHandlerStats(h.options.Service, h.md.observerResetTraffic)
|
|
go h.observeStats(ctx)
|
|
}
|
|
|
|
if h.options.Limiter != nil {
|
|
h.limiter = cache_limiter.NewCachedTrafficLimiter(h.options.Limiter,
|
|
cache_limiter.RefreshIntervalOption(h.md.limiterRefreshInterval),
|
|
cache_limiter.CleanupIntervalOption(h.md.limiterCleanupInterval),
|
|
cache_limiter.ScopeOption(limiter.ScopeClient),
|
|
)
|
|
}
|
|
|
|
for _, ro := range h.options.Recorders {
|
|
if ro.Record == xrecorder.RecorderServiceHandler {
|
|
h.recorder = ro
|
|
break
|
|
}
|
|
}
|
|
|
|
if h.md.certificate != nil && h.md.privateKey != nil {
|
|
h.certPool = tls_util.NewMemoryCertPool()
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Forward implements handler.Forwarder.
|
|
func (h *relayHandler) Forward(hop hop.Hop) {
|
|
h.hop = hop
|
|
}
|
|
|
|
// Handle is the main entry point for each inbound connection.
|
|
//
|
|
// Flow:
|
|
// 1. Create a recorder object with connection metadata.
|
|
// 2. Wrap the connection for stats collection (input/output bytes).
|
|
// 3. Rate-limit check.
|
|
// 4. Set read deadline, read the relay.Request.
|
|
// 5. Clear the read deadline.
|
|
// 6. Check the relay protocol version.
|
|
// 7. Parse request features (auth, address, network type).
|
|
// 8. Authenticate (if an Auther is configured).
|
|
// 9. Dispatch:
|
|
// - If hop is set → handleForward.
|
|
// - CmdConnect → handleConnect.
|
|
// - CmdBind → handleBind.
|
|
// 10. Deferred final stats recording.
|
|
func (h *relayHandler) Handle(ctx context.Context, conn net.Conn, opts ...handler.HandleOption) (err error) {
|
|
defer conn.Close()
|
|
|
|
start := time.Now()
|
|
|
|
ro := &xrecorder.HandlerRecorderObject{
|
|
Network: "tcp",
|
|
Service: h.options.Service,
|
|
RemoteAddr: conn.RemoteAddr().String(),
|
|
LocalAddr: conn.LocalAddr().String(),
|
|
SID: xctx.SidFromContext(ctx).String(),
|
|
Time: start,
|
|
}
|
|
|
|
if srcAddr := xctx.SrcAddrFromContext(ctx); srcAddr != nil {
|
|
ro.ClientAddr = srcAddr.String()
|
|
}
|
|
|
|
log := h.options.Logger.WithFields(map[string]any{
|
|
"network": ro.Network,
|
|
"remote": conn.RemoteAddr().String(),
|
|
"local": conn.LocalAddr().String(),
|
|
"client": ro.ClientAddr,
|
|
"sid": ro.SID,
|
|
})
|
|
|
|
log.Infof("%s <> %s", conn.RemoteAddr(), conn.LocalAddr())
|
|
|
|
pStats := xstats.Stats{}
|
|
conn = stats_wrapper.WrapConn(conn, &pStats)
|
|
|
|
defer func() {
|
|
if err != nil {
|
|
ro.Err = err.Error()
|
|
}
|
|
ro.InputBytes = pStats.Get(stats.KindInputBytes)
|
|
ro.OutputBytes = pStats.Get(stats.KindOutputBytes)
|
|
ro.Duration = time.Since(start)
|
|
if err := ro.Record(ctx, h.recorder.Recorder); err != nil {
|
|
log.Errorf("record: %v", err)
|
|
}
|
|
|
|
log.WithFields(map[string]any{
|
|
"duration": time.Since(start),
|
|
"inputBytes": ro.InputBytes,
|
|
"outputBytes": ro.OutputBytes,
|
|
}).Infof("%s >< %s", conn.RemoteAddr(), conn.LocalAddr())
|
|
}()
|
|
|
|
if !h.checkRateLimit(conn.RemoteAddr()) {
|
|
return rate_limiter.ErrRateLimit
|
|
}
|
|
|
|
if h.md.readTimeout > 0 {
|
|
conn.SetReadDeadline(time.Now().Add(h.md.readTimeout))
|
|
}
|
|
|
|
req := relay.Request{}
|
|
if _, err := req.ReadFrom(conn); err != nil {
|
|
return err
|
|
}
|
|
|
|
conn.SetReadDeadline(time.Time{})
|
|
|
|
resp := relay.Response{
|
|
Version: relay.Version1,
|
|
Status: relay.StatusOK,
|
|
}
|
|
|
|
if req.Version != relay.Version1 {
|
|
resp.Status = relay.StatusBadRequest
|
|
resp.WriteTo(conn)
|
|
return ErrBadVersion
|
|
}
|
|
|
|
var user, pass string
|
|
var address string
|
|
var networkID relay.NetworkID
|
|
for _, f := range req.Features {
|
|
switch f.Type() {
|
|
case relay.FeatureUserAuth:
|
|
if feature, _ := f.(*relay.UserAuthFeature); feature != nil {
|
|
user, pass = feature.Username, feature.Password
|
|
}
|
|
case relay.FeatureAddr:
|
|
if feature, _ := f.(*relay.AddrFeature); feature != nil {
|
|
address = net.JoinHostPort(feature.Host, strconv.Itoa(int(feature.Port)))
|
|
}
|
|
case relay.FeatureNetwork:
|
|
if feature, _ := f.(*relay.NetworkFeature); feature != nil {
|
|
networkID = feature.Network
|
|
}
|
|
}
|
|
}
|
|
|
|
if user != "" {
|
|
ro.ClientID = user
|
|
log = log.WithFields(map[string]any{"user": user})
|
|
}
|
|
|
|
if h.options.Auther != nil {
|
|
clientID, ok := h.options.Auther.Authenticate(ctx, user, pass, auth.WithService(h.options.Service))
|
|
if !ok {
|
|
resp.Status = relay.StatusUnauthorized
|
|
resp.WriteTo(conn)
|
|
return ErrUnauthorized
|
|
}
|
|
log = log.WithFields(map[string]any{"clientID": clientID})
|
|
ro.ClientID = clientID
|
|
ctx = xctx.ContextWithClientID(ctx, xctx.ClientID(clientID))
|
|
}
|
|
|
|
network := networkID.String()
|
|
if (req.Cmd & relay.FUDP) == relay.FUDP {
|
|
network = "udp"
|
|
}
|
|
ro.Network = network
|
|
ro.Host = address
|
|
log = log.WithFields(map[string]any{"network": network})
|
|
|
|
if h.hop != nil {
|
|
// Forward mode: target is selected from the hop.
|
|
return h.handleForward(ctx, conn, network, ro, log)
|
|
}
|
|
|
|
switch req.Cmd & relay.CmdMask {
|
|
case 0, relay.CmdConnect:
|
|
return h.handleConnect(ctx, conn, network, address, ro, log)
|
|
case relay.CmdBind:
|
|
return h.handleBind(ctx, conn, network, address, ro, log)
|
|
default:
|
|
resp.Status = relay.StatusBadRequest
|
|
resp.WriteTo(conn)
|
|
return ErrUnknownCmd
|
|
}
|
|
}
|
|
|
|
// Close implements io.Closer interface.
|
|
func (h *relayHandler) Close() error {
|
|
if h.cancel != nil {
|
|
h.cancel()
|
|
}
|
|
return nil
|
|
} |