gost/pkg/handler/ss/handler.go
2021-11-12 16:44:31 +08:00

149 lines
3.0 KiB
Go

package ss
import (
"bufio"
"context"
"io"
"io/ioutil"
"net"
"time"
"github.com/go-gost/gosocks5"
"github.com/go-gost/gost/pkg/bypass"
"github.com/go-gost/gost/pkg/chain"
"github.com/go-gost/gost/pkg/handler"
"github.com/go-gost/gost/pkg/internal/utils/ss"
"github.com/go-gost/gost/pkg/logger"
md "github.com/go-gost/gost/pkg/metadata"
"github.com/go-gost/gost/pkg/registry"
)
func init() {
registry.RegisterHandler("ss", NewHandler)
}
type ssHandler struct {
chain *chain.Chain
bypass bypass.Bypass
logger logger.Logger
md metadata
}
func NewHandler(opts ...handler.Option) handler.Handler {
options := &handler.Options{}
for _, opt := range opts {
opt(options)
}
return &ssHandler{
chain: options.Chain,
bypass: options.Bypass,
logger: options.Logger,
}
}
func (h *ssHandler) Init(md md.Metadata) (err error) {
return h.parseMetadata(md)
}
func (h *ssHandler) Handle(ctx context.Context, conn net.Conn) {
defer conn.Close()
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())
}()
// standard UDP relay.
if pc, ok := conn.(net.PacketConn); ok {
if h.md.enableUDP {
h.handleUDP(ctx, conn.RemoteAddr(), pc)
return
} else {
h.logger.Error("UDP relay is diabled")
}
return
}
if h.md.cipher != nil {
conn = ss.ShadowConn(h.md.cipher.StreamConn(conn), nil)
}
if h.md.readTimeout > 0 {
conn.SetReadDeadline(time.Now().Add(h.md.readTimeout))
}
br := bufio.NewReader(conn)
data, err := br.Peek(3)
if err != nil {
h.logger.Error(err)
h.discard(conn)
return
}
conn.SetReadDeadline(time.Time{})
conn = handler.NewBufferReaderConn(conn, br)
if data[2] == 0xff {
if h.md.enableUDP {
// UDP-over-TCP relay
h.handleUDPTun(ctx, conn)
} else {
h.logger.Error("UDP relay is diabled")
}
return
}
// standard TCP.
addr := &gosocks5.Addr{}
if _, err = addr.ReadFrom(conn); err != nil {
h.logger.Error(err)
h.discard(conn)
return
}
conn.SetReadDeadline(time.Time{})
h.logger = h.logger.WithFields(map[string]interface{}{
"dst": addr.String(),
})
h.logger.Infof("%s >> %s", conn.RemoteAddr(), addr)
if h.bypass != nil && h.bypass.Contains(addr.String()) {
h.logger.Info("bypass: ", addr.String())
return
}
r := (&handler.Router{}).
WithChain(h.chain).
WithRetry(h.md.retryCount).
WithLogger(h.logger)
cc, err := r.Dial(ctx, "tcp", addr.String())
if err != nil {
return
}
defer cc.Close()
t := time.Now()
h.logger.Infof("%s <-> %s", conn.RemoteAddr(), addr)
handler.Transport(conn, cc)
h.logger.
WithFields(map[string]interface{}{
"duration": time.Since(t),
}).
Infof("%s >-< %s", conn.RemoteAddr(), addr)
}
func (h *ssHandler) discard(conn net.Conn) {
io.Copy(ioutil.Discard, conn)
}