Example #1
0
func handleConnection(conn net.Conn) {
	var (
		remote *ss.Conn
	)

	if debug {
		debug.Printf("socks connect from %s\n", conn.RemoteAddr().String())
	}
	closed := false
	defer func() {
		if !closed {
			conn.Close()
		}
	}()

	var err error = nil
	if err = handShake(conn); err != nil {
		log.Println("socks handshake:", err)
		return
	}
	rawaddr, addr, err := getRequest(conn)
	if err != nil {
		log.Println("error getting request:", err)
		return
	}
	// Sending connection established message immediately to client.
	// This could save some round trip time for creating socks connection with the client.
	// But if connection failed, the client will get connection reset error.
	_, err = conn.Write([]byte{0x05, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x08, 0x43})
	if err != nil {
		debug.Println("send connection confirmation:", err)
		return
	}

	debug.Println("1", ", len:", len(rawaddr), ", addr:", addr, "cap:", cap(rawaddr))
	// If tfo configured, read the client payload first
	// since most of the time the rtt between client and local
	// are much smaller than between local and server.
	// This could save one rtt from local to server
	// by sending client data to server on the first syn packet.

	if (config.TcpFastOpen & 1) != 0 {
		ss.SetReadTimeout(conn)
		n, err := conn.Read(rawaddr[len(rawaddr):cap(rawaddr)])
		if err != nil {
			log.Println("Failed read data from client:", err)
			return
		}
		rawaddr = rawaddr[:len(rawaddr)+n]
		debug.Println("2, n:", n, ", len:", len(rawaddr), ", addr:", addr, ", cap:", cap(rawaddr))
	}

	debug.Println("3", ", len:", len(rawaddr), ", addr:", addr, ", cap:", cap(rawaddr))

	remote, err = createServerConn(rawaddr, addr)

	if err != nil {
		if len(servers.srvCipher) > 1 {
			log.Println("Failed connect to all avaiable shadowsocks server")
		}
		log.Println("Failed connect to all avaiable shadowsocks server", err)
		return
	}
	defer func() {
		if !closed {
			remote.Close()
		}
	}()

	go ss.PipeThenClose(conn, remote)
	ss.PipeThenClose(remote, conn)
	closed = true
	debug.Println("closed connection to", addr)
}
Example #2
0
func handleConnection(conn *ss.Conn) {
	var (
		host   string
		remote net.Conn
	)

	connCnt++ // this maybe not accurate, but should be enough
	if connCnt-nextLogConnCnt >= 0 {
		// XXX There's no xadd in the atomic package, so it's difficult to log
		// the message only once with low cost. Also note nextLogConnCnt maybe
		// added twice for current peak connection number level.
		log.Printf("Number of client connections reaches %d\n", nextLogConnCnt)
		nextLogConnCnt += logCntDelta
	}

	// function arguments are always evaluated, so surround debug statement
	// with if statement
	if debug {
		debug.Printf("new client %s->%s\n", conn.RemoteAddr().String(), conn.LocalAddr())
	}
	closed := false
	defer func() {
		if debug {
			debug.Printf("closed pipe %s<->%s\n", conn.RemoteAddr(), host)
		}
		connCnt--
		if !closed {
			conn.Close()
		}
	}()

	host, extra, err := getRequest(conn)
	if err != nil {
		log.Println("error getting request", conn.RemoteAddr(), conn.LocalAddr(), err)
		return
	}
	debug.Println("connecting", host)

	if (config.TcpFastOpen & 1) != 0 {
		// dial with data
		remote, err = ss.TfoDial("tcp", host, extra)
		extra = nil
	} else {
		remote, err = net.Dial("tcp", host)
	}

	if err != nil {
		if ne, ok := err.(*net.OpError); ok && (ne.Err == syscall.EMFILE || ne.Err == syscall.ENFILE) {
			// log too many open file error
			// EMFILE is process reaches open file limits, ENFILE is system limit
			log.Println("dial error:", err)
		} else {
			log.Println("error connecting to:", host, err)
		}
		return
	}
	defer func() {
		if !closed {
			remote.Close()
		}
	}()
	// write extra bytes read from
	if extra != nil {
		debug.Println("getRequest read extra data, writing to remote, len", len(extra))
		if _, err = remote.Write(extra); err != nil {
			debug.Println("write request extra error:", err)
			return
		}
	}
	if debug {
		debug.Printf("piping %s<->%s", conn.RemoteAddr(), host)
	}
	go ss.PipeThenClose(conn, remote)
	ss.PipeThenClose(remote, conn)
	closed = true
	return
}