Method handleSocks

proxy/client.go:468–537

(conn net.Conn)

}

func (proxy *ProxyClient) handleSocks(conn net.Conn) {
	logClose := func(args ...interface{}) {
		proxy.Logger.E(args...)
		conn.Close()
	}

	buf := make([]byte, 2)
	if _, err := io.ReadAtLeast(conn, buf, 2); err != nil {
		logClose("SOCKS", "Error", err)
		return
	} else if buf[0] != socksVersion5 {
		logClose("SOCKS", "Error", fmt.Sprintf(socksVersionErr, buf[0]))
		return
	}

	numMethods := int(buf[1])
	methods := make([]byte, numMethods)
	if _, err := io.ReadAtLeast(conn, methods, numMethods); err != nil {
		logClose("SOCKS", "Error", err)
		return
	}

	if proxy.UserAuth != "" {
		conn.Write([]byte{socksVersion5, 0x02}) // username & password auth

		if !proxy.authSocks(conn) {
			conn.Write([]byte{1, 1})
			logClose("SOCKS", "Invalid auth data", conn.RemoteAddr)
			return
		}

		// auth success
		conn.Write([]byte{1, 0})
	} else {
		conn.Write([]byte{socksVersion5, 0})
	}
	// handshake over
	// tunneling start
	method, addr, err := parseUDPHeader(conn, nil, false)
	if err != nil {
		logClose("SOCKS", "Error", err)
		return
	}

	host := addr.String()
	switch method {
	case 1:
		if ans, ext := proxy.canDirectConnect(host); ans == ruleBlock {
			proxy.Logger.L("SOCKS ACL", ext, host)
			conn.Close()
		} else if ans == rulePass {
			proxy.Logger.D("SOCKS ACL", ext, host)
			proxy.dialHostAndBridge(conn, host, okSOCKS)
		} else if proxy.Policy.IsSet(PolicyWebSocket) {
			proxy.Logger.D("SOCKS ACL", ext, "Websocket", host)
			proxy.DialUpstream(conn, host, okSOCKS, 0, 0)
		} else {
			proxy.Logger.D("SOCKS ACL", ext, host)