XX-net/XX-Net · warning

request not supported command mode:%d

Error message

request not supported command mode:%d

What it means

SOCKS5 CONNECT-stage command was neither 1 (TCP connect) nor 3 (UDP associate). The proxy replies 0x07 command not supported and returns.

Source

Thrown at code/default/smart_router/local/proxy_handler.py:291

            domain_len_pack = self.read_bytes(1)[0:1]
            domain_len = ord(domain_len_pack)
            domain = self.read_bytes(domain_len)
            addr_pack = domain_len_pack + domain
            addr = domain
        elif addrtype == 4:  # IPv6
            addr_pack = self.read_bytes(16)
            addr = socket.inet_ntop(socket.AF_INET6, addr_pack)
        else:
            xlog.warn("request address type unknown:%d", addrtype)
            sock.send(b"\x05\x07\x00\x01")  # Command not supported
            return
        port = struct.unpack('>H', self.rfile.read(2))[0]

        if command == 3:  # 3. UDP associate
            return self.handle_udp_associate(sock, addr, port, addrtype_pack, addr_pack)

        if command != 1:  # 1. Tcp connect
            xlog.warn("request not supported command mode:%d", command)
            sock.send(b"\x05\x07\x00\x01")  # Command not supported
            return

        # xlog.debug("socks5 %r connect to %s:%d", self.client_address, addr, port)
        reply = b"\x05\x00\x00" + addrtype_pack + addr_pack + struct.pack(">H", port)
        sock.send(reply)

        if addrtype in [1, 4]:
            handle_ip_proxy(sock, addr, port, self.client_address)
        else:
            handle_domain_proxy(sock, addr, port, self.client_address)

    def https_handler(self):
        line = self.read_crlf_line()
        line = line
        words = line.split()
        if len(words) == 3:
            command, path, version = words

View on GitHub (pinned to cfa5bc17b6)

Solutions

  1. Configure the client to use CONNECT-only mode / passive transfers
  2. Use SOCKS5 UDP associate if UDP is the actual need
  3. Choose a proxy implementation that supports BIND if the app requires it
Defensive patterns

Strategy: validation

Validate before calling

if command not in (1,3): send 0x07 reply and close

Prevention

When it happens

Trigger: SOCKS5 client issues CMD 0x02 (BIND) at the request stage.

Common situations: FTP active mode, some P2P or remote-admin clients requesting BIND through SOCKS5.

Related errors

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/95c4de2b62145413. Report an issue: GitHub.