handlers.py 文件源码

def ftp_EPRT(self, line):
        """Start an active data channel by choosing the network protocol
        to use (IPv4/IPv6) as defined in RFC-2428.
        """
        if self._epsvall:
            self.respond("501 EPRT not allowed after EPSV ALL.")
            return
        # Parse EPRT request for getting protocol, IP and PORT.
        # Request comes in as:
        # <d>proto<d>ip<d>port<d>
        # ...where <d> is an arbitrary delimiter character (usually "|") and
        # <proto> is the network protocol to use (1 for IPv4, 2 for IPv6).
        try:
            af, ip, port = line.split(line[0])[1:-1]
            port = int(port)
            if not 0 <= port <= 65535:
                raise ValueError
        except (ValueError, IndexError, OverflowError):
            self.respond("501 Invalid EPRT format.")
            return

        if af == "1":
            # test if AF_INET6 and IPV6_V6ONLY
            if (self.socket.family == socket.AF_INET6 and not
                    SUPPORTS_HYBRID_IPV6):
                self.respond('522 Network protocol not supported (use 2).')
            else:
                try:
                    octs = list(map(int, ip.split('.')))
                    if len(octs) != 4:
                        raise ValueError
                    for x in octs:
                        if not 0 <= x <= 255:
                            raise ValueError
                except (ValueError, OverflowError):
                    self.respond("501 Invalid EPRT format.")
                else:
                    self._make_eport(ip, port)
        elif af == "2":
            if self.socket.family == socket.AF_INET:
                self.respond('522 Network protocol not supported (use 1).')
            else:
                self._make_eport(ip, port)
        else:
            if self.socket.family == socket.AF_INET:
                self.respond('501 Unknown network protocol (use 1).')
            else:
                self.respond('501 Unknown network protocol (use 2).')