Function _ipaddr_info

Lib/asyncio/base_events.py:102–158

(host, port, family, type, proto, flowinfo=0, scopeid=0)

def _ipaddr_info(host, port, family, type, proto, flowinfo=0, scopeid=0):
    # Try to skip getaddrinfo if "host" is already an IP. Users might have
    # handled name resolution in their own code and pass in resolved IPs.
    if not hasattr(socket, 'inet_pton'):
        return

    if proto not in {0, socket.IPPROTO_TCP, socket.IPPROTO_UDP} or \
            host is None:
        return None

    if type == socket.SOCK_STREAM:
        proto = socket.IPPROTO_TCP
    elif type == socket.SOCK_DGRAM:
        proto = socket.IPPROTO_UDP
    else:
        return None

    if port is None:
        port = 0
    elif isinstance(port, bytes) and port == b'':
        port = 0
    elif isinstance(port, str) and port == '':
        port = 0
    else:
        # If port's a service name like "http", don't skip getaddrinfo.
        try:
            port = int(port)
        except (TypeError, ValueError):
            return None

    if family == socket.AF_UNSPEC:
        afs = [socket.AF_INET]
        if _HAS_IPv6:
            afs.append(socket.AF_INET6)
    else:
        afs = [family]

    if isinstance(host, bytes):
        host = host.decode('idna')
    if '%' in host:
        # Linux's inet_pton doesn't accept an IPv6 zone index after host,
        # like '::1%lo0'.
        return None

    for af in afs:
        try:
            socket.inet_pton(af, host)
            # The host has already been resolved.
            if _HAS_IPv6 and af == socket.AF_INET6:
                return af, type, proto, '', (host, port, flowinfo, scopeid)
            else:
                return af, type, proto, '', (host, port)
        except OSError:
            pass

    # "host" is not an IP address.
    return None