NIL), using recvfrom(2). If LENGTH is NIL, the length of BUFFER is
used, so at least one of these two arguments must be non-NIL. If
BUFFER is supplied, it had better be of an element type one octet wide.
Returns the buffer, its length, and the address of the peer
that sent it, as multiple values. On datagram sockets, sets MSG_TRUNC
so that the actual packet length is returned even if the buffer was too
NIL), using recvfrom(2). If LENGTH is NIL, the length of BUFFER is
used, so at least one of these two arguments must be non-NIL. If
BUFFER is supplied, it had better be of an element type one octet wide.
Returns the buffer, its length, and the address of the peer
that sent it, as multiple values. On datagram sockets, sets MSG_TRUNC
so that the actual packet length is returned even if the buffer was too