taglinefilesource code
sock_wspace367net/inet/packet.csock_wspace,
sock_wspace363net/inet/raw.csock_wspace,
sock_wspace271net/inet/sock.hextern unsigned long    sock_wspace(struct sock *sk);
sock_wspace4481net/inet/tcp.csock_wspace,
sock_wspace658net/inet/udp.csock_wspace,