ip_mc_leave_group
ret = ip_mc_leave_group(sk, &mreq);
extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
ret = ip_mc_leave_group(sk, &mreq);
EXPORT_SYMBOL(ip_mc_leave_group);
err = ip_mc_leave_group(sk, &imr);
err = ip_mc_leave_group(sk, &imr);
err = ip_mc_leave_group(sk, &mreq);
return ip_mc_leave_group(sk, &mreq);
return ip_mc_leave_group(sk, &mreq);