IP_ADD_MEMBERSHIP
if (option == IP_ADD_MEMBERSHIP
if (option == IP_ADD_MEMBERSHIP || option == IP_DROP_MEMBERSHIP) {
case IP_ADD_MEMBERSHIP:
case IP_ADD_MEMBERSHIP:
return IP_ADD_MEMBERSHIP;
SOCKET_OPTION_INFO_ENTRY(IPPROTO_IP, IP_ADD_MEMBERSHIP),
setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mr, sizeof(mr))<0)