find_ancillary
recv_tvp = find_ancillary(&msg, SOL_SOCKET, SCM_TIMESTAMP);
opt = find_ancillary(&msg, IPPROTO_IPV6, IPV6_RTHDR);
static void *find_ancillary(struct msghdr *msg, int cmsg_level,
recv_tvp = find_ancillary(&msg, SOL_SOCKET, SCM_TIMESTAMP);
opt = find_ancillary(&msg, IPV6_HOPLIMIT);
opt = find_ancillary(&msg, IPV6_RTHDR);
if ((hopcntopt = find_ancillary(&rmsg, IPV6_HOPLIMIT)) == NULL) {
extern void *find_ancillary(struct msghdr *, int);
if ((opt = find_ancillary(msg, IP_RECVIF)) == NULL) {
if ((opt = find_ancillary(msg, IP_RECVIF)) == NULL)