pcap_loop
int pcap_loop(pcap_t *, int, pcap_handler, u_char *);
pcap_loop(hpcap, -1, phandler, NULL);
ASSERT(pcap_loop(handle, PKTCNT, packet_ignore, 0) != -1);
if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {