pcap_t *pcap_open_live(const char *device, int snaplen,
int promisc, int to_ms, char *errbuf);
pcap_open_live() is used to obtain a packet capture handle to look
at packets on the network.
device is a string that specifies the network device to open; on Linux systems
with 2.2 or later kernels, a
device argument of "any" or
NULL can be used to capture packets from all interfaces.
snaplen specifies the snapshot length to be set on the handle.
promisc specifies if the interface is to be put into promiscuous mode.
to_ms specifies the read timeout in milliseconds.