Retrieving network device information

When we start using libpcap, we can specify a particular interface or let libpcap pick one up for us. In this recipe, we will retrieve a list of the network interfaces that are available and the address information for those interfaces.

To retrieve all of the devices, we use the pcap_findalldevs() function that returns a linked list of network interfaces. Each element in the list is of the pcap_if_t type. The pcap_if_t structure contains the following elements:

• pcap_if *next: This denotes the next element in the list. The value is NULL if it is the last element.

• char *name: This denotes the name of the device. This name can be passed to other functions to identify the device.

• char *description: This description provides a human-readable description of the device.

• pcap_addr *addresses: This is a pointer to the first element of a list of addresses for the interface.

• u_int: The PCAP_IF_ interface flags. Currently the only possible flag is PCAP_IF_LOOPBACK,...