NAME
pcap_findalldevs - get a list of capture devices
SYNOPSIS
#include <pcap/pcap.h>
char errbuf[PCAP_ERRBUF_SIZE];
int pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf);
DESCRIPTION
pcap_findalldevs() constructs a list of network devices that can be opened with pcap_create() and pcap_activate() or with pcap_open_live(). (Note that there may be network devices that cannot be opened by the process calling pcap_findalldevs(), because, for example, that process might not have sufficient privileges to open them for capturing; if so, those devices will not appear on the list.) alldevsp is set to point to the first element of the list; each element of the list is of type pcap_if_t, and has the following members:
| next | if not NULL, a pointer to the next element in the list; NULL for the last element of the list | ||||
| name | a pointer to a string giving a name for the device to pass to pcap_open_live() | ||||
| description | |||||
| if not NULL, a pointer to a string giving a human-readable description of the device | |||||
| addresses | |||||
| a pointer to the first element of a list of addresses for the interface | |||||
| flags | interface flags:
| ||||
Each element of the list of addresses is of type pcap_addr_t, and has the following members:
| next | if not NULL, a pointer to the next element in the list; NULL for the last element of the list |
| addr | a pointer to a struct sockaddr containing an address |
| netmask | |
| if not NULL, a pointer to a struct sockaddr that contains the netmask corresponding to the address pointed to by addr | |
| broadaddr | |
| if not NULL, a pointer to a struct sockaddr that contains the broadcast address corresponding to the address pointed to by addr; may be null if the interface doesn’t support broadcasts | |
| dstaddr | |
| if not NULL, a pointer to a struct sockaddr that contains the destination address corresponding to the address pointed to by addr; may be null if the interface isn’t a point-to-point interface | |
Note that not all the addresses in the list of addresses are necessarily IPv4 or IPv6 addresses - you must check the sa_family member of the struct sockaddr before interpreting the contents of the address.
The list of devices must be freed with pcap_freealldevs().
RETURN VALUE
pcap_findalldevs() returns 0 on success and -1 on failure. If -1 is returned, errbuf is filled in with an appropriate error message. errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.
SEE ALSO
pcap(3), pcap_create(3), pcap_activate(3), pcap_open_live(3), pcap_freealldevs(3)
