2 #include <sys/socket.h>
13 * Return the IP address for the given interface or "no IP" if the
14 * interface is up and running but hasn't got an IP address yet
17 const char *get_ip_addr(const char *interface) {
18 static char part[512];
20 socklen_t len = sizeof(struct sockaddr_in);
21 memset(part, 0, sizeof(part));
23 /* First check if the interface is running */
24 (void)strcpy(ifr.ifr_name, interface);
25 if (ioctl(general_socket, SIOCGIFFLAGS, &ifr) < 0 ||
26 !(ifr.ifr_flags & IFF_RUNNING))
29 /* Interface is up, get the IP address */
30 (void)strcpy(ifr.ifr_name, interface);
31 ifr.ifr_addr.sa_family = AF_INET;
32 if (ioctl(general_socket, SIOCGIFADDR, &ifr) < 0)
36 if ((ret = getnameinfo(&ifr.ifr_addr, len, part, sizeof(part), NULL, 0, NI_NUMERICHOST)) != 0) {
37 fprintf(stderr, "getnameinfo(): %s\n", gai_strerror(ret));