slstatus/components/ip.c

/* See LICENSE file for copyright and license details. */
#if defined(__linux__)
#include <errno.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>

#include "../util.h"

const char *
ipv4(const char *iface)
{
	struct ifaddrs *ifaddr, *ifa;
	int s;
	char host[NI_MAXHOST];

	if (getifaddrs(&ifaddr) == -1) {
		fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
		return NULL;
	}

	for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
		if (ifa->ifa_addr == NULL) {
			continue;
		}
		s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
		if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET)) {
			if (s != 0) {
				fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
				return NULL;
			}
			return bprintf("%s", host);
		}
	}

	freeifaddrs(ifaddr);

	return NULL;
}

const char *
ipv6(const char *iface)
{
	struct ifaddrs *ifaddr, *ifa;
	int s;
	char host[NI_MAXHOST];

	if (getifaddrs(&ifaddr) == -1) {
		fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
		return NULL;
	}

	for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
		if (ifa->ifa_addr == NULL) {
			continue;
		}
		s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in6), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
		if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET6)) {
			if (s != 0) {
				fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
				return NULL;
			}
			return bprintf("%s", host);
		}
	}

	freeifaddrs(ifaddr);

	return NULL;
}
#endif