slstatus/ip.c

#include <err.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) {
		warn("Failed to get IPv4 address for interface %s", iface);
		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) {
				warnx("Failed to get IPv4 address for interface %s", iface);
				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) {
		warn("Failed to get IPv6 address for interface %s", iface);
		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) {
				warnx("Failed to get IPv6 address for interface %s", iface);
				return NULL;
			}
			return bprintf("%s", host);
		}
	}

	freeifaddrs(ifaddr);

	return NULL;
}