#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <net/if.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stropts.h>

static void
print_broad(int s, struct lifreq *p, sa_family_t fam)
{
	char ipastr[INET6_ADDRSTRLEN];
	char *if_name = p->lifr_name;
	void *addrp = &p->lifr_addr;

	if (ioctl(s, SIOCGLIFBRDADDR, p) < 0) {
		fprintf(stderr, "ioctl(SIOCGLIFBRDADDR) error\n");
		exit(1);
	}

	if (fam == AF_INET) {
		struct in_addr addr =
			((struct sockaddr_in *)addrp)->sin_addr;

		if (inet_ntop(AF_INET, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\tbroad=%s\n", ipastr);
		
	} else if (fam == AF_INET6) {
		struct in6_addr addr =
			((struct sockaddr_in6 *)addrp)->sin6_addr;

		if (inet_ntop(AF_INET6, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\tbroad=%s\n", ipastr);
	} else {
	}
}

static void
print_netmask(int s, struct lifreq *p, sa_family_t fam)
{
	char ipastr[INET6_ADDRSTRLEN];
	char *if_name = p->lifr_name;
	void *addrp = &p->lifr_addr;

	if (ioctl(s, SIOCGLIFNETMASK, p) < 0) {
		fprintf(stderr, "ioctl(SIOCGLIFSUBNET) error\n");
		exit(1);
	}

	if (fam == AF_INET) {
		struct in_addr addr =
			((struct sockaddr_in *)addrp)->sin_addr;

		if (inet_ntop(AF_INET, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\tnetmask=%s\n", ipastr);
		
	} else if (fam == AF_INET6) {
		struct in6_addr addr =
			((struct sockaddr_in6 *)addrp)->sin6_addr;

		if (inet_ntop(AF_INET6, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\tnetmask=%s\n", ipastr);
	} else {
	}
}

static uint64_t
get_flags(int s, struct lifreq *p, sa_family_t fam)
{
	if (ioctl(s, SIOCGLIFFLAGS, p) < 0) {
		fprintf(stderr, "ioctl(SIOCGLIFFLAGS) error\n");
		exit(1);
	}
	return (p->lifr_flags);
}

static sa_family_t
print_addr(int s, struct lifreq *p)
{
	char ipastr[INET6_ADDRSTRLEN];
	char *if_name = p->lifr_name;
	void *addrp = &p->lifr_addr;

	if (p->lifr_addr.ss_family == AF_INET) {
		struct in_addr addr =
			((struct sockaddr_in *)addrp)->sin_addr;
		printf("ifname(AF_INET) = %s\n", if_name);

		if (inet_ntop(AF_INET, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\taddr=%s\n", ipastr);
		return (AF_INET);
		
	} else if (p->lifr_addr.ss_family == AF_INET6) {
		struct in6_addr addr =
			((struct sockaddr_in6 *)addrp)->sin6_addr;
		printf("ifname(AF_INET6) = %s\n", if_name);

		if (inet_ntop(AF_INET6, &addr, ipastr, sizeof(ipastr)) != NULL)
			printf("\taddr=%s\n", ipastr);
		return (AF_INET6);
	} else {
	}
}

main()
{
	int s, i;
	struct lifconf ifc;
	struct lifnum  ifn;
	struct lifreq *p;
	int num_if;

	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
		fprintf(stderr, "socket() error\n");
		exit(1);
	}

	/* Get interface number */
	ifn.lifn_family = AF_UNSPEC;	/* both AF_INET and AF_INET6 */
	ifn.lifn_flags = 0;
	if (ioctl(s, SIOCGLIFNUM, &ifn) < 0) {
		fprintf(stderr, "ioctl(SIOCGLIFNUM) error\n");
		exit(1);
	}
	num_if = ifn.lifn_count;

	ifc.lifc_len = num_if * sizeof (struct lifreq);
	if ((ifc.lifc_buf = malloc(ifc.lifc_len)) == NULL) {
		fprintf(stderr, "malloc() error\n");
		exit(1);
	}

	/* Get interface configuration (name and address) */
	ifc.lifc_family = AF_UNSPEC;
	ifc.lifc_flags = 0;
	if (ioctl(s, SIOCGLIFCONF, &ifc) < 0) {
		fprintf(stderr, "ioctl(SIOCGLIFCONF) error\n");
		exit(1);
	}
	(void) close(s);

	for (i = 0, p = ifc.lifc_req ; i < num_if; i++, p++) {
		sa_family_t fam;
		uint64_t flags;
		if ((s = socket(p->lifr_addr.ss_family, SOCK_DGRAM, 0)) < 0) {
			fprintf(stderr, "socket() error\n");
			exit(1);
		}
		fam = print_addr(s, p);
		flags = get_flags(s, p, fam);
		print_netmask(s, p, fam);
		if (flags & IFF_BROADCAST)
			print_broad(s, p, fam);
		(void) close(s);
	}
}