#include <sys/socket.h>
#include <netinet/ip.h>
#include <asm/types.h>
#include <netinet/in.h>
#define _LINUX_IN_H
#include <linux/mroute.h>
#include <net/if.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>

#define XE(y, x) do { errno = 0; if (x) { \
		int __e = errno; \
		fprintf(stderr, "(%03d) %s [%d] %s\n", \
			__LINE__, #x, __e, strerror(__e)); \
		if (y) return 2; \
		} \
	} while (0);
#define E(x) XE(1,x)
#define W(x) XE(0,x)

struct vifctln {
	vifi_t	vifc_vifi;		/* Index of VIF */
	unsigned char vifc_flags;	/* VIFF_ flags */
	unsigned char vifc_threshold;	/* ttl limit */
	unsigned int vifc_rate_limit;	/* Rate limiter values (NI) */
	struct in_addr vifc_lcl_addr;	/* Our address */
	struct in_addr vifc_rmt_addr;	/* IPIP tunnel addr */
	int vifc_ifindex;		/* Index of real Interface */
};

int main(int argc, char **argv)
{
	int igmp_socket;
	struct vifctl vc;
	struct vifctln vcn;
	struct in_addr addr;
	char buf[IFNAMSIZ];
	int ifi;
	int p = 1;

	if (argc != 3) {
		fprintf(stderr, "Syntax: %s <interface> <ip>\n"
			"where <interface> is some existing interface,\n"
			"\tif possible with MULTICAST in its flags\n"
			"and <ip> is a local address on that interface\n", argv[0]);
		return 1;
	}
	ifi = if_nametoindex(argv[1]);
	if (ifi <= 0) {
		fprintf(stderr, "invalid interface %s\n", argv[1]);
		return 1;
	}
	addr.s_addr = inet_addr(argv[2]);
	if (!addr.s_addr) {
		fprintf(stderr, "invalid address %s\n", argv[2]);
		return 1;
	}

	printf("using %s<%d> - %s\n", if_indextoname(ifi, buf), ifi, inet_ntoa(addr));


	printf("multicast routing support - general: ");

	E((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) == -1);

	E(setsockopt(igmp_socket, SOL_IP, MRT_INIT, &p, sizeof(p)));

	printf("\033[32;1mOK.\033[m\n");

	printf("multicast routing support - withOUT interface indici: ");

	memset(&vc, 0, sizeof(vc));
	vc.vifc_vifi = 0;
	vc.vifc_threshold = 1;
	vc.vifc_rate_limit = 5;
	vc.vifc_lcl_addr = addr;
	E(setsockopt(igmp_socket, IPPROTO_IP, MRT_ADD_VIF, &vc, sizeof(vc)));

	printf("\033[32;1mOK.\033[m\n");

	memset(&vc, 0, sizeof(vc));
	vc.vifc_vifi = 0;
	vc.vifc_lcl_addr = addr;
	W(setsockopt(igmp_socket, IPPROTO_IP, MRT_DEL_VIF, &vc,	sizeof(vc)));

	printf("multicast routing support - with interface indici: ");

	memset(&vcn, 0, sizeof(vcn));
	vcn.vifc_vifi = 0;
	vcn.vifc_threshold = 1;
	vcn.vifc_rate_limit = 5;
	vcn.vifc_lcl_addr = addr;
	vcn.vifc_ifindex = ifi;
	E(setsockopt(igmp_socket, IPPROTO_IP, MRT_ADD_VIF, &vcn, sizeof(vcn)));

	printf("\033[32;1mOK.\033[m\n");

	memset(&vcn, 0, sizeof(vcn));
	vcn.vifc_vifi = 0;
	vcn.vifc_lcl_addr = addr;
	vcn.vifc_ifindex = ifi;
	W(setsockopt(igmp_socket, IPPROTO_IP, MRT_DEL_VIF, &vcn, sizeof(vcn)));

	E(setsockopt(igmp_socket, SOL_IP, MRT_DONE, NULL, 0));
	close(igmp_socket);

	printf("Perfect, everything working!\n");
	return 0;	
}