#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>

#include <arpa/inet.h>
#include <netinet/in.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <unistd.h>

int stop = 0;

static void
#ifdef LINUX
msend_onint(int s)
#else
msend_onint(int s __unused)
#endif
{
	stop = 1;
}

static void
init_signals(void)
{
        struct sigaction sa;

        sa.sa_handler = msend_onint;
        sa.sa_flags = 0;
        sigemptyset(&sa.sa_mask);
        if (sigaction(SIGINT, &sa, NULL))
                err(1, "sigaction(%d)", SIGINT);
}


int
main(int argc, char **argv)
{
	char data[128];
	int sock;
	suseconds_t usecs;
	unsigned long port;
	unsigned long long count;
	struct in_addr group, if_addr;
	struct sockaddr_in to[100];	
	int i, ttl, loop = 0;
	struct timeval starttime, endtime;
	double secs, rate;

	init_signals();

	if (argc != 5){	
		printf ("msend <group-ip> <if-ip> <port> ttl\n");
		return 0;
	}

	memset (&to, 0, sizeof(struct sockaddr_in));

	ttl = strtol(argv[4], 0, 0);
	if (errno != 0)
		err(1, "Invalid TTL - %s", argv[4]);

	if (inet_aton(argv[1], &group) == 0 || \
			(ntohl(group.s_addr) & 0xe0000000) != 0xe0000000)
		err(1, "Invalid Group addres - %s", argv[1]);

 	if (inet_aton(argv[2], &if_addr) == 0)
		err(1, "Invalid interface addres - %s", argv[2]);

	if ((port = strtoul(argv[3], NULL, 10)) == 0 || port > 0xFFFF)
		err(1, "Invalid port - %s", argv[3]);

	for (i = 0; i < 100; i++) {
		to[i].sin_port = htons((uint16_t)port);
		to[i].sin_family = AF_INET	;
		to[i].sin_addr.s_addr = htonl(ntohl(group.s_addr) + i);
	}

	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP))== -1)
		err (1, "socket failed - %s", strerror(errno));

	if ( setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP,
	    &loop, sizeof(loop)) == -1)
		err (1, "setsockopt failed - %s", strerror(errno));

	if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL,
	    &ttl, sizeof(ttl)) == -1)
		err (1, "setsockopt failed - %s", strerror(errno));

	if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF,
	    &if_addr, sizeof(if_addr)) == -1)	
		err (1, "setsockopt failed - %s", strerror(errno));

	memset(data, 0, sizeof(data));
	strlcpy(data + sizeof(count),  "Got Multicast?!?\n", sizeof(data) - sizeof(count)); 

	gettimeofday(&starttime, NULL);
	for (count = 0; ; count++) {
		//memcpy(data, &count, sizeof(count));
		for (i = 0; i < 100; i++) {
			if (sendto(sock, data, sizeof(data), 0,
			 	(struct sockaddr *) &(to[i]), 
			  	sizeof(struct sockaddr_in)) < 0)
				err (1, "sendto failed - %s", strerror(errno));
		/* fprintf(stderr, "send - %d bytes  to group %s port %d"
			" ttl %d interface %s\n", sizeof (data),
			inet_ntoa(group), ntohs(to.sin_port), ttl, argv[2]); */
		}
		if (stop)
			break;
	}

	gettimeofday(&endtime, NULL);
	close(sock);

	fprintf(stderr, "\n\nStart time - %lu.%lu\n",
	     (unsigned long) starttime.tv_sec, (unsigned long) starttime.tv_usec);
	fprintf(stderr, "End time - %lu.%lu\n",
	     (unsigned long) endtime.tv_sec, (unsigned long)endtime.tv_usec);

	if (endtime.tv_usec < starttime.tv_usec) {
		endtime.tv_sec -= 1;
		usecs = endtime.tv_usec + (1000000 - starttime.tv_usec);
	} else
		usecs = endtime.tv_usec - starttime.tv_usec;

	secs = (double)(endtime.tv_sec - starttime.tv_sec) + ((double)usecs)/ 1000000.;
	rate = ((double)count) / secs;

	fprintf(stderr, "%llu packets sent for %lu.%lusec - average rate %fpps\n",
	     count, (unsigned long)endtime.tv_sec - starttime.tv_sec,
	     (unsigned long) usecs, rate);

	exit(0);
}