#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int
main(int argc, char *argv[])
{
	struct sockaddr_in sin;
	char *buffer;
	struct ip *ip;
	size_t length;
	int fd, i, n;
	const int on = 1;
	uint16_t len;

	if (argc != 5) {
		fprintf(stderr, "%s", "Usage: test_send remote_addr hdr_len buf_len send_count\n");
		return (-1);
	}
	if ((fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
		perror("socket");
	}
	if (setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &on, sizeof(int)) < 0) {
		perror("setsockopt");
	}
	memset(&sin, 0, sizeof(struct sockaddr_in));
	sin.sin_family = AF_INET;
#if defined(__FreeBSD__) || defined(__APPLE__)
	sin.sin_len = sizeof(struct sockaddr_in);
#endif
	sin.sin_port = htons(0);
	sin.sin_addr.s_addr = inet_addr(argv[1]);
	len = (uint16_t)atol(argv[2]);
	length = (size_t)atol(argv[3]);
	n = (int)atoi(argv[4]);

	if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &length, sizeof(length)) < 0) {
		perror("setsockopt");
	}
	buffer = calloc(1, length);
	ip = (struct ip *)buffer;
	ip->ip_v = IPVERSION;
	ip->ip_hl = (sizeof(struct ip) >> 2);
	ip->ip_tos = 0;
#if defined(__APPLE__)
	ip->ip_len = len;
#else
	ip->ip_len = htons(len);
#endif
	ip->ip_id = htons(17);
	ip->ip_off = 0;
	ip->ip_ttl = 40;
	ip->ip_p = IPPROTO_SCTP;
	ip->ip_sum = 0;
	ip->ip_src.s_addr = INADDR_ANY;
	ip->ip_dst.s_addr = sin.sin_addr.s_addr;

	for (i = 0; i < n; i++) {
		if (sendto(fd, buffer, length, 0, (const struct sockaddr *)&sin,
		    (socklen_t)sizeof(struct sockaddr_in)) != length) {
			perror("send");
		}
	}
	if (close(fd) < 0) {
		perror("close");
	}
	free(buffer);
	return (0);
}