udpflood.c

/* An adaptation of Eric Dumazet's udpflood tool.  */

#include <stdio.h>
#include <stddef.h>
#include <malloc.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define _GNU_SOURCE
#include <getopt.h>

static int usage(void)
{
	printf("usage: udpflood [ -l count ] [ -m message_size ] [ -c num_ip_addrs ] IP_ADDRESS\n");
	return -1;
}

static int send_packets(in_addr_t start_addr, in_addr_t end_addr,
			int port, int count, int msg_sz)
{
	char *msg = malloc(msg_sz);
	struct sockaddr_in saddr;
	in_addr_t addr;
	int fd, i, err;

	if (!msg)
		return -ENOMEM;

	memset(msg, 0, msg_sz);

	addr = start_addr;

	memset(&saddr, 0, sizeof(saddr));
	saddr.sin_family = AF_INET;
	saddr.sin_port = port;
	saddr.sin_addr.s_addr = addr;

	fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
	if (fd < 0) {
		perror("socket");
		err = fd;
		goto out_nofd;
	}
	err = connect(fd, (struct sockaddr *) &saddr, sizeof(saddr));
	if (err < 0) {
		perror("connect");
		close(fd);
		goto out;
	}

	for (i = 0; i < count; i++) {
		saddr.sin_addr.s_addr = addr;

		err = sendto(fd, msg, msg_sz, 0,
			     (struct sockaddr *) &saddr, sizeof(saddr));
		if (err < 0) {
			perror("sendto");
			goto out;
		}

		if (++addr >= end_addr)
			addr = start_addr;
	}

	err = 0;
out:
	close(fd);
out_nofd:
	free(msg);
	return err;
}

int main(int argc, char **argv, char **envp)
{
	int port, msg_sz, count, num_addrs, ret;
	in_addr_t start_addr, end_addr;

	port = 6000;
	msg_sz = 32;
	count = 10000000;
	num_addrs = 1;

	while ((ret = getopt(argc, argv, "l:s:p:c:")) >= 0) {
		switch (ret) {
		case 'l':
			sscanf(optarg, "%d", &count);
			break;
		case 's':
			sscanf(optarg, "%d", &msg_sz);
			break;
		case 'p':
			sscanf(optarg, "%d", &port);
			break;
		case 'c':
			sscanf(optarg, "%d", &num_addrs);
			break;
		case '?':
			return usage();
		}
	}

	if (!argv[optind])
		return usage();

	start_addr = inet_addr(argv[optind]);
	if (start_addr == INADDR_NONE)
		return usage();
	end_addr = start_addr + num_addrs;

	return send_packets(start_addr, end_addr, port, count, msg_sz);
}