simple_udp_flood.c

#include <time.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>

#define YIELD
//#define SLEEP
//#define SLEEP_US 1000
#define PACKETS_TO_SEND 10000ULL

static int mtu   = 1500;
static int port  = 8080;

char *payload;
char *address = "192.168.122.1";

static inline long long tv_to_us(struct timeval *tv1, struct timeval *tv2)
{
    return (long long)(tv2->tv_sec - tv1->tv_sec) * 1000000LL +
            tv2->tv_usec - tv1->tv_usec;
}

void udp_flood(int fd, struct sockaddr *dst, int pktlen)
{
    struct timeval start, end;
    long long total_us = 0;
    unsigned long long pkt_sent = 0;

    gettimeofday(&start, NULL);

    while (pkt_sent < PACKETS_TO_SEND) {
        if (sendto(fd, payload, mtu, MSG_NOSIGNAL, dst, pktlen) >= 0)
            pkt_sent++;
        else
            printf("errno %d - %s\n", errno, strerror(errno));

#ifdef YIELD
        sched_yield();
#endif

#ifdef SLEEP
        usleep(SLEEP_US);
#endif
    }

    gettimeofday(&end, NULL);
    total_us = tv_to_us(&start, &end);
    printf("%llu packets sent in %lld us\n", pkt_sent, total_us);
}

int main(int argc, char **argv)
{
    int fd;
    struct sockaddr_storage *ss;
    
    payload = malloc(mtu);
    ss      = malloc (sizeof(struct sockaddr_storage));
    if (!payload || !ss) {
        printf("Can't allocate memory\n");
        exit(1);
    }

    memset(payload, 0xF, mtu);
    ss->ss_family = AF_INET;
    ((struct sockaddr_in *)ss)->sin_port = htons(port);

    if (!inet_pton(ss->ss_family, address, &((struct sockaddr_in *)ss)->sin_addr)) {
        printf("Invalid IP address\n");
        exit(1);
    }

    if ((fd = socket((*ss).ss_family, SOCK_DGRAM, 0)) == -1) {
        printf("error creating socket\n");
        exit(1);
    }

    udp_flood(fd, (struct sockaddr *)ss, sizeof(struct sockaddr_in));
    return 0;
}