Re: Netperf UDP issue with connected sockets

[Eric Dumazet]

On Thu, 2016-11-17 at 22:19 +0100, Jesper Dangaard Brouer wrote:

> 
> Maybe you can share your udp flood "udpsnd" program source?

Very ugly. This is based on what I wrote when tracking the UDP v6
checksum bug (4f2e4ad56a65f3b7d64c258e373cb71e8d2499f4 net: mangle zero
checksum in skb_checksum_help()), because netperf sends the same message
over and over...


Use -d 2   to remove the ip_idents_reserve() overhead.


#define _GNU_SOURCE

#include <errno.h>
#include <error.h>
#include <linux/errqueue.h>
#include <netinet/in.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>

char buffer[1400];

int main(int argc, char** argv) {
  int fd, i;
  struct sockaddr_in6 addr;
  char *host = "2002:af6:798::1";
  int family = AF_INET6;
  int discover = -1;

  while ((i = getopt(argc, argv, "4H:d:")) != -1) {
    switch (i) {
    case 'H': host = optarg; break;
    case '4': family = AF_INET; break;
    case 'd': discover = atoi(optarg); break;
    }
  }
  fd = socket(family, SOCK_DGRAM, 0);
  if (fd < 0)
    error(1, errno, "failed to create socket");
  if (discover != -1)
    setsockopt(fd, SOL_IP, IP_MTU_DISCOVER,
               &discover, sizeof(discover));

  memset(&addr, 0, sizeof(addr));
  if (family == AF_INET6) {
          addr.sin6_family = AF_INET6;
          addr.sin6_port = htons(9);
      inet_pton(family, host, (void *)&addr.sin6_addr.s6_addr);
  } else {
    struct sockaddr_in *in = (struct sockaddr_in *)&addr;
    in->sin_family = family;
    in->sin_port = htons(9);
      inet_pton(family, host, &in->sin_addr);
  }
  connect(fd, (struct sockaddr *)&addr,
          (family == AF_INET6) ? sizeof(addr) :
                                 sizeof(struct sockaddr_in));
  memset(buffer, 1, 1400);
  for (i = 0; i < 655360000; i++) {
    memcpy(buffer, &i, sizeof(i));
    send(fd, buffer, 100 + rand() % 200, 0);
  }
  return 0;
}