Netmap pipe bug test

netmap_pipe_bug_test.c

#define NETMAP_WITH_LIBS
#include <net/netmap_user.h>
#include <sys/poll.h>

void sender(int tx_sync) {
  struct nm_desc *d;
  struct pollfd fds;
  printf("Using %s\n", tx_sync ? "TXSYNC ioctl" : "TX_POLL POLLIN poll");
  d = nm_open("netmap:pipe}0", NULL, 0, 0);
  fds.fd = NETMAP_FD(d);
  fds.events = POLLIN;
  while (1) {
    int wrote_something = 0;
    int ret, i;
    for (i = d->first_tx_ring; i <= d->last_tx_ring; i++) {
      unsigned int cur, next;
      struct netmap_slot *slot;
      struct netmap_ring *txring;
      char *p;
      txring = NETMAP_TXRING(d->nifp, i);
      while (!nm_ring_empty(txring)) {
        cur = txring->cur;
        slot = &txring->slot[cur];
        p = NETMAP_BUF(txring, slot->buf_idx);
        p[0] = 1; p[79] = 1;
        slot->len = 80;
        next = nm_ring_next(txring, cur);
        txring->head = next;
        txring->cur = next;
        wrote_something = 1;
      }
    }
    if (!wrote_something && !tx_sync) {
      printf("pipe is still full\n");
    }
    // filled pipe
    if (tx_sync) {
      ret = ioctl(NETMAP_FD(d), NIOCTXSYNC, NULL);
      if (ret < 0) {
        printf("ioctl err\n");
        break;
      }
    } else {
      ret = poll(&fds, 1, 1000); // sometimes it works after first the TXSYNC version was used
      if (ret == 0) {
        printf("timeout\n");
      } else if (ret == -1) {
        printf("poll err\n");
        break;
      }
    }
  }
  nm_close(d);
}

void main(int argc, char** argv) {
  printf("To be started after ./pkt-gen -i pipe{0 -f rx\n");
  if (argc != 2) {
    printf("Usage: %s p|t\n  p: use TX_POLL POLLIN poll for tx\n  t: use TXSYNC ioctl\n", argv[0]);
  } else {
    sender(*argv[1] == 't');
  }
}