void icmp_ping()

in netutils/ping/icmp_ping.c [190:437]


void icmp_ping(FAR const struct ping_info_s *info)
{
  struct ping_result_s result;
  FAR struct ping_priv_s *priv;
  FAR struct icmp_hdr_s *inhdr;
  FAR uint8_t *iobuffer;
  FAR uint8_t *ptr;
  int ret;
  int ch;
  int i;

  g_exiting = false;
  signal(SIGINT, sigexit);

  /* Initialize result structure */

  memset(&result, 0, sizeof(result));
  result.info = info;
  result.id = ping_newid();
  result.outsize = ICMP_IOBUFFER_SIZE(info->datalen);
  if (ping_gethostip(info->hostname, &result.dest) < 0)
    {
      icmp_callback(&result, ICMP_E_HOSTIP, 0);
      return;
    }

  /* Allocate memory to hold private data and ping buffer */

  priv = malloc(sizeof(*priv) + result.outsize);
  if (priv == NULL)
    {
      icmp_callback(&result, ICMP_E_MEMORY, 0);
      return;
    }

  iobuffer = (FAR uint8_t *)(priv + 1);

  priv->sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
  if (priv->sockfd < 0)
    {
      icmp_callback(&result, ICMP_E_SOCKET, errno);
      free(priv);
      return;
    }

  priv->kickoff = clock();

  memset(&priv->destaddr, 0, sizeof(struct sockaddr_in));
  priv->destaddr.sin_family      = AF_INET;
  priv->destaddr.sin_port        = 0;
  priv->destaddr.sin_addr.s_addr = result.dest.s_addr;

  memset(&priv->outhdr, 0, sizeof(struct icmp_hdr_s));
  priv->outhdr.type              = ICMP_ECHO_REQUEST;
  priv->outhdr.id                = htons(result.id);
  priv->outhdr.seqno             = htons(result.seqno);

  icmp_callback(&result, ICMP_I_BEGIN, 0);

  while (result.nrequests < info->count)
    {
      if (g_exiting)
        {
          break;
        }

      /* Copy the ICMP header into the I/O buffer */

      memcpy(iobuffer, &priv->outhdr, sizeof(struct icmp_hdr_s));

      /* Add some easily verifiable payload data */

      ptr = &iobuffer[sizeof(struct icmp_hdr_s)];
      ch  = 0x20;

      for (i = 0; i < info->datalen; i++)
        {
          *ptr++ = ch;
          if (++ch > 0x7e)
            {
              ch = 0x20;
            }
        }

      priv->start = clock();
      result.nrequests++;
      priv->nsent = sendto(priv->sockfd, iobuffer, result.outsize, 0,
                           (FAR struct sockaddr *)&priv->destaddr,
                           sizeof(struct sockaddr_in));
      if (priv->nsent < 0)
        {
          icmp_callback(&result, ICMP_E_SENDTO, errno);
          goto wait;
        }
      else if (priv->nsent != result.outsize)
        {
          icmp_callback(&result, ICMP_E_SENDSMALL, priv->nsent);
          goto wait;
        }

      priv->elapsed = 0;
      do
        {
          priv->retry          = false;
          priv->recvfd.fd      = priv->sockfd;
          priv->recvfd.events  = POLLIN;
          priv->recvfd.revents = 0;

          ret = poll(&priv->recvfd, 1,
                     info->timeout - priv->elapsed / USEC_PER_MSEC);
          if (ret < 0)
            {
              icmp_callback(&result, ICMP_E_POLL, errno);
              goto wait;
            }
          else if (ret == 0)
            {
              icmp_callback(&result, ICMP_W_TIMEOUT, info->timeout);
              goto wait;
            }

          if (priv->recvfd.revents & (POLLHUP | POLLERR))
            {
              icmp_callback(&result, ICMP_E_POLL, ENETDOWN);
              goto wait;
            }

          /* Get the ICMP response (ignoring the sender) */

          priv->addrlen = sizeof(struct sockaddr_in);
          priv->nrecvd  = recvfrom(priv->sockfd, iobuffer,
                                   result.outsize, 0,
                                   (FAR struct sockaddr *)&priv->fromaddr,
                                   &priv->addrlen);
          if (priv->nrecvd < 0)
            {
              icmp_callback(&result, ICMP_E_RECVFROM, errno);
              goto wait;
            }
          else if (priv->nrecvd < sizeof(struct icmp_hdr_s))
            {
              icmp_callback(&result, ICMP_E_RECVSMALL, priv->nrecvd);
              goto wait;
            }

          priv->elapsed = TICK2USEC(clock() - priv->start);
          inhdr         = (FAR struct icmp_hdr_s *)iobuffer;

          if (inhdr->type == ICMP_ECHO_REPLY)
            {
#ifndef CONFIG_SIM_NETUSRSOCK
              if (ntohs(inhdr->id) != result.id)
                {
                  icmp_callback(&result, ICMP_W_IDDIFF, ntohs(inhdr->id));
                  priv->retry = true;
                }
              else
#endif
              if (ntohs(inhdr->seqno) > result.seqno)
                {
                  icmp_callback(&result, ICMP_W_SEQNOBIG,
                                ntohs(inhdr->seqno));
                  priv->retry = true;
                }
              else if (ntohs(inhdr->seqno) < result.seqno)
                {
                  icmp_callback(&result, ICMP_W_SEQNOSMALL,
                                ntohs(inhdr->seqno));
                  priv->retry = true;
                }
              else
                {
                  bool verified = true;

                  icmp_callback(&result, ICMP_I_ROUNDTRIP, priv->elapsed);

                  /* Verify the payload data */

                  if (priv->nrecvd != result.outsize)
                    {
                      icmp_callback(&result, ICMP_W_RECVBIG, priv->nrecvd);
                      verified = false;
                    }
                  else
                    {
                      ptr = &iobuffer[sizeof(struct icmp_hdr_s)];
                      ch  = 0x20;

                      for (i = 0; i < info->datalen; i++, ptr++)
                        {
                          if (*ptr != ch)
                            {
                              icmp_callback(&result, ICMP_W_DATADIFF, 0);
                              verified = false;
                              break;
                            }

                          if (++ch > 0x7e)
                            {
                              ch = 0x20;
                            }
                        }
                    }

                  /* Only count the number of good replies */

                  if (verified)
                    {
                      result.nreplies++;
                    }
                }
            }
          else
            {
              icmp_callback(&result, ICMP_W_TYPE, inhdr->type);
            }
        }
      while (priv->retry && info->delay > priv->elapsed / USEC_PER_MSEC &&
             info->timeout > priv->elapsed / USEC_PER_MSEC);

      /* Wait if necessary to preserved the requested ping rate */

wait:
      priv->elapsed = TICK2MSEC(clock() - priv->start);
      if (priv->elapsed < info->delay)
        {
          struct timespec rqt;
          unsigned int remaining;
          unsigned int sec;
          unsigned int frac;  /* In deciseconds */

          remaining   = info->delay - priv->elapsed;
          sec         = remaining / MSEC_PER_SEC;
          frac        = remaining - MSEC_PER_SEC * sec;

          rqt.tv_sec  = sec;
          rqt.tv_nsec = frac * NSEC_PER_MSEC;

          nanosleep(&rqt, NULL);
        }

      priv->outhdr.seqno = htons(++result.seqno);
    }

  icmp_callback(&result, ICMP_I_FINISH, TICK2USEC(clock() - priv->kickoff));
  close(priv->sockfd);
  free(priv);
}