nuttx-apps/examples/flowc/flowc_receiver.c

/****************************************************************************
 * examples/flowc/flowc_receiver.c
 *
 *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name Gregory Nutt nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include "config.h"

#include <sys/socket.h>
#include <netinet/in.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include <arpa/inet.h>

#include "flowc.h"

/****************************************************************************
 * Public Data
 ****************************************************************************/

static char g_tty_devname[MAX_DEVNAME] = CONFIG_EXAMPLES_FLOWC_RECEVER_DEVNAME;
static char g_expected = 0x20;
static unsigned int g_nerrors;
static unsigned long g_count;

/****************************************************************************
 * Private Functions
 ****************************************************************************/

static inline void check_buffer(FAR uint8_t *buf, size_t buflen)
{
  unsigned long count;
  FAR uint8_t *ptr;
  size_t i;
  int ch;

  /* Verfiy the buffer content */

  ch = g_expected;

  for (i = 0, ptr = buf, count = g_count; i < buflen; i++, ptr++, count++)
    {
      if (*ptr != ch)
        {
          printf("receiver: ERROR: Expected %c (%02x), found %c (%02x) at count=%lu\n",
                 isprint(ch)   ? ch   : '.', ch,
                 isprint(*ptr) ? *ptr : '.', *ptr,
                 count);
          g_nerrors++;
          ch = *ptr;
        }
    }

  /* Update globals */

  g_expected = ch + 1;
  if (g_expected > 0x7e)
    {
      g_expected = 0x20;
    }

  g_count = count;
}

/****************************************************************************
 * flowc_cmdline
 ****************************************************************************/

static int flowc_cmdline(int argc, char **argv)
{
  /* Currently only a single command line option is supported:  The receiver
   * IP address.
   */

  if (argc == 2)
    {
      strncpy(g_tty_devname, argv[1], MAX_DEVNAME);
    }
  else if (argc != 1)
    {
      fprintf(stderr, "ERROR: Too many arguments\n");
      fprintf(stderr, "USAGE: %s [<tty-devname>]\n", argv[0]);
      return 1;
    }

  return 0;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

int flowc_receiver(int argc, char **argv)
{
  uint8_t inbuf[CONFIG_EXAMPLES_FLOWC_RECEIVER_BUFSIZE];
#ifdef CONFIG_EXAMPLES_FLOWC_INPUT
  struct termios term;
#endif
  ssize_t nread;
  int ret;
  int fd;

  /* Parse the command line */

  ret = flowc_cmdline(argc, argv);
  if (ret != 0)
    {
      return ret;
    }

  /* Open the serial device */

  fd = open(g_tty_devname, O_RDONLY);
  if (fd < 0)
    {
      printf("sender ERROR: Failed to open %s: %d\n", g_tty_devname, errno);
      return 1;
    }

#ifdef CONFIG_EXAMPLES_FLOWC_INPUT
  /* Set input flow control */

  tcgetattr(fd, &term);
#ifdef CRTS_IFLOW
  term.c_cflag |= CRTS_IFLOW;
#else
  term.c_cflag |= CRTSCTS;
#endif
  tcsetattr(fd, TCSANOW, &term);
#endif

  /* Then receive until all data has been received correctly (possibly
   * hanging if data is lost).
   */

  while (g_count < TOTALSIZE)
    {
      nread = read(fd, inbuf, CONFIG_EXAMPLES_FLOWC_RECEIVER_BUFSIZE);
      if (nread < 0)
        {
          printf("receiver: %lu. recv failed: %d\n", g_count, errno);
          close(fd);
          return 1;
        }

      check_buffer(inbuf, nread);
      if (g_nerrors > 25)
        {
          printf("receiver: %lu. Too many errors: %u\n", g_count, g_nerrors);
          close(fd);
          return 1;
        }

#if defined(CONFIG_EXAMPLES_FLOWC_RECEIVER_DELAY) && \
    CONFIG_EXAMPLES_FLOWC_RECEIVER_DELAY > 0
      /* Delay to force flow control */

      usleep(1000 * CONFIG_EXAMPLES_FLOWC_RECEIVER_DELAY);
#endif
    }

  close(fd);
  return 0;
}