nuttx/net/devif/devif_cansend.c

/****************************************************************************
 * net/devif/devif_cansend.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

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

#include <nuttx/config.h>

#include <string.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/net/netdev.h>

#if defined(CONFIG_NET_CAN)

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

/****************************************************************************
 * Name: devif_can_send
 *
 * Description:
 *   Called from socket logic in order to send a can packet in response to
 *   an xmit or poll request from the network interface driver.
 *
 *   This is almost identical to calling devif_send() except that the data to
 *   be sent is copied into dev->d_buf (vs. dev->d_appdata), since there is
 *   no header on the data.
 *
 * Assumptions:
 *   Called with the network locked.
 *
 ****************************************************************************/

void devif_can_send(FAR struct net_driver_s *dev, FAR const void *buf,
                    unsigned int len)
{
  unsigned int limit = NETDEV_PKTSIZE(dev) - NET_LL_HDRLEN(dev);

  if (dev == NULL || len == 0 || len > limit)
    {
      nerr("ERROR: devif_pkt_send fail: %p, sndlen: %u, pktlen: %u\n",
           dev, len, limit);
      return;
    }

  iob_update_pktlen(dev->d_iob, 0);

  /* Copy the data into the device packet buffer and set the number of
   * bytes to send
   */

  if (len <= iob_navail(false) * CONFIG_IOB_BUFSIZE)
    {
      dev->d_sndlen = iob_trycopyin(dev->d_iob, buf, len, 0, false);
    }
  else
    {
      dev->d_sndlen = 0;
    }

  if (dev->d_sndlen != len)
    {
      netdev_iob_release(dev);
      dev->d_sndlen = 0;
    }

  dev->d_len = dev->d_sndlen;
}

#endif /* CONFIG_NET_CAN */