nuttx/net/local/local_sendpacket.c
Gregory Nutt 21041af8a7 This commit modifies the Unix domain local socket design. Local sockets are built on top of pipes. The Local socket implementation maintained file descriptors to interrupt with the pipes. File descriptors have the bad property that they are valid only while running on the thread within the task that created the local socket.
As a policy, all internal OS implementations must use "detached" files which are valid in any context and do not depend on the validity of a file descriptor at any point in time.  This commit converts the usage of file descriptors to detached files throughout the local socket implementation.

Squashed commit of the following:

    net/local: Finish change to eliminate use of file descriptors.
    net/local:  A little more of the conversion.
    net/local: Beginning of chnages to eliminate use of file descriptors in the local socket implementeation. poll() will be a problem.
2017-11-02 08:23:38 -06:00

170 lines
5.3 KiB
C

/****************************************************************************
* net/local/local_sendpacket.c
*
* Copyright (C) 2015, 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 NuttX 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 <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/fs/fs.h>
#include "local/local.h"
#if defined(CONFIG_NET) && defined(CONFIG_NET_LOCAL)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define LOCAL_PREAMBLE_SIZE 8
/****************************************************************************
* Private Data
****************************************************************************/
static const uint8_t g_preamble[LOCAL_PREAMBLE_SIZE] =
{
LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE,
LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_END_BYTE
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: local_fifo_write
*
* Description:
* Write a data on the write-only FIFO.
*
* Parameters:
* filep File structure of write-only FIFO.
* buf Data to send
* len Length of data to send
*
* Return:
* Zero is returned on success; a negated errno value is returned on any
* failure.
*
****************************************************************************/
static int local_fifo_write(FAR struct file *filep, FAR const uint8_t *buf,
size_t len)
{
ssize_t nwritten;
while (len > 0)
{
nwritten = file_write(filep, buf, len);
if (nwritten < 0)
{
if (nwritten != -EINTR)
{
nerr("ERROR: nx_write failed: %d\n", nwritten);
return (int)nwritten;
}
ninfo("Ignoring signal\n");
}
else
{
DEBUGASSERT(nwritten > 0 && nwritten <= len);
len -= nwritten;
buf += nwritten;
}
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: local_send_packet
*
* Description:
* Send a packet on the write-only FIFO.
*
* Parameters:
* filep File structure of write-only FIFO.
* buf Data to send
* len Length of data to send
*
* Return:
* Zero is returned on success; a negated errno value is returned on any
* failure.
*
****************************************************************************/
int local_send_packet(FAR struct file *filep, FAR const uint8_t *buf,
size_t len)
{
uint16_t len16;
int ret;
/* Send the packet preamble */
ret = local_fifo_write(filep, g_preamble, LOCAL_PREAMBLE_SIZE);
if (ret == OK)
{
/* Send the packet length */
len16 = len;
ret = local_fifo_write(filep, (FAR const uint8_t *)&len16,
sizeof(uint16_t));
if (ret == OK)
{
/* Send the packet data */
ret = local_fifo_write(filep, buf, len);
}
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_LOCAL */