incubator-nuttx/net/net_dup.c

151 lines
4.4 KiB
C

/****************************************************************************
* net/net_dup.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <sys/socket.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include "net_internal.h"
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Function: net_dup
*
* Description:
* Clone a socket descriptor to an arbitray descriptor number. If file
* descriptors are implemented, then this is called by dup() for the case
* of socket file descriptors. If file descriptors are not implemented,
* then this function IS dup().
*
****************************************************************************/
int net_dup(int sockfd, int minsd)
{
FAR struct socket *psock1 = sockfd_socket(sockfd);
FAR struct socket *psock2;
int sockfd2;
int err;
int ret;
/* Make sure that the minimum socket descriptor is within the legal range.
* the minimum value we receive is relative to file descriptor 0; we need
* map it relative of the first socket descriptor.
*/
#if CONFIG_NFILE_DESCRIPTORS > 0
if (minsd >= CONFIG_NFILE_DESCRIPTORS)
{
minsd -= CONFIG_NFILE_DESCRIPTORS;
}
else
{
minsd = 0;
}
#endif
/* Lock the scheduler throughout the following */
sched_lock();
/* Get the socket structure underlying sockfd */
psock1 = sockfd_socket(sockfd);
/* Verify that the sockfd corresponds to valid, allocated socket */
if (!psock1 || psock1->s_crefs <= 0)
{
err = EBADF;
goto errout;
}
/* Allocate a new socket descriptor */
sockfd2 = sockfd_allocate(minsd);
if (sockfd2 < 0)
{
err = ENFILE;
goto errout;
}
/* Get the socket structure underlying the new descriptor */
psock2 = sockfd_socket(sockfd2);
if (!psock2)
{
err = ENOSYS; /* should not happen */
goto errout;
}
/* Duplicate the socket state */
ret = net_clone(psock1, psock2);
if (ret < 0)
{
err = -ret;
goto errout;
}
sched_unlock();
return sockfd2;
errout:
sched_unlock();
errno = err;
return ERROR;
}
#endif /* defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 */