nuttx/net/socket/net_vfcntl.c

/****************************************************************************
 * net/socket/net_vfcntl.c
 *
 *   Copyright (C) 2009, 2012-2015 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/socket.h>
#include <stdint.h>
#include <stdarg.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>

#include <arch/irq.h>
#include <nuttx/net/net.h>
#include "socket/socket.h"

#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0

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

/****************************************************************************
 * Name: net_vfcntl
 *
 * Description:
 *   Performs fcntl operations on socket
 *
 * Input Parameters:
 *   sockfd - Socket descriptor of the socket to operate on
 *   cmd    - The fcntl command.
 *   ap     - Command-specific arguments
 *
 * Returned Value:
 *   Zero (OK) is returned on success; -1 (ERROR) is returned on failure and
 *   the errno value is set appropriately.
 *
 ****************************************************************************/

int net_vfcntl(int sockfd, int cmd, va_list ap)
{
  FAR struct socket *psock = sockfd_socket(sockfd);
  net_lock_t flags;
  int errcode = 0;
  int ret = 0;

  ninfo("sockfd=%d cmd=%d\n", sockfd, cmd);

  /* Verify that the sockfd corresponds to valid, allocated socket */

  if (!psock || psock->s_crefs <= 0)
    {
      errcode = EBADF;
      goto errout;
    }

  /* Interrupts must be disabled in order to perform operations on socket structures */

  flags = net_lock();
  switch (cmd)
    {
      case F_DUPFD:
        /* Return a new file descriptor which shall be the lowest numbered
         * available (that is, not already open) file descriptor greater than
         * or equal to the third argument, arg, taken as an integer of type
         * int. The new file descriptor shall refer to the same open file
         * description as the original file descriptor, and shall share any
         * locks.  The FD_CLOEXEC flag associated  with the new file descriptor
         * shall be cleared to keep the file open across calls to one of the
         * exec functions.
         */

        {
          ret = net_dupsd(sockfd, va_arg(ap, int));
        }
        break;

      case F_GETFD:
        /* Get the file descriptor flags defined in <fcntl.h> that are associated
         * with the file descriptor fd.  File descriptor flags are associated
         * with a single file descriptor and do not affect other file descriptors
         * that refer to the same file.
         */

      case F_SETFD:
        /* Set the file descriptor flags defined in <fcntl.h>, that are associated
         * with fd, to the third argument, arg, taken as type int. If the
         * FD_CLOEXEC flag in the third argument is 0, the file shall remain open
         * across the exec functions; otherwise, the file shall be closed upon
         * successful execution of one  of  the  exec  functions.
         */

         errcode = ENOSYS; /* F_GETFD and F_SETFD not implemented */
         break;

      case F_GETFL:
        /* Get the file status flags and file access modes, defined in
         * <fcntl.h>, for the file description associated with fd. The file
         * access modes can be extracted from the return value using the
         * mask O_ACCMODE, which is defined  in <fcntl.h>. File status flags
         * and file access modes are associated with the file description
         * and do not affect other file descriptors that refer to the same
         * file with different open file descriptions.
         */

        {
          /* This summarizes the behavior of all NuttX sockets */

          ret = O_RDWR | O_SYNC | O_RSYNC;

#if defined(CONFIG_NET_LOCAL) || defined(CONFIG_NET_TCP_READAHEAD) || \
    defined(CONFIG_NET_UDP_READAHEAD)
          /* Unix domain sockets may be non-blocking.  TCP/IP and UDP/IP
           * sockets may also be non-blocking if read-ahead is enabled
           */

          if ((0
#ifdef CONFIG_NET_LOCAL
              || psock->s_domain == PF_LOCAL  /* Unix domain stream or datagram */
#endif
#ifdef CONFIG_NET_TCP_READAHEAD
              || psock->s_type == SOCK_STREAM /* IP or Unix domain stream */
#endif
#ifdef CONFIG_NET_UDP_READAHEAD
              || psock->s_type == SOCK_DGRAM  /* IP or Unix domain datagram */
#endif
              ) && _SS_ISNONBLOCK(psock->s_flags))
            {
              ret |= O_NONBLOCK;
            }
#endif /* CONFIG_NET_LOCAL || CONFIG_NET_TCP_READAHEAD || CONFIG_NET_UDP_READAHEAD */
        }
        break;

      case F_SETFL:
        /* Set the file status flags, defined in <fcntl.h>, for the file description
         * associated with fd from the corresponding  bits in the third argument,
         * arg, taken as type int. Bits corresponding to the file access mode and
         * the file creation flags, as defined in <fcntl.h>, that are set in arg shall
         * be ignored. If any bits in arg other than those mentioned here are changed
         * by the application, the result is unspecified.
         */

        {
#if defined(CONFIG_NET_LOCAL) || defined(CONFIG_NET_TCP_READAHEAD) || \
    defined(CONFIG_NET_UDP_READAHEAD)
           /* Non-blocking is the only configurable option.  And it applies
            * only Unix domain sockets and to read operations on TCP/IP
            * and UDP/IP sockets when read-ahead is enabled.
            */

          int mode =  va_arg(ap, int);
#if defined(CONFIG_NET_LOCAL_STREAM) || defined(CONFIG_NET_TCP_READAHEAD)
          if (psock->s_type == SOCK_STREAM) /* IP or Unix domain stream */
            {
               if ((mode & O_NONBLOCK) != 0)
                 {
                   psock->s_flags |= _SF_NONBLOCK;
                 }
               else
                 {
                   psock->s_flags &= ~_SF_NONBLOCK;
                 }
            }
          else
#endif
#if defined(CONFIG_NET_LOCAL_DGRAM) || defined(CONFIG_NET_UDP_READAHEAD)
          if (psock->s_type == SOCK_DGRAM)  /* IP or Unix domain datagram */
            {
               if ((mode & O_NONBLOCK) != 0)
                 {
                   psock->s_flags |= _SF_NONBLOCK;
                 }
               else
                 {
                   psock->s_flags &= ~_SF_NONBLOCK;
                 }
            }
          else
#endif
#endif /* CONFIG_NET_LOCAL || CONFIG_NET_TCP_READAHEAD || CONFIG_NET_UDP_READAHEAD */
            {
              ndbg("ERROR: Non-blocking not supported for this socket\n");
            }
        }
        break;

      case F_GETOWN:
        /* If fd refers to a socket, get the process or process group ID specified
         * to receive SIGURG signals when out-of-band data is available. Positive values
         * indicate a process ID; negative values, other than -1, indicate a process group
         * ID. If fd does not refer to a socket, the results are unspecified.
         */

      case F_SETOWN:
        /* If fd refers to a socket, set the process or process group ID specified
         * to receive SIGURG signals when out-of-band data is available, using the value
         * of the third argument, arg, taken as type int. Positive values indicate a
         * process ID; negative values, other than -1, indicate a process group ID. If
         * fd does not refer to a socket, the results are unspecified.
         */

      case F_GETLK:
        /* Get the first lock which blocks the lock description pointed to by the third
         * argument, arg, taken as a pointer to type struct flock, defined in <fcntl.h>.
         * The information retrieved shall overwrite the information passed to fcntl() in
         * the structure flock. If no lock is found that would prevent this lock from being
         * created, then the structure shall be left unchanged except for the lock type
         * which shall be set to F_UNLCK.
         */

      case F_SETLK:
        /* Set or clear a file segment lock according to the lock description pointed to
         * by the third argument, arg, taken as a pointer to type struct flock, defined in
         * <fcntl.h>. F_SETLK can establish shared (or read) locks (F_RDLCK) or exclusive
         * (or write) locks (F_WRLCK), as well  as  to  remove  either  type  of  lock  (F_UNLCK).
         * F_RDLCK, F_WRLCK, and F_UNLCK are defined in <fcntl.h>. If a shared or exclusive
         * lock cannot be set, fcntl() shall return immediately with a return value of -1.
         */

      case F_SETLKW:
        /* This command shall be equivalent to F_SETLK except that if a shared or exclusive
         * lock is blocked by other locks, the thread shall wait until the request can be
         * satisfied. If a signal that is to be caught is received while fcntl() is waiting
         * for a region, fcntl() shall be interrupted. Upon return from the signal handler,
         * fcntl() shall return -1 with errno set to [EINTR], and the lock operation shall
         * not be done.
         */

         errcode = ENOSYS; /* F_GETOWN, F_SETOWN, F_GETLK, F_SETLK, F_SETLKW */
         break;

      default:
         errcode = EINVAL;
         break;
  }

  net_unlock(flags);

errout:
  if (errcode != 0)
    {
      set_errno(errcode);
      return ERROR;
    }

  return ret;
}

#endif /* CONFIG_NET && CONFIG_NSOCKET_DESCRIPTORS > 0 */