+
−/* Hook for making making file descriptor functions close(), ioctl() extensible.
+
−   Copyright (C) 2009-2013 Free Software Foundation, Inc.
+
−   Written by Bruno Haible <bruno@clisp.org>, 2009.
+
−
+
−   This program is free software: you can redistribute it and/or modify it
+
−   under the terms of the GNU Lesser General Public License as published
+
−   by the Free Software Foundation; either version 3 of the License, or
+
−   (at your option) any later version.
+
−
+
−   This program is distributed in the hope that it will be useful,
+
−   but WITHOUT ANY WARRANTY; without even the implied warranty of
+
−   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+
−   Lesser General Public License for more details.
+
−
+
−   You should have received a copy of the GNU Lesser General Public License
+
−   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
−
+
−#include <config.h>
+
−
+
−/* Specification.  */
+
−#include "fd-hook.h"
+
−
+
−#include <stdlib.h>
+
−
+
−/* Currently, this entire code is only needed for the handling of sockets
+
−   on native Windows platforms.  */
+
−#if WINDOWS_SOCKETS
+
−
+
−/* The first and last link in the doubly linked list.
+
−   Initially the list is empty.  */
+
−static struct fd_hook anchor = { &anchor, &anchor, NULL, NULL };
+
−
+
−int
+
−execute_close_hooks (const struct fd_hook *remaining_list, gl_close_fn primary,
+
−                     int fd)
+
−{
+
−  if (remaining_list == &anchor)
+
−    /* End of list reached.  */
+
−    return primary (fd);
+
−  else
+
−    return remaining_list->private_close_fn (remaining_list->private_next,
+
−                                             primary, fd);
+
−}
+
−
+
−int
+
−execute_all_close_hooks (gl_close_fn primary, int fd)
+
−{
+
−  return execute_close_hooks (anchor.private_next, primary, fd);
+
−}
+
−
+
−int
+
−execute_ioctl_hooks (const struct fd_hook *remaining_list, gl_ioctl_fn primary,
+
−                     int fd, int request, void *arg)
+
−{
+
−  if (remaining_list == &anchor)
+
−    /* End of list reached.  */
+
−    return primary (fd, request, arg);
+
−  else
+
−    return remaining_list->private_ioctl_fn (remaining_list->private_next,
+
−                                             primary, fd, request, arg);
+
−}
+
−
+
−int
+
−execute_all_ioctl_hooks (gl_ioctl_fn primary,
+
−                         int fd, int request, void *arg)
+
−{
+
−  return execute_ioctl_hooks (anchor.private_next, primary, fd, request, arg);
+
−}
+
−
+
−void
+
−register_fd_hook (close_hook_fn close_hook, ioctl_hook_fn ioctl_hook, struct fd_hook *link)
+
−{
+
−  if (close_hook == NULL)
+
−    close_hook = execute_close_hooks;
+
−  if (ioctl_hook == NULL)
+
−    ioctl_hook = execute_ioctl_hooks;
+
−
+
−  if (link->private_next == NULL && link->private_prev == NULL)
+
−    {
+
−      /* Add the link to the doubly linked list.  */
+
−      link->private_next = anchor.private_next;
+
−      link->private_prev = &anchor;
+
−      link->private_close_fn = close_hook;
+
−      link->private_ioctl_fn = ioctl_hook;
+
−      anchor.private_next->private_prev = link;
+
−      anchor.private_next = link;
+
−    }
+
−  else
+
−    {
+
−      /* The link is already in use.  */
+
−      if (link->private_close_fn != close_hook
+
−          || link->private_ioctl_fn != ioctl_hook)
+
−        abort ();
+
−    }
+
−}
+
−
+
−void
+
−unregister_fd_hook (struct fd_hook *link)
+
−{
+
−  struct fd_hook *next = link->private_next;
+
−  struct fd_hook *prev = link->private_prev;
+
−
+
−  if (next != NULL && prev != NULL)
+
−    {
+
−      /* The link is in use.  Remove it from the doubly linked list.  */
+
−      prev->private_next = next;
+
−      next->private_prev = prev;
+
−      /* Clear the link, to mark it unused.  */
+
−      link->private_next = NULL;
+
−      link->private_prev = NULL;
+
−      link->private_close_fn = NULL;
+
−      link->private_ioctl_fn = NULL;
+
−    }
+
−}
+
−
+
−#endif