From 74b60c5712f2a84904b95d008953c140a9bd5dd2 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:49:50 +0200 Subject: Adding upstream version 2.9.4. Signed-off-by: Daniel Baumann --- gl/lib/fd-hook.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 gl/lib/fd-hook.c (limited to 'gl/lib/fd-hook.c') diff --git a/gl/lib/fd-hook.c b/gl/lib/fd-hook.c new file mode 100644 index 0000000..8840f63 --- /dev/null +++ b/gl/lib/fd-hook.c @@ -0,0 +1,116 @@ +/* Hook for making file descriptor functions close(), ioctl() extensible. + Copyright (C) 2009-2020 Free Software Foundation, Inc. + Written by Bruno Haible , 2009. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +/* Specification. */ +#include "fd-hook.h" + +#include + +/* 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 -- cgit v1.2.3