mpd/src/system/fd_util.c
2013-08-07 10:31:31 +02:00

354 lines
6.4 KiB
C

/*
* Copyright (C) 2003-2011 The Music Player Daemon Project
* http://www.musicpd.org
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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.
*
* 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 FOUNDATION 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.
*/
#include "config.h" /* must be first for large file support */
#include "fd_util.h"
#if !defined(_GNU_SOURCE) && (defined(HAVE_PIPE2) || defined(HAVE_ACCEPT4))
#define _GNU_SOURCE
#endif
#include <assert.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#ifdef WIN32
#include <ws2tcpip.h>
#include <winsock2.h>
#else
#include <sys/socket.h>
#endif
#ifdef HAVE_INOTIFY_INIT
#include <sys/inotify.h>
#endif
#ifdef USE_EVENTFD
#include <sys/eventfd.h>
#endif
#ifndef WIN32
static int
fd_mask_flags(int fd, int and_mask, int xor_mask)
{
int ret;
assert(fd >= 0);
ret = fcntl(fd, F_GETFD, 0);
if (ret < 0)
return ret;
return fcntl(fd, F_SETFD, (ret & and_mask) ^ xor_mask);
}
#endif /* !WIN32 */
static int
fd_set_cloexec(int fd, bool enable)
{
#ifndef WIN32
return fd_mask_flags(fd, ~FD_CLOEXEC, enable ? FD_CLOEXEC : 0);
#else
(void)fd;
(void)enable;
return 0;
#endif
}
/**
* Enables non-blocking mode for the specified file descriptor. On
* WIN32, this function only works for sockets.
*/
static int
fd_set_nonblock(int fd)
{
#ifdef WIN32
u_long val = 1;
return ioctlsocket(fd, FIONBIO, &val);
#else
int flags;
assert(fd >= 0);
flags = fcntl(fd, F_GETFL);
if (flags < 0)
return flags;
return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
#endif
}
int
dup_cloexec(int oldfd)
{
int newfd = dup(oldfd);
if (newfd >= 0)
fd_set_nonblock(newfd);
return newfd;
}
int
open_cloexec(const char *path_fs, int flags, int mode)
{
int fd;
#ifdef O_CLOEXEC
flags |= O_CLOEXEC;
#endif
#ifdef O_NOCTTY
flags |= O_NOCTTY;
#endif
fd = open(path_fs, flags, mode);
if (fd >= 0)
fd_set_cloexec(fd, true);
return fd;
}
int
pipe_cloexec(int fd[2])
{
#ifdef WIN32
return _pipe(fd, 512, _O_BINARY);
#else
int ret;
#ifdef HAVE_PIPE2
ret = pipe2(fd, O_CLOEXEC);
if (ret >= 0 || errno != ENOSYS)
return ret;
#endif
ret = pipe(fd);
if (ret >= 0) {
fd_set_cloexec(fd[0], true);
fd_set_cloexec(fd[1], true);
}
return ret;
#endif
}
int
pipe_cloexec_nonblock(int fd[2])
{
#ifdef WIN32
return _pipe(fd, 512, _O_BINARY);
#else
int ret;
#ifdef HAVE_PIPE2
ret = pipe2(fd, O_CLOEXEC|O_NONBLOCK);
if (ret >= 0 || errno != ENOSYS)
return ret;
#endif
ret = pipe(fd);
if (ret >= 0) {
fd_set_cloexec(fd[0], true);
fd_set_cloexec(fd[1], true);
fd_set_nonblock(fd[0]);
fd_set_nonblock(fd[1]);
}
return ret;
#endif
}
#ifndef WIN32
int
socketpair_cloexec(int domain, int type, int protocol, int sv[2])
{
int ret;
#ifdef SOCK_CLOEXEC
ret = socketpair(domain, type | SOCK_CLOEXEC, protocol, sv);
if (ret >= 0 || errno != EINVAL)
return ret;
#endif
ret = socketpair(domain, type, protocol, sv);
if (ret >= 0) {
fd_set_cloexec(sv[0], true);
fd_set_cloexec(sv[1], true);
}
return ret;
}
int
socketpair_cloexec_nonblock(int domain, int type, int protocol, int sv[2])
{
int ret;
#if defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
ret = socketpair(domain, type | SOCK_CLOEXEC | SOCK_NONBLOCK, protocol,
sv);
if (ret >= 0 || errno != EINVAL)
return ret;
#endif
ret = socketpair(domain, type, protocol, sv);
if (ret >= 0) {
fd_set_cloexec(sv[0], true);
fd_set_nonblock(sv[0]);
fd_set_cloexec(sv[1], true);
fd_set_nonblock(sv[1]);
}
return ret;
}
#endif
int
socket_cloexec_nonblock(int domain, int type, int protocol)
{
int fd;
#if defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
fd = socket(domain, type | SOCK_CLOEXEC | SOCK_NONBLOCK, protocol);
if (fd >= 0 || errno != EINVAL)
return fd;
#endif
fd = socket(domain, type, protocol);
if (fd >= 0) {
fd_set_cloexec(fd, true);
fd_set_nonblock(fd);
}
return fd;
}
int
accept_cloexec_nonblock(int fd, struct sockaddr *address,
size_t *address_length_r)
{
int ret;
socklen_t address_length = *address_length_r;
#ifdef HAVE_ACCEPT4
ret = accept4(fd, address, &address_length,
SOCK_CLOEXEC|SOCK_NONBLOCK);
if (ret >= 0 || errno != ENOSYS) {
if (ret >= 0)
*address_length_r = address_length;
return ret;
}
#endif
ret = accept(fd, address, &address_length);
if (ret >= 0) {
fd_set_cloexec(ret, true);
fd_set_nonblock(ret);
*address_length_r = address_length;
}
return ret;
}
#ifndef WIN32
ssize_t
recvmsg_cloexec(int sockfd, struct msghdr *msg, int flags)
{
#ifdef MSG_CMSG_CLOEXEC
flags |= MSG_CMSG_CLOEXEC;
#endif
ssize_t result = recvmsg(sockfd, msg, flags);
if (result >= 0) {
struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
while (cmsg != NULL) {
if (cmsg->cmsg_type == SCM_RIGHTS) {
const int *fd_p = (const int *)CMSG_DATA(cmsg);
fd_set_cloexec(*fd_p, true);
}
cmsg = CMSG_NXTHDR(msg, cmsg);
}
}
return result;
}
#endif
#ifdef HAVE_INOTIFY_INIT
int
inotify_init_cloexec(void)
{
int fd;
#ifdef HAVE_INOTIFY_INIT1
fd = inotify_init1(IN_CLOEXEC);
if (fd >= 0 || errno != ENOSYS)
return fd;
#endif
fd = inotify_init();
if (fd >= 0)
fd_set_cloexec(fd, true);
return fd;
}
#endif
#ifdef USE_EVENTFD
int
eventfd_cloexec_nonblock(unsigned initval, int flags)
{
return eventfd(initval, flags | EFD_CLOEXEC | EFD_NONBLOCK);
}
#endif
int
close_socket(int fd)
{
#ifdef WIN32
return closesocket(fd);
#else
return close(fd);
#endif
}