glibc/socket/opensock.c

43 lines
1.4 KiB
C

/* Create socket with an unspecified address family for use with ioctl.
Copyright (C) 1999-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library 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 2.1 of the License, or (at your option) any later version.
The GNU C Library 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 the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sys/socket.h>
/* Return a socket of any type. The socket can be used in subsequent
ioctl calls to talk to the kernel. */
int
__opensock (void)
{
/* SOCK_DGRAM is supported by all address families. */
int type = SOCK_DGRAM | SOCK_CLOEXEC;
int fd;
fd = __socket (AF_UNIX, type, 0);
if (fd >= 0)
return fd;
fd = __socket (AF_INET, type, 0);
if (fd >= 0)
return fd;
fd = __socket (AF_INET6, type, 0);
if (fd >= 0)
return fd;
__set_errno (ENOENT);
return fd;
}