mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 12:11:10 +00:00
107 lines
3.7 KiB
C
107 lines
3.7 KiB
C
/* Check recvmsg results for netlink sockets.
|
|
Copyright (C) 2015-2016 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdio.h>
|
|
#include <sys/socket.h>
|
|
|
|
#include "netlinkaccess.h"
|
|
|
|
static int
|
|
get_address_family (int fd)
|
|
{
|
|
struct sockaddr_storage sa;
|
|
socklen_t sa_len = sizeof (sa);
|
|
if (__getsockname (fd, (struct sockaddr *) &sa, &sa_len) < 0)
|
|
return -1;
|
|
/* Check that the socket family number is preserved despite in-band
|
|
signaling. */
|
|
_Static_assert (sizeof (sa.ss_family) < sizeof (int), "address family size");
|
|
_Static_assert (0 < (__typeof__ (sa.ss_family)) -1,
|
|
"address family unsigned");
|
|
return sa.ss_family;
|
|
}
|
|
|
|
void
|
|
internal_function
|
|
__netlink_assert_response (int fd, ssize_t result)
|
|
{
|
|
if (result < 0)
|
|
{
|
|
/* Check if the error is unexpected. */
|
|
bool terminate = false;
|
|
int error_code = errno;
|
|
int family = get_address_family (fd);
|
|
if (family != AF_NETLINK)
|
|
/* If the address family does not match (or getsockname
|
|
failed), report the original error. */
|
|
terminate = true;
|
|
else if (error_code == EBADF
|
|
|| error_code == ENOTCONN
|
|
|| error_code == ENOTSOCK
|
|
|| error_code == ECONNREFUSED)
|
|
/* These errors indicate that the descriptor is not a
|
|
connected socket. */
|
|
terminate = true;
|
|
else if (error_code == EAGAIN || error_code == EWOULDBLOCK)
|
|
{
|
|
/* The kernel might return EAGAIN for other reasons than a
|
|
non-blocking socket. But if the socket is not blocking,
|
|
it is not ours, so report the error. */
|
|
int mode = __fcntl (fd, F_GETFL, 0);
|
|
if (mode < 0 || (mode & O_NONBLOCK) != 0)
|
|
terminate = true;
|
|
}
|
|
if (terminate)
|
|
{
|
|
char message[200];
|
|
if (family < 0)
|
|
__snprintf (message, sizeof (message),
|
|
"Unexpected error %d on netlink descriptor %d",
|
|
error_code, fd);
|
|
else
|
|
__snprintf (message, sizeof (message),
|
|
"Unexpected error %d on netlink descriptor %d"
|
|
" (address family %d)",
|
|
error_code, fd, family);
|
|
__libc_fatal (message);
|
|
}
|
|
else
|
|
/* Restore orignal errno value. */
|
|
__set_errno (error_code);
|
|
}
|
|
else if (result < sizeof (struct nlmsghdr))
|
|
{
|
|
char message[200];
|
|
int family = get_address_family (fd);
|
|
if (family < 0)
|
|
__snprintf (message, sizeof (message),
|
|
"Unexpected netlink response of size %zd"
|
|
" on descriptor %d",
|
|
result, fd);
|
|
else
|
|
__snprintf (message, sizeof (message),
|
|
"Unexpected netlink response of size %zd"
|
|
" on descriptor %d (address family %d)",
|
|
result, fd, family);
|
|
__libc_fatal (message);
|
|
}
|
|
}
|
|
libc_hidden_def (__netlink_assert_response)
|