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/* nbdkit
* Copyright Red Hat
*
* 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.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT 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 RED HAT 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>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "internal.h"
#ifndef WIN32
/* Handle socket activation. This is controlled through special
* environment variables inherited by nbdkit. Returns 0 if no socket
* activation. Otherwise returns the number of FDs. See also
* virGetListenFDs in libvirt.org:src/util/virutil.c
*/
unsigned int
get_socket_activation (void)
{
const char *s;
unsigned int pid;
unsigned int nr_fds;
unsigned int i;
int fd;
int f;
s = getenv ("LISTEN_PID");
if (s == NULL)
return 0;
if (nbdkit_parse_unsigned ("LISTEN_PID", s, &pid) == -1)
return 0;
if (pid != getpid ()) {
fprintf (stderr, "%s: %s was not for us (ignored)\n",
program_name, "LISTEN_PID");
return 0;
}
s = getenv ("LISTEN_FDS");
if (s == NULL)
return 0;
if (nbdkit_parse_unsigned ("LISTEN_FDS", s, &nr_fds) == -1)
return 0;
/* Limit the number of fds that may be passed in to something
* reasonable.
*/
if (nr_fds == 0 || nr_fds > 16) {
fprintf (stderr, "%s: socket activation: LISTEN_FDS=%s out of range\n",
program_name, s);
exit (EXIT_FAILURE);
}
/* So these are not passed to any child processes we might start. */
unsetenv ("LISTEN_FDS");
unsetenv ("LISTEN_PID");
/* So the file descriptors don't leak into child processes. */
for (i = 0; i < nr_fds; ++i) {
fd = FIRST_SOCKET_ACTIVATION_FD + i;
f = fcntl (fd, F_GETFD);
if (f == -1 || fcntl (fd, F_SETFD, f | FD_CLOEXEC) == -1) {
/* If we cannot set FD_CLOEXEC then it probably means the file
* descriptor is invalid, so socket activation has gone wrong
* and we should exit.
*/
fprintf (stderr, "%s: socket activation: "
"invalid file descriptor fd = %d: %s\n",
program_name, fd, strerror (errno));
exit (EXIT_FAILURE);
}
}
return nr_fds;
}
#else /* WIN32 */
unsigned int
get_socket_activation (void)
{
return 0;
}
#endif /* WIN32 */
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