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qemu/util/systemd.c

81 lines
1.9 KiB
C

/*
* systemd socket activation support
*
* Copyright 2017 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Richard W.M. Jones <rjones@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/systemd.h"
#include "qemu/cutils.h"
#include "qemu/error-report.h"
#ifndef _WIN32
unsigned int check_socket_activation(void)
{
const char *s;
unsigned long pid;
unsigned long nr_fds;
unsigned int i;
int fd;
int f;
int err;
s = getenv("LISTEN_PID");
if (s == NULL) {
return 0;
}
err = qemu_strtoul(s, NULL, 10, &pid);
if (err) {
return 0;
}
if (pid != getpid()) {
return 0;
}
s = getenv("LISTEN_FDS");
if (s == NULL) {
return 0;
}
err = qemu_strtoul(s, NULL, 10, &nr_fds);
if (err) {
return 0;
}
assert(nr_fds <= UINT_MAX);
/* So these are not passed to any child processes we might start. */
unsetenv("LISTEN_FDS");
unsetenv("LISTEN_PID");
unsetenv("LISTEN_FDNAMES");
/* 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.
*/
error_report("Socket activation failed: "
"invalid file descriptor fd = %d: %s",
fd, g_strerror(errno));
exit(EXIT_FAILURE);
}
}
return (unsigned int) nr_fds;
}
#else /* !_WIN32 */
unsigned int check_socket_activation(void)
{
return 0;
}
#endif