Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu.git] / util / systemd.c
1 /*
2 * systemd socket activation support
3 *
4 * Copyright 2017 Red Hat, Inc. and/or its affiliates
5 *
6 * Authors:
7 * Richard W.M. Jones <rjones@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu/systemd.h"
15 #include "qemu/cutils.h"
16 #include "qemu/error-report.h"
17
18 #ifndef _WIN32
19 unsigned int check_socket_activation(void)
20 {
21 const char *s;
22 unsigned long pid;
23 unsigned long nr_fds;
24 unsigned int i;
25 int fd;
26 int f;
27 int err;
28
29 s = getenv("LISTEN_PID");
30 if (s == NULL) {
31 return 0;
32 }
33 err = qemu_strtoul(s, NULL, 10, &pid);
34 if (err) {
35 return 0;
36 }
37 if (pid != getpid()) {
38 return 0;
39 }
40
41 s = getenv("LISTEN_FDS");
42 if (s == NULL) {
43 return 0;
44 }
45 err = qemu_strtoul(s, NULL, 10, &nr_fds);
46 if (err) {
47 return 0;
48 }
49 assert(nr_fds <= UINT_MAX);
50
51 /* So these are not passed to any child processes we might start. */
52 unsetenv("LISTEN_FDS");
53 unsetenv("LISTEN_PID");
54
55 /* So the file descriptors don't leak into child processes. */
56 for (i = 0; i < nr_fds; ++i) {
57 fd = FIRST_SOCKET_ACTIVATION_FD + i;
58 f = fcntl(fd, F_GETFD);
59 if (f == -1 || fcntl(fd, F_SETFD, f | FD_CLOEXEC) == -1) {
60 /* If we cannot set FD_CLOEXEC then it probably means the file
61 * descriptor is invalid, so socket activation has gone wrong
62 * and we should exit.
63 */
64 error_report("Socket activation failed: "
65 "invalid file descriptor fd = %d: %s",
66 fd, g_strerror(errno));
67 exit(EXIT_FAILURE);
68 }
69 }
70
71 return (unsigned int) nr_fds;
72 }
73
74 #else /* !_WIN32 */
75 unsigned int check_socket_activation(void)
76 {
77 return 0;
78 }
79 #endif