1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/socket.h>
24 #include <sys/types.h>
25 #include <sys/timerfd.h>
33 #include <systemd/sd-daemon.h>
34 #include <systemd/sd-shutdown.h>
39 #include "utmp-wtmp.h"
42 union shutdown_buffer {
43 struct sd_shutdown_command command;
44 char space[offsetof(struct sd_shutdown_command, wall_message) + LINE_MAX];
47 static int read_packet(int fd, union shutdown_buffer *_b) {
52 struct cmsghdr cmsghdr;
53 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
56 union shutdown_buffer b; /* We maintain our own copy here, in order not to corrupt the last message */
63 iovec.iov_len = sizeof(b) - 1;
67 msghdr.msg_iov = &iovec;
68 msghdr.msg_iovlen = 1;
69 msghdr.msg_control = &control;
70 msghdr.msg_controllen = sizeof(control);
72 n = recvmsg(fd, &msghdr, MSG_DONTWAIT);
75 log_error("Short read");
79 if (errno == EAGAIN || errno == EINTR)
82 log_error("recvmsg(): %m");
86 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
87 control.cmsghdr.cmsg_level != SOL_SOCKET ||
88 control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
89 control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
90 log_warning("Received message without credentials. Ignoring.");
94 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
95 if (ucred->uid != 0) {
96 log_warning("Got request from unprivileged user. Ignoring.");
100 if ((size_t) n < offsetof(struct sd_shutdown_command, wall_message)) {
101 log_warning("Message has invalid size. Ignoring.");
105 if (b.command.mode != SD_SHUTDOWN_NONE &&
106 b.command.mode != SD_SHUTDOWN_REBOOT &&
107 b.command.mode != SD_SHUTDOWN_POWEROFF &&
108 b.command.mode != SD_SHUTDOWN_HALT &&
109 b.command.mode != SD_SHUTDOWN_KEXEC) {
110 log_warning("Message has invalid mode. Ignoring.");
120 static void warn_wall(usec_t n, struct sd_shutdown_command *c) {
121 char date[FORMAT_TIMESTAMP_MAX];
126 assert(c->warn_wall);
131 if (c->mode == SD_SHUTDOWN_HALT)
132 prefix = "The system is going down for system halt at ";
133 else if (c->mode == SD_SHUTDOWN_POWEROFF)
134 prefix = "The system is going down for power-off at ";
135 else if (c->mode == SD_SHUTDOWN_REBOOT)
136 prefix = "The system is going down for reboot at ";
137 else if (c->mode == SD_SHUTDOWN_KEXEC)
138 prefix = "The system is going down for kexec reboot at ";
140 assert_not_reached("Unknown mode!");
142 if (asprintf(&l, "%s%s%s%s!", c->wall_message, c->wall_message[0] ? "\n" : "",
143 prefix, format_timestamp(date, sizeof(date), c->usec)) < 0)
144 log_error("Failed to allocate wall message");
151 static usec_t when_wall(usec_t n, usec_t elapse) {
153 static const struct {
157 { 10 * USEC_PER_MINUTE, USEC_PER_MINUTE },
158 { USEC_PER_HOUR, 15 * USEC_PER_MINUTE },
159 { 3 * USEC_PER_HOUR, 30 * USEC_PER_MINUTE }
165 /* If the time is already passed, then don't announce */
170 for (i = 0; i < ELEMENTSOF(table); i++)
171 if (n + table[i].delay >= elapse) {
172 sub = ((left / table[i].interval) * table[i].interval);
176 if (i >= ELEMENTSOF(table))
177 sub = ((left / USEC_PER_HOUR) * USEC_PER_HOUR);
179 return elapse > sub ? elapse - sub : 1;
182 static usec_t when_nologin(usec_t elapse) {
183 return elapse > 5*USEC_PER_MINUTE ? elapse - 5*USEC_PER_MINUTE : 1;
186 static const char *mode_to_string(enum sd_shutdown_mode m) {
188 case SD_SHUTDOWN_REBOOT:
190 case SD_SHUTDOWN_POWEROFF:
192 case SD_SHUTDOWN_HALT:
194 case SD_SHUTDOWN_KEXEC:
201 static int update_schedule_file(struct sd_shutdown_command *c) {
208 r = mkdir_safe_label("/run/systemd/shutdown", 0755, 0, 0);
210 log_error("Failed to create shutdown subdirectory: %s", strerror(-r));
214 t = cescape(c->wall_message);
218 r = fopen_temporary("/run/systemd/shutdown/scheduled", &f, &temp_path);
220 log_error("Failed to save information about scheduled shutdowns: %s", strerror(-r));
225 fchmod(fileno(f), 0644);
231 (unsigned long long) c->usec,
233 mode_to_string(c->mode));
236 fputs("DRY_RUN=1\n", f);
239 fprintf(f, "WALL_MESSAGE=%s\n", t);
245 if (ferror(f) || rename(temp_path, "/run/systemd/shutdown/scheduled") < 0) {
246 log_error("Failed to write information about scheduled shutdowns: %m");
250 unlink("/run/systemd/shutdown/scheduled");
259 static bool scheduled(struct sd_shutdown_command *c) {
260 return c->usec > 0 && c->mode != SD_SHUTDOWN_NONE;
263 int main(int argc, char *argv[]) {
272 int r = EXIT_FAILURE, n_fds;
273 union shutdown_buffer b;
274 struct pollfd pollfd[_FD_MAX];
275 bool exec_shutdown = false, unlink_nologin = false;
278 if (getppid() != 1) {
279 log_error("This program should be invoked by init only.");
284 log_error("This program does not take arguments.");
288 log_set_target(LOG_TARGET_AUTO);
289 log_parse_environment();
294 n_fds = sd_listen_fds(true);
296 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
301 log_error("Need exactly one file descriptor.");
308 pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START;
309 pollfd[FD_SOCKET].events = POLLIN;
311 for (i = FD_WALL_TIMER; i < _FD_MAX; i++) {
312 pollfd[i].events = POLLIN;
313 pollfd[i].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
314 if (pollfd[i].fd < 0) {
315 log_error("timerfd_create(): %m");
320 log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid());
324 "STATUS=Processing requests...");
330 k = poll(pollfd, _FD_MAX, scheduled(&b.command) ? -1 : 0);
333 if (errno == EAGAIN || errno == EINTR)
336 log_error("poll(): %m");
344 n = now(CLOCK_REALTIME);
346 if (pollfd[FD_SOCKET].revents) {
348 k = read_packet(pollfd[FD_SOCKET].fd, &b);
352 struct itimerspec its;
353 char date[FORMAT_TIMESTAMP_MAX];
355 if (!scheduled(&b.command)) {
356 log_info("Shutdown canceled.");
361 if (b.command.warn_wall) {
362 /* Send wall messages every so often */
363 timespec_store(&its.it_value, when_wall(n, b.command.usec));
365 /* Warn immediately if less than 15 minutes are left */
366 if (n < b.command.usec &&
367 n + 15*USEC_PER_MINUTE >= b.command.usec)
368 warn_wall(n, &b.command);
370 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
371 log_error("timerfd_settime(): %m");
375 /* Disallow logins 5 minutes prior to shutdown */
377 timespec_store(&its.it_value, when_nologin(b.command.usec));
378 if (timerfd_settime(pollfd[FD_NOLOGIN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
379 log_error("timerfd_settime(): %m");
383 /* Shutdown after the specified time is reached */
385 timespec_store(&its.it_value, b.command.usec);
386 if (timerfd_settime(pollfd[FD_SHUTDOWN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
387 log_error("timerfd_settime(): %m");
391 update_schedule_file(&b.command);
394 "STATUS=Shutting down at %s (%s)...",
395 format_timestamp(date, sizeof(date), b.command.usec),
396 mode_to_string(b.command.mode));
398 log_info("Shutting down at %s (%s)...", date, mode_to_string(b.command.mode));
402 if (pollfd[FD_WALL_TIMER].revents) {
403 struct itimerspec its;
405 warn_wall(n, &b.command);
406 flush_fd(pollfd[FD_WALL_TIMER].fd);
410 timespec_store(&its.it_value, when_wall(n, b.command.usec));
411 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
412 log_error("timerfd_settime(): %m");
417 if (pollfd[FD_NOLOGIN_TIMER].revents) {
420 log_info("Creating /run/nologin, blocking further logins...");
422 e = write_one_line_file_atomic("/run/nologin", "System is going down.");
424 log_error("Failed to create /run/nologin: %s", strerror(-e));
426 unlink_nologin = true;
428 flush_fd(pollfd[FD_NOLOGIN_TIMER].fd);
431 if (pollfd[FD_SHUTDOWN_TIMER].revents) {
432 exec_shutdown = true;
439 log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid());
443 for (i = 0; i < _FD_MAX; i++)
444 if (pollfd[i].fd >= 0)
445 close_nointr_nofail(pollfd[i].fd);
448 unlink("/run/nologin");
450 unlink("/run/systemd/shutdown/scheduled");
452 if (exec_shutdown && !b.command.dry_run) {
456 sw[1] = b.command.mode;
459 execl(SYSTEMCTL_BINARY_PATH,
463 (b.command.warn_wall && b.command.wall_message[0]) ? b.command.wall_message :
464 (b.command.warn_wall ? NULL : "--no-wall"),
467 log_error("Failed to execute /sbin/shutdown: %m");
471 "STATUS=Exiting...");