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 General Public License as published by
10 the Free Software Foundation; either version 2 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 General Public License for more details.
18 You should have received a copy of the GNU 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>
32 #include <systemd/sd-daemon.h>
34 #include "shutdownd.h"
38 #include "utmp-wtmp.h"
40 static int read_packet(int fd, struct shutdownd_command *_c) {
45 struct cmsghdr cmsghdr;
46 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
48 struct shutdownd_command c;
56 iovec.iov_len = sizeof(c);
60 msghdr.msg_iov = &iovec;
61 msghdr.msg_iovlen = 1;
62 msghdr.msg_control = &control;
63 msghdr.msg_controllen = sizeof(control);
65 if ((n = recvmsg(fd, &msghdr, MSG_DONTWAIT)) <= 0) {
67 log_error("Short read");
71 if (errno == EAGAIN || errno == EINTR)
74 log_error("recvmsg(): %m");
78 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
79 control.cmsghdr.cmsg_level != SOL_SOCKET ||
80 control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
81 control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
82 log_warning("Received message without credentials. Ignoring.");
86 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
87 if (ucred->uid != 0) {
88 log_warning("Got request from unprivileged user. Ignoring.");
93 log_warning("Message has invalid size. Ignoring");
97 char_array_0(c.wall_message);
103 static void warn_wall(usec_t n, struct shutdownd_command *c) {
104 char date[FORMAT_TIMESTAMP_MAX];
109 assert(c->warn_wall);
115 prefix = "The system is going down for system halt at ";
116 else if (c->mode == 'P')
117 prefix = "The system is going down for power-off at ";
118 else if (c->mode == 'r')
119 prefix = "The system is going down for reboot at ";
121 assert_not_reached("Unknown mode!");
123 if (asprintf(&l, "%s%s%s%s!", c->wall_message, c->wall_message[0] ? "\n" : "",
124 prefix, format_timestamp(date, sizeof(date), c->elapse)) < 0)
125 log_error("Failed to allocate wall message");
132 static usec_t when_wall(usec_t n, usec_t elapse) {
134 static const struct {
138 { 10 * USEC_PER_MINUTE, USEC_PER_MINUTE },
139 { USEC_PER_HOUR, 15 * USEC_PER_MINUTE },
140 { 3 * USEC_PER_HOUR, 30 * USEC_PER_MINUTE }
146 /* If the time is already passed, then don't announce */
151 for (i = 0; i < ELEMENTSOF(table); i++)
152 if (n + table[i].delay >= elapse) {
153 sub = ((left / table[i].interval) * table[i].interval);
157 if (i >= ELEMENTSOF(table))
158 sub = ((left / USEC_PER_HOUR) * USEC_PER_HOUR);
160 return elapse > sub ? elapse - sub : 1;
163 static usec_t when_nologin(usec_t elapse) {
164 return elapse > 5*USEC_PER_MINUTE ? elapse - 5*USEC_PER_MINUTE : 1;
167 int main(int argc, char *argv[]) {
176 int r = EXIT_FAILURE, n_fds;
177 struct shutdownd_command c;
178 struct pollfd pollfd[_FD_MAX];
179 bool exec_shutdown = false, unlink_nologin = false, failed = false;
182 if (getppid() != 1) {
183 log_error("This program should be invoked by init only.");
188 log_error("This program does not take arguments.");
192 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
193 log_parse_environment();
198 if ((n_fds = sd_listen_fds(true)) < 0) {
199 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
204 log_error("Need exactly one file descriptor.");
211 pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START;
212 pollfd[FD_SOCKET].events = POLLIN;
214 for (i = 0; i < _FD_MAX; i++) {
219 pollfd[i].events = POLLIN;
221 if ((pollfd[i].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) {
222 log_error("timerfd_create(): %m");
230 log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid());
234 "STATUS=Processing requests...");
240 if (poll(pollfd, _FD_MAX, -1) < 0) {
242 if (errno == EAGAIN || errno == EINTR)
245 log_error("poll(): %m");
249 n = now(CLOCK_REALTIME);
251 if (pollfd[FD_SOCKET].revents) {
253 if ((k = read_packet(pollfd[FD_SOCKET].fd, &c)) < 0)
255 else if (k > 0 && c.elapse > 0) {
256 struct itimerspec its;
257 char date[FORMAT_TIMESTAMP_MAX];
260 /* Send wall messages every so often */
262 timespec_store(&its.it_value, when_wall(n, c.elapse));
263 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
264 log_error("timerfd_settime(): %m");
268 /* Warn immediately if less than 15 minutes are left */
270 n + 15*USEC_PER_MINUTE >= c.elapse)
274 /* Disallow logins 5 minutes prior to shutdown */
276 timespec_store(&its.it_value, when_nologin(c.elapse));
277 if (timerfd_settime(pollfd[FD_NOLOGIN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
278 log_error("timerfd_settime(): %m");
282 /* Shutdown after the specified time is reached */
284 timespec_store(&its.it_value, c.elapse);
285 if (timerfd_settime(pollfd[FD_SHUTDOWN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
286 log_error("timerfd_settime(): %m");
291 "STATUS=Shutting down at %s...",
292 format_timestamp(date, sizeof(date), c.elapse));
296 if (pollfd[FD_WALL_TIMER].revents) {
297 struct itimerspec its;
300 flush_fd(pollfd[FD_WALL_TIMER].fd);
304 timespec_store(&its.it_value, when_wall(n, c.elapse));
305 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
306 log_error("timerfd_settime(): %m");
311 if (pollfd[FD_NOLOGIN_TIMER].revents) {
314 log_info("Creating /run/nologin, blocking further logins...");
316 if ((e = write_one_line_file_atomic("/run/nologin", "System is going down.")) < 0)
317 log_error("Failed to create /run/nologin: %s", strerror(-e));
319 unlink_nologin = true;
321 flush_fd(pollfd[FD_NOLOGIN_TIMER].fd);
324 if (pollfd[FD_SHUTDOWN_TIMER].revents) {
325 exec_shutdown = true;
329 } while (c.elapse > 0);
333 log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid());
337 for (i = 0; i < _FD_MAX; i++)
338 if (pollfd[i].fd >= 0)
339 close_nointr_nofail(pollfd[i].fd);
342 unlink("/run/nologin");
344 if (exec_shutdown && !c.dry_run) {
351 execl(SYSTEMCTL_BINARY_PATH,
355 (c.warn_wall && c.wall_message[0]) ? c.wall_message :
356 (c.warn_wall ? NULL : "--no-wall"),
359 log_error("Failed to execute /sbin/shutdown: %m");
363 "STATUS=Exiting...");