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 "shutdownd.h"
36 #include "sd-daemon.h"
37 #include "utmp-wtmp.h"
39 static int read_packet(int fd, struct shutdownd_command *_c) {
44 struct cmsghdr cmsghdr;
45 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
47 struct shutdownd_command c;
55 iovec.iov_len = sizeof(c);
59 msghdr.msg_iov = &iovec;
60 msghdr.msg_iovlen = 1;
61 msghdr.msg_control = &control;
62 msghdr.msg_controllen = sizeof(control);
64 if ((n = recvmsg(fd, &msghdr, MSG_DONTWAIT)) <= 0) {
66 log_error("Short read");
70 if (errno == EAGAIN || errno == EINTR)
73 log_error("recvmsg(): %m");
77 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
78 control.cmsghdr.cmsg_level != SOL_SOCKET ||
79 control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
80 control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
81 log_warning("Received message without credentials. Ignoring.");
85 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
86 if (ucred->uid != 0) {
87 log_warning("Got request from unprivileged user. Ignoring.");
92 log_warning("Message has invalid size. Ignoring");
96 char_array_0(c.wall_message);
102 static void warn_wall(usec_t n, struct shutdownd_command *c) {
105 assert(c->warn_wall);
110 if (c->wall_message[0])
111 utmp_wall(c->wall_message);
113 char date[FORMAT_TIMESTAMP_MAX];
118 prefix = "The system is going down for system halt at ";
119 else if (c->mode == 'P')
120 prefix = "The system is going down for power-off at ";
121 else if (c->mode == 'r')
122 prefix = "The system is going down for reboot at ";
124 assert_not_reached("Unknown mode!");
126 if (asprintf(&l, "%s%s!", prefix, format_timestamp(date, sizeof(date), c->elapse)) < 0)
127 log_error("Failed to allocate wall message");
135 static usec_t when_wall(usec_t n, usec_t elapse) {
137 static const struct {
141 { 10 * USEC_PER_MINUTE, USEC_PER_MINUTE },
142 { USEC_PER_HOUR, 15 * USEC_PER_MINUTE },
143 { 3 * USEC_PER_HOUR, 30 * USEC_PER_MINUTE }
149 /* If the time is already passed, then don't announce */
154 for (i = 0; i < ELEMENTSOF(table); i++)
155 if (n + table[i].delay >= elapse) {
156 sub = ((left / table[i].interval) * table[i].interval);
160 if (i >= ELEMENTSOF(table))
161 sub = ((left / USEC_PER_HOUR) * USEC_PER_HOUR);
163 return elapse > sub ? elapse - sub : 1;
166 static usec_t when_nologin(usec_t elapse) {
167 return elapse > 5*USEC_PER_MINUTE ? elapse - 5*USEC_PER_MINUTE : 1;
170 int main(int argc, char *argv[]) {
179 int r = EXIT_FAILURE, n_fds;
181 struct shutdownd_command c;
182 struct pollfd pollfd[_FD_MAX];
183 bool exec_shutdown = false, unlink_nologin = false, failed = false;
186 if (getppid() != 1) {
187 log_error("This program should be invoked by init only.");
192 log_error("This program does not take arguments.");
196 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
197 log_parse_environment();
200 if ((n_fds = sd_listen_fds(true)) < 0) {
201 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
206 log_error("Need exactly one file descriptor.");
210 if (setsockopt(SD_LISTEN_FDS_START, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
211 log_error("SO_PASSCRED failed: %m");
218 pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START;
219 pollfd[FD_SOCKET].events = POLLIN;
221 for (i = 0; i < _FD_MAX; i++) {
226 pollfd[i].events = POLLIN;
228 if ((pollfd[i].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) {
229 log_error("timerfd_create(): %m");
237 log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid());
241 "STATUS=Processing requests...");
247 if (poll(pollfd, _FD_MAX, -1) < 0) {
249 if (errno == EAGAIN || errno == EINTR)
252 log_error("poll(): %m");
256 n = now(CLOCK_REALTIME);
258 if (pollfd[FD_SOCKET].revents) {
260 if ((k = read_packet(pollfd[FD_SOCKET].fd, &c)) < 0)
262 else if (k > 0 && c.elapse > 0) {
263 struct itimerspec its;
264 char date[FORMAT_TIMESTAMP_MAX];
267 /* Send wall messages every so often */
269 timespec_store(&its.it_value, when_wall(n, c.elapse));
270 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
271 log_error("timerfd_settime(): %m");
275 /* Warn immediately if less than 15 minutes are left */
277 n + 15*USEC_PER_MINUTE >= c.elapse)
281 /* Disallow logins 5 minutes prior to shutdown */
283 timespec_store(&its.it_value, when_nologin(c.elapse));
284 if (timerfd_settime(pollfd[FD_NOLOGIN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
285 log_error("timerfd_settime(): %m");
289 /* Shutdown after the specified time is reached */
291 timespec_store(&its.it_value, c.elapse);
292 if (timerfd_settime(pollfd[FD_SHUTDOWN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
293 log_error("timerfd_settime(): %m");
298 "STATUS=Shutting down at %s...",
299 format_timestamp(date, sizeof(date), c.elapse));
303 if (pollfd[FD_WALL_TIMER].revents) {
304 struct itimerspec its;
307 flush_fd(pollfd[FD_WALL_TIMER].fd);
311 timespec_store(&its.it_value, when_wall(n, c.elapse));
312 if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
313 log_error("timerfd_settime(): %m");
318 if (pollfd[FD_NOLOGIN_TIMER].revents) {
321 log_info("Creating /etc/nologin, blocking further logins...");
323 if ((e = touch("/etc/nologin")) < 0)
324 log_error("Failed to create /etc/nologin: %s", strerror(-e));
326 unlink_nologin = true;
328 flush_fd(pollfd[FD_NOLOGIN_TIMER].fd);
331 if (pollfd[FD_SHUTDOWN_TIMER].revents) {
332 exec_shutdown = true;
336 } while (c.elapse > 0);
340 log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid());
344 for (i = 0; i < _FD_MAX; i++)
345 if (pollfd[i].fd >= 0)
346 close_nointr_nofail(pollfd[i].fd);
349 unlink("/etc/nologin");
358 execl(SYSTEMCTL_BINARY_PATH,
362 (c.warn_wall && c.wall_message[0]) ? c.wall_message :
363 (c.warn_wall ? NULL : "--no-wall"),
366 log_error("Failed to execute /sbin/shutdown: %m");
370 "STATUS=Exiting...");