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-rw-r--r--src/shutdownd.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/src/shutdownd.c b/src/shutdownd.c
new file mode 100644
index 0000000000..b4052d4933
--- /dev/null
+++ b/src/shutdownd.c
@@ -0,0 +1,366 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/socket.h>
+#include <sys/poll.h>
+#include <sys/types.h>
+#include <sys/timerfd.h>
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <systemd/sd-daemon.h>
+
+#include "shutdownd.h"
+#include "log.h"
+#include "macro.h"
+#include "util.h"
+#include "utmp-wtmp.h"
+
+static int read_packet(int fd, struct shutdownd_command *_c) {
+ struct msghdr msghdr;
+ struct iovec iovec;
+ struct ucred *ucred;
+ union {
+ struct cmsghdr cmsghdr;
+ uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+ } control;
+ struct shutdownd_command c;
+ ssize_t n;
+
+ assert(fd >= 0);
+ assert(_c);
+
+ zero(iovec);
+ iovec.iov_base = &c;
+ iovec.iov_len = sizeof(c);
+
+ zero(control);
+ zero(msghdr);
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+
+ if ((n = recvmsg(fd, &msghdr, MSG_DONTWAIT)) <= 0) {
+ if (n >= 0) {
+ log_error("Short read");
+ return -EIO;
+ }
+
+ if (errno == EAGAIN || errno == EINTR)
+ return 0;
+
+ log_error("recvmsg(): %m");
+ return -errno;
+ }
+
+ if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
+ control.cmsghdr.cmsg_level != SOL_SOCKET ||
+ control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
+ control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
+ log_warning("Received message without credentials. Ignoring.");
+ return 0;
+ }
+
+ ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+ if (ucred->uid != 0) {
+ log_warning("Got request from unprivileged user. Ignoring.");
+ return 0;
+ }
+
+ if (n != sizeof(c)) {
+ log_warning("Message has invalid size. Ignoring");
+ return 0;
+ }
+
+ char_array_0(c.wall_message);
+
+ *_c = c;
+ return 1;
+}
+
+static void warn_wall(usec_t n, struct shutdownd_command *c) {
+ char date[FORMAT_TIMESTAMP_MAX];
+ const char *prefix;
+ char *l = NULL;
+
+ assert(c);
+ assert(c->warn_wall);
+
+ if (n >= c->elapse)
+ return;
+
+ if (c->mode == 'H')
+ prefix = "The system is going down for system halt at ";
+ else if (c->mode == 'P')
+ prefix = "The system is going down for power-off at ";
+ else if (c->mode == 'r')
+ prefix = "The system is going down for reboot at ";
+ else
+ assert_not_reached("Unknown mode!");
+
+ if (asprintf(&l, "%s%s%s%s!", c->wall_message, c->wall_message[0] ? "\n" : "",
+ prefix, format_timestamp(date, sizeof(date), c->elapse)) < 0)
+ log_error("Failed to allocate wall message");
+ else {
+ utmp_wall(l, NULL);
+ free(l);
+ }
+}
+
+static usec_t when_wall(usec_t n, usec_t elapse) {
+
+ static const struct {
+ usec_t delay;
+ usec_t interval;
+ } table[] = {
+ { 10 * USEC_PER_MINUTE, USEC_PER_MINUTE },
+ { USEC_PER_HOUR, 15 * USEC_PER_MINUTE },
+ { 3 * USEC_PER_HOUR, 30 * USEC_PER_MINUTE }
+ };
+
+ usec_t left, sub;
+ unsigned i;
+
+ /* If the time is already passed, then don't announce */
+ if (n >= elapse)
+ return 0;
+
+ left = elapse - n;
+ for (i = 0; i < ELEMENTSOF(table); i++)
+ if (n + table[i].delay >= elapse) {
+ sub = ((left / table[i].interval) * table[i].interval);
+ break;
+ }
+
+ if (i >= ELEMENTSOF(table))
+ sub = ((left / USEC_PER_HOUR) * USEC_PER_HOUR);
+
+ return elapse > sub ? elapse - sub : 1;
+}
+
+static usec_t when_nologin(usec_t elapse) {
+ return elapse > 5*USEC_PER_MINUTE ? elapse - 5*USEC_PER_MINUTE : 1;
+}
+
+int main(int argc, char *argv[]) {
+ enum {
+ FD_SOCKET,
+ FD_WALL_TIMER,
+ FD_NOLOGIN_TIMER,
+ FD_SHUTDOWN_TIMER,
+ _FD_MAX
+ };
+
+ int r = EXIT_FAILURE, n_fds;
+ struct shutdownd_command c;
+ struct pollfd pollfd[_FD_MAX];
+ bool exec_shutdown = false, unlink_nologin = false, failed = false;
+ unsigned i;
+
+ if (getppid() != 1) {
+ log_error("This program should be invoked by init only.");
+ return EXIT_FAILURE;
+ }
+
+ if (argc > 1) {
+ log_error("This program does not take arguments.");
+ return EXIT_FAILURE;
+ }
+
+ log_set_target(LOG_TARGET_AUTO);
+ log_parse_environment();
+ log_open();
+
+ umask(0022);
+
+ if ((n_fds = sd_listen_fds(true)) < 0) {
+ log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
+ return EXIT_FAILURE;
+ }
+
+ if (n_fds != 1) {
+ log_error("Need exactly one file descriptor.");
+ return EXIT_FAILURE;
+ }
+
+ zero(c);
+ zero(pollfd);
+
+ pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START;
+ pollfd[FD_SOCKET].events = POLLIN;
+
+ for (i = 0; i < _FD_MAX; i++) {
+
+ if (i == FD_SOCKET)
+ continue;
+
+ pollfd[i].events = POLLIN;
+
+ if ((pollfd[i].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) {
+ log_error("timerfd_create(): %m");
+ failed = true;
+ }
+ }
+
+ if (failed)
+ goto finish;
+
+ log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid());
+
+ sd_notify(false,
+ "READY=1\n"
+ "STATUS=Processing requests...");
+
+ do {
+ int k;
+ usec_t n;
+
+ if (poll(pollfd, _FD_MAX, -1) < 0) {
+
+ if (errno == EAGAIN || errno == EINTR)
+ continue;
+
+ log_error("poll(): %m");
+ goto finish;
+ }
+
+ n = now(CLOCK_REALTIME);
+
+ if (pollfd[FD_SOCKET].revents) {
+
+ if ((k = read_packet(pollfd[FD_SOCKET].fd, &c)) < 0)
+ goto finish;
+ else if (k > 0 && c.elapse > 0) {
+ struct itimerspec its;
+ char date[FORMAT_TIMESTAMP_MAX];
+
+ if (c.warn_wall) {
+ /* Send wall messages every so often */
+ zero(its);
+ timespec_store(&its.it_value, when_wall(n, c.elapse));
+ if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
+ log_error("timerfd_settime(): %m");
+ goto finish;
+ }
+
+ /* Warn immediately if less than 15 minutes are left */
+ if (n < c.elapse &&
+ n + 15*USEC_PER_MINUTE >= c.elapse)
+ warn_wall(n, &c);
+ }
+
+ /* Disallow logins 5 minutes prior to shutdown */
+ zero(its);
+ timespec_store(&its.it_value, when_nologin(c.elapse));
+ if (timerfd_settime(pollfd[FD_NOLOGIN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
+ log_error("timerfd_settime(): %m");
+ goto finish;
+ }
+
+ /* Shutdown after the specified time is reached */
+ zero(its);
+ timespec_store(&its.it_value, c.elapse);
+ if (timerfd_settime(pollfd[FD_SHUTDOWN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
+ log_error("timerfd_settime(): %m");
+ goto finish;
+ }
+
+ sd_notifyf(false,
+ "STATUS=Shutting down at %s...",
+ format_timestamp(date, sizeof(date), c.elapse));
+ }
+ }
+
+ if (pollfd[FD_WALL_TIMER].revents) {
+ struct itimerspec its;
+
+ warn_wall(n, &c);
+ flush_fd(pollfd[FD_WALL_TIMER].fd);
+
+ /* Restart timer */
+ zero(its);
+ timespec_store(&its.it_value, when_wall(n, c.elapse));
+ if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
+ log_error("timerfd_settime(): %m");
+ goto finish;
+ }
+ }
+
+ if (pollfd[FD_NOLOGIN_TIMER].revents) {
+ int e;
+
+ log_info("Creating /run/nologin, blocking further logins...");
+
+ if ((e = write_one_line_file_atomic("/run/nologin", "System is going down.")) < 0)
+ log_error("Failed to create /run/nologin: %s", strerror(-e));
+ else
+ unlink_nologin = true;
+
+ flush_fd(pollfd[FD_NOLOGIN_TIMER].fd);
+ }
+
+ if (pollfd[FD_SHUTDOWN_TIMER].revents) {
+ exec_shutdown = true;
+ goto finish;
+ }
+
+ } while (c.elapse > 0);
+
+ r = EXIT_SUCCESS;
+
+ log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid());
+
+finish:
+
+ for (i = 0; i < _FD_MAX; i++)
+ if (pollfd[i].fd >= 0)
+ close_nointr_nofail(pollfd[i].fd);
+
+ if (unlink_nologin)
+ unlink("/run/nologin");
+
+ if (exec_shutdown && !c.dry_run) {
+ char sw[3];
+
+ sw[0] = '-';
+ sw[1] = c.mode;
+ sw[2] = 0;
+
+ execl(SYSTEMCTL_BINARY_PATH,
+ "shutdown",
+ sw,
+ "now",
+ (c.warn_wall && c.wall_message[0]) ? c.wall_message :
+ (c.warn_wall ? NULL : "--no-wall"),
+ NULL);
+
+ log_error("Failed to execute /sbin/shutdown: %m");
+ }
+
+ sd_notify(false,
+ "STATUS=Exiting...");
+
+ return r;
+}
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