| /*-*- 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 Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser 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 <stddef.h> |
| |
| #include <systemd/sd-daemon.h> |
| #include <systemd/sd-shutdown.h> |
| |
| #include "log.h" |
| #include "macro.h" |
| #include "util.h" |
| #include "utmp-wtmp.h" |
| #include "mkdir.h" |
| #include "fileio.h" |
| |
| union shutdown_buffer { |
| struct sd_shutdown_command command; |
| char space[offsetof(struct sd_shutdown_command, wall_message) + LINE_MAX]; |
| }; |
| |
| static int read_packet(int fd, union shutdown_buffer *_b) { |
| struct ucred *ucred; |
| ssize_t n; |
| |
| union shutdown_buffer b; /* We maintain our own copy here, in |
| * order not to corrupt the last message */ |
| struct iovec iovec = { |
| iovec.iov_base = &b, |
| iovec.iov_len = sizeof(b) - 1, |
| }; |
| union { |
| struct cmsghdr cmsghdr; |
| uint8_t buf[CMSG_SPACE(sizeof(struct ucred))]; |
| } control = {}; |
| struct msghdr msghdr = { |
| .msg_iov = &iovec, |
| .msg_iovlen = 1, |
| .msg_control = &control, |
| .msg_controllen = sizeof(control), |
| }; |
| |
| assert(fd >= 0); |
| assert(_b); |
| |
| n = recvmsg(fd, &msghdr, MSG_DONTWAIT); |
| if (n <= 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 ((size_t) n < offsetof(struct sd_shutdown_command, wall_message)) { |
| log_warning("Message has invalid size. Ignoring."); |
| return 0; |
| } |
| |
| if (b.command.mode != SD_SHUTDOWN_NONE && |
| b.command.mode != SD_SHUTDOWN_REBOOT && |
| b.command.mode != SD_SHUTDOWN_POWEROFF && |
| b.command.mode != SD_SHUTDOWN_HALT && |
| b.command.mode != SD_SHUTDOWN_KEXEC) { |
| log_warning("Message has invalid mode. Ignoring."); |
| return 0; |
| } |
| |
| b.space[n] = 0; |
| |
| *_b = b; |
| return 1; |
| } |
| |
| static void warn_wall(usec_t n, struct sd_shutdown_command *c) { |
| char date[FORMAT_TIMESTAMP_MAX]; |
| const char *prefix; |
| _cleanup_free_ char *l = NULL; |
| |
| assert(c); |
| assert(c->warn_wall); |
| |
| if (n >= c->usec) |
| return; |
| |
| if (c->mode == SD_SHUTDOWN_HALT) |
| prefix = "The system is going down for system halt at "; |
| else if (c->mode == SD_SHUTDOWN_POWEROFF) |
| prefix = "The system is going down for power-off at "; |
| else if (c->mode == SD_SHUTDOWN_REBOOT) |
| prefix = "The system is going down for reboot at "; |
| else if (c->mode == SD_SHUTDOWN_KEXEC) |
| prefix = "The system is going down for kexec reboot at "; |
| else if (c->mode == SD_SHUTDOWN_NONE) |
| prefix = "The system shutdown has been cancelled 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->usec)) >= 0) |
| utmp_wall(l, NULL, NULL); |
| else |
| log_error("Failed to allocate wall message"); |
| } |
| |
| _const_ static usec_t when_wall(usec_t n, usec_t elapse) { |
| |
| static const struct { |
| usec_t delay; |
| usec_t interval; |
| } table[] = { |
| { 0, USEC_PER_MINUTE }, |
| { 10 * USEC_PER_MINUTE, 15 * USEC_PER_MINUTE }, |
| { USEC_PER_HOUR, 30 * USEC_PER_MINUTE }, |
| { 3 * USEC_PER_HOUR, USEC_PER_HOUR }, |
| }; |
| |
| usec_t left, sub; |
| unsigned i = ELEMENTSOF(table) - 1; |
| |
| /* If the time is already passed, then don't announce */ |
| if (n >= elapse) |
| return 0; |
| |
| left = elapse - n; |
| while (left < table[i].delay) |
| i--; |
| sub = (left / table[i].interval) * table[i].interval; |
| |
| assert(sub < elapse); |
| return elapse - sub; |
| } |
| |
| static usec_t when_nologin(usec_t elapse) { |
| return elapse > 5*USEC_PER_MINUTE ? elapse - 5*USEC_PER_MINUTE : 1; |
| } |
| |
| static const char *mode_to_string(enum sd_shutdown_mode m) { |
| switch (m) { |
| case SD_SHUTDOWN_REBOOT: |
| return "reboot"; |
| case SD_SHUTDOWN_POWEROFF: |
| return "poweroff"; |
| case SD_SHUTDOWN_HALT: |
| return "halt"; |
| case SD_SHUTDOWN_KEXEC: |
| return "kexec"; |
| default: |
| return NULL; |
| } |
| } |
| |
| static int update_schedule_file(struct sd_shutdown_command *c) { |
| int r; |
| _cleanup_fclose_ FILE *f = NULL; |
| _cleanup_free_ char *t = NULL, *temp_path = NULL; |
| |
| assert(c); |
| |
| r = mkdir_safe_label("/run/systemd/shutdown", 0755, 0, 0); |
| if (r < 0) { |
| log_error("Failed to create shutdown subdirectory: %s", strerror(-r)); |
| return r; |
| } |
| |
| t = cescape(c->wall_message); |
| if (!t) |
| return log_oom(); |
| |
| r = fopen_temporary("/run/systemd/shutdown/scheduled", &f, &temp_path); |
| if (r < 0) { |
| log_error("Failed to save information about scheduled shutdowns: %s", strerror(-r)); |
| return r; |
| } |
| |
| fchmod(fileno(f), 0644); |
| |
| fprintf(f, |
| "USEC="USEC_FMT"\n" |
| "WARN_WALL=%i\n" |
| "MODE=%s\n", |
| c->usec, |
| c->warn_wall, |
| mode_to_string(c->mode)); |
| |
| if (c->dry_run) |
| fputs("DRY_RUN=1\n", f); |
| |
| if (!isempty(t)) |
| fprintf(f, "WALL_MESSAGE=%s\n", t); |
| |
| fflush(f); |
| |
| if (ferror(f) || rename(temp_path, "/run/systemd/shutdown/scheduled") < 0) { |
| log_error("Failed to write information about scheduled shutdowns: %m"); |
| r = -errno; |
| |
| unlink(temp_path); |
| unlink("/run/systemd/shutdown/scheduled"); |
| } |
| |
| return r; |
| } |
| |
| static bool scheduled(struct sd_shutdown_command *c) { |
| return c->usec > 0 && c->mode != SD_SHUTDOWN_NONE; |
| } |
| |
| 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; |
| union shutdown_buffer b = {}; |
| struct pollfd pollfd[_FD_MAX] = {}; |
| bool exec_shutdown = false, unlink_nologin = 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); |
| |
| n_fds = sd_listen_fds(true); |
| if (n_fds < 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; |
| } |
| |
| pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START; |
| pollfd[FD_SOCKET].events = POLLIN; |
| |
| for (i = FD_WALL_TIMER; i < _FD_MAX; i++) { |
| pollfd[i].events = POLLIN; |
| pollfd[i].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC); |
| if (pollfd[i].fd < 0) { |
| log_error("timerfd_create(): %m"); |
| goto finish; |
| } |
| } |
| |
| log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid()); |
| |
| sd_notify(false, |
| "READY=1\n" |
| "STATUS=Processing requests..."); |
| |
| for (;;) { |
| int k; |
| usec_t n; |
| |
| k = poll(pollfd, _FD_MAX, scheduled(&b.command) ? -1 : 0); |
| if (k < 0) { |
| |
| if (errno == EAGAIN || errno == EINTR) |
| continue; |
| |
| log_error("poll(): %m"); |
| goto finish; |
| } |
| |
| /* Exit on idle */ |
| if (k == 0) |
| break; |
| |
| n = now(CLOCK_REALTIME); |
| |
| if (pollfd[FD_SOCKET].revents) { |
| |
| k = read_packet(pollfd[FD_SOCKET].fd, &b); |
| if (k < 0) |
| goto finish; |
| else if (k > 0) { |
| struct itimerspec its; |
| char date[FORMAT_TIMESTAMP_MAX]; |
| |
| if (!scheduled(&b.command)) { |
| log_info("Shutdown canceled."); |
| if (b.command.warn_wall) |
| warn_wall(0, &b.command); |
| break; |
| } |
| |
| zero(its); |
| if (b.command.warn_wall) { |
| /* Send wall messages every so often */ |
| timespec_store(&its.it_value, when_wall(n, b.command.usec)); |
| |
| /* Warn immediately if less than 15 minutes are left */ |
| if (n < b.command.usec && |
| n + 15*USEC_PER_MINUTE >= b.command.usec) |
| warn_wall(n, &b.command); |
| } |
| if (timerfd_settime(pollfd[FD_WALL_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) { |
| log_error("timerfd_settime(): %m"); |
| goto finish; |
| } |
| |
| /* Disallow logins 5 minutes prior to shutdown */ |
| zero(its); |
| timespec_store(&its.it_value, when_nologin(b.command.usec)); |
| 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, b.command.usec); |
| if (timerfd_settime(pollfd[FD_SHUTDOWN_TIMER].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) { |
| log_error("timerfd_settime(): %m"); |
| goto finish; |
| } |
| |
| update_schedule_file(&b.command); |
| |
| sd_notifyf(false, |
| "STATUS=Shutting down at %s (%s)...", |
| format_timestamp(date, sizeof(date), b.command.usec), |
| mode_to_string(b.command.mode)); |
| |
| log_info("Shutting down at %s (%s)...", date, mode_to_string(b.command.mode)); |
| } |
| } |
| |
| if (pollfd[FD_WALL_TIMER].revents) { |
| struct itimerspec its = {}; |
| |
| warn_wall(n, &b.command); |
| flush_fd(pollfd[FD_WALL_TIMER].fd); |
| |
| /* Restart timer */ |
| timespec_store(&its.it_value, when_wall(n, b.command.usec)); |
| 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..."); |
| |
| e = write_string_file_atomic("/run/nologin", "System is going down."); |
| if (e < 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; |
| } |
| } |
| |
| r = EXIT_SUCCESS; |
| |
| log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid()); |
| |
| finish: |
| |
| for (i = 0; i < _FD_MAX; i++) |
| safe_close(pollfd[i].fd); |
| |
| if (unlink_nologin) |
| unlink("/run/nologin"); |
| |
| unlink("/run/systemd/shutdown/scheduled"); |
| |
| if (exec_shutdown && !b.command.dry_run) { |
| char sw[3]; |
| |
| sw[0] = '-'; |
| sw[1] = b.command.mode; |
| sw[2] = 0; |
| |
| execl(SYSTEMCTL_BINARY_PATH, |
| "shutdown", |
| sw, |
| "now", |
| (b.command.warn_wall && b.command.wall_message[0]) ? b.command.wall_message : |
| (b.command.warn_wall ? NULL : "--no-wall"), |
| NULL); |
| |
| log_error("Failed to execute /sbin/shutdown: %m"); |
| } |
| |
| sd_notify(false, |
| "STATUS=Exiting..."); |
| |
| return r; |
| } |