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-rw-r--r--src/shutdownd.c272
1 files changed, 272 insertions, 0 deletions
diff --git a/src/shutdownd.c b/src/shutdownd.c
new file mode 100644
index 0000000000..241c4327a6
--- /dev/null
+++ b/src/shutdownd.c
@@ -0,0 +1,272 @@
+/*-*- 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 "shutdownd.h"
+#include "log.h"
+#include "macro.h"
+#include "util.h"
+#include "sd-daemon.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 invaliud size. Ignoring");
+ return 0;
+ }
+
+ *_c = c;
+ return 1;
+}
+
+int main(int argc, char *argv[]) {
+ enum {
+ FD_SOCKET,
+ FD_SHUTDOWN_TIMER,
+ FD_NOLOGIN_TIMER,
+ _FD_MAX
+ };
+
+ int r = 4, n;
+ int one = 1;
+ unsigned n_fds = 1;
+ struct shutdownd_command c;
+ struct pollfd pollfd[_FD_MAX];
+ bool exec_shutdown = false, unlink_nologin = false;
+
+ if (getppid() != 1) {
+ log_error("This program should be invoked by init only.");
+ return 1;
+ }
+
+ if (argc > 1) {
+ log_error("This program does not take arguments.");
+ return 1;
+ }
+
+ log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+ log_parse_environment();
+
+ if ((n = sd_listen_fds(true)) < 0) {
+ log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
+ return 1;
+ }
+
+ if (n != 1) {
+ log_error("Need exactly one file descriptor.");
+ return 2;
+ }
+
+ if (setsockopt(SD_LISTEN_FDS_START, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
+ log_error("SO_PASSCRED failed: %m");
+ return 3;
+ }
+
+ zero(c);
+ zero(pollfd);
+
+ pollfd[FD_SOCKET].fd = SD_LISTEN_FDS_START;
+ pollfd[FD_SOCKET].events = POLLIN;
+ pollfd[FD_SHUTDOWN_TIMER].fd = -1;
+ pollfd[FD_SHUTDOWN_TIMER].events = POLLIN;
+ pollfd[FD_NOLOGIN_TIMER].fd = -1;
+ pollfd[FD_NOLOGIN_TIMER].events = POLLIN;
+
+ log_debug("systemd-shutdownd running as pid %lu", (unsigned long) getpid());
+
+ sd_notify(false,
+ "READY=1\n"
+ "STATUS=Processing requests...");
+
+ do {
+ int k;
+
+ if (poll(pollfd, n_fds, -1) < 0) {
+
+ if (errno == EAGAIN || errno == EINTR)
+ continue;
+
+ log_error("poll(): %m");
+ goto finish;
+ }
+
+ 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 buf[27];
+
+ if (pollfd[FD_SHUTDOWN_TIMER].fd < 0)
+ if ((pollfd[FD_SHUTDOWN_TIMER].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) {
+ log_error("timerfd_create(): %m");
+ goto finish;
+ }
+
+ if (pollfd[FD_NOLOGIN_TIMER].fd < 0)
+ if ((pollfd[FD_NOLOGIN_TIMER].fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) {
+ log_error("timerfd_create(): %m");
+ goto finish;
+ }
+
+ /* Disallow logins 5 minutes prior to shutdown */
+ zero(its);
+ timespec_store(&its.it_value, c.elapse > 5*USEC_PER_MINUTE ? c.elapse - 5*USEC_PER_MINUTE : 0);
+ 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;
+ }
+
+ n_fds = 3;
+
+ ctime_r(&its.it_value.tv_sec, buf);
+
+ sd_notifyf(false,
+ "STATUS=Shutting down at %s...",
+ strstrip(buf));
+ }
+ }
+
+ if (pollfd[FD_NOLOGIN_TIMER].fd >= 0 &&
+ pollfd[FD_NOLOGIN_TIMER].revents) {
+ int e;
+
+ if ((e = touch("/etc/nologin")) < 0)
+ log_error("Failed to create /etc/nologin: %s", strerror(-e));
+ else
+ unlink_nologin = true;
+
+ /* Disarm nologin timer */
+ close_nointr_nofail(pollfd[FD_NOLOGIN_TIMER].fd);
+ pollfd[FD_NOLOGIN_TIMER].fd = -1;
+ n_fds = 2;
+
+ }
+
+ if (pollfd[FD_SHUTDOWN_TIMER].fd >= 0 &&
+ pollfd[FD_SHUTDOWN_TIMER].revents) {
+ exec_shutdown = true;
+ goto finish;
+ }
+
+ } while (c.elapse > 0);
+
+ r = 0;
+
+ log_debug("systemd-shutdownd stopped as pid %lu", (unsigned long) getpid());
+
+finish:
+ if (pollfd[FD_SOCKET].fd >= 0)
+ close_nointr_nofail(pollfd[FD_SOCKET].fd);
+
+ if (pollfd[FD_SHUTDOWN_TIMER].fd >= 0)
+ close_nointr_nofail(pollfd[FD_SHUTDOWN_TIMER].fd);
+
+ if (pollfd[FD_NOLOGIN_TIMER].fd >= 0)
+ close_nointr_nofail(pollfd[FD_NOLOGIN_TIMER].fd);
+
+ if (exec_shutdown) {
+ char sw[3];
+
+ sw[0] = '-';
+ sw[1] = c.mode;
+ sw[2] = 0;
+
+ execl(SYSTEMCTL_BINARY_PATH, "shutdown", sw, "now", NULL);
+ log_error("Failed to execute /sbin/shutdown: %m");
+ }
+
+ if (unlink_nologin)
+ unlink("/etc/nologin");
+
+ sd_notify(false,
+ "STATUS=Exiting...");
+
+ return r;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-01 11:03:06 +0000