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-rw-r--r--src/update-utmp/update-utmp.c283
1 files changed, 283 insertions, 0 deletions
diff --git a/src/update-utmp/update-utmp.c b/src/update-utmp/update-utmp.c
new file mode 100644
index 0000000..2d2122a
--- /dev/null
+++ b/src/update-utmp/update-utmp.c
@@ -0,0 +1,283 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#if HAVE_AUDIT
+#include <libaudit.h>
+#endif
+
+#include "sd-bus.h"
+
+#include "alloc-util.h"
+#include "bus-error.h"
+#include "bus-util.h"
+#include "format-util.h"
+#include "log.h"
+#include "macro.h"
+#include "main-func.h"
+#include "process-util.h"
+#include "random-util.h"
+#include "special.h"
+#include "stdio-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "util.h"
+#include "utmp-wtmp.h"
+
+typedef struct Context {
+ sd_bus *bus;
+#if HAVE_AUDIT
+ int audit_fd;
+#endif
+} Context;
+
+static void context_clear(Context *c) {
+ assert(c);
+
+ c->bus = sd_bus_flush_close_unref(c->bus);
+#if HAVE_AUDIT
+ if (c->audit_fd >= 0)
+ audit_close(c->audit_fd);
+ c->audit_fd = -1;
+#endif
+}
+
+static usec_t get_startup_monotonic_time(Context *c) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ usec_t t = 0;
+ int r;
+
+ assert(c);
+
+ r = sd_bus_get_property_trivial(
+ c->bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "UserspaceTimestampMonotonic",
+ &error,
+ 't', &t);
+ if (r < 0) {
+ log_error_errno(r, "Failed to get timestamp: %s", bus_error_message(&error, r));
+ return 0;
+ }
+
+ return t;
+}
+
+static int get_current_runlevel(Context *c) {
+ static const struct {
+ const int runlevel;
+ const char *special;
+ } table[] = {
+ /* The first target of this list that is active or has
+ * a job scheduled wins. We prefer runlevels 5 and 3
+ * here over the others, since these are the main
+ * runlevels used on Fedora. It might make sense to
+ * change the order on some distributions. */
+ { '5', SPECIAL_GRAPHICAL_TARGET },
+ { '3', SPECIAL_MULTI_USER_TARGET },
+ { '1', SPECIAL_RESCUE_TARGET },
+ };
+ int r;
+
+ assert(c);
+
+ for (unsigned n_attempts = 0;;) {
+ for (size_t i = 0; i < ELEMENTSOF(table) - 1; i++) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_free_ char *state = NULL, *path = NULL;
+
+ path = unit_dbus_path_from_name(table[i].special);
+ if (!path)
+ return log_oom();
+
+ r = sd_bus_get_property_string(
+ c->bus,
+ "org.freedesktop.systemd1",
+ path,
+ "org.freedesktop.systemd1.Unit",
+ "ActiveState",
+ &error,
+ &state);
+ if ((r == -ENOTCONN ||
+ sd_bus_error_has_names(&error,
+ SD_BUS_ERROR_NO_REPLY,
+ SD_BUS_ERROR_DISCONNECTED)) &&
+ ++n_attempts < 64) {
+
+ /* systemd might have dropped off momentarily, let's not make this an error,
+ * and wait some random time. Let's pick a random time in the range 0ms…250ms,
+ * linearly scaled by the number of failed attempts. */
+
+ usec_t usec = random_u64_range(UINT64_C(10) * USEC_PER_MSEC +
+ UINT64_C(240) * USEC_PER_MSEC * n_attempts/64);
+ log_debug_errno(r, "Failed to get state of %s, retrying after %s: %s",
+ table[i].special, FORMAT_TIMESPAN(usec, USEC_PER_MSEC), bus_error_message(&error, r));
+ (void) usleep(usec);
+ goto reconnect;
+ }
+ if (r < 0)
+ return log_warning_errno(r, "Failed to get state of %s: %s", table[i].special, bus_error_message(&error, r));
+
+ if (STR_IN_SET(state, "active", "reloading"))
+ return table[i].runlevel;
+ }
+
+ return 0;
+
+reconnect:
+ c->bus = sd_bus_flush_close_unref(c->bus);
+ r = bus_connect_system_systemd(&c->bus);
+ if (r < 0)
+ return log_error_errno(r, "Failed to reconnect to system bus: %m");
+ }
+}
+
+static int on_reboot(Context *c) {
+ int r = 0, q;
+ usec_t t;
+ usec_t boottime;
+
+ assert(c);
+
+ /* We finished start-up, so let's write the utmp
+ * record and send the audit msg */
+
+#if HAVE_AUDIT
+ if (c->audit_fd >= 0)
+ if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_BOOT, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
+ errno != EPERM)
+ r = log_error_errno(errno, "Failed to send audit message: %m");
+#endif
+
+ /* If this call fails it will return 0, which
+ * utmp_put_reboot() will then fix to the current time */
+ t = get_startup_monotonic_time(c);
+ boottime = map_clock_usec(t, CLOCK_MONOTONIC, CLOCK_REALTIME);
+ /* We query the recorded monotonic time here (instead of the system clock CLOCK_REALTIME),
+ * even though we actually want the system clock time. That's because there's a likely
+ * chance that the system clock wasn't set right during early boot. By manually converting
+ * the monotonic clock to the system clock here we can compensate
+ * for incorrectly set clocks during early boot. */
+
+ q = utmp_put_reboot(boottime);
+ if (q < 0)
+ r = log_error_errno(q, "Failed to write utmp record: %m");
+
+ return r;
+}
+
+static int on_shutdown(Context *c) {
+ int r = 0, q;
+
+ assert(c);
+
+ /* We started shut-down, so let's write the utmp
+ * record and send the audit msg */
+
+#if HAVE_AUDIT
+ if (c->audit_fd >= 0)
+ if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_SHUTDOWN, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
+ errno != EPERM)
+ r = log_error_errno(errno, "Failed to send audit message: %m");
+#endif
+
+ q = utmp_put_shutdown();
+ if (q < 0)
+ r = log_error_errno(q, "Failed to write utmp record: %m");
+
+ return r;
+}
+
+static int on_runlevel(Context *c) {
+ int r = 0, q, previous, runlevel;
+
+ assert(c);
+
+ /* We finished changing runlevel, so let's write the
+ * utmp record and send the audit msg */
+
+ /* First, get last runlevel */
+ q = utmp_get_runlevel(&previous, NULL);
+
+ if (q < 0) {
+ if (!IN_SET(q, -ESRCH, -ENOENT))
+ return log_error_errno(q, "Failed to get current runlevel: %m");
+
+ previous = 0;
+ }
+
+ /* Secondly, get new runlevel */
+ runlevel = get_current_runlevel(c);
+ if (runlevel < 0)
+ return runlevel;
+ if (runlevel == 0) {
+ log_warning("Failed to get new runlevel, utmp update skipped.");
+ return 0;
+ }
+
+ if (previous == runlevel)
+ return 0;
+
+#if HAVE_AUDIT
+ if (c->audit_fd >= 0) {
+ char s[STRLEN("old-level=_ new-level=_") + 1];
+
+ xsprintf(s, "old-level=%c new-level=%c",
+ previous > 0 ? previous : 'N',
+ runlevel);
+
+ if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_RUNLEVEL, s,
+ "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 && errno != EPERM)
+ r = log_error_errno(errno, "Failed to send audit message: %m");
+ }
+#endif
+
+ q = utmp_put_runlevel(runlevel, previous);
+ if (q < 0 && !IN_SET(q, -ESRCH, -ENOENT))
+ return log_error_errno(q, "Failed to write utmp record: %m");
+
+ return r;
+}
+
+static int run(int argc, char *argv[]) {
+ _cleanup_(context_clear) Context c = {
+#if HAVE_AUDIT
+ .audit_fd = -1,
+#endif
+ };
+ int r;
+
+ if (argc != 2)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "This program requires one argument.");
+
+ log_setup();
+
+ umask(0022);
+
+#if HAVE_AUDIT
+ /* If the kernel lacks netlink or audit support, don't worry about it. */
+ c.audit_fd = audit_open();
+ if (c.audit_fd < 0)
+ log_full_errno(IN_SET(errno, EAFNOSUPPORT, EPROTONOSUPPORT) ? LOG_DEBUG : LOG_WARNING,
+ errno, "Failed to connect to audit log, ignoring: %m");
+#endif
+ r = bus_connect_system_systemd(&c.bus);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get D-Bus connection: %m");
+
+ if (streq(argv[1], "reboot"))
+ return on_reboot(&c);
+ if (streq(argv[1], "shutdown"))
+ return on_shutdown(&c);
+ if (streq(argv[1], "runlevel"))
+ return on_runlevel(&c);
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown command %s", argv[1]);
+}
+
+DEFINE_MAIN_FUNCTION(run);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 10:06:31 +0000