update-utmp.c revision e7fb33ffefcdc68ad096eea7444da877b68390e8
/*-*- 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 <assert.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef HAVE_AUDIT
#include <libaudit.h>
#endif
#include "sd-bus.h"
#include "log.h"
#include "macro.h"
#include "util.h"
#include "special.h"
#include "utmp-wtmp.h"
#include "bus-util.h"
#include "bus-error.h"
#include "unit-name.h"
typedef struct Context {
sd_bus *bus;
#ifdef HAVE_AUDIT
int audit_fd;
#endif
} Context;
static usec_t get_startup_time(Context *c) {
_cleanup_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",
"UserspaceTimestamp",
&error,
't', &t);
if (r < 0) {
log_error("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_RUNLEVEL5_TARGET },
{ '3', SPECIAL_RUNLEVEL3_TARGET },
{ '4', SPECIAL_RUNLEVEL4_TARGET },
{ '2', SPECIAL_RUNLEVEL2_TARGET },
{ '1', SPECIAL_RESCUE_TARGET },
};
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
unsigned i;
assert(c);
for (i = 0; i < ELEMENTSOF(table); i++) {
_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 < 0) {
log_warning("Failed to get state: %s", bus_error_message(&error, -r));
return r;
}
if (streq(state, "active") || streq(state, "reloading"))
return table[i].runlevel;
}
return 0;
}
static int on_reboot(Context *c) {
int r = 0, q;
usec_t t;
assert(c);
/* We finished start-up, so let's write the utmp
* record and send the audit msg */
#ifdef HAVE_AUDIT
if (c->audit_fd >= 0)
if (audit_log_user_message(c->audit_fd, AUDIT_SYSTEM_BOOT, "init", NULL, NULL, NULL, 1) < 0 &&
errno != EPERM) {
log_error("Failed to send audit message: %m");
r = -errno;
}
#endif
/* If this call fails it will return 0, which
* utmp_put_reboot() will then fix to the current time */
t = get_startup_time(c);
q = utmp_put_reboot(t);
if (q < 0) {
log_error("Failed to write utmp record: %s", strerror(-q));
r = q;
}
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 */
#ifdef HAVE_AUDIT
if (c->audit_fd >= 0)
if (audit_log_user_message(c->audit_fd, AUDIT_SYSTEM_SHUTDOWN, "init", NULL, NULL, NULL, 1) < 0 &&
errno != EPERM) {
log_error("Failed to send audit message: %m");
r = -errno;
}
#endif
q = utmp_put_shutdown();
if (q < 0) {
log_error("Failed to write utmp record: %s", strerror(-q));
r = q;
}
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 (q != -ESRCH && q != -ENOENT) {
log_error("Failed to get current runlevel: %s", strerror(-q));
return q;
}
previous = 0;
}
/* Secondly, get new runlevel */
runlevel = get_current_runlevel(c);
if (runlevel < 0)
return runlevel;
if (previous == runlevel)
return 0;
#ifdef HAVE_AUDIT
if (c->audit_fd >= 0) {
_cleanup_free_ char *s = NULL;
if (asprintf(&s, "old-level=%c new-level=%c",
previous > 0 ? previous : 'N',
runlevel > 0 ? runlevel : 'N') < 0)
return log_oom();
if (audit_log_user_message(c->audit_fd, AUDIT_SYSTEM_RUNLEVEL, s, NULL, NULL, NULL, 1) < 0 &&
errno != EPERM) {
log_error("Failed to send audit message: %m");
r = -errno;
}
}
#endif
q = utmp_put_runlevel(runlevel, previous);
if (q < 0 && q != -ESRCH && q != -ENOENT) {
log_error("Failed to write utmp record: %s", strerror(-q));
r = q;
}
return r;
}
int main(int argc, char *argv[]) {
Context c = {
#ifdef HAVE_AUDIT
.audit_fd = -1
#endif
};
int r;
if (getppid() != 1) {
log_error("This program should be invoked by init only.");
return EXIT_FAILURE;
}
if (argc != 2) {
log_error("This program requires one argument.");
return EXIT_FAILURE;
}
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
umask(0022);
#ifdef 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 && errno != EAFNOSUPPORT && errno != EPROTONOSUPPORT)
log_error("Failed to connect to audit log: %m");
#endif
r = bus_open_system_systemd(&c.bus);
if (r < 0) {
log_error("Failed to get D-Bus connection: %s", strerror(-r));
r = -EIO;
goto finish;
}
log_debug("systemd-update-utmp running as pid %lu", (unsigned long) getpid());
if (streq(argv[1], "reboot"))
r = on_reboot(&c);
else if (streq(argv[1], "shutdown"))
r = on_shutdown(&c);
else if (streq(argv[1], "runlevel"))
r = on_runlevel(&c);
else {
log_error("Unknown command %s", argv[1]);
r = -EINVAL;
}
log_debug("systemd-update-utmp stopped as pid %lu", (unsigned long) getpid());
finish:
#ifdef HAVE_AUDIT
if (c.audit_fd >= 0)
audit_close(c.audit_fd);
#endif
if (c.bus)
sd_bus_unref(c.bus);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}