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/*-*- Mode: C; c-basic-offset: 8 -*-*/
/***
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 <utmpx.h>
#include <errno.h>
#include <assert.h>
#include <string.h>
#include <sys/utsname.h>
#include "macro.h"
#include "utmp-wtmp.h"
int utmp_get_runlevel(int *runlevel, int *previous) {
struct utmpx lookup, *found;
int r;
const char *e;
assert(runlevel);
/* If these values are set in the environment this takes
* precedence. Presumably, sysvinit does this to work around a
* race condition that would otherwise exist where we'd always
* go to disk and hence might read runlevel data that might be
* very new and does not apply to the current script being
* executed. */
if ((e = getenv("RUNLEVEL")) && e[0] > 0) {
*runlevel = e[0];
if (previous) {
/* $PREVLEVEL seems to be an Upstart thing */
if ((e = getenv("PREVLEVEL")) && e[0] > 0)
*previous = e[0];
else
*previous = 0;
}
return 0;
}
if (utmpxname(_PATH_UTMPX) < 0)
return -errno;
setutxent();
zero(lookup);
lookup.ut_type = RUN_LVL;
if (!(found = getutxid(&lookup)))
r = -errno;
else {
int a, b;
a = found->ut_pid & 0xFF;
b = (found->ut_pid >> 8) & 0xFF;
if (a < 0 || b < 0)
r = -EIO;
else {
*runlevel = a;
if (previous)
*previous = b;
r = 0;
}
}
endutxent();
return r;
}
static void init_entry(struct utmpx *store, usec_t timestamp) {
struct utsname uts;
assert(store);
zero(*store);
zero(uts);
if (timestamp <= 0)
timestamp = now(CLOCK_REALTIME);
store->ut_tv.tv_sec = timestamp / USEC_PER_SEC;
store->ut_tv.tv_usec = timestamp % USEC_PER_SEC;
if (uname(&uts) >= 0)
strncpy(store->ut_host, uts.release, sizeof(store->ut_host));
strncpy(store->ut_line, "~", sizeof(store->ut_line)); /* or ~~ ? */
strncpy(store->ut_id, "~~", sizeof(store->ut_id));
}
static int write_entry_utmp(const struct utmpx *store) {
int r;
assert(store);
/* utmp is similar to wtmp, but there is only one entry for
* each entry type resp. user; i.e. basically a key/value
* table. */
if (utmpxname(_PATH_UTMPX) < 0)
return -errno;
setutxent();
if (!pututxline(store))
r = -errno;
else
r = 0;
endutxent();
return r;
}
static int write_entry_wtmp(const struct utmpx *store) {
assert(store);
/* wtmp is a simple append-only file where each entry is
simply appended to * the end; i.e. basically a log. */
errno = 0;
updwtmpx(_PATH_WTMPX, store);
return -errno;
}
static int write_entry_both(const struct utmpx *store) {
int r, s;
r = write_entry_utmp(store);
s = write_entry_wtmp(store);
if (r >= 0)
r = s;
/* If utmp/wtmp have been disabled, that's a good thing, hence
* ignore the errors */
if (r == -ENOENT)
r = 0;
return r;
}
int utmp_put_shutdown(usec_t timestamp) {
struct utmpx store;
init_entry(&store, timestamp);
store.ut_type = RUN_LVL;
strncpy(store.ut_user, "shutdown", sizeof(store.ut_user));
return write_entry_both(&store);
}
int utmp_put_reboot(usec_t timestamp) {
struct utmpx store;
init_entry(&store, timestamp);
store.ut_type = BOOT_TIME;
strncpy(store.ut_user, "reboot", sizeof(store.ut_type));
return write_entry_both(&store);
}
int utmp_put_runlevel(usec_t timestamp, int runlevel, int previous) {
struct utmpx store;
int r;
assert(runlevel > 0);
if (previous <= 0) {
/* Find the old runlevel automatically */
if ((r = utmp_get_runlevel(&previous, NULL)) < 0) {
if (r != -ESRCH)
return r;
previous = 0;
}
if (previous == runlevel)
return 0;
}
init_entry(&store, timestamp);
store.ut_type = RUN_LVL;
store.ut_pid = (runlevel & 0xFF) | ((previous & 0xFF) << 8);
strncpy(store.ut_user, "runlevel", sizeof(store.ut_user));
return write_entry_both(&store);
}
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