[thirdparty/systemd.git] / src / utmp-wtmp.c

/*-*- 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 <utmpx.h>
#include <errno.h>
#include <assert.h>
#include <string.h>
#include <sys/utsname.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/poll.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_timestamp(struct utmpx *store, usec_t t) {
        assert(store);

        zero(*store);

        if (t <= 0)
                t = now(CLOCK_REALTIME);

        store->ut_tv.tv_sec = t / USEC_PER_SEC;
        store->ut_tv.tv_usec = t % USEC_PER_SEC;
}

static void init_entry(struct utmpx *store, usec_t t) {
        struct utsname uts;

        assert(store);

        init_timestamp(store, t);

        zero(uts);

        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 t) {
        struct utmpx store;

        init_entry(&store, t);

        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 t) {
        struct utmpx store;

        init_entry(&store, t);

        store.ut_type = BOOT_TIME;
        strncpy(store.ut_user, "reboot", sizeof(store.ut_user));

        return write_entry_both(&store);
}

static const char *sanitize_id(const char *id) {
        size_t l;

        assert(id);
        l = strlen(id);

        if (l <= sizeof(((struct utmpx*) NULL)->ut_id))
                return id;

        return id + l - sizeof(((struct utmpx*) NULL)->ut_id);
}

int utmp_put_init_process(usec_t t, const char *id, pid_t pid, pid_t sid, const char *line) {
        struct utmpx store;

        assert(id);

        init_timestamp(&store, t);

        store.ut_type = INIT_PROCESS;
        store.ut_pid = pid;
        store.ut_session = sid;

        strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id));

        if (line)
                strncpy(store.ut_line, file_name_from_path(line), sizeof(store.ut_line));

        return write_entry_both(&store);
}

int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
        struct utmpx lookup, store, *found;

        assert(id);

        setutxent();

        zero(lookup);
        lookup.ut_type = INIT_PROCESS; /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
        strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id));

        if (!(found = getutxid(&lookup)))
                return 0;

        if (found->ut_pid != pid)
                return 0;

        zero(store);

        memcpy(&store, &lookup, sizeof(store));
        store.ut_type = DEAD_PROCESS;
        store.ut_exit.e_termination = code;
        store.ut_exit.e_exit = status;

        zero(store.ut_user);
        zero(store.ut_host);
        zero(store.ut_tv);

        return write_entry_both(&store);
}


int utmp_put_runlevel(usec_t t, 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, t);

        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);
}

#define TIMEOUT_MSEC 50

static int write_to_terminal(const char *tty, const char *message) {
        int fd, r;
        const char *p;
        size_t left;
        usec_t end;

        assert(tty);
        assert(message);

        if ((fd = open(tty, O_WRONLY|O_NDELAY|O_NOCTTY|O_CLOEXEC)) < 0)
                return -errno;

        if (!isatty(fd)) {
                r = -errno;
                goto finish;
        }

        p = message;
        left = strlen(message);

        end = now(CLOCK_MONOTONIC) + TIMEOUT_MSEC*USEC_PER_MSEC;

        while (left > 0) {
                ssize_t n;
                struct pollfd pollfd;
                usec_t t;
                int k;

                t = now(CLOCK_MONOTONIC);

                if (t >= end) {
                        r = -ETIME;
                        goto finish;
                }

                zero(pollfd);
                pollfd.fd = fd;
                pollfd.events = POLLOUT;

                if ((k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC)) < 0)
                        return -errno;

                if (k <= 0) {
                        r = -ETIME;
                        goto finish;
                }

                if ((n = write(fd, p, left)) < 0) {

                        if (errno == EAGAIN)
                                continue;

                        r = -errno;
                        goto finish;
                }

                assert((size_t) n <= left);

                p += n;
                left -= n;
        }

        r = 0;

finish:
        close_nointr_nofail(fd);

        return r;
}

int utmp_wall(const char *message) {
        struct utmpx *u;
        char date[FORMAT_TIMESTAMP_MAX];
        char *text = NULL, *hn = NULL, *un = NULL, *tty = NULL;
        int r;

        if (!(hn = gethostname_malloc()) ||
            !(un = getlogname_malloc())) {
                r = -ENOMEM;
                goto finish;
        }

        getttyname_malloc(&tty);

        if (asprintf(&text,
                     "\a\r\n"
                     "Broadcast message from %s@%s%s%s (%s):\r\n\r\n"
                     "%s\r\n\r\n",
                     un, hn,
                     tty ? " on " : "", strempty(tty),
                     format_timestamp(date, sizeof(date), now(CLOCK_REALTIME)),
                     message) < 0) {
                r = -ENOMEM;
                goto finish;
        }

        setutxent();

        r = 0;

        while ((u = getutxent())) {
                int q;
                const char *path;
                char *buf = NULL;

                if (u->ut_type != USER_PROCESS || u->ut_user[0] == 0)
                        continue;

                if (path_startswith(u->ut_line, "/dev/"))
                        path = u->ut_line;
                else {
                        if (asprintf(&buf, "/dev/%s", u->ut_line) < 0) {
                                r = -ENOMEM;
                                goto finish;
                        }

                        path = buf;
                }

                if ((q = write_to_terminal(path, text)) < 0)
                        r = q;

                free(buf);
        }

finish:
        free(hn);
        free(un);
        free(tty);
        free(text);

        return r;
}
Commit	Line	Data
d6c9574f	1	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/
e537352b LP	2
	3	/***
	4	This file is part of systemd.
	5
	6	Copyright 2010 Lennart Poettering
	7
	8	systemd is free software; you can redistribute it and/or modify it
	9	under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 2 of the License, or
	11	(at your option) any later version.
	12
	13	systemd is distributed in the hope that it will be useful, but
	14	WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	20	***/
	21
	22	#include <utmpx.h>
	23	#include <errno.h>
	24	#include <assert.h>
	25	#include <string.h>
	26	#include <sys/utsname.h>
ef2f1067 LP	27	#include <fcntl.h>
	28	#include <unistd.h>
	29	#include <sys/poll.h>
e537352b LP	30
	31	#include "macro.h"
	32	#include "utmp-wtmp.h"
	33
	34	int utmp_get_runlevel(int runlevel, int previous) {
	35	struct utmpx lookup, *found;
	36	int r;
	37	const char *e;
	38
	39	assert(runlevel);
	40
	41	/* If these values are set in the environment this takes
	42	* precedence. Presumably, sysvinit does this to work around a
	43	* race condition that would otherwise exist where we'd always
	44	* go to disk and hence might read runlevel data that might be
	45	* very new and does not apply to the current script being
	46	* executed. */
	47
	48	if ((e = getenv("RUNLEVEL")) && e[0] > 0) {
	49	*runlevel = e[0];
	50
	51	if (previous) {
	52	/* $PREVLEVEL seems to be an Upstart thing */
	53
	54	if ((e = getenv("PREVLEVEL")) && e[0] > 0)
	55	*previous = e[0];
	56	else
	57	*previous = 0;
	58	}
	59
	60	return 0;
	61	}
	62
	63	if (utmpxname(_PATH_UTMPX) < 0)
	64	return -errno;
	65
	66	setutxent();
	67
	68	zero(lookup);
	69	lookup.ut_type = RUN_LVL;
	70
	71	if (!(found = getutxid(&lookup)))
	72	r = -errno;
	73	else {
	74	int a, b;
	75
	76	a = found->ut_pid & 0xFF;
	77	b = (found->ut_pid >> 8) & 0xFF;
	78
	79	if (a < 0 \|\| b < 0)
	80	r = -EIO;
	81	else {
	82	*runlevel = a;
	83
	84	if (previous)
	85	*previous = b;
	86	r = 0;
	87	}
	88	}
	89
	90	endutxent();
	91
	92	return r;
	93	}
94
169c1bda	95	static void init_timestamp(struct utmpx *store, usec_t t) {
e537352b LP	96	assert(store);
	97
	98	zero(*store);
e537352b	99
871d7de4 LP	100	if (t <= 0)
871d7de4 LP	101	t = now(CLOCK_REALTIME);
e537352b	102
871d7de4 LP	103	store->ut_tv.tv_sec = t / USEC_PER_SEC;
871d7de4 LP	104	store->ut_tv.tv_usec = t % USEC_PER_SEC;
169c1bda LP	105	}
	106
	107	static void init_entry(struct utmpx *store, usec_t t) {
	108	struct utsname uts;
	109
	110	assert(store);
	111
	112	init_timestamp(store, t);
	113
	114	zero(uts);
e537352b LP	115
	116	if (uname(&uts) >= 0)
	117	strncpy(store->ut_host, uts.release, sizeof(store->ut_host));
	118
	119	strncpy(store->ut_line, "~", sizeof(store->ut_line)); /* or ~~ ? */
	120	strncpy(store->ut_id, "~~", sizeof(store->ut_id));
	121	}
	122
	123	static int write_entry_utmp(const struct utmpx *store) {
	124	int r;
	125
	126	assert(store);
	127
	128	/* utmp is similar to wtmp, but there is only one entry for
	129	* each entry type resp. user; i.e. basically a key/value
	130	* table. */
	131
	132	if (utmpxname(_PATH_UTMPX) < 0)
	133	return -errno;
	134
	135	setutxent();
	136
	137	if (!pututxline(store))
	138	r = -errno;
	139	else
	140	r = 0;
	141
	142	endutxent();
	143
	144	return r;
	145	}
	146
	147	static int write_entry_wtmp(const struct utmpx *store) {
	148	assert(store);
	149
	150	/* wtmp is a simple append-only file where each entry is
	151	simply appended to * the end; i.e. basically a log. */
	152
	153	errno = 0;
	154	updwtmpx(_PATH_WTMPX, store);
	155	return -errno;
	156	}
	157
	158	static int write_entry_both(const struct utmpx *store) {
	159	int r, s;
	160
	161	r = write_entry_utmp(store);
	162	s = write_entry_wtmp(store);
	163
	164	if (r >= 0)
	165	r = s;
	166
	167	/* If utmp/wtmp have been disabled, that's a good thing, hence
	168	* ignore the errors */
	169	if (r == -ENOENT)
	170	r = 0;
	171
	172	return r;
	173	}
	174
871d7de4	175	int utmp_put_shutdown(usec_t t) {
e537352b LP	176	struct utmpx store;
e537352b LP	177
871d7de4	178	init_entry(&store, t);
e537352b LP	179
	180	store.ut_type = RUN_LVL;
	181	strncpy(store.ut_user, "shutdown", sizeof(store.ut_user));
	182
	183	return write_entry_both(&store);
	184	}
	185
871d7de4	186	int utmp_put_reboot(usec_t t) {
e537352b LP	187	struct utmpx store;
e537352b LP	188
871d7de4	189	init_entry(&store, t);
e537352b LP	190
e537352b LP	191	store.ut_type = BOOT_TIME;
55e39f40	192	strncpy(store.ut_user, "reboot", sizeof(store.ut_user));
e537352b LP	193
	194	return write_entry_both(&store);
	195	}
	196
169c1bda LP	197	static const char sanitize_id(const char id) {
	198	size_t l;
	199
	200	assert(id);
	201	l = strlen(id);
	202
	203	if (l <= sizeof(((struct utmpx*) NULL)->ut_id))
	204	return id;
	205
	206	return id + l - sizeof(((struct utmpx*) NULL)->ut_id);
	207	}
	208
	209	int utmp_put_init_process(usec_t t, const char id, pid_t pid, pid_t sid, const char line) {
	210	struct utmpx store;
	211
	212	assert(id);
	213
	214	init_timestamp(&store, t);
	215
	216	store.ut_type = INIT_PROCESS;
	217	store.ut_pid = pid;
	218	store.ut_session = sid;
	219
	220	strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id));
	221
	222	if (line)
	223	strncpy(store.ut_line, file_name_from_path(line), sizeof(store.ut_line));
	224
	225	return write_entry_both(&store);
	226	}
	227
	228	int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
	229	struct utmpx lookup, store, *found;
	230
	231	assert(id);
	232
	233	setutxent();
	234
	235	zero(lookup);
	236	lookup.ut_type = INIT_PROCESS; /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
	237	strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id));
	238
	239	if (!(found = getutxid(&lookup)))
	240	return 0;
	241
	242	if (found->ut_pid != pid)
	243	return 0;
	244
	245	zero(store);
	246
	247	memcpy(&store, &lookup, sizeof(store));
	248	store.ut_type = DEAD_PROCESS;
	249	store.ut_exit.e_termination = code;
	250	store.ut_exit.e_exit = status;
	251
	252	zero(store.ut_user);
	253	zero(store.ut_host);
	254	zero(store.ut_tv);
	255
	256	return write_entry_both(&store);
	257	}
	258
	259
871d7de4	260	int utmp_put_runlevel(usec_t t, int runlevel, int previous) {
e537352b LP	261	struct utmpx store;
	262	int r;
	263
	264	assert(runlevel > 0);
	265
	266	if (previous <= 0) {
	267	/* Find the old runlevel automatically */
	268
d7fc909d LP	269	if ((r = utmp_get_runlevel(&previous, NULL)) < 0) {
	270	if (r != -ESRCH)
	271	return r;
	272
	273	previous = 0;
	274	}
e537352b LP	275	}
e537352b LP	276
4927fcae LP	277	if (previous == runlevel)
	278	return 0;
	279
871d7de4	280	init_entry(&store, t);
e537352b LP	281
	282	store.ut_type = RUN_LVL;
	283	store.ut_pid = (runlevel & 0xFF) \| ((previous & 0xFF) << 8);
	284	strncpy(store.ut_user, "runlevel", sizeof(store.ut_user));
	285
	286	return write_entry_both(&store);
	287	}
ef2f1067 LP	288
	289	#define TIMEOUT_MSEC 50
	290
	291	static int write_to_terminal(const char tty, const char message) {
	292	int fd, r;
	293	const char *p;
	294	size_t left;
	295	usec_t end;
	296
	297	assert(tty);
	298	assert(message);
	299
	300	if ((fd = open(tty, O_WRONLY\|O_NDELAY\|O_NOCTTY\|O_CLOEXEC)) < 0)
	301	return -errno;
	302
	303	if (!isatty(fd)) {
	304	r = -errno;
	305	goto finish;
	306	}
	307
	308	p = message;
	309	left = strlen(message);
	310
	311	end = now(CLOCK_MONOTONIC) + TIMEOUT_MSEC*USEC_PER_MSEC;
	312
	313	while (left > 0) {
	314	ssize_t n;
	315	struct pollfd pollfd;
	316	usec_t t;
	317	int k;
	318
	319	t = now(CLOCK_MONOTONIC);
	320
	321	if (t >= end) {
	322	r = -ETIME;
	323	goto finish;
	324	}
	325
	326	zero(pollfd);
	327	pollfd.fd = fd;
	328	pollfd.events = POLLOUT;
	329
	330	if ((k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC)) < 0)
	331	return -errno;
	332
	333	if (k <= 0) {
	334	r = -ETIME;
	335	goto finish;
	336	}
	337
	338	if ((n = write(fd, p, left)) < 0) {
	339
	340	if (errno == EAGAIN)
	341	continue;
	342
	343	r = -errno;
	344	goto finish;
	345	}
	346
	347	assert((size_t) n <= left);
	348
	349	p += n;
	350	left -= n;
	351	}
352
353	r = 0;
354
355	finish:
356	close_nointr_nofail(fd);
357
358	return r;
359	}
360
361	int utmp_wall(const char *message) {
362	struct utmpx *u;
11620592	363	char date[FORMAT_TIMESTAMP_MAX];
629c210d	364	char text = NULL, hn = NULL, un = NULL, tty = NULL;
ef2f1067	365	int r;
ef2f1067 LP	366
ef2f1067 LP	367	if (!(hn = gethostname_malloc()) \|\|
8c6db833	368	!(un = getlogname_malloc())) {
ef2f1067 LP	369	r = -ENOMEM;
	370	goto finish;
	371	}
	372
11620592	373	getttyname_malloc(&tty);
ef2f1067 LP	374
	375	if (asprintf(&text,
	376	"\a\r\n"
11620592	377	"Broadcast message from %s@%s%s%s (%s):\r\n\r\n"
ef2f1067	378	"%s\r\n\r\n",
11620592 LP	379	un, hn,
	380	tty ? " on " : "", strempty(tty),
	381	format_timestamp(date, sizeof(date), now(CLOCK_REALTIME)),
	382	message) < 0) {
ef2f1067 LP	383	r = -ENOMEM;
	384	goto finish;
	385	}
	386
	387	setutxent();
	388
	389	r = 0;
	390
	391	while ((u = getutxent())) {
	392	int q;
	393	const char *path;
	394	char *buf = NULL;
	395
	396	if (u->ut_type != USER_PROCESS \|\| u->ut_user[0] == 0)
	397	continue;
	398
	399	if (path_startswith(u->ut_line, "/dev/"))
	400	path = u->ut_line;
	401	else {
	402	if (asprintf(&buf, "/dev/%s", u->ut_line) < 0) {
	403	r = -ENOMEM;
	404	goto finish;
	405	}
	406
	407	path = buf;
	408	}
	409
	410	if ((q = write_to_terminal(path, text)) < 0)
	411	r = q;
	412
	413	free(buf);
	414	}
	415
	416	finish:
	417	free(hn);
	418	free(un);
	419	free(tty);
	420	free(text);
	421
	422	return r;
	423	}