xref: /dragonfly/lib/libc/gen/utmpx.c (revision 625fc06f)
1 /*-
2  * Copyright (c) 2002 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Christos Zoulas.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "namespace.h"
31 #include <sys/types.h>
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/time.h>
36 #include <sys/wait.h>
37 
38 #include <assert.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <pwd.h>
46 #include <utmpx.h>
47 #include <vis.h>
48 #include "un-namespace.h"
49 
50 #include <db.h>
51 
52 static FILE *fp;
53 static int readonly = 0;
54 static struct utmpx ut;
55 static char utfile[MAXPATHLEN] = _PATH_UTMPX;
56 
57 static struct utmpx *utmp_update(const struct utmpx *);
58 
59 static const char vers[] = "utmpx-2.00";
60 static utx_db_t dbtype = UTX_DB_UTMPX;
61 DB *lastlogx_db = NULL;
62 
63 void past_getutmp(void *, void *);
64 void past_getutmpx(void *, void *);
65 
66 static int
_open_db(const char * fname)67 _open_db(const char *fname)
68 {
69 	struct stat st;
70 
71 	if ((fp = fopen(fname, "re+")) == NULL)
72 		if ((fp = fopen(fname, "we+")) == NULL) {
73 			if ((fp = fopen(fname, "re")) == NULL)
74 				goto fail;
75 			else
76 				readonly = 1;
77 		}
78 
79 	/* get file size in order to check if new file */
80 	if (_fstat(fileno(fp), &st) == -1)
81 		goto failclose;
82 
83 	if (st.st_size == 0) {
84 		/* new file, add signature record */
85 		(void)memset(&ut, 0, sizeof(ut));
86 		ut.ut_type = SIGNATURE;
87 		(void)memcpy(ut.ut_user, vers, sizeof(vers));
88 		if (fwrite(&ut, sizeof(ut), 1, fp) != 1)
89 			goto failclose;
90 	} else {
91 		/* old file, read signature record */
92 		if (fread(&ut, sizeof(ut), 1, fp) != 1)
93 			goto failclose;
94 		if (memcmp(ut.ut_user, vers, 5) != 0 ||
95 		    ut.ut_type != SIGNATURE) {
96 			errno = EINVAL;
97 			goto failclose;
98 		}
99 	}
100 
101 	return 0;
102 failclose:
103 	(void)fclose(fp);
104 fail:
105 	(void)memset(&ut, 0, sizeof(ut));
106 	return -1;
107 }
108 
109 int
setutxdb(utx_db_t db_type,const char * fname)110 setutxdb(utx_db_t db_type, const char *fname)
111 {
112 	switch (db_type) {
113 	case UTX_DB_UTMPX:
114 		if (fname == NULL)
115 			fname = _PATH_UTMPX;
116 		break;
117 
118 	case UTX_DB_WTMPX:
119 		if (fname == NULL)
120 			fname = _PATH_WTMPX;
121 		break;
122 
123 	default:
124 		errno = EINVAL;
125 		return -1;
126 	}
127 
128 	/* A previous db file is still open */
129 	if (fp != NULL) {
130 		fclose(fp);
131 		fp = NULL;
132 	}
133 	if ((_open_db(fname)) == -1)
134 		return -1;
135 
136 	dbtype = db_type;
137 	return 0;
138 }
139 
140 void
setutxent(void)141 setutxent(void)
142 {
143 	(void)memset(&ut, 0, sizeof(ut));
144 	if (fp == NULL)
145 		return;
146 	(void)fseeko(fp, (off_t)sizeof(ut), SEEK_SET);
147 }
148 
149 void
endutxent(void)150 endutxent(void)
151 {
152 	(void)memset(&ut, 0, sizeof(ut));
153 
154 	if (fp != NULL) {
155 		(void)fclose(fp);
156 		fp = NULL;
157 		readonly = 0;
158 	}
159 }
160 
161 struct utmpx *
getutxent(void)162 getutxent(void)
163 {
164 	if (fp == NULL) {
165 		if ((_open_db(utfile)) == -1)
166 			goto fail;
167 	}
168 
169 	if (fread(&ut, sizeof(ut), 1, fp) != 1)
170 		goto fail;
171 
172 	return &ut;
173 fail:
174 	(void)memset(&ut, 0, sizeof(ut));
175 	return NULL;
176 }
177 
178 struct utmpx *
getutxid(const struct utmpx * utx)179 getutxid(const struct utmpx *utx)
180 {
181 
182 	_DIAGASSERT(utx != NULL);
183 
184 	if (utx->ut_type == EMPTY)
185 		return NULL;
186 
187 	do {
188 		if (ut.ut_type == EMPTY)
189 			continue;
190 		switch (utx->ut_type) {
191 		case EMPTY:
192 			return NULL;
193 		case RUN_LVL:
194 		case BOOT_TIME:
195 		case OLD_TIME:
196 		case NEW_TIME:
197 			if (ut.ut_type == utx->ut_type)
198 				return &ut;
199 			break;
200 		case INIT_PROCESS:
201 		case LOGIN_PROCESS:
202 		case USER_PROCESS:
203 		case DEAD_PROCESS:
204 			switch (ut.ut_type) {
205 			case INIT_PROCESS:
206 			case LOGIN_PROCESS:
207 			case USER_PROCESS:
208 			case DEAD_PROCESS:
209 				if (memcmp(ut.ut_id, utx->ut_id,
210 				    sizeof(ut.ut_id)) == 0)
211 					return &ut;
212 				break;
213 			default:
214 				break;
215 			}
216 			break;
217 		default:
218 			return NULL;
219 		}
220 	} while (getutxent() != NULL);
221 	return NULL;
222 }
223 
224 struct utmpx *
getutxline(const struct utmpx * utx)225 getutxline(const struct utmpx *utx)
226 {
227 
228 	_DIAGASSERT(utx != NULL);
229 
230 	do {
231 		switch (ut.ut_type) {
232 		case EMPTY:
233 			break;
234 		case LOGIN_PROCESS:
235 		case USER_PROCESS:
236 			if (strncmp(ut.ut_line, utx->ut_line,
237 			    sizeof(ut.ut_line)) == 0)
238 				return &ut;
239 			break;
240 		default:
241 			break;
242 		}
243 	} while (getutxent() != NULL);
244 	return NULL;
245 }
246 
247 struct utmpx *
getutxuser(const char * user)248 getutxuser(const char *user)
249 {
250 	_DIAGASSERT(utx != NULL);
251 
252 	do {
253 		switch (ut.ut_type) {
254 		case EMPTY:
255 			break;
256 		case USER_PROCESS:
257 			if (strncmp(ut.ut_user, user, sizeof(ut.ut_user)) == 0)
258 				return &ut;
259 			break;
260 		default:
261 			break;
262 		}
263 	} while (getutxent() != NULL);
264 	return NULL;
265 }
266 
267 struct utmpx *
pututxline(const struct utmpx * utx)268 pututxline(const struct utmpx *utx)
269 {
270 	struct passwd *pw;
271 	struct lastlogx ll;
272 	struct utmpx temp, *u = NULL;
273 	int gotlock = 0;
274 
275 	_DIAGASSERT(utx != NULL);
276 
277 	if (utx == NULL)
278 		return NULL;
279 
280 	if (utx->ut_type == USER_PROCESS) {
281 		ll.ll_tv = utx->ut_tv;
282 		strcpy(ll.ll_host, utx->ut_host);
283 		strcpy(ll.ll_line, utx->ut_line);
284 		pw = getpwnam(utx->ut_name);
285 		if (pw != NULL)
286 			updlastlogx(_PATH_LASTLOGX, pw->pw_uid, &ll);
287 	}
288 
289 	if (strcmp(_PATH_UTMPX, utfile) == 0)
290 		if ((fp != NULL && readonly) || (fp == NULL && geteuid() != 0))
291 			return utmp_update(utx);
292 
293 
294 	(void)memcpy(&temp, utx, sizeof(temp));
295 
296 	if (fp == NULL) {
297 		(void)getutxent();
298 		if (fp == NULL || readonly)
299 			return NULL;
300 	}
301 
302 	if (getutxid(&temp) == NULL) {
303 		setutxent();
304 		if (getutxid(&temp) == NULL) {
305 			if (lockf(fileno(fp), F_LOCK, (off_t)0) == -1)
306 				return NULL;
307 			gotlock++;
308 			if (fseeko(fp, (off_t)0, SEEK_END) == -1)
309 				goto fail;
310 		}
311 	}
312 
313 	if (!gotlock) {
314 		/* we are not appending */
315 		if (fseeko(fp, -(off_t)sizeof(ut), SEEK_CUR) == -1)
316 			return NULL;
317 	}
318 
319 	if (fwrite(&temp, sizeof (temp), 1, fp) != 1)
320 		goto fail;
321 
322 	if (fflush(fp) == -1)
323 		goto fail;
324 
325 	u = memcpy(&ut, &temp, sizeof(ut));
326 fail:
327 	if (gotlock) {
328 		if (lockf(fileno(fp), F_ULOCK, (off_t)0) == -1)
329 			return NULL;
330 	}
331 	return u;
332 }
333 
334 static struct utmpx *
utmp_update(const struct utmpx * utx)335 utmp_update(const struct utmpx *utx)
336 {
337 	char buf[sizeof(*utx) * 4 + 1];
338 	pid_t pid;
339 	int status;
340 
341 	_DIAGASSERT(utx != NULL);
342 
343 	(void)strvisx(buf, (const char *)(const void *)utx, sizeof(*utx),
344 	    VIS_WHITE | VIS_NOLOCALE);
345 	switch (pid = fork()) {
346 	case 0:
347 		(void)execl(_PATH_UTMP_UPDATE,
348 		    strrchr(_PATH_UTMP_UPDATE, '/') + 1, buf, NULL);
349 		_exit(1);
350 		/*NOTREACHED*/
351 	case -1:
352 		return NULL;
353 	default:
354 		if (_waitpid(pid, &status, 0) == -1)
355 			return NULL;
356 		if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
357 			return memcpy(&ut, utx, sizeof(ut));
358 		return NULL;
359 	}
360 
361 }
362 
363 /*
364  * The following are extensions and not part of the X/Open spec.
365  */
366 void
updwtmpx(const char * file,const struct utmpx * utx)367 updwtmpx(const char *file, const struct utmpx *utx)
368 {
369 	(void)_updwtmpx(file, utx);
370 }
371 
372 int
_updwtmpx(const char * file,const struct utmpx * utx)373 _updwtmpx(const char *file, const struct utmpx *utx)
374 {
375 	int fd;
376 	int saved_errno;
377 	struct stat st;
378 
379 	_DIAGASSERT(file != NULL);
380 	_DIAGASSERT(utx != NULL);
381 
382 	fd = _open(file, O_WRONLY|O_APPEND|O_SHLOCK|O_CLOEXEC);
383 
384 	if (fd == -1) {
385 		if ((fd = _open(file, O_CREAT|O_WRONLY|O_EXLOCK|O_CLOEXEC, 0644)) == -1)
386 			goto fail;
387 	}
388 	if (_fstat(fd, &st) == -1)
389 		goto failclose;
390 	if (st.st_size == 0) {
391 		/* new file, add signature record */
392 		(void)memset(&ut, 0, sizeof(ut));
393 		ut.ut_type = SIGNATURE;
394 		(void)memcpy(ut.ut_user, vers, sizeof(vers));
395 		if (_write(fd, &ut, sizeof(ut)) == -1)
396 			goto failclose;
397 	}
398 	if (_write(fd, utx, sizeof(*utx)) == -1)
399 		goto failclose;
400 	if (_close(fd) == -1)
401 		return -1;
402 	return 0;
403 
404 failclose:
405 	saved_errno = errno;
406 	(void) _close(fd);
407 	errno = saved_errno;
408 fail:
409 	return -1;
410 }
411 
412 int
utmpxname(const char * fname)413 utmpxname(const char *fname)
414 {
415 	size_t len;
416 
417 	_DIAGASSERT(fname != NULL);
418 
419 	len = strlen(fname);
420 
421 	if (len >= sizeof(utfile))
422 		return 0;
423 
424 	/* must end in x! */
425 	if (fname[len - 1] != 'x')
426 		return 0;
427 
428 	(void)strlcpy(utfile, fname, sizeof(utfile));
429 	endutxent();
430 	return 1;
431 }
432 
433 
434 __sym_compat(getutmp, past_getutmp, DF404.0);
435 void
past_getutmp(void * ux __unused,void * u __unused)436 past_getutmp(void *ux __unused, void *u __unused)
437 {
438 }
439 
440 __sym_compat(getutmpx, past_getutmpx, DF404.0);
441 void
past_getutmpx(void * u __unused,void * ux __unused)442 past_getutmpx(void *u __unused, void *ux __unused)
443 {
444 }
445 
446 struct lastlogx *
getlastlogx(const char * fname,uid_t uid,struct lastlogx * ll)447 getlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
448 {
449 	DBT key, data;
450 	DB *db;
451 
452 	_DIAGASSERT(fname != NULL);
453 	_DIAGASSERT(ll != NULL);
454 
455 	db = dbopen(fname, O_RDONLY|O_SHLOCK|O_CLOEXEC, 0, DB_HASH, NULL);
456 
457 	if (db == NULL)
458 		return NULL;
459 
460 	key.data = &uid;
461 	key.size = sizeof(uid);
462 
463 	if ((db->get)(db, &key, &data, 0) != 0)
464 		goto error;
465 
466 	if (data.size != sizeof(*ll)) {
467 		errno = EFTYPE;
468 		goto error;
469 	}
470 
471 	if (ll == NULL)
472 		if ((ll = malloc(sizeof(*ll))) == NULL)
473 			goto done;
474 
475 	(void)memcpy(ll, data.data, sizeof(*ll));
476 	goto done;
477 error:
478 	ll = NULL;
479 done:
480 	(db->close)(db);
481 	return ll;
482 }
483 
484 int
updlastlogx(const char * fname,uid_t uid,struct lastlogx * ll)485 updlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
486 {
487 	DBT key, data;
488 	int error = 0;
489 	DB *db;
490 
491 	_DIAGASSERT(fname != NULL);
492 	_DIAGASSERT(ll != NULL);
493 
494 	db = dbopen(fname, O_RDWR|O_CREAT|O_EXLOCK|O_CLOEXEC, 0644, DB_HASH, NULL);
495 
496 	if (db == NULL)
497 		return -1;
498 
499 	key.data = &uid;
500 	key.size = sizeof(uid);
501 	data.data = ll;
502 	data.size = sizeof(*ll);
503 	if ((db->put)(db, &key, &data, 0) != 0)
504 		error = -1;
505 
506 	(db->close)(db);
507 	return error;
508 }
509