xref: /dragonfly/lib/libc/gen/utmpx.c (revision 7c4f4eee)
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 <db.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <pwd.h>
47 #include <utmpx.h>
48 #include <vis.h>
49 
50 static FILE *fp;
51 static int readonly = 0;
52 static struct utmpx ut;
53 static char utfile[MAXPATHLEN] = _PATH_UTMPX;
54 
55 static struct utmpx *utmp_update(const struct utmpx *);
56 
57 static const char vers[] = "utmpx-2.00";
58 static utx_db_t dbtype = UTX_DB_UTMPX;
59 DB *lastlogx_db = NULL;
60 
61 static int
62 _open_db(const char *fname)
63 {
64 	struct stat st;
65 
66 	if ((fp = fopen(fname, "re+")) == NULL)
67 		if ((fp = fopen(fname, "we+")) == NULL) {
68 			if ((fp = fopen(fname, "re")) == NULL)
69 				goto fail;
70 			else
71 				readonly = 1;
72 		}
73 
74 	/* get file size in order to check if new file */
75 	if (fstat(fileno(fp), &st) == -1)
76 		goto failclose;
77 
78 	if (st.st_size == 0) {
79 		/* new file, add signature record */
80 		(void)memset(&ut, 0, sizeof(ut));
81 		ut.ut_type = SIGNATURE;
82 		(void)memcpy(ut.ut_user, vers, sizeof(vers));
83 		if (fwrite(&ut, sizeof(ut), 1, fp) != 1)
84 			goto failclose;
85 	} else {
86 		/* old file, read signature record */
87 		if (fread(&ut, sizeof(ut), 1, fp) != 1)
88 			goto failclose;
89 		if (memcmp(ut.ut_user, vers, 5) != 0 ||
90 		    ut.ut_type != SIGNATURE) {
91 			errno = EINVAL;
92 			goto failclose;
93 		}
94 	}
95 
96 	return 0;
97 failclose:
98 	(void)fclose(fp);
99 fail:
100 	(void)memset(&ut, 0, sizeof(ut));
101 	return -1;
102 }
103 
104 int
105 setutxdb(utx_db_t db_type, const char *fname)
106 {
107 	switch (db_type) {
108 	case UTX_DB_UTMPX:
109 		if (fname == NULL)
110 			fname = _PATH_UTMPX;
111 		break;
112 
113 	case UTX_DB_WTMPX:
114 		if (fname == NULL)
115 			fname = _PATH_WTMPX;
116 		break;
117 
118 	default:
119 		errno = EINVAL;
120 		return -1;
121 	}
122 
123 	/* A previous db file is still open */
124 	if (fp != NULL) {
125 		fclose(fp);
126 		fp = NULL;
127 	}
128 	if ((_open_db(fname)) == -1)
129 		return -1;
130 
131 	dbtype = db_type;
132 	return 0;
133 }
134 
135 void
136 setutxent(void)
137 {
138 	(void)memset(&ut, 0, sizeof(ut));
139 	if (fp == NULL)
140 		return;
141 	(void)fseeko(fp, (off_t)sizeof(ut), SEEK_SET);
142 }
143 
144 void
145 endutxent(void)
146 {
147 	(void)memset(&ut, 0, sizeof(ut));
148 
149 	if (fp != NULL) {
150 		(void)fclose(fp);
151 		fp = NULL;
152 		readonly = 0;
153 	}
154 }
155 
156 struct utmpx *
157 getutxent(void)
158 {
159 	if (fp == NULL) {
160 		if ((_open_db(utfile)) == -1)
161 			goto fail;
162 	}
163 
164 	if (fread(&ut, sizeof(ut), 1, fp) != 1)
165 		goto fail;
166 
167 	return &ut;
168 fail:
169 	(void)memset(&ut, 0, sizeof(ut));
170 	return NULL;
171 }
172 
173 struct utmpx *
174 getutxid(const struct utmpx *utx)
175 {
176 
177 	_DIAGASSERT(utx != NULL);
178 
179 	if (utx->ut_type == EMPTY)
180 		return NULL;
181 
182 	do {
183 		if (ut.ut_type == EMPTY)
184 			continue;
185 		switch (utx->ut_type) {
186 		case EMPTY:
187 			return NULL;
188 		case RUN_LVL:
189 		case BOOT_TIME:
190 		case OLD_TIME:
191 		case NEW_TIME:
192 			if (ut.ut_type == utx->ut_type)
193 				return &ut;
194 			break;
195 		case INIT_PROCESS:
196 		case LOGIN_PROCESS:
197 		case USER_PROCESS:
198 		case DEAD_PROCESS:
199 			switch (ut.ut_type) {
200 			case INIT_PROCESS:
201 			case LOGIN_PROCESS:
202 			case USER_PROCESS:
203 			case DEAD_PROCESS:
204 				if (memcmp(ut.ut_id, utx->ut_id,
205 				    sizeof(ut.ut_id)) == 0)
206 					return &ut;
207 				break;
208 			default:
209 				break;
210 			}
211 			break;
212 		default:
213 			return NULL;
214 		}
215 	} while (getutxent() != NULL);
216 	return NULL;
217 }
218 
219 struct utmpx *
220 getutxline(const struct utmpx *utx)
221 {
222 
223 	_DIAGASSERT(utx != NULL);
224 
225 	do {
226 		switch (ut.ut_type) {
227 		case EMPTY:
228 			break;
229 		case LOGIN_PROCESS:
230 		case USER_PROCESS:
231 			if (strncmp(ut.ut_line, utx->ut_line,
232 			    sizeof(ut.ut_line)) == 0)
233 				return &ut;
234 			break;
235 		default:
236 			break;
237 		}
238 	} while (getutxent() != NULL);
239 	return NULL;
240 }
241 
242 struct utmpx *
243 getutxuser(const char *user)
244 {
245 	_DIAGASSERT(utx != NULL);
246 
247 	do {
248 		switch (ut.ut_type) {
249 		case EMPTY:
250 			break;
251 		case USER_PROCESS:
252 			if (strncmp(ut.ut_user, user, sizeof(ut.ut_user)) == 0)
253 				return &ut;
254 			break;
255 		default:
256 			break;
257 		}
258 	} while (getutxent() != NULL);
259 	return NULL;
260 }
261 
262 struct utmpx *
263 pututxline(const struct utmpx *utx)
264 {
265 	struct passwd *pw;
266 	struct lastlogx ll;
267 	struct utmpx temp, *u = NULL;
268 	int gotlock = 0;
269 
270 	_DIAGASSERT(utx != NULL);
271 
272 	if (utx == NULL)
273 		return NULL;
274 
275 	if (utx->ut_type == USER_PROCESS) {
276 		ll.ll_tv = utx->ut_tv;
277 		strcpy(ll.ll_host, utx->ut_host);
278 		strcpy(ll.ll_line, utx->ut_line);
279 		pw = getpwnam(utx->ut_name);
280 		if (pw != NULL)
281 			updlastlogx(_PATH_LASTLOGX, pw->pw_uid, &ll);
282 	}
283 
284 	if (strcmp(_PATH_UTMPX, utfile) == 0)
285 		if ((fp != NULL && readonly) || (fp == NULL && geteuid() != 0))
286 			return utmp_update(utx);
287 
288 
289 	(void)memcpy(&temp, utx, sizeof(temp));
290 
291 	if (fp == NULL) {
292 		(void)getutxent();
293 		if (fp == NULL || readonly)
294 			return NULL;
295 	}
296 
297 	if (getutxid(&temp) == NULL) {
298 		setutxent();
299 		if (getutxid(&temp) == NULL) {
300 			if (lockf(fileno(fp), F_LOCK, (off_t)0) == -1)
301 				return NULL;
302 			gotlock++;
303 			if (fseeko(fp, (off_t)0, SEEK_END) == -1)
304 				goto fail;
305 		}
306 	}
307 
308 	if (!gotlock) {
309 		/* we are not appending */
310 		if (fseeko(fp, -(off_t)sizeof(ut), SEEK_CUR) == -1)
311 			return NULL;
312 	}
313 
314 	if (fwrite(&temp, sizeof (temp), 1, fp) != 1)
315 		goto fail;
316 
317 	if (fflush(fp) == -1)
318 		goto fail;
319 
320 	u = memcpy(&ut, &temp, sizeof(ut));
321 fail:
322 	if (gotlock) {
323 		if (lockf(fileno(fp), F_ULOCK, (off_t)0) == -1)
324 			return NULL;
325 	}
326 	return u;
327 }
328 
329 static struct utmpx *
330 utmp_update(const struct utmpx *utx)
331 {
332 	char buf[sizeof(*utx) * 4 + 1];
333 	pid_t pid;
334 	int status;
335 
336 	_DIAGASSERT(utx != NULL);
337 
338 	(void)strvisx(buf, (const char *)(const void *)utx, sizeof(*utx),
339 	    VIS_WHITE | VIS_NOLOCALE);
340 	switch (pid = fork()) {
341 	case 0:
342 		(void)execl(_PATH_UTMP_UPDATE,
343 		    strrchr(_PATH_UTMP_UPDATE, '/') + 1, buf, NULL);
344 		_exit(1);
345 		/*NOTREACHED*/
346 	case -1:
347 		return NULL;
348 	default:
349 		if (waitpid(pid, &status, 0) == -1)
350 			return NULL;
351 		if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
352 			return memcpy(&ut, utx, sizeof(ut));
353 		return NULL;
354 	}
355 
356 }
357 
358 /*
359  * The following are extensions and not part of the X/Open spec.
360  */
361 void
362 updwtmpx(const char *file, const struct utmpx *utx)
363 {
364 	(void)_updwtmpx(file, utx);
365 }
366 
367 int
368 _updwtmpx(const char *file, const struct utmpx *utx)
369 {
370 	int fd;
371 	int saved_errno;
372 	struct stat st;
373 
374 	_DIAGASSERT(file != NULL);
375 	_DIAGASSERT(utx != NULL);
376 
377 	fd = open(file, O_WRONLY|O_APPEND|O_SHLOCK|O_CLOEXEC);
378 
379 	if (fd == -1) {
380 		if ((fd = open(file, O_CREAT|O_WRONLY|O_EXLOCK|O_CLOEXEC, 0644)) == -1)
381 			goto fail;
382 	}
383 	if (fstat(fd, &st) == -1)
384 		goto failclose;
385 	if (st.st_size == 0) {
386 		/* new file, add signature record */
387 		(void)memset(&ut, 0, sizeof(ut));
388 		ut.ut_type = SIGNATURE;
389 		(void)memcpy(ut.ut_user, vers, sizeof(vers));
390 		if (write(fd, &ut, sizeof(ut)) == -1)
391 			goto failclose;
392 	}
393 	if (write(fd, utx, sizeof(*utx)) == -1)
394 		goto failclose;
395 	if (close(fd) == -1)
396 		return -1;
397 	return 0;
398 
399 failclose:
400 	saved_errno = errno;
401 	(void) close(fd);
402 	errno = saved_errno;
403 fail:
404 	return -1;
405 }
406 
407 int
408 utmpxname(const char *fname)
409 {
410 	size_t len;
411 
412 	_DIAGASSERT(fname != NULL);
413 
414 	len = strlen(fname);
415 
416 	if (len >= sizeof(utfile))
417 		return 0;
418 
419 	/* must end in x! */
420 	if (fname[len - 1] != 'x')
421 		return 0;
422 
423 	(void)strlcpy(utfile, fname, sizeof(utfile));
424 	endutxent();
425 	return 1;
426 }
427 
428 
429 __sym_compat(getutmp, past_getutmp, DF404.0);
430 void
431 past_getutmp(void *ux, void *u)
432 {
433 }
434 
435 __sym_compat(getutmpx, past_getutmpx, DF404.0);
436 void
437 past_getutmpx(void *u, void *ux)
438 {
439 }
440 
441 struct lastlogx *
442 getlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
443 {
444 	DBT key, data;
445 	DB *db;
446 
447 	_DIAGASSERT(fname != NULL);
448 	_DIAGASSERT(ll != NULL);
449 
450 	db = dbopen(fname, O_RDONLY|O_SHLOCK|O_CLOEXEC, 0, DB_HASH, NULL);
451 
452 	if (db == NULL)
453 		return NULL;
454 
455 	key.data = &uid;
456 	key.size = sizeof(uid);
457 
458 	if ((db->get)(db, &key, &data, 0) != 0)
459 		goto error;
460 
461 	if (data.size != sizeof(*ll)) {
462 		errno = EFTYPE;
463 		goto error;
464 	}
465 
466 	if (ll == NULL)
467 		if ((ll = malloc(sizeof(*ll))) == NULL)
468 			goto done;
469 
470 	(void)memcpy(ll, data.data, sizeof(*ll));
471 	goto done;
472 error:
473 	ll = NULL;
474 done:
475 	(db->close)(db);
476 	return ll;
477 }
478 
479 int
480 updlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
481 {
482 	DBT key, data;
483 	int error = 0;
484 	DB *db;
485 
486 	_DIAGASSERT(fname != NULL);
487 	_DIAGASSERT(ll != NULL);
488 
489 	db = dbopen(fname, O_RDWR|O_CREAT|O_EXLOCK|O_CLOEXEC, 0644, DB_HASH, NULL);
490 
491 	if (db == NULL)
492 		return -1;
493 
494 	key.data = &uid;
495 	key.size = sizeof(uid);
496 	data.data = ll;
497 	data.size = sizeof(*ll);
498 	if ((db->put)(db, &key, &data, 0) != 0)
499 		error = -1;
500 
501 	(db->close)(db);
502 	return error;
503 }
504