xref: /netbsd-src/lib/libc/gen/utmpx.c (revision 08c81a9c2dc8c7300e893321eb65c0925d60871c)
1 /*	$NetBSD: utmpx.c,v 1.10 2002/07/28 00:45:11 christos Exp $	 */
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 #include <sys/cdefs.h>
39 
40 #if defined(LIBC_SCCS) && !defined(lint)
41 __RCSID("$NetBSD: utmpx.c,v 1.10 2002/07/28 00:45:11 christos Exp $");
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #include <sys/wait.h>
47 #include <sys/socket.h>
48 #include <sys/time.h>
49 #include <sys/stat.h>
50 
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <vis.h>
55 #include <utmp.h>
56 #include <utmpx.h>
57 #include <unistd.h>
58 #include <fcntl.h>
59 #include <errno.h>
60 #include <db.h>
61 
62 static FILE *fp;
63 static struct utmpx ut;
64 static char utfile[MAXPATHLEN] = _PATH_UTMPX;
65 static char llfile[MAXPATHLEN] = _PATH_LASTLOGX;
66 
67 static struct utmpx *utmp_update(const struct utmpx *);
68 
69 static const char vers[] = "utmpx-1.00";
70 
71 void
72 setutxent()
73 {
74 
75 	(void)memset(&ut, 0, sizeof(ut));
76 	if (fp == NULL)
77 		return;
78 	(void)fseeko(fp, (off_t)sizeof(ut), SEEK_SET);
79 }
80 
81 
82 void
83 endutxent()
84 {
85 
86 	(void)memset(&ut, 0, sizeof(ut));
87 	if (fp != NULL) {
88 		(void)fclose(fp);
89 		fp = NULL;
90 	}
91 }
92 
93 
94 struct utmpx *
95 getutxent()
96 {
97 
98 	if (fp == NULL) {
99 		struct stat st;
100 
101 		if ((fp = fopen(utfile, "r+")) == NULL)
102 			if ((fp = fopen(utfile, "w+")) == NULL)
103 				if ((fp = fopen(utfile, "r")) == NULL)
104 					goto fail;
105 
106 		/* get file size in order to check if new file */
107 		if (fstat(fileno(fp), &st) == -1)
108 			goto failclose;
109 
110 		if (st.st_size == 0) {
111 			/* new file, add signature record */
112 			(void)memset(&ut, 0, sizeof(ut));
113 			ut.ut_type = SIGNATURE;
114 			(void)memcpy(ut.ut_user, vers, sizeof(vers));
115 			if (fwrite(&ut, sizeof(ut), 1, fp) != 1)
116 				goto failclose;
117 		} else {
118 			/* old file, read signature record */
119 			if (fread(&ut, sizeof(ut), 1, fp) != 1)
120 				goto failclose;
121 			if (memcmp(ut.ut_user, vers, sizeof(vers)) != 0 ||
122 			    ut.ut_type != SIGNATURE)
123 				goto failclose;
124 		}
125 	}
126 
127 	if (fread(&ut, sizeof(ut), 1, fp) != 1)
128 		goto fail;
129 
130 	return &ut;
131 failclose:
132 	(void)fclose(fp);
133 fail:
134 	(void)memset(&ut, 0, sizeof(ut));
135 	return NULL;
136 }
137 
138 
139 struct utmpx *
140 getutxid(const struct utmpx *utx)
141 {
142 
143 	if (utx->ut_type == EMPTY)
144 		return NULL;
145 
146 	do {
147 		if (ut.ut_type == EMPTY)
148 			continue;
149 		switch (utx->ut_type) {
150 		case EMPTY:
151 			return NULL;
152 		case RUN_LVL:
153 		case BOOT_TIME:
154 		case OLD_TIME:
155 		case NEW_TIME:
156 			if (ut.ut_type == utx->ut_type)
157 				return &ut;
158 			break;
159 		case INIT_PROCESS:
160 		case LOGIN_PROCESS:
161 		case USER_PROCESS:
162 		case DEAD_PROCESS:
163 			switch (ut.ut_type) {
164 			case INIT_PROCESS:
165 			case LOGIN_PROCESS:
166 			case USER_PROCESS:
167 			case DEAD_PROCESS:
168 				if (memcmp(ut.ut_id, utx->ut_id,
169 				    sizeof(ut.ut_id)) == 0)
170 					return &ut;
171 				break;
172 			default:
173 				break;
174 			}
175 			break;
176 		default:
177 			return NULL;
178 		}
179 	} while (getutxent() != NULL);
180 	return NULL;
181 }
182 
183 
184 struct utmpx *
185 getutxline(const struct utmpx *utx)
186 {
187 
188 	do {
189 		switch (ut.ut_type) {
190 		case EMPTY:
191 			break;
192 		case LOGIN_PROCESS:
193 		case USER_PROCESS:
194 			if (strncmp(ut.ut_line, utx->ut_line,
195 			    sizeof(ut.ut_line)) == 0)
196 				return &ut;
197 			break;
198 		default:
199 			break;
200 		}
201 	} while (getutxent() != NULL);
202 	return NULL;
203 }
204 
205 
206 struct utmpx *
207 pututxline(const struct utmpx *utx)
208 {
209 	struct utmpx temp, *u = NULL;
210 	int gotlock = 0;
211 
212 	if (strcmp(_PATH_UTMPX, utfile) == 0 && geteuid() != 0)
213 		return utmp_update(utx);
214 
215 	if (utx == NULL)
216 		return NULL;
217 
218 	(void)memcpy(&temp, utx, sizeof(temp));
219 
220 	if (fp == NULL) {
221 		(void)getutxent();
222 		if (fp == NULL)
223 			return NULL;
224 	}
225 
226 	if (getutxid(&temp) == NULL) {
227 		setutxent();
228 		if (getutxid(&temp) == NULL) {
229 			if (lockf(fileno(fp), F_LOCK, (off_t)0) == -1)
230 				return NULL;
231 			gotlock++;
232 			if (fseeko(fp, (off_t)0, SEEK_END) == -1)
233 				goto fail;
234 		}
235 	}
236 
237 	if (!gotlock) {
238 		/* we are not appending */
239 		if (fseeko(fp, -(off_t)sizeof(ut), SEEK_CUR) == -1)
240 			return NULL;
241 	}
242 
243 	if (fwrite(&temp, sizeof (temp), 1, fp) != 1)
244 		goto fail;
245 
246 	if (fflush(fp) == -1)
247 		goto fail;
248 
249 	u = memcpy(&ut, &temp, sizeof(ut));
250 fail:
251 	if (gotlock) {
252 		if (lockf(fileno(fp), F_ULOCK, (off_t)0) == -1)
253 			return NULL;
254 	}
255 	return u;
256 }
257 
258 
259 static struct utmpx *
260 utmp_update(const struct utmpx *utx)
261 {
262 	char buf[sizeof(*utx) * 4 + 1];
263 	pid_t pid;
264 	int status;
265 
266 	(void)strvisx(buf, (const char *)(const void *)utx, sizeof(*utx),
267 	    VIS_WHITE);
268 	switch (pid = fork()) {
269 	case 0:
270 		(void)execl(_PATH_UTMP_UPDATE,
271 		    strrchr(_PATH_UTMP_UPDATE, '/') + 1, buf);
272 		exit(1);
273 		/*NOTREACHED*/
274 	case -1:
275 		return NULL;
276 	default:
277 		if (waitpid(pid, &status, 0) == -1)
278 			return NULL;
279 		if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
280 			return memcpy(&ut, utx, sizeof(ut));
281 		return NULL;
282 	}
283 
284 }
285 
286 int
287 updwtmpx(const char *file, const struct utmpx *utx)
288 {
289 	int fd = open(file, O_WRONLY|O_APPEND|O_EXLOCK);
290 
291 	if (fd == -1) {
292 		if ((fd = open(file, O_CREAT|O_WRONLY|O_EXLOCK, 0644)) == -1)
293 			return -1;
294 		(void)memset(&ut, 0, sizeof(ut));
295 		ut.ut_type = SIGNATURE;
296 		(void)memcpy(ut.ut_user, vers, sizeof(vers));
297 		(void)write(fd, &ut, sizeof(ut));
298 	}
299 	(void)write(fd, utx, sizeof(*utx));
300 	(void)close(fd);
301 	return 0;
302 }
303 
304 
305 /*
306  * The following are extensions and not part of the X/Open spec
307  */
308 int
309 utmpxname(const char *fname)
310 {
311 	size_t len = strlen(fname);
312 
313 	if (len >= sizeof(utfile))
314 		return 0;
315 
316 	/* must end in x! */
317 	if (fname[len - 1] != 'x')
318 		return 0;
319 
320 	(void)strcpy(utfile, fname);
321 	endutxent();
322 	return 1;
323 }
324 
325 
326 void
327 getutmp(const struct utmpx *ux, struct utmp *u)
328 {
329 
330 	(void)memcpy(u->ut_name, ux->ut_name, sizeof(u->ut_name));
331 	(void)memcpy(u->ut_line, ux->ut_line, sizeof(u->ut_line));
332 	(void)memcpy(u->ut_host, ux->ut_host, sizeof(u->ut_host));
333 	u->ut_time = ux->ut_tv.tv_sec;
334 }
335 
336 void
337 getutmpx(const struct utmp *u, struct utmpx *ux)
338 {
339 
340 	(void)memcpy(ux->ut_name, u->ut_name, sizeof(u->ut_name));
341 	(void)memcpy(ux->ut_line, u->ut_line, sizeof(u->ut_line));
342 	(void)memcpy(ux->ut_host, u->ut_host, sizeof(u->ut_host));
343 	ux->ut_tv.tv_sec = u->ut_time;
344 	ux->ut_tv.tv_usec = 0;
345 	(void)memset(&ux->ut_ss, 0, sizeof(ux->ut_ss));
346 	ux->ut_pid = 0;
347 	ux->ut_type = USER_PROCESS;
348 	ux->ut_session = 0;
349 	ux->ut_exit.e_termination = 0;
350 	ux->ut_exit.e_exit = 0;
351 }
352 
353 int
354 lastlogxname(const char *fname)
355 {
356 	size_t len = strlen(fname);
357 
358 	if (len >= sizeof(llfile))
359 		return 0;
360 
361 	/* must end in x! */
362 	if (fname[len - 1] != 'x')
363 		return 0;
364 
365 	(void)strcpy(llfile, fname);
366 	return 1;
367 }
368 
369 struct lastlogx *
370 getlastlogx(uid_t uid, struct lastlogx *ll)
371 {
372 	DBT key, data;
373 	DB *db = dbopen(llfile, O_RDONLY|O_SHLOCK, 0, DB_HASH, NULL);
374 
375 	if (db == NULL)
376 		return NULL;
377 
378 	key.data = &uid;
379 	key.size = sizeof(uid);
380 
381 	if ((db->get)(db, &key, &data, 0) != 0)
382 		goto error;
383 
384 	if (data.size != sizeof(*ll)) {
385 		errno = EFTYPE;
386 		goto error;
387 	}
388 
389 	if (ll == NULL)
390 		if ((ll = malloc(sizeof(*ll))) == NULL)
391 			goto done;
392 
393 	(void)memcpy(ll, data.data, sizeof(*ll));
394 	goto done;
395 error:
396 	ll = NULL;
397 done:
398 	(db->close)(db);
399 	return ll;
400 }
401 
402 int
403 updlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
404 {
405 	DBT key, data;
406 	int error = 0;
407 	DB *db = dbopen(fname, O_RDWR|O_CREAT|O_EXLOCK, 0, DB_HASH, NULL);
408 
409 	if (db == NULL)
410 		return -1;
411 
412 	key.data = &uid;
413 	key.size = sizeof(uid);
414 	data.data = ll;
415 	data.size = sizeof(*ll);
416 	if ((db->put)(db, &key, &data, 0) != 0)
417 		error = -1;
418 
419 	(db->close)(db);
420 	return error;
421 }
422