xref: /netbsd-src/lib/libpam/modules/pam_lastlog/pam_lastlog.c (revision ba65fde2d7fefa7d39838fa5fa855e62bd606b5e)
1 /*	$NetBSD: pam_lastlog.c,v 1.14 2012/01/03 19:02:55 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 2001 Mark R V Murray
7  * All rights reserved.
8  * Copyright (c) 2001 Networks Associates Technology, Inc.
9  * All rights reserved.
10  * Copyright (c) 2004 Joe R. Doupnik
11  * All rights reserved.
12  *
13  * Portions of this software were developed for the FreeBSD Project by
14  * ThinkSec AS and NAI Labs, the Security Research Division of Network
15  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
16  * ("CBOSS"), as part of the DARPA CHATS research program.
17  *
18  * Redistribution and use in source and binary forms, with or without
19  * modification, are permitted provided that the following conditions
20  * are met:
21  * 1. Redistributions of source code must retain the above copyright
22  *    notice, this list of conditions and the following disclaimer.
23  * 2. Redistributions in binary form must reproduce the above copyright
24  *    notice, this list of conditions and the following disclaimer in the
25  *    documentation and/or other materials provided with the distribution.
26  * 3. The name of the author may not be used to endorse or promote
27  *    products derived from this software without specific prior written
28  *    permission.
29  * 4. Neither the name of the University nor the names of its contributors
30  *    may be used to endorse or promote products derived from this software
31  *    without specific prior written permission.
32  *
33  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
34  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
37  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43  * SUCH DAMAGE.
44  */
45 
46 #include <sys/cdefs.h>
47 #ifdef __FreeBSD__
48 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_lastlog/pam_lastlog.c,v 1.20 2004/01/26 19:28:37 des Exp $");
49 #else
50 __RCSID("$NetBSD: pam_lastlog.c,v 1.14 2012/01/03 19:02:55 christos Exp $");
51 #endif
52 
53 #include <sys/param.h>
54 
55 #include <fcntl.h>
56 #include <util.h>
57 #include <paths.h>
58 #include <pwd.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <syslog.h>
63 #include <errno.h>
64 #include <time.h>
65 #include <unistd.h>
66 #include <stdarg.h>
67 #ifdef LOGIN_CAP
68 #include <login_cap.h>
69 #endif
70 
71 #define PAM_SM_SESSION
72 
73 #include <security/pam_appl.h>
74 #include <security/pam_modules.h>
75 #include <security/pam_mod_misc.h>
76 
77 #ifdef SUPPORT_UTMP
78 #include <utmp.h>
79 static void doutmp(const char *, const char *, const char *,
80     const struct timeval *);
81 static void dolastlog(pam_handle_t *, int, const struct passwd *, const char *,
82     const char *, const struct timeval *);
83 #endif
84 
85 #ifdef SUPPORT_UTMPX
86 #include <utmpx.h>
87 static void doutmpx(const char *, const char *, const char *,
88     const struct sockaddr_storage *ss, const struct timeval *);
89 static void dolastlogx(pam_handle_t *, int, const struct passwd *, const char *,
90     const char *, const struct sockaddr_storage *ss, const struct timeval *);
91 #endif
92 
93 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
94 static void domsg(pam_handle_t *, time_t, const char *, size_t, const char *,
95     size_t);
96 #endif
97 
98 static void
99 logit(int level, const char *fmt, ...)
100 {
101 	va_list ap;
102 	struct syslog_data data = SYSLOG_DATA_INIT;
103 
104 	openlog_r("pam_lastlog", LOG_PID, LOG_AUTHPRIV, &data);
105 	va_start(ap, fmt);
106 	vsyslog_r(level, &data, fmt, ap);
107 	va_end(ap);
108 	closelog_r(&data);
109 }
110 
111 
112 PAM_EXTERN int
113 pam_sm_open_session(pam_handle_t *pamh, int flags,
114     int argc __unused, const char *argv[] __unused)
115 {
116 	struct passwd *pwd, pwres;
117 	struct timeval now;
118 	const char *user, *rhost, *tty, *nuser;
119 	const void *vrhost, *vtty, *vss, *vnuser;
120 	const struct sockaddr_storage *ss;
121 	int pam_err;
122 	char pwbuf[1024];
123 #ifdef LOGIN_CAP
124 	login_cap_t *lc;
125 #endif
126 
127 	pam_err = pam_get_user(pamh, &user, NULL);
128 	if (pam_err != PAM_SUCCESS)
129 		return pam_err;
130 
131 	if (user == NULL ||
132 	    getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
133 	    pwd == NULL)
134 		return PAM_SERVICE_ERR;
135 
136 	PAM_LOG("Got user: %s", user);
137 
138 	pam_err = pam_get_item(pamh, PAM_RHOST, &vrhost);
139 	if (pam_err != PAM_SUCCESS)
140 		goto err;
141 	rhost = (const char *)vrhost;
142 
143 	pam_err = pam_get_item(pamh, PAM_SOCKADDR, &vss);
144 	if (pam_err != PAM_SUCCESS)
145 		goto err;
146 	ss = (const struct sockaddr_storage *)vss;
147 
148 	pam_err = pam_get_item(pamh, PAM_TTY, &vtty);
149 	if (pam_err != PAM_SUCCESS)
150 		goto err;
151 	tty = (const char *)vtty;
152 
153 	if (tty == NULL) {
154 		pam_err = PAM_SERVICE_ERR;
155 		goto err;
156 	}
157 
158 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
159 		nuser = NULL;
160 	else
161 		nuser = (const char *)vnuser;
162 
163 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
164 		tty = tty + strlen(_PATH_DEV);
165 
166 	if (*tty == '\0') {
167 		pam_err = PAM_SERVICE_ERR;
168 		goto err;
169 	}
170 
171 	(void)gettimeofday(&now, NULL);
172 
173 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
174 		int quiet;
175 		if ((flags & PAM_SILENT) != 0)
176 			quiet = 1;
177 		else {
178 #ifdef LOGIN_CAP
179 			lc = login_getpwclass(pwd);
180 			quiet = login_getcapbool(lc, "hushlogin", 0);
181 			login_close(lc);
182 #else
183 			quiet = 0;
184 #endif
185 		}
186 #ifdef SUPPORT_UTMPX
187 		doutmpx(user, rhost, tty, ss, &now);
188 		dolastlogx(pamh, quiet, pwd, rhost, tty, ss, &now);
189 		quiet = 1;
190 #endif
191 #ifdef SUPPORT_UTMP
192 		doutmp(user, rhost, tty, &now);
193 		dolastlog(pamh, quiet, pwd, rhost, tty, &now);
194 #endif
195 	}
196 err:
197 	if (openpam_get_option(pamh, "no_fail"))
198 		return PAM_SUCCESS;
199 	return pam_err;
200 }
201 
202 PAM_EXTERN int
203 pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
204     int argc __unused, const char *argv[] __unused)
205 {
206 	const void *vtty, *vnuser;
207 	const char *tty, *nuser;
208 
209 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
210 		nuser = NULL;
211 	else
212 		nuser = (const char *)vnuser;
213 
214 	pam_get_item(pamh, PAM_TTY, &vtty);
215 	if (vtty == NULL)
216 		return PAM_SERVICE_ERR;
217 	tty = (const char *)vtty;
218 
219 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
220 		tty = tty + strlen(_PATH_DEV);
221 
222 	if (*tty == '\0')
223 		return PAM_SERVICE_ERR;
224 
225 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
226 
227 #ifdef SUPPORT_UTMPX
228 		if (logoutx(tty, 0, DEAD_PROCESS))
229 			logwtmpx(tty, "", "", 0, DEAD_PROCESS);
230 		else
231 			logit(LOG_NOTICE, "%s(): no utmpx record for %s",
232 			    __func__, tty);
233 #endif
234 
235 #ifdef SUPPORT_UTMP
236 		if (logout(tty))
237 			logwtmp(tty, "", "");
238 		else
239 			logit(LOG_NOTICE, "%s(): no utmp record for %s",
240 			    __func__, tty);
241 #endif
242 	}
243         return PAM_SUCCESS;
244 }
245 
246 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
247 static void
248 domsg(pam_handle_t *pamh, time_t t, const char *host, size_t hsize,
249     const char *line, size_t lsize)
250 {
251 	char buf[MAXHOSTNAMELEN + 32], *promptresp = NULL;
252 	int pam_err;
253 
254 	if (*host) {
255 		(void)snprintf(buf, sizeof(buf), "from %.*s ",
256 		    (int)hsize, host);
257 		host = buf;
258 	}
259 
260 	pam_err = pam_prompt(pamh, PAM_TEXT_INFO, &promptresp,
261 	    "Last login: %.24s %son %.*s\n", ctime(&t), host, (int)lsize, line);
262 
263 	if (pam_err == PAM_SUCCESS && promptresp)
264 		free(promptresp);
265 }
266 #endif
267 
268 #ifdef SUPPORT_UTMPX
269 static void
270 doutmpx(const char *username, const char *hostname, const char *tty,
271     const struct sockaddr_storage *ss, const struct timeval *now)
272 {
273 	struct utmpx utmpx;
274 	const char *t;
275 
276 	memset((void *)&utmpx, 0, sizeof(utmpx));
277 	utmpx.ut_tv = *now;
278 	(void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
279 	if (hostname) {
280 		(void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
281 		if (ss)
282 			utmpx.ut_ss = *ss;
283 	}
284 	(void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
285 	utmpx.ut_type = USER_PROCESS;
286 	utmpx.ut_pid = getpid();
287 	t = tty + strlen(tty);
288 	if ((size_t)(t - tty) >= sizeof(utmpx.ut_id)) {
289 		(void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
290 		    sizeof(utmpx.ut_id));
291 	} else {
292 		(void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
293 	}
294 	if (pututxline(&utmpx) == NULL)
295 		logit(LOG_NOTICE, "Cannot update utmpx: %s", strerror(errno));
296 	endutxent();
297 	if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
298 		logit(LOG_NOTICE, "Cannot update wtmpx: %s", strerror(errno));
299 }
300 
301 static void
302 dolastlogx(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
303     const char *hostname, const char *tty, const struct sockaddr_storage *ss,
304     const struct timeval *now)
305 {
306 	struct lastlogx ll;
307 	if (!quiet) {
308 	    if (getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL)
309 		    domsg(pamh, (time_t)ll.ll_tv.tv_sec, ll.ll_host,
310 			sizeof(ll.ll_host), ll.ll_line,
311 			sizeof(ll.ll_line));
312 	}
313 	ll.ll_tv = *now;
314 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
315 
316 	if (hostname)
317 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
318 	else
319 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
320 
321 	if (ss)
322 		ll.ll_ss = *ss;
323 	else
324 		(void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
325 
326 	if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
327 		logit(LOG_NOTICE, "Cannot update lastlogx: %s", strerror(errno));
328 	PAM_LOG("Login recorded in %s", _PATH_LASTLOGX);
329 }
330 #endif
331 
332 #ifdef SUPPORT_UTMP
333 static void
334 doutmp(const char *username, const char *hostname, const char *tty,
335     const struct timeval *now)
336 {
337 	struct utmp utmp;
338 
339 	(void)memset((void *)&utmp, 0, sizeof(utmp));
340 	utmp.ut_time = now->tv_sec;
341 	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
342 	if (hostname)
343 		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
344 	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
345 	login(&utmp);
346 }
347 
348 static void
349 dolastlog(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
350     const char *hostname, const char *tty, const struct timeval *now)
351 {
352 	struct lastlog ll;
353 	int fd;
354 
355 	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) == -1) {
356 		logit(LOG_NOTICE, "Cannot open `%s': %s", _PATH_LASTLOG,
357 		    strerror(errno));
358 		return;
359 	}
360 	(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
361 
362 	if (!quiet) {
363 		if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
364 		    ll.ll_time != 0)
365 			domsg(pamh, ll.ll_time, ll.ll_host,
366 			    sizeof(ll.ll_host), ll.ll_line,
367 			    sizeof(ll.ll_line));
368 		(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
369 	}
370 
371 	ll.ll_time = now->tv_sec;
372 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
373 
374 	if (hostname)
375 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
376 	else
377 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
378 
379 	(void)write(fd, &ll, sizeof(ll));
380 	(void)close(fd);
381 
382 	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
383 }
384 #endif
385 
386 PAM_MODULE_ENTRY("pam_lastlog");
387