xref: /netbsd-src/lib/libpam/modules/pam_lastlog/pam_lastlog.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: pam_lastlog.c,v 1.12 2006/11/03 18:55:40 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 1.12 2006/11/03 18:55:40 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 <time.h>
64 #include <unistd.h>
65 #include <stdarg.h>
66 #ifdef LOGIN_CAP
67 #include <login_cap.h>
68 #endif
69 
70 #define PAM_SM_SESSION
71 
72 #include <security/pam_appl.h>
73 #include <security/pam_modules.h>
74 #include <security/pam_mod_misc.h>
75 
76 #ifdef SUPPORT_UTMP
77 #include <utmp.h>
78 static void doutmp(const char *, const char *, const char *,
79     const struct timeval *);
80 static void dolastlog(pam_handle_t *, int, const struct passwd *, const char *,
81     const char *, const struct timeval *);
82 #endif
83 
84 #ifdef SUPPORT_UTMPX
85 #include <utmpx.h>
86 static void doutmpx(const char *, const char *, const char *,
87     const struct sockaddr_storage *ss, const struct timeval *);
88 static void dolastlogx(pam_handle_t *, int, const struct passwd *, const char *,
89     const char *, const struct sockaddr_storage *ss, const struct timeval *);
90 #endif
91 
92 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
93 static void domsg(pam_handle_t *, time_t, const char *, size_t, const char *,
94     size_t);
95 #endif
96 
97 static void
98 logit(int level, const char *fmt, ...)
99 {
100 	va_list ap;
101 	struct syslog_data data = SYSLOG_DATA_INIT;
102 
103 	openlog_r("pam_lastlog", LOG_PID, LOG_AUTHPRIV, &data);
104 	va_start(ap, fmt);
105 	vsyslog_r(level, &data, fmt, ap);
106 	va_end(ap);
107 	closelog_r(&data);
108 }
109 
110 
111 PAM_EXTERN int
112 pam_sm_open_session(pam_handle_t *pamh, int flags,
113     int argc __unused, const char *argv[] __unused)
114 {
115 	struct passwd *pwd, pwres;
116 	struct timeval now;
117 	const char *user, *rhost, *tty, *nuser;
118 	const void *vrhost, *vtty, *vss, *vnuser;
119 	const struct sockaddr_storage *ss;
120 	int pam_err;
121 	char pwbuf[1024];
122 #ifdef LOGIN_CAP
123 	login_cap_t *lc;
124 #endif
125 
126 	pam_err = pam_get_user(pamh, &user, NULL);
127 	if (pam_err != PAM_SUCCESS)
128 		return pam_err;
129 
130 	if (user == NULL ||
131 	    getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
132 	    pwd == NULL)
133 		return PAM_SERVICE_ERR;
134 
135 	PAM_LOG("Got user: %s", user);
136 
137 	pam_err = pam_get_item(pamh, PAM_RHOST, &vrhost);
138 	if (pam_err != PAM_SUCCESS)
139 		goto err;
140 	rhost = (const char *)vrhost;
141 
142 	pam_err = pam_get_item(pamh, PAM_SOCKADDR, &vss);
143 	if (pam_err != PAM_SUCCESS)
144 		goto err;
145 	ss = (const struct sockaddr_storage *)vss;
146 
147 	pam_err = pam_get_item(pamh, PAM_TTY, &vtty);
148 	if (pam_err != PAM_SUCCESS)
149 		goto err;
150 	tty = (const char *)vtty;
151 
152 	if (tty == NULL) {
153 		pam_err = PAM_SERVICE_ERR;
154 		goto err;
155 	}
156 
157 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
158 		nuser = NULL;
159 	else
160 		nuser = (const char *)vnuser;
161 
162 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
163 		tty = tty + strlen(_PATH_DEV);
164 
165 	if (*tty == '\0') {
166 		pam_err = PAM_SERVICE_ERR;
167 		goto err;
168 	}
169 
170 	(void)gettimeofday(&now, NULL);
171 
172 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
173 		int quiet;
174 		if ((flags & PAM_SILENT) != 0)
175 			quiet = 1;
176 		else {
177 #ifdef LOGIN_CAP
178 			lc = login_getpwclass(pwd);
179 			quiet = login_getcapbool(lc, "hushlogin", 0);
180 			login_close(lc);
181 #else
182 			quiet = 0;
183 #endif
184 		}
185 #ifdef SUPPORT_UTMPX
186 		doutmpx(user, rhost, tty, ss, &now);
187 		dolastlogx(pamh, quiet, pwd, rhost, tty, ss, &now);
188 		quiet = 1;
189 #endif
190 #ifdef SUPPORT_UTMP
191 		doutmp(user, rhost, tty, &now);
192 		dolastlog(pamh, quiet, pwd, rhost, tty, &now);
193 #endif
194 	}
195 err:
196 	if (openpam_get_option(pamh, "no_fail"))
197 		return PAM_SUCCESS;
198 	return pam_err;
199 }
200 
201 PAM_EXTERN int
202 pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
203     int argc __unused, const char *argv[] __unused)
204 {
205 	const void *vtty, *vnuser;
206 	const char *tty, *nuser;
207 
208 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
209 		nuser = NULL;
210 	else
211 		nuser = (const char *)vnuser;
212 
213 	pam_get_item(pamh, PAM_TTY, &vtty);
214 	if (vtty == NULL)
215 		return PAM_SERVICE_ERR;
216 	tty = (const char *)vtty;
217 
218 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
219 		tty = tty + strlen(_PATH_DEV);
220 
221 	if (*tty == '\0')
222 		return PAM_SERVICE_ERR;
223 
224 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
225 
226 #ifdef SUPPORT_UTMPX
227 		if (logoutx(tty, 0, DEAD_PROCESS))
228 			logwtmpx(tty, "", "", 0, DEAD_PROCESS);
229 		else
230 			logit(LOG_NOTICE, "%s(): no utmpx record for %s",
231 			    __func__, tty);
232 #endif
233 
234 #ifdef SUPPORT_UTMP
235 		if (logout(tty))
236 			logwtmp(tty, "", "");
237 		else
238 			logit(LOG_NOTICE, "%s(): no utmp record for %s",
239 			    __func__, tty);
240 #endif
241 	}
242         return PAM_SUCCESS;
243 }
244 
245 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
246 static void
247 domsg(pam_handle_t *pamh, time_t t, const char *host, size_t hsize,
248     const char *line, size_t lsize)
249 {
250 	char buf[MAXHOSTNAMELEN + 32], *promptresp = NULL;
251 	int pam_err;
252 
253 	if (*host) {
254 		(void)snprintf(buf, sizeof(buf), "from %.*s ",
255 		    (int)hsize, host);
256 		host = buf;
257 	}
258 
259 	pam_err = pam_prompt(pamh, PAM_TEXT_INFO, &promptresp,
260 	    "Last login: %.24s %son %.*s\n", ctime(&t), host, (int)lsize, line);
261 
262 	if (pam_err == PAM_SUCCESS && promptresp)
263 		free(promptresp);
264 }
265 #endif
266 
267 #ifdef SUPPORT_UTMPX
268 static void
269 doutmpx(const char *username, const char *hostname, const char *tty,
270     const struct sockaddr_storage *ss, const struct timeval *now)
271 {
272 	struct utmpx utmpx;
273 	const char *t;
274 
275 	memset((void *)&utmpx, 0, sizeof(utmpx));
276 	utmpx.ut_tv = *now;
277 	(void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
278 	if (hostname) {
279 		(void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
280 		if (ss)
281 			utmpx.ut_ss = *ss;
282 	}
283 	(void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
284 	utmpx.ut_type = USER_PROCESS;
285 	utmpx.ut_pid = getpid();
286 	t = tty + strlen(tty);
287 	if (t - tty >= sizeof(utmpx.ut_id)) {
288 		(void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
289 		    sizeof(utmpx.ut_id));
290 	} else {
291 		(void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
292 	}
293 	if (pututxline(&utmpx) == NULL)
294 		logit(LOG_NOTICE, "Cannot update utmpx %m");
295 	endutxent();
296 	if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
297 		logit(LOG_NOTICE, "Cannot update wtmpx %m");
298 }
299 
300 static void
301 dolastlogx(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
302     const char *hostname, const char *tty, const struct sockaddr_storage *ss,
303     const struct timeval *now)
304 {
305 	struct lastlogx ll;
306 	if (!quiet) {
307 	    if (getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL)
308 		    domsg(pamh, (time_t)ll.ll_tv.tv_sec, ll.ll_host,
309 			sizeof(ll.ll_host), ll.ll_line,
310 			sizeof(ll.ll_line));
311 	}
312 	ll.ll_tv = *now;
313 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
314 
315 	if (hostname)
316 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
317 	else
318 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
319 
320 	if (ss)
321 		ll.ll_ss = *ss;
322 	else
323 		(void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
324 
325 	if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
326 		logit(LOG_NOTICE, "Cannot update lastlogx %m");
327 	PAM_LOG("Login recorded in %s", _PATH_LASTLOGX);
328 }
329 #endif
330 
331 #ifdef SUPPORT_UTMP
332 static void
333 doutmp(const char *username, const char *hostname, const char *tty,
334     const struct timeval *now)
335 {
336 	struct utmp utmp;
337 
338 	(void)memset((void *)&utmp, 0, sizeof(utmp));
339 	utmp.ut_time = now->tv_sec;
340 	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
341 	if (hostname)
342 		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
343 	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
344 	login(&utmp);
345 }
346 
347 static void
348 dolastlog(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
349     const char *hostname, const char *tty, const struct timeval *now)
350 {
351 	struct lastlog ll;
352 	int fd;
353 
354 	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) == -1) {
355 		logit(LOG_NOTICE, "Cannot open `%s' %m", _PATH_LASTLOG);
356 		return;
357 	}
358 	(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
359 
360 	if (!quiet) {
361 		if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
362 		    ll.ll_time != 0)
363 			domsg(pamh, ll.ll_time, ll.ll_host,
364 			    sizeof(ll.ll_host), ll.ll_line,
365 			    sizeof(ll.ll_line));
366 		(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
367 	}
368 
369 	ll.ll_time = now->tv_sec;
370 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
371 
372 	if (hostname)
373 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
374 	else
375 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
376 
377 	(void)write(fd, &ll, sizeof(ll));
378 	(void)close(fd);
379 
380 	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
381 }
382 #endif
383 
384 PAM_MODULE_ENTRY("pam_lastlog");
385