xref: /netbsd-src/lib/libpam/modules/pam_lastlog/pam_lastlog.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: pam_lastlog.c,v 1.10 2006/03/18 10:53:17 jnemeth 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 1.10 2006/03/18 10:53:17 jnemeth 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 #ifdef LOGIN_CAP
66 #include <login_cap.h>
67 #endif
68 
69 #define PAM_SM_SESSION
70 
71 #include <security/pam_appl.h>
72 #include <security/pam_modules.h>
73 #include <security/pam_mod_misc.h>
74 
75 #ifdef SUPPORT_UTMP
76 #include <utmp.h>
77 static void doutmp(const char *, const char *, const char *,
78     const struct timeval *);
79 static void dolastlog(pam_handle_t *, int, const struct passwd *, const char *,
80     const char *, const struct timeval *);
81 #endif
82 
83 #ifdef SUPPORT_UTMPX
84 #include <utmpx.h>
85 static void doutmpx(const char *, const char *, const char *,
86     const struct sockaddr_storage *ss, const struct timeval *);
87 static void dolastlogx(pam_handle_t *, int, const struct passwd *, const char *,
88     const char *, const struct sockaddr_storage *ss, const struct timeval *);
89 #endif
90 
91 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
92 static void domsg(pam_handle_t *, time_t, const char *, size_t, const char *,
93     size_t);
94 #endif
95 
96 PAM_EXTERN int
97 pam_sm_open_session(pam_handle_t *pamh, int flags,
98     int argc __unused, const char *argv[] __unused)
99 {
100 	struct passwd *pwd, pwres;
101 	struct timeval now;
102 	const char *user, *rhost, *tty, *nuser;
103 	const void *vrhost, *vtty, *vss, *vnuser;
104 	const struct sockaddr_storage *ss;
105 	int pam_err;
106 	char pwbuf[1024];
107 #ifdef LOGIN_CAP
108 	login_cap_t *lc;
109 #endif
110 
111 	pam_err = pam_get_user(pamh, &user, NULL);
112 	if (pam_err != PAM_SUCCESS)
113 		return pam_err;
114 
115 	if (user == NULL ||
116 	    getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
117 	    pwd == NULL)
118 		return PAM_SERVICE_ERR;
119 
120 	PAM_LOG("Got user: %s", user);
121 
122 	pam_err = pam_get_item(pamh, PAM_RHOST, &vrhost);
123 	if (pam_err != PAM_SUCCESS)
124 		goto err;
125 	rhost = (const char *)vrhost;
126 
127 	pam_err = pam_get_item(pamh, PAM_SOCKADDR, &vss);
128 	if (pam_err != PAM_SUCCESS)
129 		goto err;
130 	ss = (const struct sockaddr_storage *)vss;
131 
132 	pam_err = pam_get_item(pamh, PAM_TTY, &vtty);
133 	if (pam_err != PAM_SUCCESS)
134 		goto err;
135 	tty = (const char *)vtty;
136 
137 	if (tty == NULL) {
138 		pam_err = PAM_SERVICE_ERR;
139 		goto err;
140 	}
141 
142 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
143 		nuser = NULL;
144 	else
145 		nuser = (const char *)vnuser;
146 
147 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
148 		tty = tty + strlen(_PATH_DEV);
149 
150 	if (*tty == '\0') {
151 		pam_err = PAM_SERVICE_ERR;
152 		goto err;
153 	}
154 
155 	(void)gettimeofday(&now, NULL);
156 
157 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
158 		int quiet;
159 		if ((flags & PAM_SILENT) != 0)
160 			quiet = 1;
161 		else {
162 #ifdef LOGIN_CAP
163 			lc = login_getpwclass(pwd);
164 			quiet = login_getcapbool(lc, "hushlogin", 0);
165 			login_close(lc);
166 #else
167 			quiet = 0;
168 #endif
169 		}
170 #ifdef SUPPORT_UTMPX
171 		doutmpx(user, rhost, tty, ss, &now);
172 		dolastlogx(pamh, quiet, pwd, rhost, tty, ss, &now);
173 		quiet = 1;
174 #endif
175 #ifdef SUPPORT_UTMP
176 		doutmp(user, rhost, tty, &now);
177 		dolastlog(pamh, quiet, pwd, rhost, tty, &now);
178 #endif
179 	}
180 err:
181 	if (openpam_get_option(pamh, "no_fail"))
182 		return PAM_SUCCESS;
183 	return pam_err;
184 }
185 
186 PAM_EXTERN int
187 pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
188     int argc __unused, const char *argv[] __unused)
189 {
190 	const void *vtty, *vnuser;
191 	const char *tty, *nuser;
192 
193 	if (pam_get_item(pamh, PAM_NUSER, &vnuser) != PAM_SUCCESS)
194 		nuser = NULL;
195 	else
196 		nuser = (const char *)vnuser;
197 
198 	pam_get_item(pamh, PAM_TTY, &vtty);
199 	if (vtty == NULL)
200 		return PAM_SERVICE_ERR;
201 	tty = (const char *)vtty;
202 
203 	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
204 		tty = tty + strlen(_PATH_DEV);
205 
206 	if (*tty == '\0')
207 		return PAM_SERVICE_ERR;
208 
209 	if (openpam_get_option(pamh, "no_nested") == NULL || nuser == NULL) {
210 
211 #ifdef SUPPORT_UTMPX
212 		if (logoutx(tty, 0, DEAD_PROCESS))
213 			logwtmpx(tty, "", "", 0, DEAD_PROCESS);
214 		else
215 			syslog(LOG_NOTICE, "%s(): no utmpx record for %s",
216 			    __func__, tty);
217 #endif
218 
219 #ifdef SUPPORT_UTMP
220 		if (logout(tty))
221 			logwtmp(tty, "", "");
222 		else
223 			syslog(LOG_NOTICE, "%s(): no utmp record for %s",
224 		    __func__, tty);
225 #endif
226 	}
227         return PAM_SUCCESS;
228 }
229 
230 #if defined(SUPPORT_UTMPX) || defined(SUPPORT_UTMP)
231 static void
232 domsg(pam_handle_t *pamh, time_t t, const char *host, size_t hsize,
233     const char *line, size_t lsize)
234 {
235 	char buf[MAXHOSTNAMELEN + 32], *promptresp = NULL;
236 	int pam_err;
237 
238 	if (*host) {
239 		(void)snprintf(buf, sizeof(buf), "from %.*s ",
240 		    (int)hsize, host);
241 		host = buf;
242 	}
243 
244 	pam_err = pam_prompt(pamh, PAM_TEXT_INFO, &promptresp,
245 	    "Last login: %.24s %son %.*s\n", ctime(&t), host, (int)lsize, line);
246 
247 	if (pam_err == PAM_SUCCESS && promptresp)
248 		free(promptresp);
249 }
250 #endif
251 
252 #ifdef SUPPORT_UTMPX
253 static void
254 doutmpx(const char *username, const char *hostname, const char *tty,
255     const struct sockaddr_storage *ss, const struct timeval *now)
256 {
257 	struct utmpx utmpx;
258 	const char *t;
259 
260 	memset((void *)&utmpx, 0, sizeof(utmpx));
261 	utmpx.ut_tv = *now;
262 	(void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
263 	if (hostname) {
264 		(void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
265 		if (ss)
266 			utmpx.ut_ss = *ss;
267 	}
268 	(void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
269 	utmpx.ut_type = USER_PROCESS;
270 	utmpx.ut_pid = getpid();
271 	t = tty + strlen(tty);
272 	if (t - tty >= sizeof(utmpx.ut_id)) {
273 		(void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
274 		    sizeof(utmpx.ut_id));
275 	} else {
276 		(void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
277 	}
278 	if (pututxline(&utmpx) == NULL)
279 		syslog(LOG_NOTICE, "Cannot update utmpx %m");
280 	endutxent();
281 	if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
282 		syslog(LOG_NOTICE, "Cannot update wtmpx %m");
283 }
284 
285 static void
286 dolastlogx(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
287     const char *hostname, const char *tty, const struct sockaddr_storage *ss,
288     const struct timeval *now)
289 {
290 	struct lastlogx ll;
291 	if (!quiet) {
292 	    if (getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL)
293 		    domsg(pamh, (time_t)ll.ll_tv.tv_sec, ll.ll_host,
294 			sizeof(ll.ll_host), ll.ll_line,
295 			sizeof(ll.ll_line));
296 	}
297 	ll.ll_tv = *now;
298 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
299 
300 	if (hostname)
301 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
302 	else
303 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
304 
305 	if (ss)
306 		ll.ll_ss = *ss;
307 	else
308 		(void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
309 
310 	if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
311 		syslog(LOG_NOTICE, "Cannot update lastlogx %m");
312 	PAM_LOG("Login recorded in %s", _PATH_LASTLOGX);
313 }
314 #endif
315 
316 #ifdef SUPPORT_UTMP
317 static void
318 doutmp(const char *username, const char *hostname, const char *tty,
319     const struct timeval *now)
320 {
321 	struct utmp utmp;
322 
323 	(void)memset((void *)&utmp, 0, sizeof(utmp));
324 	utmp.ut_time = now->tv_sec;
325 	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
326 	if (hostname)
327 		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
328 	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
329 	login(&utmp);
330 }
331 
332 static void
333 dolastlog(pam_handle_t *pamh, int quiet, const struct passwd *pwd,
334     const char *hostname, const char *tty, const struct timeval *now)
335 {
336 	struct lastlog ll;
337 	int fd;
338 
339 	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) == -1) {
340 		syslog(LOG_NOTICE, "Cannot open `%s' %m", _PATH_LASTLOG);
341 		return;
342 	}
343 	(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
344 
345 	if (!quiet) {
346 		if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
347 		    ll.ll_time != 0)
348 			domsg(pamh, ll.ll_time, ll.ll_host,
349 			    sizeof(ll.ll_host), ll.ll_line,
350 			    sizeof(ll.ll_line));
351 		(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
352 	}
353 
354 	ll.ll_time = now->tv_sec;
355 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
356 
357 	if (hostname)
358 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
359 	else
360 		(void)memset(ll.ll_host, 0, sizeof(ll.ll_host));
361 
362 	(void)write(fd, &ll, sizeof(ll));
363 	(void)close(fd);
364 
365 	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
366 }
367 #endif
368 
369 PAM_MODULE_ENTRY("pam_lastlog");
370