pam_lastlog.c revision 123448 
1/*-
2 * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 2001 Mark R V Murray
5 * All rights reserved.
6 * Copyright (c) 2001 Networks Associates Technology, Inc.
7 * All rights reserved.
8 *
9 * Portions of this software were developed for the FreeBSD Project by
10 * ThinkSec AS and NAI Labs, the Security Research Division of Network
11 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
12 * ("CBOSS"), as part of the DARPA CHATS research program.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. The name of the author may not be used to endorse or promote
23 *    products derived from this software without specific prior written
24 *    permission.
25 * 4. Neither the name of the University nor the names of its contributors
26 *    may be used to endorse or promote products derived from this software
27 *    without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/lib/libpam/modules/pam_lastlog/pam_lastlog.c 123448 2003-12-11 13:55:16Z des $");
44
45#define _BSD_SOURCE
46
47#include <sys/param.h>
48
49#include <fcntl.h>
50#include <libutil.h>
51#include <paths.h>
52#include <pwd.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <syslog.h>
57#include <time.h>
58#include <unistd.h>
59#include <utmp.h>
60
61#define PAM_SM_SESSION
62
63#include <security/pam_appl.h>
64#include <security/pam_modules.h>
65#include <security/pam_mod_misc.h>
66
67PAM_EXTERN int
68pam_sm_open_session(pam_handle_t *pamh, int flags,
69    int argc __unused, const char *argv[] __unused)
70{
71	struct passwd *pwd;
72	struct utmp utmp;
73	struct lastlog ll;
74	time_t t;
75	const char *user;
76	const void *rhost, *tty;
77	off_t llpos;
78	int fd, pam_err;
79
80	pam_err = pam_get_user(pamh, &user, NULL);
81	if (pam_err != PAM_SUCCESS)
82		return (pam_err);
83	if (user == NULL || (pwd = getpwnam(user)) == NULL)
84		return (PAM_SERVICE_ERR);
85	PAM_LOG("Got user: %s", user);
86
87	pam_err = pam_get_item(pamh, PAM_RHOST, &rhost);
88	if (pam_err != PAM_SUCCESS)
89		goto err;
90	pam_err = pam_get_item(pamh, PAM_TTY, &tty);
91	if (pam_err != PAM_SUCCESS)
92		goto err;
93	if (tty == NULL) {
94		pam_err = PAM_SERVICE_ERR;
95		goto err;
96	}
97	if (strncmp(tty, _PATH_DEV, strlen(_PATH_DEV)) == 0)
98		tty = (const char *)tty + strlen(_PATH_DEV);
99	if (*(const char *)tty == '\0')
100		return (PAM_SERVICE_ERR);
101
102	fd = open(_PATH_LASTLOG, O_RDWR|O_CREAT, 0644);
103	if (fd == -1)
104		goto file_err;
105
106	/*
107	 * Record session in lastlog(5).
108	 */
109	llpos = (off_t)(pwd->pw_uid * sizeof(ll));
110	if (lseek(fd, llpos, L_SET) != llpos)
111		goto file_err;
112	if ((flags & PAM_SILENT) == 0) {
113		if (read(fd, &ll, sizeof ll) == sizeof ll && ll.ll_time != 0) {
114			t = ll.ll_time;
115			if (*ll.ll_host != '\0')
116				pam_info(pamh, "Last login: %.*s from %.*s",
117				    24 - 5, ctime(&t),
118				    (int)sizeof(ll.ll_host), ll.ll_host);
119			else
120				pam_info(pamh, "Last login: %.*s on %.*s",
121				    24 - 5, ctime(&t),
122				    (int)sizeof(ll.ll_line), ll.ll_line);
123		}
124		if (lseek(fd, llpos, L_SET) != llpos)
125			goto file_err;
126	}
127
128	bzero(&ll, sizeof(ll));
129	ll.ll_time = time(NULL);
130
131	/* note: does not need to be NUL-terminated */
132	strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
133	if (rhost != NULL && *(const char *)rhost != '\0')
134		/* note: does not need to be NUL-terminated */
135		strncpy(ll.ll_host, rhost, sizeof(ll.ll_host));
136
137	if (write(fd, (char *)&ll, sizeof(ll)) != sizeof(ll) || close(fd) != 0)
138		goto file_err;
139
140	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
141
142	/*
143	 * Record session in utmp(5) and wtmp(5).
144	 */
145	bzero(&utmp, sizeof(utmp));
146	utmp.ut_time = time(NULL);
147	/* note: does not need to be NUL-terminated */
148	strncpy(utmp.ut_name, user, sizeof(utmp.ut_name));
149	if (rhost != NULL && *(const char *)rhost != '\0')
150		strncpy(utmp.ut_host, rhost, sizeof(utmp.ut_host));
151	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
152	login(&utmp);
153
154	return (PAM_SUCCESS);
155
156file_err:
157	syslog(LOG_ERR, "%s: %m", _PATH_LASTLOG);
158	if (fd != -1)
159		close(fd);
160	pam_err = PAM_SYSTEM_ERR;
161err:
162	if (openpam_get_option(pamh, "no_fail"))
163		return (PAM_SUCCESS);
164	return (pam_err);
165}
166
167PAM_EXTERN int
168pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
169    int argc __unused, const char *argv[] __unused)
170{
171
172	return (PAM_SUCCESS);
173}
174
175PAM_MODULE_ENTRY("pam_lastlog");
176