pam_lastlog.c revision 94564 
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 94564 2002-04-12 22:27:25Z des $");
44
45#define _BSD_SOURCE
46
47#include <sys/param.h>
48
49#include <fcntl.h>
50#include <libutil.h>
51#include <pwd.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <syslog.h>
56#include <time.h>
57#include <unistd.h>
58#include <utmp.h>
59
60#define PAM_SM_SESSION
61
62#include <security/pam_appl.h>
63#include <security/pam_modules.h>
64#include <security/pam_mod_misc.h>
65
66PAM_EXTERN int
67pam_sm_open_session(pam_handle_t *pamh, int flags,
68    int argc __unused, const char *argv[] __unused)
69{
70	struct passwd *pwd;
71	struct utmp utmp;
72	struct lastlog ll;
73	const char *rhost, *user, *tty;
74	off_t llpos;
75	int fd, pam_err;
76
77	pam_err = pam_get_user(pamh, &user, NULL);
78	if (pam_err != PAM_SUCCESS)
79		return (pam_err);
80	if (user == NULL || (pwd = getpwnam(user)) == NULL)
81		return (PAM_SERVICE_ERR);
82	PAM_LOG("Got user: %s", user);
83
84	pam_err = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost);
85	if (pam_err != PAM_SUCCESS)
86		return (pam_err);
87
88	pam_err = pam_get_item(pamh, PAM_TTY, (const void **)&tty);
89	if (pam_err != PAM_SUCCESS)
90		return (pam_err);
91	if (tty == NULL)
92		return (PAM_SERVICE_ERR);
93
94	fd = open(_PATH_LASTLOG, O_RDWR|O_CREAT, 0644);
95	if (fd == -1) {
96		syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG);
97		return (PAM_SERVICE_ERR);
98	}
99
100	/*
101	 * Record session in lastlog(5).
102	 */
103	llpos = (off_t)(pwd->pw_uid * sizeof(ll));
104	if (lseek(fd, llpos, L_SET) != llpos)
105		goto file_err;
106	if ((flags & PAM_SILENT) == 0) {
107		if (read(fd, &ll, sizeof(ll)) == sizeof(ll) &&
108		    ll.ll_time != 0) {
109			pam_info(pamh, "Last login: %.*s ", 24 - 5,
110			    ctime(&ll.ll_time));
111			if (*ll.ll_host != '\0')
112				pam_info(pamh, "from %.*s\n",
113				    (int)sizeof(ll.ll_host), ll.ll_host);
114			else
115				pam_info(pamh, "on %.*s\n",
116				    (int)sizeof(ll.ll_line), ll.ll_line);
117		}
118		if (lseek(fd, llpos, L_SET) != llpos)
119			goto file_err;
120	}
121
122	bzero(&ll, sizeof(ll));
123	time(&ll.ll_time);
124
125	/* note: does not need to be NUL-terminated */
126	strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
127	if (rhost != NULL)
128		/* note: does not need to be NUL-terminated */
129		strncpy(ll.ll_host, rhost, sizeof(ll.ll_host));
130
131	if (write(fd, (char *)&ll, sizeof(ll)) != sizeof(ll) || close(fd) != 0)
132		goto file_err;
133
134	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
135
136	/*
137	 * Record session in utmp(5) and wtmp(5).
138	 */
139	bzero(&utmp, sizeof(utmp));
140	time(&utmp.ut_time);
141	/* note: does not need to be NUL-terminated */
142	strncpy(utmp.ut_name, user, sizeof(utmp.ut_name));
143	if (rhost != NULL)
144		strncpy(utmp.ut_host, rhost, sizeof(utmp.ut_host));
145	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
146	login(&utmp);
147
148	return (PAM_IGNORE);
149
150 file_err:
151	syslog(LOG_ERR, "%s: %m", _PATH_LASTLOG);
152	close(fd);
153	return (PAM_SERVICE_ERR);
154}
155
156PAM_EXTERN int
157pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
158    int argc __unused, const char *argv[] __unused)
159{
160
161	return (PAM_SUCCESS);
162}
163
164PAM_MODULE_ENTRY("pam_lastlog");
165