1/*-
2 * Copyright 2001 Mark R V Murray
3 * All rights reserved.
4 * Copyright (c) 2001 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote
21 *    products derived from this software without specific prior written
22 *    permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD$");
39
40#include <sys/types.h>
41#include <sys/stat.h>
42#include <fcntl.h>
43#include <login_cap.h>
44#include <pwd.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <unistd.h>
48
49#define PAM_SM_ACCOUNT
50
51#include <security/pam_appl.h>
52#include <security/pam_modules.h>
53#include <security/pam_mod_misc.h>
54
55#define	_PATH_NOLOGIN	"/var/run/nologin"
56
57static char nologin_def[] = _PATH_NOLOGIN;
58
59PAM_EXTERN int
60pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
61    int argc __unused, const char *argv[] __unused)
62{
63	login_cap_t *lc;
64	struct passwd *pwd;
65	struct stat st;
66	int retval, fd;
67	ssize_t ss;
68	const char *user, *nologin;
69	char *mtmp;
70
71	retval = pam_get_user(pamh, &user, NULL);
72	if (retval != PAM_SUCCESS)
73		return (retval);
74
75	PAM_LOG("Got user: %s", user);
76
77	pwd = getpwnam(user);
78	if (pwd == NULL)
79		return (PAM_USER_UNKNOWN);
80
81	/*
82	 * login_getpwclass(3) will select the "root" class by default
83	 * if pwd->pw_uid is 0.  That class should have "ignorenologin"
84	 * capability so that super-user can bypass nologin.
85	 */
86	lc = login_getpwclass(pwd);
87	if (lc == NULL) {
88		PAM_LOG("Unable to get login class for user %s", user);
89		return (PAM_SERVICE_ERR);
90	}
91
92	if (login_getcapbool(lc, "ignorenologin", 0)) {
93		login_close(lc);
94		return (PAM_SUCCESS);
95	}
96
97	nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def);
98
99	fd = open(nologin, O_RDONLY, 0);
100	if (fd < 0) {
101		login_close(lc);
102		return (PAM_SUCCESS);
103	}
104
105	PAM_LOG("Opened %s file", nologin);
106
107	if (fstat(fd, &st) == 0) {
108		mtmp = malloc(st.st_size + 1);
109		if (mtmp != NULL) {
110			ss = read(fd, mtmp, st.st_size);
111			if (ss > 0) {
112				mtmp[ss] = '\0';
113				pam_error(pamh, "%s", mtmp);
114			}
115			free(mtmp);
116		}
117	}
118
119	PAM_VERBOSE_ERROR("Administrator refusing you: %s", nologin);
120
121	close(fd);
122	login_close(lc);
123
124	return (PAM_AUTH_ERR);
125}
126
127PAM_MODULE_ENTRY("pam_nologin");
128