pam_nologin.c revision 1.1 
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: src/lib/libpam/modules/pam_nologin/pam_nologin.c,v 1.10 2002/04/12 22:27:21 des Exp $");
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_AUTH
50
51#include <security/pam_appl.h>
52#include <security/pam_modules.h>
53#include <security/pam_mod_misc.h>
54
55#define	NOLOGIN	"/var/run/nologin"
56
57static char nologin_def[] = NOLOGIN;
58
59PAM_EXTERN int
60pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
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	const char *user, *nologin;
68	char *mtmp;
69
70	retval = pam_get_user(pamh, &user, NULL);
71	if (retval != PAM_SUCCESS)
72		return (retval);
73
74	PAM_LOG("Got user: %s", user);
75
76	lc = login_getclass(NULL);
77	nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def);
78	login_close(lc);
79	lc = NULL;
80
81	fd = open(nologin, O_RDONLY, 0);
82	if (fd < 0)
83		return (PAM_SUCCESS);
84
85	PAM_LOG("Opened %s file", NOLOGIN);
86
87	pwd = getpwnam(user);
88	if (pwd && pwd->pw_uid == 0)
89		retval = PAM_SUCCESS;
90	else {
91		if (!pwd)
92			retval = PAM_USER_UNKNOWN;
93		else
94			retval = PAM_AUTH_ERR;
95	}
96
97	if (fstat(fd, &st) < 0)
98		return (retval);
99
100	mtmp = malloc(st.st_size + 1);
101	if (mtmp != NULL) {
102		read(fd, mtmp, st.st_size);
103		mtmp[st.st_size] = '\0';
104		pam_error(pamh, "%s", mtmp, NULL);
105		free(mtmp);
106	}
107
108	if (retval != PAM_SUCCESS)
109		PAM_VERBOSE_ERROR("Administrator refusing you: %s", NOLOGIN);
110
111	return (retval);
112}
113
114PAM_EXTERN int
115pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
116    int argc __unused, const char *argv[] __unused)
117{
118
119	return (PAM_SUCCESS);
120}
121
122PAM_MODULE_ENTRY("pam_nologin");
123