pam_nologin.c revision 1.2 
1/*	$NetBSD: pam_nologin.c,v 1.2 2004/12/12 08:18:46 christos Exp $	*/
2
3/*-
4 * Copyright 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 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39#include <sys/cdefs.h>
40#ifdef __FreeBSD__
41__FBSDID("$FreeBSD: src/lib/libpam/modules/pam_nologin/pam_nologin.c,v 1.10 2002/04/12 22:27:21 des Exp $");
42#else
43__RCSID("$NetBSD: pam_nologin.c,v 1.2 2004/12/12 08:18:46 christos Exp $");
44#endif
45
46
47#include <sys/types.h>
48#include <sys/stat.h>
49#include <fcntl.h>
50#include <login_cap.h>
51#include <pwd.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <unistd.h>
55
56#define PAM_SM_AUTH
57
58#include <security/pam_appl.h>
59#include <security/pam_modules.h>
60#include <security/pam_mod_misc.h>
61
62#define	NOLOGIN	"/var/run/nologin"
63
64static char nologin_def[] = NOLOGIN;
65
66PAM_EXTERN int
67pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
68    int argc __unused, const char *argv[] __unused)
69{
70	login_cap_t *lc;
71	struct passwd *pwd;
72	struct stat st;
73	int retval, fd;
74	const char *user, *nologin;
75	char *mtmp;
76
77	retval = pam_get_user(pamh, &user, NULL);
78	if (retval != PAM_SUCCESS)
79		return (retval);
80
81	PAM_LOG("Got user: %s", user);
82
83	lc = login_getclass(NULL);
84	nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def);
85	login_close(lc);
86	lc = NULL;
87
88	fd = open(nologin, O_RDONLY, 0);
89	if (fd < 0)
90		return (PAM_SUCCESS);
91
92	PAM_LOG("Opened %s file", NOLOGIN);
93
94	pwd = getpwnam(user);
95	if (pwd && pwd->pw_uid == 0)
96		retval = PAM_SUCCESS;
97	else {
98		if (!pwd)
99			retval = PAM_USER_UNKNOWN;
100		else
101			retval = PAM_AUTH_ERR;
102	}
103
104	if (fstat(fd, &st) < 0)
105		return (retval);
106
107	mtmp = malloc(st.st_size + 1);
108	if (mtmp != NULL) {
109		read(fd, mtmp, st.st_size);
110		mtmp[st.st_size] = '\0';
111		pam_error(pamh, "%s", mtmp, NULL);
112		free(mtmp);
113	}
114
115	if (retval != PAM_SUCCESS)
116		PAM_VERBOSE_ERROR("Administrator refusing you: %s", NOLOGIN);
117
118	return (retval);
119}
120
121PAM_EXTERN int
122pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
123    int argc __unused, const char *argv[] __unused)
124{
125
126	return (PAM_SUCCESS);
127}
128
129PAM_MODULE_ENTRY("pam_nologin");
130