NetBSD/lib/libpam/modules/pam_nologin/pam_nologin.c

155 lines
4.5 KiB
C

/* $NetBSD: pam_nologin.c,v 1.6 2006/02/15 20:28:32 bouyer Exp $ */
/*-
* Copyright 2001 Mark R V Murray
* All rights reserved.
* Copyright (c) 2001 Networks Associates Technology, Inc.
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* ThinkSec AS and NAI Labs, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifdef __FreeBSD__
__FBSDID("$FreeBSD: src/lib/libpam/modules/pam_nologin/pam_nologin.c,v 1.10 2002/04/12 22:27:21 des Exp $");
#else
__RCSID("$NetBSD: pam_nologin.c,v 1.6 2006/02/15 20:28:32 bouyer Exp $");
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <login_cap.h>
#include <pwd.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define PAM_SM_AUTH
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
#define NOLOGIN "/etc/nologin"
static char nologin_def[] = NOLOGIN;
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
login_cap_t *lc;
struct passwd *pwd, pwres;
struct stat st;
int retval, fd;
int ignorenologin = 0;
int rootlogin = 0;
const char *user, *nologin;
char *mtmp;
char pwbuf[1024];
if ((retval = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS)
return retval;
PAM_LOG("Got user: %s", user);
/*
* For root, the default is to ignore nologin, but the
* ignorenologin capability can override this, so we
* set the default appropriately.
*
* Do not allow login of unexisting users, so that a directory
* failure will not cause the nologin capability to be ignored.
*/
if (getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
pwd == NULL) {
return PAM_USER_UNKNOWN;
} else {
if (pwd->pw_uid == 0)
rootlogin = 1;
}
lc = login_getclass(pwd->pw_class);
ignorenologin = login_getcapbool(lc, "ignorenologin", rootlogin);
nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def);
login_close(lc);
lc = NULL;
if (ignorenologin)
return PAM_SUCCESS;
if ((fd = open(nologin, O_RDONLY, 0)) == -1) {
/*
* The file does not exist, login is granted
*/
if (errno == ENOENT)
return PAM_SUCCESS;
/*
* open failed, but the file exists. This could be
* a temporary problem (system resources exausted):
* Refuse the login.
*/
PAM_LOG("Cannot open %s file: %s", nologin, strerror(errno));
return PAM_AUTH_ERR;
}
PAM_LOG("Opened %s file", nologin);
if (fstat(fd, &st) < 0)
return PAM_AUTH_ERR;
mtmp = malloc(st.st_size + 1);
if (mtmp != NULL) {
read(fd, mtmp, st.st_size);
mtmp[st.st_size] = '\0';
pam_error(pamh, "%s", mtmp, NULL);
free(mtmp);
}
PAM_VERBOSE_ERROR("Administrator refusing you: %s", nologin);
return PAM_AUTH_ERR;
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
return (PAM_SUCCESS);
}
PAM_MODULE_ENTRY("pam_nologin");