/* $NetBSD: pam_chroot.c,v 1.5 2012/01/03 19:02:54 christos Exp $ */
/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was 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_chroot/pam_chroot.c,v 1.3 2003/04/30 00:40:24 des Exp $");
#else
__RCSID("$NetBSD: pam_chroot.c,v 1.5 2012/01/03 19:02:54 christos Exp $");
#endif
#include <sys/param.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#define PAM_SM_SESSION
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/openpam.h>
PAM_EXTERN int
pam_sm_open_session(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
const char *dir, *end, *cwd, *user;
struct passwd *pwd, pwres;
char buf[PATH_MAX];
char pwbuf[1024];
if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
user == NULL ||
getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
pwd == NULL)
return (PAM_SESSION_ERR);
if (pwd->pw_uid == 0 && !openpam_get_option(pamh, "also_root"))
return (PAM_SUCCESS);
if (pwd->pw_dir == NULL)
return (PAM_SESSION_ERR);
if ((end = strstr(pwd->pw_dir, "/./")) != NULL) {
if (snprintf(buf, sizeof(buf), "%.*s",
(int)(end - pwd->pw_dir), pwd->pw_dir) > (int)sizeof(buf)) {
openpam_log(PAM_LOG_ERROR,
"%s's home directory is too long", user);
return (PAM_SESSION_ERR);
}
dir = buf;
cwd = end + 2;
} else if ((dir = openpam_get_option(pamh, "dir")) != NULL) {
if ((cwd = openpam_get_option(pamh, "cwd")) == NULL)
cwd = "/";
} else {
if (openpam_get_option(pamh, "always")) {
openpam_log(PAM_LOG_ERROR,
"%s has no chroot directory", user);
return (PAM_SESSION_ERR);
}
return (PAM_SUCCESS);
}
openpam_log(PAM_LOG_DEBUG, "chrooting %s to %s", dir, user);
if (chroot(dir) == -1) {
openpam_log(PAM_LOG_ERROR, "chroot(): %s", strerror(errno));
return (PAM_SESSION_ERR);
}
if (chdir(cwd) == -1) {
openpam_log(PAM_LOG_ERROR, "chdir(): %s", strerror(errno));
return (PAM_SESSION_ERR);
}
pam_setenv(pamh, "HOME", cwd, 1);
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
return (PAM_SUCCESS);
}
PAM_MODULE_ENTRY("pam_chroot");
