/* $NetBSD: secmodel_overlay.c,v 1.14 2020/03/16 21:20:12 pgoyette Exp $ */
/*-
* Copyright (c) 2006 Elad Efrat <elad@NetBSD.org>
* All rights reserved.
*
* 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 ``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 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>
__KERNEL_RCSID(0, "$NetBSD: secmodel_overlay.c,v 1.14 2020/03/16 21:20:12 pgoyette Exp $");
#include <sys/types.h>
#include <sys/param.h>
#include <sys/kauth.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <secmodel/secmodel.h>
#include <secmodel/overlay/overlay.h>
#include <secmodel/bsd44/bsd44.h>
#include <secmodel/suser/suser.h>
#include <secmodel/securelevel/securelevel.h>
MODULE(MODULE_CLASS_SECMODEL, secmodel_overlay, "secmodel_bsd44");
/*
* Fall-back settings.
*/
#define OVERLAY_ISCOPE_GENERIC "org.netbsd.kauth.overlay.generic"
#define OVERLAY_ISCOPE_SYSTEM "org.netbsd.kauth.overlay.system"
#define OVERLAY_ISCOPE_PROCESS "org.netbsd.kauth.overlay.process"
#define OVERLAY_ISCOPE_NETWORK "org.netbsd.kauth.overlay.network"
#define OVERLAY_ISCOPE_MACHDEP "org.netbsd.kauth.overlay.machdep"
#define OVERLAY_ISCOPE_DEVICE "org.netbsd.kauth.overlay.device"
#define OVERLAY_ISCOPE_VNODE "org.netbsd.kauth.overlay.vnode"
static kauth_scope_t secmodel_overlay_iscope_generic;
static kauth_scope_t secmodel_overlay_iscope_system;
static kauth_scope_t secmodel_overlay_iscope_process;
static kauth_scope_t secmodel_overlay_iscope_network;
static kauth_scope_t secmodel_overlay_iscope_machdep;
static kauth_scope_t secmodel_overlay_iscope_device;
static kauth_scope_t secmodel_overlay_iscope_vnode;
static kauth_listener_t l_generic, l_system, l_process, l_network, l_machdep,
l_device, l_vnode;
static secmodel_t overlay_sm;
/*
* Initialize the overlay security model.
*/
void
secmodel_overlay_init(void)
{
/*
* Register internal fall-back scopes.
*/
secmodel_overlay_iscope_generic = kauth_register_scope(
OVERLAY_ISCOPE_GENERIC, NULL, NULL);
secmodel_overlay_iscope_system = kauth_register_scope(
OVERLAY_ISCOPE_SYSTEM, NULL, NULL);
secmodel_overlay_iscope_process = kauth_register_scope(
OVERLAY_ISCOPE_PROCESS, NULL, NULL);
secmodel_overlay_iscope_network = kauth_register_scope(
OVERLAY_ISCOPE_NETWORK, NULL, NULL);
secmodel_overlay_iscope_machdep = kauth_register_scope(
OVERLAY_ISCOPE_MACHDEP, NULL, NULL);
secmodel_overlay_iscope_device = kauth_register_scope(
OVERLAY_ISCOPE_DEVICE, NULL, NULL);
secmodel_overlay_iscope_vnode = kauth_register_scope(
OVERLAY_ISCOPE_VNODE, NULL, NULL);
/*
* Register fall-back listeners, from suser and securelevel, to each
* internal scope.
*/
kauth_listen_scope(OVERLAY_ISCOPE_GENERIC,
secmodel_suser_generic_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_SYSTEM,
secmodel_suser_system_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_SYSTEM,
secmodel_securelevel_system_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_PROCESS,
secmodel_suser_process_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_PROCESS,
secmodel_securelevel_process_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_NETWORK,
secmodel_suser_network_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_NETWORK,
secmodel_securelevel_network_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_MACHDEP,
secmodel_suser_machdep_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_MACHDEP,
secmodel_securelevel_machdep_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_DEVICE,
secmodel_suser_device_cb, NULL);
kauth_listen_scope(OVERLAY_ISCOPE_DEVICE,
secmodel_securelevel_device_cb, NULL);
}
SYSCTL_SETUP(sysctl_security_overlay_setup, "secmod overlay sysctl")
{
const struct sysctlnode *rnode;
sysctl_createv(clog, 0, NULL, &rnode,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "models", NULL,
NULL, 0, NULL, 0,
CTL_SECURITY, CTL_CREATE, CTL_EOL);
sysctl_createv(clog, 0, &rnode, &rnode,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "overlay",
SYSCTL_DESCR("Overlay security model on-top of bsd44"),
NULL, 0, NULL, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(clog, 0, &rnode, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "name", NULL,
NULL, 0, __UNCONST(SECMODEL_OVERLAY_NAME), 0,
CTL_CREATE, CTL_EOL);
}
/*
* Start the overlay security model.
*/
void
secmodel_overlay_start(void)
{
l_generic = kauth_listen_scope(KAUTH_SCOPE_GENERIC,
secmodel_overlay_generic_cb, NULL);
l_system = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
secmodel_overlay_system_cb, NULL);
l_process = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
secmodel_overlay_process_cb, NULL);
l_network = kauth_listen_scope(KAUTH_SCOPE_NETWORK,
secmodel_overlay_network_cb, NULL);
l_machdep = kauth_listen_scope(KAUTH_SCOPE_MACHDEP,
secmodel_overlay_machdep_cb, NULL);
l_device = kauth_listen_scope(KAUTH_SCOPE_DEVICE,
secmodel_overlay_device_cb, NULL);
l_vnode = kauth_listen_scope(KAUTH_SCOPE_VNODE,
secmodel_overlay_vnode_cb, NULL);
}
/*
* Stop the overlay security model.
*/
void
secmodel_overlay_stop(void)
{
kauth_unlisten_scope(l_generic);
kauth_unlisten_scope(l_system);
kauth_unlisten_scope(l_process);
kauth_unlisten_scope(l_network);
kauth_unlisten_scope(l_machdep);
kauth_unlisten_scope(l_device);
kauth_unlisten_scope(l_vnode);
}
static int
secmodel_overlay_modcmd(modcmd_t cmd, void *arg)
{
int error = 0;
switch (cmd) {
case MODULE_CMD_INIT:
error = secmodel_register(&overlay_sm,
SECMODEL_OVERLAY_ID, SECMODEL_OVERLAY_NAME,
NULL, NULL, NULL);
if (error != 0)
printf("secmodel_overlay_modcmd::init: "
"secmodel_register returned %d\n", error);
secmodel_overlay_init();
secmodel_suser_stop();
secmodel_securelevel_stop();
secmodel_overlay_start();
break;
case MODULE_CMD_FINI:
secmodel_overlay_stop();
error = secmodel_deregister(overlay_sm);
if (error != 0)
printf("secmodel_overlay_modcmd::fini: "
"secmodel_deregister returned %d\n", error);
break;
case MODULE_CMD_AUTOUNLOAD:
error = EPERM;
break;
default:
error = ENOTTY;
break;
}
return error;
}
/*
* Overlay listener for the generic scope.
*/
int
secmodel_overlay_generic_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_generic, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the system scope.
*/
int
secmodel_overlay_system_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_system, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the process scope.
*/
int
secmodel_overlay_process_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_process, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the network scope.
*/
int
secmodel_overlay_network_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_network, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the machdep scope.
*/
int
secmodel_overlay_machdep_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_machdep, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the device scope.
*/
int
secmodel_overlay_device_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_device, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}
/*
* Overlay listener for the vnode scope.
*/
int
secmodel_overlay_vnode_cb(kauth_cred_t cred, kauth_action_t action,
void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
switch (action) {
default:
result = KAUTH_RESULT_DEFER;
break;
}
if (result == KAUTH_RESULT_DEFER) {
result = kauth_authorize_action(
secmodel_overlay_iscope_vnode, cred, action,
arg0, arg1, arg2, arg3);
}
return (result);
}