/* selinux routines
 * Copyright (C) 2011 Avesh Agarwal <avagarwa@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 */

#include "security_selinux.h"
#include "lswlog.h"

static int selinux_ready = 0;

void init_avc(void)
{
	if (!is_selinux_enabled()) {
		DBG_log("selinux support is NOT enabled.\n");
		return;
	} else {
		DBG_log("selinux support is enabled.\n");
	}

	if (avc_init("libreswan", NULL, NULL, NULL, NULL) == 0)
		selinux_ready = 1;
	else
		DBG_log("selinux: could not initialize avc.\n");
}

int within_range(security_context_t sl, security_context_t range)
{
	int rtn = 1;
	security_id_t slsid;
	security_id_t rangesid;
	struct av_decision avd;
	security_class_t tclass;
	access_vector_t av;

	if (!selinux_ready) {  /* mls may not be enabled */
		DBG_log("selinux check failed");
		return 0;
	}

	/*
	 * * Get the sids for the sl and range contexts
	 */
	rtn = avc_context_to_sid(sl, &slsid);
	if (rtn != 0) {
		DBG_log("within_range: Unable to retrieve sid for sl context (%s)",
			sl);
		return 0;
	}
	rtn = avc_context_to_sid(range, &rangesid);
	if (rtn != 0) {
		DBG_log("within_range: Unable to retrieve sid for range context (%s)",
			range);
		sidput(slsid);
		return 0;
	}

	/*
	** Straight up test between sl and range
	**/
	tclass = SECCLASS_ASSOCIATION;
	av = ASSOCIATION__POLMATCH;
	rtn = avc_has_perm(slsid, rangesid, tclass, av, NULL, &avd);
	if (rtn != 0) {
		DBG_log("within_range: The sl (%s) is not within range of (%s)", sl,
			range);
		sidput(slsid);
		sidput(rangesid);
		return 0;
	}
	DBG_log("within_range: The sl (%s) is within range of (%s)", sl,
		range);
	return 1;
}