path: root/net/netlabel/netlabel_kapi.c

/*
 * NetLabel Kernel API
 *
 * This file defines the kernel API for the NetLabel system.  The NetLabel
 * system manages static and dynamic label mappings for network protocols such
 * as CIPSO and RIPSO.
 *
 * Author: Paul Moore <paul.moore@hp.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
 *
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/audit.h>
#include <net/ip.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/bug.h>
#include <asm/atomic.h>

#include "netlabel_domainhash.h"
#include "netlabel_unlabeled.h"
#include "netlabel_cipso_v4.h"
#include "netlabel_user.h"
#include "netlabel_mgmt.h"

/*
 * Configuration Functions
 */

/**
 * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
 * @domain: the domain mapping to remove
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
 * default domain mapping to be removed.  Returns zero on success, negative
 * values on failure.
 *
 */
int netlbl_cfg_map_del(const char *domain, struct netlbl_audit *audit_info)
{
	return netlbl_domhsh_remove(domain, audit_info);
}

/**
 * netlbl_cfg_unlbl_add_map - Add an unlabeled NetLabel/LSM domain mapping
 * @domain: the domain mapping to add
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
 * causes a new default domain mapping to be added.  Returns zero on success,
 * negative values on failure.
 *
 */
int netlbl_cfg_unlbl_add_map(const char *domain,
			     struct netlbl_audit *audit_info)
{
	int ret_val = -ENOMEM;
	struct netlbl_dom_map *entry;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (entry == NULL)
		return -ENOMEM;
	if (domain != NULL) {
		entry->domain = kstrdup(domain, GFP_ATOMIC);
		if (entry->domain == NULL)
			goto cfg_unlbl_add_map_failure;
	}
	entry->type = NETLBL_NLTYPE_UNLABELED;

	ret_val = netlbl_domhsh_add(entry, audit_info);
	if (ret_val != 0)
		goto cfg_unlbl_add_map_failure;

	return 0;

cfg_unlbl_add_map_failure:
	if (entry != NULL)
		kfree(entry->domain);
	kfree(entry);
	return ret_val;
}

/**
 * netlbl_cfg_cipsov4_add_map - Add a new CIPSOv4 DOI definition and mapping
 * @doi_def: the DOI definition
 * @domain: the domain mapping to add
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Add a new CIPSOv4 DOI definition and NetLabel/LSM domain mapping for this
 * new DOI definition to the NetLabel subsystem.  A @domain value of NULL adds
 * a new default domain mapping.  Returns zero on success, negative values on
 * failure.
 *
 */
int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
			       const char *domain,
			       struct netlbl_audit *audit_info)
{
	int ret_val = -ENOMEM;
	u32 doi;
	u32 doi_type;
	struct netlbl_dom_map *entry;
	const char *type_str;
	struct audit_buffer *audit_buf;

	doi = doi_def->doi;
	doi_type = doi_def->type;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (entry == NULL)
		return -ENOMEM;
	if (domain != NULL) {
		entry->domain = kstrdup(domain, GFP_ATOMIC);
		if (entry->domain == NULL)
			goto cfg_cipsov4_add_map_failure;
	}

	ret_val = cipso_v4_doi_add(doi_def);
	if (ret_val != 0)
		goto cfg_cipsov4_add_map_failure_remove_doi;
	entry->type = NETLBL_NLTYPE_CIPSOV4;
	entry->type_def.cipsov4 = cipso_v4_doi_getdef(doi);
	if (entry->type_def.cipsov4 == NULL) {
		ret_val = -ENOENT;
		goto cfg_cipsov4_add_map_failure_remove_doi;
	}
	ret_val = netlbl_domhsh_add(entry, audit_info);
	if (ret_val != 0)
		goto cfg_cipsov4_add_map_failure_release_doi;

cfg_cipsov4_add_map_return:
	audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD,
					      audit_info);
	if (audit_buf != NULL) {
		switch (doi_type) {
		case CIPSO_V4_MAP_TRANS:
			type_str = "trans";
			break;
		case CIPSO_V4_MAP_PASS:
			type_str = "pass";
			break;
		case CIPSO_V4_MAP_LOCAL:
			type_str = "local";
			break;
		default:
			type_str = "(unknown)";
		}
		audit_log_format(audit_buf,
				 " cipso_doi=%u cipso_type=%s res=%u",
				 doi, type_str, ret_val == 0 ? 1 : 0);
		audit_log_end(audit_buf);
	}

	return ret_val;

cfg_cipsov4_add_map_failure_release_doi:
	cipso_v4_doi_putdef(doi_def);
cfg_cipsov4_add_map_failure_remove_doi:
	cipso_v4_doi_remove(doi, audit_info);
cfg_cipsov4_add_map_failure:
	if (entry != NULL)
		kfree(entry->domain);
	kfree(entry);
	goto cfg_cipsov4_add_map_return;
}

/*
 * Security Attribute Functions
 */

/**
 * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
 * @catmap: the category bitmap
 * @offset: the offset to start searching at, in bits
 *
 * Description:
 * This function walks a LSM secattr category bitmap starting at @offset and
 * returns the spot of the first set bit or -ENOENT if no bits are set.
 *
 */
int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
			       u32 offset)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_idx;
	u32 node_bit;
	NETLBL_CATMAP_MAPTYPE bitmap;

	if (offset > iter->startbit) {
		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
			iter = iter->next;
			if (iter == NULL)
				return -ENOENT;
		}
		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
		node_bit = offset - iter->startbit -
			   (NETLBL_CATMAP_MAPSIZE * node_idx);
	} else {
		node_idx = 0;
		node_bit = 0;
	}
	bitmap = iter->bitmap[node_idx] >> node_bit;

	for (;;) {
		if (bitmap != 0) {
			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
				bitmap >>= 1;
				node_bit++;
			}
			return iter->startbit +
				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
		}
		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
			if (iter->next != NULL) {
				iter = iter->next;
				node_idx = 0;
			} else
				return