netlabel_cipso_v4.c

linux 内核源代码

/*
 * NetLabel CIPSO/IPv4 Support
 *
 * This file defines the CIPSO/IPv4 functions for the NetLabel system.  The
 * NetLabel system manages static and dynamic label mappings for network
 * protocols such as CIPSO and RIPSO.
 *
 * Author: Paul Moore <[e-mail]>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
 *
 * 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/types.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/audit.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>

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

/* Argument struct for cipso_v4_doi_walk() */
struct netlbl_cipsov4_doiwalk_arg {
	struct netlink_callback *nl_cb;
	struct sk_buff *skb;
	u32 seq;
};

/* NetLabel Generic NETLINK CIPSOv4 family */
static struct genl_family netlbl_cipsov4_gnl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = 0,
	.name = NETLBL_NLTYPE_CIPSOV4_NAME,
	.version = NETLBL_PROTO_VERSION,
	.maxattr = NLBL_CIPSOV4_A_MAX,
};

/* NetLabel Netlink attribute policy */
static const struct nla_policy netlbl_cipsov4_genl_policy[NLBL_CIPSOV4_A_MAX + 1] = {
	[NLBL_CIPSOV4_A_DOI] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_MTYPE] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_TAG] = { .type = NLA_U8 },
	[NLBL_CIPSOV4_A_TAGLST] = { .type = NLA_NESTED },
	[NLBL_CIPSOV4_A_MLSLVLLOC] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_MLSLVLREM] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_MLSLVL] = { .type = NLA_NESTED },
	[NLBL_CIPSOV4_A_MLSLVLLST] = { .type = NLA_NESTED },
	[NLBL_CIPSOV4_A_MLSCATLOC] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_MLSCATREM] = { .type = NLA_U32 },
	[NLBL_CIPSOV4_A_MLSCAT] = { .type = NLA_NESTED },
	[NLBL_CIPSOV4_A_MLSCATLST] = { .type = NLA_NESTED },
};

/*
 * Helper Functions
 */

/**
 * netlbl_cipsov4_doi_free - Frees a CIPSO V4 DOI definition
 * @entry: the entry's RCU field
 *
 * Description:
 * This function is designed to be used as a callback to the call_rcu()
 * function so that the memory allocated to the DOI definition can be released
 * safely.
 *
 */
static void netlbl_cipsov4_doi_free(struct rcu_head *entry)
{
	struct cipso_v4_doi *ptr;

	ptr = container_of(entry, struct cipso_v4_doi, rcu);
	switch (ptr->type) {
	case CIPSO_V4_MAP_STD:
		kfree(ptr->map.std->lvl.cipso);
		kfree(ptr->map.std->lvl.local);
		kfree(ptr->map.std->cat.cipso);
		kfree(ptr->map.std->cat.local);
		break;
	}
	kfree(ptr);
}

/**
 * netlbl_cipsov4_add_common - Parse the common sections of a ADD message
 * @info: the Generic NETLINK info block
 * @doi_def: the CIPSO V4 DOI definition
 *
 * Description:
 * Parse the common sections of a ADD message and fill in the related values
 * in @doi_def.  Returns zero on success, negative values on failure.
 *
 */
static int netlbl_cipsov4_add_common(struct genl_info *info,
				     struct cipso_v4_doi *doi_def)
{
	struct nlattr *nla;
	int nla_rem;
	u32 iter = 0;

	doi_def->doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);

	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_TAGLST],
				NLBL_CIPSOV4_A_MAX,
				netlbl_cipsov4_genl_policy) != 0)
		return -EINVAL;

	nla_for_each_nested(nla, info->attrs[NLBL_CIPSOV4_A_TAGLST], nla_rem)
		if (nla_type(nla) == NLBL_CIPSOV4_A_TAG) {
			if (iter >= CIPSO_V4_TAG_MAXCNT)
				return -EINVAL;
			doi_def->tags[iter++] = nla_get_u8(nla);
		}
	while (iter < CIPSO_V4_TAG_MAXCNT)
		doi_def->tags[iter++] = CIPSO_V4_TAG_INVALID;

	return 0;
}

/*
 * NetLabel Command Handlers
 */

/**
 * netlbl_cipsov4_add_std - Adds a CIPSO V4 DOI definition
 * @info: the Generic NETLINK info block
 *
 * Description:
 * Create a new CIPSO_V4_MAP_STD DOI definition based on the given ADD message
 * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
 * error.
 *
 */
static int netlbl_cipsov4_add_std(struct genl_info *info)
{
	int ret_val = -EINVAL;
	struct cipso_v4_doi *doi_def = NULL;
	struct nlattr *nla_a;
	struct nlattr *nla_b;
	int nla_a_rem;
	int nla_b_rem;
	u32 iter;

	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
	    !info->attrs[NLBL_CIPSOV4_A_MLSLVLLST])
		return -EINVAL;

	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
				NLBL_CIPSOV4_A_MAX,
				netlbl_cipsov4_genl_policy) != 0)
		return -EINVAL;

	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
	if (doi_def == NULL)
		return -ENOMEM;
	doi_def->map.std = kzalloc(sizeof(*doi_def->map.std), GFP_KERNEL);
	if (doi_def->map.std == NULL) {
		ret_val = -ENOMEM;
		goto add_std_failure;
	}
	doi_def->type = CIPSO_V4_MAP_STD;

	ret_val = netlbl_cipsov4_add_common(info, doi_def);
	if (ret_val != 0)
		goto add_std_failure;
	ret_val = -EINVAL;

	nla_for_each_nested(nla_a,
			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
			    nla_a_rem)
		if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
			if (nla_validate_nested(nla_a,
					    NLBL_CIPSOV4_A_MAX,
					    netlbl_cipsov4_genl_policy) != 0)
					goto add_std_failure;
			nla_for_each_nested(nla_b, nla_a, nla_b_rem)
				switch (nla_type(nla_b)) {
				case NLBL_CIPSOV4_A_MLSLVLLOC:
					if (nla_get_u32(nla_b) >
					    CIPSO_V4_MAX_LOC_LVLS)
						goto add_std_failure;
					if (nla_get_u32(nla_b) >=
					    doi_def->map.std->lvl.local_size)
					     doi_def->map.std->lvl.local_size =
						     nla_get_u32(nla_b) + 1;
					break;
				case NLBL_CIPSOV4_A_MLSLVLREM:
					if (nla_get_u32(nla_b) >
					    CIPSO_V4_MAX_REM_LVLS)
						goto add_std_failure;
					if (nla_get_u32(nla_b) >=
					    doi_def->map.std->lvl.cipso_size)
					     doi_def->map.std->lvl.cipso_size =
						     nla_get_u32(nla_b) + 1;
					break;
				}
		}
	doi_def->map.std->lvl.local = kcalloc(doi_def->map.std->lvl.local_size,
					      sizeof(u32),
					      GFP_KERNEL);
	if (doi_def->map.std->lvl.local == NULL) {
		ret_val = -ENOMEM;
		goto add_std_failure;
	}
	doi_def->map.std->lvl.cipso = kcalloc(doi_def->map.std->lvl.cipso_size,
					      sizeof(u32),
					      GFP_KERNEL);
	if (doi_def->map.std->lvl.cipso == NULL) {
		ret_val = -ENOMEM;
		goto add_std_failure;
	}
	for (iter = 0; iter < doi_def->map.std->lvl.local_size; iter++)
		doi_def->map.std->lvl.local[iter] = CIPSO_V4_INV_LVL;
	for (iter = 0; iter < doi_def->map.std->lvl.cipso_size; iter++)
		doi_def->map.std->lvl.cipso[iter] = CIPSO_V4_INV_LVL;
	nla_for_each_nested(nla_a,
			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
			    nla_a_rem)
		if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
			struct nlattr *lvl_loc;
			struct nlattr *lvl_rem;

			lvl_loc = nla_find_nested(nla_a,
						  NLBL_CIPSOV4_A_MLSLVLLOC);
			lvl_rem = nla_find_nested(nla_a,
						  NLBL_CIPSOV4_A_MLSLVLREM);
			if (lvl_loc == NULL || lvl_rem == NULL)
				goto add_std_failure;
			doi_def->map.std->lvl.local[nla_get_u32(lvl_loc)] =
				nla_get_u32(lvl_rem);
			doi_def->map.std->lvl.cipso[nla_get_u32(lvl_rem)] =
				nla_get_u32(lvl_loc);
		}

	if (info->attrs[NLBL_CIPSOV4_A_MLSCATLST]) {
		if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
					NLBL_CIPSOV4_A_MAX,
					netlbl_cipsov4_genl_policy) != 0)
			goto add_std_failure;

		nla_for_each_nested(nla_a,
				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
				    nla_a_rem)
			if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
				if (nla_validate_nested(nla_a,
					      NLBL_CIPSOV4_A_MAX,
					      netlbl_cipsov4_genl_policy) != 0)
					goto add_std_failure;
				nla_for_each_nested(nla_b, nla_a, nla_b_rem)
					switch (nla_type(nla_b)) {
					case NLBL_CIPSOV4_A_MLSCATLOC:
						if (nla_get_u32(nla_b) >
						    CIPSO_V4_MAX_LOC_CATS)
							goto add_std_failure;
						if (nla_get_u32(nla_b) >=
					      doi_def->map.std->cat.local_size)
					     doi_def->map.std->cat.local_size =
						     nla_get_u32(nla_b) + 1;
						break;
					case NLBL_CIPSOV4_A_MLSCATREM:
						if (nla_get_u32(nla_b) >
						    CIPSO_V4_MAX_REM_CATS)
							goto add_std_failure;
						if (nla_get_u32(nla_b) >=
					      doi_def->map.std->cat.cipso_size)
					     doi_def->map.std->cat.cipso_size =
						     nla_get_u32(nla_b) + 1;
						break;
					}
			}
		doi_def->map.std->cat.local = kcalloc(
					      doi_def->map.std->cat.local_size,
					      sizeof(u32),
					      GFP_KERNEL);
		if (doi_def->map.std->cat.local == NULL) {
			ret_val = -ENOMEM;
			goto add_std_failure;
		}
		doi_def->map.std->cat.cipso = kcalloc(
					      doi_def->map.std->cat.cipso_size,
					      sizeof(u32),
					      GFP_KERNEL);
		if (doi_def->map.std->cat.cipso == NULL) {
			ret_val = -ENOMEM;
			goto add_std_failure;
		}
		for (iter = 0; iter < doi_def->map.std->cat.local_size; iter++)
			doi_def->map.std->cat.local[iter] = CIPSO_V4_INV_CAT;
		for (iter = 0; iter < doi_def->map.std->cat.cipso_size; iter++)
			doi_def->map.std->cat.cipso[iter] = CIPSO_V4_INV_CAT;
		nla_for_each_nested(nla_a,
				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
				    nla_a_rem)
			if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
				struct nlattr *cat_loc;
				struct nlattr *cat_rem;

				cat_loc = nla_find_nested(nla_a,
						     NLBL_CIPSOV4_A_MLSCATLOC);
				cat_rem = nla_find_nested(nla_a,
						     NLBL_CIPSOV4_A_MLSCATREM);
				if (cat_loc == NULL || cat_rem == NULL)
					goto add_std_failure;
				doi_def->map.std->cat.local[
							nla_get_u32(cat_loc)] =
					nla_get_u32(cat_rem);
				doi_def->map.std->cat.cipso[
							nla_get_u32(cat_rem)] =
					nla_get_u32(cat_loc);
			}
	}

	ret_val = cipso_v4_doi_add(doi_def);
	if (ret_val != 0)
		goto add_std_failure;
	return 0;

add_std_failure:
	if (doi_def)
		netlbl_cipsov4_doi_free(&doi_def->rcu);
	return ret_val;
}

/**
 * netlbl_cipsov4_add_pass - Adds a CIPSO V4 DOI definition
 * @info: the Generic NETLINK info block
 *
 * Description:
 * Create a new CIPSO_V4_MAP_PASS DOI definition based on the given ADD message
 * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
 * error.
 *
 */
static int netlbl_cipsov4_add_pass(struct genl_info *info)
{
	int ret_val;
	struct cipso_v4_doi *doi_def = NULL;

	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
		return -EINVAL;

	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
	if (doi_def == NULL)
		return -ENOMEM;
	doi_def->type = CIPSO_V4_MAP_PASS;

	ret_val = netlbl_cipsov4_add_common(info, doi_def);
	if (ret_val != 0)
		goto add_pass_failure;

	ret_val = cipso_v4_doi_add(doi_def);
	if (ret_val != 0)
		goto add_pass_failure;
	return 0;

add_pass_failure:
	netlbl_cipsov4_doi_free(&doi_def->rcu);
	return ret_val;
}

/**
 * netlbl_cipsov4_add - Handle an ADD message
 * @skb: the NETLINK buffer
 * @info: the Generic NETLINK info block
 *
 * Description:
 * Create a new DOI definition based on the given ADD message and add it to the
 * CIPSO V4 engine.  Returns zero on success, negative values on failure.
 *
 */
static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)