netlabel: Initial support for the CALIPSO netlink protocol.

CALIPSO is a packet labelling protocol for IPv6 which is very similar
to CIPSO.  It is specified in RFC 5570.  Much of the code is based on
the current CIPSO code.

This adds support for adding passthrough-type CALIPSO DOIs through the
NLBL_CALIPSO_C_ADD command.  It requires attributes:

 NLBL_CALIPSO_A_TYPE which must be CALIPSO_MAP_PASS.
 NLBL_CALIPSO_A_DOI.

In passthrough mode the CALIPSO engine will map MLS secattr levels
and categories directly to the packet label.

At this stage, the major difference between this and the CIPSO
code is that IPv6 may be compiled as a module.  To allow for
this the CALIPSO functions are registered at module init time.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 216 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_calipso.c b/net/netlabel/netlabel_calipso.c
new file mode 100644
index 000000000000..8a113f91b7a1
--- /dev/null
+++ b/net/netlabel/netlabel_calipso.c
@@ -0,0 +1,216 @@
+/*
+ * NetLabel CALIPSO/IPv6 Support
+ *
+ * This file defines the CALIPSO/IPv6 functions for the NetLabel system.  The
+ * NetLabel system manages static and dynamic label mappings for network
+ * protocols such as CIPSO and CALIPSO.
+ *
+ * Authors: Paul Moore <paul@paul-moore.com>
+ *          Huw Davies <huw@codeweavers.com>
+ *
+ */
+
+/* (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+#include <net/netlabel.h>
+#include <net/calipso.h>
+#include <linux/atomic.h>
+
+#include "netlabel_user.h"
+#include "netlabel_calipso.h"
+#include "netlabel_mgmt.h"
+#include "netlabel_domainhash.h"
+
+/* NetLabel Generic NETLINK CALIPSO family */
+static struct genl_family netlbl_calipso_gnl_family = {
+	.id = GENL_ID_GENERATE,
+	.hdrsize = 0,
+	.name = NETLBL_NLTYPE_CALIPSO_NAME,
+	.version = NETLBL_PROTO_VERSION,
+	.maxattr = NLBL_CALIPSO_A_MAX,
+};
+
+/* NetLabel Netlink attribute policy */
+static const struct nla_policy calipso_genl_policy[NLBL_CALIPSO_A_MAX + 1] = {
+	[NLBL_CALIPSO_A_DOI] = { .type = NLA_U32 },
+	[NLBL_CALIPSO_A_MTYPE] = { .type = NLA_U32 },
+};
+
+/* NetLabel Command Handlers
+ */
+/**
+ * netlbl_calipso_add_pass - Adds a CALIPSO pass DOI definition
+ * @info: the Generic NETLINK info block
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Create a new CALIPSO_MAP_PASS DOI definition based on the given ADD message
+ * and add it to the CALIPSO engine.  Return zero on success and non-zero on
+ * error.
+ *
+ */
+static int netlbl_calipso_add_pass(struct genl_info *info,
+				   struct netlbl_audit *audit_info)
+{
+	int ret_val;
+	struct calipso_doi *doi_def = NULL;
+
+	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
+	if (!doi_def)
+		return -ENOMEM;
+	doi_def->type = CALIPSO_MAP_PASS;
+	doi_def->doi = nla_get_u32(info->attrs[NLBL_CALIPSO_A_DOI]);
+	ret_val = calipso_doi_add(doi_def, audit_info);
+	if (ret_val != 0)
+		calipso_doi_free(doi_def);
+
+	return ret_val;
+}
+
+/**
+ * netlbl_calipso_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
+ * CALIPSO engine.  Returns zero on success, negative values on failure.
+ *
+ */
+static int netlbl_calipso_add(struct sk_buff *skb, struct genl_info *info)
+
+{
+	int ret_val = -EINVAL;
+	struct netlbl_audit audit_info;
+
+	if (!info->attrs[NLBL_CALIPSO_A_DOI] ||
+	    !info->attrs[NLBL_CALIPSO_A_MTYPE])
+		return -EINVAL;
+
+	netlbl_netlink_auditinfo(skb, &audit_info);
+	switch (nla_get_u32(info->attrs[NLBL_CALIPSO_A_MTYPE])) {
+	case CALIPSO_MAP_PASS:
+		ret_val = netlbl_calipso_add_pass(info, &audit_info);
+		break;
+	}
+	if (ret_val == 0)
+		atomic_inc(&netlabel_mgmt_protocount);
+
+	return ret_val;
+}
+
+/* NetLabel Generic NETLINK Command Definitions
+ */
+
+static const struct genl_ops netlbl_calipso_ops[] = {
+	{
+	.cmd = NLBL_CALIPSO_C_ADD,
+	.flags = GENL_ADMIN_PERM,
+	.policy = calipso_genl_policy,
+	.doit = netlbl_calipso_add,
+	.dumpit = NULL,
+	},
+};
+
+/* NetLabel Generic NETLINK Protocol Functions
+ */
+
+/**
+ * netlbl_calipso_genl_init - Register the CALIPSO NetLabel component
+ *
+ * Description:
+ * Register the CALIPSO packet NetLabel component with the Generic NETLINK
+ * mechanism.  Returns zero on success, negative values on failure.
+ *
+ */
+int __init netlbl_calipso_genl_init(void)
+{
+	return genl_register_family_with_ops(&netlbl_calipso_gnl_family,
+					     netlbl_calipso_ops);
+}
+
+static const struct netlbl_calipso_ops *calipso_ops;
+
+/**
+ * netlbl_calipso_ops_register - Register the CALIPSO operations
+ *
+ * Description:
+ * Register the CALIPSO packet engine operations.
+ *
+ */
+const struct netlbl_calipso_ops *
+netlbl_calipso_ops_register(const struct netlbl_calipso_ops *ops)
+{
+	return xchg(&calipso_ops, ops);
+}
+EXPORT_SYMBOL(netlbl_calipso_ops_register);
+
+static const struct netlbl_calipso_ops *netlbl_calipso_ops_get(void)
+{
+	return ACCESS_ONCE(calipso_ops);
+}
+
+/**
+ * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine
+ * @doi_def: the DOI structure
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * The caller defines a new DOI for use by the CALIPSO engine and calls this
+ * function to add it to the list of acceptable domains.  The caller must
+ * ensure that the mapping table specified in @doi_def->map meets all of the
+ * requirements of the mapping type (see calipso.h for details).  Returns
+ * zero on success and non-zero on failure.
+ *
+ */
+int calipso_doi_add(struct calipso_doi *doi_def,
+		    struct netlbl_audit *audit_info)
+{
+	int ret_val = -ENOMSG;
+	const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
+
+	if (ops)
+		ret_val = ops->doi_add(doi_def, audit_info);
+	return ret_val;
+}
+
+/**
+ * calipso_doi_free - Frees a DOI definition
+ * @doi_def: the DOI definition
+ *
+ * Description:
+ * This function frees all of the memory associated with a DOI definition.
+ *
+ */
+void calipso_doi_free(struct calipso_doi *doi_def)
+{
+	const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
+
+	if (ops)
+		ops->doi_free(doi_def);
+}