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>

2 files changed, 102 insertions, 0 deletions

diff --git a/include/net/calipso.h b/include/net/calipso.h
new file mode 100644
index 0000000..38dbb47
--- /dev/null
+++ b/include/net/calipso.h
@@ -0,0 +1,79 @@
+/*
+ * CALIPSO - Common Architecture Label IPv6 Security Option
+ *
+ * This is an implementation of the CALIPSO protocol as specified in
+ * RFC 5570.
+ *
+ * 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/>.
+ *
+ */
+
+#ifndef _CALIPSO_H
+#define _CALIPSO_H
+
+#include <linux/types.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/netlabel.h>
+#include <net/request_sock.h>
+#include <linux/atomic.h>
+#include <asm/unaligned.h>
+
+/* known doi values */
+#define CALIPSO_DOI_UNKNOWN          0x00000000
+
+/* doi mapping types */
+#define CALIPSO_MAP_UNKNOWN          0
+#define CALIPSO_MAP_PASS             2
+
+/*
+ * CALIPSO DOI definitions
+ */
+
+/* DOI definition struct */
+struct calipso_doi {
+	u32 doi;
+	u32 type;
+
+	atomic_t refcount;
+	struct list_head list;
+	struct rcu_head rcu;
+};
+
+#ifdef CONFIG_NETLABEL
+int __init calipso_init(void);
+void calipso_exit(void);
+#else
+static inline int __init calipso_init(void)
+{
+	return 0;
+}
+
+static inline void calipso_exit(void)
+{
+}
+#endif /* CONFIG_NETLABEL */
+
+#endif /* _CALIPSO_H */
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 7b5a300..6af1bb6 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -40,6 +40,7 @@
 #include <linux/atomic.h>
 
 struct cipso_v4_doi;
+struct calipso_doi;
 
 /*
  * NetLabel - A management interface for maintaining network packet label
@@ -94,6 +95,8 @@ struct cipso_v4_doi;
 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
 #define NETLBL_NLTYPE_ADDRSELECT        6
 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
+#define NETLBL_NLTYPE_CALIPSO           7
+#define NETLBL_NLTYPE_CALIPSO_NAME      "NLBL_CALIPSO"
 
 /*
  * NetLabel - Kernel API for accessing the network packet label mappings.
@@ -216,6 +219,23 @@ struct netlbl_lsm_secattr {
 	} attr;
 };
 
+/**
+ * struct netlbl_calipso_ops - NetLabel CALIPSO operations
+ * @doi_add: add a CALIPSO DOI
+ * @doi_free: free a CALIPSO DOI
+ *
+ * Description:
+ * This structure is filled out by the CALIPSO engine and passed
+ * to the NetLabel core via a call to netlbl_calipso_ops_register().
+ * It enables the CALIPSO engine (and hence IPv6) to be compiled
+ * as a module.
+ */
+struct netlbl_calipso_ops {
+	int (*doi_add)(struct calipso_doi *doi_def,
+		       struct netlbl_audit *audit_info);
+	void (*doi_free)(struct calipso_doi *doi_def);
+};
+
 /*
  * LSM security attribute operations (inline)
  */
@@ -598,4 +618,7 @@ static inline struct audit_buffer *netlbl_audit_start(int type,
 }
 #endif /* CONFIG_NETLABEL */
 
+const struct netlbl_calipso_ops *
+netlbl_calipso_ops_register(const struct netlbl_calipso_ops *ops);
+
 #endif /* _NETLABEL_H */