mac802154: add llsec structures and mutators

This patch adds containers and mutators for the major ieee802154_llsec
structures to mac802154. Most of the (rather simple) ieee802154_llsec
structs are wrapped only to provide an rcu_head for orderly disposal,
but some structs - llsec keys notably - require more complex
bookkeeping.

Since each llsec key may be referenced by a number of llsec key table
entries (with differing key ids, but the same actual key), we want to
save memory and not allocate crypto transforms for each entry in the
table. Thus, the mac802154 llsec key is reference-counted instead.
Further, each key will have four associated crypto transforms - three
CCM transforms for the authsizes 4/8/16 and one CTR transform for
unauthenticated encryption. If we had a CCM* transform that allowed
authsize 0, and authsize as part of requests instead of transforms, this
would not be necessary.
Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac802154/Makefile

 obj-$(CONFIG_MAC802154)	+= mac802154.o
-mac802154-objs		:= ieee802154_dev.o rx.o tx.o mac_cmd.o mib.o monitor.o wpan.o
+mac802154-objs		:= ieee802154_dev.o rx.o tx.o mac_cmd.o mib.o \
+			   monitor.o wpan.o llsec.o
 
 ccflags-y += -D__CHECK_ENDIAN__

net/mac802154/llsec.h

+/*
+ * Copyright (C) 2014 Fraunhofer ITWM
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * Written by:
+ * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
+ */
+
+#ifndef MAC802154_LLSEC_H
+#define MAC802154_LLSEC_H
+
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include <linux/crypto.h>
+#include <linux/kref.h>
+#include <linux/spinlock.h>
+#include <net/af_ieee802154.h>
+#include <net/ieee802154_netdev.h>
+
+struct mac802154_llsec_key {
+	struct ieee802154_llsec_key key;
+
+	/* one tfm for each authsize (4/8/16) */
+	struct crypto_aead *tfm[3];
+	struct crypto_blkcipher *tfm0;
+
+	struct kref ref;
+};
+
+struct mac802154_llsec_device_key {
+	struct ieee802154_llsec_device_key devkey;
+
+	struct rcu_head rcu;
+};
+
+struct mac802154_llsec_device {
+	struct ieee802154_llsec_device dev;
+
+	struct hlist_node bucket_s;
+	struct hlist_node bucket_hw;
+
+	/* protects dev.frame_counter and the elements of dev.keys */
+	spinlock_t lock;
+
+	struct rcu_head rcu;
+};
+
+struct mac802154_llsec_seclevel {
+	struct ieee802154_llsec_seclevel level;
+
+	struct rcu_head rcu;
+};
+
+struct mac802154_llsec {
+	struct ieee802154_llsec_params params;
+	struct ieee802154_llsec_table table;
+
+	DECLARE_HASHTABLE(devices_short, 6);
+	DECLARE_HASHTABLE(devices_hw, 6);
+
+	/* protects params, all other fields are fine with RCU */
+	rwlock_t lock;
+};
+
+void mac802154_llsec_init(struct mac802154_llsec *sec);
+void mac802154_llsec_destroy(struct mac802154_llsec *sec);
+
+int mac802154_llsec_get_params(struct mac802154_llsec *sec,
+			       struct ieee802154_llsec_params *params);
+int mac802154_llsec_set_params(struct mac802154_llsec *sec,
+			       const struct ieee802154_llsec_params *params,
+			       int changed);
+
+int mac802154_llsec_key_add(struct mac802154_llsec *sec,
+			    const struct ieee802154_llsec_key_id *id,
+			    const struct ieee802154_llsec_key *key);
+int mac802154_llsec_key_del(struct mac802154_llsec *sec,
+			    const struct ieee802154_llsec_key_id *key);
+
+int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
+			    const struct ieee802154_llsec_device *dev);
+int mac802154_llsec_dev_del(struct mac802154_llsec *sec,
+			    __le64 device_addr);
+
+int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
+			       __le64 dev_addr,
+			       const struct ieee802154_llsec_device_key *key);
+int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
+			       __le64 dev_addr,
+			       const struct ieee802154_llsec_device_key *key);
+
+int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
+				 const struct ieee802154_llsec_seclevel *sl);
+int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
+				 const struct ieee802154_llsec_seclevel *sl);
+
+#endif /* MAC802154_LLSEC_H */

net/mac802154/mac802154.h

@@ -23,6 +23,7 @@
 #ifndef MAC802154_H
 #define MAC802154_H
 
+#include <net/mac802154.h>
 #include <net/ieee802154_netdev.h>
 
 /* mac802154 device private data */