diff options
Diffstat (limited to 'net/mac802154/llsec.c')
| -rw-r--r-- | net/mac802154/llsec.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c new file mode 100644 index 000000000000..a210d1eb65a9 --- /dev/null +++ b/net/mac802154/llsec.c @@ -0,0 +1,529 @@ +/* + * 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> + */ + +#include <linux/err.h> +#include <linux/bug.h> +#include <linux/completion.h> +#include <net/ieee802154.h> + +#include "mac802154.h" +#include "llsec.h" + +static void llsec_key_put(struct mac802154_llsec_key *key); +static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, + const struct ieee802154_llsec_key_id *b); + +static void llsec_dev_free(struct mac802154_llsec_device *dev); + +void mac802154_llsec_init(struct mac802154_llsec *sec) +{ + memset(sec, 0, sizeof(*sec)); + + memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN); + + INIT_LIST_HEAD(&sec->table.security_levels); + INIT_LIST_HEAD(&sec->table.devices); + INIT_LIST_HEAD(&sec->table.keys); + hash_init(sec->devices_short); + hash_init(sec->devices_hw); + rwlock_init(&sec->lock); +} + +void mac802154_llsec_destroy(struct mac802154_llsec *sec) +{ + struct ieee802154_llsec_seclevel *sl, *sn; + struct ieee802154_llsec_device *dev, *dn; + struct ieee802154_llsec_key_entry *key, *kn; + + list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) { + struct mac802154_llsec_seclevel *msl; + + msl = container_of(sl, struct mac802154_llsec_seclevel, level); + list_del(&sl->list); + kfree(msl); + } + + list_for_each_entry_safe(dev, dn, &sec->table.devices, list) { + struct mac802154_llsec_device *mdev; + + mdev = container_of(dev, struct mac802154_llsec_device, dev); + list_del(&dev->list); + llsec_dev_free(mdev); + } + + list_for_each_entry_safe(key, kn, &sec->table.keys, list) { + struct mac802154_llsec_key *mkey; + + mkey = container_of(key->key, struct mac802154_llsec_key, key); + list_del(&key->list); + llsec_key_put(mkey); + kfree(key); + } +} + + + +int mac802154_llsec_get_params(struct mac802154_llsec *sec, + struct ieee802154_llsec_params *params) +{ + read_lock_bh(&sec->lock); + *params = sec->params; + read_unlock_bh(&sec->lock); + + return 0; +} + +int mac802154_llsec_set_params(struct mac802154_llsec *sec, + const struct ieee802154_llsec_params *params, + int changed) +{ + write_lock_bh(&sec->lock); + + if (changed & IEEE802154_LLSEC_PARAM_ENABLED) + sec->params.enabled = params->enabled; + if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER) + sec->params.frame_counter = params->frame_counter; + if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL) + sec->params.out_level = params->out_level; + if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY) + sec->params.out_key = params->out_key; + if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE) + sec->params.default_key_source = params->default_key_source; + if (changed & IEEE802154_LLSEC_PARAM_PAN_ID) + sec->params.pan_id = params->pan_id; + if (changed & IEEE802154_LLSEC_PARAM_HWADDR) + sec->params.hwaddr = params->hwaddr; + if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR) + sec->params.coord_hwaddr = params->coord_hwaddr; + if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR) + sec->params.coord_shortaddr = params->coord_shortaddr; + + write_unlock_bh(&sec->lock); + + return 0; +} + + + +static struct mac802154_llsec_key* +llsec_key_alloc(const struct ieee802154_llsec_key *template) +{ + const int authsizes[3] = { 4, 8, 16 }; + struct mac802154_llsec_key *key; + int i; + + key = kzalloc(sizeof(*key), GFP_KERNEL); + if (!key) + return NULL; + + kref_init(&key->ref); + key->key = *template; + + BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm)); + + for (i = 0; i < ARRAY_SIZE(key->tfm); i++) { + key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0, + CRYPTO_ALG_ASYNC); + if (!key->tfm[i]) + goto err_tfm; + if (crypto_aead_setkey(key->tfm[i], template->key, + IEEE802154_LLSEC_KEY_SIZE)) + goto err_tfm; + if (crypto_aead_setauthsize(key->tfm[i], authsizes[i])) + goto err_tfm; + } + + key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); + if (!key->tfm0) + goto err_tfm; + + if (crypto_blkcipher_setkey(key->tfm0, template->key, + IEEE802154_LLSEC_KEY_SIZE)) + goto err_tfm0; + + return key; + +err_tfm0: + crypto_free_blkcipher(key->tfm0); +err_tfm: + for (i = 0; i < ARRAY_SIZE(key->tfm); i++) + if (key->tfm[i]) + crypto_free_aead(key->tfm[i]); + + kfree(key); + return NULL; +} + +static void llsec_key_release(struct kref *ref) +{ + struct mac802154_llsec_key *key; + int i; + + key = container_of(ref, struct mac802154_llsec_key, ref); + + for (i = 0; i < ARRAY_SIZE(key->tfm); i++) + crypto_free_aead(key->tfm[i]); + + crypto_free_blkcipher(key->tfm0); + kfree(key); +} + +static struct mac802154_llsec_key* +llsec_key_get(struct mac802154_llsec_key *key) +{ + kref_get(&key->ref); + return key; +} + +static void llsec_key_put(struct mac802154_llsec_key *key) +{ + kref_put(&key->ref, llsec_key_release); +} + +static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, + const struct ieee802154_llsec_key_id *b) +{ + if (a->mode != b->mode) + return false; + + if (a->mode == IEEE802154_SCF_KEY_IMPLICIT) + return ieee802154_addr_equal(&a->device_addr, &b->device_addr); + + if (a->id != b->id) + return false; + + switch (a->mode) { + case IEEE802154_SCF_KEY_SHORT_INDEX: + return a->short_source == b->short_source; + case IEEE802154_SCF_KEY_HW_INDEX: + return a->extended_source == b->extended_source; + } + + return false; +} + +int mac802154_llsec_key_add(struct mac802154_llsec *sec, + const struct ieee802154_llsec_key_id *id, + const struct ieee802154_llsec_key *key) +{ + struct mac802154_llsec_key *mkey = NULL; + struct ieee802154_llsec_key_entry *pos, *new; + + if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) && + key->cmd_frame_ids) + return -EINVAL; + + list_for_each_entry(pos, &sec->table.keys, list) { + if (llsec_key_id_equal(&pos->id, id)) + return -EEXIST; + + if (memcmp(pos->key->key, key->key, + IEEE802154_LLSEC_KEY_SIZE)) + continue; + + mkey = container_of(pos->key, struct mac802154_llsec_key, key); + + /* Don't allow multiple instances of the same AES key to have + * different allowed frame types/command frame ids, as this is + * not possible in the 802.15.4 PIB. + */ + if (pos->key->frame_types != key->frame_types || + pos->key->cmd_frame_ids != key->cmd_frame_ids) + return -EEXIST; + + break; + } + + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return -ENOMEM; + + if (!mkey) + mkey = llsec_key_alloc(key); + else + mkey = llsec_key_get(mkey); + + if (!mkey) + goto fail; + + new->id = *id; + new->key = &mkey->key; + + list_add_rcu(&new->list, &sec->table.keys); + + return 0; + +fail: + kfree(new); + return -ENOMEM; +} + +int mac802154_llsec_key_del(struct mac802154_llsec *sec, + const struct ieee802154_llsec_key_id *key) +{ + struct ieee802154_llsec_key_entry *pos; + + list_for_each_entry(pos, &sec->table.keys, list) { + struct mac802154_llsec_key *mkey; + + mkey = container_of(pos->key, struct mac802154_llsec_key, key); + + if (llsec_key_id_equal(&pos->id, key)) { + llsec_key_put(mkey); + return 0; + } + } + + return -ENOENT; +} + + + +static bool llsec_dev_use_shortaddr(__le16 short_addr) +{ + return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) && + short_addr != cpu_to_le16(0xffff); +} + +static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) +{ + return ((__force u16) short_addr) << 16 | (__force u16) pan_id; +} + +static u64 llsec_dev_hash_long(__le64 hwaddr) +{ + return (__force u64) hwaddr; +} + +static struct mac802154_llsec_device* +llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr, + __le16 pan_id) +{ + struct mac802154_llsec_device *dev; + u32 key = llsec_dev_hash_short(short_addr, pan_id); + + hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { + if (dev->dev.short_addr == short_addr && + dev->dev.pan_id == pan_id) + return dev; + } + + return NULL; +} + +static struct mac802154_llsec_device* +llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr) +{ + struct mac802154_llsec_device *dev; + u64 key = llsec_dev_hash_long(hwaddr); + + hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { + if (dev->dev.hwaddr == hwaddr) + return dev; + } + + return NULL; +} + +static void llsec_dev_free(struct mac802154_llsec_device *dev) +{ + struct ieee802154_llsec_device_key *pos, *pn; + struct mac802154_llsec_device_key *devkey; + + list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) { + devkey = container_of(pos, struct mac802154_llsec_device_key, + devkey); + + list_del(&pos->list); + kfree(devkey); + } + + kfree(dev); +} + +int mac802154_llsec_dev_add(struct mac802154_llsec *sec, + const struct ieee802154_llsec_device *dev) +{ + struct mac802154_llsec_device *entry; + u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id); + u64 hwkey = llsec_dev_hash_long(dev->hwaddr); + + BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN); + + if ((llsec_dev_use_shortaddr(dev->short_addr) && + llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) || + llsec_dev_find_long(sec, dev->hwaddr)) + return -EEXIST; + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + entry->dev = *dev; + spin_lock_init(&entry->lock); + INIT_LIST_HEAD(&entry->dev.keys); + + if (llsec_dev_use_shortaddr(dev->short_addr)) + hash_add_rcu(sec->devices_short, &entry->bucket_s, skey); + else + INIT_HLIST_NODE(&entry->bucket_s); + + hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey); + list_add_tail_rcu(&entry->dev.list, &sec->table.devices); + + return 0; +} + +static void llsec_dev_free_rcu(struct rcu_head *rcu) +{ + llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); +} + +int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr) +{ + struct mac802154_llsec_device *pos; + + pos = llsec_dev_find_long(sec, device_addr); + if (!pos) + return -ENOENT; + + hash_del_rcu(&pos->bucket_s); + hash_del_rcu(&pos->bucket_hw); + call_rcu(&pos->rcu, llsec_dev_free_rcu); + + return 0; +} + + + +static struct mac802154_llsec_device_key* +llsec_devkey_find(struct mac802154_llsec_device *dev, + const struct ieee802154_llsec_key_id *key) +{ + struct ieee802154_llsec_device_key *devkey; + + list_for_each_entry_rcu(devkey, &dev->dev.keys, list) { + if (!llsec_key_id_equal(key, &devkey->key_id)) + continue; + + return container_of(devkey, struct mac802154_llsec_device_key, + devkey); + } + + return NULL; +} + +int mac802154_llsec_devkey_add(struct mac802154_llsec *sec, + __le64 dev_addr, + const struct ieee802154_llsec_device_key *key) +{ + struct mac802154_llsec_device *dev; + struct mac802154_llsec_device_key *devkey; + + dev = llsec_dev_find_long(sec, dev_addr); + + if (!dev) + return -ENOENT; + + if (llsec_devkey_find(dev, &key->key_id)) + return -EEXIST; + + devkey = kmalloc(sizeof(*devkey), GFP_KERNEL); + if (!devkey) + return -ENOMEM; + + devkey->devkey = *key; + list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys); + return 0; +} + +int mac802154_llsec_devkey_del(struct mac802154_llsec *sec, + __le64 dev_addr, + const struct ieee802154_llsec_device_key *key) +{ + struct mac802154_llsec_device *dev; + struct mac802154_llsec_device_key *devkey; + + dev = llsec_dev_find_long(sec, dev_addr); + + if (!dev) + return -ENOENT; + + devkey = llsec_devkey_find(dev, &key->key_id); + if (!devkey) + return -ENOENT; + + list_del_rcu(&devkey->devkey.list); + kfree_rcu(devkey, rcu); + return 0; +} + + + +static struct mac802154_llsec_seclevel* +llsec_find_seclevel(const struct mac802154_llsec *sec, + const struct ieee802154_llsec_seclevel *sl) +{ + struct ieee802154_llsec_seclevel *pos; + + list_for_each_entry(pos, &sec->table.security_levels, list) { + if (pos->frame_type != sl->frame_type || + (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD && + pos->cmd_frame_id != sl->cmd_frame_id) || + pos->device_override != sl->device_override || + pos->sec_levels != sl->sec_levels) + continue; + + return container_of(pos, struct mac802154_llsec_seclevel, + level); + } + + return NULL; +} + +int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec, + const struct ieee802154_llsec_seclevel *sl) +{ + struct mac802154_llsec_seclevel *entry; + + if (llsec_find_seclevel(sec, sl)) + return -EEXIST; + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + entry->level = *sl; + + list_add_tail_rcu(&entry->level.list, &sec->table.security_levels); + + return 0; +} + +int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec, + const struct ieee802154_llsec_seclevel *sl) +{ + struct mac802154_llsec_seclevel *pos; + + pos = llsec_find_seclevel(sec, sl); + if (!pos) + return -ENOENT; + + list_del_rcu(&pos->level.list); + kfree_rcu(pos, rcu); + + return 0; +} |