ieee802154, mac802154: implement devkey record option

The 802.15.4-2011 standard states that for each key, a list of devices
that use this key shall be kept. Previous patches have only considered
two options:

 * a device "uses" (or may use) all keys, rendering the list useless
 * a device is restricted to a certain set of keys

Another option would be that a device *may* use all keys, but need not
do so, and we are interested in the actual set of keys the device uses.
Recording keys used by any given device may have a noticable performance
impact and might not be needed as often. The common case, in which a
device will not switch keys too often, should still perform well.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Phoebe Buckheister 2014-05-16 17:46:45 +02:00 committed by David S. Miller
parent 3e9c156e2c
commit f0f77dc6be
2 changed files with 39 additions and 0 deletions

View File

@ -280,6 +280,7 @@ struct ieee802154_llsec_device_key {
enum {
IEEE802154_LLSEC_DEVKEY_IGNORE,
IEEE802154_LLSEC_DEVKEY_RESTRICT,
IEEE802154_LLSEC_DEVKEY_RECORD,
__IEEE802154_LLSEC_DEVKEY_MAX,
};

View File

@ -920,6 +920,37 @@ llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
}
static int
llsec_update_devkey_record(struct mac802154_llsec_device *dev,
const struct ieee802154_llsec_key_id *in_key)
{
struct mac802154_llsec_device_key *devkey;
devkey = llsec_devkey_find(dev, in_key);
if (!devkey) {
struct mac802154_llsec_device_key *next;
next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
if (!next)
return -ENOMEM;
next->devkey.key_id = *in_key;
spin_lock_bh(&dev->lock);
devkey = llsec_devkey_find(dev, in_key);
if (!devkey)
list_add_rcu(&next->devkey.list, &dev->dev.keys);
else
kfree(next);
spin_unlock_bh(&dev->lock);
}
return 0;
}
static int
llsec_update_devkey_info(struct mac802154_llsec_device *dev,
const struct ieee802154_llsec_key_id *in_key,
@ -933,6 +964,13 @@ llsec_update_devkey_info(struct mac802154_llsec_device *dev,
return -ENOENT;
}
if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
int rc = llsec_update_devkey_record(dev, in_key);
if (rc < 0)
return rc;
}
spin_lock_bh(&dev->lock);
if ((!devkey && frame_counter < dev->dev.frame_counter) ||