mac802154: add comments for llsec issues

While doing a little test with the llsec implementation I saw these
issues. We should move decryption and encruption somewhere else,
otherwise while capturing with wireshark the mac header shows secuirty
fields but the payload is plaintext.

A complete other issue is what doing with HardMAC drivers where the
payload is always plaintext. I think we need a special handling then in
userspace. We currently doesn't support any HardMAC transceivers, so we
should fix the first issue for SoftMAC transceivers.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index d1c33c1..42e9672 100644 (file)
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -87,6 +87,10 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 
        skb->dev = sdata->dev;
 
+       /* TODO this should be moved after netif_receive_skb call, otherwise
+        * wireshark will show a mac header with security fields and the
+        * payload is already decrypted.
+        */
        rc = mac802154_llsec_decrypt(&sdata->sec, skb);
        if (rc) {
                pr_debug("decryption failed: %i\n", rc);

diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
index 5ee596e..b205bbe 100644 (file)
--- a/net/mac802154/tx.c
+++ b/net/mac802154/tx.c
@@ -129,6 +129,10 @@ ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
        int rc;
 
+       /* TODO we should move it to wpan_dev_hard_header and dev_hard_header
+        * functions. The reason is wireshark will show a mac header which is
+        * with security fields but the payload is not encrypted.
+        */
        rc = mac802154_llsec_encrypt(&sdata->sec, skb);
        if (rc) {
                netdev_warn(dev, "encryption failed: %i\n", rc);