mac802154: Fix MAC header and payload encrypted

According to  802.15.4-2003/2006/2015 specifications the MAC frame is
composed of MHR, MAC payload and MFR and just the outgoing MAC payload
must be encrypted.

If communication is secure,sender build Auxiliary Security Header(ASH),
insert it next to the standard MHR header with security enabled bit ON,
and secure frames before transmitting them. According to the information
carried within the ASH, recipient retrieves the right cryptographic key
and correctly un-secure MAC frames.

The error scenario occurs on Linux using IEEE802154_SCF_SECLEVEL_ENC(4)
security level when llsec_do_encrypt_unauth() function builds theses MAC
frames incorrectly. On recipients these MAC frames are discarded,logging
"got invalid frame" messages.

Signed-off-by: Diogenes Pereira <dvnp@cesar.org.br>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>

diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c
index edec2f9919d0aae91f475b6b01a9eb31b9e0f3a4..2fb703d70803c82891d04b34587bbe293cb9c6dd 100644 (file)
--- a/net/mac802154/llsec.c
+++ b/net/mac802154/llsec.c
@@ -623,13 +623,18 @@ llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
        u8 iv[16];
        struct scatterlist src;
        SKCIPHER_REQUEST_ON_STACK(req, key->tfm0);
-       int err;
+       int err, datalen;
+       unsigned char *data;
 
        llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
-       sg_init_one(&src, skb->data, skb->len);
+       /* Compute data payload offset and data length */
+       data = skb_mac_header(skb) + skb->mac_len;
+       datalen = skb_tail_pointer(skb) - data;
+       sg_init_one(&src, data, datalen);
+
        skcipher_request_set_tfm(req, key->tfm0);
        skcipher_request_set_callback(req, 0, NULL, NULL);
-       skcipher_request_set_crypt(req, &src, &src, skb->len, iv);
+       skcipher_request_set_crypt(req, &src, &src, datalen, iv);
        err = crypto_skcipher_encrypt(req);
        skcipher_request_zero(req);
        return err;