mac80211: Assign correct TID for local bridged packets

This patch assigns correct TID to frames transmitted between
two stations in the same BSS in AP mode.
The problem is that skb->protocol is not set to ETH_P_IP and it is wrong
to use that field at this stage.
The fix compares the LLC/Protocol headers explicitly to check if the
encapsulated frame is IP frame
Signed-off-by: Guy Cohen <guy.cohen@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/wme.c

@@ -28,6 +28,7 @@ struct ieee80211_sched_data
 	struct sk_buff_head requeued[TC_80211_MAX_QUEUES];
 };
 
+static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
 
 /* given a data frame determine the 802.1p/1d tag to use */
 static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
@@ -54,12 +55,12 @@ static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
 		return skb->priority - 256;
 
 	/* check there is a valid IP header present */
-	offset = ieee80211_get_hdrlen_from_skb(skb) + 8 /* LLC + proto */;
-	if (skb->protocol != htons(ETH_P_IP) ||
-	    skb->len < offset + sizeof(*ip))
+	offset = ieee80211_get_hdrlen_from_skb(skb);
+	if (skb->len < offset + sizeof(llc_ip_hdr) + sizeof(*ip) ||
+	    memcmp(skb->data + offset, llc_ip_hdr, sizeof(llc_ip_hdr)))
 		return 0;
 
-	ip = (struct iphdr *) (skb->data + offset);
+	ip = (struct iphdr *) (skb->data + offset + sizeof(llc_ip_hdr));
 
 	dscp = ip->tos & 0xfc;
 	if (dscp & 0x1c)