sch_choke: Use flow_keys_digest

Call make_flow_keys_digest to get a digest from flow keys and
use that to pass skbuff cb and for comparing flows.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_choke.c

@@ -133,16 +133,10 @@ static void choke_drop_by_idx(struct Qdisc *sch, unsigned int idx)
 	--sch->q.qlen;
 }
 
-/* private part of skb->cb[] that a qdisc is allowed to use
- * is limited to QDISC_CB_PRIV_LEN bytes.
- * As a flow key might be too large, we store a part of it only.
- */
-#define CHOKE_K_LEN min_t(u32, sizeof(struct flow_keys), QDISC_CB_PRIV_LEN - 3)
-
 struct choke_skb_cb {
 	u16			classid;
 	u8			keys_valid;
-	u8			keys[QDISC_CB_PRIV_LEN - 3];
+	struct			flow_keys_digest keys;
 };
 
 static inline struct choke_skb_cb *choke_skb_cb(const struct sk_buff *skb)
@@ -177,18 +171,18 @@ static bool choke_match_flow(struct sk_buff *skb1,
 	if (!choke_skb_cb(skb1)->keys_valid) {
 		choke_skb_cb(skb1)->keys_valid = 1;
 		skb_flow_dissect(skb1, &temp);
-		memcpy(&choke_skb_cb(skb1)->keys, &temp, CHOKE_K_LEN);
+		make_flow_keys_digest(&choke_skb_cb(skb1)->keys, &temp);
 	}
 
 	if (!choke_skb_cb(skb2)->keys_valid) {
 		choke_skb_cb(skb2)->keys_valid = 1;
 		skb_flow_dissect(skb2, &temp);
-		memcpy(&choke_skb_cb(skb2)->keys, &temp, CHOKE_K_LEN);
+		make_flow_keys_digest(&choke_skb_cb(skb2)->keys, &temp);
 	}
 
 	return !memcmp(&choke_skb_cb(skb1)->keys,
 		       &choke_skb_cb(skb2)->keys,
-		       CHOKE_K_LEN);
+		       sizeof(choke_skb_cb(skb1)->keys));
 }
 
 /*