1 files changed, 51 insertions, 14 deletions

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 1496e87cd07b..60f8ae578819 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -584,26 +584,48 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
 	return drop;
 }
 
-static void cake_update_flowkeys(struct flow_keys *keys,
+static bool cake_update_flowkeys(struct flow_keys *keys,
 				 const struct sk_buff *skb)
 {
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	struct nf_conntrack_tuple tuple = {};
-	bool rev = !skb->_nfct;
+	bool rev = !skb->_nfct, upd = false;
+	__be32 ip;
 
 	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
-		return;
+		return false;
 
 	if (!nf_ct_get_tuple_skb(&tuple, skb))
-		return;
+		return false;
 
-	keys->addrs.v4addrs.src = rev ? tuple.dst.u3.ip : tuple.src.u3.ip;
-	keys->addrs.v4addrs.dst = rev ? tuple.src.u3.ip : tuple.dst.u3.ip;
+	ip = rev ? tuple.dst.u3.ip : tuple.src.u3.ip;
+	if (ip != keys->addrs.v4addrs.src) {
+		keys->addrs.v4addrs.src = ip;
+		upd = true;
+	}
+	ip = rev ? tuple.src.u3.ip : tuple.dst.u3.ip;
+	if (ip != keys->addrs.v4addrs.dst) {
+		keys->addrs.v4addrs.dst = ip;
+		upd = true;
+	}
 
 	if (keys->ports.ports) {
-		keys->ports.src = rev ? tuple.dst.u.all : tuple.src.u.all;
-		keys->ports.dst = rev ? tuple.src.u.all : tuple.dst.u.all;
+		__be16 port;
+
+		port = rev ? tuple.dst.u.all : tuple.src.u.all;
+		if (port != keys->ports.src) {
+			keys->ports.src = port;
+			upd = true;
+		}
+		port = rev ? tuple.src.u.all : tuple.dst.u.all;
+		if (port != keys->ports.dst) {
+			port = keys->ports.dst;
+			upd = true;
+		}
 	}
+	return upd;
+#else
+	return false;
 #endif
 }
 
@@ -624,23 +646,36 @@ static bool cake_ddst(int flow_mode)
 static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
 		     int flow_mode, u16 flow_override, u16 host_override)
 {
+	bool hash_flows = (!flow_override && !!(flow_mode & CAKE_FLOW_FLOWS));
+	bool hash_hosts = (!host_override && !!(flow_mode & CAKE_FLOW_HOSTS));
+	bool nat_enabled = !!(flow_mode & CAKE_FLOW_NAT_FLAG);
 	u32 flow_hash = 0, srchost_hash = 0, dsthost_hash = 0;
 	u16 reduced_hash, srchost_idx, dsthost_idx;
 	struct flow_keys keys, host_keys;
+	bool use_skbhash = skb->l4_hash;
 
 	if (unlikely(flow_mode == CAKE_FLOW_NONE))
 		return 0;
 
-	/* If both overrides are set we can skip packet dissection entirely */
-	if ((flow_override || !(flow_mode & CAKE_FLOW_FLOWS)) &&
-	    (host_override || !(flow_mode & CAKE_FLOW_HOSTS)))
+	/* If both overrides are set, or we can use the SKB hash and nat mode is
+	 * disabled, we can skip packet dissection entirely. If nat mode is
+	 * enabled there's another check below after doing the conntrack lookup.
+	 */
+	if ((!hash_flows || (use_skbhash && !nat_enabled)) && !hash_hosts)
 		goto skip_hash;
 
 	skb_flow_dissect_flow_keys(skb, &keys,
 				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 
-	if (flow_mode & CAKE_FLOW_NAT_FLAG)
-		cake_update_flowkeys(&keys, skb);
+	/* Don't use the SKB hash if we change the lookup keys from conntrack */
+	if (nat_enabled && cake_update_flowkeys(&keys, skb))
+		use_skbhash = false;
+
+	/* If we can still use the SKB hash and don't need the host hash, we can
+	 * skip the rest of the hashing procedure
+	 */
+	if (use_skbhash && !hash_hosts)
+		goto skip_hash;
 
 	/* flow_hash_from_keys() sorts the addresses by value, so we have
 	 * to preserve their order in a separate data structure to treat
@@ -679,12 +714,14 @@ static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
 	/* This *must* be after the above switch, since as a
 	 * side-effect it sorts the src and dst addresses.
 	 */
-	if (flow_mode & CAKE_FLOW_FLOWS)
+	if (hash_flows && !use_skbhash)
 		flow_hash = flow_hash_from_keys(&keys);
 
 skip_hash:
 	if (flow_override)
 		flow_hash = flow_override - 1;
+	else if (use_skbhash)
+		flow_hash = skb->hash;
 	if (host_override) {
 		dsthost_hash = host_override - 1;
 		srchost_hash = host_override - 1;