1 files changed, 26 insertions, 64 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d56c0559b477..ca5e8ea29538 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -391,9 +391,9 @@ int udp_v4_get_port(struct sock *sk, unsigned short snum)
 	return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
 }
 
-static inline int compute_score(struct sock *sk, struct net *net,
-				__be32 saddr, unsigned short hnum, __be16 sport,
-				__be32 daddr, __be16 dport, int dif)
+static int compute_score(struct sock *sk, struct net *net,
+			 __be32 saddr, __be16 sport,
+			 __be32 daddr, unsigned short hnum, int dif)
 {
 	int score;
 	struct inet_sock *inet;
@@ -434,52 +434,6 @@ static inline int compute_score(struct sock *sk, struct net *net,
 	return score;
 }
 
-/*
- * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
- */
-static inline int compute_score2(struct sock *sk, struct net *net,
-				 __be32 saddr, __be16 sport,
-				 __be32 daddr, unsigned int hnum, int dif)
-{
-	int score;
-	struct inet_sock *inet;
-
-	if (!net_eq(sock_net(sk), net) ||
-	    ipv6_only_sock(sk))
-		return -1;
-
-	inet = inet_sk(sk);
-
-	if (inet->inet_rcv_saddr != daddr ||
-	    inet->inet_num != hnum)
-		return -1;
-
-	score = (sk->sk_family == PF_INET) ? 2 : 1;
-
-	if (inet->inet_daddr) {
-		if (inet->inet_daddr != saddr)
-			return -1;
-		score += 4;
-	}
-
-	if (inet->inet_dport) {
-		if (inet->inet_dport != sport)
-			return -1;
-		score += 4;
-	}
-
-	if (sk->sk_bound_dev_if) {
-		if (sk->sk_bound_dev_if != dif)
-			return -1;
-		score += 4;
-	}
-
-	if (sk->sk_incoming_cpu == raw_smp_processor_id())
-		score++;
-
-	return score;
-}
-
 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
 		       const __u16 lport, const __be32 faddr,
 		       const __be16 fport)
@@ -492,11 +446,11 @@ static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
 			      udp_ehash_secret + net_hash_mix(net));
 }
 
-/* called with read_rcu_lock() */
+/* called with rcu_read_lock() */
 static struct sock *udp4_lib_lookup2(struct net *net,
 		__be32 saddr, __be16 sport,
 		__be32 daddr, unsigned int hnum, int dif,
-		struct udp_hslot *hslot2, unsigned int slot2,
+		struct udp_hslot *hslot2,
 		struct sk_buff *skb)
 {
 	struct sock *sk, *result;
@@ -506,7 +460,7 @@ static struct sock *udp4_lib_lookup2(struct net *net,
 	result = NULL;
 	badness = 0;
 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
-		score = compute_score2(sk, net, saddr, sport,
+		score = compute_score(sk, net, saddr, sport,
 				      daddr, hnum, dif);
 		if (score > badness) {
 			reuseport = sk->sk_reuseport;
@@ -554,17 +508,22 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
 
 		result = udp4_lib_lookup2(net, saddr, sport,
 					  daddr, hnum, dif,
-					  hslot2, slot2, skb);
+					  hslot2, skb);
 		if (!result) {
+			unsigned int old_slot2 = slot2;
 			hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
 			slot2 = hash2 & udptable->mask;
+			/* avoid searching the same slot again. */
+			if (unlikely(slot2 == old_slot2))
+				return result;
+
 			hslot2 = &udptable->hash2[slot2];
 			if (hslot->count < hslot2->count)
 				goto begin;
 
 			result = udp4_lib_lookup2(net, saddr, sport,
-						  htonl(INADDR_ANY), hnum, dif,
-						  hslot2, slot2, skb);
+						  daddr, hnum, dif,
+						  hslot2, skb);
 		}
 		return result;
 	}
@@ -572,8 +531,8 @@ begin:
 	result = NULL;
 	badness = 0;
 	sk_for_each_rcu(sk, &hslot->head) {
-		score = compute_score(sk, net, saddr, hnum, sport,
-				      daddr, dport, dif);
+		score = compute_score(sk, net, saddr, sport,
+				      daddr, hnum, dif);
 		if (score > badness) {
 			reuseport = sk->sk_reuseport;
 			if (reuseport) {
@@ -1618,12 +1577,12 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		}
 	}
 
-	if (rcu_access_pointer(sk->sk_filter)) {
-		if (udp_lib_checksum_complete(skb))
+	if (rcu_access_pointer(sk->sk_filter) &&
+	    udp_lib_checksum_complete(skb))
 			goto csum_error;
-		if (sk_filter(sk, skb))
-			goto drop;
-	}
+
+	if (sk_filter(sk, skb))
+		goto drop;
 
 	udp_csum_pull_header(skb);
 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
@@ -1755,8 +1714,11 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
 			return err;
 	}
 
-	return skb_checksum_init_zero_check(skb, proto, uh->check,
-					    inet_compute_pseudo);
+	/* Note, we are only interested in != 0 or == 0, thus the
+	 * force to int.
+	 */
+	return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
+							 inet_compute_pseudo);
 }
 
 /*