ipv6: make lookups simpler and faster

TCP listener refactoring, part 4 :

To speed up inet lookups, we moved IPv4 addresses from inet to struct
sock_common

Now is time to do the same for IPv6, because it permits us to have fast
lookups for all kind of sockets, including upcoming SYN_RECV.

Getting IPv6 addresses in TCP lookups currently requires two extra cache
lines, plus a dereference (and memory stall).

inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6

This patch is way bigger than its IPv4 counter part, because for IPv4,
we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6,
it's not doable easily.

inet6_sk(sk)->daddr becomes sk->sk_v6_daddr
inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr

And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr
at the same offset.

We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic
macro.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 3753247..b496de1 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -55,11 +55,10 @@
 
 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 {
-	const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
 	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
 	int sk_ipv6only = ipv6_only_sock(sk);
 	int sk2_ipv6only = inet_v6_ipv6only(sk2);
-	int addr_type = ipv6_addr_type(sk_rcv_saddr6);
+	int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
 	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
 
 	/* if both are mapped, treat as IPv4 */
@@ -77,7 +76,7 @@
 		return 1;
 
 	if (sk2_rcv_saddr6 &&
-	    ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
+	    ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
 		return 1;
 
 	return 0;
@@ -105,7 +104,7 @@
 	unsigned int hash2_nulladdr =
 		udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 	unsigned int hash2_partial =
-		udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
+		udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
 
 	/* precompute partial secondary hash */
 	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
@@ -115,7 +114,7 @@
 static void udp_v6_rehash(struct sock *sk)
 {
 	u16 new_hash = udp6_portaddr_hash(sock_net(sk),
-					  &inet6_sk(sk)->rcv_saddr,
+					  &sk->sk_v6_rcv_saddr,
 					  inet_sk(sk)->inet_num);
 
 	udp_lib_rehash(sk, new_hash);
@@ -131,7 +130,6 @@
 
 	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 			sk->sk_family == PF_INET6) {
-		struct ipv6_pinfo *np = inet6_sk(sk);
 		struct inet_sock *inet = inet_sk(sk);
 
 		score = 0;
@@ -140,13 +138,13 @@
 				return -1;
 			score++;
 		}
-		if (!ipv6_addr_any(&np->rcv_saddr)) {
-			if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
+		if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
+			if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 				return -1;
 			score++;
 		}
-		if (!ipv6_addr_any(&np->daddr)) {
-			if (!ipv6_addr_equal(&np->daddr, saddr))
+		if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
+			if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 				return -1;
 			score++;
 		}
@@ -169,10 +167,9 @@
 
 	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 			sk->sk_family == PF_INET6) {
-		struct ipv6_pinfo *np = inet6_sk(sk);
 		struct inet_sock *inet = inet_sk(sk);
 
-		if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
+		if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 			return -1;
 		score = 0;
 		if (inet->inet_dport) {
@@ -180,8 +177,8 @@
 				return -1;
 			score++;
 		}
-		if (!ipv6_addr_any(&np->daddr)) {
-			if (!ipv6_addr_equal(&np->daddr, saddr))
+		if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
+			if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 				return -1;
 			score++;
 		}
@@ -549,7 +546,7 @@
 {
 	int rc;
 
-	if (!ipv6_addr_any(&inet6_sk(sk)->daddr)) {
+	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 		sock_rps_save_rxhash(sk, skb);
 		sk_mark_napi_id(sk, skb);
 	}
@@ -690,20 +687,19 @@
 
 		if (udp_sk(s)->udp_port_hash == num &&
 		    s->sk_family == PF_INET6) {
-			struct ipv6_pinfo *np = inet6_sk(s);
 			if (inet->inet_dport) {
 				if (inet->inet_dport != rmt_port)
 					continue;
 			}
-			if (!ipv6_addr_any(&np->daddr) &&
-			    !ipv6_addr_equal(&np->daddr, rmt_addr))
+			if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
+			    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr))
 				continue;
 
 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
 				continue;
 
-			if (!ipv6_addr_any(&np->rcv_saddr)) {
-				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
+			if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
+				if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))
 					continue;
 			}
 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
@@ -1063,7 +1059,7 @@
 	} else if (!up->pending) {
 		if (sk->sk_state != TCP_ESTABLISHED)
 			return -EDESTADDRREQ;
-		daddr = &np->daddr;
+		daddr = &sk->sk_v6_daddr;
 	} else
 		daddr = NULL;
 
@@ -1133,8 +1129,8 @@
 		 * sk->sk_dst_cache.
 		 */
 		if (sk->sk_state == TCP_ESTABLISHED &&
-		    ipv6_addr_equal(daddr, &np->daddr))
-			daddr = &np->daddr;
+		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
+			daddr = &sk->sk_v6_daddr;
 
 		if (addr_len >= sizeof(struct sockaddr_in6) &&
 		    sin6->sin6_scope_id &&
@@ -1145,7 +1141,7 @@
 			return -EDESTADDRREQ;
 
 		fl6.fl6_dport = inet->inet_dport;
-		daddr = &np->daddr;
+		daddr = &sk->sk_v6_daddr;
 		fl6.flowlabel = np->flow_label;
 		connected = 1;
 	}
@@ -1261,8 +1257,8 @@
 	if (dst) {
 		if (connected) {
 			ip6_dst_store(sk, dst,
-				      ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
-				      &np->daddr : NULL,
+				      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
+				      &sk->sk_v6_daddr : NULL,
 #ifdef CONFIG_IPV6_SUBTREES
 				      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 				      &np->saddr :