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>

3 files changed, 14 insertions, 18 deletions

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 6cf9f7782ad4..7f075b83128a 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -67,7 +67,7 @@ static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
 	struct dccp_hdr *dh = dccp_hdr(skb);
 
 	dccp_csum_outgoing(skb);
-	dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
+	dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
 }
 
 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
@@ -467,11 +467,11 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 
 		memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 
-		ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
+		ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
 
 		ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
 
-		newnp->rcv_saddr = newnp->saddr;
+		newsk->sk_v6_rcv_saddr = newnp->saddr;
 
 		inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
 		newsk->sk_backlog_rcv = dccp_v4_do_rcv;
@@ -538,9 +538,9 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 
 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 
-	newnp->daddr = ireq6->rmt_addr;
+	newsk->sk_v6_daddr = ireq6->rmt_addr;
 	newnp->saddr = ireq6->loc_addr;
-	newnp->rcv_saddr = ireq6->loc_addr;
+	newsk->sk_v6_rcv_saddr = ireq6->loc_addr;
 	newsk->sk_bound_dev_if = ireq6->iif;
 
 	/* Now IPv6 options...
@@ -885,7 +885,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 			return -EINVAL;
 	}
 
-	np->daddr = usin->sin6_addr;
+	sk->sk_v6_daddr = usin->sin6_addr;
 	np->flow_label = fl6.flowlabel;
 
 	/*
@@ -915,16 +915,16 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 			goto failure;
 		}
 		ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
-		ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &np->rcv_saddr);
+		ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &sk->sk_v6_rcv_saddr);
 
 		return err;
 	}
 
-	if (!ipv6_addr_any(&np->rcv_saddr))
-		saddr = &np->rcv_saddr;
+	if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+		saddr = &sk->sk_v6_rcv_saddr;
 
 	fl6.flowi6_proto = IPPROTO_DCCP;
-	fl6.daddr = np->daddr;
+	fl6.daddr = sk->sk_v6_daddr;
 	fl6.saddr = saddr ? *saddr : np->saddr;
 	fl6.flowi6_oif = sk->sk_bound_dev_if;
 	fl6.fl6_dport = usin->sin6_port;
@@ -941,7 +941,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 
 	if (saddr == NULL) {
 		saddr = &fl6.saddr;
-		np->rcv_saddr = *saddr;
+		sk->sk_v6_rcv_saddr = *saddr;
 	}
 
 	/* set the source address */
@@ -963,7 +963,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 		goto late_failure;
 
 	dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
-						      np->daddr.s6_addr32,
+						      sk->sk_v6_daddr.s6_addr32,
 						      inet->inet_sport,
 						      inet->inet_dport);
 	err = dccp_connect(sk);
diff --git a/net/dccp/ipv6.h b/net/dccp/ipv6.h
index 6eef81fdbe56..6604fc3fe953 100644
--- a/net/dccp/ipv6.h
+++ b/net/dccp/ipv6.h
@@ -30,7 +30,6 @@ struct dccp6_request_sock {
 
 struct dccp6_timewait_sock {
 	struct inet_timewait_sock   inet;
-	struct inet6_timewait_sock  tw6;
 };
 
 #endif /* _DCCP_IPV6_H */
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 662071b249cc..32e80d96d4c0 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -56,12 +56,9 @@ void dccp_time_wait(struct sock *sk, int state, int timeo)
 #if IS_ENABLED(CONFIG_IPV6)
 		if (tw->tw_family == PF_INET6) {
 			const struct ipv6_pinfo *np = inet6_sk(sk);
-			struct inet6_timewait_sock *tw6;
 
-			tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
-			tw6 = inet6_twsk((struct sock *)tw);
-			tw6->tw_v6_daddr = np->daddr;
-			tw6->tw_v6_rcv_saddr = np->rcv_saddr;
+			tw->tw_v6_daddr = sk->sk_v6_daddr;
+			tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 			tw->tw_ipv6only = np->ipv6only;
 		}
 #endif