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>

1 files changed, 2 insertions, 5 deletions

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