Merge branch 'listen_refactor_part_13'

Eric Dumazet says:

====================
inet: tcp listener refactoring, part 13

inet_hash functions are in a bad state : Too much IPv6/IPv4 copy/pasting.

Lets refactor a bit.

Idea is that we do not want to have an equivalent of inet_csk(sk)->icsk_af_ops
for request socks in order to be able to use the right variant.

In this patch series, I started to let IPv6/IPv4 converge to common helpers.

Idea is to use ipv6_addr_set_v4mapped() even for AF_INET sockets, so that
we can test
       if (sk->sk_family == AF_INET6 &&
           !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
to tell if we deal with an IPv6 socket, or IPv4 one, at least in slow paths.

Ideally, we could save 8 bytes per struct sock_common, if we
alias skc_daddr & skc_rcv_saddr to skc_v6_daddr[3]/skc_v6_rcv_saddr[3].
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 16 insertions, 86 deletions

diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 051dffb49c90..033f17816ef4 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -23,11 +23,9 @@
 #include <net/secure_seq.h>
 #include <net/ip.h>
 
-static unsigned int inet6_ehashfn(struct net *net,
-                                  const struct in6_addr *laddr,
-                                  const u16 lport,
-                                  const struct in6_addr *faddr,
-                                  const __be16 fport)
+u32 inet6_ehashfn(const struct net *net,
+                  const struct in6_addr *laddr, const u16 lport,
+                  const struct in6_addr *faddr, const __be16 fport)
 {
         static u32 inet6_ehash_secret __read_mostly;
         static u32 ipv6_hash_secret __read_mostly;
@@ -44,54 +42,6 @@ static unsigned int inet6_ehashfn(struct net *net,
                                inet6_ehash_secret + net_hash_mix(net));
 }
 
-static int inet6_sk_ehashfn(const struct sock *sk)
-{
-        const struct inet_sock *inet = inet_sk(sk);
-        const struct in6_addr *laddr = &sk->sk_v6_rcv_saddr;
-        const struct in6_addr *faddr = &sk->sk_v6_daddr;
-        const __u16 lport = inet->inet_num;
-        const __be16 fport = inet->inet_dport;
-        struct net *net = sock_net(sk);
-
-        return inet6_ehashfn(net, laddr, lport, faddr, fport);
-}
-
-int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
-{
-        struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
-        int twrefcnt = 0;
-
-        WARN_ON(!sk_unhashed(sk));
-
-        if (sk->sk_state == TCP_LISTEN) {
-                struct inet_listen_hashbucket *ilb;
-
-                ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
-                spin_lock(&ilb->lock);
-                __sk_nulls_add_node_rcu(sk, &ilb->head);
-                spin_unlock(&ilb->lock);
-        } else {
-                unsigned int hash;
-                struct hlist_nulls_head *list;
-                spinlock_t *lock;
-
-                sk->sk_hash = hash = inet6_sk_ehashfn(sk);
-                list = &inet_ehash_bucket(hashinfo, hash)->chain;
-                lock = inet_ehash_lockp(hashinfo, hash);
-                spin_lock(lock);
-                __sk_nulls_add_node_rcu(sk, list);
-                if (tw) {
-                        WARN_ON(sk->sk_hash != tw->tw_hash);
-                        twrefcnt = inet_twsk_unhash(tw);
-                }
-                spin_unlock(lock);
-        }
-
-        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
-        return twrefcnt;
-}
-EXPORT_SYMBOL(__inet6_hash);
-
 /*
  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
  * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
@@ -320,6 +270,6 @@ int inet6_hash_connect(struct inet_timewait_death_row *death_row,
                        struct sock *sk)
 {
         return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
-                        __inet6_check_established, __inet6_hash);
+                                   __inet6_check_established);
 }
 EXPORT_SYMBOL_GPL(inet6_hash_connect);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e4761b22307b..720676d073d9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -104,19 +104,6 @@ static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
         }
 }
 
-static void tcp_v6_hash(struct sock *sk)
-{
-        if (sk->sk_state != TCP_CLOSE) {
-                if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
-                        tcp_prot.hash(sk);
-                        return;
-                }
-                local_bh_disable();
-                __inet6_hash(sk, NULL);
-                local_bh_enable();
-        }
-}
-
 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 {
         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
@@ -233,11 +220,8 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
                         tp->af_specific = &tcp_sock_ipv6_specific;
 #endif
                         goto failure;
-                } else {
-                        ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
-                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
-                                               &sk->sk_v6_rcv_saddr);
                 }
+                np->saddr = sk->sk_v6_rcv_saddr;
 
                 return err;
         }
@@ -1078,11 +1062,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 
-                ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
-
-                ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
-
-                newsk->sk_v6_rcv_saddr = newnp->saddr;
+                newnp->saddr = newsk->sk_v6_rcv_saddr;
 
                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
@@ -1231,7 +1211,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                 tcp_done(newsk);
                 goto out;
         }
-        __inet6_hash(newsk, NULL);
+        __inet_hash(newsk, NULL);
 
         return newsk;
 
@@ -1890,7 +1870,7 @@ struct proto tcpv6_prot = {
         .sendpage               = tcp_sendpage,
         .backlog_rcv            = tcp_v6_do_rcv,
         .release_cb             = tcp_release_cb,
-        .hash                   = tcp_v6_hash,
+        .hash                   = inet_hash,
         .unhash                 = inet_unhash,
         .get_port               = inet_csk_get_port,
         .enter_memory_pressure  = tcp_enter_memory_pressure,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 70568a4548e4..7fe0329c0d37 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -53,11 +53,11 @@
 #include <trace/events/skb.h>
 #include "udp_impl.h"
 
-static unsigned int udp6_ehashfn(struct net *net,
-                                  const struct in6_addr *laddr,
-                                  const u16 lport,
-                                  const struct in6_addr *faddr,
-                                  const __be16 fport)
+static u32 udp6_ehashfn(const struct net *net,
+                        const struct in6_addr *laddr,
+                        const u16 lport,
+                        const struct in6_addr *faddr,
+                        const __be16 fport)
 {
         static u32 udp6_ehash_secret __read_mostly;
         static u32 udp_ipv6_hash_secret __read_mostly;
@@ -104,9 +104,9 @@ int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
         return 0;
 }
 
-static unsigned int udp6_portaddr_hash(struct net *net,
-                                       const struct in6_addr *addr6,
-                                       unsigned int port)
+static u32 udp6_portaddr_hash(const struct net *net,
+                              const struct in6_addr *addr6,
+                              unsigned int port)
 {
         unsigned int hash, mix = net_hash_mix(net);