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>

5 files changed, 34 insertions, 11 deletions

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 247cfdcc4b08..87c094961bd5 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -34,7 +34,7 @@ static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
 
 #define UDP_HTABLE_SIZE_MIN		(CONFIG_BASE_SMALL ? 128 : 256)
 
-static inline int udp_hashfn(struct net *net, unsigned num, unsigned mask)
+static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
 {
 	return (num + net_hash_mix(net)) & mask;
 }
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index 9201afe083fa..7ff588ca6817 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -38,8 +38,6 @@ static inline unsigned int __inet6_ehashfn(const u32 lhash,
 	return jhash_3words(lhash, fhash, ports, initval);
 }
 
-int __inet6_hash(struct sock *sk, struct inet_timewait_sock *twp);
-
 /*
  * 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
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index bcd64756e5fe..73fe0f9525d9 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -221,8 +221,8 @@ inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
 void inet_bind_bucket_destroy(struct kmem_cache *cachep,
 			      struct inet_bind_bucket *tb);
 
-static inline int inet_bhashfn(struct net *net, const __u16 lport,
-			       const int bhash_size)
+static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
+			       const u32 bhash_size)
 {
 	return (lport + net_hash_mix(net)) & (bhash_size - 1);
 }
@@ -231,7 +231,7 @@ void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 		    const unsigned short snum);
 
 /* These can have wildcards, don't try too hard. */
-static inline int inet_lhashfn(struct net *net, const unsigned short num)
+static inline u32 inet_lhashfn(const struct net *net, const unsigned short num)
 {
 	return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
 }
@@ -249,6 +249,7 @@ void inet_put_port(struct sock *sk);
 void inet_hashinfo_init(struct inet_hashinfo *h);
 
 int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw);
+int __inet_hash(struct sock *sk, struct inet_timewait_sock *tw);
 void inet_hash(struct sock *sk);
 void inet_unhash(struct sock *sk);
 
@@ -383,13 +384,32 @@ static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
 				     iph->daddr, dport, inet_iif(skb));
 }
 
+u32 sk_ehashfn(const struct sock *sk);
+u32 inet6_ehashfn(const struct net *net,
+		  const struct in6_addr *laddr, const u16 lport,
+		  const struct in6_addr *faddr, const __be16 fport);
+
+static inline void sk_daddr_set(struct sock *sk, __be32 addr)
+{
+	sk->sk_daddr = addr; /* alias of inet_daddr */
+#if IS_ENABLED(CONFIG_IPV6)
+	ipv6_addr_set_v4mapped(addr, &sk->sk_v6_daddr);
+#endif
+}
+
+static inline void sk_rcv_saddr_set(struct sock *sk, __be32 addr)
+{
+	sk->sk_rcv_saddr = addr; /* alias of inet_rcv_saddr */
+#if IS_ENABLED(CONFIG_IPV6)
+	ipv6_addr_set_v4mapped(addr, &sk->sk_v6_rcv_saddr);
+#endif
+}
+
 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 			struct sock *sk, u32 port_offset,
 			int (*check_established)(struct inet_timewait_death_row *,
 						 struct sock *, __u16,
-						 struct inet_timewait_sock **),
-			int (*hash)(struct sock *sk,
-				    struct inet_timewait_sock *twp));
+						 struct inet_timewait_sock **));
 
 int inet_hash_connect(struct inet_timewait_death_row *death_row,
 		      struct sock *sk);
diff --git a/include/net/netns/hash.h b/include/net/netns/hash.h
index c06ac58ca107..69a6715d9f3f 100644
--- a/include/net/netns/hash.h
+++ b/include/net/netns/hash.h
@@ -5,7 +5,7 @@
 
 struct net;
 
-static inline unsigned int net_hash_mix(struct net *net)
+static inline u32 net_hash_mix(const struct net *net)
 {
 #ifdef CONFIG_NET_NS
 	/*
@@ -13,7 +13,7 @@ static inline unsigned int net_hash_mix(struct net *net)
 	 * always zeroed
 	 */
 
-	return (unsigned)(((unsigned long)net) >> L1_CACHE_SHIFT);
+	return (u32)(((unsigned long)net) >> L1_CACHE_SHIFT);
 #else
 	return 0;
 #endif
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 3fa4f824900a..e7ef86340514 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -91,6 +91,11 @@ static inline struct request_sock *inet_reqsk(struct sock *sk)
 	return (struct request_sock *)sk;
 }
 
+static inline struct sock *req_to_sk(struct request_sock *req)
+{
+	return (struct sock *)req;
+}
+
 static inline void reqsk_free(struct request_sock *req)
 {
 	/* temporary debugging */