[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.

Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

4 files changed, 46 insertions, 8 deletions

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index d99c1ba2ece..5525227c5e9 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -314,25 +314,25 @@ typedef __u64 __bitwise __addrpair;
 				   ((__force __u64)(__be32)(__saddr)));
 #endif /* __BIG_ENDIAN */
 #define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
-	(((__sk)->sk_hash == (__hash)) && ((__sk)->sk_net == (__net))	&&	\
+	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&&	\
 	 ((*((__addrpair *)&(inet_sk(__sk)->daddr))) == (__cookie))	&&	\
 	 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports))	&&	\
 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
 #define INET_TW_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
-	(((__sk)->sk_hash == (__hash)) && ((__sk)->sk_net == (__net))	&&	\
+	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&&	\
 	 ((*((__addrpair *)&(inet_twsk(__sk)->tw_daddr))) == (__cookie)) &&	\
 	 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) &&	\
 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
 #else /* 32-bit arch */
 #define INET_ADDR_COOKIE(__name, __saddr, __daddr)
 #define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)	\
-	(((__sk)->sk_hash == (__hash)) && ((__sk)->sk_net == (__net))	&&	\
+	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&&	\
 	 (inet_sk(__sk)->daddr		== (__saddr))		&&	\
 	 (inet_sk(__sk)->rcv_saddr	== (__daddr))		&&	\
 	 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports))	&&	\
 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
 #define INET_TW_MATCH(__sk, __net, __hash,__cookie, __saddr, __daddr, __ports, __dif)	\
-	(((__sk)->sk_hash == (__hash)) && ((__sk)->sk_net == (__net))	&&	\
+	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&&	\
 	 (inet_twsk(__sk)->tw_daddr	== (__saddr))		&&	\
 	 (inet_twsk(__sk)->tw_rcv_saddr	== (__daddr))		&&	\
 	 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) &&	\
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 296547bfb0b..07fe0d1a4f0 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -207,4 +207,22 @@ extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
 			       const int timeo, const int timewait_len);
 extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
 				 struct inet_timewait_death_row *twdr);
+
+static inline
+struct net *twsk_net(const struct inet_timewait_sock *twsk)
+{
+#ifdef CONFIG_NET_NS
+	return twsk->tw_net;
+#else
+	return &init_net;
+#endif
+}
+
+static inline
+void twsk_net_set(struct inet_timewait_sock *twsk, const struct net *net)
+{
+#ifdef CONFIG_NET_NS
+	twsk->tw_net = net;
+#endif
+}
 #endif	/* _INET_TIMEWAIT_SOCK_ */
diff --git a/include/net/route.h b/include/net/route.h
index 28dba925663..c6338802e8f 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -160,7 +160,7 @@ static inline int ip_route_connect(struct rtable **rp, __be32 dst,
 					 .dport = dport } } };
 
 	int err;
-	struct net *net = sk->sk_net;
+	struct net *net = sock_net(sk);
 	if (!dst || !src) {
 		err = __ip_route_output_key(net, rp, &fl);
 		if (err)
@@ -188,7 +188,7 @@ static inline int ip_route_newports(struct rtable **rp, u8 protocol,
 		ip_rt_put(*rp);
 		*rp = NULL;
 		security_sk_classify_flow(sk, &fl);
-		return ip_route_output_flow(sk->sk_net, rp, &fl, sk, 0);
+		return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0);
 	}
 	return 0;
 }
diff --git a/include/net/sock.h b/include/net/sock.h
index b433b1ed203..7e0d4a0c4d1 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -126,7 +126,9 @@ struct sock_common {
 	atomic_t		skc_refcnt;
 	unsigned int		skc_hash;
 	struct proto		*skc_prot;
+#ifdef CONFIG_NET_NS
 	struct net	 	*skc_net;
+#endif
 };
 
 /**
@@ -1345,6 +1347,24 @@ static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_e
 }
 #endif
 
+static inline
+struct net *sock_net(const struct sock *sk)
+{
+#ifdef CONFIG_NET_NS
+	return sk->sk_net;
+#else
+	return &init_net;
+#endif
+}
+
+static inline
+void sock_net_set(struct sock *sk, const struct net *net)
+{
+#ifdef CONFIG_NET_NS
+	sk->sk_net = net;
+#endif
+}
+
 /*
  * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
  * They should not hold a referrence to a namespace in order to allow
@@ -1353,8 +1373,8 @@ static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_e
  */
 static inline void sk_change_net(struct sock *sk, struct net *net)
 {
-	put_net(sk->sk_net);
-	sk->sk_net = net;
+	put_net(sock_net(sk));
+	sock_net_set(sk, net);
 }
 
 extern void sock_enable_timestamp(struct sock *sk);