[INET6_HASHTABLES]: Move inet6_lookup functions to net/ipv6/inet6_hashtables.c

Doing this we allow tcp_diag to support IPV6 even if tcp_diag is compiled
statically and IPV6 is compiled as a module, removing the previous restriction
while not building any IPV6 code if it is not selected.

Now to work on the tcpdiag_register infrastructure and then to rename the whole
thing to inetdiag, reflecting its by then completely generic nature.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 105 insertions, 1 deletions

diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index 297c2b1..03df3b1 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -14,13 +14,117 @@
 #ifndef _INET6_HASHTABLES_H
 #define _INET6_HASHTABLES_H
 
+#include <linux/config.h>
+
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#include <linux/in6.h>
+#include <linux/ipv6.h>
 #include <linux/types.h>
 
-struct in6_addr;
+#include <net/ipv6.h>
+
 struct inet_hashinfo;
 
+/* I have no idea if this is a good hash for v6 or not. -DaveM */
+static inline int inet6_ehashfn(const struct in6_addr *laddr, const u16 lport,
+				const struct in6_addr *faddr, const u16 fport,
+				const int ehash_size)
+{
+	int hashent = (lport ^ fport);
+
+	hashent ^= (laddr->s6_addr32[3] ^ faddr->s6_addr32[3]);
+	hashent ^= hashent >> 16;
+	hashent ^= hashent >> 8;
+	return (hashent & (ehash_size - 1));
+}
+
+static inline int inet6_sk_ehashfn(const struct sock *sk, const int ehash_size)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct ipv6_pinfo *np = inet6_sk(sk);
+	const struct in6_addr *laddr = &np->rcv_saddr;
+	const struct in6_addr *faddr = &np->daddr;
+	const __u16 lport = inet->num;
+	const __u16 fport = inet->dport;
+	return inet6_ehashfn(laddr, lport, faddr, fport, ehash_size);
+}
+
+/*
+ * 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
+ *
+ * The sockhash lock must be held as a reader here.
+ */
+static inline struct sock *
+		__inet6_lookup_established(struct inet_hashinfo *hashinfo,
+					   const struct in6_addr *saddr,
+					   const u16 sport,
+					   const struct in6_addr *daddr,
+					   const u16 hnum,
+					   const int dif)
+{
+	struct sock *sk;
+	const struct hlist_node *node;
+	const __u32 ports = INET_COMBINED_PORTS(sport, hnum);
+	/* Optimize here for direct hit, only listening connections can
+	 * have wildcards anyways.
+	 */
+	const int hash = inet6_ehashfn(daddr, hnum, saddr, sport,
+				       hashinfo->ehash_size);
+	struct inet_ehash_bucket *head = &hashinfo->ehash[hash];
+
+	read_lock(&head->lock);
+	sk_for_each(sk, node, &head->chain) {
+		/* For IPV6 do the cheaper port and family tests first. */
+		if (INET6_MATCH(sk, saddr, daddr, ports, dif))
+			goto hit; /* You sunk my battleship! */
+	}
+	/* Must check for a TIME_WAIT'er before going to listener hash. */
+	sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) {
+		const struct inet_timewait_sock *tw = inet_twsk(sk);
+
+		if(*((__u32 *)&(tw->tw_dport))	== ports	&&
+		   sk->sk_family		== PF_INET6) {
+			const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk);
+
+			if (ipv6_addr_equal(&tcp6tw->tw_v6_daddr, saddr)	&&
+			    ipv6_addr_equal(&tcp6tw->tw_v6_rcv_saddr, daddr)	&&
+			    (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif))
+				goto hit;
+		}
+	}
+	read_unlock(&head->lock);
+	return NULL;
+
+hit:
+	sock_hold(sk);
+	read_unlock(&head->lock);
+	return sk;
+}
+
+extern struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
+					  const struct in6_addr *daddr,
+					  const unsigned short hnum,
+					  const int dif);
+
+static inline struct sock *__inet6_lookup(struct inet_hashinfo *hashinfo,
+					  const struct in6_addr *saddr,
+					  const u16 sport,
+					  const struct in6_addr *daddr,
+					  const u16 hnum,
+					  const int dif)
+{
+	struct sock *sk = __inet6_lookup_established(hashinfo, saddr, sport,
+						     daddr, hnum, dif);
+	if (sk)
+		return sk;
+
+	return inet6_lookup_listener(hashinfo, daddr, hnum, dif);
+}
+
 extern struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
 				 const struct in6_addr *saddr, const u16 sport,
 				 const struct in6_addr *daddr, const u16 dport,
 				 const int dif);
+#endif /* defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) */
 #endif /* _INET6_HASHTABLES_H */