[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>

net/ipv6/inet6_hashtables.c

@@ -0,0 +1,81 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Generic INET6 transport hashtables
+ *
+ * Authors:	Lotsa people, from code originally in tcp
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+
+#include <linux/module.h>
+
+#include <net/inet_connection_sock.h>
+#include <net/inet_hashtables.h>
+#include <net/inet6_hashtables.h>
+
+struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
+				   const struct in6_addr *daddr,
+				   const unsigned short hnum, const int dif)
+{
+	struct sock *sk;
+	const struct hlist_node *node;
+	struct sock *result = NULL;
+	int score, hiscore = 0;
+
+	read_lock(&hashinfo->lhash_lock);
+	sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
+		if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
+			const struct ipv6_pinfo *np = inet6_sk(sk);
+			
+			score = 1;
+			if (!ipv6_addr_any(&np->rcv_saddr)) {
+				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
+					continue;
+				score++;
+			}
+			if (sk->sk_bound_dev_if) {
+				if (sk->sk_bound_dev_if != dif)
+					continue;
+				score++;
+			}
+			if (score == 3) {
+				result = sk;
+				break;
+			}
+			if (score > hiscore) {
+				hiscore = score;
+				result = sk;
+			}
+		}
+	}
+	if (result)
+		sock_hold(result);
+	read_unlock(&hashinfo->lhash_lock);
+	return result;
+}
+
+EXPORT_SYMBOL_GPL(inet6_lookup_listener);
+
+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)
+{
+	struct sock *sk;
+
+	local_bh_disable();
+	sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
+	local_bh_enable();
+
+	return sk;
+}
+
+EXPORT_SYMBOL_GPL(inet6_lookup);