[INET]: Generalise the TCP sock ID lookup routines

And also some TIME_WAIT functions.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 282955   13122    9312  305389   4a8ed net/ipv4/built-in.o
/tmp/after.size:  281566   13122    9312  304000   4a380 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

I kept them still inlined, will uninline at some point to see what
would be the performance difference.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sock.h b/include/net/sock.h
index c902c57bf..bdae0a5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -255,28 +255,28 @@
 /*
  * Hashed lists helper routines
  */
-static inline struct sock *__sk_head(struct hlist_head *head)
+static inline struct sock *__sk_head(const struct hlist_head *head)
 {
 	return hlist_entry(head->first, struct sock, sk_node);
 }
 
-static inline struct sock *sk_head(struct hlist_head *head)
+static inline struct sock *sk_head(const struct hlist_head *head)
 {
 	return hlist_empty(head) ? NULL : __sk_head(head);
 }
 
-static inline struct sock *sk_next(struct sock *sk)
+static inline struct sock *sk_next(const struct sock *sk)
 {
 	return sk->sk_node.next ?
 		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
 }
 
-static inline int sk_unhashed(struct sock *sk)
+static inline int sk_unhashed(const struct sock *sk)
 {
 	return hlist_unhashed(&sk->sk_node);
 }
 
-static inline int sk_hashed(struct sock *sk)
+static inline int sk_hashed(const struct sock *sk)
 {
 	return sk->sk_node.pprev != NULL;
 }
@@ -494,7 +494,7 @@
 struct request_sock_ops;
 
 /* Here is the right place to enable sock refcounting debugging */
-#define SOCK_REFCNT_DEBUG
+//#define SOCK_REFCNT_DEBUG
 
 /* Networking protocol blocks we attach to sockets.
  * socket layer -> transport layer interface