[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>

1 files changed, 83 insertions, 0 deletions

diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
new file mode 100644
index 000000000000..d38d160faeb7
--- /dev/null
+++ b/net/ipv4/inet_timewait_sock.c
@@ -0,0 +1,83 @@
+/*
+ * 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 TIME_WAIT sockets functions
+ *
+ *		From code orinally in TCP
+ */
+
+#include <linux/config.h>
+
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+
+/* Must be called with locally disabled BHs. */
+void __inet_twsk_kill(struct inet_timewait_sock *tw, struct inet_hashinfo *hashinfo)
+{
+	struct inet_bind_hashbucket *bhead;
+	struct inet_bind_bucket *tb;
+	/* Unlink from established hashes. */
+	struct inet_ehash_bucket *ehead = &hashinfo->ehash[tw->tw_hashent];
+
+	write_lock(&ehead->lock);
+	if (hlist_unhashed(&tw->tw_node)) {
+		write_unlock(&ehead->lock);
+		return;
+	}
+	__hlist_del(&tw->tw_node);
+	sk_node_init(&tw->tw_node);
+	write_unlock(&ehead->lock);
+
+	/* Disassociate with bind bucket. */
+	bhead = &hashinfo->bhash[inet_bhashfn(tw->tw_num, hashinfo->bhash_size)];
+	spin_lock(&bhead->lock);
+	tb = tw->tw_tb;
+	__hlist_del(&tw->tw_bind_node);
+	tw->tw_tb = NULL;
+	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+	spin_unlock(&bhead->lock);
+#ifdef SOCK_REFCNT_DEBUG
+	if (atomic_read(&tw->tw_refcnt) != 1) {
+		printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n",
+		       tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
+	}
+#endif
+	inet_twsk_put(tw);
+}
+
+/*
+ * Enter the time wait state. This is called with locally disabled BH.
+ * Essentially we whip up a timewait bucket, copy the relevant info into it
+ * from the SK, and mess with hash chains and list linkage.
+ */
+void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
+			   struct inet_hashinfo *hashinfo)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	struct inet_ehash_bucket *ehead = &hashinfo->ehash[sk->sk_hashent];
+	struct inet_bind_hashbucket *bhead;
+	/* Step 1: Put TW into bind hash. Original socket stays there too.
+	   Note, that any socket with inet->num != 0 MUST be bound in
+	   binding cache, even if it is closed.
+	 */
+	bhead = &hashinfo->bhash[inet_bhashfn(inet->num, hashinfo->bhash_size)];
+	spin_lock(&bhead->lock);
+	tw->tw_tb = inet->bind_hash;
+	BUG_TRAP(inet->bind_hash);
+	inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
+	spin_unlock(&bhead->lock);
+
+	write_lock(&ehead->lock);
+
+	/* Step 2: Remove SK from established hash. */
+	if (__sk_del_node_init(sk))
+		sock_prot_dec_use(sk->sk_prot);
+
+	/* Step 3: Hash TW into TIMEWAIT half of established hash table. */
+	inet_twsk_add_node(tw, &(ehead + hashinfo->ehash_size)->chain);
+	atomic_inc(&tw->tw_refcnt);
+
+	write_unlock(&ehead->lock);
+}