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