1 // SPDX-License-Identifier: GPL-2.0-only
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
5  *		interface as the means of communication with the user level.
21  *	inet_twsk_bind_unhash - unhash a timewait socket from bind hash
26  *	bind hash lock must be held by caller.
27  *	Returns 1 if caller should call inet_twsk_put() after lock release.
32 	struct inet_bind_bucket *tb = tw->tw_tb;  in inet_twsk_bind_unhash()
37 	__hlist_del(&tw->tw_bind_node);  in inet_twsk_bind_unhash()
38 	tw->tw_tb = NULL;  in inet_twsk_bind_unhash()
39 	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);  in inet_twsk_bind_unhash()
46 	struct inet_hashinfo *hashinfo = tw->tw_dr->hashinfo;  in inet_twsk_kill()
47 	spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);  in inet_twsk_kill()  local
50 	spin_lock(lock);  in inet_twsk_kill()
52 	spin_unlock(lock);  in inet_twsk_kill()
55 	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num,  in inet_twsk_kill()
56 			hashinfo->bhash_size)];  in inet_twsk_kill()
58 	spin_lock(&bhead->lock);  in inet_twsk_kill()
60 	spin_unlock(&bhead->lock);  in inet_twsk_kill()
62 	atomic_dec(&tw->tw_dr->tw_count);  in inet_twsk_kill()
68 	struct module *owner = tw->tw_prot->owner;  in inet_twsk_free()
71 	pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);  in inet_twsk_free()
73 	kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);  in inet_twsk_free()
79 	if (refcount_dec_and_test(&tw->tw_refcnt))  in inet_twsk_put()
87 	hlist_nulls_add_head_rcu(&tw->tw_node, list);  in inet_twsk_add_node_rcu()
93 	hlist_add_head(&tw->tw_bind_node, list);  in inet_twsk_add_bind_node()
106 	struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash);  in inet_twsk_hashdance()
107 	spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);  in inet_twsk_hashdance()  local
110 	   Note, that any socket with inet->num != 0 MUST be bound in  in inet_twsk_hashdance()
113 	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num,  in inet_twsk_hashdance()
114 			hashinfo->bhash_size)];  in inet_twsk_hashdance()
115 	spin_lock(&bhead->lock);  in inet_twsk_hashdance()
116 	tw->tw_tb = icsk->icsk_bind_hash;  in inet_twsk_hashdance()
117 	WARN_ON(!icsk->icsk_bind_hash);  in inet_twsk_hashdance()
118 	inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);  in inet_twsk_hashdance()
119 	spin_unlock(&bhead->lock);  in inet_twsk_hashdance()
121 	spin_lock(lock);  in inet_twsk_hashdance()
123 	inet_twsk_add_node_rcu(tw, &ehead->chain);  in inet_twsk_hashdance()
127 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);  in inet_twsk_hashdance()
129 	spin_unlock(lock);  in inet_twsk_hashdance()
132 	 * - one reference for bhash chain.  in inet_twsk_hashdance()
133 	 * - one reference for ehash chain.  in inet_twsk_hashdance()
134 	 * - one reference for timer.  in inet_twsk_hashdance()
140 	refcount_set(&tw->tw_refcnt, 3);  in inet_twsk_hashdance()
148 	if (tw->tw_kill)  in tw_timer_handler()
161 	if (atomic_read(&dr->tw_count) >= dr->sysctl_max_tw_buckets)  in inet_twsk_alloc()
164 	tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,  in inet_twsk_alloc()
169 		tw->tw_dr	    = dr;  in inet_twsk_alloc()
171 		tw->tw_daddr	    = inet->inet_daddr;  in inet_twsk_alloc()
172 		tw->tw_rcv_saddr    = inet->inet_rcv_saddr;  in inet_twsk_alloc()
173 		tw->tw_bound_dev_if = sk->sk_bound_dev_if;  in inet_twsk_alloc()
174 		tw->tw_tos	    = inet->tos;  in inet_twsk_alloc()
175 		tw->tw_num	    = inet->inet_num;  in inet_twsk_alloc()
176 		tw->tw_state	    = TCP_TIME_WAIT;  in inet_twsk_alloc()
177 		tw->tw_substate	    = state;  in inet_twsk_alloc()
178 		tw->tw_sport	    = inet->inet_sport;  in inet_twsk_alloc()
179 		tw->tw_dport	    = inet->inet_dport;  in inet_twsk_alloc()
180 		tw->tw_family	    = sk->sk_family;  in inet_twsk_alloc()
181 		tw->tw_reuse	    = sk->sk_reuse;  in inet_twsk_alloc()
182 		tw->tw_reuseport    = sk->sk_reuseport;  in inet_twsk_alloc()
183 		tw->tw_hash	    = sk->sk_hash;  in inet_twsk_alloc()
184 		tw->tw_ipv6only	    = 0;  in inet_twsk_alloc()
185 		tw->tw_transparent  = inet->transparent;  in inet_twsk_alloc()
186 		tw->tw_prot	    = sk->sk_prot_creator;  in inet_twsk_alloc()
187 		atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie));  in inet_twsk_alloc()
189 		timer_setup(&tw->tw_timer, tw_timer_handler, TIMER_PINNED);  in inet_twsk_alloc()
195 		refcount_set(&tw->tw_refcnt, 0);  in inet_twsk_alloc()
197 		__module_get(tw->tw_prot->owner);  in inet_twsk_alloc()
208 /* This is for handling early-kills of TIME_WAIT sockets.
214 	if (del_timer_sync(&tw->tw_timer))  in inet_twsk_deschedule_put()
226 	 * RATIONALE: if FIN arrived and we entered TIME-WAIT state,  in __inet_twsk_schedule()
228 	 * FINs (or previous seqments) are lost (probability of such event  in __inet_twsk_schedule()
230 	 * time to detect the loss is about RTO*(2^N - 1) with exponential  in __inet_twsk_schedule()
235 	 *   Well, 240 consumes too much of resources 8)  in __inet_twsk_schedule()
244 	 * of PAWS.  in __inet_twsk_schedule()
247 	tw->tw_kill = timeo <= 4*HZ;  in __inet_twsk_schedule()
249 		BUG_ON(mod_timer(&tw->tw_timer, jiffies + timeo));  in __inet_twsk_schedule()
250 		atomic_inc(&tw->tw_dr->tw_count);  in __inet_twsk_schedule()
252 		mod_timer_pending(&tw->tw_timer, jiffies + timeo);  in __inet_twsk_schedule()
264 	for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {  in inet_twsk_purge()
265 		struct inet_ehash_bucket *head = &hashinfo->ehash[slot];  in inet_twsk_purge()
270 		sk_nulls_for_each_rcu(sk, node, &head->chain) {  in inet_twsk_purge()
271 			if (sk->sk_state != TCP_TIME_WAIT)  in inet_twsk_purge()
274 			if ((tw->tw_family != family) ||  in inet_twsk_purge()
275 				refcount_read(&twsk_net(tw)->ns.count))  in inet_twsk_purge()
278 			if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt)))  in inet_twsk_purge()
281 			if (unlikely((tw->tw_family != family) ||  in inet_twsk_purge()
282 				     refcount_read(&twsk_net(tw)->ns.count))) {  in inet_twsk_purge()
293 		/* If the nulls value we got at the end of this lookup is  in inet_twsk_purge()