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/net/ipv4/inet_hashtables.c

http://github.com/mirrors/linux
C | 827 lines | 659 code | 101 blank | 67 comment | 113 complexity | dc9bfd15f31cefceede0f14dc3be53e3 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
  4 *		operating system.  INET is implemented using the BSD Socket
  5 *		interface as the means of communication with the user level.
  6 *
  7 *		Generic INET transport hashtables
  8 *
  9 * Authors:	Lotsa people, from code originally in tcp
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/random.h>
 14#include <linux/sched.h>
 15#include <linux/slab.h>
 16#include <linux/wait.h>
 17#include <linux/vmalloc.h>
 18#include <linux/memblock.h>
 19
 20#include <net/addrconf.h>
 21#include <net/inet_connection_sock.h>
 22#include <net/inet_hashtables.h>
 23#include <net/secure_seq.h>
 24#include <net/ip.h>
 25#include <net/tcp.h>
 26#include <net/sock_reuseport.h>
 27
 28static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 29			const __u16 lport, const __be32 faddr,
 30			const __be16 fport)
 31{
 32	static u32 inet_ehash_secret __read_mostly;
 33
 34	net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
 35
 36	return __inet_ehashfn(laddr, lport, faddr, fport,
 37			      inet_ehash_secret + net_hash_mix(net));
 38}
 39
 40/* This function handles inet_sock, but also timewait and request sockets
 41 * for IPv4/IPv6.
 42 */
 43static u32 sk_ehashfn(const struct sock *sk)
 44{
 45#if IS_ENABLED(CONFIG_IPV6)
 46	if (sk->sk_family == AF_INET6 &&
 47	    !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 48		return inet6_ehashfn(sock_net(sk),
 49				     &sk->sk_v6_rcv_saddr, sk->sk_num,
 50				     &sk->sk_v6_daddr, sk->sk_dport);
 51#endif
 52	return inet_ehashfn(sock_net(sk),
 53			    sk->sk_rcv_saddr, sk->sk_num,
 54			    sk->sk_daddr, sk->sk_dport);
 55}
 56
 57/*
 58 * Allocate and initialize a new local port bind bucket.
 59 * The bindhash mutex for snum's hash chain must be held here.
 60 */
 61struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 62						 struct net *net,
 63						 struct inet_bind_hashbucket *head,
 64						 const unsigned short snum,
 65						 int l3mdev)
 66{
 67	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 68
 69	if (tb) {
 70		write_pnet(&tb->ib_net, net);
 71		tb->l3mdev    = l3mdev;
 72		tb->port      = snum;
 73		tb->fastreuse = 0;
 74		tb->fastreuseport = 0;
 75		INIT_HLIST_HEAD(&tb->owners);
 76		hlist_add_head(&tb->node, &head->chain);
 77	}
 78	return tb;
 79}
 80
 81/*
 82 * Caller must hold hashbucket lock for this tb with local BH disabled
 83 */
 84void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
 85{
 86	if (hlist_empty(&tb->owners)) {
 87		__hlist_del(&tb->node);
 88		kmem_cache_free(cachep, tb);
 89	}
 90}
 91
 92void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 93		    const unsigned short snum)
 94{
 95	inet_sk(sk)->inet_num = snum;
 96	sk_add_bind_node(sk, &tb->owners);
 97	inet_csk(sk)->icsk_bind_hash = tb;
 98}
 99
100/*
101 * Get rid of any references to a local port held by the given sock.
102 */
103static void __inet_put_port(struct sock *sk)
104{
105	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
106	const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
107			hashinfo->bhash_size);
108	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
109	struct inet_bind_bucket *tb;
110
111	spin_lock(&head->lock);
112	tb = inet_csk(sk)->icsk_bind_hash;
113	__sk_del_bind_node(sk);
114	inet_csk(sk)->icsk_bind_hash = NULL;
115	inet_sk(sk)->inet_num = 0;
116	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
117	spin_unlock(&head->lock);
118}
119
120void inet_put_port(struct sock *sk)
121{
122	local_bh_disable();
123	__inet_put_port(sk);
124	local_bh_enable();
125}
126EXPORT_SYMBOL(inet_put_port);
127
128int __inet_inherit_port(const struct sock *sk, struct sock *child)
129{
130	struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
131	unsigned short port = inet_sk(child)->inet_num;
132	const int bhash = inet_bhashfn(sock_net(sk), port,
133			table->bhash_size);
134	struct inet_bind_hashbucket *head = &table->bhash[bhash];
135	struct inet_bind_bucket *tb;
136	int l3mdev;
137
138	spin_lock(&head->lock);
139	tb = inet_csk(sk)->icsk_bind_hash;
140	if (unlikely(!tb)) {
141		spin_unlock(&head->lock);
142		return -ENOENT;
143	}
144	if (tb->port != port) {
145		l3mdev = inet_sk_bound_l3mdev(sk);
146
147		/* NOTE: using tproxy and redirecting skbs to a proxy
148		 * on a different listener port breaks the assumption
149		 * that the listener socket's icsk_bind_hash is the same
150		 * as that of the child socket. We have to look up or
151		 * create a new bind bucket for the child here. */
152		inet_bind_bucket_for_each(tb, &head->chain) {
153			if (net_eq(ib_net(tb), sock_net(sk)) &&
154			    tb->l3mdev == l3mdev && tb->port == port)
155				break;
156		}
157		if (!tb) {
158			tb = inet_bind_bucket_create(table->bind_bucket_cachep,
159						     sock_net(sk), head, port,
160						     l3mdev);
161			if (!tb) {
162				spin_unlock(&head->lock);
163				return -ENOMEM;
164			}
165		}
166	}
167	inet_bind_hash(child, tb, port);
168	spin_unlock(&head->lock);
169
170	return 0;
171}
172EXPORT_SYMBOL_GPL(__inet_inherit_port);
173
174static struct inet_listen_hashbucket *
175inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
176{
177	u32 hash;
178
179#if IS_ENABLED(CONFIG_IPV6)
180	if (sk->sk_family == AF_INET6)
181		hash = ipv6_portaddr_hash(sock_net(sk),
182					  &sk->sk_v6_rcv_saddr,
183					  inet_sk(sk)->inet_num);
184	else
185#endif
186		hash = ipv4_portaddr_hash(sock_net(sk),
187					  inet_sk(sk)->inet_rcv_saddr,
188					  inet_sk(sk)->inet_num);
189	return inet_lhash2_bucket(h, hash);
190}
191
192static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)
193{
194	struct inet_listen_hashbucket *ilb2;
195
196	if (!h->lhash2)
197		return;
198
199	ilb2 = inet_lhash2_bucket_sk(h, sk);
200
201	spin_lock(&ilb2->lock);
202	if (sk->sk_reuseport && sk->sk_family == AF_INET6)
203		hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
204				   &ilb2->head);
205	else
206		hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
207				   &ilb2->head);
208	ilb2->count++;
209	spin_unlock(&ilb2->lock);
210}
211
212static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)
213{
214	struct inet_listen_hashbucket *ilb2;
215
216	if (!h->lhash2 ||
217	    WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))
218		return;
219
220	ilb2 = inet_lhash2_bucket_sk(h, sk);
221
222	spin_lock(&ilb2->lock);
223	hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);
224	ilb2->count--;
225	spin_unlock(&ilb2->lock);
226}
227
228static inline int compute_score(struct sock *sk, struct net *net,
229				const unsigned short hnum, const __be32 daddr,
230				const int dif, const int sdif, bool exact_dif)
231{
232	int score = -1;
233
234	if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
235			!ipv6_only_sock(sk)) {
236		if (sk->sk_rcv_saddr != daddr)
237			return -1;
238
239		if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
240			return -1;
241
242		score = sk->sk_family == PF_INET ? 2 : 1;
243		if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
244			score++;
245	}
246	return score;
247}
248
249/*
250 * Here are some nice properties to exploit here. The BSD API
251 * does not allow a listening sock to specify the remote port nor the
252 * remote address for the connection. So always assume those are both
253 * wildcarded during the search since they can never be otherwise.
254 */
255
256/* called with rcu_read_lock() : No refcount taken on the socket */
257static struct sock *inet_lhash2_lookup(struct net *net,
258				struct inet_listen_hashbucket *ilb2,
259				struct sk_buff *skb, int doff,
260				const __be32 saddr, __be16 sport,
261				const __be32 daddr, const unsigned short hnum,
262				const int dif, const int sdif)
263{
264	bool exact_dif = inet_exact_dif_match(net, skb);
265	struct inet_connection_sock *icsk;
266	struct sock *sk, *result = NULL;
267	int score, hiscore = 0;
268	u32 phash = 0;
269
270	inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
271		sk = (struct sock *)icsk;
272		score = compute_score(sk, net, hnum, daddr,
273				      dif, sdif, exact_dif);
274		if (score > hiscore) {
275			if (sk->sk_reuseport) {
276				phash = inet_ehashfn(net, daddr, hnum,
277						     saddr, sport);
278				result = reuseport_select_sock(sk, phash,
279							       skb, doff);
280				if (result)
281					return result;
282			}
283			result = sk;
284			hiscore = score;
285		}
286	}
287
288	return result;
289}
290
291struct sock *__inet_lookup_listener(struct net *net,
292				    struct inet_hashinfo *hashinfo,
293				    struct sk_buff *skb, int doff,
294				    const __be32 saddr, __be16 sport,
295				    const __be32 daddr, const unsigned short hnum,
296				    const int dif, const int sdif)
297{
298	struct inet_listen_hashbucket *ilb2;
299	struct sock *result = NULL;
300	unsigned int hash2;
301
302	hash2 = ipv4_portaddr_hash(net, daddr, hnum);
303	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
304
305	result = inet_lhash2_lookup(net, ilb2, skb, doff,
306				    saddr, sport, daddr, hnum,
307				    dif, sdif);
308	if (result)
309		goto done;
310
311	/* Lookup lhash2 with INADDR_ANY */
312	hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
313	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
314
315	result = inet_lhash2_lookup(net, ilb2, skb, doff,
316				    saddr, sport, htonl(INADDR_ANY), hnum,
317				    dif, sdif);
318done:
319	if (IS_ERR(result))
320		return NULL;
321	return result;
322}
323EXPORT_SYMBOL_GPL(__inet_lookup_listener);
324
325/* All sockets share common refcount, but have different destructors */
326void sock_gen_put(struct sock *sk)
327{
328	if (!refcount_dec_and_test(&sk->sk_refcnt))
329		return;
330
331	if (sk->sk_state == TCP_TIME_WAIT)
332		inet_twsk_free(inet_twsk(sk));
333	else if (sk->sk_state == TCP_NEW_SYN_RECV)
334		reqsk_free(inet_reqsk(sk));
335	else
336		sk_free(sk);
337}
338EXPORT_SYMBOL_GPL(sock_gen_put);
339
340void sock_edemux(struct sk_buff *skb)
341{
342	sock_gen_put(skb->sk);
343}
344EXPORT_SYMBOL(sock_edemux);
345
346struct sock *__inet_lookup_established(struct net *net,
347				  struct inet_hashinfo *hashinfo,
348				  const __be32 saddr, const __be16 sport,
349				  const __be32 daddr, const u16 hnum,
350				  const int dif, const int sdif)
351{
352	INET_ADDR_COOKIE(acookie, saddr, daddr);
353	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
354	struct sock *sk;
355	const struct hlist_nulls_node *node;
356	/* Optimize here for direct hit, only listening connections can
357	 * have wildcards anyways.
358	 */
359	unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
360	unsigned int slot = hash & hashinfo->ehash_mask;
361	struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
362
363begin:
364	sk_nulls_for_each_rcu(sk, node, &head->chain) {
365		if (sk->sk_hash != hash)
366			continue;
367		if (likely(INET_MATCH(sk, net, acookie,
368				      saddr, daddr, ports, dif, sdif))) {
369			if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
370				goto out;
371			if (unlikely(!INET_MATCH(sk, net, acookie,
372						 saddr, daddr, ports,
373						 dif, sdif))) {
374				sock_gen_put(sk);
375				goto begin;
376			}
377			goto found;
378		}
379	}
380	/*
381	 * if the nulls value we got at the end of this lookup is
382	 * not the expected one, we must restart lookup.
383	 * We probably met an item that was moved to another chain.
384	 */
385	if (get_nulls_value(node) != slot)
386		goto begin;
387out:
388	sk = NULL;
389found:
390	return sk;
391}
392EXPORT_SYMBOL_GPL(__inet_lookup_established);
393
394/* called with local bh disabled */
395static int __inet_check_established(struct inet_timewait_death_row *death_row,
396				    struct sock *sk, __u16 lport,
397				    struct inet_timewait_sock **twp)
398{
399	struct inet_hashinfo *hinfo = death_row->hashinfo;
400	struct inet_sock *inet = inet_sk(sk);
401	__be32 daddr = inet->inet_rcv_saddr;
402	__be32 saddr = inet->inet_daddr;
403	int dif = sk->sk_bound_dev_if;
404	struct net *net = sock_net(sk);
405	int sdif = l3mdev_master_ifindex_by_index(net, dif);
406	INET_ADDR_COOKIE(acookie, saddr, daddr);
407	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
408	unsigned int hash = inet_ehashfn(net, daddr, lport,
409					 saddr, inet->inet_dport);
410	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
411	spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
412	struct sock *sk2;
413	const struct hlist_nulls_node *node;
414	struct inet_timewait_sock *tw = NULL;
415
416	spin_lock(lock);
417
418	sk_nulls_for_each(sk2, node, &head->chain) {
419		if (sk2->sk_hash != hash)
420			continue;
421
422		if (likely(INET_MATCH(sk2, net, acookie,
423					 saddr, daddr, ports, dif, sdif))) {
424			if (sk2->sk_state == TCP_TIME_WAIT) {
425				tw = inet_twsk(sk2);
426				if (twsk_unique(sk, sk2, twp))
427					break;
428			}
429			goto not_unique;
430		}
431	}
432
433	/* Must record num and sport now. Otherwise we will see
434	 * in hash table socket with a funny identity.
435	 */
436	inet->inet_num = lport;
437	inet->inet_sport = htons(lport);
438	sk->sk_hash = hash;
439	WARN_ON(!sk_unhashed(sk));
440	__sk_nulls_add_node_rcu(sk, &head->chain);
441	if (tw) {
442		sk_nulls_del_node_init_rcu((struct sock *)tw);
443		__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
444	}
445	spin_unlock(lock);
446	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
447
448	if (twp) {
449		*twp = tw;
450	} else if (tw) {
451		/* Silly. Should hash-dance instead... */
452		inet_twsk_deschedule_put(tw);
453	}
454	return 0;
455
456not_unique:
457	spin_unlock(lock);
458	return -EADDRNOTAVAIL;
459}
460
461static u32 inet_sk_port_offset(const struct sock *sk)
462{
463	const struct inet_sock *inet = inet_sk(sk);
464
465	return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
466					  inet->inet_daddr,
467					  inet->inet_dport);
468}
469
470/* insert a socket into ehash, and eventually remove another one
471 * (The another one can be a SYN_RECV or TIMEWAIT
472 */
473bool inet_ehash_insert(struct sock *sk, struct sock *osk)
474{
475	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
476	struct hlist_nulls_head *list;
477	struct inet_ehash_bucket *head;
478	spinlock_t *lock;
479	bool ret = true;
480
481	WARN_ON_ONCE(!sk_unhashed(sk));
482
483	sk->sk_hash = sk_ehashfn(sk);
484	head = inet_ehash_bucket(hashinfo, sk->sk_hash);
485	list = &head->chain;
486	lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
487
488	spin_lock(lock);
489	if (osk) {
490		WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
491		ret = sk_nulls_del_node_init_rcu(osk);
492	}
493	if (ret)
494		__sk_nulls_add_node_rcu(sk, list);
495	spin_unlock(lock);
496	return ret;
497}
498
499bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
500{
501	bool ok = inet_ehash_insert(sk, osk);
502
503	if (ok) {
504		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
505	} else {
506		percpu_counter_inc(sk->sk_prot->orphan_count);
507		inet_sk_set_state(sk, TCP_CLOSE);
508		sock_set_flag(sk, SOCK_DEAD);
509		inet_csk_destroy_sock(sk);
510	}
511	return ok;
512}
513EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
514
515static int inet_reuseport_add_sock(struct sock *sk,
516				   struct inet_listen_hashbucket *ilb)
517{
518	struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
519	const struct hlist_nulls_node *node;
520	struct sock *sk2;
521	kuid_t uid = sock_i_uid(sk);
522
523	sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
524		if (sk2 != sk &&
525		    sk2->sk_family == sk->sk_family &&
526		    ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
527		    sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
528		    inet_csk(sk2)->icsk_bind_hash == tb &&
529		    sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
530		    inet_rcv_saddr_equal(sk, sk2, false))
531			return reuseport_add_sock(sk, sk2,
532						  inet_rcv_saddr_any(sk));
533	}
534
535	return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
536}
537
538int __inet_hash(struct sock *sk, struct sock *osk)
539{
540	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
541	struct inet_listen_hashbucket *ilb;
542	int err = 0;
543
544	if (sk->sk_state != TCP_LISTEN) {
545		inet_ehash_nolisten(sk, osk);
546		return 0;
547	}
548	WARN_ON(!sk_unhashed(sk));
549	ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
550
551	spin_lock(&ilb->lock);
552	if (sk->sk_reuseport) {
553		err = inet_reuseport_add_sock(sk, ilb);
554		if (err)
555			goto unlock;
556	}
557	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
558		sk->sk_family == AF_INET6)
559		__sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
560	else
561		__sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
562	inet_hash2(hashinfo, sk);
563	ilb->count++;
564	sock_set_flag(sk, SOCK_RCU_FREE);
565	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
566unlock:
567	spin_unlock(&ilb->lock);
568
569	return err;
570}
571EXPORT_SYMBOL(__inet_hash);
572
573int inet_hash(struct sock *sk)
574{
575	int err = 0;
576
577	if (sk->sk_state != TCP_CLOSE) {
578		local_bh_disable();
579		err = __inet_hash(sk, NULL);
580		local_bh_enable();
581	}
582
583	return err;
584}
585EXPORT_SYMBOL_GPL(inet_hash);
586
587void inet_unhash(struct sock *sk)
588{
589	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
590	struct inet_listen_hashbucket *ilb = NULL;
591	spinlock_t *lock;
592
593	if (sk_unhashed(sk))
594		return;
595
596	if (sk->sk_state == TCP_LISTEN) {
597		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
598		lock = &ilb->lock;
599	} else {
600		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
601	}
602	spin_lock_bh(lock);
603	if (sk_unhashed(sk))
604		goto unlock;
605
606	if (rcu_access_pointer(sk->sk_reuseport_cb))
607		reuseport_detach_sock(sk);
608	if (ilb) {
609		inet_unhash2(hashinfo, sk);
610		ilb->count--;
611	}
612	__sk_nulls_del_node_init_rcu(sk);
613	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
614unlock:
615	spin_unlock_bh(lock);
616}
617EXPORT_SYMBOL_GPL(inet_unhash);
618
619int __inet_hash_connect(struct inet_timewait_death_row *death_row,
620		struct sock *sk, u32 port_offset,
621		int (*check_established)(struct inet_timewait_death_row *,
622			struct sock *, __u16, struct inet_timewait_sock **))
623{
624	struct inet_hashinfo *hinfo = death_row->hashinfo;
625	struct inet_timewait_sock *tw = NULL;
626	struct inet_bind_hashbucket *head;
627	int port = inet_sk(sk)->inet_num;
628	struct net *net = sock_net(sk);
629	struct inet_bind_bucket *tb;
630	u32 remaining, offset;
631	int ret, i, low, high;
632	static u32 hint;
633	int l3mdev;
634
635	if (port) {
636		head = &hinfo->bhash[inet_bhashfn(net, port,
637						  hinfo->bhash_size)];
638		tb = inet_csk(sk)->icsk_bind_hash;
639		spin_lock_bh(&head->lock);
640		if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
641			inet_ehash_nolisten(sk, NULL);
642			spin_unlock_bh(&head->lock);
643			return 0;
644		}
645		spin_unlock(&head->lock);
646		/* No definite answer... Walk to established hash table */
647		ret = check_established(death_row, sk, port, NULL);
648		local_bh_enable();
649		return ret;
650	}
651
652	l3mdev = inet_sk_bound_l3mdev(sk);
653
654	inet_get_local_port_range(net, &low, &high);
655	high++; /* [32768, 60999] -> [32768, 61000[ */
656	remaining = high - low;
657	if (likely(remaining > 1))
658		remaining &= ~1U;
659
660	offset = (hint + port_offset) % remaining;
661	/* In first pass we try ports of @low parity.
662	 * inet_csk_get_port() does the opposite choice.
663	 */
664	offset &= ~1U;
665other_parity_scan:
666	port = low + offset;
667	for (i = 0; i < remaining; i += 2, port += 2) {
668		if (unlikely(port >= high))
669			port -= remaining;
670		if (inet_is_local_reserved_port(net, port))
671			continue;
672		head = &hinfo->bhash[inet_bhashfn(net, port,
673						  hinfo->bhash_size)];
674		spin_lock_bh(&head->lock);
675
676		/* Does not bother with rcv_saddr checks, because
677		 * the established check is already unique enough.
678		 */
679		inet_bind_bucket_for_each(tb, &head->chain) {
680			if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
681			    tb->port == port) {
682				if (tb->fastreuse >= 0 ||
683				    tb->fastreuseport >= 0)
684					goto next_port;
685				WARN_ON(hlist_empty(&tb->owners));
686				if (!check_established(death_row, sk,
687						       port, &tw))
688					goto ok;
689				goto next_port;
690			}
691		}
692
693		tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
694					     net, head, port, l3mdev);
695		if (!tb) {
696			spin_unlock_bh(&head->lock);
697			return -ENOMEM;
698		}
699		tb->fastreuse = -1;
700		tb->fastreuseport = -1;
701		goto ok;
702next_port:
703		spin_unlock_bh(&head->lock);
704		cond_resched();
705	}
706
707	offset++;
708	if ((offset & 1) && remaining > 1)
709		goto other_parity_scan;
710
711	return -EADDRNOTAVAIL;
712
713ok:
714	hint += i + 2;
715
716	/* Head lock still held and bh's disabled */
717	inet_bind_hash(sk, tb, port);
718	if (sk_unhashed(sk)) {
719		inet_sk(sk)->inet_sport = htons(port);
720		inet_ehash_nolisten(sk, (struct sock *)tw);
721	}
722	if (tw)
723		inet_twsk_bind_unhash(tw, hinfo);
724	spin_unlock(&head->lock);
725	if (tw)
726		inet_twsk_deschedule_put(tw);
727	local_bh_enable();
728	return 0;
729}
730
731/*
732 * Bind a port for a connect operation and hash it.
733 */
734int inet_hash_connect(struct inet_timewait_death_row *death_row,
735		      struct sock *sk)
736{
737	u32 port_offset = 0;
738
739	if (!inet_sk(sk)->inet_num)
740		port_offset = inet_sk_port_offset(sk);
741	return __inet_hash_connect(death_row, sk, port_offset,
742				   __inet_check_established);
743}
744EXPORT_SYMBOL_GPL(inet_hash_connect);
745
746void inet_hashinfo_init(struct inet_hashinfo *h)
747{
748	int i;
749
750	for (i = 0; i < INET_LHTABLE_SIZE; i++) {
751		spin_lock_init(&h->listening_hash[i].lock);
752		INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
753				      i + LISTENING_NULLS_BASE);
754		h->listening_hash[i].count = 0;
755	}
756
757	h->lhash2 = NULL;
758}
759EXPORT_SYMBOL_GPL(inet_hashinfo_init);
760
761static void init_hashinfo_lhash2(struct inet_hashinfo *h)
762{
763	int i;
764
765	for (i = 0; i <= h->lhash2_mask; i++) {
766		spin_lock_init(&h->lhash2[i].lock);
767		INIT_HLIST_HEAD(&h->lhash2[i].head);
768		h->lhash2[i].count = 0;
769	}
770}
771
772void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
773				unsigned long numentries, int scale,
774				unsigned long low_limit,
775				unsigned long high_limit)
776{
777	h->lhash2 = alloc_large_system_hash(name,
778					    sizeof(*h->lhash2),
779					    numentries,
780					    scale,
781					    0,
782					    NULL,
783					    &h->lhash2_mask,
784					    low_limit,
785					    high_limit);
786	init_hashinfo_lhash2(h);
787}
788
789int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
790{
791	h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
792	if (!h->lhash2)
793		return -ENOMEM;
794
795	h->lhash2_mask = INET_LHTABLE_SIZE - 1;
796	/* INET_LHTABLE_SIZE must be a power of 2 */
797	BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
798
799	init_hashinfo_lhash2(h);
800	return 0;
801}
802EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
803
804int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
805{
806	unsigned int locksz = sizeof(spinlock_t);
807	unsigned int i, nblocks = 1;
808
809	if (locksz != 0) {
810		/* allocate 2 cache lines or at least one spinlock per cpu */
811		nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
812		nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
813
814		/* no more locks than number of hash buckets */
815		nblocks = min(nblocks, hashinfo->ehash_mask + 1);
816
817		hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
818		if (!hashinfo->ehash_locks)
819			return -ENOMEM;
820
821		for (i = 0; i < nblocks; i++)
822			spin_lock_init(&hashinfo->ehash_locks[i]);
823	}
824	hashinfo->ehash_locks_mask = nblocks - 1;
825	return 0;
826}
827EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);