1 // SPDX-License-Identifier: GPL-2.0-or-later
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.
7 * Generic INET transport hashtables
9 * Authors: Lotsa people, from code originally in tcp
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>
20 #include <net/addrconf.h>
21 #include <net/inet_connection_sock.h>
22 #include <net/inet_hashtables.h>
23 #if IS_ENABLED(CONFIG_IPV6)
24 #include <net/inet6_hashtables.h>
26 #include <net/secure_seq.h>
29 #include <net/sock_reuseport.h>
31 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
32 const __u16 lport, const __be32 faddr,
35 static u32 inet_ehash_secret __read_mostly;
37 net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
39 return __inet_ehashfn(laddr, lport, faddr, fport,
40 inet_ehash_secret + net_hash_mix(net));
43 /* This function handles inet_sock, but also timewait and request sockets
46 static u32 sk_ehashfn(const struct sock *sk)
48 #if IS_ENABLED(CONFIG_IPV6)
49 if (sk->sk_family == AF_INET6 &&
50 !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
51 return inet6_ehashfn(sock_net(sk),
52 &sk->sk_v6_rcv_saddr, sk->sk_num,
53 &sk->sk_v6_daddr, sk->sk_dport);
55 return inet_ehashfn(sock_net(sk),
56 sk->sk_rcv_saddr, sk->sk_num,
57 sk->sk_daddr, sk->sk_dport);
61 * Allocate and initialize a new local port bind bucket.
62 * The bindhash mutex for snum's hash chain must be held here.
64 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
66 struct inet_bind_hashbucket *head,
67 const unsigned short snum,
70 struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
73 write_pnet(&tb->ib_net, net);
77 tb->fastreuseport = 0;
78 INIT_HLIST_HEAD(&tb->owners);
79 hlist_add_head(&tb->node, &head->chain);
85 * Caller must hold hashbucket lock for this tb with local BH disabled
87 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
89 if (hlist_empty(&tb->owners)) {
90 __hlist_del(&tb->node);
91 kmem_cache_free(cachep, tb);
95 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
96 const unsigned short snum)
98 inet_sk(sk)->inet_num = snum;
99 sk_add_bind_node(sk, &tb->owners);
100 inet_csk(sk)->icsk_bind_hash = tb;
104 * Get rid of any references to a local port held by the given sock.
106 static void __inet_put_port(struct sock *sk)
108 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
109 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
110 hashinfo->bhash_size);
111 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
112 struct inet_bind_bucket *tb;
114 spin_lock(&head->lock);
115 tb = inet_csk(sk)->icsk_bind_hash;
116 __sk_del_bind_node(sk);
117 inet_csk(sk)->icsk_bind_hash = NULL;
118 inet_sk(sk)->inet_num = 0;
119 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
120 spin_unlock(&head->lock);
123 void inet_put_port(struct sock *sk)
129 EXPORT_SYMBOL(inet_put_port);
131 int __inet_inherit_port(const struct sock *sk, struct sock *child)
133 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
134 unsigned short port = inet_sk(child)->inet_num;
135 const int bhash = inet_bhashfn(sock_net(sk), port,
137 struct inet_bind_hashbucket *head = &table->bhash[bhash];
138 struct inet_bind_bucket *tb;
141 spin_lock(&head->lock);
142 tb = inet_csk(sk)->icsk_bind_hash;
144 spin_unlock(&head->lock);
147 if (tb->port != port) {
148 l3mdev = inet_sk_bound_l3mdev(sk);
150 /* NOTE: using tproxy and redirecting skbs to a proxy
151 * on a different listener port breaks the assumption
152 * that the listener socket's icsk_bind_hash is the same
153 * as that of the child socket. We have to look up or
154 * create a new bind bucket for the child here. */
155 inet_bind_bucket_for_each(tb, &head->chain) {
156 if (net_eq(ib_net(tb), sock_net(sk)) &&
157 tb->l3mdev == l3mdev && tb->port == port)
161 tb = inet_bind_bucket_create(table->bind_bucket_cachep,
162 sock_net(sk), head, port,
165 spin_unlock(&head->lock);
169 inet_csk_update_fastreuse(tb, child);
171 inet_bind_hash(child, tb, port);
172 spin_unlock(&head->lock);
176 EXPORT_SYMBOL_GPL(__inet_inherit_port);
178 static struct inet_listen_hashbucket *
179 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
183 #if IS_ENABLED(CONFIG_IPV6)
184 if (sk->sk_family == AF_INET6)
185 hash = ipv6_portaddr_hash(sock_net(sk),
186 &sk->sk_v6_rcv_saddr,
187 inet_sk(sk)->inet_num);
190 hash = ipv4_portaddr_hash(sock_net(sk),
191 inet_sk(sk)->inet_rcv_saddr,
192 inet_sk(sk)->inet_num);
193 return inet_lhash2_bucket(h, hash);
196 static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)
198 struct inet_listen_hashbucket *ilb2;
203 ilb2 = inet_lhash2_bucket_sk(h, sk);
205 spin_lock(&ilb2->lock);
206 if (sk->sk_reuseport && sk->sk_family == AF_INET6)
207 hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
210 hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
213 spin_unlock(&ilb2->lock);
216 static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)
218 struct inet_listen_hashbucket *ilb2;
221 WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))
224 ilb2 = inet_lhash2_bucket_sk(h, sk);
226 spin_lock(&ilb2->lock);
227 hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);
229 spin_unlock(&ilb2->lock);
232 static inline int compute_score(struct sock *sk, struct net *net,
233 const unsigned short hnum, const __be32 daddr,
234 const int dif, const int sdif)
238 if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
239 !ipv6_only_sock(sk)) {
240 if (sk->sk_rcv_saddr != daddr)
243 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
245 score = sk->sk_bound_dev_if ? 2 : 1;
247 if (sk->sk_family == PF_INET)
249 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
255 static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
256 struct sk_buff *skb, int doff,
257 __be32 saddr, __be16 sport,
258 __be32 daddr, unsigned short hnum)
260 struct sock *reuse_sk = NULL;
263 if (sk->sk_reuseport) {
264 phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
265 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
271 * Here are some nice properties to exploit here. The BSD API
272 * does not allow a listening sock to specify the remote port nor the
273 * remote address for the connection. So always assume those are both
274 * wildcarded during the search since they can never be otherwise.
277 /* called with rcu_read_lock() : No refcount taken on the socket */
278 static struct sock *inet_lhash2_lookup(struct net *net,
279 struct inet_listen_hashbucket *ilb2,
280 struct sk_buff *skb, int doff,
281 const __be32 saddr, __be16 sport,
282 const __be32 daddr, const unsigned short hnum,
283 const int dif, const int sdif)
285 struct inet_connection_sock *icsk;
286 struct sock *sk, *result = NULL;
287 int score, hiscore = 0;
289 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
290 sk = (struct sock *)icsk;
291 score = compute_score(sk, net, hnum, daddr, dif, sdif);
292 if (score > hiscore) {
293 result = lookup_reuseport(net, sk, skb, doff,
294 saddr, sport, daddr, hnum);
306 static inline struct sock *inet_lookup_run_bpf(struct net *net,
307 struct inet_hashinfo *hashinfo,
308 struct sk_buff *skb, int doff,
309 __be32 saddr, __be16 sport,
310 __be32 daddr, u16 hnum)
312 struct sock *sk, *reuse_sk;
315 if (hashinfo != &tcp_hashinfo)
316 return NULL; /* only TCP is supported */
318 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP,
319 saddr, sport, daddr, hnum, &sk);
320 if (no_reuseport || IS_ERR_OR_NULL(sk))
323 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
329 struct sock *__inet_lookup_listener(struct net *net,
330 struct inet_hashinfo *hashinfo,
331 struct sk_buff *skb, int doff,
332 const __be32 saddr, __be16 sport,
333 const __be32 daddr, const unsigned short hnum,
334 const int dif, const int sdif)
336 struct inet_listen_hashbucket *ilb2;
337 struct sock *result = NULL;
340 /* Lookup redirect from BPF */
341 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
342 result = inet_lookup_run_bpf(net, hashinfo, skb, doff,
343 saddr, sport, daddr, hnum);
348 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
349 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
351 result = inet_lhash2_lookup(net, ilb2, skb, doff,
352 saddr, sport, daddr, hnum,
357 /* Lookup lhash2 with INADDR_ANY */
358 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
359 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
361 result = inet_lhash2_lookup(net, ilb2, skb, doff,
362 saddr, sport, htonl(INADDR_ANY), hnum,
369 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
371 /* All sockets share common refcount, but have different destructors */
372 void sock_gen_put(struct sock *sk)
374 if (!refcount_dec_and_test(&sk->sk_refcnt))
377 if (sk->sk_state == TCP_TIME_WAIT)
378 inet_twsk_free(inet_twsk(sk));
379 else if (sk->sk_state == TCP_NEW_SYN_RECV)
380 reqsk_free(inet_reqsk(sk));
384 EXPORT_SYMBOL_GPL(sock_gen_put);
386 void sock_edemux(struct sk_buff *skb)
388 sock_gen_put(skb->sk);
390 EXPORT_SYMBOL(sock_edemux);
392 struct sock *__inet_lookup_established(struct net *net,
393 struct inet_hashinfo *hashinfo,
394 const __be32 saddr, const __be16 sport,
395 const __be32 daddr, const u16 hnum,
396 const int dif, const int sdif)
398 INET_ADDR_COOKIE(acookie, saddr, daddr);
399 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
401 const struct hlist_nulls_node *node;
402 /* Optimize here for direct hit, only listening connections can
403 * have wildcards anyways.
405 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
406 unsigned int slot = hash & hashinfo->ehash_mask;
407 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
410 sk_nulls_for_each_rcu(sk, node, &head->chain) {
411 if (sk->sk_hash != hash)
413 if (likely(INET_MATCH(net, sk, acookie, ports, dif, sdif))) {
414 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
416 if (unlikely(!INET_MATCH(net, sk, acookie,
417 ports, dif, sdif))) {
425 * if the nulls value we got at the end of this lookup is
426 * not the expected one, we must restart lookup.
427 * We probably met an item that was moved to another chain.
429 if (get_nulls_value(node) != slot)
436 EXPORT_SYMBOL_GPL(__inet_lookup_established);
438 /* called with local bh disabled */
439 static int __inet_check_established(struct inet_timewait_death_row *death_row,
440 struct sock *sk, __u16 lport,
441 struct inet_timewait_sock **twp)
443 struct inet_hashinfo *hinfo = death_row->hashinfo;
444 struct inet_sock *inet = inet_sk(sk);
445 __be32 daddr = inet->inet_rcv_saddr;
446 __be32 saddr = inet->inet_daddr;
447 int dif = sk->sk_bound_dev_if;
448 struct net *net = sock_net(sk);
449 int sdif = l3mdev_master_ifindex_by_index(net, dif);
450 INET_ADDR_COOKIE(acookie, saddr, daddr);
451 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
452 unsigned int hash = inet_ehashfn(net, daddr, lport,
453 saddr, inet->inet_dport);
454 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
455 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
457 const struct hlist_nulls_node *node;
458 struct inet_timewait_sock *tw = NULL;
462 sk_nulls_for_each(sk2, node, &head->chain) {
463 if (sk2->sk_hash != hash)
466 if (likely(INET_MATCH(net, sk2, acookie, ports, dif, sdif))) {
467 if (sk2->sk_state == TCP_TIME_WAIT) {
469 if (twsk_unique(sk, sk2, twp))
476 /* Must record num and sport now. Otherwise we will see
477 * in hash table socket with a funny identity.
479 inet->inet_num = lport;
480 inet->inet_sport = htons(lport);
482 WARN_ON(!sk_unhashed(sk));
483 __sk_nulls_add_node_rcu(sk, &head->chain);
485 sk_nulls_del_node_init_rcu((struct sock *)tw);
486 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
489 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
494 /* Silly. Should hash-dance instead... */
495 inet_twsk_deschedule_put(tw);
501 return -EADDRNOTAVAIL;
504 static u64 inet_sk_port_offset(const struct sock *sk)
506 const struct inet_sock *inet = inet_sk(sk);
508 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
513 /* Searches for an exsiting socket in the ehash bucket list.
514 * Returns true if found, false otherwise.
516 static bool inet_ehash_lookup_by_sk(struct sock *sk,
517 struct hlist_nulls_head *list)
519 const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num);
520 const int sdif = sk->sk_bound_dev_if;
521 const int dif = sk->sk_bound_dev_if;
522 const struct hlist_nulls_node *node;
523 struct net *net = sock_net(sk);
526 INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr);
528 sk_nulls_for_each_rcu(esk, node, list) {
529 if (esk->sk_hash != sk->sk_hash)
531 if (sk->sk_family == AF_INET) {
532 if (unlikely(INET_MATCH(net, esk, acookie,
533 ports, dif, sdif))) {
537 #if IS_ENABLED(CONFIG_IPV6)
538 else if (sk->sk_family == AF_INET6) {
539 if (unlikely(inet6_match(net, esk,
541 &sk->sk_v6_rcv_saddr,
542 ports, dif, sdif))) {
551 /* Insert a socket into ehash, and eventually remove another one
552 * (The another one can be a SYN_RECV or TIMEWAIT)
553 * If an existing socket already exists, socket sk is not inserted,
554 * and sets found_dup_sk parameter to true.
556 bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk)
558 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
559 struct hlist_nulls_head *list;
560 struct inet_ehash_bucket *head;
564 WARN_ON_ONCE(!sk_unhashed(sk));
566 sk->sk_hash = sk_ehashfn(sk);
567 head = inet_ehash_bucket(hashinfo, sk->sk_hash);
569 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
573 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
574 ret = sk_nulls_del_node_init_rcu(osk);
575 } else if (found_dup_sk) {
576 *found_dup_sk = inet_ehash_lookup_by_sk(sk, list);
582 __sk_nulls_add_node_rcu(sk, list);
589 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk)
591 bool ok = inet_ehash_insert(sk, osk, found_dup_sk);
594 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
596 this_cpu_inc(*sk->sk_prot->orphan_count);
597 inet_sk_set_state(sk, TCP_CLOSE);
598 sock_set_flag(sk, SOCK_DEAD);
599 inet_csk_destroy_sock(sk);
603 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
605 static int inet_reuseport_add_sock(struct sock *sk,
606 struct inet_listen_hashbucket *ilb)
608 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
609 const struct hlist_nulls_node *node;
611 kuid_t uid = sock_i_uid(sk);
613 sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
615 sk2->sk_family == sk->sk_family &&
616 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
617 sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
618 inet_csk(sk2)->icsk_bind_hash == tb &&
619 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
620 inet_rcv_saddr_equal(sk, sk2, false))
621 return reuseport_add_sock(sk, sk2,
622 inet_rcv_saddr_any(sk));
625 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
628 int __inet_hash(struct sock *sk, struct sock *osk)
630 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
631 struct inet_listen_hashbucket *ilb;
634 if (sk->sk_state != TCP_LISTEN) {
636 inet_ehash_nolisten(sk, osk, NULL);
640 WARN_ON(!sk_unhashed(sk));
641 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
643 spin_lock(&ilb->lock);
644 if (sk->sk_reuseport) {
645 err = inet_reuseport_add_sock(sk, ilb);
649 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
650 sk->sk_family == AF_INET6)
651 __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
653 __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
654 inet_hash2(hashinfo, sk);
656 sock_set_flag(sk, SOCK_RCU_FREE);
657 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
659 spin_unlock(&ilb->lock);
663 EXPORT_SYMBOL(__inet_hash);
665 int inet_hash(struct sock *sk)
669 if (sk->sk_state != TCP_CLOSE)
670 err = __inet_hash(sk, NULL);
674 EXPORT_SYMBOL_GPL(inet_hash);
676 static void __inet_unhash(struct sock *sk, struct inet_listen_hashbucket *ilb)
681 if (rcu_access_pointer(sk->sk_reuseport_cb))
682 reuseport_stop_listen_sock(sk);
684 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
686 inet_unhash2(hashinfo, sk);
689 __sk_nulls_del_node_init_rcu(sk);
690 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
693 void inet_unhash(struct sock *sk)
695 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
700 if (sk->sk_state == TCP_LISTEN) {
701 struct inet_listen_hashbucket *ilb;
703 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
704 /* Don't disable bottom halves while acquiring the lock to
705 * avoid circular locking dependency on PREEMPT_RT.
707 spin_lock(&ilb->lock);
708 __inet_unhash(sk, ilb);
709 spin_unlock(&ilb->lock);
711 spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
714 __inet_unhash(sk, NULL);
715 spin_unlock_bh(lock);
718 EXPORT_SYMBOL_GPL(inet_unhash);
720 /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm
721 * Note that we use 32bit integers (vs RFC 'short integers')
722 * because 2^16 is not a multiple of num_ephemeral and this
723 * property might be used by clever attacker.
724 * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though
725 * attacks were since demonstrated, thus we use 65536 instead to really
726 * give more isolation and privacy, at the expense of 256kB of kernel
729 #define INET_TABLE_PERTURB_SHIFT 16
730 #define INET_TABLE_PERTURB_SIZE (1 << INET_TABLE_PERTURB_SHIFT)
731 static u32 *table_perturb;
733 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
734 struct sock *sk, u64 port_offset,
735 int (*check_established)(struct inet_timewait_death_row *,
736 struct sock *, __u16, struct inet_timewait_sock **))
738 struct inet_hashinfo *hinfo = death_row->hashinfo;
739 struct inet_timewait_sock *tw = NULL;
740 struct inet_bind_hashbucket *head;
741 int port = inet_sk(sk)->inet_num;
742 struct net *net = sock_net(sk);
743 struct inet_bind_bucket *tb;
744 u32 remaining, offset;
745 int ret, i, low, high;
750 head = &hinfo->bhash[inet_bhashfn(net, port,
752 tb = inet_csk(sk)->icsk_bind_hash;
753 spin_lock_bh(&head->lock);
754 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
755 inet_ehash_nolisten(sk, NULL, NULL);
756 spin_unlock_bh(&head->lock);
759 spin_unlock(&head->lock);
760 /* No definite answer... Walk to established hash table */
761 ret = check_established(death_row, sk, port, NULL);
766 l3mdev = inet_sk_bound_l3mdev(sk);
768 inet_get_local_port_range(net, &low, &high);
769 high++; /* [32768, 60999] -> [32768, 61000[ */
770 remaining = high - low;
771 if (likely(remaining > 1))
774 net_get_random_once(table_perturb,
775 INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb));
776 index = port_offset & (INET_TABLE_PERTURB_SIZE - 1);
778 offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32);
781 /* In first pass we try ports of @low parity.
782 * inet_csk_get_port() does the opposite choice.
787 for (i = 0; i < remaining; i += 2, port += 2) {
788 if (unlikely(port >= high))
790 if (inet_is_local_reserved_port(net, port))
792 head = &hinfo->bhash[inet_bhashfn(net, port,
794 spin_lock_bh(&head->lock);
796 /* Does not bother with rcv_saddr checks, because
797 * the established check is already unique enough.
799 inet_bind_bucket_for_each(tb, &head->chain) {
800 if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
802 if (tb->fastreuse >= 0 ||
803 tb->fastreuseport >= 0)
805 WARN_ON(hlist_empty(&tb->owners));
806 if (!check_established(death_row, sk,
813 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
814 net, head, port, l3mdev);
816 spin_unlock_bh(&head->lock);
820 tb->fastreuseport = -1;
823 spin_unlock_bh(&head->lock);
828 if ((offset & 1) && remaining > 1)
829 goto other_parity_scan;
831 return -EADDRNOTAVAIL;
834 /* Here we want to add a little bit of randomness to the next source
835 * port that will be chosen. We use a max() with a random here so that
836 * on low contention the randomness is maximal and on high contention
837 * it may be inexistent.
839 i = max_t(int, i, (prandom_u32() & 7) * 2);
840 WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
842 /* Head lock still held and bh's disabled */
843 inet_bind_hash(sk, tb, port);
844 if (sk_unhashed(sk)) {
845 inet_sk(sk)->inet_sport = htons(port);
846 inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
849 inet_twsk_bind_unhash(tw, hinfo);
850 spin_unlock(&head->lock);
852 inet_twsk_deschedule_put(tw);
858 * Bind a port for a connect operation and hash it.
860 int inet_hash_connect(struct inet_timewait_death_row *death_row,
865 if (!inet_sk(sk)->inet_num)
866 port_offset = inet_sk_port_offset(sk);
867 return __inet_hash_connect(death_row, sk, port_offset,
868 __inet_check_established);
870 EXPORT_SYMBOL_GPL(inet_hash_connect);
872 void inet_hashinfo_init(struct inet_hashinfo *h)
876 for (i = 0; i < INET_LHTABLE_SIZE; i++) {
877 spin_lock_init(&h->listening_hash[i].lock);
878 INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
879 i + LISTENING_NULLS_BASE);
880 h->listening_hash[i].count = 0;
885 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
887 static void init_hashinfo_lhash2(struct inet_hashinfo *h)
891 for (i = 0; i <= h->lhash2_mask; i++) {
892 spin_lock_init(&h->lhash2[i].lock);
893 INIT_HLIST_HEAD(&h->lhash2[i].head);
894 h->lhash2[i].count = 0;
898 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
899 unsigned long numentries, int scale,
900 unsigned long low_limit,
901 unsigned long high_limit)
903 h->lhash2 = alloc_large_system_hash(name,
912 init_hashinfo_lhash2(h);
914 /* this one is used for source ports of outgoing connections */
915 table_perturb = alloc_large_system_hash("Table-perturb",
916 sizeof(*table_perturb),
917 INET_TABLE_PERTURB_SIZE,
919 INET_TABLE_PERTURB_SIZE,
920 INET_TABLE_PERTURB_SIZE);
923 int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
925 h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
929 h->lhash2_mask = INET_LHTABLE_SIZE - 1;
930 /* INET_LHTABLE_SIZE must be a power of 2 */
931 BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
933 init_hashinfo_lhash2(h);
936 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
938 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
940 unsigned int locksz = sizeof(spinlock_t);
941 unsigned int i, nblocks = 1;
944 /* allocate 2 cache lines or at least one spinlock per cpu */
945 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
946 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
948 /* no more locks than number of hash buckets */
949 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
951 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
952 if (!hashinfo->ehash_locks)
955 for (i = 0; i < nblocks; i++)
956 spin_lock_init(&hashinfo->ehash_locks[i]);
958 hashinfo->ehash_locks_mask = nblocks - 1;
961 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);