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 bool inet_bind_bucket_match(const struct inet_bind_bucket *tb, const struct net *net,
96 unsigned short port, int l3mdev)
98 return net_eq(ib_net(tb), net) && tb->port == port &&
102 static void inet_bind2_bucket_init(struct inet_bind2_bucket *tb,
104 struct inet_bind_hashbucket *head,
105 unsigned short port, int l3mdev,
106 const struct sock *sk)
108 write_pnet(&tb->ib_net, net);
111 #if IS_ENABLED(CONFIG_IPV6)
112 if (sk->sk_family == AF_INET6)
113 tb->v6_rcv_saddr = sk->sk_v6_rcv_saddr;
116 tb->rcv_saddr = sk->sk_rcv_saddr;
117 INIT_HLIST_HEAD(&tb->owners);
118 hlist_add_head(&tb->node, &head->chain);
121 struct inet_bind2_bucket *inet_bind2_bucket_create(struct kmem_cache *cachep,
123 struct inet_bind_hashbucket *head,
126 const struct sock *sk)
128 struct inet_bind2_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
131 inet_bind2_bucket_init(tb, net, head, port, l3mdev, sk);
136 /* Caller must hold hashbucket lock for this tb with local BH disabled */
137 void inet_bind2_bucket_destroy(struct kmem_cache *cachep, struct inet_bind2_bucket *tb)
139 if (hlist_empty(&tb->owners)) {
140 __hlist_del(&tb->node);
141 kmem_cache_free(cachep, tb);
145 static bool inet_bind2_bucket_addr_match(const struct inet_bind2_bucket *tb2,
146 const struct sock *sk)
148 #if IS_ENABLED(CONFIG_IPV6)
149 if (sk->sk_family == AF_INET6)
150 return ipv6_addr_equal(&tb2->v6_rcv_saddr,
151 &sk->sk_v6_rcv_saddr);
153 return tb2->rcv_saddr == sk->sk_rcv_saddr;
156 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
157 struct inet_bind2_bucket *tb2, unsigned short port)
159 inet_sk(sk)->inet_num = port;
160 sk_add_bind_node(sk, &tb->owners);
161 inet_csk(sk)->icsk_bind_hash = tb;
162 sk_add_bind2_node(sk, &tb2->owners);
163 inet_csk(sk)->icsk_bind2_hash = tb2;
167 * Get rid of any references to a local port held by the given sock.
169 static void __inet_put_port(struct sock *sk)
171 struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
172 struct inet_bind_hashbucket *head, *head2;
173 struct net *net = sock_net(sk);
174 struct inet_bind_bucket *tb;
177 bhash = inet_bhashfn(net, inet_sk(sk)->inet_num, hashinfo->bhash_size);
178 head = &hashinfo->bhash[bhash];
179 head2 = inet_bhashfn_portaddr(hashinfo, sk, net, inet_sk(sk)->inet_num);
181 spin_lock(&head->lock);
182 tb = inet_csk(sk)->icsk_bind_hash;
183 __sk_del_bind_node(sk);
184 inet_csk(sk)->icsk_bind_hash = NULL;
185 inet_sk(sk)->inet_num = 0;
186 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
188 spin_lock(&head2->lock);
189 if (inet_csk(sk)->icsk_bind2_hash) {
190 struct inet_bind2_bucket *tb2 = inet_csk(sk)->icsk_bind2_hash;
192 __sk_del_bind2_node(sk);
193 inet_csk(sk)->icsk_bind2_hash = NULL;
194 inet_bind2_bucket_destroy(hashinfo->bind2_bucket_cachep, tb2);
196 spin_unlock(&head2->lock);
198 spin_unlock(&head->lock);
201 void inet_put_port(struct sock *sk)
207 EXPORT_SYMBOL(inet_put_port);
209 int __inet_inherit_port(const struct sock *sk, struct sock *child)
211 struct inet_hashinfo *table = tcp_or_dccp_get_hashinfo(sk);
212 unsigned short port = inet_sk(child)->inet_num;
213 struct inet_bind_hashbucket *head, *head2;
214 bool created_inet_bind_bucket = false;
215 struct net *net = sock_net(sk);
216 bool update_fastreuse = false;
217 struct inet_bind2_bucket *tb2;
218 struct inet_bind_bucket *tb;
221 bhash = inet_bhashfn(net, port, table->bhash_size);
222 head = &table->bhash[bhash];
223 head2 = inet_bhashfn_portaddr(table, child, net, port);
225 spin_lock(&head->lock);
226 spin_lock(&head2->lock);
227 tb = inet_csk(sk)->icsk_bind_hash;
228 tb2 = inet_csk(sk)->icsk_bind2_hash;
229 if (unlikely(!tb || !tb2)) {
230 spin_unlock(&head2->lock);
231 spin_unlock(&head->lock);
234 if (tb->port != port) {
235 l3mdev = inet_sk_bound_l3mdev(sk);
237 /* NOTE: using tproxy and redirecting skbs to a proxy
238 * on a different listener port breaks the assumption
239 * that the listener socket's icsk_bind_hash is the same
240 * as that of the child socket. We have to look up or
241 * create a new bind bucket for the child here. */
242 inet_bind_bucket_for_each(tb, &head->chain) {
243 if (inet_bind_bucket_match(tb, net, port, l3mdev))
247 tb = inet_bind_bucket_create(table->bind_bucket_cachep,
248 net, head, port, l3mdev);
250 spin_unlock(&head2->lock);
251 spin_unlock(&head->lock);
254 created_inet_bind_bucket = true;
256 update_fastreuse = true;
259 } else if (!inet_bind2_bucket_addr_match(tb2, child)) {
260 l3mdev = inet_sk_bound_l3mdev(sk);
263 tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, child);
265 tb2 = inet_bind2_bucket_create(table->bind2_bucket_cachep,
272 if (update_fastreuse)
273 inet_csk_update_fastreuse(tb, child);
274 inet_bind_hash(child, tb, tb2, port);
275 spin_unlock(&head2->lock);
276 spin_unlock(&head->lock);
281 if (created_inet_bind_bucket)
282 inet_bind_bucket_destroy(table->bind_bucket_cachep, tb);
283 spin_unlock(&head2->lock);
284 spin_unlock(&head->lock);
287 EXPORT_SYMBOL_GPL(__inet_inherit_port);
289 static struct inet_listen_hashbucket *
290 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
294 #if IS_ENABLED(CONFIG_IPV6)
295 if (sk->sk_family == AF_INET6)
296 hash = ipv6_portaddr_hash(sock_net(sk),
297 &sk->sk_v6_rcv_saddr,
298 inet_sk(sk)->inet_num);
301 hash = ipv4_portaddr_hash(sock_net(sk),
302 inet_sk(sk)->inet_rcv_saddr,
303 inet_sk(sk)->inet_num);
304 return inet_lhash2_bucket(h, hash);
307 static inline int compute_score(struct sock *sk, struct net *net,
308 const unsigned short hnum, const __be32 daddr,
309 const int dif, const int sdif)
313 if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
314 !ipv6_only_sock(sk)) {
315 if (sk->sk_rcv_saddr != daddr)
318 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
320 score = sk->sk_bound_dev_if ? 2 : 1;
322 if (sk->sk_family == PF_INET)
324 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
330 static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
331 struct sk_buff *skb, int doff,
332 __be32 saddr, __be16 sport,
333 __be32 daddr, unsigned short hnum)
335 struct sock *reuse_sk = NULL;
338 if (sk->sk_reuseport) {
339 phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
340 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
346 * Here are some nice properties to exploit here. The BSD API
347 * does not allow a listening sock to specify the remote port nor the
348 * remote address for the connection. So always assume those are both
349 * wildcarded during the search since they can never be otherwise.
352 /* called with rcu_read_lock() : No refcount taken on the socket */
353 static struct sock *inet_lhash2_lookup(struct net *net,
354 struct inet_listen_hashbucket *ilb2,
355 struct sk_buff *skb, int doff,
356 const __be32 saddr, __be16 sport,
357 const __be32 daddr, const unsigned short hnum,
358 const int dif, const int sdif)
360 struct sock *sk, *result = NULL;
361 struct hlist_nulls_node *node;
362 int score, hiscore = 0;
364 sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
365 score = compute_score(sk, net, hnum, daddr, dif, sdif);
366 if (score > hiscore) {
367 result = lookup_reuseport(net, sk, skb, doff,
368 saddr, sport, daddr, hnum);
380 static inline struct sock *inet_lookup_run_bpf(struct net *net,
381 struct inet_hashinfo *hashinfo,
382 struct sk_buff *skb, int doff,
383 __be32 saddr, __be16 sport,
384 __be32 daddr, u16 hnum, const int dif)
386 struct sock *sk, *reuse_sk;
389 if (hashinfo != net->ipv4.tcp_death_row.hashinfo)
390 return NULL; /* only TCP is supported */
392 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP, saddr, sport,
393 daddr, hnum, dif, &sk);
394 if (no_reuseport || IS_ERR_OR_NULL(sk))
397 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
403 struct sock *__inet_lookup_listener(struct net *net,
404 struct inet_hashinfo *hashinfo,
405 struct sk_buff *skb, int doff,
406 const __be32 saddr, __be16 sport,
407 const __be32 daddr, const unsigned short hnum,
408 const int dif, const int sdif)
410 struct inet_listen_hashbucket *ilb2;
411 struct sock *result = NULL;
414 /* Lookup redirect from BPF */
415 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
416 result = inet_lookup_run_bpf(net, hashinfo, skb, doff,
417 saddr, sport, daddr, hnum, dif);
422 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
423 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
425 result = inet_lhash2_lookup(net, ilb2, skb, doff,
426 saddr, sport, daddr, hnum,
431 /* Lookup lhash2 with INADDR_ANY */
432 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
433 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
435 result = inet_lhash2_lookup(net, ilb2, skb, doff,
436 saddr, sport, htonl(INADDR_ANY), hnum,
443 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
445 /* All sockets share common refcount, but have different destructors */
446 void sock_gen_put(struct sock *sk)
448 if (!refcount_dec_and_test(&sk->sk_refcnt))
451 if (sk->sk_state == TCP_TIME_WAIT)
452 inet_twsk_free(inet_twsk(sk));
453 else if (sk->sk_state == TCP_NEW_SYN_RECV)
454 reqsk_free(inet_reqsk(sk));
458 EXPORT_SYMBOL_GPL(sock_gen_put);
460 void sock_edemux(struct sk_buff *skb)
462 sock_gen_put(skb->sk);
464 EXPORT_SYMBOL(sock_edemux);
466 struct sock *__inet_lookup_established(struct net *net,
467 struct inet_hashinfo *hashinfo,
468 const __be32 saddr, const __be16 sport,
469 const __be32 daddr, const u16 hnum,
470 const int dif, const int sdif)
472 INET_ADDR_COOKIE(acookie, saddr, daddr);
473 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
475 const struct hlist_nulls_node *node;
476 /* Optimize here for direct hit, only listening connections can
477 * have wildcards anyways.
479 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
480 unsigned int slot = hash & hashinfo->ehash_mask;
481 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
484 sk_nulls_for_each_rcu(sk, node, &head->chain) {
485 if (sk->sk_hash != hash)
487 if (likely(inet_match(net, sk, acookie, ports, dif, sdif))) {
488 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
490 if (unlikely(!inet_match(net, sk, acookie,
491 ports, dif, sdif))) {
499 * if the nulls value we got at the end of this lookup is
500 * not the expected one, we must restart lookup.
501 * We probably met an item that was moved to another chain.
503 if (get_nulls_value(node) != slot)
510 EXPORT_SYMBOL_GPL(__inet_lookup_established);
512 /* called with local bh disabled */
513 static int __inet_check_established(struct inet_timewait_death_row *death_row,
514 struct sock *sk, __u16 lport,
515 struct inet_timewait_sock **twp)
517 struct inet_hashinfo *hinfo = death_row->hashinfo;
518 struct inet_sock *inet = inet_sk(sk);
519 __be32 daddr = inet->inet_rcv_saddr;
520 __be32 saddr = inet->inet_daddr;
521 int dif = sk->sk_bound_dev_if;
522 struct net *net = sock_net(sk);
523 int sdif = l3mdev_master_ifindex_by_index(net, dif);
524 INET_ADDR_COOKIE(acookie, saddr, daddr);
525 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
526 unsigned int hash = inet_ehashfn(net, daddr, lport,
527 saddr, inet->inet_dport);
528 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
529 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
531 const struct hlist_nulls_node *node;
532 struct inet_timewait_sock *tw = NULL;
536 sk_nulls_for_each(sk2, node, &head->chain) {
537 if (sk2->sk_hash != hash)
540 if (likely(inet_match(net, sk2, acookie, ports, dif, sdif))) {
541 if (sk2->sk_state == TCP_TIME_WAIT) {
543 if (twsk_unique(sk, sk2, twp))
550 /* Must record num and sport now. Otherwise we will see
551 * in hash table socket with a funny identity.
553 inet->inet_num = lport;
554 inet->inet_sport = htons(lport);
556 WARN_ON(!sk_unhashed(sk));
557 __sk_nulls_add_node_rcu(sk, &head->chain);
559 sk_nulls_del_node_init_rcu((struct sock *)tw);
560 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
563 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
568 /* Silly. Should hash-dance instead... */
569 inet_twsk_deschedule_put(tw);
575 return -EADDRNOTAVAIL;
578 static u64 inet_sk_port_offset(const struct sock *sk)
580 const struct inet_sock *inet = inet_sk(sk);
582 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
587 /* Searches for an exsiting socket in the ehash bucket list.
588 * Returns true if found, false otherwise.
590 static bool inet_ehash_lookup_by_sk(struct sock *sk,
591 struct hlist_nulls_head *list)
593 const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num);
594 const int sdif = sk->sk_bound_dev_if;
595 const int dif = sk->sk_bound_dev_if;
596 const struct hlist_nulls_node *node;
597 struct net *net = sock_net(sk);
600 INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr);
602 sk_nulls_for_each_rcu(esk, node, list) {
603 if (esk->sk_hash != sk->sk_hash)
605 if (sk->sk_family == AF_INET) {
606 if (unlikely(inet_match(net, esk, acookie,
607 ports, dif, sdif))) {
611 #if IS_ENABLED(CONFIG_IPV6)
612 else if (sk->sk_family == AF_INET6) {
613 if (unlikely(inet6_match(net, esk,
615 &sk->sk_v6_rcv_saddr,
616 ports, dif, sdif))) {
625 /* Insert a socket into ehash, and eventually remove another one
626 * (The another one can be a SYN_RECV or TIMEWAIT)
627 * If an existing socket already exists, socket sk is not inserted,
628 * and sets found_dup_sk parameter to true.
630 bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk)
632 struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
633 struct inet_ehash_bucket *head;
634 struct hlist_nulls_head *list;
638 WARN_ON_ONCE(!sk_unhashed(sk));
640 sk->sk_hash = sk_ehashfn(sk);
641 head = inet_ehash_bucket(hashinfo, sk->sk_hash);
643 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
647 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
648 ret = sk_nulls_del_node_init_rcu(osk);
649 } else if (found_dup_sk) {
650 *found_dup_sk = inet_ehash_lookup_by_sk(sk, list);
656 __sk_nulls_add_node_rcu(sk, list);
663 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk)
665 bool ok = inet_ehash_insert(sk, osk, found_dup_sk);
668 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
670 this_cpu_inc(*sk->sk_prot->orphan_count);
671 inet_sk_set_state(sk, TCP_CLOSE);
672 sock_set_flag(sk, SOCK_DEAD);
673 inet_csk_destroy_sock(sk);
677 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
679 static int inet_reuseport_add_sock(struct sock *sk,
680 struct inet_listen_hashbucket *ilb)
682 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
683 const struct hlist_nulls_node *node;
685 kuid_t uid = sock_i_uid(sk);
687 sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
689 sk2->sk_family == sk->sk_family &&
690 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
691 sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
692 inet_csk(sk2)->icsk_bind_hash == tb &&
693 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
694 inet_rcv_saddr_equal(sk, sk2, false))
695 return reuseport_add_sock(sk, sk2,
696 inet_rcv_saddr_any(sk));
699 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
702 int __inet_hash(struct sock *sk, struct sock *osk)
704 struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
705 struct inet_listen_hashbucket *ilb2;
708 if (sk->sk_state != TCP_LISTEN) {
710 inet_ehash_nolisten(sk, osk, NULL);
714 WARN_ON(!sk_unhashed(sk));
715 ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
717 spin_lock(&ilb2->lock);
718 if (sk->sk_reuseport) {
719 err = inet_reuseport_add_sock(sk, ilb2);
723 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
724 sk->sk_family == AF_INET6)
725 __sk_nulls_add_node_tail_rcu(sk, &ilb2->nulls_head);
727 __sk_nulls_add_node_rcu(sk, &ilb2->nulls_head);
728 sock_set_flag(sk, SOCK_RCU_FREE);
729 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
731 spin_unlock(&ilb2->lock);
735 EXPORT_SYMBOL(__inet_hash);
737 int inet_hash(struct sock *sk)
741 if (sk->sk_state != TCP_CLOSE)
742 err = __inet_hash(sk, NULL);
746 EXPORT_SYMBOL_GPL(inet_hash);
748 void inet_unhash(struct sock *sk)
750 struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
755 if (sk->sk_state == TCP_LISTEN) {
756 struct inet_listen_hashbucket *ilb2;
758 ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
759 /* Don't disable bottom halves while acquiring the lock to
760 * avoid circular locking dependency on PREEMPT_RT.
762 spin_lock(&ilb2->lock);
763 if (sk_unhashed(sk)) {
764 spin_unlock(&ilb2->lock);
768 if (rcu_access_pointer(sk->sk_reuseport_cb))
769 reuseport_stop_listen_sock(sk);
771 __sk_nulls_del_node_init_rcu(sk);
772 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
773 spin_unlock(&ilb2->lock);
775 spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
778 if (sk_unhashed(sk)) {
779 spin_unlock_bh(lock);
782 __sk_nulls_del_node_init_rcu(sk);
783 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
784 spin_unlock_bh(lock);
787 EXPORT_SYMBOL_GPL(inet_unhash);
789 static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
790 const struct net *net, unsigned short port,
791 int l3mdev, const struct sock *sk)
793 #if IS_ENABLED(CONFIG_IPV6)
794 if (sk->sk_family == AF_INET6)
795 return net_eq(ib2_net(tb), net) && tb->port == port &&
796 tb->l3mdev == l3mdev &&
797 ipv6_addr_equal(&tb->v6_rcv_saddr, &sk->sk_v6_rcv_saddr);
800 return net_eq(ib2_net(tb), net) && tb->port == port &&
801 tb->l3mdev == l3mdev && tb->rcv_saddr == sk->sk_rcv_saddr;
804 bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const struct net *net,
805 unsigned short port, int l3mdev, const struct sock *sk)
807 #if IS_ENABLED(CONFIG_IPV6)
808 struct in6_addr addr_any = {};
810 if (sk->sk_family == AF_INET6)
811 return net_eq(ib2_net(tb), net) && tb->port == port &&
812 tb->l3mdev == l3mdev &&
813 ipv6_addr_equal(&tb->v6_rcv_saddr, &addr_any);
816 return net_eq(ib2_net(tb), net) && tb->port == port &&
817 tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
820 /* The socket's bhash2 hashbucket spinlock must be held when this is called */
821 struct inet_bind2_bucket *
822 inet_bind2_bucket_find(const struct inet_bind_hashbucket *head, const struct net *net,
823 unsigned short port, int l3mdev, const struct sock *sk)
825 struct inet_bind2_bucket *bhash2 = NULL;
827 inet_bind_bucket_for_each(bhash2, &head->chain)
828 if (inet_bind2_bucket_match(bhash2, net, port, l3mdev, sk))
834 struct inet_bind_hashbucket *
835 inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, int port)
837 struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
839 #if IS_ENABLED(CONFIG_IPV6)
840 struct in6_addr addr_any = {};
842 if (sk->sk_family == AF_INET6)
843 hash = ipv6_portaddr_hash(net, &addr_any, port);
846 hash = ipv4_portaddr_hash(net, 0, port);
848 return &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
851 int inet_bhash2_update_saddr(struct inet_bind_hashbucket *prev_saddr, struct sock *sk)
853 struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
854 struct inet_bind2_bucket *tb2, *new_tb2;
855 int l3mdev = inet_sk_bound_l3mdev(sk);
856 struct inet_bind_hashbucket *head2;
857 int port = inet_sk(sk)->inet_num;
858 struct net *net = sock_net(sk);
860 /* Allocate a bind2 bucket ahead of time to avoid permanently putting
861 * the bhash2 table in an inconsistent state if a new tb2 bucket
864 new_tb2 = kmem_cache_alloc(hinfo->bind2_bucket_cachep, GFP_ATOMIC);
868 head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
871 spin_lock_bh(&prev_saddr->lock);
872 __sk_del_bind2_node(sk);
873 inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep,
874 inet_csk(sk)->icsk_bind2_hash);
875 spin_unlock_bh(&prev_saddr->lock);
878 spin_lock_bh(&head2->lock);
879 tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
882 inet_bind2_bucket_init(tb2, net, head2, port, l3mdev, sk);
884 sk_add_bind2_node(sk, &tb2->owners);
885 inet_csk(sk)->icsk_bind2_hash = tb2;
886 spin_unlock_bh(&head2->lock);
889 kmem_cache_free(hinfo->bind2_bucket_cachep, new_tb2);
893 EXPORT_SYMBOL_GPL(inet_bhash2_update_saddr);
895 /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm
896 * Note that we use 32bit integers (vs RFC 'short integers')
897 * because 2^16 is not a multiple of num_ephemeral and this
898 * property might be used by clever attacker.
899 * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though
900 * attacks were since demonstrated, thus we use 65536 instead to really
901 * give more isolation and privacy, at the expense of 256kB of kernel
904 #define INET_TABLE_PERTURB_SHIFT 16
905 #define INET_TABLE_PERTURB_SIZE (1 << INET_TABLE_PERTURB_SHIFT)
906 static u32 *table_perturb;
908 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
909 struct sock *sk, u64 port_offset,
910 int (*check_established)(struct inet_timewait_death_row *,
911 struct sock *, __u16, struct inet_timewait_sock **))
913 struct inet_hashinfo *hinfo = death_row->hashinfo;
914 struct inet_bind_hashbucket *head, *head2;
915 struct inet_timewait_sock *tw = NULL;
916 int port = inet_sk(sk)->inet_num;
917 struct net *net = sock_net(sk);
918 struct inet_bind2_bucket *tb2;
919 struct inet_bind_bucket *tb;
920 bool tb_created = false;
921 u32 remaining, offset;
922 int ret, i, low, high;
927 head = &hinfo->bhash[inet_bhashfn(net, port,
929 tb = inet_csk(sk)->icsk_bind_hash;
930 spin_lock_bh(&head->lock);
931 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
932 inet_ehash_nolisten(sk, NULL, NULL);
933 spin_unlock_bh(&head->lock);
936 spin_unlock(&head->lock);
937 /* No definite answer... Walk to established hash table */
938 ret = check_established(death_row, sk, port, NULL);
943 l3mdev = inet_sk_bound_l3mdev(sk);
945 inet_get_local_port_range(net, &low, &high);
946 high++; /* [32768, 60999] -> [32768, 61000[ */
947 remaining = high - low;
948 if (likely(remaining > 1))
951 net_get_random_once(table_perturb,
952 INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb));
953 index = port_offset & (INET_TABLE_PERTURB_SIZE - 1);
955 offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32);
958 /* In first pass we try ports of @low parity.
959 * inet_csk_get_port() does the opposite choice.
964 for (i = 0; i < remaining; i += 2, port += 2) {
965 if (unlikely(port >= high))
967 if (inet_is_local_reserved_port(net, port))
969 head = &hinfo->bhash[inet_bhashfn(net, port,
971 spin_lock_bh(&head->lock);
973 /* Does not bother with rcv_saddr checks, because
974 * the established check is already unique enough.
976 inet_bind_bucket_for_each(tb, &head->chain) {
977 if (inet_bind_bucket_match(tb, net, port, l3mdev)) {
978 if (tb->fastreuse >= 0 ||
979 tb->fastreuseport >= 0)
981 WARN_ON(hlist_empty(&tb->owners));
982 if (!check_established(death_row, sk,
989 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
990 net, head, port, l3mdev);
992 spin_unlock_bh(&head->lock);
997 tb->fastreuseport = -1;
1000 spin_unlock_bh(&head->lock);
1005 if ((offset & 1) && remaining > 1)
1006 goto other_parity_scan;
1008 return -EADDRNOTAVAIL;
1011 /* Find the corresponding tb2 bucket since we need to
1012 * add the socket to the bhash2 table as well
1014 head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
1015 spin_lock(&head2->lock);
1017 tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
1019 tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep, net,
1020 head2, port, l3mdev, sk);
1025 /* Here we want to add a little bit of randomness to the next source
1026 * port that will be chosen. We use a max() with a random here so that
1027 * on low contention the randomness is maximal and on high contention
1028 * it may be inexistent.
1030 i = max_t(int, i, (prandom_u32() & 7) * 2);
1031 WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
1033 /* Head lock still held and bh's disabled */
1034 inet_bind_hash(sk, tb, tb2, port);
1036 spin_unlock(&head2->lock);
1038 if (sk_unhashed(sk)) {
1039 inet_sk(sk)->inet_sport = htons(port);
1040 inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
1043 inet_twsk_bind_unhash(tw, hinfo);
1044 spin_unlock(&head->lock);
1046 inet_twsk_deschedule_put(tw);
1051 spin_unlock(&head2->lock);
1053 inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
1054 spin_unlock_bh(&head->lock);
1059 * Bind a port for a connect operation and hash it.
1061 int inet_hash_connect(struct inet_timewait_death_row *death_row,
1064 u64 port_offset = 0;
1066 if (!inet_sk(sk)->inet_num)
1067 port_offset = inet_sk_port_offset(sk);
1068 return __inet_hash_connect(death_row, sk, port_offset,
1069 __inet_check_established);
1071 EXPORT_SYMBOL_GPL(inet_hash_connect);
1073 static void init_hashinfo_lhash2(struct inet_hashinfo *h)
1077 for (i = 0; i <= h->lhash2_mask; i++) {
1078 spin_lock_init(&h->lhash2[i].lock);
1079 INIT_HLIST_NULLS_HEAD(&h->lhash2[i].nulls_head,
1080 i + LISTENING_NULLS_BASE);
1084 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
1085 unsigned long numentries, int scale,
1086 unsigned long low_limit,
1087 unsigned long high_limit)
1089 h->lhash2 = alloc_large_system_hash(name,
1098 init_hashinfo_lhash2(h);
1100 /* this one is used for source ports of outgoing connections */
1101 table_perturb = alloc_large_system_hash("Table-perturb",
1102 sizeof(*table_perturb),
1103 INET_TABLE_PERTURB_SIZE,
1105 INET_TABLE_PERTURB_SIZE,
1106 INET_TABLE_PERTURB_SIZE);
1109 int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
1111 h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
1115 h->lhash2_mask = INET_LHTABLE_SIZE - 1;
1116 /* INET_LHTABLE_SIZE must be a power of 2 */
1117 BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
1119 init_hashinfo_lhash2(h);
1122 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
1124 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
1126 unsigned int locksz = sizeof(spinlock_t);
1127 unsigned int i, nblocks = 1;
1130 /* allocate 2 cache lines or at least one spinlock per cpu */
1131 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
1132 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
1134 /* no more locks than number of hash buckets */
1135 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
1137 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
1138 if (!hashinfo->ehash_locks)
1141 for (i = 0; i < nblocks; i++)
1142 spin_lock_init(&hashinfo->ehash_locks[i]);
1144 hashinfo->ehash_locks_mask = nblocks - 1;
1147 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
1149 struct inet_hashinfo *inet_pernet_hashinfo_alloc(struct inet_hashinfo *hashinfo,
1150 unsigned int ehash_entries)
1152 struct inet_hashinfo *new_hashinfo;
1155 new_hashinfo = kmemdup(hashinfo, sizeof(*hashinfo), GFP_KERNEL);
1159 new_hashinfo->ehash = vmalloc_huge(ehash_entries * sizeof(struct inet_ehash_bucket),
1160 GFP_KERNEL_ACCOUNT);
1161 if (!new_hashinfo->ehash)
1164 new_hashinfo->ehash_mask = ehash_entries - 1;
1166 if (inet_ehash_locks_alloc(new_hashinfo))
1169 for (i = 0; i < ehash_entries; i++)
1170 INIT_HLIST_NULLS_HEAD(&new_hashinfo->ehash[i].chain, i);
1172 new_hashinfo->pernet = true;
1174 return new_hashinfo;
1177 vfree(new_hashinfo->ehash);
1179 kfree(new_hashinfo);
1183 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_alloc);
1185 void inet_pernet_hashinfo_free(struct inet_hashinfo *hashinfo)
1187 if (!hashinfo->pernet)
1190 inet_ehash_locks_free(hashinfo);
1191 vfree(hashinfo->ehash);
1194 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_free);