Line data Source code
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 : #if IS_ENABLED(CONFIG_IPV6)
24 : #include <net/inet6_hashtables.h>
25 : #endif
26 : #include <net/secure_seq.h>
27 : #include <net/ip.h>
28 : #include <net/tcp.h>
29 : #include <net/sock_reuseport.h>
30 :
31 450 : static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
32 : const __u16 lport, const __be32 faddr,
33 : const __be16 fport)
34 : {
35 450 : static u32 inet_ehash_secret __read_mostly;
36 :
37 450 : net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
38 :
39 450 : return __inet_ehashfn(laddr, lport, faddr, fport,
40 450 : inet_ehash_secret + net_hash_mix(net));
41 : }
42 :
43 : /* This function handles inet_sock, but also timewait and request sockets
44 : * for IPv4/IPv6.
45 : */
46 8 : static u32 sk_ehashfn(const struct sock *sk)
47 : {
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);
54 : #endif
55 16 : return inet_ehashfn(sock_net(sk),
56 8 : sk->sk_rcv_saddr, sk->sk_num,
57 8 : sk->sk_daddr, sk->sk_dport);
58 : }
59 :
60 : /*
61 : * Allocate and initialize a new local port bind bucket.
62 : * The bindhash mutex for snum's hash chain must be held here.
63 : */
64 3 : struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
65 : struct net *net,
66 : struct inet_bind_hashbucket *head,
67 : const unsigned short snum,
68 : int l3mdev)
69 : {
70 3 : struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
71 :
72 3 : if (tb) {
73 3 : write_pnet(&tb->ib_net, net);
74 3 : tb->l3mdev = l3mdev;
75 3 : tb->port = snum;
76 3 : tb->fastreuse = 0;
77 3 : tb->fastreuseport = 0;
78 3 : INIT_HLIST_HEAD(&tb->owners);
79 3 : hlist_add_head(&tb->node, &head->chain);
80 : }
81 3 : return tb;
82 : }
83 :
84 : /*
85 : * Caller must hold hashbucket lock for this tb with local BH disabled
86 : */
87 4 : void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
88 : {
89 4 : if (hlist_empty(&tb->owners)) {
90 1 : __hlist_del(&tb->node);
91 1 : kmem_cache_free(cachep, tb);
92 : }
93 4 : }
94 :
95 7 : void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
96 : const unsigned short snum)
97 : {
98 3 : inet_sk(sk)->inet_num = snum;
99 7 : sk_add_bind_node(sk, &tb->owners);
100 4 : inet_csk(sk)->icsk_bind_hash = tb;
101 3 : }
102 :
103 : /*
104 : * Get rid of any references to a local port held by the given sock.
105 : */
106 4 : static void __inet_put_port(struct sock *sk)
107 : {
108 4 : struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
109 4 : const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
110 : hashinfo->bhash_size);
111 4 : struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
112 4 : struct inet_bind_bucket *tb;
113 :
114 4 : spin_lock(&head->lock);
115 4 : tb = inet_csk(sk)->icsk_bind_hash;
116 4 : __sk_del_bind_node(sk);
117 4 : inet_csk(sk)->icsk_bind_hash = NULL;
118 4 : inet_sk(sk)->inet_num = 0;
119 4 : inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
120 4 : spin_unlock(&head->lock);
121 4 : }
122 :
123 4 : void inet_put_port(struct sock *sk)
124 : {
125 4 : local_bh_disable();
126 4 : __inet_put_port(sk);
127 4 : local_bh_enable();
128 4 : }
129 : EXPORT_SYMBOL(inet_put_port);
130 :
131 4 : int __inet_inherit_port(const struct sock *sk, struct sock *child)
132 : {
133 4 : struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
134 4 : unsigned short port = inet_sk(child)->inet_num;
135 4 : const int bhash = inet_bhashfn(sock_net(sk), port,
136 : table->bhash_size);
137 4 : struct inet_bind_hashbucket *head = &table->bhash[bhash];
138 4 : struct inet_bind_bucket *tb;
139 4 : int l3mdev;
140 :
141 4 : spin_lock(&head->lock);
142 4 : tb = inet_csk(sk)->icsk_bind_hash;
143 4 : if (unlikely(!tb)) {
144 0 : spin_unlock(&head->lock);
145 0 : return -ENOENT;
146 : }
147 4 : if (tb->port != port) {
148 0 : l3mdev = inet_sk_bound_l3mdev(sk);
149 :
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 0 : inet_bind_bucket_for_each(tb, &head->chain) {
156 0 : if (net_eq(ib_net(tb), sock_net(sk)) &&
157 0 : tb->l3mdev == l3mdev && tb->port == port)
158 : break;
159 : }
160 0 : if (!tb) {
161 0 : tb = inet_bind_bucket_create(table->bind_bucket_cachep,
162 : sock_net(sk), head, port,
163 : l3mdev);
164 0 : if (!tb) {
165 0 : spin_unlock(&head->lock);
166 0 : return -ENOMEM;
167 : }
168 : }
169 0 : inet_csk_update_fastreuse(tb, child);
170 : }
171 4 : inet_bind_hash(child, tb, port);
172 4 : spin_unlock(&head->lock);
173 :
174 4 : return 0;
175 : }
176 : EXPORT_SYMBOL_GPL(__inet_inherit_port);
177 :
178 : static struct inet_listen_hashbucket *
179 4 : inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
180 : {
181 4 : u32 hash;
182 :
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);
188 : else
189 : #endif
190 4 : hash = ipv4_portaddr_hash(sock_net(sk),
191 4 : inet_sk(sk)->inet_rcv_saddr,
192 4 : inet_sk(sk)->inet_num);
193 4 : return inet_lhash2_bucket(h, hash);
194 : }
195 :
196 3 : static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)
197 : {
198 3 : struct inet_listen_hashbucket *ilb2;
199 :
200 3 : if (!h->lhash2)
201 : return;
202 :
203 3 : ilb2 = inet_lhash2_bucket_sk(h, sk);
204 :
205 3 : spin_lock(&ilb2->lock);
206 3 : if (sk->sk_reuseport && sk->sk_family == AF_INET6)
207 0 : hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
208 : &ilb2->head);
209 : else
210 3 : hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
211 : &ilb2->head);
212 3 : ilb2->count++;
213 3 : spin_unlock(&ilb2->lock);
214 : }
215 :
216 1 : static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)
217 : {
218 1 : struct inet_listen_hashbucket *ilb2;
219 :
220 1 : if (!h->lhash2 ||
221 1 : WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))
222 : return;
223 :
224 1 : ilb2 = inet_lhash2_bucket_sk(h, sk);
225 :
226 1 : spin_lock(&ilb2->lock);
227 1 : hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);
228 1 : ilb2->count--;
229 1 : spin_unlock(&ilb2->lock);
230 : }
231 :
232 4 : 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)
235 : {
236 4 : int score = -1;
237 :
238 4 : if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
239 : !ipv6_only_sock(sk)) {
240 4 : if (sk->sk_rcv_saddr != daddr)
241 : return -1;
242 :
243 4 : if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
244 : return -1;
245 :
246 4 : score = sk->sk_family == PF_INET ? 2 : 1;
247 4 : if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
248 0 : score++;
249 : }
250 : return score;
251 : }
252 :
253 4 : static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
254 : struct sk_buff *skb, int doff,
255 : __be32 saddr, __be16 sport,
256 : __be32 daddr, unsigned short hnum)
257 : {
258 4 : struct sock *reuse_sk = NULL;
259 4 : u32 phash;
260 :
261 4 : if (sk->sk_reuseport) {
262 0 : phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
263 0 : reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
264 : }
265 4 : return reuse_sk;
266 : }
267 :
268 : /*
269 : * Here are some nice properties to exploit here. The BSD API
270 : * does not allow a listening sock to specify the remote port nor the
271 : * remote address for the connection. So always assume those are both
272 : * wildcarded during the search since they can never be otherwise.
273 : */
274 :
275 : /* called with rcu_read_lock() : No refcount taken on the socket */
276 8 : static struct sock *inet_lhash2_lookup(struct net *net,
277 : struct inet_listen_hashbucket *ilb2,
278 : struct sk_buff *skb, int doff,
279 : const __be32 saddr, __be16 sport,
280 : const __be32 daddr, const unsigned short hnum,
281 : const int dif, const int sdif)
282 : {
283 8 : struct inet_connection_sock *icsk;
284 8 : struct sock *sk, *result = NULL;
285 8 : int score, hiscore = 0;
286 :
287 24 : inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
288 4 : sk = (struct sock *)icsk;
289 4 : score = compute_score(sk, net, hnum, daddr, dif, sdif);
290 4 : if (score > hiscore) {
291 4 : result = lookup_reuseport(net, sk, skb, doff,
292 : saddr, sport, daddr, hnum);
293 4 : if (result)
294 0 : return result;
295 :
296 : result = sk;
297 : hiscore = score;
298 : }
299 : }
300 :
301 : return result;
302 : }
303 :
304 0 : static inline struct sock *inet_lookup_run_bpf(struct net *net,
305 : struct inet_hashinfo *hashinfo,
306 : struct sk_buff *skb, int doff,
307 : __be32 saddr, __be16 sport,
308 : __be32 daddr, u16 hnum)
309 : {
310 0 : struct sock *sk, *reuse_sk;
311 0 : bool no_reuseport;
312 :
313 0 : if (hashinfo != &tcp_hashinfo)
314 : return NULL; /* only TCP is supported */
315 :
316 0 : no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP,
317 : saddr, sport, daddr, hnum, &sk);
318 0 : if (no_reuseport || IS_ERR_OR_NULL(sk))
319 0 : return sk;
320 :
321 0 : reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
322 0 : if (reuse_sk)
323 0 : sk = reuse_sk;
324 0 : return sk;
325 : }
326 :
327 4 : struct sock *__inet_lookup_listener(struct net *net,
328 : struct inet_hashinfo *hashinfo,
329 : struct sk_buff *skb, int doff,
330 : const __be32 saddr, __be16 sport,
331 : const __be32 daddr, const unsigned short hnum,
332 : const int dif, const int sdif)
333 : {
334 4 : struct inet_listen_hashbucket *ilb2;
335 4 : struct sock *result = NULL;
336 4 : unsigned int hash2;
337 :
338 : /* Lookup redirect from BPF */
339 4 : if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
340 0 : result = inet_lookup_run_bpf(net, hashinfo, skb, doff,
341 : saddr, sport, daddr, hnum);
342 0 : if (result)
343 0 : goto done;
344 : }
345 :
346 4 : hash2 = ipv4_portaddr_hash(net, daddr, hnum);
347 4 : ilb2 = inet_lhash2_bucket(hashinfo, hash2);
348 :
349 4 : result = inet_lhash2_lookup(net, ilb2, skb, doff,
350 : saddr, sport, daddr, hnum,
351 : dif, sdif);
352 4 : if (result)
353 0 : goto done;
354 :
355 : /* Lookup lhash2 with INADDR_ANY */
356 4 : hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
357 4 : ilb2 = inet_lhash2_bucket(hashinfo, hash2);
358 :
359 4 : result = inet_lhash2_lookup(net, ilb2, skb, doff,
360 : saddr, sport, htonl(INADDR_ANY), hnum,
361 : dif, sdif);
362 4 : done:
363 4 : if (IS_ERR(result))
364 0 : return NULL;
365 : return result;
366 : }
367 : EXPORT_SYMBOL_GPL(__inet_lookup_listener);
368 :
369 : /* All sockets share common refcount, but have different destructors */
370 4 : void sock_gen_put(struct sock *sk)
371 : {
372 4 : if (!refcount_dec_and_test(&sk->sk_refcnt))
373 : return;
374 :
375 0 : if (sk->sk_state == TCP_TIME_WAIT)
376 0 : inet_twsk_free(inet_twsk(sk));
377 0 : else if (sk->sk_state == TCP_NEW_SYN_RECV)
378 0 : reqsk_free(inet_reqsk(sk));
379 : else
380 0 : sk_free(sk);
381 : }
382 : EXPORT_SYMBOL_GPL(sock_gen_put);
383 :
384 4 : void sock_edemux(struct sk_buff *skb)
385 : {
386 4 : sock_gen_put(skb->sk);
387 4 : }
388 : EXPORT_SYMBOL(sock_edemux);
389 :
390 442 : struct sock *__inet_lookup_established(struct net *net,
391 : struct inet_hashinfo *hashinfo,
392 : const __be32 saddr, const __be16 sport,
393 : const __be32 daddr, const u16 hnum,
394 : const int dif, const int sdif)
395 : {
396 442 : INET_ADDR_COOKIE(acookie, saddr, daddr);
397 442 : const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
398 442 : struct sock *sk;
399 442 : const struct hlist_nulls_node *node;
400 : /* Optimize here for direct hit, only listening connections can
401 : * have wildcards anyways.
402 : */
403 442 : unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
404 442 : unsigned int slot = hash & hashinfo->ehash_mask;
405 442 : struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
406 :
407 : begin:
408 442 : sk_nulls_for_each_rcu(sk, node, &head->chain) {
409 434 : if (sk->sk_hash != hash)
410 0 : continue;
411 434 : if (likely(INET_MATCH(sk, net, acookie,
412 : saddr, daddr, ports, dif, sdif))) {
413 434 : if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
414 0 : goto out;
415 434 : if (unlikely(!INET_MATCH(sk, net, acookie,
416 : saddr, daddr, ports,
417 : dif, sdif))) {
418 0 : sock_gen_put(sk);
419 0 : goto begin;
420 : }
421 434 : goto found;
422 : }
423 : }
424 : /*
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.
428 : */
429 8 : if (get_nulls_value(node) != slot)
430 0 : goto begin;
431 8 : out:
432 : sk = NULL;
433 442 : found:
434 442 : return sk;
435 : }
436 : EXPORT_SYMBOL_GPL(__inet_lookup_established);
437 :
438 : /* called with local bh disabled */
439 0 : static int __inet_check_established(struct inet_timewait_death_row *death_row,
440 : struct sock *sk, __u16 lport,
441 : struct inet_timewait_sock **twp)
442 : {
443 0 : struct inet_hashinfo *hinfo = death_row->hashinfo;
444 0 : struct inet_sock *inet = inet_sk(sk);
445 0 : __be32 daddr = inet->inet_rcv_saddr;
446 0 : __be32 saddr = inet->inet_daddr;
447 0 : int dif = sk->sk_bound_dev_if;
448 0 : struct net *net = sock_net(sk);
449 0 : int sdif = l3mdev_master_ifindex_by_index(net, dif);
450 0 : INET_ADDR_COOKIE(acookie, saddr, daddr);
451 0 : const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
452 0 : unsigned int hash = inet_ehashfn(net, daddr, lport,
453 : saddr, inet->inet_dport);
454 0 : struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
455 0 : spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
456 0 : struct sock *sk2;
457 0 : const struct hlist_nulls_node *node;
458 0 : struct inet_timewait_sock *tw = NULL;
459 :
460 0 : spin_lock(lock);
461 :
462 0 : sk_nulls_for_each(sk2, node, &head->chain) {
463 0 : if (sk2->sk_hash != hash)
464 0 : continue;
465 :
466 0 : if (likely(INET_MATCH(sk2, net, acookie,
467 : saddr, daddr, ports, dif, sdif))) {
468 0 : if (sk2->sk_state == TCP_TIME_WAIT) {
469 0 : tw = inet_twsk(sk2);
470 0 : if (twsk_unique(sk, sk2, twp))
471 : break;
472 : }
473 0 : goto not_unique;
474 : }
475 : }
476 :
477 : /* Must record num and sport now. Otherwise we will see
478 : * in hash table socket with a funny identity.
479 : */
480 0 : inet->inet_num = lport;
481 0 : inet->inet_sport = htons(lport);
482 0 : sk->sk_hash = hash;
483 0 : WARN_ON(!sk_unhashed(sk));
484 0 : __sk_nulls_add_node_rcu(sk, &head->chain);
485 0 : if (tw) {
486 0 : sk_nulls_del_node_init_rcu((struct sock *)tw);
487 0 : __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
488 : }
489 0 : spin_unlock(lock);
490 0 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
491 :
492 0 : if (twp) {
493 0 : *twp = tw;
494 0 : } else if (tw) {
495 : /* Silly. Should hash-dance instead... */
496 0 : inet_twsk_deschedule_put(tw);
497 : }
498 : return 0;
499 :
500 0 : not_unique:
501 0 : spin_unlock(lock);
502 0 : return -EADDRNOTAVAIL;
503 : }
504 :
505 0 : static u32 inet_sk_port_offset(const struct sock *sk)
506 : {
507 0 : const struct inet_sock *inet = inet_sk(sk);
508 :
509 0 : return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
510 : inet->inet_daddr,
511 0 : inet->inet_dport);
512 : }
513 :
514 : /* Searches for an exsiting socket in the ehash bucket list.
515 : * Returns true if found, false otherwise.
516 : */
517 0 : static bool inet_ehash_lookup_by_sk(struct sock *sk,
518 : struct hlist_nulls_head *list)
519 : {
520 0 : const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num);
521 0 : const int sdif = sk->sk_bound_dev_if;
522 0 : const int dif = sk->sk_bound_dev_if;
523 0 : const struct hlist_nulls_node *node;
524 0 : struct net *net = sock_net(sk);
525 0 : struct sock *esk;
526 :
527 0 : INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr);
528 :
529 0 : sk_nulls_for_each_rcu(esk, node, list) {
530 0 : if (esk->sk_hash != sk->sk_hash)
531 0 : continue;
532 0 : if (sk->sk_family == AF_INET) {
533 0 : if (unlikely(INET_MATCH(esk, net, acookie,
534 : sk->sk_daddr,
535 : sk->sk_rcv_saddr,
536 : ports, dif, sdif))) {
537 : return true;
538 : }
539 : }
540 : #if IS_ENABLED(CONFIG_IPV6)
541 : else if (sk->sk_family == AF_INET6) {
542 : if (unlikely(INET6_MATCH(esk, net,
543 : &sk->sk_v6_daddr,
544 : &sk->sk_v6_rcv_saddr,
545 : ports, dif, sdif))) {
546 : return true;
547 : }
548 : }
549 : #endif
550 : }
551 : return false;
552 : }
553 :
554 : /* Insert a socket into ehash, and eventually remove another one
555 : * (The another one can be a SYN_RECV or TIMEWAIT)
556 : * If an existing socket already exists, socket sk is not inserted,
557 : * and sets found_dup_sk parameter to true.
558 : */
559 8 : bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk)
560 : {
561 8 : struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
562 8 : struct hlist_nulls_head *list;
563 8 : struct inet_ehash_bucket *head;
564 8 : spinlock_t *lock;
565 8 : bool ret = true;
566 :
567 8 : WARN_ON_ONCE(!sk_unhashed(sk));
568 :
569 8 : sk->sk_hash = sk_ehashfn(sk);
570 8 : head = inet_ehash_bucket(hashinfo, sk->sk_hash);
571 8 : list = &head->chain;
572 8 : lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
573 :
574 8 : spin_lock(lock);
575 8 : if (osk) {
576 4 : WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
577 4 : ret = sk_nulls_del_node_init_rcu(osk);
578 4 : } else if (found_dup_sk) {
579 0 : *found_dup_sk = inet_ehash_lookup_by_sk(sk, list);
580 0 : if (*found_dup_sk)
581 : ret = false;
582 : }
583 :
584 4 : if (ret)
585 8 : __sk_nulls_add_node_rcu(sk, list);
586 :
587 8 : spin_unlock(lock);
588 :
589 8 : return ret;
590 : }
591 :
592 4 : bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk)
593 : {
594 4 : bool ok = inet_ehash_insert(sk, osk, found_dup_sk);
595 :
596 4 : if (ok) {
597 4 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
598 : } else {
599 0 : percpu_counter_inc(sk->sk_prot->orphan_count);
600 0 : inet_sk_set_state(sk, TCP_CLOSE);
601 0 : sock_set_flag(sk, SOCK_DEAD);
602 0 : inet_csk_destroy_sock(sk);
603 : }
604 4 : return ok;
605 : }
606 : EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
607 :
608 0 : static int inet_reuseport_add_sock(struct sock *sk,
609 : struct inet_listen_hashbucket *ilb)
610 : {
611 0 : struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
612 0 : const struct hlist_nulls_node *node;
613 0 : struct sock *sk2;
614 0 : kuid_t uid = sock_i_uid(sk);
615 :
616 0 : sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
617 0 : if (sk2 != sk &&
618 : sk2->sk_family == sk->sk_family &&
619 0 : ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
620 0 : sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
621 0 : inet_csk(sk2)->icsk_bind_hash == tb &&
622 0 : sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
623 0 : inet_rcv_saddr_equal(sk, sk2, false))
624 0 : return reuseport_add_sock(sk, sk2,
625 0 : inet_rcv_saddr_any(sk));
626 : }
627 :
628 0 : return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
629 : }
630 :
631 3 : int __inet_hash(struct sock *sk, struct sock *osk)
632 : {
633 3 : struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
634 3 : struct inet_listen_hashbucket *ilb;
635 3 : int err = 0;
636 :
637 3 : if (sk->sk_state != TCP_LISTEN) {
638 0 : inet_ehash_nolisten(sk, osk, NULL);
639 0 : return 0;
640 : }
641 3 : WARN_ON(!sk_unhashed(sk));
642 3 : ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
643 :
644 3 : spin_lock(&ilb->lock);
645 3 : if (sk->sk_reuseport) {
646 0 : err = inet_reuseport_add_sock(sk, ilb);
647 0 : if (err)
648 0 : goto unlock;
649 : }
650 3 : if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
651 : sk->sk_family == AF_INET6)
652 : __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
653 : else
654 3 : __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
655 3 : inet_hash2(hashinfo, sk);
656 3 : ilb->count++;
657 3 : sock_set_flag(sk, SOCK_RCU_FREE);
658 3 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
659 3 : unlock:
660 3 : spin_unlock(&ilb->lock);
661 :
662 3 : return err;
663 : }
664 : EXPORT_SYMBOL(__inet_hash);
665 :
666 3 : int inet_hash(struct sock *sk)
667 : {
668 3 : int err = 0;
669 :
670 3 : if (sk->sk_state != TCP_CLOSE) {
671 3 : local_bh_disable();
672 3 : err = __inet_hash(sk, NULL);
673 3 : local_bh_enable();
674 : }
675 :
676 3 : return err;
677 : }
678 : EXPORT_SYMBOL_GPL(inet_hash);
679 :
680 4 : void inet_unhash(struct sock *sk)
681 : {
682 4 : struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
683 4 : struct inet_listen_hashbucket *ilb = NULL;
684 4 : spinlock_t *lock;
685 :
686 4 : if (sk_unhashed(sk))
687 : return;
688 :
689 4 : if (sk->sk_state == TCP_LISTEN) {
690 1 : ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
691 1 : lock = &ilb->lock;
692 : } else {
693 3 : lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
694 : }
695 4 : spin_lock_bh(lock);
696 4 : if (sk_unhashed(sk))
697 0 : goto unlock;
698 :
699 4 : if (rcu_access_pointer(sk->sk_reuseport_cb))
700 0 : reuseport_detach_sock(sk);
701 4 : if (ilb) {
702 1 : inet_unhash2(hashinfo, sk);
703 1 : ilb->count--;
704 : }
705 4 : __sk_nulls_del_node_init_rcu(sk);
706 4 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
707 4 : unlock:
708 4 : spin_unlock_bh(lock);
709 : }
710 : EXPORT_SYMBOL_GPL(inet_unhash);
711 :
712 : /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm
713 : * Note that we use 32bit integers (vs RFC 'short integers')
714 : * because 2^16 is not a multiple of num_ephemeral and this
715 : * property might be used by clever attacker.
716 : * RFC claims using TABLE_LENGTH=10 buckets gives an improvement,
717 : * we use 256 instead to really give more isolation and
718 : * privacy, this only consumes 1 KB of kernel memory.
719 : */
720 : #define INET_TABLE_PERTURB_SHIFT 8
721 : static u32 table_perturb[1 << INET_TABLE_PERTURB_SHIFT];
722 :
723 0 : int __inet_hash_connect(struct inet_timewait_death_row *death_row,
724 : struct sock *sk, u32 port_offset,
725 : int (*check_established)(struct inet_timewait_death_row *,
726 : struct sock *, __u16, struct inet_timewait_sock **))
727 : {
728 0 : struct inet_hashinfo *hinfo = death_row->hashinfo;
729 0 : struct inet_timewait_sock *tw = NULL;
730 0 : struct inet_bind_hashbucket *head;
731 0 : int port = inet_sk(sk)->inet_num;
732 0 : struct net *net = sock_net(sk);
733 0 : struct inet_bind_bucket *tb;
734 0 : u32 remaining, offset;
735 0 : int ret, i, low, high;
736 0 : int l3mdev;
737 0 : u32 index;
738 :
739 0 : if (port) {
740 0 : head = &hinfo->bhash[inet_bhashfn(net, port,
741 : hinfo->bhash_size)];
742 0 : tb = inet_csk(sk)->icsk_bind_hash;
743 0 : spin_lock_bh(&head->lock);
744 0 : if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
745 0 : inet_ehash_nolisten(sk, NULL, NULL);
746 0 : spin_unlock_bh(&head->lock);
747 0 : return 0;
748 : }
749 0 : spin_unlock(&head->lock);
750 : /* No definite answer... Walk to established hash table */
751 0 : ret = check_established(death_row, sk, port, NULL);
752 0 : local_bh_enable();
753 0 : return ret;
754 : }
755 :
756 0 : l3mdev = inet_sk_bound_l3mdev(sk);
757 :
758 0 : inet_get_local_port_range(net, &low, &high);
759 0 : high++; /* [32768, 60999] -> [32768, 61000[ */
760 0 : remaining = high - low;
761 0 : if (likely(remaining > 1))
762 0 : remaining &= ~1U;
763 :
764 0 : net_get_random_once(table_perturb, sizeof(table_perturb));
765 0 : index = hash_32(port_offset, INET_TABLE_PERTURB_SHIFT);
766 :
767 0 : offset = (READ_ONCE(table_perturb[index]) + port_offset) % remaining;
768 : /* In first pass we try ports of @low parity.
769 : * inet_csk_get_port() does the opposite choice.
770 : */
771 0 : offset &= ~1U;
772 0 : other_parity_scan:
773 0 : port = low + offset;
774 0 : for (i = 0; i < remaining; i += 2, port += 2) {
775 0 : if (unlikely(port >= high))
776 0 : port -= remaining;
777 0 : if (inet_is_local_reserved_port(net, port))
778 0 : continue;
779 0 : head = &hinfo->bhash[inet_bhashfn(net, port,
780 : hinfo->bhash_size)];
781 0 : spin_lock_bh(&head->lock);
782 :
783 : /* Does not bother with rcv_saddr checks, because
784 : * the established check is already unique enough.
785 : */
786 0 : inet_bind_bucket_for_each(tb, &head->chain) {
787 0 : if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
788 0 : tb->port == port) {
789 0 : if (tb->fastreuse >= 0 ||
790 0 : tb->fastreuseport >= 0)
791 0 : goto next_port;
792 0 : WARN_ON(hlist_empty(&tb->owners));
793 0 : if (!check_established(death_row, sk,
794 : port, &tw))
795 0 : goto ok;
796 0 : goto next_port;
797 : }
798 : }
799 :
800 0 : tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
801 : net, head, port, l3mdev);
802 0 : if (!tb) {
803 0 : spin_unlock_bh(&head->lock);
804 0 : return -ENOMEM;
805 : }
806 0 : tb->fastreuse = -1;
807 0 : tb->fastreuseport = -1;
808 0 : goto ok;
809 0 : next_port:
810 0 : spin_unlock_bh(&head->lock);
811 0 : cond_resched();
812 : }
813 :
814 0 : offset++;
815 0 : if ((offset & 1) && remaining > 1)
816 0 : goto other_parity_scan;
817 :
818 : return -EADDRNOTAVAIL;
819 :
820 0 : ok:
821 : /* If our first attempt found a candidate, skip next candidate
822 : * in 1/16 of cases to add some noise.
823 : */
824 0 : if (!i && !(prandom_u32() % 16))
825 0 : i = 2;
826 0 : WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
827 :
828 : /* Head lock still held and bh's disabled */
829 0 : inet_bind_hash(sk, tb, port);
830 0 : if (sk_unhashed(sk)) {
831 0 : inet_sk(sk)->inet_sport = htons(port);
832 0 : inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
833 : }
834 0 : if (tw)
835 0 : inet_twsk_bind_unhash(tw, hinfo);
836 0 : spin_unlock(&head->lock);
837 0 : if (tw)
838 0 : inet_twsk_deschedule_put(tw);
839 0 : local_bh_enable();
840 0 : return 0;
841 : }
842 :
843 : /*
844 : * Bind a port for a connect operation and hash it.
845 : */
846 0 : int inet_hash_connect(struct inet_timewait_death_row *death_row,
847 : struct sock *sk)
848 : {
849 0 : u32 port_offset = 0;
850 :
851 0 : if (!inet_sk(sk)->inet_num)
852 0 : port_offset = inet_sk_port_offset(sk);
853 0 : return __inet_hash_connect(death_row, sk, port_offset,
854 : __inet_check_established);
855 : }
856 : EXPORT_SYMBOL_GPL(inet_hash_connect);
857 :
858 1 : void inet_hashinfo_init(struct inet_hashinfo *h)
859 : {
860 1 : int i;
861 :
862 33 : for (i = 0; i < INET_LHTABLE_SIZE; i++) {
863 32 : spin_lock_init(&h->listening_hash[i].lock);
864 32 : INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
865 : i + LISTENING_NULLS_BASE);
866 32 : h->listening_hash[i].count = 0;
867 : }
868 :
869 1 : h->lhash2 = NULL;
870 1 : }
871 : EXPORT_SYMBOL_GPL(inet_hashinfo_init);
872 :
873 1 : static void init_hashinfo_lhash2(struct inet_hashinfo *h)
874 : {
875 1 : int i;
876 :
877 513 : for (i = 0; i <= h->lhash2_mask; i++) {
878 512 : spin_lock_init(&h->lhash2[i].lock);
879 512 : INIT_HLIST_HEAD(&h->lhash2[i].head);
880 512 : h->lhash2[i].count = 0;
881 : }
882 1 : }
883 :
884 1 : void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
885 : unsigned long numentries, int scale,
886 : unsigned long low_limit,
887 : unsigned long high_limit)
888 : {
889 1 : h->lhash2 = alloc_large_system_hash(name,
890 : sizeof(*h->lhash2),
891 : numentries,
892 : scale,
893 : 0,
894 : NULL,
895 : &h->lhash2_mask,
896 : low_limit,
897 : high_limit);
898 1 : init_hashinfo_lhash2(h);
899 1 : }
900 :
901 0 : int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
902 : {
903 0 : h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
904 0 : if (!h->lhash2)
905 : return -ENOMEM;
906 :
907 0 : h->lhash2_mask = INET_LHTABLE_SIZE - 1;
908 : /* INET_LHTABLE_SIZE must be a power of 2 */
909 0 : BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
910 :
911 0 : init_hashinfo_lhash2(h);
912 0 : return 0;
913 : }
914 : EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
915 :
916 1 : int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
917 : {
918 1 : unsigned int locksz = sizeof(spinlock_t);
919 1 : unsigned int i, nblocks = 1;
920 :
921 1 : if (locksz != 0) {
922 : /* allocate 2 cache lines or at least one spinlock per cpu */
923 1 : nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
924 1 : nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
925 :
926 : /* no more locks than number of hash buckets */
927 1 : nblocks = min(nblocks, hashinfo->ehash_mask + 1);
928 :
929 1 : hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
930 1 : if (!hashinfo->ehash_locks)
931 : return -ENOMEM;
932 :
933 9 : for (i = 0; i < nblocks; i++)
934 8 : spin_lock_init(&hashinfo->ehash_locks[i]);
935 : }
936 1 : hashinfo->ehash_locks_mask = nblocks - 1;
937 1 : return 0;
938 : }
939 : EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
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