1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Generic INET transport hashtables 7 * 8 * Authors: Lotsa people, from code originally in tcp 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/random.h> 18 #include <linux/sched.h> 19 #include <linux/slab.h> 20 #include <linux/wait.h> 21 #include <linux/vmalloc.h> 22 23 #include <net/addrconf.h> 24 #include <net/inet_connection_sock.h> 25 #include <net/inet_hashtables.h> 26 #include <net/secure_seq.h> 27 #include <net/ip.h> 28 #include <net/tcp.h> 29 #include <net/sock_reuseport.h> 30 31 static u32 inet_ehashfn(const struct net *net, const __be32 laddr, 32 const __u16 lport, const __be32 faddr, 33 const __be16 fport) 34 { 35 static u32 inet_ehash_secret __read_mostly; 36 37 net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret)); 38 39 return __inet_ehashfn(laddr, lport, faddr, fport, 40 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 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 return inet_ehashfn(sock_net(sk), 56 sk->sk_rcv_saddr, sk->sk_num, 57 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 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 { 69 struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC); 70 71 if (tb) { 72 write_pnet(&tb->ib_net, net); 73 tb->port = snum; 74 tb->fastreuse = 0; 75 tb->fastreuseport = 0; 76 INIT_HLIST_HEAD(&tb->owners); 77 hlist_add_head(&tb->node, &head->chain); 78 } 79 return tb; 80 } 81 82 /* 83 * Caller must hold hashbucket lock for this tb with local BH disabled 84 */ 85 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) 86 { 87 if (hlist_empty(&tb->owners)) { 88 __hlist_del(&tb->node); 89 kmem_cache_free(cachep, tb); 90 } 91 } 92 93 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, 94 const unsigned short snum) 95 { 96 inet_sk(sk)->inet_num = snum; 97 sk_add_bind_node(sk, &tb->owners); 98 inet_csk(sk)->icsk_bind_hash = tb; 99 } 100 101 /* 102 * Get rid of any references to a local port held by the given sock. 103 */ 104 static void __inet_put_port(struct sock *sk) 105 { 106 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 107 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num, 108 hashinfo->bhash_size); 109 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; 110 struct inet_bind_bucket *tb; 111 112 spin_lock(&head->lock); 113 tb = inet_csk(sk)->icsk_bind_hash; 114 __sk_del_bind_node(sk); 115 inet_csk(sk)->icsk_bind_hash = NULL; 116 inet_sk(sk)->inet_num = 0; 117 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); 118 spin_unlock(&head->lock); 119 } 120 121 void inet_put_port(struct sock *sk) 122 { 123 local_bh_disable(); 124 __inet_put_port(sk); 125 local_bh_enable(); 126 } 127 EXPORT_SYMBOL(inet_put_port); 128 129 int __inet_inherit_port(const struct sock *sk, struct sock *child) 130 { 131 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; 132 unsigned short port = inet_sk(child)->inet_num; 133 const int bhash = inet_bhashfn(sock_net(sk), port, 134 table->bhash_size); 135 struct inet_bind_hashbucket *head = &table->bhash[bhash]; 136 struct inet_bind_bucket *tb; 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 /* NOTE: using tproxy and redirecting skbs to a proxy 146 * on a different listener port breaks the assumption 147 * that the listener socket's icsk_bind_hash is the same 148 * as that of the child socket. We have to look up or 149 * create a new bind bucket for the child here. */ 150 inet_bind_bucket_for_each(tb, &head->chain) { 151 if (net_eq(ib_net(tb), sock_net(sk)) && 152 tb->port == port) 153 break; 154 } 155 if (!tb) { 156 tb = inet_bind_bucket_create(table->bind_bucket_cachep, 157 sock_net(sk), head, port); 158 if (!tb) { 159 spin_unlock(&head->lock); 160 return -ENOMEM; 161 } 162 } 163 } 164 inet_bind_hash(child, tb, port); 165 spin_unlock(&head->lock); 166 167 return 0; 168 } 169 EXPORT_SYMBOL_GPL(__inet_inherit_port); 170 171 static inline int compute_score(struct sock *sk, struct net *net, 172 const unsigned short hnum, const __be32 daddr, 173 const int dif, const int sdif, bool exact_dif) 174 { 175 int score = -1; 176 struct inet_sock *inet = inet_sk(sk); 177 178 if (net_eq(sock_net(sk), net) && inet->inet_num == hnum && 179 !ipv6_only_sock(sk)) { 180 __be32 rcv_saddr = inet->inet_rcv_saddr; 181 score = sk->sk_family == PF_INET ? 2 : 1; 182 if (rcv_saddr) { 183 if (rcv_saddr != daddr) 184 return -1; 185 score += 4; 186 } 187 if (sk->sk_bound_dev_if || exact_dif) { 188 bool dev_match = (sk->sk_bound_dev_if == dif || 189 sk->sk_bound_dev_if == sdif); 190 191 if (exact_dif && !dev_match) 192 return -1; 193 if (sk->sk_bound_dev_if && dev_match) 194 score += 4; 195 } 196 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 197 score++; 198 } 199 return score; 200 } 201 202 /* 203 * Here are some nice properties to exploit here. The BSD API 204 * does not allow a listening sock to specify the remote port nor the 205 * remote address for the connection. So always assume those are both 206 * wildcarded during the search since they can never be otherwise. 207 */ 208 209 /* called with rcu_read_lock() : No refcount taken on the socket */ 210 struct sock *__inet_lookup_listener(struct net *net, 211 struct inet_hashinfo *hashinfo, 212 struct sk_buff *skb, int doff, 213 const __be32 saddr, __be16 sport, 214 const __be32 daddr, const unsigned short hnum, 215 const int dif, const int sdif) 216 { 217 unsigned int hash = inet_lhashfn(net, hnum); 218 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; 219 int score, hiscore = 0, matches = 0, reuseport = 0; 220 bool exact_dif = inet_exact_dif_match(net, skb); 221 struct sock *sk, *result = NULL; 222 u32 phash = 0; 223 224 sk_for_each_rcu(sk, &ilb->head) { 225 score = compute_score(sk, net, hnum, daddr, 226 dif, sdif, exact_dif); 227 if (score > hiscore) { 228 reuseport = sk->sk_reuseport; 229 if (reuseport) { 230 phash = inet_ehashfn(net, daddr, hnum, 231 saddr, sport); 232 result = reuseport_select_sock(sk, phash, 233 skb, doff); 234 if (result) 235 return result; 236 matches = 1; 237 } 238 result = sk; 239 hiscore = score; 240 } else if (score == hiscore && reuseport) { 241 matches++; 242 if (reciprocal_scale(phash, matches) == 0) 243 result = sk; 244 phash = next_pseudo_random32(phash); 245 } 246 } 247 return result; 248 } 249 EXPORT_SYMBOL_GPL(__inet_lookup_listener); 250 251 /* All sockets share common refcount, but have different destructors */ 252 void sock_gen_put(struct sock *sk) 253 { 254 if (!refcount_dec_and_test(&sk->sk_refcnt)) 255 return; 256 257 if (sk->sk_state == TCP_TIME_WAIT) 258 inet_twsk_free(inet_twsk(sk)); 259 else if (sk->sk_state == TCP_NEW_SYN_RECV) 260 reqsk_free(inet_reqsk(sk)); 261 else 262 sk_free(sk); 263 } 264 EXPORT_SYMBOL_GPL(sock_gen_put); 265 266 void sock_edemux(struct sk_buff *skb) 267 { 268 sock_gen_put(skb->sk); 269 } 270 EXPORT_SYMBOL(sock_edemux); 271 272 struct sock *__inet_lookup_established(struct net *net, 273 struct inet_hashinfo *hashinfo, 274 const __be32 saddr, const __be16 sport, 275 const __be32 daddr, const u16 hnum, 276 const int dif, const int sdif) 277 { 278 INET_ADDR_COOKIE(acookie, saddr, daddr); 279 const __portpair ports = INET_COMBINED_PORTS(sport, hnum); 280 struct sock *sk; 281 const struct hlist_nulls_node *node; 282 /* Optimize here for direct hit, only listening connections can 283 * have wildcards anyways. 284 */ 285 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport); 286 unsigned int slot = hash & hashinfo->ehash_mask; 287 struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; 288 289 begin: 290 sk_nulls_for_each_rcu(sk, node, &head->chain) { 291 if (sk->sk_hash != hash) 292 continue; 293 if (likely(INET_MATCH(sk, net, acookie, 294 saddr, daddr, ports, dif, sdif))) { 295 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) 296 goto out; 297 if (unlikely(!INET_MATCH(sk, net, acookie, 298 saddr, daddr, ports, 299 dif, sdif))) { 300 sock_gen_put(sk); 301 goto begin; 302 } 303 goto found; 304 } 305 } 306 /* 307 * if the nulls value we got at the end of this lookup is 308 * not the expected one, we must restart lookup. 309 * We probably met an item that was moved to another chain. 310 */ 311 if (get_nulls_value(node) != slot) 312 goto begin; 313 out: 314 sk = NULL; 315 found: 316 return sk; 317 } 318 EXPORT_SYMBOL_GPL(__inet_lookup_established); 319 320 /* called with local bh disabled */ 321 static int __inet_check_established(struct inet_timewait_death_row *death_row, 322 struct sock *sk, __u16 lport, 323 struct inet_timewait_sock **twp) 324 { 325 struct inet_hashinfo *hinfo = death_row->hashinfo; 326 struct inet_sock *inet = inet_sk(sk); 327 __be32 daddr = inet->inet_rcv_saddr; 328 __be32 saddr = inet->inet_daddr; 329 int dif = sk->sk_bound_dev_if; 330 struct net *net = sock_net(sk); 331 int sdif = l3mdev_master_ifindex_by_index(net, dif); 332 INET_ADDR_COOKIE(acookie, saddr, daddr); 333 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); 334 unsigned int hash = inet_ehashfn(net, daddr, lport, 335 saddr, inet->inet_dport); 336 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); 337 spinlock_t *lock = inet_ehash_lockp(hinfo, hash); 338 struct sock *sk2; 339 const struct hlist_nulls_node *node; 340 struct inet_timewait_sock *tw = NULL; 341 342 spin_lock(lock); 343 344 sk_nulls_for_each(sk2, node, &head->chain) { 345 if (sk2->sk_hash != hash) 346 continue; 347 348 if (likely(INET_MATCH(sk2, net, acookie, 349 saddr, daddr, ports, dif, sdif))) { 350 if (sk2->sk_state == TCP_TIME_WAIT) { 351 tw = inet_twsk(sk2); 352 if (twsk_unique(sk, sk2, twp)) 353 break; 354 } 355 goto not_unique; 356 } 357 } 358 359 /* Must record num and sport now. Otherwise we will see 360 * in hash table socket with a funny identity. 361 */ 362 inet->inet_num = lport; 363 inet->inet_sport = htons(lport); 364 sk->sk_hash = hash; 365 WARN_ON(!sk_unhashed(sk)); 366 __sk_nulls_add_node_rcu(sk, &head->chain); 367 if (tw) { 368 sk_nulls_del_node_init_rcu((struct sock *)tw); 369 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED); 370 } 371 spin_unlock(lock); 372 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 373 374 if (twp) { 375 *twp = tw; 376 } else if (tw) { 377 /* Silly. Should hash-dance instead... */ 378 inet_twsk_deschedule_put(tw); 379 } 380 return 0; 381 382 not_unique: 383 spin_unlock(lock); 384 return -EADDRNOTAVAIL; 385 } 386 387 static u32 inet_sk_port_offset(const struct sock *sk) 388 { 389 const struct inet_sock *inet = inet_sk(sk); 390 391 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr, 392 inet->inet_daddr, 393 inet->inet_dport); 394 } 395 396 /* insert a socket into ehash, and eventually remove another one 397 * (The another one can be a SYN_RECV or TIMEWAIT 398 */ 399 bool inet_ehash_insert(struct sock *sk, struct sock *osk) 400 { 401 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 402 struct hlist_nulls_head *list; 403 struct inet_ehash_bucket *head; 404 spinlock_t *lock; 405 bool ret = true; 406 407 WARN_ON_ONCE(!sk_unhashed(sk)); 408 409 sk->sk_hash = sk_ehashfn(sk); 410 head = inet_ehash_bucket(hashinfo, sk->sk_hash); 411 list = &head->chain; 412 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 413 414 spin_lock(lock); 415 if (osk) { 416 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); 417 ret = sk_nulls_del_node_init_rcu(osk); 418 } 419 if (ret) 420 __sk_nulls_add_node_rcu(sk, list); 421 spin_unlock(lock); 422 return ret; 423 } 424 425 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk) 426 { 427 bool ok = inet_ehash_insert(sk, osk); 428 429 if (ok) { 430 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 431 } else { 432 percpu_counter_inc(sk->sk_prot->orphan_count); 433 sk->sk_state = TCP_CLOSE; 434 sock_set_flag(sk, SOCK_DEAD); 435 inet_csk_destroy_sock(sk); 436 } 437 return ok; 438 } 439 EXPORT_SYMBOL_GPL(inet_ehash_nolisten); 440 441 static int inet_reuseport_add_sock(struct sock *sk, 442 struct inet_listen_hashbucket *ilb) 443 { 444 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; 445 struct sock *sk2; 446 kuid_t uid = sock_i_uid(sk); 447 448 sk_for_each_rcu(sk2, &ilb->head) { 449 if (sk2 != sk && 450 sk2->sk_family == sk->sk_family && 451 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 452 sk2->sk_bound_dev_if == sk->sk_bound_dev_if && 453 inet_csk(sk2)->icsk_bind_hash == tb && 454 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 455 inet_rcv_saddr_equal(sk, sk2, false)) 456 return reuseport_add_sock(sk, sk2); 457 } 458 459 return reuseport_alloc(sk); 460 } 461 462 int __inet_hash(struct sock *sk, struct sock *osk) 463 { 464 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 465 struct inet_listen_hashbucket *ilb; 466 int err = 0; 467 468 if (sk->sk_state != TCP_LISTEN) { 469 inet_ehash_nolisten(sk, osk); 470 return 0; 471 } 472 WARN_ON(!sk_unhashed(sk)); 473 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 474 475 spin_lock(&ilb->lock); 476 if (sk->sk_reuseport) { 477 err = inet_reuseport_add_sock(sk, ilb); 478 if (err) 479 goto unlock; 480 } 481 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 482 sk->sk_family == AF_INET6) 483 hlist_add_tail_rcu(&sk->sk_node, &ilb->head); 484 else 485 hlist_add_head_rcu(&sk->sk_node, &ilb->head); 486 sock_set_flag(sk, SOCK_RCU_FREE); 487 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 488 unlock: 489 spin_unlock(&ilb->lock); 490 491 return err; 492 } 493 EXPORT_SYMBOL(__inet_hash); 494 495 int inet_hash(struct sock *sk) 496 { 497 int err = 0; 498 499 if (sk->sk_state != TCP_CLOSE) { 500 local_bh_disable(); 501 err = __inet_hash(sk, NULL); 502 local_bh_enable(); 503 } 504 505 return err; 506 } 507 EXPORT_SYMBOL_GPL(inet_hash); 508 509 void inet_unhash(struct sock *sk) 510 { 511 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 512 spinlock_t *lock; 513 bool listener = false; 514 int done; 515 516 if (sk_unhashed(sk)) 517 return; 518 519 if (sk->sk_state == TCP_LISTEN) { 520 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock; 521 listener = true; 522 } else { 523 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 524 } 525 spin_lock_bh(lock); 526 if (rcu_access_pointer(sk->sk_reuseport_cb)) 527 reuseport_detach_sock(sk); 528 if (listener) 529 done = __sk_del_node_init(sk); 530 else 531 done = __sk_nulls_del_node_init_rcu(sk); 532 if (done) 533 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 534 spin_unlock_bh(lock); 535 } 536 EXPORT_SYMBOL_GPL(inet_unhash); 537 538 int __inet_hash_connect(struct inet_timewait_death_row *death_row, 539 struct sock *sk, u32 port_offset, 540 int (*check_established)(struct inet_timewait_death_row *, 541 struct sock *, __u16, struct inet_timewait_sock **)) 542 { 543 struct inet_hashinfo *hinfo = death_row->hashinfo; 544 struct inet_timewait_sock *tw = NULL; 545 struct inet_bind_hashbucket *head; 546 int port = inet_sk(sk)->inet_num; 547 struct net *net = sock_net(sk); 548 struct inet_bind_bucket *tb; 549 u32 remaining, offset; 550 int ret, i, low, high; 551 static u32 hint; 552 553 if (port) { 554 head = &hinfo->bhash[inet_bhashfn(net, port, 555 hinfo->bhash_size)]; 556 tb = inet_csk(sk)->icsk_bind_hash; 557 spin_lock_bh(&head->lock); 558 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { 559 inet_ehash_nolisten(sk, NULL); 560 spin_unlock_bh(&head->lock); 561 return 0; 562 } 563 spin_unlock(&head->lock); 564 /* No definite answer... Walk to established hash table */ 565 ret = check_established(death_row, sk, port, NULL); 566 local_bh_enable(); 567 return ret; 568 } 569 570 inet_get_local_port_range(net, &low, &high); 571 high++; /* [32768, 60999] -> [32768, 61000[ */ 572 remaining = high - low; 573 if (likely(remaining > 1)) 574 remaining &= ~1U; 575 576 offset = (hint + port_offset) % remaining; 577 /* In first pass we try ports of @low parity. 578 * inet_csk_get_port() does the opposite choice. 579 */ 580 offset &= ~1U; 581 other_parity_scan: 582 port = low + offset; 583 for (i = 0; i < remaining; i += 2, port += 2) { 584 if (unlikely(port >= high)) 585 port -= remaining; 586 if (inet_is_local_reserved_port(net, port)) 587 continue; 588 head = &hinfo->bhash[inet_bhashfn(net, port, 589 hinfo->bhash_size)]; 590 spin_lock_bh(&head->lock); 591 592 /* Does not bother with rcv_saddr checks, because 593 * the established check is already unique enough. 594 */ 595 inet_bind_bucket_for_each(tb, &head->chain) { 596 if (net_eq(ib_net(tb), net) && tb->port == port) { 597 if (tb->fastreuse >= 0 || 598 tb->fastreuseport >= 0) 599 goto next_port; 600 WARN_ON(hlist_empty(&tb->owners)); 601 if (!check_established(death_row, sk, 602 port, &tw)) 603 goto ok; 604 goto next_port; 605 } 606 } 607 608 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, 609 net, head, port); 610 if (!tb) { 611 spin_unlock_bh(&head->lock); 612 return -ENOMEM; 613 } 614 tb->fastreuse = -1; 615 tb->fastreuseport = -1; 616 goto ok; 617 next_port: 618 spin_unlock_bh(&head->lock); 619 cond_resched(); 620 } 621 622 offset++; 623 if ((offset & 1) && remaining > 1) 624 goto other_parity_scan; 625 626 return -EADDRNOTAVAIL; 627 628 ok: 629 hint += i + 2; 630 631 /* Head lock still held and bh's disabled */ 632 inet_bind_hash(sk, tb, port); 633 if (sk_unhashed(sk)) { 634 inet_sk(sk)->inet_sport = htons(port); 635 inet_ehash_nolisten(sk, (struct sock *)tw); 636 } 637 if (tw) 638 inet_twsk_bind_unhash(tw, hinfo); 639 spin_unlock(&head->lock); 640 if (tw) 641 inet_twsk_deschedule_put(tw); 642 local_bh_enable(); 643 return 0; 644 } 645 646 /* 647 * Bind a port for a connect operation and hash it. 648 */ 649 int inet_hash_connect(struct inet_timewait_death_row *death_row, 650 struct sock *sk) 651 { 652 u32 port_offset = 0; 653 654 if (!inet_sk(sk)->inet_num) 655 port_offset = inet_sk_port_offset(sk); 656 return __inet_hash_connect(death_row, sk, port_offset, 657 __inet_check_established); 658 } 659 EXPORT_SYMBOL_GPL(inet_hash_connect); 660 661 void inet_hashinfo_init(struct inet_hashinfo *h) 662 { 663 int i; 664 665 for (i = 0; i < INET_LHTABLE_SIZE; i++) { 666 spin_lock_init(&h->listening_hash[i].lock); 667 INIT_HLIST_HEAD(&h->listening_hash[i].head); 668 } 669 } 670 EXPORT_SYMBOL_GPL(inet_hashinfo_init); 671 672 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) 673 { 674 unsigned int locksz = sizeof(spinlock_t); 675 unsigned int i, nblocks = 1; 676 677 if (locksz != 0) { 678 /* allocate 2 cache lines or at least one spinlock per cpu */ 679 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); 680 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); 681 682 /* no more locks than number of hash buckets */ 683 nblocks = min(nblocks, hashinfo->ehash_mask + 1); 684 685 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); 686 if (!hashinfo->ehash_locks) 687 return -ENOMEM; 688 689 for (i = 0; i < nblocks; i++) 690 spin_lock_init(&hashinfo->ehash_locks[i]); 691 } 692 hashinfo->ehash_locks_mask = nblocks - 1; 693 return 0; 694 } 695 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); 696