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, 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 if (sk->sk_bound_dev_if != dif) 189 return -1; 190 score += 4; 191 } 192 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 193 score++; 194 } 195 return score; 196 } 197 198 /* 199 * Here are some nice properties to exploit here. The BSD API 200 * does not allow a listening sock to specify the remote port nor the 201 * remote address for the connection. So always assume those are both 202 * wildcarded during the search since they can never be otherwise. 203 */ 204 205 /* called with rcu_read_lock() : No refcount taken on the socket */ 206 struct sock *__inet_lookup_listener(struct net *net, 207 struct inet_hashinfo *hashinfo, 208 struct sk_buff *skb, int doff, 209 const __be32 saddr, __be16 sport, 210 const __be32 daddr, const unsigned short hnum, 211 const int dif) 212 { 213 unsigned int hash = inet_lhashfn(net, hnum); 214 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; 215 int score, hiscore = 0, matches = 0, reuseport = 0; 216 bool exact_dif = inet_exact_dif_match(net, skb); 217 struct sock *sk, *result = NULL; 218 u32 phash = 0; 219 220 sk_for_each_rcu(sk, &ilb->head) { 221 score = compute_score(sk, net, hnum, daddr, dif, exact_dif); 222 if (score > hiscore) { 223 reuseport = sk->sk_reuseport; 224 if (reuseport) { 225 phash = inet_ehashfn(net, daddr, hnum, 226 saddr, sport); 227 result = reuseport_select_sock(sk, phash, 228 skb, doff); 229 if (result) 230 return result; 231 matches = 1; 232 } 233 result = sk; 234 hiscore = score; 235 } else if (score == hiscore && reuseport) { 236 matches++; 237 if (reciprocal_scale(phash, matches) == 0) 238 result = sk; 239 phash = next_pseudo_random32(phash); 240 } 241 } 242 return result; 243 } 244 EXPORT_SYMBOL_GPL(__inet_lookup_listener); 245 246 /* All sockets share common refcount, but have different destructors */ 247 void sock_gen_put(struct sock *sk) 248 { 249 if (!refcount_dec_and_test(&sk->sk_refcnt)) 250 return; 251 252 if (sk->sk_state == TCP_TIME_WAIT) 253 inet_twsk_free(inet_twsk(sk)); 254 else if (sk->sk_state == TCP_NEW_SYN_RECV) 255 reqsk_free(inet_reqsk(sk)); 256 else 257 sk_free(sk); 258 } 259 EXPORT_SYMBOL_GPL(sock_gen_put); 260 261 void sock_edemux(struct sk_buff *skb) 262 { 263 sock_gen_put(skb->sk); 264 } 265 EXPORT_SYMBOL(sock_edemux); 266 267 struct sock *__inet_lookup_established(struct net *net, 268 struct inet_hashinfo *hashinfo, 269 const __be32 saddr, const __be16 sport, 270 const __be32 daddr, const u16 hnum, 271 const int dif) 272 { 273 INET_ADDR_COOKIE(acookie, saddr, daddr); 274 const __portpair ports = INET_COMBINED_PORTS(sport, hnum); 275 struct sock *sk; 276 const struct hlist_nulls_node *node; 277 /* Optimize here for direct hit, only listening connections can 278 * have wildcards anyways. 279 */ 280 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport); 281 unsigned int slot = hash & hashinfo->ehash_mask; 282 struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; 283 284 begin: 285 sk_nulls_for_each_rcu(sk, node, &head->chain) { 286 if (sk->sk_hash != hash) 287 continue; 288 if (likely(INET_MATCH(sk, net, acookie, 289 saddr, daddr, ports, dif))) { 290 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) 291 goto out; 292 if (unlikely(!INET_MATCH(sk, net, acookie, 293 saddr, daddr, ports, dif))) { 294 sock_gen_put(sk); 295 goto begin; 296 } 297 goto found; 298 } 299 } 300 /* 301 * if the nulls value we got at the end of this lookup is 302 * not the expected one, we must restart lookup. 303 * We probably met an item that was moved to another chain. 304 */ 305 if (get_nulls_value(node) != slot) 306 goto begin; 307 out: 308 sk = NULL; 309 found: 310 return sk; 311 } 312 EXPORT_SYMBOL_GPL(__inet_lookup_established); 313 314 /* called with local bh disabled */ 315 static int __inet_check_established(struct inet_timewait_death_row *death_row, 316 struct sock *sk, __u16 lport, 317 struct inet_timewait_sock **twp) 318 { 319 struct inet_hashinfo *hinfo = death_row->hashinfo; 320 struct inet_sock *inet = inet_sk(sk); 321 __be32 daddr = inet->inet_rcv_saddr; 322 __be32 saddr = inet->inet_daddr; 323 int dif = sk->sk_bound_dev_if; 324 INET_ADDR_COOKIE(acookie, saddr, daddr); 325 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); 326 struct net *net = sock_net(sk); 327 unsigned int hash = inet_ehashfn(net, daddr, lport, 328 saddr, inet->inet_dport); 329 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); 330 spinlock_t *lock = inet_ehash_lockp(hinfo, hash); 331 struct sock *sk2; 332 const struct hlist_nulls_node *node; 333 struct inet_timewait_sock *tw = NULL; 334 335 spin_lock(lock); 336 337 sk_nulls_for_each(sk2, node, &head->chain) { 338 if (sk2->sk_hash != hash) 339 continue; 340 341 if (likely(INET_MATCH(sk2, net, acookie, 342 saddr, daddr, ports, dif))) { 343 if (sk2->sk_state == TCP_TIME_WAIT) { 344 tw = inet_twsk(sk2); 345 if (twsk_unique(sk, sk2, twp)) 346 break; 347 } 348 goto not_unique; 349 } 350 } 351 352 /* Must record num and sport now. Otherwise we will see 353 * in hash table socket with a funny identity. 354 */ 355 inet->inet_num = lport; 356 inet->inet_sport = htons(lport); 357 sk->sk_hash = hash; 358 WARN_ON(!sk_unhashed(sk)); 359 __sk_nulls_add_node_rcu(sk, &head->chain); 360 if (tw) { 361 sk_nulls_del_node_init_rcu((struct sock *)tw); 362 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED); 363 } 364 spin_unlock(lock); 365 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 366 367 if (twp) { 368 *twp = tw; 369 } else if (tw) { 370 /* Silly. Should hash-dance instead... */ 371 inet_twsk_deschedule_put(tw); 372 } 373 return 0; 374 375 not_unique: 376 spin_unlock(lock); 377 return -EADDRNOTAVAIL; 378 } 379 380 static u32 inet_sk_port_offset(const struct sock *sk) 381 { 382 const struct inet_sock *inet = inet_sk(sk); 383 384 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr, 385 inet->inet_daddr, 386 inet->inet_dport); 387 } 388 389 /* insert a socket into ehash, and eventually remove another one 390 * (The another one can be a SYN_RECV or TIMEWAIT 391 */ 392 bool inet_ehash_insert(struct sock *sk, struct sock *osk) 393 { 394 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 395 struct hlist_nulls_head *list; 396 struct inet_ehash_bucket *head; 397 spinlock_t *lock; 398 bool ret = true; 399 400 WARN_ON_ONCE(!sk_unhashed(sk)); 401 402 sk->sk_hash = sk_ehashfn(sk); 403 head = inet_ehash_bucket(hashinfo, sk->sk_hash); 404 list = &head->chain; 405 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 406 407 spin_lock(lock); 408 if (osk) { 409 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); 410 ret = sk_nulls_del_node_init_rcu(osk); 411 } 412 if (ret) 413 __sk_nulls_add_node_rcu(sk, list); 414 spin_unlock(lock); 415 return ret; 416 } 417 418 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk) 419 { 420 bool ok = inet_ehash_insert(sk, osk); 421 422 if (ok) { 423 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 424 } else { 425 percpu_counter_inc(sk->sk_prot->orphan_count); 426 sk->sk_state = TCP_CLOSE; 427 sock_set_flag(sk, SOCK_DEAD); 428 inet_csk_destroy_sock(sk); 429 } 430 return ok; 431 } 432 EXPORT_SYMBOL_GPL(inet_ehash_nolisten); 433 434 static int inet_reuseport_add_sock(struct sock *sk, 435 struct inet_listen_hashbucket *ilb) 436 { 437 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; 438 struct sock *sk2; 439 kuid_t uid = sock_i_uid(sk); 440 441 sk_for_each_rcu(sk2, &ilb->head) { 442 if (sk2 != sk && 443 sk2->sk_family == sk->sk_family && 444 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 445 sk2->sk_bound_dev_if == sk->sk_bound_dev_if && 446 inet_csk(sk2)->icsk_bind_hash == tb && 447 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 448 inet_rcv_saddr_equal(sk, sk2, false)) 449 return reuseport_add_sock(sk, sk2); 450 } 451 452 /* Initial allocation may have already happened via setsockopt */ 453 if (!rcu_access_pointer(sk->sk_reuseport_cb)) 454 return reuseport_alloc(sk); 455 return 0; 456 } 457 458 int __inet_hash(struct sock *sk, struct sock *osk) 459 { 460 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 461 struct inet_listen_hashbucket *ilb; 462 int err = 0; 463 464 if (sk->sk_state != TCP_LISTEN) { 465 inet_ehash_nolisten(sk, osk); 466 return 0; 467 } 468 WARN_ON(!sk_unhashed(sk)); 469 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 470 471 spin_lock(&ilb->lock); 472 if (sk->sk_reuseport) { 473 err = inet_reuseport_add_sock(sk, ilb); 474 if (err) 475 goto unlock; 476 } 477 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 478 sk->sk_family == AF_INET6) 479 hlist_add_tail_rcu(&sk->sk_node, &ilb->head); 480 else 481 hlist_add_head_rcu(&sk->sk_node, &ilb->head); 482 sock_set_flag(sk, SOCK_RCU_FREE); 483 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 484 unlock: 485 spin_unlock(&ilb->lock); 486 487 return err; 488 } 489 EXPORT_SYMBOL(__inet_hash); 490 491 int inet_hash(struct sock *sk) 492 { 493 int err = 0; 494 495 if (sk->sk_state != TCP_CLOSE) { 496 local_bh_disable(); 497 err = __inet_hash(sk, NULL); 498 local_bh_enable(); 499 } 500 501 return err; 502 } 503 EXPORT_SYMBOL_GPL(inet_hash); 504 505 void inet_unhash(struct sock *sk) 506 { 507 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 508 spinlock_t *lock; 509 bool listener = false; 510 int done; 511 512 if (sk_unhashed(sk)) 513 return; 514 515 if (sk->sk_state == TCP_LISTEN) { 516 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock; 517 listener = true; 518 } else { 519 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 520 } 521 spin_lock_bh(lock); 522 if (rcu_access_pointer(sk->sk_reuseport_cb)) 523 reuseport_detach_sock(sk); 524 if (listener) 525 done = __sk_del_node_init(sk); 526 else 527 done = __sk_nulls_del_node_init_rcu(sk); 528 if (done) 529 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 530 spin_unlock_bh(lock); 531 } 532 EXPORT_SYMBOL_GPL(inet_unhash); 533 534 int __inet_hash_connect(struct inet_timewait_death_row *death_row, 535 struct sock *sk, u32 port_offset, 536 int (*check_established)(struct inet_timewait_death_row *, 537 struct sock *, __u16, struct inet_timewait_sock **)) 538 { 539 struct inet_hashinfo *hinfo = death_row->hashinfo; 540 struct inet_timewait_sock *tw = NULL; 541 struct inet_bind_hashbucket *head; 542 int port = inet_sk(sk)->inet_num; 543 struct net *net = sock_net(sk); 544 struct inet_bind_bucket *tb; 545 u32 remaining, offset; 546 int ret, i, low, high; 547 static u32 hint; 548 549 if (port) { 550 head = &hinfo->bhash[inet_bhashfn(net, port, 551 hinfo->bhash_size)]; 552 tb = inet_csk(sk)->icsk_bind_hash; 553 spin_lock_bh(&head->lock); 554 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { 555 inet_ehash_nolisten(sk, NULL); 556 spin_unlock_bh(&head->lock); 557 return 0; 558 } 559 spin_unlock(&head->lock); 560 /* No definite answer... Walk to established hash table */ 561 ret = check_established(death_row, sk, port, NULL); 562 local_bh_enable(); 563 return ret; 564 } 565 566 inet_get_local_port_range(net, &low, &high); 567 high++; /* [32768, 60999] -> [32768, 61000[ */ 568 remaining = high - low; 569 if (likely(remaining > 1)) 570 remaining &= ~1U; 571 572 offset = (hint + port_offset) % remaining; 573 /* In first pass we try ports of @low parity. 574 * inet_csk_get_port() does the opposite choice. 575 */ 576 offset &= ~1U; 577 other_parity_scan: 578 port = low + offset; 579 for (i = 0; i < remaining; i += 2, port += 2) { 580 if (unlikely(port >= high)) 581 port -= remaining; 582 if (inet_is_local_reserved_port(net, port)) 583 continue; 584 head = &hinfo->bhash[inet_bhashfn(net, port, 585 hinfo->bhash_size)]; 586 spin_lock_bh(&head->lock); 587 588 /* Does not bother with rcv_saddr checks, because 589 * the established check is already unique enough. 590 */ 591 inet_bind_bucket_for_each(tb, &head->chain) { 592 if (net_eq(ib_net(tb), net) && tb->port == port) { 593 if (tb->fastreuse >= 0 || 594 tb->fastreuseport >= 0) 595 goto next_port; 596 WARN_ON(hlist_empty(&tb->owners)); 597 if (!check_established(death_row, sk, 598 port, &tw)) 599 goto ok; 600 goto next_port; 601 } 602 } 603 604 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, 605 net, head, port); 606 if (!tb) { 607 spin_unlock_bh(&head->lock); 608 return -ENOMEM; 609 } 610 tb->fastreuse = -1; 611 tb->fastreuseport = -1; 612 goto ok; 613 next_port: 614 spin_unlock_bh(&head->lock); 615 cond_resched(); 616 } 617 618 offset++; 619 if ((offset & 1) && remaining > 1) 620 goto other_parity_scan; 621 622 return -EADDRNOTAVAIL; 623 624 ok: 625 hint += i + 2; 626 627 /* Head lock still held and bh's disabled */ 628 inet_bind_hash(sk, tb, port); 629 if (sk_unhashed(sk)) { 630 inet_sk(sk)->inet_sport = htons(port); 631 inet_ehash_nolisten(sk, (struct sock *)tw); 632 } 633 if (tw) 634 inet_twsk_bind_unhash(tw, hinfo); 635 spin_unlock(&head->lock); 636 if (tw) 637 inet_twsk_deschedule_put(tw); 638 local_bh_enable(); 639 return 0; 640 } 641 642 /* 643 * Bind a port for a connect operation and hash it. 644 */ 645 int inet_hash_connect(struct inet_timewait_death_row *death_row, 646 struct sock *sk) 647 { 648 u32 port_offset = 0; 649 650 if (!inet_sk(sk)->inet_num) 651 port_offset = inet_sk_port_offset(sk); 652 return __inet_hash_connect(death_row, sk, port_offset, 653 __inet_check_established); 654 } 655 EXPORT_SYMBOL_GPL(inet_hash_connect); 656 657 void inet_hashinfo_init(struct inet_hashinfo *h) 658 { 659 int i; 660 661 for (i = 0; i < INET_LHTABLE_SIZE; i++) { 662 spin_lock_init(&h->listening_hash[i].lock); 663 INIT_HLIST_HEAD(&h->listening_hash[i].head); 664 } 665 } 666 EXPORT_SYMBOL_GPL(inet_hashinfo_init); 667 668 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) 669 { 670 unsigned int locksz = sizeof(spinlock_t); 671 unsigned int i, nblocks = 1; 672 673 if (locksz != 0) { 674 /* allocate 2 cache lines or at least one spinlock per cpu */ 675 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); 676 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); 677 678 /* no more locks than number of hash buckets */ 679 nblocks = min(nblocks, hashinfo->ehash_mask + 1); 680 681 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); 682 if (!hashinfo->ehash_locks) 683 return -ENOMEM; 684 685 for (i = 0; i < nblocks; i++) 686 spin_lock_init(&hashinfo->ehash_locks[i]); 687 } 688 hashinfo->ehash_locks_mask = nblocks - 1; 689 return 0; 690 } 691 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); 692