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 #include <linux/memblock.h> 23 24 #include <net/addrconf.h> 25 #include <net/inet_connection_sock.h> 26 #include <net/inet_hashtables.h> 27 #include <net/secure_seq.h> 28 #include <net/ip.h> 29 #include <net/tcp.h> 30 #include <net/sock_reuseport.h> 31 32 static u32 inet_ehashfn(const struct net *net, const __be32 laddr, 33 const __u16 lport, const __be32 faddr, 34 const __be16 fport) 35 { 36 static u32 inet_ehash_secret __read_mostly; 37 38 net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret)); 39 40 return __inet_ehashfn(laddr, lport, faddr, fport, 41 inet_ehash_secret + net_hash_mix(net)); 42 } 43 44 /* This function handles inet_sock, but also timewait and request sockets 45 * for IPv4/IPv6. 46 */ 47 static u32 sk_ehashfn(const struct sock *sk) 48 { 49 #if IS_ENABLED(CONFIG_IPV6) 50 if (sk->sk_family == AF_INET6 && 51 !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) 52 return inet6_ehashfn(sock_net(sk), 53 &sk->sk_v6_rcv_saddr, sk->sk_num, 54 &sk->sk_v6_daddr, sk->sk_dport); 55 #endif 56 return inet_ehashfn(sock_net(sk), 57 sk->sk_rcv_saddr, sk->sk_num, 58 sk->sk_daddr, sk->sk_dport); 59 } 60 61 /* 62 * Allocate and initialize a new local port bind bucket. 63 * The bindhash mutex for snum's hash chain must be held here. 64 */ 65 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep, 66 struct net *net, 67 struct inet_bind_hashbucket *head, 68 const unsigned short snum) 69 { 70 struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC); 71 72 if (tb) { 73 write_pnet(&tb->ib_net, net); 74 tb->port = snum; 75 tb->fastreuse = 0; 76 tb->fastreuseport = 0; 77 INIT_HLIST_HEAD(&tb->owners); 78 hlist_add_head(&tb->node, &head->chain); 79 } 80 return tb; 81 } 82 83 /* 84 * Caller must hold hashbucket lock for this tb with local BH disabled 85 */ 86 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) 87 { 88 if (hlist_empty(&tb->owners)) { 89 __hlist_del(&tb->node); 90 kmem_cache_free(cachep, tb); 91 } 92 } 93 94 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, 95 const unsigned short snum) 96 { 97 inet_sk(sk)->inet_num = snum; 98 sk_add_bind_node(sk, &tb->owners); 99 inet_csk(sk)->icsk_bind_hash = tb; 100 } 101 102 /* 103 * Get rid of any references to a local port held by the given sock. 104 */ 105 static void __inet_put_port(struct sock *sk) 106 { 107 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 108 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num, 109 hashinfo->bhash_size); 110 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; 111 struct inet_bind_bucket *tb; 112 113 spin_lock(&head->lock); 114 tb = inet_csk(sk)->icsk_bind_hash; 115 __sk_del_bind_node(sk); 116 inet_csk(sk)->icsk_bind_hash = NULL; 117 inet_sk(sk)->inet_num = 0; 118 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); 119 spin_unlock(&head->lock); 120 } 121 122 void inet_put_port(struct sock *sk) 123 { 124 local_bh_disable(); 125 __inet_put_port(sk); 126 local_bh_enable(); 127 } 128 EXPORT_SYMBOL(inet_put_port); 129 130 int __inet_inherit_port(const struct sock *sk, struct sock *child) 131 { 132 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; 133 unsigned short port = inet_sk(child)->inet_num; 134 const int bhash = inet_bhashfn(sock_net(sk), port, 135 table->bhash_size); 136 struct inet_bind_hashbucket *head = &table->bhash[bhash]; 137 struct inet_bind_bucket *tb; 138 139 spin_lock(&head->lock); 140 tb = inet_csk(sk)->icsk_bind_hash; 141 if (unlikely(!tb)) { 142 spin_unlock(&head->lock); 143 return -ENOENT; 144 } 145 if (tb->port != port) { 146 /* NOTE: using tproxy and redirecting skbs to a proxy 147 * on a different listener port breaks the assumption 148 * that the listener socket's icsk_bind_hash is the same 149 * as that of the child socket. We have to look up or 150 * create a new bind bucket for the child here. */ 151 inet_bind_bucket_for_each(tb, &head->chain) { 152 if (net_eq(ib_net(tb), sock_net(sk)) && 153 tb->port == port) 154 break; 155 } 156 if (!tb) { 157 tb = inet_bind_bucket_create(table->bind_bucket_cachep, 158 sock_net(sk), head, port); 159 if (!tb) { 160 spin_unlock(&head->lock); 161 return -ENOMEM; 162 } 163 } 164 } 165 inet_bind_hash(child, tb, port); 166 spin_unlock(&head->lock); 167 168 return 0; 169 } 170 EXPORT_SYMBOL_GPL(__inet_inherit_port); 171 172 static struct inet_listen_hashbucket * 173 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk) 174 { 175 u32 hash; 176 177 #if IS_ENABLED(CONFIG_IPV6) 178 if (sk->sk_family == AF_INET6) 179 hash = ipv6_portaddr_hash(sock_net(sk), 180 &sk->sk_v6_rcv_saddr, 181 inet_sk(sk)->inet_num); 182 else 183 #endif 184 hash = ipv4_portaddr_hash(sock_net(sk), 185 inet_sk(sk)->inet_rcv_saddr, 186 inet_sk(sk)->inet_num); 187 return inet_lhash2_bucket(h, hash); 188 } 189 190 static void inet_hash2(struct inet_hashinfo *h, struct sock *sk) 191 { 192 struct inet_listen_hashbucket *ilb2; 193 194 if (!h->lhash2) 195 return; 196 197 ilb2 = inet_lhash2_bucket_sk(h, sk); 198 199 spin_lock(&ilb2->lock); 200 if (sk->sk_reuseport && sk->sk_family == AF_INET6) 201 hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, 202 &ilb2->head); 203 else 204 hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, 205 &ilb2->head); 206 ilb2->count++; 207 spin_unlock(&ilb2->lock); 208 } 209 210 static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk) 211 { 212 struct inet_listen_hashbucket *ilb2; 213 214 if (!h->lhash2 || 215 WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node))) 216 return; 217 218 ilb2 = inet_lhash2_bucket_sk(h, sk); 219 220 spin_lock(&ilb2->lock); 221 hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node); 222 ilb2->count--; 223 spin_unlock(&ilb2->lock); 224 } 225 226 static inline int compute_score(struct sock *sk, struct net *net, 227 const unsigned short hnum, const __be32 daddr, 228 const int dif, const int sdif, bool exact_dif) 229 { 230 int score = -1; 231 struct inet_sock *inet = inet_sk(sk); 232 233 if (net_eq(sock_net(sk), net) && inet->inet_num == hnum && 234 !ipv6_only_sock(sk)) { 235 __be32 rcv_saddr = inet->inet_rcv_saddr; 236 score = sk->sk_family == PF_INET ? 2 : 1; 237 if (rcv_saddr) { 238 if (rcv_saddr != daddr) 239 return -1; 240 score += 4; 241 } 242 if (sk->sk_bound_dev_if || exact_dif) { 243 bool dev_match = (sk->sk_bound_dev_if == dif || 244 sk->sk_bound_dev_if == sdif); 245 246 if (!dev_match) 247 return -1; 248 if (sk->sk_bound_dev_if) 249 score += 4; 250 } 251 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 252 score++; 253 } 254 return score; 255 } 256 257 /* 258 * Here are some nice properties to exploit here. The BSD API 259 * does not allow a listening sock to specify the remote port nor the 260 * remote address for the connection. So always assume those are both 261 * wildcarded during the search since they can never be otherwise. 262 */ 263 264 /* called with rcu_read_lock() : No refcount taken on the socket */ 265 static struct sock *inet_lhash2_lookup(struct net *net, 266 struct inet_listen_hashbucket *ilb2, 267 struct sk_buff *skb, int doff, 268 const __be32 saddr, __be16 sport, 269 const __be32 daddr, const unsigned short hnum, 270 const int dif, const int sdif) 271 { 272 bool exact_dif = inet_exact_dif_match(net, skb); 273 struct inet_connection_sock *icsk; 274 struct sock *sk, *result = NULL; 275 int score, hiscore = 0; 276 u32 phash = 0; 277 278 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { 279 sk = (struct sock *)icsk; 280 score = compute_score(sk, net, hnum, daddr, 281 dif, sdif, exact_dif); 282 if (score > hiscore) { 283 if (sk->sk_reuseport) { 284 phash = inet_ehashfn(net, daddr, hnum, 285 saddr, sport); 286 result = reuseport_select_sock(sk, phash, 287 skb, doff); 288 if (result) 289 return result; 290 } 291 result = sk; 292 hiscore = score; 293 } 294 } 295 296 return result; 297 } 298 299 struct sock *__inet_lookup_listener(struct net *net, 300 struct inet_hashinfo *hashinfo, 301 struct sk_buff *skb, int doff, 302 const __be32 saddr, __be16 sport, 303 const __be32 daddr, const unsigned short hnum, 304 const int dif, const int sdif) 305 { 306 unsigned int hash = inet_lhashfn(net, hnum); 307 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; 308 bool exact_dif = inet_exact_dif_match(net, skb); 309 struct inet_listen_hashbucket *ilb2; 310 struct sock *sk, *result = NULL; 311 int score, hiscore = 0; 312 unsigned int hash2; 313 u32 phash = 0; 314 315 if (ilb->count <= 10 || !hashinfo->lhash2) 316 goto port_lookup; 317 318 /* Too many sk in the ilb bucket (which is hashed by port alone). 319 * Try lhash2 (which is hashed by port and addr) instead. 320 */ 321 322 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 323 ilb2 = inet_lhash2_bucket(hashinfo, hash2); 324 if (ilb2->count > ilb->count) 325 goto port_lookup; 326 327 result = inet_lhash2_lookup(net, ilb2, skb, doff, 328 saddr, sport, daddr, hnum, 329 dif, sdif); 330 if (result) 331 goto done; 332 333 /* Lookup lhash2 with INADDR_ANY */ 334 335 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 336 ilb2 = inet_lhash2_bucket(hashinfo, hash2); 337 if (ilb2->count > ilb->count) 338 goto port_lookup; 339 340 result = inet_lhash2_lookup(net, ilb2, skb, doff, 341 saddr, sport, daddr, hnum, 342 dif, sdif); 343 goto done; 344 345 port_lookup: 346 sk_for_each_rcu(sk, &ilb->head) { 347 score = compute_score(sk, net, hnum, daddr, 348 dif, sdif, exact_dif); 349 if (score > hiscore) { 350 if (sk->sk_reuseport) { 351 phash = inet_ehashfn(net, daddr, hnum, 352 saddr, sport); 353 result = reuseport_select_sock(sk, phash, 354 skb, doff); 355 if (result) 356 goto done; 357 } 358 result = sk; 359 hiscore = score; 360 } 361 } 362 done: 363 if (unlikely(IS_ERR(result))) 364 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 void sock_gen_put(struct sock *sk) 371 { 372 if (!refcount_dec_and_test(&sk->sk_refcnt)) 373 return; 374 375 if (sk->sk_state == TCP_TIME_WAIT) 376 inet_twsk_free(inet_twsk(sk)); 377 else if (sk->sk_state == TCP_NEW_SYN_RECV) 378 reqsk_free(inet_reqsk(sk)); 379 else 380 sk_free(sk); 381 } 382 EXPORT_SYMBOL_GPL(sock_gen_put); 383 384 void sock_edemux(struct sk_buff *skb) 385 { 386 sock_gen_put(skb->sk); 387 } 388 EXPORT_SYMBOL(sock_edemux); 389 390 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 INET_ADDR_COOKIE(acookie, saddr, daddr); 397 const __portpair ports = INET_COMBINED_PORTS(sport, hnum); 398 struct sock *sk; 399 const struct hlist_nulls_node *node; 400 /* Optimize here for direct hit, only listening connections can 401 * have wildcards anyways. 402 */ 403 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport); 404 unsigned int slot = hash & hashinfo->ehash_mask; 405 struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; 406 407 begin: 408 sk_nulls_for_each_rcu(sk, node, &head->chain) { 409 if (sk->sk_hash != hash) 410 continue; 411 if (likely(INET_MATCH(sk, net, acookie, 412 saddr, daddr, ports, dif, sdif))) { 413 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) 414 goto out; 415 if (unlikely(!INET_MATCH(sk, net, acookie, 416 saddr, daddr, ports, 417 dif, sdif))) { 418 sock_gen_put(sk); 419 goto begin; 420 } 421 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 if (get_nulls_value(node) != slot) 430 goto begin; 431 out: 432 sk = NULL; 433 found: 434 return sk; 435 } 436 EXPORT_SYMBOL_GPL(__inet_lookup_established); 437 438 /* called with local bh disabled */ 439 static int __inet_check_established(struct inet_timewait_death_row *death_row, 440 struct sock *sk, __u16 lport, 441 struct inet_timewait_sock **twp) 442 { 443 struct inet_hashinfo *hinfo = death_row->hashinfo; 444 struct inet_sock *inet = inet_sk(sk); 445 __be32 daddr = inet->inet_rcv_saddr; 446 __be32 saddr = inet->inet_daddr; 447 int dif = sk->sk_bound_dev_if; 448 struct net *net = sock_net(sk); 449 int sdif = l3mdev_master_ifindex_by_index(net, dif); 450 INET_ADDR_COOKIE(acookie, saddr, daddr); 451 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); 452 unsigned int hash = inet_ehashfn(net, daddr, lport, 453 saddr, inet->inet_dport); 454 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); 455 spinlock_t *lock = inet_ehash_lockp(hinfo, hash); 456 struct sock *sk2; 457 const struct hlist_nulls_node *node; 458 struct inet_timewait_sock *tw = NULL; 459 460 spin_lock(lock); 461 462 sk_nulls_for_each(sk2, node, &head->chain) { 463 if (sk2->sk_hash != hash) 464 continue; 465 466 if (likely(INET_MATCH(sk2, net, acookie, 467 saddr, daddr, ports, dif, sdif))) { 468 if (sk2->sk_state == TCP_TIME_WAIT) { 469 tw = inet_twsk(sk2); 470 if (twsk_unique(sk, sk2, twp)) 471 break; 472 } 473 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 inet->inet_num = lport; 481 inet->inet_sport = htons(lport); 482 sk->sk_hash = hash; 483 WARN_ON(!sk_unhashed(sk)); 484 __sk_nulls_add_node_rcu(sk, &head->chain); 485 if (tw) { 486 sk_nulls_del_node_init_rcu((struct sock *)tw); 487 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED); 488 } 489 spin_unlock(lock); 490 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 491 492 if (twp) { 493 *twp = tw; 494 } else if (tw) { 495 /* Silly. Should hash-dance instead... */ 496 inet_twsk_deschedule_put(tw); 497 } 498 return 0; 499 500 not_unique: 501 spin_unlock(lock); 502 return -EADDRNOTAVAIL; 503 } 504 505 static u32 inet_sk_port_offset(const struct sock *sk) 506 { 507 const struct inet_sock *inet = inet_sk(sk); 508 509 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr, 510 inet->inet_daddr, 511 inet->inet_dport); 512 } 513 514 /* insert a socket into ehash, and eventually remove another one 515 * (The another one can be a SYN_RECV or TIMEWAIT 516 */ 517 bool inet_ehash_insert(struct sock *sk, struct sock *osk) 518 { 519 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 520 struct hlist_nulls_head *list; 521 struct inet_ehash_bucket *head; 522 spinlock_t *lock; 523 bool ret = true; 524 525 WARN_ON_ONCE(!sk_unhashed(sk)); 526 527 sk->sk_hash = sk_ehashfn(sk); 528 head = inet_ehash_bucket(hashinfo, sk->sk_hash); 529 list = &head->chain; 530 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 531 532 spin_lock(lock); 533 if (osk) { 534 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); 535 ret = sk_nulls_del_node_init_rcu(osk); 536 } 537 if (ret) 538 __sk_nulls_add_node_rcu(sk, list); 539 spin_unlock(lock); 540 return ret; 541 } 542 543 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk) 544 { 545 bool ok = inet_ehash_insert(sk, osk); 546 547 if (ok) { 548 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 549 } else { 550 percpu_counter_inc(sk->sk_prot->orphan_count); 551 inet_sk_set_state(sk, TCP_CLOSE); 552 sock_set_flag(sk, SOCK_DEAD); 553 inet_csk_destroy_sock(sk); 554 } 555 return ok; 556 } 557 EXPORT_SYMBOL_GPL(inet_ehash_nolisten); 558 559 static int inet_reuseport_add_sock(struct sock *sk, 560 struct inet_listen_hashbucket *ilb) 561 { 562 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; 563 struct sock *sk2; 564 kuid_t uid = sock_i_uid(sk); 565 566 sk_for_each_rcu(sk2, &ilb->head) { 567 if (sk2 != sk && 568 sk2->sk_family == sk->sk_family && 569 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 570 sk2->sk_bound_dev_if == sk->sk_bound_dev_if && 571 inet_csk(sk2)->icsk_bind_hash == tb && 572 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 573 inet_rcv_saddr_equal(sk, sk2, false)) 574 return reuseport_add_sock(sk, sk2, 575 inet_rcv_saddr_any(sk)); 576 } 577 578 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 579 } 580 581 int __inet_hash(struct sock *sk, struct sock *osk) 582 { 583 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 584 struct inet_listen_hashbucket *ilb; 585 int err = 0; 586 587 if (sk->sk_state != TCP_LISTEN) { 588 inet_ehash_nolisten(sk, osk); 589 return 0; 590 } 591 WARN_ON(!sk_unhashed(sk)); 592 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 593 594 spin_lock(&ilb->lock); 595 if (sk->sk_reuseport) { 596 err = inet_reuseport_add_sock(sk, ilb); 597 if (err) 598 goto unlock; 599 } 600 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 601 sk->sk_family == AF_INET6) 602 hlist_add_tail_rcu(&sk->sk_node, &ilb->head); 603 else 604 hlist_add_head_rcu(&sk->sk_node, &ilb->head); 605 inet_hash2(hashinfo, sk); 606 ilb->count++; 607 sock_set_flag(sk, SOCK_RCU_FREE); 608 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 609 unlock: 610 spin_unlock(&ilb->lock); 611 612 return err; 613 } 614 EXPORT_SYMBOL(__inet_hash); 615 616 int inet_hash(struct sock *sk) 617 { 618 int err = 0; 619 620 if (sk->sk_state != TCP_CLOSE) { 621 local_bh_disable(); 622 err = __inet_hash(sk, NULL); 623 local_bh_enable(); 624 } 625 626 return err; 627 } 628 EXPORT_SYMBOL_GPL(inet_hash); 629 630 void inet_unhash(struct sock *sk) 631 { 632 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 633 struct inet_listen_hashbucket *ilb = NULL; 634 spinlock_t *lock; 635 636 if (sk_unhashed(sk)) 637 return; 638 639 if (sk->sk_state == TCP_LISTEN) { 640 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 641 lock = &ilb->lock; 642 } else { 643 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 644 } 645 spin_lock_bh(lock); 646 if (sk_unhashed(sk)) 647 goto unlock; 648 649 if (rcu_access_pointer(sk->sk_reuseport_cb)) 650 reuseport_detach_sock(sk); 651 if (ilb) { 652 inet_unhash2(hashinfo, sk); 653 __sk_del_node_init(sk); 654 ilb->count--; 655 } else { 656 __sk_nulls_del_node_init_rcu(sk); 657 } 658 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 659 unlock: 660 spin_unlock_bh(lock); 661 } 662 EXPORT_SYMBOL_GPL(inet_unhash); 663 664 int __inet_hash_connect(struct inet_timewait_death_row *death_row, 665 struct sock *sk, u32 port_offset, 666 int (*check_established)(struct inet_timewait_death_row *, 667 struct sock *, __u16, struct inet_timewait_sock **)) 668 { 669 struct inet_hashinfo *hinfo = death_row->hashinfo; 670 struct inet_timewait_sock *tw = NULL; 671 struct inet_bind_hashbucket *head; 672 int port = inet_sk(sk)->inet_num; 673 struct net *net = sock_net(sk); 674 struct inet_bind_bucket *tb; 675 u32 remaining, offset; 676 int ret, i, low, high; 677 static u32 hint; 678 679 if (port) { 680 head = &hinfo->bhash[inet_bhashfn(net, port, 681 hinfo->bhash_size)]; 682 tb = inet_csk(sk)->icsk_bind_hash; 683 spin_lock_bh(&head->lock); 684 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { 685 inet_ehash_nolisten(sk, NULL); 686 spin_unlock_bh(&head->lock); 687 return 0; 688 } 689 spin_unlock(&head->lock); 690 /* No definite answer... Walk to established hash table */ 691 ret = check_established(death_row, sk, port, NULL); 692 local_bh_enable(); 693 return ret; 694 } 695 696 inet_get_local_port_range(net, &low, &high); 697 high++; /* [32768, 60999] -> [32768, 61000[ */ 698 remaining = high - low; 699 if (likely(remaining > 1)) 700 remaining &= ~1U; 701 702 offset = (hint + port_offset) % remaining; 703 /* In first pass we try ports of @low parity. 704 * inet_csk_get_port() does the opposite choice. 705 */ 706 offset &= ~1U; 707 other_parity_scan: 708 port = low + offset; 709 for (i = 0; i < remaining; i += 2, port += 2) { 710 if (unlikely(port >= high)) 711 port -= remaining; 712 if (inet_is_local_reserved_port(net, port)) 713 continue; 714 head = &hinfo->bhash[inet_bhashfn(net, port, 715 hinfo->bhash_size)]; 716 spin_lock_bh(&head->lock); 717 718 /* Does not bother with rcv_saddr checks, because 719 * the established check is already unique enough. 720 */ 721 inet_bind_bucket_for_each(tb, &head->chain) { 722 if (net_eq(ib_net(tb), net) && tb->port == port) { 723 if (tb->fastreuse >= 0 || 724 tb->fastreuseport >= 0) 725 goto next_port; 726 WARN_ON(hlist_empty(&tb->owners)); 727 if (!check_established(death_row, sk, 728 port, &tw)) 729 goto ok; 730 goto next_port; 731 } 732 } 733 734 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, 735 net, head, port); 736 if (!tb) { 737 spin_unlock_bh(&head->lock); 738 return -ENOMEM; 739 } 740 tb->fastreuse = -1; 741 tb->fastreuseport = -1; 742 goto ok; 743 next_port: 744 spin_unlock_bh(&head->lock); 745 cond_resched(); 746 } 747 748 offset++; 749 if ((offset & 1) && remaining > 1) 750 goto other_parity_scan; 751 752 return -EADDRNOTAVAIL; 753 754 ok: 755 hint += i + 2; 756 757 /* Head lock still held and bh's disabled */ 758 inet_bind_hash(sk, tb, port); 759 if (sk_unhashed(sk)) { 760 inet_sk(sk)->inet_sport = htons(port); 761 inet_ehash_nolisten(sk, (struct sock *)tw); 762 } 763 if (tw) 764 inet_twsk_bind_unhash(tw, hinfo); 765 spin_unlock(&head->lock); 766 if (tw) 767 inet_twsk_deschedule_put(tw); 768 local_bh_enable(); 769 return 0; 770 } 771 772 /* 773 * Bind a port for a connect operation and hash it. 774 */ 775 int inet_hash_connect(struct inet_timewait_death_row *death_row, 776 struct sock *sk) 777 { 778 u32 port_offset = 0; 779 780 if (!inet_sk(sk)->inet_num) 781 port_offset = inet_sk_port_offset(sk); 782 return __inet_hash_connect(death_row, sk, port_offset, 783 __inet_check_established); 784 } 785 EXPORT_SYMBOL_GPL(inet_hash_connect); 786 787 void inet_hashinfo_init(struct inet_hashinfo *h) 788 { 789 int i; 790 791 for (i = 0; i < INET_LHTABLE_SIZE; i++) { 792 spin_lock_init(&h->listening_hash[i].lock); 793 INIT_HLIST_HEAD(&h->listening_hash[i].head); 794 h->listening_hash[i].count = 0; 795 } 796 797 h->lhash2 = NULL; 798 } 799 EXPORT_SYMBOL_GPL(inet_hashinfo_init); 800 801 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, 802 unsigned long numentries, int scale, 803 unsigned long low_limit, 804 unsigned long high_limit) 805 { 806 unsigned int i; 807 808 h->lhash2 = alloc_large_system_hash(name, 809 sizeof(*h->lhash2), 810 numentries, 811 scale, 812 0, 813 NULL, 814 &h->lhash2_mask, 815 low_limit, 816 high_limit); 817 818 for (i = 0; i <= h->lhash2_mask; i++) { 819 spin_lock_init(&h->lhash2[i].lock); 820 INIT_HLIST_HEAD(&h->lhash2[i].head); 821 h->lhash2[i].count = 0; 822 } 823 } 824 825 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) 826 { 827 unsigned int locksz = sizeof(spinlock_t); 828 unsigned int i, nblocks = 1; 829 830 if (locksz != 0) { 831 /* allocate 2 cache lines or at least one spinlock per cpu */ 832 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); 833 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); 834 835 /* no more locks than number of hash buckets */ 836 nblocks = min(nblocks, hashinfo->ehash_mask + 1); 837 838 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); 839 if (!hashinfo->ehash_locks) 840 return -ENOMEM; 841 842 for (i = 0; i < nblocks; i++) 843 spin_lock_init(&hashinfo->ehash_locks[i]); 844 } 845 hashinfo->ehash_locks_mask = nblocks - 1; 846 return 0; 847 } 848 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); 849