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 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 int l3mdev) 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->l3mdev = l3mdev; 75 tb->port = snum; 76 tb->fastreuse = 0; 77 tb->fastreuseport = 0; 78 INIT_HLIST_HEAD(&tb->owners); 79 hlist_add_head(&tb->node, &head->chain); 80 } 81 return tb; 82 } 83 84 /* 85 * Caller must hold hashbucket lock for this tb with local BH disabled 86 */ 87 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) 88 { 89 if (hlist_empty(&tb->owners)) { 90 __hlist_del(&tb->node); 91 kmem_cache_free(cachep, tb); 92 } 93 } 94 95 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, 96 const unsigned short snum) 97 { 98 inet_sk(sk)->inet_num = snum; 99 sk_add_bind_node(sk, &tb->owners); 100 inet_csk(sk)->icsk_bind_hash = tb; 101 } 102 103 /* 104 * Get rid of any references to a local port held by the given sock. 105 */ 106 static void __inet_put_port(struct sock *sk) 107 { 108 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 109 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num, 110 hashinfo->bhash_size); 111 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; 112 struct inet_bind_bucket *tb; 113 114 spin_lock(&head->lock); 115 tb = inet_csk(sk)->icsk_bind_hash; 116 __sk_del_bind_node(sk); 117 inet_csk(sk)->icsk_bind_hash = NULL; 118 inet_sk(sk)->inet_num = 0; 119 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); 120 spin_unlock(&head->lock); 121 } 122 123 void inet_put_port(struct sock *sk) 124 { 125 local_bh_disable(); 126 __inet_put_port(sk); 127 local_bh_enable(); 128 } 129 EXPORT_SYMBOL(inet_put_port); 130 131 int __inet_inherit_port(const struct sock *sk, struct sock *child) 132 { 133 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; 134 unsigned short port = inet_sk(child)->inet_num; 135 const int bhash = inet_bhashfn(sock_net(sk), port, 136 table->bhash_size); 137 struct inet_bind_hashbucket *head = &table->bhash[bhash]; 138 struct inet_bind_bucket *tb; 139 int l3mdev; 140 141 spin_lock(&head->lock); 142 tb = inet_csk(sk)->icsk_bind_hash; 143 if (unlikely(!tb)) { 144 spin_unlock(&head->lock); 145 return -ENOENT; 146 } 147 if (tb->port != port) { 148 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 inet_bind_bucket_for_each(tb, &head->chain) { 156 if (net_eq(ib_net(tb), sock_net(sk)) && 157 tb->l3mdev == l3mdev && tb->port == port) 158 break; 159 } 160 if (!tb) { 161 tb = inet_bind_bucket_create(table->bind_bucket_cachep, 162 sock_net(sk), head, port, 163 l3mdev); 164 if (!tb) { 165 spin_unlock(&head->lock); 166 return -ENOMEM; 167 } 168 } 169 inet_csk_update_fastreuse(tb, child); 170 } 171 inet_bind_hash(child, tb, port); 172 spin_unlock(&head->lock); 173 174 return 0; 175 } 176 EXPORT_SYMBOL_GPL(__inet_inherit_port); 177 178 static struct inet_listen_hashbucket * 179 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk) 180 { 181 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 hash = ipv4_portaddr_hash(sock_net(sk), 191 inet_sk(sk)->inet_rcv_saddr, 192 inet_sk(sk)->inet_num); 193 return inet_lhash2_bucket(h, hash); 194 } 195 196 static void inet_hash2(struct inet_hashinfo *h, struct sock *sk) 197 { 198 struct inet_listen_hashbucket *ilb2; 199 200 if (!h->lhash2) 201 return; 202 203 ilb2 = inet_lhash2_bucket_sk(h, sk); 204 205 spin_lock(&ilb2->lock); 206 if (sk->sk_reuseport && sk->sk_family == AF_INET6) 207 hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, 208 &ilb2->head); 209 else 210 hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, 211 &ilb2->head); 212 ilb2->count++; 213 spin_unlock(&ilb2->lock); 214 } 215 216 static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk) 217 { 218 struct inet_listen_hashbucket *ilb2; 219 220 if (!h->lhash2 || 221 WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node))) 222 return; 223 224 ilb2 = inet_lhash2_bucket_sk(h, sk); 225 226 spin_lock(&ilb2->lock); 227 hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node); 228 ilb2->count--; 229 spin_unlock(&ilb2->lock); 230 } 231 232 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 int score = -1; 237 238 if (net_eq(sock_net(sk), net) && sk->sk_num == hnum && 239 !ipv6_only_sock(sk)) { 240 if (sk->sk_rcv_saddr != daddr) 241 return -1; 242 243 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) 244 return -1; 245 246 score = sk->sk_family == PF_INET ? 2 : 1; 247 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) 248 score++; 249 } 250 return score; 251 } 252 253 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 struct sock *reuse_sk = NULL; 259 u32 phash; 260 261 if (sk->sk_reuseport) { 262 phash = inet_ehashfn(net, daddr, hnum, saddr, sport); 263 reuse_sk = reuseport_select_sock(sk, phash, skb, doff); 264 } 265 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 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 struct inet_connection_sock *icsk; 284 struct sock *sk, *result = NULL; 285 int score, hiscore = 0; 286 287 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { 288 sk = (struct sock *)icsk; 289 score = compute_score(sk, net, hnum, daddr, dif, sdif); 290 if (score > hiscore) { 291 result = lookup_reuseport(net, sk, skb, doff, 292 saddr, sport, daddr, hnum); 293 if (result) 294 return result; 295 296 result = sk; 297 hiscore = score; 298 } 299 } 300 301 return result; 302 } 303 304 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 struct sock *sk, *reuse_sk; 311 bool no_reuseport; 312 313 if (hashinfo != &tcp_hashinfo) 314 return NULL; /* only TCP is supported */ 315 316 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP, 317 saddr, sport, daddr, hnum, &sk); 318 if (no_reuseport || IS_ERR_OR_NULL(sk)) 319 return sk; 320 321 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum); 322 if (reuse_sk) 323 sk = reuse_sk; 324 return sk; 325 } 326 327 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 struct inet_listen_hashbucket *ilb2; 335 struct sock *result = NULL; 336 unsigned int hash2; 337 338 /* Lookup redirect from BPF */ 339 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { 340 result = inet_lookup_run_bpf(net, hashinfo, skb, doff, 341 saddr, sport, daddr, hnum); 342 if (result) 343 goto done; 344 } 345 346 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 347 ilb2 = inet_lhash2_bucket(hashinfo, hash2); 348 349 result = inet_lhash2_lookup(net, ilb2, skb, doff, 350 saddr, sport, daddr, hnum, 351 dif, sdif); 352 if (result) 353 goto done; 354 355 /* Lookup lhash2 with INADDR_ANY */ 356 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 357 ilb2 = inet_lhash2_bucket(hashinfo, hash2); 358 359 result = inet_lhash2_lookup(net, ilb2, skb, doff, 360 saddr, sport, htonl(INADDR_ANY), hnum, 361 dif, sdif); 362 done: 363 if (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 /* Searches for an exsiting socket in the ehash bucket list. 515 * Returns true if found, false otherwise. 516 */ 517 static bool inet_ehash_lookup_by_sk(struct sock *sk, 518 struct hlist_nulls_head *list) 519 { 520 const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num); 521 const int sdif = sk->sk_bound_dev_if; 522 const int dif = sk->sk_bound_dev_if; 523 const struct hlist_nulls_node *node; 524 struct net *net = sock_net(sk); 525 struct sock *esk; 526 527 INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr); 528 529 sk_nulls_for_each_rcu(esk, node, list) { 530 if (esk->sk_hash != sk->sk_hash) 531 continue; 532 if (sk->sk_family == AF_INET) { 533 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 bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk) 560 { 561 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 562 struct hlist_nulls_head *list; 563 struct inet_ehash_bucket *head; 564 spinlock_t *lock; 565 bool ret = true; 566 567 WARN_ON_ONCE(!sk_unhashed(sk)); 568 569 sk->sk_hash = sk_ehashfn(sk); 570 head = inet_ehash_bucket(hashinfo, sk->sk_hash); 571 list = &head->chain; 572 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 573 574 spin_lock(lock); 575 if (osk) { 576 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); 577 ret = sk_nulls_del_node_init_rcu(osk); 578 } else if (found_dup_sk) { 579 *found_dup_sk = inet_ehash_lookup_by_sk(sk, list); 580 if (*found_dup_sk) 581 ret = false; 582 } 583 584 if (ret) 585 __sk_nulls_add_node_rcu(sk, list); 586 587 spin_unlock(lock); 588 589 return ret; 590 } 591 592 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk) 593 { 594 bool ok = inet_ehash_insert(sk, osk, found_dup_sk); 595 596 if (ok) { 597 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 598 } else { 599 percpu_counter_inc(sk->sk_prot->orphan_count); 600 inet_sk_set_state(sk, TCP_CLOSE); 601 sock_set_flag(sk, SOCK_DEAD); 602 inet_csk_destroy_sock(sk); 603 } 604 return ok; 605 } 606 EXPORT_SYMBOL_GPL(inet_ehash_nolisten); 607 608 static int inet_reuseport_add_sock(struct sock *sk, 609 struct inet_listen_hashbucket *ilb) 610 { 611 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; 612 const struct hlist_nulls_node *node; 613 struct sock *sk2; 614 kuid_t uid = sock_i_uid(sk); 615 616 sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) { 617 if (sk2 != sk && 618 sk2->sk_family == sk->sk_family && 619 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 620 sk2->sk_bound_dev_if == sk->sk_bound_dev_if && 621 inet_csk(sk2)->icsk_bind_hash == tb && 622 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 623 inet_rcv_saddr_equal(sk, sk2, false)) 624 return reuseport_add_sock(sk, sk2, 625 inet_rcv_saddr_any(sk)); 626 } 627 628 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 629 } 630 631 int __inet_hash(struct sock *sk, struct sock *osk) 632 { 633 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 634 struct inet_listen_hashbucket *ilb; 635 int err = 0; 636 637 if (sk->sk_state != TCP_LISTEN) { 638 inet_ehash_nolisten(sk, osk, NULL); 639 return 0; 640 } 641 WARN_ON(!sk_unhashed(sk)); 642 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 643 644 spin_lock(&ilb->lock); 645 if (sk->sk_reuseport) { 646 err = inet_reuseport_add_sock(sk, ilb); 647 if (err) 648 goto unlock; 649 } 650 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 __sk_nulls_add_node_rcu(sk, &ilb->nulls_head); 655 inet_hash2(hashinfo, sk); 656 ilb->count++; 657 sock_set_flag(sk, SOCK_RCU_FREE); 658 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 659 unlock: 660 spin_unlock(&ilb->lock); 661 662 return err; 663 } 664 EXPORT_SYMBOL(__inet_hash); 665 666 int inet_hash(struct sock *sk) 667 { 668 int err = 0; 669 670 if (sk->sk_state != TCP_CLOSE) { 671 local_bh_disable(); 672 err = __inet_hash(sk, NULL); 673 local_bh_enable(); 674 } 675 676 return err; 677 } 678 EXPORT_SYMBOL_GPL(inet_hash); 679 680 void inet_unhash(struct sock *sk) 681 { 682 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 683 struct inet_listen_hashbucket *ilb = NULL; 684 spinlock_t *lock; 685 686 if (sk_unhashed(sk)) 687 return; 688 689 if (sk->sk_state == TCP_LISTEN) { 690 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; 691 lock = &ilb->lock; 692 } else { 693 lock = inet_ehash_lockp(hashinfo, sk->sk_hash); 694 } 695 spin_lock_bh(lock); 696 if (sk_unhashed(sk)) 697 goto unlock; 698 699 if (rcu_access_pointer(sk->sk_reuseport_cb)) 700 reuseport_detach_sock(sk); 701 if (ilb) { 702 inet_unhash2(hashinfo, sk); 703 ilb->count--; 704 } 705 __sk_nulls_del_node_init_rcu(sk); 706 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 707 unlock: 708 spin_unlock_bh(lock); 709 } 710 EXPORT_SYMBOL_GPL(inet_unhash); 711 712 int __inet_hash_connect(struct inet_timewait_death_row *death_row, 713 struct sock *sk, u32 port_offset, 714 int (*check_established)(struct inet_timewait_death_row *, 715 struct sock *, __u16, struct inet_timewait_sock **)) 716 { 717 struct inet_hashinfo *hinfo = death_row->hashinfo; 718 struct inet_timewait_sock *tw = NULL; 719 struct inet_bind_hashbucket *head; 720 int port = inet_sk(sk)->inet_num; 721 struct net *net = sock_net(sk); 722 struct inet_bind_bucket *tb; 723 u32 remaining, offset; 724 int ret, i, low, high; 725 static u32 hint; 726 int l3mdev; 727 728 if (port) { 729 head = &hinfo->bhash[inet_bhashfn(net, port, 730 hinfo->bhash_size)]; 731 tb = inet_csk(sk)->icsk_bind_hash; 732 spin_lock_bh(&head->lock); 733 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { 734 inet_ehash_nolisten(sk, NULL, NULL); 735 spin_unlock_bh(&head->lock); 736 return 0; 737 } 738 spin_unlock(&head->lock); 739 /* No definite answer... Walk to established hash table */ 740 ret = check_established(death_row, sk, port, NULL); 741 local_bh_enable(); 742 return ret; 743 } 744 745 l3mdev = inet_sk_bound_l3mdev(sk); 746 747 inet_get_local_port_range(net, &low, &high); 748 high++; /* [32768, 60999] -> [32768, 61000[ */ 749 remaining = high - low; 750 if (likely(remaining > 1)) 751 remaining &= ~1U; 752 753 offset = (hint + port_offset) % remaining; 754 /* In first pass we try ports of @low parity. 755 * inet_csk_get_port() does the opposite choice. 756 */ 757 offset &= ~1U; 758 other_parity_scan: 759 port = low + offset; 760 for (i = 0; i < remaining; i += 2, port += 2) { 761 if (unlikely(port >= high)) 762 port -= remaining; 763 if (inet_is_local_reserved_port(net, port)) 764 continue; 765 head = &hinfo->bhash[inet_bhashfn(net, port, 766 hinfo->bhash_size)]; 767 spin_lock_bh(&head->lock); 768 769 /* Does not bother with rcv_saddr checks, because 770 * the established check is already unique enough. 771 */ 772 inet_bind_bucket_for_each(tb, &head->chain) { 773 if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && 774 tb->port == port) { 775 if (tb->fastreuse >= 0 || 776 tb->fastreuseport >= 0) 777 goto next_port; 778 WARN_ON(hlist_empty(&tb->owners)); 779 if (!check_established(death_row, sk, 780 port, &tw)) 781 goto ok; 782 goto next_port; 783 } 784 } 785 786 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, 787 net, head, port, l3mdev); 788 if (!tb) { 789 spin_unlock_bh(&head->lock); 790 return -ENOMEM; 791 } 792 tb->fastreuse = -1; 793 tb->fastreuseport = -1; 794 goto ok; 795 next_port: 796 spin_unlock_bh(&head->lock); 797 cond_resched(); 798 } 799 800 offset++; 801 if ((offset & 1) && remaining > 1) 802 goto other_parity_scan; 803 804 return -EADDRNOTAVAIL; 805 806 ok: 807 hint += i + 2; 808 809 /* Head lock still held and bh's disabled */ 810 inet_bind_hash(sk, tb, port); 811 if (sk_unhashed(sk)) { 812 inet_sk(sk)->inet_sport = htons(port); 813 inet_ehash_nolisten(sk, (struct sock *)tw, NULL); 814 } 815 if (tw) 816 inet_twsk_bind_unhash(tw, hinfo); 817 spin_unlock(&head->lock); 818 if (tw) 819 inet_twsk_deschedule_put(tw); 820 local_bh_enable(); 821 return 0; 822 } 823 824 /* 825 * Bind a port for a connect operation and hash it. 826 */ 827 int inet_hash_connect(struct inet_timewait_death_row *death_row, 828 struct sock *sk) 829 { 830 u32 port_offset = 0; 831 832 if (!inet_sk(sk)->inet_num) 833 port_offset = inet_sk_port_offset(sk); 834 return __inet_hash_connect(death_row, sk, port_offset, 835 __inet_check_established); 836 } 837 EXPORT_SYMBOL_GPL(inet_hash_connect); 838 839 void inet_hashinfo_init(struct inet_hashinfo *h) 840 { 841 int i; 842 843 for (i = 0; i < INET_LHTABLE_SIZE; i++) { 844 spin_lock_init(&h->listening_hash[i].lock); 845 INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head, 846 i + LISTENING_NULLS_BASE); 847 h->listening_hash[i].count = 0; 848 } 849 850 h->lhash2 = NULL; 851 } 852 EXPORT_SYMBOL_GPL(inet_hashinfo_init); 853 854 static void init_hashinfo_lhash2(struct inet_hashinfo *h) 855 { 856 int i; 857 858 for (i = 0; i <= h->lhash2_mask; i++) { 859 spin_lock_init(&h->lhash2[i].lock); 860 INIT_HLIST_HEAD(&h->lhash2[i].head); 861 h->lhash2[i].count = 0; 862 } 863 } 864 865 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, 866 unsigned long numentries, int scale, 867 unsigned long low_limit, 868 unsigned long high_limit) 869 { 870 h->lhash2 = alloc_large_system_hash(name, 871 sizeof(*h->lhash2), 872 numentries, 873 scale, 874 0, 875 NULL, 876 &h->lhash2_mask, 877 low_limit, 878 high_limit); 879 init_hashinfo_lhash2(h); 880 } 881 882 int inet_hashinfo2_init_mod(struct inet_hashinfo *h) 883 { 884 h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL); 885 if (!h->lhash2) 886 return -ENOMEM; 887 888 h->lhash2_mask = INET_LHTABLE_SIZE - 1; 889 /* INET_LHTABLE_SIZE must be a power of 2 */ 890 BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask); 891 892 init_hashinfo_lhash2(h); 893 return 0; 894 } 895 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod); 896 897 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) 898 { 899 unsigned int locksz = sizeof(spinlock_t); 900 unsigned int i, nblocks = 1; 901 902 if (locksz != 0) { 903 /* allocate 2 cache lines or at least one spinlock per cpu */ 904 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); 905 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); 906 907 /* no more locks than number of hash buckets */ 908 nblocks = min(nblocks, hashinfo->ehash_mask + 1); 909 910 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); 911 if (!hashinfo->ehash_locks) 912 return -ENOMEM; 913 914 for (i = 0; i < nblocks; i++) 915 spin_lock_init(&hashinfo->ehash_locks[i]); 916 } 917 hashinfo->ehash_locks_mask = nblocks - 1; 918 return 0; 919 } 920 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); 921