net/ipv4/inet_hashtables.c

   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                 inet_csk_update_fastreuse(tb, child);
 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 inline int compute_score(struct sock *sk, struct net *net,
 173                                 const unsigned short hnum, const __be32 daddr,
 174                                 const int dif, const int sdif, bool exact_dif)
 175 {
 176         int score = -1;
 177         struct inet_sock *inet = inet_sk(sk);
 178
 179         if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
 180                         !ipv6_only_sock(sk)) {
 181                 __be32 rcv_saddr = inet->inet_rcv_saddr;
 182                 score = sk->sk_family == PF_INET ? 2 : 1;
 183                 if (rcv_saddr) {
 184                         if (rcv_saddr != daddr)
 185                                 return -1;
 186                         score += 4;
 187                 }
 188                 if (sk->sk_bound_dev_if || exact_dif) {
 189                         bool dev_match = (sk->sk_bound_dev_if == dif ||
 190                                           sk->sk_bound_dev_if == sdif);
 191
 192                         if (!dev_match)
 193                                 return -1;
 194                         if (sk->sk_bound_dev_if)
 195                                 score += 4;
 196                 }
 197                 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 198                         score++;
 199         }
 200         return score;
 201 }
 202
 203 /*
 204  * Here are some nice properties to exploit here. The BSD API
 205  * does not allow a listening sock to specify the remote port nor the
 206  * remote address for the connection. So always assume those are both
 207  * wildcarded during the search since they can never be otherwise.
 208  */
 209
 210 /* called with rcu_read_lock() : No refcount taken on the socket */
 211 struct sock *__inet_lookup_listener(struct net *net,
 212                                     struct inet_hashinfo *hashinfo,
 213                                     struct sk_buff *skb, int doff,
 214                                     const __be32 saddr, __be16 sport,
 215                                     const __be32 daddr, const unsigned short hnum,
 216                                     const int dif, const int sdif)
 217 {
 218         unsigned int hash = inet_lhashfn(net, hnum);
 219         struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
 220         int score, hiscore = 0, matches = 0, reuseport = 0;
 221         bool exact_dif = inet_exact_dif_match(net, skb);
 222         struct sock *sk, *result = NULL;
 223         struct hlist_nulls_node *node;
 224         u32 phash = 0;
 225
 226         sk_nulls_for_each_rcu(sk, node, &ilb->nulls_head) {
 227                 score = compute_score(sk, net, hnum, daddr,
 228                                       dif, sdif, exact_dif);
 229                 if (score > hiscore) {
 230                         reuseport = sk->sk_reuseport;
 231                         if (reuseport) {
 232                                 phash = inet_ehashfn(net, daddr, hnum,
 233                                                      saddr, sport);
 234                                 result = reuseport_select_sock(sk, phash,
 235                                                                skb, doff);
 236                                 if (result)
 237                                         return result;
 238                                 matches = 1;
 239                         }
 240                         result = sk;
 241                         hiscore = score;
 242                 } else if (score == hiscore && reuseport) {
 243                         matches++;
 244                         if (reciprocal_scale(phash, matches) == 0)
 245                                 result = sk;
 246                         phash = next_pseudo_random32(phash);
 247                 }
 248         }
 249         return result;
 250 }
 251 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 252
 253 /* All sockets share common refcount, but have different destructors */
 254 void sock_gen_put(struct sock *sk)
 255 {
 256         if (!refcount_dec_and_test(&sk->sk_refcnt))
 257                 return;
 258
 259         if (sk->sk_state == TCP_TIME_WAIT)
 260                 inet_twsk_free(inet_twsk(sk));
 261         else if (sk->sk_state == TCP_NEW_SYN_RECV)
 262                 reqsk_free(inet_reqsk(sk));
 263         else
 264                 sk_free(sk);
 265 }
 266 EXPORT_SYMBOL_GPL(sock_gen_put);
 267
 268 void sock_edemux(struct sk_buff *skb)
 269 {
 270         sock_gen_put(skb->sk);
 271 }
 272 EXPORT_SYMBOL(sock_edemux);
 273
 274 struct sock *__inet_lookup_established(struct net *net,
 275                                   struct inet_hashinfo *hashinfo,
 276                                   const __be32 saddr, const __be16 sport,
 277                                   const __be32 daddr, const u16 hnum,
 278                                   const int dif, const int sdif)
 279 {
 280         INET_ADDR_COOKIE(acookie, saddr, daddr);
 281         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
 282         struct sock *sk;
 283         const struct hlist_nulls_node *node;
 284         /* Optimize here for direct hit, only listening connections can
 285          * have wildcards anyways.
 286          */
 287         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
 288         unsigned int slot = hash & hashinfo->ehash_mask;
 289         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
 290
 291 begin:
 292         sk_nulls_for_each_rcu(sk, node, &head->chain) {
 293                 if (sk->sk_hash != hash)
 294                         continue;
 295                 if (likely(INET_MATCH(sk, net, acookie,
 296                                       saddr, daddr, ports, dif, sdif))) {
 297                         if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 298                                 goto out;
 299                         if (unlikely(!INET_MATCH(sk, net, acookie,
 300                                                  saddr, daddr, ports,
 301                                                  dif, sdif))) {
 302                                 sock_gen_put(sk);
 303                                 goto begin;
 304                         }
 305                         goto found;
 306                 }
 307         }
 308         /*
 309          * if the nulls value we got at the end of this lookup is
 310          * not the expected one, we must restart lookup.
 311          * We probably met an item that was moved to another chain.
 312          */
 313         if (get_nulls_value(node) != slot)
 314                 goto begin;
 315 out:
 316         sk = NULL;
 317 found:
 318         return sk;
 319 }
 320 EXPORT_SYMBOL_GPL(__inet_lookup_established);
 321
 322 /* called with local bh disabled */
 323 static int __inet_check_established(struct inet_timewait_death_row *death_row,
 324                                     struct sock *sk, __u16 lport,
 325                                     struct inet_timewait_sock **twp)
 326 {
 327         struct inet_hashinfo *hinfo = death_row->hashinfo;
 328         struct inet_sock *inet = inet_sk(sk);
 329         __be32 daddr = inet->inet_rcv_saddr;
 330         __be32 saddr = inet->inet_daddr;
 331         int dif = sk->sk_bound_dev_if;
 332         struct net *net = sock_net(sk);
 333         int sdif = l3mdev_master_ifindex_by_index(net, dif);
 334         INET_ADDR_COOKIE(acookie, saddr, daddr);
 335         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 336         unsigned int hash = inet_ehashfn(net, daddr, lport,
 337                                          saddr, inet->inet_dport);
 338         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
 339         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
 340         struct sock *sk2;
 341         const struct hlist_nulls_node *node;
 342         struct inet_timewait_sock *tw = NULL;
 343
 344         spin_lock(lock);
 345
 346         sk_nulls_for_each(sk2, node, &head->chain) {
 347                 if (sk2->sk_hash != hash)
 348                         continue;
 349
 350                 if (likely(INET_MATCH(sk2, net, acookie,
 351                                          saddr, daddr, ports, dif, sdif))) {
 352                         if (sk2->sk_state == TCP_TIME_WAIT) {
 353                                 tw = inet_twsk(sk2);
 354                                 if (twsk_unique(sk, sk2, twp))
 355                                         break;
 356                         }
 357                         goto not_unique;
 358                 }
 359         }
 360
 361         /* Must record num and sport now. Otherwise we will see
 362          * in hash table socket with a funny identity.
 363          */
 364         inet->inet_num = lport;
 365         inet->inet_sport = htons(lport);
 366         sk->sk_hash = hash;
 367         WARN_ON(!sk_unhashed(sk));
 368         __sk_nulls_add_node_rcu(sk, &head->chain);
 369         if (tw) {
 370                 sk_nulls_del_node_init_rcu((struct sock *)tw);
 371                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
 372         }
 373         spin_unlock(lock);
 374         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 375
 376         if (twp) {
 377                 *twp = tw;
 378         } else if (tw) {
 379                 /* Silly. Should hash-dance instead... */
 380                 inet_twsk_deschedule_put(tw);
 381         }
 382         return 0;
 383
 384 not_unique:
 385         spin_unlock(lock);
 386         return -EADDRNOTAVAIL;
 387 }
 388
 389 static u32 inet_sk_port_offset(const struct sock *sk)
 390 {
 391         const struct inet_sock *inet = inet_sk(sk);
 392
 393         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
 394                                           inet->inet_daddr,
 395                                           inet->inet_dport);
 396 }
 397
 398 /* insert a socket into ehash, and eventually remove another one
 399  * (The another one can be a SYN_RECV or TIMEWAIT
 400  */
 401 bool inet_ehash_insert(struct sock *sk, struct sock *osk)
 402 {
 403         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 404         struct hlist_nulls_head *list;
 405         struct inet_ehash_bucket *head;
 406         spinlock_t *lock;
 407         bool ret = true;
 408
 409         WARN_ON_ONCE(!sk_unhashed(sk));
 410
 411         sk->sk_hash = sk_ehashfn(sk);
 412         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
 413         list = &head->chain;
 414         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 415
 416         spin_lock(lock);
 417         if (osk) {
 418                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
 419                 ret = sk_nulls_del_node_init_rcu(osk);
 420         }
 421         if (ret)
 422                 __sk_nulls_add_node_rcu(sk, list);
 423         spin_unlock(lock);
 424         return ret;
 425 }
 426
 427 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
 428 {
 429         bool ok = inet_ehash_insert(sk, osk);
 430
 431         if (ok) {
 432                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 433         } else {
 434                 percpu_counter_inc(sk->sk_prot->orphan_count);
 435                 sk->sk_state = TCP_CLOSE;
 436                 sock_set_flag(sk, SOCK_DEAD);
 437                 inet_csk_destroy_sock(sk);
 438         }
 439         return ok;
 440 }
 441 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 442
 443 static int inet_reuseport_add_sock(struct sock *sk,
 444                                    struct inet_listen_hashbucket *ilb)
 445 {
 446         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
 447         const struct hlist_nulls_node *node;
 448         struct sock *sk2;
 449         kuid_t uid = sock_i_uid(sk);
 450
 451         sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
 452                 if (sk2 != sk &&
 453                     sk2->sk_family == sk->sk_family &&
 454                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
 455                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
 456                     inet_csk(sk2)->icsk_bind_hash == tb &&
 457                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
 458                     inet_rcv_saddr_equal(sk, sk2, false))
 459                         return reuseport_add_sock(sk, sk2);
 460         }
 461
 462         return reuseport_alloc(sk);
 463 }
 464
 465 int __inet_hash(struct sock *sk, struct sock *osk)
 466 {
 467         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 468         struct inet_listen_hashbucket *ilb;
 469         int err = 0;
 470
 471         if (sk->sk_state != TCP_LISTEN) {
 472                 inet_ehash_nolisten(sk, osk);
 473                 return 0;
 474         }
 475         WARN_ON(!sk_unhashed(sk));
 476         ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
 477
 478         spin_lock(&ilb->lock);
 479         if (sk->sk_reuseport) {
 480                 err = inet_reuseport_add_sock(sk, ilb);
 481                 if (err)
 482                         goto unlock;
 483         }
 484         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 485                 sk->sk_family == AF_INET6)
 486                 __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
 487         else
 488                 __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
 489         sock_set_flag(sk, SOCK_RCU_FREE);
 490         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 491 unlock:
 492         spin_unlock(&ilb->lock);
 493
 494         return err;
 495 }
 496 EXPORT_SYMBOL(__inet_hash);
 497
 498 int inet_hash(struct sock *sk)
 499 {
 500         int err = 0;
 501
 502         if (sk->sk_state != TCP_CLOSE) {
 503                 local_bh_disable();
 504                 err = __inet_hash(sk, NULL);
 505                 local_bh_enable();
 506         }
 507
 508         return err;
 509 }
 510 EXPORT_SYMBOL_GPL(inet_hash);
 511
 512 void inet_unhash(struct sock *sk)
 513 {
 514         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 515         spinlock_t *lock;
 516         bool listener = false;
 517         int done;
 518
 519         if (sk_unhashed(sk))
 520                 return;
 521
 522         if (sk->sk_state == TCP_LISTEN) {
 523                 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock;
 524                 listener = true;
 525         } else {
 526                 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 527         }
 528         spin_lock_bh(lock);
 529         if (rcu_access_pointer(sk->sk_reuseport_cb))
 530                 reuseport_detach_sock(sk);
 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_NULLS_HEAD(&h->listening_hash[i].nulls_head,
 668                                       i + LISTENING_NULLS_BASE);
 669         }
 670 }
 671 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
 672
 673 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
 674 {
 675         unsigned int locksz = sizeof(spinlock_t);
 676         unsigned int i, nblocks = 1;
 677
 678         if (locksz != 0) {
 679                 /* allocate 2 cache lines or at least one spinlock per cpu */
 680                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
 681                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
 682
 683                 /* no more locks than number of hash buckets */
 684                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
 685
 686                 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
 687                 if (!hashinfo->ehash_locks)
 688                         return -ENOMEM;
 689
 690                 for (i = 0; i < nblocks; i++)
 691                         spin_lock_init(&hashinfo->ehash_locks[i]);
 692         }
 693         hashinfo->ehash_locks_mask = nblocks - 1;
 694         return 0;
 695 }
 696 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);