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 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                 tb->num_owners = 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         tb->num_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         tb->num_owners--;
 118         inet_csk(sk)->icsk_bind_hash = NULL;
 119         inet_sk(sk)->inet_num = 0;
 120         inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
 121         spin_unlock(&head->lock);
 122 }
 123
 124 void inet_put_port(struct sock *sk)
 125 {
 126         local_bh_disable();
 127         __inet_put_port(sk);
 128         local_bh_enable();
 129 }
 130 EXPORT_SYMBOL(inet_put_port);
 131
 132 int __inet_inherit_port(const struct sock *sk, struct sock *child)
 133 {
 134         struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
 135         unsigned short port = inet_sk(child)->inet_num;
 136         const int bhash = inet_bhashfn(sock_net(sk), port,
 137                         table->bhash_size);
 138         struct inet_bind_hashbucket *head = &table->bhash[bhash];
 139         struct inet_bind_bucket *tb;
 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                 /* NOTE: using tproxy and redirecting skbs to a proxy
 149                  * on a different listener port breaks the assumption
 150                  * that the listener socket's icsk_bind_hash is the same
 151                  * as that of the child socket. We have to look up or
 152                  * create a new bind bucket for the child here. */
 153                 inet_bind_bucket_for_each(tb, &head->chain) {
 154                         if (net_eq(ib_net(tb), sock_net(sk)) &&
 155                             tb->port == port)
 156                                 break;
 157                 }
 158                 if (!tb) {
 159                         tb = inet_bind_bucket_create(table->bind_bucket_cachep,
 160                                                      sock_net(sk), head, port);
 161                         if (!tb) {
 162                                 spin_unlock(&head->lock);
 163                                 return -ENOMEM;
 164                         }
 165                 }
 166                 inet_csk_update_fastreuse(tb, child);
 167         }
 168         inet_bind_hash(child, tb, port);
 169         spin_unlock(&head->lock);
 170
 171         return 0;
 172 }
 173 EXPORT_SYMBOL_GPL(__inet_inherit_port);
 174
 175 static inline int compute_score(struct sock *sk, struct net *net,
 176                                 const unsigned short hnum, const __be32 daddr,
 177                                 const int dif, bool exact_dif)
 178 {
 179         int score = -1;
 180         struct inet_sock *inet = inet_sk(sk);
 181
 182         if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
 183                         !ipv6_only_sock(sk)) {
 184                 __be32 rcv_saddr = inet->inet_rcv_saddr;
 185                 score = sk->sk_family == PF_INET ? 2 : 1;
 186                 if (rcv_saddr) {
 187                         if (rcv_saddr != daddr)
 188                                 return -1;
 189                         score += 4;
 190                 }
 191                 if (sk->sk_bound_dev_if || exact_dif) {
 192                         if (sk->sk_bound_dev_if != dif)
 193                                 return -1;
 194                         score += 4;
 195                 }
 196                 if (sk->sk_incoming_cpu == raw_smp_processor_id())
 197                         score++;
 198         }
 199         return score;
 200 }
 201
 202 /*
 203  * Here are some nice properties to exploit here. The BSD API
 204  * does not allow a listening sock to specify the remote port nor the
 205  * remote address for the connection. So always assume those are both
 206  * wildcarded during the search since they can never be otherwise.
 207  */
 208
 209 /* called with rcu_read_lock() : No refcount taken on the socket */
 210 struct sock *__inet_lookup_listener(struct net *net,
 211                                     struct inet_hashinfo *hashinfo,
 212                                     struct sk_buff *skb, int doff,
 213                                     const __be32 saddr, __be16 sport,
 214                                     const __be32 daddr, const unsigned short hnum,
 215                                     const int dif)
 216 {
 217         unsigned int hash = inet_lhashfn(net, hnum);
 218         struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
 219         int score, hiscore = 0, matches = 0, reuseport = 0;
 220         bool exact_dif = inet_exact_dif_match(net, skb);
 221         struct sock *sk, *result = NULL;
 222         struct hlist_nulls_node *node;
 223         u32 phash = 0;
 224
 225         sk_nulls_for_each_rcu(sk, node, &ilb->nulls_head) {
 226                 score = compute_score(sk, net, hnum, daddr, dif, exact_dif);
 227                 if (score > hiscore) {
 228                         reuseport = sk->sk_reuseport;
 229                         if (reuseport) {
 230                                 phash = inet_ehashfn(net, daddr, hnum,
 231                                                      saddr, sport);
 232                                 result = reuseport_select_sock(sk, phash,
 233                                                                skb, doff);
 234                                 if (result)
 235                                         return result;
 236                                 matches = 1;
 237                         }
 238                         result = sk;
 239                         hiscore = score;
 240                 } else if (score == hiscore && reuseport) {
 241                         matches++;
 242                         if (reciprocal_scale(phash, matches) == 0)
 243                                 result = sk;
 244                         phash = next_pseudo_random32(phash);
 245                 }
 246         }
 247         return result;
 248 }
 249 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 250
 251 /* All sockets share common refcount, but have different destructors */
 252 void sock_gen_put(struct sock *sk)
 253 {
 254         if (!atomic_dec_and_test(&sk->sk_refcnt))
 255                 return;
 256
 257         if (sk->sk_state == TCP_TIME_WAIT)
 258                 inet_twsk_free(inet_twsk(sk));
 259         else if (sk->sk_state == TCP_NEW_SYN_RECV)
 260                 reqsk_free(inet_reqsk(sk));
 261         else
 262                 sk_free(sk);
 263 }
 264 EXPORT_SYMBOL_GPL(sock_gen_put);
 265
 266 void sock_edemux(struct sk_buff *skb)
 267 {
 268         sock_gen_put(skb->sk);
 269 }
 270 EXPORT_SYMBOL(sock_edemux);
 271
 272 struct sock *__inet_lookup_established(struct net *net,
 273                                   struct inet_hashinfo *hashinfo,
 274                                   const __be32 saddr, const __be16 sport,
 275                                   const __be32 daddr, const u16 hnum,
 276                                   const int dif)
 277 {
 278         INET_ADDR_COOKIE(acookie, saddr, daddr);
 279         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
 280         struct sock *sk;
 281         const struct hlist_nulls_node *node;
 282         /* Optimize here for direct hit, only listening connections can
 283          * have wildcards anyways.
 284          */
 285         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
 286         unsigned int slot = hash & hashinfo->ehash_mask;
 287         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
 288
 289 begin:
 290         sk_nulls_for_each_rcu(sk, node, &head->chain) {
 291                 if (sk->sk_hash != hash)
 292                         continue;
 293                 if (likely(INET_MATCH(sk, net, acookie,
 294                                       saddr, daddr, ports, dif))) {
 295                         if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
 296                                 goto out;
 297                         if (unlikely(!INET_MATCH(sk, net, acookie,
 298                                                  saddr, daddr, ports, dif))) {
 299                                 sock_gen_put(sk);
 300                                 goto begin;
 301                         }
 302                         goto found;
 303                 }
 304         }
 305         /*
 306          * if the nulls value we got at the end of this lookup is
 307          * not the expected one, we must restart lookup.
 308          * We probably met an item that was moved to another chain.
 309          */
 310         if (get_nulls_value(node) != slot)
 311                 goto begin;
 312 out:
 313         sk = NULL;
 314 found:
 315         return sk;
 316 }
 317 EXPORT_SYMBOL_GPL(__inet_lookup_established);
 318
 319 /* called with local bh disabled */
 320 static int __inet_check_established(struct inet_timewait_death_row *death_row,
 321                                     struct sock *sk, __u16 lport,
 322                                     struct inet_timewait_sock **twp)
 323 {
 324         struct inet_hashinfo *hinfo = death_row->hashinfo;
 325         struct inet_sock *inet = inet_sk(sk);
 326         __be32 daddr = inet->inet_rcv_saddr;
 327         __be32 saddr = inet->inet_daddr;
 328         int dif = sk->sk_bound_dev_if;
 329         INET_ADDR_COOKIE(acookie, saddr, daddr);
 330         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 331         struct net *net = sock_net(sk);
 332         unsigned int hash = inet_ehashfn(net, daddr, lport,
 333                                          saddr, inet->inet_dport);
 334         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
 335         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
 336         struct sock *sk2;
 337         const struct hlist_nulls_node *node;
 338         struct inet_timewait_sock *tw = NULL;
 339
 340         spin_lock(lock);
 341
 342         sk_nulls_for_each(sk2, node, &head->chain) {
 343                 if (sk2->sk_hash != hash)
 344                         continue;
 345
 346                 if (likely(INET_MATCH(sk2, net, acookie,
 347                                          saddr, daddr, ports, dif))) {
 348                         if (sk2->sk_state == TCP_TIME_WAIT) {
 349                                 tw = inet_twsk(sk2);
 350                                 if (twsk_unique(sk, sk2, twp))
 351                                         break;
 352                         }
 353                         goto not_unique;
 354                 }
 355         }
 356
 357         /* Must record num and sport now. Otherwise we will see
 358          * in hash table socket with a funny identity.
 359          */
 360         inet->inet_num = lport;
 361         inet->inet_sport = htons(lport);
 362         sk->sk_hash = hash;
 363         WARN_ON(!sk_unhashed(sk));
 364         __sk_nulls_add_node_rcu(sk, &head->chain);
 365         if (tw) {
 366                 sk_nulls_del_node_init_rcu((struct sock *)tw);
 367                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
 368         }
 369         spin_unlock(lock);
 370         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 371
 372         if (twp) {
 373                 *twp = tw;
 374         } else if (tw) {
 375                 /* Silly. Should hash-dance instead... */
 376                 inet_twsk_deschedule_put(tw);
 377         }
 378         return 0;
 379
 380 not_unique:
 381         spin_unlock(lock);
 382         return -EADDRNOTAVAIL;
 383 }
 384
 385 static u32 inet_sk_port_offset(const struct sock *sk)
 386 {
 387         const struct inet_sock *inet = inet_sk(sk);
 388
 389         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
 390                                           inet->inet_daddr,
 391                                           inet->inet_dport);
 392 }
 393
 394 /* insert a socket into ehash, and eventually remove another one
 395  * (The another one can be a SYN_RECV or TIMEWAIT
 396  */
 397 bool inet_ehash_insert(struct sock *sk, struct sock *osk)
 398 {
 399         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 400         struct hlist_nulls_head *list;
 401         struct inet_ehash_bucket *head;
 402         spinlock_t *lock;
 403         bool ret = true;
 404
 405         WARN_ON_ONCE(!sk_unhashed(sk));
 406
 407         sk->sk_hash = sk_ehashfn(sk);
 408         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
 409         list = &head->chain;
 410         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 411
 412         spin_lock(lock);
 413         if (osk) {
 414                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
 415                 ret = sk_nulls_del_node_init_rcu(osk);
 416         }
 417         if (ret)
 418                 __sk_nulls_add_node_rcu(sk, list);
 419         spin_unlock(lock);
 420         return ret;
 421 }
 422
 423 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
 424 {
 425         bool ok = inet_ehash_insert(sk, osk);
 426
 427         if (ok) {
 428                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 429         } else {
 430                 percpu_counter_inc(sk->sk_prot->orphan_count);
 431                 sk->sk_state = TCP_CLOSE;
 432                 sock_set_flag(sk, SOCK_DEAD);
 433                 inet_csk_destroy_sock(sk);
 434         }
 435         return ok;
 436 }
 437 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 438
 439 static int inet_reuseport_add_sock(struct sock *sk,
 440                                    struct inet_listen_hashbucket *ilb,
 441                                    int (*saddr_same)(const struct sock *sk1,
 442                                                      const struct sock *sk2,
 443                                                      bool match_wildcard))
 444 {
 445         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
 446         const struct hlist_nulls_node *node;
 447         struct sock *sk2;
 448         kuid_t uid = sock_i_uid(sk);
 449
 450         sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
 451                 if (sk2 != sk &&
 452                     sk2->sk_family == sk->sk_family &&
 453                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
 454                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
 455                     inet_csk(sk2)->icsk_bind_hash == tb &&
 456                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
 457                     saddr_same(sk, sk2, false))
 458                         return reuseport_add_sock(sk, sk2);
 459         }
 460
 461         return reuseport_alloc(sk);
 462 }
 463
 464 int __inet_hash(struct sock *sk, struct sock *osk,
 465                  int (*saddr_same)(const struct sock *sk1,
 466                                    const struct sock *sk2,
 467                                    bool match_wildcard))
 468 {
 469         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 470         struct inet_listen_hashbucket *ilb;
 471         int err = 0;
 472
 473         if (sk->sk_state != TCP_LISTEN) {
 474                 inet_ehash_nolisten(sk, osk);
 475                 return 0;
 476         }
 477         WARN_ON(!sk_unhashed(sk));
 478         ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
 479
 480         spin_lock(&ilb->lock);
 481         if (sk->sk_reuseport) {
 482                 err = inet_reuseport_add_sock(sk, ilb, saddr_same);
 483                 if (err)
 484                         goto unlock;
 485         }
 486         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 487                 sk->sk_family == AF_INET6)
 488                 __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
 489         else
 490                 __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
 491         sock_set_flag(sk, SOCK_RCU_FREE);
 492         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 493 unlock:
 494         spin_unlock(&ilb->lock);
 495
 496         return err;
 497 }
 498 EXPORT_SYMBOL(__inet_hash);
 499
 500 int inet_hash(struct sock *sk)
 501 {
 502         int err = 0;
 503
 504         if (sk->sk_state != TCP_CLOSE) {
 505                 local_bh_disable();
 506                 err = __inet_hash(sk, NULL, ipv4_rcv_saddr_equal);
 507                 local_bh_enable();
 508         }
 509
 510         return err;
 511 }
 512 EXPORT_SYMBOL_GPL(inet_hash);
 513
 514 void inet_unhash(struct sock *sk)
 515 {
 516         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 517         spinlock_t *lock;
 518         bool listener = false;
 519         int done;
 520
 521         if (sk_unhashed(sk))
 522                 return;
 523
 524         if (sk->sk_state == TCP_LISTEN) {
 525                 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock;
 526                 listener = true;
 527         } else {
 528                 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 529         }
 530         spin_lock_bh(lock);
 531         if (rcu_access_pointer(sk->sk_reuseport_cb))
 532                 reuseport_detach_sock(sk);
 533         done = __sk_nulls_del_node_init_rcu(sk);
 534         if (done)
 535                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 536         spin_unlock_bh(lock);
 537 }
 538 EXPORT_SYMBOL_GPL(inet_unhash);
 539
 540 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 541                 struct sock *sk, u32 port_offset,
 542                 int (*check_established)(struct inet_timewait_death_row *,
 543                         struct sock *, __u16, struct inet_timewait_sock **))
 544 {
 545         struct inet_hashinfo *hinfo = death_row->hashinfo;
 546         struct inet_timewait_sock *tw = NULL;
 547         struct inet_bind_hashbucket *head;
 548         int port = inet_sk(sk)->inet_num;
 549         struct net *net = sock_net(sk);
 550         struct inet_bind_bucket *tb;
 551         u32 remaining, offset;
 552         int ret, i, low, high;
 553         static u32 hint;
 554
 555         if (port) {
 556                 head = &hinfo->bhash[inet_bhashfn(net, port,
 557                                                   hinfo->bhash_size)];
 558                 tb = inet_csk(sk)->icsk_bind_hash;
 559                 spin_lock_bh(&head->lock);
 560                 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
 561                         inet_ehash_nolisten(sk, NULL);
 562                         spin_unlock_bh(&head->lock);
 563                         return 0;
 564                 }
 565                 spin_unlock(&head->lock);
 566                 /* No definite answer... Walk to established hash table */
 567                 ret = check_established(death_row, sk, port, NULL);
 568                 local_bh_enable();
 569                 return ret;
 570         }
 571
 572         inet_get_local_port_range(net, &low, &high);
 573         high++; /* [32768, 60999] -> [32768, 61000[ */
 574         remaining = high - low;
 575         if (likely(remaining > 1))
 576                 remaining &= ~1U;
 577
 578         offset = (hint + port_offset) % remaining;
 579         /* In first pass we try ports of @low parity.
 580          * inet_csk_get_port() does the opposite choice.
 581          */
 582         offset &= ~1U;
 583 other_parity_scan:
 584         port = low + offset;
 585         for (i = 0; i < remaining; i += 2, port += 2) {
 586                 if (unlikely(port >= high))
 587                         port -= remaining;
 588                 if (inet_is_local_reserved_port(net, port))
 589                         continue;
 590                 head = &hinfo->bhash[inet_bhashfn(net, port,
 591                                                   hinfo->bhash_size)];
 592                 spin_lock_bh(&head->lock);
 593
 594                 /* Does not bother with rcv_saddr checks, because
 595                  * the established check is already unique enough.
 596                  */
 597                 inet_bind_bucket_for_each(tb, &head->chain) {
 598                         if (net_eq(ib_net(tb), net) && tb->port == port) {
 599                                 if (tb->fastreuse >= 0 ||
 600                                     tb->fastreuseport >= 0)
 601                                         goto next_port;
 602                                 WARN_ON(hlist_empty(&tb->owners));
 603                                 if (!check_established(death_row, sk,
 604                                                        port, &tw))
 605                                         goto ok;
 606                                 goto next_port;
 607                         }
 608                 }
 609
 610                 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
 611                                              net, head, port);
 612                 if (!tb) {
 613                         spin_unlock_bh(&head->lock);
 614                         return -ENOMEM;
 615                 }
 616                 tb->fastreuse = -1;
 617                 tb->fastreuseport = -1;
 618                 goto ok;
 619 next_port:
 620                 spin_unlock_bh(&head->lock);
 621                 cond_resched();
 622         }
 623
 624         offset++;
 625         if ((offset & 1) && remaining > 1)
 626                 goto other_parity_scan;
 627
 628         return -EADDRNOTAVAIL;
 629
 630 ok:
 631         hint += i + 2;
 632
 633         /* Head lock still held and bh's disabled */
 634         inet_bind_hash(sk, tb, port);
 635         if (sk_unhashed(sk)) {
 636                 inet_sk(sk)->inet_sport = htons(port);
 637                 inet_ehash_nolisten(sk, (struct sock *)tw);
 638         }
 639         if (tw)
 640                 inet_twsk_bind_unhash(tw, hinfo);
 641         spin_unlock(&head->lock);
 642         if (tw)
 643                 inet_twsk_deschedule_put(tw);
 644         local_bh_enable();
 645         return 0;
 646 }
 647
 648 /*
 649  * Bind a port for a connect operation and hash it.
 650  */
 651 int inet_hash_connect(struct inet_timewait_death_row *death_row,
 652                       struct sock *sk)
 653 {
 654         u32 port_offset = 0;
 655
 656         if (!inet_sk(sk)->inet_num)
 657                 port_offset = inet_sk_port_offset(sk);
 658         return __inet_hash_connect(death_row, sk, port_offset,
 659                                    __inet_check_established);
 660 }
 661 EXPORT_SYMBOL_GPL(inet_hash_connect);
 662
 663 void inet_hashinfo_init(struct inet_hashinfo *h)
 664 {
 665         int i;
 666
 667         for (i = 0; i < INET_LHTABLE_SIZE; i++) {
 668                 spin_lock_init(&h->listening_hash[i].lock);
 669                 INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
 670                                       i + LISTENING_NULLS_BASE);
 671         }
 672 }
 673 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
 674
 675 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
 676 {
 677         unsigned int locksz = sizeof(spinlock_t);
 678         unsigned int i, nblocks = 1;
 679
 680         if (locksz != 0) {
 681                 /* allocate 2 cache lines or at least one spinlock per cpu */
 682                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
 683                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
 684
 685                 /* no more locks than number of hash buckets */
 686                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
 687
 688                 hashinfo->ehash_locks = kmalloc_array(nblocks, locksz,
 689                                                       GFP_KERNEL | __GFP_NOWARN);
 690                 if (!hashinfo->ehash_locks)
 691                         hashinfo->ehash_locks = vmalloc(nblocks * locksz);
 692
 693                 if (!hashinfo->ehash_locks)
 694                         return -ENOMEM;
 695
 696                 for (i = 0; i < nblocks; i++)
 697                         spin_lock_init(&hashinfo->ehash_locks[i]);
 698         }
 699         hashinfo->ehash_locks_mask = nblocks - 1;
 700         return 0;
 701 }
 702 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);