net/ipv4/inet_hashtables.c

   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/hotdata.h>
  28 #include <net/ip.h>
  29 #include <net/tcp.h>
  30 #include <net/sock_reuseport.h>
  31
  32 u32 inet_ehashfn(const struct net *net, const __be32 laddr,
  33                  const __u16 lport, const __be32 faddr,
  34                  const __be16 fport)
  35 {
  36         net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
  37
  38         return __inet_ehashfn(laddr, lport, faddr, fport,
  39                               inet_ehash_secret + net_hash_mix(net));
  40 }
  41 EXPORT_SYMBOL_GPL(inet_ehashfn);
  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->bhash2);
  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->bhash2)) {
  90                 __hlist_del(&tb->node);
  91                 kmem_cache_free(cachep, tb);
  92         }
  93 }
  94
  95 bool inet_bind_bucket_match(const struct inet_bind_bucket *tb, const struct net *net,
  96                             unsigned short port, int l3mdev)
  97 {
  98         return net_eq(ib_net(tb), net) && tb->port == port &&
  99                 tb->l3mdev == l3mdev;
 100 }
 101
 102 static void inet_bind2_bucket_init(struct inet_bind2_bucket *tb2,
 103                                    struct net *net,
 104                                    struct inet_bind_hashbucket *head,
 105                                    struct inet_bind_bucket *tb,
 106                                    const struct sock *sk)
 107 {
 108         write_pnet(&tb2->ib_net, net);
 109         tb2->l3mdev = tb->l3mdev;
 110         tb2->port = tb->port;
 111 #if IS_ENABLED(CONFIG_IPV6)
 112         BUILD_BUG_ON(USHRT_MAX < (IPV6_ADDR_ANY | IPV6_ADDR_MAPPED));
 113         if (sk->sk_family == AF_INET6) {
 114                 tb2->addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
 115                 tb2->v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 116         } else {
 117                 tb2->addr_type = IPV6_ADDR_MAPPED;
 118                 ipv6_addr_set_v4mapped(sk->sk_rcv_saddr, &tb2->v6_rcv_saddr);
 119         }
 120 #else
 121         tb2->rcv_saddr = sk->sk_rcv_saddr;
 122 #endif
 123         INIT_HLIST_HEAD(&tb2->owners);
 124         hlist_add_head(&tb2->node, &head->chain);
 125         hlist_add_head(&tb2->bhash_node, &tb->bhash2);
 126 }
 127
 128 struct inet_bind2_bucket *inet_bind2_bucket_create(struct kmem_cache *cachep,
 129                                                    struct net *net,
 130                                                    struct inet_bind_hashbucket *head,
 131                                                    struct inet_bind_bucket *tb,
 132                                                    const struct sock *sk)
 133 {
 134         struct inet_bind2_bucket *tb2 = kmem_cache_alloc(cachep, GFP_ATOMIC);
 135
 136         if (tb2)
 137                 inet_bind2_bucket_init(tb2, net, head, tb, sk);
 138
 139         return tb2;
 140 }
 141
 142 /* Caller must hold hashbucket lock for this tb with local BH disabled */
 143 void inet_bind2_bucket_destroy(struct kmem_cache *cachep, struct inet_bind2_bucket *tb)
 144 {
 145         if (hlist_empty(&tb->owners)) {
 146                 __hlist_del(&tb->node);
 147                 __hlist_del(&tb->bhash_node);
 148                 kmem_cache_free(cachep, tb);
 149         }
 150 }
 151
 152 static bool inet_bind2_bucket_addr_match(const struct inet_bind2_bucket *tb2,
 153                                          const struct sock *sk)
 154 {
 155 #if IS_ENABLED(CONFIG_IPV6)
 156         if (sk->sk_family == AF_INET6)
 157                 return ipv6_addr_equal(&tb2->v6_rcv_saddr, &sk->sk_v6_rcv_saddr);
 158
 159         if (tb2->addr_type != IPV6_ADDR_MAPPED)
 160                 return false;
 161 #endif
 162         return tb2->rcv_saddr == sk->sk_rcv_saddr;
 163 }
 164
 165 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 166                     struct inet_bind2_bucket *tb2, unsigned short port)
 167 {
 168         inet_sk(sk)->inet_num = port;
 169         inet_csk(sk)->icsk_bind_hash = tb;
 170         inet_csk(sk)->icsk_bind2_hash = tb2;
 171         sk_add_bind_node(sk, &tb2->owners);
 172 }
 173
 174 /*
 175  * Get rid of any references to a local port held by the given sock.
 176  */
 177 static void __inet_put_port(struct sock *sk)
 178 {
 179         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 180         struct inet_bind_hashbucket *head, *head2;
 181         struct net *net = sock_net(sk);
 182         struct inet_bind_bucket *tb;
 183         int bhash;
 184
 185         bhash = inet_bhashfn(net, inet_sk(sk)->inet_num, hashinfo->bhash_size);
 186         head = &hashinfo->bhash[bhash];
 187         head2 = inet_bhashfn_portaddr(hashinfo, sk, net, inet_sk(sk)->inet_num);
 188
 189         spin_lock(&head->lock);
 190         tb = inet_csk(sk)->icsk_bind_hash;
 191         inet_csk(sk)->icsk_bind_hash = NULL;
 192         inet_sk(sk)->inet_num = 0;
 193
 194         spin_lock(&head2->lock);
 195         if (inet_csk(sk)->icsk_bind2_hash) {
 196                 struct inet_bind2_bucket *tb2 = inet_csk(sk)->icsk_bind2_hash;
 197
 198                 __sk_del_bind_node(sk);
 199                 inet_csk(sk)->icsk_bind2_hash = NULL;
 200                 inet_bind2_bucket_destroy(hashinfo->bind2_bucket_cachep, tb2);
 201         }
 202         spin_unlock(&head2->lock);
 203
 204         inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
 205         spin_unlock(&head->lock);
 206 }
 207
 208 void inet_put_port(struct sock *sk)
 209 {
 210         local_bh_disable();
 211         __inet_put_port(sk);
 212         local_bh_enable();
 213 }
 214 EXPORT_SYMBOL(inet_put_port);
 215
 216 int __inet_inherit_port(const struct sock *sk, struct sock *child)
 217 {
 218         struct inet_hashinfo *table = tcp_or_dccp_get_hashinfo(sk);
 219         unsigned short port = inet_sk(child)->inet_num;
 220         struct inet_bind_hashbucket *head, *head2;
 221         bool created_inet_bind_bucket = false;
 222         struct net *net = sock_net(sk);
 223         bool update_fastreuse = false;
 224         struct inet_bind2_bucket *tb2;
 225         struct inet_bind_bucket *tb;
 226         int bhash, l3mdev;
 227
 228         bhash = inet_bhashfn(net, port, table->bhash_size);
 229         head = &table->bhash[bhash];
 230         head2 = inet_bhashfn_portaddr(table, child, net, port);
 231
 232         spin_lock(&head->lock);
 233         spin_lock(&head2->lock);
 234         tb = inet_csk(sk)->icsk_bind_hash;
 235         tb2 = inet_csk(sk)->icsk_bind2_hash;
 236         if (unlikely(!tb || !tb2)) {
 237                 spin_unlock(&head2->lock);
 238                 spin_unlock(&head->lock);
 239                 return -ENOENT;
 240         }
 241         if (tb->port != port) {
 242                 l3mdev = inet_sk_bound_l3mdev(sk);
 243
 244                 /* NOTE: using tproxy and redirecting skbs to a proxy
 245                  * on a different listener port breaks the assumption
 246                  * that the listener socket's icsk_bind_hash is the same
 247                  * as that of the child socket. We have to look up or
 248                  * create a new bind bucket for the child here. */
 249                 inet_bind_bucket_for_each(tb, &head->chain) {
 250                         if (inet_bind_bucket_match(tb, net, port, l3mdev))
 251                                 break;
 252                 }
 253                 if (!tb) {
 254                         tb = inet_bind_bucket_create(table->bind_bucket_cachep,
 255                                                      net, head, port, l3mdev);
 256                         if (!tb) {
 257                                 spin_unlock(&head2->lock);
 258                                 spin_unlock(&head->lock);
 259                                 return -ENOMEM;
 260                         }
 261                         created_inet_bind_bucket = true;
 262                 }
 263                 update_fastreuse = true;
 264
 265                 goto bhash2_find;
 266         } else if (!inet_bind2_bucket_addr_match(tb2, child)) {
 267                 l3mdev = inet_sk_bound_l3mdev(sk);
 268
 269 bhash2_find:
 270                 tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, child);
 271                 if (!tb2) {
 272                         tb2 = inet_bind2_bucket_create(table->bind2_bucket_cachep,
 273                                                        net, head2, tb, child);
 274                         if (!tb2)
 275                                 goto error;
 276                 }
 277         }
 278         if (update_fastreuse)
 279                 inet_csk_update_fastreuse(tb, child);
 280         inet_bind_hash(child, tb, tb2, port);
 281         spin_unlock(&head2->lock);
 282         spin_unlock(&head->lock);
 283
 284         return 0;
 285
 286 error:
 287         if (created_inet_bind_bucket)
 288                 inet_bind_bucket_destroy(table->bind_bucket_cachep, tb);
 289         spin_unlock(&head2->lock);
 290         spin_unlock(&head->lock);
 291         return -ENOMEM;
 292 }
 293 EXPORT_SYMBOL_GPL(__inet_inherit_port);
 294
 295 static struct inet_listen_hashbucket *
 296 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
 297 {
 298         u32 hash;
 299
 300 #if IS_ENABLED(CONFIG_IPV6)
 301         if (sk->sk_family == AF_INET6)
 302                 hash = ipv6_portaddr_hash(sock_net(sk),
 303                                           &sk->sk_v6_rcv_saddr,
 304                                           inet_sk(sk)->inet_num);
 305         else
 306 #endif
 307                 hash = ipv4_portaddr_hash(sock_net(sk),
 308                                           inet_sk(sk)->inet_rcv_saddr,
 309                                           inet_sk(sk)->inet_num);
 310         return inet_lhash2_bucket(h, hash);
 311 }
 312
 313 static inline int compute_score(struct sock *sk, struct net *net,
 314                                 const unsigned short hnum, const __be32 daddr,
 315                                 const int dif, const int sdif)
 316 {
 317         int score = -1;
 318
 319         if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
 320                         !ipv6_only_sock(sk)) {
 321                 if (sk->sk_rcv_saddr != daddr)
 322                         return -1;
 323
 324                 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
 325                         return -1;
 326                 score =  sk->sk_bound_dev_if ? 2 : 1;
 327
 328                 if (sk->sk_family == PF_INET)
 329                         score++;
 330                 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 331                         score++;
 332         }
 333         return score;
 334 }
 335
 336 /**
 337  * inet_lookup_reuseport() - execute reuseport logic on AF_INET socket if necessary.
 338  * @net: network namespace.
 339  * @sk: AF_INET socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
 340  * @skb: context for a potential SK_REUSEPORT program.
 341  * @doff: header offset.
 342  * @saddr: source address.
 343  * @sport: source port.
 344  * @daddr: destination address.
 345  * @hnum: destination port in host byte order.
 346  * @ehashfn: hash function used to generate the fallback hash.
 347  *
 348  * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
 349  *         the selected sock or an error.
 350  */
 351 struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,
 352                                    struct sk_buff *skb, int doff,
 353                                    __be32 saddr, __be16 sport,
 354                                    __be32 daddr, unsigned short hnum,
 355                                    inet_ehashfn_t *ehashfn)
 356 {
 357         struct sock *reuse_sk = NULL;
 358         u32 phash;
 359
 360         if (sk->sk_reuseport) {
 361                 phash = INDIRECT_CALL_2(ehashfn, udp_ehashfn, inet_ehashfn,
 362                                         net, daddr, hnum, saddr, sport);
 363                 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
 364         }
 365         return reuse_sk;
 366 }
 367 EXPORT_SYMBOL_GPL(inet_lookup_reuseport);
 368
 369 /*
 370  * Here are some nice properties to exploit here. The BSD API
 371  * does not allow a listening sock to specify the remote port nor the
 372  * remote address for the connection. So always assume those are both
 373  * wildcarded during the search since they can never be otherwise.
 374  */
 375
 376 /* called with rcu_read_lock() : No refcount taken on the socket */
 377 static struct sock *inet_lhash2_lookup(struct net *net,
 378                                 struct inet_listen_hashbucket *ilb2,
 379                                 struct sk_buff *skb, int doff,
 380                                 const __be32 saddr, __be16 sport,
 381                                 const __be32 daddr, const unsigned short hnum,
 382                                 const int dif, const int sdif)
 383 {
 384         struct sock *sk, *result = NULL;
 385         struct hlist_nulls_node *node;
 386         int score, hiscore = 0;
 387
 388         sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
 389                 score = compute_score(sk, net, hnum, daddr, dif, sdif);
 390                 if (score > hiscore) {
 391                         result = inet_lookup_reuseport(net, sk, skb, doff,
 392                                                        saddr, sport, daddr, hnum, inet_ehashfn);
 393                         if (result)
 394                                 return result;
 395
 396                         result = sk;
 397                         hiscore = score;
 398                 }
 399         }
 400
 401         return result;
 402 }
 403
 404 struct sock *inet_lookup_run_sk_lookup(struct net *net,
 405                                        int protocol,
 406                                        struct sk_buff *skb, int doff,
 407                                        __be32 saddr, __be16 sport,
 408                                        __be32 daddr, u16 hnum, const int dif,
 409                                        inet_ehashfn_t *ehashfn)
 410 {
 411         struct sock *sk, *reuse_sk;
 412         bool no_reuseport;
 413
 414         no_reuseport = bpf_sk_lookup_run_v4(net, protocol, saddr, sport,
 415                                             daddr, hnum, dif, &sk);
 416         if (no_reuseport || IS_ERR_OR_NULL(sk))
 417                 return sk;
 418
 419         reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum,
 420                                          ehashfn);
 421         if (reuse_sk)
 422                 sk = reuse_sk;
 423         return sk;
 424 }
 425
 426 struct sock *__inet_lookup_listener(struct net *net,
 427                                     struct inet_hashinfo *hashinfo,
 428                                     struct sk_buff *skb, int doff,
 429                                     const __be32 saddr, __be16 sport,
 430                                     const __be32 daddr, const unsigned short hnum,
 431                                     const int dif, const int sdif)
 432 {
 433         struct inet_listen_hashbucket *ilb2;
 434         struct sock *result = NULL;
 435         unsigned int hash2;
 436
 437         /* Lookup redirect from BPF */
 438         if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
 439             hashinfo == net->ipv4.tcp_death_row.hashinfo) {
 440                 result = inet_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
 441                                                    saddr, sport, daddr, hnum, dif,
 442                                                    inet_ehashfn);
 443                 if (result)
 444                         goto done;
 445         }
 446
 447         hash2 = ipv4_portaddr_hash(net, daddr, hnum);
 448         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
 449
 450         result = inet_lhash2_lookup(net, ilb2, skb, doff,
 451                                     saddr, sport, daddr, hnum,
 452                                     dif, sdif);
 453         if (result)
 454                 goto done;
 455
 456         /* Lookup lhash2 with INADDR_ANY */
 457         hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
 458         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
 459
 460         result = inet_lhash2_lookup(net, ilb2, skb, doff,
 461                                     saddr, sport, htonl(INADDR_ANY), hnum,
 462                                     dif, sdif);
 463 done:
 464         if (IS_ERR(result))
 465                 return NULL;
 466         return result;
 467 }
 468 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 469
 470 /* All sockets share common refcount, but have different destructors */
 471 void sock_gen_put(struct sock *sk)
 472 {
 473         if (!refcount_dec_and_test(&sk->sk_refcnt))
 474                 return;
 475
 476         if (sk->sk_state == TCP_TIME_WAIT)
 477                 inet_twsk_free(inet_twsk(sk));
 478         else if (sk->sk_state == TCP_NEW_SYN_RECV)
 479                 reqsk_free(inet_reqsk(sk));
 480         else
 481                 sk_free(sk);
 482 }
 483 EXPORT_SYMBOL_GPL(sock_gen_put);
 484
 485 void sock_edemux(struct sk_buff *skb)
 486 {
 487         sock_gen_put(skb->sk);
 488 }
 489 EXPORT_SYMBOL(sock_edemux);
 490
 491 struct sock *__inet_lookup_established(struct net *net,
 492                                   struct inet_hashinfo *hashinfo,
 493                                   const __be32 saddr, const __be16 sport,
 494                                   const __be32 daddr, const u16 hnum,
 495                                   const int dif, const int sdif)
 496 {
 497         INET_ADDR_COOKIE(acookie, saddr, daddr);
 498         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
 499         struct sock *sk;
 500         const struct hlist_nulls_node *node;
 501         /* Optimize here for direct hit, only listening connections can
 502          * have wildcards anyways.
 503          */
 504         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
 505         unsigned int slot = hash & hashinfo->ehash_mask;
 506         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
 507
 508 begin:
 509         sk_nulls_for_each_rcu(sk, node, &head->chain) {
 510                 if (sk->sk_hash != hash)
 511                         continue;
 512                 if (likely(inet_match(net, sk, acookie, ports, dif, sdif))) {
 513                         if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 514                                 goto out;
 515                         if (unlikely(!inet_match(net, sk, acookie,
 516                                                  ports, dif, sdif))) {
 517                                 sock_gen_put(sk);
 518                                 goto begin;
 519                         }
 520                         goto found;
 521                 }
 522         }
 523         /*
 524          * if the nulls value we got at the end of this lookup is
 525          * not the expected one, we must restart lookup.
 526          * We probably met an item that was moved to another chain.
 527          */
 528         if (get_nulls_value(node) != slot)
 529                 goto begin;
 530 out:
 531         sk = NULL;
 532 found:
 533         return sk;
 534 }
 535 EXPORT_SYMBOL_GPL(__inet_lookup_established);
 536
 537 /* called with local bh disabled */
 538 static int __inet_check_established(struct inet_timewait_death_row *death_row,
 539                                     struct sock *sk, __u16 lport,
 540                                     struct inet_timewait_sock **twp)
 541 {
 542         struct inet_hashinfo *hinfo = death_row->hashinfo;
 543         struct inet_sock *inet = inet_sk(sk);
 544         __be32 daddr = inet->inet_rcv_saddr;
 545         __be32 saddr = inet->inet_daddr;
 546         int dif = sk->sk_bound_dev_if;
 547         struct net *net = sock_net(sk);
 548         int sdif = l3mdev_master_ifindex_by_index(net, dif);
 549         INET_ADDR_COOKIE(acookie, saddr, daddr);
 550         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 551         unsigned int hash = inet_ehashfn(net, daddr, lport,
 552                                          saddr, inet->inet_dport);
 553         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
 554         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
 555         struct sock *sk2;
 556         const struct hlist_nulls_node *node;
 557         struct inet_timewait_sock *tw = NULL;
 558
 559         spin_lock(lock);
 560
 561         sk_nulls_for_each(sk2, node, &head->chain) {
 562                 if (sk2->sk_hash != hash)
 563                         continue;
 564
 565                 if (likely(inet_match(net, sk2, acookie, ports, dif, sdif))) {
 566                         if (sk2->sk_state == TCP_TIME_WAIT) {
 567                                 tw = inet_twsk(sk2);
 568                                 if (sk->sk_protocol == IPPROTO_TCP &&
 569                                     tcp_twsk_unique(sk, sk2, twp))
 570                                         break;
 571                         }
 572                         goto not_unique;
 573                 }
 574         }
 575
 576         /* Must record num and sport now. Otherwise we will see
 577          * in hash table socket with a funny identity.
 578          */
 579         inet->inet_num = lport;
 580         inet->inet_sport = htons(lport);
 581         sk->sk_hash = hash;
 582         WARN_ON(!sk_unhashed(sk));
 583         __sk_nulls_add_node_rcu(sk, &head->chain);
 584         if (tw) {
 585                 sk_nulls_del_node_init_rcu((struct sock *)tw);
 586                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
 587         }
 588         spin_unlock(lock);
 589         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 590
 591         if (twp) {
 592                 *twp = tw;
 593         } else if (tw) {
 594                 /* Silly. Should hash-dance instead... */
 595                 inet_twsk_deschedule_put(tw);
 596         }
 597         return 0;
 598
 599 not_unique:
 600         spin_unlock(lock);
 601         return -EADDRNOTAVAIL;
 602 }
 603
 604 static u64 inet_sk_port_offset(const struct sock *sk)
 605 {
 606         const struct inet_sock *inet = inet_sk(sk);
 607
 608         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
 609                                           inet->inet_daddr,
 610                                           inet->inet_dport);
 611 }
 612
 613 /* Searches for an exsiting socket in the ehash bucket list.
 614  * Returns true if found, false otherwise.
 615  */
 616 static bool inet_ehash_lookup_by_sk(struct sock *sk,
 617                                     struct hlist_nulls_head *list)
 618 {
 619         const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num);
 620         const int sdif = sk->sk_bound_dev_if;
 621         const int dif = sk->sk_bound_dev_if;
 622         const struct hlist_nulls_node *node;
 623         struct net *net = sock_net(sk);
 624         struct sock *esk;
 625
 626         INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr);
 627
 628         sk_nulls_for_each_rcu(esk, node, list) {
 629                 if (esk->sk_hash != sk->sk_hash)
 630                         continue;
 631                 if (sk->sk_family == AF_INET) {
 632                         if (unlikely(inet_match(net, esk, acookie,
 633                                                 ports, dif, sdif))) {
 634                                 return true;
 635                         }
 636                 }
 637 #if IS_ENABLED(CONFIG_IPV6)
 638                 else if (sk->sk_family == AF_INET6) {
 639                         if (unlikely(inet6_match(net, esk,
 640                                                  &sk->sk_v6_daddr,
 641                                                  &sk->sk_v6_rcv_saddr,
 642                                                  ports, dif, sdif))) {
 643                                 return true;
 644                         }
 645                 }
 646 #endif
 647         }
 648         return false;
 649 }
 650
 651 /* Insert a socket into ehash, and eventually remove another one
 652  * (The another one can be a SYN_RECV or TIMEWAIT)
 653  * If an existing socket already exists, socket sk is not inserted,
 654  * and sets found_dup_sk parameter to true.
 655  */
 656 bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk)
 657 {
 658         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 659         struct inet_ehash_bucket *head;
 660         struct hlist_nulls_head *list;
 661         spinlock_t *lock;
 662         bool ret = true;
 663
 664         WARN_ON_ONCE(!sk_unhashed(sk));
 665
 666         sk->sk_hash = sk_ehashfn(sk);
 667         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
 668         list = &head->chain;
 669         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 670
 671         spin_lock(lock);
 672         if (osk) {
 673                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
 674                 ret = sk_nulls_del_node_init_rcu(osk);
 675         } else if (found_dup_sk) {
 676                 *found_dup_sk = inet_ehash_lookup_by_sk(sk, list);
 677                 if (*found_dup_sk)
 678                         ret = false;
 679         }
 680
 681         if (ret)
 682                 __sk_nulls_add_node_rcu(sk, list);
 683
 684         spin_unlock(lock);
 685
 686         return ret;
 687 }
 688
 689 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk)
 690 {
 691         bool ok = inet_ehash_insert(sk, osk, found_dup_sk);
 692
 693         if (ok) {
 694                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 695         } else {
 696                 this_cpu_inc(*sk->sk_prot->orphan_count);
 697                 inet_sk_set_state(sk, TCP_CLOSE);
 698                 sock_set_flag(sk, SOCK_DEAD);
 699                 inet_csk_destroy_sock(sk);
 700         }
 701         return ok;
 702 }
 703 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 704
 705 static int inet_reuseport_add_sock(struct sock *sk,
 706                                    struct inet_listen_hashbucket *ilb)
 707 {
 708         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
 709         const struct hlist_nulls_node *node;
 710         struct sock *sk2;
 711         kuid_t uid = sock_i_uid(sk);
 712
 713         sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
 714                 if (sk2 != sk &&
 715                     sk2->sk_family == sk->sk_family &&
 716                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
 717                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
 718                     inet_csk(sk2)->icsk_bind_hash == tb &&
 719                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
 720                     inet_rcv_saddr_equal(sk, sk2, false))
 721                         return reuseport_add_sock(sk, sk2,
 722                                                   inet_rcv_saddr_any(sk));
 723         }
 724
 725         return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
 726 }
 727
 728 int __inet_hash(struct sock *sk, struct sock *osk)
 729 {
 730         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 731         struct inet_listen_hashbucket *ilb2;
 732         int err = 0;
 733
 734         if (sk->sk_state != TCP_LISTEN) {
 735                 local_bh_disable();
 736                 inet_ehash_nolisten(sk, osk, NULL);
 737                 local_bh_enable();
 738                 return 0;
 739         }
 740         WARN_ON(!sk_unhashed(sk));
 741         ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
 742
 743         spin_lock(&ilb2->lock);
 744         if (sk->sk_reuseport) {
 745                 err = inet_reuseport_add_sock(sk, ilb2);
 746                 if (err)
 747                         goto unlock;
 748         }
 749         sock_set_flag(sk, SOCK_RCU_FREE);
 750         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 751                 sk->sk_family == AF_INET6)
 752                 __sk_nulls_add_node_tail_rcu(sk, &ilb2->nulls_head);
 753         else
 754                 __sk_nulls_add_node_rcu(sk, &ilb2->nulls_head);
 755         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 756 unlock:
 757         spin_unlock(&ilb2->lock);
 758
 759         return err;
 760 }
 761 EXPORT_SYMBOL(__inet_hash);
 762
 763 int inet_hash(struct sock *sk)
 764 {
 765         int err = 0;
 766
 767         if (sk->sk_state != TCP_CLOSE)
 768                 err = __inet_hash(sk, NULL);
 769
 770         return err;
 771 }
 772 EXPORT_SYMBOL_GPL(inet_hash);
 773
 774 void inet_unhash(struct sock *sk)
 775 {
 776         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 777
 778         if (sk_unhashed(sk))
 779                 return;
 780
 781         if (sk->sk_state == TCP_LISTEN) {
 782                 struct inet_listen_hashbucket *ilb2;
 783
 784                 ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
 785                 /* Don't disable bottom halves while acquiring the lock to
 786                  * avoid circular locking dependency on PREEMPT_RT.
 787                  */
 788                 spin_lock(&ilb2->lock);
 789                 if (sk_unhashed(sk)) {
 790                         spin_unlock(&ilb2->lock);
 791                         return;
 792                 }
 793
 794                 if (rcu_access_pointer(sk->sk_reuseport_cb))
 795                         reuseport_stop_listen_sock(sk);
 796
 797                 __sk_nulls_del_node_init_rcu(sk);
 798                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 799                 spin_unlock(&ilb2->lock);
 800         } else {
 801                 spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 802
 803                 spin_lock_bh(lock);
 804                 if (sk_unhashed(sk)) {
 805                         spin_unlock_bh(lock);
 806                         return;
 807                 }
 808                 __sk_nulls_del_node_init_rcu(sk);
 809                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 810                 spin_unlock_bh(lock);
 811         }
 812 }
 813 EXPORT_SYMBOL_GPL(inet_unhash);
 814
 815 static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
 816                                     const struct net *net, unsigned short port,
 817                                     int l3mdev, const struct sock *sk)
 818 {
 819         if (!net_eq(ib2_net(tb), net) || tb->port != port ||
 820             tb->l3mdev != l3mdev)
 821                 return false;
 822
 823         return inet_bind2_bucket_addr_match(tb, sk);
 824 }
 825
 826 bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const struct net *net,
 827                                       unsigned short port, int l3mdev, const struct sock *sk)
 828 {
 829         if (!net_eq(ib2_net(tb), net) || tb->port != port ||
 830             tb->l3mdev != l3mdev)
 831                 return false;
 832
 833 #if IS_ENABLED(CONFIG_IPV6)
 834         if (tb->addr_type == IPV6_ADDR_ANY)
 835                 return true;
 836
 837         if (tb->addr_type != IPV6_ADDR_MAPPED)
 838                 return false;
 839
 840         if (sk->sk_family == AF_INET6 &&
 841             !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 842                 return false;
 843 #endif
 844         return tb->rcv_saddr == 0;
 845 }
 846
 847 /* The socket's bhash2 hashbucket spinlock must be held when this is called */
 848 struct inet_bind2_bucket *
 849 inet_bind2_bucket_find(const struct inet_bind_hashbucket *head, const struct net *net,
 850                        unsigned short port, int l3mdev, const struct sock *sk)
 851 {
 852         struct inet_bind2_bucket *bhash2 = NULL;
 853
 854         inet_bind_bucket_for_each(bhash2, &head->chain)
 855                 if (inet_bind2_bucket_match(bhash2, net, port, l3mdev, sk))
 856                         break;
 857
 858         return bhash2;
 859 }
 860
 861 struct inet_bind_hashbucket *
 862 inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, int port)
 863 {
 864         struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
 865         u32 hash;
 866
 867 #if IS_ENABLED(CONFIG_IPV6)
 868         if (sk->sk_family == AF_INET6)
 869                 hash = ipv6_portaddr_hash(net, &in6addr_any, port);
 870         else
 871 #endif
 872                 hash = ipv4_portaddr_hash(net, 0, port);
 873
 874         return &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
 875 }
 876
 877 static void inet_update_saddr(struct sock *sk, void *saddr, int family)
 878 {
 879         if (family == AF_INET) {
 880                 inet_sk(sk)->inet_saddr = *(__be32 *)saddr;
 881                 sk_rcv_saddr_set(sk, inet_sk(sk)->inet_saddr);
 882         }
 883 #if IS_ENABLED(CONFIG_IPV6)
 884         else {
 885                 sk->sk_v6_rcv_saddr = *(struct in6_addr *)saddr;
 886         }
 887 #endif
 888 }
 889
 890 static int __inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family, bool reset)
 891 {
 892         struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
 893         struct inet_bind_hashbucket *head, *head2;
 894         struct inet_bind2_bucket *tb2, *new_tb2;
 895         int l3mdev = inet_sk_bound_l3mdev(sk);
 896         int port = inet_sk(sk)->inet_num;
 897         struct net *net = sock_net(sk);
 898         int bhash;
 899
 900         if (!inet_csk(sk)->icsk_bind2_hash) {
 901                 /* Not bind()ed before. */
 902                 if (reset)
 903                         inet_reset_saddr(sk);
 904                 else
 905                         inet_update_saddr(sk, saddr, family);
 906
 907                 return 0;
 908         }
 909
 910         /* Allocate a bind2 bucket ahead of time to avoid permanently putting
 911          * the bhash2 table in an inconsistent state if a new tb2 bucket
 912          * allocation fails.
 913          */
 914         new_tb2 = kmem_cache_alloc(hinfo->bind2_bucket_cachep, GFP_ATOMIC);
 915         if (!new_tb2) {
 916                 if (reset) {
 917                         /* The (INADDR_ANY, port) bucket might have already
 918                          * been freed, then we cannot fixup icsk_bind2_hash,
 919                          * so we give up and unlink sk from bhash/bhash2 not
 920                          * to leave inconsistency in bhash2.
 921                          */
 922                         inet_put_port(sk);
 923                         inet_reset_saddr(sk);
 924                 }
 925
 926                 return -ENOMEM;
 927         }
 928
 929         bhash = inet_bhashfn(net, port, hinfo->bhash_size);
 930         head = &hinfo->bhash[bhash];
 931         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
 932
 933         /* If we change saddr locklessly, another thread
 934          * iterating over bhash might see corrupted address.
 935          */
 936         spin_lock_bh(&head->lock);
 937
 938         spin_lock(&head2->lock);
 939         __sk_del_bind_node(sk);
 940         inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep, inet_csk(sk)->icsk_bind2_hash);
 941         spin_unlock(&head2->lock);
 942
 943         if (reset)
 944                 inet_reset_saddr(sk);
 945         else
 946                 inet_update_saddr(sk, saddr, family);
 947
 948         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
 949
 950         spin_lock(&head2->lock);
 951         tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
 952         if (!tb2) {
 953                 tb2 = new_tb2;
 954                 inet_bind2_bucket_init(tb2, net, head2, inet_csk(sk)->icsk_bind_hash, sk);
 955         }
 956         inet_csk(sk)->icsk_bind2_hash = tb2;
 957         sk_add_bind_node(sk, &tb2->owners);
 958         spin_unlock(&head2->lock);
 959
 960         spin_unlock_bh(&head->lock);
 961
 962         if (tb2 != new_tb2)
 963                 kmem_cache_free(hinfo->bind2_bucket_cachep, new_tb2);
 964
 965         return 0;
 966 }
 967
 968 int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family)
 969 {
 970         return __inet_bhash2_update_saddr(sk, saddr, family, false);
 971 }
 972 EXPORT_SYMBOL_GPL(inet_bhash2_update_saddr);
 973
 974 void inet_bhash2_reset_saddr(struct sock *sk)
 975 {
 976         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 977                 __inet_bhash2_update_saddr(sk, NULL, 0, true);
 978 }
 979 EXPORT_SYMBOL_GPL(inet_bhash2_reset_saddr);
 980
 981 /* RFC 6056 3.3.4.  Algorithm 4: Double-Hash Port Selection Algorithm
 982  * Note that we use 32bit integers (vs RFC 'short integers')
 983  * because 2^16 is not a multiple of num_ephemeral and this
 984  * property might be used by clever attacker.
 985  *
 986  * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though
 987  * attacks were since demonstrated, thus we use 65536 by default instead
 988  * to really give more isolation and privacy, at the expense of 256kB
 989  * of kernel memory.
 990  */
 991 #define INET_TABLE_PERTURB_SIZE (1 << CONFIG_INET_TABLE_PERTURB_ORDER)
 992 static u32 *table_perturb;
 993
 994 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 995                 struct sock *sk, u64 port_offset,
 996                 int (*check_established)(struct inet_timewait_death_row *,
 997                         struct sock *, __u16, struct inet_timewait_sock **))
 998 {
 999         struct inet_hashinfo *hinfo = death_row->hashinfo;
1000         struct inet_bind_hashbucket *head, *head2;
1001         struct inet_timewait_sock *tw = NULL;
1002         int port = inet_sk(sk)->inet_num;
1003         struct net *net = sock_net(sk);
1004         struct inet_bind2_bucket *tb2;
1005         struct inet_bind_bucket *tb;
1006         bool tb_created = false;
1007         u32 remaining, offset;
1008         int ret, i, low, high;
1009         bool local_ports;
1010         int step, l3mdev;
1011         u32 index;
1012
1013         if (port) {
1014                 local_bh_disable();
1015                 ret = check_established(death_row, sk, port, NULL);
1016                 local_bh_enable();
1017                 return ret;
1018         }
1019
1020         l3mdev = inet_sk_bound_l3mdev(sk);
1021
1022         local_ports = inet_sk_get_local_port_range(sk, &low, &high);
1023         step = local_ports ? 1 : 2;
1024
1025         high++; /* [32768, 60999] -> [32768, 61000[ */
1026         remaining = high - low;
1027         if (!local_ports && remaining > 1)
1028                 remaining &= ~1U;
1029
1030         get_random_sleepable_once(table_perturb,
1031                                   INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb));
1032         index = port_offset & (INET_TABLE_PERTURB_SIZE - 1);
1033
1034         offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32);
1035         offset %= remaining;
1036
1037         /* In first pass we try ports of @low parity.
1038          * inet_csk_get_port() does the opposite choice.
1039          */
1040         if (!local_ports)
1041                 offset &= ~1U;
1042 other_parity_scan:
1043         port = low + offset;
1044         for (i = 0; i < remaining; i += step, port += step) {
1045                 if (unlikely(port >= high))
1046                         port -= remaining;
1047                 if (inet_is_local_reserved_port(net, port))
1048                         continue;
1049                 head = &hinfo->bhash[inet_bhashfn(net, port,
1050                                                   hinfo->bhash_size)];
1051                 spin_lock_bh(&head->lock);
1052
1053                 /* Does not bother with rcv_saddr checks, because
1054                  * the established check is already unique enough.
1055                  */
1056                 inet_bind_bucket_for_each(tb, &head->chain) {
1057                         if (inet_bind_bucket_match(tb, net, port, l3mdev)) {
1058                                 if (tb->fastreuse >= 0 ||
1059                                     tb->fastreuseport >= 0)
1060                                         goto next_port;
1061                                 WARN_ON(hlist_empty(&tb->bhash2));
1062                                 if (!check_established(death_row, sk,
1063                                                        port, &tw))
1064                                         goto ok;
1065                                 goto next_port;
1066                         }
1067                 }
1068
1069                 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
1070                                              net, head, port, l3mdev);
1071                 if (!tb) {
1072                         spin_unlock_bh(&head->lock);
1073                         return -ENOMEM;
1074                 }
1075                 tb_created = true;
1076                 tb->fastreuse = -1;
1077                 tb->fastreuseport = -1;
1078                 goto ok;
1079 next_port:
1080                 spin_unlock_bh(&head->lock);
1081                 cond_resched();
1082         }
1083
1084         if (!local_ports) {
1085                 offset++;
1086                 if ((offset & 1) && remaining > 1)
1087                         goto other_parity_scan;
1088         }
1089         return -EADDRNOTAVAIL;
1090
1091 ok:
1092         /* Find the corresponding tb2 bucket since we need to
1093          * add the socket to the bhash2 table as well
1094          */
1095         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
1096         spin_lock(&head2->lock);
1097
1098         tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
1099         if (!tb2) {
1100                 tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep, net,
1101                                                head2, tb, sk);
1102                 if (!tb2)
1103                         goto error;
1104         }
1105
1106         /* Here we want to add a little bit of randomness to the next source
1107          * port that will be chosen. We use a max() with a random here so that
1108          * on low contention the randomness is maximal and on high contention
1109          * it may be inexistent.
1110          */
1111         i = max_t(int, i, get_random_u32_below(8) * step);
1112         WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + step);
1113
1114         /* Head lock still held and bh's disabled */
1115         inet_bind_hash(sk, tb, tb2, port);
1116
1117         if (sk_unhashed(sk)) {
1118                 inet_sk(sk)->inet_sport = htons(port);
1119                 inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
1120         }
1121         if (tw)
1122                 inet_twsk_bind_unhash(tw, hinfo);
1123
1124         spin_unlock(&head2->lock);
1125         spin_unlock(&head->lock);
1126
1127         if (tw)
1128                 inet_twsk_deschedule_put(tw);
1129         local_bh_enable();
1130         return 0;
1131
1132 error:
1133         if (sk_hashed(sk)) {
1134                 spinlock_t *lock = inet_ehash_lockp(hinfo, sk->sk_hash);
1135
1136                 sock_prot_inuse_add(net, sk->sk_prot, -1);
1137
1138                 spin_lock(lock);
1139                 __sk_nulls_del_node_init_rcu(sk);
1140                 spin_unlock(lock);
1141
1142                 sk->sk_hash = 0;
1143                 inet_sk(sk)->inet_sport = 0;
1144                 inet_sk(sk)->inet_num = 0;
1145
1146                 if (tw)
1147                         inet_twsk_bind_unhash(tw, hinfo);
1148         }
1149
1150         spin_unlock(&head2->lock);
1151         if (tb_created)
1152                 inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
1153         spin_unlock(&head->lock);
1154
1155         if (tw)
1156                 inet_twsk_deschedule_put(tw);
1157
1158         local_bh_enable();
1159
1160         return -ENOMEM;
1161 }
1162
1163 /*
1164  * Bind a port for a connect operation and hash it.
1165  */
1166 int inet_hash_connect(struct inet_timewait_death_row *death_row,
1167                       struct sock *sk)
1168 {
1169         u64 port_offset = 0;
1170
1171         if (!inet_sk(sk)->inet_num)
1172                 port_offset = inet_sk_port_offset(sk);
1173         return __inet_hash_connect(death_row, sk, port_offset,
1174                                    __inet_check_established);
1175 }
1176 EXPORT_SYMBOL_GPL(inet_hash_connect);
1177
1178 static void init_hashinfo_lhash2(struct inet_hashinfo *h)
1179 {
1180         int i;
1181
1182         for (i = 0; i <= h->lhash2_mask; i++) {
1183                 spin_lock_init(&h->lhash2[i].lock);
1184                 INIT_HLIST_NULLS_HEAD(&h->lhash2[i].nulls_head,
1185                                       i + LISTENING_NULLS_BASE);
1186         }
1187 }
1188
1189 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
1190                                 unsigned long numentries, int scale,
1191                                 unsigned long low_limit,
1192                                 unsigned long high_limit)
1193 {
1194         h->lhash2 = alloc_large_system_hash(name,
1195                                             sizeof(*h->lhash2),
1196                                             numentries,
1197                                             scale,
1198                                             0,
1199                                             NULL,
1200                                             &h->lhash2_mask,
1201                                             low_limit,
1202                                             high_limit);
1203         init_hashinfo_lhash2(h);
1204
1205         /* this one is used for source ports of outgoing connections */
1206         table_perturb = alloc_large_system_hash("Table-perturb",
1207                                                 sizeof(*table_perturb),
1208                                                 INET_TABLE_PERTURB_SIZE,
1209                                                 0, 0, NULL, NULL,
1210                                                 INET_TABLE_PERTURB_SIZE,
1211                                                 INET_TABLE_PERTURB_SIZE);
1212 }
1213
1214 int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
1215 {
1216         h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
1217         if (!h->lhash2)
1218                 return -ENOMEM;
1219
1220         h->lhash2_mask = INET_LHTABLE_SIZE - 1;
1221         /* INET_LHTABLE_SIZE must be a power of 2 */
1222         BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
1223
1224         init_hashinfo_lhash2(h);
1225         return 0;
1226 }
1227 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
1228
1229 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
1230 {
1231         unsigned int locksz = sizeof(spinlock_t);
1232         unsigned int i, nblocks = 1;
1233
1234         if (locksz != 0) {
1235                 /* allocate 2 cache lines or at least one spinlock per cpu */
1236                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
1237                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
1238
1239                 /* no more locks than number of hash buckets */
1240                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
1241
1242                 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
1243                 if (!hashinfo->ehash_locks)
1244                         return -ENOMEM;
1245
1246                 for (i = 0; i < nblocks; i++)
1247                         spin_lock_init(&hashinfo->ehash_locks[i]);
1248         }
1249         hashinfo->ehash_locks_mask = nblocks - 1;
1250         return 0;
1251 }
1252 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
1253
1254 struct inet_hashinfo *inet_pernet_hashinfo_alloc(struct inet_hashinfo *hashinfo,
1255                                                  unsigned int ehash_entries)
1256 {
1257         struct inet_hashinfo *new_hashinfo;
1258         int i;
1259
1260         new_hashinfo = kmemdup(hashinfo, sizeof(*hashinfo), GFP_KERNEL);
1261         if (!new_hashinfo)
1262                 goto err;
1263
1264         new_hashinfo->ehash = vmalloc_huge(ehash_entries * sizeof(struct inet_ehash_bucket),
1265                                            GFP_KERNEL_ACCOUNT);
1266         if (!new_hashinfo->ehash)
1267                 goto free_hashinfo;
1268
1269         new_hashinfo->ehash_mask = ehash_entries - 1;
1270
1271         if (inet_ehash_locks_alloc(new_hashinfo))
1272                 goto free_ehash;
1273
1274         for (i = 0; i < ehash_entries; i++)
1275                 INIT_HLIST_NULLS_HEAD(&new_hashinfo->ehash[i].chain, i);
1276
1277         new_hashinfo->pernet = true;
1278
1279         return new_hashinfo;
1280
1281 free_ehash:
1282         vfree(new_hashinfo->ehash);
1283 free_hashinfo:
1284         kfree(new_hashinfo);
1285 err:
1286         return NULL;
1287 }
1288 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_alloc);
1289
1290 void inet_pernet_hashinfo_free(struct inet_hashinfo *hashinfo)
1291 {
1292         if (!hashinfo->pernet)
1293                 return;
1294
1295         inet_ehash_locks_free(hashinfo);
1296         vfree(hashinfo->ehash);
1297         kfree(hashinfo);
1298 }
1299 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_free);