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/ip.h>
  28 #include <net/tcp.h>
  29 #include <net/sock_reuseport.h>
  30
  31 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 EXPORT_SYMBOL_GPL(inet_ehashfn);
  43
  44 /* This function handles inet_sock, but also timewait and request sockets
  45  * for IPv4/IPv6.
  46  */
  47 static u32 sk_ehashfn(const struct sock *sk)
  48 {
  49 #if IS_ENABLED(CONFIG_IPV6)
  50         if (sk->sk_family == AF_INET6 &&
  51             !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
  52                 return inet6_ehashfn(sock_net(sk),
  53                                      &sk->sk_v6_rcv_saddr, sk->sk_num,
  54                                      &sk->sk_v6_daddr, sk->sk_dport);
  55 #endif
  56         return inet_ehashfn(sock_net(sk),
  57                             sk->sk_rcv_saddr, sk->sk_num,
  58                             sk->sk_daddr, sk->sk_dport);
  59 }
  60
  61 /*
  62  * Allocate and initialize a new local port bind bucket.
  63  * The bindhash mutex for snum's hash chain must be held here.
  64  */
  65 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
  66                                                  struct net *net,
  67                                                  struct inet_bind_hashbucket *head,
  68                                                  const unsigned short snum,
  69                                                  int l3mdev)
  70 {
  71         struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
  72
  73         if (tb) {
  74                 write_pnet(&tb->ib_net, net);
  75                 tb->l3mdev    = l3mdev;
  76                 tb->port      = snum;
  77                 tb->fastreuse = 0;
  78                 tb->fastreuseport = 0;
  79                 INIT_HLIST_HEAD(&tb->owners);
  80                 hlist_add_head(&tb->node, &head->chain);
  81         }
  82         return tb;
  83 }
  84
  85 /*
  86  * Caller must hold hashbucket lock for this tb with local BH disabled
  87  */
  88 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
  89 {
  90         if (hlist_empty(&tb->owners)) {
  91                 __hlist_del(&tb->node);
  92                 kmem_cache_free(cachep, tb);
  93         }
  94 }
  95
  96 bool inet_bind_bucket_match(const struct inet_bind_bucket *tb, const struct net *net,
  97                             unsigned short port, int l3mdev)
  98 {
  99         return net_eq(ib_net(tb), net) && tb->port == port &&
 100                 tb->l3mdev == l3mdev;
 101 }
 102
 103 static void inet_bind2_bucket_init(struct inet_bind2_bucket *tb,
 104                                    struct net *net,
 105                                    struct inet_bind_hashbucket *head,
 106                                    unsigned short port, int l3mdev,
 107                                    const struct sock *sk)
 108 {
 109         write_pnet(&tb->ib_net, net);
 110         tb->l3mdev    = l3mdev;
 111         tb->port      = port;
 112 #if IS_ENABLED(CONFIG_IPV6)
 113         tb->family    = sk->sk_family;
 114         if (sk->sk_family == AF_INET6)
 115                 tb->v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 116         else
 117 #endif
 118                 tb->rcv_saddr = sk->sk_rcv_saddr;
 119         INIT_HLIST_HEAD(&tb->owners);
 120         INIT_HLIST_HEAD(&tb->deathrow);
 121         hlist_add_head(&tb->node, &head->chain);
 122 }
 123
 124 struct inet_bind2_bucket *inet_bind2_bucket_create(struct kmem_cache *cachep,
 125                                                    struct net *net,
 126                                                    struct inet_bind_hashbucket *head,
 127                                                    unsigned short port,
 128                                                    int l3mdev,
 129                                                    const struct sock *sk)
 130 {
 131         struct inet_bind2_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 132
 133         if (tb)
 134                 inet_bind2_bucket_init(tb, net, head, port, l3mdev, sk);
 135
 136         return tb;
 137 }
 138
 139 /* Caller must hold hashbucket lock for this tb with local BH disabled */
 140 void inet_bind2_bucket_destroy(struct kmem_cache *cachep, struct inet_bind2_bucket *tb)
 141 {
 142         if (hlist_empty(&tb->owners) && hlist_empty(&tb->deathrow)) {
 143                 __hlist_del(&tb->node);
 144                 kmem_cache_free(cachep, tb);
 145         }
 146 }
 147
 148 static bool inet_bind2_bucket_addr_match(const struct inet_bind2_bucket *tb2,
 149                                          const struct sock *sk)
 150 {
 151 #if IS_ENABLED(CONFIG_IPV6)
 152         if (sk->sk_family != tb2->family) {
 153                 if (sk->sk_family == AF_INET)
 154                         return ipv6_addr_v4mapped(&tb2->v6_rcv_saddr) &&
 155                                 tb2->v6_rcv_saddr.s6_addr32[3] == sk->sk_rcv_saddr;
 156
 157                 return ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr) &&
 158                         sk->sk_v6_rcv_saddr.s6_addr32[3] == tb2->rcv_saddr;
 159         }
 160
 161         if (sk->sk_family == AF_INET6)
 162                 return ipv6_addr_equal(&tb2->v6_rcv_saddr,
 163                                        &sk->sk_v6_rcv_saddr);
 164 #endif
 165         return tb2->rcv_saddr == sk->sk_rcv_saddr;
 166 }
 167
 168 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 169                     struct inet_bind2_bucket *tb2, unsigned short port)
 170 {
 171         inet_sk(sk)->inet_num = port;
 172         sk_add_bind_node(sk, &tb->owners);
 173         inet_csk(sk)->icsk_bind_hash = tb;
 174         sk_add_bind2_node(sk, &tb2->owners);
 175         inet_csk(sk)->icsk_bind2_hash = tb2;
 176 }
 177
 178 /*
 179  * Get rid of any references to a local port held by the given sock.
 180  */
 181 static void __inet_put_port(struct sock *sk)
 182 {
 183         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 184         struct inet_bind_hashbucket *head, *head2;
 185         struct net *net = sock_net(sk);
 186         struct inet_bind_bucket *tb;
 187         int bhash;
 188
 189         bhash = inet_bhashfn(net, inet_sk(sk)->inet_num, hashinfo->bhash_size);
 190         head = &hashinfo->bhash[bhash];
 191         head2 = inet_bhashfn_portaddr(hashinfo, sk, net, inet_sk(sk)->inet_num);
 192
 193         spin_lock(&head->lock);
 194         tb = inet_csk(sk)->icsk_bind_hash;
 195         __sk_del_bind_node(sk);
 196         inet_csk(sk)->icsk_bind_hash = NULL;
 197         inet_sk(sk)->inet_num = 0;
 198         inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
 199
 200         spin_lock(&head2->lock);
 201         if (inet_csk(sk)->icsk_bind2_hash) {
 202                 struct inet_bind2_bucket *tb2 = inet_csk(sk)->icsk_bind2_hash;
 203
 204                 __sk_del_bind2_node(sk);
 205                 inet_csk(sk)->icsk_bind2_hash = NULL;
 206                 inet_bind2_bucket_destroy(hashinfo->bind2_bucket_cachep, tb2);
 207         }
 208         spin_unlock(&head2->lock);
 209
 210         spin_unlock(&head->lock);
 211 }
 212
 213 void inet_put_port(struct sock *sk)
 214 {
 215         local_bh_disable();
 216         __inet_put_port(sk);
 217         local_bh_enable();
 218 }
 219 EXPORT_SYMBOL(inet_put_port);
 220
 221 int __inet_inherit_port(const struct sock *sk, struct sock *child)
 222 {
 223         struct inet_hashinfo *table = tcp_or_dccp_get_hashinfo(sk);
 224         unsigned short port = inet_sk(child)->inet_num;
 225         struct inet_bind_hashbucket *head, *head2;
 226         bool created_inet_bind_bucket = false;
 227         struct net *net = sock_net(sk);
 228         bool update_fastreuse = false;
 229         struct inet_bind2_bucket *tb2;
 230         struct inet_bind_bucket *tb;
 231         int bhash, l3mdev;
 232
 233         bhash = inet_bhashfn(net, port, table->bhash_size);
 234         head = &table->bhash[bhash];
 235         head2 = inet_bhashfn_portaddr(table, child, net, port);
 236
 237         spin_lock(&head->lock);
 238         spin_lock(&head2->lock);
 239         tb = inet_csk(sk)->icsk_bind_hash;
 240         tb2 = inet_csk(sk)->icsk_bind2_hash;
 241         if (unlikely(!tb || !tb2)) {
 242                 spin_unlock(&head2->lock);
 243                 spin_unlock(&head->lock);
 244                 return -ENOENT;
 245         }
 246         if (tb->port != port) {
 247                 l3mdev = inet_sk_bound_l3mdev(sk);
 248
 249                 /* NOTE: using tproxy and redirecting skbs to a proxy
 250                  * on a different listener port breaks the assumption
 251                  * that the listener socket's icsk_bind_hash is the same
 252                  * as that of the child socket. We have to look up or
 253                  * create a new bind bucket for the child here. */
 254                 inet_bind_bucket_for_each(tb, &head->chain) {
 255                         if (inet_bind_bucket_match(tb, net, port, l3mdev))
 256                                 break;
 257                 }
 258                 if (!tb) {
 259                         tb = inet_bind_bucket_create(table->bind_bucket_cachep,
 260                                                      net, head, port, l3mdev);
 261                         if (!tb) {
 262                                 spin_unlock(&head2->lock);
 263                                 spin_unlock(&head->lock);
 264                                 return -ENOMEM;
 265                         }
 266                         created_inet_bind_bucket = true;
 267                 }
 268                 update_fastreuse = true;
 269
 270                 goto bhash2_find;
 271         } else if (!inet_bind2_bucket_addr_match(tb2, child)) {
 272                 l3mdev = inet_sk_bound_l3mdev(sk);
 273
 274 bhash2_find:
 275                 tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, child);
 276                 if (!tb2) {
 277                         tb2 = inet_bind2_bucket_create(table->bind2_bucket_cachep,
 278                                                        net, head2, port,
 279                                                        l3mdev, child);
 280                         if (!tb2)
 281                                 goto error;
 282                 }
 283         }
 284         if (update_fastreuse)
 285                 inet_csk_update_fastreuse(tb, child);
 286         inet_bind_hash(child, tb, tb2, port);
 287         spin_unlock(&head2->lock);
 288         spin_unlock(&head->lock);
 289
 290         return 0;
 291
 292 error:
 293         if (created_inet_bind_bucket)
 294                 inet_bind_bucket_destroy(table->bind_bucket_cachep, tb);
 295         spin_unlock(&head2->lock);
 296         spin_unlock(&head->lock);
 297         return -ENOMEM;
 298 }
 299 EXPORT_SYMBOL_GPL(__inet_inherit_port);
 300
 301 static struct inet_listen_hashbucket *
 302 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
 303 {
 304         u32 hash;
 305
 306 #if IS_ENABLED(CONFIG_IPV6)
 307         if (sk->sk_family == AF_INET6)
 308                 hash = ipv6_portaddr_hash(sock_net(sk),
 309                                           &sk->sk_v6_rcv_saddr,
 310                                           inet_sk(sk)->inet_num);
 311         else
 312 #endif
 313                 hash = ipv4_portaddr_hash(sock_net(sk),
 314                                           inet_sk(sk)->inet_rcv_saddr,
 315                                           inet_sk(sk)->inet_num);
 316         return inet_lhash2_bucket(h, hash);
 317 }
 318
 319 static inline int compute_score(struct sock *sk, struct net *net,
 320                                 const unsigned short hnum, const __be32 daddr,
 321                                 const int dif, const int sdif)
 322 {
 323         int score = -1;
 324
 325         if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
 326                         !ipv6_only_sock(sk)) {
 327                 if (sk->sk_rcv_saddr != daddr)
 328                         return -1;
 329
 330                 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
 331                         return -1;
 332                 score =  sk->sk_bound_dev_if ? 2 : 1;
 333
 334                 if (sk->sk_family == PF_INET)
 335                         score++;
 336                 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 337                         score++;
 338         }
 339         return score;
 340 }
 341
 342 /**
 343  * inet_lookup_reuseport() - execute reuseport logic on AF_INET socket if necessary.
 344  * @net: network namespace.
 345  * @sk: AF_INET socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
 346  * @skb: context for a potential SK_REUSEPORT program.
 347  * @doff: header offset.
 348  * @saddr: source address.
 349  * @sport: source port.
 350  * @daddr: destination address.
 351  * @hnum: destination port in host byte order.
 352  * @ehashfn: hash function used to generate the fallback hash.
 353  *
 354  * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
 355  *         the selected sock or an error.
 356  */
 357 struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,
 358                                    struct sk_buff *skb, int doff,
 359                                    __be32 saddr, __be16 sport,
 360                                    __be32 daddr, unsigned short hnum,
 361                                    inet_ehashfn_t *ehashfn)
 362 {
 363         struct sock *reuse_sk = NULL;
 364         u32 phash;
 365
 366         if (sk->sk_reuseport) {
 367                 phash = INDIRECT_CALL_2(ehashfn, udp_ehashfn, inet_ehashfn,
 368                                         net, daddr, hnum, saddr, sport);
 369                 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
 370         }
 371         return reuse_sk;
 372 }
 373 EXPORT_SYMBOL_GPL(inet_lookup_reuseport);
 374
 375 /*
 376  * Here are some nice properties to exploit here. The BSD API
 377  * does not allow a listening sock to specify the remote port nor the
 378  * remote address for the connection. So always assume those are both
 379  * wildcarded during the search since they can never be otherwise.
 380  */
 381
 382 /* called with rcu_read_lock() : No refcount taken on the socket */
 383 static struct sock *inet_lhash2_lookup(struct net *net,
 384                                 struct inet_listen_hashbucket *ilb2,
 385                                 struct sk_buff *skb, int doff,
 386                                 const __be32 saddr, __be16 sport,
 387                                 const __be32 daddr, const unsigned short hnum,
 388                                 const int dif, const int sdif)
 389 {
 390         struct sock *sk, *result = NULL;
 391         struct hlist_nulls_node *node;
 392         int score, hiscore = 0;
 393
 394         sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
 395                 score = compute_score(sk, net, hnum, daddr, dif, sdif);
 396                 if (score > hiscore) {
 397                         result = inet_lookup_reuseport(net, sk, skb, doff,
 398                                                        saddr, sport, daddr, hnum, inet_ehashfn);
 399                         if (result)
 400                                 return result;
 401
 402                         result = sk;
 403                         hiscore = score;
 404                 }
 405         }
 406
 407         return result;
 408 }
 409
 410 struct sock *inet_lookup_run_sk_lookup(struct net *net,
 411                                        int protocol,
 412                                        struct sk_buff *skb, int doff,
 413                                        __be32 saddr, __be16 sport,
 414                                        __be32 daddr, u16 hnum, const int dif,
 415                                        inet_ehashfn_t *ehashfn)
 416 {
 417         struct sock *sk, *reuse_sk;
 418         bool no_reuseport;
 419
 420         no_reuseport = bpf_sk_lookup_run_v4(net, protocol, saddr, sport,
 421                                             daddr, hnum, dif, &sk);
 422         if (no_reuseport || IS_ERR_OR_NULL(sk))
 423                 return sk;
 424
 425         reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum,
 426                                          ehashfn);
 427         if (reuse_sk)
 428                 sk = reuse_sk;
 429         return sk;
 430 }
 431
 432 struct sock *__inet_lookup_listener(struct net *net,
 433                                     struct inet_hashinfo *hashinfo,
 434                                     struct sk_buff *skb, int doff,
 435                                     const __be32 saddr, __be16 sport,
 436                                     const __be32 daddr, const unsigned short hnum,
 437                                     const int dif, const int sdif)
 438 {
 439         struct inet_listen_hashbucket *ilb2;
 440         struct sock *result = NULL;
 441         unsigned int hash2;
 442
 443         /* Lookup redirect from BPF */
 444         if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
 445             hashinfo == net->ipv4.tcp_death_row.hashinfo) {
 446                 result = inet_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
 447                                                    saddr, sport, daddr, hnum, dif,
 448                                                    inet_ehashfn);
 449                 if (result)
 450                         goto done;
 451         }
 452
 453         hash2 = ipv4_portaddr_hash(net, daddr, hnum);
 454         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
 455
 456         result = inet_lhash2_lookup(net, ilb2, skb, doff,
 457                                     saddr, sport, daddr, hnum,
 458                                     dif, sdif);
 459         if (result)
 460                 goto done;
 461
 462         /* Lookup lhash2 with INADDR_ANY */
 463         hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
 464         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
 465
 466         result = inet_lhash2_lookup(net, ilb2, skb, doff,
 467                                     saddr, sport, htonl(INADDR_ANY), hnum,
 468                                     dif, sdif);
 469 done:
 470         if (IS_ERR(result))
 471                 return NULL;
 472         return result;
 473 }
 474 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 475
 476 /* All sockets share common refcount, but have different destructors */
 477 void sock_gen_put(struct sock *sk)
 478 {
 479         if (!refcount_dec_and_test(&sk->sk_refcnt))
 480                 return;
 481
 482         if (sk->sk_state == TCP_TIME_WAIT)
 483                 inet_twsk_free(inet_twsk(sk));
 484         else if (sk->sk_state == TCP_NEW_SYN_RECV)
 485                 reqsk_free(inet_reqsk(sk));
 486         else
 487                 sk_free(sk);
 488 }
 489 EXPORT_SYMBOL_GPL(sock_gen_put);
 490
 491 void sock_edemux(struct sk_buff *skb)
 492 {
 493         sock_gen_put(skb->sk);
 494 }
 495 EXPORT_SYMBOL(sock_edemux);
 496
 497 struct sock *__inet_lookup_established(struct net *net,
 498                                   struct inet_hashinfo *hashinfo,
 499                                   const __be32 saddr, const __be16 sport,
 500                                   const __be32 daddr, const u16 hnum,
 501                                   const int dif, const int sdif)
 502 {
 503         INET_ADDR_COOKIE(acookie, saddr, daddr);
 504         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
 505         struct sock *sk;
 506         const struct hlist_nulls_node *node;
 507         /* Optimize here for direct hit, only listening connections can
 508          * have wildcards anyways.
 509          */
 510         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
 511         unsigned int slot = hash & hashinfo->ehash_mask;
 512         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
 513
 514 begin:
 515         sk_nulls_for_each_rcu(sk, node, &head->chain) {
 516                 if (sk->sk_hash != hash)
 517                         continue;
 518                 if (likely(inet_match(net, sk, acookie, ports, dif, sdif))) {
 519                         if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 520                                 goto out;
 521                         if (unlikely(!inet_match(net, sk, acookie,
 522                                                  ports, dif, sdif))) {
 523                                 sock_gen_put(sk);
 524                                 goto begin;
 525                         }
 526                         goto found;
 527                 }
 528         }
 529         /*
 530          * if the nulls value we got at the end of this lookup is
 531          * not the expected one, we must restart lookup.
 532          * We probably met an item that was moved to another chain.
 533          */
 534         if (get_nulls_value(node) != slot)
 535                 goto begin;
 536 out:
 537         sk = NULL;
 538 found:
 539         return sk;
 540 }
 541 EXPORT_SYMBOL_GPL(__inet_lookup_established);
 542
 543 /* called with local bh disabled */
 544 static int __inet_check_established(struct inet_timewait_death_row *death_row,
 545                                     struct sock *sk, __u16 lport,
 546                                     struct inet_timewait_sock **twp)
 547 {
 548         struct inet_hashinfo *hinfo = death_row->hashinfo;
 549         struct inet_sock *inet = inet_sk(sk);
 550         __be32 daddr = inet->inet_rcv_saddr;
 551         __be32 saddr = inet->inet_daddr;
 552         int dif = sk->sk_bound_dev_if;
 553         struct net *net = sock_net(sk);
 554         int sdif = l3mdev_master_ifindex_by_index(net, dif);
 555         INET_ADDR_COOKIE(acookie, saddr, daddr);
 556         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 557         unsigned int hash = inet_ehashfn(net, daddr, lport,
 558                                          saddr, inet->inet_dport);
 559         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
 560         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
 561         struct sock *sk2;
 562         const struct hlist_nulls_node *node;
 563         struct inet_timewait_sock *tw = NULL;
 564
 565         spin_lock(lock);
 566
 567         sk_nulls_for_each(sk2, node, &head->chain) {
 568                 if (sk2->sk_hash != hash)
 569                         continue;
 570
 571                 if (likely(inet_match(net, sk2, acookie, ports, dif, sdif))) {
 572                         if (sk2->sk_state == TCP_TIME_WAIT) {
 573                                 tw = inet_twsk(sk2);
 574                                 if (twsk_unique(sk, sk2, twp))
 575                                         break;
 576                         }
 577                         goto not_unique;
 578                 }
 579         }
 580
 581         /* Must record num and sport now. Otherwise we will see
 582          * in hash table socket with a funny identity.
 583          */
 584         inet->inet_num = lport;
 585         inet->inet_sport = htons(lport);
 586         sk->sk_hash = hash;
 587         WARN_ON(!sk_unhashed(sk));
 588         __sk_nulls_add_node_rcu(sk, &head->chain);
 589         if (tw) {
 590                 sk_nulls_del_node_init_rcu((struct sock *)tw);
 591                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
 592         }
 593         spin_unlock(lock);
 594         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 595
 596         if (twp) {
 597                 *twp = tw;
 598         } else if (tw) {
 599                 /* Silly. Should hash-dance instead... */
 600                 inet_twsk_deschedule_put(tw);
 601         }
 602         return 0;
 603
 604 not_unique:
 605         spin_unlock(lock);
 606         return -EADDRNOTAVAIL;
 607 }
 608
 609 static u64 inet_sk_port_offset(const struct sock *sk)
 610 {
 611         const struct inet_sock *inet = inet_sk(sk);
 612
 613         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
 614                                           inet->inet_daddr,
 615                                           inet->inet_dport);
 616 }
 617
 618 /* Searches for an exsiting socket in the ehash bucket list.
 619  * Returns true if found, false otherwise.
 620  */
 621 static bool inet_ehash_lookup_by_sk(struct sock *sk,
 622                                     struct hlist_nulls_head *list)
 623 {
 624         const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num);
 625         const int sdif = sk->sk_bound_dev_if;
 626         const int dif = sk->sk_bound_dev_if;
 627         const struct hlist_nulls_node *node;
 628         struct net *net = sock_net(sk);
 629         struct sock *esk;
 630
 631         INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr);
 632
 633         sk_nulls_for_each_rcu(esk, node, list) {
 634                 if (esk->sk_hash != sk->sk_hash)
 635                         continue;
 636                 if (sk->sk_family == AF_INET) {
 637                         if (unlikely(inet_match(net, esk, acookie,
 638                                                 ports, dif, sdif))) {
 639                                 return true;
 640                         }
 641                 }
 642 #if IS_ENABLED(CONFIG_IPV6)
 643                 else if (sk->sk_family == AF_INET6) {
 644                         if (unlikely(inet6_match(net, esk,
 645                                                  &sk->sk_v6_daddr,
 646                                                  &sk->sk_v6_rcv_saddr,
 647                                                  ports, dif, sdif))) {
 648                                 return true;
 649                         }
 650                 }
 651 #endif
 652         }
 653         return false;
 654 }
 655
 656 /* Insert a socket into ehash, and eventually remove another one
 657  * (The another one can be a SYN_RECV or TIMEWAIT)
 658  * If an existing socket already exists, socket sk is not inserted,
 659  * and sets found_dup_sk parameter to true.
 660  */
 661 bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk)
 662 {
 663         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 664         struct inet_ehash_bucket *head;
 665         struct hlist_nulls_head *list;
 666         spinlock_t *lock;
 667         bool ret = true;
 668
 669         WARN_ON_ONCE(!sk_unhashed(sk));
 670
 671         sk->sk_hash = sk_ehashfn(sk);
 672         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
 673         list = &head->chain;
 674         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 675
 676         spin_lock(lock);
 677         if (osk) {
 678                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
 679                 ret = sk_nulls_del_node_init_rcu(osk);
 680         } else if (found_dup_sk) {
 681                 *found_dup_sk = inet_ehash_lookup_by_sk(sk, list);
 682                 if (*found_dup_sk)
 683                         ret = false;
 684         }
 685
 686         if (ret)
 687                 __sk_nulls_add_node_rcu(sk, list);
 688
 689         spin_unlock(lock);
 690
 691         return ret;
 692 }
 693
 694 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk)
 695 {
 696         bool ok = inet_ehash_insert(sk, osk, found_dup_sk);
 697
 698         if (ok) {
 699                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 700         } else {
 701                 this_cpu_inc(*sk->sk_prot->orphan_count);
 702                 inet_sk_set_state(sk, TCP_CLOSE);
 703                 sock_set_flag(sk, SOCK_DEAD);
 704                 inet_csk_destroy_sock(sk);
 705         }
 706         return ok;
 707 }
 708 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 709
 710 static int inet_reuseport_add_sock(struct sock *sk,
 711                                    struct inet_listen_hashbucket *ilb)
 712 {
 713         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
 714         const struct hlist_nulls_node *node;
 715         struct sock *sk2;
 716         kuid_t uid = sock_i_uid(sk);
 717
 718         sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
 719                 if (sk2 != sk &&
 720                     sk2->sk_family == sk->sk_family &&
 721                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
 722                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
 723                     inet_csk(sk2)->icsk_bind_hash == tb &&
 724                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
 725                     inet_rcv_saddr_equal(sk, sk2, false))
 726                         return reuseport_add_sock(sk, sk2,
 727                                                   inet_rcv_saddr_any(sk));
 728         }
 729
 730         return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
 731 }
 732
 733 int __inet_hash(struct sock *sk, struct sock *osk)
 734 {
 735         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 736         struct inet_listen_hashbucket *ilb2;
 737         int err = 0;
 738
 739         if (sk->sk_state != TCP_LISTEN) {
 740                 local_bh_disable();
 741                 inet_ehash_nolisten(sk, osk, NULL);
 742                 local_bh_enable();
 743                 return 0;
 744         }
 745         WARN_ON(!sk_unhashed(sk));
 746         ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
 747
 748         spin_lock(&ilb2->lock);
 749         if (sk->sk_reuseport) {
 750                 err = inet_reuseport_add_sock(sk, ilb2);
 751                 if (err)
 752                         goto unlock;
 753         }
 754         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 755                 sk->sk_family == AF_INET6)
 756                 __sk_nulls_add_node_tail_rcu(sk, &ilb2->nulls_head);
 757         else
 758                 __sk_nulls_add_node_rcu(sk, &ilb2->nulls_head);
 759         sock_set_flag(sk, SOCK_RCU_FREE);
 760         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 761 unlock:
 762         spin_unlock(&ilb2->lock);
 763
 764         return err;
 765 }
 766 EXPORT_SYMBOL(__inet_hash);
 767
 768 int inet_hash(struct sock *sk)
 769 {
 770         int err = 0;
 771
 772         if (sk->sk_state != TCP_CLOSE)
 773                 err = __inet_hash(sk, NULL);
 774
 775         return err;
 776 }
 777 EXPORT_SYMBOL_GPL(inet_hash);
 778
 779 void inet_unhash(struct sock *sk)
 780 {
 781         struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
 782
 783         if (sk_unhashed(sk))
 784                 return;
 785
 786         if (sk->sk_state == TCP_LISTEN) {
 787                 struct inet_listen_hashbucket *ilb2;
 788
 789                 ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
 790                 /* Don't disable bottom halves while acquiring the lock to
 791                  * avoid circular locking dependency on PREEMPT_RT.
 792                  */
 793                 spin_lock(&ilb2->lock);
 794                 if (sk_unhashed(sk)) {
 795                         spin_unlock(&ilb2->lock);
 796                         return;
 797                 }
 798
 799                 if (rcu_access_pointer(sk->sk_reuseport_cb))
 800                         reuseport_stop_listen_sock(sk);
 801
 802                 __sk_nulls_del_node_init_rcu(sk);
 803                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 804                 spin_unlock(&ilb2->lock);
 805         } else {
 806                 spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 807
 808                 spin_lock_bh(lock);
 809                 if (sk_unhashed(sk)) {
 810                         spin_unlock_bh(lock);
 811                         return;
 812                 }
 813                 __sk_nulls_del_node_init_rcu(sk);
 814                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 815                 spin_unlock_bh(lock);
 816         }
 817 }
 818 EXPORT_SYMBOL_GPL(inet_unhash);
 819
 820 static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
 821                                     const struct net *net, unsigned short port,
 822                                     int l3mdev, const struct sock *sk)
 823 {
 824         if (!net_eq(ib2_net(tb), net) || tb->port != port ||
 825             tb->l3mdev != l3mdev)
 826                 return false;
 827
 828         return inet_bind2_bucket_addr_match(tb, sk);
 829 }
 830
 831 bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const struct net *net,
 832                                       unsigned short port, int l3mdev, const struct sock *sk)
 833 {
 834         if (!net_eq(ib2_net(tb), net) || tb->port != port ||
 835             tb->l3mdev != l3mdev)
 836                 return false;
 837
 838 #if IS_ENABLED(CONFIG_IPV6)
 839         if (sk->sk_family != tb->family) {
 840                 if (sk->sk_family == AF_INET)
 841                         return ipv6_addr_any(&tb->v6_rcv_saddr) ||
 842                                 ipv6_addr_v4mapped_any(&tb->v6_rcv_saddr);
 843
 844                 return false;
 845         }
 846
 847         if (sk->sk_family == AF_INET6)
 848                 return ipv6_addr_any(&tb->v6_rcv_saddr);
 849 #endif
 850         return tb->rcv_saddr == 0;
 851 }
 852
 853 /* The socket's bhash2 hashbucket spinlock must be held when this is called */
 854 struct inet_bind2_bucket *
 855 inet_bind2_bucket_find(const struct inet_bind_hashbucket *head, const struct net *net,
 856                        unsigned short port, int l3mdev, const struct sock *sk)
 857 {
 858         struct inet_bind2_bucket *bhash2 = NULL;
 859
 860         inet_bind_bucket_for_each(bhash2, &head->chain)
 861                 if (inet_bind2_bucket_match(bhash2, net, port, l3mdev, sk))
 862                         break;
 863
 864         return bhash2;
 865 }
 866
 867 struct inet_bind_hashbucket *
 868 inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, int port)
 869 {
 870         struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
 871         u32 hash;
 872
 873 #if IS_ENABLED(CONFIG_IPV6)
 874         if (sk->sk_family == AF_INET6)
 875                 hash = ipv6_portaddr_hash(net, &in6addr_any, port);
 876         else
 877 #endif
 878                 hash = ipv4_portaddr_hash(net, 0, port);
 879
 880         return &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
 881 }
 882
 883 static void inet_update_saddr(struct sock *sk, void *saddr, int family)
 884 {
 885         if (family == AF_INET) {
 886                 inet_sk(sk)->inet_saddr = *(__be32 *)saddr;
 887                 sk_rcv_saddr_set(sk, inet_sk(sk)->inet_saddr);
 888         }
 889 #if IS_ENABLED(CONFIG_IPV6)
 890         else {
 891                 sk->sk_v6_rcv_saddr = *(struct in6_addr *)saddr;
 892         }
 893 #endif
 894 }
 895
 896 static int __inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family, bool reset)
 897 {
 898         struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
 899         struct inet_bind_hashbucket *head, *head2;
 900         struct inet_bind2_bucket *tb2, *new_tb2;
 901         int l3mdev = inet_sk_bound_l3mdev(sk);
 902         int port = inet_sk(sk)->inet_num;
 903         struct net *net = sock_net(sk);
 904         int bhash;
 905
 906         if (!inet_csk(sk)->icsk_bind2_hash) {
 907                 /* Not bind()ed before. */
 908                 if (reset)
 909                         inet_reset_saddr(sk);
 910                 else
 911                         inet_update_saddr(sk, saddr, family);
 912
 913                 return 0;
 914         }
 915
 916         /* Allocate a bind2 bucket ahead of time to avoid permanently putting
 917          * the bhash2 table in an inconsistent state if a new tb2 bucket
 918          * allocation fails.
 919          */
 920         new_tb2 = kmem_cache_alloc(hinfo->bind2_bucket_cachep, GFP_ATOMIC);
 921         if (!new_tb2) {
 922                 if (reset) {
 923                         /* The (INADDR_ANY, port) bucket might have already
 924                          * been freed, then we cannot fixup icsk_bind2_hash,
 925                          * so we give up and unlink sk from bhash/bhash2 not
 926                          * to leave inconsistency in bhash2.
 927                          */
 928                         inet_put_port(sk);
 929                         inet_reset_saddr(sk);
 930                 }
 931
 932                 return -ENOMEM;
 933         }
 934
 935         bhash = inet_bhashfn(net, port, hinfo->bhash_size);
 936         head = &hinfo->bhash[bhash];
 937         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
 938
 939         /* If we change saddr locklessly, another thread
 940          * iterating over bhash might see corrupted address.
 941          */
 942         spin_lock_bh(&head->lock);
 943
 944         spin_lock(&head2->lock);
 945         __sk_del_bind2_node(sk);
 946         inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep, inet_csk(sk)->icsk_bind2_hash);
 947         spin_unlock(&head2->lock);
 948
 949         if (reset)
 950                 inet_reset_saddr(sk);
 951         else
 952                 inet_update_saddr(sk, saddr, family);
 953
 954         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
 955
 956         spin_lock(&head2->lock);
 957         tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
 958         if (!tb2) {
 959                 tb2 = new_tb2;
 960                 inet_bind2_bucket_init(tb2, net, head2, port, l3mdev, sk);
 961         }
 962         sk_add_bind2_node(sk, &tb2->owners);
 963         inet_csk(sk)->icsk_bind2_hash = tb2;
 964         spin_unlock(&head2->lock);
 965
 966         spin_unlock_bh(&head->lock);
 967
 968         if (tb2 != new_tb2)
 969                 kmem_cache_free(hinfo->bind2_bucket_cachep, new_tb2);
 970
 971         return 0;
 972 }
 973
 974 int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family)
 975 {
 976         return __inet_bhash2_update_saddr(sk, saddr, family, false);
 977 }
 978 EXPORT_SYMBOL_GPL(inet_bhash2_update_saddr);
 979
 980 void inet_bhash2_reset_saddr(struct sock *sk)
 981 {
 982         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 983                 __inet_bhash2_update_saddr(sk, NULL, 0, true);
 984 }
 985 EXPORT_SYMBOL_GPL(inet_bhash2_reset_saddr);
 986
 987 /* RFC 6056 3.3.4.  Algorithm 4: Double-Hash Port Selection Algorithm
 988  * Note that we use 32bit integers (vs RFC 'short integers')
 989  * because 2^16 is not a multiple of num_ephemeral and this
 990  * property might be used by clever attacker.
 991  *
 992  * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though
 993  * attacks were since demonstrated, thus we use 65536 by default instead
 994  * to really give more isolation and privacy, at the expense of 256kB
 995  * of kernel memory.
 996  */
 997 #define INET_TABLE_PERTURB_SIZE (1 << CONFIG_INET_TABLE_PERTURB_ORDER)
 998 static u32 *table_perturb;
 999
1000 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
1001                 struct sock *sk, u64 port_offset,
1002                 int (*check_established)(struct inet_timewait_death_row *,
1003                         struct sock *, __u16, struct inet_timewait_sock **))
1004 {
1005         struct inet_hashinfo *hinfo = death_row->hashinfo;
1006         struct inet_bind_hashbucket *head, *head2;
1007         struct inet_timewait_sock *tw = NULL;
1008         int port = inet_sk(sk)->inet_num;
1009         struct net *net = sock_net(sk);
1010         struct inet_bind2_bucket *tb2;
1011         struct inet_bind_bucket *tb;
1012         bool tb_created = false;
1013         u32 remaining, offset;
1014         int ret, i, low, high;
1015         int l3mdev;
1016         u32 index;
1017
1018         if (port) {
1019                 local_bh_disable();
1020                 ret = check_established(death_row, sk, port, NULL);
1021                 local_bh_enable();
1022                 return ret;
1023         }
1024
1025         l3mdev = inet_sk_bound_l3mdev(sk);
1026
1027         inet_sk_get_local_port_range(sk, &low, &high);
1028         high++; /* [32768, 60999] -> [32768, 61000[ */
1029         remaining = high - low;
1030         if (likely(remaining > 1))
1031                 remaining &= ~1U;
1032
1033         get_random_sleepable_once(table_perturb,
1034                                   INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb));
1035         index = port_offset & (INET_TABLE_PERTURB_SIZE - 1);
1036
1037         offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32);
1038         offset %= remaining;
1039
1040         /* In first pass we try ports of @low parity.
1041          * inet_csk_get_port() does the opposite choice.
1042          */
1043         offset &= ~1U;
1044 other_parity_scan:
1045         port = low + offset;
1046         for (i = 0; i < remaining; i += 2, port += 2) {
1047                 if (unlikely(port >= high))
1048                         port -= remaining;
1049                 if (inet_is_local_reserved_port(net, port))
1050                         continue;
1051                 head = &hinfo->bhash[inet_bhashfn(net, port,
1052                                                   hinfo->bhash_size)];
1053                 spin_lock_bh(&head->lock);
1054
1055                 /* Does not bother with rcv_saddr checks, because
1056                  * the established check is already unique enough.
1057                  */
1058                 inet_bind_bucket_for_each(tb, &head->chain) {
1059                         if (inet_bind_bucket_match(tb, net, port, l3mdev)) {
1060                                 if (tb->fastreuse >= 0 ||
1061                                     tb->fastreuseport >= 0)
1062                                         goto next_port;
1063                                 WARN_ON(hlist_empty(&tb->owners));
1064                                 if (!check_established(death_row, sk,
1065                                                        port, &tw))
1066                                         goto ok;
1067                                 goto next_port;
1068                         }
1069                 }
1070
1071                 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
1072                                              net, head, port, l3mdev);
1073                 if (!tb) {
1074                         spin_unlock_bh(&head->lock);
1075                         return -ENOMEM;
1076                 }
1077                 tb_created = true;
1078                 tb->fastreuse = -1;
1079                 tb->fastreuseport = -1;
1080                 goto ok;
1081 next_port:
1082                 spin_unlock_bh(&head->lock);
1083                 cond_resched();
1084         }
1085
1086         offset++;
1087         if ((offset & 1) && remaining > 1)
1088                 goto other_parity_scan;
1089
1090         return -EADDRNOTAVAIL;
1091
1092 ok:
1093         /* Find the corresponding tb2 bucket since we need to
1094          * add the socket to the bhash2 table as well
1095          */
1096         head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
1097         spin_lock(&head2->lock);
1098
1099         tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
1100         if (!tb2) {
1101                 tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep, net,
1102                                                head2, port, l3mdev, sk);
1103                 if (!tb2)
1104                         goto error;
1105         }
1106
1107         /* Here we want to add a little bit of randomness to the next source
1108          * port that will be chosen. We use a max() with a random here so that
1109          * on low contention the randomness is maximal and on high contention
1110          * it may be inexistent.
1111          */
1112         i = max_t(int, i, get_random_u32_below(8) * 2);
1113         WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
1114
1115         /* Head lock still held and bh's disabled */
1116         inet_bind_hash(sk, tb, tb2, port);
1117
1118         if (sk_unhashed(sk)) {
1119                 inet_sk(sk)->inet_sport = htons(port);
1120                 inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
1121         }
1122         if (tw)
1123                 inet_twsk_bind_unhash(tw, hinfo);
1124
1125         spin_unlock(&head2->lock);
1126         spin_unlock(&head->lock);
1127
1128         if (tw)
1129                 inet_twsk_deschedule_put(tw);
1130         local_bh_enable();
1131         return 0;
1132
1133 error:
1134         spin_unlock(&head2->lock);
1135         if (tb_created)
1136                 inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
1137         spin_unlock_bh(&head->lock);
1138         return -ENOMEM;
1139 }
1140
1141 /*
1142  * Bind a port for a connect operation and hash it.
1143  */
1144 int inet_hash_connect(struct inet_timewait_death_row *death_row,
1145                       struct sock *sk)
1146 {
1147         u64 port_offset = 0;
1148
1149         if (!inet_sk(sk)->inet_num)
1150                 port_offset = inet_sk_port_offset(sk);
1151         return __inet_hash_connect(death_row, sk, port_offset,
1152                                    __inet_check_established);
1153 }
1154 EXPORT_SYMBOL_GPL(inet_hash_connect);
1155
1156 static void init_hashinfo_lhash2(struct inet_hashinfo *h)
1157 {
1158         int i;
1159
1160         for (i = 0; i <= h->lhash2_mask; i++) {
1161                 spin_lock_init(&h->lhash2[i].lock);
1162                 INIT_HLIST_NULLS_HEAD(&h->lhash2[i].nulls_head,
1163                                       i + LISTENING_NULLS_BASE);
1164         }
1165 }
1166
1167 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
1168                                 unsigned long numentries, int scale,
1169                                 unsigned long low_limit,
1170                                 unsigned long high_limit)
1171 {
1172         h->lhash2 = alloc_large_system_hash(name,
1173                                             sizeof(*h->lhash2),
1174                                             numentries,
1175                                             scale,
1176                                             0,
1177                                             NULL,
1178                                             &h->lhash2_mask,
1179                                             low_limit,
1180                                             high_limit);
1181         init_hashinfo_lhash2(h);
1182
1183         /* this one is used for source ports of outgoing connections */
1184         table_perturb = alloc_large_system_hash("Table-perturb",
1185                                                 sizeof(*table_perturb),
1186                                                 INET_TABLE_PERTURB_SIZE,
1187                                                 0, 0, NULL, NULL,
1188                                                 INET_TABLE_PERTURB_SIZE,
1189                                                 INET_TABLE_PERTURB_SIZE);
1190 }
1191
1192 int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
1193 {
1194         h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
1195         if (!h->lhash2)
1196                 return -ENOMEM;
1197
1198         h->lhash2_mask = INET_LHTABLE_SIZE - 1;
1199         /* INET_LHTABLE_SIZE must be a power of 2 */
1200         BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
1201
1202         init_hashinfo_lhash2(h);
1203         return 0;
1204 }
1205 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
1206
1207 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
1208 {
1209         unsigned int locksz = sizeof(spinlock_t);
1210         unsigned int i, nblocks = 1;
1211
1212         if (locksz != 0) {
1213                 /* allocate 2 cache lines or at least one spinlock per cpu */
1214                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
1215                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
1216
1217                 /* no more locks than number of hash buckets */
1218                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
1219
1220                 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
1221                 if (!hashinfo->ehash_locks)
1222                         return -ENOMEM;
1223
1224                 for (i = 0; i < nblocks; i++)
1225                         spin_lock_init(&hashinfo->ehash_locks[i]);
1226         }
1227         hashinfo->ehash_locks_mask = nblocks - 1;
1228         return 0;
1229 }
1230 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
1231
1232 struct inet_hashinfo *inet_pernet_hashinfo_alloc(struct inet_hashinfo *hashinfo,
1233                                                  unsigned int ehash_entries)
1234 {
1235         struct inet_hashinfo *new_hashinfo;
1236         int i;
1237
1238         new_hashinfo = kmemdup(hashinfo, sizeof(*hashinfo), GFP_KERNEL);
1239         if (!new_hashinfo)
1240                 goto err;
1241
1242         new_hashinfo->ehash = vmalloc_huge(ehash_entries * sizeof(struct inet_ehash_bucket),
1243                                            GFP_KERNEL_ACCOUNT);
1244         if (!new_hashinfo->ehash)
1245                 goto free_hashinfo;
1246
1247         new_hashinfo->ehash_mask = ehash_entries - 1;
1248
1249         if (inet_ehash_locks_alloc(new_hashinfo))
1250                 goto free_ehash;
1251
1252         for (i = 0; i < ehash_entries; i++)
1253                 INIT_HLIST_NULLS_HEAD(&new_hashinfo->ehash[i].chain, i);
1254
1255         new_hashinfo->pernet = true;
1256
1257         return new_hashinfo;
1258
1259 free_ehash:
1260         vfree(new_hashinfo->ehash);
1261 free_hashinfo:
1262         kfree(new_hashinfo);
1263 err:
1264         return NULL;
1265 }
1266 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_alloc);
1267
1268 void inet_pernet_hashinfo_free(struct inet_hashinfo *hashinfo)
1269 {
1270         if (!hashinfo->pernet)
1271                 return;
1272
1273         inet_ehash_locks_free(hashinfo);
1274         vfree(hashinfo->ehash);
1275         kfree(hashinfo);
1276 }
1277 EXPORT_SYMBOL_GPL(inet_pernet_hashinfo_free);