net/core/sock_map.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
   3
   4 #include <linux/bpf.h>
   5 #include <linux/filter.h>
   6 #include <linux/errno.h>
   7 #include <linux/file.h>
   8 #include <linux/net.h>
   9 #include <linux/workqueue.h>
  10 #include <linux/skmsg.h>
  11 #include <linux/list.h>
  12 #include <linux/jhash.h>
  13 #include <linux/sock_diag.h>
  14 #include <net/udp.h>
  15
  16 struct bpf_stab {
  17         struct bpf_map map;
  18         struct sock **sks;
  19         struct sk_psock_progs progs;
  20         raw_spinlock_t lock;
  21 };
  22
  23 #define SOCK_CREATE_FLAG_MASK                           \
  24         (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
  25
  26 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
  27 {
  28         struct bpf_stab *stab;
  29         u64 cost;
  30         int err;
  31
  32         if (!capable(CAP_NET_ADMIN))
  33                 return ERR_PTR(-EPERM);
  34         if (attr->max_entries == 0 ||
  35             attr->key_size    != 4 ||
  36             (attr->value_size != sizeof(u32) &&
  37              attr->value_size != sizeof(u64)) ||
  38             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
  39                 return ERR_PTR(-EINVAL);
  40
  41         stab = kzalloc(sizeof(*stab), GFP_USER);
  42         if (!stab)
  43                 return ERR_PTR(-ENOMEM);
  44
  45         bpf_map_init_from_attr(&stab->map, attr);
  46         raw_spin_lock_init(&stab->lock);
  47
  48         /* Make sure page count doesn't overflow. */
  49         cost = (u64) stab->map.max_entries * sizeof(struct sock *);
  50         err = bpf_map_charge_init(&stab->map.memory, cost);
  51         if (err)
  52                 goto free_stab;
  53
  54         stab->sks = bpf_map_area_alloc(stab->map.max_entries *
  55                                        sizeof(struct sock *),
  56                                        stab->map.numa_node);
  57         if (stab->sks)
  58                 return &stab->map;
  59         err = -ENOMEM;
  60         bpf_map_charge_finish(&stab->map.memory);
  61 free_stab:
  62         kfree(stab);
  63         return ERR_PTR(err);
  64 }
  65
  66 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
  67 {
  68         u32 ufd = attr->target_fd;
  69         struct bpf_map *map;
  70         struct fd f;
  71         int ret;
  72
  73         if (attr->attach_flags || attr->replace_bpf_fd)
  74                 return -EINVAL;
  75
  76         f = fdget(ufd);
  77         map = __bpf_map_get(f);
  78         if (IS_ERR(map))
  79                 return PTR_ERR(map);
  80         ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
  81         fdput(f);
  82         return ret;
  83 }
  84
  85 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
  86 {
  87         u32 ufd = attr->target_fd;
  88         struct bpf_prog *prog;
  89         struct bpf_map *map;
  90         struct fd f;
  91         int ret;
  92
  93         if (attr->attach_flags || attr->replace_bpf_fd)
  94                 return -EINVAL;
  95
  96         f = fdget(ufd);
  97         map = __bpf_map_get(f);
  98         if (IS_ERR(map))
  99                 return PTR_ERR(map);
 100
 101         prog = bpf_prog_get(attr->attach_bpf_fd);
 102         if (IS_ERR(prog)) {
 103                 ret = PTR_ERR(prog);
 104                 goto put_map;
 105         }
 106
 107         if (prog->type != ptype) {
 108                 ret = -EINVAL;
 109                 goto put_prog;
 110         }
 111
 112         ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
 113 put_prog:
 114         bpf_prog_put(prog);
 115 put_map:
 116         fdput(f);
 117         return ret;
 118 }
 119
 120 static void sock_map_sk_acquire(struct sock *sk)
 121         __acquires(&sk->sk_lock.slock)
 122 {
 123         lock_sock(sk);
 124         preempt_disable();
 125         rcu_read_lock();
 126 }
 127
 128 static void sock_map_sk_release(struct sock *sk)
 129         __releases(&sk->sk_lock.slock)
 130 {
 131         rcu_read_unlock();
 132         preempt_enable();
 133         release_sock(sk);
 134 }
 135
 136 static void sock_map_add_link(struct sk_psock *psock,
 137                               struct sk_psock_link *link,
 138                               struct bpf_map *map, void *link_raw)
 139 {
 140         link->link_raw = link_raw;
 141         link->map = map;
 142         spin_lock_bh(&psock->link_lock);
 143         list_add_tail(&link->list, &psock->link);
 144         spin_unlock_bh(&psock->link_lock);
 145 }
 146
 147 static void sock_map_del_link(struct sock *sk,
 148                               struct sk_psock *psock, void *link_raw)
 149 {
 150         struct sk_psock_link *link, *tmp;
 151         bool strp_stop = false;
 152
 153         spin_lock_bh(&psock->link_lock);
 154         list_for_each_entry_safe(link, tmp, &psock->link, list) {
 155                 if (link->link_raw == link_raw) {
 156                         struct bpf_map *map = link->map;
 157                         struct bpf_stab *stab = container_of(map, struct bpf_stab,
 158                                                              map);
 159                         if (psock->parser.enabled && stab->progs.skb_parser)
 160                                 strp_stop = true;
 161                         list_del(&link->list);
 162                         sk_psock_free_link(link);
 163                 }
 164         }
 165         spin_unlock_bh(&psock->link_lock);
 166         if (strp_stop) {
 167                 write_lock_bh(&sk->sk_callback_lock);
 168                 sk_psock_stop_strp(sk, psock);
 169                 write_unlock_bh(&sk->sk_callback_lock);
 170         }
 171 }
 172
 173 static void sock_map_unref(struct sock *sk, void *link_raw)
 174 {
 175         struct sk_psock *psock = sk_psock(sk);
 176
 177         if (likely(psock)) {
 178                 sock_map_del_link(sk, psock, link_raw);
 179                 sk_psock_put(sk, psock);
 180         }
 181 }
 182
 183 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
 184 {
 185         struct proto *prot;
 186
 187         sock_owned_by_me(sk);
 188
 189         switch (sk->sk_type) {
 190         case SOCK_STREAM:
 191                 prot = tcp_bpf_get_proto(sk, psock);
 192                 break;
 193
 194         case SOCK_DGRAM:
 195                 prot = udp_bpf_get_proto(sk, psock);
 196                 break;
 197
 198         default:
 199                 return -EINVAL;
 200         }
 201
 202         if (IS_ERR(prot))
 203                 return PTR_ERR(prot);
 204
 205         sk_psock_update_proto(sk, psock, prot);
 206         return 0;
 207 }
 208
 209 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
 210 {
 211         struct sk_psock *psock;
 212
 213         rcu_read_lock();
 214         psock = sk_psock(sk);
 215         if (psock) {
 216                 if (sk->sk_prot->close != sock_map_close) {
 217                         psock = ERR_PTR(-EBUSY);
 218                         goto out;
 219                 }
 220
 221                 if (!refcount_inc_not_zero(&psock->refcnt))
 222                         psock = ERR_PTR(-EBUSY);
 223         }
 224 out:
 225         rcu_read_unlock();
 226         return psock;
 227 }
 228
 229 static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
 230                          struct sock *sk)
 231 {
 232         struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
 233         struct sk_psock *psock;
 234         bool skb_progs;
 235         int ret;
 236
 237         skb_verdict = READ_ONCE(progs->skb_verdict);
 238         skb_parser = READ_ONCE(progs->skb_parser);
 239         skb_progs = skb_parser && skb_verdict;
 240         if (skb_progs) {
 241                 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
 242                 if (IS_ERR(skb_verdict))
 243                         return PTR_ERR(skb_verdict);
 244                 skb_parser = bpf_prog_inc_not_zero(skb_parser);
 245                 if (IS_ERR(skb_parser)) {
 246                         bpf_prog_put(skb_verdict);
 247                         return PTR_ERR(skb_parser);
 248                 }
 249         }
 250
 251         msg_parser = READ_ONCE(progs->msg_parser);
 252         if (msg_parser) {
 253                 msg_parser = bpf_prog_inc_not_zero(msg_parser);
 254                 if (IS_ERR(msg_parser)) {
 255                         ret = PTR_ERR(msg_parser);
 256                         goto out;
 257                 }
 258         }
 259
 260         psock = sock_map_psock_get_checked(sk);
 261         if (IS_ERR(psock)) {
 262                 ret = PTR_ERR(psock);
 263                 goto out_progs;
 264         }
 265
 266         if (psock) {
 267                 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
 268                     (skb_progs  && READ_ONCE(psock->progs.skb_parser))) {
 269                         sk_psock_put(sk, psock);
 270                         ret = -EBUSY;
 271                         goto out_progs;
 272                 }
 273         } else {
 274                 psock = sk_psock_init(sk, map->numa_node);
 275                 if (!psock) {
 276                         ret = -ENOMEM;
 277                         goto out_progs;
 278                 }
 279         }
 280
 281         if (msg_parser)
 282                 psock_set_prog(&psock->progs.msg_parser, msg_parser);
 283
 284         ret = sock_map_init_proto(sk, psock);
 285         if (ret < 0)
 286                 goto out_drop;
 287
 288         write_lock_bh(&sk->sk_callback_lock);
 289         if (skb_progs && !psock->parser.enabled) {
 290                 ret = sk_psock_init_strp(sk, psock);
 291                 if (ret) {
 292                         write_unlock_bh(&sk->sk_callback_lock);
 293                         goto out_drop;
 294                 }
 295                 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
 296                 psock_set_prog(&psock->progs.skb_parser, skb_parser);
 297                 sk_psock_start_strp(sk, psock);
 298         }
 299         write_unlock_bh(&sk->sk_callback_lock);
 300         return 0;
 301 out_drop:
 302         sk_psock_put(sk, psock);
 303 out_progs:
 304         if (msg_parser)
 305                 bpf_prog_put(msg_parser);
 306 out:
 307         if (skb_progs) {
 308                 bpf_prog_put(skb_verdict);
 309                 bpf_prog_put(skb_parser);
 310         }
 311         return ret;
 312 }
 313
 314 static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
 315 {
 316         struct sk_psock *psock;
 317         int ret;
 318
 319         psock = sock_map_psock_get_checked(sk);
 320         if (IS_ERR(psock))
 321                 return PTR_ERR(psock);
 322
 323         if (!psock) {
 324                 psock = sk_psock_init(sk, map->numa_node);
 325                 if (!psock)
 326                         return -ENOMEM;
 327         }
 328
 329         ret = sock_map_init_proto(sk, psock);
 330         if (ret < 0)
 331                 sk_psock_put(sk, psock);
 332         return ret;
 333 }
 334
 335 static void sock_map_free(struct bpf_map *map)
 336 {
 337         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 338         int i;
 339
 340         /* After the sync no updates or deletes will be in-flight so it
 341          * is safe to walk map and remove entries without risking a race
 342          * in EEXIST update case.
 343          */
 344         synchronize_rcu();
 345         for (i = 0; i < stab->map.max_entries; i++) {
 346                 struct sock **psk = &stab->sks[i];
 347                 struct sock *sk;
 348
 349                 sk = xchg(psk, NULL);
 350                 if (sk) {
 351                         lock_sock(sk);
 352                         rcu_read_lock();
 353                         sock_map_unref(sk, psk);
 354                         rcu_read_unlock();
 355                         release_sock(sk);
 356                 }
 357         }
 358
 359         /* wait for psock readers accessing its map link */
 360         synchronize_rcu();
 361
 362         bpf_map_area_free(stab->sks);
 363         kfree(stab);
 364 }
 365
 366 static void sock_map_release_progs(struct bpf_map *map)
 367 {
 368         psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
 369 }
 370
 371 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 372 {
 373         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 374
 375         WARN_ON_ONCE(!rcu_read_lock_held());
 376
 377         if (unlikely(key >= map->max_entries))
 378                 return NULL;
 379         return READ_ONCE(stab->sks[key]);
 380 }
 381
 382 static void *sock_map_lookup(struct bpf_map *map, void *key)
 383 {
 384         struct sock *sk;
 385
 386         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 387         if (!sk || !sk_fullsock(sk))
 388                 return NULL;
 389         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
 390                 return NULL;
 391         return sk;
 392 }
 393
 394 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
 395 {
 396         struct sock *sk;
 397
 398         if (map->value_size != sizeof(u64))
 399                 return ERR_PTR(-ENOSPC);
 400
 401         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 402         if (!sk)
 403                 return ERR_PTR(-ENOENT);
 404
 405         sock_gen_cookie(sk);
 406         return &sk->sk_cookie;
 407 }
 408
 409 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
 410                              struct sock **psk)
 411 {
 412         struct sock *sk;
 413         int err = 0;
 414
 415         raw_spin_lock_bh(&stab->lock);
 416         sk = *psk;
 417         if (!sk_test || sk_test == sk)
 418                 sk = xchg(psk, NULL);
 419
 420         if (likely(sk))
 421                 sock_map_unref(sk, psk);
 422         else
 423                 err = -EINVAL;
 424
 425         raw_spin_unlock_bh(&stab->lock);
 426         return err;
 427 }
 428
 429 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
 430                                       void *link_raw)
 431 {
 432         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 433
 434         __sock_map_delete(stab, sk, link_raw);
 435 }
 436
 437 static int sock_map_delete_elem(struct bpf_map *map, void *key)
 438 {
 439         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 440         u32 i = *(u32 *)key;
 441         struct sock **psk;
 442
 443         if (unlikely(i >= map->max_entries))
 444                 return -EINVAL;
 445
 446         psk = &stab->sks[i];
 447         return __sock_map_delete(stab, NULL, psk);
 448 }
 449
 450 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
 451 {
 452         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 453         u32 i = key ? *(u32 *)key : U32_MAX;
 454         u32 *key_next = next;
 455
 456         if (i == stab->map.max_entries - 1)
 457                 return -ENOENT;
 458         if (i >= stab->map.max_entries)
 459                 *key_next = 0;
 460         else
 461                 *key_next = i + 1;
 462         return 0;
 463 }
 464
 465 static bool sock_map_redirect_allowed(const struct sock *sk);
 466
 467 static int sock_map_update_common(struct bpf_map *map, u32 idx,
 468                                   struct sock *sk, u64 flags)
 469 {
 470         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 471         struct sk_psock_link *link;
 472         struct sk_psock *psock;
 473         struct sock *osk;
 474         int ret;
 475
 476         WARN_ON_ONCE(!rcu_read_lock_held());
 477         if (unlikely(flags > BPF_EXIST))
 478                 return -EINVAL;
 479         if (unlikely(idx >= map->max_entries))
 480                 return -E2BIG;
 481         if (inet_csk_has_ulp(sk))
 482                 return -EINVAL;
 483
 484         link = sk_psock_init_link();
 485         if (!link)
 486                 return -ENOMEM;
 487
 488         /* Only sockets we can redirect into/from in BPF need to hold
 489          * refs to parser/verdict progs and have their sk_data_ready
 490          * and sk_write_space callbacks overridden.
 491          */
 492         if (sock_map_redirect_allowed(sk))
 493                 ret = sock_map_link(map, &stab->progs, sk);
 494         else
 495                 ret = sock_map_link_no_progs(map, sk);
 496         if (ret < 0)
 497                 goto out_free;
 498
 499         psock = sk_psock(sk);
 500         WARN_ON_ONCE(!psock);
 501
 502         raw_spin_lock_bh(&stab->lock);
 503         osk = stab->sks[idx];
 504         if (osk && flags == BPF_NOEXIST) {
 505                 ret = -EEXIST;
 506                 goto out_unlock;
 507         } else if (!osk && flags == BPF_EXIST) {
 508                 ret = -ENOENT;
 509                 goto out_unlock;
 510         }
 511
 512         sock_map_add_link(psock, link, map, &stab->sks[idx]);
 513         stab->sks[idx] = sk;
 514         if (osk)
 515                 sock_map_unref(osk, &stab->sks[idx]);
 516         raw_spin_unlock_bh(&stab->lock);
 517         return 0;
 518 out_unlock:
 519         raw_spin_unlock_bh(&stab->lock);
 520         if (psock)
 521                 sk_psock_put(sk, psock);
 522 out_free:
 523         sk_psock_free_link(link);
 524         return ret;
 525 }
 526
 527 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
 528 {
 529         return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
 530                ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
 531                ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
 532 }
 533
 534 static bool sk_is_tcp(const struct sock *sk)
 535 {
 536         return sk->sk_type == SOCK_STREAM &&
 537                sk->sk_protocol == IPPROTO_TCP;
 538 }
 539
 540 static bool sk_is_udp(const struct sock *sk)
 541 {
 542         return sk->sk_type == SOCK_DGRAM &&
 543                sk->sk_protocol == IPPROTO_UDP;
 544 }
 545
 546 static bool sock_map_redirect_allowed(const struct sock *sk)
 547 {
 548         return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
 549 }
 550
 551 static bool sock_map_sk_is_suitable(const struct sock *sk)
 552 {
 553         return sk_is_tcp(sk) || sk_is_udp(sk);
 554 }
 555
 556 static bool sock_map_sk_state_allowed(const struct sock *sk)
 557 {
 558         if (sk_is_tcp(sk))
 559                 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 560         else if (sk_is_udp(sk))
 561                 return sk_hashed(sk);
 562
 563         return false;
 564 }
 565
 566 static int sock_map_update_elem(struct bpf_map *map, void *key,
 567                                 void *value, u64 flags)
 568 {
 569         u32 idx = *(u32 *)key;
 570         struct socket *sock;
 571         struct sock *sk;
 572         int ret;
 573         u64 ufd;
 574
 575         if (map->value_size == sizeof(u64))
 576                 ufd = *(u64 *)value;
 577         else
 578                 ufd = *(u32 *)value;
 579         if (ufd > S32_MAX)
 580                 return -EINVAL;
 581
 582         sock = sockfd_lookup(ufd, &ret);
 583         if (!sock)
 584                 return ret;
 585         sk = sock->sk;
 586         if (!sk) {
 587                 ret = -EINVAL;
 588                 goto out;
 589         }
 590         if (!sock_map_sk_is_suitable(sk)) {
 591                 ret = -EOPNOTSUPP;
 592                 goto out;
 593         }
 594
 595         sock_map_sk_acquire(sk);
 596         if (!sock_map_sk_state_allowed(sk))
 597                 ret = -EOPNOTSUPP;
 598         else
 599                 ret = sock_map_update_common(map, idx, sk, flags);
 600         sock_map_sk_release(sk);
 601 out:
 602         fput(sock->file);
 603         return ret;
 604 }
 605
 606 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 607            struct bpf_map *, map, void *, key, u64, flags)
 608 {
 609         WARN_ON_ONCE(!rcu_read_lock_held());
 610
 611         if (likely(sock_map_sk_is_suitable(sops->sk) &&
 612                    sock_map_op_okay(sops)))
 613                 return sock_map_update_common(map, *(u32 *)key, sops->sk,
 614                                               flags);
 615         return -EOPNOTSUPP;
 616 }
 617
 618 const struct bpf_func_proto bpf_sock_map_update_proto = {
 619         .func           = bpf_sock_map_update,
 620         .gpl_only       = false,
 621         .pkt_access     = true,
 622         .ret_type       = RET_INTEGER,
 623         .arg1_type      = ARG_PTR_TO_CTX,
 624         .arg2_type      = ARG_CONST_MAP_PTR,
 625         .arg3_type      = ARG_PTR_TO_MAP_KEY,
 626         .arg4_type      = ARG_ANYTHING,
 627 };
 628
 629 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 630            struct bpf_map *, map, u32, key, u64, flags)
 631 {
 632         struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
 633         struct sock *sk;
 634
 635         if (unlikely(flags & ~(BPF_F_INGRESS)))
 636                 return SK_DROP;
 637
 638         sk = __sock_map_lookup_elem(map, key);
 639         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 640                 return SK_DROP;
 641
 642         tcb->bpf.flags = flags;
 643         tcb->bpf.sk_redir = sk;
 644         return SK_PASS;
 645 }
 646
 647 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 648         .func           = bpf_sk_redirect_map,
 649         .gpl_only       = false,
 650         .ret_type       = RET_INTEGER,
 651         .arg1_type      = ARG_PTR_TO_CTX,
 652         .arg2_type      = ARG_CONST_MAP_PTR,
 653         .arg3_type      = ARG_ANYTHING,
 654         .arg4_type      = ARG_ANYTHING,
 655 };
 656
 657 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 658            struct bpf_map *, map, u32, key, u64, flags)
 659 {
 660         struct sock *sk;
 661
 662         if (unlikely(flags & ~(BPF_F_INGRESS)))
 663                 return SK_DROP;
 664
 665         sk = __sock_map_lookup_elem(map, key);
 666         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 667                 return SK_DROP;
 668
 669         msg->flags = flags;
 670         msg->sk_redir = sk;
 671         return SK_PASS;
 672 }
 673
 674 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 675         .func           = bpf_msg_redirect_map,
 676         .gpl_only       = false,
 677         .ret_type       = RET_INTEGER,
 678         .arg1_type      = ARG_PTR_TO_CTX,
 679         .arg2_type      = ARG_CONST_MAP_PTR,
 680         .arg3_type      = ARG_ANYTHING,
 681         .arg4_type      = ARG_ANYTHING,
 682 };
 683
 684 static int sock_map_btf_id;
 685 const struct bpf_map_ops sock_map_ops = {
 686         .map_alloc              = sock_map_alloc,
 687         .map_free               = sock_map_free,
 688         .map_get_next_key       = sock_map_get_next_key,
 689         .map_lookup_elem_sys_only = sock_map_lookup_sys,
 690         .map_update_elem        = sock_map_update_elem,
 691         .map_delete_elem        = sock_map_delete_elem,
 692         .map_lookup_elem        = sock_map_lookup,
 693         .map_release_uref       = sock_map_release_progs,
 694         .map_check_btf          = map_check_no_btf,
 695         .map_btf_name           = "bpf_stab",
 696         .map_btf_id             = &sock_map_btf_id,
 697 };
 698
 699 struct bpf_shtab_elem {
 700         struct rcu_head rcu;
 701         u32 hash;
 702         struct sock *sk;
 703         struct hlist_node node;
 704         u8 key[];
 705 };
 706
 707 struct bpf_shtab_bucket {
 708         struct hlist_head head;
 709         raw_spinlock_t lock;
 710 };
 711
 712 struct bpf_shtab {
 713         struct bpf_map map;
 714         struct bpf_shtab_bucket *buckets;
 715         u32 buckets_num;
 716         u32 elem_size;
 717         struct sk_psock_progs progs;
 718         atomic_t count;
 719 };
 720
 721 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 722 {
 723         return jhash(key, len, 0);
 724 }
 725
 726 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 727                                                         u32 hash)
 728 {
 729         return &htab->buckets[hash & (htab->buckets_num - 1)];
 730 }
 731
 732 static struct bpf_shtab_elem *
 733 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 734                           u32 key_size)
 735 {
 736         struct bpf_shtab_elem *elem;
 737
 738         hlist_for_each_entry_rcu(elem, head, node) {
 739                 if (elem->hash == hash &&
 740                     !memcmp(&elem->key, key, key_size))
 741                         return elem;
 742         }
 743
 744         return NULL;
 745 }
 746
 747 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 748 {
 749         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 750         u32 key_size = map->key_size, hash;
 751         struct bpf_shtab_bucket *bucket;
 752         struct bpf_shtab_elem *elem;
 753
 754         WARN_ON_ONCE(!rcu_read_lock_held());
 755
 756         hash = sock_hash_bucket_hash(key, key_size);
 757         bucket = sock_hash_select_bucket(htab, hash);
 758         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 759
 760         return elem ? elem->sk : NULL;
 761 }
 762
 763 static void sock_hash_free_elem(struct bpf_shtab *htab,
 764                                 struct bpf_shtab_elem *elem)
 765 {
 766         atomic_dec(&htab->count);
 767         kfree_rcu(elem, rcu);
 768 }
 769
 770 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 771                                        void *link_raw)
 772 {
 773         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 774         struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 775         struct bpf_shtab_bucket *bucket;
 776
 777         WARN_ON_ONCE(!rcu_read_lock_held());
 778         bucket = sock_hash_select_bucket(htab, elem->hash);
 779
 780         /* elem may be deleted in parallel from the map, but access here
 781          * is okay since it's going away only after RCU grace period.
 782          * However, we need to check whether it's still present.
 783          */
 784         raw_spin_lock_bh(&bucket->lock);
 785         elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 786                                                elem->key, map->key_size);
 787         if (elem_probe && elem_probe == elem) {
 788                 hlist_del_rcu(&elem->node);
 789                 sock_map_unref(elem->sk, elem);
 790                 sock_hash_free_elem(htab, elem);
 791         }
 792         raw_spin_unlock_bh(&bucket->lock);
 793 }
 794
 795 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
 796 {
 797         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 798         u32 hash, key_size = map->key_size;
 799         struct bpf_shtab_bucket *bucket;
 800         struct bpf_shtab_elem *elem;
 801         int ret = -ENOENT;
 802
 803         hash = sock_hash_bucket_hash(key, key_size);
 804         bucket = sock_hash_select_bucket(htab, hash);
 805
 806         raw_spin_lock_bh(&bucket->lock);
 807         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 808         if (elem) {
 809                 hlist_del_rcu(&elem->node);
 810                 sock_map_unref(elem->sk, elem);
 811                 sock_hash_free_elem(htab, elem);
 812                 ret = 0;
 813         }
 814         raw_spin_unlock_bh(&bucket->lock);
 815         return ret;
 816 }
 817
 818 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 819                                                    void *key, u32 key_size,
 820                                                    u32 hash, struct sock *sk,
 821                                                    struct bpf_shtab_elem *old)
 822 {
 823         struct bpf_shtab_elem *new;
 824
 825         if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 826                 if (!old) {
 827                         atomic_dec(&htab->count);
 828                         return ERR_PTR(-E2BIG);
 829                 }
 830         }
 831
 832         new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
 833                            htab->map.numa_node);
 834         if (!new) {
 835                 atomic_dec(&htab->count);
 836                 return ERR_PTR(-ENOMEM);
 837         }
 838         memcpy(new->key, key, key_size);
 839         new->sk = sk;
 840         new->hash = hash;
 841         return new;
 842 }
 843
 844 static int sock_hash_update_common(struct bpf_map *map, void *key,
 845                                    struct sock *sk, u64 flags)
 846 {
 847         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 848         u32 key_size = map->key_size, hash;
 849         struct bpf_shtab_elem *elem, *elem_new;
 850         struct bpf_shtab_bucket *bucket;
 851         struct sk_psock_link *link;
 852         struct sk_psock *psock;
 853         int ret;
 854
 855         WARN_ON_ONCE(!rcu_read_lock_held());
 856         if (unlikely(flags > BPF_EXIST))
 857                 return -EINVAL;
 858         if (inet_csk_has_ulp(sk))
 859                 return -EINVAL;
 860
 861         link = sk_psock_init_link();
 862         if (!link)
 863                 return -ENOMEM;
 864
 865         /* Only sockets we can redirect into/from in BPF need to hold
 866          * refs to parser/verdict progs and have their sk_data_ready
 867          * and sk_write_space callbacks overridden.
 868          */
 869         if (sock_map_redirect_allowed(sk))
 870                 ret = sock_map_link(map, &htab->progs, sk);
 871         else
 872                 ret = sock_map_link_no_progs(map, sk);
 873         if (ret < 0)
 874                 goto out_free;
 875
 876         psock = sk_psock(sk);
 877         WARN_ON_ONCE(!psock);
 878
 879         hash = sock_hash_bucket_hash(key, key_size);
 880         bucket = sock_hash_select_bucket(htab, hash);
 881
 882         raw_spin_lock_bh(&bucket->lock);
 883         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 884         if (elem && flags == BPF_NOEXIST) {
 885                 ret = -EEXIST;
 886                 goto out_unlock;
 887         } else if (!elem && flags == BPF_EXIST) {
 888                 ret = -ENOENT;
 889                 goto out_unlock;
 890         }
 891
 892         elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
 893         if (IS_ERR(elem_new)) {
 894                 ret = PTR_ERR(elem_new);
 895                 goto out_unlock;
 896         }
 897
 898         sock_map_add_link(psock, link, map, elem_new);
 899         /* Add new element to the head of the list, so that
 900          * concurrent search will find it before old elem.
 901          */
 902         hlist_add_head_rcu(&elem_new->node, &bucket->head);
 903         if (elem) {
 904                 hlist_del_rcu(&elem->node);
 905                 sock_map_unref(elem->sk, elem);
 906                 sock_hash_free_elem(htab, elem);
 907         }
 908         raw_spin_unlock_bh(&bucket->lock);
 909         return 0;
 910 out_unlock:
 911         raw_spin_unlock_bh(&bucket->lock);
 912         sk_psock_put(sk, psock);
 913 out_free:
 914         sk_psock_free_link(link);
 915         return ret;
 916 }
 917
 918 static int sock_hash_update_elem(struct bpf_map *map, void *key,
 919                                  void *value, u64 flags)
 920 {
 921         struct socket *sock;
 922         struct sock *sk;
 923         int ret;
 924         u64 ufd;
 925
 926         if (map->value_size == sizeof(u64))
 927                 ufd = *(u64 *)value;
 928         else
 929                 ufd = *(u32 *)value;
 930         if (ufd > S32_MAX)
 931                 return -EINVAL;
 932
 933         sock = sockfd_lookup(ufd, &ret);
 934         if (!sock)
 935                 return ret;
 936         sk = sock->sk;
 937         if (!sk) {
 938                 ret = -EINVAL;
 939                 goto out;
 940         }
 941         if (!sock_map_sk_is_suitable(sk)) {
 942                 ret = -EOPNOTSUPP;
 943                 goto out;
 944         }
 945
 946         sock_map_sk_acquire(sk);
 947         if (!sock_map_sk_state_allowed(sk))
 948                 ret = -EOPNOTSUPP;
 949         else
 950                 ret = sock_hash_update_common(map, key, sk, flags);
 951         sock_map_sk_release(sk);
 952 out:
 953         fput(sock->file);
 954         return ret;
 955 }
 956
 957 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
 958                                   void *key_next)
 959 {
 960         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 961         struct bpf_shtab_elem *elem, *elem_next;
 962         u32 hash, key_size = map->key_size;
 963         struct hlist_head *head;
 964         int i = 0;
 965
 966         if (!key)
 967                 goto find_first_elem;
 968         hash = sock_hash_bucket_hash(key, key_size);
 969         head = &sock_hash_select_bucket(htab, hash)->head;
 970         elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
 971         if (!elem)
 972                 goto find_first_elem;
 973
 974         elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)),
 975                                      struct bpf_shtab_elem, node);
 976         if (elem_next) {
 977                 memcpy(key_next, elem_next->key, key_size);
 978                 return 0;
 979         }
 980
 981         i = hash & (htab->buckets_num - 1);
 982         i++;
 983 find_first_elem:
 984         for (; i < htab->buckets_num; i++) {
 985                 head = &sock_hash_select_bucket(htab, i)->head;
 986                 elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
 987                                              struct bpf_shtab_elem, node);
 988                 if (elem_next) {
 989                         memcpy(key_next, elem_next->key, key_size);
 990                         return 0;
 991                 }
 992         }
 993
 994         return -ENOENT;
 995 }
 996
 997 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
 998 {
 999         struct bpf_shtab *htab;
1000         int i, err;
1001         u64 cost;
1002
1003         if (!capable(CAP_NET_ADMIN))
1004                 return ERR_PTR(-EPERM);
1005         if (attr->max_entries == 0 ||
1006             attr->key_size    == 0 ||
1007             (attr->value_size != sizeof(u32) &&
1008              attr->value_size != sizeof(u64)) ||
1009             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1010                 return ERR_PTR(-EINVAL);
1011         if (attr->key_size > MAX_BPF_STACK)
1012                 return ERR_PTR(-E2BIG);
1013
1014         htab = kzalloc(sizeof(*htab), GFP_USER);
1015         if (!htab)
1016                 return ERR_PTR(-ENOMEM);
1017
1018         bpf_map_init_from_attr(&htab->map, attr);
1019
1020         htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1021         htab->elem_size = sizeof(struct bpf_shtab_elem) +
1022                           round_up(htab->map.key_size, 8);
1023         if (htab->buckets_num == 0 ||
1024             htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1025                 err = -EINVAL;
1026                 goto free_htab;
1027         }
1028
1029         cost = (u64) htab->buckets_num * sizeof(struct bpf_shtab_bucket) +
1030                (u64) htab->elem_size * htab->map.max_entries;
1031         if (cost >= U32_MAX - PAGE_SIZE) {
1032                 err = -EINVAL;
1033                 goto free_htab;
1034         }
1035         err = bpf_map_charge_init(&htab->map.memory, cost);
1036         if (err)
1037                 goto free_htab;
1038
1039         htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1040                                            sizeof(struct bpf_shtab_bucket),
1041                                            htab->map.numa_node);
1042         if (!htab->buckets) {
1043                 bpf_map_charge_finish(&htab->map.memory);
1044                 err = -ENOMEM;
1045                 goto free_htab;
1046         }
1047
1048         for (i = 0; i < htab->buckets_num; i++) {
1049                 INIT_HLIST_HEAD(&htab->buckets[i].head);
1050                 raw_spin_lock_init(&htab->buckets[i].lock);
1051         }
1052
1053         return &htab->map;
1054 free_htab:
1055         kfree(htab);
1056         return ERR_PTR(err);
1057 }
1058
1059 static void sock_hash_free(struct bpf_map *map)
1060 {
1061         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1062         struct bpf_shtab_bucket *bucket;
1063         struct hlist_head unlink_list;
1064         struct bpf_shtab_elem *elem;
1065         struct hlist_node *node;
1066         int i;
1067
1068         /* After the sync no updates or deletes will be in-flight so it
1069          * is safe to walk map and remove entries without risking a race
1070          * in EEXIST update case.
1071          */
1072         synchronize_rcu();
1073         for (i = 0; i < htab->buckets_num; i++) {
1074                 bucket = sock_hash_select_bucket(htab, i);
1075
1076                 /* We are racing with sock_hash_delete_from_link to
1077                  * enter the spin-lock critical section. Every socket on
1078                  * the list is still linked to sockhash. Since link
1079                  * exists, psock exists and holds a ref to socket. That
1080                  * lets us to grab a socket ref too.
1081                  */
1082                 raw_spin_lock_bh(&bucket->lock);
1083                 hlist_for_each_entry(elem, &bucket->head, node)
1084                         sock_hold(elem->sk);
1085                 hlist_move_list(&bucket->head, &unlink_list);
1086                 raw_spin_unlock_bh(&bucket->lock);
1087
1088                 /* Process removed entries out of atomic context to
1089                  * block for socket lock before deleting the psock's
1090                  * link to sockhash.
1091                  */
1092                 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1093                         hlist_del(&elem->node);
1094                         lock_sock(elem->sk);
1095                         rcu_read_lock();
1096                         sock_map_unref(elem->sk, elem);
1097                         rcu_read_unlock();
1098                         release_sock(elem->sk);
1099                         sock_put(elem->sk);
1100                         sock_hash_free_elem(htab, elem);
1101                 }
1102         }
1103
1104         /* wait for psock readers accessing its map link */
1105         synchronize_rcu();
1106
1107         bpf_map_area_free(htab->buckets);
1108         kfree(htab);
1109 }
1110
1111 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1112 {
1113         struct sock *sk;
1114
1115         if (map->value_size != sizeof(u64))
1116                 return ERR_PTR(-ENOSPC);
1117
1118         sk = __sock_hash_lookup_elem(map, key);
1119         if (!sk)
1120                 return ERR_PTR(-ENOENT);
1121
1122         sock_gen_cookie(sk);
1123         return &sk->sk_cookie;
1124 }
1125
1126 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1127 {
1128         struct sock *sk;
1129
1130         sk = __sock_hash_lookup_elem(map, key);
1131         if (!sk || !sk_fullsock(sk))
1132                 return NULL;
1133         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1134                 return NULL;
1135         return sk;
1136 }
1137
1138 static void sock_hash_release_progs(struct bpf_map *map)
1139 {
1140         psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1141 }
1142
1143 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1144            struct bpf_map *, map, void *, key, u64, flags)
1145 {
1146         WARN_ON_ONCE(!rcu_read_lock_held());
1147
1148         if (likely(sock_map_sk_is_suitable(sops->sk) &&
1149                    sock_map_op_okay(sops)))
1150                 return sock_hash_update_common(map, key, sops->sk, flags);
1151         return -EOPNOTSUPP;
1152 }
1153
1154 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1155         .func           = bpf_sock_hash_update,
1156         .gpl_only       = false,
1157         .pkt_access     = true,
1158         .ret_type       = RET_INTEGER,
1159         .arg1_type      = ARG_PTR_TO_CTX,
1160         .arg2_type      = ARG_CONST_MAP_PTR,
1161         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1162         .arg4_type      = ARG_ANYTHING,
1163 };
1164
1165 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1166            struct bpf_map *, map, void *, key, u64, flags)
1167 {
1168         struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
1169         struct sock *sk;
1170
1171         if (unlikely(flags & ~(BPF_F_INGRESS)))
1172                 return SK_DROP;
1173
1174         sk = __sock_hash_lookup_elem(map, key);
1175         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1176                 return SK_DROP;
1177
1178         tcb->bpf.flags = flags;
1179         tcb->bpf.sk_redir = sk;
1180         return SK_PASS;
1181 }
1182
1183 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1184         .func           = bpf_sk_redirect_hash,
1185         .gpl_only       = false,
1186         .ret_type       = RET_INTEGER,
1187         .arg1_type      = ARG_PTR_TO_CTX,
1188         .arg2_type      = ARG_CONST_MAP_PTR,
1189         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1190         .arg4_type      = ARG_ANYTHING,
1191 };
1192
1193 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1194            struct bpf_map *, map, void *, key, u64, flags)
1195 {
1196         struct sock *sk;
1197
1198         if (unlikely(flags & ~(BPF_F_INGRESS)))
1199                 return SK_DROP;
1200
1201         sk = __sock_hash_lookup_elem(map, key);
1202         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1203                 return SK_DROP;
1204
1205         msg->flags = flags;
1206         msg->sk_redir = sk;
1207         return SK_PASS;
1208 }
1209
1210 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1211         .func           = bpf_msg_redirect_hash,
1212         .gpl_only       = false,
1213         .ret_type       = RET_INTEGER,
1214         .arg1_type      = ARG_PTR_TO_CTX,
1215         .arg2_type      = ARG_CONST_MAP_PTR,
1216         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1217         .arg4_type      = ARG_ANYTHING,
1218 };
1219
1220 static int sock_hash_map_btf_id;
1221 const struct bpf_map_ops sock_hash_ops = {
1222         .map_alloc              = sock_hash_alloc,
1223         .map_free               = sock_hash_free,
1224         .map_get_next_key       = sock_hash_get_next_key,
1225         .map_update_elem        = sock_hash_update_elem,
1226         .map_delete_elem        = sock_hash_delete_elem,
1227         .map_lookup_elem        = sock_hash_lookup,
1228         .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1229         .map_release_uref       = sock_hash_release_progs,
1230         .map_check_btf          = map_check_no_btf,
1231         .map_btf_name           = "bpf_shtab",
1232         .map_btf_id             = &sock_hash_map_btf_id,
1233 };
1234
1235 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1236 {
1237         switch (map->map_type) {
1238         case BPF_MAP_TYPE_SOCKMAP:
1239                 return &container_of(map, struct bpf_stab, map)->progs;
1240         case BPF_MAP_TYPE_SOCKHASH:
1241                 return &container_of(map, struct bpf_shtab, map)->progs;
1242         default:
1243                 break;
1244         }
1245
1246         return NULL;
1247 }
1248
1249 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1250                          struct bpf_prog *old, u32 which)
1251 {
1252         struct sk_psock_progs *progs = sock_map_progs(map);
1253         struct bpf_prog **pprog;
1254
1255         if (!progs)
1256                 return -EOPNOTSUPP;
1257
1258         switch (which) {
1259         case BPF_SK_MSG_VERDICT:
1260                 pprog = &progs->msg_parser;
1261                 break;
1262         case BPF_SK_SKB_STREAM_PARSER:
1263                 pprog = &progs->skb_parser;
1264                 break;
1265         case BPF_SK_SKB_STREAM_VERDICT:
1266                 pprog = &progs->skb_verdict;
1267                 break;
1268         default:
1269                 return -EOPNOTSUPP;
1270         }
1271
1272         if (old)
1273                 return psock_replace_prog(pprog, prog, old);
1274
1275         psock_set_prog(pprog, prog);
1276         return 0;
1277 }
1278
1279 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1280 {
1281         switch (link->map->map_type) {
1282         case BPF_MAP_TYPE_SOCKMAP:
1283                 return sock_map_delete_from_link(link->map, sk,
1284                                                  link->link_raw);
1285         case BPF_MAP_TYPE_SOCKHASH:
1286                 return sock_hash_delete_from_link(link->map, sk,
1287                                                   link->link_raw);
1288         default:
1289                 break;
1290         }
1291 }
1292
1293 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1294 {
1295         struct sk_psock_link *link;
1296
1297         while ((link = sk_psock_link_pop(psock))) {
1298                 sock_map_unlink(sk, link);
1299                 sk_psock_free_link(link);
1300         }
1301 }
1302
1303 void sock_map_unhash(struct sock *sk)
1304 {
1305         void (*saved_unhash)(struct sock *sk);
1306         struct sk_psock *psock;
1307
1308         rcu_read_lock();
1309         psock = sk_psock(sk);
1310         if (unlikely(!psock)) {
1311                 rcu_read_unlock();
1312                 if (sk->sk_prot->unhash)
1313                         sk->sk_prot->unhash(sk);
1314                 return;
1315         }
1316
1317         saved_unhash = psock->saved_unhash;
1318         sock_map_remove_links(sk, psock);
1319         rcu_read_unlock();
1320         saved_unhash(sk);
1321 }
1322
1323 void sock_map_close(struct sock *sk, long timeout)
1324 {
1325         void (*saved_close)(struct sock *sk, long timeout);
1326         struct sk_psock *psock;
1327
1328         lock_sock(sk);
1329         rcu_read_lock();
1330         psock = sk_psock(sk);
1331         if (unlikely(!psock)) {
1332                 rcu_read_unlock();
1333                 release_sock(sk);
1334                 return sk->sk_prot->close(sk, timeout);
1335         }
1336
1337         saved_close = psock->saved_close;
1338         sock_map_remove_links(sk, psock);
1339         rcu_read_unlock();
1340         release_sock(sk);
1341         saved_close(sk, timeout);
1342 }