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/btf_ids.h>
   6 #include <linux/filter.h>
   7 #include <linux/errno.h>
   8 #include <linux/file.h>
   9 #include <linux/net.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/skmsg.h>
  12 #include <linux/list.h>
  13 #include <linux/jhash.h>
  14 #include <linux/sock_diag.h>
  15 #include <net/udp.h>
  16
  17 struct bpf_stab {
  18         struct bpf_map map;
  19         struct sock **sks;
  20         struct sk_psock_progs progs;
  21         raw_spinlock_t lock;
  22 };
  23
  24 #define SOCK_CREATE_FLAG_MASK                           \
  25         (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
  26
  27 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
  28                                 struct bpf_prog *old, u32 which);
  29 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map);
  30
  31 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
  32 {
  33         struct bpf_stab *stab;
  34
  35         if (!capable(CAP_NET_ADMIN))
  36                 return ERR_PTR(-EPERM);
  37         if (attr->max_entries == 0 ||
  38             attr->key_size    != 4 ||
  39             (attr->value_size != sizeof(u32) &&
  40              attr->value_size != sizeof(u64)) ||
  41             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
  42                 return ERR_PTR(-EINVAL);
  43
  44         stab = kzalloc(sizeof(*stab), GFP_USER | __GFP_ACCOUNT);
  45         if (!stab)
  46                 return ERR_PTR(-ENOMEM);
  47
  48         bpf_map_init_from_attr(&stab->map, attr);
  49         raw_spin_lock_init(&stab->lock);
  50
  51         stab->sks = bpf_map_area_alloc(stab->map.max_entries *
  52                                        sizeof(struct sock *),
  53                                        stab->map.numa_node);
  54         if (!stab->sks) {
  55                 kfree(stab);
  56                 return ERR_PTR(-ENOMEM);
  57         }
  58
  59         return &stab->map;
  60 }
  61
  62 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
  63 {
  64         u32 ufd = attr->target_fd;
  65         struct bpf_map *map;
  66         struct fd f;
  67         int ret;
  68
  69         if (attr->attach_flags || attr->replace_bpf_fd)
  70                 return -EINVAL;
  71
  72         f = fdget(ufd);
  73         map = __bpf_map_get(f);
  74         if (IS_ERR(map))
  75                 return PTR_ERR(map);
  76         ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
  77         fdput(f);
  78         return ret;
  79 }
  80
  81 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
  82 {
  83         u32 ufd = attr->target_fd;
  84         struct bpf_prog *prog;
  85         struct bpf_map *map;
  86         struct fd f;
  87         int ret;
  88
  89         if (attr->attach_flags || attr->replace_bpf_fd)
  90                 return -EINVAL;
  91
  92         f = fdget(ufd);
  93         map = __bpf_map_get(f);
  94         if (IS_ERR(map))
  95                 return PTR_ERR(map);
  96
  97         prog = bpf_prog_get(attr->attach_bpf_fd);
  98         if (IS_ERR(prog)) {
  99                 ret = PTR_ERR(prog);
 100                 goto put_map;
 101         }
 102
 103         if (prog->type != ptype) {
 104                 ret = -EINVAL;
 105                 goto put_prog;
 106         }
 107
 108         ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
 109 put_prog:
 110         bpf_prog_put(prog);
 111 put_map:
 112         fdput(f);
 113         return ret;
 114 }
 115
 116 static void sock_map_sk_acquire(struct sock *sk)
 117         __acquires(&sk->sk_lock.slock)
 118 {
 119         lock_sock(sk);
 120         preempt_disable();
 121         rcu_read_lock();
 122 }
 123
 124 static void sock_map_sk_release(struct sock *sk)
 125         __releases(&sk->sk_lock.slock)
 126 {
 127         rcu_read_unlock();
 128         preempt_enable();
 129         release_sock(sk);
 130 }
 131
 132 static void sock_map_add_link(struct sk_psock *psock,
 133                               struct sk_psock_link *link,
 134                               struct bpf_map *map, void *link_raw)
 135 {
 136         link->link_raw = link_raw;
 137         link->map = map;
 138         spin_lock_bh(&psock->link_lock);
 139         list_add_tail(&link->list, &psock->link);
 140         spin_unlock_bh(&psock->link_lock);
 141 }
 142
 143 static void sock_map_del_link(struct sock *sk,
 144                               struct sk_psock *psock, void *link_raw)
 145 {
 146         bool strp_stop = false, verdict_stop = false;
 147         struct sk_psock_link *link, *tmp;
 148
 149         spin_lock_bh(&psock->link_lock);
 150         list_for_each_entry_safe(link, tmp, &psock->link, list) {
 151                 if (link->link_raw == link_raw) {
 152                         struct bpf_map *map = link->map;
 153                         struct bpf_stab *stab = container_of(map, struct bpf_stab,
 154                                                              map);
 155                         if (psock->saved_data_ready && stab->progs.stream_parser)
 156                                 strp_stop = true;
 157                         if (psock->saved_data_ready && stab->progs.stream_verdict)
 158                                 verdict_stop = true;
 159                         if (psock->saved_data_ready && stab->progs.skb_verdict)
 160                                 verdict_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 || verdict_stop) {
 167                 write_lock_bh(&sk->sk_callback_lock);
 168                 if (strp_stop)
 169                         sk_psock_stop_strp(sk, psock);
 170                 else
 171                         sk_psock_stop_verdict(sk, psock);
 172                 write_unlock_bh(&sk->sk_callback_lock);
 173         }
 174 }
 175
 176 static void sock_map_unref(struct sock *sk, void *link_raw)
 177 {
 178         struct sk_psock *psock = sk_psock(sk);
 179
 180         if (likely(psock)) {
 181                 sock_map_del_link(sk, psock, link_raw);
 182                 sk_psock_put(sk, psock);
 183         }
 184 }
 185
 186 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
 187 {
 188         if (!sk->sk_prot->psock_update_sk_prot)
 189                 return -EINVAL;
 190         psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
 191         return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
 192 }
 193
 194 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
 195 {
 196         struct sk_psock *psock;
 197
 198         rcu_read_lock();
 199         psock = sk_psock(sk);
 200         if (psock) {
 201                 if (sk->sk_prot->close != sock_map_close) {
 202                         psock = ERR_PTR(-EBUSY);
 203                         goto out;
 204                 }
 205
 206                 if (!refcount_inc_not_zero(&psock->refcnt))
 207                         psock = ERR_PTR(-EBUSY);
 208         }
 209 out:
 210         rcu_read_unlock();
 211         return psock;
 212 }
 213
 214 static bool sock_map_redirect_allowed(const struct sock *sk);
 215
 216 static int sock_map_link(struct bpf_map *map, struct sock *sk)
 217 {
 218         struct sk_psock_progs *progs = sock_map_progs(map);
 219         struct bpf_prog *stream_verdict = NULL;
 220         struct bpf_prog *stream_parser = NULL;
 221         struct bpf_prog *skb_verdict = NULL;
 222         struct bpf_prog *msg_parser = NULL;
 223         struct sk_psock *psock;
 224         int ret;
 225
 226         /* Only sockets we can redirect into/from in BPF need to hold
 227          * refs to parser/verdict progs and have their sk_data_ready
 228          * and sk_write_space callbacks overridden.
 229          */
 230         if (!sock_map_redirect_allowed(sk))
 231                 goto no_progs;
 232
 233         stream_verdict = READ_ONCE(progs->stream_verdict);
 234         if (stream_verdict) {
 235                 stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
 236                 if (IS_ERR(stream_verdict))
 237                         return PTR_ERR(stream_verdict);
 238         }
 239
 240         stream_parser = READ_ONCE(progs->stream_parser);
 241         if (stream_parser) {
 242                 stream_parser = bpf_prog_inc_not_zero(stream_parser);
 243                 if (IS_ERR(stream_parser)) {
 244                         ret = PTR_ERR(stream_parser);
 245                         goto out_put_stream_verdict;
 246                 }
 247         }
 248
 249         msg_parser = READ_ONCE(progs->msg_parser);
 250         if (msg_parser) {
 251                 msg_parser = bpf_prog_inc_not_zero(msg_parser);
 252                 if (IS_ERR(msg_parser)) {
 253                         ret = PTR_ERR(msg_parser);
 254                         goto out_put_stream_parser;
 255                 }
 256         }
 257
 258         skb_verdict = READ_ONCE(progs->skb_verdict);
 259         if (skb_verdict) {
 260                 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
 261                 if (IS_ERR(skb_verdict)) {
 262                         ret = PTR_ERR(skb_verdict);
 263                         goto out_put_msg_parser;
 264                 }
 265         }
 266
 267 no_progs:
 268         psock = sock_map_psock_get_checked(sk);
 269         if (IS_ERR(psock)) {
 270                 ret = PTR_ERR(psock);
 271                 goto out_progs;
 272         }
 273
 274         if (psock) {
 275                 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
 276                     (stream_parser  && READ_ONCE(psock->progs.stream_parser)) ||
 277                     (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 278                     (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
 279                     (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 280                     (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
 281                         sk_psock_put(sk, psock);
 282                         ret = -EBUSY;
 283                         goto out_progs;
 284                 }
 285         } else {
 286                 psock = sk_psock_init(sk, map->numa_node);
 287                 if (IS_ERR(psock)) {
 288                         ret = PTR_ERR(psock);
 289                         goto out_progs;
 290                 }
 291         }
 292
 293         if (msg_parser)
 294                 psock_set_prog(&psock->progs.msg_parser, msg_parser);
 295
 296         ret = sock_map_init_proto(sk, psock);
 297         if (ret < 0)
 298                 goto out_drop;
 299
 300         write_lock_bh(&sk->sk_callback_lock);
 301         if (stream_parser && stream_verdict && !psock->saved_data_ready) {
 302                 ret = sk_psock_init_strp(sk, psock);
 303                 if (ret)
 304                         goto out_unlock_drop;
 305                 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 306                 psock_set_prog(&psock->progs.stream_parser, stream_parser);
 307                 sk_psock_start_strp(sk, psock);
 308         } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
 309                 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 310                 sk_psock_start_verdict(sk,psock);
 311         } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
 312                 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
 313                 sk_psock_start_verdict(sk, psock);
 314         }
 315         write_unlock_bh(&sk->sk_callback_lock);
 316         return 0;
 317 out_unlock_drop:
 318         write_unlock_bh(&sk->sk_callback_lock);
 319 out_drop:
 320         sk_psock_put(sk, psock);
 321 out_progs:
 322         if (skb_verdict)
 323                 bpf_prog_put(skb_verdict);
 324 out_put_msg_parser:
 325         if (msg_parser)
 326                 bpf_prog_put(msg_parser);
 327 out_put_stream_parser:
 328         if (stream_parser)
 329                 bpf_prog_put(stream_parser);
 330 out_put_stream_verdict:
 331         if (stream_verdict)
 332                 bpf_prog_put(stream_verdict);
 333         return ret;
 334 }
 335
 336 static void sock_map_free(struct bpf_map *map)
 337 {
 338         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 339         int i;
 340
 341         /* After the sync no updates or deletes will be in-flight so it
 342          * is safe to walk map and remove entries without risking a race
 343          * in EEXIST update case.
 344          */
 345         synchronize_rcu();
 346         for (i = 0; i < stab->map.max_entries; i++) {
 347                 struct sock **psk = &stab->sks[i];
 348                 struct sock *sk;
 349
 350                 sk = xchg(psk, NULL);
 351                 if (sk) {
 352                         lock_sock(sk);
 353                         rcu_read_lock();
 354                         sock_map_unref(sk, psk);
 355                         rcu_read_unlock();
 356                         release_sock(sk);
 357                 }
 358         }
 359
 360         /* wait for psock readers accessing its map link */
 361         synchronize_rcu();
 362
 363         bpf_map_area_free(stab->sks);
 364         kfree(stab);
 365 }
 366
 367 static void sock_map_release_progs(struct bpf_map *map)
 368 {
 369         psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
 370 }
 371
 372 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 373 {
 374         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 375
 376         WARN_ON_ONCE(!rcu_read_lock_held());
 377
 378         if (unlikely(key >= map->max_entries))
 379                 return NULL;
 380         return READ_ONCE(stab->sks[key]);
 381 }
 382
 383 static void *sock_map_lookup(struct bpf_map *map, void *key)
 384 {
 385         struct sock *sk;
 386
 387         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 388         if (!sk)
 389                 return NULL;
 390         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
 391                 return NULL;
 392         return sk;
 393 }
 394
 395 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
 396 {
 397         struct sock *sk;
 398
 399         if (map->value_size != sizeof(u64))
 400                 return ERR_PTR(-ENOSPC);
 401
 402         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 403         if (!sk)
 404                 return ERR_PTR(-ENOENT);
 405
 406         __sock_gen_cookie(sk);
 407         return &sk->sk_cookie;
 408 }
 409
 410 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
 411                              struct sock **psk)
 412 {
 413         struct sock *sk;
 414         int err = 0;
 415
 416         raw_spin_lock_bh(&stab->lock);
 417         sk = *psk;
 418         if (!sk_test || sk_test == sk)
 419                 sk = xchg(psk, NULL);
 420
 421         if (likely(sk))
 422                 sock_map_unref(sk, psk);
 423         else
 424                 err = -EINVAL;
 425
 426         raw_spin_unlock_bh(&stab->lock);
 427         return err;
 428 }
 429
 430 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
 431                                       void *link_raw)
 432 {
 433         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 434
 435         __sock_map_delete(stab, sk, link_raw);
 436 }
 437
 438 static int sock_map_delete_elem(struct bpf_map *map, void *key)
 439 {
 440         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 441         u32 i = *(u32 *)key;
 442         struct sock **psk;
 443
 444         if (unlikely(i >= map->max_entries))
 445                 return -EINVAL;
 446
 447         psk = &stab->sks[i];
 448         return __sock_map_delete(stab, NULL, psk);
 449 }
 450
 451 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
 452 {
 453         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 454         u32 i = key ? *(u32 *)key : U32_MAX;
 455         u32 *key_next = next;
 456
 457         if (i == stab->map.max_entries - 1)
 458                 return -ENOENT;
 459         if (i >= stab->map.max_entries)
 460                 *key_next = 0;
 461         else
 462                 *key_next = i + 1;
 463         return 0;
 464 }
 465
 466 static int sock_map_update_common(struct bpf_map *map, u32 idx,
 467                                   struct sock *sk, u64 flags)
 468 {
 469         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 470         struct sk_psock_link *link;
 471         struct sk_psock *psock;
 472         struct sock *osk;
 473         int ret;
 474
 475         WARN_ON_ONCE(!rcu_read_lock_held());
 476         if (unlikely(flags > BPF_EXIST))
 477                 return -EINVAL;
 478         if (unlikely(idx >= map->max_entries))
 479                 return -E2BIG;
 480
 481         link = sk_psock_init_link();
 482         if (!link)
 483                 return -ENOMEM;
 484
 485         ret = sock_map_link(map, sk);
 486         if (ret < 0)
 487                 goto out_free;
 488
 489         psock = sk_psock(sk);
 490         WARN_ON_ONCE(!psock);
 491
 492         raw_spin_lock_bh(&stab->lock);
 493         osk = stab->sks[idx];
 494         if (osk && flags == BPF_NOEXIST) {
 495                 ret = -EEXIST;
 496                 goto out_unlock;
 497         } else if (!osk && flags == BPF_EXIST) {
 498                 ret = -ENOENT;
 499                 goto out_unlock;
 500         }
 501
 502         sock_map_add_link(psock, link, map, &stab->sks[idx]);
 503         stab->sks[idx] = sk;
 504         if (osk)
 505                 sock_map_unref(osk, &stab->sks[idx]);
 506         raw_spin_unlock_bh(&stab->lock);
 507         return 0;
 508 out_unlock:
 509         raw_spin_unlock_bh(&stab->lock);
 510         if (psock)
 511                 sk_psock_put(sk, psock);
 512 out_free:
 513         sk_psock_free_link(link);
 514         return ret;
 515 }
 516
 517 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
 518 {
 519         return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
 520                ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
 521                ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
 522 }
 523
 524 static bool sk_is_tcp(const struct sock *sk)
 525 {
 526         return sk->sk_type == SOCK_STREAM &&
 527                sk->sk_protocol == IPPROTO_TCP;
 528 }
 529
 530 static bool sk_is_udp(const struct sock *sk)
 531 {
 532         return sk->sk_type == SOCK_DGRAM &&
 533                sk->sk_protocol == IPPROTO_UDP;
 534 }
 535
 536 static bool sock_map_redirect_allowed(const struct sock *sk)
 537 {
 538         if (sk_is_tcp(sk))
 539                 return sk->sk_state != TCP_LISTEN;
 540         else
 541                 return sk->sk_state == TCP_ESTABLISHED;
 542 }
 543
 544 static bool sock_map_sk_is_suitable(const struct sock *sk)
 545 {
 546         return !!sk->sk_prot->psock_update_sk_prot;
 547 }
 548
 549 static bool sock_map_sk_state_allowed(const struct sock *sk)
 550 {
 551         if (sk_is_tcp(sk))
 552                 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 553         else if (sk_is_udp(sk))
 554                 return sk_hashed(sk);
 555
 556         return false;
 557 }
 558
 559 static int sock_hash_update_common(struct bpf_map *map, void *key,
 560                                    struct sock *sk, u64 flags);
 561
 562 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 563                              u64 flags)
 564 {
 565         struct socket *sock;
 566         struct sock *sk;
 567         int ret;
 568         u64 ufd;
 569
 570         if (map->value_size == sizeof(u64))
 571                 ufd = *(u64 *)value;
 572         else
 573                 ufd = *(u32 *)value;
 574         if (ufd > S32_MAX)
 575                 return -EINVAL;
 576
 577         sock = sockfd_lookup(ufd, &ret);
 578         if (!sock)
 579                 return ret;
 580         sk = sock->sk;
 581         if (!sk) {
 582                 ret = -EINVAL;
 583                 goto out;
 584         }
 585         if (!sock_map_sk_is_suitable(sk)) {
 586                 ret = -EOPNOTSUPP;
 587                 goto out;
 588         }
 589
 590         sock_map_sk_acquire(sk);
 591         if (!sock_map_sk_state_allowed(sk))
 592                 ret = -EOPNOTSUPP;
 593         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 594                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 595         else
 596                 ret = sock_hash_update_common(map, key, sk, flags);
 597         sock_map_sk_release(sk);
 598 out:
 599         sockfd_put(sock);
 600         return ret;
 601 }
 602
 603 static int sock_map_update_elem(struct bpf_map *map, void *key,
 604                                 void *value, u64 flags)
 605 {
 606         struct sock *sk = (struct sock *)value;
 607         int ret;
 608
 609         if (unlikely(!sk || !sk_fullsock(sk)))
 610                 return -EINVAL;
 611
 612         if (!sock_map_sk_is_suitable(sk))
 613                 return -EOPNOTSUPP;
 614
 615         local_bh_disable();
 616         bh_lock_sock(sk);
 617         if (!sock_map_sk_state_allowed(sk))
 618                 ret = -EOPNOTSUPP;
 619         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 620                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 621         else
 622                 ret = sock_hash_update_common(map, key, sk, flags);
 623         bh_unlock_sock(sk);
 624         local_bh_enable();
 625         return ret;
 626 }
 627
 628 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 629            struct bpf_map *, map, void *, key, u64, flags)
 630 {
 631         WARN_ON_ONCE(!rcu_read_lock_held());
 632
 633         if (likely(sock_map_sk_is_suitable(sops->sk) &&
 634                    sock_map_op_okay(sops)))
 635                 return sock_map_update_common(map, *(u32 *)key, sops->sk,
 636                                               flags);
 637         return -EOPNOTSUPP;
 638 }
 639
 640 const struct bpf_func_proto bpf_sock_map_update_proto = {
 641         .func           = bpf_sock_map_update,
 642         .gpl_only       = false,
 643         .pkt_access     = true,
 644         .ret_type       = RET_INTEGER,
 645         .arg1_type      = ARG_PTR_TO_CTX,
 646         .arg2_type      = ARG_CONST_MAP_PTR,
 647         .arg3_type      = ARG_PTR_TO_MAP_KEY,
 648         .arg4_type      = ARG_ANYTHING,
 649 };
 650
 651 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 652            struct bpf_map *, map, u32, key, u64, flags)
 653 {
 654         struct sock *sk;
 655
 656         if (unlikely(flags & ~(BPF_F_INGRESS)))
 657                 return SK_DROP;
 658
 659         sk = __sock_map_lookup_elem(map, key);
 660         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 661                 return SK_DROP;
 662
 663         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 664         return SK_PASS;
 665 }
 666
 667 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 668         .func           = bpf_sk_redirect_map,
 669         .gpl_only       = false,
 670         .ret_type       = RET_INTEGER,
 671         .arg1_type      = ARG_PTR_TO_CTX,
 672         .arg2_type      = ARG_CONST_MAP_PTR,
 673         .arg3_type      = ARG_ANYTHING,
 674         .arg4_type      = ARG_ANYTHING,
 675 };
 676
 677 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 678            struct bpf_map *, map, u32, key, u64, flags)
 679 {
 680         struct sock *sk;
 681
 682         if (unlikely(flags & ~(BPF_F_INGRESS)))
 683                 return SK_DROP;
 684
 685         sk = __sock_map_lookup_elem(map, key);
 686         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 687                 return SK_DROP;
 688
 689         msg->flags = flags;
 690         msg->sk_redir = sk;
 691         return SK_PASS;
 692 }
 693
 694 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 695         .func           = bpf_msg_redirect_map,
 696         .gpl_only       = false,
 697         .ret_type       = RET_INTEGER,
 698         .arg1_type      = ARG_PTR_TO_CTX,
 699         .arg2_type      = ARG_CONST_MAP_PTR,
 700         .arg3_type      = ARG_ANYTHING,
 701         .arg4_type      = ARG_ANYTHING,
 702 };
 703
 704 struct sock_map_seq_info {
 705         struct bpf_map *map;
 706         struct sock *sk;
 707         u32 index;
 708 };
 709
 710 struct bpf_iter__sockmap {
 711         __bpf_md_ptr(struct bpf_iter_meta *, meta);
 712         __bpf_md_ptr(struct bpf_map *, map);
 713         __bpf_md_ptr(void *, key);
 714         __bpf_md_ptr(struct sock *, sk);
 715 };
 716
 717 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
 718                      struct bpf_map *map, void *key,
 719                      struct sock *sk)
 720
 721 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
 722 {
 723         if (unlikely(info->index >= info->map->max_entries))
 724                 return NULL;
 725
 726         info->sk = __sock_map_lookup_elem(info->map, info->index);
 727
 728         /* can't return sk directly, since that might be NULL */
 729         return info;
 730 }
 731
 732 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
 733         __acquires(rcu)
 734 {
 735         struct sock_map_seq_info *info = seq->private;
 736
 737         if (*pos == 0)
 738                 ++*pos;
 739
 740         /* pairs with sock_map_seq_stop */
 741         rcu_read_lock();
 742         return sock_map_seq_lookup_elem(info);
 743 }
 744
 745 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 746         __must_hold(rcu)
 747 {
 748         struct sock_map_seq_info *info = seq->private;
 749
 750         ++*pos;
 751         ++info->index;
 752
 753         return sock_map_seq_lookup_elem(info);
 754 }
 755
 756 static int sock_map_seq_show(struct seq_file *seq, void *v)
 757         __must_hold(rcu)
 758 {
 759         struct sock_map_seq_info *info = seq->private;
 760         struct bpf_iter__sockmap ctx = {};
 761         struct bpf_iter_meta meta;
 762         struct bpf_prog *prog;
 763
 764         meta.seq = seq;
 765         prog = bpf_iter_get_info(&meta, !v);
 766         if (!prog)
 767                 return 0;
 768
 769         ctx.meta = &meta;
 770         ctx.map = info->map;
 771         if (v) {
 772                 ctx.key = &info->index;
 773                 ctx.sk = info->sk;
 774         }
 775
 776         return bpf_iter_run_prog(prog, &ctx);
 777 }
 778
 779 static void sock_map_seq_stop(struct seq_file *seq, void *v)
 780         __releases(rcu)
 781 {
 782         if (!v)
 783                 (void)sock_map_seq_show(seq, NULL);
 784
 785         /* pairs with sock_map_seq_start */
 786         rcu_read_unlock();
 787 }
 788
 789 static const struct seq_operations sock_map_seq_ops = {
 790         .start  = sock_map_seq_start,
 791         .next   = sock_map_seq_next,
 792         .stop   = sock_map_seq_stop,
 793         .show   = sock_map_seq_show,
 794 };
 795
 796 static int sock_map_init_seq_private(void *priv_data,
 797                                      struct bpf_iter_aux_info *aux)
 798 {
 799         struct sock_map_seq_info *info = priv_data;
 800
 801         info->map = aux->map;
 802         return 0;
 803 }
 804
 805 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
 806         .seq_ops                = &sock_map_seq_ops,
 807         .init_seq_private       = sock_map_init_seq_private,
 808         .seq_priv_size          = sizeof(struct sock_map_seq_info),
 809 };
 810
 811 static int sock_map_btf_id;
 812 const struct bpf_map_ops sock_map_ops = {
 813         .map_meta_equal         = bpf_map_meta_equal,
 814         .map_alloc              = sock_map_alloc,
 815         .map_free               = sock_map_free,
 816         .map_get_next_key       = sock_map_get_next_key,
 817         .map_lookup_elem_sys_only = sock_map_lookup_sys,
 818         .map_update_elem        = sock_map_update_elem,
 819         .map_delete_elem        = sock_map_delete_elem,
 820         .map_lookup_elem        = sock_map_lookup,
 821         .map_release_uref       = sock_map_release_progs,
 822         .map_check_btf          = map_check_no_btf,
 823         .map_btf_name           = "bpf_stab",
 824         .map_btf_id             = &sock_map_btf_id,
 825         .iter_seq_info          = &sock_map_iter_seq_info,
 826 };
 827
 828 struct bpf_shtab_elem {
 829         struct rcu_head rcu;
 830         u32 hash;
 831         struct sock *sk;
 832         struct hlist_node node;
 833         u8 key[];
 834 };
 835
 836 struct bpf_shtab_bucket {
 837         struct hlist_head head;
 838         raw_spinlock_t lock;
 839 };
 840
 841 struct bpf_shtab {
 842         struct bpf_map map;
 843         struct bpf_shtab_bucket *buckets;
 844         u32 buckets_num;
 845         u32 elem_size;
 846         struct sk_psock_progs progs;
 847         atomic_t count;
 848 };
 849
 850 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 851 {
 852         return jhash(key, len, 0);
 853 }
 854
 855 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 856                                                         u32 hash)
 857 {
 858         return &htab->buckets[hash & (htab->buckets_num - 1)];
 859 }
 860
 861 static struct bpf_shtab_elem *
 862 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 863                           u32 key_size)
 864 {
 865         struct bpf_shtab_elem *elem;
 866
 867         hlist_for_each_entry_rcu(elem, head, node) {
 868                 if (elem->hash == hash &&
 869                     !memcmp(&elem->key, key, key_size))
 870                         return elem;
 871         }
 872
 873         return NULL;
 874 }
 875
 876 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 877 {
 878         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 879         u32 key_size = map->key_size, hash;
 880         struct bpf_shtab_bucket *bucket;
 881         struct bpf_shtab_elem *elem;
 882
 883         WARN_ON_ONCE(!rcu_read_lock_held());
 884
 885         hash = sock_hash_bucket_hash(key, key_size);
 886         bucket = sock_hash_select_bucket(htab, hash);
 887         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 888
 889         return elem ? elem->sk : NULL;
 890 }
 891
 892 static void sock_hash_free_elem(struct bpf_shtab *htab,
 893                                 struct bpf_shtab_elem *elem)
 894 {
 895         atomic_dec(&htab->count);
 896         kfree_rcu(elem, rcu);
 897 }
 898
 899 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 900                                        void *link_raw)
 901 {
 902         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 903         struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 904         struct bpf_shtab_bucket *bucket;
 905
 906         WARN_ON_ONCE(!rcu_read_lock_held());
 907         bucket = sock_hash_select_bucket(htab, elem->hash);
 908
 909         /* elem may be deleted in parallel from the map, but access here
 910          * is okay since it's going away only after RCU grace period.
 911          * However, we need to check whether it's still present.
 912          */
 913         raw_spin_lock_bh(&bucket->lock);
 914         elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 915                                                elem->key, map->key_size);
 916         if (elem_probe && elem_probe == elem) {
 917                 hlist_del_rcu(&elem->node);
 918                 sock_map_unref(elem->sk, elem);
 919                 sock_hash_free_elem(htab, elem);
 920         }
 921         raw_spin_unlock_bh(&bucket->lock);
 922 }
 923
 924 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
 925 {
 926         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 927         u32 hash, key_size = map->key_size;
 928         struct bpf_shtab_bucket *bucket;
 929         struct bpf_shtab_elem *elem;
 930         int ret = -ENOENT;
 931
 932         hash = sock_hash_bucket_hash(key, key_size);
 933         bucket = sock_hash_select_bucket(htab, hash);
 934
 935         raw_spin_lock_bh(&bucket->lock);
 936         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 937         if (elem) {
 938                 hlist_del_rcu(&elem->node);
 939                 sock_map_unref(elem->sk, elem);
 940                 sock_hash_free_elem(htab, elem);
 941                 ret = 0;
 942         }
 943         raw_spin_unlock_bh(&bucket->lock);
 944         return ret;
 945 }
 946
 947 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 948                                                    void *key, u32 key_size,
 949                                                    u32 hash, struct sock *sk,
 950                                                    struct bpf_shtab_elem *old)
 951 {
 952         struct bpf_shtab_elem *new;
 953
 954         if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 955                 if (!old) {
 956                         atomic_dec(&htab->count);
 957                         return ERR_PTR(-E2BIG);
 958                 }
 959         }
 960
 961         new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
 962                                    GFP_ATOMIC | __GFP_NOWARN,
 963                                    htab->map.numa_node);
 964         if (!new) {
 965                 atomic_dec(&htab->count);
 966                 return ERR_PTR(-ENOMEM);
 967         }
 968         memcpy(new->key, key, key_size);
 969         new->sk = sk;
 970         new->hash = hash;
 971         return new;
 972 }
 973
 974 static int sock_hash_update_common(struct bpf_map *map, void *key,
 975                                    struct sock *sk, u64 flags)
 976 {
 977         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 978         u32 key_size = map->key_size, hash;
 979         struct bpf_shtab_elem *elem, *elem_new;
 980         struct bpf_shtab_bucket *bucket;
 981         struct sk_psock_link *link;
 982         struct sk_psock *psock;
 983         int ret;
 984
 985         WARN_ON_ONCE(!rcu_read_lock_held());
 986         if (unlikely(flags > BPF_EXIST))
 987                 return -EINVAL;
 988
 989         link = sk_psock_init_link();
 990         if (!link)
 991                 return -ENOMEM;
 992
 993         ret = sock_map_link(map, sk);
 994         if (ret < 0)
 995                 goto out_free;
 996
 997         psock = sk_psock(sk);
 998         WARN_ON_ONCE(!psock);
 999
1000         hash = sock_hash_bucket_hash(key, key_size);
1001         bucket = sock_hash_select_bucket(htab, hash);
1002
1003         raw_spin_lock_bh(&bucket->lock);
1004         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1005         if (elem && flags == BPF_NOEXIST) {
1006                 ret = -EEXIST;
1007                 goto out_unlock;
1008         } else if (!elem && flags == BPF_EXIST) {
1009                 ret = -ENOENT;
1010                 goto out_unlock;
1011         }
1012
1013         elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1014         if (IS_ERR(elem_new)) {
1015                 ret = PTR_ERR(elem_new);
1016                 goto out_unlock;
1017         }
1018
1019         sock_map_add_link(psock, link, map, elem_new);
1020         /* Add new element to the head of the list, so that
1021          * concurrent search will find it before old elem.
1022          */
1023         hlist_add_head_rcu(&elem_new->node, &bucket->head);
1024         if (elem) {
1025                 hlist_del_rcu(&elem->node);
1026                 sock_map_unref(elem->sk, elem);
1027                 sock_hash_free_elem(htab, elem);
1028         }
1029         raw_spin_unlock_bh(&bucket->lock);
1030         return 0;
1031 out_unlock:
1032         raw_spin_unlock_bh(&bucket->lock);
1033         sk_psock_put(sk, psock);
1034 out_free:
1035         sk_psock_free_link(link);
1036         return ret;
1037 }
1038
1039 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1040                                   void *key_next)
1041 {
1042         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1043         struct bpf_shtab_elem *elem, *elem_next;
1044         u32 hash, key_size = map->key_size;
1045         struct hlist_head *head;
1046         int i = 0;
1047
1048         if (!key)
1049                 goto find_first_elem;
1050         hash = sock_hash_bucket_hash(key, key_size);
1051         head = &sock_hash_select_bucket(htab, hash)->head;
1052         elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1053         if (!elem)
1054                 goto find_first_elem;
1055
1056         elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1057                                      struct bpf_shtab_elem, node);
1058         if (elem_next) {
1059                 memcpy(key_next, elem_next->key, key_size);
1060                 return 0;
1061         }
1062
1063         i = hash & (htab->buckets_num - 1);
1064         i++;
1065 find_first_elem:
1066         for (; i < htab->buckets_num; i++) {
1067                 head = &sock_hash_select_bucket(htab, i)->head;
1068                 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1069                                              struct bpf_shtab_elem, node);
1070                 if (elem_next) {
1071                         memcpy(key_next, elem_next->key, key_size);
1072                         return 0;
1073                 }
1074         }
1075
1076         return -ENOENT;
1077 }
1078
1079 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1080 {
1081         struct bpf_shtab *htab;
1082         int i, err;
1083
1084         if (!capable(CAP_NET_ADMIN))
1085                 return ERR_PTR(-EPERM);
1086         if (attr->max_entries == 0 ||
1087             attr->key_size    == 0 ||
1088             (attr->value_size != sizeof(u32) &&
1089              attr->value_size != sizeof(u64)) ||
1090             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1091                 return ERR_PTR(-EINVAL);
1092         if (attr->key_size > MAX_BPF_STACK)
1093                 return ERR_PTR(-E2BIG);
1094
1095         htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
1096         if (!htab)
1097                 return ERR_PTR(-ENOMEM);
1098
1099         bpf_map_init_from_attr(&htab->map, attr);
1100
1101         htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1102         htab->elem_size = sizeof(struct bpf_shtab_elem) +
1103                           round_up(htab->map.key_size, 8);
1104         if (htab->buckets_num == 0 ||
1105             htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1106                 err = -EINVAL;
1107                 goto free_htab;
1108         }
1109
1110         htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1111                                            sizeof(struct bpf_shtab_bucket),
1112                                            htab->map.numa_node);
1113         if (!htab->buckets) {
1114                 err = -ENOMEM;
1115                 goto free_htab;
1116         }
1117
1118         for (i = 0; i < htab->buckets_num; i++) {
1119                 INIT_HLIST_HEAD(&htab->buckets[i].head);
1120                 raw_spin_lock_init(&htab->buckets[i].lock);
1121         }
1122
1123         return &htab->map;
1124 free_htab:
1125         kfree(htab);
1126         return ERR_PTR(err);
1127 }
1128
1129 static void sock_hash_free(struct bpf_map *map)
1130 {
1131         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1132         struct bpf_shtab_bucket *bucket;
1133         struct hlist_head unlink_list;
1134         struct bpf_shtab_elem *elem;
1135         struct hlist_node *node;
1136         int i;
1137
1138         /* After the sync no updates or deletes will be in-flight so it
1139          * is safe to walk map and remove entries without risking a race
1140          * in EEXIST update case.
1141          */
1142         synchronize_rcu();
1143         for (i = 0; i < htab->buckets_num; i++) {
1144                 bucket = sock_hash_select_bucket(htab, i);
1145
1146                 /* We are racing with sock_hash_delete_from_link to
1147                  * enter the spin-lock critical section. Every socket on
1148                  * the list is still linked to sockhash. Since link
1149                  * exists, psock exists and holds a ref to socket. That
1150                  * lets us to grab a socket ref too.
1151                  */
1152                 raw_spin_lock_bh(&bucket->lock);
1153                 hlist_for_each_entry(elem, &bucket->head, node)
1154                         sock_hold(elem->sk);
1155                 hlist_move_list(&bucket->head, &unlink_list);
1156                 raw_spin_unlock_bh(&bucket->lock);
1157
1158                 /* Process removed entries out of atomic context to
1159                  * block for socket lock before deleting the psock's
1160                  * link to sockhash.
1161                  */
1162                 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1163                         hlist_del(&elem->node);
1164                         lock_sock(elem->sk);
1165                         rcu_read_lock();
1166                         sock_map_unref(elem->sk, elem);
1167                         rcu_read_unlock();
1168                         release_sock(elem->sk);
1169                         sock_put(elem->sk);
1170                         sock_hash_free_elem(htab, elem);
1171                 }
1172         }
1173
1174         /* wait for psock readers accessing its map link */
1175         synchronize_rcu();
1176
1177         bpf_map_area_free(htab->buckets);
1178         kfree(htab);
1179 }
1180
1181 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1182 {
1183         struct sock *sk;
1184
1185         if (map->value_size != sizeof(u64))
1186                 return ERR_PTR(-ENOSPC);
1187
1188         sk = __sock_hash_lookup_elem(map, key);
1189         if (!sk)
1190                 return ERR_PTR(-ENOENT);
1191
1192         __sock_gen_cookie(sk);
1193         return &sk->sk_cookie;
1194 }
1195
1196 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1197 {
1198         struct sock *sk;
1199
1200         sk = __sock_hash_lookup_elem(map, key);
1201         if (!sk)
1202                 return NULL;
1203         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1204                 return NULL;
1205         return sk;
1206 }
1207
1208 static void sock_hash_release_progs(struct bpf_map *map)
1209 {
1210         psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1211 }
1212
1213 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1214            struct bpf_map *, map, void *, key, u64, flags)
1215 {
1216         WARN_ON_ONCE(!rcu_read_lock_held());
1217
1218         if (likely(sock_map_sk_is_suitable(sops->sk) &&
1219                    sock_map_op_okay(sops)))
1220                 return sock_hash_update_common(map, key, sops->sk, flags);
1221         return -EOPNOTSUPP;
1222 }
1223
1224 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1225         .func           = bpf_sock_hash_update,
1226         .gpl_only       = false,
1227         .pkt_access     = true,
1228         .ret_type       = RET_INTEGER,
1229         .arg1_type      = ARG_PTR_TO_CTX,
1230         .arg2_type      = ARG_CONST_MAP_PTR,
1231         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1232         .arg4_type      = ARG_ANYTHING,
1233 };
1234
1235 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1236            struct bpf_map *, map, void *, key, u64, flags)
1237 {
1238         struct sock *sk;
1239
1240         if (unlikely(flags & ~(BPF_F_INGRESS)))
1241                 return SK_DROP;
1242
1243         sk = __sock_hash_lookup_elem(map, key);
1244         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1245                 return SK_DROP;
1246
1247         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1248         return SK_PASS;
1249 }
1250
1251 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1252         .func           = bpf_sk_redirect_hash,
1253         .gpl_only       = false,
1254         .ret_type       = RET_INTEGER,
1255         .arg1_type      = ARG_PTR_TO_CTX,
1256         .arg2_type      = ARG_CONST_MAP_PTR,
1257         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1258         .arg4_type      = ARG_ANYTHING,
1259 };
1260
1261 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1262            struct bpf_map *, map, void *, key, u64, flags)
1263 {
1264         struct sock *sk;
1265
1266         if (unlikely(flags & ~(BPF_F_INGRESS)))
1267                 return SK_DROP;
1268
1269         sk = __sock_hash_lookup_elem(map, key);
1270         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1271                 return SK_DROP;
1272
1273         msg->flags = flags;
1274         msg->sk_redir = sk;
1275         return SK_PASS;
1276 }
1277
1278 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1279         .func           = bpf_msg_redirect_hash,
1280         .gpl_only       = false,
1281         .ret_type       = RET_INTEGER,
1282         .arg1_type      = ARG_PTR_TO_CTX,
1283         .arg2_type      = ARG_CONST_MAP_PTR,
1284         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1285         .arg4_type      = ARG_ANYTHING,
1286 };
1287
1288 struct sock_hash_seq_info {
1289         struct bpf_map *map;
1290         struct bpf_shtab *htab;
1291         u32 bucket_id;
1292 };
1293
1294 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1295                                      struct bpf_shtab_elem *prev_elem)
1296 {
1297         const struct bpf_shtab *htab = info->htab;
1298         struct bpf_shtab_bucket *bucket;
1299         struct bpf_shtab_elem *elem;
1300         struct hlist_node *node;
1301
1302         /* try to find next elem in the same bucket */
1303         if (prev_elem) {
1304                 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1305                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1306                 if (elem)
1307                         return elem;
1308
1309                 /* no more elements, continue in the next bucket */
1310                 info->bucket_id++;
1311         }
1312
1313         for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1314                 bucket = &htab->buckets[info->bucket_id];
1315                 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1316                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1317                 if (elem)
1318                         return elem;
1319         }
1320
1321         return NULL;
1322 }
1323
1324 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1325         __acquires(rcu)
1326 {
1327         struct sock_hash_seq_info *info = seq->private;
1328
1329         if (*pos == 0)
1330                 ++*pos;
1331
1332         /* pairs with sock_hash_seq_stop */
1333         rcu_read_lock();
1334         return sock_hash_seq_find_next(info, NULL);
1335 }
1336
1337 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1338         __must_hold(rcu)
1339 {
1340         struct sock_hash_seq_info *info = seq->private;
1341
1342         ++*pos;
1343         return sock_hash_seq_find_next(info, v);
1344 }
1345
1346 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1347         __must_hold(rcu)
1348 {
1349         struct sock_hash_seq_info *info = seq->private;
1350         struct bpf_iter__sockmap ctx = {};
1351         struct bpf_shtab_elem *elem = v;
1352         struct bpf_iter_meta meta;
1353         struct bpf_prog *prog;
1354
1355         meta.seq = seq;
1356         prog = bpf_iter_get_info(&meta, !elem);
1357         if (!prog)
1358                 return 0;
1359
1360         ctx.meta = &meta;
1361         ctx.map = info->map;
1362         if (elem) {
1363                 ctx.key = elem->key;
1364                 ctx.sk = elem->sk;
1365         }
1366
1367         return bpf_iter_run_prog(prog, &ctx);
1368 }
1369
1370 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1371         __releases(rcu)
1372 {
1373         if (!v)
1374                 (void)sock_hash_seq_show(seq, NULL);
1375
1376         /* pairs with sock_hash_seq_start */
1377         rcu_read_unlock();
1378 }
1379
1380 static const struct seq_operations sock_hash_seq_ops = {
1381         .start  = sock_hash_seq_start,
1382         .next   = sock_hash_seq_next,
1383         .stop   = sock_hash_seq_stop,
1384         .show   = sock_hash_seq_show,
1385 };
1386
1387 static int sock_hash_init_seq_private(void *priv_data,
1388                                      struct bpf_iter_aux_info *aux)
1389 {
1390         struct sock_hash_seq_info *info = priv_data;
1391
1392         info->map = aux->map;
1393         info->htab = container_of(aux->map, struct bpf_shtab, map);
1394         return 0;
1395 }
1396
1397 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1398         .seq_ops                = &sock_hash_seq_ops,
1399         .init_seq_private       = sock_hash_init_seq_private,
1400         .seq_priv_size          = sizeof(struct sock_hash_seq_info),
1401 };
1402
1403 static int sock_hash_map_btf_id;
1404 const struct bpf_map_ops sock_hash_ops = {
1405         .map_meta_equal         = bpf_map_meta_equal,
1406         .map_alloc              = sock_hash_alloc,
1407         .map_free               = sock_hash_free,
1408         .map_get_next_key       = sock_hash_get_next_key,
1409         .map_update_elem        = sock_map_update_elem,
1410         .map_delete_elem        = sock_hash_delete_elem,
1411         .map_lookup_elem        = sock_hash_lookup,
1412         .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1413         .map_release_uref       = sock_hash_release_progs,
1414         .map_check_btf          = map_check_no_btf,
1415         .map_btf_name           = "bpf_shtab",
1416         .map_btf_id             = &sock_hash_map_btf_id,
1417         .iter_seq_info          = &sock_hash_iter_seq_info,
1418 };
1419
1420 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1421 {
1422         switch (map->map_type) {
1423         case BPF_MAP_TYPE_SOCKMAP:
1424                 return &container_of(map, struct bpf_stab, map)->progs;
1425         case BPF_MAP_TYPE_SOCKHASH:
1426                 return &container_of(map, struct bpf_shtab, map)->progs;
1427         default:
1428                 break;
1429         }
1430
1431         return NULL;
1432 }
1433
1434 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1435                                 struct bpf_prog *old, u32 which)
1436 {
1437         struct sk_psock_progs *progs = sock_map_progs(map);
1438         struct bpf_prog **pprog;
1439
1440         if (!progs)
1441                 return -EOPNOTSUPP;
1442
1443         switch (which) {
1444         case BPF_SK_MSG_VERDICT:
1445                 pprog = &progs->msg_parser;
1446                 break;
1447 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1448         case BPF_SK_SKB_STREAM_PARSER:
1449                 pprog = &progs->stream_parser;
1450                 break;
1451 #endif
1452         case BPF_SK_SKB_STREAM_VERDICT:
1453                 if (progs->skb_verdict)
1454                         return -EBUSY;
1455                 pprog = &progs->stream_verdict;
1456                 break;
1457         case BPF_SK_SKB_VERDICT:
1458                 if (progs->stream_verdict)
1459                         return -EBUSY;
1460                 pprog = &progs->skb_verdict;
1461                 break;
1462         default:
1463                 return -EOPNOTSUPP;
1464         }
1465
1466         if (old)
1467                 return psock_replace_prog(pprog, prog, old);
1468
1469         psock_set_prog(pprog, prog);
1470         return 0;
1471 }
1472
1473 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1474 {
1475         switch (link->map->map_type) {
1476         case BPF_MAP_TYPE_SOCKMAP:
1477                 return sock_map_delete_from_link(link->map, sk,
1478                                                  link->link_raw);
1479         case BPF_MAP_TYPE_SOCKHASH:
1480                 return sock_hash_delete_from_link(link->map, sk,
1481                                                   link->link_raw);
1482         default:
1483                 break;
1484         }
1485 }
1486
1487 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1488 {
1489         struct sk_psock_link *link;
1490
1491         while ((link = sk_psock_link_pop(psock))) {
1492                 sock_map_unlink(sk, link);
1493                 sk_psock_free_link(link);
1494         }
1495 }
1496
1497 void sock_map_unhash(struct sock *sk)
1498 {
1499         void (*saved_unhash)(struct sock *sk);
1500         struct sk_psock *psock;
1501
1502         rcu_read_lock();
1503         psock = sk_psock(sk);
1504         if (unlikely(!psock)) {
1505                 rcu_read_unlock();
1506                 if (sk->sk_prot->unhash)
1507                         sk->sk_prot->unhash(sk);
1508                 return;
1509         }
1510
1511         saved_unhash = psock->saved_unhash;
1512         sock_map_remove_links(sk, psock);
1513         rcu_read_unlock();
1514         saved_unhash(sk);
1515 }
1516
1517 void sock_map_close(struct sock *sk, long timeout)
1518 {
1519         void (*saved_close)(struct sock *sk, long timeout);
1520         struct sk_psock *psock;
1521
1522         lock_sock(sk);
1523         rcu_read_lock();
1524         psock = sk_psock_get(sk);
1525         if (unlikely(!psock)) {
1526                 rcu_read_unlock();
1527                 release_sock(sk);
1528                 return sk->sk_prot->close(sk, timeout);
1529         }
1530
1531         saved_close = psock->saved_close;
1532         sock_map_remove_links(sk, psock);
1533         rcu_read_unlock();
1534         sk_psock_stop(psock, true);
1535         sk_psock_put(sk, psock);
1536         release_sock(sk);
1537         saved_close(sk, timeout);
1538 }
1539
1540 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1541                                        union bpf_iter_link_info *linfo,
1542                                        struct bpf_iter_aux_info *aux)
1543 {
1544         struct bpf_map *map;
1545         int err = -EINVAL;
1546
1547         if (!linfo->map.map_fd)
1548                 return -EBADF;
1549
1550         map = bpf_map_get_with_uref(linfo->map.map_fd);
1551         if (IS_ERR(map))
1552                 return PTR_ERR(map);
1553
1554         if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1555             map->map_type != BPF_MAP_TYPE_SOCKHASH)
1556                 goto put_map;
1557
1558         if (prog->aux->max_rdonly_access > map->key_size) {
1559                 err = -EACCES;
1560                 goto put_map;
1561         }
1562
1563         aux->map = map;
1564         return 0;
1565
1566 put_map:
1567         bpf_map_put_with_uref(map);
1568         return err;
1569 }
1570
1571 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1572 {
1573         bpf_map_put_with_uref(aux->map);
1574 }
1575
1576 static struct bpf_iter_reg sock_map_iter_reg = {
1577         .target                 = "sockmap",
1578         .attach_target          = sock_map_iter_attach_target,
1579         .detach_target          = sock_map_iter_detach_target,
1580         .show_fdinfo            = bpf_iter_map_show_fdinfo,
1581         .fill_link_info         = bpf_iter_map_fill_link_info,
1582         .ctx_arg_info_size      = 2,
1583         .ctx_arg_info           = {
1584                 { offsetof(struct bpf_iter__sockmap, key),
1585                   PTR_TO_RDONLY_BUF_OR_NULL },
1586                 { offsetof(struct bpf_iter__sockmap, sk),
1587                   PTR_TO_BTF_ID_OR_NULL },
1588         },
1589 };
1590
1591 static int __init bpf_sockmap_iter_init(void)
1592 {
1593         sock_map_iter_reg.ctx_arg_info[1].btf_id =
1594                 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1595         return bpf_iter_reg_target(&sock_map_iter_reg);
1596 }
1597 late_initcall(bpf_sockmap_iter_init);