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((u64) 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         rcu_read_lock();
 121 }
 122
 123 static void sock_map_sk_release(struct sock *sk)
 124         __releases(&sk->sk_lock.slock)
 125 {
 126         rcu_read_unlock();
 127         release_sock(sk);
 128 }
 129
 130 static void sock_map_add_link(struct sk_psock *psock,
 131                               struct sk_psock_link *link,
 132                               struct bpf_map *map, void *link_raw)
 133 {
 134         link->link_raw = link_raw;
 135         link->map = map;
 136         spin_lock_bh(&psock->link_lock);
 137         list_add_tail(&link->list, &psock->link);
 138         spin_unlock_bh(&psock->link_lock);
 139 }
 140
 141 static void sock_map_del_link(struct sock *sk,
 142                               struct sk_psock *psock, void *link_raw)
 143 {
 144         bool strp_stop = false, verdict_stop = false;
 145         struct sk_psock_link *link, *tmp;
 146
 147         spin_lock_bh(&psock->link_lock);
 148         list_for_each_entry_safe(link, tmp, &psock->link, list) {
 149                 if (link->link_raw == link_raw) {
 150                         struct bpf_map *map = link->map;
 151                         struct sk_psock_progs *progs = sock_map_progs(map);
 152
 153                         if (psock->saved_data_ready && progs->stream_parser)
 154                                 strp_stop = true;
 155                         if (psock->saved_data_ready && progs->stream_verdict)
 156                                 verdict_stop = true;
 157                         if (psock->saved_data_ready && progs->skb_verdict)
 158                                 verdict_stop = true;
 159                         list_del(&link->list);
 160                         sk_psock_free_link(link);
 161                 }
 162         }
 163         spin_unlock_bh(&psock->link_lock);
 164         if (strp_stop || verdict_stop) {
 165                 write_lock_bh(&sk->sk_callback_lock);
 166                 if (strp_stop)
 167                         sk_psock_stop_strp(sk, psock);
 168                 if (verdict_stop)
 169                         sk_psock_stop_verdict(sk, psock);
 170
 171                 if (psock->psock_update_sk_prot)
 172                         psock->psock_update_sk_prot(sk, psock, false);
 173                 write_unlock_bh(&sk->sk_callback_lock);
 174         }
 175 }
 176
 177 static void sock_map_unref(struct sock *sk, void *link_raw)
 178 {
 179         struct sk_psock *psock = sk_psock(sk);
 180
 181         if (likely(psock)) {
 182                 sock_map_del_link(sk, psock, link_raw);
 183                 sk_psock_put(sk, psock);
 184         }
 185 }
 186
 187 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
 188 {
 189         if (!sk->sk_prot->psock_update_sk_prot)
 190                 return -EINVAL;
 191         psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
 192         return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
 193 }
 194
 195 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
 196 {
 197         struct sk_psock *psock;
 198
 199         rcu_read_lock();
 200         psock = sk_psock(sk);
 201         if (psock) {
 202                 if (sk->sk_prot->close != sock_map_close) {
 203                         psock = ERR_PTR(-EBUSY);
 204                         goto out;
 205                 }
 206
 207                 if (!refcount_inc_not_zero(&psock->refcnt))
 208                         psock = ERR_PTR(-EBUSY);
 209         }
 210 out:
 211         rcu_read_unlock();
 212         return psock;
 213 }
 214
 215 static int sock_map_link(struct bpf_map *map, struct sock *sk)
 216 {
 217         struct sk_psock_progs *progs = sock_map_progs(map);
 218         struct bpf_prog *stream_verdict = NULL;
 219         struct bpf_prog *stream_parser = NULL;
 220         struct bpf_prog *skb_verdict = NULL;
 221         struct bpf_prog *msg_parser = NULL;
 222         struct sk_psock *psock;
 223         int ret;
 224
 225         stream_verdict = READ_ONCE(progs->stream_verdict);
 226         if (stream_verdict) {
 227                 stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
 228                 if (IS_ERR(stream_verdict))
 229                         return PTR_ERR(stream_verdict);
 230         }
 231
 232         stream_parser = READ_ONCE(progs->stream_parser);
 233         if (stream_parser) {
 234                 stream_parser = bpf_prog_inc_not_zero(stream_parser);
 235                 if (IS_ERR(stream_parser)) {
 236                         ret = PTR_ERR(stream_parser);
 237                         goto out_put_stream_verdict;
 238                 }
 239         }
 240
 241         msg_parser = READ_ONCE(progs->msg_parser);
 242         if (msg_parser) {
 243                 msg_parser = bpf_prog_inc_not_zero(msg_parser);
 244                 if (IS_ERR(msg_parser)) {
 245                         ret = PTR_ERR(msg_parser);
 246                         goto out_put_stream_parser;
 247                 }
 248         }
 249
 250         skb_verdict = READ_ONCE(progs->skb_verdict);
 251         if (skb_verdict) {
 252                 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
 253                 if (IS_ERR(skb_verdict)) {
 254                         ret = PTR_ERR(skb_verdict);
 255                         goto out_put_msg_parser;
 256                 }
 257         }
 258
 259         psock = sock_map_psock_get_checked(sk);
 260         if (IS_ERR(psock)) {
 261                 ret = PTR_ERR(psock);
 262                 goto out_progs;
 263         }
 264
 265         if (psock) {
 266                 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
 267                     (stream_parser  && READ_ONCE(psock->progs.stream_parser)) ||
 268                     (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 269                     (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
 270                     (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 271                     (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
 272                         sk_psock_put(sk, psock);
 273                         ret = -EBUSY;
 274                         goto out_progs;
 275                 }
 276         } else {
 277                 psock = sk_psock_init(sk, map->numa_node);
 278                 if (IS_ERR(psock)) {
 279                         ret = PTR_ERR(psock);
 280                         goto out_progs;
 281                 }
 282         }
 283
 284         if (msg_parser)
 285                 psock_set_prog(&psock->progs.msg_parser, msg_parser);
 286         if (stream_parser)
 287                 psock_set_prog(&psock->progs.stream_parser, stream_parser);
 288         if (stream_verdict)
 289                 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 290         if (skb_verdict)
 291                 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
 292
 293         /* msg_* and stream_* programs references tracked in psock after this
 294          * point. Reference dec and cleanup will occur through psock destructor
 295          */
 296         ret = sock_map_init_proto(sk, psock);
 297         if (ret < 0) {
 298                 sk_psock_put(sk, psock);
 299                 goto out;
 300         }
 301
 302         write_lock_bh(&sk->sk_callback_lock);
 303         if (stream_parser && stream_verdict && !psock->saved_data_ready) {
 304                 ret = sk_psock_init_strp(sk, psock);
 305                 if (ret) {
 306                         write_unlock_bh(&sk->sk_callback_lock);
 307                         sk_psock_put(sk, psock);
 308                         goto out;
 309                 }
 310                 sk_psock_start_strp(sk, psock);
 311         } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
 312                 sk_psock_start_verdict(sk,psock);
 313         } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
 314                 sk_psock_start_verdict(sk, psock);
 315         }
 316         write_unlock_bh(&sk->sk_callback_lock);
 317         return 0;
 318 out_progs:
 319         if (skb_verdict)
 320                 bpf_prog_put(skb_verdict);
 321 out_put_msg_parser:
 322         if (msg_parser)
 323                 bpf_prog_put(msg_parser);
 324 out_put_stream_parser:
 325         if (stream_parser)
 326                 bpf_prog_put(stream_parser);
 327 out_put_stream_verdict:
 328         if (stream_verdict)
 329                 bpf_prog_put(stream_verdict);
 330 out:
 331         return ret;
 332 }
 333
 334 static void sock_map_free(struct bpf_map *map)
 335 {
 336         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 337         int i;
 338
 339         /* After the sync no updates or deletes will be in-flight so it
 340          * is safe to walk map and remove entries without risking a race
 341          * in EEXIST update case.
 342          */
 343         synchronize_rcu();
 344         for (i = 0; i < stab->map.max_entries; i++) {
 345                 struct sock **psk = &stab->sks[i];
 346                 struct sock *sk;
 347
 348                 sk = xchg(psk, NULL);
 349                 if (sk) {
 350                         sock_hold(sk);
 351                         lock_sock(sk);
 352                         rcu_read_lock();
 353                         sock_map_unref(sk, psk);
 354                         rcu_read_unlock();
 355                         release_sock(sk);
 356                         sock_put(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 sock_map_redirect_allowed(const struct sock *sk)
 531 {
 532         if (sk_is_tcp(sk))
 533                 return sk->sk_state != TCP_LISTEN;
 534         else
 535                 return sk->sk_state == TCP_ESTABLISHED;
 536 }
 537
 538 static bool sock_map_sk_is_suitable(const struct sock *sk)
 539 {
 540         return !!sk->sk_prot->psock_update_sk_prot;
 541 }
 542
 543 static bool sock_map_sk_state_allowed(const struct sock *sk)
 544 {
 545         if (sk_is_tcp(sk))
 546                 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 547         return true;
 548 }
 549
 550 static int sock_hash_update_common(struct bpf_map *map, void *key,
 551                                    struct sock *sk, u64 flags);
 552
 553 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 554                              u64 flags)
 555 {
 556         struct socket *sock;
 557         struct sock *sk;
 558         int ret;
 559         u64 ufd;
 560
 561         if (map->value_size == sizeof(u64))
 562                 ufd = *(u64 *)value;
 563         else
 564                 ufd = *(u32 *)value;
 565         if (ufd > S32_MAX)
 566                 return -EINVAL;
 567
 568         sock = sockfd_lookup(ufd, &ret);
 569         if (!sock)
 570                 return ret;
 571         sk = sock->sk;
 572         if (!sk) {
 573                 ret = -EINVAL;
 574                 goto out;
 575         }
 576         if (!sock_map_sk_is_suitable(sk)) {
 577                 ret = -EOPNOTSUPP;
 578                 goto out;
 579         }
 580
 581         sock_map_sk_acquire(sk);
 582         if (!sock_map_sk_state_allowed(sk))
 583                 ret = -EOPNOTSUPP;
 584         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 585                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 586         else
 587                 ret = sock_hash_update_common(map, key, sk, flags);
 588         sock_map_sk_release(sk);
 589 out:
 590         sockfd_put(sock);
 591         return ret;
 592 }
 593
 594 static int sock_map_update_elem(struct bpf_map *map, void *key,
 595                                 void *value, u64 flags)
 596 {
 597         struct sock *sk = (struct sock *)value;
 598         int ret;
 599
 600         if (unlikely(!sk || !sk_fullsock(sk)))
 601                 return -EINVAL;
 602
 603         if (!sock_map_sk_is_suitable(sk))
 604                 return -EOPNOTSUPP;
 605
 606         local_bh_disable();
 607         bh_lock_sock(sk);
 608         if (!sock_map_sk_state_allowed(sk))
 609                 ret = -EOPNOTSUPP;
 610         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 611                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 612         else
 613                 ret = sock_hash_update_common(map, key, sk, flags);
 614         bh_unlock_sock(sk);
 615         local_bh_enable();
 616         return ret;
 617 }
 618
 619 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 620            struct bpf_map *, map, void *, key, u64, flags)
 621 {
 622         WARN_ON_ONCE(!rcu_read_lock_held());
 623
 624         if (likely(sock_map_sk_is_suitable(sops->sk) &&
 625                    sock_map_op_okay(sops)))
 626                 return sock_map_update_common(map, *(u32 *)key, sops->sk,
 627                                               flags);
 628         return -EOPNOTSUPP;
 629 }
 630
 631 const struct bpf_func_proto bpf_sock_map_update_proto = {
 632         .func           = bpf_sock_map_update,
 633         .gpl_only       = false,
 634         .pkt_access     = true,
 635         .ret_type       = RET_INTEGER,
 636         .arg1_type      = ARG_PTR_TO_CTX,
 637         .arg2_type      = ARG_CONST_MAP_PTR,
 638         .arg3_type      = ARG_PTR_TO_MAP_KEY,
 639         .arg4_type      = ARG_ANYTHING,
 640 };
 641
 642 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 643            struct bpf_map *, map, u32, key, u64, flags)
 644 {
 645         struct sock *sk;
 646
 647         if (unlikely(flags & ~(BPF_F_INGRESS)))
 648                 return SK_DROP;
 649
 650         sk = __sock_map_lookup_elem(map, key);
 651         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 652                 return SK_DROP;
 653
 654         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 655         return SK_PASS;
 656 }
 657
 658 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 659         .func           = bpf_sk_redirect_map,
 660         .gpl_only       = false,
 661         .ret_type       = RET_INTEGER,
 662         .arg1_type      = ARG_PTR_TO_CTX,
 663         .arg2_type      = ARG_CONST_MAP_PTR,
 664         .arg3_type      = ARG_ANYTHING,
 665         .arg4_type      = ARG_ANYTHING,
 666 };
 667
 668 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 669            struct bpf_map *, map, u32, key, u64, flags)
 670 {
 671         struct sock *sk;
 672
 673         if (unlikely(flags & ~(BPF_F_INGRESS)))
 674                 return SK_DROP;
 675
 676         sk = __sock_map_lookup_elem(map, key);
 677         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 678                 return SK_DROP;
 679         if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
 680                 return SK_DROP;
 681
 682         msg->flags = flags;
 683         msg->sk_redir = sk;
 684         return SK_PASS;
 685 }
 686
 687 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 688         .func           = bpf_msg_redirect_map,
 689         .gpl_only       = false,
 690         .ret_type       = RET_INTEGER,
 691         .arg1_type      = ARG_PTR_TO_CTX,
 692         .arg2_type      = ARG_CONST_MAP_PTR,
 693         .arg3_type      = ARG_ANYTHING,
 694         .arg4_type      = ARG_ANYTHING,
 695 };
 696
 697 struct sock_map_seq_info {
 698         struct bpf_map *map;
 699         struct sock *sk;
 700         u32 index;
 701 };
 702
 703 struct bpf_iter__sockmap {
 704         __bpf_md_ptr(struct bpf_iter_meta *, meta);
 705         __bpf_md_ptr(struct bpf_map *, map);
 706         __bpf_md_ptr(void *, key);
 707         __bpf_md_ptr(struct sock *, sk);
 708 };
 709
 710 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
 711                      struct bpf_map *map, void *key,
 712                      struct sock *sk)
 713
 714 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
 715 {
 716         if (unlikely(info->index >= info->map->max_entries))
 717                 return NULL;
 718
 719         info->sk = __sock_map_lookup_elem(info->map, info->index);
 720
 721         /* can't return sk directly, since that might be NULL */
 722         return info;
 723 }
 724
 725 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
 726         __acquires(rcu)
 727 {
 728         struct sock_map_seq_info *info = seq->private;
 729
 730         if (*pos == 0)
 731                 ++*pos;
 732
 733         /* pairs with sock_map_seq_stop */
 734         rcu_read_lock();
 735         return sock_map_seq_lookup_elem(info);
 736 }
 737
 738 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 739         __must_hold(rcu)
 740 {
 741         struct sock_map_seq_info *info = seq->private;
 742
 743         ++*pos;
 744         ++info->index;
 745
 746         return sock_map_seq_lookup_elem(info);
 747 }
 748
 749 static int sock_map_seq_show(struct seq_file *seq, void *v)
 750         __must_hold(rcu)
 751 {
 752         struct sock_map_seq_info *info = seq->private;
 753         struct bpf_iter__sockmap ctx = {};
 754         struct bpf_iter_meta meta;
 755         struct bpf_prog *prog;
 756
 757         meta.seq = seq;
 758         prog = bpf_iter_get_info(&meta, !v);
 759         if (!prog)
 760                 return 0;
 761
 762         ctx.meta = &meta;
 763         ctx.map = info->map;
 764         if (v) {
 765                 ctx.key = &info->index;
 766                 ctx.sk = info->sk;
 767         }
 768
 769         return bpf_iter_run_prog(prog, &ctx);
 770 }
 771
 772 static void sock_map_seq_stop(struct seq_file *seq, void *v)
 773         __releases(rcu)
 774 {
 775         if (!v)
 776                 (void)sock_map_seq_show(seq, NULL);
 777
 778         /* pairs with sock_map_seq_start */
 779         rcu_read_unlock();
 780 }
 781
 782 static const struct seq_operations sock_map_seq_ops = {
 783         .start  = sock_map_seq_start,
 784         .next   = sock_map_seq_next,
 785         .stop   = sock_map_seq_stop,
 786         .show   = sock_map_seq_show,
 787 };
 788
 789 static int sock_map_init_seq_private(void *priv_data,
 790                                      struct bpf_iter_aux_info *aux)
 791 {
 792         struct sock_map_seq_info *info = priv_data;
 793
 794         bpf_map_inc_with_uref(aux->map);
 795         info->map = aux->map;
 796         return 0;
 797 }
 798
 799 static void sock_map_fini_seq_private(void *priv_data)
 800 {
 801         struct sock_map_seq_info *info = priv_data;
 802
 803         bpf_map_put_with_uref(info->map);
 804 }
 805
 806 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
 807         .seq_ops                = &sock_map_seq_ops,
 808         .init_seq_private       = sock_map_init_seq_private,
 809         .fini_seq_private       = sock_map_fini_seq_private,
 810         .seq_priv_size          = sizeof(struct sock_map_seq_info),
 811 };
 812
 813 static int sock_map_btf_id;
 814 const struct bpf_map_ops sock_map_ops = {
 815         .map_meta_equal         = bpf_map_meta_equal,
 816         .map_alloc              = sock_map_alloc,
 817         .map_free               = sock_map_free,
 818         .map_get_next_key       = sock_map_get_next_key,
 819         .map_lookup_elem_sys_only = sock_map_lookup_sys,
 820         .map_update_elem        = sock_map_update_elem,
 821         .map_delete_elem        = sock_map_delete_elem,
 822         .map_lookup_elem        = sock_map_lookup,
 823         .map_release_uref       = sock_map_release_progs,
 824         .map_check_btf          = map_check_no_btf,
 825         .map_btf_name           = "bpf_stab",
 826         .map_btf_id             = &sock_map_btf_id,
 827         .iter_seq_info          = &sock_map_iter_seq_info,
 828 };
 829
 830 struct bpf_shtab_elem {
 831         struct rcu_head rcu;
 832         u32 hash;
 833         struct sock *sk;
 834         struct hlist_node node;
 835         u8 key[];
 836 };
 837
 838 struct bpf_shtab_bucket {
 839         struct hlist_head head;
 840         raw_spinlock_t lock;
 841 };
 842
 843 struct bpf_shtab {
 844         struct bpf_map map;
 845         struct bpf_shtab_bucket *buckets;
 846         u32 buckets_num;
 847         u32 elem_size;
 848         struct sk_psock_progs progs;
 849         atomic_t count;
 850 };
 851
 852 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 853 {
 854         return jhash(key, len, 0);
 855 }
 856
 857 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 858                                                         u32 hash)
 859 {
 860         return &htab->buckets[hash & (htab->buckets_num - 1)];
 861 }
 862
 863 static struct bpf_shtab_elem *
 864 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 865                           u32 key_size)
 866 {
 867         struct bpf_shtab_elem *elem;
 868
 869         hlist_for_each_entry_rcu(elem, head, node) {
 870                 if (elem->hash == hash &&
 871                     !memcmp(&elem->key, key, key_size))
 872                         return elem;
 873         }
 874
 875         return NULL;
 876 }
 877
 878 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 879 {
 880         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 881         u32 key_size = map->key_size, hash;
 882         struct bpf_shtab_bucket *bucket;
 883         struct bpf_shtab_elem *elem;
 884
 885         WARN_ON_ONCE(!rcu_read_lock_held());
 886
 887         hash = sock_hash_bucket_hash(key, key_size);
 888         bucket = sock_hash_select_bucket(htab, hash);
 889         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 890
 891         return elem ? elem->sk : NULL;
 892 }
 893
 894 static void sock_hash_free_elem(struct bpf_shtab *htab,
 895                                 struct bpf_shtab_elem *elem)
 896 {
 897         atomic_dec(&htab->count);
 898         kfree_rcu(elem, rcu);
 899 }
 900
 901 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 902                                        void *link_raw)
 903 {
 904         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 905         struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 906         struct bpf_shtab_bucket *bucket;
 907
 908         WARN_ON_ONCE(!rcu_read_lock_held());
 909         bucket = sock_hash_select_bucket(htab, elem->hash);
 910
 911         /* elem may be deleted in parallel from the map, but access here
 912          * is okay since it's going away only after RCU grace period.
 913          * However, we need to check whether it's still present.
 914          */
 915         raw_spin_lock_bh(&bucket->lock);
 916         elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 917                                                elem->key, map->key_size);
 918         if (elem_probe && elem_probe == elem) {
 919                 hlist_del_rcu(&elem->node);
 920                 sock_map_unref(elem->sk, elem);
 921                 sock_hash_free_elem(htab, elem);
 922         }
 923         raw_spin_unlock_bh(&bucket->lock);
 924 }
 925
 926 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
 927 {
 928         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 929         u32 hash, key_size = map->key_size;
 930         struct bpf_shtab_bucket *bucket;
 931         struct bpf_shtab_elem *elem;
 932         int ret = -ENOENT;
 933
 934         hash = sock_hash_bucket_hash(key, key_size);
 935         bucket = sock_hash_select_bucket(htab, hash);
 936
 937         raw_spin_lock_bh(&bucket->lock);
 938         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 939         if (elem) {
 940                 hlist_del_rcu(&elem->node);
 941                 sock_map_unref(elem->sk, elem);
 942                 sock_hash_free_elem(htab, elem);
 943                 ret = 0;
 944         }
 945         raw_spin_unlock_bh(&bucket->lock);
 946         return ret;
 947 }
 948
 949 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 950                                                    void *key, u32 key_size,
 951                                                    u32 hash, struct sock *sk,
 952                                                    struct bpf_shtab_elem *old)
 953 {
 954         struct bpf_shtab_elem *new;
 955
 956         if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 957                 if (!old) {
 958                         atomic_dec(&htab->count);
 959                         return ERR_PTR(-E2BIG);
 960                 }
 961         }
 962
 963         new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
 964                                    GFP_ATOMIC | __GFP_NOWARN,
 965                                    htab->map.numa_node);
 966         if (!new) {
 967                 atomic_dec(&htab->count);
 968                 return ERR_PTR(-ENOMEM);
 969         }
 970         memcpy(new->key, key, key_size);
 971         new->sk = sk;
 972         new->hash = hash;
 973         return new;
 974 }
 975
 976 static int sock_hash_update_common(struct bpf_map *map, void *key,
 977                                    struct sock *sk, u64 flags)
 978 {
 979         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 980         u32 key_size = map->key_size, hash;
 981         struct bpf_shtab_elem *elem, *elem_new;
 982         struct bpf_shtab_bucket *bucket;
 983         struct sk_psock_link *link;
 984         struct sk_psock *psock;
 985         int ret;
 986
 987         WARN_ON_ONCE(!rcu_read_lock_held());
 988         if (unlikely(flags > BPF_EXIST))
 989                 return -EINVAL;
 990
 991         link = sk_psock_init_link();
 992         if (!link)
 993                 return -ENOMEM;
 994
 995         ret = sock_map_link(map, sk);
 996         if (ret < 0)
 997                 goto out_free;
 998
 999         psock = sk_psock(sk);
1000         WARN_ON_ONCE(!psock);
1001
1002         hash = sock_hash_bucket_hash(key, key_size);
1003         bucket = sock_hash_select_bucket(htab, hash);
1004
1005         raw_spin_lock_bh(&bucket->lock);
1006         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1007         if (elem && flags == BPF_NOEXIST) {
1008                 ret = -EEXIST;
1009                 goto out_unlock;
1010         } else if (!elem && flags == BPF_EXIST) {
1011                 ret = -ENOENT;
1012                 goto out_unlock;
1013         }
1014
1015         elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1016         if (IS_ERR(elem_new)) {
1017                 ret = PTR_ERR(elem_new);
1018                 goto out_unlock;
1019         }
1020
1021         sock_map_add_link(psock, link, map, elem_new);
1022         /* Add new element to the head of the list, so that
1023          * concurrent search will find it before old elem.
1024          */
1025         hlist_add_head_rcu(&elem_new->node, &bucket->head);
1026         if (elem) {
1027                 hlist_del_rcu(&elem->node);
1028                 sock_map_unref(elem->sk, elem);
1029                 sock_hash_free_elem(htab, elem);
1030         }
1031         raw_spin_unlock_bh(&bucket->lock);
1032         return 0;
1033 out_unlock:
1034         raw_spin_unlock_bh(&bucket->lock);
1035         sk_psock_put(sk, psock);
1036 out_free:
1037         sk_psock_free_link(link);
1038         return ret;
1039 }
1040
1041 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1042                                   void *key_next)
1043 {
1044         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1045         struct bpf_shtab_elem *elem, *elem_next;
1046         u32 hash, key_size = map->key_size;
1047         struct hlist_head *head;
1048         int i = 0;
1049
1050         if (!key)
1051                 goto find_first_elem;
1052         hash = sock_hash_bucket_hash(key, key_size);
1053         head = &sock_hash_select_bucket(htab, hash)->head;
1054         elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1055         if (!elem)
1056                 goto find_first_elem;
1057
1058         elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1059                                      struct bpf_shtab_elem, node);
1060         if (elem_next) {
1061                 memcpy(key_next, elem_next->key, key_size);
1062                 return 0;
1063         }
1064
1065         i = hash & (htab->buckets_num - 1);
1066         i++;
1067 find_first_elem:
1068         for (; i < htab->buckets_num; i++) {
1069                 head = &sock_hash_select_bucket(htab, i)->head;
1070                 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1071                                              struct bpf_shtab_elem, node);
1072                 if (elem_next) {
1073                         memcpy(key_next, elem_next->key, key_size);
1074                         return 0;
1075                 }
1076         }
1077
1078         return -ENOENT;
1079 }
1080
1081 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1082 {
1083         struct bpf_shtab *htab;
1084         int i, err;
1085
1086         if (!capable(CAP_NET_ADMIN))
1087                 return ERR_PTR(-EPERM);
1088         if (attr->max_entries == 0 ||
1089             attr->key_size    == 0 ||
1090             (attr->value_size != sizeof(u32) &&
1091              attr->value_size != sizeof(u64)) ||
1092             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1093                 return ERR_PTR(-EINVAL);
1094         if (attr->key_size > MAX_BPF_STACK)
1095                 return ERR_PTR(-E2BIG);
1096
1097         htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
1098         if (!htab)
1099                 return ERR_PTR(-ENOMEM);
1100
1101         bpf_map_init_from_attr(&htab->map, attr);
1102
1103         htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1104         htab->elem_size = sizeof(struct bpf_shtab_elem) +
1105                           round_up(htab->map.key_size, 8);
1106         if (htab->buckets_num == 0 ||
1107             htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1108                 err = -EINVAL;
1109                 goto free_htab;
1110         }
1111
1112         htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1113                                            sizeof(struct bpf_shtab_bucket),
1114                                            htab->map.numa_node);
1115         if (!htab->buckets) {
1116                 err = -ENOMEM;
1117                 goto free_htab;
1118         }
1119
1120         for (i = 0; i < htab->buckets_num; i++) {
1121                 INIT_HLIST_HEAD(&htab->buckets[i].head);
1122                 raw_spin_lock_init(&htab->buckets[i].lock);
1123         }
1124
1125         return &htab->map;
1126 free_htab:
1127         kfree(htab);
1128         return ERR_PTR(err);
1129 }
1130
1131 static void sock_hash_free(struct bpf_map *map)
1132 {
1133         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1134         struct bpf_shtab_bucket *bucket;
1135         struct hlist_head unlink_list;
1136         struct bpf_shtab_elem *elem;
1137         struct hlist_node *node;
1138         int i;
1139
1140         /* After the sync no updates or deletes will be in-flight so it
1141          * is safe to walk map and remove entries without risking a race
1142          * in EEXIST update case.
1143          */
1144         synchronize_rcu();
1145         for (i = 0; i < htab->buckets_num; i++) {
1146                 bucket = sock_hash_select_bucket(htab, i);
1147
1148                 /* We are racing with sock_hash_delete_from_link to
1149                  * enter the spin-lock critical section. Every socket on
1150                  * the list is still linked to sockhash. Since link
1151                  * exists, psock exists and holds a ref to socket. That
1152                  * lets us to grab a socket ref too.
1153                  */
1154                 raw_spin_lock_bh(&bucket->lock);
1155                 hlist_for_each_entry(elem, &bucket->head, node)
1156                         sock_hold(elem->sk);
1157                 hlist_move_list(&bucket->head, &unlink_list);
1158                 raw_spin_unlock_bh(&bucket->lock);
1159
1160                 /* Process removed entries out of atomic context to
1161                  * block for socket lock before deleting the psock's
1162                  * link to sockhash.
1163                  */
1164                 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1165                         hlist_del(&elem->node);
1166                         lock_sock(elem->sk);
1167                         rcu_read_lock();
1168                         sock_map_unref(elem->sk, elem);
1169                         rcu_read_unlock();
1170                         release_sock(elem->sk);
1171                         sock_put(elem->sk);
1172                         sock_hash_free_elem(htab, elem);
1173                 }
1174         }
1175
1176         /* wait for psock readers accessing its map link */
1177         synchronize_rcu();
1178
1179         bpf_map_area_free(htab->buckets);
1180         kfree(htab);
1181 }
1182
1183 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1184 {
1185         struct sock *sk;
1186
1187         if (map->value_size != sizeof(u64))
1188                 return ERR_PTR(-ENOSPC);
1189
1190         sk = __sock_hash_lookup_elem(map, key);
1191         if (!sk)
1192                 return ERR_PTR(-ENOENT);
1193
1194         __sock_gen_cookie(sk);
1195         return &sk->sk_cookie;
1196 }
1197
1198 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1199 {
1200         struct sock *sk;
1201
1202         sk = __sock_hash_lookup_elem(map, key);
1203         if (!sk)
1204                 return NULL;
1205         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1206                 return NULL;
1207         return sk;
1208 }
1209
1210 static void sock_hash_release_progs(struct bpf_map *map)
1211 {
1212         psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1213 }
1214
1215 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1216            struct bpf_map *, map, void *, key, u64, flags)
1217 {
1218         WARN_ON_ONCE(!rcu_read_lock_held());
1219
1220         if (likely(sock_map_sk_is_suitable(sops->sk) &&
1221                    sock_map_op_okay(sops)))
1222                 return sock_hash_update_common(map, key, sops->sk, flags);
1223         return -EOPNOTSUPP;
1224 }
1225
1226 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1227         .func           = bpf_sock_hash_update,
1228         .gpl_only       = false,
1229         .pkt_access     = true,
1230         .ret_type       = RET_INTEGER,
1231         .arg1_type      = ARG_PTR_TO_CTX,
1232         .arg2_type      = ARG_CONST_MAP_PTR,
1233         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1234         .arg4_type      = ARG_ANYTHING,
1235 };
1236
1237 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1238            struct bpf_map *, map, void *, key, u64, flags)
1239 {
1240         struct sock *sk;
1241
1242         if (unlikely(flags & ~(BPF_F_INGRESS)))
1243                 return SK_DROP;
1244
1245         sk = __sock_hash_lookup_elem(map, key);
1246         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1247                 return SK_DROP;
1248
1249         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1250         return SK_PASS;
1251 }
1252
1253 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1254         .func           = bpf_sk_redirect_hash,
1255         .gpl_only       = false,
1256         .ret_type       = RET_INTEGER,
1257         .arg1_type      = ARG_PTR_TO_CTX,
1258         .arg2_type      = ARG_CONST_MAP_PTR,
1259         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1260         .arg4_type      = ARG_ANYTHING,
1261 };
1262
1263 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1264            struct bpf_map *, map, void *, key, u64, flags)
1265 {
1266         struct sock *sk;
1267
1268         if (unlikely(flags & ~(BPF_F_INGRESS)))
1269                 return SK_DROP;
1270
1271         sk = __sock_hash_lookup_elem(map, key);
1272         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1273                 return SK_DROP;
1274         if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
1275                 return SK_DROP;
1276
1277         msg->flags = flags;
1278         msg->sk_redir = sk;
1279         return SK_PASS;
1280 }
1281
1282 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1283         .func           = bpf_msg_redirect_hash,
1284         .gpl_only       = false,
1285         .ret_type       = RET_INTEGER,
1286         .arg1_type      = ARG_PTR_TO_CTX,
1287         .arg2_type      = ARG_CONST_MAP_PTR,
1288         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1289         .arg4_type      = ARG_ANYTHING,
1290 };
1291
1292 struct sock_hash_seq_info {
1293         struct bpf_map *map;
1294         struct bpf_shtab *htab;
1295         u32 bucket_id;
1296 };
1297
1298 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1299                                      struct bpf_shtab_elem *prev_elem)
1300 {
1301         const struct bpf_shtab *htab = info->htab;
1302         struct bpf_shtab_bucket *bucket;
1303         struct bpf_shtab_elem *elem;
1304         struct hlist_node *node;
1305
1306         /* try to find next elem in the same bucket */
1307         if (prev_elem) {
1308                 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1309                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1310                 if (elem)
1311                         return elem;
1312
1313                 /* no more elements, continue in the next bucket */
1314                 info->bucket_id++;
1315         }
1316
1317         for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1318                 bucket = &htab->buckets[info->bucket_id];
1319                 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1320                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1321                 if (elem)
1322                         return elem;
1323         }
1324
1325         return NULL;
1326 }
1327
1328 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1329         __acquires(rcu)
1330 {
1331         struct sock_hash_seq_info *info = seq->private;
1332
1333         if (*pos == 0)
1334                 ++*pos;
1335
1336         /* pairs with sock_hash_seq_stop */
1337         rcu_read_lock();
1338         return sock_hash_seq_find_next(info, NULL);
1339 }
1340
1341 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1342         __must_hold(rcu)
1343 {
1344         struct sock_hash_seq_info *info = seq->private;
1345
1346         ++*pos;
1347         return sock_hash_seq_find_next(info, v);
1348 }
1349
1350 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1351         __must_hold(rcu)
1352 {
1353         struct sock_hash_seq_info *info = seq->private;
1354         struct bpf_iter__sockmap ctx = {};
1355         struct bpf_shtab_elem *elem = v;
1356         struct bpf_iter_meta meta;
1357         struct bpf_prog *prog;
1358
1359         meta.seq = seq;
1360         prog = bpf_iter_get_info(&meta, !elem);
1361         if (!prog)
1362                 return 0;
1363
1364         ctx.meta = &meta;
1365         ctx.map = info->map;
1366         if (elem) {
1367                 ctx.key = elem->key;
1368                 ctx.sk = elem->sk;
1369         }
1370
1371         return bpf_iter_run_prog(prog, &ctx);
1372 }
1373
1374 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1375         __releases(rcu)
1376 {
1377         if (!v)
1378                 (void)sock_hash_seq_show(seq, NULL);
1379
1380         /* pairs with sock_hash_seq_start */
1381         rcu_read_unlock();
1382 }
1383
1384 static const struct seq_operations sock_hash_seq_ops = {
1385         .start  = sock_hash_seq_start,
1386         .next   = sock_hash_seq_next,
1387         .stop   = sock_hash_seq_stop,
1388         .show   = sock_hash_seq_show,
1389 };
1390
1391 static int sock_hash_init_seq_private(void *priv_data,
1392                                       struct bpf_iter_aux_info *aux)
1393 {
1394         struct sock_hash_seq_info *info = priv_data;
1395
1396         bpf_map_inc_with_uref(aux->map);
1397         info->map = aux->map;
1398         info->htab = container_of(aux->map, struct bpf_shtab, map);
1399         return 0;
1400 }
1401
1402 static void sock_hash_fini_seq_private(void *priv_data)
1403 {
1404         struct sock_hash_seq_info *info = priv_data;
1405
1406         bpf_map_put_with_uref(info->map);
1407 }
1408
1409 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1410         .seq_ops                = &sock_hash_seq_ops,
1411         .init_seq_private       = sock_hash_init_seq_private,
1412         .fini_seq_private       = sock_hash_fini_seq_private,
1413         .seq_priv_size          = sizeof(struct sock_hash_seq_info),
1414 };
1415
1416 static int sock_hash_map_btf_id;
1417 const struct bpf_map_ops sock_hash_ops = {
1418         .map_meta_equal         = bpf_map_meta_equal,
1419         .map_alloc              = sock_hash_alloc,
1420         .map_free               = sock_hash_free,
1421         .map_get_next_key       = sock_hash_get_next_key,
1422         .map_update_elem        = sock_map_update_elem,
1423         .map_delete_elem        = sock_hash_delete_elem,
1424         .map_lookup_elem        = sock_hash_lookup,
1425         .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1426         .map_release_uref       = sock_hash_release_progs,
1427         .map_check_btf          = map_check_no_btf,
1428         .map_btf_name           = "bpf_shtab",
1429         .map_btf_id             = &sock_hash_map_btf_id,
1430         .iter_seq_info          = &sock_hash_iter_seq_info,
1431 };
1432
1433 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1434 {
1435         switch (map->map_type) {
1436         case BPF_MAP_TYPE_SOCKMAP:
1437                 return &container_of(map, struct bpf_stab, map)->progs;
1438         case BPF_MAP_TYPE_SOCKHASH:
1439                 return &container_of(map, struct bpf_shtab, map)->progs;
1440         default:
1441                 break;
1442         }
1443
1444         return NULL;
1445 }
1446
1447 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1448                                 struct bpf_prog *old, u32 which)
1449 {
1450         struct sk_psock_progs *progs = sock_map_progs(map);
1451         struct bpf_prog **pprog;
1452
1453         if (!progs)
1454                 return -EOPNOTSUPP;
1455
1456         switch (which) {
1457         case BPF_SK_MSG_VERDICT:
1458                 pprog = &progs->msg_parser;
1459                 break;
1460 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1461         case BPF_SK_SKB_STREAM_PARSER:
1462                 pprog = &progs->stream_parser;
1463                 break;
1464 #endif
1465         case BPF_SK_SKB_STREAM_VERDICT:
1466                 if (progs->skb_verdict)
1467                         return -EBUSY;
1468                 pprog = &progs->stream_verdict;
1469                 break;
1470         case BPF_SK_SKB_VERDICT:
1471                 if (progs->stream_verdict)
1472                         return -EBUSY;
1473                 pprog = &progs->skb_verdict;
1474                 break;
1475         default:
1476                 return -EOPNOTSUPP;
1477         }
1478
1479         if (old)
1480                 return psock_replace_prog(pprog, prog, old);
1481
1482         psock_set_prog(pprog, prog);
1483         return 0;
1484 }
1485
1486 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1487 {
1488         switch (link->map->map_type) {
1489         case BPF_MAP_TYPE_SOCKMAP:
1490                 return sock_map_delete_from_link(link->map, sk,
1491                                                  link->link_raw);
1492         case BPF_MAP_TYPE_SOCKHASH:
1493                 return sock_hash_delete_from_link(link->map, sk,
1494                                                   link->link_raw);
1495         default:
1496                 break;
1497         }
1498 }
1499
1500 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1501 {
1502         struct sk_psock_link *link;
1503
1504         while ((link = sk_psock_link_pop(psock))) {
1505                 sock_map_unlink(sk, link);
1506                 sk_psock_free_link(link);
1507         }
1508 }
1509
1510 void sock_map_unhash(struct sock *sk)
1511 {
1512         void (*saved_unhash)(struct sock *sk);
1513         struct sk_psock *psock;
1514
1515         rcu_read_lock();
1516         psock = sk_psock(sk);
1517         if (unlikely(!psock)) {
1518                 rcu_read_unlock();
1519                 saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
1520         } else {
1521                 saved_unhash = psock->saved_unhash;
1522                 sock_map_remove_links(sk, psock);
1523                 rcu_read_unlock();
1524         }
1525         if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
1526                 return;
1527         if (saved_unhash)
1528                 saved_unhash(sk);
1529 }
1530 EXPORT_SYMBOL_GPL(sock_map_unhash);
1531
1532 void sock_map_destroy(struct sock *sk)
1533 {
1534         void (*saved_destroy)(struct sock *sk);
1535         struct sk_psock *psock;
1536
1537         rcu_read_lock();
1538         psock = sk_psock_get(sk);
1539         if (unlikely(!psock)) {
1540                 rcu_read_unlock();
1541                 saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
1542         } else {
1543                 saved_destroy = psock->saved_destroy;
1544                 sock_map_remove_links(sk, psock);
1545                 rcu_read_unlock();
1546                 sk_psock_stop(psock);
1547                 sk_psock_put(sk, psock);
1548         }
1549         if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
1550                 return;
1551         if (saved_destroy)
1552                 saved_destroy(sk);
1553 }
1554 EXPORT_SYMBOL_GPL(sock_map_destroy);
1555
1556 void sock_map_close(struct sock *sk, long timeout)
1557 {
1558         void (*saved_close)(struct sock *sk, long timeout);
1559         struct sk_psock *psock;
1560
1561         lock_sock(sk);
1562         rcu_read_lock();
1563         psock = sk_psock_get(sk);
1564         if (unlikely(!psock)) {
1565                 rcu_read_unlock();
1566                 release_sock(sk);
1567                 saved_close = READ_ONCE(sk->sk_prot)->close;
1568         } else {
1569                 saved_close = psock->saved_close;
1570                 sock_map_remove_links(sk, psock);
1571                 rcu_read_unlock();
1572                 sk_psock_stop(psock);
1573                 release_sock(sk);
1574                 cancel_work_sync(&psock->work);
1575                 sk_psock_put(sk, psock);
1576         }
1577         /* Make sure we do not recurse. This is a bug.
1578          * Leak the socket instead of crashing on a stack overflow.
1579          */
1580         if (WARN_ON_ONCE(saved_close == sock_map_close))
1581                 return;
1582         saved_close(sk, timeout);
1583 }
1584 EXPORT_SYMBOL_GPL(sock_map_close);
1585
1586 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1587                                        union bpf_iter_link_info *linfo,
1588                                        struct bpf_iter_aux_info *aux)
1589 {
1590         struct bpf_map *map;
1591         int err = -EINVAL;
1592
1593         if (!linfo->map.map_fd)
1594                 return -EBADF;
1595
1596         map = bpf_map_get_with_uref(linfo->map.map_fd);
1597         if (IS_ERR(map))
1598                 return PTR_ERR(map);
1599
1600         if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1601             map->map_type != BPF_MAP_TYPE_SOCKHASH)
1602                 goto put_map;
1603
1604         if (prog->aux->max_rdonly_access > map->key_size) {
1605                 err = -EACCES;
1606                 goto put_map;
1607         }
1608
1609         aux->map = map;
1610         return 0;
1611
1612 put_map:
1613         bpf_map_put_with_uref(map);
1614         return err;
1615 }
1616
1617 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1618 {
1619         bpf_map_put_with_uref(aux->map);
1620 }
1621
1622 static struct bpf_iter_reg sock_map_iter_reg = {
1623         .target                 = "sockmap",
1624         .attach_target          = sock_map_iter_attach_target,
1625         .detach_target          = sock_map_iter_detach_target,
1626         .show_fdinfo            = bpf_iter_map_show_fdinfo,
1627         .fill_link_info         = bpf_iter_map_fill_link_info,
1628         .ctx_arg_info_size      = 2,
1629         .ctx_arg_info           = {
1630                 { offsetof(struct bpf_iter__sockmap, key),
1631                   PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1632                 { offsetof(struct bpf_iter__sockmap, sk),
1633                   PTR_TO_BTF_ID_OR_NULL },
1634         },
1635 };
1636
1637 static int __init bpf_sockmap_iter_init(void)
1638 {
1639         sock_map_iter_reg.ctx_arg_info[1].btf_id =
1640                 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1641         return bpf_iter_reg_target(&sock_map_iter_reg);
1642 }
1643 late_initcall(bpf_sockmap_iter_init);