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