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         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 (attr->max_entries == 0 ||
  36             attr->key_size    != 4 ||
  37             (attr->value_size != sizeof(u32) &&
  38              attr->value_size != sizeof(u64)) ||
  39             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
  40                 return ERR_PTR(-EINVAL);
  41
  42         stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE);
  43         if (!stab)
  44                 return ERR_PTR(-ENOMEM);
  45
  46         bpf_map_init_from_attr(&stab->map, attr);
  47         spin_lock_init(&stab->lock);
  48
  49         stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
  50                                        sizeof(struct sock *),
  51                                        stab->map.numa_node);
  52         if (!stab->sks) {
  53                 bpf_map_area_free(stab);
  54                 return ERR_PTR(-ENOMEM);
  55         }
  56
  57         return &stab->map;
  58 }
  59
  60 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
  61 {
  62         u32 ufd = attr->target_fd;
  63         struct bpf_map *map;
  64         struct fd f;
  65         int ret;
  66
  67         if (attr->attach_flags || attr->replace_bpf_fd)
  68                 return -EINVAL;
  69
  70         f = fdget(ufd);
  71         map = __bpf_map_get(f);
  72         if (IS_ERR(map))
  73                 return PTR_ERR(map);
  74         ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
  75         fdput(f);
  76         return ret;
  77 }
  78
  79 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
  80 {
  81         u32 ufd = attr->target_fd;
  82         struct bpf_prog *prog;
  83         struct bpf_map *map;
  84         struct fd f;
  85         int ret;
  86
  87         if (attr->attach_flags || attr->replace_bpf_fd)
  88                 return -EINVAL;
  89
  90         f = fdget(ufd);
  91         map = __bpf_map_get(f);
  92         if (IS_ERR(map))
  93                 return PTR_ERR(map);
  94
  95         prog = bpf_prog_get(attr->attach_bpf_fd);
  96         if (IS_ERR(prog)) {
  97                 ret = PTR_ERR(prog);
  98                 goto put_map;
  99         }
 100
 101         if (prog->type != ptype) {
 102                 ret = -EINVAL;
 103                 goto put_prog;
 104         }
 105
 106         ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
 107 put_prog:
 108         bpf_prog_put(prog);
 109 put_map:
 110         fdput(f);
 111         return ret;
 112 }
 113
 114 static void sock_map_sk_acquire(struct sock *sk)
 115         __acquires(&sk->sk_lock.slock)
 116 {
 117         lock_sock(sk);
 118         rcu_read_lock();
 119 }
 120
 121 static void sock_map_sk_release(struct sock *sk)
 122         __releases(&sk->sk_lock.slock)
 123 {
 124         rcu_read_unlock();
 125         release_sock(sk);
 126 }
 127
 128 static void sock_map_add_link(struct sk_psock *psock,
 129                               struct sk_psock_link *link,
 130                               struct bpf_map *map, void *link_raw)
 131 {
 132         link->link_raw = link_raw;
 133         link->map = map;
 134         spin_lock_bh(&psock->link_lock);
 135         list_add_tail(&link->list, &psock->link);
 136         spin_unlock_bh(&psock->link_lock);
 137 }
 138
 139 static void sock_map_del_link(struct sock *sk,
 140                               struct sk_psock *psock, void *link_raw)
 141 {
 142         bool strp_stop = false, verdict_stop = false;
 143         struct sk_psock_link *link, *tmp;
 144
 145         spin_lock_bh(&psock->link_lock);
 146         list_for_each_entry_safe(link, tmp, &psock->link, list) {
 147                 if (link->link_raw == link_raw) {
 148                         struct bpf_map *map = link->map;
 149                         struct sk_psock_progs *progs = sock_map_progs(map);
 150
 151                         if (psock->saved_data_ready && progs->stream_parser)
 152                                 strp_stop = true;
 153                         if (psock->saved_data_ready && progs->stream_verdict)
 154                                 verdict_stop = true;
 155                         if (psock->saved_data_ready && progs->skb_verdict)
 156                                 verdict_stop = true;
 157                         list_del(&link->list);
 158                         sk_psock_free_link(link);
 159                 }
 160         }
 161         spin_unlock_bh(&psock->link_lock);
 162         if (strp_stop || verdict_stop) {
 163                 write_lock_bh(&sk->sk_callback_lock);
 164                 if (strp_stop)
 165                         sk_psock_stop_strp(sk, psock);
 166                 if (verdict_stop)
 167                         sk_psock_stop_verdict(sk, psock);
 168
 169                 if (psock->psock_update_sk_prot)
 170                         psock->psock_update_sk_prot(sk, psock, false);
 171                 write_unlock_bh(&sk->sk_callback_lock);
 172         }
 173 }
 174
 175 static void sock_map_unref(struct sock *sk, void *link_raw)
 176 {
 177         struct sk_psock *psock = sk_psock(sk);
 178
 179         if (likely(psock)) {
 180                 sock_map_del_link(sk, psock, link_raw);
 181                 sk_psock_put(sk, psock);
 182         }
 183 }
 184
 185 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
 186 {
 187         if (!sk->sk_prot->psock_update_sk_prot)
 188                 return -EINVAL;
 189         psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
 190         return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
 191 }
 192
 193 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
 194 {
 195         struct sk_psock *psock;
 196
 197         rcu_read_lock();
 198         psock = sk_psock(sk);
 199         if (psock) {
 200                 if (sk->sk_prot->close != sock_map_close) {
 201                         psock = ERR_PTR(-EBUSY);
 202                         goto out;
 203                 }
 204
 205                 if (!refcount_inc_not_zero(&psock->refcnt))
 206                         psock = ERR_PTR(-EBUSY);
 207         }
 208 out:
 209         rcu_read_unlock();
 210         return psock;
 211 }
 212
 213 static int sock_map_link(struct bpf_map *map, struct sock *sk)
 214 {
 215         struct sk_psock_progs *progs = sock_map_progs(map);
 216         struct bpf_prog *stream_verdict = NULL;
 217         struct bpf_prog *stream_parser = NULL;
 218         struct bpf_prog *skb_verdict = NULL;
 219         struct bpf_prog *msg_parser = NULL;
 220         struct sk_psock *psock;
 221         int ret;
 222
 223         stream_verdict = READ_ONCE(progs->stream_verdict);
 224         if (stream_verdict) {
 225                 stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
 226                 if (IS_ERR(stream_verdict))
 227                         return PTR_ERR(stream_verdict);
 228         }
 229
 230         stream_parser = READ_ONCE(progs->stream_parser);
 231         if (stream_parser) {
 232                 stream_parser = bpf_prog_inc_not_zero(stream_parser);
 233                 if (IS_ERR(stream_parser)) {
 234                         ret = PTR_ERR(stream_parser);
 235                         goto out_put_stream_verdict;
 236                 }
 237         }
 238
 239         msg_parser = READ_ONCE(progs->msg_parser);
 240         if (msg_parser) {
 241                 msg_parser = bpf_prog_inc_not_zero(msg_parser);
 242                 if (IS_ERR(msg_parser)) {
 243                         ret = PTR_ERR(msg_parser);
 244                         goto out_put_stream_parser;
 245                 }
 246         }
 247
 248         skb_verdict = READ_ONCE(progs->skb_verdict);
 249         if (skb_verdict) {
 250                 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
 251                 if (IS_ERR(skb_verdict)) {
 252                         ret = PTR_ERR(skb_verdict);
 253                         goto out_put_msg_parser;
 254                 }
 255         }
 256
 257         psock = sock_map_psock_get_checked(sk);
 258         if (IS_ERR(psock)) {
 259                 ret = PTR_ERR(psock);
 260                 goto out_progs;
 261         }
 262
 263         if (psock) {
 264                 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
 265                     (stream_parser  && READ_ONCE(psock->progs.stream_parser)) ||
 266                     (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 267                     (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
 268                     (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 269                     (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
 270                         sk_psock_put(sk, psock);
 271                         ret = -EBUSY;
 272                         goto out_progs;
 273                 }
 274         } else {
 275                 psock = sk_psock_init(sk, map->numa_node);
 276                 if (IS_ERR(psock)) {
 277                         ret = PTR_ERR(psock);
 278                         goto out_progs;
 279                 }
 280         }
 281
 282         if (msg_parser)
 283                 psock_set_prog(&psock->progs.msg_parser, msg_parser);
 284         if (stream_parser)
 285                 psock_set_prog(&psock->progs.stream_parser, stream_parser);
 286         if (stream_verdict)
 287                 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 288         if (skb_verdict)
 289                 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
 290
 291         /* msg_* and stream_* programs references tracked in psock after this
 292          * point. Reference dec and cleanup will occur through psock destructor
 293          */
 294         ret = sock_map_init_proto(sk, psock);
 295         if (ret < 0) {
 296                 sk_psock_put(sk, psock);
 297                 goto out;
 298         }
 299
 300         write_lock_bh(&sk->sk_callback_lock);
 301         if (stream_parser && stream_verdict && !psock->saved_data_ready) {
 302                 ret = sk_psock_init_strp(sk, psock);
 303                 if (ret) {
 304                         write_unlock_bh(&sk->sk_callback_lock);
 305                         sk_psock_put(sk, psock);
 306                         goto out;
 307                 }
 308                 sk_psock_start_strp(sk, psock);
 309         } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
 310                 sk_psock_start_verdict(sk,psock);
 311         } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
 312                 sk_psock_start_verdict(sk, psock);
 313         }
 314         write_unlock_bh(&sk->sk_callback_lock);
 315         return 0;
 316 out_progs:
 317         if (skb_verdict)
 318                 bpf_prog_put(skb_verdict);
 319 out_put_msg_parser:
 320         if (msg_parser)
 321                 bpf_prog_put(msg_parser);
 322 out_put_stream_parser:
 323         if (stream_parser)
 324                 bpf_prog_put(stream_parser);
 325 out_put_stream_verdict:
 326         if (stream_verdict)
 327                 bpf_prog_put(stream_verdict);
 328 out:
 329         return ret;
 330 }
 331
 332 static void sock_map_free(struct bpf_map *map)
 333 {
 334         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 335         int i;
 336
 337         /* After the sync no updates or deletes will be in-flight so it
 338          * is safe to walk map and remove entries without risking a race
 339          * in EEXIST update case.
 340          */
 341         synchronize_rcu();
 342         for (i = 0; i < stab->map.max_entries; i++) {
 343                 struct sock **psk = &stab->sks[i];
 344                 struct sock *sk;
 345
 346                 sk = xchg(psk, NULL);
 347                 if (sk) {
 348                         sock_hold(sk);
 349                         lock_sock(sk);
 350                         rcu_read_lock();
 351                         sock_map_unref(sk, psk);
 352                         rcu_read_unlock();
 353                         release_sock(sk);
 354                         sock_put(sk);
 355                 }
 356         }
 357
 358         /* wait for psock readers accessing its map link */
 359         synchronize_rcu();
 360
 361         bpf_map_area_free(stab->sks);
 362         bpf_map_area_free(stab);
 363 }
 364
 365 static void sock_map_release_progs(struct bpf_map *map)
 366 {
 367         psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
 368 }
 369
 370 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 371 {
 372         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 373
 374         WARN_ON_ONCE(!rcu_read_lock_held());
 375
 376         if (unlikely(key >= map->max_entries))
 377                 return NULL;
 378         return READ_ONCE(stab->sks[key]);
 379 }
 380
 381 static void *sock_map_lookup(struct bpf_map *map, void *key)
 382 {
 383         struct sock *sk;
 384
 385         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 386         if (!sk)
 387                 return NULL;
 388         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
 389                 return NULL;
 390         return sk;
 391 }
 392
 393 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
 394 {
 395         struct sock *sk;
 396
 397         if (map->value_size != sizeof(u64))
 398                 return ERR_PTR(-ENOSPC);
 399
 400         sk = __sock_map_lookup_elem(map, *(u32 *)key);
 401         if (!sk)
 402                 return ERR_PTR(-ENOENT);
 403
 404         __sock_gen_cookie(sk);
 405         return &sk->sk_cookie;
 406 }
 407
 408 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
 409                              struct sock **psk)
 410 {
 411         struct sock *sk;
 412         int err = 0;
 413
 414         spin_lock_bh(&stab->lock);
 415         sk = *psk;
 416         if (!sk_test || sk_test == sk)
 417                 sk = xchg(psk, NULL);
 418
 419         if (likely(sk))
 420                 sock_map_unref(sk, psk);
 421         else
 422                 err = -EINVAL;
 423
 424         spin_unlock_bh(&stab->lock);
 425         return err;
 426 }
 427
 428 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
 429                                       void *link_raw)
 430 {
 431         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 432
 433         __sock_map_delete(stab, sk, link_raw);
 434 }
 435
 436 static long sock_map_delete_elem(struct bpf_map *map, void *key)
 437 {
 438         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 439         u32 i = *(u32 *)key;
 440         struct sock **psk;
 441
 442         if (unlikely(i >= map->max_entries))
 443                 return -EINVAL;
 444
 445         psk = &stab->sks[i];
 446         return __sock_map_delete(stab, NULL, psk);
 447 }
 448
 449 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
 450 {
 451         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 452         u32 i = key ? *(u32 *)key : U32_MAX;
 453         u32 *key_next = next;
 454
 455         if (i == stab->map.max_entries - 1)
 456                 return -ENOENT;
 457         if (i >= stab->map.max_entries)
 458                 *key_next = 0;
 459         else
 460                 *key_next = i + 1;
 461         return 0;
 462 }
 463
 464 static int sock_map_update_common(struct bpf_map *map, u32 idx,
 465                                   struct sock *sk, u64 flags)
 466 {
 467         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 468         struct sk_psock_link *link;
 469         struct sk_psock *psock;
 470         struct sock *osk;
 471         int ret;
 472
 473         WARN_ON_ONCE(!rcu_read_lock_held());
 474         if (unlikely(flags > BPF_EXIST))
 475                 return -EINVAL;
 476         if (unlikely(idx >= map->max_entries))
 477                 return -E2BIG;
 478
 479         link = sk_psock_init_link();
 480         if (!link)
 481                 return -ENOMEM;
 482
 483         ret = sock_map_link(map, sk);
 484         if (ret < 0)
 485                 goto out_free;
 486
 487         psock = sk_psock(sk);
 488         WARN_ON_ONCE(!psock);
 489
 490         spin_lock_bh(&stab->lock);
 491         osk = stab->sks[idx];
 492         if (osk && flags == BPF_NOEXIST) {
 493                 ret = -EEXIST;
 494                 goto out_unlock;
 495         } else if (!osk && flags == BPF_EXIST) {
 496                 ret = -ENOENT;
 497                 goto out_unlock;
 498         }
 499
 500         sock_map_add_link(psock, link, map, &stab->sks[idx]);
 501         stab->sks[idx] = sk;
 502         if (osk)
 503                 sock_map_unref(osk, &stab->sks[idx]);
 504         spin_unlock_bh(&stab->lock);
 505         return 0;
 506 out_unlock:
 507         spin_unlock_bh(&stab->lock);
 508         if (psock)
 509                 sk_psock_put(sk, psock);
 510 out_free:
 511         sk_psock_free_link(link);
 512         return ret;
 513 }
 514
 515 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
 516 {
 517         return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
 518                ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
 519                ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
 520 }
 521
 522 static bool sock_map_redirect_allowed(const struct sock *sk)
 523 {
 524         if (sk_is_tcp(sk))
 525                 return sk->sk_state != TCP_LISTEN;
 526         else
 527                 return sk->sk_state == TCP_ESTABLISHED;
 528 }
 529
 530 static bool sock_map_sk_is_suitable(const struct sock *sk)
 531 {
 532         return !!sk->sk_prot->psock_update_sk_prot;
 533 }
 534
 535 static bool sock_map_sk_state_allowed(const struct sock *sk)
 536 {
 537         if (sk_is_tcp(sk))
 538                 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 539         if (sk_is_stream_unix(sk))
 540                 return (1 << sk->sk_state) & TCPF_ESTABLISHED;
 541         return true;
 542 }
 543
 544 static int sock_hash_update_common(struct bpf_map *map, void *key,
 545                                    struct sock *sk, u64 flags);
 546
 547 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 548                              u64 flags)
 549 {
 550         struct socket *sock;
 551         struct sock *sk;
 552         int ret;
 553         u64 ufd;
 554
 555         if (map->value_size == sizeof(u64))
 556                 ufd = *(u64 *)value;
 557         else
 558                 ufd = *(u32 *)value;
 559         if (ufd > S32_MAX)
 560                 return -EINVAL;
 561
 562         sock = sockfd_lookup(ufd, &ret);
 563         if (!sock)
 564                 return ret;
 565         sk = sock->sk;
 566         if (!sk) {
 567                 ret = -EINVAL;
 568                 goto out;
 569         }
 570         if (!sock_map_sk_is_suitable(sk)) {
 571                 ret = -EOPNOTSUPP;
 572                 goto out;
 573         }
 574
 575         sock_map_sk_acquire(sk);
 576         if (!sock_map_sk_state_allowed(sk))
 577                 ret = -EOPNOTSUPP;
 578         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 579                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 580         else
 581                 ret = sock_hash_update_common(map, key, sk, flags);
 582         sock_map_sk_release(sk);
 583 out:
 584         sockfd_put(sock);
 585         return ret;
 586 }
 587
 588 static long sock_map_update_elem(struct bpf_map *map, void *key,
 589                                  void *value, u64 flags)
 590 {
 591         struct sock *sk = (struct sock *)value;
 592         int ret;
 593
 594         if (unlikely(!sk || !sk_fullsock(sk)))
 595                 return -EINVAL;
 596
 597         if (!sock_map_sk_is_suitable(sk))
 598                 return -EOPNOTSUPP;
 599
 600         local_bh_disable();
 601         bh_lock_sock(sk);
 602         if (!sock_map_sk_state_allowed(sk))
 603                 ret = -EOPNOTSUPP;
 604         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 605                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 606         else
 607                 ret = sock_hash_update_common(map, key, sk, flags);
 608         bh_unlock_sock(sk);
 609         local_bh_enable();
 610         return ret;
 611 }
 612
 613 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 614            struct bpf_map *, map, void *, key, u64, flags)
 615 {
 616         WARN_ON_ONCE(!rcu_read_lock_held());
 617
 618         if (likely(sock_map_sk_is_suitable(sops->sk) &&
 619                    sock_map_op_okay(sops)))
 620                 return sock_map_update_common(map, *(u32 *)key, sops->sk,
 621                                               flags);
 622         return -EOPNOTSUPP;
 623 }
 624
 625 const struct bpf_func_proto bpf_sock_map_update_proto = {
 626         .func           = bpf_sock_map_update,
 627         .gpl_only       = false,
 628         .pkt_access     = true,
 629         .ret_type       = RET_INTEGER,
 630         .arg1_type      = ARG_PTR_TO_CTX,
 631         .arg2_type      = ARG_CONST_MAP_PTR,
 632         .arg3_type      = ARG_PTR_TO_MAP_KEY,
 633         .arg4_type      = ARG_ANYTHING,
 634 };
 635
 636 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 637            struct bpf_map *, map, u32, key, u64, flags)
 638 {
 639         struct sock *sk;
 640
 641         if (unlikely(flags & ~(BPF_F_INGRESS)))
 642                 return SK_DROP;
 643
 644         sk = __sock_map_lookup_elem(map, key);
 645         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 646                 return SK_DROP;
 647
 648         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 649         return SK_PASS;
 650 }
 651
 652 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 653         .func           = bpf_sk_redirect_map,
 654         .gpl_only       = false,
 655         .ret_type       = RET_INTEGER,
 656         .arg1_type      = ARG_PTR_TO_CTX,
 657         .arg2_type      = ARG_CONST_MAP_PTR,
 658         .arg3_type      = ARG_ANYTHING,
 659         .arg4_type      = ARG_ANYTHING,
 660 };
 661
 662 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 663            struct bpf_map *, map, u32, key, u64, flags)
 664 {
 665         struct sock *sk;
 666
 667         if (unlikely(flags & ~(BPF_F_INGRESS)))
 668                 return SK_DROP;
 669
 670         sk = __sock_map_lookup_elem(map, key);
 671         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 672                 return SK_DROP;
 673         if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
 674                 return SK_DROP;
 675
 676         msg->flags = flags;
 677         msg->sk_redir = sk;
 678         return SK_PASS;
 679 }
 680
 681 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 682         .func           = bpf_msg_redirect_map,
 683         .gpl_only       = false,
 684         .ret_type       = RET_INTEGER,
 685         .arg1_type      = ARG_PTR_TO_CTX,
 686         .arg2_type      = ARG_CONST_MAP_PTR,
 687         .arg3_type      = ARG_ANYTHING,
 688         .arg4_type      = ARG_ANYTHING,
 689 };
 690
 691 struct sock_map_seq_info {
 692         struct bpf_map *map;
 693         struct sock *sk;
 694         u32 index;
 695 };
 696
 697 struct bpf_iter__sockmap {
 698         __bpf_md_ptr(struct bpf_iter_meta *, meta);
 699         __bpf_md_ptr(struct bpf_map *, map);
 700         __bpf_md_ptr(void *, key);
 701         __bpf_md_ptr(struct sock *, sk);
 702 };
 703
 704 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
 705                      struct bpf_map *map, void *key,
 706                      struct sock *sk)
 707
 708 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
 709 {
 710         if (unlikely(info->index >= info->map->max_entries))
 711                 return NULL;
 712
 713         info->sk = __sock_map_lookup_elem(info->map, info->index);
 714
 715         /* can't return sk directly, since that might be NULL */
 716         return info;
 717 }
 718
 719 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
 720         __acquires(rcu)
 721 {
 722         struct sock_map_seq_info *info = seq->private;
 723
 724         if (*pos == 0)
 725                 ++*pos;
 726
 727         /* pairs with sock_map_seq_stop */
 728         rcu_read_lock();
 729         return sock_map_seq_lookup_elem(info);
 730 }
 731
 732 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 733         __must_hold(rcu)
 734 {
 735         struct sock_map_seq_info *info = seq->private;
 736
 737         ++*pos;
 738         ++info->index;
 739
 740         return sock_map_seq_lookup_elem(info);
 741 }
 742
 743 static int sock_map_seq_show(struct seq_file *seq, void *v)
 744         __must_hold(rcu)
 745 {
 746         struct sock_map_seq_info *info = seq->private;
 747         struct bpf_iter__sockmap ctx = {};
 748         struct bpf_iter_meta meta;
 749         struct bpf_prog *prog;
 750
 751         meta.seq = seq;
 752         prog = bpf_iter_get_info(&meta, !v);
 753         if (!prog)
 754                 return 0;
 755
 756         ctx.meta = &meta;
 757         ctx.map = info->map;
 758         if (v) {
 759                 ctx.key = &info->index;
 760                 ctx.sk = info->sk;
 761         }
 762
 763         return bpf_iter_run_prog(prog, &ctx);
 764 }
 765
 766 static void sock_map_seq_stop(struct seq_file *seq, void *v)
 767         __releases(rcu)
 768 {
 769         if (!v)
 770                 (void)sock_map_seq_show(seq, NULL);
 771
 772         /* pairs with sock_map_seq_start */
 773         rcu_read_unlock();
 774 }
 775
 776 static const struct seq_operations sock_map_seq_ops = {
 777         .start  = sock_map_seq_start,
 778         .next   = sock_map_seq_next,
 779         .stop   = sock_map_seq_stop,
 780         .show   = sock_map_seq_show,
 781 };
 782
 783 static int sock_map_init_seq_private(void *priv_data,
 784                                      struct bpf_iter_aux_info *aux)
 785 {
 786         struct sock_map_seq_info *info = priv_data;
 787
 788         bpf_map_inc_with_uref(aux->map);
 789         info->map = aux->map;
 790         return 0;
 791 }
 792
 793 static void sock_map_fini_seq_private(void *priv_data)
 794 {
 795         struct sock_map_seq_info *info = priv_data;
 796
 797         bpf_map_put_with_uref(info->map);
 798 }
 799
 800 static u64 sock_map_mem_usage(const struct bpf_map *map)
 801 {
 802         u64 usage = sizeof(struct bpf_stab);
 803
 804         usage += (u64)map->max_entries * sizeof(struct sock *);
 805         return usage;
 806 }
 807
 808 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
 809         .seq_ops                = &sock_map_seq_ops,
 810         .init_seq_private       = sock_map_init_seq_private,
 811         .fini_seq_private       = sock_map_fini_seq_private,
 812         .seq_priv_size          = sizeof(struct sock_map_seq_info),
 813 };
 814
 815 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab)
 816 const struct bpf_map_ops sock_map_ops = {
 817         .map_meta_equal         = bpf_map_meta_equal,
 818         .map_alloc              = sock_map_alloc,
 819         .map_free               = sock_map_free,
 820         .map_get_next_key       = sock_map_get_next_key,
 821         .map_lookup_elem_sys_only = sock_map_lookup_sys,
 822         .map_update_elem        = sock_map_update_elem,
 823         .map_delete_elem        = sock_map_delete_elem,
 824         .map_lookup_elem        = sock_map_lookup,
 825         .map_release_uref       = sock_map_release_progs,
 826         .map_check_btf          = map_check_no_btf,
 827         .map_mem_usage          = sock_map_mem_usage,
 828         .map_btf_id             = &sock_map_btf_ids[0],
 829         .iter_seq_info          = &sock_map_iter_seq_info,
 830 };
 831
 832 struct bpf_shtab_elem {
 833         struct rcu_head rcu;
 834         u32 hash;
 835         struct sock *sk;
 836         struct hlist_node node;
 837         u8 key[];
 838 };
 839
 840 struct bpf_shtab_bucket {
 841         struct hlist_head head;
 842         spinlock_t lock;
 843 };
 844
 845 struct bpf_shtab {
 846         struct bpf_map map;
 847         struct bpf_shtab_bucket *buckets;
 848         u32 buckets_num;
 849         u32 elem_size;
 850         struct sk_psock_progs progs;
 851         atomic_t count;
 852 };
 853
 854 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 855 {
 856         return jhash(key, len, 0);
 857 }
 858
 859 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 860                                                         u32 hash)
 861 {
 862         return &htab->buckets[hash & (htab->buckets_num - 1)];
 863 }
 864
 865 static struct bpf_shtab_elem *
 866 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 867                           u32 key_size)
 868 {
 869         struct bpf_shtab_elem *elem;
 870
 871         hlist_for_each_entry_rcu(elem, head, node) {
 872                 if (elem->hash == hash &&
 873                     !memcmp(&elem->key, key, key_size))
 874                         return elem;
 875         }
 876
 877         return NULL;
 878 }
 879
 880 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 881 {
 882         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 883         u32 key_size = map->key_size, hash;
 884         struct bpf_shtab_bucket *bucket;
 885         struct bpf_shtab_elem *elem;
 886
 887         WARN_ON_ONCE(!rcu_read_lock_held());
 888
 889         hash = sock_hash_bucket_hash(key, key_size);
 890         bucket = sock_hash_select_bucket(htab, hash);
 891         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 892
 893         return elem ? elem->sk : NULL;
 894 }
 895
 896 static void sock_hash_free_elem(struct bpf_shtab *htab,
 897                                 struct bpf_shtab_elem *elem)
 898 {
 899         atomic_dec(&htab->count);
 900         kfree_rcu(elem, rcu);
 901 }
 902
 903 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 904                                        void *link_raw)
 905 {
 906         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 907         struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 908         struct bpf_shtab_bucket *bucket;
 909
 910         WARN_ON_ONCE(!rcu_read_lock_held());
 911         bucket = sock_hash_select_bucket(htab, elem->hash);
 912
 913         /* elem may be deleted in parallel from the map, but access here
 914          * is okay since it's going away only after RCU grace period.
 915          * However, we need to check whether it's still present.
 916          */
 917         spin_lock_bh(&bucket->lock);
 918         elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 919                                                elem->key, map->key_size);
 920         if (elem_probe && elem_probe == elem) {
 921                 hlist_del_rcu(&elem->node);
 922                 sock_map_unref(elem->sk, elem);
 923                 sock_hash_free_elem(htab, elem);
 924         }
 925         spin_unlock_bh(&bucket->lock);
 926 }
 927
 928 static long sock_hash_delete_elem(struct bpf_map *map, void *key)
 929 {
 930         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 931         u32 hash, key_size = map->key_size;
 932         struct bpf_shtab_bucket *bucket;
 933         struct bpf_shtab_elem *elem;
 934         int ret = -ENOENT;
 935
 936         hash = sock_hash_bucket_hash(key, key_size);
 937         bucket = sock_hash_select_bucket(htab, hash);
 938
 939         spin_lock_bh(&bucket->lock);
 940         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 941         if (elem) {
 942                 hlist_del_rcu(&elem->node);
 943                 sock_map_unref(elem->sk, elem);
 944                 sock_hash_free_elem(htab, elem);
 945                 ret = 0;
 946         }
 947         spin_unlock_bh(&bucket->lock);
 948         return ret;
 949 }
 950
 951 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 952                                                    void *key, u32 key_size,
 953                                                    u32 hash, struct sock *sk,
 954                                                    struct bpf_shtab_elem *old)
 955 {
 956         struct bpf_shtab_elem *new;
 957
 958         if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 959                 if (!old) {
 960                         atomic_dec(&htab->count);
 961                         return ERR_PTR(-E2BIG);
 962                 }
 963         }
 964
 965         new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
 966                                    GFP_ATOMIC | __GFP_NOWARN,
 967                                    htab->map.numa_node);
 968         if (!new) {
 969                 atomic_dec(&htab->count);
 970                 return ERR_PTR(-ENOMEM);
 971         }
 972         memcpy(new->key, key, key_size);
 973         new->sk = sk;
 974         new->hash = hash;
 975         return new;
 976 }
 977
 978 static int sock_hash_update_common(struct bpf_map *map, void *key,
 979                                    struct sock *sk, u64 flags)
 980 {
 981         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 982         u32 key_size = map->key_size, hash;
 983         struct bpf_shtab_elem *elem, *elem_new;
 984         struct bpf_shtab_bucket *bucket;
 985         struct sk_psock_link *link;
 986         struct sk_psock *psock;
 987         int ret;
 988
 989         WARN_ON_ONCE(!rcu_read_lock_held());
 990         if (unlikely(flags > BPF_EXIST))
 991                 return -EINVAL;
 992
 993         link = sk_psock_init_link();
 994         if (!link)
 995                 return -ENOMEM;
 996
 997         ret = sock_map_link(map, sk);
 998         if (ret < 0)
 999                 goto out_free;
1000
1001         psock = sk_psock(sk);
1002         WARN_ON_ONCE(!psock);
1003
1004         hash = sock_hash_bucket_hash(key, key_size);
1005         bucket = sock_hash_select_bucket(htab, hash);
1006
1007         spin_lock_bh(&bucket->lock);
1008         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1009         if (elem && flags == BPF_NOEXIST) {
1010                 ret = -EEXIST;
1011                 goto out_unlock;
1012         } else if (!elem && flags == BPF_EXIST) {
1013                 ret = -ENOENT;
1014                 goto out_unlock;
1015         }
1016
1017         elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1018         if (IS_ERR(elem_new)) {
1019                 ret = PTR_ERR(elem_new);
1020                 goto out_unlock;
1021         }
1022
1023         sock_map_add_link(psock, link, map, elem_new);
1024         /* Add new element to the head of the list, so that
1025          * concurrent search will find it before old elem.
1026          */
1027         hlist_add_head_rcu(&elem_new->node, &bucket->head);
1028         if (elem) {
1029                 hlist_del_rcu(&elem->node);
1030                 sock_map_unref(elem->sk, elem);
1031                 sock_hash_free_elem(htab, elem);
1032         }
1033         spin_unlock_bh(&bucket->lock);
1034         return 0;
1035 out_unlock:
1036         spin_unlock_bh(&bucket->lock);
1037         sk_psock_put(sk, psock);
1038 out_free:
1039         sk_psock_free_link(link);
1040         return ret;
1041 }
1042
1043 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1044                                   void *key_next)
1045 {
1046         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1047         struct bpf_shtab_elem *elem, *elem_next;
1048         u32 hash, key_size = map->key_size;
1049         struct hlist_head *head;
1050         int i = 0;
1051
1052         if (!key)
1053                 goto find_first_elem;
1054         hash = sock_hash_bucket_hash(key, key_size);
1055         head = &sock_hash_select_bucket(htab, hash)->head;
1056         elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1057         if (!elem)
1058                 goto find_first_elem;
1059
1060         elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1061                                      struct bpf_shtab_elem, node);
1062         if (elem_next) {
1063                 memcpy(key_next, elem_next->key, key_size);
1064                 return 0;
1065         }
1066
1067         i = hash & (htab->buckets_num - 1);
1068         i++;
1069 find_first_elem:
1070         for (; i < htab->buckets_num; i++) {
1071                 head = &sock_hash_select_bucket(htab, i)->head;
1072                 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1073                                              struct bpf_shtab_elem, node);
1074                 if (elem_next) {
1075                         memcpy(key_next, elem_next->key, key_size);
1076                         return 0;
1077                 }
1078         }
1079
1080         return -ENOENT;
1081 }
1082
1083 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1084 {
1085         struct bpf_shtab *htab;
1086         int i, err;
1087
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 = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
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                 spin_lock_init(&htab->buckets[i].lock);
1123         }
1124
1125         return &htab->map;
1126 free_htab:
1127         bpf_map_area_free(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                 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                 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         bpf_map_area_free(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 u64 sock_hash_mem_usage(const struct bpf_map *map)
1410 {
1411         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1412         u64 usage = sizeof(*htab);
1413
1414         usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket);
1415         usage += atomic_read(&htab->count) * (u64)htab->elem_size;
1416         return usage;
1417 }
1418
1419 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1420         .seq_ops                = &sock_hash_seq_ops,
1421         .init_seq_private       = sock_hash_init_seq_private,
1422         .fini_seq_private       = sock_hash_fini_seq_private,
1423         .seq_priv_size          = sizeof(struct sock_hash_seq_info),
1424 };
1425
1426 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab)
1427 const struct bpf_map_ops sock_hash_ops = {
1428         .map_meta_equal         = bpf_map_meta_equal,
1429         .map_alloc              = sock_hash_alloc,
1430         .map_free               = sock_hash_free,
1431         .map_get_next_key       = sock_hash_get_next_key,
1432         .map_update_elem        = sock_map_update_elem,
1433         .map_delete_elem        = sock_hash_delete_elem,
1434         .map_lookup_elem        = sock_hash_lookup,
1435         .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1436         .map_release_uref       = sock_hash_release_progs,
1437         .map_check_btf          = map_check_no_btf,
1438         .map_mem_usage          = sock_hash_mem_usage,
1439         .map_btf_id             = &sock_hash_map_btf_ids[0],
1440         .iter_seq_info          = &sock_hash_iter_seq_info,
1441 };
1442
1443 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1444 {
1445         switch (map->map_type) {
1446         case BPF_MAP_TYPE_SOCKMAP:
1447                 return &container_of(map, struct bpf_stab, map)->progs;
1448         case BPF_MAP_TYPE_SOCKHASH:
1449                 return &container_of(map, struct bpf_shtab, map)->progs;
1450         default:
1451                 break;
1452         }
1453
1454         return NULL;
1455 }
1456
1457 static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
1458                                 u32 which)
1459 {
1460         struct sk_psock_progs *progs = sock_map_progs(map);
1461
1462         if (!progs)
1463                 return -EOPNOTSUPP;
1464
1465         switch (which) {
1466         case BPF_SK_MSG_VERDICT:
1467                 *pprog = &progs->msg_parser;
1468                 break;
1469 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1470         case BPF_SK_SKB_STREAM_PARSER:
1471                 *pprog = &progs->stream_parser;
1472                 break;
1473 #endif
1474         case BPF_SK_SKB_STREAM_VERDICT:
1475                 if (progs->skb_verdict)
1476                         return -EBUSY;
1477                 *pprog = &progs->stream_verdict;
1478                 break;
1479         case BPF_SK_SKB_VERDICT:
1480                 if (progs->stream_verdict)
1481                         return -EBUSY;
1482                 *pprog = &progs->skb_verdict;
1483                 break;
1484         default:
1485                 return -EOPNOTSUPP;
1486         }
1487
1488         return 0;
1489 }
1490
1491 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1492                                 struct bpf_prog *old, u32 which)
1493 {
1494         struct bpf_prog **pprog;
1495         int ret;
1496
1497         ret = sock_map_prog_lookup(map, &pprog, which);
1498         if (ret)
1499                 return ret;
1500
1501         if (old)
1502                 return psock_replace_prog(pprog, prog, old);
1503
1504         psock_set_prog(pprog, prog);
1505         return 0;
1506 }
1507
1508 int sock_map_bpf_prog_query(const union bpf_attr *attr,
1509                             union bpf_attr __user *uattr)
1510 {
1511         __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
1512         u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;
1513         struct bpf_prog **pprog;
1514         struct bpf_prog *prog;
1515         struct bpf_map *map;
1516         struct fd f;
1517         u32 id = 0;
1518         int ret;
1519
1520         if (attr->query.query_flags)
1521                 return -EINVAL;
1522
1523         f = fdget(ufd);
1524         map = __bpf_map_get(f);
1525         if (IS_ERR(map))
1526                 return PTR_ERR(map);
1527
1528         rcu_read_lock();
1529
1530         ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);
1531         if (ret)
1532                 goto end;
1533
1534         prog = *pprog;
1535         prog_cnt = !prog ? 0 : 1;
1536
1537         if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
1538                 goto end;
1539
1540         /* we do not hold the refcnt, the bpf prog may be released
1541          * asynchronously and the id would be set to 0.
1542          */
1543         id = data_race(prog->aux->id);
1544         if (id == 0)
1545                 prog_cnt = 0;
1546
1547 end:
1548         rcu_read_unlock();
1549
1550         if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
1551             (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||
1552             copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
1553                 ret = -EFAULT;
1554
1555         fdput(f);
1556         return ret;
1557 }
1558
1559 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1560 {
1561         switch (link->map->map_type) {
1562         case BPF_MAP_TYPE_SOCKMAP:
1563                 return sock_map_delete_from_link(link->map, sk,
1564                                                  link->link_raw);
1565         case BPF_MAP_TYPE_SOCKHASH:
1566                 return sock_hash_delete_from_link(link->map, sk,
1567                                                   link->link_raw);
1568         default:
1569                 break;
1570         }
1571 }
1572
1573 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1574 {
1575         struct sk_psock_link *link;
1576
1577         while ((link = sk_psock_link_pop(psock))) {
1578                 sock_map_unlink(sk, link);
1579                 sk_psock_free_link(link);
1580         }
1581 }
1582
1583 void sock_map_unhash(struct sock *sk)
1584 {
1585         void (*saved_unhash)(struct sock *sk);
1586         struct sk_psock *psock;
1587
1588         rcu_read_lock();
1589         psock = sk_psock(sk);
1590         if (unlikely(!psock)) {
1591                 rcu_read_unlock();
1592                 saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
1593         } else {
1594                 saved_unhash = psock->saved_unhash;
1595                 sock_map_remove_links(sk, psock);
1596                 rcu_read_unlock();
1597         }
1598         if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
1599                 return;
1600         if (saved_unhash)
1601                 saved_unhash(sk);
1602 }
1603 EXPORT_SYMBOL_GPL(sock_map_unhash);
1604
1605 void sock_map_destroy(struct sock *sk)
1606 {
1607         void (*saved_destroy)(struct sock *sk);
1608         struct sk_psock *psock;
1609
1610         rcu_read_lock();
1611         psock = sk_psock_get(sk);
1612         if (unlikely(!psock)) {
1613                 rcu_read_unlock();
1614                 saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
1615         } else {
1616                 saved_destroy = psock->saved_destroy;
1617                 sock_map_remove_links(sk, psock);
1618                 rcu_read_unlock();
1619                 sk_psock_stop(psock);
1620                 sk_psock_put(sk, psock);
1621         }
1622         if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
1623                 return;
1624         if (saved_destroy)
1625                 saved_destroy(sk);
1626 }
1627 EXPORT_SYMBOL_GPL(sock_map_destroy);
1628
1629 void sock_map_close(struct sock *sk, long timeout)
1630 {
1631         void (*saved_close)(struct sock *sk, long timeout);
1632         struct sk_psock *psock;
1633
1634         lock_sock(sk);
1635         rcu_read_lock();
1636         psock = sk_psock_get(sk);
1637         if (unlikely(!psock)) {
1638                 rcu_read_unlock();
1639                 release_sock(sk);
1640                 saved_close = READ_ONCE(sk->sk_prot)->close;
1641         } else {
1642                 saved_close = psock->saved_close;
1643                 sock_map_remove_links(sk, psock);
1644                 rcu_read_unlock();
1645                 sk_psock_stop(psock);
1646                 release_sock(sk);
1647                 cancel_delayed_work_sync(&psock->work);
1648                 sk_psock_put(sk, psock);
1649         }
1650
1651         /* Make sure we do not recurse. This is a bug.
1652          * Leak the socket instead of crashing on a stack overflow.
1653          */
1654         if (WARN_ON_ONCE(saved_close == sock_map_close))
1655                 return;
1656         saved_close(sk, timeout);
1657 }
1658 EXPORT_SYMBOL_GPL(sock_map_close);
1659
1660 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1661                                        union bpf_iter_link_info *linfo,
1662                                        struct bpf_iter_aux_info *aux)
1663 {
1664         struct bpf_map *map;
1665         int err = -EINVAL;
1666
1667         if (!linfo->map.map_fd)
1668                 return -EBADF;
1669
1670         map = bpf_map_get_with_uref(linfo->map.map_fd);
1671         if (IS_ERR(map))
1672                 return PTR_ERR(map);
1673
1674         if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1675             map->map_type != BPF_MAP_TYPE_SOCKHASH)
1676                 goto put_map;
1677
1678         if (prog->aux->max_rdonly_access > map->key_size) {
1679                 err = -EACCES;
1680                 goto put_map;
1681         }
1682
1683         aux->map = map;
1684         return 0;
1685
1686 put_map:
1687         bpf_map_put_with_uref(map);
1688         return err;
1689 }
1690
1691 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1692 {
1693         bpf_map_put_with_uref(aux->map);
1694 }
1695
1696 static struct bpf_iter_reg sock_map_iter_reg = {
1697         .target                 = "sockmap",
1698         .attach_target          = sock_map_iter_attach_target,
1699         .detach_target          = sock_map_iter_detach_target,
1700         .show_fdinfo            = bpf_iter_map_show_fdinfo,
1701         .fill_link_info         = bpf_iter_map_fill_link_info,
1702         .ctx_arg_info_size      = 2,
1703         .ctx_arg_info           = {
1704                 { offsetof(struct bpf_iter__sockmap, key),
1705                   PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1706                 { offsetof(struct bpf_iter__sockmap, sk),
1707                   PTR_TO_BTF_ID_OR_NULL },
1708         },
1709 };
1710
1711 static int __init bpf_sockmap_iter_init(void)
1712 {
1713         sock_map_iter_reg.ctx_arg_info[1].btf_id =
1714                 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1715         return bpf_iter_reg_target(&sock_map_iter_reg);
1716 }
1717 late_initcall(bpf_sockmap_iter_init);