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         if (irqs_disabled())
 415                 return -EOPNOTSUPP; /* locks here are hardirq-unsafe */
 416
 417         spin_lock_bh(&stab->lock);
 418         sk = *psk;
 419         if (!sk_test || sk_test == sk)
 420                 sk = xchg(psk, NULL);
 421
 422         if (likely(sk))
 423                 sock_map_unref(sk, psk);
 424         else
 425                 err = -EINVAL;
 426
 427         spin_unlock_bh(&stab->lock);
 428         return err;
 429 }
 430
 431 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
 432                                       void *link_raw)
 433 {
 434         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 435
 436         __sock_map_delete(stab, sk, link_raw);
 437 }
 438
 439 static long sock_map_delete_elem(struct bpf_map *map, void *key)
 440 {
 441         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 442         u32 i = *(u32 *)key;
 443         struct sock **psk;
 444
 445         if (unlikely(i >= map->max_entries))
 446                 return -EINVAL;
 447
 448         psk = &stab->sks[i];
 449         return __sock_map_delete(stab, NULL, psk);
 450 }
 451
 452 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
 453 {
 454         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 455         u32 i = key ? *(u32 *)key : U32_MAX;
 456         u32 *key_next = next;
 457
 458         if (i == stab->map.max_entries - 1)
 459                 return -ENOENT;
 460         if (i >= stab->map.max_entries)
 461                 *key_next = 0;
 462         else
 463                 *key_next = i + 1;
 464         return 0;
 465 }
 466
 467 static int sock_map_update_common(struct bpf_map *map, u32 idx,
 468                                   struct sock *sk, u64 flags)
 469 {
 470         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 471         struct sk_psock_link *link;
 472         struct sk_psock *psock;
 473         struct sock *osk;
 474         int ret;
 475
 476         WARN_ON_ONCE(!rcu_read_lock_held());
 477         if (unlikely(flags > BPF_EXIST))
 478                 return -EINVAL;
 479         if (unlikely(idx >= map->max_entries))
 480                 return -E2BIG;
 481
 482         link = sk_psock_init_link();
 483         if (!link)
 484                 return -ENOMEM;
 485
 486         ret = sock_map_link(map, sk);
 487         if (ret < 0)
 488                 goto out_free;
 489
 490         psock = sk_psock(sk);
 491         WARN_ON_ONCE(!psock);
 492
 493         spin_lock_bh(&stab->lock);
 494         osk = stab->sks[idx];
 495         if (osk && flags == BPF_NOEXIST) {
 496                 ret = -EEXIST;
 497                 goto out_unlock;
 498         } else if (!osk && flags == BPF_EXIST) {
 499                 ret = -ENOENT;
 500                 goto out_unlock;
 501         }
 502
 503         sock_map_add_link(psock, link, map, &stab->sks[idx]);
 504         stab->sks[idx] = sk;
 505         if (osk)
 506                 sock_map_unref(osk, &stab->sks[idx]);
 507         spin_unlock_bh(&stab->lock);
 508         return 0;
 509 out_unlock:
 510         spin_unlock_bh(&stab->lock);
 511         if (psock)
 512                 sk_psock_put(sk, psock);
 513 out_free:
 514         sk_psock_free_link(link);
 515         return ret;
 516 }
 517
 518 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
 519 {
 520         return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
 521                ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
 522                ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
 523 }
 524
 525 static bool sock_map_redirect_allowed(const struct sock *sk)
 526 {
 527         if (sk_is_tcp(sk))
 528                 return sk->sk_state != TCP_LISTEN;
 529         else
 530                 return sk->sk_state == TCP_ESTABLISHED;
 531 }
 532
 533 static bool sock_map_sk_is_suitable(const struct sock *sk)
 534 {
 535         return !!sk->sk_prot->psock_update_sk_prot;
 536 }
 537
 538 static bool sock_map_sk_state_allowed(const struct sock *sk)
 539 {
 540         if (sk_is_tcp(sk))
 541                 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 542         if (sk_is_stream_unix(sk))
 543                 return (1 << sk->sk_state) & TCPF_ESTABLISHED;
 544         return true;
 545 }
 546
 547 static int sock_hash_update_common(struct bpf_map *map, void *key,
 548                                    struct sock *sk, u64 flags);
 549
 550 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 551                              u64 flags)
 552 {
 553         struct socket *sock;
 554         struct sock *sk;
 555         int ret;
 556         u64 ufd;
 557
 558         if (map->value_size == sizeof(u64))
 559                 ufd = *(u64 *)value;
 560         else
 561                 ufd = *(u32 *)value;
 562         if (ufd > S32_MAX)
 563                 return -EINVAL;
 564
 565         sock = sockfd_lookup(ufd, &ret);
 566         if (!sock)
 567                 return ret;
 568         sk = sock->sk;
 569         if (!sk) {
 570                 ret = -EINVAL;
 571                 goto out;
 572         }
 573         if (!sock_map_sk_is_suitable(sk)) {
 574                 ret = -EOPNOTSUPP;
 575                 goto out;
 576         }
 577
 578         sock_map_sk_acquire(sk);
 579         if (!sock_map_sk_state_allowed(sk))
 580                 ret = -EOPNOTSUPP;
 581         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 582                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 583         else
 584                 ret = sock_hash_update_common(map, key, sk, flags);
 585         sock_map_sk_release(sk);
 586 out:
 587         sockfd_put(sock);
 588         return ret;
 589 }
 590
 591 static long sock_map_update_elem(struct bpf_map *map, void *key,
 592                                  void *value, u64 flags)
 593 {
 594         struct sock *sk = (struct sock *)value;
 595         int ret;
 596
 597         if (unlikely(!sk || !sk_fullsock(sk)))
 598                 return -EINVAL;
 599
 600         if (!sock_map_sk_is_suitable(sk))
 601                 return -EOPNOTSUPP;
 602
 603         local_bh_disable();
 604         bh_lock_sock(sk);
 605         if (!sock_map_sk_state_allowed(sk))
 606                 ret = -EOPNOTSUPP;
 607         else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 608                 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 609         else
 610                 ret = sock_hash_update_common(map, key, sk, flags);
 611         bh_unlock_sock(sk);
 612         local_bh_enable();
 613         return ret;
 614 }
 615
 616 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 617            struct bpf_map *, map, void *, key, u64, flags)
 618 {
 619         WARN_ON_ONCE(!rcu_read_lock_held());
 620
 621         if (likely(sock_map_sk_is_suitable(sops->sk) &&
 622                    sock_map_op_okay(sops)))
 623                 return sock_map_update_common(map, *(u32 *)key, sops->sk,
 624                                               flags);
 625         return -EOPNOTSUPP;
 626 }
 627
 628 const struct bpf_func_proto bpf_sock_map_update_proto = {
 629         .func           = bpf_sock_map_update,
 630         .gpl_only       = false,
 631         .pkt_access     = true,
 632         .ret_type       = RET_INTEGER,
 633         .arg1_type      = ARG_PTR_TO_CTX,
 634         .arg2_type      = ARG_CONST_MAP_PTR,
 635         .arg3_type      = ARG_PTR_TO_MAP_KEY,
 636         .arg4_type      = ARG_ANYTHING,
 637 };
 638
 639 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 640            struct bpf_map *, map, u32, key, u64, flags)
 641 {
 642         struct sock *sk;
 643
 644         if (unlikely(flags & ~(BPF_F_INGRESS)))
 645                 return SK_DROP;
 646
 647         sk = __sock_map_lookup_elem(map, key);
 648         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 649                 return SK_DROP;
 650
 651         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 652         return SK_PASS;
 653 }
 654
 655 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 656         .func           = bpf_sk_redirect_map,
 657         .gpl_only       = false,
 658         .ret_type       = RET_INTEGER,
 659         .arg1_type      = ARG_PTR_TO_CTX,
 660         .arg2_type      = ARG_CONST_MAP_PTR,
 661         .arg3_type      = ARG_ANYTHING,
 662         .arg4_type      = ARG_ANYTHING,
 663 };
 664
 665 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 666            struct bpf_map *, map, u32, key, u64, flags)
 667 {
 668         struct sock *sk;
 669
 670         if (unlikely(flags & ~(BPF_F_INGRESS)))
 671                 return SK_DROP;
 672
 673         sk = __sock_map_lookup_elem(map, key);
 674         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 675                 return SK_DROP;
 676         if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
 677                 return SK_DROP;
 678
 679         msg->flags = flags;
 680         msg->sk_redir = sk;
 681         return SK_PASS;
 682 }
 683
 684 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 685         .func           = bpf_msg_redirect_map,
 686         .gpl_only       = false,
 687         .ret_type       = RET_INTEGER,
 688         .arg1_type      = ARG_PTR_TO_CTX,
 689         .arg2_type      = ARG_CONST_MAP_PTR,
 690         .arg3_type      = ARG_ANYTHING,
 691         .arg4_type      = ARG_ANYTHING,
 692 };
 693
 694 struct sock_map_seq_info {
 695         struct bpf_map *map;
 696         struct sock *sk;
 697         u32 index;
 698 };
 699
 700 struct bpf_iter__sockmap {
 701         __bpf_md_ptr(struct bpf_iter_meta *, meta);
 702         __bpf_md_ptr(struct bpf_map *, map);
 703         __bpf_md_ptr(void *, key);
 704         __bpf_md_ptr(struct sock *, sk);
 705 };
 706
 707 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
 708                      struct bpf_map *map, void *key,
 709                      struct sock *sk)
 710
 711 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
 712 {
 713         if (unlikely(info->index >= info->map->max_entries))
 714                 return NULL;
 715
 716         info->sk = __sock_map_lookup_elem(info->map, info->index);
 717
 718         /* can't return sk directly, since that might be NULL */
 719         return info;
 720 }
 721
 722 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
 723         __acquires(rcu)
 724 {
 725         struct sock_map_seq_info *info = seq->private;
 726
 727         if (*pos == 0)
 728                 ++*pos;
 729
 730         /* pairs with sock_map_seq_stop */
 731         rcu_read_lock();
 732         return sock_map_seq_lookup_elem(info);
 733 }
 734
 735 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 736         __must_hold(rcu)
 737 {
 738         struct sock_map_seq_info *info = seq->private;
 739
 740         ++*pos;
 741         ++info->index;
 742
 743         return sock_map_seq_lookup_elem(info);
 744 }
 745
 746 static int sock_map_seq_show(struct seq_file *seq, void *v)
 747         __must_hold(rcu)
 748 {
 749         struct sock_map_seq_info *info = seq->private;
 750         struct bpf_iter__sockmap ctx = {};
 751         struct bpf_iter_meta meta;
 752         struct bpf_prog *prog;
 753
 754         meta.seq = seq;
 755         prog = bpf_iter_get_info(&meta, !v);
 756         if (!prog)
 757                 return 0;
 758
 759         ctx.meta = &meta;
 760         ctx.map = info->map;
 761         if (v) {
 762                 ctx.key = &info->index;
 763                 ctx.sk = info->sk;
 764         }
 765
 766         return bpf_iter_run_prog(prog, &ctx);
 767 }
 768
 769 static void sock_map_seq_stop(struct seq_file *seq, void *v)
 770         __releases(rcu)
 771 {
 772         if (!v)
 773                 (void)sock_map_seq_show(seq, NULL);
 774
 775         /* pairs with sock_map_seq_start */
 776         rcu_read_unlock();
 777 }
 778
 779 static const struct seq_operations sock_map_seq_ops = {
 780         .start  = sock_map_seq_start,
 781         .next   = sock_map_seq_next,
 782         .stop   = sock_map_seq_stop,
 783         .show   = sock_map_seq_show,
 784 };
 785
 786 static int sock_map_init_seq_private(void *priv_data,
 787                                      struct bpf_iter_aux_info *aux)
 788 {
 789         struct sock_map_seq_info *info = priv_data;
 790
 791         bpf_map_inc_with_uref(aux->map);
 792         info->map = aux->map;
 793         return 0;
 794 }
 795
 796 static void sock_map_fini_seq_private(void *priv_data)
 797 {
 798         struct sock_map_seq_info *info = priv_data;
 799
 800         bpf_map_put_with_uref(info->map);
 801 }
 802
 803 static u64 sock_map_mem_usage(const struct bpf_map *map)
 804 {
 805         u64 usage = sizeof(struct bpf_stab);
 806
 807         usage += (u64)map->max_entries * sizeof(struct sock *);
 808         return usage;
 809 }
 810
 811 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
 812         .seq_ops                = &sock_map_seq_ops,
 813         .init_seq_private       = sock_map_init_seq_private,
 814         .fini_seq_private       = sock_map_fini_seq_private,
 815         .seq_priv_size          = sizeof(struct sock_map_seq_info),
 816 };
 817
 818 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab)
 819 const struct bpf_map_ops sock_map_ops = {
 820         .map_meta_equal         = bpf_map_meta_equal,
 821         .map_alloc              = sock_map_alloc,
 822         .map_free               = sock_map_free,
 823         .map_get_next_key       = sock_map_get_next_key,
 824         .map_lookup_elem_sys_only = sock_map_lookup_sys,
 825         .map_update_elem        = sock_map_update_elem,
 826         .map_delete_elem        = sock_map_delete_elem,
 827         .map_lookup_elem        = sock_map_lookup,
 828         .map_release_uref       = sock_map_release_progs,
 829         .map_check_btf          = map_check_no_btf,
 830         .map_mem_usage          = sock_map_mem_usage,
 831         .map_btf_id             = &sock_map_btf_ids[0],
 832         .iter_seq_info          = &sock_map_iter_seq_info,
 833 };
 834
 835 struct bpf_shtab_elem {
 836         struct rcu_head rcu;
 837         u32 hash;
 838         struct sock *sk;
 839         struct hlist_node node;
 840         u8 key[];
 841 };
 842
 843 struct bpf_shtab_bucket {
 844         struct hlist_head head;
 845         spinlock_t lock;
 846 };
 847
 848 struct bpf_shtab {
 849         struct bpf_map map;
 850         struct bpf_shtab_bucket *buckets;
 851         u32 buckets_num;
 852         u32 elem_size;
 853         struct sk_psock_progs progs;
 854         atomic_t count;
 855 };
 856
 857 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 858 {
 859         return jhash(key, len, 0);
 860 }
 861
 862 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 863                                                         u32 hash)
 864 {
 865         return &htab->buckets[hash & (htab->buckets_num - 1)];
 866 }
 867
 868 static struct bpf_shtab_elem *
 869 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 870                           u32 key_size)
 871 {
 872         struct bpf_shtab_elem *elem;
 873
 874         hlist_for_each_entry_rcu(elem, head, node) {
 875                 if (elem->hash == hash &&
 876                     !memcmp(&elem->key, key, key_size))
 877                         return elem;
 878         }
 879
 880         return NULL;
 881 }
 882
 883 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 884 {
 885         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 886         u32 key_size = map->key_size, hash;
 887         struct bpf_shtab_bucket *bucket;
 888         struct bpf_shtab_elem *elem;
 889
 890         WARN_ON_ONCE(!rcu_read_lock_held());
 891
 892         hash = sock_hash_bucket_hash(key, key_size);
 893         bucket = sock_hash_select_bucket(htab, hash);
 894         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 895
 896         return elem ? elem->sk : NULL;
 897 }
 898
 899 static void sock_hash_free_elem(struct bpf_shtab *htab,
 900                                 struct bpf_shtab_elem *elem)
 901 {
 902         atomic_dec(&htab->count);
 903         kfree_rcu(elem, rcu);
 904 }
 905
 906 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 907                                        void *link_raw)
 908 {
 909         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 910         struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 911         struct bpf_shtab_bucket *bucket;
 912
 913         WARN_ON_ONCE(!rcu_read_lock_held());
 914         bucket = sock_hash_select_bucket(htab, elem->hash);
 915
 916         /* elem may be deleted in parallel from the map, but access here
 917          * is okay since it's going away only after RCU grace period.
 918          * However, we need to check whether it's still present.
 919          */
 920         spin_lock_bh(&bucket->lock);
 921         elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 922                                                elem->key, map->key_size);
 923         if (elem_probe && elem_probe == elem) {
 924                 hlist_del_rcu(&elem->node);
 925                 sock_map_unref(elem->sk, elem);
 926                 sock_hash_free_elem(htab, elem);
 927         }
 928         spin_unlock_bh(&bucket->lock);
 929 }
 930
 931 static long sock_hash_delete_elem(struct bpf_map *map, void *key)
 932 {
 933         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 934         u32 hash, key_size = map->key_size;
 935         struct bpf_shtab_bucket *bucket;
 936         struct bpf_shtab_elem *elem;
 937         int ret = -ENOENT;
 938
 939         if (irqs_disabled())
 940                 return -EOPNOTSUPP; /* locks here are hardirq-unsafe */
 941
 942         hash = sock_hash_bucket_hash(key, key_size);
 943         bucket = sock_hash_select_bucket(htab, hash);
 944
 945         spin_lock_bh(&bucket->lock);
 946         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 947         if (elem) {
 948                 hlist_del_rcu(&elem->node);
 949                 sock_map_unref(elem->sk, elem);
 950                 sock_hash_free_elem(htab, elem);
 951                 ret = 0;
 952         }
 953         spin_unlock_bh(&bucket->lock);
 954         return ret;
 955 }
 956
 957 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 958                                                    void *key, u32 key_size,
 959                                                    u32 hash, struct sock *sk,
 960                                                    struct bpf_shtab_elem *old)
 961 {
 962         struct bpf_shtab_elem *new;
 963
 964         if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 965                 if (!old) {
 966                         atomic_dec(&htab->count);
 967                         return ERR_PTR(-E2BIG);
 968                 }
 969         }
 970
 971         new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
 972                                    GFP_ATOMIC | __GFP_NOWARN,
 973                                    htab->map.numa_node);
 974         if (!new) {
 975                 atomic_dec(&htab->count);
 976                 return ERR_PTR(-ENOMEM);
 977         }
 978         memcpy(new->key, key, key_size);
 979         new->sk = sk;
 980         new->hash = hash;
 981         return new;
 982 }
 983
 984 static int sock_hash_update_common(struct bpf_map *map, void *key,
 985                                    struct sock *sk, u64 flags)
 986 {
 987         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 988         u32 key_size = map->key_size, hash;
 989         struct bpf_shtab_elem *elem, *elem_new;
 990         struct bpf_shtab_bucket *bucket;
 991         struct sk_psock_link *link;
 992         struct sk_psock *psock;
 993         int ret;
 994
 995         WARN_ON_ONCE(!rcu_read_lock_held());
 996         if (unlikely(flags > BPF_EXIST))
 997                 return -EINVAL;
 998
 999         link = sk_psock_init_link();
1000         if (!link)
1001                 return -ENOMEM;
1002
1003         ret = sock_map_link(map, sk);
1004         if (ret < 0)
1005                 goto out_free;
1006
1007         psock = sk_psock(sk);
1008         WARN_ON_ONCE(!psock);
1009
1010         hash = sock_hash_bucket_hash(key, key_size);
1011         bucket = sock_hash_select_bucket(htab, hash);
1012
1013         spin_lock_bh(&bucket->lock);
1014         elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1015         if (elem && flags == BPF_NOEXIST) {
1016                 ret = -EEXIST;
1017                 goto out_unlock;
1018         } else if (!elem && flags == BPF_EXIST) {
1019                 ret = -ENOENT;
1020                 goto out_unlock;
1021         }
1022
1023         elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1024         if (IS_ERR(elem_new)) {
1025                 ret = PTR_ERR(elem_new);
1026                 goto out_unlock;
1027         }
1028
1029         sock_map_add_link(psock, link, map, elem_new);
1030         /* Add new element to the head of the list, so that
1031          * concurrent search will find it before old elem.
1032          */
1033         hlist_add_head_rcu(&elem_new->node, &bucket->head);
1034         if (elem) {
1035                 hlist_del_rcu(&elem->node);
1036                 sock_map_unref(elem->sk, elem);
1037                 sock_hash_free_elem(htab, elem);
1038         }
1039         spin_unlock_bh(&bucket->lock);
1040         return 0;
1041 out_unlock:
1042         spin_unlock_bh(&bucket->lock);
1043         sk_psock_put(sk, psock);
1044 out_free:
1045         sk_psock_free_link(link);
1046         return ret;
1047 }
1048
1049 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1050                                   void *key_next)
1051 {
1052         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1053         struct bpf_shtab_elem *elem, *elem_next;
1054         u32 hash, key_size = map->key_size;
1055         struct hlist_head *head;
1056         int i = 0;
1057
1058         if (!key)
1059                 goto find_first_elem;
1060         hash = sock_hash_bucket_hash(key, key_size);
1061         head = &sock_hash_select_bucket(htab, hash)->head;
1062         elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1063         if (!elem)
1064                 goto find_first_elem;
1065
1066         elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1067                                      struct bpf_shtab_elem, node);
1068         if (elem_next) {
1069                 memcpy(key_next, elem_next->key, key_size);
1070                 return 0;
1071         }
1072
1073         i = hash & (htab->buckets_num - 1);
1074         i++;
1075 find_first_elem:
1076         for (; i < htab->buckets_num; i++) {
1077                 head = &sock_hash_select_bucket(htab, i)->head;
1078                 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1079                                              struct bpf_shtab_elem, node);
1080                 if (elem_next) {
1081                         memcpy(key_next, elem_next->key, key_size);
1082                         return 0;
1083                 }
1084         }
1085
1086         return -ENOENT;
1087 }
1088
1089 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1090 {
1091         struct bpf_shtab *htab;
1092         int i, err;
1093
1094         if (attr->max_entries == 0 ||
1095             attr->key_size    == 0 ||
1096             (attr->value_size != sizeof(u32) &&
1097              attr->value_size != sizeof(u64)) ||
1098             attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1099                 return ERR_PTR(-EINVAL);
1100         if (attr->key_size > MAX_BPF_STACK)
1101                 return ERR_PTR(-E2BIG);
1102
1103         htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
1104         if (!htab)
1105                 return ERR_PTR(-ENOMEM);
1106
1107         bpf_map_init_from_attr(&htab->map, attr);
1108
1109         htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1110         htab->elem_size = sizeof(struct bpf_shtab_elem) +
1111                           round_up(htab->map.key_size, 8);
1112         if (htab->buckets_num == 0 ||
1113             htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1114                 err = -EINVAL;
1115                 goto free_htab;
1116         }
1117
1118         htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1119                                            sizeof(struct bpf_shtab_bucket),
1120                                            htab->map.numa_node);
1121         if (!htab->buckets) {
1122                 err = -ENOMEM;
1123                 goto free_htab;
1124         }
1125
1126         for (i = 0; i < htab->buckets_num; i++) {
1127                 INIT_HLIST_HEAD(&htab->buckets[i].head);
1128                 spin_lock_init(&htab->buckets[i].lock);
1129         }
1130
1131         return &htab->map;
1132 free_htab:
1133         bpf_map_area_free(htab);
1134         return ERR_PTR(err);
1135 }
1136
1137 static void sock_hash_free(struct bpf_map *map)
1138 {
1139         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1140         struct bpf_shtab_bucket *bucket;
1141         struct hlist_head unlink_list;
1142         struct bpf_shtab_elem *elem;
1143         struct hlist_node *node;
1144         int i;
1145
1146         /* After the sync no updates or deletes will be in-flight so it
1147          * is safe to walk map and remove entries without risking a race
1148          * in EEXIST update case.
1149          */
1150         synchronize_rcu();
1151         for (i = 0; i < htab->buckets_num; i++) {
1152                 bucket = sock_hash_select_bucket(htab, i);
1153
1154                 /* We are racing with sock_hash_delete_from_link to
1155                  * enter the spin-lock critical section. Every socket on
1156                  * the list is still linked to sockhash. Since link
1157                  * exists, psock exists and holds a ref to socket. That
1158                  * lets us to grab a socket ref too.
1159                  */
1160                 spin_lock_bh(&bucket->lock);
1161                 hlist_for_each_entry(elem, &bucket->head, node)
1162                         sock_hold(elem->sk);
1163                 hlist_move_list(&bucket->head, &unlink_list);
1164                 spin_unlock_bh(&bucket->lock);
1165
1166                 /* Process removed entries out of atomic context to
1167                  * block for socket lock before deleting the psock's
1168                  * link to sockhash.
1169                  */
1170                 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1171                         hlist_del(&elem->node);
1172                         lock_sock(elem->sk);
1173                         rcu_read_lock();
1174                         sock_map_unref(elem->sk, elem);
1175                         rcu_read_unlock();
1176                         release_sock(elem->sk);
1177                         sock_put(elem->sk);
1178                         sock_hash_free_elem(htab, elem);
1179                 }
1180         }
1181
1182         /* wait for psock readers accessing its map link */
1183         synchronize_rcu();
1184
1185         bpf_map_area_free(htab->buckets);
1186         bpf_map_area_free(htab);
1187 }
1188
1189 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1190 {
1191         struct sock *sk;
1192
1193         if (map->value_size != sizeof(u64))
1194                 return ERR_PTR(-ENOSPC);
1195
1196         sk = __sock_hash_lookup_elem(map, key);
1197         if (!sk)
1198                 return ERR_PTR(-ENOENT);
1199
1200         __sock_gen_cookie(sk);
1201         return &sk->sk_cookie;
1202 }
1203
1204 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1205 {
1206         struct sock *sk;
1207
1208         sk = __sock_hash_lookup_elem(map, key);
1209         if (!sk)
1210                 return NULL;
1211         if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1212                 return NULL;
1213         return sk;
1214 }
1215
1216 static void sock_hash_release_progs(struct bpf_map *map)
1217 {
1218         psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1219 }
1220
1221 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1222            struct bpf_map *, map, void *, key, u64, flags)
1223 {
1224         WARN_ON_ONCE(!rcu_read_lock_held());
1225
1226         if (likely(sock_map_sk_is_suitable(sops->sk) &&
1227                    sock_map_op_okay(sops)))
1228                 return sock_hash_update_common(map, key, sops->sk, flags);
1229         return -EOPNOTSUPP;
1230 }
1231
1232 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1233         .func           = bpf_sock_hash_update,
1234         .gpl_only       = false,
1235         .pkt_access     = true,
1236         .ret_type       = RET_INTEGER,
1237         .arg1_type      = ARG_PTR_TO_CTX,
1238         .arg2_type      = ARG_CONST_MAP_PTR,
1239         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1240         .arg4_type      = ARG_ANYTHING,
1241 };
1242
1243 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1244            struct bpf_map *, map, void *, key, u64, flags)
1245 {
1246         struct sock *sk;
1247
1248         if (unlikely(flags & ~(BPF_F_INGRESS)))
1249                 return SK_DROP;
1250
1251         sk = __sock_hash_lookup_elem(map, key);
1252         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1253                 return SK_DROP;
1254
1255         skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1256         return SK_PASS;
1257 }
1258
1259 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1260         .func           = bpf_sk_redirect_hash,
1261         .gpl_only       = false,
1262         .ret_type       = RET_INTEGER,
1263         .arg1_type      = ARG_PTR_TO_CTX,
1264         .arg2_type      = ARG_CONST_MAP_PTR,
1265         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1266         .arg4_type      = ARG_ANYTHING,
1267 };
1268
1269 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1270            struct bpf_map *, map, void *, key, u64, flags)
1271 {
1272         struct sock *sk;
1273
1274         if (unlikely(flags & ~(BPF_F_INGRESS)))
1275                 return SK_DROP;
1276
1277         sk = __sock_hash_lookup_elem(map, key);
1278         if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1279                 return SK_DROP;
1280         if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
1281                 return SK_DROP;
1282
1283         msg->flags = flags;
1284         msg->sk_redir = sk;
1285         return SK_PASS;
1286 }
1287
1288 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1289         .func           = bpf_msg_redirect_hash,
1290         .gpl_only       = false,
1291         .ret_type       = RET_INTEGER,
1292         .arg1_type      = ARG_PTR_TO_CTX,
1293         .arg2_type      = ARG_CONST_MAP_PTR,
1294         .arg3_type      = ARG_PTR_TO_MAP_KEY,
1295         .arg4_type      = ARG_ANYTHING,
1296 };
1297
1298 struct sock_hash_seq_info {
1299         struct bpf_map *map;
1300         struct bpf_shtab *htab;
1301         u32 bucket_id;
1302 };
1303
1304 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1305                                      struct bpf_shtab_elem *prev_elem)
1306 {
1307         const struct bpf_shtab *htab = info->htab;
1308         struct bpf_shtab_bucket *bucket;
1309         struct bpf_shtab_elem *elem;
1310         struct hlist_node *node;
1311
1312         /* try to find next elem in the same bucket */
1313         if (prev_elem) {
1314                 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1315                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1316                 if (elem)
1317                         return elem;
1318
1319                 /* no more elements, continue in the next bucket */
1320                 info->bucket_id++;
1321         }
1322
1323         for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1324                 bucket = &htab->buckets[info->bucket_id];
1325                 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1326                 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1327                 if (elem)
1328                         return elem;
1329         }
1330
1331         return NULL;
1332 }
1333
1334 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1335         __acquires(rcu)
1336 {
1337         struct sock_hash_seq_info *info = seq->private;
1338
1339         if (*pos == 0)
1340                 ++*pos;
1341
1342         /* pairs with sock_hash_seq_stop */
1343         rcu_read_lock();
1344         return sock_hash_seq_find_next(info, NULL);
1345 }
1346
1347 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1348         __must_hold(rcu)
1349 {
1350         struct sock_hash_seq_info *info = seq->private;
1351
1352         ++*pos;
1353         return sock_hash_seq_find_next(info, v);
1354 }
1355
1356 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1357         __must_hold(rcu)
1358 {
1359         struct sock_hash_seq_info *info = seq->private;
1360         struct bpf_iter__sockmap ctx = {};
1361         struct bpf_shtab_elem *elem = v;
1362         struct bpf_iter_meta meta;
1363         struct bpf_prog *prog;
1364
1365         meta.seq = seq;
1366         prog = bpf_iter_get_info(&meta, !elem);
1367         if (!prog)
1368                 return 0;
1369
1370         ctx.meta = &meta;
1371         ctx.map = info->map;
1372         if (elem) {
1373                 ctx.key = elem->key;
1374                 ctx.sk = elem->sk;
1375         }
1376
1377         return bpf_iter_run_prog(prog, &ctx);
1378 }
1379
1380 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1381         __releases(rcu)
1382 {
1383         if (!v)
1384                 (void)sock_hash_seq_show(seq, NULL);
1385
1386         /* pairs with sock_hash_seq_start */
1387         rcu_read_unlock();
1388 }
1389
1390 static const struct seq_operations sock_hash_seq_ops = {
1391         .start  = sock_hash_seq_start,
1392         .next   = sock_hash_seq_next,
1393         .stop   = sock_hash_seq_stop,
1394         .show   = sock_hash_seq_show,
1395 };
1396
1397 static int sock_hash_init_seq_private(void *priv_data,
1398                                       struct bpf_iter_aux_info *aux)
1399 {
1400         struct sock_hash_seq_info *info = priv_data;
1401
1402         bpf_map_inc_with_uref(aux->map);
1403         info->map = aux->map;
1404         info->htab = container_of(aux->map, struct bpf_shtab, map);
1405         return 0;
1406 }
1407
1408 static void sock_hash_fini_seq_private(void *priv_data)
1409 {
1410         struct sock_hash_seq_info *info = priv_data;
1411
1412         bpf_map_put_with_uref(info->map);
1413 }
1414
1415 static u64 sock_hash_mem_usage(const struct bpf_map *map)
1416 {
1417         struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1418         u64 usage = sizeof(*htab);
1419
1420         usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket);
1421         usage += atomic_read(&htab->count) * (u64)htab->elem_size;
1422         return usage;
1423 }
1424
1425 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1426         .seq_ops                = &sock_hash_seq_ops,
1427         .init_seq_private       = sock_hash_init_seq_private,
1428         .fini_seq_private       = sock_hash_fini_seq_private,
1429         .seq_priv_size          = sizeof(struct sock_hash_seq_info),
1430 };
1431
1432 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab)
1433 const struct bpf_map_ops sock_hash_ops = {
1434         .map_meta_equal         = bpf_map_meta_equal,
1435         .map_alloc              = sock_hash_alloc,
1436         .map_free               = sock_hash_free,
1437         .map_get_next_key       = sock_hash_get_next_key,
1438         .map_update_elem        = sock_map_update_elem,
1439         .map_delete_elem        = sock_hash_delete_elem,
1440         .map_lookup_elem        = sock_hash_lookup,
1441         .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1442         .map_release_uref       = sock_hash_release_progs,
1443         .map_check_btf          = map_check_no_btf,
1444         .map_mem_usage          = sock_hash_mem_usage,
1445         .map_btf_id             = &sock_hash_map_btf_ids[0],
1446         .iter_seq_info          = &sock_hash_iter_seq_info,
1447 };
1448
1449 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1450 {
1451         switch (map->map_type) {
1452         case BPF_MAP_TYPE_SOCKMAP:
1453                 return &container_of(map, struct bpf_stab, map)->progs;
1454         case BPF_MAP_TYPE_SOCKHASH:
1455                 return &container_of(map, struct bpf_shtab, map)->progs;
1456         default:
1457                 break;
1458         }
1459
1460         return NULL;
1461 }
1462
1463 static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
1464                                 u32 which)
1465 {
1466         struct sk_psock_progs *progs = sock_map_progs(map);
1467
1468         if (!progs)
1469                 return -EOPNOTSUPP;
1470
1471         switch (which) {
1472         case BPF_SK_MSG_VERDICT:
1473                 *pprog = &progs->msg_parser;
1474                 break;
1475 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1476         case BPF_SK_SKB_STREAM_PARSER:
1477                 *pprog = &progs->stream_parser;
1478                 break;
1479 #endif
1480         case BPF_SK_SKB_STREAM_VERDICT:
1481                 if (progs->skb_verdict)
1482                         return -EBUSY;
1483                 *pprog = &progs->stream_verdict;
1484                 break;
1485         case BPF_SK_SKB_VERDICT:
1486                 if (progs->stream_verdict)
1487                         return -EBUSY;
1488                 *pprog = &progs->skb_verdict;
1489                 break;
1490         default:
1491                 return -EOPNOTSUPP;
1492         }
1493
1494         return 0;
1495 }
1496
1497 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1498                                 struct bpf_prog *old, u32 which)
1499 {
1500         struct bpf_prog **pprog;
1501         int ret;
1502
1503         ret = sock_map_prog_lookup(map, &pprog, which);
1504         if (ret)
1505                 return ret;
1506
1507         if (old)
1508                 return psock_replace_prog(pprog, prog, old);
1509
1510         psock_set_prog(pprog, prog);
1511         return 0;
1512 }
1513
1514 int sock_map_bpf_prog_query(const union bpf_attr *attr,
1515                             union bpf_attr __user *uattr)
1516 {
1517         __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
1518         u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;
1519         struct bpf_prog **pprog;
1520         struct bpf_prog *prog;
1521         struct bpf_map *map;
1522         struct fd f;
1523         u32 id = 0;
1524         int ret;
1525
1526         if (attr->query.query_flags)
1527                 return -EINVAL;
1528
1529         f = fdget(ufd);
1530         map = __bpf_map_get(f);
1531         if (IS_ERR(map))
1532                 return PTR_ERR(map);
1533
1534         rcu_read_lock();
1535
1536         ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);
1537         if (ret)
1538                 goto end;
1539
1540         prog = *pprog;
1541         prog_cnt = !prog ? 0 : 1;
1542
1543         if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
1544                 goto end;
1545
1546         /* we do not hold the refcnt, the bpf prog may be released
1547          * asynchronously and the id would be set to 0.
1548          */
1549         id = data_race(prog->aux->id);
1550         if (id == 0)
1551                 prog_cnt = 0;
1552
1553 end:
1554         rcu_read_unlock();
1555
1556         if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
1557             (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||
1558             copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
1559                 ret = -EFAULT;
1560
1561         fdput(f);
1562         return ret;
1563 }
1564
1565 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1566 {
1567         switch (link->map->map_type) {
1568         case BPF_MAP_TYPE_SOCKMAP:
1569                 return sock_map_delete_from_link(link->map, sk,
1570                                                  link->link_raw);
1571         case BPF_MAP_TYPE_SOCKHASH:
1572                 return sock_hash_delete_from_link(link->map, sk,
1573                                                   link->link_raw);
1574         default:
1575                 break;
1576         }
1577 }
1578
1579 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1580 {
1581         struct sk_psock_link *link;
1582
1583         while ((link = sk_psock_link_pop(psock))) {
1584                 sock_map_unlink(sk, link);
1585                 sk_psock_free_link(link);
1586         }
1587 }
1588
1589 void sock_map_unhash(struct sock *sk)
1590 {
1591         void (*saved_unhash)(struct sock *sk);
1592         struct sk_psock *psock;
1593
1594         rcu_read_lock();
1595         psock = sk_psock(sk);
1596         if (unlikely(!psock)) {
1597                 rcu_read_unlock();
1598                 saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
1599         } else {
1600                 saved_unhash = psock->saved_unhash;
1601                 sock_map_remove_links(sk, psock);
1602                 rcu_read_unlock();
1603         }
1604         if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
1605                 return;
1606         if (saved_unhash)
1607                 saved_unhash(sk);
1608 }
1609 EXPORT_SYMBOL_GPL(sock_map_unhash);
1610
1611 void sock_map_destroy(struct sock *sk)
1612 {
1613         void (*saved_destroy)(struct sock *sk);
1614         struct sk_psock *psock;
1615
1616         rcu_read_lock();
1617         psock = sk_psock_get(sk);
1618         if (unlikely(!psock)) {
1619                 rcu_read_unlock();
1620                 saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
1621         } else {
1622                 saved_destroy = psock->saved_destroy;
1623                 sock_map_remove_links(sk, psock);
1624                 rcu_read_unlock();
1625                 sk_psock_stop(psock);
1626                 sk_psock_put(sk, psock);
1627         }
1628         if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
1629                 return;
1630         if (saved_destroy)
1631                 saved_destroy(sk);
1632 }
1633 EXPORT_SYMBOL_GPL(sock_map_destroy);
1634
1635 void sock_map_close(struct sock *sk, long timeout)
1636 {
1637         void (*saved_close)(struct sock *sk, long timeout);
1638         struct sk_psock *psock;
1639
1640         lock_sock(sk);
1641         rcu_read_lock();
1642         psock = sk_psock_get(sk);
1643         if (unlikely(!psock)) {
1644                 rcu_read_unlock();
1645                 release_sock(sk);
1646                 saved_close = READ_ONCE(sk->sk_prot)->close;
1647         } else {
1648                 saved_close = psock->saved_close;
1649                 sock_map_remove_links(sk, psock);
1650                 rcu_read_unlock();
1651                 sk_psock_stop(psock);
1652                 release_sock(sk);
1653                 cancel_delayed_work_sync(&psock->work);
1654                 sk_psock_put(sk, psock);
1655         }
1656
1657         /* Make sure we do not recurse. This is a bug.
1658          * Leak the socket instead of crashing on a stack overflow.
1659          */
1660         if (WARN_ON_ONCE(saved_close == sock_map_close))
1661                 return;
1662         saved_close(sk, timeout);
1663 }
1664 EXPORT_SYMBOL_GPL(sock_map_close);
1665
1666 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1667                                        union bpf_iter_link_info *linfo,
1668                                        struct bpf_iter_aux_info *aux)
1669 {
1670         struct bpf_map *map;
1671         int err = -EINVAL;
1672
1673         if (!linfo->map.map_fd)
1674                 return -EBADF;
1675
1676         map = bpf_map_get_with_uref(linfo->map.map_fd);
1677         if (IS_ERR(map))
1678                 return PTR_ERR(map);
1679
1680         if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1681             map->map_type != BPF_MAP_TYPE_SOCKHASH)
1682                 goto put_map;
1683
1684         if (prog->aux->max_rdonly_access > map->key_size) {
1685                 err = -EACCES;
1686                 goto put_map;
1687         }
1688
1689         aux->map = map;
1690         return 0;
1691
1692 put_map:
1693         bpf_map_put_with_uref(map);
1694         return err;
1695 }
1696
1697 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1698 {
1699         bpf_map_put_with_uref(aux->map);
1700 }
1701
1702 static struct bpf_iter_reg sock_map_iter_reg = {
1703         .target                 = "sockmap",
1704         .attach_target          = sock_map_iter_attach_target,
1705         .detach_target          = sock_map_iter_detach_target,
1706         .show_fdinfo            = bpf_iter_map_show_fdinfo,
1707         .fill_link_info         = bpf_iter_map_fill_link_info,
1708         .ctx_arg_info_size      = 2,
1709         .ctx_arg_info           = {
1710                 { offsetof(struct bpf_iter__sockmap, key),
1711                   PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1712                 { offsetof(struct bpf_iter__sockmap, sk),
1713                   PTR_TO_BTF_ID_OR_NULL },
1714         },
1715 };
1716
1717 static int __init bpf_sockmap_iter_init(void)
1718 {
1719         sock_map_iter_reg.ctx_arg_info[1].btf_id =
1720                 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1721         return bpf_iter_reg_target(&sock_map_iter_reg);
1722 }
1723 late_initcall(bpf_sockmap_iter_init);