linux/net/core/sock_map.c
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   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
  17struct bpf_stab {
  18        struct bpf_map map;
  19        struct sock **sks;
  20        struct sk_psock_progs progs;
  21        raw_spinlock_t lock;
  22};
  23
  24#define SOCK_CREATE_FLAG_MASK                           \
  25        (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
  26
  27static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
  28                                struct bpf_prog *old, u32 which);
  29static struct sk_psock_progs *sock_map_progs(struct bpf_map *map);
  30
  31static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
  32{
  33        struct bpf_stab *stab;
  34
  35        if (!capable(CAP_NET_ADMIN))
  36                return ERR_PTR(-EPERM);
  37        if (attr->max_entries == 0 ||
  38            attr->key_size    != 4 ||
  39            (attr->value_size != sizeof(u32) &&
  40             attr->value_size != sizeof(u64)) ||
  41            attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
  42                return ERR_PTR(-EINVAL);
  43
  44        stab = kzalloc(sizeof(*stab), GFP_USER | __GFP_ACCOUNT);
  45        if (!stab)
  46                return ERR_PTR(-ENOMEM);
  47
  48        bpf_map_init_from_attr(&stab->map, attr);
  49        raw_spin_lock_init(&stab->lock);
  50
  51        stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
  52                                       sizeof(struct sock *),
  53                                       stab->map.numa_node);
  54        if (!stab->sks) {
  55                kfree(stab);
  56                return ERR_PTR(-ENOMEM);
  57        }
  58
  59        return &stab->map;
  60}
  61
  62int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
  63{
  64        u32 ufd = attr->target_fd;
  65        struct bpf_map *map;
  66        struct fd f;
  67        int ret;
  68
  69        if (attr->attach_flags || attr->replace_bpf_fd)
  70                return -EINVAL;
  71
  72        f = fdget(ufd);
  73        map = __bpf_map_get(f);
  74        if (IS_ERR(map))
  75                return PTR_ERR(map);
  76        ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
  77        fdput(f);
  78        return ret;
  79}
  80
  81int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
  82{
  83        u32 ufd = attr->target_fd;
  84        struct bpf_prog *prog;
  85        struct bpf_map *map;
  86        struct fd f;
  87        int ret;
  88
  89        if (attr->attach_flags || attr->replace_bpf_fd)
  90                return -EINVAL;
  91
  92        f = fdget(ufd);
  93        map = __bpf_map_get(f);
  94        if (IS_ERR(map))
  95                return PTR_ERR(map);
  96
  97        prog = bpf_prog_get(attr->attach_bpf_fd);
  98        if (IS_ERR(prog)) {
  99                ret = PTR_ERR(prog);
 100                goto put_map;
 101        }
 102
 103        if (prog->type != ptype) {
 104                ret = -EINVAL;
 105                goto put_prog;
 106        }
 107
 108        ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
 109put_prog:
 110        bpf_prog_put(prog);
 111put_map:
 112        fdput(f);
 113        return ret;
 114}
 115
 116static void sock_map_sk_acquire(struct sock *sk)
 117        __acquires(&sk->sk_lock.slock)
 118{
 119        lock_sock(sk);
 120        preempt_disable();
 121        rcu_read_lock();
 122}
 123
 124static void sock_map_sk_release(struct sock *sk)
 125        __releases(&sk->sk_lock.slock)
 126{
 127        rcu_read_unlock();
 128        preempt_enable();
 129        release_sock(sk);
 130}
 131
 132static void sock_map_add_link(struct sk_psock *psock,
 133                              struct sk_psock_link *link,
 134                              struct bpf_map *map, void *link_raw)
 135{
 136        link->link_raw = link_raw;
 137        link->map = map;
 138        spin_lock_bh(&psock->link_lock);
 139        list_add_tail(&link->list, &psock->link);
 140        spin_unlock_bh(&psock->link_lock);
 141}
 142
 143static void sock_map_del_link(struct sock *sk,
 144                              struct sk_psock *psock, void *link_raw)
 145{
 146        bool strp_stop = false, verdict_stop = false;
 147        struct sk_psock_link *link, *tmp;
 148
 149        spin_lock_bh(&psock->link_lock);
 150        list_for_each_entry_safe(link, tmp, &psock->link, list) {
 151                if (link->link_raw == link_raw) {
 152                        struct bpf_map *map = link->map;
 153                        struct bpf_stab *stab = container_of(map, struct bpf_stab,
 154                                                             map);
 155                        if (psock->saved_data_ready && stab->progs.stream_parser)
 156                                strp_stop = true;
 157                        if (psock->saved_data_ready && stab->progs.stream_verdict)
 158                                verdict_stop = true;
 159                        if (psock->saved_data_ready && stab->progs.skb_verdict)
 160                                verdict_stop = true;
 161                        list_del(&link->list);
 162                        sk_psock_free_link(link);
 163                }
 164        }
 165        spin_unlock_bh(&psock->link_lock);
 166        if (strp_stop || verdict_stop) {
 167                write_lock_bh(&sk->sk_callback_lock);
 168                if (strp_stop)
 169                        sk_psock_stop_strp(sk, psock);
 170                else
 171                        sk_psock_stop_verdict(sk, psock);
 172                write_unlock_bh(&sk->sk_callback_lock);
 173        }
 174}
 175
 176static void sock_map_unref(struct sock *sk, void *link_raw)
 177{
 178        struct sk_psock *psock = sk_psock(sk);
 179
 180        if (likely(psock)) {
 181                sock_map_del_link(sk, psock, link_raw);
 182                sk_psock_put(sk, psock);
 183        }
 184}
 185
 186static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
 187{
 188        if (!sk->sk_prot->psock_update_sk_prot)
 189                return -EINVAL;
 190        psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
 191        return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
 192}
 193
 194static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
 195{
 196        struct sk_psock *psock;
 197
 198        rcu_read_lock();
 199        psock = sk_psock(sk);
 200        if (psock) {
 201                if (sk->sk_prot->close != sock_map_close) {
 202                        psock = ERR_PTR(-EBUSY);
 203                        goto out;
 204                }
 205
 206                if (!refcount_inc_not_zero(&psock->refcnt))
 207                        psock = ERR_PTR(-EBUSY);
 208        }
 209out:
 210        rcu_read_unlock();
 211        return psock;
 212}
 213
 214static bool sock_map_redirect_allowed(const struct sock *sk);
 215
 216static int sock_map_link(struct bpf_map *map, struct sock *sk)
 217{
 218        struct sk_psock_progs *progs = sock_map_progs(map);
 219        struct bpf_prog *stream_verdict = NULL;
 220        struct bpf_prog *stream_parser = NULL;
 221        struct bpf_prog *skb_verdict = NULL;
 222        struct bpf_prog *msg_parser = NULL;
 223        struct sk_psock *psock;
 224        int ret;
 225
 226        /* Only sockets we can redirect into/from in BPF need to hold
 227         * refs to parser/verdict progs and have their sk_data_ready
 228         * and sk_write_space callbacks overridden.
 229         */
 230        if (!sock_map_redirect_allowed(sk))
 231                goto no_progs;
 232
 233        stream_verdict = READ_ONCE(progs->stream_verdict);
 234        if (stream_verdict) {
 235                stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
 236                if (IS_ERR(stream_verdict))
 237                        return PTR_ERR(stream_verdict);
 238        }
 239
 240        stream_parser = READ_ONCE(progs->stream_parser);
 241        if (stream_parser) {
 242                stream_parser = bpf_prog_inc_not_zero(stream_parser);
 243                if (IS_ERR(stream_parser)) {
 244                        ret = PTR_ERR(stream_parser);
 245                        goto out_put_stream_verdict;
 246                }
 247        }
 248
 249        msg_parser = READ_ONCE(progs->msg_parser);
 250        if (msg_parser) {
 251                msg_parser = bpf_prog_inc_not_zero(msg_parser);
 252                if (IS_ERR(msg_parser)) {
 253                        ret = PTR_ERR(msg_parser);
 254                        goto out_put_stream_parser;
 255                }
 256        }
 257
 258        skb_verdict = READ_ONCE(progs->skb_verdict);
 259        if (skb_verdict) {
 260                skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
 261                if (IS_ERR(skb_verdict)) {
 262                        ret = PTR_ERR(skb_verdict);
 263                        goto out_put_msg_parser;
 264                }
 265        }
 266
 267no_progs:
 268        psock = sock_map_psock_get_checked(sk);
 269        if (IS_ERR(psock)) {
 270                ret = PTR_ERR(psock);
 271                goto out_progs;
 272        }
 273
 274        if (psock) {
 275                if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
 276                    (stream_parser  && READ_ONCE(psock->progs.stream_parser)) ||
 277                    (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 278                    (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
 279                    (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
 280                    (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
 281                        sk_psock_put(sk, psock);
 282                        ret = -EBUSY;
 283                        goto out_progs;
 284                }
 285        } else {
 286                psock = sk_psock_init(sk, map->numa_node);
 287                if (IS_ERR(psock)) {
 288                        ret = PTR_ERR(psock);
 289                        goto out_progs;
 290                }
 291        }
 292
 293        if (msg_parser)
 294                psock_set_prog(&psock->progs.msg_parser, msg_parser);
 295
 296        ret = sock_map_init_proto(sk, psock);
 297        if (ret < 0)
 298                goto out_drop;
 299
 300        write_lock_bh(&sk->sk_callback_lock);
 301        if (stream_parser && stream_verdict && !psock->saved_data_ready) {
 302                ret = sk_psock_init_strp(sk, psock);
 303                if (ret)
 304                        goto out_unlock_drop;
 305                psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 306                psock_set_prog(&psock->progs.stream_parser, stream_parser);
 307                sk_psock_start_strp(sk, psock);
 308        } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
 309                psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
 310                sk_psock_start_verdict(sk,psock);
 311        } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
 312                psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
 313                sk_psock_start_verdict(sk, psock);
 314        }
 315        write_unlock_bh(&sk->sk_callback_lock);
 316        return 0;
 317out_unlock_drop:
 318        write_unlock_bh(&sk->sk_callback_lock);
 319out_drop:
 320        sk_psock_put(sk, psock);
 321out_progs:
 322        if (skb_verdict)
 323                bpf_prog_put(skb_verdict);
 324out_put_msg_parser:
 325        if (msg_parser)
 326                bpf_prog_put(msg_parser);
 327out_put_stream_parser:
 328        if (stream_parser)
 329                bpf_prog_put(stream_parser);
 330out_put_stream_verdict:
 331        if (stream_verdict)
 332                bpf_prog_put(stream_verdict);
 333        return ret;
 334}
 335
 336static void sock_map_free(struct bpf_map *map)
 337{
 338        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 339        int i;
 340
 341        /* After the sync no updates or deletes will be in-flight so it
 342         * is safe to walk map and remove entries without risking a race
 343         * in EEXIST update case.
 344         */
 345        synchronize_rcu();
 346        for (i = 0; i < stab->map.max_entries; i++) {
 347                struct sock **psk = &stab->sks[i];
 348                struct sock *sk;
 349
 350                sk = xchg(psk, NULL);
 351                if (sk) {
 352                        lock_sock(sk);
 353                        rcu_read_lock();
 354                        sock_map_unref(sk, psk);
 355                        rcu_read_unlock();
 356                        release_sock(sk);
 357                }
 358        }
 359
 360        /* wait for psock readers accessing its map link */
 361        synchronize_rcu();
 362
 363        bpf_map_area_free(stab->sks);
 364        kfree(stab);
 365}
 366
 367static void sock_map_release_progs(struct bpf_map *map)
 368{
 369        psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
 370}
 371
 372static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 373{
 374        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 375
 376        WARN_ON_ONCE(!rcu_read_lock_held());
 377
 378        if (unlikely(key >= map->max_entries))
 379                return NULL;
 380        return READ_ONCE(stab->sks[key]);
 381}
 382
 383static void *sock_map_lookup(struct bpf_map *map, void *key)
 384{
 385        struct sock *sk;
 386
 387        sk = __sock_map_lookup_elem(map, *(u32 *)key);
 388        if (!sk)
 389                return NULL;
 390        if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
 391                return NULL;
 392        return sk;
 393}
 394
 395static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
 396{
 397        struct sock *sk;
 398
 399        if (map->value_size != sizeof(u64))
 400                return ERR_PTR(-ENOSPC);
 401
 402        sk = __sock_map_lookup_elem(map, *(u32 *)key);
 403        if (!sk)
 404                return ERR_PTR(-ENOENT);
 405
 406        __sock_gen_cookie(sk);
 407        return &sk->sk_cookie;
 408}
 409
 410static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
 411                             struct sock **psk)
 412{
 413        struct sock *sk;
 414        int err = 0;
 415
 416        raw_spin_lock_bh(&stab->lock);
 417        sk = *psk;
 418        if (!sk_test || sk_test == sk)
 419                sk = xchg(psk, NULL);
 420
 421        if (likely(sk))
 422                sock_map_unref(sk, psk);
 423        else
 424                err = -EINVAL;
 425
 426        raw_spin_unlock_bh(&stab->lock);
 427        return err;
 428}
 429
 430static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
 431                                      void *link_raw)
 432{
 433        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 434
 435        __sock_map_delete(stab, sk, link_raw);
 436}
 437
 438static int sock_map_delete_elem(struct bpf_map *map, void *key)
 439{
 440        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 441        u32 i = *(u32 *)key;
 442        struct sock **psk;
 443
 444        if (unlikely(i >= map->max_entries))
 445                return -EINVAL;
 446
 447        psk = &stab->sks[i];
 448        return __sock_map_delete(stab, NULL, psk);
 449}
 450
 451static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
 452{
 453        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 454        u32 i = key ? *(u32 *)key : U32_MAX;
 455        u32 *key_next = next;
 456
 457        if (i == stab->map.max_entries - 1)
 458                return -ENOENT;
 459        if (i >= stab->map.max_entries)
 460                *key_next = 0;
 461        else
 462                *key_next = i + 1;
 463        return 0;
 464}
 465
 466static int sock_map_update_common(struct bpf_map *map, u32 idx,
 467                                  struct sock *sk, u64 flags)
 468{
 469        struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 470        struct sk_psock_link *link;
 471        struct sk_psock *psock;
 472        struct sock *osk;
 473        int ret;
 474
 475        WARN_ON_ONCE(!rcu_read_lock_held());
 476        if (unlikely(flags > BPF_EXIST))
 477                return -EINVAL;
 478        if (unlikely(idx >= map->max_entries))
 479                return -E2BIG;
 480
 481        link = sk_psock_init_link();
 482        if (!link)
 483                return -ENOMEM;
 484
 485        ret = sock_map_link(map, sk);
 486        if (ret < 0)
 487                goto out_free;
 488
 489        psock = sk_psock(sk);
 490        WARN_ON_ONCE(!psock);
 491
 492        raw_spin_lock_bh(&stab->lock);
 493        osk = stab->sks[idx];
 494        if (osk && flags == BPF_NOEXIST) {
 495                ret = -EEXIST;
 496                goto out_unlock;
 497        } else if (!osk && flags == BPF_EXIST) {
 498                ret = -ENOENT;
 499                goto out_unlock;
 500        }
 501
 502        sock_map_add_link(psock, link, map, &stab->sks[idx]);
 503        stab->sks[idx] = sk;
 504        if (osk)
 505                sock_map_unref(osk, &stab->sks[idx]);
 506        raw_spin_unlock_bh(&stab->lock);
 507        return 0;
 508out_unlock:
 509        raw_spin_unlock_bh(&stab->lock);
 510        if (psock)
 511                sk_psock_put(sk, psock);
 512out_free:
 513        sk_psock_free_link(link);
 514        return ret;
 515}
 516
 517static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
 518{
 519        return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
 520               ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
 521               ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
 522}
 523
 524static bool sk_is_tcp(const struct sock *sk)
 525{
 526        return sk->sk_type == SOCK_STREAM &&
 527               sk->sk_protocol == IPPROTO_TCP;
 528}
 529
 530static bool sk_is_udp(const struct sock *sk)
 531{
 532        return sk->sk_type == SOCK_DGRAM &&
 533               sk->sk_protocol == IPPROTO_UDP;
 534}
 535
 536static bool sock_map_redirect_allowed(const struct sock *sk)
 537{
 538        if (sk_is_tcp(sk))
 539                return sk->sk_state != TCP_LISTEN;
 540        else
 541                return sk->sk_state == TCP_ESTABLISHED;
 542}
 543
 544static bool sock_map_sk_is_suitable(const struct sock *sk)
 545{
 546        return !!sk->sk_prot->psock_update_sk_prot;
 547}
 548
 549static bool sock_map_sk_state_allowed(const struct sock *sk)
 550{
 551        if (sk_is_tcp(sk))
 552                return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
 553        else if (sk_is_udp(sk))
 554                return sk_hashed(sk);
 555
 556        return false;
 557}
 558
 559static int sock_hash_update_common(struct bpf_map *map, void *key,
 560                                   struct sock *sk, u64 flags);
 561
 562int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 563                             u64 flags)
 564{
 565        struct socket *sock;
 566        struct sock *sk;
 567        int ret;
 568        u64 ufd;
 569
 570        if (map->value_size == sizeof(u64))
 571                ufd = *(u64 *)value;
 572        else
 573                ufd = *(u32 *)value;
 574        if (ufd > S32_MAX)
 575                return -EINVAL;
 576
 577        sock = sockfd_lookup(ufd, &ret);
 578        if (!sock)
 579                return ret;
 580        sk = sock->sk;
 581        if (!sk) {
 582                ret = -EINVAL;
 583                goto out;
 584        }
 585        if (!sock_map_sk_is_suitable(sk)) {
 586                ret = -EOPNOTSUPP;
 587                goto out;
 588        }
 589
 590        sock_map_sk_acquire(sk);
 591        if (!sock_map_sk_state_allowed(sk))
 592                ret = -EOPNOTSUPP;
 593        else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 594                ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 595        else
 596                ret = sock_hash_update_common(map, key, sk, flags);
 597        sock_map_sk_release(sk);
 598out:
 599        sockfd_put(sock);
 600        return ret;
 601}
 602
 603static int sock_map_update_elem(struct bpf_map *map, void *key,
 604                                void *value, u64 flags)
 605{
 606        struct sock *sk = (struct sock *)value;
 607        int ret;
 608
 609        if (unlikely(!sk || !sk_fullsock(sk)))
 610                return -EINVAL;
 611
 612        if (!sock_map_sk_is_suitable(sk))
 613                return -EOPNOTSUPP;
 614
 615        local_bh_disable();
 616        bh_lock_sock(sk);
 617        if (!sock_map_sk_state_allowed(sk))
 618                ret = -EOPNOTSUPP;
 619        else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
 620                ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
 621        else
 622                ret = sock_hash_update_common(map, key, sk, flags);
 623        bh_unlock_sock(sk);
 624        local_bh_enable();
 625        return ret;
 626}
 627
 628BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
 629           struct bpf_map *, map, void *, key, u64, flags)
 630{
 631        WARN_ON_ONCE(!rcu_read_lock_held());
 632
 633        if (likely(sock_map_sk_is_suitable(sops->sk) &&
 634                   sock_map_op_okay(sops)))
 635                return sock_map_update_common(map, *(u32 *)key, sops->sk,
 636                                              flags);
 637        return -EOPNOTSUPP;
 638}
 639
 640const struct bpf_func_proto bpf_sock_map_update_proto = {
 641        .func           = bpf_sock_map_update,
 642        .gpl_only       = false,
 643        .pkt_access     = true,
 644        .ret_type       = RET_INTEGER,
 645        .arg1_type      = ARG_PTR_TO_CTX,
 646        .arg2_type      = ARG_CONST_MAP_PTR,
 647        .arg3_type      = ARG_PTR_TO_MAP_KEY,
 648        .arg4_type      = ARG_ANYTHING,
 649};
 650
 651BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 652           struct bpf_map *, map, u32, key, u64, flags)
 653{
 654        struct sock *sk;
 655
 656        if (unlikely(flags & ~(BPF_F_INGRESS)))
 657                return SK_DROP;
 658
 659        sk = __sock_map_lookup_elem(map, key);
 660        if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 661                return SK_DROP;
 662
 663        skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 664        return SK_PASS;
 665}
 666
 667const struct bpf_func_proto bpf_sk_redirect_map_proto = {
 668        .func           = bpf_sk_redirect_map,
 669        .gpl_only       = false,
 670        .ret_type       = RET_INTEGER,
 671        .arg1_type      = ARG_PTR_TO_CTX,
 672        .arg2_type      = ARG_CONST_MAP_PTR,
 673        .arg3_type      = ARG_ANYTHING,
 674        .arg4_type      = ARG_ANYTHING,
 675};
 676
 677BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 678           struct bpf_map *, map, u32, key, u64, flags)
 679{
 680        struct sock *sk;
 681
 682        if (unlikely(flags & ~(BPF_F_INGRESS)))
 683                return SK_DROP;
 684
 685        sk = __sock_map_lookup_elem(map, key);
 686        if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 687                return SK_DROP;
 688
 689        msg->flags = flags;
 690        msg->sk_redir = sk;
 691        return SK_PASS;
 692}
 693
 694const struct bpf_func_proto bpf_msg_redirect_map_proto = {
 695        .func           = bpf_msg_redirect_map,
 696        .gpl_only       = false,
 697        .ret_type       = RET_INTEGER,
 698        .arg1_type      = ARG_PTR_TO_CTX,
 699        .arg2_type      = ARG_CONST_MAP_PTR,
 700        .arg3_type      = ARG_ANYTHING,
 701        .arg4_type      = ARG_ANYTHING,
 702};
 703
 704struct sock_map_seq_info {
 705        struct bpf_map *map;
 706        struct sock *sk;
 707        u32 index;
 708};
 709
 710struct bpf_iter__sockmap {
 711        __bpf_md_ptr(struct bpf_iter_meta *, meta);
 712        __bpf_md_ptr(struct bpf_map *, map);
 713        __bpf_md_ptr(void *, key);
 714        __bpf_md_ptr(struct sock *, sk);
 715};
 716
 717DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
 718                     struct bpf_map *map, void *key,
 719                     struct sock *sk)
 720
 721static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
 722{
 723        if (unlikely(info->index >= info->map->max_entries))
 724                return NULL;
 725
 726        info->sk = __sock_map_lookup_elem(info->map, info->index);
 727
 728        /* can't return sk directly, since that might be NULL */
 729        return info;
 730}
 731
 732static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
 733        __acquires(rcu)
 734{
 735        struct sock_map_seq_info *info = seq->private;
 736
 737        if (*pos == 0)
 738                ++*pos;
 739
 740        /* pairs with sock_map_seq_stop */
 741        rcu_read_lock();
 742        return sock_map_seq_lookup_elem(info);
 743}
 744
 745static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 746        __must_hold(rcu)
 747{
 748        struct sock_map_seq_info *info = seq->private;
 749
 750        ++*pos;
 751        ++info->index;
 752
 753        return sock_map_seq_lookup_elem(info);
 754}
 755
 756static int sock_map_seq_show(struct seq_file *seq, void *v)
 757        __must_hold(rcu)
 758{
 759        struct sock_map_seq_info *info = seq->private;
 760        struct bpf_iter__sockmap ctx = {};
 761        struct bpf_iter_meta meta;
 762        struct bpf_prog *prog;
 763
 764        meta.seq = seq;
 765        prog = bpf_iter_get_info(&meta, !v);
 766        if (!prog)
 767                return 0;
 768
 769        ctx.meta = &meta;
 770        ctx.map = info->map;
 771        if (v) {
 772                ctx.key = &info->index;
 773                ctx.sk = info->sk;
 774        }
 775
 776        return bpf_iter_run_prog(prog, &ctx);
 777}
 778
 779static void sock_map_seq_stop(struct seq_file *seq, void *v)
 780        __releases(rcu)
 781{
 782        if (!v)
 783                (void)sock_map_seq_show(seq, NULL);
 784
 785        /* pairs with sock_map_seq_start */
 786        rcu_read_unlock();
 787}
 788
 789static const struct seq_operations sock_map_seq_ops = {
 790        .start  = sock_map_seq_start,
 791        .next   = sock_map_seq_next,
 792        .stop   = sock_map_seq_stop,
 793        .show   = sock_map_seq_show,
 794};
 795
 796static int sock_map_init_seq_private(void *priv_data,
 797                                     struct bpf_iter_aux_info *aux)
 798{
 799        struct sock_map_seq_info *info = priv_data;
 800
 801        info->map = aux->map;
 802        return 0;
 803}
 804
 805static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
 806        .seq_ops                = &sock_map_seq_ops,
 807        .init_seq_private       = sock_map_init_seq_private,
 808        .seq_priv_size          = sizeof(struct sock_map_seq_info),
 809};
 810
 811static int sock_map_btf_id;
 812const struct bpf_map_ops sock_map_ops = {
 813        .map_meta_equal         = bpf_map_meta_equal,
 814        .map_alloc              = sock_map_alloc,
 815        .map_free               = sock_map_free,
 816        .map_get_next_key       = sock_map_get_next_key,
 817        .map_lookup_elem_sys_only = sock_map_lookup_sys,
 818        .map_update_elem        = sock_map_update_elem,
 819        .map_delete_elem        = sock_map_delete_elem,
 820        .map_lookup_elem        = sock_map_lookup,
 821        .map_release_uref       = sock_map_release_progs,
 822        .map_check_btf          = map_check_no_btf,
 823        .map_btf_name           = "bpf_stab",
 824        .map_btf_id             = &sock_map_btf_id,
 825        .iter_seq_info          = &sock_map_iter_seq_info,
 826};
 827
 828struct bpf_shtab_elem {
 829        struct rcu_head rcu;
 830        u32 hash;
 831        struct sock *sk;
 832        struct hlist_node node;
 833        u8 key[];
 834};
 835
 836struct bpf_shtab_bucket {
 837        struct hlist_head head;
 838        raw_spinlock_t lock;
 839};
 840
 841struct bpf_shtab {
 842        struct bpf_map map;
 843        struct bpf_shtab_bucket *buckets;
 844        u32 buckets_num;
 845        u32 elem_size;
 846        struct sk_psock_progs progs;
 847        atomic_t count;
 848};
 849
 850static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
 851{
 852        return jhash(key, len, 0);
 853}
 854
 855static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
 856                                                        u32 hash)
 857{
 858        return &htab->buckets[hash & (htab->buckets_num - 1)];
 859}
 860
 861static struct bpf_shtab_elem *
 862sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
 863                          u32 key_size)
 864{
 865        struct bpf_shtab_elem *elem;
 866
 867        hlist_for_each_entry_rcu(elem, head, node) {
 868                if (elem->hash == hash &&
 869                    !memcmp(&elem->key, key, key_size))
 870                        return elem;
 871        }
 872
 873        return NULL;
 874}
 875
 876static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
 877{
 878        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 879        u32 key_size = map->key_size, hash;
 880        struct bpf_shtab_bucket *bucket;
 881        struct bpf_shtab_elem *elem;
 882
 883        WARN_ON_ONCE(!rcu_read_lock_held());
 884
 885        hash = sock_hash_bucket_hash(key, key_size);
 886        bucket = sock_hash_select_bucket(htab, hash);
 887        elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 888
 889        return elem ? elem->sk : NULL;
 890}
 891
 892static void sock_hash_free_elem(struct bpf_shtab *htab,
 893                                struct bpf_shtab_elem *elem)
 894{
 895        atomic_dec(&htab->count);
 896        kfree_rcu(elem, rcu);
 897}
 898
 899static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
 900                                       void *link_raw)
 901{
 902        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 903        struct bpf_shtab_elem *elem_probe, *elem = link_raw;
 904        struct bpf_shtab_bucket *bucket;
 905
 906        WARN_ON_ONCE(!rcu_read_lock_held());
 907        bucket = sock_hash_select_bucket(htab, elem->hash);
 908
 909        /* elem may be deleted in parallel from the map, but access here
 910         * is okay since it's going away only after RCU grace period.
 911         * However, we need to check whether it's still present.
 912         */
 913        raw_spin_lock_bh(&bucket->lock);
 914        elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
 915                                               elem->key, map->key_size);
 916        if (elem_probe && elem_probe == elem) {
 917                hlist_del_rcu(&elem->node);
 918                sock_map_unref(elem->sk, elem);
 919                sock_hash_free_elem(htab, elem);
 920        }
 921        raw_spin_unlock_bh(&bucket->lock);
 922}
 923
 924static int sock_hash_delete_elem(struct bpf_map *map, void *key)
 925{
 926        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 927        u32 hash, key_size = map->key_size;
 928        struct bpf_shtab_bucket *bucket;
 929        struct bpf_shtab_elem *elem;
 930        int ret = -ENOENT;
 931
 932        hash = sock_hash_bucket_hash(key, key_size);
 933        bucket = sock_hash_select_bucket(htab, hash);
 934
 935        raw_spin_lock_bh(&bucket->lock);
 936        elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
 937        if (elem) {
 938                hlist_del_rcu(&elem->node);
 939                sock_map_unref(elem->sk, elem);
 940                sock_hash_free_elem(htab, elem);
 941                ret = 0;
 942        }
 943        raw_spin_unlock_bh(&bucket->lock);
 944        return ret;
 945}
 946
 947static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
 948                                                   void *key, u32 key_size,
 949                                                   u32 hash, struct sock *sk,
 950                                                   struct bpf_shtab_elem *old)
 951{
 952        struct bpf_shtab_elem *new;
 953
 954        if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
 955                if (!old) {
 956                        atomic_dec(&htab->count);
 957                        return ERR_PTR(-E2BIG);
 958                }
 959        }
 960
 961        new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
 962                                   GFP_ATOMIC | __GFP_NOWARN,
 963                                   htab->map.numa_node);
 964        if (!new) {
 965                atomic_dec(&htab->count);
 966                return ERR_PTR(-ENOMEM);
 967        }
 968        memcpy(new->key, key, key_size);
 969        new->sk = sk;
 970        new->hash = hash;
 971        return new;
 972}
 973
 974static int sock_hash_update_common(struct bpf_map *map, void *key,
 975                                   struct sock *sk, u64 flags)
 976{
 977        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
 978        u32 key_size = map->key_size, hash;
 979        struct bpf_shtab_elem *elem, *elem_new;
 980        struct bpf_shtab_bucket *bucket;
 981        struct sk_psock_link *link;
 982        struct sk_psock *psock;
 983        int ret;
 984
 985        WARN_ON_ONCE(!rcu_read_lock_held());
 986        if (unlikely(flags > BPF_EXIST))
 987                return -EINVAL;
 988
 989        link = sk_psock_init_link();
 990        if (!link)
 991                return -ENOMEM;
 992
 993        ret = sock_map_link(map, sk);
 994        if (ret < 0)
 995                goto out_free;
 996
 997        psock = sk_psock(sk);
 998        WARN_ON_ONCE(!psock);
 999
1000        hash = sock_hash_bucket_hash(key, key_size);
1001        bucket = sock_hash_select_bucket(htab, hash);
1002
1003        raw_spin_lock_bh(&bucket->lock);
1004        elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1005        if (elem && flags == BPF_NOEXIST) {
1006                ret = -EEXIST;
1007                goto out_unlock;
1008        } else if (!elem && flags == BPF_EXIST) {
1009                ret = -ENOENT;
1010                goto out_unlock;
1011        }
1012
1013        elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1014        if (IS_ERR(elem_new)) {
1015                ret = PTR_ERR(elem_new);
1016                goto out_unlock;
1017        }
1018
1019        sock_map_add_link(psock, link, map, elem_new);
1020        /* Add new element to the head of the list, so that
1021         * concurrent search will find it before old elem.
1022         */
1023        hlist_add_head_rcu(&elem_new->node, &bucket->head);
1024        if (elem) {
1025                hlist_del_rcu(&elem->node);
1026                sock_map_unref(elem->sk, elem);
1027                sock_hash_free_elem(htab, elem);
1028        }
1029        raw_spin_unlock_bh(&bucket->lock);
1030        return 0;
1031out_unlock:
1032        raw_spin_unlock_bh(&bucket->lock);
1033        sk_psock_put(sk, psock);
1034out_free:
1035        sk_psock_free_link(link);
1036        return ret;
1037}
1038
1039static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1040                                  void *key_next)
1041{
1042        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1043        struct bpf_shtab_elem *elem, *elem_next;
1044        u32 hash, key_size = map->key_size;
1045        struct hlist_head *head;
1046        int i = 0;
1047
1048        if (!key)
1049                goto find_first_elem;
1050        hash = sock_hash_bucket_hash(key, key_size);
1051        head = &sock_hash_select_bucket(htab, hash)->head;
1052        elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1053        if (!elem)
1054                goto find_first_elem;
1055
1056        elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1057                                     struct bpf_shtab_elem, node);
1058        if (elem_next) {
1059                memcpy(key_next, elem_next->key, key_size);
1060                return 0;
1061        }
1062
1063        i = hash & (htab->buckets_num - 1);
1064        i++;
1065find_first_elem:
1066        for (; i < htab->buckets_num; i++) {
1067                head = &sock_hash_select_bucket(htab, i)->head;
1068                elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1069                                             struct bpf_shtab_elem, node);
1070                if (elem_next) {
1071                        memcpy(key_next, elem_next->key, key_size);
1072                        return 0;
1073                }
1074        }
1075
1076        return -ENOENT;
1077}
1078
1079static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1080{
1081        struct bpf_shtab *htab;
1082        int i, err;
1083
1084        if (!capable(CAP_NET_ADMIN))
1085                return ERR_PTR(-EPERM);
1086        if (attr->max_entries == 0 ||
1087            attr->key_size    == 0 ||
1088            (attr->value_size != sizeof(u32) &&
1089             attr->value_size != sizeof(u64)) ||
1090            attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1091                return ERR_PTR(-EINVAL);
1092        if (attr->key_size > MAX_BPF_STACK)
1093                return ERR_PTR(-E2BIG);
1094
1095        htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
1096        if (!htab)
1097                return ERR_PTR(-ENOMEM);
1098
1099        bpf_map_init_from_attr(&htab->map, attr);
1100
1101        htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1102        htab->elem_size = sizeof(struct bpf_shtab_elem) +
1103                          round_up(htab->map.key_size, 8);
1104        if (htab->buckets_num == 0 ||
1105            htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1106                err = -EINVAL;
1107                goto free_htab;
1108        }
1109
1110        htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1111                                           sizeof(struct bpf_shtab_bucket),
1112                                           htab->map.numa_node);
1113        if (!htab->buckets) {
1114                err = -ENOMEM;
1115                goto free_htab;
1116        }
1117
1118        for (i = 0; i < htab->buckets_num; i++) {
1119                INIT_HLIST_HEAD(&htab->buckets[i].head);
1120                raw_spin_lock_init(&htab->buckets[i].lock);
1121        }
1122
1123        return &htab->map;
1124free_htab:
1125        kfree(htab);
1126        return ERR_PTR(err);
1127}
1128
1129static void sock_hash_free(struct bpf_map *map)
1130{
1131        struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1132        struct bpf_shtab_bucket *bucket;
1133        struct hlist_head unlink_list;
1134        struct bpf_shtab_elem *elem;
1135        struct hlist_node *node;
1136        int i;
1137
1138        /* After the sync no updates or deletes will be in-flight so it
1139         * is safe to walk map and remove entries without risking a race
1140         * in EEXIST update case.
1141         */
1142        synchronize_rcu();
1143        for (i = 0; i < htab->buckets_num; i++) {
1144                bucket = sock_hash_select_bucket(htab, i);
1145
1146                /* We are racing with sock_hash_delete_from_link to
1147                 * enter the spin-lock critical section. Every socket on
1148                 * the list is still linked to sockhash. Since link
1149                 * exists, psock exists and holds a ref to socket. That
1150                 * lets us to grab a socket ref too.
1151                 */
1152                raw_spin_lock_bh(&bucket->lock);
1153                hlist_for_each_entry(elem, &bucket->head, node)
1154                        sock_hold(elem->sk);
1155                hlist_move_list(&bucket->head, &unlink_list);
1156                raw_spin_unlock_bh(&bucket->lock);
1157
1158                /* Process removed entries out of atomic context to
1159                 * block for socket lock before deleting the psock's
1160                 * link to sockhash.
1161                 */
1162                hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1163                        hlist_del(&elem->node);
1164                        lock_sock(elem->sk);
1165                        rcu_read_lock();
1166                        sock_map_unref(elem->sk, elem);
1167                        rcu_read_unlock();
1168                        release_sock(elem->sk);
1169                        sock_put(elem->sk);
1170                        sock_hash_free_elem(htab, elem);
1171                }
1172        }
1173
1174        /* wait for psock readers accessing its map link */
1175        synchronize_rcu();
1176
1177        bpf_map_area_free(htab->buckets);
1178        kfree(htab);
1179}
1180
1181static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1182{
1183        struct sock *sk;
1184
1185        if (map->value_size != sizeof(u64))
1186                return ERR_PTR(-ENOSPC);
1187
1188        sk = __sock_hash_lookup_elem(map, key);
1189        if (!sk)
1190                return ERR_PTR(-ENOENT);
1191
1192        __sock_gen_cookie(sk);
1193        return &sk->sk_cookie;
1194}
1195
1196static void *sock_hash_lookup(struct bpf_map *map, void *key)
1197{
1198        struct sock *sk;
1199
1200        sk = __sock_hash_lookup_elem(map, key);
1201        if (!sk)
1202                return NULL;
1203        if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1204                return NULL;
1205        return sk;
1206}
1207
1208static void sock_hash_release_progs(struct bpf_map *map)
1209{
1210        psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1211}
1212
1213BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1214           struct bpf_map *, map, void *, key, u64, flags)
1215{
1216        WARN_ON_ONCE(!rcu_read_lock_held());
1217
1218        if (likely(sock_map_sk_is_suitable(sops->sk) &&
1219                   sock_map_op_okay(sops)))
1220                return sock_hash_update_common(map, key, sops->sk, flags);
1221        return -EOPNOTSUPP;
1222}
1223
1224const struct bpf_func_proto bpf_sock_hash_update_proto = {
1225        .func           = bpf_sock_hash_update,
1226        .gpl_only       = false,
1227        .pkt_access     = true,
1228        .ret_type       = RET_INTEGER,
1229        .arg1_type      = ARG_PTR_TO_CTX,
1230        .arg2_type      = ARG_CONST_MAP_PTR,
1231        .arg3_type      = ARG_PTR_TO_MAP_KEY,
1232        .arg4_type      = ARG_ANYTHING,
1233};
1234
1235BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1236           struct bpf_map *, map, void *, key, u64, flags)
1237{
1238        struct sock *sk;
1239
1240        if (unlikely(flags & ~(BPF_F_INGRESS)))
1241                return SK_DROP;
1242
1243        sk = __sock_hash_lookup_elem(map, key);
1244        if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1245                return SK_DROP;
1246
1247        skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1248        return SK_PASS;
1249}
1250
1251const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1252        .func           = bpf_sk_redirect_hash,
1253        .gpl_only       = false,
1254        .ret_type       = RET_INTEGER,
1255        .arg1_type      = ARG_PTR_TO_CTX,
1256        .arg2_type      = ARG_CONST_MAP_PTR,
1257        .arg3_type      = ARG_PTR_TO_MAP_KEY,
1258        .arg4_type      = ARG_ANYTHING,
1259};
1260
1261BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1262           struct bpf_map *, map, void *, key, u64, flags)
1263{
1264        struct sock *sk;
1265
1266        if (unlikely(flags & ~(BPF_F_INGRESS)))
1267                return SK_DROP;
1268
1269        sk = __sock_hash_lookup_elem(map, key);
1270        if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1271                return SK_DROP;
1272
1273        msg->flags = flags;
1274        msg->sk_redir = sk;
1275        return SK_PASS;
1276}
1277
1278const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1279        .func           = bpf_msg_redirect_hash,
1280        .gpl_only       = false,
1281        .ret_type       = RET_INTEGER,
1282        .arg1_type      = ARG_PTR_TO_CTX,
1283        .arg2_type      = ARG_CONST_MAP_PTR,
1284        .arg3_type      = ARG_PTR_TO_MAP_KEY,
1285        .arg4_type      = ARG_ANYTHING,
1286};
1287
1288struct sock_hash_seq_info {
1289        struct bpf_map *map;
1290        struct bpf_shtab *htab;
1291        u32 bucket_id;
1292};
1293
1294static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1295                                     struct bpf_shtab_elem *prev_elem)
1296{
1297        const struct bpf_shtab *htab = info->htab;
1298        struct bpf_shtab_bucket *bucket;
1299        struct bpf_shtab_elem *elem;
1300        struct hlist_node *node;
1301
1302        /* try to find next elem in the same bucket */
1303        if (prev_elem) {
1304                node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1305                elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1306                if (elem)
1307                        return elem;
1308
1309                /* no more elements, continue in the next bucket */
1310                info->bucket_id++;
1311        }
1312
1313        for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1314                bucket = &htab->buckets[info->bucket_id];
1315                node = rcu_dereference(hlist_first_rcu(&bucket->head));
1316                elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1317                if (elem)
1318                        return elem;
1319        }
1320
1321        return NULL;
1322}
1323
1324static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1325        __acquires(rcu)
1326{
1327        struct sock_hash_seq_info *info = seq->private;
1328
1329        if (*pos == 0)
1330                ++*pos;
1331
1332        /* pairs with sock_hash_seq_stop */
1333        rcu_read_lock();
1334        return sock_hash_seq_find_next(info, NULL);
1335}
1336
1337static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1338        __must_hold(rcu)
1339{
1340        struct sock_hash_seq_info *info = seq->private;
1341
1342        ++*pos;
1343        return sock_hash_seq_find_next(info, v);
1344}
1345
1346static int sock_hash_seq_show(struct seq_file *seq, void *v)
1347        __must_hold(rcu)
1348{
1349        struct sock_hash_seq_info *info = seq->private;
1350        struct bpf_iter__sockmap ctx = {};
1351        struct bpf_shtab_elem *elem = v;
1352        struct bpf_iter_meta meta;
1353        struct bpf_prog *prog;
1354
1355        meta.seq = seq;
1356        prog = bpf_iter_get_info(&meta, !elem);
1357        if (!prog)
1358                return 0;
1359
1360        ctx.meta = &meta;
1361        ctx.map = info->map;
1362        if (elem) {
1363                ctx.key = elem->key;
1364                ctx.sk = elem->sk;
1365        }
1366
1367        return bpf_iter_run_prog(prog, &ctx);
1368}
1369
1370static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1371        __releases(rcu)
1372{
1373        if (!v)
1374                (void)sock_hash_seq_show(seq, NULL);
1375
1376        /* pairs with sock_hash_seq_start */
1377        rcu_read_unlock();
1378}
1379
1380static const struct seq_operations sock_hash_seq_ops = {
1381        .start  = sock_hash_seq_start,
1382        .next   = sock_hash_seq_next,
1383        .stop   = sock_hash_seq_stop,
1384        .show   = sock_hash_seq_show,
1385};
1386
1387static int sock_hash_init_seq_private(void *priv_data,
1388                                     struct bpf_iter_aux_info *aux)
1389{
1390        struct sock_hash_seq_info *info = priv_data;
1391
1392        info->map = aux->map;
1393        info->htab = container_of(aux->map, struct bpf_shtab, map);
1394        return 0;
1395}
1396
1397static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1398        .seq_ops                = &sock_hash_seq_ops,
1399        .init_seq_private       = sock_hash_init_seq_private,
1400        .seq_priv_size          = sizeof(struct sock_hash_seq_info),
1401};
1402
1403static int sock_hash_map_btf_id;
1404const struct bpf_map_ops sock_hash_ops = {
1405        .map_meta_equal         = bpf_map_meta_equal,
1406        .map_alloc              = sock_hash_alloc,
1407        .map_free               = sock_hash_free,
1408        .map_get_next_key       = sock_hash_get_next_key,
1409        .map_update_elem        = sock_map_update_elem,
1410        .map_delete_elem        = sock_hash_delete_elem,
1411        .map_lookup_elem        = sock_hash_lookup,
1412        .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1413        .map_release_uref       = sock_hash_release_progs,
1414        .map_check_btf          = map_check_no_btf,
1415        .map_btf_name           = "bpf_shtab",
1416        .map_btf_id             = &sock_hash_map_btf_id,
1417        .iter_seq_info          = &sock_hash_iter_seq_info,
1418};
1419
1420static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1421{
1422        switch (map->map_type) {
1423        case BPF_MAP_TYPE_SOCKMAP:
1424                return &container_of(map, struct bpf_stab, map)->progs;
1425        case BPF_MAP_TYPE_SOCKHASH:
1426                return &container_of(map, struct bpf_shtab, map)->progs;
1427        default:
1428                break;
1429        }
1430
1431        return NULL;
1432}
1433
1434static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1435                                struct bpf_prog *old, u32 which)
1436{
1437        struct sk_psock_progs *progs = sock_map_progs(map);
1438        struct bpf_prog **pprog;
1439
1440        if (!progs)
1441                return -EOPNOTSUPP;
1442
1443        switch (which) {
1444        case BPF_SK_MSG_VERDICT:
1445                pprog = &progs->msg_parser;
1446                break;
1447#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1448        case BPF_SK_SKB_STREAM_PARSER:
1449                pprog = &progs->stream_parser;
1450                break;
1451#endif
1452        case BPF_SK_SKB_STREAM_VERDICT:
1453                if (progs->skb_verdict)
1454                        return -EBUSY;
1455                pprog = &progs->stream_verdict;
1456                break;
1457        case BPF_SK_SKB_VERDICT:
1458                if (progs->stream_verdict)
1459                        return -EBUSY;
1460                pprog = &progs->skb_verdict;
1461                break;
1462        default:
1463                return -EOPNOTSUPP;
1464        }
1465
1466        if (old)
1467                return psock_replace_prog(pprog, prog, old);
1468
1469        psock_set_prog(pprog, prog);
1470        return 0;
1471}
1472
1473static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1474{
1475        switch (link->map->map_type) {
1476        case BPF_MAP_TYPE_SOCKMAP:
1477                return sock_map_delete_from_link(link->map, sk,
1478                                                 link->link_raw);
1479        case BPF_MAP_TYPE_SOCKHASH:
1480                return sock_hash_delete_from_link(link->map, sk,
1481                                                  link->link_raw);
1482        default:
1483                break;
1484        }
1485}
1486
1487static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1488{
1489        struct sk_psock_link *link;
1490
1491        while ((link = sk_psock_link_pop(psock))) {
1492                sock_map_unlink(sk, link);
1493                sk_psock_free_link(link);
1494        }
1495}
1496
1497void sock_map_unhash(struct sock *sk)
1498{
1499        void (*saved_unhash)(struct sock *sk);
1500        struct sk_psock *psock;
1501
1502        rcu_read_lock();
1503        psock = sk_psock(sk);
1504        if (unlikely(!psock)) {
1505                rcu_read_unlock();
1506                if (sk->sk_prot->unhash)
1507                        sk->sk_prot->unhash(sk);
1508                return;
1509        }
1510
1511        saved_unhash = psock->saved_unhash;
1512        sock_map_remove_links(sk, psock);
1513        rcu_read_unlock();
1514        saved_unhash(sk);
1515}
1516
1517void sock_map_close(struct sock *sk, long timeout)
1518{
1519        void (*saved_close)(struct sock *sk, long timeout);
1520        struct sk_psock *psock;
1521
1522        lock_sock(sk);
1523        rcu_read_lock();
1524        psock = sk_psock_get(sk);
1525        if (unlikely(!psock)) {
1526                rcu_read_unlock();
1527                release_sock(sk);
1528                return sk->sk_prot->close(sk, timeout);
1529        }
1530
1531        saved_close = psock->saved_close;
1532        sock_map_remove_links(sk, psock);
1533        rcu_read_unlock();
1534        sk_psock_stop(psock, true);
1535        sk_psock_put(sk, psock);
1536        release_sock(sk);
1537        saved_close(sk, timeout);
1538}
1539
1540static int sock_map_iter_attach_target(struct bpf_prog *prog,
1541                                       union bpf_iter_link_info *linfo,
1542                                       struct bpf_iter_aux_info *aux)
1543{
1544        struct bpf_map *map;
1545        int err = -EINVAL;
1546
1547        if (!linfo->map.map_fd)
1548                return -EBADF;
1549
1550        map = bpf_map_get_with_uref(linfo->map.map_fd);
1551        if (IS_ERR(map))
1552                return PTR_ERR(map);
1553
1554        if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1555            map->map_type != BPF_MAP_TYPE_SOCKHASH)
1556                goto put_map;
1557
1558        if (prog->aux->max_rdonly_access > map->key_size) {
1559                err = -EACCES;
1560                goto put_map;
1561        }
1562
1563        aux->map = map;
1564        return 0;
1565
1566put_map:
1567        bpf_map_put_with_uref(map);
1568        return err;
1569}
1570
1571static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1572{
1573        bpf_map_put_with_uref(aux->map);
1574}
1575
1576static struct bpf_iter_reg sock_map_iter_reg = {
1577        .target                 = "sockmap",
1578        .attach_target          = sock_map_iter_attach_target,
1579        .detach_target          = sock_map_iter_detach_target,
1580        .show_fdinfo            = bpf_iter_map_show_fdinfo,
1581        .fill_link_info         = bpf_iter_map_fill_link_info,
1582        .ctx_arg_info_size      = 2,
1583        .ctx_arg_info           = {
1584                { offsetof(struct bpf_iter__sockmap, key),
1585                  PTR_TO_RDONLY_BUF_OR_NULL },
1586                { offsetof(struct bpf_iter__sockmap, sk),
1587                  PTR_TO_BTF_ID_OR_NULL },
1588        },
1589};
1590
1591static int __init bpf_sockmap_iter_init(void)
1592{
1593        sock_map_iter_reg.ctx_arg_info[1].btf_id =
1594                btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1595        return bpf_iter_reg_target(&sock_map_iter_reg);
1596}
1597late_initcall(bpf_sockmap_iter_init);
1598