1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ 3 4 #include <linux/bpf.h> 5 #include <linux/btf_ids.h> 6 #include <linux/filter.h> 7 #include <linux/errno.h> 8 #include <linux/file.h> 9 #include <linux/net.h> 10 #include <linux/workqueue.h> 11 #include <linux/skmsg.h> 12 #include <linux/list.h> 13 #include <linux/jhash.h> 14 #include <linux/sock_diag.h> 15 #include <net/udp.h> 16 17 struct bpf_stab { 18 struct bpf_map map; 19 struct sock **sks; 20 struct sk_psock_progs progs; 21 raw_spinlock_t lock; 22 }; 23 24 #define SOCK_CREATE_FLAG_MASK \ 25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) 26 27 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 28 struct bpf_prog *old, u32 which); 29 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map); 30 31 static struct bpf_map *sock_map_alloc(union bpf_attr *attr) 32 { 33 struct bpf_stab *stab; 34 35 if (!capable(CAP_NET_ADMIN)) 36 return ERR_PTR(-EPERM); 37 if (attr->max_entries == 0 || 38 attr->key_size != 4 || 39 (attr->value_size != sizeof(u32) && 40 attr->value_size != sizeof(u64)) || 41 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 42 return ERR_PTR(-EINVAL); 43 44 stab = kzalloc(sizeof(*stab), GFP_USER | __GFP_ACCOUNT); 45 if (!stab) 46 return ERR_PTR(-ENOMEM); 47 48 bpf_map_init_from_attr(&stab->map, attr); 49 raw_spin_lock_init(&stab->lock); 50 51 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries * 52 sizeof(struct sock *), 53 stab->map.numa_node); 54 if (!stab->sks) { 55 kfree(stab); 56 return ERR_PTR(-ENOMEM); 57 } 58 59 return &stab->map; 60 } 61 62 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) 63 { 64 u32 ufd = attr->target_fd; 65 struct bpf_map *map; 66 struct fd f; 67 int ret; 68 69 if (attr->attach_flags || attr->replace_bpf_fd) 70 return -EINVAL; 71 72 f = fdget(ufd); 73 map = __bpf_map_get(f); 74 if (IS_ERR(map)) 75 return PTR_ERR(map); 76 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type); 77 fdput(f); 78 return ret; 79 } 80 81 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) 82 { 83 u32 ufd = attr->target_fd; 84 struct bpf_prog *prog; 85 struct bpf_map *map; 86 struct fd f; 87 int ret; 88 89 if (attr->attach_flags || attr->replace_bpf_fd) 90 return -EINVAL; 91 92 f = fdget(ufd); 93 map = __bpf_map_get(f); 94 if (IS_ERR(map)) 95 return PTR_ERR(map); 96 97 prog = bpf_prog_get(attr->attach_bpf_fd); 98 if (IS_ERR(prog)) { 99 ret = PTR_ERR(prog); 100 goto put_map; 101 } 102 103 if (prog->type != ptype) { 104 ret = -EINVAL; 105 goto put_prog; 106 } 107 108 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type); 109 put_prog: 110 bpf_prog_put(prog); 111 put_map: 112 fdput(f); 113 return ret; 114 } 115 116 static void sock_map_sk_acquire(struct sock *sk) 117 __acquires(&sk->sk_lock.slock) 118 { 119 lock_sock(sk); 120 preempt_disable(); 121 rcu_read_lock(); 122 } 123 124 static void sock_map_sk_release(struct sock *sk) 125 __releases(&sk->sk_lock.slock) 126 { 127 rcu_read_unlock(); 128 preempt_enable(); 129 release_sock(sk); 130 } 131 132 static void sock_map_add_link(struct sk_psock *psock, 133 struct sk_psock_link *link, 134 struct bpf_map *map, void *link_raw) 135 { 136 link->link_raw = link_raw; 137 link->map = map; 138 spin_lock_bh(&psock->link_lock); 139 list_add_tail(&link->list, &psock->link); 140 spin_unlock_bh(&psock->link_lock); 141 } 142 143 static void sock_map_del_link(struct sock *sk, 144 struct sk_psock *psock, void *link_raw) 145 { 146 bool strp_stop = false, verdict_stop = false; 147 struct sk_psock_link *link, *tmp; 148 149 spin_lock_bh(&psock->link_lock); 150 list_for_each_entry_safe(link, tmp, &psock->link, list) { 151 if (link->link_raw == link_raw) { 152 struct bpf_map *map = link->map; 153 struct bpf_stab *stab = container_of(map, struct bpf_stab, 154 map); 155 if (psock->saved_data_ready && stab->progs.stream_parser) 156 strp_stop = true; 157 if (psock->saved_data_ready && stab->progs.stream_verdict) 158 verdict_stop = true; 159 if (psock->saved_data_ready && stab->progs.skb_verdict) 160 verdict_stop = true; 161 list_del(&link->list); 162 sk_psock_free_link(link); 163 } 164 } 165 spin_unlock_bh(&psock->link_lock); 166 if (strp_stop || verdict_stop) { 167 write_lock_bh(&sk->sk_callback_lock); 168 if (strp_stop) 169 sk_psock_stop_strp(sk, psock); 170 else 171 sk_psock_stop_verdict(sk, psock); 172 write_unlock_bh(&sk->sk_callback_lock); 173 } 174 } 175 176 static void sock_map_unref(struct sock *sk, void *link_raw) 177 { 178 struct sk_psock *psock = sk_psock(sk); 179 180 if (likely(psock)) { 181 sock_map_del_link(sk, psock, link_raw); 182 sk_psock_put(sk, psock); 183 } 184 } 185 186 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock) 187 { 188 if (!sk->sk_prot->psock_update_sk_prot) 189 return -EINVAL; 190 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot; 191 return sk->sk_prot->psock_update_sk_prot(sk, psock, false); 192 } 193 194 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk) 195 { 196 struct sk_psock *psock; 197 198 rcu_read_lock(); 199 psock = sk_psock(sk); 200 if (psock) { 201 if (sk->sk_prot->close != sock_map_close) { 202 psock = ERR_PTR(-EBUSY); 203 goto out; 204 } 205 206 if (!refcount_inc_not_zero(&psock->refcnt)) 207 psock = ERR_PTR(-EBUSY); 208 } 209 out: 210 rcu_read_unlock(); 211 return psock; 212 } 213 214 static bool sock_map_redirect_allowed(const struct sock *sk); 215 216 static 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 } 266 267 no_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; 317 out_unlock_drop: 318 write_unlock_bh(&sk->sk_callback_lock); 319 out_drop: 320 sk_psock_put(sk, psock); 321 out_progs: 322 if (skb_verdict) 323 bpf_prog_put(skb_verdict); 324 out_put_msg_parser: 325 if (msg_parser) 326 bpf_prog_put(msg_parser); 327 out_put_stream_parser: 328 if (stream_parser) 329 bpf_prog_put(stream_parser); 330 out_put_stream_verdict: 331 if (stream_verdict) 332 bpf_prog_put(stream_verdict); 333 return ret; 334 } 335 336 static 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 } 366 367 static void sock_map_release_progs(struct bpf_map *map) 368 { 369 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); 370 } 371 372 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) 373 { 374 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 375 376 WARN_ON_ONCE(!rcu_read_lock_held()); 377 378 if (unlikely(key >= map->max_entries)) 379 return NULL; 380 return READ_ONCE(stab->sks[key]); 381 } 382 383 static void *sock_map_lookup(struct bpf_map *map, void *key) 384 { 385 struct sock *sk; 386 387 sk = __sock_map_lookup_elem(map, *(u32 *)key); 388 if (!sk) 389 return NULL; 390 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) 391 return NULL; 392 return sk; 393 } 394 395 static void *sock_map_lookup_sys(struct bpf_map *map, void *key) 396 { 397 struct sock *sk; 398 399 if (map->value_size != sizeof(u64)) 400 return ERR_PTR(-ENOSPC); 401 402 sk = __sock_map_lookup_elem(map, *(u32 *)key); 403 if (!sk) 404 return ERR_PTR(-ENOENT); 405 406 __sock_gen_cookie(sk); 407 return &sk->sk_cookie; 408 } 409 410 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, 411 struct sock **psk) 412 { 413 struct sock *sk; 414 int err = 0; 415 416 raw_spin_lock_bh(&stab->lock); 417 sk = *psk; 418 if (!sk_test || sk_test == sk) 419 sk = xchg(psk, NULL); 420 421 if (likely(sk)) 422 sock_map_unref(sk, psk); 423 else 424 err = -EINVAL; 425 426 raw_spin_unlock_bh(&stab->lock); 427 return err; 428 } 429 430 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, 431 void *link_raw) 432 { 433 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 434 435 __sock_map_delete(stab, sk, link_raw); 436 } 437 438 static int sock_map_delete_elem(struct bpf_map *map, void *key) 439 { 440 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 441 u32 i = *(u32 *)key; 442 struct sock **psk; 443 444 if (unlikely(i >= map->max_entries)) 445 return -EINVAL; 446 447 psk = &stab->sks[i]; 448 return __sock_map_delete(stab, NULL, psk); 449 } 450 451 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next) 452 { 453 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 454 u32 i = key ? *(u32 *)key : U32_MAX; 455 u32 *key_next = next; 456 457 if (i == stab->map.max_entries - 1) 458 return -ENOENT; 459 if (i >= stab->map.max_entries) 460 *key_next = 0; 461 else 462 *key_next = i + 1; 463 return 0; 464 } 465 466 static int sock_map_update_common(struct bpf_map *map, u32 idx, 467 struct sock *sk, u64 flags) 468 { 469 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 470 struct sk_psock_link *link; 471 struct sk_psock *psock; 472 struct sock *osk; 473 int ret; 474 475 WARN_ON_ONCE(!rcu_read_lock_held()); 476 if (unlikely(flags > BPF_EXIST)) 477 return -EINVAL; 478 if (unlikely(idx >= map->max_entries)) 479 return -E2BIG; 480 481 link = sk_psock_init_link(); 482 if (!link) 483 return -ENOMEM; 484 485 ret = sock_map_link(map, sk); 486 if (ret < 0) 487 goto out_free; 488 489 psock = sk_psock(sk); 490 WARN_ON_ONCE(!psock); 491 492 raw_spin_lock_bh(&stab->lock); 493 osk = stab->sks[idx]; 494 if (osk && flags == BPF_NOEXIST) { 495 ret = -EEXIST; 496 goto out_unlock; 497 } else if (!osk && flags == BPF_EXIST) { 498 ret = -ENOENT; 499 goto out_unlock; 500 } 501 502 sock_map_add_link(psock, link, map, &stab->sks[idx]); 503 stab->sks[idx] = sk; 504 if (osk) 505 sock_map_unref(osk, &stab->sks[idx]); 506 raw_spin_unlock_bh(&stab->lock); 507 return 0; 508 out_unlock: 509 raw_spin_unlock_bh(&stab->lock); 510 if (psock) 511 sk_psock_put(sk, psock); 512 out_free: 513 sk_psock_free_link(link); 514 return ret; 515 } 516 517 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops) 518 { 519 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || 520 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB || 521 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB; 522 } 523 524 static bool sk_is_tcp(const struct sock *sk) 525 { 526 return sk->sk_type == SOCK_STREAM && 527 sk->sk_protocol == IPPROTO_TCP; 528 } 529 530 static bool sk_is_udp(const struct sock *sk) 531 { 532 return sk->sk_type == SOCK_DGRAM && 533 sk->sk_protocol == IPPROTO_UDP; 534 } 535 536 static 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 } 543 544 static bool sock_map_sk_is_suitable(const struct sock *sk) 545 { 546 return !!sk->sk_prot->psock_update_sk_prot; 547 } 548 549 static 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 } 558 559 static int sock_hash_update_common(struct bpf_map *map, void *key, 560 struct sock *sk, u64 flags); 561 562 int 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); 598 out: 599 sockfd_put(sock); 600 return ret; 601 } 602 603 static 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 } 627 628 BPF_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 } 639 640 const 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 }; 650 651 BPF_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 } 666 667 const 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 }; 676 677 BPF_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 } 693 694 const 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 }; 703 704 struct sock_map_seq_info { 705 struct bpf_map *map; 706 struct sock *sk; 707 u32 index; 708 }; 709 710 struct 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 }; 716 717 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta, 718 struct bpf_map *map, void *key, 719 struct sock *sk) 720 721 static 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 } 731 732 static 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 } 744 745 static 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 } 755 756 static 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 } 778 779 static 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 } 788 789 static 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 }; 795 796 static 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 } 804 805 static 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 }; 810 811 static int sock_map_btf_id; 812 const 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 }; 827 828 struct bpf_shtab_elem { 829 struct rcu_head rcu; 830 u32 hash; 831 struct sock *sk; 832 struct hlist_node node; 833 u8 key[]; 834 }; 835 836 struct bpf_shtab_bucket { 837 struct hlist_head head; 838 raw_spinlock_t lock; 839 }; 840 841 struct 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 }; 849 850 static inline u32 sock_hash_bucket_hash(const void *key, u32 len) 851 { 852 return jhash(key, len, 0); 853 } 854 855 static 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 } 860 861 static struct bpf_shtab_elem * 862 sock_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 } 875 876 static 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 } 891 892 static 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 } 898 899 static 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 } 923 924 static 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 } 946 947 static 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 } 973 974 static 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; 1031 out_unlock: 1032 raw_spin_unlock_bh(&bucket->lock); 1033 sk_psock_put(sk, psock); 1034 out_free: 1035 sk_psock_free_link(link); 1036 return ret; 1037 } 1038 1039 static 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++; 1065 find_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 1079 static 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; 1124 free_htab: 1125 kfree(htab); 1126 return ERR_PTR(err); 1127 } 1128 1129 static 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 1181 static 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 1196 static 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 1208 static void sock_hash_release_progs(struct bpf_map *map) 1209 { 1210 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs); 1211 } 1212 1213 BPF_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 1224 const 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 1235 BPF_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 1251 const 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 1261 BPF_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 1278 const 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 1288 struct sock_hash_seq_info { 1289 struct bpf_map *map; 1290 struct bpf_shtab *htab; 1291 u32 bucket_id; 1292 }; 1293 1294 static 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 1324 static 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 1337 static 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 1346 static 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 1370 static 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 1380 static 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 1387 static 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 1397 static 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 1403 static int sock_hash_map_btf_id; 1404 const 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 1420 static 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 1434 static 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 1473 static 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 1487 static 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 1497 void 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 1517 void 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 1540 static 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 1566 put_map: 1567 bpf_map_put_with_uref(map); 1568 return err; 1569 } 1570 1571 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux) 1572 { 1573 bpf_map_put_with_uref(aux->map); 1574 } 1575 1576 static 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 1591 static 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 } 1597 late_initcall(bpf_sockmap_iter_init); 1598