1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ 3 4 #include <linux/bpf.h> 5 #include <linux/btf_ids.h> 6 #include <linux/filter.h> 7 #include <linux/errno.h> 8 #include <linux/file.h> 9 #include <linux/net.h> 10 #include <linux/workqueue.h> 11 #include <linux/skmsg.h> 12 #include <linux/list.h> 13 #include <linux/jhash.h> 14 #include <linux/sock_diag.h> 15 #include <net/udp.h> 16 17 struct bpf_stab { 18 struct bpf_map map; 19 struct sock **sks; 20 struct sk_psock_progs progs; 21 spinlock_t lock; 22 }; 23 24 #define SOCK_CREATE_FLAG_MASK \ 25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) 26 27 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 28 struct bpf_prog *old, u32 which); 29 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map); 30 31 static struct bpf_map *sock_map_alloc(union bpf_attr *attr) 32 { 33 struct bpf_stab *stab; 34 35 if (attr->max_entries == 0 || 36 attr->key_size != 4 || 37 (attr->value_size != sizeof(u32) && 38 attr->value_size != sizeof(u64)) || 39 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 40 return ERR_PTR(-EINVAL); 41 42 stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE); 43 if (!stab) 44 return ERR_PTR(-ENOMEM); 45 46 bpf_map_init_from_attr(&stab->map, attr); 47 spin_lock_init(&stab->lock); 48 49 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries * 50 sizeof(struct sock *), 51 stab->map.numa_node); 52 if (!stab->sks) { 53 bpf_map_area_free(stab); 54 return ERR_PTR(-ENOMEM); 55 } 56 57 return &stab->map; 58 } 59 60 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) 61 { 62 u32 ufd = attr->target_fd; 63 struct bpf_map *map; 64 struct fd f; 65 int ret; 66 67 if (attr->attach_flags || attr->replace_bpf_fd) 68 return -EINVAL; 69 70 f = fdget(ufd); 71 map = __bpf_map_get(f); 72 if (IS_ERR(map)) 73 return PTR_ERR(map); 74 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type); 75 fdput(f); 76 return ret; 77 } 78 79 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) 80 { 81 u32 ufd = attr->target_fd; 82 struct bpf_prog *prog; 83 struct bpf_map *map; 84 struct fd f; 85 int ret; 86 87 if (attr->attach_flags || attr->replace_bpf_fd) 88 return -EINVAL; 89 90 f = fdget(ufd); 91 map = __bpf_map_get(f); 92 if (IS_ERR(map)) 93 return PTR_ERR(map); 94 95 prog = bpf_prog_get(attr->attach_bpf_fd); 96 if (IS_ERR(prog)) { 97 ret = PTR_ERR(prog); 98 goto put_map; 99 } 100 101 if (prog->type != ptype) { 102 ret = -EINVAL; 103 goto put_prog; 104 } 105 106 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type); 107 put_prog: 108 bpf_prog_put(prog); 109 put_map: 110 fdput(f); 111 return ret; 112 } 113 114 static void sock_map_sk_acquire(struct sock *sk) 115 __acquires(&sk->sk_lock.slock) 116 { 117 lock_sock(sk); 118 rcu_read_lock(); 119 } 120 121 static void sock_map_sk_release(struct sock *sk) 122 __releases(&sk->sk_lock.slock) 123 { 124 rcu_read_unlock(); 125 release_sock(sk); 126 } 127 128 static void sock_map_add_link(struct sk_psock *psock, 129 struct sk_psock_link *link, 130 struct bpf_map *map, void *link_raw) 131 { 132 link->link_raw = link_raw; 133 link->map = map; 134 spin_lock_bh(&psock->link_lock); 135 list_add_tail(&link->list, &psock->link); 136 spin_unlock_bh(&psock->link_lock); 137 } 138 139 static void sock_map_del_link(struct sock *sk, 140 struct sk_psock *psock, void *link_raw) 141 { 142 bool strp_stop = false, verdict_stop = false; 143 struct sk_psock_link *link, *tmp; 144 145 spin_lock_bh(&psock->link_lock); 146 list_for_each_entry_safe(link, tmp, &psock->link, list) { 147 if (link->link_raw == link_raw) { 148 struct bpf_map *map = link->map; 149 struct sk_psock_progs *progs = sock_map_progs(map); 150 151 if (psock->saved_data_ready && progs->stream_parser) 152 strp_stop = true; 153 if (psock->saved_data_ready && progs->stream_verdict) 154 verdict_stop = true; 155 if (psock->saved_data_ready && progs->skb_verdict) 156 verdict_stop = true; 157 list_del(&link->list); 158 sk_psock_free_link(link); 159 } 160 } 161 spin_unlock_bh(&psock->link_lock); 162 if (strp_stop || verdict_stop) { 163 write_lock_bh(&sk->sk_callback_lock); 164 if (strp_stop) 165 sk_psock_stop_strp(sk, psock); 166 if (verdict_stop) 167 sk_psock_stop_verdict(sk, psock); 168 169 if (psock->psock_update_sk_prot) 170 psock->psock_update_sk_prot(sk, psock, false); 171 write_unlock_bh(&sk->sk_callback_lock); 172 } 173 } 174 175 static void sock_map_unref(struct sock *sk, void *link_raw) 176 { 177 struct sk_psock *psock = sk_psock(sk); 178 179 if (likely(psock)) { 180 sock_map_del_link(sk, psock, link_raw); 181 sk_psock_put(sk, psock); 182 } 183 } 184 185 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock) 186 { 187 if (!sk->sk_prot->psock_update_sk_prot) 188 return -EINVAL; 189 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot; 190 return sk->sk_prot->psock_update_sk_prot(sk, psock, false); 191 } 192 193 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk) 194 { 195 struct sk_psock *psock; 196 197 rcu_read_lock(); 198 psock = sk_psock(sk); 199 if (psock) { 200 if (sk->sk_prot->close != sock_map_close) { 201 psock = ERR_PTR(-EBUSY); 202 goto out; 203 } 204 205 if (!refcount_inc_not_zero(&psock->refcnt)) 206 psock = ERR_PTR(-EBUSY); 207 } 208 out: 209 rcu_read_unlock(); 210 return psock; 211 } 212 213 static int sock_map_link(struct bpf_map *map, struct sock *sk) 214 { 215 struct sk_psock_progs *progs = sock_map_progs(map); 216 struct bpf_prog *stream_verdict = NULL; 217 struct bpf_prog *stream_parser = NULL; 218 struct bpf_prog *skb_verdict = NULL; 219 struct bpf_prog *msg_parser = NULL; 220 struct sk_psock *psock; 221 int ret; 222 223 stream_verdict = READ_ONCE(progs->stream_verdict); 224 if (stream_verdict) { 225 stream_verdict = bpf_prog_inc_not_zero(stream_verdict); 226 if (IS_ERR(stream_verdict)) 227 return PTR_ERR(stream_verdict); 228 } 229 230 stream_parser = READ_ONCE(progs->stream_parser); 231 if (stream_parser) { 232 stream_parser = bpf_prog_inc_not_zero(stream_parser); 233 if (IS_ERR(stream_parser)) { 234 ret = PTR_ERR(stream_parser); 235 goto out_put_stream_verdict; 236 } 237 } 238 239 msg_parser = READ_ONCE(progs->msg_parser); 240 if (msg_parser) { 241 msg_parser = bpf_prog_inc_not_zero(msg_parser); 242 if (IS_ERR(msg_parser)) { 243 ret = PTR_ERR(msg_parser); 244 goto out_put_stream_parser; 245 } 246 } 247 248 skb_verdict = READ_ONCE(progs->skb_verdict); 249 if (skb_verdict) { 250 skb_verdict = bpf_prog_inc_not_zero(skb_verdict); 251 if (IS_ERR(skb_verdict)) { 252 ret = PTR_ERR(skb_verdict); 253 goto out_put_msg_parser; 254 } 255 } 256 257 psock = sock_map_psock_get_checked(sk); 258 if (IS_ERR(psock)) { 259 ret = PTR_ERR(psock); 260 goto out_progs; 261 } 262 263 if (psock) { 264 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || 265 (stream_parser && READ_ONCE(psock->progs.stream_parser)) || 266 (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) || 267 (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) || 268 (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) || 269 (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) { 270 sk_psock_put(sk, psock); 271 ret = -EBUSY; 272 goto out_progs; 273 } 274 } else { 275 psock = sk_psock_init(sk, map->numa_node); 276 if (IS_ERR(psock)) { 277 ret = PTR_ERR(psock); 278 goto out_progs; 279 } 280 } 281 282 if (msg_parser) 283 psock_set_prog(&psock->progs.msg_parser, msg_parser); 284 if (stream_parser) 285 psock_set_prog(&psock->progs.stream_parser, stream_parser); 286 if (stream_verdict) 287 psock_set_prog(&psock->progs.stream_verdict, stream_verdict); 288 if (skb_verdict) 289 psock_set_prog(&psock->progs.skb_verdict, skb_verdict); 290 291 /* msg_* and stream_* programs references tracked in psock after this 292 * point. Reference dec and cleanup will occur through psock destructor 293 */ 294 ret = sock_map_init_proto(sk, psock); 295 if (ret < 0) { 296 sk_psock_put(sk, psock); 297 goto out; 298 } 299 300 write_lock_bh(&sk->sk_callback_lock); 301 if (stream_parser && stream_verdict && !psock->saved_data_ready) { 302 ret = sk_psock_init_strp(sk, psock); 303 if (ret) { 304 write_unlock_bh(&sk->sk_callback_lock); 305 sk_psock_put(sk, psock); 306 goto out; 307 } 308 sk_psock_start_strp(sk, psock); 309 } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) { 310 sk_psock_start_verdict(sk,psock); 311 } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) { 312 sk_psock_start_verdict(sk, psock); 313 } 314 write_unlock_bh(&sk->sk_callback_lock); 315 return 0; 316 out_progs: 317 if (skb_verdict) 318 bpf_prog_put(skb_verdict); 319 out_put_msg_parser: 320 if (msg_parser) 321 bpf_prog_put(msg_parser); 322 out_put_stream_parser: 323 if (stream_parser) 324 bpf_prog_put(stream_parser); 325 out_put_stream_verdict: 326 if (stream_verdict) 327 bpf_prog_put(stream_verdict); 328 out: 329 return ret; 330 } 331 332 static void sock_map_free(struct bpf_map *map) 333 { 334 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 335 int i; 336 337 /* After the sync no updates or deletes will be in-flight so it 338 * is safe to walk map and remove entries without risking a race 339 * in EEXIST update case. 340 */ 341 synchronize_rcu(); 342 for (i = 0; i < stab->map.max_entries; i++) { 343 struct sock **psk = &stab->sks[i]; 344 struct sock *sk; 345 346 sk = xchg(psk, NULL); 347 if (sk) { 348 sock_hold(sk); 349 lock_sock(sk); 350 rcu_read_lock(); 351 sock_map_unref(sk, psk); 352 rcu_read_unlock(); 353 release_sock(sk); 354 sock_put(sk); 355 } 356 } 357 358 /* wait for psock readers accessing its map link */ 359 synchronize_rcu(); 360 361 bpf_map_area_free(stab->sks); 362 bpf_map_area_free(stab); 363 } 364 365 static void sock_map_release_progs(struct bpf_map *map) 366 { 367 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); 368 } 369 370 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) 371 { 372 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 373 374 WARN_ON_ONCE(!rcu_read_lock_held()); 375 376 if (unlikely(key >= map->max_entries)) 377 return NULL; 378 return READ_ONCE(stab->sks[key]); 379 } 380 381 static void *sock_map_lookup(struct bpf_map *map, void *key) 382 { 383 struct sock *sk; 384 385 sk = __sock_map_lookup_elem(map, *(u32 *)key); 386 if (!sk) 387 return NULL; 388 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) 389 return NULL; 390 return sk; 391 } 392 393 static void *sock_map_lookup_sys(struct bpf_map *map, void *key) 394 { 395 struct sock *sk; 396 397 if (map->value_size != sizeof(u64)) 398 return ERR_PTR(-ENOSPC); 399 400 sk = __sock_map_lookup_elem(map, *(u32 *)key); 401 if (!sk) 402 return ERR_PTR(-ENOENT); 403 404 __sock_gen_cookie(sk); 405 return &sk->sk_cookie; 406 } 407 408 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, 409 struct sock **psk) 410 { 411 struct sock *sk; 412 int err = 0; 413 414 if (irqs_disabled()) 415 return -EOPNOTSUPP; /* locks here are hardirq-unsafe */ 416 417 spin_lock_bh(&stab->lock); 418 sk = *psk; 419 if (!sk_test || sk_test == sk) 420 sk = xchg(psk, NULL); 421 422 if (likely(sk)) 423 sock_map_unref(sk, psk); 424 else 425 err = -EINVAL; 426 427 spin_unlock_bh(&stab->lock); 428 return err; 429 } 430 431 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, 432 void *link_raw) 433 { 434 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 435 436 __sock_map_delete(stab, sk, link_raw); 437 } 438 439 static long sock_map_delete_elem(struct bpf_map *map, void *key) 440 { 441 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 442 u32 i = *(u32 *)key; 443 struct sock **psk; 444 445 if (unlikely(i >= map->max_entries)) 446 return -EINVAL; 447 448 psk = &stab->sks[i]; 449 return __sock_map_delete(stab, NULL, psk); 450 } 451 452 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next) 453 { 454 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 455 u32 i = key ? *(u32 *)key : U32_MAX; 456 u32 *key_next = next; 457 458 if (i == stab->map.max_entries - 1) 459 return -ENOENT; 460 if (i >= stab->map.max_entries) 461 *key_next = 0; 462 else 463 *key_next = i + 1; 464 return 0; 465 } 466 467 static int sock_map_update_common(struct bpf_map *map, u32 idx, 468 struct sock *sk, u64 flags) 469 { 470 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 471 struct sk_psock_link *link; 472 struct sk_psock *psock; 473 struct sock *osk; 474 int ret; 475 476 WARN_ON_ONCE(!rcu_read_lock_held()); 477 if (unlikely(flags > BPF_EXIST)) 478 return -EINVAL; 479 if (unlikely(idx >= map->max_entries)) 480 return -E2BIG; 481 482 link = sk_psock_init_link(); 483 if (!link) 484 return -ENOMEM; 485 486 ret = sock_map_link(map, sk); 487 if (ret < 0) 488 goto out_free; 489 490 psock = sk_psock(sk); 491 WARN_ON_ONCE(!psock); 492 493 spin_lock_bh(&stab->lock); 494 osk = stab->sks[idx]; 495 if (osk && flags == BPF_NOEXIST) { 496 ret = -EEXIST; 497 goto out_unlock; 498 } else if (!osk && flags == BPF_EXIST) { 499 ret = -ENOENT; 500 goto out_unlock; 501 } 502 503 sock_map_add_link(psock, link, map, &stab->sks[idx]); 504 stab->sks[idx] = sk; 505 if (osk) 506 sock_map_unref(osk, &stab->sks[idx]); 507 spin_unlock_bh(&stab->lock); 508 return 0; 509 out_unlock: 510 spin_unlock_bh(&stab->lock); 511 if (psock) 512 sk_psock_put(sk, psock); 513 out_free: 514 sk_psock_free_link(link); 515 return ret; 516 } 517 518 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops) 519 { 520 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || 521 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB || 522 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB; 523 } 524 525 static bool sock_map_redirect_allowed(const struct sock *sk) 526 { 527 if (sk_is_tcp(sk)) 528 return sk->sk_state != TCP_LISTEN; 529 else 530 return sk->sk_state == TCP_ESTABLISHED; 531 } 532 533 static bool sock_map_sk_is_suitable(const struct sock *sk) 534 { 535 return !!sk->sk_prot->psock_update_sk_prot; 536 } 537 538 static bool sock_map_sk_state_allowed(const struct sock *sk) 539 { 540 if (sk_is_tcp(sk)) 541 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN); 542 if (sk_is_stream_unix(sk)) 543 return (1 << sk->sk_state) & TCPF_ESTABLISHED; 544 return true; 545 } 546 547 static int sock_hash_update_common(struct bpf_map *map, void *key, 548 struct sock *sk, u64 flags); 549 550 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, 551 u64 flags) 552 { 553 struct socket *sock; 554 struct sock *sk; 555 int ret; 556 u64 ufd; 557 558 if (map->value_size == sizeof(u64)) 559 ufd = *(u64 *)value; 560 else 561 ufd = *(u32 *)value; 562 if (ufd > S32_MAX) 563 return -EINVAL; 564 565 sock = sockfd_lookup(ufd, &ret); 566 if (!sock) 567 return ret; 568 sk = sock->sk; 569 if (!sk) { 570 ret = -EINVAL; 571 goto out; 572 } 573 if (!sock_map_sk_is_suitable(sk)) { 574 ret = -EOPNOTSUPP; 575 goto out; 576 } 577 578 sock_map_sk_acquire(sk); 579 if (!sock_map_sk_state_allowed(sk)) 580 ret = -EOPNOTSUPP; 581 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 582 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 583 else 584 ret = sock_hash_update_common(map, key, sk, flags); 585 sock_map_sk_release(sk); 586 out: 587 sockfd_put(sock); 588 return ret; 589 } 590 591 static long sock_map_update_elem(struct bpf_map *map, void *key, 592 void *value, u64 flags) 593 { 594 struct sock *sk = (struct sock *)value; 595 int ret; 596 597 if (unlikely(!sk || !sk_fullsock(sk))) 598 return -EINVAL; 599 600 if (!sock_map_sk_is_suitable(sk)) 601 return -EOPNOTSUPP; 602 603 local_bh_disable(); 604 bh_lock_sock(sk); 605 if (!sock_map_sk_state_allowed(sk)) 606 ret = -EOPNOTSUPP; 607 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 608 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 609 else 610 ret = sock_hash_update_common(map, key, sk, flags); 611 bh_unlock_sock(sk); 612 local_bh_enable(); 613 return ret; 614 } 615 616 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, 617 struct bpf_map *, map, void *, key, u64, flags) 618 { 619 WARN_ON_ONCE(!rcu_read_lock_held()); 620 621 if (likely(sock_map_sk_is_suitable(sops->sk) && 622 sock_map_op_okay(sops))) 623 return sock_map_update_common(map, *(u32 *)key, sops->sk, 624 flags); 625 return -EOPNOTSUPP; 626 } 627 628 const struct bpf_func_proto bpf_sock_map_update_proto = { 629 .func = bpf_sock_map_update, 630 .gpl_only = false, 631 .pkt_access = true, 632 .ret_type = RET_INTEGER, 633 .arg1_type = ARG_PTR_TO_CTX, 634 .arg2_type = ARG_CONST_MAP_PTR, 635 .arg3_type = ARG_PTR_TO_MAP_KEY, 636 .arg4_type = ARG_ANYTHING, 637 }; 638 639 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, 640 struct bpf_map *, map, u32, key, u64, flags) 641 { 642 struct sock *sk; 643 644 if (unlikely(flags & ~(BPF_F_INGRESS))) 645 return SK_DROP; 646 647 sk = __sock_map_lookup_elem(map, key); 648 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 649 return SK_DROP; 650 651 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); 652 return SK_PASS; 653 } 654 655 const struct bpf_func_proto bpf_sk_redirect_map_proto = { 656 .func = bpf_sk_redirect_map, 657 .gpl_only = false, 658 .ret_type = RET_INTEGER, 659 .arg1_type = ARG_PTR_TO_CTX, 660 .arg2_type = ARG_CONST_MAP_PTR, 661 .arg3_type = ARG_ANYTHING, 662 .arg4_type = ARG_ANYTHING, 663 }; 664 665 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg, 666 struct bpf_map *, map, u32, key, u64, flags) 667 { 668 struct sock *sk; 669 670 if (unlikely(flags & ~(BPF_F_INGRESS))) 671 return SK_DROP; 672 673 sk = __sock_map_lookup_elem(map, key); 674 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 675 return SK_DROP; 676 if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk)) 677 return SK_DROP; 678 679 msg->flags = flags; 680 msg->sk_redir = sk; 681 return SK_PASS; 682 } 683 684 const struct bpf_func_proto bpf_msg_redirect_map_proto = { 685 .func = bpf_msg_redirect_map, 686 .gpl_only = false, 687 .ret_type = RET_INTEGER, 688 .arg1_type = ARG_PTR_TO_CTX, 689 .arg2_type = ARG_CONST_MAP_PTR, 690 .arg3_type = ARG_ANYTHING, 691 .arg4_type = ARG_ANYTHING, 692 }; 693 694 struct sock_map_seq_info { 695 struct bpf_map *map; 696 struct sock *sk; 697 u32 index; 698 }; 699 700 struct bpf_iter__sockmap { 701 __bpf_md_ptr(struct bpf_iter_meta *, meta); 702 __bpf_md_ptr(struct bpf_map *, map); 703 __bpf_md_ptr(void *, key); 704 __bpf_md_ptr(struct sock *, sk); 705 }; 706 707 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta, 708 struct bpf_map *map, void *key, 709 struct sock *sk) 710 711 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info) 712 { 713 if (unlikely(info->index >= info->map->max_entries)) 714 return NULL; 715 716 info->sk = __sock_map_lookup_elem(info->map, info->index); 717 718 /* can't return sk directly, since that might be NULL */ 719 return info; 720 } 721 722 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos) 723 __acquires(rcu) 724 { 725 struct sock_map_seq_info *info = seq->private; 726 727 if (*pos == 0) 728 ++*pos; 729 730 /* pairs with sock_map_seq_stop */ 731 rcu_read_lock(); 732 return sock_map_seq_lookup_elem(info); 733 } 734 735 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 736 __must_hold(rcu) 737 { 738 struct sock_map_seq_info *info = seq->private; 739 740 ++*pos; 741 ++info->index; 742 743 return sock_map_seq_lookup_elem(info); 744 } 745 746 static int sock_map_seq_show(struct seq_file *seq, void *v) 747 __must_hold(rcu) 748 { 749 struct sock_map_seq_info *info = seq->private; 750 struct bpf_iter__sockmap ctx = {}; 751 struct bpf_iter_meta meta; 752 struct bpf_prog *prog; 753 754 meta.seq = seq; 755 prog = bpf_iter_get_info(&meta, !v); 756 if (!prog) 757 return 0; 758 759 ctx.meta = &meta; 760 ctx.map = info->map; 761 if (v) { 762 ctx.key = &info->index; 763 ctx.sk = info->sk; 764 } 765 766 return bpf_iter_run_prog(prog, &ctx); 767 } 768 769 static void sock_map_seq_stop(struct seq_file *seq, void *v) 770 __releases(rcu) 771 { 772 if (!v) 773 (void)sock_map_seq_show(seq, NULL); 774 775 /* pairs with sock_map_seq_start */ 776 rcu_read_unlock(); 777 } 778 779 static const struct seq_operations sock_map_seq_ops = { 780 .start = sock_map_seq_start, 781 .next = sock_map_seq_next, 782 .stop = sock_map_seq_stop, 783 .show = sock_map_seq_show, 784 }; 785 786 static int sock_map_init_seq_private(void *priv_data, 787 struct bpf_iter_aux_info *aux) 788 { 789 struct sock_map_seq_info *info = priv_data; 790 791 bpf_map_inc_with_uref(aux->map); 792 info->map = aux->map; 793 return 0; 794 } 795 796 static void sock_map_fini_seq_private(void *priv_data) 797 { 798 struct sock_map_seq_info *info = priv_data; 799 800 bpf_map_put_with_uref(info->map); 801 } 802 803 static u64 sock_map_mem_usage(const struct bpf_map *map) 804 { 805 u64 usage = sizeof(struct bpf_stab); 806 807 usage += (u64)map->max_entries * sizeof(struct sock *); 808 return usage; 809 } 810 811 static const struct bpf_iter_seq_info sock_map_iter_seq_info = { 812 .seq_ops = &sock_map_seq_ops, 813 .init_seq_private = sock_map_init_seq_private, 814 .fini_seq_private = sock_map_fini_seq_private, 815 .seq_priv_size = sizeof(struct sock_map_seq_info), 816 }; 817 818 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab) 819 const struct bpf_map_ops sock_map_ops = { 820 .map_meta_equal = bpf_map_meta_equal, 821 .map_alloc = sock_map_alloc, 822 .map_free = sock_map_free, 823 .map_get_next_key = sock_map_get_next_key, 824 .map_lookup_elem_sys_only = sock_map_lookup_sys, 825 .map_update_elem = sock_map_update_elem, 826 .map_delete_elem = sock_map_delete_elem, 827 .map_lookup_elem = sock_map_lookup, 828 .map_release_uref = sock_map_release_progs, 829 .map_check_btf = map_check_no_btf, 830 .map_mem_usage = sock_map_mem_usage, 831 .map_btf_id = &sock_map_btf_ids[0], 832 .iter_seq_info = &sock_map_iter_seq_info, 833 }; 834 835 struct bpf_shtab_elem { 836 struct rcu_head rcu; 837 u32 hash; 838 struct sock *sk; 839 struct hlist_node node; 840 u8 key[]; 841 }; 842 843 struct bpf_shtab_bucket { 844 struct hlist_head head; 845 spinlock_t lock; 846 }; 847 848 struct bpf_shtab { 849 struct bpf_map map; 850 struct bpf_shtab_bucket *buckets; 851 u32 buckets_num; 852 u32 elem_size; 853 struct sk_psock_progs progs; 854 atomic_t count; 855 }; 856 857 static inline u32 sock_hash_bucket_hash(const void *key, u32 len) 858 { 859 return jhash(key, len, 0); 860 } 861 862 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab, 863 u32 hash) 864 { 865 return &htab->buckets[hash & (htab->buckets_num - 1)]; 866 } 867 868 static struct bpf_shtab_elem * 869 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, 870 u32 key_size) 871 { 872 struct bpf_shtab_elem *elem; 873 874 hlist_for_each_entry_rcu(elem, head, node) { 875 if (elem->hash == hash && 876 !memcmp(&elem->key, key, key_size)) 877 return elem; 878 } 879 880 return NULL; 881 } 882 883 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) 884 { 885 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 886 u32 key_size = map->key_size, hash; 887 struct bpf_shtab_bucket *bucket; 888 struct bpf_shtab_elem *elem; 889 890 WARN_ON_ONCE(!rcu_read_lock_held()); 891 892 hash = sock_hash_bucket_hash(key, key_size); 893 bucket = sock_hash_select_bucket(htab, hash); 894 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 895 896 return elem ? elem->sk : NULL; 897 } 898 899 static void sock_hash_free_elem(struct bpf_shtab *htab, 900 struct bpf_shtab_elem *elem) 901 { 902 atomic_dec(&htab->count); 903 kfree_rcu(elem, rcu); 904 } 905 906 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, 907 void *link_raw) 908 { 909 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 910 struct bpf_shtab_elem *elem_probe, *elem = link_raw; 911 struct bpf_shtab_bucket *bucket; 912 913 WARN_ON_ONCE(!rcu_read_lock_held()); 914 bucket = sock_hash_select_bucket(htab, elem->hash); 915 916 /* elem may be deleted in parallel from the map, but access here 917 * is okay since it's going away only after RCU grace period. 918 * However, we need to check whether it's still present. 919 */ 920 spin_lock_bh(&bucket->lock); 921 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash, 922 elem->key, map->key_size); 923 if (elem_probe && elem_probe == elem) { 924 hlist_del_rcu(&elem->node); 925 sock_map_unref(elem->sk, elem); 926 sock_hash_free_elem(htab, elem); 927 } 928 spin_unlock_bh(&bucket->lock); 929 } 930 931 static long sock_hash_delete_elem(struct bpf_map *map, void *key) 932 { 933 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 934 u32 hash, key_size = map->key_size; 935 struct bpf_shtab_bucket *bucket; 936 struct bpf_shtab_elem *elem; 937 int ret = -ENOENT; 938 939 if (irqs_disabled()) 940 return -EOPNOTSUPP; /* locks here are hardirq-unsafe */ 941 942 hash = sock_hash_bucket_hash(key, key_size); 943 bucket = sock_hash_select_bucket(htab, hash); 944 945 spin_lock_bh(&bucket->lock); 946 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 947 if (elem) { 948 hlist_del_rcu(&elem->node); 949 sock_map_unref(elem->sk, elem); 950 sock_hash_free_elem(htab, elem); 951 ret = 0; 952 } 953 spin_unlock_bh(&bucket->lock); 954 return ret; 955 } 956 957 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab, 958 void *key, u32 key_size, 959 u32 hash, struct sock *sk, 960 struct bpf_shtab_elem *old) 961 { 962 struct bpf_shtab_elem *new; 963 964 if (atomic_inc_return(&htab->count) > htab->map.max_entries) { 965 if (!old) { 966 atomic_dec(&htab->count); 967 return ERR_PTR(-E2BIG); 968 } 969 } 970 971 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size, 972 GFP_ATOMIC | __GFP_NOWARN, 973 htab->map.numa_node); 974 if (!new) { 975 atomic_dec(&htab->count); 976 return ERR_PTR(-ENOMEM); 977 } 978 memcpy(new->key, key, key_size); 979 new->sk = sk; 980 new->hash = hash; 981 return new; 982 } 983 984 static int sock_hash_update_common(struct bpf_map *map, void *key, 985 struct sock *sk, u64 flags) 986 { 987 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 988 u32 key_size = map->key_size, hash; 989 struct bpf_shtab_elem *elem, *elem_new; 990 struct bpf_shtab_bucket *bucket; 991 struct sk_psock_link *link; 992 struct sk_psock *psock; 993 int ret; 994 995 WARN_ON_ONCE(!rcu_read_lock_held()); 996 if (unlikely(flags > BPF_EXIST)) 997 return -EINVAL; 998 999 link = sk_psock_init_link(); 1000 if (!link) 1001 return -ENOMEM; 1002 1003 ret = sock_map_link(map, sk); 1004 if (ret < 0) 1005 goto out_free; 1006 1007 psock = sk_psock(sk); 1008 WARN_ON_ONCE(!psock); 1009 1010 hash = sock_hash_bucket_hash(key, key_size); 1011 bucket = sock_hash_select_bucket(htab, hash); 1012 1013 spin_lock_bh(&bucket->lock); 1014 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 1015 if (elem && flags == BPF_NOEXIST) { 1016 ret = -EEXIST; 1017 goto out_unlock; 1018 } else if (!elem && flags == BPF_EXIST) { 1019 ret = -ENOENT; 1020 goto out_unlock; 1021 } 1022 1023 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); 1024 if (IS_ERR(elem_new)) { 1025 ret = PTR_ERR(elem_new); 1026 goto out_unlock; 1027 } 1028 1029 sock_map_add_link(psock, link, map, elem_new); 1030 /* Add new element to the head of the list, so that 1031 * concurrent search will find it before old elem. 1032 */ 1033 hlist_add_head_rcu(&elem_new->node, &bucket->head); 1034 if (elem) { 1035 hlist_del_rcu(&elem->node); 1036 sock_map_unref(elem->sk, elem); 1037 sock_hash_free_elem(htab, elem); 1038 } 1039 spin_unlock_bh(&bucket->lock); 1040 return 0; 1041 out_unlock: 1042 spin_unlock_bh(&bucket->lock); 1043 sk_psock_put(sk, psock); 1044 out_free: 1045 sk_psock_free_link(link); 1046 return ret; 1047 } 1048 1049 static int sock_hash_get_next_key(struct bpf_map *map, void *key, 1050 void *key_next) 1051 { 1052 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1053 struct bpf_shtab_elem *elem, *elem_next; 1054 u32 hash, key_size = map->key_size; 1055 struct hlist_head *head; 1056 int i = 0; 1057 1058 if (!key) 1059 goto find_first_elem; 1060 hash = sock_hash_bucket_hash(key, key_size); 1061 head = &sock_hash_select_bucket(htab, hash)->head; 1062 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); 1063 if (!elem) 1064 goto find_first_elem; 1065 1066 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)), 1067 struct bpf_shtab_elem, node); 1068 if (elem_next) { 1069 memcpy(key_next, elem_next->key, key_size); 1070 return 0; 1071 } 1072 1073 i = hash & (htab->buckets_num - 1); 1074 i++; 1075 find_first_elem: 1076 for (; i < htab->buckets_num; i++) { 1077 head = &sock_hash_select_bucket(htab, i)->head; 1078 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)), 1079 struct bpf_shtab_elem, node); 1080 if (elem_next) { 1081 memcpy(key_next, elem_next->key, key_size); 1082 return 0; 1083 } 1084 } 1085 1086 return -ENOENT; 1087 } 1088 1089 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) 1090 { 1091 struct bpf_shtab *htab; 1092 int i, err; 1093 1094 if (attr->max_entries == 0 || 1095 attr->key_size == 0 || 1096 (attr->value_size != sizeof(u32) && 1097 attr->value_size != sizeof(u64)) || 1098 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 1099 return ERR_PTR(-EINVAL); 1100 if (attr->key_size > MAX_BPF_STACK) 1101 return ERR_PTR(-E2BIG); 1102 1103 htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); 1104 if (!htab) 1105 return ERR_PTR(-ENOMEM); 1106 1107 bpf_map_init_from_attr(&htab->map, attr); 1108 1109 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries); 1110 htab->elem_size = sizeof(struct bpf_shtab_elem) + 1111 round_up(htab->map.key_size, 8); 1112 if (htab->buckets_num == 0 || 1113 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) { 1114 err = -EINVAL; 1115 goto free_htab; 1116 } 1117 1118 htab->buckets = bpf_map_area_alloc(htab->buckets_num * 1119 sizeof(struct bpf_shtab_bucket), 1120 htab->map.numa_node); 1121 if (!htab->buckets) { 1122 err = -ENOMEM; 1123 goto free_htab; 1124 } 1125 1126 for (i = 0; i < htab->buckets_num; i++) { 1127 INIT_HLIST_HEAD(&htab->buckets[i].head); 1128 spin_lock_init(&htab->buckets[i].lock); 1129 } 1130 1131 return &htab->map; 1132 free_htab: 1133 bpf_map_area_free(htab); 1134 return ERR_PTR(err); 1135 } 1136 1137 static void sock_hash_free(struct bpf_map *map) 1138 { 1139 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1140 struct bpf_shtab_bucket *bucket; 1141 struct hlist_head unlink_list; 1142 struct bpf_shtab_elem *elem; 1143 struct hlist_node *node; 1144 int i; 1145 1146 /* After the sync no updates or deletes will be in-flight so it 1147 * is safe to walk map and remove entries without risking a race 1148 * in EEXIST update case. 1149 */ 1150 synchronize_rcu(); 1151 for (i = 0; i < htab->buckets_num; i++) { 1152 bucket = sock_hash_select_bucket(htab, i); 1153 1154 /* We are racing with sock_hash_delete_from_link to 1155 * enter the spin-lock critical section. Every socket on 1156 * the list is still linked to sockhash. Since link 1157 * exists, psock exists and holds a ref to socket. That 1158 * lets us to grab a socket ref too. 1159 */ 1160 spin_lock_bh(&bucket->lock); 1161 hlist_for_each_entry(elem, &bucket->head, node) 1162 sock_hold(elem->sk); 1163 hlist_move_list(&bucket->head, &unlink_list); 1164 spin_unlock_bh(&bucket->lock); 1165 1166 /* Process removed entries out of atomic context to 1167 * block for socket lock before deleting the psock's 1168 * link to sockhash. 1169 */ 1170 hlist_for_each_entry_safe(elem, node, &unlink_list, node) { 1171 hlist_del(&elem->node); 1172 lock_sock(elem->sk); 1173 rcu_read_lock(); 1174 sock_map_unref(elem->sk, elem); 1175 rcu_read_unlock(); 1176 release_sock(elem->sk); 1177 sock_put(elem->sk); 1178 sock_hash_free_elem(htab, elem); 1179 } 1180 } 1181 1182 /* wait for psock readers accessing its map link */ 1183 synchronize_rcu(); 1184 1185 bpf_map_area_free(htab->buckets); 1186 bpf_map_area_free(htab); 1187 } 1188 1189 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key) 1190 { 1191 struct sock *sk; 1192 1193 if (map->value_size != sizeof(u64)) 1194 return ERR_PTR(-ENOSPC); 1195 1196 sk = __sock_hash_lookup_elem(map, key); 1197 if (!sk) 1198 return ERR_PTR(-ENOENT); 1199 1200 __sock_gen_cookie(sk); 1201 return &sk->sk_cookie; 1202 } 1203 1204 static void *sock_hash_lookup(struct bpf_map *map, void *key) 1205 { 1206 struct sock *sk; 1207 1208 sk = __sock_hash_lookup_elem(map, key); 1209 if (!sk) 1210 return NULL; 1211 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) 1212 return NULL; 1213 return sk; 1214 } 1215 1216 static void sock_hash_release_progs(struct bpf_map *map) 1217 { 1218 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs); 1219 } 1220 1221 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, 1222 struct bpf_map *, map, void *, key, u64, flags) 1223 { 1224 WARN_ON_ONCE(!rcu_read_lock_held()); 1225 1226 if (likely(sock_map_sk_is_suitable(sops->sk) && 1227 sock_map_op_okay(sops))) 1228 return sock_hash_update_common(map, key, sops->sk, flags); 1229 return -EOPNOTSUPP; 1230 } 1231 1232 const struct bpf_func_proto bpf_sock_hash_update_proto = { 1233 .func = bpf_sock_hash_update, 1234 .gpl_only = false, 1235 .pkt_access = true, 1236 .ret_type = RET_INTEGER, 1237 .arg1_type = ARG_PTR_TO_CTX, 1238 .arg2_type = ARG_CONST_MAP_PTR, 1239 .arg3_type = ARG_PTR_TO_MAP_KEY, 1240 .arg4_type = ARG_ANYTHING, 1241 }; 1242 1243 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, 1244 struct bpf_map *, map, void *, key, u64, flags) 1245 { 1246 struct sock *sk; 1247 1248 if (unlikely(flags & ~(BPF_F_INGRESS))) 1249 return SK_DROP; 1250 1251 sk = __sock_hash_lookup_elem(map, key); 1252 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 1253 return SK_DROP; 1254 1255 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); 1256 return SK_PASS; 1257 } 1258 1259 const struct bpf_func_proto bpf_sk_redirect_hash_proto = { 1260 .func = bpf_sk_redirect_hash, 1261 .gpl_only = false, 1262 .ret_type = RET_INTEGER, 1263 .arg1_type = ARG_PTR_TO_CTX, 1264 .arg2_type = ARG_CONST_MAP_PTR, 1265 .arg3_type = ARG_PTR_TO_MAP_KEY, 1266 .arg4_type = ARG_ANYTHING, 1267 }; 1268 1269 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg, 1270 struct bpf_map *, map, void *, key, u64, flags) 1271 { 1272 struct sock *sk; 1273 1274 if (unlikely(flags & ~(BPF_F_INGRESS))) 1275 return SK_DROP; 1276 1277 sk = __sock_hash_lookup_elem(map, key); 1278 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 1279 return SK_DROP; 1280 if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk)) 1281 return SK_DROP; 1282 1283 msg->flags = flags; 1284 msg->sk_redir = sk; 1285 return SK_PASS; 1286 } 1287 1288 const struct bpf_func_proto bpf_msg_redirect_hash_proto = { 1289 .func = bpf_msg_redirect_hash, 1290 .gpl_only = false, 1291 .ret_type = RET_INTEGER, 1292 .arg1_type = ARG_PTR_TO_CTX, 1293 .arg2_type = ARG_CONST_MAP_PTR, 1294 .arg3_type = ARG_PTR_TO_MAP_KEY, 1295 .arg4_type = ARG_ANYTHING, 1296 }; 1297 1298 struct sock_hash_seq_info { 1299 struct bpf_map *map; 1300 struct bpf_shtab *htab; 1301 u32 bucket_id; 1302 }; 1303 1304 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info, 1305 struct bpf_shtab_elem *prev_elem) 1306 { 1307 const struct bpf_shtab *htab = info->htab; 1308 struct bpf_shtab_bucket *bucket; 1309 struct bpf_shtab_elem *elem; 1310 struct hlist_node *node; 1311 1312 /* try to find next elem in the same bucket */ 1313 if (prev_elem) { 1314 node = rcu_dereference(hlist_next_rcu(&prev_elem->node)); 1315 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); 1316 if (elem) 1317 return elem; 1318 1319 /* no more elements, continue in the next bucket */ 1320 info->bucket_id++; 1321 } 1322 1323 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) { 1324 bucket = &htab->buckets[info->bucket_id]; 1325 node = rcu_dereference(hlist_first_rcu(&bucket->head)); 1326 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); 1327 if (elem) 1328 return elem; 1329 } 1330 1331 return NULL; 1332 } 1333 1334 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos) 1335 __acquires(rcu) 1336 { 1337 struct sock_hash_seq_info *info = seq->private; 1338 1339 if (*pos == 0) 1340 ++*pos; 1341 1342 /* pairs with sock_hash_seq_stop */ 1343 rcu_read_lock(); 1344 return sock_hash_seq_find_next(info, NULL); 1345 } 1346 1347 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1348 __must_hold(rcu) 1349 { 1350 struct sock_hash_seq_info *info = seq->private; 1351 1352 ++*pos; 1353 return sock_hash_seq_find_next(info, v); 1354 } 1355 1356 static int sock_hash_seq_show(struct seq_file *seq, void *v) 1357 __must_hold(rcu) 1358 { 1359 struct sock_hash_seq_info *info = seq->private; 1360 struct bpf_iter__sockmap ctx = {}; 1361 struct bpf_shtab_elem *elem = v; 1362 struct bpf_iter_meta meta; 1363 struct bpf_prog *prog; 1364 1365 meta.seq = seq; 1366 prog = bpf_iter_get_info(&meta, !elem); 1367 if (!prog) 1368 return 0; 1369 1370 ctx.meta = &meta; 1371 ctx.map = info->map; 1372 if (elem) { 1373 ctx.key = elem->key; 1374 ctx.sk = elem->sk; 1375 } 1376 1377 return bpf_iter_run_prog(prog, &ctx); 1378 } 1379 1380 static void sock_hash_seq_stop(struct seq_file *seq, void *v) 1381 __releases(rcu) 1382 { 1383 if (!v) 1384 (void)sock_hash_seq_show(seq, NULL); 1385 1386 /* pairs with sock_hash_seq_start */ 1387 rcu_read_unlock(); 1388 } 1389 1390 static const struct seq_operations sock_hash_seq_ops = { 1391 .start = sock_hash_seq_start, 1392 .next = sock_hash_seq_next, 1393 .stop = sock_hash_seq_stop, 1394 .show = sock_hash_seq_show, 1395 }; 1396 1397 static int sock_hash_init_seq_private(void *priv_data, 1398 struct bpf_iter_aux_info *aux) 1399 { 1400 struct sock_hash_seq_info *info = priv_data; 1401 1402 bpf_map_inc_with_uref(aux->map); 1403 info->map = aux->map; 1404 info->htab = container_of(aux->map, struct bpf_shtab, map); 1405 return 0; 1406 } 1407 1408 static void sock_hash_fini_seq_private(void *priv_data) 1409 { 1410 struct sock_hash_seq_info *info = priv_data; 1411 1412 bpf_map_put_with_uref(info->map); 1413 } 1414 1415 static u64 sock_hash_mem_usage(const struct bpf_map *map) 1416 { 1417 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1418 u64 usage = sizeof(*htab); 1419 1420 usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket); 1421 usage += atomic_read(&htab->count) * (u64)htab->elem_size; 1422 return usage; 1423 } 1424 1425 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = { 1426 .seq_ops = &sock_hash_seq_ops, 1427 .init_seq_private = sock_hash_init_seq_private, 1428 .fini_seq_private = sock_hash_fini_seq_private, 1429 .seq_priv_size = sizeof(struct sock_hash_seq_info), 1430 }; 1431 1432 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab) 1433 const struct bpf_map_ops sock_hash_ops = { 1434 .map_meta_equal = bpf_map_meta_equal, 1435 .map_alloc = sock_hash_alloc, 1436 .map_free = sock_hash_free, 1437 .map_get_next_key = sock_hash_get_next_key, 1438 .map_update_elem = sock_map_update_elem, 1439 .map_delete_elem = sock_hash_delete_elem, 1440 .map_lookup_elem = sock_hash_lookup, 1441 .map_lookup_elem_sys_only = sock_hash_lookup_sys, 1442 .map_release_uref = sock_hash_release_progs, 1443 .map_check_btf = map_check_no_btf, 1444 .map_mem_usage = sock_hash_mem_usage, 1445 .map_btf_id = &sock_hash_map_btf_ids[0], 1446 .iter_seq_info = &sock_hash_iter_seq_info, 1447 }; 1448 1449 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 1450 { 1451 switch (map->map_type) { 1452 case BPF_MAP_TYPE_SOCKMAP: 1453 return &container_of(map, struct bpf_stab, map)->progs; 1454 case BPF_MAP_TYPE_SOCKHASH: 1455 return &container_of(map, struct bpf_shtab, map)->progs; 1456 default: 1457 break; 1458 } 1459 1460 return NULL; 1461 } 1462 1463 static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog, 1464 u32 which) 1465 { 1466 struct sk_psock_progs *progs = sock_map_progs(map); 1467 1468 if (!progs) 1469 return -EOPNOTSUPP; 1470 1471 switch (which) { 1472 case BPF_SK_MSG_VERDICT: 1473 *pprog = &progs->msg_parser; 1474 break; 1475 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) 1476 case BPF_SK_SKB_STREAM_PARSER: 1477 *pprog = &progs->stream_parser; 1478 break; 1479 #endif 1480 case BPF_SK_SKB_STREAM_VERDICT: 1481 if (progs->skb_verdict) 1482 return -EBUSY; 1483 *pprog = &progs->stream_verdict; 1484 break; 1485 case BPF_SK_SKB_VERDICT: 1486 if (progs->stream_verdict) 1487 return -EBUSY; 1488 *pprog = &progs->skb_verdict; 1489 break; 1490 default: 1491 return -EOPNOTSUPP; 1492 } 1493 1494 return 0; 1495 } 1496 1497 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 1498 struct bpf_prog *old, u32 which) 1499 { 1500 struct bpf_prog **pprog; 1501 int ret; 1502 1503 ret = sock_map_prog_lookup(map, &pprog, which); 1504 if (ret) 1505 return ret; 1506 1507 if (old) 1508 return psock_replace_prog(pprog, prog, old); 1509 1510 psock_set_prog(pprog, prog); 1511 return 0; 1512 } 1513 1514 int sock_map_bpf_prog_query(const union bpf_attr *attr, 1515 union bpf_attr __user *uattr) 1516 { 1517 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); 1518 u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd; 1519 struct bpf_prog **pprog; 1520 struct bpf_prog *prog; 1521 struct bpf_map *map; 1522 struct fd f; 1523 u32 id = 0; 1524 int ret; 1525 1526 if (attr->query.query_flags) 1527 return -EINVAL; 1528 1529 f = fdget(ufd); 1530 map = __bpf_map_get(f); 1531 if (IS_ERR(map)) 1532 return PTR_ERR(map); 1533 1534 rcu_read_lock(); 1535 1536 ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type); 1537 if (ret) 1538 goto end; 1539 1540 prog = *pprog; 1541 prog_cnt = !prog ? 0 : 1; 1542 1543 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) 1544 goto end; 1545 1546 /* we do not hold the refcnt, the bpf prog may be released 1547 * asynchronously and the id would be set to 0. 1548 */ 1549 id = data_race(prog->aux->id); 1550 if (id == 0) 1551 prog_cnt = 0; 1552 1553 end: 1554 rcu_read_unlock(); 1555 1556 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) || 1557 (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) || 1558 copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) 1559 ret = -EFAULT; 1560 1561 fdput(f); 1562 return ret; 1563 } 1564 1565 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link) 1566 { 1567 switch (link->map->map_type) { 1568 case BPF_MAP_TYPE_SOCKMAP: 1569 return sock_map_delete_from_link(link->map, sk, 1570 link->link_raw); 1571 case BPF_MAP_TYPE_SOCKHASH: 1572 return sock_hash_delete_from_link(link->map, sk, 1573 link->link_raw); 1574 default: 1575 break; 1576 } 1577 } 1578 1579 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock) 1580 { 1581 struct sk_psock_link *link; 1582 1583 while ((link = sk_psock_link_pop(psock))) { 1584 sock_map_unlink(sk, link); 1585 sk_psock_free_link(link); 1586 } 1587 } 1588 1589 void sock_map_unhash(struct sock *sk) 1590 { 1591 void (*saved_unhash)(struct sock *sk); 1592 struct sk_psock *psock; 1593 1594 rcu_read_lock(); 1595 psock = sk_psock(sk); 1596 if (unlikely(!psock)) { 1597 rcu_read_unlock(); 1598 saved_unhash = READ_ONCE(sk->sk_prot)->unhash; 1599 } else { 1600 saved_unhash = psock->saved_unhash; 1601 sock_map_remove_links(sk, psock); 1602 rcu_read_unlock(); 1603 } 1604 if (WARN_ON_ONCE(saved_unhash == sock_map_unhash)) 1605 return; 1606 if (saved_unhash) 1607 saved_unhash(sk); 1608 } 1609 EXPORT_SYMBOL_GPL(sock_map_unhash); 1610 1611 void sock_map_destroy(struct sock *sk) 1612 { 1613 void (*saved_destroy)(struct sock *sk); 1614 struct sk_psock *psock; 1615 1616 rcu_read_lock(); 1617 psock = sk_psock_get(sk); 1618 if (unlikely(!psock)) { 1619 rcu_read_unlock(); 1620 saved_destroy = READ_ONCE(sk->sk_prot)->destroy; 1621 } else { 1622 saved_destroy = psock->saved_destroy; 1623 sock_map_remove_links(sk, psock); 1624 rcu_read_unlock(); 1625 sk_psock_stop(psock); 1626 sk_psock_put(sk, psock); 1627 } 1628 if (WARN_ON_ONCE(saved_destroy == sock_map_destroy)) 1629 return; 1630 if (saved_destroy) 1631 saved_destroy(sk); 1632 } 1633 EXPORT_SYMBOL_GPL(sock_map_destroy); 1634 1635 void sock_map_close(struct sock *sk, long timeout) 1636 { 1637 void (*saved_close)(struct sock *sk, long timeout); 1638 struct sk_psock *psock; 1639 1640 lock_sock(sk); 1641 rcu_read_lock(); 1642 psock = sk_psock_get(sk); 1643 if (unlikely(!psock)) { 1644 rcu_read_unlock(); 1645 release_sock(sk); 1646 saved_close = READ_ONCE(sk->sk_prot)->close; 1647 } else { 1648 saved_close = psock->saved_close; 1649 sock_map_remove_links(sk, psock); 1650 rcu_read_unlock(); 1651 sk_psock_stop(psock); 1652 release_sock(sk); 1653 cancel_delayed_work_sync(&psock->work); 1654 sk_psock_put(sk, psock); 1655 } 1656 1657 /* Make sure we do not recurse. This is a bug. 1658 * Leak the socket instead of crashing on a stack overflow. 1659 */ 1660 if (WARN_ON_ONCE(saved_close == sock_map_close)) 1661 return; 1662 saved_close(sk, timeout); 1663 } 1664 EXPORT_SYMBOL_GPL(sock_map_close); 1665 1666 static int sock_map_iter_attach_target(struct bpf_prog *prog, 1667 union bpf_iter_link_info *linfo, 1668 struct bpf_iter_aux_info *aux) 1669 { 1670 struct bpf_map *map; 1671 int err = -EINVAL; 1672 1673 if (!linfo->map.map_fd) 1674 return -EBADF; 1675 1676 map = bpf_map_get_with_uref(linfo->map.map_fd); 1677 if (IS_ERR(map)) 1678 return PTR_ERR(map); 1679 1680 if (map->map_type != BPF_MAP_TYPE_SOCKMAP && 1681 map->map_type != BPF_MAP_TYPE_SOCKHASH) 1682 goto put_map; 1683 1684 if (prog->aux->max_rdonly_access > map->key_size) { 1685 err = -EACCES; 1686 goto put_map; 1687 } 1688 1689 aux->map = map; 1690 return 0; 1691 1692 put_map: 1693 bpf_map_put_with_uref(map); 1694 return err; 1695 } 1696 1697 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux) 1698 { 1699 bpf_map_put_with_uref(aux->map); 1700 } 1701 1702 static struct bpf_iter_reg sock_map_iter_reg = { 1703 .target = "sockmap", 1704 .attach_target = sock_map_iter_attach_target, 1705 .detach_target = sock_map_iter_detach_target, 1706 .show_fdinfo = bpf_iter_map_show_fdinfo, 1707 .fill_link_info = bpf_iter_map_fill_link_info, 1708 .ctx_arg_info_size = 2, 1709 .ctx_arg_info = { 1710 { offsetof(struct bpf_iter__sockmap, key), 1711 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY }, 1712 { offsetof(struct bpf_iter__sockmap, sk), 1713 PTR_TO_BTF_ID_OR_NULL }, 1714 }, 1715 }; 1716 1717 static int __init bpf_sockmap_iter_init(void) 1718 { 1719 sock_map_iter_reg.ctx_arg_info[1].btf_id = 1720 btf_sock_ids[BTF_SOCK_TYPE_SOCK]; 1721 return bpf_iter_reg_target(&sock_map_iter_reg); 1722 } 1723 late_initcall(bpf_sockmap_iter_init); 1724