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 (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 raw_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 preempt_disable(); 119 rcu_read_lock(); 120 } 121 122 static void sock_map_sk_release(struct sock *sk) 123 __releases(&sk->sk_lock.slock) 124 { 125 rcu_read_unlock(); 126 preempt_enable(); 127 release_sock(sk); 128 } 129 130 static void sock_map_add_link(struct sk_psock *psock, 131 struct sk_psock_link *link, 132 struct bpf_map *map, void *link_raw) 133 { 134 link->link_raw = link_raw; 135 link->map = map; 136 spin_lock_bh(&psock->link_lock); 137 list_add_tail(&link->list, &psock->link); 138 spin_unlock_bh(&psock->link_lock); 139 } 140 141 static void sock_map_del_link(struct sock *sk, 142 struct sk_psock *psock, void *link_raw) 143 { 144 bool strp_stop = false, verdict_stop = false; 145 struct sk_psock_link *link, *tmp; 146 147 spin_lock_bh(&psock->link_lock); 148 list_for_each_entry_safe(link, tmp, &psock->link, list) { 149 if (link->link_raw == link_raw) { 150 struct bpf_map *map = link->map; 151 struct bpf_stab *stab = container_of(map, struct bpf_stab, 152 map); 153 if (psock->saved_data_ready && stab->progs.stream_parser) 154 strp_stop = true; 155 if (psock->saved_data_ready && stab->progs.stream_verdict) 156 verdict_stop = true; 157 if (psock->saved_data_ready && stab->progs.skb_verdict) 158 verdict_stop = true; 159 list_del(&link->list); 160 sk_psock_free_link(link); 161 } 162 } 163 spin_unlock_bh(&psock->link_lock); 164 if (strp_stop || verdict_stop) { 165 write_lock_bh(&sk->sk_callback_lock); 166 if (strp_stop) 167 sk_psock_stop_strp(sk, psock); 168 if (verdict_stop) 169 sk_psock_stop_verdict(sk, psock); 170 171 if (psock->psock_update_sk_prot) 172 psock->psock_update_sk_prot(sk, psock, false); 173 write_unlock_bh(&sk->sk_callback_lock); 174 } 175 } 176 177 static void sock_map_unref(struct sock *sk, void *link_raw) 178 { 179 struct sk_psock *psock = sk_psock(sk); 180 181 if (likely(psock)) { 182 sock_map_del_link(sk, psock, link_raw); 183 sk_psock_put(sk, psock); 184 } 185 } 186 187 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock) 188 { 189 if (!sk->sk_prot->psock_update_sk_prot) 190 return -EINVAL; 191 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot; 192 return sk->sk_prot->psock_update_sk_prot(sk, psock, false); 193 } 194 195 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk) 196 { 197 struct sk_psock *psock; 198 199 rcu_read_lock(); 200 psock = sk_psock(sk); 201 if (psock) { 202 if (sk->sk_prot->close != sock_map_close) { 203 psock = ERR_PTR(-EBUSY); 204 goto out; 205 } 206 207 if (!refcount_inc_not_zero(&psock->refcnt)) 208 psock = ERR_PTR(-EBUSY); 209 } 210 out: 211 rcu_read_unlock(); 212 return psock; 213 } 214 215 static int sock_map_link(struct bpf_map *map, struct sock *sk) 216 { 217 struct sk_psock_progs *progs = sock_map_progs(map); 218 struct bpf_prog *stream_verdict = NULL; 219 struct bpf_prog *stream_parser = NULL; 220 struct bpf_prog *skb_verdict = NULL; 221 struct bpf_prog *msg_parser = NULL; 222 struct sk_psock *psock; 223 int ret; 224 225 stream_verdict = READ_ONCE(progs->stream_verdict); 226 if (stream_verdict) { 227 stream_verdict = bpf_prog_inc_not_zero(stream_verdict); 228 if (IS_ERR(stream_verdict)) 229 return PTR_ERR(stream_verdict); 230 } 231 232 stream_parser = READ_ONCE(progs->stream_parser); 233 if (stream_parser) { 234 stream_parser = bpf_prog_inc_not_zero(stream_parser); 235 if (IS_ERR(stream_parser)) { 236 ret = PTR_ERR(stream_parser); 237 goto out_put_stream_verdict; 238 } 239 } 240 241 msg_parser = READ_ONCE(progs->msg_parser); 242 if (msg_parser) { 243 msg_parser = bpf_prog_inc_not_zero(msg_parser); 244 if (IS_ERR(msg_parser)) { 245 ret = PTR_ERR(msg_parser); 246 goto out_put_stream_parser; 247 } 248 } 249 250 skb_verdict = READ_ONCE(progs->skb_verdict); 251 if (skb_verdict) { 252 skb_verdict = bpf_prog_inc_not_zero(skb_verdict); 253 if (IS_ERR(skb_verdict)) { 254 ret = PTR_ERR(skb_verdict); 255 goto out_put_msg_parser; 256 } 257 } 258 259 psock = sock_map_psock_get_checked(sk); 260 if (IS_ERR(psock)) { 261 ret = PTR_ERR(psock); 262 goto out_progs; 263 } 264 265 if (psock) { 266 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || 267 (stream_parser && READ_ONCE(psock->progs.stream_parser)) || 268 (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) || 269 (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) || 270 (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) || 271 (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) { 272 sk_psock_put(sk, psock); 273 ret = -EBUSY; 274 goto out_progs; 275 } 276 } else { 277 psock = sk_psock_init(sk, map->numa_node); 278 if (IS_ERR(psock)) { 279 ret = PTR_ERR(psock); 280 goto out_progs; 281 } 282 } 283 284 if (msg_parser) 285 psock_set_prog(&psock->progs.msg_parser, msg_parser); 286 if (stream_parser) 287 psock_set_prog(&psock->progs.stream_parser, stream_parser); 288 if (stream_verdict) 289 psock_set_prog(&psock->progs.stream_verdict, stream_verdict); 290 if (skb_verdict) 291 psock_set_prog(&psock->progs.skb_verdict, skb_verdict); 292 293 /* msg_* and stream_* programs references tracked in psock after this 294 * point. Reference dec and cleanup will occur through psock destructor 295 */ 296 ret = sock_map_init_proto(sk, psock); 297 if (ret < 0) { 298 sk_psock_put(sk, psock); 299 goto out; 300 } 301 302 write_lock_bh(&sk->sk_callback_lock); 303 if (stream_parser && stream_verdict && !psock->saved_data_ready) { 304 ret = sk_psock_init_strp(sk, psock); 305 if (ret) { 306 write_unlock_bh(&sk->sk_callback_lock); 307 sk_psock_put(sk, psock); 308 goto out; 309 } 310 sk_psock_start_strp(sk, psock); 311 } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) { 312 sk_psock_start_verdict(sk,psock); 313 } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) { 314 sk_psock_start_verdict(sk, psock); 315 } 316 write_unlock_bh(&sk->sk_callback_lock); 317 return 0; 318 out_progs: 319 if (skb_verdict) 320 bpf_prog_put(skb_verdict); 321 out_put_msg_parser: 322 if (msg_parser) 323 bpf_prog_put(msg_parser); 324 out_put_stream_parser: 325 if (stream_parser) 326 bpf_prog_put(stream_parser); 327 out_put_stream_verdict: 328 if (stream_verdict) 329 bpf_prog_put(stream_verdict); 330 out: 331 return ret; 332 } 333 334 static void sock_map_free(struct bpf_map *map) 335 { 336 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 337 int i; 338 339 /* After the sync no updates or deletes will be in-flight so it 340 * is safe to walk map and remove entries without risking a race 341 * in EEXIST update case. 342 */ 343 synchronize_rcu(); 344 for (i = 0; i < stab->map.max_entries; i++) { 345 struct sock **psk = &stab->sks[i]; 346 struct sock *sk; 347 348 sk = xchg(psk, NULL); 349 if (sk) { 350 sock_hold(sk); 351 lock_sock(sk); 352 rcu_read_lock(); 353 sock_map_unref(sk, psk); 354 rcu_read_unlock(); 355 release_sock(sk); 356 sock_put(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 bpf_map_area_free(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 long 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 sock_map_redirect_allowed(const struct sock *sk) 525 { 526 if (sk_is_tcp(sk)) 527 return sk->sk_state != TCP_LISTEN; 528 else 529 return sk->sk_state == TCP_ESTABLISHED; 530 } 531 532 static bool sock_map_sk_is_suitable(const struct sock *sk) 533 { 534 return !!sk->sk_prot->psock_update_sk_prot; 535 } 536 537 static bool sock_map_sk_state_allowed(const struct sock *sk) 538 { 539 if (sk_is_tcp(sk)) 540 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN); 541 return true; 542 } 543 544 static int sock_hash_update_common(struct bpf_map *map, void *key, 545 struct sock *sk, u64 flags); 546 547 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, 548 u64 flags) 549 { 550 struct socket *sock; 551 struct sock *sk; 552 int ret; 553 u64 ufd; 554 555 if (map->value_size == sizeof(u64)) 556 ufd = *(u64 *)value; 557 else 558 ufd = *(u32 *)value; 559 if (ufd > S32_MAX) 560 return -EINVAL; 561 562 sock = sockfd_lookup(ufd, &ret); 563 if (!sock) 564 return ret; 565 sk = sock->sk; 566 if (!sk) { 567 ret = -EINVAL; 568 goto out; 569 } 570 if (!sock_map_sk_is_suitable(sk)) { 571 ret = -EOPNOTSUPP; 572 goto out; 573 } 574 575 sock_map_sk_acquire(sk); 576 if (!sock_map_sk_state_allowed(sk)) 577 ret = -EOPNOTSUPP; 578 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 579 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 580 else 581 ret = sock_hash_update_common(map, key, sk, flags); 582 sock_map_sk_release(sk); 583 out: 584 sockfd_put(sock); 585 return ret; 586 } 587 588 static long sock_map_update_elem(struct bpf_map *map, void *key, 589 void *value, u64 flags) 590 { 591 struct sock *sk = (struct sock *)value; 592 int ret; 593 594 if (unlikely(!sk || !sk_fullsock(sk))) 595 return -EINVAL; 596 597 if (!sock_map_sk_is_suitable(sk)) 598 return -EOPNOTSUPP; 599 600 local_bh_disable(); 601 bh_lock_sock(sk); 602 if (!sock_map_sk_state_allowed(sk)) 603 ret = -EOPNOTSUPP; 604 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 605 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 606 else 607 ret = sock_hash_update_common(map, key, sk, flags); 608 bh_unlock_sock(sk); 609 local_bh_enable(); 610 return ret; 611 } 612 613 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, 614 struct bpf_map *, map, void *, key, u64, flags) 615 { 616 WARN_ON_ONCE(!rcu_read_lock_held()); 617 618 if (likely(sock_map_sk_is_suitable(sops->sk) && 619 sock_map_op_okay(sops))) 620 return sock_map_update_common(map, *(u32 *)key, sops->sk, 621 flags); 622 return -EOPNOTSUPP; 623 } 624 625 const struct bpf_func_proto bpf_sock_map_update_proto = { 626 .func = bpf_sock_map_update, 627 .gpl_only = false, 628 .pkt_access = true, 629 .ret_type = RET_INTEGER, 630 .arg1_type = ARG_PTR_TO_CTX, 631 .arg2_type = ARG_CONST_MAP_PTR, 632 .arg3_type = ARG_PTR_TO_MAP_KEY, 633 .arg4_type = ARG_ANYTHING, 634 }; 635 636 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, 637 struct bpf_map *, map, u32, key, u64, flags) 638 { 639 struct sock *sk; 640 641 if (unlikely(flags & ~(BPF_F_INGRESS))) 642 return SK_DROP; 643 644 sk = __sock_map_lookup_elem(map, key); 645 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 646 return SK_DROP; 647 648 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); 649 return SK_PASS; 650 } 651 652 const struct bpf_func_proto bpf_sk_redirect_map_proto = { 653 .func = bpf_sk_redirect_map, 654 .gpl_only = false, 655 .ret_type = RET_INTEGER, 656 .arg1_type = ARG_PTR_TO_CTX, 657 .arg2_type = ARG_CONST_MAP_PTR, 658 .arg3_type = ARG_ANYTHING, 659 .arg4_type = ARG_ANYTHING, 660 }; 661 662 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg, 663 struct bpf_map *, map, u32, key, u64, flags) 664 { 665 struct sock *sk; 666 667 if (unlikely(flags & ~(BPF_F_INGRESS))) 668 return SK_DROP; 669 670 sk = __sock_map_lookup_elem(map, key); 671 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 672 return SK_DROP; 673 674 msg->flags = flags; 675 msg->sk_redir = sk; 676 return SK_PASS; 677 } 678 679 const struct bpf_func_proto bpf_msg_redirect_map_proto = { 680 .func = bpf_msg_redirect_map, 681 .gpl_only = false, 682 .ret_type = RET_INTEGER, 683 .arg1_type = ARG_PTR_TO_CTX, 684 .arg2_type = ARG_CONST_MAP_PTR, 685 .arg3_type = ARG_ANYTHING, 686 .arg4_type = ARG_ANYTHING, 687 }; 688 689 struct sock_map_seq_info { 690 struct bpf_map *map; 691 struct sock *sk; 692 u32 index; 693 }; 694 695 struct bpf_iter__sockmap { 696 __bpf_md_ptr(struct bpf_iter_meta *, meta); 697 __bpf_md_ptr(struct bpf_map *, map); 698 __bpf_md_ptr(void *, key); 699 __bpf_md_ptr(struct sock *, sk); 700 }; 701 702 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta, 703 struct bpf_map *map, void *key, 704 struct sock *sk) 705 706 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info) 707 { 708 if (unlikely(info->index >= info->map->max_entries)) 709 return NULL; 710 711 info->sk = __sock_map_lookup_elem(info->map, info->index); 712 713 /* can't return sk directly, since that might be NULL */ 714 return info; 715 } 716 717 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos) 718 __acquires(rcu) 719 { 720 struct sock_map_seq_info *info = seq->private; 721 722 if (*pos == 0) 723 ++*pos; 724 725 /* pairs with sock_map_seq_stop */ 726 rcu_read_lock(); 727 return sock_map_seq_lookup_elem(info); 728 } 729 730 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 731 __must_hold(rcu) 732 { 733 struct sock_map_seq_info *info = seq->private; 734 735 ++*pos; 736 ++info->index; 737 738 return sock_map_seq_lookup_elem(info); 739 } 740 741 static int sock_map_seq_show(struct seq_file *seq, void *v) 742 __must_hold(rcu) 743 { 744 struct sock_map_seq_info *info = seq->private; 745 struct bpf_iter__sockmap ctx = {}; 746 struct bpf_iter_meta meta; 747 struct bpf_prog *prog; 748 749 meta.seq = seq; 750 prog = bpf_iter_get_info(&meta, !v); 751 if (!prog) 752 return 0; 753 754 ctx.meta = &meta; 755 ctx.map = info->map; 756 if (v) { 757 ctx.key = &info->index; 758 ctx.sk = info->sk; 759 } 760 761 return bpf_iter_run_prog(prog, &ctx); 762 } 763 764 static void sock_map_seq_stop(struct seq_file *seq, void *v) 765 __releases(rcu) 766 { 767 if (!v) 768 (void)sock_map_seq_show(seq, NULL); 769 770 /* pairs with sock_map_seq_start */ 771 rcu_read_unlock(); 772 } 773 774 static const struct seq_operations sock_map_seq_ops = { 775 .start = sock_map_seq_start, 776 .next = sock_map_seq_next, 777 .stop = sock_map_seq_stop, 778 .show = sock_map_seq_show, 779 }; 780 781 static int sock_map_init_seq_private(void *priv_data, 782 struct bpf_iter_aux_info *aux) 783 { 784 struct sock_map_seq_info *info = priv_data; 785 786 bpf_map_inc_with_uref(aux->map); 787 info->map = aux->map; 788 return 0; 789 } 790 791 static void sock_map_fini_seq_private(void *priv_data) 792 { 793 struct sock_map_seq_info *info = priv_data; 794 795 bpf_map_put_with_uref(info->map); 796 } 797 798 static u64 sock_map_mem_usage(const struct bpf_map *map) 799 { 800 u64 usage = sizeof(struct bpf_stab); 801 802 usage += (u64)map->max_entries * sizeof(struct sock *); 803 return usage; 804 } 805 806 static const struct bpf_iter_seq_info sock_map_iter_seq_info = { 807 .seq_ops = &sock_map_seq_ops, 808 .init_seq_private = sock_map_init_seq_private, 809 .fini_seq_private = sock_map_fini_seq_private, 810 .seq_priv_size = sizeof(struct sock_map_seq_info), 811 }; 812 813 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab) 814 const struct bpf_map_ops sock_map_ops = { 815 .map_meta_equal = bpf_map_meta_equal, 816 .map_alloc = sock_map_alloc, 817 .map_free = sock_map_free, 818 .map_get_next_key = sock_map_get_next_key, 819 .map_lookup_elem_sys_only = sock_map_lookup_sys, 820 .map_update_elem = sock_map_update_elem, 821 .map_delete_elem = sock_map_delete_elem, 822 .map_lookup_elem = sock_map_lookup, 823 .map_release_uref = sock_map_release_progs, 824 .map_check_btf = map_check_no_btf, 825 .map_mem_usage = sock_map_mem_usage, 826 .map_btf_id = &sock_map_btf_ids[0], 827 .iter_seq_info = &sock_map_iter_seq_info, 828 }; 829 830 struct bpf_shtab_elem { 831 struct rcu_head rcu; 832 u32 hash; 833 struct sock *sk; 834 struct hlist_node node; 835 u8 key[]; 836 }; 837 838 struct bpf_shtab_bucket { 839 struct hlist_head head; 840 raw_spinlock_t lock; 841 }; 842 843 struct bpf_shtab { 844 struct bpf_map map; 845 struct bpf_shtab_bucket *buckets; 846 u32 buckets_num; 847 u32 elem_size; 848 struct sk_psock_progs progs; 849 atomic_t count; 850 }; 851 852 static inline u32 sock_hash_bucket_hash(const void *key, u32 len) 853 { 854 return jhash(key, len, 0); 855 } 856 857 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab, 858 u32 hash) 859 { 860 return &htab->buckets[hash & (htab->buckets_num - 1)]; 861 } 862 863 static struct bpf_shtab_elem * 864 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, 865 u32 key_size) 866 { 867 struct bpf_shtab_elem *elem; 868 869 hlist_for_each_entry_rcu(elem, head, node) { 870 if (elem->hash == hash && 871 !memcmp(&elem->key, key, key_size)) 872 return elem; 873 } 874 875 return NULL; 876 } 877 878 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) 879 { 880 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 881 u32 key_size = map->key_size, hash; 882 struct bpf_shtab_bucket *bucket; 883 struct bpf_shtab_elem *elem; 884 885 WARN_ON_ONCE(!rcu_read_lock_held()); 886 887 hash = sock_hash_bucket_hash(key, key_size); 888 bucket = sock_hash_select_bucket(htab, hash); 889 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 890 891 return elem ? elem->sk : NULL; 892 } 893 894 static void sock_hash_free_elem(struct bpf_shtab *htab, 895 struct bpf_shtab_elem *elem) 896 { 897 atomic_dec(&htab->count); 898 kfree_rcu(elem, rcu); 899 } 900 901 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, 902 void *link_raw) 903 { 904 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 905 struct bpf_shtab_elem *elem_probe, *elem = link_raw; 906 struct bpf_shtab_bucket *bucket; 907 908 WARN_ON_ONCE(!rcu_read_lock_held()); 909 bucket = sock_hash_select_bucket(htab, elem->hash); 910 911 /* elem may be deleted in parallel from the map, but access here 912 * is okay since it's going away only after RCU grace period. 913 * However, we need to check whether it's still present. 914 */ 915 raw_spin_lock_bh(&bucket->lock); 916 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash, 917 elem->key, map->key_size); 918 if (elem_probe && elem_probe == elem) { 919 hlist_del_rcu(&elem->node); 920 sock_map_unref(elem->sk, elem); 921 sock_hash_free_elem(htab, elem); 922 } 923 raw_spin_unlock_bh(&bucket->lock); 924 } 925 926 static long sock_hash_delete_elem(struct bpf_map *map, void *key) 927 { 928 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 929 u32 hash, key_size = map->key_size; 930 struct bpf_shtab_bucket *bucket; 931 struct bpf_shtab_elem *elem; 932 int ret = -ENOENT; 933 934 hash = sock_hash_bucket_hash(key, key_size); 935 bucket = sock_hash_select_bucket(htab, hash); 936 937 raw_spin_lock_bh(&bucket->lock); 938 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 939 if (elem) { 940 hlist_del_rcu(&elem->node); 941 sock_map_unref(elem->sk, elem); 942 sock_hash_free_elem(htab, elem); 943 ret = 0; 944 } 945 raw_spin_unlock_bh(&bucket->lock); 946 return ret; 947 } 948 949 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab, 950 void *key, u32 key_size, 951 u32 hash, struct sock *sk, 952 struct bpf_shtab_elem *old) 953 { 954 struct bpf_shtab_elem *new; 955 956 if (atomic_inc_return(&htab->count) > htab->map.max_entries) { 957 if (!old) { 958 atomic_dec(&htab->count); 959 return ERR_PTR(-E2BIG); 960 } 961 } 962 963 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size, 964 GFP_ATOMIC | __GFP_NOWARN, 965 htab->map.numa_node); 966 if (!new) { 967 atomic_dec(&htab->count); 968 return ERR_PTR(-ENOMEM); 969 } 970 memcpy(new->key, key, key_size); 971 new->sk = sk; 972 new->hash = hash; 973 return new; 974 } 975 976 static int sock_hash_update_common(struct bpf_map *map, void *key, 977 struct sock *sk, u64 flags) 978 { 979 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 980 u32 key_size = map->key_size, hash; 981 struct bpf_shtab_elem *elem, *elem_new; 982 struct bpf_shtab_bucket *bucket; 983 struct sk_psock_link *link; 984 struct sk_psock *psock; 985 int ret; 986 987 WARN_ON_ONCE(!rcu_read_lock_held()); 988 if (unlikely(flags > BPF_EXIST)) 989 return -EINVAL; 990 991 link = sk_psock_init_link(); 992 if (!link) 993 return -ENOMEM; 994 995 ret = sock_map_link(map, sk); 996 if (ret < 0) 997 goto out_free; 998 999 psock = sk_psock(sk); 1000 WARN_ON_ONCE(!psock); 1001 1002 hash = sock_hash_bucket_hash(key, key_size); 1003 bucket = sock_hash_select_bucket(htab, hash); 1004 1005 raw_spin_lock_bh(&bucket->lock); 1006 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 1007 if (elem && flags == BPF_NOEXIST) { 1008 ret = -EEXIST; 1009 goto out_unlock; 1010 } else if (!elem && flags == BPF_EXIST) { 1011 ret = -ENOENT; 1012 goto out_unlock; 1013 } 1014 1015 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); 1016 if (IS_ERR(elem_new)) { 1017 ret = PTR_ERR(elem_new); 1018 goto out_unlock; 1019 } 1020 1021 sock_map_add_link(psock, link, map, elem_new); 1022 /* Add new element to the head of the list, so that 1023 * concurrent search will find it before old elem. 1024 */ 1025 hlist_add_head_rcu(&elem_new->node, &bucket->head); 1026 if (elem) { 1027 hlist_del_rcu(&elem->node); 1028 sock_map_unref(elem->sk, elem); 1029 sock_hash_free_elem(htab, elem); 1030 } 1031 raw_spin_unlock_bh(&bucket->lock); 1032 return 0; 1033 out_unlock: 1034 raw_spin_unlock_bh(&bucket->lock); 1035 sk_psock_put(sk, psock); 1036 out_free: 1037 sk_psock_free_link(link); 1038 return ret; 1039 } 1040 1041 static int sock_hash_get_next_key(struct bpf_map *map, void *key, 1042 void *key_next) 1043 { 1044 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1045 struct bpf_shtab_elem *elem, *elem_next; 1046 u32 hash, key_size = map->key_size; 1047 struct hlist_head *head; 1048 int i = 0; 1049 1050 if (!key) 1051 goto find_first_elem; 1052 hash = sock_hash_bucket_hash(key, key_size); 1053 head = &sock_hash_select_bucket(htab, hash)->head; 1054 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); 1055 if (!elem) 1056 goto find_first_elem; 1057 1058 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)), 1059 struct bpf_shtab_elem, node); 1060 if (elem_next) { 1061 memcpy(key_next, elem_next->key, key_size); 1062 return 0; 1063 } 1064 1065 i = hash & (htab->buckets_num - 1); 1066 i++; 1067 find_first_elem: 1068 for (; i < htab->buckets_num; i++) { 1069 head = &sock_hash_select_bucket(htab, i)->head; 1070 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)), 1071 struct bpf_shtab_elem, node); 1072 if (elem_next) { 1073 memcpy(key_next, elem_next->key, key_size); 1074 return 0; 1075 } 1076 } 1077 1078 return -ENOENT; 1079 } 1080 1081 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) 1082 { 1083 struct bpf_shtab *htab; 1084 int i, err; 1085 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 = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); 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 bpf_map_area_free(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 bpf_map_area_free(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 bpf_map_inc_with_uref(aux->map); 1393 info->map = aux->map; 1394 info->htab = container_of(aux->map, struct bpf_shtab, map); 1395 return 0; 1396 } 1397 1398 static void sock_hash_fini_seq_private(void *priv_data) 1399 { 1400 struct sock_hash_seq_info *info = priv_data; 1401 1402 bpf_map_put_with_uref(info->map); 1403 } 1404 1405 static u64 sock_hash_mem_usage(const struct bpf_map *map) 1406 { 1407 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1408 u64 usage = sizeof(*htab); 1409 1410 usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket); 1411 usage += atomic_read(&htab->count) * (u64)htab->elem_size; 1412 return usage; 1413 } 1414 1415 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = { 1416 .seq_ops = &sock_hash_seq_ops, 1417 .init_seq_private = sock_hash_init_seq_private, 1418 .fini_seq_private = sock_hash_fini_seq_private, 1419 .seq_priv_size = sizeof(struct sock_hash_seq_info), 1420 }; 1421 1422 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab) 1423 const struct bpf_map_ops sock_hash_ops = { 1424 .map_meta_equal = bpf_map_meta_equal, 1425 .map_alloc = sock_hash_alloc, 1426 .map_free = sock_hash_free, 1427 .map_get_next_key = sock_hash_get_next_key, 1428 .map_update_elem = sock_map_update_elem, 1429 .map_delete_elem = sock_hash_delete_elem, 1430 .map_lookup_elem = sock_hash_lookup, 1431 .map_lookup_elem_sys_only = sock_hash_lookup_sys, 1432 .map_release_uref = sock_hash_release_progs, 1433 .map_check_btf = map_check_no_btf, 1434 .map_mem_usage = sock_hash_mem_usage, 1435 .map_btf_id = &sock_hash_map_btf_ids[0], 1436 .iter_seq_info = &sock_hash_iter_seq_info, 1437 }; 1438 1439 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 1440 { 1441 switch (map->map_type) { 1442 case BPF_MAP_TYPE_SOCKMAP: 1443 return &container_of(map, struct bpf_stab, map)->progs; 1444 case BPF_MAP_TYPE_SOCKHASH: 1445 return &container_of(map, struct bpf_shtab, map)->progs; 1446 default: 1447 break; 1448 } 1449 1450 return NULL; 1451 } 1452 1453 static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog, 1454 u32 which) 1455 { 1456 struct sk_psock_progs *progs = sock_map_progs(map); 1457 1458 if (!progs) 1459 return -EOPNOTSUPP; 1460 1461 switch (which) { 1462 case BPF_SK_MSG_VERDICT: 1463 *pprog = &progs->msg_parser; 1464 break; 1465 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) 1466 case BPF_SK_SKB_STREAM_PARSER: 1467 *pprog = &progs->stream_parser; 1468 break; 1469 #endif 1470 case BPF_SK_SKB_STREAM_VERDICT: 1471 if (progs->skb_verdict) 1472 return -EBUSY; 1473 *pprog = &progs->stream_verdict; 1474 break; 1475 case BPF_SK_SKB_VERDICT: 1476 if (progs->stream_verdict) 1477 return -EBUSY; 1478 *pprog = &progs->skb_verdict; 1479 break; 1480 default: 1481 return -EOPNOTSUPP; 1482 } 1483 1484 return 0; 1485 } 1486 1487 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 1488 struct bpf_prog *old, u32 which) 1489 { 1490 struct bpf_prog **pprog; 1491 int ret; 1492 1493 ret = sock_map_prog_lookup(map, &pprog, which); 1494 if (ret) 1495 return ret; 1496 1497 if (old) 1498 return psock_replace_prog(pprog, prog, old); 1499 1500 psock_set_prog(pprog, prog); 1501 return 0; 1502 } 1503 1504 int sock_map_bpf_prog_query(const union bpf_attr *attr, 1505 union bpf_attr __user *uattr) 1506 { 1507 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); 1508 u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd; 1509 struct bpf_prog **pprog; 1510 struct bpf_prog *prog; 1511 struct bpf_map *map; 1512 struct fd f; 1513 u32 id = 0; 1514 int ret; 1515 1516 if (attr->query.query_flags) 1517 return -EINVAL; 1518 1519 f = fdget(ufd); 1520 map = __bpf_map_get(f); 1521 if (IS_ERR(map)) 1522 return PTR_ERR(map); 1523 1524 rcu_read_lock(); 1525 1526 ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type); 1527 if (ret) 1528 goto end; 1529 1530 prog = *pprog; 1531 prog_cnt = !prog ? 0 : 1; 1532 1533 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) 1534 goto end; 1535 1536 /* we do not hold the refcnt, the bpf prog may be released 1537 * asynchronously and the id would be set to 0. 1538 */ 1539 id = data_race(prog->aux->id); 1540 if (id == 0) 1541 prog_cnt = 0; 1542 1543 end: 1544 rcu_read_unlock(); 1545 1546 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) || 1547 (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) || 1548 copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) 1549 ret = -EFAULT; 1550 1551 fdput(f); 1552 return ret; 1553 } 1554 1555 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link) 1556 { 1557 switch (link->map->map_type) { 1558 case BPF_MAP_TYPE_SOCKMAP: 1559 return sock_map_delete_from_link(link->map, sk, 1560 link->link_raw); 1561 case BPF_MAP_TYPE_SOCKHASH: 1562 return sock_hash_delete_from_link(link->map, sk, 1563 link->link_raw); 1564 default: 1565 break; 1566 } 1567 } 1568 1569 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock) 1570 { 1571 struct sk_psock_link *link; 1572 1573 while ((link = sk_psock_link_pop(psock))) { 1574 sock_map_unlink(sk, link); 1575 sk_psock_free_link(link); 1576 } 1577 } 1578 1579 void sock_map_unhash(struct sock *sk) 1580 { 1581 void (*saved_unhash)(struct sock *sk); 1582 struct sk_psock *psock; 1583 1584 rcu_read_lock(); 1585 psock = sk_psock(sk); 1586 if (unlikely(!psock)) { 1587 rcu_read_unlock(); 1588 saved_unhash = READ_ONCE(sk->sk_prot)->unhash; 1589 } else { 1590 saved_unhash = psock->saved_unhash; 1591 sock_map_remove_links(sk, psock); 1592 rcu_read_unlock(); 1593 } 1594 if (WARN_ON_ONCE(saved_unhash == sock_map_unhash)) 1595 return; 1596 if (saved_unhash) 1597 saved_unhash(sk); 1598 } 1599 EXPORT_SYMBOL_GPL(sock_map_unhash); 1600 1601 void sock_map_destroy(struct sock *sk) 1602 { 1603 void (*saved_destroy)(struct sock *sk); 1604 struct sk_psock *psock; 1605 1606 rcu_read_lock(); 1607 psock = sk_psock_get(sk); 1608 if (unlikely(!psock)) { 1609 rcu_read_unlock(); 1610 saved_destroy = READ_ONCE(sk->sk_prot)->destroy; 1611 } else { 1612 saved_destroy = psock->saved_destroy; 1613 sock_map_remove_links(sk, psock); 1614 rcu_read_unlock(); 1615 sk_psock_stop(psock); 1616 sk_psock_put(sk, psock); 1617 } 1618 if (WARN_ON_ONCE(saved_destroy == sock_map_destroy)) 1619 return; 1620 if (saved_destroy) 1621 saved_destroy(sk); 1622 } 1623 EXPORT_SYMBOL_GPL(sock_map_destroy); 1624 1625 void sock_map_close(struct sock *sk, long timeout) 1626 { 1627 void (*saved_close)(struct sock *sk, long timeout); 1628 struct sk_psock *psock; 1629 1630 lock_sock(sk); 1631 rcu_read_lock(); 1632 psock = sk_psock_get(sk); 1633 if (unlikely(!psock)) { 1634 rcu_read_unlock(); 1635 release_sock(sk); 1636 saved_close = READ_ONCE(sk->sk_prot)->close; 1637 } else { 1638 saved_close = psock->saved_close; 1639 sock_map_remove_links(sk, psock); 1640 rcu_read_unlock(); 1641 sk_psock_stop(psock); 1642 release_sock(sk); 1643 cancel_delayed_work_sync(&psock->work); 1644 sk_psock_put(sk, psock); 1645 } 1646 1647 /* Make sure we do not recurse. This is a bug. 1648 * Leak the socket instead of crashing on a stack overflow. 1649 */ 1650 if (WARN_ON_ONCE(saved_close == sock_map_close)) 1651 return; 1652 saved_close(sk, timeout); 1653 } 1654 EXPORT_SYMBOL_GPL(sock_map_close); 1655 1656 static int sock_map_iter_attach_target(struct bpf_prog *prog, 1657 union bpf_iter_link_info *linfo, 1658 struct bpf_iter_aux_info *aux) 1659 { 1660 struct bpf_map *map; 1661 int err = -EINVAL; 1662 1663 if (!linfo->map.map_fd) 1664 return -EBADF; 1665 1666 map = bpf_map_get_with_uref(linfo->map.map_fd); 1667 if (IS_ERR(map)) 1668 return PTR_ERR(map); 1669 1670 if (map->map_type != BPF_MAP_TYPE_SOCKMAP && 1671 map->map_type != BPF_MAP_TYPE_SOCKHASH) 1672 goto put_map; 1673 1674 if (prog->aux->max_rdonly_access > map->key_size) { 1675 err = -EACCES; 1676 goto put_map; 1677 } 1678 1679 aux->map = map; 1680 return 0; 1681 1682 put_map: 1683 bpf_map_put_with_uref(map); 1684 return err; 1685 } 1686 1687 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux) 1688 { 1689 bpf_map_put_with_uref(aux->map); 1690 } 1691 1692 static struct bpf_iter_reg sock_map_iter_reg = { 1693 .target = "sockmap", 1694 .attach_target = sock_map_iter_attach_target, 1695 .detach_target = sock_map_iter_detach_target, 1696 .show_fdinfo = bpf_iter_map_show_fdinfo, 1697 .fill_link_info = bpf_iter_map_fill_link_info, 1698 .ctx_arg_info_size = 2, 1699 .ctx_arg_info = { 1700 { offsetof(struct bpf_iter__sockmap, key), 1701 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY }, 1702 { offsetof(struct bpf_iter__sockmap, sk), 1703 PTR_TO_BTF_ID_OR_NULL }, 1704 }, 1705 }; 1706 1707 static int __init bpf_sockmap_iter_init(void) 1708 { 1709 sock_map_iter_reg.ctx_arg_info[1].btf_id = 1710 btf_sock_ids[BTF_SOCK_TYPE_SOCK]; 1711 return bpf_iter_reg_target(&sock_map_iter_reg); 1712 } 1713 late_initcall(bpf_sockmap_iter_init); 1714