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/filter.h> 6 #include <linux/errno.h> 7 #include <linux/file.h> 8 #include <linux/net.h> 9 #include <linux/workqueue.h> 10 #include <linux/skmsg.h> 11 #include <linux/list.h> 12 #include <linux/jhash.h> 13 14 struct bpf_stab { 15 struct bpf_map map; 16 struct sock **sks; 17 struct sk_psock_progs progs; 18 raw_spinlock_t lock; 19 }; 20 21 #define SOCK_CREATE_FLAG_MASK \ 22 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) 23 24 static struct bpf_map *sock_map_alloc(union bpf_attr *attr) 25 { 26 struct bpf_stab *stab; 27 u64 cost; 28 int err; 29 30 if (!capable(CAP_NET_ADMIN)) 31 return ERR_PTR(-EPERM); 32 if (attr->max_entries == 0 || 33 attr->key_size != 4 || 34 attr->value_size != 4 || 35 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 36 return ERR_PTR(-EINVAL); 37 38 stab = kzalloc(sizeof(*stab), GFP_USER); 39 if (!stab) 40 return ERR_PTR(-ENOMEM); 41 42 bpf_map_init_from_attr(&stab->map, attr); 43 raw_spin_lock_init(&stab->lock); 44 45 /* Make sure page count doesn't overflow. */ 46 cost = (u64) stab->map.max_entries * sizeof(struct sock *); 47 if (cost >= U32_MAX - PAGE_SIZE) { 48 err = -EINVAL; 49 goto free_stab; 50 } 51 52 stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; 53 err = bpf_map_precharge_memlock(stab->map.pages); 54 if (err) 55 goto free_stab; 56 57 stab->sks = bpf_map_area_alloc(stab->map.max_entries * 58 sizeof(struct sock *), 59 stab->map.numa_node); 60 if (stab->sks) 61 return &stab->map; 62 err = -ENOMEM; 63 free_stab: 64 kfree(stab); 65 return ERR_PTR(err); 66 } 67 68 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) 69 { 70 u32 ufd = attr->target_fd; 71 struct bpf_map *map; 72 struct fd f; 73 int ret; 74 75 f = fdget(ufd); 76 map = __bpf_map_get(f); 77 if (IS_ERR(map)) 78 return PTR_ERR(map); 79 ret = sock_map_prog_update(map, prog, attr->attach_type); 80 fdput(f); 81 return ret; 82 } 83 84 static void sock_map_sk_acquire(struct sock *sk) 85 __acquires(&sk->sk_lock.slock) 86 { 87 lock_sock(sk); 88 preempt_disable(); 89 rcu_read_lock(); 90 } 91 92 static void sock_map_sk_release(struct sock *sk) 93 __releases(&sk->sk_lock.slock) 94 { 95 rcu_read_unlock(); 96 preempt_enable(); 97 release_sock(sk); 98 } 99 100 static void sock_map_add_link(struct sk_psock *psock, 101 struct sk_psock_link *link, 102 struct bpf_map *map, void *link_raw) 103 { 104 link->link_raw = link_raw; 105 link->map = map; 106 spin_lock_bh(&psock->link_lock); 107 list_add_tail(&link->list, &psock->link); 108 spin_unlock_bh(&psock->link_lock); 109 } 110 111 static void sock_map_del_link(struct sock *sk, 112 struct sk_psock *psock, void *link_raw) 113 { 114 struct sk_psock_link *link, *tmp; 115 bool strp_stop = false; 116 117 spin_lock_bh(&psock->link_lock); 118 list_for_each_entry_safe(link, tmp, &psock->link, list) { 119 if (link->link_raw == link_raw) { 120 struct bpf_map *map = link->map; 121 struct bpf_stab *stab = container_of(map, struct bpf_stab, 122 map); 123 if (psock->parser.enabled && stab->progs.skb_parser) 124 strp_stop = true; 125 list_del(&link->list); 126 sk_psock_free_link(link); 127 } 128 } 129 spin_unlock_bh(&psock->link_lock); 130 if (strp_stop) { 131 write_lock_bh(&sk->sk_callback_lock); 132 sk_psock_stop_strp(sk, psock); 133 write_unlock_bh(&sk->sk_callback_lock); 134 } 135 } 136 137 static void sock_map_unref(struct sock *sk, void *link_raw) 138 { 139 struct sk_psock *psock = sk_psock(sk); 140 141 if (likely(psock)) { 142 sock_map_del_link(sk, psock, link_raw); 143 sk_psock_put(sk, psock); 144 } 145 } 146 147 static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, 148 struct sock *sk) 149 { 150 struct bpf_prog *msg_parser, *skb_parser, *skb_verdict; 151 bool skb_progs, sk_psock_is_new = false; 152 struct sk_psock *psock; 153 int ret; 154 155 skb_verdict = READ_ONCE(progs->skb_verdict); 156 skb_parser = READ_ONCE(progs->skb_parser); 157 skb_progs = skb_parser && skb_verdict; 158 if (skb_progs) { 159 skb_verdict = bpf_prog_inc_not_zero(skb_verdict); 160 if (IS_ERR(skb_verdict)) 161 return PTR_ERR(skb_verdict); 162 skb_parser = bpf_prog_inc_not_zero(skb_parser); 163 if (IS_ERR(skb_parser)) { 164 bpf_prog_put(skb_verdict); 165 return PTR_ERR(skb_parser); 166 } 167 } 168 169 msg_parser = READ_ONCE(progs->msg_parser); 170 if (msg_parser) { 171 msg_parser = bpf_prog_inc_not_zero(msg_parser); 172 if (IS_ERR(msg_parser)) { 173 ret = PTR_ERR(msg_parser); 174 goto out; 175 } 176 } 177 178 psock = sk_psock_get_checked(sk); 179 if (IS_ERR(psock)) { 180 ret = PTR_ERR(psock); 181 goto out_progs; 182 } 183 184 if (psock) { 185 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || 186 (skb_progs && READ_ONCE(psock->progs.skb_parser))) { 187 sk_psock_put(sk, psock); 188 ret = -EBUSY; 189 goto out_progs; 190 } 191 } else { 192 psock = sk_psock_init(sk, map->numa_node); 193 if (!psock) { 194 ret = -ENOMEM; 195 goto out_progs; 196 } 197 sk_psock_is_new = true; 198 } 199 200 if (msg_parser) 201 psock_set_prog(&psock->progs.msg_parser, msg_parser); 202 if (sk_psock_is_new) { 203 ret = tcp_bpf_init(sk); 204 if (ret < 0) 205 goto out_drop; 206 } else { 207 tcp_bpf_reinit(sk); 208 } 209 210 write_lock_bh(&sk->sk_callback_lock); 211 if (skb_progs && !psock->parser.enabled) { 212 ret = sk_psock_init_strp(sk, psock); 213 if (ret) { 214 write_unlock_bh(&sk->sk_callback_lock); 215 goto out_drop; 216 } 217 psock_set_prog(&psock->progs.skb_verdict, skb_verdict); 218 psock_set_prog(&psock->progs.skb_parser, skb_parser); 219 sk_psock_start_strp(sk, psock); 220 } 221 write_unlock_bh(&sk->sk_callback_lock); 222 return 0; 223 out_drop: 224 sk_psock_put(sk, psock); 225 out_progs: 226 if (msg_parser) 227 bpf_prog_put(msg_parser); 228 out: 229 if (skb_progs) { 230 bpf_prog_put(skb_verdict); 231 bpf_prog_put(skb_parser); 232 } 233 return ret; 234 } 235 236 static void sock_map_free(struct bpf_map *map) 237 { 238 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 239 int i; 240 241 synchronize_rcu(); 242 rcu_read_lock(); 243 raw_spin_lock_bh(&stab->lock); 244 for (i = 0; i < stab->map.max_entries; i++) { 245 struct sock **psk = &stab->sks[i]; 246 struct sock *sk; 247 248 sk = xchg(psk, NULL); 249 if (sk) 250 sock_map_unref(sk, psk); 251 } 252 raw_spin_unlock_bh(&stab->lock); 253 rcu_read_unlock(); 254 255 bpf_map_area_free(stab->sks); 256 kfree(stab); 257 } 258 259 static void sock_map_release_progs(struct bpf_map *map) 260 { 261 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); 262 } 263 264 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) 265 { 266 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 267 268 WARN_ON_ONCE(!rcu_read_lock_held()); 269 270 if (unlikely(key >= map->max_entries)) 271 return NULL; 272 return READ_ONCE(stab->sks[key]); 273 } 274 275 static void *sock_map_lookup(struct bpf_map *map, void *key) 276 { 277 return ERR_PTR(-EOPNOTSUPP); 278 } 279 280 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, 281 struct sock **psk) 282 { 283 struct sock *sk; 284 285 raw_spin_lock_bh(&stab->lock); 286 sk = *psk; 287 if (!sk_test || sk_test == sk) 288 *psk = NULL; 289 raw_spin_unlock_bh(&stab->lock); 290 if (unlikely(!sk)) 291 return -EINVAL; 292 sock_map_unref(sk, psk); 293 return 0; 294 } 295 296 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, 297 void *link_raw) 298 { 299 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 300 301 __sock_map_delete(stab, sk, link_raw); 302 } 303 304 static int sock_map_delete_elem(struct bpf_map *map, void *key) 305 { 306 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 307 u32 i = *(u32 *)key; 308 struct sock **psk; 309 310 if (unlikely(i >= map->max_entries)) 311 return -EINVAL; 312 313 psk = &stab->sks[i]; 314 return __sock_map_delete(stab, NULL, psk); 315 } 316 317 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next) 318 { 319 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 320 u32 i = key ? *(u32 *)key : U32_MAX; 321 u32 *key_next = next; 322 323 if (i == stab->map.max_entries - 1) 324 return -ENOENT; 325 if (i >= stab->map.max_entries) 326 *key_next = 0; 327 else 328 *key_next = i + 1; 329 return 0; 330 } 331 332 static int sock_map_update_common(struct bpf_map *map, u32 idx, 333 struct sock *sk, u64 flags) 334 { 335 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 336 struct sk_psock_link *link; 337 struct sk_psock *psock; 338 struct sock *osk; 339 int ret; 340 341 WARN_ON_ONCE(!rcu_read_lock_held()); 342 if (unlikely(flags > BPF_EXIST)) 343 return -EINVAL; 344 if (unlikely(idx >= map->max_entries)) 345 return -E2BIG; 346 347 link = sk_psock_init_link(); 348 if (!link) 349 return -ENOMEM; 350 351 ret = sock_map_link(map, &stab->progs, sk); 352 if (ret < 0) 353 goto out_free; 354 355 psock = sk_psock(sk); 356 WARN_ON_ONCE(!psock); 357 358 raw_spin_lock_bh(&stab->lock); 359 osk = stab->sks[idx]; 360 if (osk && flags == BPF_NOEXIST) { 361 ret = -EEXIST; 362 goto out_unlock; 363 } else if (!osk && flags == BPF_EXIST) { 364 ret = -ENOENT; 365 goto out_unlock; 366 } 367 368 sock_map_add_link(psock, link, map, &stab->sks[idx]); 369 stab->sks[idx] = sk; 370 if (osk) 371 sock_map_unref(osk, &stab->sks[idx]); 372 raw_spin_unlock_bh(&stab->lock); 373 return 0; 374 out_unlock: 375 raw_spin_unlock_bh(&stab->lock); 376 if (psock) 377 sk_psock_put(sk, psock); 378 out_free: 379 sk_psock_free_link(link); 380 return ret; 381 } 382 383 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops) 384 { 385 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || 386 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB; 387 } 388 389 static bool sock_map_sk_is_suitable(const struct sock *sk) 390 { 391 return sk->sk_type == SOCK_STREAM && 392 sk->sk_protocol == IPPROTO_TCP; 393 } 394 395 static int sock_map_update_elem(struct bpf_map *map, void *key, 396 void *value, u64 flags) 397 { 398 u32 ufd = *(u32 *)value; 399 u32 idx = *(u32 *)key; 400 struct socket *sock; 401 struct sock *sk; 402 int ret; 403 404 sock = sockfd_lookup(ufd, &ret); 405 if (!sock) 406 return ret; 407 sk = sock->sk; 408 if (!sk) { 409 ret = -EINVAL; 410 goto out; 411 } 412 if (!sock_map_sk_is_suitable(sk) || 413 sk->sk_state != TCP_ESTABLISHED) { 414 ret = -EOPNOTSUPP; 415 goto out; 416 } 417 418 sock_map_sk_acquire(sk); 419 ret = sock_map_update_common(map, idx, sk, flags); 420 sock_map_sk_release(sk); 421 out: 422 fput(sock->file); 423 return ret; 424 } 425 426 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, 427 struct bpf_map *, map, void *, key, u64, flags) 428 { 429 WARN_ON_ONCE(!rcu_read_lock_held()); 430 431 if (likely(sock_map_sk_is_suitable(sops->sk) && 432 sock_map_op_okay(sops))) 433 return sock_map_update_common(map, *(u32 *)key, sops->sk, 434 flags); 435 return -EOPNOTSUPP; 436 } 437 438 const struct bpf_func_proto bpf_sock_map_update_proto = { 439 .func = bpf_sock_map_update, 440 .gpl_only = false, 441 .pkt_access = true, 442 .ret_type = RET_INTEGER, 443 .arg1_type = ARG_PTR_TO_CTX, 444 .arg2_type = ARG_CONST_MAP_PTR, 445 .arg3_type = ARG_PTR_TO_MAP_KEY, 446 .arg4_type = ARG_ANYTHING, 447 }; 448 449 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, 450 struct bpf_map *, map, u32, key, u64, flags) 451 { 452 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 453 454 if (unlikely(flags & ~(BPF_F_INGRESS))) 455 return SK_DROP; 456 tcb->bpf.flags = flags; 457 tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key); 458 if (!tcb->bpf.sk_redir) 459 return SK_DROP; 460 return SK_PASS; 461 } 462 463 const struct bpf_func_proto bpf_sk_redirect_map_proto = { 464 .func = bpf_sk_redirect_map, 465 .gpl_only = false, 466 .ret_type = RET_INTEGER, 467 .arg1_type = ARG_PTR_TO_CTX, 468 .arg2_type = ARG_CONST_MAP_PTR, 469 .arg3_type = ARG_ANYTHING, 470 .arg4_type = ARG_ANYTHING, 471 }; 472 473 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg, 474 struct bpf_map *, map, u32, key, u64, flags) 475 { 476 if (unlikely(flags & ~(BPF_F_INGRESS))) 477 return SK_DROP; 478 msg->flags = flags; 479 msg->sk_redir = __sock_map_lookup_elem(map, key); 480 if (!msg->sk_redir) 481 return SK_DROP; 482 return SK_PASS; 483 } 484 485 const struct bpf_func_proto bpf_msg_redirect_map_proto = { 486 .func = bpf_msg_redirect_map, 487 .gpl_only = false, 488 .ret_type = RET_INTEGER, 489 .arg1_type = ARG_PTR_TO_CTX, 490 .arg2_type = ARG_CONST_MAP_PTR, 491 .arg3_type = ARG_ANYTHING, 492 .arg4_type = ARG_ANYTHING, 493 }; 494 495 const struct bpf_map_ops sock_map_ops = { 496 .map_alloc = sock_map_alloc, 497 .map_free = sock_map_free, 498 .map_get_next_key = sock_map_get_next_key, 499 .map_update_elem = sock_map_update_elem, 500 .map_delete_elem = sock_map_delete_elem, 501 .map_lookup_elem = sock_map_lookup, 502 .map_release_uref = sock_map_release_progs, 503 .map_check_btf = map_check_no_btf, 504 }; 505 506 struct bpf_htab_elem { 507 struct rcu_head rcu; 508 u32 hash; 509 struct sock *sk; 510 struct hlist_node node; 511 u8 key[0]; 512 }; 513 514 struct bpf_htab_bucket { 515 struct hlist_head head; 516 raw_spinlock_t lock; 517 }; 518 519 struct bpf_htab { 520 struct bpf_map map; 521 struct bpf_htab_bucket *buckets; 522 u32 buckets_num; 523 u32 elem_size; 524 struct sk_psock_progs progs; 525 atomic_t count; 526 }; 527 528 static inline u32 sock_hash_bucket_hash(const void *key, u32 len) 529 { 530 return jhash(key, len, 0); 531 } 532 533 static struct bpf_htab_bucket *sock_hash_select_bucket(struct bpf_htab *htab, 534 u32 hash) 535 { 536 return &htab->buckets[hash & (htab->buckets_num - 1)]; 537 } 538 539 static struct bpf_htab_elem * 540 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, 541 u32 key_size) 542 { 543 struct bpf_htab_elem *elem; 544 545 hlist_for_each_entry_rcu(elem, head, node) { 546 if (elem->hash == hash && 547 !memcmp(&elem->key, key, key_size)) 548 return elem; 549 } 550 551 return NULL; 552 } 553 554 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) 555 { 556 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 557 u32 key_size = map->key_size, hash; 558 struct bpf_htab_bucket *bucket; 559 struct bpf_htab_elem *elem; 560 561 WARN_ON_ONCE(!rcu_read_lock_held()); 562 563 hash = sock_hash_bucket_hash(key, key_size); 564 bucket = sock_hash_select_bucket(htab, hash); 565 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 566 567 return elem ? elem->sk : NULL; 568 } 569 570 static void sock_hash_free_elem(struct bpf_htab *htab, 571 struct bpf_htab_elem *elem) 572 { 573 atomic_dec(&htab->count); 574 kfree_rcu(elem, rcu); 575 } 576 577 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, 578 void *link_raw) 579 { 580 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 581 struct bpf_htab_elem *elem_probe, *elem = link_raw; 582 struct bpf_htab_bucket *bucket; 583 584 WARN_ON_ONCE(!rcu_read_lock_held()); 585 bucket = sock_hash_select_bucket(htab, elem->hash); 586 587 /* elem may be deleted in parallel from the map, but access here 588 * is okay since it's going away only after RCU grace period. 589 * However, we need to check whether it's still present. 590 */ 591 raw_spin_lock_bh(&bucket->lock); 592 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash, 593 elem->key, map->key_size); 594 if (elem_probe && elem_probe == elem) { 595 hlist_del_rcu(&elem->node); 596 sock_map_unref(elem->sk, elem); 597 sock_hash_free_elem(htab, elem); 598 } 599 raw_spin_unlock_bh(&bucket->lock); 600 } 601 602 static int sock_hash_delete_elem(struct bpf_map *map, void *key) 603 { 604 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 605 u32 hash, key_size = map->key_size; 606 struct bpf_htab_bucket *bucket; 607 struct bpf_htab_elem *elem; 608 int ret = -ENOENT; 609 610 hash = sock_hash_bucket_hash(key, key_size); 611 bucket = sock_hash_select_bucket(htab, hash); 612 613 raw_spin_lock_bh(&bucket->lock); 614 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 615 if (elem) { 616 hlist_del_rcu(&elem->node); 617 sock_map_unref(elem->sk, elem); 618 sock_hash_free_elem(htab, elem); 619 ret = 0; 620 } 621 raw_spin_unlock_bh(&bucket->lock); 622 return ret; 623 } 624 625 static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab, 626 void *key, u32 key_size, 627 u32 hash, struct sock *sk, 628 struct bpf_htab_elem *old) 629 { 630 struct bpf_htab_elem *new; 631 632 if (atomic_inc_return(&htab->count) > htab->map.max_entries) { 633 if (!old) { 634 atomic_dec(&htab->count); 635 return ERR_PTR(-E2BIG); 636 } 637 } 638 639 new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, 640 htab->map.numa_node); 641 if (!new) { 642 atomic_dec(&htab->count); 643 return ERR_PTR(-ENOMEM); 644 } 645 memcpy(new->key, key, key_size); 646 new->sk = sk; 647 new->hash = hash; 648 return new; 649 } 650 651 static int sock_hash_update_common(struct bpf_map *map, void *key, 652 struct sock *sk, u64 flags) 653 { 654 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 655 u32 key_size = map->key_size, hash; 656 struct bpf_htab_elem *elem, *elem_new; 657 struct bpf_htab_bucket *bucket; 658 struct sk_psock_link *link; 659 struct sk_psock *psock; 660 int ret; 661 662 WARN_ON_ONCE(!rcu_read_lock_held()); 663 if (unlikely(flags > BPF_EXIST)) 664 return -EINVAL; 665 666 link = sk_psock_init_link(); 667 if (!link) 668 return -ENOMEM; 669 670 ret = sock_map_link(map, &htab->progs, sk); 671 if (ret < 0) 672 goto out_free; 673 674 psock = sk_psock(sk); 675 WARN_ON_ONCE(!psock); 676 677 hash = sock_hash_bucket_hash(key, key_size); 678 bucket = sock_hash_select_bucket(htab, hash); 679 680 raw_spin_lock_bh(&bucket->lock); 681 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 682 if (elem && flags == BPF_NOEXIST) { 683 ret = -EEXIST; 684 goto out_unlock; 685 } else if (!elem && flags == BPF_EXIST) { 686 ret = -ENOENT; 687 goto out_unlock; 688 } 689 690 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); 691 if (IS_ERR(elem_new)) { 692 ret = PTR_ERR(elem_new); 693 goto out_unlock; 694 } 695 696 sock_map_add_link(psock, link, map, elem_new); 697 /* Add new element to the head of the list, so that 698 * concurrent search will find it before old elem. 699 */ 700 hlist_add_head_rcu(&elem_new->node, &bucket->head); 701 if (elem) { 702 hlist_del_rcu(&elem->node); 703 sock_map_unref(elem->sk, elem); 704 sock_hash_free_elem(htab, elem); 705 } 706 raw_spin_unlock_bh(&bucket->lock); 707 return 0; 708 out_unlock: 709 raw_spin_unlock_bh(&bucket->lock); 710 sk_psock_put(sk, psock); 711 out_free: 712 sk_psock_free_link(link); 713 return ret; 714 } 715 716 static int sock_hash_update_elem(struct bpf_map *map, void *key, 717 void *value, u64 flags) 718 { 719 u32 ufd = *(u32 *)value; 720 struct socket *sock; 721 struct sock *sk; 722 int ret; 723 724 sock = sockfd_lookup(ufd, &ret); 725 if (!sock) 726 return ret; 727 sk = sock->sk; 728 if (!sk) { 729 ret = -EINVAL; 730 goto out; 731 } 732 if (!sock_map_sk_is_suitable(sk) || 733 sk->sk_state != TCP_ESTABLISHED) { 734 ret = -EOPNOTSUPP; 735 goto out; 736 } 737 738 sock_map_sk_acquire(sk); 739 ret = sock_hash_update_common(map, key, sk, flags); 740 sock_map_sk_release(sk); 741 out: 742 fput(sock->file); 743 return ret; 744 } 745 746 static int sock_hash_get_next_key(struct bpf_map *map, void *key, 747 void *key_next) 748 { 749 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 750 struct bpf_htab_elem *elem, *elem_next; 751 u32 hash, key_size = map->key_size; 752 struct hlist_head *head; 753 int i = 0; 754 755 if (!key) 756 goto find_first_elem; 757 hash = sock_hash_bucket_hash(key, key_size); 758 head = &sock_hash_select_bucket(htab, hash)->head; 759 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); 760 if (!elem) 761 goto find_first_elem; 762 763 elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)), 764 struct bpf_htab_elem, node); 765 if (elem_next) { 766 memcpy(key_next, elem_next->key, key_size); 767 return 0; 768 } 769 770 i = hash & (htab->buckets_num - 1); 771 i++; 772 find_first_elem: 773 for (; i < htab->buckets_num; i++) { 774 head = &sock_hash_select_bucket(htab, i)->head; 775 elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)), 776 struct bpf_htab_elem, node); 777 if (elem_next) { 778 memcpy(key_next, elem_next->key, key_size); 779 return 0; 780 } 781 } 782 783 return -ENOENT; 784 } 785 786 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) 787 { 788 struct bpf_htab *htab; 789 int i, err; 790 u64 cost; 791 792 if (!capable(CAP_NET_ADMIN)) 793 return ERR_PTR(-EPERM); 794 if (attr->max_entries == 0 || 795 attr->key_size == 0 || 796 attr->value_size != 4 || 797 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 798 return ERR_PTR(-EINVAL); 799 if (attr->key_size > MAX_BPF_STACK) 800 return ERR_PTR(-E2BIG); 801 802 htab = kzalloc(sizeof(*htab), GFP_USER); 803 if (!htab) 804 return ERR_PTR(-ENOMEM); 805 806 bpf_map_init_from_attr(&htab->map, attr); 807 808 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries); 809 htab->elem_size = sizeof(struct bpf_htab_elem) + 810 round_up(htab->map.key_size, 8); 811 if (htab->buckets_num == 0 || 812 htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) { 813 err = -EINVAL; 814 goto free_htab; 815 } 816 817 cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) + 818 (u64) htab->elem_size * htab->map.max_entries; 819 if (cost >= U32_MAX - PAGE_SIZE) { 820 err = -EINVAL; 821 goto free_htab; 822 } 823 824 htab->buckets = bpf_map_area_alloc(htab->buckets_num * 825 sizeof(struct bpf_htab_bucket), 826 htab->map.numa_node); 827 if (!htab->buckets) { 828 err = -ENOMEM; 829 goto free_htab; 830 } 831 832 for (i = 0; i < htab->buckets_num; i++) { 833 INIT_HLIST_HEAD(&htab->buckets[i].head); 834 raw_spin_lock_init(&htab->buckets[i].lock); 835 } 836 837 return &htab->map; 838 free_htab: 839 kfree(htab); 840 return ERR_PTR(err); 841 } 842 843 static void sock_hash_free(struct bpf_map *map) 844 { 845 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 846 struct bpf_htab_bucket *bucket; 847 struct bpf_htab_elem *elem; 848 struct hlist_node *node; 849 int i; 850 851 synchronize_rcu(); 852 rcu_read_lock(); 853 for (i = 0; i < htab->buckets_num; i++) { 854 bucket = sock_hash_select_bucket(htab, i); 855 raw_spin_lock_bh(&bucket->lock); 856 hlist_for_each_entry_safe(elem, node, &bucket->head, node) { 857 hlist_del_rcu(&elem->node); 858 sock_map_unref(elem->sk, elem); 859 } 860 raw_spin_unlock_bh(&bucket->lock); 861 } 862 rcu_read_unlock(); 863 864 bpf_map_area_free(htab->buckets); 865 kfree(htab); 866 } 867 868 static void sock_hash_release_progs(struct bpf_map *map) 869 { 870 psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs); 871 } 872 873 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, 874 struct bpf_map *, map, void *, key, u64, flags) 875 { 876 WARN_ON_ONCE(!rcu_read_lock_held()); 877 878 if (likely(sock_map_sk_is_suitable(sops->sk) && 879 sock_map_op_okay(sops))) 880 return sock_hash_update_common(map, key, sops->sk, flags); 881 return -EOPNOTSUPP; 882 } 883 884 const struct bpf_func_proto bpf_sock_hash_update_proto = { 885 .func = bpf_sock_hash_update, 886 .gpl_only = false, 887 .pkt_access = true, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_PTR_TO_CTX, 890 .arg2_type = ARG_CONST_MAP_PTR, 891 .arg3_type = ARG_PTR_TO_MAP_KEY, 892 .arg4_type = ARG_ANYTHING, 893 }; 894 895 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, 896 struct bpf_map *, map, void *, key, u64, flags) 897 { 898 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 899 900 if (unlikely(flags & ~(BPF_F_INGRESS))) 901 return SK_DROP; 902 tcb->bpf.flags = flags; 903 tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key); 904 if (!tcb->bpf.sk_redir) 905 return SK_DROP; 906 return SK_PASS; 907 } 908 909 const struct bpf_func_proto bpf_sk_redirect_hash_proto = { 910 .func = bpf_sk_redirect_hash, 911 .gpl_only = false, 912 .ret_type = RET_INTEGER, 913 .arg1_type = ARG_PTR_TO_CTX, 914 .arg2_type = ARG_CONST_MAP_PTR, 915 .arg3_type = ARG_PTR_TO_MAP_KEY, 916 .arg4_type = ARG_ANYTHING, 917 }; 918 919 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg, 920 struct bpf_map *, map, void *, key, u64, flags) 921 { 922 if (unlikely(flags & ~(BPF_F_INGRESS))) 923 return SK_DROP; 924 msg->flags = flags; 925 msg->sk_redir = __sock_hash_lookup_elem(map, key); 926 if (!msg->sk_redir) 927 return SK_DROP; 928 return SK_PASS; 929 } 930 931 const struct bpf_func_proto bpf_msg_redirect_hash_proto = { 932 .func = bpf_msg_redirect_hash, 933 .gpl_only = false, 934 .ret_type = RET_INTEGER, 935 .arg1_type = ARG_PTR_TO_CTX, 936 .arg2_type = ARG_CONST_MAP_PTR, 937 .arg3_type = ARG_PTR_TO_MAP_KEY, 938 .arg4_type = ARG_ANYTHING, 939 }; 940 941 const struct bpf_map_ops sock_hash_ops = { 942 .map_alloc = sock_hash_alloc, 943 .map_free = sock_hash_free, 944 .map_get_next_key = sock_hash_get_next_key, 945 .map_update_elem = sock_hash_update_elem, 946 .map_delete_elem = sock_hash_delete_elem, 947 .map_lookup_elem = sock_map_lookup, 948 .map_release_uref = sock_hash_release_progs, 949 .map_check_btf = map_check_no_btf, 950 }; 951 952 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 953 { 954 switch (map->map_type) { 955 case BPF_MAP_TYPE_SOCKMAP: 956 return &container_of(map, struct bpf_stab, map)->progs; 957 case BPF_MAP_TYPE_SOCKHASH: 958 return &container_of(map, struct bpf_htab, map)->progs; 959 default: 960 break; 961 } 962 963 return NULL; 964 } 965 966 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 967 u32 which) 968 { 969 struct sk_psock_progs *progs = sock_map_progs(map); 970 971 if (!progs) 972 return -EOPNOTSUPP; 973 974 switch (which) { 975 case BPF_SK_MSG_VERDICT: 976 psock_set_prog(&progs->msg_parser, prog); 977 break; 978 case BPF_SK_SKB_STREAM_PARSER: 979 psock_set_prog(&progs->skb_parser, prog); 980 break; 981 case BPF_SK_SKB_STREAM_VERDICT: 982 psock_set_prog(&progs->skb_verdict, prog); 983 break; 984 default: 985 return -EOPNOTSUPP; 986 } 987 988 return 0; 989 } 990 991 void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link) 992 { 993 switch (link->map->map_type) { 994 case BPF_MAP_TYPE_SOCKMAP: 995 return sock_map_delete_from_link(link->map, sk, 996 link->link_raw); 997 case BPF_MAP_TYPE_SOCKHASH: 998 return sock_hash_delete_from_link(link->map, sk, 999 link->link_raw); 1000 default: 1001 break; 1002 } 1003 } 1004