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