1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ 3 4 #include <linux/skmsg.h> 5 #include <linux/filter.h> 6 #include <linux/bpf.h> 7 #include <linux/init.h> 8 #include <linux/wait.h> 9 #include <linux/util_macros.h> 10 11 #include <net/inet_common.h> 12 #include <net/tls.h> 13 14 void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) 15 { 16 struct tcp_sock *tcp; 17 int copied; 18 19 if (!skb || !skb->len || !sk_is_tcp(sk)) 20 return; 21 22 if (skb_bpf_strparser(skb)) 23 return; 24 25 tcp = tcp_sk(sk); 26 copied = tcp->copied_seq + skb->len; 27 WRITE_ONCE(tcp->copied_seq, copied); 28 tcp_rcv_space_adjust(sk); 29 __tcp_cleanup_rbuf(sk, skb->len); 30 } 31 32 static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, 33 struct sk_msg *msg, u32 apply_bytes, int flags) 34 { 35 bool apply = apply_bytes; 36 struct scatterlist *sge; 37 u32 size, copied = 0; 38 struct sk_msg *tmp; 39 int i, ret = 0; 40 41 tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL); 42 if (unlikely(!tmp)) 43 return -ENOMEM; 44 45 lock_sock(sk); 46 tmp->sg.start = msg->sg.start; 47 i = msg->sg.start; 48 do { 49 sge = sk_msg_elem(msg, i); 50 size = (apply && apply_bytes < sge->length) ? 51 apply_bytes : sge->length; 52 if (!sk_wmem_schedule(sk, size)) { 53 if (!copied) 54 ret = -ENOMEM; 55 break; 56 } 57 58 sk_mem_charge(sk, size); 59 sk_msg_xfer(tmp, msg, i, size); 60 copied += size; 61 if (sge->length) 62 get_page(sk_msg_page(tmp, i)); 63 sk_msg_iter_var_next(i); 64 tmp->sg.end = i; 65 if (apply) { 66 apply_bytes -= size; 67 if (!apply_bytes) { 68 if (sge->length) 69 sk_msg_iter_var_prev(i); 70 break; 71 } 72 } 73 } while (i != msg->sg.end); 74 75 if (!ret) { 76 msg->sg.start = i; 77 sk_psock_queue_msg(psock, tmp); 78 sk_psock_data_ready(sk, psock); 79 } else { 80 sk_msg_free(sk, tmp); 81 kfree(tmp); 82 } 83 84 release_sock(sk); 85 return ret; 86 } 87 88 static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes, 89 int flags, bool uncharge) 90 { 91 bool apply = apply_bytes; 92 struct scatterlist *sge; 93 struct msghdr msghdr = { .msg_flags = flags | MSG_SPLICE_PAGES, }; 94 struct page *page; 95 int size, ret = 0; 96 u32 off; 97 98 while (1) { 99 struct bio_vec bvec; 100 bool has_tx_ulp; 101 102 sge = sk_msg_elem(msg, msg->sg.start); 103 size = (apply && apply_bytes < sge->length) ? 104 apply_bytes : sge->length; 105 off = sge->offset; 106 page = sg_page(sge); 107 108 tcp_rate_check_app_limited(sk); 109 retry: 110 has_tx_ulp = tls_sw_has_ctx_tx(sk); 111 if (has_tx_ulp) 112 msghdr.msg_flags |= MSG_SENDPAGE_NOPOLICY; 113 114 if (flags & MSG_SENDPAGE_NOTLAST) 115 msghdr.msg_flags |= MSG_MORE; 116 117 bvec_set_page(&bvec, page, size, off); 118 iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size); 119 ret = tcp_sendmsg_locked(sk, &msghdr, size); 120 if (ret <= 0) 121 return ret; 122 123 if (apply) 124 apply_bytes -= ret; 125 msg->sg.size -= ret; 126 sge->offset += ret; 127 sge->length -= ret; 128 if (uncharge) 129 sk_mem_uncharge(sk, ret); 130 if (ret != size) { 131 size -= ret; 132 off += ret; 133 goto retry; 134 } 135 if (!sge->length) { 136 put_page(page); 137 sk_msg_iter_next(msg, start); 138 sg_init_table(sge, 1); 139 if (msg->sg.start == msg->sg.end) 140 break; 141 } 142 if (apply && !apply_bytes) 143 break; 144 } 145 146 return 0; 147 } 148 149 static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg, 150 u32 apply_bytes, int flags, bool uncharge) 151 { 152 int ret; 153 154 lock_sock(sk); 155 ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge); 156 release_sock(sk); 157 return ret; 158 } 159 160 int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, 161 struct sk_msg *msg, u32 bytes, int flags) 162 { 163 struct sk_psock *psock = sk_psock_get(sk); 164 int ret; 165 166 if (unlikely(!psock)) 167 return -EPIPE; 168 169 ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) : 170 tcp_bpf_push_locked(sk, msg, bytes, flags, false); 171 sk_psock_put(sk, psock); 172 return ret; 173 } 174 EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir); 175 176 #ifdef CONFIG_BPF_SYSCALL 177 static int tcp_msg_wait_data(struct sock *sk, struct sk_psock *psock, 178 long timeo) 179 { 180 DEFINE_WAIT_FUNC(wait, woken_wake_function); 181 int ret = 0; 182 183 if (sk->sk_shutdown & RCV_SHUTDOWN) 184 return 1; 185 186 if (!timeo) 187 return ret; 188 189 add_wait_queue(sk_sleep(sk), &wait); 190 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); 191 ret = sk_wait_event(sk, &timeo, 192 !list_empty(&psock->ingress_msg) || 193 !skb_queue_empty_lockless(&sk->sk_receive_queue), &wait); 194 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); 195 remove_wait_queue(sk_sleep(sk), &wait); 196 return ret; 197 } 198 199 static bool is_next_msg_fin(struct sk_psock *psock) 200 { 201 struct scatterlist *sge; 202 struct sk_msg *msg_rx; 203 int i; 204 205 msg_rx = sk_psock_peek_msg(psock); 206 i = msg_rx->sg.start; 207 sge = sk_msg_elem(msg_rx, i); 208 if (!sge->length) { 209 struct sk_buff *skb = msg_rx->skb; 210 211 if (skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 212 return true; 213 } 214 return false; 215 } 216 217 static int tcp_bpf_recvmsg_parser(struct sock *sk, 218 struct msghdr *msg, 219 size_t len, 220 int flags, 221 int *addr_len) 222 { 223 struct tcp_sock *tcp = tcp_sk(sk); 224 u32 seq = tcp->copied_seq; 225 struct sk_psock *psock; 226 int copied = 0; 227 228 if (unlikely(flags & MSG_ERRQUEUE)) 229 return inet_recv_error(sk, msg, len, addr_len); 230 231 if (!len) 232 return 0; 233 234 psock = sk_psock_get(sk); 235 if (unlikely(!psock)) 236 return tcp_recvmsg(sk, msg, len, flags, addr_len); 237 238 lock_sock(sk); 239 240 /* We may have received data on the sk_receive_queue pre-accept and 241 * then we can not use read_skb in this context because we haven't 242 * assigned a sk_socket yet so have no link to the ops. The work-around 243 * is to check the sk_receive_queue and in these cases read skbs off 244 * queue again. The read_skb hook is not running at this point because 245 * of lock_sock so we avoid having multiple runners in read_skb. 246 */ 247 if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) { 248 tcp_data_ready(sk); 249 /* This handles the ENOMEM errors if we both receive data 250 * pre accept and are already under memory pressure. At least 251 * let user know to retry. 252 */ 253 if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) { 254 copied = -EAGAIN; 255 goto out; 256 } 257 } 258 259 msg_bytes_ready: 260 copied = sk_msg_recvmsg(sk, psock, msg, len, flags); 261 /* The typical case for EFAULT is the socket was gracefully 262 * shutdown with a FIN pkt. So check here the other case is 263 * some error on copy_page_to_iter which would be unexpected. 264 * On fin return correct return code to zero. 265 */ 266 if (copied == -EFAULT) { 267 bool is_fin = is_next_msg_fin(psock); 268 269 if (is_fin) { 270 copied = 0; 271 seq++; 272 goto out; 273 } 274 } 275 seq += copied; 276 if (!copied) { 277 long timeo; 278 int data; 279 280 if (sock_flag(sk, SOCK_DONE)) 281 goto out; 282 283 if (sk->sk_err) { 284 copied = sock_error(sk); 285 goto out; 286 } 287 288 if (sk->sk_shutdown & RCV_SHUTDOWN) 289 goto out; 290 291 if (sk->sk_state == TCP_CLOSE) { 292 copied = -ENOTCONN; 293 goto out; 294 } 295 296 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 297 if (!timeo) { 298 copied = -EAGAIN; 299 goto out; 300 } 301 302 if (signal_pending(current)) { 303 copied = sock_intr_errno(timeo); 304 goto out; 305 } 306 307 data = tcp_msg_wait_data(sk, psock, timeo); 308 if (data && !sk_psock_queue_empty(psock)) 309 goto msg_bytes_ready; 310 copied = -EAGAIN; 311 } 312 out: 313 WRITE_ONCE(tcp->copied_seq, seq); 314 tcp_rcv_space_adjust(sk); 315 if (copied > 0) 316 __tcp_cleanup_rbuf(sk, copied); 317 release_sock(sk); 318 sk_psock_put(sk, psock); 319 return copied; 320 } 321 322 static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 323 int flags, int *addr_len) 324 { 325 struct sk_psock *psock; 326 int copied, ret; 327 328 if (unlikely(flags & MSG_ERRQUEUE)) 329 return inet_recv_error(sk, msg, len, addr_len); 330 331 if (!len) 332 return 0; 333 334 psock = sk_psock_get(sk); 335 if (unlikely(!psock)) 336 return tcp_recvmsg(sk, msg, len, flags, addr_len); 337 if (!skb_queue_empty(&sk->sk_receive_queue) && 338 sk_psock_queue_empty(psock)) { 339 sk_psock_put(sk, psock); 340 return tcp_recvmsg(sk, msg, len, flags, addr_len); 341 } 342 lock_sock(sk); 343 msg_bytes_ready: 344 copied = sk_msg_recvmsg(sk, psock, msg, len, flags); 345 if (!copied) { 346 long timeo; 347 int data; 348 349 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 350 data = tcp_msg_wait_data(sk, psock, timeo); 351 if (data) { 352 if (!sk_psock_queue_empty(psock)) 353 goto msg_bytes_ready; 354 release_sock(sk); 355 sk_psock_put(sk, psock); 356 return tcp_recvmsg(sk, msg, len, flags, addr_len); 357 } 358 copied = -EAGAIN; 359 } 360 ret = copied; 361 release_sock(sk); 362 sk_psock_put(sk, psock); 363 return ret; 364 } 365 366 static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, 367 struct sk_msg *msg, int *copied, int flags) 368 { 369 bool cork = false, enospc = sk_msg_full(msg), redir_ingress; 370 struct sock *sk_redir; 371 u32 tosend, origsize, sent, delta = 0; 372 u32 eval; 373 int ret; 374 375 more_data: 376 if (psock->eval == __SK_NONE) { 377 /* Track delta in msg size to add/subtract it on SK_DROP from 378 * returned to user copied size. This ensures user doesn't 379 * get a positive return code with msg_cut_data and SK_DROP 380 * verdict. 381 */ 382 delta = msg->sg.size; 383 psock->eval = sk_psock_msg_verdict(sk, psock, msg); 384 delta -= msg->sg.size; 385 } 386 387 if (msg->cork_bytes && 388 msg->cork_bytes > msg->sg.size && !enospc) { 389 psock->cork_bytes = msg->cork_bytes - msg->sg.size; 390 if (!psock->cork) { 391 psock->cork = kzalloc(sizeof(*psock->cork), 392 GFP_ATOMIC | __GFP_NOWARN); 393 if (!psock->cork) 394 return -ENOMEM; 395 } 396 memcpy(psock->cork, msg, sizeof(*msg)); 397 return 0; 398 } 399 400 tosend = msg->sg.size; 401 if (psock->apply_bytes && psock->apply_bytes < tosend) 402 tosend = psock->apply_bytes; 403 eval = __SK_NONE; 404 405 switch (psock->eval) { 406 case __SK_PASS: 407 ret = tcp_bpf_push(sk, msg, tosend, flags, true); 408 if (unlikely(ret)) { 409 *copied -= sk_msg_free(sk, msg); 410 break; 411 } 412 sk_msg_apply_bytes(psock, tosend); 413 break; 414 case __SK_REDIRECT: 415 redir_ingress = psock->redir_ingress; 416 sk_redir = psock->sk_redir; 417 sk_msg_apply_bytes(psock, tosend); 418 if (!psock->apply_bytes) { 419 /* Clean up before releasing the sock lock. */ 420 eval = psock->eval; 421 psock->eval = __SK_NONE; 422 psock->sk_redir = NULL; 423 } 424 if (psock->cork) { 425 cork = true; 426 psock->cork = NULL; 427 } 428 sk_msg_return(sk, msg, tosend); 429 release_sock(sk); 430 431 origsize = msg->sg.size; 432 ret = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress, 433 msg, tosend, flags); 434 sent = origsize - msg->sg.size; 435 436 if (eval == __SK_REDIRECT) 437 sock_put(sk_redir); 438 439 lock_sock(sk); 440 if (unlikely(ret < 0)) { 441 int free = sk_msg_free_nocharge(sk, msg); 442 443 if (!cork) 444 *copied -= free; 445 } 446 if (cork) { 447 sk_msg_free(sk, msg); 448 kfree(msg); 449 msg = NULL; 450 ret = 0; 451 } 452 break; 453 case __SK_DROP: 454 default: 455 sk_msg_free_partial(sk, msg, tosend); 456 sk_msg_apply_bytes(psock, tosend); 457 *copied -= (tosend + delta); 458 return -EACCES; 459 } 460 461 if (likely(!ret)) { 462 if (!psock->apply_bytes) { 463 psock->eval = __SK_NONE; 464 if (psock->sk_redir) { 465 sock_put(psock->sk_redir); 466 psock->sk_redir = NULL; 467 } 468 } 469 if (msg && 470 msg->sg.data[msg->sg.start].page_link && 471 msg->sg.data[msg->sg.start].length) { 472 if (eval == __SK_REDIRECT) 473 sk_mem_charge(sk, tosend - sent); 474 goto more_data; 475 } 476 } 477 return ret; 478 } 479 480 static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 481 { 482 struct sk_msg tmp, *msg_tx = NULL; 483 int copied = 0, err = 0; 484 struct sk_psock *psock; 485 long timeo; 486 int flags; 487 488 /* Don't let internal sendpage flags through */ 489 flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED); 490 flags |= MSG_NO_SHARED_FRAGS; 491 492 psock = sk_psock_get(sk); 493 if (unlikely(!psock)) 494 return tcp_sendmsg(sk, msg, size); 495 496 lock_sock(sk); 497 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 498 while (msg_data_left(msg)) { 499 bool enospc = false; 500 u32 copy, osize; 501 502 if (sk->sk_err) { 503 err = -sk->sk_err; 504 goto out_err; 505 } 506 507 copy = msg_data_left(msg); 508 if (!sk_stream_memory_free(sk)) 509 goto wait_for_sndbuf; 510 if (psock->cork) { 511 msg_tx = psock->cork; 512 } else { 513 msg_tx = &tmp; 514 sk_msg_init(msg_tx); 515 } 516 517 osize = msg_tx->sg.size; 518 err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1); 519 if (err) { 520 if (err != -ENOSPC) 521 goto wait_for_memory; 522 enospc = true; 523 copy = msg_tx->sg.size - osize; 524 } 525 526 err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx, 527 copy); 528 if (err < 0) { 529 sk_msg_trim(sk, msg_tx, osize); 530 goto out_err; 531 } 532 533 copied += copy; 534 if (psock->cork_bytes) { 535 if (size > psock->cork_bytes) 536 psock->cork_bytes = 0; 537 else 538 psock->cork_bytes -= size; 539 if (psock->cork_bytes && !enospc) 540 goto out_err; 541 /* All cork bytes are accounted, rerun the prog. */ 542 psock->eval = __SK_NONE; 543 psock->cork_bytes = 0; 544 } 545 546 err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags); 547 if (unlikely(err < 0)) 548 goto out_err; 549 continue; 550 wait_for_sndbuf: 551 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 552 wait_for_memory: 553 err = sk_stream_wait_memory(sk, &timeo); 554 if (err) { 555 if (msg_tx && msg_tx != psock->cork) 556 sk_msg_free(sk, msg_tx); 557 goto out_err; 558 } 559 } 560 out_err: 561 if (err < 0) 562 err = sk_stream_error(sk, msg->msg_flags, err); 563 release_sock(sk); 564 sk_psock_put(sk, psock); 565 return copied ? copied : err; 566 } 567 568 static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset, 569 size_t size, int flags) 570 { 571 struct sk_msg tmp, *msg = NULL; 572 int err = 0, copied = 0; 573 struct sk_psock *psock; 574 bool enospc = false; 575 576 psock = sk_psock_get(sk); 577 if (unlikely(!psock)) 578 return tcp_sendpage(sk, page, offset, size, flags); 579 580 lock_sock(sk); 581 if (psock->cork) { 582 msg = psock->cork; 583 } else { 584 msg = &tmp; 585 sk_msg_init(msg); 586 } 587 588 /* Catch case where ring is full and sendpage is stalled. */ 589 if (unlikely(sk_msg_full(msg))) 590 goto out_err; 591 592 sk_msg_page_add(msg, page, size, offset); 593 sk_mem_charge(sk, size); 594 copied = size; 595 if (sk_msg_full(msg)) 596 enospc = true; 597 if (psock->cork_bytes) { 598 if (size > psock->cork_bytes) 599 psock->cork_bytes = 0; 600 else 601 psock->cork_bytes -= size; 602 if (psock->cork_bytes && !enospc) 603 goto out_err; 604 /* All cork bytes are accounted, rerun the prog. */ 605 psock->eval = __SK_NONE; 606 psock->cork_bytes = 0; 607 } 608 609 err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags); 610 out_err: 611 release_sock(sk); 612 sk_psock_put(sk, psock); 613 return copied ? copied : err; 614 } 615 616 enum { 617 TCP_BPF_IPV4, 618 TCP_BPF_IPV6, 619 TCP_BPF_NUM_PROTS, 620 }; 621 622 enum { 623 TCP_BPF_BASE, 624 TCP_BPF_TX, 625 TCP_BPF_RX, 626 TCP_BPF_TXRX, 627 TCP_BPF_NUM_CFGS, 628 }; 629 630 static struct proto *tcpv6_prot_saved __read_mostly; 631 static DEFINE_SPINLOCK(tcpv6_prot_lock); 632 static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS]; 633 634 static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS], 635 struct proto *base) 636 { 637 prot[TCP_BPF_BASE] = *base; 638 prot[TCP_BPF_BASE].destroy = sock_map_destroy; 639 prot[TCP_BPF_BASE].close = sock_map_close; 640 prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg; 641 prot[TCP_BPF_BASE].sock_is_readable = sk_msg_is_readable; 642 643 prot[TCP_BPF_TX] = prot[TCP_BPF_BASE]; 644 prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg; 645 prot[TCP_BPF_TX].sendpage = tcp_bpf_sendpage; 646 647 prot[TCP_BPF_RX] = prot[TCP_BPF_BASE]; 648 prot[TCP_BPF_RX].recvmsg = tcp_bpf_recvmsg_parser; 649 650 prot[TCP_BPF_TXRX] = prot[TCP_BPF_TX]; 651 prot[TCP_BPF_TXRX].recvmsg = tcp_bpf_recvmsg_parser; 652 } 653 654 static void tcp_bpf_check_v6_needs_rebuild(struct proto *ops) 655 { 656 if (unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) { 657 spin_lock_bh(&tcpv6_prot_lock); 658 if (likely(ops != tcpv6_prot_saved)) { 659 tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops); 660 smp_store_release(&tcpv6_prot_saved, ops); 661 } 662 spin_unlock_bh(&tcpv6_prot_lock); 663 } 664 } 665 666 static int __init tcp_bpf_v4_build_proto(void) 667 { 668 tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot); 669 return 0; 670 } 671 late_initcall(tcp_bpf_v4_build_proto); 672 673 static int tcp_bpf_assert_proto_ops(struct proto *ops) 674 { 675 /* In order to avoid retpoline, we make assumptions when we call 676 * into ops if e.g. a psock is not present. Make sure they are 677 * indeed valid assumptions. 678 */ 679 return ops->recvmsg == tcp_recvmsg && 680 ops->sendmsg == tcp_sendmsg && 681 ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP; 682 } 683 684 int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) 685 { 686 int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4; 687 int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE; 688 689 if (psock->progs.stream_verdict || psock->progs.skb_verdict) { 690 config = (config == TCP_BPF_TX) ? TCP_BPF_TXRX : TCP_BPF_RX; 691 } 692 693 if (restore) { 694 if (inet_csk_has_ulp(sk)) { 695 /* TLS does not have an unhash proto in SW cases, 696 * but we need to ensure we stop using the sock_map 697 * unhash routine because the associated psock is being 698 * removed. So use the original unhash handler. 699 */ 700 WRITE_ONCE(sk->sk_prot->unhash, psock->saved_unhash); 701 tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space); 702 } else { 703 sk->sk_write_space = psock->saved_write_space; 704 /* Pairs with lockless read in sk_clone_lock() */ 705 sock_replace_proto(sk, psock->sk_proto); 706 } 707 return 0; 708 } 709 710 if (sk->sk_family == AF_INET6) { 711 if (tcp_bpf_assert_proto_ops(psock->sk_proto)) 712 return -EINVAL; 713 714 tcp_bpf_check_v6_needs_rebuild(psock->sk_proto); 715 } 716 717 /* Pairs with lockless read in sk_clone_lock() */ 718 sock_replace_proto(sk, &tcp_bpf_prots[family][config]); 719 return 0; 720 } 721 EXPORT_SYMBOL_GPL(tcp_bpf_update_proto); 722 723 /* If a child got cloned from a listening socket that had tcp_bpf 724 * protocol callbacks installed, we need to restore the callbacks to 725 * the default ones because the child does not inherit the psock state 726 * that tcp_bpf callbacks expect. 727 */ 728 void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) 729 { 730 struct proto *prot = newsk->sk_prot; 731 732 if (is_insidevar(prot, tcp_bpf_prots)) 733 newsk->sk_prot = sk->sk_prot_creator; 734 } 735 #endif /* CONFIG_BPF_SYSCALL */ 736