| .. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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| 1 | 2 | /* |
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| 2 | 3 | * Extension Header handling for IPv6 |
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| 3 | 4 | * Linux INET6 implementation |
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| .. | .. |
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| 6 | 7 | * Pedro Roque <roque@di.fc.ul.pt> |
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| 7 | 8 | * Andi Kleen <ak@muc.de> |
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| 8 | 9 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
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| 9 | | - * |
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| 10 | | - * This program is free software; you can redistribute it and/or |
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| 11 | | - * modify it under the terms of the GNU General Public License |
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| 12 | | - * as published by the Free Software Foundation; either version |
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| 13 | | - * 2 of the License, or (at your option) any later version. |
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| 14 | 10 | */ |
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| 15 | 11 | |
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| 16 | 12 | /* Changes: |
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| .. | .. |
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| 52 | 48 | #ifdef CONFIG_IPV6_SEG6_HMAC |
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| 53 | 49 | #include <net/seg6_hmac.h> |
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| 54 | 50 | #endif |
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| 51 | +#include <net/rpl.h> |
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| 55 | 52 | |
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| 56 | 53 | #include <linux/uaccess.h> |
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| 57 | 54 | |
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| .. | .. |
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| 101 | 98 | */ |
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| 102 | 99 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) |
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| 103 | 100 | break; |
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| 104 | | - /* fall through */ |
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| 101 | + fallthrough; |
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| 105 | 102 | case 2: /* send ICMP PARM PROB regardless and drop packet */ |
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| 106 | 103 | icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); |
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| 107 | 104 | return false; |
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| .. | .. |
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| 471 | 468 | return -1; |
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| 472 | 469 | } |
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| 473 | 470 | |
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| 471 | +static int ipv6_rpl_srh_rcv(struct sk_buff *skb) |
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| 472 | +{ |
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| 473 | + struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; |
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| 474 | + struct inet6_skb_parm *opt = IP6CB(skb); |
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| 475 | + struct net *net = dev_net(skb->dev); |
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| 476 | + struct inet6_dev *idev; |
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| 477 | + struct ipv6hdr *oldhdr; |
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| 478 | + struct in6_addr addr; |
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| 479 | + unsigned char *buf; |
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| 480 | + int accept_rpl_seg; |
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| 481 | + int i, err; |
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| 482 | + u64 n = 0; |
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| 483 | + u32 r; |
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| 484 | + |
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| 485 | + idev = __in6_dev_get(skb->dev); |
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| 486 | + |
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| 487 | + accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; |
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| 488 | + if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) |
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| 489 | + accept_rpl_seg = idev->cnf.rpl_seg_enabled; |
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| 490 | + |
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| 491 | + if (!accept_rpl_seg) { |
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| 492 | + kfree_skb(skb); |
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| 493 | + return -1; |
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| 494 | + } |
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| 495 | + |
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| 496 | +looped_back: |
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| 497 | + hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); |
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| 498 | + |
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| 499 | + if (hdr->segments_left == 0) { |
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| 500 | + if (hdr->nexthdr == NEXTHDR_IPV6) { |
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| 501 | + int offset = (hdr->hdrlen + 1) << 3; |
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| 502 | + |
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| 503 | + skb_postpull_rcsum(skb, skb_network_header(skb), |
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| 504 | + skb_network_header_len(skb)); |
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| 505 | + |
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| 506 | + if (!pskb_pull(skb, offset)) { |
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| 507 | + kfree_skb(skb); |
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| 508 | + return -1; |
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| 509 | + } |
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| 510 | + skb_postpull_rcsum(skb, skb_transport_header(skb), |
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| 511 | + offset); |
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| 512 | + |
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| 513 | + skb_reset_network_header(skb); |
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| 514 | + skb_reset_transport_header(skb); |
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| 515 | + skb->encapsulation = 0; |
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| 516 | + |
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| 517 | + __skb_tunnel_rx(skb, skb->dev, net); |
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| 518 | + |
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| 519 | + netif_rx(skb); |
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| 520 | + return -1; |
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| 521 | + } |
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| 522 | + |
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| 523 | + opt->srcrt = skb_network_header_len(skb); |
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| 524 | + opt->lastopt = opt->srcrt; |
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| 525 | + skb->transport_header += (hdr->hdrlen + 1) << 3; |
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| 526 | + opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); |
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| 527 | + |
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| 528 | + return 1; |
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| 529 | + } |
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| 530 | + |
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| 531 | + if (!pskb_may_pull(skb, sizeof(*hdr))) { |
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| 532 | + kfree_skb(skb); |
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| 533 | + return -1; |
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| 534 | + } |
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| 535 | + |
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| 536 | + n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); |
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| 537 | + r = do_div(n, (16 - hdr->cmpri)); |
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| 538 | + /* checks if calculation was without remainder and n fits into |
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| 539 | + * unsigned char which is segments_left field. Should not be |
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| 540 | + * higher than that. |
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| 541 | + */ |
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| 542 | + if (r || (n + 1) > 255) { |
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| 543 | + kfree_skb(skb); |
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| 544 | + return -1; |
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| 545 | + } |
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| 546 | + |
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| 547 | + if (hdr->segments_left > n + 1) { |
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| 548 | + __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
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| 549 | + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
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| 550 | + ((&hdr->segments_left) - |
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| 551 | + skb_network_header(skb))); |
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| 552 | + return -1; |
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| 553 | + } |
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| 554 | + |
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| 555 | + if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, |
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| 556 | + hdr->cmpre))) { |
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| 557 | + kfree_skb(skb); |
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| 558 | + return -1; |
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| 559 | + } |
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| 560 | + |
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| 561 | + hdr->segments_left--; |
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| 562 | + i = n - hdr->segments_left; |
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| 563 | + |
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| 564 | + buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); |
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| 565 | + if (unlikely(!buf)) { |
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| 566 | + kfree_skb(skb); |
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| 567 | + return -1; |
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| 568 | + } |
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| 569 | + |
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| 570 | + ohdr = (struct ipv6_rpl_sr_hdr *)buf; |
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| 571 | + ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); |
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| 572 | + chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); |
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| 573 | + |
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| 574 | + if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || |
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| 575 | + (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { |
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| 576 | + kfree_skb(skb); |
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| 577 | + kfree(buf); |
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| 578 | + return -1; |
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| 579 | + } |
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| 580 | + |
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| 581 | + err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); |
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| 582 | + if (err) { |
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| 583 | + icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); |
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| 584 | + kfree_skb(skb); |
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| 585 | + kfree(buf); |
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| 586 | + return -1; |
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| 587 | + } |
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| 588 | + |
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| 589 | + addr = ipv6_hdr(skb)->daddr; |
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| 590 | + ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i]; |
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| 591 | + ohdr->rpl_segaddr[i] = addr; |
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| 592 | + |
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| 593 | + ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); |
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| 594 | + |
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| 595 | + oldhdr = ipv6_hdr(skb); |
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| 596 | + |
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| 597 | + skb_pull(skb, ((hdr->hdrlen + 1) << 3)); |
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| 598 | + skb_postpull_rcsum(skb, oldhdr, |
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| 599 | + sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); |
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| 600 | + if (unlikely(!hdr->segments_left)) { |
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| 601 | + if (pskb_expand_head(skb, sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), 0, |
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| 602 | + GFP_ATOMIC)) { |
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| 603 | + __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); |
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| 604 | + kfree_skb(skb); |
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| 605 | + kfree(buf); |
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| 606 | + return -1; |
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| 607 | + } |
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| 608 | + |
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| 609 | + oldhdr = ipv6_hdr(skb); |
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| 610 | + } |
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| 611 | + skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); |
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| 612 | + skb_reset_network_header(skb); |
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| 613 | + skb_mac_header_rebuild(skb); |
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| 614 | + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); |
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| 615 | + |
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| 616 | + memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); |
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| 617 | + memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); |
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| 618 | + |
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| 619 | + ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); |
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| 620 | + skb_postpush_rcsum(skb, ipv6_hdr(skb), |
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| 621 | + sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); |
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| 622 | + |
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| 623 | + kfree(buf); |
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| 624 | + |
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| 625 | + skb_dst_drop(skb); |
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| 626 | + |
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| 627 | + ip6_route_input(skb); |
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| 628 | + |
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| 629 | + if (skb_dst(skb)->error) { |
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| 630 | + dst_input(skb); |
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| 631 | + return -1; |
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| 632 | + } |
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| 633 | + |
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| 634 | + if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { |
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| 635 | + if (ipv6_hdr(skb)->hop_limit <= 1) { |
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| 636 | + __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
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| 637 | + icmpv6_send(skb, ICMPV6_TIME_EXCEED, |
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| 638 | + ICMPV6_EXC_HOPLIMIT, 0); |
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| 639 | + kfree_skb(skb); |
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| 640 | + return -1; |
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| 641 | + } |
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| 642 | + ipv6_hdr(skb)->hop_limit--; |
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| 643 | + |
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| 644 | + skb_pull(skb, sizeof(struct ipv6hdr)); |
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| 645 | + goto looped_back; |
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| 646 | + } |
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| 647 | + |
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| 648 | + dst_input(skb); |
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| 649 | + |
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| 650 | + return -1; |
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| 651 | +} |
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| 652 | + |
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| 474 | 653 | /******************************** |
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| 475 | 654 | Routing header. |
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| 476 | 655 | ********************************/ |
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| .. | .. |
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| 509 | 688 | return -1; |
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| 510 | 689 | } |
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| 511 | 690 | |
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| 512 | | - /* segment routing */ |
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| 513 | | - if (hdr->type == IPV6_SRCRT_TYPE_4) |
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| 691 | + switch (hdr->type) { |
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| 692 | + case IPV6_SRCRT_TYPE_4: |
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| 693 | + /* segment routing */ |
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| 514 | 694 | return ipv6_srh_rcv(skb); |
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| 695 | + case IPV6_SRCRT_TYPE_3: |
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| 696 | + /* rpl segment routing */ |
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| 697 | + return ipv6_rpl_srh_rcv(skb); |
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| 698 | + default: |
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| 699 | + break; |
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| 700 | + } |
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| 515 | 701 | |
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| 516 | 702 | looped_back: |
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| 517 | 703 | if (hdr->segments_left == 0) { |
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| .. | .. |
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| 1038 | 1224 | * @opt: original options |
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| 1039 | 1225 | * @newtype: option type to replace in @opt |
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| 1040 | 1226 | * @newopt: new option of type @newtype to replace (user-mem) |
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| 1041 | | - * @newoptlen: length of @newopt |
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| 1042 | 1227 | * |
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| 1043 | 1228 | * Returns a new set of options which is a copy of @opt with the |
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| 1044 | 1229 | * option type @newtype replaced with @newopt. |
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