1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Extension Header handling for IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * Andi Kleen <ak@muc.de> 9 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 10 */ 11 12 /* Changes: 13 * yoshfuji : ensure not to overrun while parsing 14 * tlv options. 15 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). 16 * YOSHIFUJI Hideaki @USAGI Register inbound extension header 17 * handlers as inet6_protocol{}. 18 */ 19 20 #include <linux/errno.h> 21 #include <linux/types.h> 22 #include <linux/socket.h> 23 #include <linux/sockios.h> 24 #include <linux/net.h> 25 #include <linux/netdevice.h> 26 #include <linux/in6.h> 27 #include <linux/icmpv6.h> 28 #include <linux/slab.h> 29 #include <linux/export.h> 30 31 #include <net/dst.h> 32 #include <net/sock.h> 33 #include <net/snmp.h> 34 35 #include <net/ipv6.h> 36 #include <net/protocol.h> 37 #include <net/transp_v6.h> 38 #include <net/rawv6.h> 39 #include <net/ndisc.h> 40 #include <net/ip6_route.h> 41 #include <net/addrconf.h> 42 #include <net/calipso.h> 43 #if IS_ENABLED(CONFIG_IPV6_MIP6) 44 #include <net/xfrm.h> 45 #endif 46 #include <linux/seg6.h> 47 #include <net/seg6.h> 48 #ifdef CONFIG_IPV6_SEG6_HMAC 49 #include <net/seg6_hmac.h> 50 #endif 51 #include <net/rpl.h> 52 53 #include <linux/uaccess.h> 54 55 /* 56 * Parsing tlv encoded headers. 57 * 58 * Parsing function "func" returns true, if parsing succeed 59 * and false, if it failed. 60 * It MUST NOT touch skb->h. 61 */ 62 63 struct tlvtype_proc { 64 int type; 65 bool (*func)(struct sk_buff *skb, int offset); 66 }; 67 68 /********************* 69 Generic functions 70 *********************/ 71 72 /* An unknown option is detected, decide what to do */ 73 74 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, 75 bool disallow_unknowns) 76 { 77 if (disallow_unknowns) { 78 /* If unknown TLVs are disallowed by configuration 79 * then always silently drop packet. Note this also 80 * means no ICMP parameter problem is sent which 81 * could be a good property to mitigate a reflection DOS 82 * attack. 83 */ 84 85 goto drop; 86 } 87 88 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 89 case 0: /* ignore */ 90 return true; 91 92 case 1: /* drop packet */ 93 break; 94 95 case 3: /* Send ICMP if not a multicast address and drop packet */ 96 /* Actually, it is redundant check. icmp_send 97 will recheck in any case. 98 */ 99 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 100 break; 101 fallthrough; 102 case 2: /* send ICMP PARM PROB regardless and drop packet */ 103 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); 104 return false; 105 } 106 107 drop: 108 kfree_skb(skb); 109 return false; 110 } 111 112 /* Parse tlv encoded option header (hop-by-hop or destination) */ 113 114 static bool ip6_parse_tlv(const struct tlvtype_proc *procs, 115 struct sk_buff *skb, 116 int max_count) 117 { 118 int len = (skb_transport_header(skb)[1] + 1) << 3; 119 const unsigned char *nh = skb_network_header(skb); 120 int off = skb_network_header_len(skb); 121 const struct tlvtype_proc *curr; 122 bool disallow_unknowns = false; 123 int tlv_count = 0; 124 int padlen = 0; 125 126 if (unlikely(max_count < 0)) { 127 disallow_unknowns = true; 128 max_count = -max_count; 129 } 130 131 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 132 goto bad; 133 134 off += 2; 135 len -= 2; 136 137 while (len > 0) { 138 int optlen = nh[off + 1] + 2; 139 int i; 140 141 switch (nh[off]) { 142 case IPV6_TLV_PAD1: 143 optlen = 1; 144 padlen++; 145 if (padlen > 7) 146 goto bad; 147 break; 148 149 case IPV6_TLV_PADN: 150 /* RFC 2460 states that the purpose of PadN is 151 * to align the containing header to multiples 152 * of 8. 7 is therefore the highest valid value. 153 * See also RFC 4942, Section 2.1.9.5. 154 */ 155 padlen += optlen; 156 if (padlen > 7) 157 goto bad; 158 /* RFC 4942 recommends receiving hosts to 159 * actively check PadN payload to contain 160 * only zeroes. 161 */ 162 for (i = 2; i < optlen; i++) { 163 if (nh[off + i] != 0) 164 goto bad; 165 } 166 break; 167 168 default: /* Other TLV code so scan list */ 169 if (optlen > len) 170 goto bad; 171 172 tlv_count++; 173 if (tlv_count > max_count) 174 goto bad; 175 176 for (curr = procs; curr->type >= 0; curr++) { 177 if (curr->type == nh[off]) { 178 /* type specific length/alignment 179 checks will be performed in the 180 func(). */ 181 if (curr->func(skb, off) == false) 182 return false; 183 break; 184 } 185 } 186 if (curr->type < 0 && 187 !ip6_tlvopt_unknown(skb, off, disallow_unknowns)) 188 return false; 189 190 padlen = 0; 191 break; 192 } 193 off += optlen; 194 len -= optlen; 195 } 196 197 if (len == 0) 198 return true; 199 bad: 200 kfree_skb(skb); 201 return false; 202 } 203 204 /***************************** 205 Destination options header. 206 *****************************/ 207 208 #if IS_ENABLED(CONFIG_IPV6_MIP6) 209 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 210 { 211 struct ipv6_destopt_hao *hao; 212 struct inet6_skb_parm *opt = IP6CB(skb); 213 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 214 int ret; 215 216 if (opt->dsthao) { 217 net_dbg_ratelimited("hao duplicated\n"); 218 goto discard; 219 } 220 opt->dsthao = opt->dst1; 221 opt->dst1 = 0; 222 223 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 224 225 if (hao->length != 16) { 226 net_dbg_ratelimited("hao invalid option length = %d\n", 227 hao->length); 228 goto discard; 229 } 230 231 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 232 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 233 &hao->addr); 234 goto discard; 235 } 236 237 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 238 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 239 if (unlikely(ret < 0)) 240 goto discard; 241 242 if (skb_cloned(skb)) { 243 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 244 goto discard; 245 246 /* update all variable using below by copied skbuff */ 247 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 248 optoff); 249 ipv6h = ipv6_hdr(skb); 250 } 251 252 if (skb->ip_summed == CHECKSUM_COMPLETE) 253 skb->ip_summed = CHECKSUM_NONE; 254 255 swap(ipv6h->saddr, hao->addr); 256 257 if (skb->tstamp == 0) 258 __net_timestamp(skb); 259 260 return true; 261 262 discard: 263 kfree_skb(skb); 264 return false; 265 } 266 #endif 267 268 static const struct tlvtype_proc tlvprocdestopt_lst[] = { 269 #if IS_ENABLED(CONFIG_IPV6_MIP6) 270 { 271 .type = IPV6_TLV_HAO, 272 .func = ipv6_dest_hao, 273 }, 274 #endif 275 {-1, NULL} 276 }; 277 278 static int ipv6_destopt_rcv(struct sk_buff *skb) 279 { 280 struct inet6_dev *idev = __in6_dev_get(skb->dev); 281 struct inet6_skb_parm *opt = IP6CB(skb); 282 #if IS_ENABLED(CONFIG_IPV6_MIP6) 283 __u16 dstbuf; 284 #endif 285 struct dst_entry *dst = skb_dst(skb); 286 struct net *net = dev_net(skb->dev); 287 int extlen; 288 289 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 290 !pskb_may_pull(skb, (skb_transport_offset(skb) + 291 ((skb_transport_header(skb)[1] + 1) << 3)))) { 292 __IP6_INC_STATS(dev_net(dst->dev), idev, 293 IPSTATS_MIB_INHDRERRORS); 294 fail_and_free: 295 kfree_skb(skb); 296 return -1; 297 } 298 299 extlen = (skb_transport_header(skb)[1] + 1) << 3; 300 if (extlen > net->ipv6.sysctl.max_dst_opts_len) 301 goto fail_and_free; 302 303 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 304 #if IS_ENABLED(CONFIG_IPV6_MIP6) 305 dstbuf = opt->dst1; 306 #endif 307 308 if (ip6_parse_tlv(tlvprocdestopt_lst, skb, 309 init_net.ipv6.sysctl.max_dst_opts_cnt)) { 310 skb->transport_header += extlen; 311 opt = IP6CB(skb); 312 #if IS_ENABLED(CONFIG_IPV6_MIP6) 313 opt->nhoff = dstbuf; 314 #else 315 opt->nhoff = opt->dst1; 316 #endif 317 return 1; 318 } 319 320 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 321 return -1; 322 } 323 324 static void seg6_update_csum(struct sk_buff *skb) 325 { 326 struct ipv6_sr_hdr *hdr; 327 struct in6_addr *addr; 328 __be32 from, to; 329 330 /* srh is at transport offset and seg_left is already decremented 331 * but daddr is not yet updated with next segment 332 */ 333 334 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 335 addr = hdr->segments + hdr->segments_left; 336 337 hdr->segments_left++; 338 from = *(__be32 *)hdr; 339 340 hdr->segments_left--; 341 to = *(__be32 *)hdr; 342 343 /* update skb csum with diff resulting from seg_left decrement */ 344 345 update_csum_diff4(skb, from, to); 346 347 /* compute csum diff between current and next segment and update */ 348 349 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 350 (__be32 *)addr); 351 } 352 353 static int ipv6_srh_rcv(struct sk_buff *skb) 354 { 355 struct inet6_skb_parm *opt = IP6CB(skb); 356 struct net *net = dev_net(skb->dev); 357 struct ipv6_sr_hdr *hdr; 358 struct inet6_dev *idev; 359 struct in6_addr *addr; 360 int accept_seg6; 361 362 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 363 364 idev = __in6_dev_get(skb->dev); 365 366 accept_seg6 = net->ipv6.devconf_all->seg6_enabled; 367 if (accept_seg6 > idev->cnf.seg6_enabled) 368 accept_seg6 = idev->cnf.seg6_enabled; 369 370 if (!accept_seg6) { 371 kfree_skb(skb); 372 return -1; 373 } 374 375 #ifdef CONFIG_IPV6_SEG6_HMAC 376 if (!seg6_hmac_validate_skb(skb)) { 377 kfree_skb(skb); 378 return -1; 379 } 380 #endif 381 382 looped_back: 383 if (hdr->segments_left == 0) { 384 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 385 int offset = (hdr->hdrlen + 1) << 3; 386 387 skb_postpull_rcsum(skb, skb_network_header(skb), 388 skb_network_header_len(skb)); 389 390 if (!pskb_pull(skb, offset)) { 391 kfree_skb(skb); 392 return -1; 393 } 394 skb_postpull_rcsum(skb, skb_transport_header(skb), 395 offset); 396 397 skb_reset_network_header(skb); 398 skb_reset_transport_header(skb); 399 skb->encapsulation = 0; 400 if (hdr->nexthdr == NEXTHDR_IPV4) 401 skb->protocol = htons(ETH_P_IP); 402 __skb_tunnel_rx(skb, skb->dev, net); 403 404 netif_rx(skb); 405 return -1; 406 } 407 408 opt->srcrt = skb_network_header_len(skb); 409 opt->lastopt = opt->srcrt; 410 skb->transport_header += (hdr->hdrlen + 1) << 3; 411 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 412 413 return 1; 414 } 415 416 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 417 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 418 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 419 ((&hdr->segments_left) - 420 skb_network_header(skb))); 421 return -1; 422 } 423 424 if (skb_cloned(skb)) { 425 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 426 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 427 IPSTATS_MIB_OUTDISCARDS); 428 kfree_skb(skb); 429 return -1; 430 } 431 } 432 433 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 434 435 hdr->segments_left--; 436 addr = hdr->segments + hdr->segments_left; 437 438 skb_push(skb, sizeof(struct ipv6hdr)); 439 440 if (skb->ip_summed == CHECKSUM_COMPLETE) 441 seg6_update_csum(skb); 442 443 ipv6_hdr(skb)->daddr = *addr; 444 445 skb_dst_drop(skb); 446 447 ip6_route_input(skb); 448 449 if (skb_dst(skb)->error) { 450 dst_input(skb); 451 return -1; 452 } 453 454 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 455 if (ipv6_hdr(skb)->hop_limit <= 1) { 456 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 457 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 458 ICMPV6_EXC_HOPLIMIT, 0); 459 kfree_skb(skb); 460 return -1; 461 } 462 ipv6_hdr(skb)->hop_limit--; 463 464 skb_pull(skb, sizeof(struct ipv6hdr)); 465 goto looped_back; 466 } 467 468 dst_input(skb); 469 470 return -1; 471 } 472 473 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 474 { 475 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 476 struct inet6_skb_parm *opt = IP6CB(skb); 477 struct net *net = dev_net(skb->dev); 478 struct inet6_dev *idev; 479 struct ipv6hdr *oldhdr; 480 struct in6_addr addr; 481 unsigned char *buf; 482 int accept_rpl_seg; 483 int i, err; 484 u64 n = 0; 485 u32 r; 486 487 idev = __in6_dev_get(skb->dev); 488 489 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 490 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 491 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 492 493 if (!accept_rpl_seg) { 494 kfree_skb(skb); 495 return -1; 496 } 497 498 looped_back: 499 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 500 501 if (hdr->segments_left == 0) { 502 if (hdr->nexthdr == NEXTHDR_IPV6) { 503 int offset = (hdr->hdrlen + 1) << 3; 504 505 skb_postpull_rcsum(skb, skb_network_header(skb), 506 skb_network_header_len(skb)); 507 508 if (!pskb_pull(skb, offset)) { 509 kfree_skb(skb); 510 return -1; 511 } 512 skb_postpull_rcsum(skb, skb_transport_header(skb), 513 offset); 514 515 skb_reset_network_header(skb); 516 skb_reset_transport_header(skb); 517 skb->encapsulation = 0; 518 519 __skb_tunnel_rx(skb, skb->dev, net); 520 521 netif_rx(skb); 522 return -1; 523 } 524 525 opt->srcrt = skb_network_header_len(skb); 526 opt->lastopt = opt->srcrt; 527 skb->transport_header += (hdr->hdrlen + 1) << 3; 528 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 529 530 return 1; 531 } 532 533 if (!pskb_may_pull(skb, sizeof(*hdr))) { 534 kfree_skb(skb); 535 return -1; 536 } 537 538 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 539 r = do_div(n, (16 - hdr->cmpri)); 540 /* checks if calculation was without remainder and n fits into 541 * unsigned char which is segments_left field. Should not be 542 * higher than that. 543 */ 544 if (r || (n + 1) > 255) { 545 kfree_skb(skb); 546 return -1; 547 } 548 549 if (hdr->segments_left > n + 1) { 550 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 551 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 552 ((&hdr->segments_left) - 553 skb_network_header(skb))); 554 return -1; 555 } 556 557 if (skb_cloned(skb)) { 558 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0, 559 GFP_ATOMIC)) { 560 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 561 IPSTATS_MIB_OUTDISCARDS); 562 kfree_skb(skb); 563 return -1; 564 } 565 } else { 566 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE); 567 if (unlikely(err)) { 568 kfree_skb(skb); 569 return -1; 570 } 571 } 572 573 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 574 575 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 576 hdr->cmpre))) { 577 kfree_skb(skb); 578 return -1; 579 } 580 581 hdr->segments_left--; 582 i = n - hdr->segments_left; 583 584 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 585 if (unlikely(!buf)) { 586 kfree_skb(skb); 587 return -1; 588 } 589 590 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 591 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 592 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 593 594 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 595 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 596 kfree_skb(skb); 597 kfree(buf); 598 return -1; 599 } 600 601 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 602 if (err) { 603 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 604 kfree_skb(skb); 605 kfree(buf); 606 return -1; 607 } 608 609 addr = ipv6_hdr(skb)->daddr; 610 ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i]; 611 ohdr->rpl_segaddr[i] = addr; 612 613 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 614 615 oldhdr = ipv6_hdr(skb); 616 617 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 618 skb_postpull_rcsum(skb, oldhdr, 619 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 620 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 621 skb_reset_network_header(skb); 622 skb_mac_header_rebuild(skb); 623 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 624 625 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 626 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 627 628 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 629 skb_postpush_rcsum(skb, ipv6_hdr(skb), 630 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 631 632 kfree(buf); 633 634 skb_dst_drop(skb); 635 636 ip6_route_input(skb); 637 638 if (skb_dst(skb)->error) { 639 dst_input(skb); 640 return -1; 641 } 642 643 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 644 if (ipv6_hdr(skb)->hop_limit <= 1) { 645 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 646 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 647 ICMPV6_EXC_HOPLIMIT, 0); 648 kfree_skb(skb); 649 return -1; 650 } 651 ipv6_hdr(skb)->hop_limit--; 652 653 skb_pull(skb, sizeof(struct ipv6hdr)); 654 goto looped_back; 655 } 656 657 dst_input(skb); 658 659 return -1; 660 } 661 662 /******************************** 663 Routing header. 664 ********************************/ 665 666 /* called with rcu_read_lock() */ 667 static int ipv6_rthdr_rcv(struct sk_buff *skb) 668 { 669 struct inet6_dev *idev = __in6_dev_get(skb->dev); 670 struct inet6_skb_parm *opt = IP6CB(skb); 671 struct in6_addr *addr = NULL; 672 struct in6_addr daddr; 673 int n, i; 674 struct ipv6_rt_hdr *hdr; 675 struct rt0_hdr *rthdr; 676 struct net *net = dev_net(skb->dev); 677 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 678 679 idev = __in6_dev_get(skb->dev); 680 if (idev && accept_source_route > idev->cnf.accept_source_route) 681 accept_source_route = idev->cnf.accept_source_route; 682 683 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 684 !pskb_may_pull(skb, (skb_transport_offset(skb) + 685 ((skb_transport_header(skb)[1] + 1) << 3)))) { 686 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 687 kfree_skb(skb); 688 return -1; 689 } 690 691 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 692 693 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 694 skb->pkt_type != PACKET_HOST) { 695 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 696 kfree_skb(skb); 697 return -1; 698 } 699 700 switch (hdr->type) { 701 case IPV6_SRCRT_TYPE_4: 702 /* segment routing */ 703 return ipv6_srh_rcv(skb); 704 case IPV6_SRCRT_TYPE_3: 705 /* rpl segment routing */ 706 return ipv6_rpl_srh_rcv(skb); 707 default: 708 break; 709 } 710 711 looped_back: 712 if (hdr->segments_left == 0) { 713 switch (hdr->type) { 714 #if IS_ENABLED(CONFIG_IPV6_MIP6) 715 case IPV6_SRCRT_TYPE_2: 716 /* Silently discard type 2 header unless it was 717 * processed by own 718 */ 719 if (!addr) { 720 __IP6_INC_STATS(net, idev, 721 IPSTATS_MIB_INADDRERRORS); 722 kfree_skb(skb); 723 return -1; 724 } 725 break; 726 #endif 727 default: 728 break; 729 } 730 731 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 732 skb->transport_header += (hdr->hdrlen + 1) << 3; 733 opt->dst0 = opt->dst1; 734 opt->dst1 = 0; 735 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 736 return 1; 737 } 738 739 switch (hdr->type) { 740 #if IS_ENABLED(CONFIG_IPV6_MIP6) 741 case IPV6_SRCRT_TYPE_2: 742 if (accept_source_route < 0) 743 goto unknown_rh; 744 /* Silently discard invalid RTH type 2 */ 745 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 746 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 747 kfree_skb(skb); 748 return -1; 749 } 750 break; 751 #endif 752 default: 753 goto unknown_rh; 754 } 755 756 /* 757 * This is the routing header forwarding algorithm from 758 * RFC 2460, page 16. 759 */ 760 761 n = hdr->hdrlen >> 1; 762 763 if (hdr->segments_left > n) { 764 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 765 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 766 ((&hdr->segments_left) - 767 skb_network_header(skb))); 768 return -1; 769 } 770 771 /* We are about to mangle packet header. Be careful! 772 Do not damage packets queued somewhere. 773 */ 774 if (skb_cloned(skb)) { 775 /* the copy is a forwarded packet */ 776 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 777 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 778 IPSTATS_MIB_OUTDISCARDS); 779 kfree_skb(skb); 780 return -1; 781 } 782 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 783 } 784 785 if (skb->ip_summed == CHECKSUM_COMPLETE) 786 skb->ip_summed = CHECKSUM_NONE; 787 788 i = n - --hdr->segments_left; 789 790 rthdr = (struct rt0_hdr *) hdr; 791 addr = rthdr->addr; 792 addr += i - 1; 793 794 switch (hdr->type) { 795 #if IS_ENABLED(CONFIG_IPV6_MIP6) 796 case IPV6_SRCRT_TYPE_2: 797 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 798 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 799 IPPROTO_ROUTING) < 0) { 800 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 801 kfree_skb(skb); 802 return -1; 803 } 804 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 805 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 806 kfree_skb(skb); 807 return -1; 808 } 809 break; 810 #endif 811 default: 812 break; 813 } 814 815 if (ipv6_addr_is_multicast(addr)) { 816 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 817 kfree_skb(skb); 818 return -1; 819 } 820 821 daddr = *addr; 822 *addr = ipv6_hdr(skb)->daddr; 823 ipv6_hdr(skb)->daddr = daddr; 824 825 skb_dst_drop(skb); 826 ip6_route_input(skb); 827 if (skb_dst(skb)->error) { 828 skb_push(skb, skb->data - skb_network_header(skb)); 829 dst_input(skb); 830 return -1; 831 } 832 833 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 834 if (ipv6_hdr(skb)->hop_limit <= 1) { 835 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 836 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 837 0); 838 kfree_skb(skb); 839 return -1; 840 } 841 ipv6_hdr(skb)->hop_limit--; 842 goto looped_back; 843 } 844 845 skb_push(skb, skb->data - skb_network_header(skb)); 846 dst_input(skb); 847 return -1; 848 849 unknown_rh: 850 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 851 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 852 (&hdr->type) - skb_network_header(skb)); 853 return -1; 854 } 855 856 static const struct inet6_protocol rthdr_protocol = { 857 .handler = ipv6_rthdr_rcv, 858 .flags = INET6_PROTO_NOPOLICY, 859 }; 860 861 static const struct inet6_protocol destopt_protocol = { 862 .handler = ipv6_destopt_rcv, 863 .flags = INET6_PROTO_NOPOLICY, 864 }; 865 866 static const struct inet6_protocol nodata_protocol = { 867 .handler = dst_discard, 868 .flags = INET6_PROTO_NOPOLICY, 869 }; 870 871 int __init ipv6_exthdrs_init(void) 872 { 873 int ret; 874 875 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 876 if (ret) 877 goto out; 878 879 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 880 if (ret) 881 goto out_rthdr; 882 883 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 884 if (ret) 885 goto out_destopt; 886 887 out: 888 return ret; 889 out_destopt: 890 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 891 out_rthdr: 892 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 893 goto out; 894 }; 895 896 void ipv6_exthdrs_exit(void) 897 { 898 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 899 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 900 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 901 } 902 903 /********************************** 904 Hop-by-hop options. 905 **********************************/ 906 907 /* 908 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 909 */ 910 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 911 { 912 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 913 } 914 915 /* Router Alert as of RFC 2711 */ 916 917 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 918 { 919 const unsigned char *nh = skb_network_header(skb); 920 921 if (nh[optoff + 1] == 2) { 922 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 923 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 924 return true; 925 } 926 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 927 nh[optoff + 1]); 928 kfree_skb(skb); 929 return false; 930 } 931 932 /* Jumbo payload */ 933 934 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 935 { 936 const unsigned char *nh = skb_network_header(skb); 937 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev); 938 struct net *net = ipv6_skb_net(skb); 939 u32 pkt_len; 940 941 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 942 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 943 nh[optoff+1]); 944 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 945 goto drop; 946 } 947 948 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 949 if (pkt_len <= IPV6_MAXPLEN) { 950 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 951 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 952 return false; 953 } 954 if (ipv6_hdr(skb)->payload_len) { 955 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 956 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 957 return false; 958 } 959 960 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 961 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); 962 goto drop; 963 } 964 965 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 966 goto drop; 967 968 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 969 return true; 970 971 drop: 972 kfree_skb(skb); 973 return false; 974 } 975 976 /* CALIPSO RFC 5570 */ 977 978 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 979 { 980 const unsigned char *nh = skb_network_header(skb); 981 982 if (nh[optoff + 1] < 8) 983 goto drop; 984 985 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 986 goto drop; 987 988 if (!calipso_validate(skb, nh + optoff)) 989 goto drop; 990 991 return true; 992 993 drop: 994 kfree_skb(skb); 995 return false; 996 } 997 998 static const struct tlvtype_proc tlvprochopopt_lst[] = { 999 { 1000 .type = IPV6_TLV_ROUTERALERT, 1001 .func = ipv6_hop_ra, 1002 }, 1003 { 1004 .type = IPV6_TLV_JUMBO, 1005 .func = ipv6_hop_jumbo, 1006 }, 1007 { 1008 .type = IPV6_TLV_CALIPSO, 1009 .func = ipv6_hop_calipso, 1010 }, 1011 { -1, } 1012 }; 1013 1014 int ipv6_parse_hopopts(struct sk_buff *skb) 1015 { 1016 struct inet6_skb_parm *opt = IP6CB(skb); 1017 struct net *net = dev_net(skb->dev); 1018 int extlen; 1019 1020 /* 1021 * skb_network_header(skb) is equal to skb->data, and 1022 * skb_network_header_len(skb) is always equal to 1023 * sizeof(struct ipv6hdr) by definition of 1024 * hop-by-hop options. 1025 */ 1026 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1027 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1028 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1029 fail_and_free: 1030 kfree_skb(skb); 1031 return -1; 1032 } 1033 1034 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1035 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1036 goto fail_and_free; 1037 1038 opt->flags |= IP6SKB_HOPBYHOP; 1039 if (ip6_parse_tlv(tlvprochopopt_lst, skb, 1040 init_net.ipv6.sysctl.max_hbh_opts_cnt)) { 1041 skb->transport_header += extlen; 1042 opt = IP6CB(skb); 1043 opt->nhoff = sizeof(struct ipv6hdr); 1044 return 1; 1045 } 1046 return -1; 1047 } 1048 1049 /* 1050 * Creating outbound headers. 1051 * 1052 * "build" functions work when skb is filled from head to tail (datagram) 1053 * "push" functions work when headers are added from tail to head (tcp) 1054 * 1055 * In both cases we assume, that caller reserved enough room 1056 * for headers. 1057 */ 1058 1059 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1060 struct ipv6_rt_hdr *opt, 1061 struct in6_addr **addr_p, struct in6_addr *saddr) 1062 { 1063 struct rt0_hdr *phdr, *ihdr; 1064 int hops; 1065 1066 ihdr = (struct rt0_hdr *) opt; 1067 1068 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1069 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1070 1071 hops = ihdr->rt_hdr.hdrlen >> 1; 1072 1073 if (hops > 1) 1074 memcpy(phdr->addr, ihdr->addr + 1, 1075 (hops - 1) * sizeof(struct in6_addr)); 1076 1077 phdr->addr[hops - 1] = **addr_p; 1078 *addr_p = ihdr->addr; 1079 1080 phdr->rt_hdr.nexthdr = *proto; 1081 *proto = NEXTHDR_ROUTING; 1082 } 1083 1084 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1085 struct ipv6_rt_hdr *opt, 1086 struct in6_addr **addr_p, struct in6_addr *saddr) 1087 { 1088 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1089 int plen, hops; 1090 1091 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1092 plen = (sr_ihdr->hdrlen + 1) << 3; 1093 1094 sr_phdr = skb_push(skb, plen); 1095 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1096 1097 hops = sr_ihdr->first_segment + 1; 1098 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1099 (hops - 1) * sizeof(struct in6_addr)); 1100 1101 sr_phdr->segments[0] = **addr_p; 1102 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1103 1104 if (sr_ihdr->hdrlen > hops * 2) { 1105 int tlvs_offset, tlvs_length; 1106 1107 tlvs_offset = (1 + hops * 2) << 3; 1108 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1109 memcpy((char *)sr_phdr + tlvs_offset, 1110 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1111 } 1112 1113 #ifdef CONFIG_IPV6_SEG6_HMAC 1114 if (sr_has_hmac(sr_phdr)) { 1115 struct net *net = NULL; 1116 1117 if (skb->dev) 1118 net = dev_net(skb->dev); 1119 else if (skb->sk) 1120 net = sock_net(skb->sk); 1121 1122 WARN_ON(!net); 1123 1124 if (net) 1125 seg6_push_hmac(net, saddr, sr_phdr); 1126 } 1127 #endif 1128 1129 sr_phdr->nexthdr = *proto; 1130 *proto = NEXTHDR_ROUTING; 1131 } 1132 1133 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1134 struct ipv6_rt_hdr *opt, 1135 struct in6_addr **addr_p, struct in6_addr *saddr) 1136 { 1137 switch (opt->type) { 1138 case IPV6_SRCRT_TYPE_0: 1139 case IPV6_SRCRT_STRICT: 1140 case IPV6_SRCRT_TYPE_2: 1141 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1142 break; 1143 case IPV6_SRCRT_TYPE_4: 1144 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1145 break; 1146 default: 1147 break; 1148 } 1149 } 1150 1151 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1152 { 1153 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1154 1155 memcpy(h, opt, ipv6_optlen(opt)); 1156 h->nexthdr = *proto; 1157 *proto = type; 1158 } 1159 1160 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1161 u8 *proto, 1162 struct in6_addr **daddr, struct in6_addr *saddr) 1163 { 1164 if (opt->srcrt) { 1165 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1166 /* 1167 * IPV6_RTHDRDSTOPTS is ignored 1168 * unless IPV6_RTHDR is set (RFC3542). 1169 */ 1170 if (opt->dst0opt) 1171 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1172 } 1173 if (opt->hopopt) 1174 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1175 } 1176 1177 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1178 { 1179 if (opt->dst1opt) 1180 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1181 } 1182 EXPORT_SYMBOL(ipv6_push_frag_opts); 1183 1184 struct ipv6_txoptions * 1185 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1186 { 1187 struct ipv6_txoptions *opt2; 1188 1189 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1190 if (opt2) { 1191 long dif = (char *)opt2 - (char *)opt; 1192 memcpy(opt2, opt, opt->tot_len); 1193 if (opt2->hopopt) 1194 *((char **)&opt2->hopopt) += dif; 1195 if (opt2->dst0opt) 1196 *((char **)&opt2->dst0opt) += dif; 1197 if (opt2->dst1opt) 1198 *((char **)&opt2->dst1opt) += dif; 1199 if (opt2->srcrt) 1200 *((char **)&opt2->srcrt) += dif; 1201 refcount_set(&opt2->refcnt, 1); 1202 } 1203 return opt2; 1204 } 1205 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1206 1207 static void ipv6_renew_option(int renewtype, 1208 struct ipv6_opt_hdr **dest, 1209 struct ipv6_opt_hdr *old, 1210 struct ipv6_opt_hdr *new, 1211 int newtype, char **p) 1212 { 1213 struct ipv6_opt_hdr *src; 1214 1215 src = (renewtype == newtype ? new : old); 1216 if (!src) 1217 return; 1218 1219 memcpy(*p, src, ipv6_optlen(src)); 1220 *dest = (struct ipv6_opt_hdr *)*p; 1221 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1222 } 1223 1224 /** 1225 * ipv6_renew_options - replace a specific ext hdr with a new one. 1226 * 1227 * @sk: sock from which to allocate memory 1228 * @opt: original options 1229 * @newtype: option type to replace in @opt 1230 * @newopt: new option of type @newtype to replace (user-mem) 1231 * 1232 * Returns a new set of options which is a copy of @opt with the 1233 * option type @newtype replaced with @newopt. 1234 * 1235 * @opt may be NULL, in which case a new set of options is returned 1236 * containing just @newopt. 1237 * 1238 * @newopt may be NULL, in which case the specified option type is 1239 * not copied into the new set of options. 1240 * 1241 * The new set of options is allocated from the socket option memory 1242 * buffer of @sk. 1243 */ 1244 struct ipv6_txoptions * 1245 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1246 int newtype, struct ipv6_opt_hdr *newopt) 1247 { 1248 int tot_len = 0; 1249 char *p; 1250 struct ipv6_txoptions *opt2; 1251 1252 if (opt) { 1253 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1254 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1255 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1256 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1257 if (newtype != IPV6_RTHDR && opt->srcrt) 1258 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1259 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1260 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1261 } 1262 1263 if (newopt) 1264 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1265 1266 if (!tot_len) 1267 return NULL; 1268 1269 tot_len += sizeof(*opt2); 1270 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1271 if (!opt2) 1272 return ERR_PTR(-ENOBUFS); 1273 1274 memset(opt2, 0, tot_len); 1275 refcount_set(&opt2->refcnt, 1); 1276 opt2->tot_len = tot_len; 1277 p = (char *)(opt2 + 1); 1278 1279 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1280 (opt ? opt->hopopt : NULL), 1281 newopt, newtype, &p); 1282 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1283 (opt ? opt->dst0opt : NULL), 1284 newopt, newtype, &p); 1285 ipv6_renew_option(IPV6_RTHDR, 1286 (struct ipv6_opt_hdr **)&opt2->srcrt, 1287 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1288 newopt, newtype, &p); 1289 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1290 (opt ? opt->dst1opt : NULL), 1291 newopt, newtype, &p); 1292 1293 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1294 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1295 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1296 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1297 1298 return opt2; 1299 } 1300 1301 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1302 struct ipv6_txoptions *opt) 1303 { 1304 /* 1305 * ignore the dest before srcrt unless srcrt is being included. 1306 * --yoshfuji 1307 */ 1308 if (opt && opt->dst0opt && !opt->srcrt) { 1309 if (opt_space != opt) { 1310 memcpy(opt_space, opt, sizeof(*opt_space)); 1311 opt = opt_space; 1312 } 1313 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1314 opt->dst0opt = NULL; 1315 } 1316 1317 return opt; 1318 } 1319 EXPORT_SYMBOL_GPL(ipv6_fixup_options); 1320 1321 /** 1322 * fl6_update_dst - update flowi destination address with info given 1323 * by srcrt option, if any. 1324 * 1325 * @fl6: flowi6 for which daddr is to be updated 1326 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1327 * @orig: copy of original daddr address if modified 1328 * 1329 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1330 * and initial value of fl6->daddr set in orig 1331 */ 1332 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1333 const struct ipv6_txoptions *opt, 1334 struct in6_addr *orig) 1335 { 1336 if (!opt || !opt->srcrt) 1337 return NULL; 1338 1339 *orig = fl6->daddr; 1340 1341 switch (opt->srcrt->type) { 1342 case IPV6_SRCRT_TYPE_0: 1343 case IPV6_SRCRT_STRICT: 1344 case IPV6_SRCRT_TYPE_2: 1345 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1346 break; 1347 case IPV6_SRCRT_TYPE_4: 1348 { 1349 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1350 1351 fl6->daddr = srh->segments[srh->segments_left]; 1352 break; 1353 } 1354 default: 1355 return NULL; 1356 } 1357 1358 return orig; 1359 } 1360 EXPORT_SYMBOL_GPL(fl6_update_dst); 1361