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 #include <linux/ioam6.h> 53 #include <net/ioam6.h> 54 #include <net/dst_metadata.h> 55 56 #include <linux/uaccess.h> 57 58 /* 59 * Parsing tlv encoded headers. 60 * 61 * Parsing function "func" returns true, if parsing succeed 62 * and false, if it failed. 63 * It MUST NOT touch skb->h. 64 */ 65 66 struct tlvtype_proc { 67 int type; 68 bool (*func)(struct sk_buff *skb, int offset); 69 }; 70 71 /********************* 72 Generic functions 73 *********************/ 74 75 /* An unknown option is detected, decide what to do */ 76 77 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, 78 bool disallow_unknowns) 79 { 80 if (disallow_unknowns) { 81 /* If unknown TLVs are disallowed by configuration 82 * then always silently drop packet. Note this also 83 * means no ICMP parameter problem is sent which 84 * could be a good property to mitigate a reflection DOS 85 * attack. 86 */ 87 88 goto drop; 89 } 90 91 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 92 case 0: /* ignore */ 93 return true; 94 95 case 1: /* drop packet */ 96 break; 97 98 case 3: /* Send ICMP if not a multicast address and drop packet */ 99 /* Actually, it is redundant check. icmp_send 100 will recheck in any case. 101 */ 102 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 103 break; 104 fallthrough; 105 case 2: /* send ICMP PARM PROB regardless and drop packet */ 106 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); 107 return false; 108 } 109 110 drop: 111 kfree_skb(skb); 112 return false; 113 } 114 115 /* Parse tlv encoded option header (hop-by-hop or destination) */ 116 117 static bool ip6_parse_tlv(const struct tlvtype_proc *procs, 118 struct sk_buff *skb, 119 int max_count) 120 { 121 int len = (skb_transport_header(skb)[1] + 1) << 3; 122 const unsigned char *nh = skb_network_header(skb); 123 int off = skb_network_header_len(skb); 124 const struct tlvtype_proc *curr; 125 bool disallow_unknowns = false; 126 int tlv_count = 0; 127 int padlen = 0; 128 129 if (unlikely(max_count < 0)) { 130 disallow_unknowns = true; 131 max_count = -max_count; 132 } 133 134 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 135 goto bad; 136 137 off += 2; 138 len -= 2; 139 140 while (len > 0) { 141 int optlen, i; 142 143 if (nh[off] == IPV6_TLV_PAD1) { 144 padlen++; 145 if (padlen > 7) 146 goto bad; 147 off++; 148 len--; 149 continue; 150 } 151 if (len < 2) 152 goto bad; 153 optlen = nh[off + 1] + 2; 154 if (optlen > len) 155 goto bad; 156 157 if (nh[off] == IPV6_TLV_PADN) { 158 /* RFC 2460 states that the purpose of PadN is 159 * to align the containing header to multiples 160 * of 8. 7 is therefore the highest valid value. 161 * See also RFC 4942, Section 2.1.9.5. 162 */ 163 padlen += optlen; 164 if (padlen > 7) 165 goto bad; 166 /* RFC 4942 recommends receiving hosts to 167 * actively check PadN payload to contain 168 * only zeroes. 169 */ 170 for (i = 2; i < optlen; i++) { 171 if (nh[off + i] != 0) 172 goto bad; 173 } 174 } else { 175 tlv_count++; 176 if (tlv_count > max_count) 177 goto bad; 178 179 for (curr = procs; curr->type >= 0; curr++) { 180 if (curr->type == nh[off]) { 181 /* type specific length/alignment 182 checks will be performed in the 183 func(). */ 184 if (curr->func(skb, off) == false) 185 return false; 186 break; 187 } 188 } 189 if (curr->type < 0 && 190 !ip6_tlvopt_unknown(skb, off, disallow_unknowns)) 191 return false; 192 193 padlen = 0; 194 } 195 off += optlen; 196 len -= optlen; 197 } 198 199 if (len == 0) 200 return true; 201 bad: 202 kfree_skb(skb); 203 return false; 204 } 205 206 /***************************** 207 Destination options header. 208 *****************************/ 209 210 #if IS_ENABLED(CONFIG_IPV6_MIP6) 211 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 212 { 213 struct ipv6_destopt_hao *hao; 214 struct inet6_skb_parm *opt = IP6CB(skb); 215 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 216 int ret; 217 218 if (opt->dsthao) { 219 net_dbg_ratelimited("hao duplicated\n"); 220 goto discard; 221 } 222 opt->dsthao = opt->dst1; 223 opt->dst1 = 0; 224 225 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 226 227 if (hao->length != 16) { 228 net_dbg_ratelimited("hao invalid option length = %d\n", 229 hao->length); 230 goto discard; 231 } 232 233 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 234 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 235 &hao->addr); 236 goto discard; 237 } 238 239 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 240 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 241 if (unlikely(ret < 0)) 242 goto discard; 243 244 if (skb_cloned(skb)) { 245 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 246 goto discard; 247 248 /* update all variable using below by copied skbuff */ 249 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 250 optoff); 251 ipv6h = ipv6_hdr(skb); 252 } 253 254 if (skb->ip_summed == CHECKSUM_COMPLETE) 255 skb->ip_summed = CHECKSUM_NONE; 256 257 swap(ipv6h->saddr, hao->addr); 258 259 if (skb->tstamp == 0) 260 __net_timestamp(skb); 261 262 return true; 263 264 discard: 265 kfree_skb(skb); 266 return false; 267 } 268 #endif 269 270 static const struct tlvtype_proc tlvprocdestopt_lst[] = { 271 #if IS_ENABLED(CONFIG_IPV6_MIP6) 272 { 273 .type = IPV6_TLV_HAO, 274 .func = ipv6_dest_hao, 275 }, 276 #endif 277 {-1, NULL} 278 }; 279 280 static int ipv6_destopt_rcv(struct sk_buff *skb) 281 { 282 struct inet6_dev *idev = __in6_dev_get(skb->dev); 283 struct inet6_skb_parm *opt = IP6CB(skb); 284 #if IS_ENABLED(CONFIG_IPV6_MIP6) 285 __u16 dstbuf; 286 #endif 287 struct dst_entry *dst = skb_dst(skb); 288 struct net *net = dev_net(skb->dev); 289 int extlen; 290 291 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 292 !pskb_may_pull(skb, (skb_transport_offset(skb) + 293 ((skb_transport_header(skb)[1] + 1) << 3)))) { 294 __IP6_INC_STATS(dev_net(dst->dev), idev, 295 IPSTATS_MIB_INHDRERRORS); 296 fail_and_free: 297 kfree_skb(skb); 298 return -1; 299 } 300 301 extlen = (skb_transport_header(skb)[1] + 1) << 3; 302 if (extlen > net->ipv6.sysctl.max_dst_opts_len) 303 goto fail_and_free; 304 305 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 306 #if IS_ENABLED(CONFIG_IPV6_MIP6) 307 dstbuf = opt->dst1; 308 #endif 309 310 if (ip6_parse_tlv(tlvprocdestopt_lst, skb, 311 net->ipv6.sysctl.max_dst_opts_cnt)) { 312 skb->transport_header += extlen; 313 opt = IP6CB(skb); 314 #if IS_ENABLED(CONFIG_IPV6_MIP6) 315 opt->nhoff = dstbuf; 316 #else 317 opt->nhoff = opt->dst1; 318 #endif 319 return 1; 320 } 321 322 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 323 return -1; 324 } 325 326 static void seg6_update_csum(struct sk_buff *skb) 327 { 328 struct ipv6_sr_hdr *hdr; 329 struct in6_addr *addr; 330 __be32 from, to; 331 332 /* srh is at transport offset and seg_left is already decremented 333 * but daddr is not yet updated with next segment 334 */ 335 336 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 337 addr = hdr->segments + hdr->segments_left; 338 339 hdr->segments_left++; 340 from = *(__be32 *)hdr; 341 342 hdr->segments_left--; 343 to = *(__be32 *)hdr; 344 345 /* update skb csum with diff resulting from seg_left decrement */ 346 347 update_csum_diff4(skb, from, to); 348 349 /* compute csum diff between current and next segment and update */ 350 351 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 352 (__be32 *)addr); 353 } 354 355 static int ipv6_srh_rcv(struct sk_buff *skb) 356 { 357 struct inet6_skb_parm *opt = IP6CB(skb); 358 struct net *net = dev_net(skb->dev); 359 struct ipv6_sr_hdr *hdr; 360 struct inet6_dev *idev; 361 struct in6_addr *addr; 362 int accept_seg6; 363 364 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 365 366 idev = __in6_dev_get(skb->dev); 367 368 accept_seg6 = net->ipv6.devconf_all->seg6_enabled; 369 if (accept_seg6 > idev->cnf.seg6_enabled) 370 accept_seg6 = idev->cnf.seg6_enabled; 371 372 if (!accept_seg6) { 373 kfree_skb(skb); 374 return -1; 375 } 376 377 #ifdef CONFIG_IPV6_SEG6_HMAC 378 if (!seg6_hmac_validate_skb(skb)) { 379 kfree_skb(skb); 380 return -1; 381 } 382 #endif 383 384 looped_back: 385 if (hdr->segments_left == 0) { 386 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 387 int offset = (hdr->hdrlen + 1) << 3; 388 389 skb_postpull_rcsum(skb, skb_network_header(skb), 390 skb_network_header_len(skb)); 391 392 if (!pskb_pull(skb, offset)) { 393 kfree_skb(skb); 394 return -1; 395 } 396 skb_postpull_rcsum(skb, skb_transport_header(skb), 397 offset); 398 399 skb_reset_network_header(skb); 400 skb_reset_transport_header(skb); 401 skb->encapsulation = 0; 402 if (hdr->nexthdr == NEXTHDR_IPV4) 403 skb->protocol = htons(ETH_P_IP); 404 __skb_tunnel_rx(skb, skb->dev, net); 405 406 netif_rx(skb); 407 return -1; 408 } 409 410 opt->srcrt = skb_network_header_len(skb); 411 opt->lastopt = opt->srcrt; 412 skb->transport_header += (hdr->hdrlen + 1) << 3; 413 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 414 415 return 1; 416 } 417 418 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 419 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 420 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 421 ((&hdr->segments_left) - 422 skb_network_header(skb))); 423 return -1; 424 } 425 426 if (skb_cloned(skb)) { 427 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 428 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 429 IPSTATS_MIB_OUTDISCARDS); 430 kfree_skb(skb); 431 return -1; 432 } 433 } 434 435 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 436 437 hdr->segments_left--; 438 addr = hdr->segments + hdr->segments_left; 439 440 skb_push(skb, sizeof(struct ipv6hdr)); 441 442 if (skb->ip_summed == CHECKSUM_COMPLETE) 443 seg6_update_csum(skb); 444 445 ipv6_hdr(skb)->daddr = *addr; 446 447 skb_dst_drop(skb); 448 449 ip6_route_input(skb); 450 451 if (skb_dst(skb)->error) { 452 dst_input(skb); 453 return -1; 454 } 455 456 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 457 if (ipv6_hdr(skb)->hop_limit <= 1) { 458 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 459 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 460 ICMPV6_EXC_HOPLIMIT, 0); 461 kfree_skb(skb); 462 return -1; 463 } 464 ipv6_hdr(skb)->hop_limit--; 465 466 skb_pull(skb, sizeof(struct ipv6hdr)); 467 goto looped_back; 468 } 469 470 dst_input(skb); 471 472 return -1; 473 } 474 475 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 476 { 477 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 478 struct inet6_skb_parm *opt = IP6CB(skb); 479 struct net *net = dev_net(skb->dev); 480 struct inet6_dev *idev; 481 struct ipv6hdr *oldhdr; 482 struct in6_addr addr; 483 unsigned char *buf; 484 int accept_rpl_seg; 485 int i, err; 486 u64 n = 0; 487 u32 r; 488 489 idev = __in6_dev_get(skb->dev); 490 491 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 492 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 493 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 494 495 if (!accept_rpl_seg) { 496 kfree_skb(skb); 497 return -1; 498 } 499 500 looped_back: 501 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 502 503 if (hdr->segments_left == 0) { 504 if (hdr->nexthdr == NEXTHDR_IPV6) { 505 int offset = (hdr->hdrlen + 1) << 3; 506 507 skb_postpull_rcsum(skb, skb_network_header(skb), 508 skb_network_header_len(skb)); 509 510 if (!pskb_pull(skb, offset)) { 511 kfree_skb(skb); 512 return -1; 513 } 514 skb_postpull_rcsum(skb, skb_transport_header(skb), 515 offset); 516 517 skb_reset_network_header(skb); 518 skb_reset_transport_header(skb); 519 skb->encapsulation = 0; 520 521 __skb_tunnel_rx(skb, skb->dev, net); 522 523 netif_rx(skb); 524 return -1; 525 } 526 527 opt->srcrt = skb_network_header_len(skb); 528 opt->lastopt = opt->srcrt; 529 skb->transport_header += (hdr->hdrlen + 1) << 3; 530 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 531 532 return 1; 533 } 534 535 if (!pskb_may_pull(skb, sizeof(*hdr))) { 536 kfree_skb(skb); 537 return -1; 538 } 539 540 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 541 r = do_div(n, (16 - hdr->cmpri)); 542 /* checks if calculation was without remainder and n fits into 543 * unsigned char which is segments_left field. Should not be 544 * higher than that. 545 */ 546 if (r || (n + 1) > 255) { 547 kfree_skb(skb); 548 return -1; 549 } 550 551 if (hdr->segments_left > n + 1) { 552 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 553 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 554 ((&hdr->segments_left) - 555 skb_network_header(skb))); 556 return -1; 557 } 558 559 if (skb_cloned(skb)) { 560 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0, 561 GFP_ATOMIC)) { 562 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 563 IPSTATS_MIB_OUTDISCARDS); 564 kfree_skb(skb); 565 return -1; 566 } 567 } else { 568 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE); 569 if (unlikely(err)) { 570 kfree_skb(skb); 571 return -1; 572 } 573 } 574 575 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 576 577 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 578 hdr->cmpre))) { 579 kfree_skb(skb); 580 return -1; 581 } 582 583 hdr->segments_left--; 584 i = n - hdr->segments_left; 585 586 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 587 if (unlikely(!buf)) { 588 kfree_skb(skb); 589 return -1; 590 } 591 592 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 593 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 594 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 595 596 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 597 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 598 kfree_skb(skb); 599 kfree(buf); 600 return -1; 601 } 602 603 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 604 if (err) { 605 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 606 kfree_skb(skb); 607 kfree(buf); 608 return -1; 609 } 610 611 addr = ipv6_hdr(skb)->daddr; 612 ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i]; 613 ohdr->rpl_segaddr[i] = addr; 614 615 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 616 617 oldhdr = ipv6_hdr(skb); 618 619 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 620 skb_postpull_rcsum(skb, oldhdr, 621 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 622 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 623 skb_reset_network_header(skb); 624 skb_mac_header_rebuild(skb); 625 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 626 627 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 628 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 629 630 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 631 skb_postpush_rcsum(skb, ipv6_hdr(skb), 632 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 633 634 kfree(buf); 635 636 skb_dst_drop(skb); 637 638 ip6_route_input(skb); 639 640 if (skb_dst(skb)->error) { 641 dst_input(skb); 642 return -1; 643 } 644 645 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 646 if (ipv6_hdr(skb)->hop_limit <= 1) { 647 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 648 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 649 ICMPV6_EXC_HOPLIMIT, 0); 650 kfree_skb(skb); 651 return -1; 652 } 653 ipv6_hdr(skb)->hop_limit--; 654 655 skb_pull(skb, sizeof(struct ipv6hdr)); 656 goto looped_back; 657 } 658 659 dst_input(skb); 660 661 return -1; 662 } 663 664 /******************************** 665 Routing header. 666 ********************************/ 667 668 /* called with rcu_read_lock() */ 669 static int ipv6_rthdr_rcv(struct sk_buff *skb) 670 { 671 struct inet6_dev *idev = __in6_dev_get(skb->dev); 672 struct inet6_skb_parm *opt = IP6CB(skb); 673 struct in6_addr *addr = NULL; 674 struct in6_addr daddr; 675 int n, i; 676 struct ipv6_rt_hdr *hdr; 677 struct rt0_hdr *rthdr; 678 struct net *net = dev_net(skb->dev); 679 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 680 681 idev = __in6_dev_get(skb->dev); 682 if (idev && accept_source_route > idev->cnf.accept_source_route) 683 accept_source_route = idev->cnf.accept_source_route; 684 685 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 686 !pskb_may_pull(skb, (skb_transport_offset(skb) + 687 ((skb_transport_header(skb)[1] + 1) << 3)))) { 688 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 689 kfree_skb(skb); 690 return -1; 691 } 692 693 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 694 695 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 696 skb->pkt_type != PACKET_HOST) { 697 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 698 kfree_skb(skb); 699 return -1; 700 } 701 702 switch (hdr->type) { 703 case IPV6_SRCRT_TYPE_4: 704 /* segment routing */ 705 return ipv6_srh_rcv(skb); 706 case IPV6_SRCRT_TYPE_3: 707 /* rpl segment routing */ 708 return ipv6_rpl_srh_rcv(skb); 709 default: 710 break; 711 } 712 713 looped_back: 714 if (hdr->segments_left == 0) { 715 switch (hdr->type) { 716 #if IS_ENABLED(CONFIG_IPV6_MIP6) 717 case IPV6_SRCRT_TYPE_2: 718 /* Silently discard type 2 header unless it was 719 * processed by own 720 */ 721 if (!addr) { 722 __IP6_INC_STATS(net, idev, 723 IPSTATS_MIB_INADDRERRORS); 724 kfree_skb(skb); 725 return -1; 726 } 727 break; 728 #endif 729 default: 730 break; 731 } 732 733 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 734 skb->transport_header += (hdr->hdrlen + 1) << 3; 735 opt->dst0 = opt->dst1; 736 opt->dst1 = 0; 737 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 738 return 1; 739 } 740 741 switch (hdr->type) { 742 #if IS_ENABLED(CONFIG_IPV6_MIP6) 743 case IPV6_SRCRT_TYPE_2: 744 if (accept_source_route < 0) 745 goto unknown_rh; 746 /* Silently discard invalid RTH type 2 */ 747 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 748 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 749 kfree_skb(skb); 750 return -1; 751 } 752 break; 753 #endif 754 default: 755 goto unknown_rh; 756 } 757 758 /* 759 * This is the routing header forwarding algorithm from 760 * RFC 2460, page 16. 761 */ 762 763 n = hdr->hdrlen >> 1; 764 765 if (hdr->segments_left > n) { 766 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 767 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 768 ((&hdr->segments_left) - 769 skb_network_header(skb))); 770 return -1; 771 } 772 773 /* We are about to mangle packet header. Be careful! 774 Do not damage packets queued somewhere. 775 */ 776 if (skb_cloned(skb)) { 777 /* the copy is a forwarded packet */ 778 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 779 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 780 IPSTATS_MIB_OUTDISCARDS); 781 kfree_skb(skb); 782 return -1; 783 } 784 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 785 } 786 787 if (skb->ip_summed == CHECKSUM_COMPLETE) 788 skb->ip_summed = CHECKSUM_NONE; 789 790 i = n - --hdr->segments_left; 791 792 rthdr = (struct rt0_hdr *) hdr; 793 addr = rthdr->addr; 794 addr += i - 1; 795 796 switch (hdr->type) { 797 #if IS_ENABLED(CONFIG_IPV6_MIP6) 798 case IPV6_SRCRT_TYPE_2: 799 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 800 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 801 IPPROTO_ROUTING) < 0) { 802 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 803 kfree_skb(skb); 804 return -1; 805 } 806 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 807 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 808 kfree_skb(skb); 809 return -1; 810 } 811 break; 812 #endif 813 default: 814 break; 815 } 816 817 if (ipv6_addr_is_multicast(addr)) { 818 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 819 kfree_skb(skb); 820 return -1; 821 } 822 823 daddr = *addr; 824 *addr = ipv6_hdr(skb)->daddr; 825 ipv6_hdr(skb)->daddr = daddr; 826 827 skb_dst_drop(skb); 828 ip6_route_input(skb); 829 if (skb_dst(skb)->error) { 830 skb_push(skb, skb->data - skb_network_header(skb)); 831 dst_input(skb); 832 return -1; 833 } 834 835 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 836 if (ipv6_hdr(skb)->hop_limit <= 1) { 837 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 838 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 839 0); 840 kfree_skb(skb); 841 return -1; 842 } 843 ipv6_hdr(skb)->hop_limit--; 844 goto looped_back; 845 } 846 847 skb_push(skb, skb->data - skb_network_header(skb)); 848 dst_input(skb); 849 return -1; 850 851 unknown_rh: 852 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 853 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 854 (&hdr->type) - skb_network_header(skb)); 855 return -1; 856 } 857 858 static const struct inet6_protocol rthdr_protocol = { 859 .handler = ipv6_rthdr_rcv, 860 .flags = INET6_PROTO_NOPOLICY, 861 }; 862 863 static const struct inet6_protocol destopt_protocol = { 864 .handler = ipv6_destopt_rcv, 865 .flags = INET6_PROTO_NOPOLICY, 866 }; 867 868 static const struct inet6_protocol nodata_protocol = { 869 .handler = dst_discard, 870 .flags = INET6_PROTO_NOPOLICY, 871 }; 872 873 int __init ipv6_exthdrs_init(void) 874 { 875 int ret; 876 877 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 878 if (ret) 879 goto out; 880 881 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 882 if (ret) 883 goto out_rthdr; 884 885 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 886 if (ret) 887 goto out_destopt; 888 889 out: 890 return ret; 891 out_destopt: 892 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 893 out_rthdr: 894 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 895 goto out; 896 }; 897 898 void ipv6_exthdrs_exit(void) 899 { 900 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 901 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 902 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 903 } 904 905 /********************************** 906 Hop-by-hop options. 907 **********************************/ 908 909 /* 910 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 911 */ 912 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 913 { 914 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 915 } 916 917 /* Router Alert as of RFC 2711 */ 918 919 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 920 { 921 const unsigned char *nh = skb_network_header(skb); 922 923 if (nh[optoff + 1] == 2) { 924 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 925 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 926 return true; 927 } 928 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 929 nh[optoff + 1]); 930 kfree_skb(skb); 931 return false; 932 } 933 934 /* IOAM */ 935 936 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 937 { 938 struct ioam6_trace_hdr *trace; 939 struct ioam6_namespace *ns; 940 struct ioam6_hdr *hdr; 941 942 /* Bad alignment (must be 4n-aligned) */ 943 if (optoff & 3) 944 goto drop; 945 946 /* Ignore if IOAM is not enabled on ingress */ 947 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled) 948 goto ignore; 949 950 /* Truncated Option header */ 951 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 952 if (hdr->opt_len < 2) 953 goto drop; 954 955 switch (hdr->type) { 956 case IOAM6_TYPE_PREALLOC: 957 /* Truncated Pre-allocated Trace header */ 958 if (hdr->opt_len < 2 + sizeof(*trace)) 959 goto drop; 960 961 /* Malformed Pre-allocated Trace header */ 962 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 963 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 964 goto drop; 965 966 /* Ignore if the IOAM namespace is unknown */ 967 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id); 968 if (!ns) 969 goto ignore; 970 971 if (!skb_valid_dst(skb)) 972 ip6_route_input(skb); 973 974 ioam6_fill_trace_data(skb, ns, trace); 975 break; 976 default: 977 break; 978 } 979 980 ignore: 981 return true; 982 983 drop: 984 kfree_skb(skb); 985 return false; 986 } 987 988 /* Jumbo payload */ 989 990 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 991 { 992 const unsigned char *nh = skb_network_header(skb); 993 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev); 994 struct net *net = ipv6_skb_net(skb); 995 u32 pkt_len; 996 997 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 998 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 999 nh[optoff+1]); 1000 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1001 goto drop; 1002 } 1003 1004 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1005 if (pkt_len <= IPV6_MAXPLEN) { 1006 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1007 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 1008 return false; 1009 } 1010 if (ipv6_hdr(skb)->payload_len) { 1011 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1012 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 1013 return false; 1014 } 1015 1016 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1017 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); 1018 goto drop; 1019 } 1020 1021 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1022 goto drop; 1023 1024 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1025 return true; 1026 1027 drop: 1028 kfree_skb(skb); 1029 return false; 1030 } 1031 1032 /* CALIPSO RFC 5570 */ 1033 1034 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1035 { 1036 const unsigned char *nh = skb_network_header(skb); 1037 1038 if (nh[optoff + 1] < 8) 1039 goto drop; 1040 1041 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1042 goto drop; 1043 1044 if (!calipso_validate(skb, nh + optoff)) 1045 goto drop; 1046 1047 return true; 1048 1049 drop: 1050 kfree_skb(skb); 1051 return false; 1052 } 1053 1054 static const struct tlvtype_proc tlvprochopopt_lst[] = { 1055 { 1056 .type = IPV6_TLV_ROUTERALERT, 1057 .func = ipv6_hop_ra, 1058 }, 1059 { 1060 .type = IPV6_TLV_IOAM, 1061 .func = ipv6_hop_ioam, 1062 }, 1063 { 1064 .type = IPV6_TLV_JUMBO, 1065 .func = ipv6_hop_jumbo, 1066 }, 1067 { 1068 .type = IPV6_TLV_CALIPSO, 1069 .func = ipv6_hop_calipso, 1070 }, 1071 { -1, } 1072 }; 1073 1074 int ipv6_parse_hopopts(struct sk_buff *skb) 1075 { 1076 struct inet6_skb_parm *opt = IP6CB(skb); 1077 struct net *net = dev_net(skb->dev); 1078 int extlen; 1079 1080 /* 1081 * skb_network_header(skb) is equal to skb->data, and 1082 * skb_network_header_len(skb) is always equal to 1083 * sizeof(struct ipv6hdr) by definition of 1084 * hop-by-hop options. 1085 */ 1086 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1087 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1088 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1089 fail_and_free: 1090 kfree_skb(skb); 1091 return -1; 1092 } 1093 1094 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1095 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1096 goto fail_and_free; 1097 1098 opt->flags |= IP6SKB_HOPBYHOP; 1099 if (ip6_parse_tlv(tlvprochopopt_lst, skb, 1100 net->ipv6.sysctl.max_hbh_opts_cnt)) { 1101 skb->transport_header += extlen; 1102 opt = IP6CB(skb); 1103 opt->nhoff = sizeof(struct ipv6hdr); 1104 return 1; 1105 } 1106 return -1; 1107 } 1108 1109 /* 1110 * Creating outbound headers. 1111 * 1112 * "build" functions work when skb is filled from head to tail (datagram) 1113 * "push" functions work when headers are added from tail to head (tcp) 1114 * 1115 * In both cases we assume, that caller reserved enough room 1116 * for headers. 1117 */ 1118 1119 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1120 struct ipv6_rt_hdr *opt, 1121 struct in6_addr **addr_p, struct in6_addr *saddr) 1122 { 1123 struct rt0_hdr *phdr, *ihdr; 1124 int hops; 1125 1126 ihdr = (struct rt0_hdr *) opt; 1127 1128 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1129 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1130 1131 hops = ihdr->rt_hdr.hdrlen >> 1; 1132 1133 if (hops > 1) 1134 memcpy(phdr->addr, ihdr->addr + 1, 1135 (hops - 1) * sizeof(struct in6_addr)); 1136 1137 phdr->addr[hops - 1] = **addr_p; 1138 *addr_p = ihdr->addr; 1139 1140 phdr->rt_hdr.nexthdr = *proto; 1141 *proto = NEXTHDR_ROUTING; 1142 } 1143 1144 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1145 struct ipv6_rt_hdr *opt, 1146 struct in6_addr **addr_p, struct in6_addr *saddr) 1147 { 1148 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1149 int plen, hops; 1150 1151 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1152 plen = (sr_ihdr->hdrlen + 1) << 3; 1153 1154 sr_phdr = skb_push(skb, plen); 1155 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1156 1157 hops = sr_ihdr->first_segment + 1; 1158 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1159 (hops - 1) * sizeof(struct in6_addr)); 1160 1161 sr_phdr->segments[0] = **addr_p; 1162 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1163 1164 if (sr_ihdr->hdrlen > hops * 2) { 1165 int tlvs_offset, tlvs_length; 1166 1167 tlvs_offset = (1 + hops * 2) << 3; 1168 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1169 memcpy((char *)sr_phdr + tlvs_offset, 1170 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1171 } 1172 1173 #ifdef CONFIG_IPV6_SEG6_HMAC 1174 if (sr_has_hmac(sr_phdr)) { 1175 struct net *net = NULL; 1176 1177 if (skb->dev) 1178 net = dev_net(skb->dev); 1179 else if (skb->sk) 1180 net = sock_net(skb->sk); 1181 1182 WARN_ON(!net); 1183 1184 if (net) 1185 seg6_push_hmac(net, saddr, sr_phdr); 1186 } 1187 #endif 1188 1189 sr_phdr->nexthdr = *proto; 1190 *proto = NEXTHDR_ROUTING; 1191 } 1192 1193 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1194 struct ipv6_rt_hdr *opt, 1195 struct in6_addr **addr_p, struct in6_addr *saddr) 1196 { 1197 switch (opt->type) { 1198 case IPV6_SRCRT_TYPE_0: 1199 case IPV6_SRCRT_STRICT: 1200 case IPV6_SRCRT_TYPE_2: 1201 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1202 break; 1203 case IPV6_SRCRT_TYPE_4: 1204 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1205 break; 1206 default: 1207 break; 1208 } 1209 } 1210 1211 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1212 { 1213 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1214 1215 memcpy(h, opt, ipv6_optlen(opt)); 1216 h->nexthdr = *proto; 1217 *proto = type; 1218 } 1219 1220 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1221 u8 *proto, 1222 struct in6_addr **daddr, struct in6_addr *saddr) 1223 { 1224 if (opt->srcrt) { 1225 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1226 /* 1227 * IPV6_RTHDRDSTOPTS is ignored 1228 * unless IPV6_RTHDR is set (RFC3542). 1229 */ 1230 if (opt->dst0opt) 1231 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1232 } 1233 if (opt->hopopt) 1234 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1235 } 1236 1237 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1238 { 1239 if (opt->dst1opt) 1240 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1241 } 1242 EXPORT_SYMBOL(ipv6_push_frag_opts); 1243 1244 struct ipv6_txoptions * 1245 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1246 { 1247 struct ipv6_txoptions *opt2; 1248 1249 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1250 if (opt2) { 1251 long dif = (char *)opt2 - (char *)opt; 1252 memcpy(opt2, opt, opt->tot_len); 1253 if (opt2->hopopt) 1254 *((char **)&opt2->hopopt) += dif; 1255 if (opt2->dst0opt) 1256 *((char **)&opt2->dst0opt) += dif; 1257 if (opt2->dst1opt) 1258 *((char **)&opt2->dst1opt) += dif; 1259 if (opt2->srcrt) 1260 *((char **)&opt2->srcrt) += dif; 1261 refcount_set(&opt2->refcnt, 1); 1262 } 1263 return opt2; 1264 } 1265 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1266 1267 static void ipv6_renew_option(int renewtype, 1268 struct ipv6_opt_hdr **dest, 1269 struct ipv6_opt_hdr *old, 1270 struct ipv6_opt_hdr *new, 1271 int newtype, char **p) 1272 { 1273 struct ipv6_opt_hdr *src; 1274 1275 src = (renewtype == newtype ? new : old); 1276 if (!src) 1277 return; 1278 1279 memcpy(*p, src, ipv6_optlen(src)); 1280 *dest = (struct ipv6_opt_hdr *)*p; 1281 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1282 } 1283 1284 /** 1285 * ipv6_renew_options - replace a specific ext hdr with a new one. 1286 * 1287 * @sk: sock from which to allocate memory 1288 * @opt: original options 1289 * @newtype: option type to replace in @opt 1290 * @newopt: new option of type @newtype to replace (user-mem) 1291 * 1292 * Returns a new set of options which is a copy of @opt with the 1293 * option type @newtype replaced with @newopt. 1294 * 1295 * @opt may be NULL, in which case a new set of options is returned 1296 * containing just @newopt. 1297 * 1298 * @newopt may be NULL, in which case the specified option type is 1299 * not copied into the new set of options. 1300 * 1301 * The new set of options is allocated from the socket option memory 1302 * buffer of @sk. 1303 */ 1304 struct ipv6_txoptions * 1305 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1306 int newtype, struct ipv6_opt_hdr *newopt) 1307 { 1308 int tot_len = 0; 1309 char *p; 1310 struct ipv6_txoptions *opt2; 1311 1312 if (opt) { 1313 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1314 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1315 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1316 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1317 if (newtype != IPV6_RTHDR && opt->srcrt) 1318 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1319 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1320 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1321 } 1322 1323 if (newopt) 1324 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1325 1326 if (!tot_len) 1327 return NULL; 1328 1329 tot_len += sizeof(*opt2); 1330 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1331 if (!opt2) 1332 return ERR_PTR(-ENOBUFS); 1333 1334 memset(opt2, 0, tot_len); 1335 refcount_set(&opt2->refcnt, 1); 1336 opt2->tot_len = tot_len; 1337 p = (char *)(opt2 + 1); 1338 1339 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1340 (opt ? opt->hopopt : NULL), 1341 newopt, newtype, &p); 1342 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1343 (opt ? opt->dst0opt : NULL), 1344 newopt, newtype, &p); 1345 ipv6_renew_option(IPV6_RTHDR, 1346 (struct ipv6_opt_hdr **)&opt2->srcrt, 1347 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1348 newopt, newtype, &p); 1349 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1350 (opt ? opt->dst1opt : NULL), 1351 newopt, newtype, &p); 1352 1353 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1354 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1355 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1356 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1357 1358 return opt2; 1359 } 1360 1361 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1362 struct ipv6_txoptions *opt) 1363 { 1364 /* 1365 * ignore the dest before srcrt unless srcrt is being included. 1366 * --yoshfuji 1367 */ 1368 if (opt && opt->dst0opt && !opt->srcrt) { 1369 if (opt_space != opt) { 1370 memcpy(opt_space, opt, sizeof(*opt_space)); 1371 opt = opt_space; 1372 } 1373 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1374 opt->dst0opt = NULL; 1375 } 1376 1377 return opt; 1378 } 1379 EXPORT_SYMBOL_GPL(ipv6_fixup_options); 1380 1381 /** 1382 * fl6_update_dst - update flowi destination address with info given 1383 * by srcrt option, if any. 1384 * 1385 * @fl6: flowi6 for which daddr is to be updated 1386 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1387 * @orig: copy of original daddr address if modified 1388 * 1389 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1390 * and initial value of fl6->daddr set in orig 1391 */ 1392 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1393 const struct ipv6_txoptions *opt, 1394 struct in6_addr *orig) 1395 { 1396 if (!opt || !opt->srcrt) 1397 return NULL; 1398 1399 *orig = fl6->daddr; 1400 1401 switch (opt->srcrt->type) { 1402 case IPV6_SRCRT_TYPE_0: 1403 case IPV6_SRCRT_STRICT: 1404 case IPV6_SRCRT_TYPE_2: 1405 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1406 break; 1407 case IPV6_SRCRT_TYPE_4: 1408 { 1409 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1410 1411 fl6->daddr = srh->segments[srh->segments_left]; 1412 break; 1413 } 1414 default: 1415 return NULL; 1416 } 1417 1418 return orig; 1419 } 1420 EXPORT_SYMBOL_GPL(fl6_update_dst); 1421