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 Generic functions 60 *********************/ 61 62 /* An unknown option is detected, decide what to do */ 63 64 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, 65 bool disallow_unknowns) 66 { 67 if (disallow_unknowns) { 68 /* If unknown TLVs are disallowed by configuration 69 * then always silently drop packet. Note this also 70 * means no ICMP parameter problem is sent which 71 * could be a good property to mitigate a reflection DOS 72 * attack. 73 */ 74 75 goto drop; 76 } 77 78 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 79 case 0: /* ignore */ 80 return true; 81 82 case 1: /* drop packet */ 83 break; 84 85 case 3: /* Send ICMP if not a multicast address and drop packet */ 86 /* Actually, it is redundant check. icmp_send 87 will recheck in any case. 88 */ 89 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 90 break; 91 fallthrough; 92 case 2: /* send ICMP PARM PROB regardless and drop packet */ 93 icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff, 94 SKB_DROP_REASON_UNHANDLED_PROTO); 95 return false; 96 } 97 98 drop: 99 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO); 100 return false; 101 } 102 103 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff); 104 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff); 105 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff); 106 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff); 107 #if IS_ENABLED(CONFIG_IPV6_MIP6) 108 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff); 109 #endif 110 111 /* Parse tlv encoded option header (hop-by-hop or destination) */ 112 113 static bool ip6_parse_tlv(bool hopbyhop, 114 struct sk_buff *skb, 115 int max_count) 116 { 117 int len = (skb_transport_header(skb)[1] + 1) << 3; 118 const unsigned char *nh = skb_network_header(skb); 119 int off = skb_network_header_len(skb); 120 bool disallow_unknowns = false; 121 int tlv_count = 0; 122 int padlen = 0; 123 124 if (unlikely(max_count < 0)) { 125 disallow_unknowns = true; 126 max_count = -max_count; 127 } 128 129 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 130 goto bad; 131 132 off += 2; 133 len -= 2; 134 135 while (len > 0) { 136 int optlen, i; 137 138 if (nh[off] == IPV6_TLV_PAD1) { 139 padlen++; 140 if (padlen > 7) 141 goto bad; 142 off++; 143 len--; 144 continue; 145 } 146 if (len < 2) 147 goto bad; 148 optlen = nh[off + 1] + 2; 149 if (optlen > len) 150 goto bad; 151 152 if (nh[off] == IPV6_TLV_PADN) { 153 /* RFC 2460 states that the purpose of PadN is 154 * to align the containing header to multiples 155 * of 8. 7 is therefore the highest valid value. 156 * See also RFC 4942, Section 2.1.9.5. 157 */ 158 padlen += optlen; 159 if (padlen > 7) 160 goto bad; 161 /* RFC 4942 recommends receiving hosts to 162 * actively check PadN payload to contain 163 * only zeroes. 164 */ 165 for (i = 2; i < optlen; i++) { 166 if (nh[off + i] != 0) 167 goto bad; 168 } 169 } else { 170 tlv_count++; 171 if (tlv_count > max_count) 172 goto bad; 173 174 if (hopbyhop) { 175 switch (nh[off]) { 176 case IPV6_TLV_ROUTERALERT: 177 if (!ipv6_hop_ra(skb, off)) 178 return false; 179 break; 180 case IPV6_TLV_IOAM: 181 if (!ipv6_hop_ioam(skb, off)) 182 return false; 183 break; 184 case IPV6_TLV_JUMBO: 185 if (!ipv6_hop_jumbo(skb, off)) 186 return false; 187 break; 188 case IPV6_TLV_CALIPSO: 189 if (!ipv6_hop_calipso(skb, off)) 190 return false; 191 break; 192 default: 193 if (!ip6_tlvopt_unknown(skb, off, 194 disallow_unknowns)) 195 return false; 196 break; 197 } 198 } else { 199 switch (nh[off]) { 200 #if IS_ENABLED(CONFIG_IPV6_MIP6) 201 case IPV6_TLV_HAO: 202 if (!ipv6_dest_hao(skb, off)) 203 return false; 204 break; 205 #endif 206 default: 207 if (!ip6_tlvopt_unknown(skb, off, 208 disallow_unknowns)) 209 return false; 210 break; 211 } 212 } 213 padlen = 0; 214 } 215 off += optlen; 216 len -= optlen; 217 } 218 219 if (len == 0) 220 return true; 221 bad: 222 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 223 return false; 224 } 225 226 /***************************** 227 Destination options header. 228 *****************************/ 229 230 #if IS_ENABLED(CONFIG_IPV6_MIP6) 231 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 232 { 233 struct ipv6_destopt_hao *hao; 234 struct inet6_skb_parm *opt = IP6CB(skb); 235 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 236 SKB_DR(reason); 237 int ret; 238 239 if (opt->dsthao) { 240 net_dbg_ratelimited("hao duplicated\n"); 241 goto discard; 242 } 243 opt->dsthao = opt->dst1; 244 opt->dst1 = 0; 245 246 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 247 248 if (hao->length != 16) { 249 net_dbg_ratelimited("hao invalid option length = %d\n", 250 hao->length); 251 SKB_DR_SET(reason, IP_INHDR); 252 goto discard; 253 } 254 255 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 256 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 257 &hao->addr); 258 SKB_DR_SET(reason, INVALID_PROTO); 259 goto discard; 260 } 261 262 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 263 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 264 if (unlikely(ret < 0)) { 265 SKB_DR_SET(reason, XFRM_POLICY); 266 goto discard; 267 } 268 269 if (skb_cloned(skb)) { 270 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 271 goto discard; 272 273 /* update all variable using below by copied skbuff */ 274 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 275 optoff); 276 ipv6h = ipv6_hdr(skb); 277 } 278 279 if (skb->ip_summed == CHECKSUM_COMPLETE) 280 skb->ip_summed = CHECKSUM_NONE; 281 282 swap(ipv6h->saddr, hao->addr); 283 284 if (skb->tstamp == 0) 285 __net_timestamp(skb); 286 287 return true; 288 289 discard: 290 kfree_skb_reason(skb, reason); 291 return false; 292 } 293 #endif 294 295 static int ipv6_destopt_rcv(struct sk_buff *skb) 296 { 297 struct inet6_dev *idev = __in6_dev_get(skb->dev); 298 struct inet6_skb_parm *opt = IP6CB(skb); 299 #if IS_ENABLED(CONFIG_IPV6_MIP6) 300 __u16 dstbuf; 301 #endif 302 struct dst_entry *dst = skb_dst(skb); 303 struct net *net = dev_net(skb->dev); 304 int extlen; 305 306 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 307 !pskb_may_pull(skb, (skb_transport_offset(skb) + 308 ((skb_transport_header(skb)[1] + 1) << 3)))) { 309 __IP6_INC_STATS(dev_net(dst->dev), idev, 310 IPSTATS_MIB_INHDRERRORS); 311 fail_and_free: 312 kfree_skb(skb); 313 return -1; 314 } 315 316 extlen = (skb_transport_header(skb)[1] + 1) << 3; 317 if (extlen > net->ipv6.sysctl.max_dst_opts_len) 318 goto fail_and_free; 319 320 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 321 #if IS_ENABLED(CONFIG_IPV6_MIP6) 322 dstbuf = opt->dst1; 323 #endif 324 325 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) { 326 skb->transport_header += extlen; 327 opt = IP6CB(skb); 328 #if IS_ENABLED(CONFIG_IPV6_MIP6) 329 opt->nhoff = dstbuf; 330 #else 331 opt->nhoff = opt->dst1; 332 #endif 333 return 1; 334 } 335 336 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 337 return -1; 338 } 339 340 static void seg6_update_csum(struct sk_buff *skb) 341 { 342 struct ipv6_sr_hdr *hdr; 343 struct in6_addr *addr; 344 __be32 from, to; 345 346 /* srh is at transport offset and seg_left is already decremented 347 * but daddr is not yet updated with next segment 348 */ 349 350 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 351 addr = hdr->segments + hdr->segments_left; 352 353 hdr->segments_left++; 354 from = *(__be32 *)hdr; 355 356 hdr->segments_left--; 357 to = *(__be32 *)hdr; 358 359 /* update skb csum with diff resulting from seg_left decrement */ 360 361 update_csum_diff4(skb, from, to); 362 363 /* compute csum diff between current and next segment and update */ 364 365 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 366 (__be32 *)addr); 367 } 368 369 static int ipv6_srh_rcv(struct sk_buff *skb) 370 { 371 struct inet6_skb_parm *opt = IP6CB(skb); 372 struct net *net = dev_net(skb->dev); 373 struct ipv6_sr_hdr *hdr; 374 struct inet6_dev *idev; 375 struct in6_addr *addr; 376 int accept_seg6; 377 378 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 379 380 idev = __in6_dev_get(skb->dev); 381 382 accept_seg6 = net->ipv6.devconf_all->seg6_enabled; 383 if (accept_seg6 > idev->cnf.seg6_enabled) 384 accept_seg6 = idev->cnf.seg6_enabled; 385 386 if (!accept_seg6) { 387 kfree_skb(skb); 388 return -1; 389 } 390 391 #ifdef CONFIG_IPV6_SEG6_HMAC 392 if (!seg6_hmac_validate_skb(skb)) { 393 kfree_skb(skb); 394 return -1; 395 } 396 #endif 397 398 looped_back: 399 if (hdr->segments_left == 0) { 400 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 401 int offset = (hdr->hdrlen + 1) << 3; 402 403 skb_postpull_rcsum(skb, skb_network_header(skb), 404 skb_network_header_len(skb)); 405 406 if (!pskb_pull(skb, offset)) { 407 kfree_skb(skb); 408 return -1; 409 } 410 skb_postpull_rcsum(skb, skb_transport_header(skb), 411 offset); 412 413 skb_reset_network_header(skb); 414 skb_reset_transport_header(skb); 415 skb->encapsulation = 0; 416 if (hdr->nexthdr == NEXTHDR_IPV4) 417 skb->protocol = htons(ETH_P_IP); 418 __skb_tunnel_rx(skb, skb->dev, net); 419 420 netif_rx(skb); 421 return -1; 422 } 423 424 opt->srcrt = skb_network_header_len(skb); 425 opt->lastopt = opt->srcrt; 426 skb->transport_header += (hdr->hdrlen + 1) << 3; 427 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 428 429 return 1; 430 } 431 432 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 433 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 434 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 435 ((&hdr->segments_left) - 436 skb_network_header(skb))); 437 return -1; 438 } 439 440 if (skb_cloned(skb)) { 441 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 442 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 443 IPSTATS_MIB_OUTDISCARDS); 444 kfree_skb(skb); 445 return -1; 446 } 447 } 448 449 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 450 451 hdr->segments_left--; 452 addr = hdr->segments + hdr->segments_left; 453 454 skb_push(skb, sizeof(struct ipv6hdr)); 455 456 if (skb->ip_summed == CHECKSUM_COMPLETE) 457 seg6_update_csum(skb); 458 459 ipv6_hdr(skb)->daddr = *addr; 460 461 ip6_route_input(skb); 462 463 if (skb_dst(skb)->error) { 464 dst_input(skb); 465 return -1; 466 } 467 468 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 469 if (ipv6_hdr(skb)->hop_limit <= 1) { 470 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 471 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 472 ICMPV6_EXC_HOPLIMIT, 0); 473 kfree_skb(skb); 474 return -1; 475 } 476 ipv6_hdr(skb)->hop_limit--; 477 478 skb_pull(skb, sizeof(struct ipv6hdr)); 479 goto looped_back; 480 } 481 482 dst_input(skb); 483 484 return -1; 485 } 486 487 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 488 { 489 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 490 struct inet6_skb_parm *opt = IP6CB(skb); 491 struct net *net = dev_net(skb->dev); 492 struct inet6_dev *idev; 493 struct ipv6hdr *oldhdr; 494 unsigned char *buf; 495 int accept_rpl_seg; 496 int i, err; 497 u64 n = 0; 498 u32 r; 499 500 idev = __in6_dev_get(skb->dev); 501 502 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 503 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 504 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 505 506 if (!accept_rpl_seg) { 507 kfree_skb(skb); 508 return -1; 509 } 510 511 looped_back: 512 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 513 514 if (hdr->segments_left == 0) { 515 if (hdr->nexthdr == NEXTHDR_IPV6) { 516 int offset = (hdr->hdrlen + 1) << 3; 517 518 skb_postpull_rcsum(skb, skb_network_header(skb), 519 skb_network_header_len(skb)); 520 521 if (!pskb_pull(skb, offset)) { 522 kfree_skb(skb); 523 return -1; 524 } 525 skb_postpull_rcsum(skb, skb_transport_header(skb), 526 offset); 527 528 skb_reset_network_header(skb); 529 skb_reset_transport_header(skb); 530 skb->encapsulation = 0; 531 532 __skb_tunnel_rx(skb, skb->dev, net); 533 534 netif_rx(skb); 535 return -1; 536 } 537 538 opt->srcrt = skb_network_header_len(skb); 539 opt->lastopt = opt->srcrt; 540 skb->transport_header += (hdr->hdrlen + 1) << 3; 541 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 542 543 return 1; 544 } 545 546 if (!pskb_may_pull(skb, sizeof(*hdr))) { 547 kfree_skb(skb); 548 return -1; 549 } 550 551 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 552 r = do_div(n, (16 - hdr->cmpri)); 553 /* checks if calculation was without remainder and n fits into 554 * unsigned char which is segments_left field. Should not be 555 * higher than that. 556 */ 557 if (r || (n + 1) > 255) { 558 kfree_skb(skb); 559 return -1; 560 } 561 562 if (hdr->segments_left > n + 1) { 563 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 564 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 565 ((&hdr->segments_left) - 566 skb_network_header(skb))); 567 return -1; 568 } 569 570 if (skb_cloned(skb)) { 571 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0, 572 GFP_ATOMIC)) { 573 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 574 IPSTATS_MIB_OUTDISCARDS); 575 kfree_skb(skb); 576 return -1; 577 } 578 } else { 579 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE); 580 if (unlikely(err)) { 581 kfree_skb(skb); 582 return -1; 583 } 584 } 585 586 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 587 588 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 589 hdr->cmpre))) { 590 kfree_skb(skb); 591 return -1; 592 } 593 594 hdr->segments_left--; 595 i = n - hdr->segments_left; 596 597 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 598 if (unlikely(!buf)) { 599 kfree_skb(skb); 600 return -1; 601 } 602 603 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 604 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 605 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 606 607 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 608 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 609 kfree_skb(skb); 610 kfree(buf); 611 return -1; 612 } 613 614 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 615 if (err) { 616 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 617 kfree_skb(skb); 618 kfree(buf); 619 return -1; 620 } 621 622 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); 623 624 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 625 626 oldhdr = ipv6_hdr(skb); 627 628 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 629 skb_postpull_rcsum(skb, oldhdr, 630 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 631 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 632 skb_reset_network_header(skb); 633 skb_mac_header_rebuild(skb); 634 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 635 636 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 637 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 638 639 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 640 skb_postpush_rcsum(skb, ipv6_hdr(skb), 641 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 642 643 kfree(buf); 644 645 skb_dst_drop(skb); 646 647 ip6_route_input(skb); 648 649 if (skb_dst(skb)->error) { 650 dst_input(skb); 651 return -1; 652 } 653 654 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 655 if (ipv6_hdr(skb)->hop_limit <= 1) { 656 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 657 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 658 ICMPV6_EXC_HOPLIMIT, 0); 659 kfree_skb(skb); 660 return -1; 661 } 662 ipv6_hdr(skb)->hop_limit--; 663 664 skb_pull(skb, sizeof(struct ipv6hdr)); 665 goto looped_back; 666 } 667 668 dst_input(skb); 669 670 return -1; 671 } 672 673 /******************************** 674 Routing header. 675 ********************************/ 676 677 /* called with rcu_read_lock() */ 678 static int ipv6_rthdr_rcv(struct sk_buff *skb) 679 { 680 struct inet6_dev *idev = __in6_dev_get(skb->dev); 681 struct inet6_skb_parm *opt = IP6CB(skb); 682 struct in6_addr *addr = NULL; 683 struct in6_addr daddr; 684 int n, i; 685 struct ipv6_rt_hdr *hdr; 686 struct rt0_hdr *rthdr; 687 struct net *net = dev_net(skb->dev); 688 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 689 690 if (idev && accept_source_route > idev->cnf.accept_source_route) 691 accept_source_route = idev->cnf.accept_source_route; 692 693 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 694 !pskb_may_pull(skb, (skb_transport_offset(skb) + 695 ((skb_transport_header(skb)[1] + 1) << 3)))) { 696 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 697 kfree_skb(skb); 698 return -1; 699 } 700 701 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 702 703 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 704 skb->pkt_type != PACKET_HOST) { 705 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 706 kfree_skb(skb); 707 return -1; 708 } 709 710 switch (hdr->type) { 711 case IPV6_SRCRT_TYPE_4: 712 /* segment routing */ 713 return ipv6_srh_rcv(skb); 714 case IPV6_SRCRT_TYPE_3: 715 /* rpl segment routing */ 716 return ipv6_rpl_srh_rcv(skb); 717 default: 718 break; 719 } 720 721 looped_back: 722 if (hdr->segments_left == 0) { 723 switch (hdr->type) { 724 #if IS_ENABLED(CONFIG_IPV6_MIP6) 725 case IPV6_SRCRT_TYPE_2: 726 /* Silently discard type 2 header unless it was 727 * processed by own 728 */ 729 if (!addr) { 730 __IP6_INC_STATS(net, idev, 731 IPSTATS_MIB_INADDRERRORS); 732 kfree_skb(skb); 733 return -1; 734 } 735 break; 736 #endif 737 default: 738 break; 739 } 740 741 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 742 skb->transport_header += (hdr->hdrlen + 1) << 3; 743 opt->dst0 = opt->dst1; 744 opt->dst1 = 0; 745 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 746 return 1; 747 } 748 749 switch (hdr->type) { 750 #if IS_ENABLED(CONFIG_IPV6_MIP6) 751 case IPV6_SRCRT_TYPE_2: 752 if (accept_source_route < 0) 753 goto unknown_rh; 754 /* Silently discard invalid RTH type 2 */ 755 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 756 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 757 kfree_skb(skb); 758 return -1; 759 } 760 break; 761 #endif 762 default: 763 goto unknown_rh; 764 } 765 766 /* 767 * This is the routing header forwarding algorithm from 768 * RFC 2460, page 16. 769 */ 770 771 n = hdr->hdrlen >> 1; 772 773 if (hdr->segments_left > n) { 774 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 775 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 776 ((&hdr->segments_left) - 777 skb_network_header(skb))); 778 return -1; 779 } 780 781 /* We are about to mangle packet header. Be careful! 782 Do not damage packets queued somewhere. 783 */ 784 if (skb_cloned(skb)) { 785 /* the copy is a forwarded packet */ 786 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 787 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 788 IPSTATS_MIB_OUTDISCARDS); 789 kfree_skb(skb); 790 return -1; 791 } 792 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 793 } 794 795 if (skb->ip_summed == CHECKSUM_COMPLETE) 796 skb->ip_summed = CHECKSUM_NONE; 797 798 i = n - --hdr->segments_left; 799 800 rthdr = (struct rt0_hdr *) hdr; 801 addr = rthdr->addr; 802 addr += i - 1; 803 804 switch (hdr->type) { 805 #if IS_ENABLED(CONFIG_IPV6_MIP6) 806 case IPV6_SRCRT_TYPE_2: 807 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 808 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 809 IPPROTO_ROUTING) < 0) { 810 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 811 kfree_skb(skb); 812 return -1; 813 } 814 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 815 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 816 kfree_skb(skb); 817 return -1; 818 } 819 break; 820 #endif 821 default: 822 break; 823 } 824 825 if (ipv6_addr_is_multicast(addr)) { 826 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 827 kfree_skb(skb); 828 return -1; 829 } 830 831 daddr = *addr; 832 *addr = ipv6_hdr(skb)->daddr; 833 ipv6_hdr(skb)->daddr = daddr; 834 835 ip6_route_input(skb); 836 if (skb_dst(skb)->error) { 837 skb_push(skb, skb->data - skb_network_header(skb)); 838 dst_input(skb); 839 return -1; 840 } 841 842 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 843 if (ipv6_hdr(skb)->hop_limit <= 1) { 844 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 845 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 846 0); 847 kfree_skb(skb); 848 return -1; 849 } 850 ipv6_hdr(skb)->hop_limit--; 851 goto looped_back; 852 } 853 854 skb_push(skb, skb->data - skb_network_header(skb)); 855 dst_input(skb); 856 return -1; 857 858 unknown_rh: 859 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 860 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 861 (&hdr->type) - skb_network_header(skb)); 862 return -1; 863 } 864 865 static const struct inet6_protocol rthdr_protocol = { 866 .handler = ipv6_rthdr_rcv, 867 .flags = INET6_PROTO_NOPOLICY, 868 }; 869 870 static const struct inet6_protocol destopt_protocol = { 871 .handler = ipv6_destopt_rcv, 872 .flags = INET6_PROTO_NOPOLICY, 873 }; 874 875 static const struct inet6_protocol nodata_protocol = { 876 .handler = dst_discard, 877 .flags = INET6_PROTO_NOPOLICY, 878 }; 879 880 int __init ipv6_exthdrs_init(void) 881 { 882 int ret; 883 884 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 885 if (ret) 886 goto out; 887 888 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 889 if (ret) 890 goto out_rthdr; 891 892 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 893 if (ret) 894 goto out_destopt; 895 896 out: 897 return ret; 898 out_destopt: 899 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 900 out_rthdr: 901 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 902 goto out; 903 }; 904 905 void ipv6_exthdrs_exit(void) 906 { 907 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 908 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 909 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 910 } 911 912 /********************************** 913 Hop-by-hop options. 914 **********************************/ 915 916 /* 917 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 918 */ 919 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 920 { 921 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 922 } 923 924 /* Router Alert as of RFC 2711 */ 925 926 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 927 { 928 const unsigned char *nh = skb_network_header(skb); 929 930 if (nh[optoff + 1] == 2) { 931 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 932 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 933 return true; 934 } 935 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 936 nh[optoff + 1]); 937 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 938 return false; 939 } 940 941 /* IOAM */ 942 943 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 944 { 945 struct ioam6_trace_hdr *trace; 946 struct ioam6_namespace *ns; 947 struct ioam6_hdr *hdr; 948 949 /* Bad alignment (must be 4n-aligned) */ 950 if (optoff & 3) 951 goto drop; 952 953 /* Ignore if IOAM is not enabled on ingress */ 954 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled) 955 goto ignore; 956 957 /* Truncated Option header */ 958 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 959 if (hdr->opt_len < 2) 960 goto drop; 961 962 switch (hdr->type) { 963 case IOAM6_TYPE_PREALLOC: 964 /* Truncated Pre-allocated Trace header */ 965 if (hdr->opt_len < 2 + sizeof(*trace)) 966 goto drop; 967 968 /* Malformed Pre-allocated Trace header */ 969 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 970 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 971 goto drop; 972 973 /* Ignore if the IOAM namespace is unknown */ 974 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id); 975 if (!ns) 976 goto ignore; 977 978 if (!skb_valid_dst(skb)) 979 ip6_route_input(skb); 980 981 ioam6_fill_trace_data(skb, ns, trace, true); 982 break; 983 default: 984 break; 985 } 986 987 ignore: 988 return true; 989 990 drop: 991 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 992 return false; 993 } 994 995 /* Jumbo payload */ 996 997 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 998 { 999 const unsigned char *nh = skb_network_header(skb); 1000 SKB_DR(reason); 1001 u32 pkt_len; 1002 1003 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 1004 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 1005 nh[optoff+1]); 1006 SKB_DR_SET(reason, IP_INHDR); 1007 goto drop; 1008 } 1009 1010 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1011 if (pkt_len <= IPV6_MAXPLEN) { 1012 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, 1013 SKB_DROP_REASON_IP_INHDR); 1014 return false; 1015 } 1016 if (ipv6_hdr(skb)->payload_len) { 1017 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff, 1018 SKB_DROP_REASON_IP_INHDR); 1019 return false; 1020 } 1021 1022 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1023 SKB_DR_SET(reason, PKT_TOO_SMALL); 1024 goto drop; 1025 } 1026 1027 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1028 goto drop; 1029 1030 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1031 return true; 1032 1033 drop: 1034 kfree_skb_reason(skb, reason); 1035 return false; 1036 } 1037 1038 /* CALIPSO RFC 5570 */ 1039 1040 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1041 { 1042 const unsigned char *nh = skb_network_header(skb); 1043 1044 if (nh[optoff + 1] < 8) 1045 goto drop; 1046 1047 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1048 goto drop; 1049 1050 if (!calipso_validate(skb, nh + optoff)) 1051 goto drop; 1052 1053 return true; 1054 1055 drop: 1056 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 1057 return false; 1058 } 1059 1060 int ipv6_parse_hopopts(struct sk_buff *skb) 1061 { 1062 struct inet6_skb_parm *opt = IP6CB(skb); 1063 struct net *net = dev_net(skb->dev); 1064 int extlen; 1065 1066 /* 1067 * skb_network_header(skb) is equal to skb->data, and 1068 * skb_network_header_len(skb) is always equal to 1069 * sizeof(struct ipv6hdr) by definition of 1070 * hop-by-hop options. 1071 */ 1072 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1073 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1074 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1075 fail_and_free: 1076 kfree_skb(skb); 1077 return -1; 1078 } 1079 1080 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1081 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1082 goto fail_and_free; 1083 1084 opt->flags |= IP6SKB_HOPBYHOP; 1085 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) { 1086 skb->transport_header += extlen; 1087 opt = IP6CB(skb); 1088 opt->nhoff = sizeof(struct ipv6hdr); 1089 return 1; 1090 } 1091 return -1; 1092 } 1093 1094 /* 1095 * Creating outbound headers. 1096 * 1097 * "build" functions work when skb is filled from head to tail (datagram) 1098 * "push" functions work when headers are added from tail to head (tcp) 1099 * 1100 * In both cases we assume, that caller reserved enough room 1101 * for headers. 1102 */ 1103 1104 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1105 struct ipv6_rt_hdr *opt, 1106 struct in6_addr **addr_p, struct in6_addr *saddr) 1107 { 1108 struct rt0_hdr *phdr, *ihdr; 1109 int hops; 1110 1111 ihdr = (struct rt0_hdr *) opt; 1112 1113 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1114 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1115 1116 hops = ihdr->rt_hdr.hdrlen >> 1; 1117 1118 if (hops > 1) 1119 memcpy(phdr->addr, ihdr->addr + 1, 1120 (hops - 1) * sizeof(struct in6_addr)); 1121 1122 phdr->addr[hops - 1] = **addr_p; 1123 *addr_p = ihdr->addr; 1124 1125 phdr->rt_hdr.nexthdr = *proto; 1126 *proto = NEXTHDR_ROUTING; 1127 } 1128 1129 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1130 struct ipv6_rt_hdr *opt, 1131 struct in6_addr **addr_p, struct in6_addr *saddr) 1132 { 1133 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1134 int plen, hops; 1135 1136 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1137 plen = (sr_ihdr->hdrlen + 1) << 3; 1138 1139 sr_phdr = skb_push(skb, plen); 1140 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1141 1142 hops = sr_ihdr->first_segment + 1; 1143 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1144 (hops - 1) * sizeof(struct in6_addr)); 1145 1146 sr_phdr->segments[0] = **addr_p; 1147 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1148 1149 if (sr_ihdr->hdrlen > hops * 2) { 1150 int tlvs_offset, tlvs_length; 1151 1152 tlvs_offset = (1 + hops * 2) << 3; 1153 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1154 memcpy((char *)sr_phdr + tlvs_offset, 1155 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1156 } 1157 1158 #ifdef CONFIG_IPV6_SEG6_HMAC 1159 if (sr_has_hmac(sr_phdr)) { 1160 struct net *net = NULL; 1161 1162 if (skb->dev) 1163 net = dev_net(skb->dev); 1164 else if (skb->sk) 1165 net = sock_net(skb->sk); 1166 1167 WARN_ON(!net); 1168 1169 if (net) 1170 seg6_push_hmac(net, saddr, sr_phdr); 1171 } 1172 #endif 1173 1174 sr_phdr->nexthdr = *proto; 1175 *proto = NEXTHDR_ROUTING; 1176 } 1177 1178 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1179 struct ipv6_rt_hdr *opt, 1180 struct in6_addr **addr_p, struct in6_addr *saddr) 1181 { 1182 switch (opt->type) { 1183 case IPV6_SRCRT_TYPE_0: 1184 case IPV6_SRCRT_STRICT: 1185 case IPV6_SRCRT_TYPE_2: 1186 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1187 break; 1188 case IPV6_SRCRT_TYPE_4: 1189 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1190 break; 1191 default: 1192 break; 1193 } 1194 } 1195 1196 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1197 { 1198 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1199 1200 memcpy(h, opt, ipv6_optlen(opt)); 1201 h->nexthdr = *proto; 1202 *proto = type; 1203 } 1204 1205 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1206 u8 *proto, 1207 struct in6_addr **daddr, struct in6_addr *saddr) 1208 { 1209 if (opt->srcrt) { 1210 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1211 /* 1212 * IPV6_RTHDRDSTOPTS is ignored 1213 * unless IPV6_RTHDR is set (RFC3542). 1214 */ 1215 if (opt->dst0opt) 1216 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1217 } 1218 if (opt->hopopt) 1219 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1220 } 1221 1222 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1223 { 1224 if (opt->dst1opt) 1225 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1226 } 1227 EXPORT_SYMBOL(ipv6_push_frag_opts); 1228 1229 struct ipv6_txoptions * 1230 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1231 { 1232 struct ipv6_txoptions *opt2; 1233 1234 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1235 if (opt2) { 1236 long dif = (char *)opt2 - (char *)opt; 1237 memcpy(opt2, opt, opt->tot_len); 1238 if (opt2->hopopt) 1239 *((char **)&opt2->hopopt) += dif; 1240 if (opt2->dst0opt) 1241 *((char **)&opt2->dst0opt) += dif; 1242 if (opt2->dst1opt) 1243 *((char **)&opt2->dst1opt) += dif; 1244 if (opt2->srcrt) 1245 *((char **)&opt2->srcrt) += dif; 1246 refcount_set(&opt2->refcnt, 1); 1247 } 1248 return opt2; 1249 } 1250 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1251 1252 static void ipv6_renew_option(int renewtype, 1253 struct ipv6_opt_hdr **dest, 1254 struct ipv6_opt_hdr *old, 1255 struct ipv6_opt_hdr *new, 1256 int newtype, char **p) 1257 { 1258 struct ipv6_opt_hdr *src; 1259 1260 src = (renewtype == newtype ? new : old); 1261 if (!src) 1262 return; 1263 1264 memcpy(*p, src, ipv6_optlen(src)); 1265 *dest = (struct ipv6_opt_hdr *)*p; 1266 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1267 } 1268 1269 /** 1270 * ipv6_renew_options - replace a specific ext hdr with a new one. 1271 * 1272 * @sk: sock from which to allocate memory 1273 * @opt: original options 1274 * @newtype: option type to replace in @opt 1275 * @newopt: new option of type @newtype to replace (user-mem) 1276 * 1277 * Returns a new set of options which is a copy of @opt with the 1278 * option type @newtype replaced with @newopt. 1279 * 1280 * @opt may be NULL, in which case a new set of options is returned 1281 * containing just @newopt. 1282 * 1283 * @newopt may be NULL, in which case the specified option type is 1284 * not copied into the new set of options. 1285 * 1286 * The new set of options is allocated from the socket option memory 1287 * buffer of @sk. 1288 */ 1289 struct ipv6_txoptions * 1290 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1291 int newtype, struct ipv6_opt_hdr *newopt) 1292 { 1293 int tot_len = 0; 1294 char *p; 1295 struct ipv6_txoptions *opt2; 1296 1297 if (opt) { 1298 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1299 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1300 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1301 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1302 if (newtype != IPV6_RTHDR && opt->srcrt) 1303 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1304 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1305 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1306 } 1307 1308 if (newopt) 1309 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1310 1311 if (!tot_len) 1312 return NULL; 1313 1314 tot_len += sizeof(*opt2); 1315 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1316 if (!opt2) 1317 return ERR_PTR(-ENOBUFS); 1318 1319 memset(opt2, 0, tot_len); 1320 refcount_set(&opt2->refcnt, 1); 1321 opt2->tot_len = tot_len; 1322 p = (char *)(opt2 + 1); 1323 1324 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1325 (opt ? opt->hopopt : NULL), 1326 newopt, newtype, &p); 1327 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1328 (opt ? opt->dst0opt : NULL), 1329 newopt, newtype, &p); 1330 ipv6_renew_option(IPV6_RTHDR, 1331 (struct ipv6_opt_hdr **)&opt2->srcrt, 1332 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1333 newopt, newtype, &p); 1334 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1335 (opt ? opt->dst1opt : NULL), 1336 newopt, newtype, &p); 1337 1338 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1339 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1340 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1341 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1342 1343 return opt2; 1344 } 1345 1346 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1347 struct ipv6_txoptions *opt) 1348 { 1349 /* 1350 * ignore the dest before srcrt unless srcrt is being included. 1351 * --yoshfuji 1352 */ 1353 if (opt->dst0opt && !opt->srcrt) { 1354 if (opt_space != opt) { 1355 memcpy(opt_space, opt, sizeof(*opt_space)); 1356 opt = opt_space; 1357 } 1358 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1359 opt->dst0opt = NULL; 1360 } 1361 1362 return opt; 1363 } 1364 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1365 1366 /** 1367 * fl6_update_dst - update flowi destination address with info given 1368 * by srcrt option, if any. 1369 * 1370 * @fl6: flowi6 for which daddr is to be updated 1371 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1372 * @orig: copy of original daddr address if modified 1373 * 1374 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1375 * and initial value of fl6->daddr set in orig 1376 */ 1377 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1378 const struct ipv6_txoptions *opt, 1379 struct in6_addr *orig) 1380 { 1381 if (!opt || !opt->srcrt) 1382 return NULL; 1383 1384 *orig = fl6->daddr; 1385 1386 switch (opt->srcrt->type) { 1387 case IPV6_SRCRT_TYPE_0: 1388 case IPV6_SRCRT_STRICT: 1389 case IPV6_SRCRT_TYPE_2: 1390 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1391 break; 1392 case IPV6_SRCRT_TYPE_4: 1393 { 1394 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1395 1396 fl6->daddr = srh->segments[srh->segments_left]; 1397 break; 1398 } 1399 default: 1400 return NULL; 1401 } 1402 1403 return orig; 1404 } 1405 EXPORT_SYMBOL_GPL(fl6_update_dst); 1406