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(skb, ICMPV6_UNK_OPTION, optoff); 94 return false; 95 } 96 97 drop: 98 kfree_skb(skb); 99 return false; 100 } 101 102 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff); 103 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff); 104 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff); 105 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff); 106 #if IS_ENABLED(CONFIG_IPV6_MIP6) 107 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff); 108 #endif 109 110 /* Parse tlv encoded option header (hop-by-hop or destination) */ 111 112 static bool ip6_parse_tlv(bool hopbyhop, 113 struct sk_buff *skb, 114 int max_count) 115 { 116 int len = (skb_transport_header(skb)[1] + 1) << 3; 117 const unsigned char *nh = skb_network_header(skb); 118 int off = skb_network_header_len(skb); 119 bool disallow_unknowns = false; 120 int tlv_count = 0; 121 int padlen = 0; 122 123 if (unlikely(max_count < 0)) { 124 disallow_unknowns = true; 125 max_count = -max_count; 126 } 127 128 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 129 goto bad; 130 131 off += 2; 132 len -= 2; 133 134 while (len > 0) { 135 int optlen, i; 136 137 if (nh[off] == IPV6_TLV_PAD1) { 138 padlen++; 139 if (padlen > 7) 140 goto bad; 141 off++; 142 len--; 143 continue; 144 } 145 if (len < 2) 146 goto bad; 147 optlen = nh[off + 1] + 2; 148 if (optlen > len) 149 goto bad; 150 151 if (nh[off] == IPV6_TLV_PADN) { 152 /* RFC 2460 states that the purpose of PadN is 153 * to align the containing header to multiples 154 * of 8. 7 is therefore the highest valid value. 155 * See also RFC 4942, Section 2.1.9.5. 156 */ 157 padlen += optlen; 158 if (padlen > 7) 159 goto bad; 160 /* RFC 4942 recommends receiving hosts to 161 * actively check PadN payload to contain 162 * only zeroes. 163 */ 164 for (i = 2; i < optlen; i++) { 165 if (nh[off + i] != 0) 166 goto bad; 167 } 168 } else { 169 tlv_count++; 170 if (tlv_count > max_count) 171 goto bad; 172 173 if (hopbyhop) { 174 switch (nh[off]) { 175 case IPV6_TLV_ROUTERALERT: 176 if (!ipv6_hop_ra(skb, off)) 177 return false; 178 break; 179 case IPV6_TLV_IOAM: 180 if (!ipv6_hop_ioam(skb, off)) 181 return false; 182 break; 183 case IPV6_TLV_JUMBO: 184 if (!ipv6_hop_jumbo(skb, off)) 185 return false; 186 break; 187 case IPV6_TLV_CALIPSO: 188 if (!ipv6_hop_calipso(skb, off)) 189 return false; 190 break; 191 default: 192 if (!ip6_tlvopt_unknown(skb, off, 193 disallow_unknowns)) 194 return false; 195 break; 196 } 197 } else { 198 switch (nh[off]) { 199 #if IS_ENABLED(CONFIG_IPV6_MIP6) 200 case IPV6_TLV_HAO: 201 if (!ipv6_dest_hao(skb, off)) 202 return false; 203 break; 204 #endif 205 default: 206 if (!ip6_tlvopt_unknown(skb, off, 207 disallow_unknowns)) 208 return false; 209 break; 210 } 211 } 212 padlen = 0; 213 } 214 off += optlen; 215 len -= optlen; 216 } 217 218 if (len == 0) 219 return true; 220 bad: 221 kfree_skb(skb); 222 return false; 223 } 224 225 /***************************** 226 Destination options header. 227 *****************************/ 228 229 #if IS_ENABLED(CONFIG_IPV6_MIP6) 230 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 231 { 232 struct ipv6_destopt_hao *hao; 233 struct inet6_skb_parm *opt = IP6CB(skb); 234 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 235 int ret; 236 237 if (opt->dsthao) { 238 net_dbg_ratelimited("hao duplicated\n"); 239 goto discard; 240 } 241 opt->dsthao = opt->dst1; 242 opt->dst1 = 0; 243 244 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 245 246 if (hao->length != 16) { 247 net_dbg_ratelimited("hao invalid option length = %d\n", 248 hao->length); 249 goto discard; 250 } 251 252 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 253 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 254 &hao->addr); 255 goto discard; 256 } 257 258 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 259 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 260 if (unlikely(ret < 0)) 261 goto discard; 262 263 if (skb_cloned(skb)) { 264 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 265 goto discard; 266 267 /* update all variable using below by copied skbuff */ 268 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 269 optoff); 270 ipv6h = ipv6_hdr(skb); 271 } 272 273 if (skb->ip_summed == CHECKSUM_COMPLETE) 274 skb->ip_summed = CHECKSUM_NONE; 275 276 swap(ipv6h->saddr, hao->addr); 277 278 if (skb->tstamp == 0) 279 __net_timestamp(skb); 280 281 return true; 282 283 discard: 284 kfree_skb(skb); 285 return false; 286 } 287 #endif 288 289 static int ipv6_destopt_rcv(struct sk_buff *skb) 290 { 291 struct inet6_dev *idev = __in6_dev_get(skb->dev); 292 struct inet6_skb_parm *opt = IP6CB(skb); 293 #if IS_ENABLED(CONFIG_IPV6_MIP6) 294 __u16 dstbuf; 295 #endif 296 struct dst_entry *dst = skb_dst(skb); 297 struct net *net = dev_net(skb->dev); 298 int extlen; 299 300 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 301 !pskb_may_pull(skb, (skb_transport_offset(skb) + 302 ((skb_transport_header(skb)[1] + 1) << 3)))) { 303 __IP6_INC_STATS(dev_net(dst->dev), idev, 304 IPSTATS_MIB_INHDRERRORS); 305 fail_and_free: 306 kfree_skb(skb); 307 return -1; 308 } 309 310 extlen = (skb_transport_header(skb)[1] + 1) << 3; 311 if (extlen > net->ipv6.sysctl.max_dst_opts_len) 312 goto fail_and_free; 313 314 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 315 #if IS_ENABLED(CONFIG_IPV6_MIP6) 316 dstbuf = opt->dst1; 317 #endif 318 319 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) { 320 skb->transport_header += extlen; 321 opt = IP6CB(skb); 322 #if IS_ENABLED(CONFIG_IPV6_MIP6) 323 opt->nhoff = dstbuf; 324 #else 325 opt->nhoff = opt->dst1; 326 #endif 327 return 1; 328 } 329 330 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 331 return -1; 332 } 333 334 static void seg6_update_csum(struct sk_buff *skb) 335 { 336 struct ipv6_sr_hdr *hdr; 337 struct in6_addr *addr; 338 __be32 from, to; 339 340 /* srh is at transport offset and seg_left is already decremented 341 * but daddr is not yet updated with next segment 342 */ 343 344 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 345 addr = hdr->segments + hdr->segments_left; 346 347 hdr->segments_left++; 348 from = *(__be32 *)hdr; 349 350 hdr->segments_left--; 351 to = *(__be32 *)hdr; 352 353 /* update skb csum with diff resulting from seg_left decrement */ 354 355 update_csum_diff4(skb, from, to); 356 357 /* compute csum diff between current and next segment and update */ 358 359 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 360 (__be32 *)addr); 361 } 362 363 static int ipv6_srh_rcv(struct sk_buff *skb) 364 { 365 struct inet6_skb_parm *opt = IP6CB(skb); 366 struct net *net = dev_net(skb->dev); 367 struct ipv6_sr_hdr *hdr; 368 struct inet6_dev *idev; 369 struct in6_addr *addr; 370 int accept_seg6; 371 372 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 373 374 idev = __in6_dev_get(skb->dev); 375 376 accept_seg6 = net->ipv6.devconf_all->seg6_enabled; 377 if (accept_seg6 > idev->cnf.seg6_enabled) 378 accept_seg6 = idev->cnf.seg6_enabled; 379 380 if (!accept_seg6) { 381 kfree_skb(skb); 382 return -1; 383 } 384 385 #ifdef CONFIG_IPV6_SEG6_HMAC 386 if (!seg6_hmac_validate_skb(skb)) { 387 kfree_skb(skb); 388 return -1; 389 } 390 #endif 391 392 looped_back: 393 if (hdr->segments_left == 0) { 394 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 395 int offset = (hdr->hdrlen + 1) << 3; 396 397 skb_postpull_rcsum(skb, skb_network_header(skb), 398 skb_network_header_len(skb)); 399 400 if (!pskb_pull(skb, offset)) { 401 kfree_skb(skb); 402 return -1; 403 } 404 skb_postpull_rcsum(skb, skb_transport_header(skb), 405 offset); 406 407 skb_reset_network_header(skb); 408 skb_reset_transport_header(skb); 409 skb->encapsulation = 0; 410 if (hdr->nexthdr == NEXTHDR_IPV4) 411 skb->protocol = htons(ETH_P_IP); 412 __skb_tunnel_rx(skb, skb->dev, net); 413 414 netif_rx(skb); 415 return -1; 416 } 417 418 opt->srcrt = skb_network_header_len(skb); 419 opt->lastopt = opt->srcrt; 420 skb->transport_header += (hdr->hdrlen + 1) << 3; 421 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 422 423 return 1; 424 } 425 426 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 427 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 428 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 429 ((&hdr->segments_left) - 430 skb_network_header(skb))); 431 return -1; 432 } 433 434 if (skb_cloned(skb)) { 435 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 436 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 437 IPSTATS_MIB_OUTDISCARDS); 438 kfree_skb(skb); 439 return -1; 440 } 441 } 442 443 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 444 445 hdr->segments_left--; 446 addr = hdr->segments + hdr->segments_left; 447 448 skb_push(skb, sizeof(struct ipv6hdr)); 449 450 if (skb->ip_summed == CHECKSUM_COMPLETE) 451 seg6_update_csum(skb); 452 453 ipv6_hdr(skb)->daddr = *addr; 454 455 skb_dst_drop(skb); 456 457 ip6_route_input(skb); 458 459 if (skb_dst(skb)->error) { 460 dst_input(skb); 461 return -1; 462 } 463 464 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 465 if (ipv6_hdr(skb)->hop_limit <= 1) { 466 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 467 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 468 ICMPV6_EXC_HOPLIMIT, 0); 469 kfree_skb(skb); 470 return -1; 471 } 472 ipv6_hdr(skb)->hop_limit--; 473 474 skb_pull(skb, sizeof(struct ipv6hdr)); 475 goto looped_back; 476 } 477 478 dst_input(skb); 479 480 return -1; 481 } 482 483 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 484 { 485 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 486 struct inet6_skb_parm *opt = IP6CB(skb); 487 struct net *net = dev_net(skb->dev); 488 struct inet6_dev *idev; 489 struct ipv6hdr *oldhdr; 490 struct in6_addr addr; 491 unsigned char *buf; 492 int accept_rpl_seg; 493 int i, err; 494 u64 n = 0; 495 u32 r; 496 497 idev = __in6_dev_get(skb->dev); 498 499 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 500 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 501 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 502 503 if (!accept_rpl_seg) { 504 kfree_skb(skb); 505 return -1; 506 } 507 508 looped_back: 509 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 510 511 if (hdr->segments_left == 0) { 512 if (hdr->nexthdr == NEXTHDR_IPV6) { 513 int offset = (hdr->hdrlen + 1) << 3; 514 515 skb_postpull_rcsum(skb, skb_network_header(skb), 516 skb_network_header_len(skb)); 517 518 if (!pskb_pull(skb, offset)) { 519 kfree_skb(skb); 520 return -1; 521 } 522 skb_postpull_rcsum(skb, skb_transport_header(skb), 523 offset); 524 525 skb_reset_network_header(skb); 526 skb_reset_transport_header(skb); 527 skb->encapsulation = 0; 528 529 __skb_tunnel_rx(skb, skb->dev, net); 530 531 netif_rx(skb); 532 return -1; 533 } 534 535 opt->srcrt = skb_network_header_len(skb); 536 opt->lastopt = opt->srcrt; 537 skb->transport_header += (hdr->hdrlen + 1) << 3; 538 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 539 540 return 1; 541 } 542 543 if (!pskb_may_pull(skb, sizeof(*hdr))) { 544 kfree_skb(skb); 545 return -1; 546 } 547 548 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 549 r = do_div(n, (16 - hdr->cmpri)); 550 /* checks if calculation was without remainder and n fits into 551 * unsigned char which is segments_left field. Should not be 552 * higher than that. 553 */ 554 if (r || (n + 1) > 255) { 555 kfree_skb(skb); 556 return -1; 557 } 558 559 if (hdr->segments_left > n + 1) { 560 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 561 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 562 ((&hdr->segments_left) - 563 skb_network_header(skb))); 564 return -1; 565 } 566 567 if (skb_cloned(skb)) { 568 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0, 569 GFP_ATOMIC)) { 570 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 571 IPSTATS_MIB_OUTDISCARDS); 572 kfree_skb(skb); 573 return -1; 574 } 575 } else { 576 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE); 577 if (unlikely(err)) { 578 kfree_skb(skb); 579 return -1; 580 } 581 } 582 583 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 584 585 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 586 hdr->cmpre))) { 587 kfree_skb(skb); 588 return -1; 589 } 590 591 hdr->segments_left--; 592 i = n - hdr->segments_left; 593 594 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 595 if (unlikely(!buf)) { 596 kfree_skb(skb); 597 return -1; 598 } 599 600 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 601 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 602 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 603 604 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 605 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 606 kfree_skb(skb); 607 kfree(buf); 608 return -1; 609 } 610 611 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 612 if (err) { 613 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 614 kfree_skb(skb); 615 kfree(buf); 616 return -1; 617 } 618 619 addr = ipv6_hdr(skb)->daddr; 620 ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i]; 621 ohdr->rpl_segaddr[i] = addr; 622 623 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 624 625 oldhdr = ipv6_hdr(skb); 626 627 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 628 skb_postpull_rcsum(skb, oldhdr, 629 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 630 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 631 skb_reset_network_header(skb); 632 skb_mac_header_rebuild(skb); 633 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 634 635 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 636 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 637 638 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 639 skb_postpush_rcsum(skb, ipv6_hdr(skb), 640 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 641 642 kfree(buf); 643 644 skb_dst_drop(skb); 645 646 ip6_route_input(skb); 647 648 if (skb_dst(skb)->error) { 649 dst_input(skb); 650 return -1; 651 } 652 653 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 654 if (ipv6_hdr(skb)->hop_limit <= 1) { 655 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 656 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 657 ICMPV6_EXC_HOPLIMIT, 0); 658 kfree_skb(skb); 659 return -1; 660 } 661 ipv6_hdr(skb)->hop_limit--; 662 663 skb_pull(skb, sizeof(struct ipv6hdr)); 664 goto looped_back; 665 } 666 667 dst_input(skb); 668 669 return -1; 670 } 671 672 /******************************** 673 Routing header. 674 ********************************/ 675 676 /* called with rcu_read_lock() */ 677 static int ipv6_rthdr_rcv(struct sk_buff *skb) 678 { 679 struct inet6_dev *idev = __in6_dev_get(skb->dev); 680 struct inet6_skb_parm *opt = IP6CB(skb); 681 struct in6_addr *addr = NULL; 682 struct in6_addr daddr; 683 int n, i; 684 struct ipv6_rt_hdr *hdr; 685 struct rt0_hdr *rthdr; 686 struct net *net = dev_net(skb->dev); 687 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 688 689 if (idev && accept_source_route > idev->cnf.accept_source_route) 690 accept_source_route = idev->cnf.accept_source_route; 691 692 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 693 !pskb_may_pull(skb, (skb_transport_offset(skb) + 694 ((skb_transport_header(skb)[1] + 1) << 3)))) { 695 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 696 kfree_skb(skb); 697 return -1; 698 } 699 700 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 701 702 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 703 skb->pkt_type != PACKET_HOST) { 704 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 705 kfree_skb(skb); 706 return -1; 707 } 708 709 switch (hdr->type) { 710 case IPV6_SRCRT_TYPE_4: 711 /* segment routing */ 712 return ipv6_srh_rcv(skb); 713 case IPV6_SRCRT_TYPE_3: 714 /* rpl segment routing */ 715 return ipv6_rpl_srh_rcv(skb); 716 default: 717 break; 718 } 719 720 looped_back: 721 if (hdr->segments_left == 0) { 722 switch (hdr->type) { 723 #if IS_ENABLED(CONFIG_IPV6_MIP6) 724 case IPV6_SRCRT_TYPE_2: 725 /* Silently discard type 2 header unless it was 726 * processed by own 727 */ 728 if (!addr) { 729 __IP6_INC_STATS(net, idev, 730 IPSTATS_MIB_INADDRERRORS); 731 kfree_skb(skb); 732 return -1; 733 } 734 break; 735 #endif 736 default: 737 break; 738 } 739 740 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 741 skb->transport_header += (hdr->hdrlen + 1) << 3; 742 opt->dst0 = opt->dst1; 743 opt->dst1 = 0; 744 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 745 return 1; 746 } 747 748 switch (hdr->type) { 749 #if IS_ENABLED(CONFIG_IPV6_MIP6) 750 case IPV6_SRCRT_TYPE_2: 751 if (accept_source_route < 0) 752 goto unknown_rh; 753 /* Silently discard invalid RTH type 2 */ 754 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 755 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 756 kfree_skb(skb); 757 return -1; 758 } 759 break; 760 #endif 761 default: 762 goto unknown_rh; 763 } 764 765 /* 766 * This is the routing header forwarding algorithm from 767 * RFC 2460, page 16. 768 */ 769 770 n = hdr->hdrlen >> 1; 771 772 if (hdr->segments_left > n) { 773 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 774 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 775 ((&hdr->segments_left) - 776 skb_network_header(skb))); 777 return -1; 778 } 779 780 /* We are about to mangle packet header. Be careful! 781 Do not damage packets queued somewhere. 782 */ 783 if (skb_cloned(skb)) { 784 /* the copy is a forwarded packet */ 785 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 786 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 787 IPSTATS_MIB_OUTDISCARDS); 788 kfree_skb(skb); 789 return -1; 790 } 791 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 792 } 793 794 if (skb->ip_summed == CHECKSUM_COMPLETE) 795 skb->ip_summed = CHECKSUM_NONE; 796 797 i = n - --hdr->segments_left; 798 799 rthdr = (struct rt0_hdr *) hdr; 800 addr = rthdr->addr; 801 addr += i - 1; 802 803 switch (hdr->type) { 804 #if IS_ENABLED(CONFIG_IPV6_MIP6) 805 case IPV6_SRCRT_TYPE_2: 806 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 807 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 808 IPPROTO_ROUTING) < 0) { 809 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 810 kfree_skb(skb); 811 return -1; 812 } 813 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 814 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 815 kfree_skb(skb); 816 return -1; 817 } 818 break; 819 #endif 820 default: 821 break; 822 } 823 824 if (ipv6_addr_is_multicast(addr)) { 825 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 826 kfree_skb(skb); 827 return -1; 828 } 829 830 daddr = *addr; 831 *addr = ipv6_hdr(skb)->daddr; 832 ipv6_hdr(skb)->daddr = daddr; 833 834 skb_dst_drop(skb); 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(skb); 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(skb); 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 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev); 1001 struct net *net = ipv6_skb_net(skb); 1002 u32 pkt_len; 1003 1004 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 1005 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 1006 nh[optoff+1]); 1007 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1008 goto drop; 1009 } 1010 1011 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1012 if (pkt_len <= IPV6_MAXPLEN) { 1013 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1014 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 1015 return false; 1016 } 1017 if (ipv6_hdr(skb)->payload_len) { 1018 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 1019 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 1020 return false; 1021 } 1022 1023 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1024 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); 1025 goto drop; 1026 } 1027 1028 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1029 goto drop; 1030 1031 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1032 return true; 1033 1034 drop: 1035 kfree_skb(skb); 1036 return false; 1037 } 1038 1039 /* CALIPSO RFC 5570 */ 1040 1041 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1042 { 1043 const unsigned char *nh = skb_network_header(skb); 1044 1045 if (nh[optoff + 1] < 8) 1046 goto drop; 1047 1048 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1049 goto drop; 1050 1051 if (!calipso_validate(skb, nh + optoff)) 1052 goto drop; 1053 1054 return true; 1055 1056 drop: 1057 kfree_skb(skb); 1058 return false; 1059 } 1060 1061 int ipv6_parse_hopopts(struct sk_buff *skb) 1062 { 1063 struct inet6_skb_parm *opt = IP6CB(skb); 1064 struct net *net = dev_net(skb->dev); 1065 int extlen; 1066 1067 /* 1068 * skb_network_header(skb) is equal to skb->data, and 1069 * skb_network_header_len(skb) is always equal to 1070 * sizeof(struct ipv6hdr) by definition of 1071 * hop-by-hop options. 1072 */ 1073 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1074 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1075 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1076 fail_and_free: 1077 kfree_skb(skb); 1078 return -1; 1079 } 1080 1081 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1082 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1083 goto fail_and_free; 1084 1085 opt->flags |= IP6SKB_HOPBYHOP; 1086 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) { 1087 skb->transport_header += extlen; 1088 opt = IP6CB(skb); 1089 opt->nhoff = sizeof(struct ipv6hdr); 1090 return 1; 1091 } 1092 return -1; 1093 } 1094 1095 /* 1096 * Creating outbound headers. 1097 * 1098 * "build" functions work when skb is filled from head to tail (datagram) 1099 * "push" functions work when headers are added from tail to head (tcp) 1100 * 1101 * In both cases we assume, that caller reserved enough room 1102 * for headers. 1103 */ 1104 1105 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1106 struct ipv6_rt_hdr *opt, 1107 struct in6_addr **addr_p, struct in6_addr *saddr) 1108 { 1109 struct rt0_hdr *phdr, *ihdr; 1110 int hops; 1111 1112 ihdr = (struct rt0_hdr *) opt; 1113 1114 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1115 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1116 1117 hops = ihdr->rt_hdr.hdrlen >> 1; 1118 1119 if (hops > 1) 1120 memcpy(phdr->addr, ihdr->addr + 1, 1121 (hops - 1) * sizeof(struct in6_addr)); 1122 1123 phdr->addr[hops - 1] = **addr_p; 1124 *addr_p = ihdr->addr; 1125 1126 phdr->rt_hdr.nexthdr = *proto; 1127 *proto = NEXTHDR_ROUTING; 1128 } 1129 1130 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1131 struct ipv6_rt_hdr *opt, 1132 struct in6_addr **addr_p, struct in6_addr *saddr) 1133 { 1134 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1135 int plen, hops; 1136 1137 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1138 plen = (sr_ihdr->hdrlen + 1) << 3; 1139 1140 sr_phdr = skb_push(skb, plen); 1141 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1142 1143 hops = sr_ihdr->first_segment + 1; 1144 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1145 (hops - 1) * sizeof(struct in6_addr)); 1146 1147 sr_phdr->segments[0] = **addr_p; 1148 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1149 1150 if (sr_ihdr->hdrlen > hops * 2) { 1151 int tlvs_offset, tlvs_length; 1152 1153 tlvs_offset = (1 + hops * 2) << 3; 1154 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1155 memcpy((char *)sr_phdr + tlvs_offset, 1156 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1157 } 1158 1159 #ifdef CONFIG_IPV6_SEG6_HMAC 1160 if (sr_has_hmac(sr_phdr)) { 1161 struct net *net = NULL; 1162 1163 if (skb->dev) 1164 net = dev_net(skb->dev); 1165 else if (skb->sk) 1166 net = sock_net(skb->sk); 1167 1168 WARN_ON(!net); 1169 1170 if (net) 1171 seg6_push_hmac(net, saddr, sr_phdr); 1172 } 1173 #endif 1174 1175 sr_phdr->nexthdr = *proto; 1176 *proto = NEXTHDR_ROUTING; 1177 } 1178 1179 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1180 struct ipv6_rt_hdr *opt, 1181 struct in6_addr **addr_p, struct in6_addr *saddr) 1182 { 1183 switch (opt->type) { 1184 case IPV6_SRCRT_TYPE_0: 1185 case IPV6_SRCRT_STRICT: 1186 case IPV6_SRCRT_TYPE_2: 1187 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1188 break; 1189 case IPV6_SRCRT_TYPE_4: 1190 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1191 break; 1192 default: 1193 break; 1194 } 1195 } 1196 1197 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1198 { 1199 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1200 1201 memcpy(h, opt, ipv6_optlen(opt)); 1202 h->nexthdr = *proto; 1203 *proto = type; 1204 } 1205 1206 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1207 u8 *proto, 1208 struct in6_addr **daddr, struct in6_addr *saddr) 1209 { 1210 if (opt->srcrt) { 1211 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1212 /* 1213 * IPV6_RTHDRDSTOPTS is ignored 1214 * unless IPV6_RTHDR is set (RFC3542). 1215 */ 1216 if (opt->dst0opt) 1217 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1218 } 1219 if (opt->hopopt) 1220 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1221 } 1222 1223 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1224 { 1225 if (opt->dst1opt) 1226 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1227 } 1228 EXPORT_SYMBOL(ipv6_push_frag_opts); 1229 1230 struct ipv6_txoptions * 1231 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1232 { 1233 struct ipv6_txoptions *opt2; 1234 1235 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1236 if (opt2) { 1237 long dif = (char *)opt2 - (char *)opt; 1238 memcpy(opt2, opt, opt->tot_len); 1239 if (opt2->hopopt) 1240 *((char **)&opt2->hopopt) += dif; 1241 if (opt2->dst0opt) 1242 *((char **)&opt2->dst0opt) += dif; 1243 if (opt2->dst1opt) 1244 *((char **)&opt2->dst1opt) += dif; 1245 if (opt2->srcrt) 1246 *((char **)&opt2->srcrt) += dif; 1247 refcount_set(&opt2->refcnt, 1); 1248 } 1249 return opt2; 1250 } 1251 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1252 1253 static void ipv6_renew_option(int renewtype, 1254 struct ipv6_opt_hdr **dest, 1255 struct ipv6_opt_hdr *old, 1256 struct ipv6_opt_hdr *new, 1257 int newtype, char **p) 1258 { 1259 struct ipv6_opt_hdr *src; 1260 1261 src = (renewtype == newtype ? new : old); 1262 if (!src) 1263 return; 1264 1265 memcpy(*p, src, ipv6_optlen(src)); 1266 *dest = (struct ipv6_opt_hdr *)*p; 1267 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1268 } 1269 1270 /** 1271 * ipv6_renew_options - replace a specific ext hdr with a new one. 1272 * 1273 * @sk: sock from which to allocate memory 1274 * @opt: original options 1275 * @newtype: option type to replace in @opt 1276 * @newopt: new option of type @newtype to replace (user-mem) 1277 * 1278 * Returns a new set of options which is a copy of @opt with the 1279 * option type @newtype replaced with @newopt. 1280 * 1281 * @opt may be NULL, in which case a new set of options is returned 1282 * containing just @newopt. 1283 * 1284 * @newopt may be NULL, in which case the specified option type is 1285 * not copied into the new set of options. 1286 * 1287 * The new set of options is allocated from the socket option memory 1288 * buffer of @sk. 1289 */ 1290 struct ipv6_txoptions * 1291 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1292 int newtype, struct ipv6_opt_hdr *newopt) 1293 { 1294 int tot_len = 0; 1295 char *p; 1296 struct ipv6_txoptions *opt2; 1297 1298 if (opt) { 1299 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1300 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1301 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1302 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1303 if (newtype != IPV6_RTHDR && opt->srcrt) 1304 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1305 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1306 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1307 } 1308 1309 if (newopt) 1310 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1311 1312 if (!tot_len) 1313 return NULL; 1314 1315 tot_len += sizeof(*opt2); 1316 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1317 if (!opt2) 1318 return ERR_PTR(-ENOBUFS); 1319 1320 memset(opt2, 0, tot_len); 1321 refcount_set(&opt2->refcnt, 1); 1322 opt2->tot_len = tot_len; 1323 p = (char *)(opt2 + 1); 1324 1325 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1326 (opt ? opt->hopopt : NULL), 1327 newopt, newtype, &p); 1328 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1329 (opt ? opt->dst0opt : NULL), 1330 newopt, newtype, &p); 1331 ipv6_renew_option(IPV6_RTHDR, 1332 (struct ipv6_opt_hdr **)&opt2->srcrt, 1333 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1334 newopt, newtype, &p); 1335 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1336 (opt ? opt->dst1opt : NULL), 1337 newopt, newtype, &p); 1338 1339 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1340 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1341 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1342 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1343 1344 return opt2; 1345 } 1346 1347 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1348 struct ipv6_txoptions *opt) 1349 { 1350 /* 1351 * ignore the dest before srcrt unless srcrt is being included. 1352 * --yoshfuji 1353 */ 1354 if (opt->dst0opt && !opt->srcrt) { 1355 if (opt_space != opt) { 1356 memcpy(opt_space, opt, sizeof(*opt_space)); 1357 opt = opt_space; 1358 } 1359 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1360 opt->dst0opt = NULL; 1361 } 1362 1363 return opt; 1364 } 1365 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1366 1367 /** 1368 * fl6_update_dst - update flowi destination address with info given 1369 * by srcrt option, if any. 1370 * 1371 * @fl6: flowi6 for which daddr is to be updated 1372 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1373 * @orig: copy of original daddr address if modified 1374 * 1375 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1376 * and initial value of fl6->daddr set in orig 1377 */ 1378 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1379 const struct ipv6_txoptions *opt, 1380 struct in6_addr *orig) 1381 { 1382 if (!opt || !opt->srcrt) 1383 return NULL; 1384 1385 *orig = fl6->daddr; 1386 1387 switch (opt->srcrt->type) { 1388 case IPV6_SRCRT_TYPE_0: 1389 case IPV6_SRCRT_STRICT: 1390 case IPV6_SRCRT_TYPE_2: 1391 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1392 break; 1393 case IPV6_SRCRT_TYPE_4: 1394 { 1395 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1396 1397 fl6->daddr = srh->segments[srh->segments_left]; 1398 break; 1399 } 1400 default: 1401 return NULL; 1402 } 1403 1404 return orig; 1405 } 1406 EXPORT_SYMBOL_GPL(fl6_update_dst); 1407