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 skb_dst_drop(skb); 462 463 ip6_route_input(skb); 464 465 if (skb_dst(skb)->error) { 466 dst_input(skb); 467 return -1; 468 } 469 470 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 471 if (ipv6_hdr(skb)->hop_limit <= 1) { 472 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 473 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 474 ICMPV6_EXC_HOPLIMIT, 0); 475 kfree_skb(skb); 476 return -1; 477 } 478 ipv6_hdr(skb)->hop_limit--; 479 480 skb_pull(skb, sizeof(struct ipv6hdr)); 481 goto looped_back; 482 } 483 484 dst_input(skb); 485 486 return -1; 487 } 488 489 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 490 { 491 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 492 struct inet6_skb_parm *opt = IP6CB(skb); 493 struct net *net = dev_net(skb->dev); 494 struct inet6_dev *idev; 495 struct ipv6hdr *oldhdr; 496 unsigned char *buf; 497 int accept_rpl_seg; 498 int i, err; 499 u64 n = 0; 500 u32 r; 501 502 idev = __in6_dev_get(skb->dev); 503 504 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 505 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 506 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 507 508 if (!accept_rpl_seg) { 509 kfree_skb(skb); 510 return -1; 511 } 512 513 looped_back: 514 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 515 516 if (hdr->segments_left == 0) { 517 if (hdr->nexthdr == NEXTHDR_IPV6) { 518 int offset = (hdr->hdrlen + 1) << 3; 519 520 skb_postpull_rcsum(skb, skb_network_header(skb), 521 skb_network_header_len(skb)); 522 523 if (!pskb_pull(skb, offset)) { 524 kfree_skb(skb); 525 return -1; 526 } 527 skb_postpull_rcsum(skb, skb_transport_header(skb), 528 offset); 529 530 skb_reset_network_header(skb); 531 skb_reset_transport_header(skb); 532 skb->encapsulation = 0; 533 534 __skb_tunnel_rx(skb, skb->dev, net); 535 536 netif_rx(skb); 537 return -1; 538 } 539 540 opt->srcrt = skb_network_header_len(skb); 541 opt->lastopt = opt->srcrt; 542 skb->transport_header += (hdr->hdrlen + 1) << 3; 543 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 544 545 return 1; 546 } 547 548 if (!pskb_may_pull(skb, sizeof(*hdr))) { 549 kfree_skb(skb); 550 return -1; 551 } 552 553 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 554 r = do_div(n, (16 - hdr->cmpri)); 555 /* checks if calculation was without remainder and n fits into 556 * unsigned char which is segments_left field. Should not be 557 * higher than that. 558 */ 559 if (r || (n + 1) > 255) { 560 kfree_skb(skb); 561 return -1; 562 } 563 564 if (hdr->segments_left > n + 1) { 565 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 566 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 567 ((&hdr->segments_left) - 568 skb_network_header(skb))); 569 return -1; 570 } 571 572 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 573 hdr->cmpre))) { 574 kfree_skb(skb); 575 return -1; 576 } 577 578 hdr->segments_left--; 579 i = n - hdr->segments_left; 580 581 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 582 if (unlikely(!buf)) { 583 kfree_skb(skb); 584 return -1; 585 } 586 587 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 588 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 589 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 590 591 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 592 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 593 kfree_skb(skb); 594 kfree(buf); 595 return -1; 596 } 597 598 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 599 if (err) { 600 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 601 kfree_skb(skb); 602 kfree(buf); 603 return -1; 604 } 605 606 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); 607 608 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 609 610 oldhdr = ipv6_hdr(skb); 611 612 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 613 skb_postpull_rcsum(skb, oldhdr, 614 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 615 if (unlikely(!hdr->segments_left)) { 616 if (pskb_expand_head(skb, sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), 0, 617 GFP_ATOMIC)) { 618 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); 619 kfree_skb(skb); 620 kfree(buf); 621 return -1; 622 } 623 624 oldhdr = ipv6_hdr(skb); 625 } 626 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 627 skb_reset_network_header(skb); 628 skb_mac_header_rebuild(skb); 629 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 630 631 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 632 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 633 634 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 635 skb_postpush_rcsum(skb, ipv6_hdr(skb), 636 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 637 638 kfree(buf); 639 640 skb_dst_drop(skb); 641 642 ip6_route_input(skb); 643 644 if (skb_dst(skb)->error) { 645 dst_input(skb); 646 return -1; 647 } 648 649 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 650 if (ipv6_hdr(skb)->hop_limit <= 1) { 651 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 652 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 653 ICMPV6_EXC_HOPLIMIT, 0); 654 kfree_skb(skb); 655 return -1; 656 } 657 ipv6_hdr(skb)->hop_limit--; 658 659 skb_pull(skb, sizeof(struct ipv6hdr)); 660 goto looped_back; 661 } 662 663 dst_input(skb); 664 665 return -1; 666 } 667 668 /******************************** 669 Routing header. 670 ********************************/ 671 672 /* called with rcu_read_lock() */ 673 static int ipv6_rthdr_rcv(struct sk_buff *skb) 674 { 675 struct inet6_dev *idev = __in6_dev_get(skb->dev); 676 struct inet6_skb_parm *opt = IP6CB(skb); 677 struct in6_addr *addr = NULL; 678 struct in6_addr daddr; 679 int n, i; 680 struct ipv6_rt_hdr *hdr; 681 struct rt0_hdr *rthdr; 682 struct net *net = dev_net(skb->dev); 683 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 684 685 if (idev && accept_source_route > idev->cnf.accept_source_route) 686 accept_source_route = idev->cnf.accept_source_route; 687 688 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 689 !pskb_may_pull(skb, (skb_transport_offset(skb) + 690 ((skb_transport_header(skb)[1] + 1) << 3)))) { 691 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 692 kfree_skb(skb); 693 return -1; 694 } 695 696 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 697 698 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 699 skb->pkt_type != PACKET_HOST) { 700 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 701 kfree_skb(skb); 702 return -1; 703 } 704 705 switch (hdr->type) { 706 case IPV6_SRCRT_TYPE_4: 707 /* segment routing */ 708 return ipv6_srh_rcv(skb); 709 case IPV6_SRCRT_TYPE_3: 710 /* rpl segment routing */ 711 return ipv6_rpl_srh_rcv(skb); 712 default: 713 break; 714 } 715 716 looped_back: 717 if (hdr->segments_left == 0) { 718 switch (hdr->type) { 719 #if IS_ENABLED(CONFIG_IPV6_MIP6) 720 case IPV6_SRCRT_TYPE_2: 721 /* Silently discard type 2 header unless it was 722 * processed by own 723 */ 724 if (!addr) { 725 __IP6_INC_STATS(net, idev, 726 IPSTATS_MIB_INADDRERRORS); 727 kfree_skb(skb); 728 return -1; 729 } 730 break; 731 #endif 732 default: 733 break; 734 } 735 736 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 737 skb->transport_header += (hdr->hdrlen + 1) << 3; 738 opt->dst0 = opt->dst1; 739 opt->dst1 = 0; 740 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 741 return 1; 742 } 743 744 switch (hdr->type) { 745 #if IS_ENABLED(CONFIG_IPV6_MIP6) 746 case IPV6_SRCRT_TYPE_2: 747 if (accept_source_route < 0) 748 goto unknown_rh; 749 /* Silently discard invalid RTH type 2 */ 750 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 751 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 752 kfree_skb(skb); 753 return -1; 754 } 755 break; 756 #endif 757 default: 758 goto unknown_rh; 759 } 760 761 /* 762 * This is the routing header forwarding algorithm from 763 * RFC 2460, page 16. 764 */ 765 766 n = hdr->hdrlen >> 1; 767 768 if (hdr->segments_left > n) { 769 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 770 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 771 ((&hdr->segments_left) - 772 skb_network_header(skb))); 773 return -1; 774 } 775 776 /* We are about to mangle packet header. Be careful! 777 Do not damage packets queued somewhere. 778 */ 779 if (skb_cloned(skb)) { 780 /* the copy is a forwarded packet */ 781 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 782 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 783 IPSTATS_MIB_OUTDISCARDS); 784 kfree_skb(skb); 785 return -1; 786 } 787 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 788 } 789 790 if (skb->ip_summed == CHECKSUM_COMPLETE) 791 skb->ip_summed = CHECKSUM_NONE; 792 793 i = n - --hdr->segments_left; 794 795 rthdr = (struct rt0_hdr *) hdr; 796 addr = rthdr->addr; 797 addr += i - 1; 798 799 switch (hdr->type) { 800 #if IS_ENABLED(CONFIG_IPV6_MIP6) 801 case IPV6_SRCRT_TYPE_2: 802 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 803 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 804 IPPROTO_ROUTING) < 0) { 805 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 806 kfree_skb(skb); 807 return -1; 808 } 809 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 810 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 811 kfree_skb(skb); 812 return -1; 813 } 814 break; 815 #endif 816 default: 817 break; 818 } 819 820 if (ipv6_addr_is_multicast(addr)) { 821 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 822 kfree_skb(skb); 823 return -1; 824 } 825 826 daddr = *addr; 827 *addr = ipv6_hdr(skb)->daddr; 828 ipv6_hdr(skb)->daddr = daddr; 829 830 skb_dst_drop(skb); 831 ip6_route_input(skb); 832 if (skb_dst(skb)->error) { 833 skb_push(skb, skb->data - skb_network_header(skb)); 834 dst_input(skb); 835 return -1; 836 } 837 838 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 839 if (ipv6_hdr(skb)->hop_limit <= 1) { 840 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 841 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 842 0); 843 kfree_skb(skb); 844 return -1; 845 } 846 ipv6_hdr(skb)->hop_limit--; 847 goto looped_back; 848 } 849 850 skb_push(skb, skb->data - skb_network_header(skb)); 851 dst_input(skb); 852 return -1; 853 854 unknown_rh: 855 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 856 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 857 (&hdr->type) - skb_network_header(skb)); 858 return -1; 859 } 860 861 static const struct inet6_protocol rthdr_protocol = { 862 .handler = ipv6_rthdr_rcv, 863 .flags = INET6_PROTO_NOPOLICY, 864 }; 865 866 static const struct inet6_protocol destopt_protocol = { 867 .handler = ipv6_destopt_rcv, 868 .flags = INET6_PROTO_NOPOLICY, 869 }; 870 871 static const struct inet6_protocol nodata_protocol = { 872 .handler = dst_discard, 873 .flags = INET6_PROTO_NOPOLICY, 874 }; 875 876 int __init ipv6_exthdrs_init(void) 877 { 878 int ret; 879 880 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 881 if (ret) 882 goto out; 883 884 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 885 if (ret) 886 goto out_rthdr; 887 888 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 889 if (ret) 890 goto out_destopt; 891 892 out: 893 return ret; 894 out_destopt: 895 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 896 out_rthdr: 897 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 898 goto out; 899 }; 900 901 void ipv6_exthdrs_exit(void) 902 { 903 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 904 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 905 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 906 } 907 908 /********************************** 909 Hop-by-hop options. 910 **********************************/ 911 912 /* 913 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 914 */ 915 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 916 { 917 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 918 } 919 920 /* Router Alert as of RFC 2711 */ 921 922 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 923 { 924 const unsigned char *nh = skb_network_header(skb); 925 926 if (nh[optoff + 1] == 2) { 927 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 928 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 929 return true; 930 } 931 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 932 nh[optoff + 1]); 933 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 934 return false; 935 } 936 937 /* IOAM */ 938 939 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 940 { 941 struct ioam6_trace_hdr *trace; 942 struct ioam6_namespace *ns; 943 struct ioam6_hdr *hdr; 944 945 /* Bad alignment (must be 4n-aligned) */ 946 if (optoff & 3) 947 goto drop; 948 949 /* Ignore if IOAM is not enabled on ingress */ 950 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled) 951 goto ignore; 952 953 /* Truncated Option header */ 954 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 955 if (hdr->opt_len < 2) 956 goto drop; 957 958 switch (hdr->type) { 959 case IOAM6_TYPE_PREALLOC: 960 /* Truncated Pre-allocated Trace header */ 961 if (hdr->opt_len < 2 + sizeof(*trace)) 962 goto drop; 963 964 /* Malformed Pre-allocated Trace header */ 965 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 966 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 967 goto drop; 968 969 /* Ignore if the IOAM namespace is unknown */ 970 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id); 971 if (!ns) 972 goto ignore; 973 974 if (!skb_valid_dst(skb)) 975 ip6_route_input(skb); 976 977 ioam6_fill_trace_data(skb, ns, trace, true); 978 break; 979 default: 980 break; 981 } 982 983 ignore: 984 return true; 985 986 drop: 987 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 988 return false; 989 } 990 991 /* Jumbo payload */ 992 993 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 994 { 995 const unsigned char *nh = skb_network_header(skb); 996 SKB_DR(reason); 997 u32 pkt_len; 998 999 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 1000 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 1001 nh[optoff+1]); 1002 SKB_DR_SET(reason, IP_INHDR); 1003 goto drop; 1004 } 1005 1006 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1007 if (pkt_len <= IPV6_MAXPLEN) { 1008 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, 1009 SKB_DROP_REASON_IP_INHDR); 1010 return false; 1011 } 1012 if (ipv6_hdr(skb)->payload_len) { 1013 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff, 1014 SKB_DROP_REASON_IP_INHDR); 1015 return false; 1016 } 1017 1018 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1019 SKB_DR_SET(reason, PKT_TOO_SMALL); 1020 goto drop; 1021 } 1022 1023 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1024 goto drop; 1025 1026 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1027 return true; 1028 1029 drop: 1030 kfree_skb_reason(skb, reason); 1031 return false; 1032 } 1033 1034 /* CALIPSO RFC 5570 */ 1035 1036 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1037 { 1038 const unsigned char *nh = skb_network_header(skb); 1039 1040 if (nh[optoff + 1] < 8) 1041 goto drop; 1042 1043 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1044 goto drop; 1045 1046 if (!calipso_validate(skb, nh + optoff)) 1047 goto drop; 1048 1049 return true; 1050 1051 drop: 1052 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 1053 return false; 1054 } 1055 1056 int ipv6_parse_hopopts(struct sk_buff *skb) 1057 { 1058 struct inet6_skb_parm *opt = IP6CB(skb); 1059 struct net *net = dev_net(skb->dev); 1060 int extlen; 1061 1062 /* 1063 * skb_network_header(skb) is equal to skb->data, and 1064 * skb_network_header_len(skb) is always equal to 1065 * sizeof(struct ipv6hdr) by definition of 1066 * hop-by-hop options. 1067 */ 1068 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1069 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1070 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1071 fail_and_free: 1072 kfree_skb(skb); 1073 return -1; 1074 } 1075 1076 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1077 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1078 goto fail_and_free; 1079 1080 opt->flags |= IP6SKB_HOPBYHOP; 1081 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) { 1082 skb->transport_header += extlen; 1083 opt = IP6CB(skb); 1084 opt->nhoff = sizeof(struct ipv6hdr); 1085 return 1; 1086 } 1087 return -1; 1088 } 1089 1090 /* 1091 * Creating outbound headers. 1092 * 1093 * "build" functions work when skb is filled from head to tail (datagram) 1094 * "push" functions work when headers are added from tail to head (tcp) 1095 * 1096 * In both cases we assume, that caller reserved enough room 1097 * for headers. 1098 */ 1099 1100 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1101 struct ipv6_rt_hdr *opt, 1102 struct in6_addr **addr_p, struct in6_addr *saddr) 1103 { 1104 struct rt0_hdr *phdr, *ihdr; 1105 int hops; 1106 1107 ihdr = (struct rt0_hdr *) opt; 1108 1109 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1110 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1111 1112 hops = ihdr->rt_hdr.hdrlen >> 1; 1113 1114 if (hops > 1) 1115 memcpy(phdr->addr, ihdr->addr + 1, 1116 (hops - 1) * sizeof(struct in6_addr)); 1117 1118 phdr->addr[hops - 1] = **addr_p; 1119 *addr_p = ihdr->addr; 1120 1121 phdr->rt_hdr.nexthdr = *proto; 1122 *proto = NEXTHDR_ROUTING; 1123 } 1124 1125 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1126 struct ipv6_rt_hdr *opt, 1127 struct in6_addr **addr_p, struct in6_addr *saddr) 1128 { 1129 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1130 int plen, hops; 1131 1132 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1133 plen = (sr_ihdr->hdrlen + 1) << 3; 1134 1135 sr_phdr = skb_push(skb, plen); 1136 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1137 1138 hops = sr_ihdr->first_segment + 1; 1139 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1140 (hops - 1) * sizeof(struct in6_addr)); 1141 1142 sr_phdr->segments[0] = **addr_p; 1143 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1144 1145 if (sr_ihdr->hdrlen > hops * 2) { 1146 int tlvs_offset, tlvs_length; 1147 1148 tlvs_offset = (1 + hops * 2) << 3; 1149 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1150 memcpy((char *)sr_phdr + tlvs_offset, 1151 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1152 } 1153 1154 #ifdef CONFIG_IPV6_SEG6_HMAC 1155 if (sr_has_hmac(sr_phdr)) { 1156 struct net *net = NULL; 1157 1158 if (skb->dev) 1159 net = dev_net(skb->dev); 1160 else if (skb->sk) 1161 net = sock_net(skb->sk); 1162 1163 WARN_ON(!net); 1164 1165 if (net) 1166 seg6_push_hmac(net, saddr, sr_phdr); 1167 } 1168 #endif 1169 1170 sr_phdr->nexthdr = *proto; 1171 *proto = NEXTHDR_ROUTING; 1172 } 1173 1174 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1175 struct ipv6_rt_hdr *opt, 1176 struct in6_addr **addr_p, struct in6_addr *saddr) 1177 { 1178 switch (opt->type) { 1179 case IPV6_SRCRT_TYPE_0: 1180 case IPV6_SRCRT_STRICT: 1181 case IPV6_SRCRT_TYPE_2: 1182 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1183 break; 1184 case IPV6_SRCRT_TYPE_4: 1185 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1186 break; 1187 default: 1188 break; 1189 } 1190 } 1191 1192 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1193 { 1194 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1195 1196 memcpy(h, opt, ipv6_optlen(opt)); 1197 h->nexthdr = *proto; 1198 *proto = type; 1199 } 1200 1201 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1202 u8 *proto, 1203 struct in6_addr **daddr, struct in6_addr *saddr) 1204 { 1205 if (opt->srcrt) { 1206 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1207 /* 1208 * IPV6_RTHDRDSTOPTS is ignored 1209 * unless IPV6_RTHDR is set (RFC3542). 1210 */ 1211 if (opt->dst0opt) 1212 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1213 } 1214 if (opt->hopopt) 1215 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1216 } 1217 1218 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1219 { 1220 if (opt->dst1opt) 1221 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1222 } 1223 EXPORT_SYMBOL(ipv6_push_frag_opts); 1224 1225 struct ipv6_txoptions * 1226 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1227 { 1228 struct ipv6_txoptions *opt2; 1229 1230 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1231 if (opt2) { 1232 long dif = (char *)opt2 - (char *)opt; 1233 memcpy(opt2, opt, opt->tot_len); 1234 if (opt2->hopopt) 1235 *((char **)&opt2->hopopt) += dif; 1236 if (opt2->dst0opt) 1237 *((char **)&opt2->dst0opt) += dif; 1238 if (opt2->dst1opt) 1239 *((char **)&opt2->dst1opt) += dif; 1240 if (opt2->srcrt) 1241 *((char **)&opt2->srcrt) += dif; 1242 refcount_set(&opt2->refcnt, 1); 1243 } 1244 return opt2; 1245 } 1246 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1247 1248 static void ipv6_renew_option(int renewtype, 1249 struct ipv6_opt_hdr **dest, 1250 struct ipv6_opt_hdr *old, 1251 struct ipv6_opt_hdr *new, 1252 int newtype, char **p) 1253 { 1254 struct ipv6_opt_hdr *src; 1255 1256 src = (renewtype == newtype ? new : old); 1257 if (!src) 1258 return; 1259 1260 memcpy(*p, src, ipv6_optlen(src)); 1261 *dest = (struct ipv6_opt_hdr *)*p; 1262 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1263 } 1264 1265 /** 1266 * ipv6_renew_options - replace a specific ext hdr with a new one. 1267 * 1268 * @sk: sock from which to allocate memory 1269 * @opt: original options 1270 * @newtype: option type to replace in @opt 1271 * @newopt: new option of type @newtype to replace (user-mem) 1272 * 1273 * Returns a new set of options which is a copy of @opt with the 1274 * option type @newtype replaced with @newopt. 1275 * 1276 * @opt may be NULL, in which case a new set of options is returned 1277 * containing just @newopt. 1278 * 1279 * @newopt may be NULL, in which case the specified option type is 1280 * not copied into the new set of options. 1281 * 1282 * The new set of options is allocated from the socket option memory 1283 * buffer of @sk. 1284 */ 1285 struct ipv6_txoptions * 1286 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1287 int newtype, struct ipv6_opt_hdr *newopt) 1288 { 1289 int tot_len = 0; 1290 char *p; 1291 struct ipv6_txoptions *opt2; 1292 1293 if (opt) { 1294 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1295 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1296 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1297 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1298 if (newtype != IPV6_RTHDR && opt->srcrt) 1299 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1300 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1301 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1302 } 1303 1304 if (newopt) 1305 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1306 1307 if (!tot_len) 1308 return NULL; 1309 1310 tot_len += sizeof(*opt2); 1311 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1312 if (!opt2) 1313 return ERR_PTR(-ENOBUFS); 1314 1315 memset(opt2, 0, tot_len); 1316 refcount_set(&opt2->refcnt, 1); 1317 opt2->tot_len = tot_len; 1318 p = (char *)(opt2 + 1); 1319 1320 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1321 (opt ? opt->hopopt : NULL), 1322 newopt, newtype, &p); 1323 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1324 (opt ? opt->dst0opt : NULL), 1325 newopt, newtype, &p); 1326 ipv6_renew_option(IPV6_RTHDR, 1327 (struct ipv6_opt_hdr **)&opt2->srcrt, 1328 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1329 newopt, newtype, &p); 1330 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1331 (opt ? opt->dst1opt : NULL), 1332 newopt, newtype, &p); 1333 1334 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1335 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1336 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1337 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1338 1339 return opt2; 1340 } 1341 1342 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1343 struct ipv6_txoptions *opt) 1344 { 1345 /* 1346 * ignore the dest before srcrt unless srcrt is being included. 1347 * --yoshfuji 1348 */ 1349 if (opt->dst0opt && !opt->srcrt) { 1350 if (opt_space != opt) { 1351 memcpy(opt_space, opt, sizeof(*opt_space)); 1352 opt = opt_space; 1353 } 1354 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1355 opt->dst0opt = NULL; 1356 } 1357 1358 return opt; 1359 } 1360 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1361 1362 /** 1363 * fl6_update_dst - update flowi destination address with info given 1364 * by srcrt option, if any. 1365 * 1366 * @fl6: flowi6 for which daddr is to be updated 1367 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1368 * @orig: copy of original daddr address if modified 1369 * 1370 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1371 * and initial value of fl6->daddr set in orig 1372 */ 1373 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1374 const struct ipv6_txoptions *opt, 1375 struct in6_addr *orig) 1376 { 1377 if (!opt || !opt->srcrt) 1378 return NULL; 1379 1380 *orig = fl6->daddr; 1381 1382 switch (opt->srcrt->type) { 1383 case IPV6_SRCRT_TYPE_0: 1384 case IPV6_SRCRT_STRICT: 1385 case IPV6_SRCRT_TYPE_2: 1386 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1387 break; 1388 case IPV6_SRCRT_TYPE_4: 1389 { 1390 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1391 1392 fl6->daddr = srh->segments[srh->segments_left]; 1393 break; 1394 } 1395 default: 1396 return NULL; 1397 } 1398 1399 return orig; 1400 } 1401 EXPORT_SYMBOL_GPL(fl6_update_dst); 1402