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 <linux/ioam6_genl.h> 54 #include <net/ioam6.h> 55 #include <net/dst_metadata.h> 56 57 #include <linux/uaccess.h> 58 59 /********************* 60 Generic functions 61 *********************/ 62 63 /* An unknown option is detected, decide what to do */ 64 65 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, 66 bool disallow_unknowns) 67 { 68 if (disallow_unknowns) { 69 /* If unknown TLVs are disallowed by configuration 70 * then always silently drop packet. Note this also 71 * means no ICMP parameter problem is sent which 72 * could be a good property to mitigate a reflection DOS 73 * attack. 74 */ 75 76 goto drop; 77 } 78 79 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 80 case 0: /* ignore */ 81 return true; 82 83 case 1: /* drop packet */ 84 break; 85 86 case 3: /* Send ICMP if not a multicast address and drop packet */ 87 /* Actually, it is redundant check. icmp_send 88 will recheck in any case. 89 */ 90 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 91 break; 92 fallthrough; 93 case 2: /* send ICMP PARM PROB regardless and drop packet */ 94 icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff, 95 SKB_DROP_REASON_UNHANDLED_PROTO); 96 return false; 97 } 98 99 drop: 100 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO); 101 return false; 102 } 103 104 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff); 105 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff); 106 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff); 107 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff); 108 #if IS_ENABLED(CONFIG_IPV6_MIP6) 109 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff); 110 #endif 111 112 /* Parse tlv encoded option header (hop-by-hop or destination) */ 113 114 static bool ip6_parse_tlv(bool hopbyhop, 115 struct sk_buff *skb, 116 int max_count) 117 { 118 int len = (skb_transport_header(skb)[1] + 1) << 3; 119 const unsigned char *nh = skb_network_header(skb); 120 int off = skb_network_header_len(skb); 121 bool disallow_unknowns = false; 122 int tlv_count = 0; 123 int padlen = 0; 124 125 if (unlikely(max_count < 0)) { 126 disallow_unknowns = true; 127 max_count = -max_count; 128 } 129 130 off += 2; 131 len -= 2; 132 133 while (len > 0) { 134 int optlen, i; 135 136 if (nh[off] == IPV6_TLV_PAD1) { 137 padlen++; 138 if (padlen > 7) 139 goto bad; 140 off++; 141 len--; 142 continue; 143 } 144 if (len < 2) 145 goto bad; 146 optlen = nh[off + 1] + 2; 147 if (optlen > len) 148 goto bad; 149 150 if (nh[off] == IPV6_TLV_PADN) { 151 /* RFC 2460 states that the purpose of PadN is 152 * to align the containing header to multiples 153 * of 8. 7 is therefore the highest valid value. 154 * See also RFC 4942, Section 2.1.9.5. 155 */ 156 padlen += optlen; 157 if (padlen > 7) 158 goto bad; 159 /* RFC 4942 recommends receiving hosts to 160 * actively check PadN payload to contain 161 * only zeroes. 162 */ 163 for (i = 2; i < optlen; i++) { 164 if (nh[off + i] != 0) 165 goto bad; 166 } 167 } else { 168 tlv_count++; 169 if (tlv_count > max_count) 170 goto bad; 171 172 if (hopbyhop) { 173 switch (nh[off]) { 174 case IPV6_TLV_ROUTERALERT: 175 if (!ipv6_hop_ra(skb, off)) 176 return false; 177 break; 178 case IPV6_TLV_IOAM: 179 if (!ipv6_hop_ioam(skb, off)) 180 return false; 181 break; 182 case IPV6_TLV_JUMBO: 183 if (!ipv6_hop_jumbo(skb, off)) 184 return false; 185 break; 186 case IPV6_TLV_CALIPSO: 187 if (!ipv6_hop_calipso(skb, off)) 188 return false; 189 break; 190 default: 191 if (!ip6_tlvopt_unknown(skb, off, 192 disallow_unknowns)) 193 return false; 194 break; 195 } 196 } else { 197 switch (nh[off]) { 198 #if IS_ENABLED(CONFIG_IPV6_MIP6) 199 case IPV6_TLV_HAO: 200 if (!ipv6_dest_hao(skb, off)) 201 return false; 202 break; 203 #endif 204 default: 205 if (!ip6_tlvopt_unknown(skb, off, 206 disallow_unknowns)) 207 return false; 208 break; 209 } 210 } 211 padlen = 0; 212 213 /* recompute the network header pointer in case it has changed */ 214 nh = skb_network_header(skb); 215 } 216 off += optlen; 217 len -= optlen; 218 } 219 220 if (len == 0) 221 return true; 222 bad: 223 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 224 return false; 225 } 226 227 /***************************** 228 Destination options header. 229 *****************************/ 230 231 #if IS_ENABLED(CONFIG_IPV6_MIP6) 232 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 233 { 234 struct ipv6_destopt_hao *hao; 235 struct inet6_skb_parm *opt = IP6CB(skb); 236 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 237 SKB_DR(reason); 238 int ret; 239 240 if (opt->dsthao) { 241 net_dbg_ratelimited("hao duplicated\n"); 242 goto discard; 243 } 244 opt->dsthao = opt->dst1; 245 opt->dst1 = 0; 246 247 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 248 249 if (hao->length != 16) { 250 net_dbg_ratelimited("hao invalid option length = %d\n", 251 hao->length); 252 SKB_DR_SET(reason, IP_INHDR); 253 goto discard; 254 } 255 256 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 257 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 258 &hao->addr); 259 SKB_DR_SET(reason, INVALID_PROTO); 260 goto discard; 261 } 262 263 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 264 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 265 if (unlikely(ret < 0)) { 266 SKB_DR_SET(reason, XFRM_POLICY); 267 goto discard; 268 } 269 270 if (skb_cloned(skb)) { 271 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 272 goto discard; 273 274 /* update all variable using below by copied skbuff */ 275 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 276 optoff); 277 ipv6h = ipv6_hdr(skb); 278 } 279 280 if (skb->ip_summed == CHECKSUM_COMPLETE) 281 skb->ip_summed = CHECKSUM_NONE; 282 283 swap(ipv6h->saddr, hao->addr); 284 285 if (skb->tstamp == 0) 286 __net_timestamp(skb); 287 288 return true; 289 290 discard: 291 kfree_skb_reason(skb, reason); 292 return false; 293 } 294 #endif 295 296 static int ipv6_destopt_rcv(struct sk_buff *skb) 297 { 298 struct inet6_dev *idev = __in6_dev_get(skb->dev); 299 struct inet6_skb_parm *opt = IP6CB(skb); 300 #if IS_ENABLED(CONFIG_IPV6_MIP6) 301 __u16 dstbuf; 302 #endif 303 struct dst_entry *dst = skb_dst(skb); 304 struct net *net = dev_net(skb->dev); 305 int extlen; 306 307 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 308 !pskb_may_pull(skb, (skb_transport_offset(skb) + 309 ((skb_transport_header(skb)[1] + 1) << 3)))) { 310 __IP6_INC_STATS(dev_net(dst_dev(dst)), idev, 311 IPSTATS_MIB_INHDRERRORS); 312 fail_and_free: 313 kfree_skb(skb); 314 return -1; 315 } 316 317 extlen = (skb_transport_header(skb)[1] + 1) << 3; 318 if (extlen > READ_ONCE(net->ipv6.sysctl.max_dst_opts_len)) 319 goto fail_and_free; 320 321 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 322 #if IS_ENABLED(CONFIG_IPV6_MIP6) 323 dstbuf = opt->dst1; 324 #endif 325 326 if (ip6_parse_tlv(false, skb, 327 READ_ONCE(net->ipv6.sysctl.max_dst_opts_cnt))) { 328 skb->transport_header += extlen; 329 opt = IP6CB(skb); 330 #if IS_ENABLED(CONFIG_IPV6_MIP6) 331 opt->nhoff = dstbuf; 332 #else 333 opt->nhoff = opt->dst1; 334 #endif 335 return 1; 336 } 337 338 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 339 return -1; 340 } 341 342 static void seg6_update_csum(struct sk_buff *skb) 343 { 344 struct ipv6_sr_hdr *hdr; 345 struct in6_addr *addr; 346 __be32 from, to; 347 348 /* srh is at transport offset and seg_left is already decremented 349 * but daddr is not yet updated with next segment 350 */ 351 352 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 353 addr = hdr->segments + hdr->segments_left; 354 355 hdr->segments_left++; 356 from = *(__be32 *)hdr; 357 358 hdr->segments_left--; 359 to = *(__be32 *)hdr; 360 361 /* update skb csum with diff resulting from seg_left decrement */ 362 363 update_csum_diff4(skb, from, to); 364 365 /* compute csum diff between current and next segment and update */ 366 367 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 368 (__be32 *)addr); 369 } 370 371 static int ipv6_srh_rcv(struct sk_buff *skb) 372 { 373 struct inet6_skb_parm *opt = IP6CB(skb); 374 struct net *net = dev_net(skb->dev); 375 struct ipv6_sr_hdr *hdr; 376 struct inet6_dev *idev; 377 struct in6_addr *addr; 378 int accept_seg6; 379 380 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 381 382 idev = __in6_dev_get(skb->dev); 383 if (!idev) { 384 kfree_skb(skb); 385 return -1; 386 } 387 388 accept_seg6 = min(READ_ONCE(net->ipv6.devconf_all->seg6_enabled), 389 READ_ONCE(idev->cnf.seg6_enabled)); 390 391 if (!accept_seg6) { 392 kfree_skb(skb); 393 return -1; 394 } 395 396 #ifdef CONFIG_IPV6_SEG6_HMAC 397 if (!seg6_hmac_validate_skb(skb)) { 398 kfree_skb(skb); 399 return -1; 400 } 401 #endif 402 403 looped_back: 404 if (hdr->segments_left == 0) { 405 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 406 int offset = (hdr->hdrlen + 1) << 3; 407 408 skb_postpull_rcsum(skb, skb_network_header(skb), 409 skb_network_header_len(skb)); 410 skb_pull(skb, offset); 411 skb_postpull_rcsum(skb, skb_transport_header(skb), 412 offset); 413 414 skb_reset_network_header(skb); 415 skb_reset_transport_header(skb); 416 skb->encapsulation = 0; 417 if (hdr->nexthdr == NEXTHDR_IPV4) 418 skb->protocol = htons(ETH_P_IP); 419 __skb_tunnel_rx(skb, skb->dev, net); 420 421 netif_rx(skb); 422 return -1; 423 } 424 425 opt->srcrt = skb_network_header_len(skb); 426 opt->lastopt = opt->srcrt; 427 skb->transport_header += (hdr->hdrlen + 1) << 3; 428 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 429 430 return 1; 431 } 432 433 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 434 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 435 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 436 ((&hdr->segments_left) - 437 skb_network_header(skb))); 438 return -1; 439 } 440 441 if (skb_cloned(skb)) { 442 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 443 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 444 IPSTATS_MIB_OUTDISCARDS); 445 kfree_skb(skb); 446 return -1; 447 } 448 449 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 450 } 451 452 hdr->segments_left--; 453 addr = hdr->segments + hdr->segments_left; 454 455 skb_push(skb, sizeof(struct ipv6hdr)); 456 457 if (skb->ip_summed == CHECKSUM_COMPLETE) 458 seg6_update_csum(skb); 459 460 ipv6_hdr(skb)->daddr = *addr; 461 462 ip6_route_input(skb); 463 464 if (skb_dst(skb)->error) { 465 dst_input(skb); 466 return -1; 467 } 468 469 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 470 if (ipv6_hdr(skb)->hop_limit <= 1) { 471 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 472 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 473 ICMPV6_EXC_HOPLIMIT, 0); 474 kfree_skb(skb); 475 return -1; 476 } 477 ipv6_hdr(skb)->hop_limit--; 478 479 skb_pull(skb, sizeof(struct ipv6hdr)); 480 goto looped_back; 481 } 482 483 dst_input(skb); 484 485 return -1; 486 } 487 488 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 489 { 490 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 491 struct inet6_skb_parm *opt = IP6CB(skb); 492 struct net *net = dev_net(skb->dev); 493 struct inet6_dev *idev; 494 struct ipv6hdr *oldhdr; 495 unsigned int chdr_len; 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 = min(READ_ONCE(net->ipv6.devconf_all->rpl_seg_enabled), 505 READ_ONCE(idev->cnf.rpl_seg_enabled)); 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 skb_pull(skb, offset); 521 skb_postpull_rcsum(skb, skb_transport_header(skb), 522 offset); 523 524 skb_reset_network_header(skb); 525 skb_reset_transport_header(skb); 526 skb->encapsulation = 0; 527 528 __skb_tunnel_rx(skb, skb->dev, net); 529 530 netif_rx(skb); 531 return -1; 532 } 533 534 opt->srcrt = skb_network_header_len(skb); 535 opt->lastopt = opt->srcrt; 536 skb->transport_header += (hdr->hdrlen + 1) << 3; 537 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 538 539 return 1; 540 } 541 542 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 543 r = do_div(n, (16 - hdr->cmpri)); 544 /* checks if calculation was without remainder and n fits into 545 * unsigned char which is segments_left field. Should not be 546 * higher than that. 547 */ 548 if (r || (n + 1) > 127) { 549 kfree_skb(skb); 550 return -1; 551 } 552 553 if (hdr->segments_left > n + 1) { 554 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 555 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 556 ((&hdr->segments_left) - 557 skb_network_header(skb))); 558 return -1; 559 } 560 561 hdr->segments_left--; 562 i = n - hdr->segments_left; 563 564 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 565 if (unlikely(!buf)) { 566 kfree_skb(skb); 567 return -1; 568 } 569 570 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 571 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 572 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 573 574 if (ipv6_addr_is_multicast(&ohdr->rpl_segaddr[i])) { 575 kfree_skb(skb); 576 kfree(buf); 577 return -1; 578 } 579 580 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 581 if (err) { 582 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 583 kfree_skb(skb); 584 kfree(buf); 585 return -1; 586 } 587 588 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); 589 590 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 591 592 oldhdr = ipv6_hdr(skb); 593 594 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 595 skb_postpull_rcsum(skb, oldhdr, 596 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 597 chdr_len = sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3); 598 if (unlikely(!hdr->segments_left || 599 skb_headroom(skb) < chdr_len + skb->mac_len)) { 600 if (pskb_expand_head(skb, chdr_len + skb->mac_len, 0, 601 GFP_ATOMIC)) { 602 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); 603 kfree_skb(skb); 604 kfree(buf); 605 return -1; 606 } 607 608 oldhdr = ipv6_hdr(skb); 609 } 610 skb_push(skb, chdr_len); 611 skb_reset_network_header(skb); 612 skb_mac_header_rebuild(skb); 613 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 614 615 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 616 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 617 618 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 619 skb_postpush_rcsum(skb, ipv6_hdr(skb), 620 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 621 622 kfree(buf); 623 624 ip6_route_input(skb); 625 626 if (skb_dst(skb)->error) { 627 dst_input(skb); 628 return -1; 629 } 630 631 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 632 if (ipv6_hdr(skb)->hop_limit <= 1) { 633 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 634 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 635 ICMPV6_EXC_HOPLIMIT, 0); 636 kfree_skb(skb); 637 return -1; 638 } 639 ipv6_hdr(skb)->hop_limit--; 640 641 skb_pull(skb, sizeof(struct ipv6hdr)); 642 goto looped_back; 643 } 644 645 dst_input(skb); 646 647 return -1; 648 } 649 650 /******************************** 651 Routing header. 652 ********************************/ 653 654 /* called with rcu_read_lock() */ 655 static int ipv6_rthdr_rcv(struct sk_buff *skb) 656 { 657 struct inet6_dev *idev = __in6_dev_get(skb->dev); 658 struct inet6_skb_parm *opt = IP6CB(skb); 659 struct in6_addr *addr = NULL; 660 int n, i; 661 struct ipv6_rt_hdr *hdr; 662 struct rt0_hdr *rthdr; 663 struct net *net = dev_net(skb->dev); 664 int accept_source_route; 665 666 accept_source_route = READ_ONCE(net->ipv6.devconf_all->accept_source_route); 667 668 if (idev) 669 accept_source_route = min(accept_source_route, 670 READ_ONCE(idev->cnf.accept_source_route)); 671 672 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 673 !pskb_may_pull(skb, (skb_transport_offset(skb) + 674 ((skb_transport_header(skb)[1] + 1) << 3)))) { 675 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 676 kfree_skb(skb); 677 return -1; 678 } 679 680 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 681 682 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 683 skb->pkt_type != PACKET_HOST) { 684 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 685 kfree_skb(skb); 686 return -1; 687 } 688 689 switch (hdr->type) { 690 case IPV6_SRCRT_TYPE_4: 691 /* segment routing */ 692 return ipv6_srh_rcv(skb); 693 case IPV6_SRCRT_TYPE_3: 694 /* rpl segment routing */ 695 return ipv6_rpl_srh_rcv(skb); 696 default: 697 break; 698 } 699 700 looped_back: 701 if (hdr->segments_left == 0) { 702 switch (hdr->type) { 703 #if IS_ENABLED(CONFIG_IPV6_MIP6) 704 case IPV6_SRCRT_TYPE_2: 705 /* Silently discard type 2 header unless it was 706 * processed by own 707 */ 708 if (!addr) { 709 __IP6_INC_STATS(net, idev, 710 IPSTATS_MIB_INADDRERRORS); 711 kfree_skb(skb); 712 return -1; 713 } 714 break; 715 #endif 716 default: 717 break; 718 } 719 720 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 721 skb->transport_header += (hdr->hdrlen + 1) << 3; 722 opt->dst0 = opt->dst1; 723 opt->dst1 = 0; 724 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 725 return 1; 726 } 727 728 switch (hdr->type) { 729 #if IS_ENABLED(CONFIG_IPV6_MIP6) 730 case IPV6_SRCRT_TYPE_2: 731 if (accept_source_route < 0) 732 goto unknown_rh; 733 /* Silently discard invalid RTH type 2 */ 734 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 735 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 736 kfree_skb(skb); 737 return -1; 738 } 739 break; 740 #endif 741 default: 742 goto unknown_rh; 743 } 744 745 /* 746 * This is the routing header forwarding algorithm from 747 * RFC 2460, page 16. 748 */ 749 750 n = hdr->hdrlen >> 1; 751 752 if (hdr->segments_left > n) { 753 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 754 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 755 ((&hdr->segments_left) - 756 skb_network_header(skb))); 757 return -1; 758 } 759 760 /* We are about to mangle packet header. Be careful! 761 Do not damage packets queued somewhere. 762 */ 763 if (skb_cloned(skb)) { 764 /* the copy is a forwarded packet */ 765 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 766 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 767 IPSTATS_MIB_OUTDISCARDS); 768 kfree_skb(skb); 769 return -1; 770 } 771 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 772 } 773 774 if (skb->ip_summed == CHECKSUM_COMPLETE) 775 skb->ip_summed = CHECKSUM_NONE; 776 777 i = n - --hdr->segments_left; 778 779 rthdr = (struct rt0_hdr *) hdr; 780 addr = rthdr->addr; 781 addr += i - 1; 782 783 switch (hdr->type) { 784 #if IS_ENABLED(CONFIG_IPV6_MIP6) 785 case IPV6_SRCRT_TYPE_2: 786 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 787 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 788 IPPROTO_ROUTING) < 0) { 789 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 790 kfree_skb(skb); 791 return -1; 792 } 793 if (!ipv6_chk_home_addr(skb_dst_dev_net(skb), addr)) { 794 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 795 kfree_skb(skb); 796 return -1; 797 } 798 break; 799 #endif 800 default: 801 break; 802 } 803 804 if (ipv6_addr_is_multicast(addr)) { 805 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 806 kfree_skb(skb); 807 return -1; 808 } 809 810 swap(*addr, ipv6_hdr(skb)->daddr); 811 812 ip6_route_input(skb); 813 if (skb_dst(skb)->error) { 814 skb_push(skb, -skb_network_offset(skb)); 815 dst_input(skb); 816 return -1; 817 } 818 819 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 820 if (ipv6_hdr(skb)->hop_limit <= 1) { 821 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 822 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 823 0); 824 kfree_skb(skb); 825 return -1; 826 } 827 ipv6_hdr(skb)->hop_limit--; 828 goto looped_back; 829 } 830 831 skb_push(skb, -skb_network_offset(skb)); 832 dst_input(skb); 833 return -1; 834 835 unknown_rh: 836 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 837 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 838 (&hdr->type) - skb_network_header(skb)); 839 return -1; 840 } 841 842 static const struct inet6_protocol rthdr_protocol = { 843 .handler = ipv6_rthdr_rcv, 844 .flags = INET6_PROTO_NOPOLICY, 845 }; 846 847 static const struct inet6_protocol destopt_protocol = { 848 .handler = ipv6_destopt_rcv, 849 .flags = INET6_PROTO_NOPOLICY, 850 }; 851 852 static const struct inet6_protocol nodata_protocol = { 853 .handler = dst_discard, 854 .flags = INET6_PROTO_NOPOLICY, 855 }; 856 857 int __init ipv6_exthdrs_init(void) 858 { 859 int ret; 860 861 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 862 if (ret) 863 goto out; 864 865 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 866 if (ret) 867 goto out_rthdr; 868 869 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 870 if (ret) 871 goto out_destopt; 872 873 out: 874 return ret; 875 out_destopt: 876 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 877 out_rthdr: 878 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 879 goto out; 880 }; 881 882 void ipv6_exthdrs_exit(void) 883 { 884 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 885 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 886 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 887 } 888 889 /********************************** 890 Hop-by-hop options. 891 **********************************/ 892 893 /* Router Alert as of RFC 2711 */ 894 895 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 896 { 897 const unsigned char *nh = skb_network_header(skb); 898 899 if (nh[optoff + 1] == 2) { 900 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 901 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 902 return true; 903 } 904 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 905 nh[optoff + 1]); 906 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 907 return false; 908 } 909 910 /* IOAM */ 911 912 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 913 { 914 enum skb_drop_reason drop_reason; 915 struct ioam6_trace_hdr *trace; 916 struct ioam6_namespace *ns; 917 struct inet6_dev *idev; 918 struct ioam6_hdr *hdr; 919 920 drop_reason = SKB_DROP_REASON_IP_INHDR; 921 922 /* Bad alignment (must be 4n-aligned) */ 923 if (optoff & 3) 924 goto drop; 925 926 /* Does the device still have IPv6 configuration? */ 927 idev = __in6_dev_get(skb->dev); 928 if (!idev) { 929 drop_reason = SKB_DROP_REASON_IPV6DISABLED; 930 goto drop; 931 } 932 933 /* Ignore if IOAM is not enabled on ingress */ 934 if (!READ_ONCE(idev->cnf.ioam6_enabled)) 935 goto ignore; 936 937 /* Truncated Option header */ 938 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 939 if (hdr->opt_len < 2) 940 goto drop; 941 942 switch (hdr->type) { 943 case IOAM6_TYPE_PREALLOC: 944 /* Truncated Pre-allocated Trace header */ 945 if (hdr->opt_len < 2 + sizeof(*trace)) 946 goto drop; 947 948 /* Malformed Pre-allocated Trace header */ 949 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 950 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 951 goto drop; 952 953 /* Inconsistent Pre-allocated Trace header */ 954 if (trace->nodelen != 955 ioam6_trace_compute_nodelen(be32_to_cpu(trace->type_be32))) 956 goto drop; 957 958 /* Ignore if the IOAM namespace is unknown */ 959 ns = ioam6_namespace(dev_net(skb->dev), trace->namespace_id); 960 if (!ns) 961 goto ignore; 962 963 if (!skb_valid_dst(skb)) 964 ip6_route_input(skb); 965 966 /* About to mangle packet header */ 967 if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) 968 goto drop; 969 970 /* Trace and hdr pointers may have changed */ 971 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 972 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 973 974 ioam6_fill_trace_data(skb, ns, trace, true); 975 976 ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev), 977 GFP_ATOMIC, (void *)trace, hdr->opt_len - 2); 978 break; 979 default: 980 break; 981 } 982 983 ignore: 984 return true; 985 986 drop: 987 kfree_skb_reason(skb, drop_reason); 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 > READ_ONCE(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, 1082 READ_ONCE(net->ipv6.sysctl.max_hbh_opts_cnt))) { 1083 skb->transport_header += extlen; 1084 opt = IP6CB(skb); 1085 opt->nhoff = sizeof(struct ipv6hdr); 1086 return 1; 1087 } 1088 return -1; 1089 } 1090 1091 /* 1092 * Creating outbound headers. 1093 * 1094 * "build" functions work when skb is filled from head to tail (datagram) 1095 * "push" functions work when headers are added from tail to head (tcp) 1096 * 1097 * In both cases we assume, that caller reserved enough room 1098 * for headers. 1099 */ 1100 1101 static u8 ipv6_push_rthdr0(struct sk_buff *skb, u8 proto, 1102 struct ipv6_rt_hdr *opt, 1103 struct in6_addr **addr_p, struct in6_addr *saddr) 1104 { 1105 struct rt0_hdr *phdr, *ihdr; 1106 int hops; 1107 1108 ihdr = (struct rt0_hdr *) opt; 1109 1110 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1111 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1112 1113 hops = ihdr->rt_hdr.hdrlen >> 1; 1114 1115 if (hops > 1) 1116 memcpy(phdr->addr, ihdr->addr + 1, 1117 (hops - 1) * sizeof(struct in6_addr)); 1118 1119 phdr->addr[hops - 1] = **addr_p; 1120 *addr_p = ihdr->addr; 1121 1122 phdr->rt_hdr.nexthdr = proto; 1123 return NEXTHDR_ROUTING; 1124 } 1125 1126 static u8 ipv6_push_rthdr4(struct sk_buff *skb, u8 proto, 1127 struct ipv6_rt_hdr *opt, 1128 struct in6_addr **addr_p, struct in6_addr *saddr) 1129 { 1130 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1131 int plen, hops; 1132 1133 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1134 plen = (sr_ihdr->hdrlen + 1) << 3; 1135 1136 sr_phdr = skb_push(skb, plen); 1137 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1138 1139 hops = sr_ihdr->first_segment + 1; 1140 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1141 (hops - 1) * sizeof(struct in6_addr)); 1142 1143 sr_phdr->segments[0] = **addr_p; 1144 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1145 1146 if (sr_ihdr->hdrlen > hops * 2) { 1147 int tlvs_offset, tlvs_length; 1148 1149 tlvs_offset = (1 + hops * 2) << 3; 1150 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1151 memcpy((char *)sr_phdr + tlvs_offset, 1152 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1153 } 1154 1155 #ifdef CONFIG_IPV6_SEG6_HMAC 1156 if (sr_has_hmac(sr_phdr)) { 1157 struct net *net = NULL; 1158 1159 if (skb->dev) 1160 net = dev_net(skb->dev); 1161 else if (skb->sk) 1162 net = sock_net(skb->sk); 1163 1164 WARN_ON(!net); 1165 1166 if (net) 1167 seg6_push_hmac(net, saddr, sr_phdr); 1168 } 1169 #endif 1170 1171 sr_phdr->nexthdr = proto; 1172 return NEXTHDR_ROUTING; 1173 } 1174 1175 static u8 ipv6_push_rthdr(struct sk_buff *skb, u8 proto, 1176 struct ipv6_rt_hdr *opt, 1177 struct in6_addr **addr_p, struct in6_addr *saddr) 1178 { 1179 switch (opt->type) { 1180 case IPV6_SRCRT_TYPE_0: 1181 case IPV6_SRCRT_STRICT: 1182 case IPV6_SRCRT_TYPE_2: 1183 proto = ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1184 break; 1185 case IPV6_SRCRT_TYPE_4: 1186 proto = ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1187 break; 1188 default: 1189 break; 1190 } 1191 return proto; 1192 } 1193 1194 static u8 ipv6_push_exthdr(struct sk_buff *skb, u8 proto, u8 type, struct ipv6_opt_hdr *opt) 1195 { 1196 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1197 1198 memcpy(h, opt, ipv6_optlen(opt)); 1199 h->nexthdr = proto; 1200 return type; 1201 } 1202 1203 u8 ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1204 u8 proto, 1205 struct in6_addr **daddr, struct in6_addr *saddr) 1206 { 1207 if (opt->srcrt) { 1208 proto = ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1209 /* 1210 * IPV6_RTHDRDSTOPTS is ignored 1211 * unless IPV6_RTHDR is set (RFC3542). 1212 */ 1213 if (opt->dst0opt) 1214 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1215 } 1216 if (opt->hopopt) 1217 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1218 return proto; 1219 } 1220 1221 u8 ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 proto) 1222 { 1223 if (opt->dst1opt) 1224 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1225 return proto; 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_kmemdup(sk, opt, opt->tot_len, GFP_ATOMIC); 1235 if (opt2) { 1236 long dif = (char *)opt2 - (char *)opt; 1237 if (opt2->hopopt) 1238 *((char **)&opt2->hopopt) += dif; 1239 if (opt2->dst0opt) 1240 *((char **)&opt2->dst0opt) += dif; 1241 if (opt2->dst1opt) 1242 *((char **)&opt2->dst1opt) += dif; 1243 if (opt2->srcrt) 1244 *((char **)&opt2->srcrt) += dif; 1245 refcount_set(&opt2->refcnt, 1); 1246 } 1247 return opt2; 1248 } 1249 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1250 1251 static void ipv6_renew_option(int renewtype, 1252 struct ipv6_opt_hdr **dest, 1253 struct ipv6_opt_hdr *old, 1254 struct ipv6_opt_hdr *new, 1255 int newtype, char **p) 1256 { 1257 struct ipv6_opt_hdr *src; 1258 1259 src = (renewtype == newtype ? new : old); 1260 if (!src) 1261 return; 1262 1263 memcpy(*p, src, ipv6_optlen(src)); 1264 *dest = (struct ipv6_opt_hdr *)*p; 1265 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1266 } 1267 1268 /** 1269 * ipv6_renew_options - replace a specific ext hdr with a new one. 1270 * 1271 * @sk: sock from which to allocate memory 1272 * @opt: original options 1273 * @newtype: option type to replace in @opt 1274 * @newopt: new option of type @newtype to replace (user-mem) 1275 * 1276 * Returns a new set of options which is a copy of @opt with the 1277 * option type @newtype replaced with @newopt. 1278 * 1279 * @opt may be NULL, in which case a new set of options is returned 1280 * containing just @newopt. 1281 * 1282 * @newopt may be NULL, in which case the specified option type is 1283 * not copied into the new set of options. 1284 * 1285 * The new set of options is allocated from the socket option memory 1286 * buffer of @sk. 1287 */ 1288 struct ipv6_txoptions * 1289 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1290 int newtype, struct ipv6_opt_hdr *newopt) 1291 { 1292 int tot_len = 0; 1293 char *p; 1294 struct ipv6_txoptions *opt2; 1295 1296 if (opt) { 1297 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1298 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1299 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1300 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1301 if (newtype != IPV6_RTHDR && opt->srcrt) 1302 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1303 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1304 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1305 } 1306 1307 if (newopt) 1308 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1309 1310 if (!tot_len) 1311 return NULL; 1312 1313 tot_len += sizeof(*opt2); 1314 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1315 if (!opt2) 1316 return ERR_PTR(-ENOBUFS); 1317 1318 memset(opt2, 0, tot_len); 1319 refcount_set(&opt2->refcnt, 1); 1320 opt2->tot_len = tot_len; 1321 p = (char *)(opt2 + 1); 1322 1323 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1324 (opt ? opt->hopopt : NULL), 1325 newopt, newtype, &p); 1326 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1327 (opt ? opt->dst0opt : NULL), 1328 newopt, newtype, &p); 1329 ipv6_renew_option(IPV6_RTHDR, 1330 (struct ipv6_opt_hdr **)&opt2->srcrt, 1331 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1332 newopt, newtype, &p); 1333 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1334 (opt ? opt->dst1opt : NULL), 1335 newopt, newtype, &p); 1336 1337 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1338 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1339 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1340 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1341 1342 return opt2; 1343 } 1344 1345 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1346 struct ipv6_txoptions *opt) 1347 { 1348 /* 1349 * ignore the dest before srcrt unless srcrt is being included. 1350 * --yoshfuji 1351 */ 1352 if (opt->dst0opt && !opt->srcrt) { 1353 if (opt_space != opt) { 1354 memcpy(opt_space, opt, sizeof(*opt_space)); 1355 opt = opt_space; 1356 } 1357 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1358 opt->dst0opt = NULL; 1359 } 1360 1361 return opt; 1362 } 1363 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1364 1365 /** 1366 * __fl6_update_dst - update flowi destination address with info given 1367 * by srcrt option, if any. 1368 * 1369 * @fl6: flowi6 for which daddr is to be updated 1370 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1371 * @orig: copy of original daddr address if modified 1372 * 1373 * Return: NULL if no srcrt or invalid srcrt type, otherwise returns orig 1374 * and initial value of fl6->daddr set in orig 1375 */ 1376 struct in6_addr *__fl6_update_dst(struct flowi6 *fl6, 1377 const struct ipv6_txoptions *opt, 1378 struct in6_addr *orig) 1379 { 1380 if (!opt->srcrt) 1381 return NULL; 1382 1383 *orig = fl6->daddr; 1384 1385 switch (opt->srcrt->type) { 1386 case IPV6_SRCRT_TYPE_0: 1387 case IPV6_SRCRT_STRICT: 1388 case IPV6_SRCRT_TYPE_2: 1389 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1390 break; 1391 case IPV6_SRCRT_TYPE_4: 1392 { 1393 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1394 1395 fl6->daddr = srh->segments[srh->segments_left]; 1396 break; 1397 } 1398 default: 1399 return NULL; 1400 } 1401 1402 return orig; 1403 } 1404 EXPORT_SYMBOL_GPL(__fl6_update_dst); 1405