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, struct inet6_dev *idev) 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 in6_addr *addr; 377 int accept_seg6; 378 379 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 380 381 accept_seg6 = min(READ_ONCE(net->ipv6.devconf_all->seg6_enabled), 382 READ_ONCE(idev->cnf.seg6_enabled)); 383 384 if (!accept_seg6) { 385 kfree_skb(skb); 386 return -1; 387 } 388 389 #ifdef CONFIG_IPV6_SEG6_HMAC 390 if (!seg6_hmac_validate_skb(skb)) { 391 kfree_skb(skb); 392 return -1; 393 } 394 #endif 395 396 looped_back: 397 if (hdr->segments_left == 0) { 398 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 399 int offset = (hdr->hdrlen + 1) << 3; 400 401 skb_postpull_rcsum(skb, skb_network_header(skb), 402 skb_network_header_len(skb)); 403 skb_pull(skb, offset); 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 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 443 } 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 ip6_route_input(skb); 456 457 if (skb_dst(skb)->error) { 458 dst_input(skb); 459 return -1; 460 } 461 462 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 463 if (ipv6_hdr(skb)->hop_limit <= 1) { 464 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 465 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 466 ICMPV6_EXC_HOPLIMIT, 0); 467 kfree_skb(skb); 468 return -1; 469 } 470 ipv6_hdr(skb)->hop_limit--; 471 472 skb_pull(skb, sizeof(struct ipv6hdr)); 473 goto looped_back; 474 } 475 476 dst_input(skb); 477 478 return -1; 479 } 480 481 static int ipv6_rpl_srh_rcv(struct sk_buff *skb, struct inet6_dev *idev) 482 { 483 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 484 struct inet6_skb_parm *opt = IP6CB(skb); 485 struct net *net = dev_net(skb->dev); 486 struct ipv6hdr *oldhdr; 487 unsigned int chdr_len; 488 unsigned char *buf; 489 int accept_rpl_seg; 490 int i, err; 491 u64 n = 0; 492 u32 r; 493 494 accept_rpl_seg = min(READ_ONCE(net->ipv6.devconf_all->rpl_seg_enabled), 495 READ_ONCE(idev->cnf.rpl_seg_enabled)); 496 if (!accept_rpl_seg) { 497 kfree_skb(skb); 498 return -1; 499 } 500 501 looped_back: 502 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 503 504 if (hdr->segments_left == 0) { 505 if (hdr->nexthdr == NEXTHDR_IPV6) { 506 int offset = (hdr->hdrlen + 1) << 3; 507 508 skb_postpull_rcsum(skb, skb_network_header(skb), 509 skb_network_header_len(skb)); 510 skb_pull(skb, offset); 511 skb_postpull_rcsum(skb, skb_transport_header(skb), 512 offset); 513 514 skb_reset_network_header(skb); 515 skb_reset_transport_header(skb); 516 skb->encapsulation = 0; 517 518 __skb_tunnel_rx(skb, skb->dev, net); 519 520 netif_rx(skb); 521 return -1; 522 } 523 524 opt->srcrt = skb_network_header_len(skb); 525 opt->lastopt = opt->srcrt; 526 skb->transport_header += (hdr->hdrlen + 1) << 3; 527 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 528 529 return 1; 530 } 531 532 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 533 r = do_div(n, (16 - hdr->cmpri)); 534 /* checks if calculation was without remainder and n fits into 535 * unsigned char which is segments_left field. Should not be 536 * higher than that. 537 */ 538 if (r || (n + 1) > 127) { 539 kfree_skb(skb); 540 return -1; 541 } 542 543 if (hdr->segments_left > n + 1) { 544 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 545 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 546 ((&hdr->segments_left) - 547 skb_network_header(skb))); 548 return -1; 549 } 550 551 hdr->segments_left--; 552 i = n - hdr->segments_left; 553 554 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 555 if (unlikely(!buf)) { 556 kfree_skb(skb); 557 return -1; 558 } 559 560 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 561 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 562 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 563 564 if (ipv6_addr_is_multicast(&ohdr->rpl_segaddr[i])) { 565 kfree_skb(skb); 566 kfree(buf); 567 return -1; 568 } 569 570 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 571 if (err) { 572 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 573 kfree_skb(skb); 574 kfree(buf); 575 return -1; 576 } 577 578 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); 579 580 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 581 582 oldhdr = ipv6_hdr(skb); 583 584 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 585 skb_postpull_rcsum(skb, oldhdr, 586 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 587 chdr_len = sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3); 588 if (unlikely(!hdr->segments_left || 589 skb_headroom(skb) < chdr_len + skb->mac_len)) { 590 if (pskb_expand_head(skb, chdr_len + skb->mac_len, 0, 591 GFP_ATOMIC)) { 592 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); 593 kfree_skb(skb); 594 kfree(buf); 595 return -1; 596 } 597 598 oldhdr = ipv6_hdr(skb); 599 } 600 skb_push(skb, chdr_len); 601 skb_reset_network_header(skb); 602 skb_mac_header_rebuild(skb); 603 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 604 605 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 606 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 607 608 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 609 skb_postpush_rcsum(skb, ipv6_hdr(skb), 610 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 611 612 kfree(buf); 613 614 ip6_route_input(skb); 615 616 if (skb_dst(skb)->error) { 617 dst_input(skb); 618 return -1; 619 } 620 621 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 622 if (ipv6_hdr(skb)->hop_limit <= 1) { 623 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 624 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 625 ICMPV6_EXC_HOPLIMIT, 0); 626 kfree_skb(skb); 627 return -1; 628 } 629 ipv6_hdr(skb)->hop_limit--; 630 631 skb_pull(skb, sizeof(struct ipv6hdr)); 632 goto looped_back; 633 } 634 635 dst_input(skb); 636 637 return -1; 638 } 639 640 /******************************** 641 Routing header. 642 ********************************/ 643 644 /* called with rcu_read_lock() */ 645 static int ipv6_rthdr_rcv(struct sk_buff *skb) 646 { 647 struct inet6_dev *idev = __in6_dev_get(skb->dev); 648 struct inet6_skb_parm *opt = IP6CB(skb); 649 struct in6_addr *addr = NULL; 650 int n, i; 651 struct ipv6_rt_hdr *hdr; 652 struct rt0_hdr *rthdr; 653 struct net *net = dev_net(skb->dev); 654 int accept_source_route; 655 656 accept_source_route = READ_ONCE(net->ipv6.devconf_all->accept_source_route); 657 658 if (idev) 659 accept_source_route = min(accept_source_route, 660 READ_ONCE(idev->cnf.accept_source_route)); 661 662 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 663 !pskb_may_pull(skb, (skb_transport_offset(skb) + 664 ((skb_transport_header(skb)[1] + 1) << 3)))) { 665 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 666 kfree_skb(skb); 667 return -1; 668 } 669 670 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 671 672 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 673 skb->pkt_type != PACKET_HOST) { 674 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 675 kfree_skb(skb); 676 return -1; 677 } 678 679 switch (hdr->type) { 680 case IPV6_SRCRT_TYPE_4: 681 /* segment routing */ 682 if (!idev) 683 goto disabled; 684 return ipv6_srh_rcv(skb, idev); 685 case IPV6_SRCRT_TYPE_3: 686 /* rpl segment routing */ 687 if (!idev) 688 goto disabled; 689 return ipv6_rpl_srh_rcv(skb, idev); 690 default: 691 break; 692 } 693 694 looped_back: 695 if (hdr->segments_left == 0) { 696 switch (hdr->type) { 697 #if IS_ENABLED(CONFIG_IPV6_MIP6) 698 case IPV6_SRCRT_TYPE_2: 699 /* Silently discard type 2 header unless it was 700 * processed by own 701 */ 702 if (!addr) { 703 __IP6_INC_STATS(net, idev, 704 IPSTATS_MIB_INADDRERRORS); 705 kfree_skb(skb); 706 return -1; 707 } 708 break; 709 #endif 710 default: 711 break; 712 } 713 714 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 715 skb->transport_header += (hdr->hdrlen + 1) << 3; 716 opt->dst0 = opt->dst1; 717 opt->dst1 = 0; 718 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 719 return 1; 720 } 721 722 switch (hdr->type) { 723 #if IS_ENABLED(CONFIG_IPV6_MIP6) 724 case IPV6_SRCRT_TYPE_2: 725 if (accept_source_route < 0) 726 goto unknown_rh; 727 /* Silently discard invalid RTH type 2 */ 728 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 729 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 730 kfree_skb(skb); 731 return -1; 732 } 733 break; 734 #endif 735 default: 736 goto unknown_rh; 737 } 738 739 /* 740 * This is the routing header forwarding algorithm from 741 * RFC 2460, page 16. 742 */ 743 744 n = hdr->hdrlen >> 1; 745 746 if (hdr->segments_left > n) { 747 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 748 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 749 ((&hdr->segments_left) - 750 skb_network_header(skb))); 751 return -1; 752 } 753 754 /* We are about to mangle packet header. Be careful! 755 Do not damage packets queued somewhere. 756 */ 757 if (skb_cloned(skb)) { 758 /* the copy is a forwarded packet */ 759 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 760 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 761 IPSTATS_MIB_OUTDISCARDS); 762 kfree_skb(skb); 763 return -1; 764 } 765 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 766 } 767 768 if (skb->ip_summed == CHECKSUM_COMPLETE) 769 skb->ip_summed = CHECKSUM_NONE; 770 771 i = n - --hdr->segments_left; 772 773 rthdr = (struct rt0_hdr *) hdr; 774 addr = rthdr->addr; 775 addr += i - 1; 776 777 switch (hdr->type) { 778 #if IS_ENABLED(CONFIG_IPV6_MIP6) 779 case IPV6_SRCRT_TYPE_2: 780 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 781 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 782 IPPROTO_ROUTING) < 0) { 783 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 784 kfree_skb(skb); 785 return -1; 786 } 787 if (!ipv6_chk_home_addr(skb_dst_dev_net(skb), addr)) { 788 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 789 kfree_skb(skb); 790 return -1; 791 } 792 break; 793 #endif 794 default: 795 break; 796 } 797 798 if (ipv6_addr_is_multicast(addr)) { 799 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 800 kfree_skb(skb); 801 return -1; 802 } 803 804 swap(*addr, ipv6_hdr(skb)->daddr); 805 806 ip6_route_input(skb); 807 if (skb_dst(skb)->error) { 808 skb_push(skb, -skb_network_offset(skb)); 809 dst_input(skb); 810 return -1; 811 } 812 813 if (skb_dst_dev(skb)->flags & IFF_LOOPBACK) { 814 if (ipv6_hdr(skb)->hop_limit <= 1) { 815 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 816 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 817 0); 818 kfree_skb(skb); 819 return -1; 820 } 821 ipv6_hdr(skb)->hop_limit--; 822 goto looped_back; 823 } 824 825 skb_push(skb, -skb_network_offset(skb)); 826 dst_input(skb); 827 return -1; 828 829 unknown_rh: 830 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 831 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 832 (&hdr->type) - skb_network_header(skb)); 833 return -1; 834 835 disabled: 836 kfree_skb_reason(skb, SKB_DROP_REASON_IPV6DISABLED); 837 return -1; 838 } 839 840 static const struct inet6_protocol rthdr_protocol = { 841 .handler = ipv6_rthdr_rcv, 842 .flags = INET6_PROTO_NOPOLICY, 843 }; 844 845 static const struct inet6_protocol destopt_protocol = { 846 .handler = ipv6_destopt_rcv, 847 .flags = INET6_PROTO_NOPOLICY, 848 }; 849 850 static const struct inet6_protocol nodata_protocol = { 851 .handler = dst_discard, 852 .flags = INET6_PROTO_NOPOLICY, 853 }; 854 855 int __init ipv6_exthdrs_init(void) 856 { 857 int ret; 858 859 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 860 if (ret) 861 goto out; 862 863 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 864 if (ret) 865 goto out_rthdr; 866 867 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 868 if (ret) 869 goto out_destopt; 870 871 out: 872 return ret; 873 out_destopt: 874 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 875 out_rthdr: 876 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 877 goto out; 878 }; 879 880 void ipv6_exthdrs_exit(void) 881 { 882 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 883 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 884 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 885 } 886 887 /********************************** 888 Hop-by-hop options. 889 **********************************/ 890 891 /* Router Alert as of RFC 2711 */ 892 893 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 894 { 895 const unsigned char *nh = skb_network_header(skb); 896 897 if (nh[optoff + 1] == 2) { 898 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 899 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 900 return true; 901 } 902 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 903 nh[optoff + 1]); 904 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 905 return false; 906 } 907 908 /* IOAM */ 909 910 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 911 { 912 enum skb_drop_reason drop_reason; 913 struct ioam6_trace_hdr *trace; 914 struct ioam6_namespace *ns; 915 struct inet6_dev *idev; 916 struct ioam6_hdr *hdr; 917 918 drop_reason = SKB_DROP_REASON_IP_INHDR; 919 920 /* Bad alignment (must be 4n-aligned) */ 921 if (optoff & 3) 922 goto drop; 923 924 /* Does the device still have IPv6 configuration? */ 925 idev = __in6_dev_get(skb->dev); 926 if (!idev) { 927 drop_reason = SKB_DROP_REASON_IPV6DISABLED; 928 goto drop; 929 } 930 931 /* Ignore if IOAM is not enabled on ingress */ 932 if (!READ_ONCE(idev->cnf.ioam6_enabled)) 933 goto ignore; 934 935 /* Truncated Option header */ 936 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 937 if (hdr->opt_len < 2) 938 goto drop; 939 940 switch (hdr->type) { 941 case IOAM6_TYPE_PREALLOC: 942 /* Truncated Pre-allocated Trace header */ 943 if (hdr->opt_len < 2 + sizeof(*trace)) 944 goto drop; 945 946 /* Malformed Pre-allocated Trace header */ 947 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 948 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 949 goto drop; 950 951 /* Inconsistent Pre-allocated Trace header */ 952 if (trace->nodelen != 953 ioam6_trace_compute_nodelen(be32_to_cpu(trace->type_be32))) 954 goto drop; 955 956 /* Ignore if the IOAM namespace is unknown */ 957 ns = ioam6_namespace(dev_net(skb->dev), trace->namespace_id); 958 if (!ns) 959 goto ignore; 960 961 if (!skb_valid_dst(skb)) 962 ip6_route_input(skb); 963 964 /* About to mangle packet header */ 965 if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) 966 goto drop; 967 968 /* Trace and hdr pointers may have changed */ 969 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 970 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 971 972 ioam6_fill_trace_data(skb, ns, trace, true); 973 974 ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev), 975 GFP_ATOMIC, (void *)trace, hdr->opt_len - 2); 976 break; 977 default: 978 break; 979 } 980 981 ignore: 982 return true; 983 984 drop: 985 kfree_skb_reason(skb, drop_reason); 986 return false; 987 } 988 989 /* Jumbo payload */ 990 991 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 992 { 993 const unsigned char *nh = skb_network_header(skb); 994 SKB_DR(reason); 995 u32 pkt_len; 996 997 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 998 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 999 nh[optoff+1]); 1000 SKB_DR_SET(reason, IP_INHDR); 1001 goto drop; 1002 } 1003 1004 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1005 if (pkt_len <= IPV6_MAXPLEN) { 1006 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, 1007 SKB_DROP_REASON_IP_INHDR); 1008 return false; 1009 } 1010 if (ipv6_hdr(skb)->payload_len) { 1011 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff, 1012 SKB_DROP_REASON_IP_INHDR); 1013 return false; 1014 } 1015 1016 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1017 SKB_DR_SET(reason, PKT_TOO_SMALL); 1018 goto drop; 1019 } 1020 1021 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1022 goto drop; 1023 1024 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1025 return true; 1026 1027 drop: 1028 kfree_skb_reason(skb, reason); 1029 return false; 1030 } 1031 1032 /* CALIPSO RFC 5570 */ 1033 1034 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1035 { 1036 const unsigned char *nh = skb_network_header(skb); 1037 1038 if (nh[optoff + 1] < 8) 1039 goto drop; 1040 1041 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1042 goto drop; 1043 1044 if (!calipso_validate(skb, nh + optoff)) 1045 goto drop; 1046 1047 return true; 1048 1049 drop: 1050 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 1051 return false; 1052 } 1053 1054 int ipv6_parse_hopopts(struct sk_buff *skb) 1055 { 1056 struct inet6_skb_parm *opt = IP6CB(skb); 1057 struct net *net = dev_net(skb->dev); 1058 int extlen; 1059 1060 /* 1061 * skb_network_header(skb) is equal to skb->data, and 1062 * skb_network_header_len(skb) is always equal to 1063 * sizeof(struct ipv6hdr) by definition of 1064 * hop-by-hop options. 1065 */ 1066 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1067 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1068 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1069 fail_and_free: 1070 kfree_skb(skb); 1071 return -1; 1072 } 1073 1074 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1075 if (extlen > READ_ONCE(net->ipv6.sysctl.max_hbh_opts_len)) 1076 goto fail_and_free; 1077 1078 opt->flags |= IP6SKB_HOPBYHOP; 1079 if (ip6_parse_tlv(true, skb, 1080 READ_ONCE(net->ipv6.sysctl.max_hbh_opts_cnt))) { 1081 skb->transport_header += extlen; 1082 opt = IP6CB(skb); 1083 opt->nhoff = sizeof(struct ipv6hdr); 1084 return 1; 1085 } 1086 return -1; 1087 } 1088 1089 /* 1090 * Creating outbound headers. 1091 * 1092 * "build" functions work when skb is filled from head to tail (datagram) 1093 * "push" functions work when headers are added from tail to head (tcp) 1094 * 1095 * In both cases we assume, that caller reserved enough room 1096 * for headers. 1097 */ 1098 1099 static u8 ipv6_push_rthdr0(struct sk_buff *skb, u8 proto, 1100 struct ipv6_rt_hdr *opt, 1101 struct in6_addr **addr_p, struct in6_addr *saddr) 1102 { 1103 struct rt0_hdr *phdr, *ihdr; 1104 int hops; 1105 1106 ihdr = (struct rt0_hdr *) opt; 1107 1108 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1109 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1110 1111 hops = ihdr->rt_hdr.hdrlen >> 1; 1112 1113 if (hops > 1) 1114 memcpy(phdr->addr, ihdr->addr + 1, 1115 (hops - 1) * sizeof(struct in6_addr)); 1116 1117 phdr->addr[hops - 1] = **addr_p; 1118 *addr_p = ihdr->addr; 1119 1120 phdr->rt_hdr.nexthdr = proto; 1121 return NEXTHDR_ROUTING; 1122 } 1123 1124 static u8 ipv6_push_rthdr4(struct sk_buff *skb, u8 proto, 1125 struct ipv6_rt_hdr *opt, 1126 struct in6_addr **addr_p, struct in6_addr *saddr) 1127 { 1128 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1129 int plen, hops; 1130 1131 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1132 plen = (sr_ihdr->hdrlen + 1) << 3; 1133 1134 sr_phdr = skb_push(skb, plen); 1135 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1136 1137 hops = sr_ihdr->first_segment + 1; 1138 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1139 (hops - 1) * sizeof(struct in6_addr)); 1140 1141 sr_phdr->segments[0] = **addr_p; 1142 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1143 1144 if (sr_ihdr->hdrlen > hops * 2) { 1145 int tlvs_offset, tlvs_length; 1146 1147 tlvs_offset = (1 + hops * 2) << 3; 1148 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1149 memcpy((char *)sr_phdr + tlvs_offset, 1150 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1151 } 1152 1153 #ifdef CONFIG_IPV6_SEG6_HMAC 1154 if (sr_has_hmac(sr_phdr)) { 1155 struct net *net = NULL; 1156 1157 if (skb->dev) 1158 net = dev_net(skb->dev); 1159 else if (skb->sk) 1160 net = sock_net(skb->sk); 1161 1162 WARN_ON(!net); 1163 1164 if (net) 1165 seg6_push_hmac(net, saddr, sr_phdr); 1166 } 1167 #endif 1168 1169 sr_phdr->nexthdr = proto; 1170 return NEXTHDR_ROUTING; 1171 } 1172 1173 static u8 ipv6_push_rthdr(struct sk_buff *skb, u8 proto, 1174 struct ipv6_rt_hdr *opt, 1175 struct in6_addr **addr_p, struct in6_addr *saddr) 1176 { 1177 switch (opt->type) { 1178 case IPV6_SRCRT_TYPE_0: 1179 case IPV6_SRCRT_STRICT: 1180 case IPV6_SRCRT_TYPE_2: 1181 proto = ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1182 break; 1183 case IPV6_SRCRT_TYPE_4: 1184 proto = ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1185 break; 1186 default: 1187 break; 1188 } 1189 return proto; 1190 } 1191 1192 static u8 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 return type; 1199 } 1200 1201 u8 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 proto = 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 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1213 } 1214 if (opt->hopopt) 1215 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1216 return proto; 1217 } 1218 1219 u8 ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 proto) 1220 { 1221 if (opt->dst1opt) 1222 proto = ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1223 return proto; 1224 } 1225 EXPORT_SYMBOL(ipv6_push_frag_opts); 1226 1227 struct ipv6_txoptions * 1228 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1229 { 1230 struct ipv6_txoptions *opt2; 1231 1232 opt2 = sock_kmemdup(sk, opt, opt->tot_len, GFP_ATOMIC); 1233 if (opt2) { 1234 long dif = (char *)opt2 - (char *)opt; 1235 if (opt2->hopopt) 1236 *((char **)&opt2->hopopt) += dif; 1237 if (opt2->dst0opt) 1238 *((char **)&opt2->dst0opt) += dif; 1239 if (opt2->dst1opt) 1240 *((char **)&opt2->dst1opt) += dif; 1241 if (opt2->srcrt) 1242 *((char **)&opt2->srcrt) += dif; 1243 refcount_set(&opt2->refcnt, 1); 1244 } 1245 return opt2; 1246 } 1247 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1248 1249 static void ipv6_renew_option(int renewtype, 1250 struct ipv6_opt_hdr **dest, 1251 struct ipv6_opt_hdr *old, 1252 struct ipv6_opt_hdr *new, 1253 int newtype, char **p) 1254 { 1255 struct ipv6_opt_hdr *src; 1256 1257 src = (renewtype == newtype ? new : old); 1258 if (!src) 1259 return; 1260 1261 memcpy(*p, src, ipv6_optlen(src)); 1262 *dest = (struct ipv6_opt_hdr *)*p; 1263 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1264 } 1265 1266 /** 1267 * ipv6_renew_options - replace a specific ext hdr with a new one. 1268 * 1269 * @sk: sock from which to allocate memory 1270 * @opt: original options 1271 * @newtype: option type to replace in @opt 1272 * @newopt: new option of type @newtype to replace (user-mem) 1273 * 1274 * Returns a new set of options which is a copy of @opt with the 1275 * option type @newtype replaced with @newopt. 1276 * 1277 * @opt may be NULL, in which case a new set of options is returned 1278 * containing just @newopt. 1279 * 1280 * @newopt may be NULL, in which case the specified option type is 1281 * not copied into the new set of options. 1282 * 1283 * The new set of options is allocated from the socket option memory 1284 * buffer of @sk. 1285 */ 1286 struct ipv6_txoptions * 1287 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1288 int newtype, struct ipv6_opt_hdr *newopt) 1289 { 1290 int tot_len = 0; 1291 char *p; 1292 struct ipv6_txoptions *opt2; 1293 1294 if (opt) { 1295 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1296 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1297 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1298 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1299 if (newtype != IPV6_RTHDR && opt->srcrt) 1300 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1301 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1302 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1303 } 1304 1305 if (newopt) 1306 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1307 1308 if (!tot_len) 1309 return NULL; 1310 1311 tot_len += sizeof(*opt2); 1312 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1313 if (!opt2) 1314 return ERR_PTR(-ENOBUFS); 1315 1316 memset(opt2, 0, tot_len); 1317 refcount_set(&opt2->refcnt, 1); 1318 opt2->tot_len = tot_len; 1319 p = (char *)(opt2 + 1); 1320 1321 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1322 (opt ? opt->hopopt : NULL), 1323 newopt, newtype, &p); 1324 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1325 (opt ? opt->dst0opt : NULL), 1326 newopt, newtype, &p); 1327 ipv6_renew_option(IPV6_RTHDR, 1328 (struct ipv6_opt_hdr **)&opt2->srcrt, 1329 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1330 newopt, newtype, &p); 1331 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1332 (opt ? opt->dst1opt : NULL), 1333 newopt, newtype, &p); 1334 1335 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1336 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1337 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1338 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1339 1340 return opt2; 1341 } 1342 1343 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1344 struct ipv6_txoptions *opt) 1345 { 1346 /* 1347 * ignore the dest before srcrt unless srcrt is being included. 1348 * --yoshfuji 1349 */ 1350 if (opt->dst0opt && !opt->srcrt) { 1351 if (opt_space != opt) { 1352 memcpy(opt_space, opt, sizeof(*opt_space)); 1353 opt = opt_space; 1354 } 1355 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1356 opt->dst0opt = NULL; 1357 } 1358 1359 return opt; 1360 } 1361 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1362 1363 /** 1364 * __fl6_update_dst - update flowi destination address with info given 1365 * by srcrt option, if any. 1366 * 1367 * @fl6: flowi6 for which daddr is to be updated 1368 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1369 * @orig: copy of original daddr address if modified 1370 * 1371 * Return: NULL if no srcrt or invalid srcrt type, otherwise returns orig 1372 * and initial value of fl6->daddr set in orig 1373 */ 1374 struct in6_addr *__fl6_update_dst(struct flowi6 *fl6, 1375 const struct ipv6_txoptions *opt, 1376 struct in6_addr *orig) 1377 { 1378 if (!opt->srcrt) 1379 return NULL; 1380 1381 *orig = fl6->daddr; 1382 1383 switch (opt->srcrt->type) { 1384 case IPV6_SRCRT_TYPE_0: 1385 case IPV6_SRCRT_STRICT: 1386 case IPV6_SRCRT_TYPE_2: 1387 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1388 break; 1389 case IPV6_SRCRT_TYPE_4: 1390 { 1391 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1392 1393 fl6->daddr = srh->segments[srh->segments_left]; 1394 break; 1395 } 1396 default: 1397 return NULL; 1398 } 1399 1400 return orig; 1401 } 1402 EXPORT_SYMBOL_GPL(__fl6_update_dst); 1403