1 /* 2 * Extension Header handling for IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Andi Kleen <ak@muc.de> 8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 /* Changes: 17 * yoshfuji : ensure not to overrun while parsing 18 * tlv options. 19 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). 20 * YOSHIFUJI Hideaki @USAGI Register inbound extension header 21 * handlers as inet6_protocol{}. 22 */ 23 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/netdevice.h> 30 #include <linux/in6.h> 31 #include <linux/icmpv6.h> 32 #include <linux/slab.h> 33 34 #include <net/dst.h> 35 #include <net/sock.h> 36 #include <net/snmp.h> 37 38 #include <net/ipv6.h> 39 #include <net/protocol.h> 40 #include <net/transp_v6.h> 41 #include <net/rawv6.h> 42 #include <net/ndisc.h> 43 #include <net/ip6_route.h> 44 #include <net/addrconf.h> 45 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 46 #include <net/xfrm.h> 47 #endif 48 49 #include <asm/uaccess.h> 50 51 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type) 52 { 53 const unsigned char *nh = skb_network_header(skb); 54 int packet_len = skb->tail - skb->network_header; 55 struct ipv6_opt_hdr *hdr; 56 int len; 57 58 if (offset + 2 > packet_len) 59 goto bad; 60 hdr = (struct ipv6_opt_hdr *)(nh + offset); 61 len = ((hdr->hdrlen + 1) << 3); 62 63 if (offset + len > packet_len) 64 goto bad; 65 66 offset += 2; 67 len -= 2; 68 69 while (len > 0) { 70 int opttype = nh[offset]; 71 int optlen; 72 73 if (opttype == type) 74 return offset; 75 76 switch (opttype) { 77 case IPV6_TLV_PAD0: 78 optlen = 1; 79 break; 80 default: 81 optlen = nh[offset + 1] + 2; 82 if (optlen > len) 83 goto bad; 84 break; 85 } 86 offset += optlen; 87 len -= optlen; 88 } 89 /* not_found */ 90 bad: 91 return -1; 92 } 93 EXPORT_SYMBOL_GPL(ipv6_find_tlv); 94 95 /* 96 * Parsing tlv encoded headers. 97 * 98 * Parsing function "func" returns 1, if parsing succeed 99 * and 0, if it failed. 100 * It MUST NOT touch skb->h. 101 */ 102 103 struct tlvtype_proc { 104 int type; 105 int (*func)(struct sk_buff *skb, int offset); 106 }; 107 108 /********************* 109 Generic functions 110 *********************/ 111 112 /* An unknown option is detected, decide what to do */ 113 114 static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff) 115 { 116 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 117 case 0: /* ignore */ 118 return 1; 119 120 case 1: /* drop packet */ 121 break; 122 123 case 3: /* Send ICMP if not a multicast address and drop packet */ 124 /* Actually, it is redundant check. icmp_send 125 will recheck in any case. 126 */ 127 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 128 break; 129 case 2: /* send ICMP PARM PROB regardless and drop packet */ 130 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); 131 return 0; 132 } 133 134 kfree_skb(skb); 135 return 0; 136 } 137 138 /* Parse tlv encoded option header (hop-by-hop or destination) */ 139 140 static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) 141 { 142 struct tlvtype_proc *curr; 143 const unsigned char *nh = skb_network_header(skb); 144 int off = skb_network_header_len(skb); 145 int len = (skb_transport_header(skb)[1] + 1) << 3; 146 147 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 148 goto bad; 149 150 off += 2; 151 len -= 2; 152 153 while (len > 0) { 154 int optlen = nh[off + 1] + 2; 155 156 switch (nh[off]) { 157 case IPV6_TLV_PAD0: 158 optlen = 1; 159 break; 160 161 case IPV6_TLV_PADN: 162 break; 163 164 default: /* Other TLV code so scan list */ 165 if (optlen > len) 166 goto bad; 167 for (curr=procs; curr->type >= 0; curr++) { 168 if (curr->type == nh[off]) { 169 /* type specific length/alignment 170 checks will be performed in the 171 func(). */ 172 if (curr->func(skb, off) == 0) 173 return 0; 174 break; 175 } 176 } 177 if (curr->type < 0) { 178 if (ip6_tlvopt_unknown(skb, off) == 0) 179 return 0; 180 } 181 break; 182 } 183 off += optlen; 184 len -= optlen; 185 } 186 if (len == 0) 187 return 1; 188 bad: 189 kfree_skb(skb); 190 return 0; 191 } 192 193 /***************************** 194 Destination options header. 195 *****************************/ 196 197 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 198 static int ipv6_dest_hao(struct sk_buff *skb, int optoff) 199 { 200 struct ipv6_destopt_hao *hao; 201 struct inet6_skb_parm *opt = IP6CB(skb); 202 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 203 struct in6_addr tmp_addr; 204 int ret; 205 206 if (opt->dsthao) { 207 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); 208 goto discard; 209 } 210 opt->dsthao = opt->dst1; 211 opt->dst1 = 0; 212 213 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 214 215 if (hao->length != 16) { 216 LIMIT_NETDEBUG( 217 KERN_DEBUG "hao invalid option length = %d\n", hao->length); 218 goto discard; 219 } 220 221 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 222 LIMIT_NETDEBUG( 223 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr); 224 goto discard; 225 } 226 227 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 228 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 229 if (unlikely(ret < 0)) 230 goto discard; 231 232 if (skb_cloned(skb)) { 233 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 234 goto discard; 235 236 /* update all variable using below by copied skbuff */ 237 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 238 optoff); 239 ipv6h = ipv6_hdr(skb); 240 } 241 242 if (skb->ip_summed == CHECKSUM_COMPLETE) 243 skb->ip_summed = CHECKSUM_NONE; 244 245 ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); 246 ipv6_addr_copy(&ipv6h->saddr, &hao->addr); 247 ipv6_addr_copy(&hao->addr, &tmp_addr); 248 249 if (skb->tstamp.tv64 == 0) 250 __net_timestamp(skb); 251 252 return 1; 253 254 discard: 255 kfree_skb(skb); 256 return 0; 257 } 258 #endif 259 260 static struct tlvtype_proc tlvprocdestopt_lst[] = { 261 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 262 { 263 .type = IPV6_TLV_HAO, 264 .func = ipv6_dest_hao, 265 }, 266 #endif 267 {-1, NULL} 268 }; 269 270 static int ipv6_destopt_rcv(struct sk_buff *skb) 271 { 272 struct inet6_skb_parm *opt = IP6CB(skb); 273 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 274 __u16 dstbuf; 275 #endif 276 struct dst_entry *dst; 277 278 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 279 !pskb_may_pull(skb, (skb_transport_offset(skb) + 280 ((skb_transport_header(skb)[1] + 1) << 3)))) { 281 IP6_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)), 282 IPSTATS_MIB_INHDRERRORS); 283 kfree_skb(skb); 284 return -1; 285 } 286 287 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 288 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 289 dstbuf = opt->dst1; 290 #endif 291 292 dst = dst_clone(skb_dst(skb)); 293 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { 294 dst_release(dst); 295 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 296 opt = IP6CB(skb); 297 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 298 opt->nhoff = dstbuf; 299 #else 300 opt->nhoff = opt->dst1; 301 #endif 302 return 1; 303 } 304 305 IP6_INC_STATS_BH(dev_net(dst->dev), 306 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 307 dst_release(dst); 308 return -1; 309 } 310 311 /******************************** 312 Routing header. 313 ********************************/ 314 315 /* called with rcu_read_lock() */ 316 static int ipv6_rthdr_rcv(struct sk_buff *skb) 317 { 318 struct inet6_skb_parm *opt = IP6CB(skb); 319 struct in6_addr *addr = NULL; 320 struct in6_addr daddr; 321 struct inet6_dev *idev; 322 int n, i; 323 struct ipv6_rt_hdr *hdr; 324 struct rt0_hdr *rthdr; 325 struct net *net = dev_net(skb->dev); 326 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 327 328 idev = __in6_dev_get(skb->dev); 329 if (idev && accept_source_route > idev->cnf.accept_source_route) 330 accept_source_route = idev->cnf.accept_source_route; 331 332 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 333 !pskb_may_pull(skb, (skb_transport_offset(skb) + 334 ((skb_transport_header(skb)[1] + 1) << 3)))) { 335 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 336 IPSTATS_MIB_INHDRERRORS); 337 kfree_skb(skb); 338 return -1; 339 } 340 341 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 342 343 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 344 skb->pkt_type != PACKET_HOST) { 345 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 346 IPSTATS_MIB_INADDRERRORS); 347 kfree_skb(skb); 348 return -1; 349 } 350 351 looped_back: 352 if (hdr->segments_left == 0) { 353 switch (hdr->type) { 354 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 355 case IPV6_SRCRT_TYPE_2: 356 /* Silently discard type 2 header unless it was 357 * processed by own 358 */ 359 if (!addr) { 360 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 361 IPSTATS_MIB_INADDRERRORS); 362 kfree_skb(skb); 363 return -1; 364 } 365 break; 366 #endif 367 default: 368 break; 369 } 370 371 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 372 skb->transport_header += (hdr->hdrlen + 1) << 3; 373 opt->dst0 = opt->dst1; 374 opt->dst1 = 0; 375 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 376 return 1; 377 } 378 379 switch (hdr->type) { 380 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 381 case IPV6_SRCRT_TYPE_2: 382 if (accept_source_route < 0) 383 goto unknown_rh; 384 /* Silently discard invalid RTH type 2 */ 385 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 386 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 387 IPSTATS_MIB_INHDRERRORS); 388 kfree_skb(skb); 389 return -1; 390 } 391 break; 392 #endif 393 default: 394 goto unknown_rh; 395 } 396 397 /* 398 * This is the routing header forwarding algorithm from 399 * RFC 2460, page 16. 400 */ 401 402 n = hdr->hdrlen >> 1; 403 404 if (hdr->segments_left > n) { 405 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 406 IPSTATS_MIB_INHDRERRORS); 407 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 408 ((&hdr->segments_left) - 409 skb_network_header(skb))); 410 return -1; 411 } 412 413 /* We are about to mangle packet header. Be careful! 414 Do not damage packets queued somewhere. 415 */ 416 if (skb_cloned(skb)) { 417 /* the copy is a forwarded packet */ 418 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 419 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 420 IPSTATS_MIB_OUTDISCARDS); 421 kfree_skb(skb); 422 return -1; 423 } 424 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 425 } 426 427 if (skb->ip_summed == CHECKSUM_COMPLETE) 428 skb->ip_summed = CHECKSUM_NONE; 429 430 i = n - --hdr->segments_left; 431 432 rthdr = (struct rt0_hdr *) hdr; 433 addr = rthdr->addr; 434 addr += i - 1; 435 436 switch (hdr->type) { 437 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 438 case IPV6_SRCRT_TYPE_2: 439 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 440 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 441 IPPROTO_ROUTING) < 0) { 442 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 443 IPSTATS_MIB_INADDRERRORS); 444 kfree_skb(skb); 445 return -1; 446 } 447 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 448 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 449 IPSTATS_MIB_INADDRERRORS); 450 kfree_skb(skb); 451 return -1; 452 } 453 break; 454 #endif 455 default: 456 break; 457 } 458 459 if (ipv6_addr_is_multicast(addr)) { 460 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 461 IPSTATS_MIB_INADDRERRORS); 462 kfree_skb(skb); 463 return -1; 464 } 465 466 ipv6_addr_copy(&daddr, addr); 467 ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr); 468 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr); 469 470 skb_dst_drop(skb); 471 ip6_route_input(skb); 472 if (skb_dst(skb)->error) { 473 skb_push(skb, skb->data - skb_network_header(skb)); 474 dst_input(skb); 475 return -1; 476 } 477 478 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 479 if (ipv6_hdr(skb)->hop_limit <= 1) { 480 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 481 IPSTATS_MIB_INHDRERRORS); 482 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 483 0); 484 kfree_skb(skb); 485 return -1; 486 } 487 ipv6_hdr(skb)->hop_limit--; 488 goto looped_back; 489 } 490 491 skb_push(skb, skb->data - skb_network_header(skb)); 492 dst_input(skb); 493 return -1; 494 495 unknown_rh: 496 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 497 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 498 (&hdr->type) - skb_network_header(skb)); 499 return -1; 500 } 501 502 static const struct inet6_protocol rthdr_protocol = { 503 .handler = ipv6_rthdr_rcv, 504 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 505 }; 506 507 static const struct inet6_protocol destopt_protocol = { 508 .handler = ipv6_destopt_rcv, 509 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 510 }; 511 512 static const struct inet6_protocol nodata_protocol = { 513 .handler = dst_discard, 514 .flags = INET6_PROTO_NOPOLICY, 515 }; 516 517 int __init ipv6_exthdrs_init(void) 518 { 519 int ret; 520 521 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 522 if (ret) 523 goto out; 524 525 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 526 if (ret) 527 goto out_rthdr; 528 529 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 530 if (ret) 531 goto out_destopt; 532 533 out: 534 return ret; 535 out_rthdr: 536 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 537 out_destopt: 538 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 539 goto out; 540 }; 541 542 void ipv6_exthdrs_exit(void) 543 { 544 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 545 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 546 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 547 } 548 549 /********************************** 550 Hop-by-hop options. 551 **********************************/ 552 553 /* 554 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 555 */ 556 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) 557 { 558 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev); 559 } 560 561 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 562 { 563 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 564 } 565 566 /* Router Alert as of RFC 2711 */ 567 568 static int ipv6_hop_ra(struct sk_buff *skb, int optoff) 569 { 570 const unsigned char *nh = skb_network_header(skb); 571 572 if (nh[optoff + 1] == 2) { 573 IP6CB(skb)->ra = optoff; 574 return 1; 575 } 576 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", 577 nh[optoff + 1]); 578 kfree_skb(skb); 579 return 0; 580 } 581 582 /* Jumbo payload */ 583 584 static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 585 { 586 const unsigned char *nh = skb_network_header(skb); 587 struct net *net = ipv6_skb_net(skb); 588 u32 pkt_len; 589 590 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 591 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 592 nh[optoff+1]); 593 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 594 IPSTATS_MIB_INHDRERRORS); 595 goto drop; 596 } 597 598 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 599 if (pkt_len <= IPV6_MAXPLEN) { 600 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 601 IPSTATS_MIB_INHDRERRORS); 602 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 603 return 0; 604 } 605 if (ipv6_hdr(skb)->payload_len) { 606 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 607 IPSTATS_MIB_INHDRERRORS); 608 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 609 return 0; 610 } 611 612 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 613 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 614 IPSTATS_MIB_INTRUNCATEDPKTS); 615 goto drop; 616 } 617 618 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 619 goto drop; 620 621 return 1; 622 623 drop: 624 kfree_skb(skb); 625 return 0; 626 } 627 628 static struct tlvtype_proc tlvprochopopt_lst[] = { 629 { 630 .type = IPV6_TLV_ROUTERALERT, 631 .func = ipv6_hop_ra, 632 }, 633 { 634 .type = IPV6_TLV_JUMBO, 635 .func = ipv6_hop_jumbo, 636 }, 637 { -1, } 638 }; 639 640 int ipv6_parse_hopopts(struct sk_buff *skb) 641 { 642 struct inet6_skb_parm *opt = IP6CB(skb); 643 644 /* 645 * skb_network_header(skb) is equal to skb->data, and 646 * skb_network_header_len(skb) is always equal to 647 * sizeof(struct ipv6hdr) by definition of 648 * hop-by-hop options. 649 */ 650 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 651 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 652 ((skb_transport_header(skb)[1] + 1) << 3)))) { 653 kfree_skb(skb); 654 return -1; 655 } 656 657 opt->hop = sizeof(struct ipv6hdr); 658 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 659 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 660 opt = IP6CB(skb); 661 opt->nhoff = sizeof(struct ipv6hdr); 662 return 1; 663 } 664 return -1; 665 } 666 667 /* 668 * Creating outbound headers. 669 * 670 * "build" functions work when skb is filled from head to tail (datagram) 671 * "push" functions work when headers are added from tail to head (tcp) 672 * 673 * In both cases we assume, that caller reserved enough room 674 * for headers. 675 */ 676 677 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 678 struct ipv6_rt_hdr *opt, 679 struct in6_addr **addr_p) 680 { 681 struct rt0_hdr *phdr, *ihdr; 682 int hops; 683 684 ihdr = (struct rt0_hdr *) opt; 685 686 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 687 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 688 689 hops = ihdr->rt_hdr.hdrlen >> 1; 690 691 if (hops > 1) 692 memcpy(phdr->addr, ihdr->addr + 1, 693 (hops - 1) * sizeof(struct in6_addr)); 694 695 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); 696 *addr_p = ihdr->addr; 697 698 phdr->rt_hdr.nexthdr = *proto; 699 *proto = NEXTHDR_ROUTING; 700 } 701 702 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 703 { 704 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 705 706 memcpy(h, opt, ipv6_optlen(opt)); 707 h->nexthdr = *proto; 708 *proto = type; 709 } 710 711 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 712 u8 *proto, 713 struct in6_addr **daddr) 714 { 715 if (opt->srcrt) { 716 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 717 /* 718 * IPV6_RTHDRDSTOPTS is ignored 719 * unless IPV6_RTHDR is set (RFC3542). 720 */ 721 if (opt->dst0opt) 722 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 723 } 724 if (opt->hopopt) 725 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 726 } 727 728 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 729 730 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 731 { 732 if (opt->dst1opt) 733 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 734 } 735 736 struct ipv6_txoptions * 737 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 738 { 739 struct ipv6_txoptions *opt2; 740 741 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 742 if (opt2) { 743 long dif = (char*)opt2 - (char*)opt; 744 memcpy(opt2, opt, opt->tot_len); 745 if (opt2->hopopt) 746 *((char**)&opt2->hopopt) += dif; 747 if (opt2->dst0opt) 748 *((char**)&opt2->dst0opt) += dif; 749 if (opt2->dst1opt) 750 *((char**)&opt2->dst1opt) += dif; 751 if (opt2->srcrt) 752 *((char**)&opt2->srcrt) += dif; 753 } 754 return opt2; 755 } 756 757 EXPORT_SYMBOL_GPL(ipv6_dup_options); 758 759 static int ipv6_renew_option(void *ohdr, 760 struct ipv6_opt_hdr __user *newopt, int newoptlen, 761 int inherit, 762 struct ipv6_opt_hdr **hdr, 763 char **p) 764 { 765 if (inherit) { 766 if (ohdr) { 767 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 768 *hdr = (struct ipv6_opt_hdr *)*p; 769 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 770 } 771 } else { 772 if (newopt) { 773 if (copy_from_user(*p, newopt, newoptlen)) 774 return -EFAULT; 775 *hdr = (struct ipv6_opt_hdr *)*p; 776 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 777 return -EINVAL; 778 *p += CMSG_ALIGN(newoptlen); 779 } 780 } 781 return 0; 782 } 783 784 struct ipv6_txoptions * 785 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 786 int newtype, 787 struct ipv6_opt_hdr __user *newopt, int newoptlen) 788 { 789 int tot_len = 0; 790 char *p; 791 struct ipv6_txoptions *opt2; 792 int err; 793 794 if (opt) { 795 if (newtype != IPV6_HOPOPTS && opt->hopopt) 796 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 797 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 798 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 799 if (newtype != IPV6_RTHDR && opt->srcrt) 800 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 801 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 802 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 803 } 804 805 if (newopt && newoptlen) 806 tot_len += CMSG_ALIGN(newoptlen); 807 808 if (!tot_len) 809 return NULL; 810 811 tot_len += sizeof(*opt2); 812 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 813 if (!opt2) 814 return ERR_PTR(-ENOBUFS); 815 816 memset(opt2, 0, tot_len); 817 818 opt2->tot_len = tot_len; 819 p = (char *)(opt2 + 1); 820 821 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 822 newtype != IPV6_HOPOPTS, 823 &opt2->hopopt, &p); 824 if (err) 825 goto out; 826 827 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 828 newtype != IPV6_RTHDRDSTOPTS, 829 &opt2->dst0opt, &p); 830 if (err) 831 goto out; 832 833 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 834 newtype != IPV6_RTHDR, 835 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 836 if (err) 837 goto out; 838 839 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 840 newtype != IPV6_DSTOPTS, 841 &opt2->dst1opt, &p); 842 if (err) 843 goto out; 844 845 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 846 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 847 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 848 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 849 850 return opt2; 851 out: 852 sock_kfree_s(sk, opt2, opt2->tot_len); 853 return ERR_PTR(err); 854 } 855 856 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 857 struct ipv6_txoptions *opt) 858 { 859 /* 860 * ignore the dest before srcrt unless srcrt is being included. 861 * --yoshfuji 862 */ 863 if (opt && opt->dst0opt && !opt->srcrt) { 864 if (opt_space != opt) { 865 memcpy(opt_space, opt, sizeof(*opt_space)); 866 opt = opt_space; 867 } 868 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 869 opt->dst0opt = NULL; 870 } 871 872 return opt; 873 } 874 875 /** 876 * fl6_update_dst - update flowi destination address with info given 877 * by srcrt option, if any. 878 * 879 * @fl: flowi for which fl6_dst is to be updated 880 * @opt: struct ipv6_txoptions in which to look for srcrt opt 881 * @orig: copy of original fl6_dst address if modified 882 * 883 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 884 * and initial value of fl->fl6_dst set in orig 885 */ 886 struct in6_addr *fl6_update_dst(struct flowi *fl, 887 const struct ipv6_txoptions *opt, 888 struct in6_addr *orig) 889 { 890 if (!opt || !opt->srcrt) 891 return NULL; 892 893 ipv6_addr_copy(orig, &fl->fl6_dst); 894 ipv6_addr_copy(&fl->fl6_dst, ((struct rt0_hdr *)opt->srcrt)->addr); 895 return orig; 896 } 897 898 EXPORT_SYMBOL_GPL(fl6_update_dst); 899