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 #include <linux/export.h> 34 35 #include <net/dst.h> 36 #include <net/sock.h> 37 #include <net/snmp.h> 38 39 #include <net/ipv6.h> 40 #include <net/protocol.h> 41 #include <net/transp_v6.h> 42 #include <net/rawv6.h> 43 #include <net/ndisc.h> 44 #include <net/ip6_route.h> 45 #include <net/addrconf.h> 46 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 47 #include <net/xfrm.h> 48 #endif 49 50 #include <asm/uaccess.h> 51 52 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type) 53 { 54 const unsigned char *nh = skb_network_header(skb); 55 int packet_len = skb->tail - skb->network_header; 56 struct ipv6_opt_hdr *hdr; 57 int len; 58 59 if (offset + 2 > packet_len) 60 goto bad; 61 hdr = (struct ipv6_opt_hdr *)(nh + offset); 62 len = ((hdr->hdrlen + 1) << 3); 63 64 if (offset + len > packet_len) 65 goto bad; 66 67 offset += 2; 68 len -= 2; 69 70 while (len > 0) { 71 int opttype = nh[offset]; 72 int optlen; 73 74 if (opttype == type) 75 return offset; 76 77 switch (opttype) { 78 case IPV6_TLV_PAD0: 79 optlen = 1; 80 break; 81 default: 82 optlen = nh[offset + 1] + 2; 83 if (optlen > len) 84 goto bad; 85 break; 86 } 87 offset += optlen; 88 len -= optlen; 89 } 90 /* not_found */ 91 bad: 92 return -1; 93 } 94 EXPORT_SYMBOL_GPL(ipv6_find_tlv); 95 96 /* 97 * Parsing tlv encoded headers. 98 * 99 * Parsing function "func" returns 1, if parsing succeed 100 * and 0, if it failed. 101 * It MUST NOT touch skb->h. 102 */ 103 104 struct tlvtype_proc { 105 int type; 106 int (*func)(struct sk_buff *skb, int offset); 107 }; 108 109 /********************* 110 Generic functions 111 *********************/ 112 113 /* An unknown option is detected, decide what to do */ 114 115 static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff) 116 { 117 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 118 case 0: /* ignore */ 119 return 1; 120 121 case 1: /* drop packet */ 122 break; 123 124 case 3: /* Send ICMP if not a multicast address and drop packet */ 125 /* Actually, it is redundant check. icmp_send 126 will recheck in any case. 127 */ 128 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 129 break; 130 case 2: /* send ICMP PARM PROB regardless and drop packet */ 131 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); 132 return 0; 133 } 134 135 kfree_skb(skb); 136 return 0; 137 } 138 139 /* Parse tlv encoded option header (hop-by-hop or destination) */ 140 141 static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) 142 { 143 struct tlvtype_proc *curr; 144 const unsigned char *nh = skb_network_header(skb); 145 int off = skb_network_header_len(skb); 146 int len = (skb_transport_header(skb)[1] + 1) << 3; 147 148 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 149 goto bad; 150 151 off += 2; 152 len -= 2; 153 154 while (len > 0) { 155 int optlen = nh[off + 1] + 2; 156 157 switch (nh[off]) { 158 case IPV6_TLV_PAD0: 159 optlen = 1; 160 break; 161 162 case IPV6_TLV_PADN: 163 break; 164 165 default: /* Other TLV code so scan list */ 166 if (optlen > len) 167 goto bad; 168 for (curr=procs; curr->type >= 0; curr++) { 169 if (curr->type == nh[off]) { 170 /* type specific length/alignment 171 checks will be performed in the 172 func(). */ 173 if (curr->func(skb, off) == 0) 174 return 0; 175 break; 176 } 177 } 178 if (curr->type < 0) { 179 if (ip6_tlvopt_unknown(skb, off) == 0) 180 return 0; 181 } 182 break; 183 } 184 off += optlen; 185 len -= optlen; 186 } 187 if (len == 0) 188 return 1; 189 bad: 190 kfree_skb(skb); 191 return 0; 192 } 193 194 /***************************** 195 Destination options header. 196 *****************************/ 197 198 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 199 static int ipv6_dest_hao(struct sk_buff *skb, int optoff) 200 { 201 struct ipv6_destopt_hao *hao; 202 struct inet6_skb_parm *opt = IP6CB(skb); 203 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 204 struct in6_addr tmp_addr; 205 int ret; 206 207 if (opt->dsthao) { 208 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); 209 goto discard; 210 } 211 opt->dsthao = opt->dst1; 212 opt->dst1 = 0; 213 214 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 215 216 if (hao->length != 16) { 217 LIMIT_NETDEBUG( 218 KERN_DEBUG "hao invalid option length = %d\n", hao->length); 219 goto discard; 220 } 221 222 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 223 LIMIT_NETDEBUG( 224 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr); 225 goto discard; 226 } 227 228 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 229 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 230 if (unlikely(ret < 0)) 231 goto discard; 232 233 if (skb_cloned(skb)) { 234 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 235 goto discard; 236 237 /* update all variable using below by copied skbuff */ 238 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 239 optoff); 240 ipv6h = ipv6_hdr(skb); 241 } 242 243 if (skb->ip_summed == CHECKSUM_COMPLETE) 244 skb->ip_summed = CHECKSUM_NONE; 245 246 ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); 247 ipv6_addr_copy(&ipv6h->saddr, &hao->addr); 248 ipv6_addr_copy(&hao->addr, &tmp_addr); 249 250 if (skb->tstamp.tv64 == 0) 251 __net_timestamp(skb); 252 253 return 1; 254 255 discard: 256 kfree_skb(skb); 257 return 0; 258 } 259 #endif 260 261 static struct tlvtype_proc tlvprocdestopt_lst[] = { 262 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 263 { 264 .type = IPV6_TLV_HAO, 265 .func = ipv6_dest_hao, 266 }, 267 #endif 268 {-1, NULL} 269 }; 270 271 static int ipv6_destopt_rcv(struct sk_buff *skb) 272 { 273 struct inet6_skb_parm *opt = IP6CB(skb); 274 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 275 __u16 dstbuf; 276 #endif 277 struct dst_entry *dst = skb_dst(skb); 278 279 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 280 !pskb_may_pull(skb, (skb_transport_offset(skb) + 281 ((skb_transport_header(skb)[1] + 1) << 3)))) { 282 IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst), 283 IPSTATS_MIB_INHDRERRORS); 284 kfree_skb(skb); 285 return -1; 286 } 287 288 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 289 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 290 dstbuf = opt->dst1; 291 #endif 292 293 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { 294 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 295 opt = IP6CB(skb); 296 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 297 opt->nhoff = dstbuf; 298 #else 299 opt->nhoff = opt->dst1; 300 #endif 301 return 1; 302 } 303 304 IP6_INC_STATS_BH(dev_net(dst->dev), 305 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 306 return -1; 307 } 308 309 /******************************** 310 Routing header. 311 ********************************/ 312 313 /* called with rcu_read_lock() */ 314 static int ipv6_rthdr_rcv(struct sk_buff *skb) 315 { 316 struct inet6_skb_parm *opt = IP6CB(skb); 317 struct in6_addr *addr = NULL; 318 struct in6_addr daddr; 319 struct inet6_dev *idev; 320 int n, i; 321 struct ipv6_rt_hdr *hdr; 322 struct rt0_hdr *rthdr; 323 struct net *net = dev_net(skb->dev); 324 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 325 326 idev = __in6_dev_get(skb->dev); 327 if (idev && accept_source_route > idev->cnf.accept_source_route) 328 accept_source_route = idev->cnf.accept_source_route; 329 330 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 331 !pskb_may_pull(skb, (skb_transport_offset(skb) + 332 ((skb_transport_header(skb)[1] + 1) << 3)))) { 333 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 334 IPSTATS_MIB_INHDRERRORS); 335 kfree_skb(skb); 336 return -1; 337 } 338 339 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 340 341 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 342 skb->pkt_type != PACKET_HOST) { 343 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 344 IPSTATS_MIB_INADDRERRORS); 345 kfree_skb(skb); 346 return -1; 347 } 348 349 looped_back: 350 if (hdr->segments_left == 0) { 351 switch (hdr->type) { 352 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 353 case IPV6_SRCRT_TYPE_2: 354 /* Silently discard type 2 header unless it was 355 * processed by own 356 */ 357 if (!addr) { 358 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 359 IPSTATS_MIB_INADDRERRORS); 360 kfree_skb(skb); 361 return -1; 362 } 363 break; 364 #endif 365 default: 366 break; 367 } 368 369 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 370 skb->transport_header += (hdr->hdrlen + 1) << 3; 371 opt->dst0 = opt->dst1; 372 opt->dst1 = 0; 373 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 374 return 1; 375 } 376 377 switch (hdr->type) { 378 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 379 case IPV6_SRCRT_TYPE_2: 380 if (accept_source_route < 0) 381 goto unknown_rh; 382 /* Silently discard invalid RTH type 2 */ 383 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 384 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 385 IPSTATS_MIB_INHDRERRORS); 386 kfree_skb(skb); 387 return -1; 388 } 389 break; 390 #endif 391 default: 392 goto unknown_rh; 393 } 394 395 /* 396 * This is the routing header forwarding algorithm from 397 * RFC 2460, page 16. 398 */ 399 400 n = hdr->hdrlen >> 1; 401 402 if (hdr->segments_left > n) { 403 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 404 IPSTATS_MIB_INHDRERRORS); 405 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 406 ((&hdr->segments_left) - 407 skb_network_header(skb))); 408 return -1; 409 } 410 411 /* We are about to mangle packet header. Be careful! 412 Do not damage packets queued somewhere. 413 */ 414 if (skb_cloned(skb)) { 415 /* the copy is a forwarded packet */ 416 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 417 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 418 IPSTATS_MIB_OUTDISCARDS); 419 kfree_skb(skb); 420 return -1; 421 } 422 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 423 } 424 425 if (skb->ip_summed == CHECKSUM_COMPLETE) 426 skb->ip_summed = CHECKSUM_NONE; 427 428 i = n - --hdr->segments_left; 429 430 rthdr = (struct rt0_hdr *) hdr; 431 addr = rthdr->addr; 432 addr += i - 1; 433 434 switch (hdr->type) { 435 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 436 case IPV6_SRCRT_TYPE_2: 437 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 438 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 439 IPPROTO_ROUTING) < 0) { 440 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 441 IPSTATS_MIB_INADDRERRORS); 442 kfree_skb(skb); 443 return -1; 444 } 445 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 446 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 447 IPSTATS_MIB_INADDRERRORS); 448 kfree_skb(skb); 449 return -1; 450 } 451 break; 452 #endif 453 default: 454 break; 455 } 456 457 if (ipv6_addr_is_multicast(addr)) { 458 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 459 IPSTATS_MIB_INADDRERRORS); 460 kfree_skb(skb); 461 return -1; 462 } 463 464 ipv6_addr_copy(&daddr, addr); 465 ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr); 466 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr); 467 468 skb_dst_drop(skb); 469 ip6_route_input(skb); 470 if (skb_dst(skb)->error) { 471 skb_push(skb, skb->data - skb_network_header(skb)); 472 dst_input(skb); 473 return -1; 474 } 475 476 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 477 if (ipv6_hdr(skb)->hop_limit <= 1) { 478 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 479 IPSTATS_MIB_INHDRERRORS); 480 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 481 0); 482 kfree_skb(skb); 483 return -1; 484 } 485 ipv6_hdr(skb)->hop_limit--; 486 goto looped_back; 487 } 488 489 skb_push(skb, skb->data - skb_network_header(skb)); 490 dst_input(skb); 491 return -1; 492 493 unknown_rh: 494 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 495 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 496 (&hdr->type) - skb_network_header(skb)); 497 return -1; 498 } 499 500 static const struct inet6_protocol rthdr_protocol = { 501 .handler = ipv6_rthdr_rcv, 502 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 503 }; 504 505 static const struct inet6_protocol destopt_protocol = { 506 .handler = ipv6_destopt_rcv, 507 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 508 }; 509 510 static const struct inet6_protocol nodata_protocol = { 511 .handler = dst_discard, 512 .flags = INET6_PROTO_NOPOLICY, 513 }; 514 515 int __init ipv6_exthdrs_init(void) 516 { 517 int ret; 518 519 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 520 if (ret) 521 goto out; 522 523 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 524 if (ret) 525 goto out_rthdr; 526 527 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 528 if (ret) 529 goto out_destopt; 530 531 out: 532 return ret; 533 out_rthdr: 534 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 535 out_destopt: 536 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 537 goto out; 538 }; 539 540 void ipv6_exthdrs_exit(void) 541 { 542 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 543 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 544 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 545 } 546 547 /********************************** 548 Hop-by-hop options. 549 **********************************/ 550 551 /* 552 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 553 */ 554 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) 555 { 556 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev); 557 } 558 559 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 560 { 561 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 562 } 563 564 /* Router Alert as of RFC 2711 */ 565 566 static int ipv6_hop_ra(struct sk_buff *skb, int optoff) 567 { 568 const unsigned char *nh = skb_network_header(skb); 569 570 if (nh[optoff + 1] == 2) { 571 IP6CB(skb)->ra = optoff; 572 return 1; 573 } 574 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", 575 nh[optoff + 1]); 576 kfree_skb(skb); 577 return 0; 578 } 579 580 /* Jumbo payload */ 581 582 static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 583 { 584 const unsigned char *nh = skb_network_header(skb); 585 struct net *net = ipv6_skb_net(skb); 586 u32 pkt_len; 587 588 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 589 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 590 nh[optoff+1]); 591 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 592 IPSTATS_MIB_INHDRERRORS); 593 goto drop; 594 } 595 596 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 597 if (pkt_len <= IPV6_MAXPLEN) { 598 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 599 IPSTATS_MIB_INHDRERRORS); 600 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 601 return 0; 602 } 603 if (ipv6_hdr(skb)->payload_len) { 604 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 605 IPSTATS_MIB_INHDRERRORS); 606 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 607 return 0; 608 } 609 610 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 611 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 612 IPSTATS_MIB_INTRUNCATEDPKTS); 613 goto drop; 614 } 615 616 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 617 goto drop; 618 619 return 1; 620 621 drop: 622 kfree_skb(skb); 623 return 0; 624 } 625 626 static struct tlvtype_proc tlvprochopopt_lst[] = { 627 { 628 .type = IPV6_TLV_ROUTERALERT, 629 .func = ipv6_hop_ra, 630 }, 631 { 632 .type = IPV6_TLV_JUMBO, 633 .func = ipv6_hop_jumbo, 634 }, 635 { -1, } 636 }; 637 638 int ipv6_parse_hopopts(struct sk_buff *skb) 639 { 640 struct inet6_skb_parm *opt = IP6CB(skb); 641 642 /* 643 * skb_network_header(skb) is equal to skb->data, and 644 * skb_network_header_len(skb) is always equal to 645 * sizeof(struct ipv6hdr) by definition of 646 * hop-by-hop options. 647 */ 648 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 649 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 650 ((skb_transport_header(skb)[1] + 1) << 3)))) { 651 kfree_skb(skb); 652 return -1; 653 } 654 655 opt->hop = sizeof(struct ipv6hdr); 656 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 657 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 658 opt = IP6CB(skb); 659 opt->nhoff = sizeof(struct ipv6hdr); 660 return 1; 661 } 662 return -1; 663 } 664 665 /* 666 * Creating outbound headers. 667 * 668 * "build" functions work when skb is filled from head to tail (datagram) 669 * "push" functions work when headers are added from tail to head (tcp) 670 * 671 * In both cases we assume, that caller reserved enough room 672 * for headers. 673 */ 674 675 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 676 struct ipv6_rt_hdr *opt, 677 struct in6_addr **addr_p) 678 { 679 struct rt0_hdr *phdr, *ihdr; 680 int hops; 681 682 ihdr = (struct rt0_hdr *) opt; 683 684 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 685 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 686 687 hops = ihdr->rt_hdr.hdrlen >> 1; 688 689 if (hops > 1) 690 memcpy(phdr->addr, ihdr->addr + 1, 691 (hops - 1) * sizeof(struct in6_addr)); 692 693 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); 694 *addr_p = ihdr->addr; 695 696 phdr->rt_hdr.nexthdr = *proto; 697 *proto = NEXTHDR_ROUTING; 698 } 699 700 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 701 { 702 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 703 704 memcpy(h, opt, ipv6_optlen(opt)); 705 h->nexthdr = *proto; 706 *proto = type; 707 } 708 709 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 710 u8 *proto, 711 struct in6_addr **daddr) 712 { 713 if (opt->srcrt) { 714 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 715 /* 716 * IPV6_RTHDRDSTOPTS is ignored 717 * unless IPV6_RTHDR is set (RFC3542). 718 */ 719 if (opt->dst0opt) 720 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 721 } 722 if (opt->hopopt) 723 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 724 } 725 726 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 727 728 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 729 { 730 if (opt->dst1opt) 731 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 732 } 733 734 struct ipv6_txoptions * 735 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 736 { 737 struct ipv6_txoptions *opt2; 738 739 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 740 if (opt2) { 741 long dif = (char*)opt2 - (char*)opt; 742 memcpy(opt2, opt, opt->tot_len); 743 if (opt2->hopopt) 744 *((char**)&opt2->hopopt) += dif; 745 if (opt2->dst0opt) 746 *((char**)&opt2->dst0opt) += dif; 747 if (opt2->dst1opt) 748 *((char**)&opt2->dst1opt) += dif; 749 if (opt2->srcrt) 750 *((char**)&opt2->srcrt) += dif; 751 } 752 return opt2; 753 } 754 755 EXPORT_SYMBOL_GPL(ipv6_dup_options); 756 757 static int ipv6_renew_option(void *ohdr, 758 struct ipv6_opt_hdr __user *newopt, int newoptlen, 759 int inherit, 760 struct ipv6_opt_hdr **hdr, 761 char **p) 762 { 763 if (inherit) { 764 if (ohdr) { 765 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 766 *hdr = (struct ipv6_opt_hdr *)*p; 767 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 768 } 769 } else { 770 if (newopt) { 771 if (copy_from_user(*p, newopt, newoptlen)) 772 return -EFAULT; 773 *hdr = (struct ipv6_opt_hdr *)*p; 774 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 775 return -EINVAL; 776 *p += CMSG_ALIGN(newoptlen); 777 } 778 } 779 return 0; 780 } 781 782 struct ipv6_txoptions * 783 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 784 int newtype, 785 struct ipv6_opt_hdr __user *newopt, int newoptlen) 786 { 787 int tot_len = 0; 788 char *p; 789 struct ipv6_txoptions *opt2; 790 int err; 791 792 if (opt) { 793 if (newtype != IPV6_HOPOPTS && opt->hopopt) 794 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 795 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 796 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 797 if (newtype != IPV6_RTHDR && opt->srcrt) 798 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 799 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 800 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 801 } 802 803 if (newopt && newoptlen) 804 tot_len += CMSG_ALIGN(newoptlen); 805 806 if (!tot_len) 807 return NULL; 808 809 tot_len += sizeof(*opt2); 810 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 811 if (!opt2) 812 return ERR_PTR(-ENOBUFS); 813 814 memset(opt2, 0, tot_len); 815 816 opt2->tot_len = tot_len; 817 p = (char *)(opt2 + 1); 818 819 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 820 newtype != IPV6_HOPOPTS, 821 &opt2->hopopt, &p); 822 if (err) 823 goto out; 824 825 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 826 newtype != IPV6_RTHDRDSTOPTS, 827 &opt2->dst0opt, &p); 828 if (err) 829 goto out; 830 831 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 832 newtype != IPV6_RTHDR, 833 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 834 if (err) 835 goto out; 836 837 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 838 newtype != IPV6_DSTOPTS, 839 &opt2->dst1opt, &p); 840 if (err) 841 goto out; 842 843 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 844 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 845 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 846 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 847 848 return opt2; 849 out: 850 sock_kfree_s(sk, opt2, opt2->tot_len); 851 return ERR_PTR(err); 852 } 853 854 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 855 struct ipv6_txoptions *opt) 856 { 857 /* 858 * ignore the dest before srcrt unless srcrt is being included. 859 * --yoshfuji 860 */ 861 if (opt && opt->dst0opt && !opt->srcrt) { 862 if (opt_space != opt) { 863 memcpy(opt_space, opt, sizeof(*opt_space)); 864 opt = opt_space; 865 } 866 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 867 opt->dst0opt = NULL; 868 } 869 870 return opt; 871 } 872 873 /** 874 * fl6_update_dst - update flowi destination address with info given 875 * by srcrt option, if any. 876 * 877 * @fl6: flowi6 for which daddr is to be updated 878 * @opt: struct ipv6_txoptions in which to look for srcrt opt 879 * @orig: copy of original daddr address if modified 880 * 881 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 882 * and initial value of fl6->daddr set in orig 883 */ 884 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 885 const struct ipv6_txoptions *opt, 886 struct in6_addr *orig) 887 { 888 if (!opt || !opt->srcrt) 889 return NULL; 890 891 ipv6_addr_copy(orig, &fl6->daddr); 892 ipv6_addr_copy(&fl6->daddr, ((struct rt0_hdr *)opt->srcrt)->addr); 893 return orig; 894 } 895 896 EXPORT_SYMBOL_GPL(fl6_update_dst); 897