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 static int ipv6_rthdr_rcv(struct sk_buff *skb) 316 { 317 struct inet6_skb_parm *opt = IP6CB(skb); 318 struct in6_addr *addr = NULL; 319 struct in6_addr daddr; 320 struct inet6_dev *idev; 321 int n, i; 322 struct ipv6_rt_hdr *hdr; 323 struct rt0_hdr *rthdr; 324 struct net *net = dev_net(skb->dev); 325 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 326 327 idev = in6_dev_get(skb->dev); 328 if (idev) { 329 if (accept_source_route > idev->cnf.accept_source_route) 330 accept_source_route = idev->cnf.accept_source_route; 331 in6_dev_put(idev); 332 } 333 334 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 335 !pskb_may_pull(skb, (skb_transport_offset(skb) + 336 ((skb_transport_header(skb)[1] + 1) << 3)))) { 337 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 338 IPSTATS_MIB_INHDRERRORS); 339 kfree_skb(skb); 340 return -1; 341 } 342 343 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 344 345 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 346 skb->pkt_type != PACKET_HOST) { 347 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 348 IPSTATS_MIB_INADDRERRORS); 349 kfree_skb(skb); 350 return -1; 351 } 352 353 looped_back: 354 if (hdr->segments_left == 0) { 355 switch (hdr->type) { 356 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 357 case IPV6_SRCRT_TYPE_2: 358 /* Silently discard type 2 header unless it was 359 * processed by own 360 */ 361 if (!addr) { 362 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 363 IPSTATS_MIB_INADDRERRORS); 364 kfree_skb(skb); 365 return -1; 366 } 367 break; 368 #endif 369 default: 370 break; 371 } 372 373 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 374 skb->transport_header += (hdr->hdrlen + 1) << 3; 375 opt->dst0 = opt->dst1; 376 opt->dst1 = 0; 377 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 378 return 1; 379 } 380 381 switch (hdr->type) { 382 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 383 case IPV6_SRCRT_TYPE_2: 384 if (accept_source_route < 0) 385 goto unknown_rh; 386 /* Silently discard invalid RTH type 2 */ 387 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 388 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 389 IPSTATS_MIB_INHDRERRORS); 390 kfree_skb(skb); 391 return -1; 392 } 393 break; 394 #endif 395 default: 396 goto unknown_rh; 397 } 398 399 /* 400 * This is the routing header forwarding algorithm from 401 * RFC 2460, page 16. 402 */ 403 404 n = hdr->hdrlen >> 1; 405 406 if (hdr->segments_left > n) { 407 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 408 IPSTATS_MIB_INHDRERRORS); 409 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 410 ((&hdr->segments_left) - 411 skb_network_header(skb))); 412 return -1; 413 } 414 415 /* We are about to mangle packet header. Be careful! 416 Do not damage packets queued somewhere. 417 */ 418 if (skb_cloned(skb)) { 419 /* the copy is a forwarded packet */ 420 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 421 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 422 IPSTATS_MIB_OUTDISCARDS); 423 kfree_skb(skb); 424 return -1; 425 } 426 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 427 } 428 429 if (skb->ip_summed == CHECKSUM_COMPLETE) 430 skb->ip_summed = CHECKSUM_NONE; 431 432 i = n - --hdr->segments_left; 433 434 rthdr = (struct rt0_hdr *) hdr; 435 addr = rthdr->addr; 436 addr += i - 1; 437 438 switch (hdr->type) { 439 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 440 case IPV6_SRCRT_TYPE_2: 441 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 442 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 443 IPPROTO_ROUTING) < 0) { 444 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 445 IPSTATS_MIB_INADDRERRORS); 446 kfree_skb(skb); 447 return -1; 448 } 449 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 450 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 451 IPSTATS_MIB_INADDRERRORS); 452 kfree_skb(skb); 453 return -1; 454 } 455 break; 456 #endif 457 default: 458 break; 459 } 460 461 if (ipv6_addr_is_multicast(addr)) { 462 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 463 IPSTATS_MIB_INADDRERRORS); 464 kfree_skb(skb); 465 return -1; 466 } 467 468 ipv6_addr_copy(&daddr, addr); 469 ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr); 470 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr); 471 472 skb_dst_drop(skb); 473 ip6_route_input(skb); 474 if (skb_dst(skb)->error) { 475 skb_push(skb, skb->data - skb_network_header(skb)); 476 dst_input(skb); 477 return -1; 478 } 479 480 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 481 if (ipv6_hdr(skb)->hop_limit <= 1) { 482 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 483 IPSTATS_MIB_INHDRERRORS); 484 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 485 0); 486 kfree_skb(skb); 487 return -1; 488 } 489 ipv6_hdr(skb)->hop_limit--; 490 goto looped_back; 491 } 492 493 skb_push(skb, skb->data - skb_network_header(skb)); 494 dst_input(skb); 495 return -1; 496 497 unknown_rh: 498 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 499 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 500 (&hdr->type) - skb_network_header(skb)); 501 return -1; 502 } 503 504 static const struct inet6_protocol rthdr_protocol = { 505 .handler = ipv6_rthdr_rcv, 506 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 507 }; 508 509 static const struct inet6_protocol destopt_protocol = { 510 .handler = ipv6_destopt_rcv, 511 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 512 }; 513 514 static const struct inet6_protocol nodata_protocol = { 515 .handler = dst_discard, 516 .flags = INET6_PROTO_NOPOLICY, 517 }; 518 519 int __init ipv6_exthdrs_init(void) 520 { 521 int ret; 522 523 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 524 if (ret) 525 goto out; 526 527 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 528 if (ret) 529 goto out_rthdr; 530 531 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 532 if (ret) 533 goto out_destopt; 534 535 out: 536 return ret; 537 out_rthdr: 538 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 539 out_destopt: 540 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 541 goto out; 542 }; 543 544 void ipv6_exthdrs_exit(void) 545 { 546 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 547 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 548 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 549 } 550 551 /********************************** 552 Hop-by-hop options. 553 **********************************/ 554 555 /* 556 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 557 */ 558 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) 559 { 560 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev); 561 } 562 563 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 564 { 565 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 566 } 567 568 /* Router Alert as of RFC 2711 */ 569 570 static int ipv6_hop_ra(struct sk_buff *skb, int optoff) 571 { 572 const unsigned char *nh = skb_network_header(skb); 573 574 if (nh[optoff + 1] == 2) { 575 IP6CB(skb)->ra = optoff; 576 return 1; 577 } 578 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", 579 nh[optoff + 1]); 580 kfree_skb(skb); 581 return 0; 582 } 583 584 /* Jumbo payload */ 585 586 static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 587 { 588 const unsigned char *nh = skb_network_header(skb); 589 struct net *net = ipv6_skb_net(skb); 590 u32 pkt_len; 591 592 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 593 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 594 nh[optoff+1]); 595 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 596 IPSTATS_MIB_INHDRERRORS); 597 goto drop; 598 } 599 600 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 601 if (pkt_len <= IPV6_MAXPLEN) { 602 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 603 IPSTATS_MIB_INHDRERRORS); 604 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 605 return 0; 606 } 607 if (ipv6_hdr(skb)->payload_len) { 608 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 609 IPSTATS_MIB_INHDRERRORS); 610 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 611 return 0; 612 } 613 614 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 615 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 616 IPSTATS_MIB_INTRUNCATEDPKTS); 617 goto drop; 618 } 619 620 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 621 goto drop; 622 623 return 1; 624 625 drop: 626 kfree_skb(skb); 627 return 0; 628 } 629 630 static struct tlvtype_proc tlvprochopopt_lst[] = { 631 { 632 .type = IPV6_TLV_ROUTERALERT, 633 .func = ipv6_hop_ra, 634 }, 635 { 636 .type = IPV6_TLV_JUMBO, 637 .func = ipv6_hop_jumbo, 638 }, 639 { -1, } 640 }; 641 642 int ipv6_parse_hopopts(struct sk_buff *skb) 643 { 644 struct inet6_skb_parm *opt = IP6CB(skb); 645 646 /* 647 * skb_network_header(skb) is equal to skb->data, and 648 * skb_network_header_len(skb) is always equal to 649 * sizeof(struct ipv6hdr) by definition of 650 * hop-by-hop options. 651 */ 652 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 653 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 654 ((skb_transport_header(skb)[1] + 1) << 3)))) { 655 kfree_skb(skb); 656 return -1; 657 } 658 659 opt->hop = sizeof(struct ipv6hdr); 660 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 661 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 662 opt = IP6CB(skb); 663 opt->nhoff = sizeof(struct ipv6hdr); 664 return 1; 665 } 666 return -1; 667 } 668 669 /* 670 * Creating outbound headers. 671 * 672 * "build" functions work when skb is filled from head to tail (datagram) 673 * "push" functions work when headers are added from tail to head (tcp) 674 * 675 * In both cases we assume, that caller reserved enough room 676 * for headers. 677 */ 678 679 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 680 struct ipv6_rt_hdr *opt, 681 struct in6_addr **addr_p) 682 { 683 struct rt0_hdr *phdr, *ihdr; 684 int hops; 685 686 ihdr = (struct rt0_hdr *) opt; 687 688 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 689 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 690 691 hops = ihdr->rt_hdr.hdrlen >> 1; 692 693 if (hops > 1) 694 memcpy(phdr->addr, ihdr->addr + 1, 695 (hops - 1) * sizeof(struct in6_addr)); 696 697 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); 698 *addr_p = ihdr->addr; 699 700 phdr->rt_hdr.nexthdr = *proto; 701 *proto = NEXTHDR_ROUTING; 702 } 703 704 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 705 { 706 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 707 708 memcpy(h, opt, ipv6_optlen(opt)); 709 h->nexthdr = *proto; 710 *proto = type; 711 } 712 713 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 714 u8 *proto, 715 struct in6_addr **daddr) 716 { 717 if (opt->srcrt) { 718 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 719 /* 720 * IPV6_RTHDRDSTOPTS is ignored 721 * unless IPV6_RTHDR is set (RFC3542). 722 */ 723 if (opt->dst0opt) 724 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 725 } 726 if (opt->hopopt) 727 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 728 } 729 730 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 731 732 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 733 { 734 if (opt->dst1opt) 735 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 736 } 737 738 struct ipv6_txoptions * 739 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 740 { 741 struct ipv6_txoptions *opt2; 742 743 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 744 if (opt2) { 745 long dif = (char*)opt2 - (char*)opt; 746 memcpy(opt2, opt, opt->tot_len); 747 if (opt2->hopopt) 748 *((char**)&opt2->hopopt) += dif; 749 if (opt2->dst0opt) 750 *((char**)&opt2->dst0opt) += dif; 751 if (opt2->dst1opt) 752 *((char**)&opt2->dst1opt) += dif; 753 if (opt2->srcrt) 754 *((char**)&opt2->srcrt) += dif; 755 } 756 return opt2; 757 } 758 759 EXPORT_SYMBOL_GPL(ipv6_dup_options); 760 761 static int ipv6_renew_option(void *ohdr, 762 struct ipv6_opt_hdr __user *newopt, int newoptlen, 763 int inherit, 764 struct ipv6_opt_hdr **hdr, 765 char **p) 766 { 767 if (inherit) { 768 if (ohdr) { 769 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 770 *hdr = (struct ipv6_opt_hdr *)*p; 771 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 772 } 773 } else { 774 if (newopt) { 775 if (copy_from_user(*p, newopt, newoptlen)) 776 return -EFAULT; 777 *hdr = (struct ipv6_opt_hdr *)*p; 778 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 779 return -EINVAL; 780 *p += CMSG_ALIGN(newoptlen); 781 } 782 } 783 return 0; 784 } 785 786 struct ipv6_txoptions * 787 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 788 int newtype, 789 struct ipv6_opt_hdr __user *newopt, int newoptlen) 790 { 791 int tot_len = 0; 792 char *p; 793 struct ipv6_txoptions *opt2; 794 int err; 795 796 if (opt) { 797 if (newtype != IPV6_HOPOPTS && opt->hopopt) 798 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 799 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 800 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 801 if (newtype != IPV6_RTHDR && opt->srcrt) 802 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 803 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 804 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 805 } 806 807 if (newopt && newoptlen) 808 tot_len += CMSG_ALIGN(newoptlen); 809 810 if (!tot_len) 811 return NULL; 812 813 tot_len += sizeof(*opt2); 814 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 815 if (!opt2) 816 return ERR_PTR(-ENOBUFS); 817 818 memset(opt2, 0, tot_len); 819 820 opt2->tot_len = tot_len; 821 p = (char *)(opt2 + 1); 822 823 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 824 newtype != IPV6_HOPOPTS, 825 &opt2->hopopt, &p); 826 if (err) 827 goto out; 828 829 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 830 newtype != IPV6_RTHDRDSTOPTS, 831 &opt2->dst0opt, &p); 832 if (err) 833 goto out; 834 835 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 836 newtype != IPV6_RTHDR, 837 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 838 if (err) 839 goto out; 840 841 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 842 newtype != IPV6_DSTOPTS, 843 &opt2->dst1opt, &p); 844 if (err) 845 goto out; 846 847 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 848 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 849 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 850 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 851 852 return opt2; 853 out: 854 sock_kfree_s(sk, opt2, opt2->tot_len); 855 return ERR_PTR(err); 856 } 857 858 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 859 struct ipv6_txoptions *opt) 860 { 861 /* 862 * ignore the dest before srcrt unless srcrt is being included. 863 * --yoshfuji 864 */ 865 if (opt && opt->dst0opt && !opt->srcrt) { 866 if (opt_space != opt) { 867 memcpy(opt_space, opt, sizeof(*opt_space)); 868 opt = opt_space; 869 } 870 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 871 opt->dst0opt = NULL; 872 } 873 874 return opt; 875 } 876 877