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 33 #include <net/dst.h> 34 #include <net/sock.h> 35 #include <net/snmp.h> 36 37 #include <net/ipv6.h> 38 #include <net/protocol.h> 39 #include <net/transp_v6.h> 40 #include <net/rawv6.h> 41 #include <net/ndisc.h> 42 #include <net/ip6_route.h> 43 #include <net/addrconf.h> 44 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 45 #include <net/xfrm.h> 46 #endif 47 48 #include <asm/uaccess.h> 49 50 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type) 51 { 52 const unsigned char *nh = skb_network_header(skb); 53 int packet_len = skb->tail - skb->network_header; 54 struct ipv6_opt_hdr *hdr; 55 int len; 56 57 if (offset + 2 > packet_len) 58 goto bad; 59 hdr = (struct ipv6_opt_hdr *)(nh + offset); 60 len = ((hdr->hdrlen + 1) << 3); 61 62 if (offset + len > packet_len) 63 goto bad; 64 65 offset += 2; 66 len -= 2; 67 68 while (len > 0) { 69 int opttype = nh[offset]; 70 int optlen; 71 72 if (opttype == type) 73 return offset; 74 75 switch (opttype) { 76 case IPV6_TLV_PAD0: 77 optlen = 1; 78 break; 79 default: 80 optlen = nh[offset + 1] + 2; 81 if (optlen > len) 82 goto bad; 83 break; 84 } 85 offset += optlen; 86 len -= optlen; 87 } 88 /* not_found */ 89 bad: 90 return -1; 91 } 92 EXPORT_SYMBOL_GPL(ipv6_find_tlv); 93 94 /* 95 * Parsing tlv encoded headers. 96 * 97 * Parsing function "func" returns 1, if parsing succeed 98 * and 0, if it failed. 99 * It MUST NOT touch skb->h. 100 */ 101 102 struct tlvtype_proc { 103 int type; 104 int (*func)(struct sk_buff *skb, int offset); 105 }; 106 107 /********************* 108 Generic functions 109 *********************/ 110 111 /* An unknown option is detected, decide what to do */ 112 113 static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff) 114 { 115 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 116 case 0: /* ignore */ 117 return 1; 118 119 case 1: /* drop packet */ 120 break; 121 122 case 3: /* Send ICMP if not a multicast address and drop packet */ 123 /* Actually, it is redundant check. icmp_send 124 will recheck in any case. 125 */ 126 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 127 break; 128 case 2: /* send ICMP PARM PROB regardless and drop packet */ 129 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); 130 return 0; 131 } 132 133 kfree_skb(skb); 134 return 0; 135 } 136 137 /* Parse tlv encoded option header (hop-by-hop or destination) */ 138 139 static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) 140 { 141 struct tlvtype_proc *curr; 142 const unsigned char *nh = skb_network_header(skb); 143 int off = skb_network_header_len(skb); 144 int len = (skb_transport_header(skb)[1] + 1) << 3; 145 146 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 147 goto bad; 148 149 off += 2; 150 len -= 2; 151 152 while (len > 0) { 153 int optlen = nh[off + 1] + 2; 154 155 switch (nh[off]) { 156 case IPV6_TLV_PAD0: 157 optlen = 1; 158 break; 159 160 case IPV6_TLV_PADN: 161 break; 162 163 default: /* Other TLV code so scan list */ 164 if (optlen > len) 165 goto bad; 166 for (curr=procs; curr->type >= 0; curr++) { 167 if (curr->type == nh[off]) { 168 /* type specific length/alignment 169 checks will be performed in the 170 func(). */ 171 if (curr->func(skb, off) == 0) 172 return 0; 173 break; 174 } 175 } 176 if (curr->type < 0) { 177 if (ip6_tlvopt_unknown(skb, off) == 0) 178 return 0; 179 } 180 break; 181 } 182 off += optlen; 183 len -= optlen; 184 } 185 if (len == 0) 186 return 1; 187 bad: 188 kfree_skb(skb); 189 return 0; 190 } 191 192 /***************************** 193 Destination options header. 194 *****************************/ 195 196 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 197 static int ipv6_dest_hao(struct sk_buff *skb, int optoff) 198 { 199 struct ipv6_destopt_hao *hao; 200 struct inet6_skb_parm *opt = IP6CB(skb); 201 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 202 struct in6_addr tmp_addr; 203 int ret; 204 205 if (opt->dsthao) { 206 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); 207 goto discard; 208 } 209 opt->dsthao = opt->dst1; 210 opt->dst1 = 0; 211 212 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 213 214 if (hao->length != 16) { 215 LIMIT_NETDEBUG( 216 KERN_DEBUG "hao invalid option length = %d\n", hao->length); 217 goto discard; 218 } 219 220 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 221 LIMIT_NETDEBUG( 222 KERN_DEBUG "hao is not an unicast addr: " NIP6_FMT "\n", NIP6(hao->addr)); 223 goto discard; 224 } 225 226 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 227 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 228 if (unlikely(ret < 0)) 229 goto discard; 230 231 if (skb_cloned(skb)) { 232 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 233 goto discard; 234 235 /* update all variable using below by copied skbuff */ 236 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 237 optoff); 238 ipv6h = ipv6_hdr(skb); 239 } 240 241 if (skb->ip_summed == CHECKSUM_COMPLETE) 242 skb->ip_summed = CHECKSUM_NONE; 243 244 ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); 245 ipv6_addr_copy(&ipv6h->saddr, &hao->addr); 246 ipv6_addr_copy(&hao->addr, &tmp_addr); 247 248 if (skb->tstamp.tv64 == 0) 249 __net_timestamp(skb); 250 251 return 1; 252 253 discard: 254 kfree_skb(skb); 255 return 0; 256 } 257 #endif 258 259 static struct tlvtype_proc tlvprocdestopt_lst[] = { 260 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 261 { 262 .type = IPV6_TLV_HAO, 263 .func = ipv6_dest_hao, 264 }, 265 #endif 266 {-1, NULL} 267 }; 268 269 static int ipv6_destopt_rcv(struct sk_buff *skb) 270 { 271 struct inet6_skb_parm *opt = IP6CB(skb); 272 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 273 __u16 dstbuf; 274 #endif 275 struct dst_entry *dst; 276 277 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 278 !pskb_may_pull(skb, (skb_transport_offset(skb) + 279 ((skb_transport_header(skb)[1] + 1) << 3)))) { 280 IP6_INC_STATS_BH(dev_net(skb->dst->dev), ip6_dst_idev(skb->dst), 281 IPSTATS_MIB_INHDRERRORS); 282 kfree_skb(skb); 283 return -1; 284 } 285 286 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 287 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 288 dstbuf = opt->dst1; 289 #endif 290 291 dst = dst_clone(skb->dst); 292 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { 293 dst_release(dst); 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 dst_release(dst); 307 return -1; 308 } 309 310 /******************************** 311 Routing header. 312 ********************************/ 313 314 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) { 328 if (accept_source_route > idev->cnf.accept_source_route) 329 accept_source_route = idev->cnf.accept_source_route; 330 in6_dev_put(idev); 331 } 332 333 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 334 !pskb_may_pull(skb, (skb_transport_offset(skb) + 335 ((skb_transport_header(skb)[1] + 1) << 3)))) { 336 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 337 IPSTATS_MIB_INHDRERRORS); 338 kfree_skb(skb); 339 return -1; 340 } 341 342 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 343 344 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 345 skb->pkt_type != PACKET_HOST) { 346 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 347 IPSTATS_MIB_INADDRERRORS); 348 kfree_skb(skb); 349 return -1; 350 } 351 352 looped_back: 353 if (hdr->segments_left == 0) { 354 switch (hdr->type) { 355 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 356 case IPV6_SRCRT_TYPE_2: 357 /* Silently discard type 2 header unless it was 358 * processed by own 359 */ 360 if (!addr) { 361 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 362 IPSTATS_MIB_INADDRERRORS); 363 kfree_skb(skb); 364 return -1; 365 } 366 break; 367 #endif 368 default: 369 break; 370 } 371 372 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 373 skb->transport_header += (hdr->hdrlen + 1) << 3; 374 opt->dst0 = opt->dst1; 375 opt->dst1 = 0; 376 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 377 return 1; 378 } 379 380 switch (hdr->type) { 381 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 382 case IPV6_SRCRT_TYPE_2: 383 if (accept_source_route < 0) 384 goto unknown_rh; 385 /* Silently discard invalid RTH type 2 */ 386 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 387 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 388 IPSTATS_MIB_INHDRERRORS); 389 kfree_skb(skb); 390 return -1; 391 } 392 break; 393 #endif 394 default: 395 goto unknown_rh; 396 } 397 398 /* 399 * This is the routing header forwarding algorithm from 400 * RFC 2460, page 16. 401 */ 402 403 n = hdr->hdrlen >> 1; 404 405 if (hdr->segments_left > n) { 406 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 407 IPSTATS_MIB_INHDRERRORS); 408 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 409 ((&hdr->segments_left) - 410 skb_network_header(skb))); 411 return -1; 412 } 413 414 /* We are about to mangle packet header. Be careful! 415 Do not damage packets queued somewhere. 416 */ 417 if (skb_cloned(skb)) { 418 /* the copy is a forwarded packet */ 419 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 420 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 421 IPSTATS_MIB_OUTDISCARDS); 422 kfree_skb(skb); 423 return -1; 424 } 425 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 426 } 427 428 if (skb->ip_summed == CHECKSUM_COMPLETE) 429 skb->ip_summed = CHECKSUM_NONE; 430 431 i = n - --hdr->segments_left; 432 433 rthdr = (struct rt0_hdr *) hdr; 434 addr = rthdr->addr; 435 addr += i - 1; 436 437 switch (hdr->type) { 438 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 439 case IPV6_SRCRT_TYPE_2: 440 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 441 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 442 IPPROTO_ROUTING) < 0) { 443 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 444 IPSTATS_MIB_INADDRERRORS); 445 kfree_skb(skb); 446 return -1; 447 } 448 if (!ipv6_chk_home_addr(dev_net(skb->dst->dev), addr)) { 449 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 450 IPSTATS_MIB_INADDRERRORS); 451 kfree_skb(skb); 452 return -1; 453 } 454 break; 455 #endif 456 default: 457 break; 458 } 459 460 if (ipv6_addr_is_multicast(addr)) { 461 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 462 IPSTATS_MIB_INADDRERRORS); 463 kfree_skb(skb); 464 return -1; 465 } 466 467 ipv6_addr_copy(&daddr, addr); 468 ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr); 469 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr); 470 471 dst_release(xchg(&skb->dst, NULL)); 472 ip6_route_input(skb); 473 if (skb->dst->error) { 474 skb_push(skb, skb->data - skb_network_header(skb)); 475 dst_input(skb); 476 return -1; 477 } 478 479 if (skb->dst->dev->flags&IFF_LOOPBACK) { 480 if (ipv6_hdr(skb)->hop_limit <= 1) { 481 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), 482 IPSTATS_MIB_INHDRERRORS); 483 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 484 0, skb->dev); 485 kfree_skb(skb); 486 return -1; 487 } 488 ipv6_hdr(skb)->hop_limit--; 489 goto looped_back; 490 } 491 492 skb_push(skb, skb->data - skb_network_header(skb)); 493 dst_input(skb); 494 return -1; 495 496 unknown_rh: 497 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); 498 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 499 (&hdr->type) - skb_network_header(skb)); 500 return -1; 501 } 502 503 static struct inet6_protocol rthdr_protocol = { 504 .handler = ipv6_rthdr_rcv, 505 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 506 }; 507 508 static struct inet6_protocol destopt_protocol = { 509 .handler = ipv6_destopt_rcv, 510 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 511 }; 512 513 static struct inet6_protocol nodata_protocol = { 514 .handler = dst_discard, 515 .flags = INET6_PROTO_NOPOLICY, 516 }; 517 518 int __init ipv6_exthdrs_init(void) 519 { 520 int ret; 521 522 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 523 if (ret) 524 goto out; 525 526 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 527 if (ret) 528 goto out_rthdr; 529 530 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 531 if (ret) 532 goto out_destopt; 533 534 out: 535 return ret; 536 out_rthdr: 537 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 538 out_destopt: 539 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 540 goto out; 541 }; 542 543 void ipv6_exthdrs_exit(void) 544 { 545 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 546 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 547 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 548 } 549 550 /********************************** 551 Hop-by-hop options. 552 **********************************/ 553 554 /* 555 * Note: we cannot rely on skb->dst before we assign it in ip6_route_input(). 556 */ 557 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) 558 { 559 return skb->dst ? ip6_dst_idev(skb->dst) : __in6_dev_get(skb->dev); 560 } 561 562 /* Router Alert as of RFC 2711 */ 563 564 static int ipv6_hop_ra(struct sk_buff *skb, int optoff) 565 { 566 const unsigned char *nh = skb_network_header(skb); 567 568 if (nh[optoff + 1] == 2) { 569 IP6CB(skb)->ra = optoff; 570 return 1; 571 } 572 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", 573 nh[optoff + 1]); 574 kfree_skb(skb); 575 return 0; 576 } 577 578 /* Jumbo payload */ 579 580 static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 581 { 582 const unsigned char *nh = skb_network_header(skb); 583 u32 pkt_len; 584 struct net *net = dev_net(skb->dst->dev); 585 586 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 587 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 588 nh[optoff+1]); 589 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 590 IPSTATS_MIB_INHDRERRORS); 591 goto drop; 592 } 593 594 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 595 if (pkt_len <= IPV6_MAXPLEN) { 596 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 597 IPSTATS_MIB_INHDRERRORS); 598 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 599 return 0; 600 } 601 if (ipv6_hdr(skb)->payload_len) { 602 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 603 IPSTATS_MIB_INHDRERRORS); 604 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 605 return 0; 606 } 607 608 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 609 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 610 IPSTATS_MIB_INTRUNCATEDPKTS); 611 goto drop; 612 } 613 614 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 615 goto drop; 616 617 return 1; 618 619 drop: 620 kfree_skb(skb); 621 return 0; 622 } 623 624 static struct tlvtype_proc tlvprochopopt_lst[] = { 625 { 626 .type = IPV6_TLV_ROUTERALERT, 627 .func = ipv6_hop_ra, 628 }, 629 { 630 .type = IPV6_TLV_JUMBO, 631 .func = ipv6_hop_jumbo, 632 }, 633 { -1, } 634 }; 635 636 int ipv6_parse_hopopts(struct sk_buff *skb) 637 { 638 struct inet6_skb_parm *opt = IP6CB(skb); 639 640 /* 641 * skb_network_header(skb) is equal to skb->data, and 642 * skb_network_header_len(skb) is always equal to 643 * sizeof(struct ipv6hdr) by definition of 644 * hop-by-hop options. 645 */ 646 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 647 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 648 ((skb_transport_header(skb)[1] + 1) << 3)))) { 649 kfree_skb(skb); 650 return -1; 651 } 652 653 opt->hop = sizeof(struct ipv6hdr); 654 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 655 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 656 opt = IP6CB(skb); 657 opt->nhoff = sizeof(struct ipv6hdr); 658 return 1; 659 } 660 return -1; 661 } 662 663 /* 664 * Creating outbound headers. 665 * 666 * "build" functions work when skb is filled from head to tail (datagram) 667 * "push" functions work when headers are added from tail to head (tcp) 668 * 669 * In both cases we assume, that caller reserved enough room 670 * for headers. 671 */ 672 673 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 674 struct ipv6_rt_hdr *opt, 675 struct in6_addr **addr_p) 676 { 677 struct rt0_hdr *phdr, *ihdr; 678 int hops; 679 680 ihdr = (struct rt0_hdr *) opt; 681 682 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 683 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 684 685 hops = ihdr->rt_hdr.hdrlen >> 1; 686 687 if (hops > 1) 688 memcpy(phdr->addr, ihdr->addr + 1, 689 (hops - 1) * sizeof(struct in6_addr)); 690 691 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); 692 *addr_p = ihdr->addr; 693 694 phdr->rt_hdr.nexthdr = *proto; 695 *proto = NEXTHDR_ROUTING; 696 } 697 698 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 699 { 700 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 701 702 memcpy(h, opt, ipv6_optlen(opt)); 703 h->nexthdr = *proto; 704 *proto = type; 705 } 706 707 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 708 u8 *proto, 709 struct in6_addr **daddr) 710 { 711 if (opt->srcrt) { 712 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 713 /* 714 * IPV6_RTHDRDSTOPTS is ignored 715 * unless IPV6_RTHDR is set (RFC3542). 716 */ 717 if (opt->dst0opt) 718 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 719 } 720 if (opt->hopopt) 721 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 722 } 723 724 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 725 726 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 727 { 728 if (opt->dst1opt) 729 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 730 } 731 732 struct ipv6_txoptions * 733 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 734 { 735 struct ipv6_txoptions *opt2; 736 737 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 738 if (opt2) { 739 long dif = (char*)opt2 - (char*)opt; 740 memcpy(opt2, opt, opt->tot_len); 741 if (opt2->hopopt) 742 *((char**)&opt2->hopopt) += dif; 743 if (opt2->dst0opt) 744 *((char**)&opt2->dst0opt) += dif; 745 if (opt2->dst1opt) 746 *((char**)&opt2->dst1opt) += dif; 747 if (opt2->srcrt) 748 *((char**)&opt2->srcrt) += dif; 749 } 750 return opt2; 751 } 752 753 EXPORT_SYMBOL_GPL(ipv6_dup_options); 754 755 static int ipv6_renew_option(void *ohdr, 756 struct ipv6_opt_hdr __user *newopt, int newoptlen, 757 int inherit, 758 struct ipv6_opt_hdr **hdr, 759 char **p) 760 { 761 if (inherit) { 762 if (ohdr) { 763 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 764 *hdr = (struct ipv6_opt_hdr *)*p; 765 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 766 } 767 } else { 768 if (newopt) { 769 if (copy_from_user(*p, newopt, newoptlen)) 770 return -EFAULT; 771 *hdr = (struct ipv6_opt_hdr *)*p; 772 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 773 return -EINVAL; 774 *p += CMSG_ALIGN(newoptlen); 775 } 776 } 777 return 0; 778 } 779 780 struct ipv6_txoptions * 781 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 782 int newtype, 783 struct ipv6_opt_hdr __user *newopt, int newoptlen) 784 { 785 int tot_len = 0; 786 char *p; 787 struct ipv6_txoptions *opt2; 788 int err; 789 790 if (opt) { 791 if (newtype != IPV6_HOPOPTS && opt->hopopt) 792 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 793 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 794 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 795 if (newtype != IPV6_RTHDR && opt->srcrt) 796 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 797 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 798 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 799 } 800 801 if (newopt && newoptlen) 802 tot_len += CMSG_ALIGN(newoptlen); 803 804 if (!tot_len) 805 return NULL; 806 807 tot_len += sizeof(*opt2); 808 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 809 if (!opt2) 810 return ERR_PTR(-ENOBUFS); 811 812 memset(opt2, 0, tot_len); 813 814 opt2->tot_len = tot_len; 815 p = (char *)(opt2 + 1); 816 817 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 818 newtype != IPV6_HOPOPTS, 819 &opt2->hopopt, &p); 820 if (err) 821 goto out; 822 823 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 824 newtype != IPV6_RTHDRDSTOPTS, 825 &opt2->dst0opt, &p); 826 if (err) 827 goto out; 828 829 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 830 newtype != IPV6_RTHDR, 831 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 832 if (err) 833 goto out; 834 835 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 836 newtype != IPV6_DSTOPTS, 837 &opt2->dst1opt, &p); 838 if (err) 839 goto out; 840 841 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 842 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 843 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 844 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 845 846 return opt2; 847 out: 848 sock_kfree_s(sk, opt2, opt2->tot_len); 849 return ERR_PTR(err); 850 } 851 852 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 853 struct ipv6_txoptions *opt) 854 { 855 /* 856 * ignore the dest before srcrt unless srcrt is being included. 857 * --yoshfuji 858 */ 859 if (opt && opt->dst0opt && !opt->srcrt) { 860 if (opt_space != opt) { 861 memcpy(opt_space, opt, sizeof(*opt_space)); 862 opt = opt_space; 863 } 864 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 865 opt->dst0opt = NULL; 866 } 867 868 return opt; 869 } 870 871