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_PAD1: 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 int i; 157 158 switch (nh[off]) { 159 case IPV6_TLV_PAD1: 160 optlen = 1; 161 break; 162 163 case IPV6_TLV_PADN: 164 /* RFC 2460 states that the purpose of PadN is 165 * to align the containing header to multiples 166 * of 8. 7 is therefore the highest valid value. 167 * See also RFC 4942, Section 2.1.9.5. 168 */ 169 if (optlen > 7) 170 goto bad; 171 /* RFC 4942 recommends receiving hosts to 172 * actively check PadN payload to contain 173 * only zeroes. 174 */ 175 for (i = 2; i < optlen; i++) { 176 if (nh[off + i] != 0) 177 goto bad; 178 } 179 break; 180 181 default: /* Other TLV code so scan list */ 182 if (optlen > len) 183 goto bad; 184 for (curr=procs; curr->type >= 0; curr++) { 185 if (curr->type == nh[off]) { 186 /* type specific length/alignment 187 checks will be performed in the 188 func(). */ 189 if (curr->func(skb, off) == 0) 190 return 0; 191 break; 192 } 193 } 194 if (curr->type < 0) { 195 if (ip6_tlvopt_unknown(skb, off) == 0) 196 return 0; 197 } 198 break; 199 } 200 off += optlen; 201 len -= optlen; 202 } 203 if (len == 0) 204 return 1; 205 bad: 206 kfree_skb(skb); 207 return 0; 208 } 209 210 /***************************** 211 Destination options header. 212 *****************************/ 213 214 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 215 static int ipv6_dest_hao(struct sk_buff *skb, int optoff) 216 { 217 struct ipv6_destopt_hao *hao; 218 struct inet6_skb_parm *opt = IP6CB(skb); 219 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 220 struct in6_addr tmp_addr; 221 int ret; 222 223 if (opt->dsthao) { 224 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); 225 goto discard; 226 } 227 opt->dsthao = opt->dst1; 228 opt->dst1 = 0; 229 230 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 231 232 if (hao->length != 16) { 233 LIMIT_NETDEBUG( 234 KERN_DEBUG "hao invalid option length = %d\n", hao->length); 235 goto discard; 236 } 237 238 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 239 LIMIT_NETDEBUG( 240 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr); 241 goto discard; 242 } 243 244 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 245 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 246 if (unlikely(ret < 0)) 247 goto discard; 248 249 if (skb_cloned(skb)) { 250 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 251 goto discard; 252 253 /* update all variable using below by copied skbuff */ 254 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 255 optoff); 256 ipv6h = ipv6_hdr(skb); 257 } 258 259 if (skb->ip_summed == CHECKSUM_COMPLETE) 260 skb->ip_summed = CHECKSUM_NONE; 261 262 tmp_addr = ipv6h->saddr; 263 ipv6h->saddr = hao->addr; 264 hao->addr = tmp_addr; 265 266 if (skb->tstamp.tv64 == 0) 267 __net_timestamp(skb); 268 269 return 1; 270 271 discard: 272 kfree_skb(skb); 273 return 0; 274 } 275 #endif 276 277 static struct tlvtype_proc tlvprocdestopt_lst[] = { 278 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 279 { 280 .type = IPV6_TLV_HAO, 281 .func = ipv6_dest_hao, 282 }, 283 #endif 284 {-1, NULL} 285 }; 286 287 static int ipv6_destopt_rcv(struct sk_buff *skb) 288 { 289 struct inet6_skb_parm *opt = IP6CB(skb); 290 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 291 __u16 dstbuf; 292 #endif 293 struct dst_entry *dst = skb_dst(skb); 294 295 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 296 !pskb_may_pull(skb, (skb_transport_offset(skb) + 297 ((skb_transport_header(skb)[1] + 1) << 3)))) { 298 IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst), 299 IPSTATS_MIB_INHDRERRORS); 300 kfree_skb(skb); 301 return -1; 302 } 303 304 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 305 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 306 dstbuf = opt->dst1; 307 #endif 308 309 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { 310 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 311 opt = IP6CB(skb); 312 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 313 opt->nhoff = dstbuf; 314 #else 315 opt->nhoff = opt->dst1; 316 #endif 317 return 1; 318 } 319 320 IP6_INC_STATS_BH(dev_net(dst->dev), 321 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 322 return -1; 323 } 324 325 /******************************** 326 Routing header. 327 ********************************/ 328 329 /* called with rcu_read_lock() */ 330 static int ipv6_rthdr_rcv(struct sk_buff *skb) 331 { 332 struct inet6_skb_parm *opt = IP6CB(skb); 333 struct in6_addr *addr = NULL; 334 struct in6_addr daddr; 335 struct inet6_dev *idev; 336 int n, i; 337 struct ipv6_rt_hdr *hdr; 338 struct rt0_hdr *rthdr; 339 struct net *net = dev_net(skb->dev); 340 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 341 342 idev = __in6_dev_get(skb->dev); 343 if (idev && accept_source_route > idev->cnf.accept_source_route) 344 accept_source_route = idev->cnf.accept_source_route; 345 346 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 347 !pskb_may_pull(skb, (skb_transport_offset(skb) + 348 ((skb_transport_header(skb)[1] + 1) << 3)))) { 349 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 350 IPSTATS_MIB_INHDRERRORS); 351 kfree_skb(skb); 352 return -1; 353 } 354 355 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 356 357 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 358 skb->pkt_type != PACKET_HOST) { 359 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 360 IPSTATS_MIB_INADDRERRORS); 361 kfree_skb(skb); 362 return -1; 363 } 364 365 looped_back: 366 if (hdr->segments_left == 0) { 367 switch (hdr->type) { 368 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 369 case IPV6_SRCRT_TYPE_2: 370 /* Silently discard type 2 header unless it was 371 * processed by own 372 */ 373 if (!addr) { 374 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 375 IPSTATS_MIB_INADDRERRORS); 376 kfree_skb(skb); 377 return -1; 378 } 379 break; 380 #endif 381 default: 382 break; 383 } 384 385 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 386 skb->transport_header += (hdr->hdrlen + 1) << 3; 387 opt->dst0 = opt->dst1; 388 opt->dst1 = 0; 389 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 390 return 1; 391 } 392 393 switch (hdr->type) { 394 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 395 case IPV6_SRCRT_TYPE_2: 396 if (accept_source_route < 0) 397 goto unknown_rh; 398 /* Silently discard invalid RTH type 2 */ 399 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 400 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 401 IPSTATS_MIB_INHDRERRORS); 402 kfree_skb(skb); 403 return -1; 404 } 405 break; 406 #endif 407 default: 408 goto unknown_rh; 409 } 410 411 /* 412 * This is the routing header forwarding algorithm from 413 * RFC 2460, page 16. 414 */ 415 416 n = hdr->hdrlen >> 1; 417 418 if (hdr->segments_left > n) { 419 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 420 IPSTATS_MIB_INHDRERRORS); 421 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 422 ((&hdr->segments_left) - 423 skb_network_header(skb))); 424 return -1; 425 } 426 427 /* We are about to mangle packet header. Be careful! 428 Do not damage packets queued somewhere. 429 */ 430 if (skb_cloned(skb)) { 431 /* the copy is a forwarded packet */ 432 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 433 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 434 IPSTATS_MIB_OUTDISCARDS); 435 kfree_skb(skb); 436 return -1; 437 } 438 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 439 } 440 441 if (skb->ip_summed == CHECKSUM_COMPLETE) 442 skb->ip_summed = CHECKSUM_NONE; 443 444 i = n - --hdr->segments_left; 445 446 rthdr = (struct rt0_hdr *) hdr; 447 addr = rthdr->addr; 448 addr += i - 1; 449 450 switch (hdr->type) { 451 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 452 case IPV6_SRCRT_TYPE_2: 453 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 454 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 455 IPPROTO_ROUTING) < 0) { 456 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 457 IPSTATS_MIB_INADDRERRORS); 458 kfree_skb(skb); 459 return -1; 460 } 461 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), 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 break; 468 #endif 469 default: 470 break; 471 } 472 473 if (ipv6_addr_is_multicast(addr)) { 474 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 475 IPSTATS_MIB_INADDRERRORS); 476 kfree_skb(skb); 477 return -1; 478 } 479 480 daddr = *addr; 481 *addr = ipv6_hdr(skb)->daddr; 482 ipv6_hdr(skb)->daddr = daddr; 483 484 skb_dst_drop(skb); 485 ip6_route_input(skb); 486 if (skb_dst(skb)->error) { 487 skb_push(skb, skb->data - skb_network_header(skb)); 488 dst_input(skb); 489 return -1; 490 } 491 492 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 493 if (ipv6_hdr(skb)->hop_limit <= 1) { 494 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 495 IPSTATS_MIB_INHDRERRORS); 496 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 497 0); 498 kfree_skb(skb); 499 return -1; 500 } 501 ipv6_hdr(skb)->hop_limit--; 502 goto looped_back; 503 } 504 505 skb_push(skb, skb->data - skb_network_header(skb)); 506 dst_input(skb); 507 return -1; 508 509 unknown_rh: 510 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 511 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 512 (&hdr->type) - skb_network_header(skb)); 513 return -1; 514 } 515 516 static const struct inet6_protocol rthdr_protocol = { 517 .handler = ipv6_rthdr_rcv, 518 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 519 }; 520 521 static const struct inet6_protocol destopt_protocol = { 522 .handler = ipv6_destopt_rcv, 523 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, 524 }; 525 526 static const struct inet6_protocol nodata_protocol = { 527 .handler = dst_discard, 528 .flags = INET6_PROTO_NOPOLICY, 529 }; 530 531 int __init ipv6_exthdrs_init(void) 532 { 533 int ret; 534 535 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 536 if (ret) 537 goto out; 538 539 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 540 if (ret) 541 goto out_rthdr; 542 543 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 544 if (ret) 545 goto out_destopt; 546 547 out: 548 return ret; 549 out_rthdr: 550 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 551 out_destopt: 552 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 553 goto out; 554 }; 555 556 void ipv6_exthdrs_exit(void) 557 { 558 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 559 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 560 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 561 } 562 563 /********************************** 564 Hop-by-hop options. 565 **********************************/ 566 567 /* 568 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 569 */ 570 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) 571 { 572 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev); 573 } 574 575 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 576 { 577 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 578 } 579 580 /* Router Alert as of RFC 2711 */ 581 582 static int ipv6_hop_ra(struct sk_buff *skb, int optoff) 583 { 584 const unsigned char *nh = skb_network_header(skb); 585 586 if (nh[optoff + 1] == 2) { 587 IP6CB(skb)->ra = optoff; 588 return 1; 589 } 590 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", 591 nh[optoff + 1]); 592 kfree_skb(skb); 593 return 0; 594 } 595 596 /* Jumbo payload */ 597 598 static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 599 { 600 const unsigned char *nh = skb_network_header(skb); 601 struct net *net = ipv6_skb_net(skb); 602 u32 pkt_len; 603 604 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 605 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 606 nh[optoff+1]); 607 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 608 IPSTATS_MIB_INHDRERRORS); 609 goto drop; 610 } 611 612 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 613 if (pkt_len <= IPV6_MAXPLEN) { 614 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 615 IPSTATS_MIB_INHDRERRORS); 616 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 617 return 0; 618 } 619 if (ipv6_hdr(skb)->payload_len) { 620 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 621 IPSTATS_MIB_INHDRERRORS); 622 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 623 return 0; 624 } 625 626 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 627 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), 628 IPSTATS_MIB_INTRUNCATEDPKTS); 629 goto drop; 630 } 631 632 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 633 goto drop; 634 635 return 1; 636 637 drop: 638 kfree_skb(skb); 639 return 0; 640 } 641 642 static struct tlvtype_proc tlvprochopopt_lst[] = { 643 { 644 .type = IPV6_TLV_ROUTERALERT, 645 .func = ipv6_hop_ra, 646 }, 647 { 648 .type = IPV6_TLV_JUMBO, 649 .func = ipv6_hop_jumbo, 650 }, 651 { -1, } 652 }; 653 654 int ipv6_parse_hopopts(struct sk_buff *skb) 655 { 656 struct inet6_skb_parm *opt = IP6CB(skb); 657 658 /* 659 * skb_network_header(skb) is equal to skb->data, and 660 * skb_network_header_len(skb) is always equal to 661 * sizeof(struct ipv6hdr) by definition of 662 * hop-by-hop options. 663 */ 664 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 665 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 666 ((skb_transport_header(skb)[1] + 1) << 3)))) { 667 kfree_skb(skb); 668 return -1; 669 } 670 671 opt->hop = sizeof(struct ipv6hdr); 672 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 673 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 674 opt = IP6CB(skb); 675 opt->nhoff = sizeof(struct ipv6hdr); 676 return 1; 677 } 678 return -1; 679 } 680 681 /* 682 * Creating outbound headers. 683 * 684 * "build" functions work when skb is filled from head to tail (datagram) 685 * "push" functions work when headers are added from tail to head (tcp) 686 * 687 * In both cases we assume, that caller reserved enough room 688 * for headers. 689 */ 690 691 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 692 struct ipv6_rt_hdr *opt, 693 struct in6_addr **addr_p) 694 { 695 struct rt0_hdr *phdr, *ihdr; 696 int hops; 697 698 ihdr = (struct rt0_hdr *) opt; 699 700 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 701 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 702 703 hops = ihdr->rt_hdr.hdrlen >> 1; 704 705 if (hops > 1) 706 memcpy(phdr->addr, ihdr->addr + 1, 707 (hops - 1) * sizeof(struct in6_addr)); 708 709 phdr->addr[hops - 1] = **addr_p; 710 *addr_p = ihdr->addr; 711 712 phdr->rt_hdr.nexthdr = *proto; 713 *proto = NEXTHDR_ROUTING; 714 } 715 716 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 717 { 718 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 719 720 memcpy(h, opt, ipv6_optlen(opt)); 721 h->nexthdr = *proto; 722 *proto = type; 723 } 724 725 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 726 u8 *proto, 727 struct in6_addr **daddr) 728 { 729 if (opt->srcrt) { 730 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 731 /* 732 * IPV6_RTHDRDSTOPTS is ignored 733 * unless IPV6_RTHDR is set (RFC3542). 734 */ 735 if (opt->dst0opt) 736 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 737 } 738 if (opt->hopopt) 739 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 740 } 741 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 742 743 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 744 { 745 if (opt->dst1opt) 746 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 747 } 748 749 struct ipv6_txoptions * 750 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 751 { 752 struct ipv6_txoptions *opt2; 753 754 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 755 if (opt2) { 756 long dif = (char *)opt2 - (char *)opt; 757 memcpy(opt2, opt, opt->tot_len); 758 if (opt2->hopopt) 759 *((char **)&opt2->hopopt) += dif; 760 if (opt2->dst0opt) 761 *((char **)&opt2->dst0opt) += dif; 762 if (opt2->dst1opt) 763 *((char **)&opt2->dst1opt) += dif; 764 if (opt2->srcrt) 765 *((char **)&opt2->srcrt) += dif; 766 } 767 return opt2; 768 } 769 EXPORT_SYMBOL_GPL(ipv6_dup_options); 770 771 static int ipv6_renew_option(void *ohdr, 772 struct ipv6_opt_hdr __user *newopt, int newoptlen, 773 int inherit, 774 struct ipv6_opt_hdr **hdr, 775 char **p) 776 { 777 if (inherit) { 778 if (ohdr) { 779 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 780 *hdr = (struct ipv6_opt_hdr *)*p; 781 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 782 } 783 } else { 784 if (newopt) { 785 if (copy_from_user(*p, newopt, newoptlen)) 786 return -EFAULT; 787 *hdr = (struct ipv6_opt_hdr *)*p; 788 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 789 return -EINVAL; 790 *p += CMSG_ALIGN(newoptlen); 791 } 792 } 793 return 0; 794 } 795 796 struct ipv6_txoptions * 797 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 798 int newtype, 799 struct ipv6_opt_hdr __user *newopt, int newoptlen) 800 { 801 int tot_len = 0; 802 char *p; 803 struct ipv6_txoptions *opt2; 804 int err; 805 806 if (opt) { 807 if (newtype != IPV6_HOPOPTS && opt->hopopt) 808 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 809 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 810 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 811 if (newtype != IPV6_RTHDR && opt->srcrt) 812 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 813 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 814 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 815 } 816 817 if (newopt && newoptlen) 818 tot_len += CMSG_ALIGN(newoptlen); 819 820 if (!tot_len) 821 return NULL; 822 823 tot_len += sizeof(*opt2); 824 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 825 if (!opt2) 826 return ERR_PTR(-ENOBUFS); 827 828 memset(opt2, 0, tot_len); 829 830 opt2->tot_len = tot_len; 831 p = (char *)(opt2 + 1); 832 833 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 834 newtype != IPV6_HOPOPTS, 835 &opt2->hopopt, &p); 836 if (err) 837 goto out; 838 839 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 840 newtype != IPV6_RTHDRDSTOPTS, 841 &opt2->dst0opt, &p); 842 if (err) 843 goto out; 844 845 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 846 newtype != IPV6_RTHDR, 847 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 848 if (err) 849 goto out; 850 851 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 852 newtype != IPV6_DSTOPTS, 853 &opt2->dst1opt, &p); 854 if (err) 855 goto out; 856 857 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 858 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 859 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 860 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 861 862 return opt2; 863 out: 864 sock_kfree_s(sk, opt2, opt2->tot_len); 865 return ERR_PTR(err); 866 } 867 868 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 869 struct ipv6_txoptions *opt) 870 { 871 /* 872 * ignore the dest before srcrt unless srcrt is being included. 873 * --yoshfuji 874 */ 875 if (opt && opt->dst0opt && !opt->srcrt) { 876 if (opt_space != opt) { 877 memcpy(opt_space, opt, sizeof(*opt_space)); 878 opt = opt_space; 879 } 880 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 881 opt->dst0opt = NULL; 882 } 883 884 return opt; 885 } 886 EXPORT_SYMBOL_GPL(ipv6_fixup_options); 887 888 /** 889 * fl6_update_dst - update flowi destination address with info given 890 * by srcrt option, if any. 891 * 892 * @fl6: flowi6 for which daddr is to be updated 893 * @opt: struct ipv6_txoptions in which to look for srcrt opt 894 * @orig: copy of original daddr address if modified 895 * 896 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 897 * and initial value of fl6->daddr set in orig 898 */ 899 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 900 const struct ipv6_txoptions *opt, 901 struct in6_addr *orig) 902 { 903 if (!opt || !opt->srcrt) 904 return NULL; 905 906 *orig = fl6->daddr; 907 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 908 return orig; 909 } 910 EXPORT_SYMBOL_GPL(fl6_update_dst); 911