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 * $Id: exthdrs.c,v 1.13 2001/06/19 15:58:56 davem Exp $ 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18 /* Changes: 19 * yoshfuji : ensure not to overrun while parsing 20 * tlv options. 21 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). 22 * YOSHIFUJI Hideaki @USAGI Register inbound extension header 23 * handlers as inet6_protocol{}. 24 */ 25 26 #include <linux/errno.h> 27 #include <linux/types.h> 28 #include <linux/socket.h> 29 #include <linux/sockios.h> 30 #include <linux/net.h> 31 #include <linux/netdevice.h> 32 #include <linux/in6.h> 33 #include <linux/icmpv6.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: " NIP6_FMT "\n", NIP6(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; 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(ip6_dst_idev(skb->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 dst = dst_clone(skb->dst); 294 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { 295 dst_release(dst); 296 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 297 opt = IP6CB(skb); 298 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 299 opt->nhoff = dstbuf; 300 #else 301 opt->nhoff = opt->dst1; 302 #endif 303 return 1; 304 } 305 306 IP6_INC_STATS_BH(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 int accept_source_route = ipv6_devconf.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(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(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(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(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(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(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(ip6_dst_idev(skb->dst), 444 IPSTATS_MIB_INADDRERRORS); 445 kfree_skb(skb); 446 return -1; 447 } 448 if (!ipv6_chk_home_addr(&init_net, addr)) { 449 IP6_INC_STATS_BH(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(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(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(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; 584 585 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 586 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 587 nh[optoff+1]); 588 IP6_INC_STATS_BH(ipv6_skb_idev(skb), 589 IPSTATS_MIB_INHDRERRORS); 590 goto drop; 591 } 592 593 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 594 if (pkt_len <= IPV6_MAXPLEN) { 595 IP6_INC_STATS_BH(ipv6_skb_idev(skb), IPSTATS_MIB_INHDRERRORS); 596 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); 597 return 0; 598 } 599 if (ipv6_hdr(skb)->payload_len) { 600 IP6_INC_STATS_BH(ipv6_skb_idev(skb), IPSTATS_MIB_INHDRERRORS); 601 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); 602 return 0; 603 } 604 605 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 606 IP6_INC_STATS_BH(ipv6_skb_idev(skb), IPSTATS_MIB_INTRUNCATEDPKTS); 607 goto drop; 608 } 609 610 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 611 goto drop; 612 613 return 1; 614 615 drop: 616 kfree_skb(skb); 617 return 0; 618 } 619 620 static struct tlvtype_proc tlvprochopopt_lst[] = { 621 { 622 .type = IPV6_TLV_ROUTERALERT, 623 .func = ipv6_hop_ra, 624 }, 625 { 626 .type = IPV6_TLV_JUMBO, 627 .func = ipv6_hop_jumbo, 628 }, 629 { -1, } 630 }; 631 632 int ipv6_parse_hopopts(struct sk_buff *skb) 633 { 634 struct inet6_skb_parm *opt = IP6CB(skb); 635 636 /* 637 * skb_network_header(skb) is equal to skb->data, and 638 * skb_network_header_len(skb) is always equal to 639 * sizeof(struct ipv6hdr) by definition of 640 * hop-by-hop options. 641 */ 642 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 643 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 644 ((skb_transport_header(skb)[1] + 1) << 3)))) { 645 kfree_skb(skb); 646 return -1; 647 } 648 649 opt->hop = sizeof(struct ipv6hdr); 650 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { 651 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; 652 opt = IP6CB(skb); 653 opt->nhoff = sizeof(struct ipv6hdr); 654 return 1; 655 } 656 return -1; 657 } 658 659 /* 660 * Creating outbound headers. 661 * 662 * "build" functions work when skb is filled from head to tail (datagram) 663 * "push" functions work when headers are added from tail to head (tcp) 664 * 665 * In both cases we assume, that caller reserved enough room 666 * for headers. 667 */ 668 669 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 670 struct ipv6_rt_hdr *opt, 671 struct in6_addr **addr_p) 672 { 673 struct rt0_hdr *phdr, *ihdr; 674 int hops; 675 676 ihdr = (struct rt0_hdr *) opt; 677 678 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 679 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 680 681 hops = ihdr->rt_hdr.hdrlen >> 1; 682 683 if (hops > 1) 684 memcpy(phdr->addr, ihdr->addr + 1, 685 (hops - 1) * sizeof(struct in6_addr)); 686 687 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); 688 *addr_p = ihdr->addr; 689 690 phdr->rt_hdr.nexthdr = *proto; 691 *proto = NEXTHDR_ROUTING; 692 } 693 694 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 695 { 696 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); 697 698 memcpy(h, opt, ipv6_optlen(opt)); 699 h->nexthdr = *proto; 700 *proto = type; 701 } 702 703 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 704 u8 *proto, 705 struct in6_addr **daddr) 706 { 707 if (opt->srcrt) { 708 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); 709 /* 710 * IPV6_RTHDRDSTOPTS is ignored 711 * unless IPV6_RTHDR is set (RFC3542). 712 */ 713 if (opt->dst0opt) 714 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 715 } 716 if (opt->hopopt) 717 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 718 } 719 720 EXPORT_SYMBOL(ipv6_push_nfrag_opts); 721 722 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 723 { 724 if (opt->dst1opt) 725 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 726 } 727 728 struct ipv6_txoptions * 729 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 730 { 731 struct ipv6_txoptions *opt2; 732 733 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 734 if (opt2) { 735 long dif = (char*)opt2 - (char*)opt; 736 memcpy(opt2, opt, opt->tot_len); 737 if (opt2->hopopt) 738 *((char**)&opt2->hopopt) += dif; 739 if (opt2->dst0opt) 740 *((char**)&opt2->dst0opt) += dif; 741 if (opt2->dst1opt) 742 *((char**)&opt2->dst1opt) += dif; 743 if (opt2->srcrt) 744 *((char**)&opt2->srcrt) += dif; 745 } 746 return opt2; 747 } 748 749 EXPORT_SYMBOL_GPL(ipv6_dup_options); 750 751 static int ipv6_renew_option(void *ohdr, 752 struct ipv6_opt_hdr __user *newopt, int newoptlen, 753 int inherit, 754 struct ipv6_opt_hdr **hdr, 755 char **p) 756 { 757 if (inherit) { 758 if (ohdr) { 759 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); 760 *hdr = (struct ipv6_opt_hdr *)*p; 761 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); 762 } 763 } else { 764 if (newopt) { 765 if (copy_from_user(*p, newopt, newoptlen)) 766 return -EFAULT; 767 *hdr = (struct ipv6_opt_hdr *)*p; 768 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) 769 return -EINVAL; 770 *p += CMSG_ALIGN(newoptlen); 771 } 772 } 773 return 0; 774 } 775 776 struct ipv6_txoptions * 777 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 778 int newtype, 779 struct ipv6_opt_hdr __user *newopt, int newoptlen) 780 { 781 int tot_len = 0; 782 char *p; 783 struct ipv6_txoptions *opt2; 784 int err; 785 786 if (opt) { 787 if (newtype != IPV6_HOPOPTS && opt->hopopt) 788 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 789 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 790 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 791 if (newtype != IPV6_RTHDR && opt->srcrt) 792 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 793 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 794 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 795 } 796 797 if (newopt && newoptlen) 798 tot_len += CMSG_ALIGN(newoptlen); 799 800 if (!tot_len) 801 return NULL; 802 803 tot_len += sizeof(*opt2); 804 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 805 if (!opt2) 806 return ERR_PTR(-ENOBUFS); 807 808 memset(opt2, 0, tot_len); 809 810 opt2->tot_len = tot_len; 811 p = (char *)(opt2 + 1); 812 813 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, 814 newtype != IPV6_HOPOPTS, 815 &opt2->hopopt, &p); 816 if (err) 817 goto out; 818 819 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, 820 newtype != IPV6_RTHDRDSTOPTS, 821 &opt2->dst0opt, &p); 822 if (err) 823 goto out; 824 825 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, 826 newtype != IPV6_RTHDR, 827 (struct ipv6_opt_hdr **)&opt2->srcrt, &p); 828 if (err) 829 goto out; 830 831 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, 832 newtype != IPV6_DSTOPTS, 833 &opt2->dst1opt, &p); 834 if (err) 835 goto out; 836 837 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 838 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 839 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 840 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 841 842 return opt2; 843 out: 844 sock_kfree_s(sk, opt2, opt2->tot_len); 845 return ERR_PTR(err); 846 } 847 848 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, 849 struct ipv6_txoptions *opt) 850 { 851 /* 852 * ignore the dest before srcrt unless srcrt is being included. 853 * --yoshfuji 854 */ 855 if (opt && opt->dst0opt && !opt->srcrt) { 856 if (opt_space != opt) { 857 memcpy(opt_space, opt, sizeof(*opt_space)); 858 opt = opt_space; 859 } 860 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 861 opt->dst0opt = NULL; 862 } 863 864 return opt; 865 } 866 867