1 /* 2 * IPv6 over IPv6 tunnel device 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Ville Nuorvala <vnuorval@tcs.hut.fi> 7 * 8 * $Id$ 9 * 10 * Based on: 11 * linux/net/ipv6/sit.c 12 * 13 * RFC 2473 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License 17 * as published by the Free Software Foundation; either version 18 * 2 of the License, or (at your option) any later version. 19 * 20 */ 21 22 #include <linux/module.h> 23 #include <linux/capability.h> 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/sockios.h> 27 #include <linux/if.h> 28 #include <linux/in.h> 29 #include <linux/ip.h> 30 #include <linux/if_tunnel.h> 31 #include <linux/net.h> 32 #include <linux/in6.h> 33 #include <linux/netdevice.h> 34 #include <linux/if_arp.h> 35 #include <linux/icmpv6.h> 36 #include <linux/init.h> 37 #include <linux/route.h> 38 #include <linux/rtnetlink.h> 39 #include <linux/netfilter_ipv6.h> 40 41 #include <asm/uaccess.h> 42 #include <asm/atomic.h> 43 44 #include <net/ip.h> 45 #include <net/ipv6.h> 46 #include <net/ip6_route.h> 47 #include <net/addrconf.h> 48 #include <net/ip6_tunnel.h> 49 #include <net/xfrm.h> 50 #include <net/dsfield.h> 51 #include <net/inet_ecn.h> 52 53 MODULE_AUTHOR("Ville Nuorvala"); 54 MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel"); 55 MODULE_LICENSE("GPL"); 56 57 #define IPV6_TLV_TEL_DST_SIZE 8 58 59 #ifdef IP6_TNL_DEBUG 60 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__) 61 #else 62 #define IP6_TNL_TRACE(x...) do {;} while(0) 63 #endif 64 65 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 66 67 #define HASH_SIZE 32 68 69 #define HASH(addr) (((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ 70 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ 71 (HASH_SIZE - 1)) 72 73 static int ip6ip6_fb_tnl_dev_init(struct net_device *dev); 74 static int ip6ip6_tnl_dev_init(struct net_device *dev); 75 static void ip6ip6_tnl_dev_setup(struct net_device *dev); 76 77 /* the IPv6 tunnel fallback device */ 78 static struct net_device *ip6ip6_fb_tnl_dev; 79 80 81 /* lists for storing tunnels in use */ 82 static struct ip6_tnl *tnls_r_l[HASH_SIZE]; 83 static struct ip6_tnl *tnls_wc[1]; 84 static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l }; 85 86 /* lock for the tunnel lists */ 87 static DEFINE_RWLOCK(ip6ip6_lock); 88 89 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 90 { 91 struct dst_entry *dst = t->dst_cache; 92 93 if (dst && dst->obsolete && 94 dst->ops->check(dst, t->dst_cookie) == NULL) { 95 t->dst_cache = NULL; 96 dst_release(dst); 97 return NULL; 98 } 99 100 return dst; 101 } 102 103 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) 104 { 105 dst_release(t->dst_cache); 106 t->dst_cache = NULL; 107 } 108 109 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 110 { 111 struct rt6_info *rt = (struct rt6_info *) dst; 112 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 113 dst_release(t->dst_cache); 114 t->dst_cache = dst; 115 } 116 117 /** 118 * ip6ip6_tnl_lookup - fetch tunnel matching the end-point addresses 119 * @remote: the address of the tunnel exit-point 120 * @local: the address of the tunnel entry-point 121 * 122 * Return: 123 * tunnel matching given end-points if found, 124 * else fallback tunnel if its device is up, 125 * else %NULL 126 **/ 127 128 static struct ip6_tnl * 129 ip6ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local) 130 { 131 unsigned h0 = HASH(remote); 132 unsigned h1 = HASH(local); 133 struct ip6_tnl *t; 134 135 for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) { 136 if (ipv6_addr_equal(local, &t->parms.laddr) && 137 ipv6_addr_equal(remote, &t->parms.raddr) && 138 (t->dev->flags & IFF_UP)) 139 return t; 140 } 141 if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP)) 142 return t; 143 144 return NULL; 145 } 146 147 /** 148 * ip6ip6_bucket - get head of list matching given tunnel parameters 149 * @p: parameters containing tunnel end-points 150 * 151 * Description: 152 * ip6ip6_bucket() returns the head of the list matching the 153 * &struct in6_addr entries laddr and raddr in @p. 154 * 155 * Return: head of IPv6 tunnel list 156 **/ 157 158 static struct ip6_tnl ** 159 ip6ip6_bucket(struct ip6_tnl_parm *p) 160 { 161 struct in6_addr *remote = &p->raddr; 162 struct in6_addr *local = &p->laddr; 163 unsigned h = 0; 164 int prio = 0; 165 166 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 167 prio = 1; 168 h = HASH(remote) ^ HASH(local); 169 } 170 return &tnls[prio][h]; 171 } 172 173 /** 174 * ip6ip6_tnl_link - add tunnel to hash table 175 * @t: tunnel to be added 176 **/ 177 178 static void 179 ip6ip6_tnl_link(struct ip6_tnl *t) 180 { 181 struct ip6_tnl **tp = ip6ip6_bucket(&t->parms); 182 183 t->next = *tp; 184 write_lock_bh(&ip6ip6_lock); 185 *tp = t; 186 write_unlock_bh(&ip6ip6_lock); 187 } 188 189 /** 190 * ip6ip6_tnl_unlink - remove tunnel from hash table 191 * @t: tunnel to be removed 192 **/ 193 194 static void 195 ip6ip6_tnl_unlink(struct ip6_tnl *t) 196 { 197 struct ip6_tnl **tp; 198 199 for (tp = ip6ip6_bucket(&t->parms); *tp; tp = &(*tp)->next) { 200 if (t == *tp) { 201 write_lock_bh(&ip6ip6_lock); 202 *tp = t->next; 203 write_unlock_bh(&ip6ip6_lock); 204 break; 205 } 206 } 207 } 208 209 /** 210 * ip6_tnl_create() - create a new tunnel 211 * @p: tunnel parameters 212 * @pt: pointer to new tunnel 213 * 214 * Description: 215 * Create tunnel matching given parameters. 216 * 217 * Return: 218 * 0 on success 219 **/ 220 221 static int 222 ip6_tnl_create(struct ip6_tnl_parm *p, struct ip6_tnl **pt) 223 { 224 struct net_device *dev; 225 struct ip6_tnl *t; 226 char name[IFNAMSIZ]; 227 int err; 228 229 if (p->name[0]) { 230 strlcpy(name, p->name, IFNAMSIZ); 231 } else { 232 int i; 233 for (i = 1; i < IP6_TNL_MAX; i++) { 234 sprintf(name, "ip6tnl%d", i); 235 if (__dev_get_by_name(name) == NULL) 236 break; 237 } 238 if (i == IP6_TNL_MAX) 239 return -ENOBUFS; 240 } 241 dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup); 242 if (dev == NULL) 243 return -ENOMEM; 244 245 t = netdev_priv(dev); 246 dev->init = ip6ip6_tnl_dev_init; 247 t->parms = *p; 248 249 if ((err = register_netdevice(dev)) < 0) { 250 free_netdev(dev); 251 return err; 252 } 253 dev_hold(dev); 254 255 ip6ip6_tnl_link(t); 256 *pt = t; 257 return 0; 258 } 259 260 /** 261 * ip6ip6_tnl_locate - find or create tunnel matching given parameters 262 * @p: tunnel parameters 263 * @create: != 0 if allowed to create new tunnel if no match found 264 * 265 * Description: 266 * ip6ip6_tnl_locate() first tries to locate an existing tunnel 267 * based on @parms. If this is unsuccessful, but @create is set a new 268 * tunnel device is created and registered for use. 269 * 270 * Return: 271 * 0 if tunnel located or created, 272 * -EINVAL if parameters incorrect, 273 * -ENODEV if no matching tunnel available 274 **/ 275 276 static int 277 ip6ip6_tnl_locate(struct ip6_tnl_parm *p, struct ip6_tnl **pt, int create) 278 { 279 struct in6_addr *remote = &p->raddr; 280 struct in6_addr *local = &p->laddr; 281 struct ip6_tnl *t; 282 283 if (p->proto != IPPROTO_IPV6) 284 return -EINVAL; 285 286 for (t = *ip6ip6_bucket(p); t; t = t->next) { 287 if (ipv6_addr_equal(local, &t->parms.laddr) && 288 ipv6_addr_equal(remote, &t->parms.raddr)) { 289 *pt = t; 290 return (create ? -EEXIST : 0); 291 } 292 } 293 if (!create) 294 return -ENODEV; 295 296 return ip6_tnl_create(p, pt); 297 } 298 299 /** 300 * ip6ip6_tnl_dev_uninit - tunnel device uninitializer 301 * @dev: the device to be destroyed 302 * 303 * Description: 304 * ip6ip6_tnl_dev_uninit() removes tunnel from its list 305 **/ 306 307 static void 308 ip6ip6_tnl_dev_uninit(struct net_device *dev) 309 { 310 struct ip6_tnl *t = netdev_priv(dev); 311 312 if (dev == ip6ip6_fb_tnl_dev) { 313 write_lock_bh(&ip6ip6_lock); 314 tnls_wc[0] = NULL; 315 write_unlock_bh(&ip6ip6_lock); 316 } else { 317 ip6ip6_tnl_unlink(t); 318 } 319 ip6_tnl_dst_reset(t); 320 dev_put(dev); 321 } 322 323 /** 324 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 325 * @skb: received socket buffer 326 * 327 * Return: 328 * 0 if none was found, 329 * else index to encapsulation limit 330 **/ 331 332 static __u16 333 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 334 { 335 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 336 __u8 nexthdr = ipv6h->nexthdr; 337 __u16 off = sizeof (*ipv6h); 338 339 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 340 __u16 optlen = 0; 341 struct ipv6_opt_hdr *hdr; 342 if (raw + off + sizeof (*hdr) > skb->data && 343 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 344 break; 345 346 hdr = (struct ipv6_opt_hdr *) (raw + off); 347 if (nexthdr == NEXTHDR_FRAGMENT) { 348 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 349 if (frag_hdr->frag_off) 350 break; 351 optlen = 8; 352 } else if (nexthdr == NEXTHDR_AUTH) { 353 optlen = (hdr->hdrlen + 2) << 2; 354 } else { 355 optlen = ipv6_optlen(hdr); 356 } 357 if (nexthdr == NEXTHDR_DEST) { 358 __u16 i = off + 2; 359 while (1) { 360 struct ipv6_tlv_tnl_enc_lim *tel; 361 362 /* No more room for encapsulation limit */ 363 if (i + sizeof (*tel) > off + optlen) 364 break; 365 366 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 367 /* return index of option if found and valid */ 368 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 369 tel->length == 1) 370 return i; 371 /* else jump to next option */ 372 if (tel->type) 373 i += tel->length + 2; 374 else 375 i++; 376 } 377 } 378 nexthdr = hdr->nexthdr; 379 off += optlen; 380 } 381 return 0; 382 } 383 384 /** 385 * ip6ip6_err - tunnel error handler 386 * 387 * Description: 388 * ip6ip6_err() should handle errors in the tunnel according 389 * to the specifications in RFC 2473. 390 **/ 391 392 static int 393 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 394 int type, int code, int offset, __u32 info) 395 { 396 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 397 struct ip6_tnl *t; 398 int rel_msg = 0; 399 int rel_type = ICMPV6_DEST_UNREACH; 400 int rel_code = ICMPV6_ADDR_UNREACH; 401 __u32 rel_info = 0; 402 __u16 len; 403 int err = -ENOENT; 404 405 /* If the packet doesn't contain the original IPv6 header we are 406 in trouble since we might need the source address for further 407 processing of the error. */ 408 409 read_lock(&ip6ip6_lock); 410 if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL) 411 goto out; 412 413 err = 0; 414 415 switch (type) { 416 __u32 teli; 417 struct ipv6_tlv_tnl_enc_lim *tel; 418 __u32 mtu; 419 case ICMPV6_DEST_UNREACH: 420 if (net_ratelimit()) 421 printk(KERN_WARNING 422 "%s: Path to destination invalid " 423 "or inactive!\n", t->parms.name); 424 rel_msg = 1; 425 break; 426 case ICMPV6_TIME_EXCEED: 427 if (code == ICMPV6_EXC_HOPLIMIT) { 428 if (net_ratelimit()) 429 printk(KERN_WARNING 430 "%s: Too small hop limit or " 431 "routing loop in tunnel!\n", 432 t->parms.name); 433 rel_msg = 1; 434 } 435 break; 436 case ICMPV6_PARAMPROB: 437 /* ignore if parameter problem not caused by a tunnel 438 encapsulation limit sub-option */ 439 if (code != ICMPV6_HDR_FIELD) { 440 break; 441 } 442 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 443 444 if (teli && teli == ntohl(info) - 2) { 445 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 446 if (tel->encap_limit == 0) { 447 if (net_ratelimit()) 448 printk(KERN_WARNING 449 "%s: Too small encapsulation " 450 "limit or routing loop in " 451 "tunnel!\n", t->parms.name); 452 rel_msg = 1; 453 } 454 } 455 break; 456 case ICMPV6_PKT_TOOBIG: 457 mtu = ntohl(info) - offset; 458 if (mtu < IPV6_MIN_MTU) 459 mtu = IPV6_MIN_MTU; 460 t->dev->mtu = mtu; 461 462 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 463 rel_type = ICMPV6_PKT_TOOBIG; 464 rel_code = 0; 465 rel_info = mtu; 466 rel_msg = 1; 467 } 468 break; 469 } 470 if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { 471 struct rt6_info *rt; 472 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 473 if (!skb2) 474 goto out; 475 476 dst_release(skb2->dst); 477 skb2->dst = NULL; 478 skb_pull(skb2, offset); 479 skb2->nh.raw = skb2->data; 480 481 /* Try to guess incoming interface */ 482 rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); 483 484 if (rt && rt->rt6i_dev) 485 skb2->dev = rt->rt6i_dev; 486 487 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 488 489 if (rt) 490 dst_release(&rt->u.dst); 491 492 kfree_skb(skb2); 493 } 494 out: 495 read_unlock(&ip6ip6_lock); 496 return err; 497 } 498 499 static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, 500 struct sk_buff *skb) 501 { 502 struct ipv6hdr *inner_iph = skb->nh.ipv6h; 503 504 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) 505 IP6_ECN_set_ce(inner_iph); 506 } 507 508 /** 509 * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally 510 * @skb: received socket buffer 511 * 512 * Return: 0 513 **/ 514 515 static int 516 ip6ip6_rcv(struct sk_buff *skb) 517 { 518 struct ipv6hdr *ipv6h; 519 struct ip6_tnl *t; 520 521 ipv6h = skb->nh.ipv6h; 522 523 read_lock(&ip6ip6_lock); 524 525 if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { 526 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 527 read_unlock(&ip6ip6_lock); 528 goto discard; 529 } 530 531 if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) { 532 t->stat.rx_dropped++; 533 read_unlock(&ip6ip6_lock); 534 goto discard; 535 } 536 secpath_reset(skb); 537 skb->mac.raw = skb->nh.raw; 538 skb->nh.raw = skb->data; 539 skb->protocol = htons(ETH_P_IPV6); 540 skb->pkt_type = PACKET_HOST; 541 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 542 skb->dev = t->dev; 543 dst_release(skb->dst); 544 skb->dst = NULL; 545 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 546 ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); 547 ip6ip6_ecn_decapsulate(ipv6h, skb); 548 t->stat.rx_packets++; 549 t->stat.rx_bytes += skb->len; 550 netif_rx(skb); 551 read_unlock(&ip6ip6_lock); 552 return 0; 553 } 554 read_unlock(&ip6ip6_lock); 555 return 1; 556 557 discard: 558 kfree_skb(skb); 559 return 0; 560 } 561 562 static inline struct ipv6_txoptions *create_tel(__u8 encap_limit) 563 { 564 struct ipv6_tlv_tnl_enc_lim *tel; 565 struct ipv6_txoptions *opt; 566 __u8 *raw; 567 568 int opt_len = sizeof(*opt) + 8; 569 570 if (!(opt = kmalloc(opt_len, GFP_ATOMIC))) { 571 return NULL; 572 } 573 memset(opt, 0, opt_len); 574 opt->tot_len = opt_len; 575 opt->dst0opt = (struct ipv6_opt_hdr *) (opt + 1); 576 opt->opt_nflen = 8; 577 578 tel = (struct ipv6_tlv_tnl_enc_lim *) (opt->dst0opt + 1); 579 tel->type = IPV6_TLV_TNL_ENCAP_LIMIT; 580 tel->length = 1; 581 tel->encap_limit = encap_limit; 582 583 raw = (__u8 *) opt->dst0opt; 584 raw[5] = IPV6_TLV_PADN; 585 raw[6] = 1; 586 587 return opt; 588 } 589 590 /** 591 * ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 592 * @t: the outgoing tunnel device 593 * @hdr: IPv6 header from the incoming packet 594 * 595 * Description: 596 * Avoid trivial tunneling loop by checking that tunnel exit-point 597 * doesn't match source of incoming packet. 598 * 599 * Return: 600 * 1 if conflict, 601 * 0 else 602 **/ 603 604 static inline int 605 ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 606 { 607 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 608 } 609 610 /** 611 * ip6ip6_tnl_xmit - encapsulate packet and send 612 * @skb: the outgoing socket buffer 613 * @dev: the outgoing tunnel device 614 * 615 * Description: 616 * Build new header and do some sanity checks on the packet before sending 617 * it. 618 * 619 * Return: 620 * 0 621 **/ 622 623 static int 624 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 625 { 626 struct ip6_tnl *t = netdev_priv(dev); 627 struct net_device_stats *stats = &t->stat; 628 struct ipv6hdr *ipv6h = skb->nh.ipv6h; 629 struct ipv6_txoptions *opt = NULL; 630 int encap_limit = -1; 631 __u16 offset; 632 struct flowi fl; 633 struct dst_entry *dst; 634 struct net_device *tdev; 635 int mtu; 636 int max_headroom = sizeof(struct ipv6hdr); 637 u8 proto; 638 int err; 639 int pkt_len; 640 int dsfield; 641 642 if (t->recursion++) { 643 stats->collisions++; 644 goto tx_err; 645 } 646 if (skb->protocol != htons(ETH_P_IPV6) || 647 !(t->parms.flags & IP6_TNL_F_CAP_XMIT) || 648 ip6ip6_tnl_addr_conflict(t, ipv6h)) { 649 goto tx_err; 650 } 651 if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) { 652 struct ipv6_tlv_tnl_enc_lim *tel; 653 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset]; 654 if (tel->encap_limit == 0) { 655 icmpv6_send(skb, ICMPV6_PARAMPROB, 656 ICMPV6_HDR_FIELD, offset + 2, skb->dev); 657 goto tx_err; 658 } 659 encap_limit = tel->encap_limit - 1; 660 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) { 661 encap_limit = t->parms.encap_limit; 662 } 663 memcpy(&fl, &t->fl, sizeof (fl)); 664 proto = fl.proto; 665 666 dsfield = ipv6_get_dsfield(ipv6h); 667 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 668 fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_TCLASS_MASK); 669 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 670 fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_FLOWLABEL_MASK); 671 672 if (encap_limit >= 0 && (opt = create_tel(encap_limit)) == NULL) 673 goto tx_err; 674 675 if ((dst = ip6_tnl_dst_check(t)) != NULL) 676 dst_hold(dst); 677 else { 678 dst = ip6_route_output(NULL, &fl); 679 680 if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0) 681 goto tx_err_link_failure; 682 } 683 684 tdev = dst->dev; 685 686 if (tdev == dev) { 687 stats->collisions++; 688 if (net_ratelimit()) 689 printk(KERN_WARNING 690 "%s: Local routing loop detected!\n", 691 t->parms.name); 692 goto tx_err_dst_release; 693 } 694 mtu = dst_mtu(dst) - sizeof (*ipv6h); 695 if (opt) { 696 max_headroom += 8; 697 mtu -= 8; 698 } 699 if (mtu < IPV6_MIN_MTU) 700 mtu = IPV6_MIN_MTU; 701 if (skb->dst && mtu < dst_mtu(skb->dst)) { 702 struct rt6_info *rt = (struct rt6_info *) skb->dst; 703 rt->rt6i_flags |= RTF_MODIFIED; 704 rt->u.dst.metrics[RTAX_MTU-1] = mtu; 705 } 706 if (skb->len > mtu) { 707 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 708 goto tx_err_dst_release; 709 } 710 711 /* 712 * Okay, now see if we can stuff it in the buffer as-is. 713 */ 714 max_headroom += LL_RESERVED_SPACE(tdev); 715 716 if (skb_headroom(skb) < max_headroom || 717 skb_cloned(skb) || skb_shared(skb)) { 718 struct sk_buff *new_skb; 719 720 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 721 goto tx_err_dst_release; 722 723 if (skb->sk) 724 skb_set_owner_w(new_skb, skb->sk); 725 kfree_skb(skb); 726 skb = new_skb; 727 } 728 dst_release(skb->dst); 729 skb->dst = dst_clone(dst); 730 731 skb->h.raw = skb->nh.raw; 732 733 if (opt) 734 ipv6_push_nfrag_opts(skb, opt, &proto, NULL); 735 736 skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr)); 737 ipv6h = skb->nh.ipv6h; 738 *(u32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000); 739 dsfield = INET_ECN_encapsulate(0, dsfield); 740 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 741 ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 742 ipv6h->hop_limit = t->parms.hop_limit; 743 ipv6h->nexthdr = proto; 744 ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src); 745 ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst); 746 nf_reset(skb); 747 pkt_len = skb->len; 748 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, 749 skb->dst->dev, dst_output); 750 751 if (err == NET_XMIT_SUCCESS || err == NET_XMIT_CN) { 752 stats->tx_bytes += pkt_len; 753 stats->tx_packets++; 754 } else { 755 stats->tx_errors++; 756 stats->tx_aborted_errors++; 757 } 758 ip6_tnl_dst_store(t, dst); 759 760 kfree(opt); 761 762 t->recursion--; 763 return 0; 764 tx_err_link_failure: 765 stats->tx_carrier_errors++; 766 dst_link_failure(skb); 767 tx_err_dst_release: 768 dst_release(dst); 769 kfree(opt); 770 tx_err: 771 stats->tx_errors++; 772 stats->tx_dropped++; 773 kfree_skb(skb); 774 t->recursion--; 775 return 0; 776 } 777 778 static void ip6_tnl_set_cap(struct ip6_tnl *t) 779 { 780 struct ip6_tnl_parm *p = &t->parms; 781 struct in6_addr *laddr = &p->laddr; 782 struct in6_addr *raddr = &p->raddr; 783 int ltype = ipv6_addr_type(laddr); 784 int rtype = ipv6_addr_type(raddr); 785 786 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 787 788 if (ltype != IPV6_ADDR_ANY && rtype != IPV6_ADDR_ANY && 789 ((ltype|rtype) & 790 (IPV6_ADDR_UNICAST| 791 IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL| 792 IPV6_ADDR_MAPPED|IPV6_ADDR_RESERVED)) == IPV6_ADDR_UNICAST) { 793 struct net_device *ldev = NULL; 794 int l_ok = 1; 795 int r_ok = 1; 796 797 if (p->link) 798 ldev = dev_get_by_index(p->link); 799 800 if (ltype&IPV6_ADDR_UNICAST && !ipv6_chk_addr(laddr, ldev, 0)) 801 l_ok = 0; 802 803 if (rtype&IPV6_ADDR_UNICAST && ipv6_chk_addr(raddr, NULL, 0)) 804 r_ok = 0; 805 806 if (l_ok && r_ok) { 807 if (ltype&IPV6_ADDR_UNICAST) 808 p->flags |= IP6_TNL_F_CAP_XMIT; 809 if (rtype&IPV6_ADDR_UNICAST) 810 p->flags |= IP6_TNL_F_CAP_RCV; 811 } 812 if (ldev) 813 dev_put(ldev); 814 } 815 } 816 817 static void ip6ip6_tnl_link_config(struct ip6_tnl *t) 818 { 819 struct net_device *dev = t->dev; 820 struct ip6_tnl_parm *p = &t->parms; 821 struct flowi *fl = &t->fl; 822 823 memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 824 memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 825 826 /* Set up flowi template */ 827 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 828 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 829 fl->oif = p->link; 830 fl->fl6_flowlabel = 0; 831 832 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 833 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 834 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 835 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 836 837 ip6_tnl_set_cap(t); 838 839 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 840 dev->flags |= IFF_POINTOPOINT; 841 else 842 dev->flags &= ~IFF_POINTOPOINT; 843 844 dev->iflink = p->link; 845 846 if (p->flags & IP6_TNL_F_CAP_XMIT) { 847 struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr, 848 p->link, 0); 849 850 if (rt == NULL) 851 return; 852 853 if (rt->rt6i_dev) { 854 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 855 sizeof (struct ipv6hdr); 856 857 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 858 859 if (dev->mtu < IPV6_MIN_MTU) 860 dev->mtu = IPV6_MIN_MTU; 861 } 862 dst_release(&rt->u.dst); 863 } 864 } 865 866 /** 867 * ip6ip6_tnl_change - update the tunnel parameters 868 * @t: tunnel to be changed 869 * @p: tunnel configuration parameters 870 * @active: != 0 if tunnel is ready for use 871 * 872 * Description: 873 * ip6ip6_tnl_change() updates the tunnel parameters 874 **/ 875 876 static int 877 ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) 878 { 879 ipv6_addr_copy(&t->parms.laddr, &p->laddr); 880 ipv6_addr_copy(&t->parms.raddr, &p->raddr); 881 t->parms.flags = p->flags; 882 t->parms.hop_limit = p->hop_limit; 883 t->parms.encap_limit = p->encap_limit; 884 t->parms.flowinfo = p->flowinfo; 885 t->parms.link = p->link; 886 ip6_tnl_dst_reset(t); 887 ip6ip6_tnl_link_config(t); 888 return 0; 889 } 890 891 /** 892 * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace 893 * @dev: virtual device associated with tunnel 894 * @ifr: parameters passed from userspace 895 * @cmd: command to be performed 896 * 897 * Description: 898 * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels 899 * from userspace. 900 * 901 * The possible commands are the following: 902 * %SIOCGETTUNNEL: get tunnel parameters for device 903 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 904 * %SIOCCHGTUNNEL: change tunnel parameters to those given 905 * %SIOCDELTUNNEL: delete tunnel 906 * 907 * The fallback device "ip6tnl0", created during module 908 * initialization, can be used for creating other tunnel devices. 909 * 910 * Return: 911 * 0 on success, 912 * %-EFAULT if unable to copy data to or from userspace, 913 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 914 * %-EINVAL if passed tunnel parameters are invalid, 915 * %-EEXIST if changing a tunnel's parameters would cause a conflict 916 * %-ENODEV if attempting to change or delete a nonexisting device 917 **/ 918 919 static int 920 ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 921 { 922 int err = 0; 923 int create; 924 struct ip6_tnl_parm p; 925 struct ip6_tnl *t = NULL; 926 927 switch (cmd) { 928 case SIOCGETTUNNEL: 929 if (dev == ip6ip6_fb_tnl_dev) { 930 if (copy_from_user(&p, 931 ifr->ifr_ifru.ifru_data, 932 sizeof (p))) { 933 err = -EFAULT; 934 break; 935 } 936 if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV) 937 t = netdev_priv(dev); 938 else if (err) 939 break; 940 } else 941 t = netdev_priv(dev); 942 943 memcpy(&p, &t->parms, sizeof (p)); 944 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 945 err = -EFAULT; 946 } 947 break; 948 case SIOCADDTUNNEL: 949 case SIOCCHGTUNNEL: 950 err = -EPERM; 951 create = (cmd == SIOCADDTUNNEL); 952 if (!capable(CAP_NET_ADMIN)) 953 break; 954 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 955 err = -EFAULT; 956 break; 957 } 958 if (!create && dev != ip6ip6_fb_tnl_dev) { 959 t = netdev_priv(dev); 960 } 961 if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) { 962 break; 963 } 964 if (cmd == SIOCCHGTUNNEL) { 965 if (t->dev != dev) { 966 err = -EEXIST; 967 break; 968 } 969 ip6ip6_tnl_unlink(t); 970 err = ip6ip6_tnl_change(t, &p); 971 ip6ip6_tnl_link(t); 972 netdev_state_change(dev); 973 } 974 if (copy_to_user(ifr->ifr_ifru.ifru_data, 975 &t->parms, sizeof (p))) { 976 err = -EFAULT; 977 } else { 978 err = 0; 979 } 980 break; 981 case SIOCDELTUNNEL: 982 err = -EPERM; 983 if (!capable(CAP_NET_ADMIN)) 984 break; 985 986 if (dev == ip6ip6_fb_tnl_dev) { 987 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, 988 sizeof (p))) { 989 err = -EFAULT; 990 break; 991 } 992 err = ip6ip6_tnl_locate(&p, &t, 0); 993 if (err) 994 break; 995 if (t == netdev_priv(ip6ip6_fb_tnl_dev)) { 996 err = -EPERM; 997 break; 998 } 999 } else { 1000 t = netdev_priv(dev); 1001 } 1002 err = unregister_netdevice(t->dev); 1003 break; 1004 default: 1005 err = -EINVAL; 1006 } 1007 return err; 1008 } 1009 1010 /** 1011 * ip6ip6_tnl_get_stats - return the stats for tunnel device 1012 * @dev: virtual device associated with tunnel 1013 * 1014 * Return: stats for device 1015 **/ 1016 1017 static struct net_device_stats * 1018 ip6ip6_tnl_get_stats(struct net_device *dev) 1019 { 1020 return &(((struct ip6_tnl *)netdev_priv(dev))->stat); 1021 } 1022 1023 /** 1024 * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device 1025 * @dev: virtual device associated with tunnel 1026 * @new_mtu: the new mtu 1027 * 1028 * Return: 1029 * 0 on success, 1030 * %-EINVAL if mtu too small 1031 **/ 1032 1033 static int 1034 ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1035 { 1036 if (new_mtu < IPV6_MIN_MTU) { 1037 return -EINVAL; 1038 } 1039 dev->mtu = new_mtu; 1040 return 0; 1041 } 1042 1043 /** 1044 * ip6ip6_tnl_dev_setup - setup virtual tunnel device 1045 * @dev: virtual device associated with tunnel 1046 * 1047 * Description: 1048 * Initialize function pointers and device parameters 1049 **/ 1050 1051 static void ip6ip6_tnl_dev_setup(struct net_device *dev) 1052 { 1053 SET_MODULE_OWNER(dev); 1054 dev->uninit = ip6ip6_tnl_dev_uninit; 1055 dev->destructor = free_netdev; 1056 dev->hard_start_xmit = ip6ip6_tnl_xmit; 1057 dev->get_stats = ip6ip6_tnl_get_stats; 1058 dev->do_ioctl = ip6ip6_tnl_ioctl; 1059 dev->change_mtu = ip6ip6_tnl_change_mtu; 1060 1061 dev->type = ARPHRD_TUNNEL6; 1062 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1063 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1064 dev->flags |= IFF_NOARP; 1065 dev->addr_len = sizeof(struct in6_addr); 1066 } 1067 1068 1069 /** 1070 * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1071 * @dev: virtual device associated with tunnel 1072 **/ 1073 1074 static inline void 1075 ip6ip6_tnl_dev_init_gen(struct net_device *dev) 1076 { 1077 struct ip6_tnl *t = netdev_priv(dev); 1078 t->fl.proto = IPPROTO_IPV6; 1079 t->dev = dev; 1080 strcpy(t->parms.name, dev->name); 1081 } 1082 1083 /** 1084 * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1085 * @dev: virtual device associated with tunnel 1086 **/ 1087 1088 static int 1089 ip6ip6_tnl_dev_init(struct net_device *dev) 1090 { 1091 struct ip6_tnl *t = netdev_priv(dev); 1092 ip6ip6_tnl_dev_init_gen(dev); 1093 ip6ip6_tnl_link_config(t); 1094 return 0; 1095 } 1096 1097 /** 1098 * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1099 * @dev: fallback device 1100 * 1101 * Return: 0 1102 **/ 1103 1104 static int 1105 ip6ip6_fb_tnl_dev_init(struct net_device *dev) 1106 { 1107 struct ip6_tnl *t = netdev_priv(dev); 1108 ip6ip6_tnl_dev_init_gen(dev); 1109 dev_hold(dev); 1110 tnls_wc[0] = t; 1111 return 0; 1112 } 1113 1114 static struct xfrm6_tunnel ip6ip6_handler = { 1115 .handler = ip6ip6_rcv, 1116 .err_handler = ip6ip6_err, 1117 .priority = 1, 1118 }; 1119 1120 /** 1121 * ip6_tunnel_init - register protocol and reserve needed resources 1122 * 1123 * Return: 0 on success 1124 **/ 1125 1126 static int __init ip6_tunnel_init(void) 1127 { 1128 int err; 1129 1130 if (xfrm6_tunnel_register(&ip6ip6_handler)) { 1131 printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); 1132 return -EAGAIN; 1133 } 1134 ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1135 ip6ip6_tnl_dev_setup); 1136 1137 if (!ip6ip6_fb_tnl_dev) { 1138 err = -ENOMEM; 1139 goto fail; 1140 } 1141 ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; 1142 1143 if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { 1144 free_netdev(ip6ip6_fb_tnl_dev); 1145 goto fail; 1146 } 1147 return 0; 1148 fail: 1149 xfrm6_tunnel_deregister(&ip6ip6_handler); 1150 return err; 1151 } 1152 1153 /** 1154 * ip6_tunnel_cleanup - free resources and unregister protocol 1155 **/ 1156 1157 static void __exit ip6_tunnel_cleanup(void) 1158 { 1159 if (xfrm6_tunnel_deregister(&ip6ip6_handler)) 1160 printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); 1161 1162 unregister_netdev(ip6ip6_fb_tnl_dev); 1163 } 1164 1165 module_init(ip6_tunnel_init); 1166 module_exit(ip6_tunnel_cleanup); 1167