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/config.h> 23 #include <linux/module.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/protocol.h> 47 #include <net/ip6_route.h> 48 #include <net/addrconf.h> 49 #include <net/ip6_tunnel.h> 50 #include <net/xfrm.h> 51 #include <net/dsfield.h> 52 #include <net/inet_ecn.h> 53 54 MODULE_AUTHOR("Ville Nuorvala"); 55 MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel"); 56 MODULE_LICENSE("GPL"); 57 58 #define IPV6_TLV_TEL_DST_SIZE 8 59 60 #ifdef IP6_TNL_DEBUG 61 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__) 62 #else 63 #define IP6_TNL_TRACE(x...) do {;} while(0) 64 #endif 65 66 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 67 68 #define HASH_SIZE 32 69 70 #define HASH(addr) (((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ 71 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ 72 (HASH_SIZE - 1)) 73 74 static int ip6ip6_fb_tnl_dev_init(struct net_device *dev); 75 static int ip6ip6_tnl_dev_init(struct net_device *dev); 76 static void ip6ip6_tnl_dev_setup(struct net_device *dev); 77 78 /* the IPv6 tunnel fallback device */ 79 static struct net_device *ip6ip6_fb_tnl_dev; 80 81 82 /* lists for storing tunnels in use */ 83 static struct ip6_tnl *tnls_r_l[HASH_SIZE]; 84 static struct ip6_tnl *tnls_wc[1]; 85 static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l }; 86 87 /* lock for the tunnel lists */ 88 static DEFINE_RWLOCK(ip6ip6_lock); 89 90 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 91 { 92 struct dst_entry *dst = t->dst_cache; 93 94 if (dst && dst->obsolete && 95 dst->ops->check(dst, t->dst_cookie) == NULL) { 96 t->dst_cache = NULL; 97 dst_release(dst); 98 return NULL; 99 } 100 101 return dst; 102 } 103 104 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) 105 { 106 dst_release(t->dst_cache); 107 t->dst_cache = NULL; 108 } 109 110 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 111 { 112 struct rt6_info *rt = (struct rt6_info *) dst; 113 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 114 dst_release(t->dst_cache); 115 t->dst_cache = dst; 116 } 117 118 /** 119 * ip6ip6_tnl_lookup - fetch tunnel matching the end-point addresses 120 * @remote: the address of the tunnel exit-point 121 * @local: the address of the tunnel entry-point 122 * 123 * Return: 124 * tunnel matching given end-points if found, 125 * else fallback tunnel if its device is up, 126 * else %NULL 127 **/ 128 129 static struct ip6_tnl * 130 ip6ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local) 131 { 132 unsigned h0 = HASH(remote); 133 unsigned h1 = HASH(local); 134 struct ip6_tnl *t; 135 136 for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) { 137 if (ipv6_addr_equal(local, &t->parms.laddr) && 138 ipv6_addr_equal(remote, &t->parms.raddr) && 139 (t->dev->flags & IFF_UP)) 140 return t; 141 } 142 if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP)) 143 return t; 144 145 return NULL; 146 } 147 148 /** 149 * ip6ip6_bucket - get head of list matching given tunnel parameters 150 * @p: parameters containing tunnel end-points 151 * 152 * Description: 153 * ip6ip6_bucket() returns the head of the list matching the 154 * &struct in6_addr entries laddr and raddr in @p. 155 * 156 * Return: head of IPv6 tunnel list 157 **/ 158 159 static struct ip6_tnl ** 160 ip6ip6_bucket(struct ip6_tnl_parm *p) 161 { 162 struct in6_addr *remote = &p->raddr; 163 struct in6_addr *local = &p->laddr; 164 unsigned h = 0; 165 int prio = 0; 166 167 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 168 prio = 1; 169 h = HASH(remote) ^ HASH(local); 170 } 171 return &tnls[prio][h]; 172 } 173 174 /** 175 * ip6ip6_tnl_link - add tunnel to hash table 176 * @t: tunnel to be added 177 **/ 178 179 static void 180 ip6ip6_tnl_link(struct ip6_tnl *t) 181 { 182 struct ip6_tnl **tp = ip6ip6_bucket(&t->parms); 183 184 t->next = *tp; 185 write_lock_bh(&ip6ip6_lock); 186 *tp = t; 187 write_unlock_bh(&ip6ip6_lock); 188 } 189 190 /** 191 * ip6ip6_tnl_unlink - remove tunnel from hash table 192 * @t: tunnel to be removed 193 **/ 194 195 static void 196 ip6ip6_tnl_unlink(struct ip6_tnl *t) 197 { 198 struct ip6_tnl **tp; 199 200 for (tp = ip6ip6_bucket(&t->parms); *tp; tp = &(*tp)->next) { 201 if (t == *tp) { 202 write_lock_bh(&ip6ip6_lock); 203 *tp = t->next; 204 write_unlock_bh(&ip6ip6_lock); 205 break; 206 } 207 } 208 } 209 210 /** 211 * ip6_tnl_create() - create a new tunnel 212 * @p: tunnel parameters 213 * @pt: pointer to new tunnel 214 * 215 * Description: 216 * Create tunnel matching given parameters. 217 * 218 * Return: 219 * 0 on success 220 **/ 221 222 static int 223 ip6_tnl_create(struct ip6_tnl_parm *p, struct ip6_tnl **pt) 224 { 225 struct net_device *dev; 226 struct ip6_tnl *t; 227 char name[IFNAMSIZ]; 228 int err; 229 230 if (p->name[0]) { 231 strlcpy(name, p->name, IFNAMSIZ); 232 } else { 233 int i; 234 for (i = 1; i < IP6_TNL_MAX; i++) { 235 sprintf(name, "ip6tnl%d", i); 236 if (__dev_get_by_name(name) == NULL) 237 break; 238 } 239 if (i == IP6_TNL_MAX) 240 return -ENOBUFS; 241 } 242 dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup); 243 if (dev == NULL) 244 return -ENOMEM; 245 246 t = netdev_priv(dev); 247 dev->init = ip6ip6_tnl_dev_init; 248 t->parms = *p; 249 250 if ((err = register_netdevice(dev)) < 0) { 251 free_netdev(dev); 252 return err; 253 } 254 dev_hold(dev); 255 256 ip6ip6_tnl_link(t); 257 *pt = t; 258 return 0; 259 } 260 261 /** 262 * ip6ip6_tnl_locate - find or create tunnel matching given parameters 263 * @p: tunnel parameters 264 * @create: != 0 if allowed to create new tunnel if no match found 265 * 266 * Description: 267 * ip6ip6_tnl_locate() first tries to locate an existing tunnel 268 * based on @parms. If this is unsuccessful, but @create is set a new 269 * tunnel device is created and registered for use. 270 * 271 * Return: 272 * 0 if tunnel located or created, 273 * -EINVAL if parameters incorrect, 274 * -ENODEV if no matching tunnel available 275 **/ 276 277 static int 278 ip6ip6_tnl_locate(struct ip6_tnl_parm *p, struct ip6_tnl **pt, int create) 279 { 280 struct in6_addr *remote = &p->raddr; 281 struct in6_addr *local = &p->laddr; 282 struct ip6_tnl *t; 283 284 if (p->proto != IPPROTO_IPV6) 285 return -EINVAL; 286 287 for (t = *ip6ip6_bucket(p); t; t = t->next) { 288 if (ipv6_addr_equal(local, &t->parms.laddr) && 289 ipv6_addr_equal(remote, &t->parms.raddr)) { 290 *pt = t; 291 return (create ? -EEXIST : 0); 292 } 293 } 294 if (!create) 295 return -ENODEV; 296 297 return ip6_tnl_create(p, pt); 298 } 299 300 /** 301 * ip6ip6_tnl_dev_uninit - tunnel device uninitializer 302 * @dev: the device to be destroyed 303 * 304 * Description: 305 * ip6ip6_tnl_dev_uninit() removes tunnel from its list 306 **/ 307 308 static void 309 ip6ip6_tnl_dev_uninit(struct net_device *dev) 310 { 311 struct ip6_tnl *t = netdev_priv(dev); 312 313 if (dev == ip6ip6_fb_tnl_dev) { 314 write_lock_bh(&ip6ip6_lock); 315 tnls_wc[0] = NULL; 316 write_unlock_bh(&ip6ip6_lock); 317 } else { 318 ip6ip6_tnl_unlink(t); 319 } 320 ip6_tnl_dst_reset(t); 321 dev_put(dev); 322 } 323 324 /** 325 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 326 * @skb: received socket buffer 327 * 328 * Return: 329 * 0 if none was found, 330 * else index to encapsulation limit 331 **/ 332 333 static __u16 334 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 335 { 336 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 337 __u8 nexthdr = ipv6h->nexthdr; 338 __u16 off = sizeof (*ipv6h); 339 340 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 341 __u16 optlen = 0; 342 struct ipv6_opt_hdr *hdr; 343 if (raw + off + sizeof (*hdr) > skb->data && 344 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 345 break; 346 347 hdr = (struct ipv6_opt_hdr *) (raw + off); 348 if (nexthdr == NEXTHDR_FRAGMENT) { 349 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 350 if (frag_hdr->frag_off) 351 break; 352 optlen = 8; 353 } else if (nexthdr == NEXTHDR_AUTH) { 354 optlen = (hdr->hdrlen + 2) << 2; 355 } else { 356 optlen = ipv6_optlen(hdr); 357 } 358 if (nexthdr == NEXTHDR_DEST) { 359 __u16 i = off + 2; 360 while (1) { 361 struct ipv6_tlv_tnl_enc_lim *tel; 362 363 /* No more room for encapsulation limit */ 364 if (i + sizeof (*tel) > off + optlen) 365 break; 366 367 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 368 /* return index of option if found and valid */ 369 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 370 tel->length == 1) 371 return i; 372 /* else jump to next option */ 373 if (tel->type) 374 i += tel->length + 2; 375 else 376 i++; 377 } 378 } 379 nexthdr = hdr->nexthdr; 380 off += optlen; 381 } 382 return 0; 383 } 384 385 /** 386 * ip6ip6_err - tunnel error handler 387 * 388 * Description: 389 * ip6ip6_err() should handle errors in the tunnel according 390 * to the specifications in RFC 2473. 391 **/ 392 393 static void 394 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 395 int type, int code, int offset, __u32 info) 396 { 397 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 398 struct ip6_tnl *t; 399 int rel_msg = 0; 400 int rel_type = ICMPV6_DEST_UNREACH; 401 int rel_code = ICMPV6_ADDR_UNREACH; 402 __u32 rel_info = 0; 403 __u16 len; 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 switch (type) { 414 __u32 teli; 415 struct ipv6_tlv_tnl_enc_lim *tel; 416 __u32 mtu; 417 case ICMPV6_DEST_UNREACH: 418 if (net_ratelimit()) 419 printk(KERN_WARNING 420 "%s: Path to destination invalid " 421 "or inactive!\n", t->parms.name); 422 rel_msg = 1; 423 break; 424 case ICMPV6_TIME_EXCEED: 425 if (code == ICMPV6_EXC_HOPLIMIT) { 426 if (net_ratelimit()) 427 printk(KERN_WARNING 428 "%s: Too small hop limit or " 429 "routing loop in tunnel!\n", 430 t->parms.name); 431 rel_msg = 1; 432 } 433 break; 434 case ICMPV6_PARAMPROB: 435 /* ignore if parameter problem not caused by a tunnel 436 encapsulation limit sub-option */ 437 if (code != ICMPV6_HDR_FIELD) { 438 break; 439 } 440 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 441 442 if (teli && teli == ntohl(info) - 2) { 443 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 444 if (tel->encap_limit == 0) { 445 if (net_ratelimit()) 446 printk(KERN_WARNING 447 "%s: Too small encapsulation " 448 "limit or routing loop in " 449 "tunnel!\n", t->parms.name); 450 rel_msg = 1; 451 } 452 } 453 break; 454 case ICMPV6_PKT_TOOBIG: 455 mtu = ntohl(info) - offset; 456 if (mtu < IPV6_MIN_MTU) 457 mtu = IPV6_MIN_MTU; 458 t->dev->mtu = mtu; 459 460 if ((len = sizeof (*ipv6h) + ipv6h->payload_len) > mtu) { 461 rel_type = ICMPV6_PKT_TOOBIG; 462 rel_code = 0; 463 rel_info = mtu; 464 rel_msg = 1; 465 } 466 break; 467 } 468 if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { 469 struct rt6_info *rt; 470 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 471 if (!skb2) 472 goto out; 473 474 dst_release(skb2->dst); 475 skb2->dst = NULL; 476 skb_pull(skb2, offset); 477 skb2->nh.raw = skb2->data; 478 479 /* Try to guess incoming interface */ 480 rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); 481 482 if (rt && rt->rt6i_dev) 483 skb2->dev = rt->rt6i_dev; 484 485 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 486 487 if (rt) 488 dst_release(&rt->u.dst); 489 490 kfree_skb(skb2); 491 } 492 out: 493 read_unlock(&ip6ip6_lock); 494 } 495 496 static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, 497 struct sk_buff *skb) 498 { 499 struct ipv6hdr *inner_iph = skb->nh.ipv6h; 500 501 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) 502 IP6_ECN_set_ce(inner_iph); 503 } 504 505 /** 506 * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally 507 * @skb: received socket buffer 508 * 509 * Return: 0 510 **/ 511 512 static int 513 ip6ip6_rcv(struct sk_buff **pskb) 514 { 515 struct sk_buff *skb = *pskb; 516 struct ipv6hdr *ipv6h; 517 struct ip6_tnl *t; 518 519 if (!pskb_may_pull(skb, sizeof (*ipv6h))) 520 goto discard; 521 522 ipv6h = skb->nh.ipv6h; 523 524 read_lock(&ip6ip6_lock); 525 526 if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { 527 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 528 read_unlock(&ip6ip6_lock); 529 kfree_skb(skb); 530 return 0; 531 } 532 533 if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) { 534 t->stat.rx_dropped++; 535 read_unlock(&ip6ip6_lock); 536 goto discard; 537 } 538 secpath_reset(skb); 539 skb->mac.raw = skb->nh.raw; 540 skb->nh.raw = skb->data; 541 skb->protocol = htons(ETH_P_IPV6); 542 skb->pkt_type = PACKET_HOST; 543 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 544 skb->dev = t->dev; 545 dst_release(skb->dst); 546 skb->dst = NULL; 547 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 548 ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); 549 ip6ip6_ecn_decapsulate(ipv6h, skb); 550 t->stat.rx_packets++; 551 t->stat.rx_bytes += skb->len; 552 netif_rx(skb); 553 read_unlock(&ip6ip6_lock); 554 return 0; 555 } 556 read_unlock(&ip6ip6_lock); 557 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev); 558 discard: 559 return 1; 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 ip6ip6_tnl_link_config(t); 887 return 0; 888 } 889 890 /** 891 * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace 892 * @dev: virtual device associated with tunnel 893 * @ifr: parameters passed from userspace 894 * @cmd: command to be performed 895 * 896 * Description: 897 * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels 898 * from userspace. 899 * 900 * The possible commands are the following: 901 * %SIOCGETTUNNEL: get tunnel parameters for device 902 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 903 * %SIOCCHGTUNNEL: change tunnel parameters to those given 904 * %SIOCDELTUNNEL: delete tunnel 905 * 906 * The fallback device "ip6tnl0", created during module 907 * initialization, can be used for creating other tunnel devices. 908 * 909 * Return: 910 * 0 on success, 911 * %-EFAULT if unable to copy data to or from userspace, 912 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 913 * %-EINVAL if passed tunnel parameters are invalid, 914 * %-EEXIST if changing a tunnel's parameters would cause a conflict 915 * %-ENODEV if attempting to change or delete a nonexisting device 916 **/ 917 918 static int 919 ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 920 { 921 int err = 0; 922 int create; 923 struct ip6_tnl_parm p; 924 struct ip6_tnl *t = NULL; 925 926 switch (cmd) { 927 case SIOCGETTUNNEL: 928 if (dev == ip6ip6_fb_tnl_dev) { 929 if (copy_from_user(&p, 930 ifr->ifr_ifru.ifru_data, 931 sizeof (p))) { 932 err = -EFAULT; 933 break; 934 } 935 if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV) 936 t = netdev_priv(dev); 937 else if (err) 938 break; 939 } else 940 t = netdev_priv(dev); 941 942 memcpy(&p, &t->parms, sizeof (p)); 943 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 944 err = -EFAULT; 945 } 946 break; 947 case SIOCADDTUNNEL: 948 case SIOCCHGTUNNEL: 949 err = -EPERM; 950 create = (cmd == SIOCADDTUNNEL); 951 if (!capable(CAP_NET_ADMIN)) 952 break; 953 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 954 err = -EFAULT; 955 break; 956 } 957 if (!create && dev != ip6ip6_fb_tnl_dev) { 958 t = netdev_priv(dev); 959 } 960 if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) { 961 break; 962 } 963 if (cmd == SIOCCHGTUNNEL) { 964 if (t->dev != dev) { 965 err = -EEXIST; 966 break; 967 } 968 ip6ip6_tnl_unlink(t); 969 err = ip6ip6_tnl_change(t, &p); 970 ip6ip6_tnl_link(t); 971 netdev_state_change(dev); 972 } 973 if (copy_to_user(ifr->ifr_ifru.ifru_data, 974 &t->parms, sizeof (p))) { 975 err = -EFAULT; 976 } else { 977 err = 0; 978 } 979 break; 980 case SIOCDELTUNNEL: 981 err = -EPERM; 982 if (!capable(CAP_NET_ADMIN)) 983 break; 984 985 if (dev == ip6ip6_fb_tnl_dev) { 986 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, 987 sizeof (p))) { 988 err = -EFAULT; 989 break; 990 } 991 err = ip6ip6_tnl_locate(&p, &t, 0); 992 if (err) 993 break; 994 if (t == netdev_priv(ip6ip6_fb_tnl_dev)) { 995 err = -EPERM; 996 break; 997 } 998 } else { 999 t = netdev_priv(dev); 1000 } 1001 err = unregister_netdevice(t->dev); 1002 break; 1003 default: 1004 err = -EINVAL; 1005 } 1006 return err; 1007 } 1008 1009 /** 1010 * ip6ip6_tnl_get_stats - return the stats for tunnel device 1011 * @dev: virtual device associated with tunnel 1012 * 1013 * Return: stats for device 1014 **/ 1015 1016 static struct net_device_stats * 1017 ip6ip6_tnl_get_stats(struct net_device *dev) 1018 { 1019 return &(((struct ip6_tnl *)netdev_priv(dev))->stat); 1020 } 1021 1022 /** 1023 * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device 1024 * @dev: virtual device associated with tunnel 1025 * @new_mtu: the new mtu 1026 * 1027 * Return: 1028 * 0 on success, 1029 * %-EINVAL if mtu too small 1030 **/ 1031 1032 static int 1033 ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1034 { 1035 if (new_mtu < IPV6_MIN_MTU) { 1036 return -EINVAL; 1037 } 1038 dev->mtu = new_mtu; 1039 return 0; 1040 } 1041 1042 /** 1043 * ip6ip6_tnl_dev_setup - setup virtual tunnel device 1044 * @dev: virtual device associated with tunnel 1045 * 1046 * Description: 1047 * Initialize function pointers and device parameters 1048 **/ 1049 1050 static void ip6ip6_tnl_dev_setup(struct net_device *dev) 1051 { 1052 SET_MODULE_OWNER(dev); 1053 dev->uninit = ip6ip6_tnl_dev_uninit; 1054 dev->destructor = free_netdev; 1055 dev->hard_start_xmit = ip6ip6_tnl_xmit; 1056 dev->get_stats = ip6ip6_tnl_get_stats; 1057 dev->do_ioctl = ip6ip6_tnl_ioctl; 1058 dev->change_mtu = ip6ip6_tnl_change_mtu; 1059 1060 dev->type = ARPHRD_TUNNEL6; 1061 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1062 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1063 dev->flags |= IFF_NOARP; 1064 dev->addr_len = sizeof(struct in6_addr); 1065 } 1066 1067 1068 /** 1069 * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1070 * @dev: virtual device associated with tunnel 1071 **/ 1072 1073 static inline void 1074 ip6ip6_tnl_dev_init_gen(struct net_device *dev) 1075 { 1076 struct ip6_tnl *t = netdev_priv(dev); 1077 t->fl.proto = IPPROTO_IPV6; 1078 t->dev = dev; 1079 strcpy(t->parms.name, dev->name); 1080 } 1081 1082 /** 1083 * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1084 * @dev: virtual device associated with tunnel 1085 **/ 1086 1087 static int 1088 ip6ip6_tnl_dev_init(struct net_device *dev) 1089 { 1090 struct ip6_tnl *t = netdev_priv(dev); 1091 ip6ip6_tnl_dev_init_gen(dev); 1092 ip6ip6_tnl_link_config(t); 1093 return 0; 1094 } 1095 1096 /** 1097 * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1098 * @dev: fallback device 1099 * 1100 * Return: 0 1101 **/ 1102 1103 static int 1104 ip6ip6_fb_tnl_dev_init(struct net_device *dev) 1105 { 1106 struct ip6_tnl *t = netdev_priv(dev); 1107 ip6ip6_tnl_dev_init_gen(dev); 1108 dev_hold(dev); 1109 tnls_wc[0] = t; 1110 return 0; 1111 } 1112 1113 #ifdef CONFIG_INET6_TUNNEL 1114 static struct xfrm6_tunnel ip6ip6_handler = { 1115 .handler = ip6ip6_rcv, 1116 .err_handler = ip6ip6_err, 1117 }; 1118 1119 static inline int ip6ip6_register(void) 1120 { 1121 return xfrm6_tunnel_register(&ip6ip6_handler); 1122 } 1123 1124 static inline int ip6ip6_unregister(void) 1125 { 1126 return xfrm6_tunnel_deregister(&ip6ip6_handler); 1127 } 1128 #else 1129 static struct inet6_protocol xfrm6_tunnel_protocol = { 1130 .handler = ip6ip6_rcv, 1131 .err_handler = ip6ip6_err, 1132 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1133 }; 1134 1135 static inline int ip6ip6_register(void) 1136 { 1137 return inet6_add_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6); 1138 } 1139 1140 static inline int ip6ip6_unregister(void) 1141 { 1142 return inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6); 1143 } 1144 #endif 1145 1146 /** 1147 * ip6_tunnel_init - register protocol and reserve needed resources 1148 * 1149 * Return: 0 on success 1150 **/ 1151 1152 static int __init ip6_tunnel_init(void) 1153 { 1154 int err; 1155 1156 if (ip6ip6_register() < 0) { 1157 printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); 1158 return -EAGAIN; 1159 } 1160 ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1161 ip6ip6_tnl_dev_setup); 1162 1163 if (!ip6ip6_fb_tnl_dev) { 1164 err = -ENOMEM; 1165 goto fail; 1166 } 1167 ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; 1168 1169 if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { 1170 free_netdev(ip6ip6_fb_tnl_dev); 1171 goto fail; 1172 } 1173 return 0; 1174 fail: 1175 ip6ip6_unregister(); 1176 return err; 1177 } 1178 1179 /** 1180 * ip6_tunnel_cleanup - free resources and unregister protocol 1181 **/ 1182 1183 static void __exit ip6_tunnel_cleanup(void) 1184 { 1185 if (ip6ip6_unregister() < 0) 1186 printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); 1187 1188 unregister_netdev(ip6ip6_fb_tnl_dev); 1189 } 1190 1191 module_init(ip6_tunnel_init); 1192 module_exit(ip6_tunnel_cleanup); 1193