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) ((__force u32)((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 * created tunnel or NULL 219 **/ 220 221 static struct ip6_tnl *ip6_tnl_create(struct ip6_tnl_parm *p) 222 { 223 struct net_device *dev; 224 struct ip6_tnl *t; 225 char name[IFNAMSIZ]; 226 int err; 227 228 if (p->name[0]) { 229 strlcpy(name, p->name, IFNAMSIZ); 230 } else { 231 int i; 232 for (i = 1; i < IP6_TNL_MAX; i++) { 233 sprintf(name, "ip6tnl%d", i); 234 if (__dev_get_by_name(name) == NULL) 235 break; 236 } 237 if (i == IP6_TNL_MAX) 238 goto failed; 239 } 240 dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup); 241 if (dev == NULL) 242 goto failed; 243 244 t = netdev_priv(dev); 245 dev->init = ip6ip6_tnl_dev_init; 246 t->parms = *p; 247 248 if ((err = register_netdevice(dev)) < 0) { 249 free_netdev(dev); 250 goto failed; 251 } 252 dev_hold(dev); 253 ip6ip6_tnl_link(t); 254 return t; 255 failed: 256 return NULL; 257 } 258 259 /** 260 * ip6ip6_tnl_locate - find or create tunnel matching given parameters 261 * @p: tunnel parameters 262 * @create: != 0 if allowed to create new tunnel if no match found 263 * 264 * Description: 265 * ip6ip6_tnl_locate() first tries to locate an existing tunnel 266 * based on @parms. If this is unsuccessful, but @create is set a new 267 * tunnel device is created and registered for use. 268 * 269 * Return: 270 * matching tunnel or NULL 271 **/ 272 273 static struct ip6_tnl *ip6ip6_tnl_locate(struct ip6_tnl_parm *p, int create) 274 { 275 struct in6_addr *remote = &p->raddr; 276 struct in6_addr *local = &p->laddr; 277 struct ip6_tnl *t; 278 279 for (t = *ip6ip6_bucket(p); t; t = t->next) { 280 if (ipv6_addr_equal(local, &t->parms.laddr) && 281 ipv6_addr_equal(remote, &t->parms.raddr)) 282 return t; 283 } 284 if (!create) 285 return NULL; 286 return ip6_tnl_create(p); 287 } 288 289 /** 290 * ip6ip6_tnl_dev_uninit - tunnel device uninitializer 291 * @dev: the device to be destroyed 292 * 293 * Description: 294 * ip6ip6_tnl_dev_uninit() removes tunnel from its list 295 **/ 296 297 static void 298 ip6ip6_tnl_dev_uninit(struct net_device *dev) 299 { 300 struct ip6_tnl *t = netdev_priv(dev); 301 302 if (dev == ip6ip6_fb_tnl_dev) { 303 write_lock_bh(&ip6ip6_lock); 304 tnls_wc[0] = NULL; 305 write_unlock_bh(&ip6ip6_lock); 306 } else { 307 ip6ip6_tnl_unlink(t); 308 } 309 ip6_tnl_dst_reset(t); 310 dev_put(dev); 311 } 312 313 /** 314 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 315 * @skb: received socket buffer 316 * 317 * Return: 318 * 0 if none was found, 319 * else index to encapsulation limit 320 **/ 321 322 static __u16 323 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 324 { 325 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 326 __u8 nexthdr = ipv6h->nexthdr; 327 __u16 off = sizeof (*ipv6h); 328 329 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 330 __u16 optlen = 0; 331 struct ipv6_opt_hdr *hdr; 332 if (raw + off + sizeof (*hdr) > skb->data && 333 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 334 break; 335 336 hdr = (struct ipv6_opt_hdr *) (raw + off); 337 if (nexthdr == NEXTHDR_FRAGMENT) { 338 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 339 if (frag_hdr->frag_off) 340 break; 341 optlen = 8; 342 } else if (nexthdr == NEXTHDR_AUTH) { 343 optlen = (hdr->hdrlen + 2) << 2; 344 } else { 345 optlen = ipv6_optlen(hdr); 346 } 347 if (nexthdr == NEXTHDR_DEST) { 348 __u16 i = off + 2; 349 while (1) { 350 struct ipv6_tlv_tnl_enc_lim *tel; 351 352 /* No more room for encapsulation limit */ 353 if (i + sizeof (*tel) > off + optlen) 354 break; 355 356 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 357 /* return index of option if found and valid */ 358 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 359 tel->length == 1) 360 return i; 361 /* else jump to next option */ 362 if (tel->type) 363 i += tel->length + 2; 364 else 365 i++; 366 } 367 } 368 nexthdr = hdr->nexthdr; 369 off += optlen; 370 } 371 return 0; 372 } 373 374 /** 375 * ip6ip6_err - tunnel error handler 376 * 377 * Description: 378 * ip6ip6_err() should handle errors in the tunnel according 379 * to the specifications in RFC 2473. 380 **/ 381 382 static int 383 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 384 int type, int code, int offset, __be32 info) 385 { 386 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 387 struct ip6_tnl *t; 388 int rel_msg = 0; 389 int rel_type = ICMPV6_DEST_UNREACH; 390 int rel_code = ICMPV6_ADDR_UNREACH; 391 __u32 rel_info = 0; 392 __u16 len; 393 int err = -ENOENT; 394 395 /* If the packet doesn't contain the original IPv6 header we are 396 in trouble since we might need the source address for further 397 processing of the error. */ 398 399 read_lock(&ip6ip6_lock); 400 if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL) 401 goto out; 402 403 err = 0; 404 405 switch (type) { 406 __u32 teli; 407 struct ipv6_tlv_tnl_enc_lim *tel; 408 __u32 mtu; 409 case ICMPV6_DEST_UNREACH: 410 if (net_ratelimit()) 411 printk(KERN_WARNING 412 "%s: Path to destination invalid " 413 "or inactive!\n", t->parms.name); 414 rel_msg = 1; 415 break; 416 case ICMPV6_TIME_EXCEED: 417 if (code == ICMPV6_EXC_HOPLIMIT) { 418 if (net_ratelimit()) 419 printk(KERN_WARNING 420 "%s: Too small hop limit or " 421 "routing loop in tunnel!\n", 422 t->parms.name); 423 rel_msg = 1; 424 } 425 break; 426 case ICMPV6_PARAMPROB: 427 teli = 0; 428 if (code == ICMPV6_HDR_FIELD) 429 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 430 431 if (teli && teli == ntohl(info) - 2) { 432 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 433 if (tel->encap_limit == 0) { 434 if (net_ratelimit()) 435 printk(KERN_WARNING 436 "%s: Too small encapsulation " 437 "limit or routing loop in " 438 "tunnel!\n", t->parms.name); 439 rel_msg = 1; 440 } 441 } else if (net_ratelimit()) { 442 printk(KERN_WARNING 443 "%s: Recipient unable to parse tunneled " 444 "packet!\n ", t->parms.name); 445 } 446 break; 447 case ICMPV6_PKT_TOOBIG: 448 mtu = ntohl(info) - offset; 449 if (mtu < IPV6_MIN_MTU) 450 mtu = IPV6_MIN_MTU; 451 t->dev->mtu = mtu; 452 453 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 454 rel_type = ICMPV6_PKT_TOOBIG; 455 rel_code = 0; 456 rel_info = mtu; 457 rel_msg = 1; 458 } 459 break; 460 } 461 if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { 462 struct rt6_info *rt; 463 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 464 465 if (!skb2) 466 goto out; 467 468 dst_release(skb2->dst); 469 skb2->dst = NULL; 470 skb_pull(skb2, offset); 471 skb2->nh.raw = skb2->data; 472 473 /* Try to guess incoming interface */ 474 rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); 475 476 if (rt && rt->rt6i_dev) 477 skb2->dev = rt->rt6i_dev; 478 479 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 480 481 if (rt) 482 dst_release(&rt->u.dst); 483 484 kfree_skb(skb2); 485 } 486 out: 487 read_unlock(&ip6ip6_lock); 488 return err; 489 } 490 491 static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, 492 struct sk_buff *skb) 493 { 494 struct ipv6hdr *inner_iph = skb->nh.ipv6h; 495 496 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) 497 IP6_ECN_set_ce(inner_iph); 498 } 499 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) 500 { 501 struct ip6_tnl_parm *p = &t->parms; 502 int ret = 0; 503 504 if (p->flags & IP6_TNL_F_CAP_RCV) { 505 struct net_device *ldev = NULL; 506 507 if (p->link) 508 ldev = dev_get_by_index(p->link); 509 510 if ((ipv6_addr_is_multicast(&p->laddr) || 511 likely(ipv6_chk_addr(&p->laddr, ldev, 0))) && 512 likely(!ipv6_chk_addr(&p->raddr, NULL, 0))) 513 ret = 1; 514 515 if (ldev) 516 dev_put(ldev); 517 } 518 return ret; 519 } 520 521 /** 522 * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally 523 * @skb: received socket buffer 524 * 525 * Return: 0 526 **/ 527 528 static int 529 ip6ip6_rcv(struct sk_buff *skb) 530 { 531 struct ipv6hdr *ipv6h; 532 struct ip6_tnl *t; 533 534 ipv6h = skb->nh.ipv6h; 535 536 read_lock(&ip6ip6_lock); 537 538 if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { 539 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 540 read_unlock(&ip6ip6_lock); 541 goto discard; 542 } 543 544 if (!ip6_tnl_rcv_ctl(t)) { 545 t->stat.rx_dropped++; 546 read_unlock(&ip6ip6_lock); 547 goto discard; 548 } 549 secpath_reset(skb); 550 skb->mac.raw = skb->nh.raw; 551 skb->nh.raw = skb->data; 552 skb->protocol = htons(ETH_P_IPV6); 553 skb->pkt_type = PACKET_HOST; 554 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 555 skb->dev = t->dev; 556 dst_release(skb->dst); 557 skb->dst = NULL; 558 nf_reset(skb); 559 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 560 ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); 561 ip6ip6_ecn_decapsulate(ipv6h, skb); 562 t->stat.rx_packets++; 563 t->stat.rx_bytes += skb->len; 564 netif_rx(skb); 565 read_unlock(&ip6ip6_lock); 566 return 0; 567 } 568 read_unlock(&ip6ip6_lock); 569 return 1; 570 571 discard: 572 kfree_skb(skb); 573 return 0; 574 } 575 576 struct ipv6_tel_txoption { 577 struct ipv6_txoptions ops; 578 __u8 dst_opt[8]; 579 }; 580 581 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 582 { 583 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 584 585 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 586 opt->dst_opt[3] = 1; 587 opt->dst_opt[4] = encap_limit; 588 opt->dst_opt[5] = IPV6_TLV_PADN; 589 opt->dst_opt[6] = 1; 590 591 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 592 opt->ops.opt_nflen = 8; 593 } 594 595 /** 596 * ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 597 * @t: the outgoing tunnel device 598 * @hdr: IPv6 header from the incoming packet 599 * 600 * Description: 601 * Avoid trivial tunneling loop by checking that tunnel exit-point 602 * doesn't match source of incoming packet. 603 * 604 * Return: 605 * 1 if conflict, 606 * 0 else 607 **/ 608 609 static inline int 610 ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 611 { 612 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 613 } 614 615 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 616 { 617 struct ip6_tnl_parm *p = &t->parms; 618 int ret = 0; 619 620 if (p->flags & IP6_TNL_F_CAP_XMIT) { 621 struct net_device *ldev = NULL; 622 623 if (p->link) 624 ldev = dev_get_by_index(p->link); 625 626 if (unlikely(!ipv6_chk_addr(&p->laddr, ldev, 0))) 627 printk(KERN_WARNING 628 "%s xmit: Local address not yet configured!\n", 629 p->name); 630 else if (!ipv6_addr_is_multicast(&p->raddr) && 631 unlikely(ipv6_chk_addr(&p->raddr, NULL, 0))) 632 printk(KERN_WARNING 633 "%s xmit: Routing loop! " 634 "Remote address found on this node!\n", 635 p->name); 636 else 637 ret = 1; 638 if (ldev) 639 dev_put(ldev); 640 } 641 return ret; 642 } 643 /** 644 * ip6ip6_tnl_xmit - encapsulate packet and send 645 * @skb: the outgoing socket buffer 646 * @dev: the outgoing tunnel device 647 * 648 * Description: 649 * Build new header and do some sanity checks on the packet before sending 650 * it. 651 * 652 * Return: 653 * 0 654 **/ 655 656 static int 657 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 658 { 659 struct ip6_tnl *t = netdev_priv(dev); 660 struct net_device_stats *stats = &t->stat; 661 struct ipv6hdr *ipv6h = skb->nh.ipv6h; 662 int encap_limit = -1; 663 struct ipv6_tel_txoption opt; 664 __u16 offset; 665 struct flowi fl; 666 struct dst_entry *dst; 667 struct net_device *tdev; 668 int mtu; 669 int max_headroom = sizeof(struct ipv6hdr); 670 u8 proto; 671 int err; 672 int pkt_len; 673 int dsfield; 674 675 if (t->recursion++) { 676 stats->collisions++; 677 goto tx_err; 678 } 679 if (skb->protocol != htons(ETH_P_IPV6) || 680 !ip6_tnl_xmit_ctl(t) || ip6ip6_tnl_addr_conflict(t, ipv6h)) 681 goto tx_err; 682 683 if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) { 684 struct ipv6_tlv_tnl_enc_lim *tel; 685 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset]; 686 if (tel->encap_limit == 0) { 687 icmpv6_send(skb, ICMPV6_PARAMPROB, 688 ICMPV6_HDR_FIELD, offset + 2, skb->dev); 689 goto tx_err; 690 } 691 encap_limit = tel->encap_limit - 1; 692 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 693 encap_limit = t->parms.encap_limit; 694 695 memcpy(&fl, &t->fl, sizeof (fl)); 696 proto = fl.proto; 697 698 dsfield = ipv6_get_dsfield(ipv6h); 699 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 700 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 701 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 702 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 703 704 if ((dst = ip6_tnl_dst_check(t)) != NULL) 705 dst_hold(dst); 706 else { 707 dst = ip6_route_output(NULL, &fl); 708 709 if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0) 710 goto tx_err_link_failure; 711 } 712 713 tdev = dst->dev; 714 715 if (tdev == dev) { 716 stats->collisions++; 717 if (net_ratelimit()) 718 printk(KERN_WARNING 719 "%s: Local routing loop detected!\n", 720 t->parms.name); 721 goto tx_err_dst_release; 722 } 723 mtu = dst_mtu(dst) - sizeof (*ipv6h); 724 if (encap_limit >= 0) { 725 max_headroom += 8; 726 mtu -= 8; 727 } 728 if (mtu < IPV6_MIN_MTU) 729 mtu = IPV6_MIN_MTU; 730 if (skb->dst && mtu < dst_mtu(skb->dst)) { 731 struct rt6_info *rt = (struct rt6_info *) skb->dst; 732 rt->rt6i_flags |= RTF_MODIFIED; 733 rt->u.dst.metrics[RTAX_MTU-1] = mtu; 734 } 735 if (skb->len > mtu) { 736 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 737 goto tx_err_dst_release; 738 } 739 740 /* 741 * Okay, now see if we can stuff it in the buffer as-is. 742 */ 743 max_headroom += LL_RESERVED_SPACE(tdev); 744 745 if (skb_headroom(skb) < max_headroom || 746 skb_cloned(skb) || skb_shared(skb)) { 747 struct sk_buff *new_skb; 748 749 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 750 goto tx_err_dst_release; 751 752 if (skb->sk) 753 skb_set_owner_w(new_skb, skb->sk); 754 kfree_skb(skb); 755 skb = new_skb; 756 } 757 dst_release(skb->dst); 758 skb->dst = dst_clone(dst); 759 760 skb->h.raw = skb->nh.raw; 761 762 if (encap_limit >= 0) { 763 init_tel_txopt(&opt, encap_limit); 764 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 765 } 766 skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr)); 767 ipv6h = skb->nh.ipv6h; 768 *(__be32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000); 769 dsfield = INET_ECN_encapsulate(0, dsfield); 770 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 771 ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 772 ipv6h->hop_limit = t->parms.hop_limit; 773 ipv6h->nexthdr = proto; 774 ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src); 775 ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst); 776 nf_reset(skb); 777 pkt_len = skb->len; 778 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, 779 skb->dst->dev, dst_output); 780 781 if (net_xmit_eval(err) == 0) { 782 stats->tx_bytes += pkt_len; 783 stats->tx_packets++; 784 } else { 785 stats->tx_errors++; 786 stats->tx_aborted_errors++; 787 } 788 ip6_tnl_dst_store(t, dst); 789 t->recursion--; 790 return 0; 791 tx_err_link_failure: 792 stats->tx_carrier_errors++; 793 dst_link_failure(skb); 794 tx_err_dst_release: 795 dst_release(dst); 796 tx_err: 797 stats->tx_errors++; 798 stats->tx_dropped++; 799 kfree_skb(skb); 800 t->recursion--; 801 return 0; 802 } 803 804 static void ip6_tnl_set_cap(struct ip6_tnl *t) 805 { 806 struct ip6_tnl_parm *p = &t->parms; 807 int ltype = ipv6_addr_type(&p->laddr); 808 int rtype = ipv6_addr_type(&p->raddr); 809 810 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 811 812 if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 813 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 814 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 815 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 816 if (ltype&IPV6_ADDR_UNICAST) 817 p->flags |= IP6_TNL_F_CAP_XMIT; 818 if (rtype&IPV6_ADDR_UNICAST) 819 p->flags |= IP6_TNL_F_CAP_RCV; 820 } 821 } 822 823 static void ip6ip6_tnl_link_config(struct ip6_tnl *t) 824 { 825 struct net_device *dev = t->dev; 826 struct ip6_tnl_parm *p = &t->parms; 827 struct flowi *fl = &t->fl; 828 829 memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 830 memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 831 832 /* Set up flowi template */ 833 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 834 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 835 fl->oif = p->link; 836 fl->fl6_flowlabel = 0; 837 838 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 839 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 840 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 841 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 842 843 ip6_tnl_set_cap(t); 844 845 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 846 dev->flags |= IFF_POINTOPOINT; 847 else 848 dev->flags &= ~IFF_POINTOPOINT; 849 850 dev->iflink = p->link; 851 852 if (p->flags & IP6_TNL_F_CAP_XMIT) { 853 int strict = (ipv6_addr_type(&p->raddr) & 854 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 855 856 struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr, 857 p->link, strict); 858 859 if (rt == NULL) 860 return; 861 862 if (rt->rt6i_dev) { 863 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 864 sizeof (struct ipv6hdr); 865 866 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 867 868 if (dev->mtu < IPV6_MIN_MTU) 869 dev->mtu = IPV6_MIN_MTU; 870 } 871 dst_release(&rt->u.dst); 872 } 873 } 874 875 /** 876 * ip6ip6_tnl_change - update the tunnel parameters 877 * @t: tunnel to be changed 878 * @p: tunnel configuration parameters 879 * @active: != 0 if tunnel is ready for use 880 * 881 * Description: 882 * ip6ip6_tnl_change() updates the tunnel parameters 883 **/ 884 885 static int 886 ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) 887 { 888 ipv6_addr_copy(&t->parms.laddr, &p->laddr); 889 ipv6_addr_copy(&t->parms.raddr, &p->raddr); 890 t->parms.flags = p->flags; 891 t->parms.hop_limit = p->hop_limit; 892 t->parms.encap_limit = p->encap_limit; 893 t->parms.flowinfo = p->flowinfo; 894 t->parms.link = p->link; 895 ip6_tnl_dst_reset(t); 896 ip6ip6_tnl_link_config(t); 897 return 0; 898 } 899 900 /** 901 * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace 902 * @dev: virtual device associated with tunnel 903 * @ifr: parameters passed from userspace 904 * @cmd: command to be performed 905 * 906 * Description: 907 * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels 908 * from userspace. 909 * 910 * The possible commands are the following: 911 * %SIOCGETTUNNEL: get tunnel parameters for device 912 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 913 * %SIOCCHGTUNNEL: change tunnel parameters to those given 914 * %SIOCDELTUNNEL: delete tunnel 915 * 916 * The fallback device "ip6tnl0", created during module 917 * initialization, can be used for creating other tunnel devices. 918 * 919 * Return: 920 * 0 on success, 921 * %-EFAULT if unable to copy data to or from userspace, 922 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 923 * %-EINVAL if passed tunnel parameters are invalid, 924 * %-EEXIST if changing a tunnel's parameters would cause a conflict 925 * %-ENODEV if attempting to change or delete a nonexisting device 926 **/ 927 928 static int 929 ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 930 { 931 int err = 0; 932 struct ip6_tnl_parm p; 933 struct ip6_tnl *t = NULL; 934 935 switch (cmd) { 936 case SIOCGETTUNNEL: 937 if (dev == ip6ip6_fb_tnl_dev) { 938 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 939 err = -EFAULT; 940 break; 941 } 942 t = ip6ip6_tnl_locate(&p, 0); 943 } 944 if (t == NULL) 945 t = netdev_priv(dev); 946 memcpy(&p, &t->parms, sizeof (p)); 947 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 948 err = -EFAULT; 949 } 950 break; 951 case SIOCADDTUNNEL: 952 case SIOCCHGTUNNEL: 953 err = -EPERM; 954 if (!capable(CAP_NET_ADMIN)) 955 break; 956 err = -EFAULT; 957 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 958 break; 959 err = -EINVAL; 960 if (p.proto != IPPROTO_IPV6) 961 break; 962 t = ip6ip6_tnl_locate(&p, cmd == SIOCADDTUNNEL); 963 if (dev != ip6ip6_fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 964 if (t != NULL) { 965 if (t->dev != dev) { 966 err = -EEXIST; 967 break; 968 } 969 } else 970 t = netdev_priv(dev); 971 972 ip6ip6_tnl_unlink(t); 973 err = ip6ip6_tnl_change(t, &p); 974 ip6ip6_tnl_link(t); 975 netdev_state_change(dev); 976 } 977 if (t) { 978 err = 0; 979 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) 980 err = -EFAULT; 981 982 } else 983 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 984 break; 985 case SIOCDELTUNNEL: 986 err = -EPERM; 987 if (!capable(CAP_NET_ADMIN)) 988 break; 989 990 if (dev == ip6ip6_fb_tnl_dev) { 991 err = -EFAULT; 992 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 993 break; 994 err = -ENOENT; 995 if ((t = ip6ip6_tnl_locate(&p, 0)) == NULL) 996 break; 997 err = -EPERM; 998 if (t->dev == ip6ip6_fb_tnl_dev) 999 break; 1000 dev = t->dev; 1001 } 1002 err = 0; 1003 unregister_netdevice(dev); 1004 break; 1005 default: 1006 err = -EINVAL; 1007 } 1008 return err; 1009 } 1010 1011 /** 1012 * ip6ip6_tnl_get_stats - return the stats for tunnel device 1013 * @dev: virtual device associated with tunnel 1014 * 1015 * Return: stats for device 1016 **/ 1017 1018 static struct net_device_stats * 1019 ip6ip6_tnl_get_stats(struct net_device *dev) 1020 { 1021 return &(((struct ip6_tnl *)netdev_priv(dev))->stat); 1022 } 1023 1024 /** 1025 * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device 1026 * @dev: virtual device associated with tunnel 1027 * @new_mtu: the new mtu 1028 * 1029 * Return: 1030 * 0 on success, 1031 * %-EINVAL if mtu too small 1032 **/ 1033 1034 static int 1035 ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1036 { 1037 if (new_mtu < IPV6_MIN_MTU) { 1038 return -EINVAL; 1039 } 1040 dev->mtu = new_mtu; 1041 return 0; 1042 } 1043 1044 /** 1045 * ip6ip6_tnl_dev_setup - setup virtual tunnel device 1046 * @dev: virtual device associated with tunnel 1047 * 1048 * Description: 1049 * Initialize function pointers and device parameters 1050 **/ 1051 1052 static void ip6ip6_tnl_dev_setup(struct net_device *dev) 1053 { 1054 SET_MODULE_OWNER(dev); 1055 dev->uninit = ip6ip6_tnl_dev_uninit; 1056 dev->destructor = free_netdev; 1057 dev->hard_start_xmit = ip6ip6_tnl_xmit; 1058 dev->get_stats = ip6ip6_tnl_get_stats; 1059 dev->do_ioctl = ip6ip6_tnl_ioctl; 1060 dev->change_mtu = ip6ip6_tnl_change_mtu; 1061 1062 dev->type = ARPHRD_TUNNEL6; 1063 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1064 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1065 dev->flags |= IFF_NOARP; 1066 dev->addr_len = sizeof(struct in6_addr); 1067 } 1068 1069 1070 /** 1071 * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1072 * @dev: virtual device associated with tunnel 1073 **/ 1074 1075 static inline void 1076 ip6ip6_tnl_dev_init_gen(struct net_device *dev) 1077 { 1078 struct ip6_tnl *t = netdev_priv(dev); 1079 t->fl.proto = IPPROTO_IPV6; 1080 t->dev = dev; 1081 strcpy(t->parms.name, dev->name); 1082 } 1083 1084 /** 1085 * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1086 * @dev: virtual device associated with tunnel 1087 **/ 1088 1089 static int 1090 ip6ip6_tnl_dev_init(struct net_device *dev) 1091 { 1092 struct ip6_tnl *t = netdev_priv(dev); 1093 ip6ip6_tnl_dev_init_gen(dev); 1094 ip6ip6_tnl_link_config(t); 1095 return 0; 1096 } 1097 1098 /** 1099 * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1100 * @dev: fallback device 1101 * 1102 * Return: 0 1103 **/ 1104 1105 static int 1106 ip6ip6_fb_tnl_dev_init(struct net_device *dev) 1107 { 1108 struct ip6_tnl *t = netdev_priv(dev); 1109 ip6ip6_tnl_dev_init_gen(dev); 1110 dev_hold(dev); 1111 tnls_wc[0] = t; 1112 return 0; 1113 } 1114 1115 static struct xfrm6_tunnel ip6ip6_handler = { 1116 .handler = ip6ip6_rcv, 1117 .err_handler = ip6ip6_err, 1118 .priority = 1, 1119 }; 1120 1121 /** 1122 * ip6_tunnel_init - register protocol and reserve needed resources 1123 * 1124 * Return: 0 on success 1125 **/ 1126 1127 static int __init ip6_tunnel_init(void) 1128 { 1129 int err; 1130 1131 if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) { 1132 printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); 1133 return -EAGAIN; 1134 } 1135 ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1136 ip6ip6_tnl_dev_setup); 1137 1138 if (!ip6ip6_fb_tnl_dev) { 1139 err = -ENOMEM; 1140 goto fail; 1141 } 1142 ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; 1143 1144 if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { 1145 free_netdev(ip6ip6_fb_tnl_dev); 1146 goto fail; 1147 } 1148 return 0; 1149 fail: 1150 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); 1151 return err; 1152 } 1153 1154 static void __exit ip6ip6_destroy_tunnels(void) 1155 { 1156 int h; 1157 struct ip6_tnl *t; 1158 1159 for (h = 0; h < HASH_SIZE; h++) { 1160 while ((t = tnls_r_l[h]) != NULL) 1161 unregister_netdevice(t->dev); 1162 } 1163 1164 t = tnls_wc[0]; 1165 unregister_netdevice(t->dev); 1166 } 1167 1168 /** 1169 * ip6_tunnel_cleanup - free resources and unregister protocol 1170 **/ 1171 1172 static void __exit ip6_tunnel_cleanup(void) 1173 { 1174 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1175 printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); 1176 1177 rtnl_lock(); 1178 ip6ip6_destroy_tunnels(); 1179 rtnl_unlock(); 1180 } 1181 1182 module_init(ip6_tunnel_init); 1183 module_exit(ip6_tunnel_cleanup); 1184