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/capability.h> 25 #include <linux/errno.h> 26 #include <linux/types.h> 27 #include <linux/sockios.h> 28 #include <linux/if.h> 29 #include <linux/in.h> 30 #include <linux/ip.h> 31 #include <linux/if_tunnel.h> 32 #include <linux/net.h> 33 #include <linux/in6.h> 34 #include <linux/netdevice.h> 35 #include <linux/if_arp.h> 36 #include <linux/icmpv6.h> 37 #include <linux/init.h> 38 #include <linux/route.h> 39 #include <linux/rtnetlink.h> 40 #include <linux/netfilter_ipv6.h> 41 42 #include <asm/uaccess.h> 43 #include <asm/atomic.h> 44 45 #include <net/ip.h> 46 #include <net/ipv6.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 int 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 int err = -ENOENT; 405 406 /* If the packet doesn't contain the original IPv6 header we are 407 in trouble since we might need the source address for further 408 processing of the error. */ 409 410 read_lock(&ip6ip6_lock); 411 if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL) 412 goto out; 413 414 err = 0; 415 416 switch (type) { 417 __u32 teli; 418 struct ipv6_tlv_tnl_enc_lim *tel; 419 __u32 mtu; 420 case ICMPV6_DEST_UNREACH: 421 if (net_ratelimit()) 422 printk(KERN_WARNING 423 "%s: Path to destination invalid " 424 "or inactive!\n", t->parms.name); 425 rel_msg = 1; 426 break; 427 case ICMPV6_TIME_EXCEED: 428 if (code == ICMPV6_EXC_HOPLIMIT) { 429 if (net_ratelimit()) 430 printk(KERN_WARNING 431 "%s: Too small hop limit or " 432 "routing loop in tunnel!\n", 433 t->parms.name); 434 rel_msg = 1; 435 } 436 break; 437 case ICMPV6_PARAMPROB: 438 /* ignore if parameter problem not caused by a tunnel 439 encapsulation limit sub-option */ 440 if (code != ICMPV6_HDR_FIELD) { 441 break; 442 } 443 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 444 445 if (teli && teli == ntohl(info) - 2) { 446 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 447 if (tel->encap_limit == 0) { 448 if (net_ratelimit()) 449 printk(KERN_WARNING 450 "%s: Too small encapsulation " 451 "limit or routing loop in " 452 "tunnel!\n", t->parms.name); 453 rel_msg = 1; 454 } 455 } 456 break; 457 case ICMPV6_PKT_TOOBIG: 458 mtu = ntohl(info) - offset; 459 if (mtu < IPV6_MIN_MTU) 460 mtu = IPV6_MIN_MTU; 461 t->dev->mtu = mtu; 462 463 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 464 rel_type = ICMPV6_PKT_TOOBIG; 465 rel_code = 0; 466 rel_info = mtu; 467 rel_msg = 1; 468 } 469 break; 470 } 471 if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { 472 struct rt6_info *rt; 473 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 474 if (!skb2) 475 goto out; 476 477 dst_release(skb2->dst); 478 skb2->dst = NULL; 479 skb_pull(skb2, offset); 480 skb2->nh.raw = skb2->data; 481 482 /* Try to guess incoming interface */ 483 rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); 484 485 if (rt && rt->rt6i_dev) 486 skb2->dev = rt->rt6i_dev; 487 488 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 489 490 if (rt) 491 dst_release(&rt->u.dst); 492 493 kfree_skb(skb2); 494 } 495 out: 496 read_unlock(&ip6ip6_lock); 497 return err; 498 } 499 500 static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, 501 struct sk_buff *skb) 502 { 503 struct ipv6hdr *inner_iph = skb->nh.ipv6h; 504 505 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) 506 IP6_ECN_set_ce(inner_iph); 507 } 508 509 /** 510 * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally 511 * @skb: received socket buffer 512 * 513 * Return: 0 514 **/ 515 516 static int 517 ip6ip6_rcv(struct sk_buff *skb) 518 { 519 struct ipv6hdr *ipv6h; 520 struct ip6_tnl *t; 521 522 if (!pskb_may_pull(skb, sizeof (*ipv6h))) 523 goto discard; 524 525 ipv6h = skb->nh.ipv6h; 526 527 read_lock(&ip6ip6_lock); 528 529 if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { 530 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 531 read_unlock(&ip6ip6_lock); 532 kfree_skb(skb); 533 return 0; 534 } 535 536 if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) { 537 t->stat.rx_dropped++; 538 read_unlock(&ip6ip6_lock); 539 goto discard; 540 } 541 secpath_reset(skb); 542 skb->mac.raw = skb->nh.raw; 543 skb->nh.raw = skb->data; 544 skb->protocol = htons(ETH_P_IPV6); 545 skb->pkt_type = PACKET_HOST; 546 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 547 skb->dev = t->dev; 548 dst_release(skb->dst); 549 skb->dst = NULL; 550 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 551 ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); 552 ip6ip6_ecn_decapsulate(ipv6h, skb); 553 t->stat.rx_packets++; 554 t->stat.rx_bytes += skb->len; 555 netif_rx(skb); 556 read_unlock(&ip6ip6_lock); 557 return 0; 558 } 559 read_unlock(&ip6ip6_lock); 560 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev); 561 discard: 562 return 1; 563 } 564 565 static inline struct ipv6_txoptions *create_tel(__u8 encap_limit) 566 { 567 struct ipv6_tlv_tnl_enc_lim *tel; 568 struct ipv6_txoptions *opt; 569 __u8 *raw; 570 571 int opt_len = sizeof(*opt) + 8; 572 573 if (!(opt = kmalloc(opt_len, GFP_ATOMIC))) { 574 return NULL; 575 } 576 memset(opt, 0, opt_len); 577 opt->tot_len = opt_len; 578 opt->dst0opt = (struct ipv6_opt_hdr *) (opt + 1); 579 opt->opt_nflen = 8; 580 581 tel = (struct ipv6_tlv_tnl_enc_lim *) (opt->dst0opt + 1); 582 tel->type = IPV6_TLV_TNL_ENCAP_LIMIT; 583 tel->length = 1; 584 tel->encap_limit = encap_limit; 585 586 raw = (__u8 *) opt->dst0opt; 587 raw[5] = IPV6_TLV_PADN; 588 raw[6] = 1; 589 590 return opt; 591 } 592 593 /** 594 * ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 595 * @t: the outgoing tunnel device 596 * @hdr: IPv6 header from the incoming packet 597 * 598 * Description: 599 * Avoid trivial tunneling loop by checking that tunnel exit-point 600 * doesn't match source of incoming packet. 601 * 602 * Return: 603 * 1 if conflict, 604 * 0 else 605 **/ 606 607 static inline int 608 ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 609 { 610 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 611 } 612 613 /** 614 * ip6ip6_tnl_xmit - encapsulate packet and send 615 * @skb: the outgoing socket buffer 616 * @dev: the outgoing tunnel device 617 * 618 * Description: 619 * Build new header and do some sanity checks on the packet before sending 620 * it. 621 * 622 * Return: 623 * 0 624 **/ 625 626 static int 627 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 628 { 629 struct ip6_tnl *t = netdev_priv(dev); 630 struct net_device_stats *stats = &t->stat; 631 struct ipv6hdr *ipv6h = skb->nh.ipv6h; 632 struct ipv6_txoptions *opt = NULL; 633 int encap_limit = -1; 634 __u16 offset; 635 struct flowi fl; 636 struct dst_entry *dst; 637 struct net_device *tdev; 638 int mtu; 639 int max_headroom = sizeof(struct ipv6hdr); 640 u8 proto; 641 int err; 642 int pkt_len; 643 int dsfield; 644 645 if (t->recursion++) { 646 stats->collisions++; 647 goto tx_err; 648 } 649 if (skb->protocol != htons(ETH_P_IPV6) || 650 !(t->parms.flags & IP6_TNL_F_CAP_XMIT) || 651 ip6ip6_tnl_addr_conflict(t, ipv6h)) { 652 goto tx_err; 653 } 654 if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) { 655 struct ipv6_tlv_tnl_enc_lim *tel; 656 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset]; 657 if (tel->encap_limit == 0) { 658 icmpv6_send(skb, ICMPV6_PARAMPROB, 659 ICMPV6_HDR_FIELD, offset + 2, skb->dev); 660 goto tx_err; 661 } 662 encap_limit = tel->encap_limit - 1; 663 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) { 664 encap_limit = t->parms.encap_limit; 665 } 666 memcpy(&fl, &t->fl, sizeof (fl)); 667 proto = fl.proto; 668 669 dsfield = ipv6_get_dsfield(ipv6h); 670 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 671 fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_TCLASS_MASK); 672 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 673 fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_FLOWLABEL_MASK); 674 675 if (encap_limit >= 0 && (opt = create_tel(encap_limit)) == NULL) 676 goto tx_err; 677 678 if ((dst = ip6_tnl_dst_check(t)) != NULL) 679 dst_hold(dst); 680 else { 681 dst = ip6_route_output(NULL, &fl); 682 683 if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0) 684 goto tx_err_link_failure; 685 } 686 687 tdev = dst->dev; 688 689 if (tdev == dev) { 690 stats->collisions++; 691 if (net_ratelimit()) 692 printk(KERN_WARNING 693 "%s: Local routing loop detected!\n", 694 t->parms.name); 695 goto tx_err_dst_release; 696 } 697 mtu = dst_mtu(dst) - sizeof (*ipv6h); 698 if (opt) { 699 max_headroom += 8; 700 mtu -= 8; 701 } 702 if (mtu < IPV6_MIN_MTU) 703 mtu = IPV6_MIN_MTU; 704 if (skb->dst && mtu < dst_mtu(skb->dst)) { 705 struct rt6_info *rt = (struct rt6_info *) skb->dst; 706 rt->rt6i_flags |= RTF_MODIFIED; 707 rt->u.dst.metrics[RTAX_MTU-1] = mtu; 708 } 709 if (skb->len > mtu) { 710 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 711 goto tx_err_dst_release; 712 } 713 714 /* 715 * Okay, now see if we can stuff it in the buffer as-is. 716 */ 717 max_headroom += LL_RESERVED_SPACE(tdev); 718 719 if (skb_headroom(skb) < max_headroom || 720 skb_cloned(skb) || skb_shared(skb)) { 721 struct sk_buff *new_skb; 722 723 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 724 goto tx_err_dst_release; 725 726 if (skb->sk) 727 skb_set_owner_w(new_skb, skb->sk); 728 kfree_skb(skb); 729 skb = new_skb; 730 } 731 dst_release(skb->dst); 732 skb->dst = dst_clone(dst); 733 734 skb->h.raw = skb->nh.raw; 735 736 if (opt) 737 ipv6_push_nfrag_opts(skb, opt, &proto, NULL); 738 739 skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr)); 740 ipv6h = skb->nh.ipv6h; 741 *(u32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000); 742 dsfield = INET_ECN_encapsulate(0, dsfield); 743 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 744 ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 745 ipv6h->hop_limit = t->parms.hop_limit; 746 ipv6h->nexthdr = proto; 747 ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src); 748 ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst); 749 nf_reset(skb); 750 pkt_len = skb->len; 751 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, 752 skb->dst->dev, dst_output); 753 754 if (err == NET_XMIT_SUCCESS || err == NET_XMIT_CN) { 755 stats->tx_bytes += pkt_len; 756 stats->tx_packets++; 757 } else { 758 stats->tx_errors++; 759 stats->tx_aborted_errors++; 760 } 761 ip6_tnl_dst_store(t, dst); 762 763 kfree(opt); 764 765 t->recursion--; 766 return 0; 767 tx_err_link_failure: 768 stats->tx_carrier_errors++; 769 dst_link_failure(skb); 770 tx_err_dst_release: 771 dst_release(dst); 772 kfree(opt); 773 tx_err: 774 stats->tx_errors++; 775 stats->tx_dropped++; 776 kfree_skb(skb); 777 t->recursion--; 778 return 0; 779 } 780 781 static void ip6_tnl_set_cap(struct ip6_tnl *t) 782 { 783 struct ip6_tnl_parm *p = &t->parms; 784 struct in6_addr *laddr = &p->laddr; 785 struct in6_addr *raddr = &p->raddr; 786 int ltype = ipv6_addr_type(laddr); 787 int rtype = ipv6_addr_type(raddr); 788 789 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 790 791 if (ltype != IPV6_ADDR_ANY && rtype != IPV6_ADDR_ANY && 792 ((ltype|rtype) & 793 (IPV6_ADDR_UNICAST| 794 IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL| 795 IPV6_ADDR_MAPPED|IPV6_ADDR_RESERVED)) == IPV6_ADDR_UNICAST) { 796 struct net_device *ldev = NULL; 797 int l_ok = 1; 798 int r_ok = 1; 799 800 if (p->link) 801 ldev = dev_get_by_index(p->link); 802 803 if (ltype&IPV6_ADDR_UNICAST && !ipv6_chk_addr(laddr, ldev, 0)) 804 l_ok = 0; 805 806 if (rtype&IPV6_ADDR_UNICAST && ipv6_chk_addr(raddr, NULL, 0)) 807 r_ok = 0; 808 809 if (l_ok && r_ok) { 810 if (ltype&IPV6_ADDR_UNICAST) 811 p->flags |= IP6_TNL_F_CAP_XMIT; 812 if (rtype&IPV6_ADDR_UNICAST) 813 p->flags |= IP6_TNL_F_CAP_RCV; 814 } 815 if (ldev) 816 dev_put(ldev); 817 } 818 } 819 820 static void ip6ip6_tnl_link_config(struct ip6_tnl *t) 821 { 822 struct net_device *dev = t->dev; 823 struct ip6_tnl_parm *p = &t->parms; 824 struct flowi *fl = &t->fl; 825 826 memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 827 memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 828 829 /* Set up flowi template */ 830 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 831 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 832 fl->oif = p->link; 833 fl->fl6_flowlabel = 0; 834 835 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 836 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 837 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 838 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 839 840 ip6_tnl_set_cap(t); 841 842 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 843 dev->flags |= IFF_POINTOPOINT; 844 else 845 dev->flags &= ~IFF_POINTOPOINT; 846 847 dev->iflink = p->link; 848 849 if (p->flags & IP6_TNL_F_CAP_XMIT) { 850 struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr, 851 p->link, 0); 852 853 if (rt == NULL) 854 return; 855 856 if (rt->rt6i_dev) { 857 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 858 sizeof (struct ipv6hdr); 859 860 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 861 862 if (dev->mtu < IPV6_MIN_MTU) 863 dev->mtu = IPV6_MIN_MTU; 864 } 865 dst_release(&rt->u.dst); 866 } 867 } 868 869 /** 870 * ip6ip6_tnl_change - update the tunnel parameters 871 * @t: tunnel to be changed 872 * @p: tunnel configuration parameters 873 * @active: != 0 if tunnel is ready for use 874 * 875 * Description: 876 * ip6ip6_tnl_change() updates the tunnel parameters 877 **/ 878 879 static int 880 ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) 881 { 882 ipv6_addr_copy(&t->parms.laddr, &p->laddr); 883 ipv6_addr_copy(&t->parms.raddr, &p->raddr); 884 t->parms.flags = p->flags; 885 t->parms.hop_limit = p->hop_limit; 886 t->parms.encap_limit = p->encap_limit; 887 t->parms.flowinfo = p->flowinfo; 888 t->parms.link = p->link; 889 ip6_tnl_dst_reset(t); 890 ip6ip6_tnl_link_config(t); 891 return 0; 892 } 893 894 /** 895 * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace 896 * @dev: virtual device associated with tunnel 897 * @ifr: parameters passed from userspace 898 * @cmd: command to be performed 899 * 900 * Description: 901 * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels 902 * from userspace. 903 * 904 * The possible commands are the following: 905 * %SIOCGETTUNNEL: get tunnel parameters for device 906 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 907 * %SIOCCHGTUNNEL: change tunnel parameters to those given 908 * %SIOCDELTUNNEL: delete tunnel 909 * 910 * The fallback device "ip6tnl0", created during module 911 * initialization, can be used for creating other tunnel devices. 912 * 913 * Return: 914 * 0 on success, 915 * %-EFAULT if unable to copy data to or from userspace, 916 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 917 * %-EINVAL if passed tunnel parameters are invalid, 918 * %-EEXIST if changing a tunnel's parameters would cause a conflict 919 * %-ENODEV if attempting to change or delete a nonexisting device 920 **/ 921 922 static int 923 ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 924 { 925 int err = 0; 926 int create; 927 struct ip6_tnl_parm p; 928 struct ip6_tnl *t = NULL; 929 930 switch (cmd) { 931 case SIOCGETTUNNEL: 932 if (dev == ip6ip6_fb_tnl_dev) { 933 if (copy_from_user(&p, 934 ifr->ifr_ifru.ifru_data, 935 sizeof (p))) { 936 err = -EFAULT; 937 break; 938 } 939 if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV) 940 t = netdev_priv(dev); 941 else if (err) 942 break; 943 } else 944 t = netdev_priv(dev); 945 946 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 create = (cmd == SIOCADDTUNNEL); 955 if (!capable(CAP_NET_ADMIN)) 956 break; 957 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 958 err = -EFAULT; 959 break; 960 } 961 if (!create && dev != ip6ip6_fb_tnl_dev) { 962 t = netdev_priv(dev); 963 } 964 if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) { 965 break; 966 } 967 if (cmd == SIOCCHGTUNNEL) { 968 if (t->dev != dev) { 969 err = -EEXIST; 970 break; 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 (copy_to_user(ifr->ifr_ifru.ifru_data, 978 &t->parms, sizeof (p))) { 979 err = -EFAULT; 980 } else { 981 err = 0; 982 } 983 break; 984 case SIOCDELTUNNEL: 985 err = -EPERM; 986 if (!capable(CAP_NET_ADMIN)) 987 break; 988 989 if (dev == ip6ip6_fb_tnl_dev) { 990 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, 991 sizeof (p))) { 992 err = -EFAULT; 993 break; 994 } 995 err = ip6ip6_tnl_locate(&p, &t, 0); 996 if (err) 997 break; 998 if (t == netdev_priv(ip6ip6_fb_tnl_dev)) { 999 err = -EPERM; 1000 break; 1001 } 1002 } else { 1003 t = netdev_priv(dev); 1004 } 1005 err = unregister_netdevice(t->dev); 1006 break; 1007 default: 1008 err = -EINVAL; 1009 } 1010 return err; 1011 } 1012 1013 /** 1014 * ip6ip6_tnl_get_stats - return the stats for tunnel device 1015 * @dev: virtual device associated with tunnel 1016 * 1017 * Return: stats for device 1018 **/ 1019 1020 static struct net_device_stats * 1021 ip6ip6_tnl_get_stats(struct net_device *dev) 1022 { 1023 return &(((struct ip6_tnl *)netdev_priv(dev))->stat); 1024 } 1025 1026 /** 1027 * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device 1028 * @dev: virtual device associated with tunnel 1029 * @new_mtu: the new mtu 1030 * 1031 * Return: 1032 * 0 on success, 1033 * %-EINVAL if mtu too small 1034 **/ 1035 1036 static int 1037 ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1038 { 1039 if (new_mtu < IPV6_MIN_MTU) { 1040 return -EINVAL; 1041 } 1042 dev->mtu = new_mtu; 1043 return 0; 1044 } 1045 1046 /** 1047 * ip6ip6_tnl_dev_setup - setup virtual tunnel device 1048 * @dev: virtual device associated with tunnel 1049 * 1050 * Description: 1051 * Initialize function pointers and device parameters 1052 **/ 1053 1054 static void ip6ip6_tnl_dev_setup(struct net_device *dev) 1055 { 1056 SET_MODULE_OWNER(dev); 1057 dev->uninit = ip6ip6_tnl_dev_uninit; 1058 dev->destructor = free_netdev; 1059 dev->hard_start_xmit = ip6ip6_tnl_xmit; 1060 dev->get_stats = ip6ip6_tnl_get_stats; 1061 dev->do_ioctl = ip6ip6_tnl_ioctl; 1062 dev->change_mtu = ip6ip6_tnl_change_mtu; 1063 1064 dev->type = ARPHRD_TUNNEL6; 1065 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1066 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1067 dev->flags |= IFF_NOARP; 1068 dev->addr_len = sizeof(struct in6_addr); 1069 } 1070 1071 1072 /** 1073 * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1074 * @dev: virtual device associated with tunnel 1075 **/ 1076 1077 static inline void 1078 ip6ip6_tnl_dev_init_gen(struct net_device *dev) 1079 { 1080 struct ip6_tnl *t = netdev_priv(dev); 1081 t->fl.proto = IPPROTO_IPV6; 1082 t->dev = dev; 1083 strcpy(t->parms.name, dev->name); 1084 } 1085 1086 /** 1087 * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1088 * @dev: virtual device associated with tunnel 1089 **/ 1090 1091 static int 1092 ip6ip6_tnl_dev_init(struct net_device *dev) 1093 { 1094 struct ip6_tnl *t = netdev_priv(dev); 1095 ip6ip6_tnl_dev_init_gen(dev); 1096 ip6ip6_tnl_link_config(t); 1097 return 0; 1098 } 1099 1100 /** 1101 * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1102 * @dev: fallback device 1103 * 1104 * Return: 0 1105 **/ 1106 1107 static int 1108 ip6ip6_fb_tnl_dev_init(struct net_device *dev) 1109 { 1110 struct ip6_tnl *t = netdev_priv(dev); 1111 ip6ip6_tnl_dev_init_gen(dev); 1112 dev_hold(dev); 1113 tnls_wc[0] = t; 1114 return 0; 1115 } 1116 1117 static struct xfrm6_tunnel ip6ip6_handler = { 1118 .handler = ip6ip6_rcv, 1119 .err_handler = ip6ip6_err, 1120 .priority = 1, 1121 }; 1122 1123 /** 1124 * ip6_tunnel_init - register protocol and reserve needed resources 1125 * 1126 * Return: 0 on success 1127 **/ 1128 1129 static int __init ip6_tunnel_init(void) 1130 { 1131 int err; 1132 1133 if (xfrm6_tunnel_register(&ip6ip6_handler)) { 1134 printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); 1135 return -EAGAIN; 1136 } 1137 ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1138 ip6ip6_tnl_dev_setup); 1139 1140 if (!ip6ip6_fb_tnl_dev) { 1141 err = -ENOMEM; 1142 goto fail; 1143 } 1144 ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; 1145 1146 if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { 1147 free_netdev(ip6ip6_fb_tnl_dev); 1148 goto fail; 1149 } 1150 return 0; 1151 fail: 1152 xfrm6_tunnel_deregister(&ip6ip6_handler); 1153 return err; 1154 } 1155 1156 /** 1157 * ip6_tunnel_cleanup - free resources and unregister protocol 1158 **/ 1159 1160 static void __exit ip6_tunnel_cleanup(void) 1161 { 1162 if (xfrm6_tunnel_deregister(&ip6ip6_handler)) 1163 printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); 1164 1165 unregister_netdev(ip6ip6_fb_tnl_dev); 1166 } 1167 1168 module_init(ip6_tunnel_init); 1169 module_exit(ip6_tunnel_cleanup); 1170