1 /* 2 * IPv6 tunneling device 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Ville Nuorvala <vnuorval@tcs.hut.fi> 7 * Yasuyuki Kozakai <kozakai@linux-ipv6.org> 8 * 9 * Based on: 10 * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c 11 * 12 * RFC 2473 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 * 19 */ 20 21 #include <linux/module.h> 22 #include <linux/capability.h> 23 #include <linux/errno.h> 24 #include <linux/types.h> 25 #include <linux/sockios.h> 26 #include <linux/icmp.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 #include <linux/slab.h> 41 42 #include <asm/uaccess.h> 43 #include <asm/atomic.h> 44 45 #include <net/icmp.h> 46 #include <net/ip.h> 47 #include <net/ipv6.h> 48 #include <net/ip6_route.h> 49 #include <net/addrconf.h> 50 #include <net/ip6_tunnel.h> 51 #include <net/xfrm.h> 52 #include <net/dsfield.h> 53 #include <net/inet_ecn.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 MODULE_AUTHOR("Ville Nuorvala"); 58 MODULE_DESCRIPTION("IPv6 tunneling device"); 59 MODULE_LICENSE("GPL"); 60 MODULE_ALIAS_NETDEV("ip6tnl0"); 61 62 #ifdef IP6_TNL_DEBUG 63 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __func__) 64 #else 65 #define IP6_TNL_TRACE(x...) do {;} while(0) 66 #endif 67 68 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 69 #define IPV6_TCLASS_SHIFT 20 70 71 #define HASH_SIZE 32 72 73 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ 74 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ 75 (HASH_SIZE - 1)) 76 77 static int ip6_tnl_dev_init(struct net_device *dev); 78 static void ip6_tnl_dev_setup(struct net_device *dev); 79 80 static int ip6_tnl_net_id __read_mostly; 81 struct ip6_tnl_net { 82 /* the IPv6 tunnel fallback device */ 83 struct net_device *fb_tnl_dev; 84 /* lists for storing tunnels in use */ 85 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 86 struct ip6_tnl __rcu *tnls_wc[1]; 87 struct ip6_tnl __rcu **tnls[2]; 88 }; 89 90 /* often modified stats are per cpu, other are shared (netdev->stats) */ 91 struct pcpu_tstats { 92 unsigned long rx_packets; 93 unsigned long rx_bytes; 94 unsigned long tx_packets; 95 unsigned long tx_bytes; 96 }; 97 98 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 99 { 100 struct pcpu_tstats sum = { 0 }; 101 int i; 102 103 for_each_possible_cpu(i) { 104 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 105 106 sum.rx_packets += tstats->rx_packets; 107 sum.rx_bytes += tstats->rx_bytes; 108 sum.tx_packets += tstats->tx_packets; 109 sum.tx_bytes += tstats->tx_bytes; 110 } 111 dev->stats.rx_packets = sum.rx_packets; 112 dev->stats.rx_bytes = sum.rx_bytes; 113 dev->stats.tx_packets = sum.tx_packets; 114 dev->stats.tx_bytes = sum.tx_bytes; 115 return &dev->stats; 116 } 117 118 /* 119 * Locking : hash tables are protected by RCU and RTNL 120 */ 121 122 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 123 { 124 struct dst_entry *dst = t->dst_cache; 125 126 if (dst && dst->obsolete && 127 dst->ops->check(dst, t->dst_cookie) == NULL) { 128 t->dst_cache = NULL; 129 dst_release(dst); 130 return NULL; 131 } 132 133 return dst; 134 } 135 136 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) 137 { 138 dst_release(t->dst_cache); 139 t->dst_cache = NULL; 140 } 141 142 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 143 { 144 struct rt6_info *rt = (struct rt6_info *) dst; 145 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 146 dst_release(t->dst_cache); 147 t->dst_cache = dst; 148 } 149 150 /** 151 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 152 * @remote: the address of the tunnel exit-point 153 * @local: the address of the tunnel entry-point 154 * 155 * Return: 156 * tunnel matching given end-points if found, 157 * else fallback tunnel if its device is up, 158 * else %NULL 159 **/ 160 161 #define for_each_ip6_tunnel_rcu(start) \ 162 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 163 164 static struct ip6_tnl * 165 ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local) 166 { 167 unsigned int h0 = HASH(remote); 168 unsigned int h1 = HASH(local); 169 struct ip6_tnl *t; 170 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 171 172 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) { 173 if (ipv6_addr_equal(local, &t->parms.laddr) && 174 ipv6_addr_equal(remote, &t->parms.raddr) && 175 (t->dev->flags & IFF_UP)) 176 return t; 177 } 178 t = rcu_dereference(ip6n->tnls_wc[0]); 179 if (t && (t->dev->flags & IFF_UP)) 180 return t; 181 182 return NULL; 183 } 184 185 /** 186 * ip6_tnl_bucket - get head of list matching given tunnel parameters 187 * @p: parameters containing tunnel end-points 188 * 189 * Description: 190 * ip6_tnl_bucket() returns the head of the list matching the 191 * &struct in6_addr entries laddr and raddr in @p. 192 * 193 * Return: head of IPv6 tunnel list 194 **/ 195 196 static struct ip6_tnl __rcu ** 197 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, struct ip6_tnl_parm *p) 198 { 199 struct in6_addr *remote = &p->raddr; 200 struct in6_addr *local = &p->laddr; 201 unsigned h = 0; 202 int prio = 0; 203 204 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 205 prio = 1; 206 h = HASH(remote) ^ HASH(local); 207 } 208 return &ip6n->tnls[prio][h]; 209 } 210 211 /** 212 * ip6_tnl_link - add tunnel to hash table 213 * @t: tunnel to be added 214 **/ 215 216 static void 217 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 218 { 219 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 220 221 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 222 rcu_assign_pointer(*tp, t); 223 } 224 225 /** 226 * ip6_tnl_unlink - remove tunnel from hash table 227 * @t: tunnel to be removed 228 **/ 229 230 static void 231 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 232 { 233 struct ip6_tnl __rcu **tp; 234 struct ip6_tnl *iter; 235 236 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 237 (iter = rtnl_dereference(*tp)) != NULL; 238 tp = &iter->next) { 239 if (t == iter) { 240 rcu_assign_pointer(*tp, t->next); 241 break; 242 } 243 } 244 } 245 246 static void ip6_dev_free(struct net_device *dev) 247 { 248 free_percpu(dev->tstats); 249 free_netdev(dev); 250 } 251 252 /** 253 * ip6_tnl_create() - create a new tunnel 254 * @p: tunnel parameters 255 * @pt: pointer to new tunnel 256 * 257 * Description: 258 * Create tunnel matching given parameters. 259 * 260 * Return: 261 * created tunnel or NULL 262 **/ 263 264 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p) 265 { 266 struct net_device *dev; 267 struct ip6_tnl *t; 268 char name[IFNAMSIZ]; 269 int err; 270 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 271 272 if (p->name[0]) 273 strlcpy(name, p->name, IFNAMSIZ); 274 else 275 sprintf(name, "ip6tnl%%d"); 276 277 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 278 if (dev == NULL) 279 goto failed; 280 281 dev_net_set(dev, net); 282 283 if (strchr(name, '%')) { 284 if (dev_alloc_name(dev, name) < 0) 285 goto failed_free; 286 } 287 288 t = netdev_priv(dev); 289 t->parms = *p; 290 err = ip6_tnl_dev_init(dev); 291 if (err < 0) 292 goto failed_free; 293 294 if ((err = register_netdevice(dev)) < 0) 295 goto failed_free; 296 297 dev_hold(dev); 298 ip6_tnl_link(ip6n, t); 299 return t; 300 301 failed_free: 302 ip6_dev_free(dev); 303 failed: 304 return NULL; 305 } 306 307 /** 308 * ip6_tnl_locate - find or create tunnel matching given parameters 309 * @p: tunnel parameters 310 * @create: != 0 if allowed to create new tunnel if no match found 311 * 312 * Description: 313 * ip6_tnl_locate() first tries to locate an existing tunnel 314 * based on @parms. If this is unsuccessful, but @create is set a new 315 * tunnel device is created and registered for use. 316 * 317 * Return: 318 * matching tunnel or NULL 319 **/ 320 321 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 322 struct ip6_tnl_parm *p, int create) 323 { 324 struct in6_addr *remote = &p->raddr; 325 struct in6_addr *local = &p->laddr; 326 struct ip6_tnl __rcu **tp; 327 struct ip6_tnl *t; 328 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 329 330 for (tp = ip6_tnl_bucket(ip6n, p); 331 (t = rtnl_dereference(*tp)) != NULL; 332 tp = &t->next) { 333 if (ipv6_addr_equal(local, &t->parms.laddr) && 334 ipv6_addr_equal(remote, &t->parms.raddr)) 335 return t; 336 } 337 if (!create) 338 return NULL; 339 return ip6_tnl_create(net, p); 340 } 341 342 /** 343 * ip6_tnl_dev_uninit - tunnel device uninitializer 344 * @dev: the device to be destroyed 345 * 346 * Description: 347 * ip6_tnl_dev_uninit() removes tunnel from its list 348 **/ 349 350 static void 351 ip6_tnl_dev_uninit(struct net_device *dev) 352 { 353 struct ip6_tnl *t = netdev_priv(dev); 354 struct net *net = dev_net(dev); 355 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 356 357 if (dev == ip6n->fb_tnl_dev) 358 rcu_assign_pointer(ip6n->tnls_wc[0], NULL); 359 else 360 ip6_tnl_unlink(ip6n, t); 361 ip6_tnl_dst_reset(t); 362 dev_put(dev); 363 } 364 365 /** 366 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 367 * @skb: received socket buffer 368 * 369 * Return: 370 * 0 if none was found, 371 * else index to encapsulation limit 372 **/ 373 374 static __u16 375 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 376 { 377 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 378 __u8 nexthdr = ipv6h->nexthdr; 379 __u16 off = sizeof (*ipv6h); 380 381 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 382 __u16 optlen = 0; 383 struct ipv6_opt_hdr *hdr; 384 if (raw + off + sizeof (*hdr) > skb->data && 385 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 386 break; 387 388 hdr = (struct ipv6_opt_hdr *) (raw + off); 389 if (nexthdr == NEXTHDR_FRAGMENT) { 390 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 391 if (frag_hdr->frag_off) 392 break; 393 optlen = 8; 394 } else if (nexthdr == NEXTHDR_AUTH) { 395 optlen = (hdr->hdrlen + 2) << 2; 396 } else { 397 optlen = ipv6_optlen(hdr); 398 } 399 if (nexthdr == NEXTHDR_DEST) { 400 __u16 i = off + 2; 401 while (1) { 402 struct ipv6_tlv_tnl_enc_lim *tel; 403 404 /* No more room for encapsulation limit */ 405 if (i + sizeof (*tel) > off + optlen) 406 break; 407 408 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 409 /* return index of option if found and valid */ 410 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 411 tel->length == 1) 412 return i; 413 /* else jump to next option */ 414 if (tel->type) 415 i += tel->length + 2; 416 else 417 i++; 418 } 419 } 420 nexthdr = hdr->nexthdr; 421 off += optlen; 422 } 423 return 0; 424 } 425 426 /** 427 * ip6_tnl_err - tunnel error handler 428 * 429 * Description: 430 * ip6_tnl_err() should handle errors in the tunnel according 431 * to the specifications in RFC 2473. 432 **/ 433 434 static int 435 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 436 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 437 { 438 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 439 struct ip6_tnl *t; 440 int rel_msg = 0; 441 u8 rel_type = ICMPV6_DEST_UNREACH; 442 u8 rel_code = ICMPV6_ADDR_UNREACH; 443 __u32 rel_info = 0; 444 __u16 len; 445 int err = -ENOENT; 446 447 /* If the packet doesn't contain the original IPv6 header we are 448 in trouble since we might need the source address for further 449 processing of the error. */ 450 451 rcu_read_lock(); 452 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 453 &ipv6h->saddr)) == NULL) 454 goto out; 455 456 if (t->parms.proto != ipproto && t->parms.proto != 0) 457 goto out; 458 459 err = 0; 460 461 switch (*type) { 462 __u32 teli; 463 struct ipv6_tlv_tnl_enc_lim *tel; 464 __u32 mtu; 465 case ICMPV6_DEST_UNREACH: 466 if (net_ratelimit()) 467 printk(KERN_WARNING 468 "%s: Path to destination invalid " 469 "or inactive!\n", t->parms.name); 470 rel_msg = 1; 471 break; 472 case ICMPV6_TIME_EXCEED: 473 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 474 if (net_ratelimit()) 475 printk(KERN_WARNING 476 "%s: Too small hop limit or " 477 "routing loop in tunnel!\n", 478 t->parms.name); 479 rel_msg = 1; 480 } 481 break; 482 case ICMPV6_PARAMPROB: 483 teli = 0; 484 if ((*code) == ICMPV6_HDR_FIELD) 485 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 486 487 if (teli && teli == *info - 2) { 488 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 489 if (tel->encap_limit == 0) { 490 if (net_ratelimit()) 491 printk(KERN_WARNING 492 "%s: Too small encapsulation " 493 "limit or routing loop in " 494 "tunnel!\n", t->parms.name); 495 rel_msg = 1; 496 } 497 } else if (net_ratelimit()) { 498 printk(KERN_WARNING 499 "%s: Recipient unable to parse tunneled " 500 "packet!\n ", t->parms.name); 501 } 502 break; 503 case ICMPV6_PKT_TOOBIG: 504 mtu = *info - offset; 505 if (mtu < IPV6_MIN_MTU) 506 mtu = IPV6_MIN_MTU; 507 t->dev->mtu = mtu; 508 509 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 510 rel_type = ICMPV6_PKT_TOOBIG; 511 rel_code = 0; 512 rel_info = mtu; 513 rel_msg = 1; 514 } 515 break; 516 } 517 518 *type = rel_type; 519 *code = rel_code; 520 *info = rel_info; 521 *msg = rel_msg; 522 523 out: 524 rcu_read_unlock(); 525 return err; 526 } 527 528 static int 529 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 530 u8 type, u8 code, int offset, __be32 info) 531 { 532 int rel_msg = 0; 533 u8 rel_type = type; 534 u8 rel_code = code; 535 __u32 rel_info = ntohl(info); 536 int err; 537 struct sk_buff *skb2; 538 struct iphdr *eiph; 539 struct flowi fl; 540 struct rtable *rt; 541 542 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 543 &rel_msg, &rel_info, offset); 544 if (err < 0) 545 return err; 546 547 if (rel_msg == 0) 548 return 0; 549 550 switch (rel_type) { 551 case ICMPV6_DEST_UNREACH: 552 if (rel_code != ICMPV6_ADDR_UNREACH) 553 return 0; 554 rel_type = ICMP_DEST_UNREACH; 555 rel_code = ICMP_HOST_UNREACH; 556 break; 557 case ICMPV6_PKT_TOOBIG: 558 if (rel_code != 0) 559 return 0; 560 rel_type = ICMP_DEST_UNREACH; 561 rel_code = ICMP_FRAG_NEEDED; 562 break; 563 default: 564 return 0; 565 } 566 567 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 568 return 0; 569 570 skb2 = skb_clone(skb, GFP_ATOMIC); 571 if (!skb2) 572 return 0; 573 574 skb_dst_drop(skb2); 575 576 skb_pull(skb2, offset); 577 skb_reset_network_header(skb2); 578 eiph = ip_hdr(skb2); 579 580 /* Try to guess incoming interface */ 581 memset(&fl, 0, sizeof(fl)); 582 fl.fl4_dst = eiph->saddr; 583 fl.fl4_tos = RT_TOS(eiph->tos); 584 fl.proto = IPPROTO_IPIP; 585 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) 586 goto out; 587 588 skb2->dev = rt->dst.dev; 589 590 /* route "incoming" packet */ 591 if (rt->rt_flags & RTCF_LOCAL) { 592 ip_rt_put(rt); 593 rt = NULL; 594 fl.fl4_dst = eiph->daddr; 595 fl.fl4_src = eiph->saddr; 596 fl.fl4_tos = eiph->tos; 597 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) || 598 rt->dst.dev->type != ARPHRD_TUNNEL) { 599 ip_rt_put(rt); 600 goto out; 601 } 602 skb_dst_set(skb2, (struct dst_entry *)rt); 603 } else { 604 ip_rt_put(rt); 605 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 606 skb2->dev) || 607 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 608 goto out; 609 } 610 611 /* change mtu on this route */ 612 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 613 if (rel_info > dst_mtu(skb_dst(skb2))) 614 goto out; 615 616 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info); 617 } 618 619 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 620 621 out: 622 kfree_skb(skb2); 623 return 0; 624 } 625 626 static int 627 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 628 u8 type, u8 code, int offset, __be32 info) 629 { 630 int rel_msg = 0; 631 u8 rel_type = type; 632 u8 rel_code = code; 633 __u32 rel_info = ntohl(info); 634 int err; 635 636 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 637 &rel_msg, &rel_info, offset); 638 if (err < 0) 639 return err; 640 641 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 642 struct rt6_info *rt; 643 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 644 645 if (!skb2) 646 return 0; 647 648 skb_dst_drop(skb2); 649 skb_pull(skb2, offset); 650 skb_reset_network_header(skb2); 651 652 /* Try to guess incoming interface */ 653 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 654 NULL, 0, 0); 655 656 if (rt && rt->rt6i_dev) 657 skb2->dev = rt->rt6i_dev; 658 659 icmpv6_send(skb2, rel_type, rel_code, rel_info); 660 661 if (rt) 662 dst_release(&rt->dst); 663 664 kfree_skb(skb2); 665 } 666 667 return 0; 668 } 669 670 static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 671 struct ipv6hdr *ipv6h, 672 struct sk_buff *skb) 673 { 674 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 675 676 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 677 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 678 679 if (INET_ECN_is_ce(dsfield)) 680 IP_ECN_set_ce(ip_hdr(skb)); 681 } 682 683 static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 684 struct ipv6hdr *ipv6h, 685 struct sk_buff *skb) 686 { 687 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 688 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 689 690 if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) 691 IP6_ECN_set_ce(ipv6_hdr(skb)); 692 } 693 694 /* called with rcu_read_lock() */ 695 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) 696 { 697 struct ip6_tnl_parm *p = &t->parms; 698 int ret = 0; 699 struct net *net = dev_net(t->dev); 700 701 if (p->flags & IP6_TNL_F_CAP_RCV) { 702 struct net_device *ldev = NULL; 703 704 if (p->link) 705 ldev = dev_get_by_index_rcu(net, p->link); 706 707 if ((ipv6_addr_is_multicast(&p->laddr) || 708 likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) && 709 likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0))) 710 ret = 1; 711 712 } 713 return ret; 714 } 715 716 /** 717 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 718 * @skb: received socket buffer 719 * @protocol: ethernet protocol ID 720 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 721 * 722 * Return: 0 723 **/ 724 725 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 726 __u8 ipproto, 727 void (*dscp_ecn_decapsulate)(struct ip6_tnl *t, 728 struct ipv6hdr *ipv6h, 729 struct sk_buff *skb)) 730 { 731 struct ip6_tnl *t; 732 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 733 734 rcu_read_lock(); 735 736 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 737 &ipv6h->daddr)) != NULL) { 738 struct pcpu_tstats *tstats; 739 740 if (t->parms.proto != ipproto && t->parms.proto != 0) { 741 rcu_read_unlock(); 742 goto discard; 743 } 744 745 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 746 rcu_read_unlock(); 747 goto discard; 748 } 749 750 if (!ip6_tnl_rcv_ctl(t)) { 751 t->dev->stats.rx_dropped++; 752 rcu_read_unlock(); 753 goto discard; 754 } 755 secpath_reset(skb); 756 skb->mac_header = skb->network_header; 757 skb_reset_network_header(skb); 758 skb->protocol = htons(protocol); 759 skb->pkt_type = PACKET_HOST; 760 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 761 762 tstats = this_cpu_ptr(t->dev->tstats); 763 tstats->rx_packets++; 764 tstats->rx_bytes += skb->len; 765 766 __skb_tunnel_rx(skb, t->dev); 767 768 dscp_ecn_decapsulate(t, ipv6h, skb); 769 770 netif_rx(skb); 771 772 rcu_read_unlock(); 773 return 0; 774 } 775 rcu_read_unlock(); 776 return 1; 777 778 discard: 779 kfree_skb(skb); 780 return 0; 781 } 782 783 static int ip4ip6_rcv(struct sk_buff *skb) 784 { 785 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 786 ip4ip6_dscp_ecn_decapsulate); 787 } 788 789 static int ip6ip6_rcv(struct sk_buff *skb) 790 { 791 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 792 ip6ip6_dscp_ecn_decapsulate); 793 } 794 795 struct ipv6_tel_txoption { 796 struct ipv6_txoptions ops; 797 __u8 dst_opt[8]; 798 }; 799 800 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 801 { 802 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 803 804 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 805 opt->dst_opt[3] = 1; 806 opt->dst_opt[4] = encap_limit; 807 opt->dst_opt[5] = IPV6_TLV_PADN; 808 opt->dst_opt[6] = 1; 809 810 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 811 opt->ops.opt_nflen = 8; 812 } 813 814 /** 815 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 816 * @t: the outgoing tunnel device 817 * @hdr: IPv6 header from the incoming packet 818 * 819 * Description: 820 * Avoid trivial tunneling loop by checking that tunnel exit-point 821 * doesn't match source of incoming packet. 822 * 823 * Return: 824 * 1 if conflict, 825 * 0 else 826 **/ 827 828 static inline int 829 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 830 { 831 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 832 } 833 834 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 835 { 836 struct ip6_tnl_parm *p = &t->parms; 837 int ret = 0; 838 struct net *net = dev_net(t->dev); 839 840 if (p->flags & IP6_TNL_F_CAP_XMIT) { 841 struct net_device *ldev = NULL; 842 843 rcu_read_lock(); 844 if (p->link) 845 ldev = dev_get_by_index_rcu(net, p->link); 846 847 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 848 printk(KERN_WARNING 849 "%s xmit: Local address not yet configured!\n", 850 p->name); 851 else if (!ipv6_addr_is_multicast(&p->raddr) && 852 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 853 printk(KERN_WARNING 854 "%s xmit: Routing loop! " 855 "Remote address found on this node!\n", 856 p->name); 857 else 858 ret = 1; 859 rcu_read_unlock(); 860 } 861 return ret; 862 } 863 /** 864 * ip6_tnl_xmit2 - encapsulate packet and send 865 * @skb: the outgoing socket buffer 866 * @dev: the outgoing tunnel device 867 * @dsfield: dscp code for outer header 868 * @fl: flow of tunneled packet 869 * @encap_limit: encapsulation limit 870 * @pmtu: Path MTU is stored if packet is too big 871 * 872 * Description: 873 * Build new header and do some sanity checks on the packet before sending 874 * it. 875 * 876 * Return: 877 * 0 on success 878 * -1 fail 879 * %-EMSGSIZE message too big. return mtu in this case. 880 **/ 881 882 static int ip6_tnl_xmit2(struct sk_buff *skb, 883 struct net_device *dev, 884 __u8 dsfield, 885 struct flowi *fl, 886 int encap_limit, 887 __u32 *pmtu) 888 { 889 struct net *net = dev_net(dev); 890 struct ip6_tnl *t = netdev_priv(dev); 891 struct net_device_stats *stats = &t->dev->stats; 892 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 893 struct ipv6_tel_txoption opt; 894 struct dst_entry *dst; 895 struct net_device *tdev; 896 int mtu; 897 unsigned int max_headroom = sizeof(struct ipv6hdr); 898 u8 proto; 899 int err = -1; 900 int pkt_len; 901 902 if ((dst = ip6_tnl_dst_check(t)) != NULL) 903 dst_hold(dst); 904 else { 905 dst = ip6_route_output(net, NULL, fl); 906 907 if (dst->error || xfrm_lookup(net, &dst, fl, NULL, 0) < 0) 908 goto tx_err_link_failure; 909 } 910 911 tdev = dst->dev; 912 913 if (tdev == dev) { 914 stats->collisions++; 915 if (net_ratelimit()) 916 printk(KERN_WARNING 917 "%s: Local routing loop detected!\n", 918 t->parms.name); 919 goto tx_err_dst_release; 920 } 921 mtu = dst_mtu(dst) - sizeof (*ipv6h); 922 if (encap_limit >= 0) { 923 max_headroom += 8; 924 mtu -= 8; 925 } 926 if (mtu < IPV6_MIN_MTU) 927 mtu = IPV6_MIN_MTU; 928 if (skb_dst(skb)) 929 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 930 if (skb->len > mtu) { 931 *pmtu = mtu; 932 err = -EMSGSIZE; 933 goto tx_err_dst_release; 934 } 935 936 /* 937 * Okay, now see if we can stuff it in the buffer as-is. 938 */ 939 max_headroom += LL_RESERVED_SPACE(tdev); 940 941 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 942 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 943 struct sk_buff *new_skb; 944 945 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 946 goto tx_err_dst_release; 947 948 if (skb->sk) 949 skb_set_owner_w(new_skb, skb->sk); 950 kfree_skb(skb); 951 skb = new_skb; 952 } 953 skb_dst_drop(skb); 954 skb_dst_set(skb, dst_clone(dst)); 955 956 skb->transport_header = skb->network_header; 957 958 proto = fl->proto; 959 if (encap_limit >= 0) { 960 init_tel_txopt(&opt, encap_limit); 961 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 962 } 963 skb_push(skb, sizeof(struct ipv6hdr)); 964 skb_reset_network_header(skb); 965 ipv6h = ipv6_hdr(skb); 966 *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000); 967 dsfield = INET_ECN_encapsulate(0, dsfield); 968 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 969 ipv6h->hop_limit = t->parms.hop_limit; 970 ipv6h->nexthdr = proto; 971 ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src); 972 ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst); 973 nf_reset(skb); 974 pkt_len = skb->len; 975 err = ip6_local_out(skb); 976 977 if (net_xmit_eval(err) == 0) { 978 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats); 979 980 tstats->tx_bytes += pkt_len; 981 tstats->tx_packets++; 982 } else { 983 stats->tx_errors++; 984 stats->tx_aborted_errors++; 985 } 986 ip6_tnl_dst_store(t, dst); 987 return 0; 988 tx_err_link_failure: 989 stats->tx_carrier_errors++; 990 dst_link_failure(skb); 991 tx_err_dst_release: 992 dst_release(dst); 993 return err; 994 } 995 996 static inline int 997 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 998 { 999 struct ip6_tnl *t = netdev_priv(dev); 1000 struct iphdr *iph = ip_hdr(skb); 1001 int encap_limit = -1; 1002 struct flowi fl; 1003 __u8 dsfield; 1004 __u32 mtu; 1005 int err; 1006 1007 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1008 !ip6_tnl_xmit_ctl(t)) 1009 return -1; 1010 1011 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1012 encap_limit = t->parms.encap_limit; 1013 1014 memcpy(&fl, &t->fl, sizeof (fl)); 1015 fl.proto = IPPROTO_IPIP; 1016 1017 dsfield = ipv4_get_dsfield(iph); 1018 1019 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1020 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1021 & IPV6_TCLASS_MASK; 1022 1023 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1024 if (err != 0) { 1025 /* XXX: send ICMP error even if DF is not set. */ 1026 if (err == -EMSGSIZE) 1027 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1028 htonl(mtu)); 1029 return -1; 1030 } 1031 1032 return 0; 1033 } 1034 1035 static inline int 1036 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1037 { 1038 struct ip6_tnl *t = netdev_priv(dev); 1039 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1040 int encap_limit = -1; 1041 __u16 offset; 1042 struct flowi fl; 1043 __u8 dsfield; 1044 __u32 mtu; 1045 int err; 1046 1047 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1048 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1049 return -1; 1050 1051 offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb)); 1052 if (offset > 0) { 1053 struct ipv6_tlv_tnl_enc_lim *tel; 1054 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1055 if (tel->encap_limit == 0) { 1056 icmpv6_send(skb, ICMPV6_PARAMPROB, 1057 ICMPV6_HDR_FIELD, offset + 2); 1058 return -1; 1059 } 1060 encap_limit = tel->encap_limit - 1; 1061 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1062 encap_limit = t->parms.encap_limit; 1063 1064 memcpy(&fl, &t->fl, sizeof (fl)); 1065 fl.proto = IPPROTO_IPV6; 1066 1067 dsfield = ipv6_get_dsfield(ipv6h); 1068 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1069 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1070 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1071 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1072 1073 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1074 if (err != 0) { 1075 if (err == -EMSGSIZE) 1076 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1077 return -1; 1078 } 1079 1080 return 0; 1081 } 1082 1083 static netdev_tx_t 1084 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1085 { 1086 struct ip6_tnl *t = netdev_priv(dev); 1087 struct net_device_stats *stats = &t->dev->stats; 1088 int ret; 1089 1090 switch (skb->protocol) { 1091 case htons(ETH_P_IP): 1092 ret = ip4ip6_tnl_xmit(skb, dev); 1093 break; 1094 case htons(ETH_P_IPV6): 1095 ret = ip6ip6_tnl_xmit(skb, dev); 1096 break; 1097 default: 1098 goto tx_err; 1099 } 1100 1101 if (ret < 0) 1102 goto tx_err; 1103 1104 return NETDEV_TX_OK; 1105 1106 tx_err: 1107 stats->tx_errors++; 1108 stats->tx_dropped++; 1109 kfree_skb(skb); 1110 return NETDEV_TX_OK; 1111 } 1112 1113 static void ip6_tnl_set_cap(struct ip6_tnl *t) 1114 { 1115 struct ip6_tnl_parm *p = &t->parms; 1116 int ltype = ipv6_addr_type(&p->laddr); 1117 int rtype = ipv6_addr_type(&p->raddr); 1118 1119 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 1120 1121 if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1122 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1123 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 1124 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 1125 if (ltype&IPV6_ADDR_UNICAST) 1126 p->flags |= IP6_TNL_F_CAP_XMIT; 1127 if (rtype&IPV6_ADDR_UNICAST) 1128 p->flags |= IP6_TNL_F_CAP_RCV; 1129 } 1130 } 1131 1132 static void ip6_tnl_link_config(struct ip6_tnl *t) 1133 { 1134 struct net_device *dev = t->dev; 1135 struct ip6_tnl_parm *p = &t->parms; 1136 struct flowi *fl = &t->fl; 1137 1138 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1139 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1140 1141 /* Set up flowi template */ 1142 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 1143 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 1144 fl->oif = p->link; 1145 fl->fl6_flowlabel = 0; 1146 1147 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1148 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1149 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1150 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1151 1152 ip6_tnl_set_cap(t); 1153 1154 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1155 dev->flags |= IFF_POINTOPOINT; 1156 else 1157 dev->flags &= ~IFF_POINTOPOINT; 1158 1159 dev->iflink = p->link; 1160 1161 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1162 int strict = (ipv6_addr_type(&p->raddr) & 1163 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1164 1165 struct rt6_info *rt = rt6_lookup(dev_net(dev), 1166 &p->raddr, &p->laddr, 1167 p->link, strict); 1168 1169 if (rt == NULL) 1170 return; 1171 1172 if (rt->rt6i_dev) { 1173 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 1174 sizeof (struct ipv6hdr); 1175 1176 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 1177 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1178 dev->mtu-=8; 1179 1180 if (dev->mtu < IPV6_MIN_MTU) 1181 dev->mtu = IPV6_MIN_MTU; 1182 } 1183 dst_release(&rt->dst); 1184 } 1185 } 1186 1187 /** 1188 * ip6_tnl_change - update the tunnel parameters 1189 * @t: tunnel to be changed 1190 * @p: tunnel configuration parameters 1191 * 1192 * Description: 1193 * ip6_tnl_change() updates the tunnel parameters 1194 **/ 1195 1196 static int 1197 ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) 1198 { 1199 ipv6_addr_copy(&t->parms.laddr, &p->laddr); 1200 ipv6_addr_copy(&t->parms.raddr, &p->raddr); 1201 t->parms.flags = p->flags; 1202 t->parms.hop_limit = p->hop_limit; 1203 t->parms.encap_limit = p->encap_limit; 1204 t->parms.flowinfo = p->flowinfo; 1205 t->parms.link = p->link; 1206 t->parms.proto = p->proto; 1207 ip6_tnl_dst_reset(t); 1208 ip6_tnl_link_config(t); 1209 return 0; 1210 } 1211 1212 /** 1213 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1214 * @dev: virtual device associated with tunnel 1215 * @ifr: parameters passed from userspace 1216 * @cmd: command to be performed 1217 * 1218 * Description: 1219 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1220 * from userspace. 1221 * 1222 * The possible commands are the following: 1223 * %SIOCGETTUNNEL: get tunnel parameters for device 1224 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1225 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1226 * %SIOCDELTUNNEL: delete tunnel 1227 * 1228 * The fallback device "ip6tnl0", created during module 1229 * initialization, can be used for creating other tunnel devices. 1230 * 1231 * Return: 1232 * 0 on success, 1233 * %-EFAULT if unable to copy data to or from userspace, 1234 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1235 * %-EINVAL if passed tunnel parameters are invalid, 1236 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1237 * %-ENODEV if attempting to change or delete a nonexisting device 1238 **/ 1239 1240 static int 1241 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1242 { 1243 int err = 0; 1244 struct ip6_tnl_parm p; 1245 struct ip6_tnl *t = NULL; 1246 struct net *net = dev_net(dev); 1247 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1248 1249 switch (cmd) { 1250 case SIOCGETTUNNEL: 1251 if (dev == ip6n->fb_tnl_dev) { 1252 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 1253 err = -EFAULT; 1254 break; 1255 } 1256 t = ip6_tnl_locate(net, &p, 0); 1257 } 1258 if (t == NULL) 1259 t = netdev_priv(dev); 1260 memcpy(&p, &t->parms, sizeof (p)); 1261 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 1262 err = -EFAULT; 1263 } 1264 break; 1265 case SIOCADDTUNNEL: 1266 case SIOCCHGTUNNEL: 1267 err = -EPERM; 1268 if (!capable(CAP_NET_ADMIN)) 1269 break; 1270 err = -EFAULT; 1271 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1272 break; 1273 err = -EINVAL; 1274 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1275 p.proto != 0) 1276 break; 1277 t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL); 1278 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1279 if (t != NULL) { 1280 if (t->dev != dev) { 1281 err = -EEXIST; 1282 break; 1283 } 1284 } else 1285 t = netdev_priv(dev); 1286 1287 ip6_tnl_unlink(ip6n, t); 1288 synchronize_net(); 1289 err = ip6_tnl_change(t, &p); 1290 ip6_tnl_link(ip6n, t); 1291 netdev_state_change(dev); 1292 } 1293 if (t) { 1294 err = 0; 1295 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) 1296 err = -EFAULT; 1297 1298 } else 1299 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1300 break; 1301 case SIOCDELTUNNEL: 1302 err = -EPERM; 1303 if (!capable(CAP_NET_ADMIN)) 1304 break; 1305 1306 if (dev == ip6n->fb_tnl_dev) { 1307 err = -EFAULT; 1308 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1309 break; 1310 err = -ENOENT; 1311 if ((t = ip6_tnl_locate(net, &p, 0)) == NULL) 1312 break; 1313 err = -EPERM; 1314 if (t->dev == ip6n->fb_tnl_dev) 1315 break; 1316 dev = t->dev; 1317 } 1318 err = 0; 1319 unregister_netdevice(dev); 1320 break; 1321 default: 1322 err = -EINVAL; 1323 } 1324 return err; 1325 } 1326 1327 /** 1328 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1329 * @dev: virtual device associated with tunnel 1330 * @new_mtu: the new mtu 1331 * 1332 * Return: 1333 * 0 on success, 1334 * %-EINVAL if mtu too small 1335 **/ 1336 1337 static int 1338 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1339 { 1340 if (new_mtu < IPV6_MIN_MTU) { 1341 return -EINVAL; 1342 } 1343 dev->mtu = new_mtu; 1344 return 0; 1345 } 1346 1347 1348 static const struct net_device_ops ip6_tnl_netdev_ops = { 1349 .ndo_uninit = ip6_tnl_dev_uninit, 1350 .ndo_start_xmit = ip6_tnl_xmit, 1351 .ndo_do_ioctl = ip6_tnl_ioctl, 1352 .ndo_change_mtu = ip6_tnl_change_mtu, 1353 .ndo_get_stats = ip6_get_stats, 1354 }; 1355 1356 1357 /** 1358 * ip6_tnl_dev_setup - setup virtual tunnel device 1359 * @dev: virtual device associated with tunnel 1360 * 1361 * Description: 1362 * Initialize function pointers and device parameters 1363 **/ 1364 1365 static void ip6_tnl_dev_setup(struct net_device *dev) 1366 { 1367 struct ip6_tnl *t; 1368 1369 dev->netdev_ops = &ip6_tnl_netdev_ops; 1370 dev->destructor = ip6_dev_free; 1371 1372 dev->type = ARPHRD_TUNNEL6; 1373 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1374 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1375 t = netdev_priv(dev); 1376 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1377 dev->mtu-=8; 1378 dev->flags |= IFF_NOARP; 1379 dev->addr_len = sizeof(struct in6_addr); 1380 dev->features |= NETIF_F_NETNS_LOCAL; 1381 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1382 } 1383 1384 1385 /** 1386 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1387 * @dev: virtual device associated with tunnel 1388 **/ 1389 1390 static inline int 1391 ip6_tnl_dev_init_gen(struct net_device *dev) 1392 { 1393 struct ip6_tnl *t = netdev_priv(dev); 1394 1395 t->dev = dev; 1396 strcpy(t->parms.name, dev->name); 1397 dev->tstats = alloc_percpu(struct pcpu_tstats); 1398 if (!dev->tstats) 1399 return -ENOMEM; 1400 return 0; 1401 } 1402 1403 /** 1404 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1405 * @dev: virtual device associated with tunnel 1406 **/ 1407 1408 static int ip6_tnl_dev_init(struct net_device *dev) 1409 { 1410 struct ip6_tnl *t = netdev_priv(dev); 1411 int err = ip6_tnl_dev_init_gen(dev); 1412 1413 if (err) 1414 return err; 1415 ip6_tnl_link_config(t); 1416 return 0; 1417 } 1418 1419 /** 1420 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1421 * @dev: fallback device 1422 * 1423 * Return: 0 1424 **/ 1425 1426 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1427 { 1428 struct ip6_tnl *t = netdev_priv(dev); 1429 struct net *net = dev_net(dev); 1430 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1431 int err = ip6_tnl_dev_init_gen(dev); 1432 1433 if (err) 1434 return err; 1435 1436 t->parms.proto = IPPROTO_IPV6; 1437 dev_hold(dev); 1438 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1439 return 0; 1440 } 1441 1442 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1443 .handler = ip4ip6_rcv, 1444 .err_handler = ip4ip6_err, 1445 .priority = 1, 1446 }; 1447 1448 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1449 .handler = ip6ip6_rcv, 1450 .err_handler = ip6ip6_err, 1451 .priority = 1, 1452 }; 1453 1454 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1455 { 1456 int h; 1457 struct ip6_tnl *t; 1458 LIST_HEAD(list); 1459 1460 for (h = 0; h < HASH_SIZE; h++) { 1461 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1462 while (t != NULL) { 1463 unregister_netdevice_queue(t->dev, &list); 1464 t = rtnl_dereference(t->next); 1465 } 1466 } 1467 1468 t = rtnl_dereference(ip6n->tnls_wc[0]); 1469 unregister_netdevice_queue(t->dev, &list); 1470 unregister_netdevice_many(&list); 1471 } 1472 1473 static int __net_init ip6_tnl_init_net(struct net *net) 1474 { 1475 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1476 int err; 1477 1478 ip6n->tnls[0] = ip6n->tnls_wc; 1479 ip6n->tnls[1] = ip6n->tnls_r_l; 1480 1481 err = -ENOMEM; 1482 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1483 ip6_tnl_dev_setup); 1484 1485 if (!ip6n->fb_tnl_dev) 1486 goto err_alloc_dev; 1487 dev_net_set(ip6n->fb_tnl_dev, net); 1488 1489 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1490 if (err < 0) 1491 goto err_register; 1492 1493 err = register_netdev(ip6n->fb_tnl_dev); 1494 if (err < 0) 1495 goto err_register; 1496 return 0; 1497 1498 err_register: 1499 ip6_dev_free(ip6n->fb_tnl_dev); 1500 err_alloc_dev: 1501 return err; 1502 } 1503 1504 static void __net_exit ip6_tnl_exit_net(struct net *net) 1505 { 1506 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1507 1508 rtnl_lock(); 1509 ip6_tnl_destroy_tunnels(ip6n); 1510 rtnl_unlock(); 1511 } 1512 1513 static struct pernet_operations ip6_tnl_net_ops = { 1514 .init = ip6_tnl_init_net, 1515 .exit = ip6_tnl_exit_net, 1516 .id = &ip6_tnl_net_id, 1517 .size = sizeof(struct ip6_tnl_net), 1518 }; 1519 1520 /** 1521 * ip6_tunnel_init - register protocol and reserve needed resources 1522 * 1523 * Return: 0 on success 1524 **/ 1525 1526 static int __init ip6_tunnel_init(void) 1527 { 1528 int err; 1529 1530 err = register_pernet_device(&ip6_tnl_net_ops); 1531 if (err < 0) 1532 goto out_pernet; 1533 1534 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1535 if (err < 0) { 1536 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n"); 1537 goto out_ip4ip6; 1538 } 1539 1540 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1541 if (err < 0) { 1542 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n"); 1543 goto out_ip6ip6; 1544 } 1545 1546 return 0; 1547 1548 out_ip6ip6: 1549 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1550 out_ip4ip6: 1551 unregister_pernet_device(&ip6_tnl_net_ops); 1552 out_pernet: 1553 return err; 1554 } 1555 1556 /** 1557 * ip6_tunnel_cleanup - free resources and unregister protocol 1558 **/ 1559 1560 static void __exit ip6_tunnel_cleanup(void) 1561 { 1562 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1563 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n"); 1564 1565 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1566 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n"); 1567 1568 unregister_pernet_device(&ip6_tnl_net_ops); 1569 } 1570 1571 module_init(ip6_tunnel_init); 1572 module_exit(ip6_tunnel_cleanup); 1573