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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 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/icmp.h> 29 #include <linux/if.h> 30 #include <linux/in.h> 31 #include <linux/ip.h> 32 #include <linux/if_tunnel.h> 33 #include <linux/net.h> 34 #include <linux/in6.h> 35 #include <linux/netdevice.h> 36 #include <linux/if_arp.h> 37 #include <linux/icmpv6.h> 38 #include <linux/init.h> 39 #include <linux/route.h> 40 #include <linux/rtnetlink.h> 41 #include <linux/netfilter_ipv6.h> 42 #include <linux/slab.h> 43 #include <linux/hash.h> 44 #include <linux/etherdevice.h> 45 46 #include <asm/uaccess.h> 47 #include <linux/atomic.h> 48 49 #include <net/icmp.h> 50 #include <net/ip.h> 51 #include <net/ip_tunnels.h> 52 #include <net/ipv6.h> 53 #include <net/ip6_route.h> 54 #include <net/addrconf.h> 55 #include <net/ip6_tunnel.h> 56 #include <net/xfrm.h> 57 #include <net/dsfield.h> 58 #include <net/inet_ecn.h> 59 #include <net/net_namespace.h> 60 #include <net/netns/generic.h> 61 62 MODULE_AUTHOR("Ville Nuorvala"); 63 MODULE_DESCRIPTION("IPv6 tunneling device"); 64 MODULE_LICENSE("GPL"); 65 MODULE_ALIAS_NETDEV("ip6tnl0"); 66 67 #ifdef IP6_TNL_DEBUG 68 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__) 69 #else 70 #define IP6_TNL_TRACE(x...) do {;} while(0) 71 #endif 72 73 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 74 #define IPV6_TCLASS_SHIFT 20 75 76 #define HASH_SIZE_SHIFT 5 77 #define HASH_SIZE (1 << HASH_SIZE_SHIFT) 78 79 static bool log_ecn_error = true; 80 module_param(log_ecn_error, bool, 0644); 81 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 82 83 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 84 { 85 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 86 87 return hash_32(hash, HASH_SIZE_SHIFT); 88 } 89 90 static int ip6_tnl_dev_init(struct net_device *dev); 91 static void ip6_tnl_dev_setup(struct net_device *dev); 92 static struct rtnl_link_ops ip6_link_ops __read_mostly; 93 94 static int ip6_tnl_net_id __read_mostly; 95 struct ip6_tnl_net { 96 /* the IPv6 tunnel fallback device */ 97 struct net_device *fb_tnl_dev; 98 /* lists for storing tunnels in use */ 99 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 100 struct ip6_tnl __rcu *tnls_wc[1]; 101 struct ip6_tnl __rcu **tnls[2]; 102 }; 103 104 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 105 { 106 struct pcpu_tstats sum = { 0 }; 107 int i; 108 109 for_each_possible_cpu(i) { 110 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 111 112 sum.rx_packets += tstats->rx_packets; 113 sum.rx_bytes += tstats->rx_bytes; 114 sum.tx_packets += tstats->tx_packets; 115 sum.tx_bytes += tstats->tx_bytes; 116 } 117 dev->stats.rx_packets = sum.rx_packets; 118 dev->stats.rx_bytes = sum.rx_bytes; 119 dev->stats.tx_packets = sum.tx_packets; 120 dev->stats.tx_bytes = sum.tx_bytes; 121 return &dev->stats; 122 } 123 124 /* 125 * Locking : hash tables are protected by RCU and RTNL 126 */ 127 128 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 129 { 130 struct dst_entry *dst = t->dst_cache; 131 132 if (dst && dst->obsolete && 133 dst->ops->check(dst, t->dst_cookie) == NULL) { 134 t->dst_cache = NULL; 135 dst_release(dst); 136 return NULL; 137 } 138 139 return dst; 140 } 141 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check); 142 143 void ip6_tnl_dst_reset(struct ip6_tnl *t) 144 { 145 dst_release(t->dst_cache); 146 t->dst_cache = NULL; 147 } 148 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset); 149 150 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 151 { 152 struct rt6_info *rt = (struct rt6_info *) dst; 153 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 154 dst_release(t->dst_cache); 155 t->dst_cache = dst; 156 } 157 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store); 158 159 /** 160 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 161 * @remote: the address of the tunnel exit-point 162 * @local: the address of the tunnel entry-point 163 * 164 * Return: 165 * tunnel matching given end-points if found, 166 * else fallback tunnel if its device is up, 167 * else %NULL 168 **/ 169 170 #define for_each_ip6_tunnel_rcu(start) \ 171 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 172 173 static struct ip6_tnl * 174 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local) 175 { 176 unsigned int hash = HASH(remote, local); 177 struct ip6_tnl *t; 178 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 179 180 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 181 if (ipv6_addr_equal(local, &t->parms.laddr) && 182 ipv6_addr_equal(remote, &t->parms.raddr) && 183 (t->dev->flags & IFF_UP)) 184 return t; 185 } 186 t = rcu_dereference(ip6n->tnls_wc[0]); 187 if (t && (t->dev->flags & IFF_UP)) 188 return t; 189 190 return NULL; 191 } 192 193 /** 194 * ip6_tnl_bucket - get head of list matching given tunnel parameters 195 * @p: parameters containing tunnel end-points 196 * 197 * Description: 198 * ip6_tnl_bucket() returns the head of the list matching the 199 * &struct in6_addr entries laddr and raddr in @p. 200 * 201 * Return: head of IPv6 tunnel list 202 **/ 203 204 static struct ip6_tnl __rcu ** 205 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p) 206 { 207 const struct in6_addr *remote = &p->raddr; 208 const struct in6_addr *local = &p->laddr; 209 unsigned int h = 0; 210 int prio = 0; 211 212 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 213 prio = 1; 214 h = HASH(remote, local); 215 } 216 return &ip6n->tnls[prio][h]; 217 } 218 219 /** 220 * ip6_tnl_link - add tunnel to hash table 221 * @t: tunnel to be added 222 **/ 223 224 static void 225 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 226 { 227 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 228 229 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 230 rcu_assign_pointer(*tp, t); 231 } 232 233 /** 234 * ip6_tnl_unlink - remove tunnel from hash table 235 * @t: tunnel to be removed 236 **/ 237 238 static void 239 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 240 { 241 struct ip6_tnl __rcu **tp; 242 struct ip6_tnl *iter; 243 244 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 245 (iter = rtnl_dereference(*tp)) != NULL; 246 tp = &iter->next) { 247 if (t == iter) { 248 rcu_assign_pointer(*tp, t->next); 249 break; 250 } 251 } 252 } 253 254 static void ip6_dev_free(struct net_device *dev) 255 { 256 free_percpu(dev->tstats); 257 free_netdev(dev); 258 } 259 260 static int ip6_tnl_create2(struct net_device *dev) 261 { 262 struct ip6_tnl *t = netdev_priv(dev); 263 struct net *net = dev_net(dev); 264 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 265 int err; 266 267 t = netdev_priv(dev); 268 err = ip6_tnl_dev_init(dev); 269 if (err < 0) 270 goto out; 271 272 err = register_netdevice(dev); 273 if (err < 0) 274 goto out; 275 276 strcpy(t->parms.name, dev->name); 277 dev->rtnl_link_ops = &ip6_link_ops; 278 279 dev_hold(dev); 280 ip6_tnl_link(ip6n, t); 281 return 0; 282 283 out: 284 return err; 285 } 286 287 /** 288 * ip6_tnl_create - create a new tunnel 289 * @p: tunnel parameters 290 * @pt: pointer to new tunnel 291 * 292 * Description: 293 * Create tunnel matching given parameters. 294 * 295 * Return: 296 * created tunnel or NULL 297 **/ 298 299 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 300 { 301 struct net_device *dev; 302 struct ip6_tnl *t; 303 char name[IFNAMSIZ]; 304 int err; 305 306 if (p->name[0]) 307 strlcpy(name, p->name, IFNAMSIZ); 308 else 309 sprintf(name, "ip6tnl%%d"); 310 311 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 312 if (dev == NULL) 313 goto failed; 314 315 dev_net_set(dev, net); 316 317 t = netdev_priv(dev); 318 t->parms = *p; 319 t->net = dev_net(dev); 320 err = ip6_tnl_create2(dev); 321 if (err < 0) 322 goto failed_free; 323 324 return t; 325 326 failed_free: 327 ip6_dev_free(dev); 328 failed: 329 return NULL; 330 } 331 332 /** 333 * ip6_tnl_locate - find or create tunnel matching given parameters 334 * @p: tunnel parameters 335 * @create: != 0 if allowed to create new tunnel if no match found 336 * 337 * Description: 338 * ip6_tnl_locate() first tries to locate an existing tunnel 339 * based on @parms. If this is unsuccessful, but @create is set a new 340 * tunnel device is created and registered for use. 341 * 342 * Return: 343 * matching tunnel or NULL 344 **/ 345 346 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 347 struct __ip6_tnl_parm *p, int create) 348 { 349 const struct in6_addr *remote = &p->raddr; 350 const struct in6_addr *local = &p->laddr; 351 struct ip6_tnl __rcu **tp; 352 struct ip6_tnl *t; 353 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 354 355 for (tp = ip6_tnl_bucket(ip6n, p); 356 (t = rtnl_dereference(*tp)) != NULL; 357 tp = &t->next) { 358 if (ipv6_addr_equal(local, &t->parms.laddr) && 359 ipv6_addr_equal(remote, &t->parms.raddr)) 360 return t; 361 } 362 if (!create) 363 return NULL; 364 return ip6_tnl_create(net, p); 365 } 366 367 /** 368 * ip6_tnl_dev_uninit - tunnel device uninitializer 369 * @dev: the device to be destroyed 370 * 371 * Description: 372 * ip6_tnl_dev_uninit() removes tunnel from its list 373 **/ 374 375 static void 376 ip6_tnl_dev_uninit(struct net_device *dev) 377 { 378 struct ip6_tnl *t = netdev_priv(dev); 379 struct net *net = t->net; 380 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 381 382 if (dev == ip6n->fb_tnl_dev) 383 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 384 else 385 ip6_tnl_unlink(ip6n, t); 386 ip6_tnl_dst_reset(t); 387 dev_put(dev); 388 } 389 390 /** 391 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 392 * @skb: received socket buffer 393 * 394 * Return: 395 * 0 if none was found, 396 * else index to encapsulation limit 397 **/ 398 399 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) 400 { 401 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw; 402 __u8 nexthdr = ipv6h->nexthdr; 403 __u16 off = sizeof (*ipv6h); 404 405 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 406 __u16 optlen = 0; 407 struct ipv6_opt_hdr *hdr; 408 if (raw + off + sizeof (*hdr) > skb->data && 409 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 410 break; 411 412 hdr = (struct ipv6_opt_hdr *) (raw + off); 413 if (nexthdr == NEXTHDR_FRAGMENT) { 414 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 415 if (frag_hdr->frag_off) 416 break; 417 optlen = 8; 418 } else if (nexthdr == NEXTHDR_AUTH) { 419 optlen = (hdr->hdrlen + 2) << 2; 420 } else { 421 optlen = ipv6_optlen(hdr); 422 } 423 if (nexthdr == NEXTHDR_DEST) { 424 __u16 i = off + 2; 425 while (1) { 426 struct ipv6_tlv_tnl_enc_lim *tel; 427 428 /* No more room for encapsulation limit */ 429 if (i + sizeof (*tel) > off + optlen) 430 break; 431 432 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 433 /* return index of option if found and valid */ 434 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 435 tel->length == 1) 436 return i; 437 /* else jump to next option */ 438 if (tel->type) 439 i += tel->length + 2; 440 else 441 i++; 442 } 443 } 444 nexthdr = hdr->nexthdr; 445 off += optlen; 446 } 447 return 0; 448 } 449 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim); 450 451 /** 452 * ip6_tnl_err - tunnel error handler 453 * 454 * Description: 455 * ip6_tnl_err() should handle errors in the tunnel according 456 * to the specifications in RFC 2473. 457 **/ 458 459 static int 460 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 461 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 462 { 463 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data; 464 struct ip6_tnl *t; 465 int rel_msg = 0; 466 u8 rel_type = ICMPV6_DEST_UNREACH; 467 u8 rel_code = ICMPV6_ADDR_UNREACH; 468 __u32 rel_info = 0; 469 __u16 len; 470 int err = -ENOENT; 471 472 /* If the packet doesn't contain the original IPv6 header we are 473 in trouble since we might need the source address for further 474 processing of the error. */ 475 476 rcu_read_lock(); 477 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 478 &ipv6h->saddr)) == NULL) 479 goto out; 480 481 if (t->parms.proto != ipproto && t->parms.proto != 0) 482 goto out; 483 484 err = 0; 485 486 switch (*type) { 487 __u32 teli; 488 struct ipv6_tlv_tnl_enc_lim *tel; 489 __u32 mtu; 490 case ICMPV6_DEST_UNREACH: 491 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n", 492 t->parms.name); 493 rel_msg = 1; 494 break; 495 case ICMPV6_TIME_EXCEED: 496 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 497 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", 498 t->parms.name); 499 rel_msg = 1; 500 } 501 break; 502 case ICMPV6_PARAMPROB: 503 teli = 0; 504 if ((*code) == ICMPV6_HDR_FIELD) 505 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); 506 507 if (teli && teli == *info - 2) { 508 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 509 if (tel->encap_limit == 0) { 510 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", 511 t->parms.name); 512 rel_msg = 1; 513 } 514 } else { 515 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n", 516 t->parms.name); 517 } 518 break; 519 case ICMPV6_PKT_TOOBIG: 520 mtu = *info - offset; 521 if (mtu < IPV6_MIN_MTU) 522 mtu = IPV6_MIN_MTU; 523 t->dev->mtu = mtu; 524 525 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 526 rel_type = ICMPV6_PKT_TOOBIG; 527 rel_code = 0; 528 rel_info = mtu; 529 rel_msg = 1; 530 } 531 break; 532 } 533 534 *type = rel_type; 535 *code = rel_code; 536 *info = rel_info; 537 *msg = rel_msg; 538 539 out: 540 rcu_read_unlock(); 541 return err; 542 } 543 544 static int 545 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 546 u8 type, u8 code, int offset, __be32 info) 547 { 548 int rel_msg = 0; 549 u8 rel_type = type; 550 u8 rel_code = code; 551 __u32 rel_info = ntohl(info); 552 int err; 553 struct sk_buff *skb2; 554 const struct iphdr *eiph; 555 struct rtable *rt; 556 struct flowi4 fl4; 557 558 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 559 &rel_msg, &rel_info, offset); 560 if (err < 0) 561 return err; 562 563 if (rel_msg == 0) 564 return 0; 565 566 switch (rel_type) { 567 case ICMPV6_DEST_UNREACH: 568 if (rel_code != ICMPV6_ADDR_UNREACH) 569 return 0; 570 rel_type = ICMP_DEST_UNREACH; 571 rel_code = ICMP_HOST_UNREACH; 572 break; 573 case ICMPV6_PKT_TOOBIG: 574 if (rel_code != 0) 575 return 0; 576 rel_type = ICMP_DEST_UNREACH; 577 rel_code = ICMP_FRAG_NEEDED; 578 break; 579 case NDISC_REDIRECT: 580 rel_type = ICMP_REDIRECT; 581 rel_code = ICMP_REDIR_HOST; 582 default: 583 return 0; 584 } 585 586 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 587 return 0; 588 589 skb2 = skb_clone(skb, GFP_ATOMIC); 590 if (!skb2) 591 return 0; 592 593 skb_dst_drop(skb2); 594 595 skb_pull(skb2, offset); 596 skb_reset_network_header(skb2); 597 eiph = ip_hdr(skb2); 598 599 /* Try to guess incoming interface */ 600 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 601 eiph->saddr, 0, 602 0, 0, 603 IPPROTO_IPIP, RT_TOS(eiph->tos), 0); 604 if (IS_ERR(rt)) 605 goto out; 606 607 skb2->dev = rt->dst.dev; 608 609 /* route "incoming" packet */ 610 if (rt->rt_flags & RTCF_LOCAL) { 611 ip_rt_put(rt); 612 rt = NULL; 613 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 614 eiph->daddr, eiph->saddr, 615 0, 0, 616 IPPROTO_IPIP, 617 RT_TOS(eiph->tos), 0); 618 if (IS_ERR(rt) || 619 rt->dst.dev->type != ARPHRD_TUNNEL) { 620 if (!IS_ERR(rt)) 621 ip_rt_put(rt); 622 goto out; 623 } 624 skb_dst_set(skb2, &rt->dst); 625 } else { 626 ip_rt_put(rt); 627 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 628 skb2->dev) || 629 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 630 goto out; 631 } 632 633 /* change mtu on this route */ 634 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 635 if (rel_info > dst_mtu(skb_dst(skb2))) 636 goto out; 637 638 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info); 639 } 640 if (rel_type == ICMP_REDIRECT) 641 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2); 642 643 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 644 645 out: 646 kfree_skb(skb2); 647 return 0; 648 } 649 650 static int 651 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 652 u8 type, u8 code, int offset, __be32 info) 653 { 654 int rel_msg = 0; 655 u8 rel_type = type; 656 u8 rel_code = code; 657 __u32 rel_info = ntohl(info); 658 int err; 659 660 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 661 &rel_msg, &rel_info, offset); 662 if (err < 0) 663 return err; 664 665 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 666 struct rt6_info *rt; 667 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 668 669 if (!skb2) 670 return 0; 671 672 skb_dst_drop(skb2); 673 skb_pull(skb2, offset); 674 skb_reset_network_header(skb2); 675 676 /* Try to guess incoming interface */ 677 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 678 NULL, 0, 0); 679 680 if (rt && rt->dst.dev) 681 skb2->dev = rt->dst.dev; 682 683 icmpv6_send(skb2, rel_type, rel_code, rel_info); 684 685 ip6_rt_put(rt); 686 687 kfree_skb(skb2); 688 } 689 690 return 0; 691 } 692 693 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 694 const struct ipv6hdr *ipv6h, 695 struct sk_buff *skb) 696 { 697 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 698 699 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 700 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 701 702 return IP6_ECN_decapsulate(ipv6h, skb); 703 } 704 705 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 706 const struct ipv6hdr *ipv6h, 707 struct sk_buff *skb) 708 { 709 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 710 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 711 712 return IP6_ECN_decapsulate(ipv6h, skb); 713 } 714 715 __u32 ip6_tnl_get_cap(struct ip6_tnl *t, 716 const struct in6_addr *laddr, 717 const struct in6_addr *raddr) 718 { 719 struct __ip6_tnl_parm *p = &t->parms; 720 int ltype = ipv6_addr_type(laddr); 721 int rtype = ipv6_addr_type(raddr); 722 __u32 flags = 0; 723 724 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) { 725 flags = IP6_TNL_F_CAP_PER_PACKET; 726 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 727 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 728 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 729 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 730 if (ltype&IPV6_ADDR_UNICAST) 731 flags |= IP6_TNL_F_CAP_XMIT; 732 if (rtype&IPV6_ADDR_UNICAST) 733 flags |= IP6_TNL_F_CAP_RCV; 734 } 735 return flags; 736 } 737 EXPORT_SYMBOL(ip6_tnl_get_cap); 738 739 /* called with rcu_read_lock() */ 740 int ip6_tnl_rcv_ctl(struct ip6_tnl *t, 741 const struct in6_addr *laddr, 742 const struct in6_addr *raddr) 743 { 744 struct __ip6_tnl_parm *p = &t->parms; 745 int ret = 0; 746 struct net *net = t->net; 747 748 if ((p->flags & IP6_TNL_F_CAP_RCV) || 749 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && 750 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) { 751 struct net_device *ldev = NULL; 752 753 if (p->link) 754 ldev = dev_get_by_index_rcu(net, p->link); 755 756 if ((ipv6_addr_is_multicast(laddr) || 757 likely(ipv6_chk_addr(net, laddr, ldev, 0))) && 758 likely(!ipv6_chk_addr(net, raddr, NULL, 0))) 759 ret = 1; 760 } 761 return ret; 762 } 763 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl); 764 765 /** 766 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 767 * @skb: received socket buffer 768 * @protocol: ethernet protocol ID 769 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 770 * 771 * Return: 0 772 **/ 773 774 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 775 __u8 ipproto, 776 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t, 777 const struct ipv6hdr *ipv6h, 778 struct sk_buff *skb)) 779 { 780 struct ip6_tnl *t; 781 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 782 int err; 783 784 rcu_read_lock(); 785 786 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 787 &ipv6h->daddr)) != NULL) { 788 struct pcpu_tstats *tstats; 789 790 if (t->parms.proto != ipproto && t->parms.proto != 0) { 791 rcu_read_unlock(); 792 goto discard; 793 } 794 795 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 796 rcu_read_unlock(); 797 goto discard; 798 } 799 800 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 801 t->dev->stats.rx_dropped++; 802 rcu_read_unlock(); 803 goto discard; 804 } 805 skb->mac_header = skb->network_header; 806 skb_reset_network_header(skb); 807 skb->protocol = htons(protocol); 808 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 809 810 __skb_tunnel_rx(skb, t->dev, t->net); 811 812 err = dscp_ecn_decapsulate(t, ipv6h, skb); 813 if (unlikely(err)) { 814 if (log_ecn_error) 815 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n", 816 &ipv6h->saddr, 817 ipv6_get_dsfield(ipv6h)); 818 if (err > 1) { 819 ++t->dev->stats.rx_frame_errors; 820 ++t->dev->stats.rx_errors; 821 rcu_read_unlock(); 822 goto discard; 823 } 824 } 825 826 tstats = this_cpu_ptr(t->dev->tstats); 827 tstats->rx_packets++; 828 tstats->rx_bytes += skb->len; 829 830 netif_rx(skb); 831 832 rcu_read_unlock(); 833 return 0; 834 } 835 rcu_read_unlock(); 836 return 1; 837 838 discard: 839 kfree_skb(skb); 840 return 0; 841 } 842 843 static int ip4ip6_rcv(struct sk_buff *skb) 844 { 845 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 846 ip4ip6_dscp_ecn_decapsulate); 847 } 848 849 static int ip6ip6_rcv(struct sk_buff *skb) 850 { 851 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 852 ip6ip6_dscp_ecn_decapsulate); 853 } 854 855 struct ipv6_tel_txoption { 856 struct ipv6_txoptions ops; 857 __u8 dst_opt[8]; 858 }; 859 860 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 861 { 862 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 863 864 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 865 opt->dst_opt[3] = 1; 866 opt->dst_opt[4] = encap_limit; 867 opt->dst_opt[5] = IPV6_TLV_PADN; 868 opt->dst_opt[6] = 1; 869 870 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 871 opt->ops.opt_nflen = 8; 872 } 873 874 /** 875 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 876 * @t: the outgoing tunnel device 877 * @hdr: IPv6 header from the incoming packet 878 * 879 * Description: 880 * Avoid trivial tunneling loop by checking that tunnel exit-point 881 * doesn't match source of incoming packet. 882 * 883 * Return: 884 * 1 if conflict, 885 * 0 else 886 **/ 887 888 static inline bool 889 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 890 { 891 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 892 } 893 894 int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 895 { 896 struct __ip6_tnl_parm *p = &t->parms; 897 int ret = 0; 898 struct net *net = t->net; 899 900 if (p->flags & IP6_TNL_F_CAP_XMIT) { 901 struct net_device *ldev = NULL; 902 903 rcu_read_lock(); 904 if (p->link) 905 ldev = dev_get_by_index_rcu(net, p->link); 906 907 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 908 pr_warn("%s xmit: Local address not yet configured!\n", 909 p->name); 910 else if (!ipv6_addr_is_multicast(&p->raddr) && 911 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 912 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n", 913 p->name); 914 else 915 ret = 1; 916 rcu_read_unlock(); 917 } 918 return ret; 919 } 920 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl); 921 922 /** 923 * ip6_tnl_xmit2 - encapsulate packet and send 924 * @skb: the outgoing socket buffer 925 * @dev: the outgoing tunnel device 926 * @dsfield: dscp code for outer header 927 * @fl: flow of tunneled packet 928 * @encap_limit: encapsulation limit 929 * @pmtu: Path MTU is stored if packet is too big 930 * 931 * Description: 932 * Build new header and do some sanity checks on the packet before sending 933 * it. 934 * 935 * Return: 936 * 0 on success 937 * -1 fail 938 * %-EMSGSIZE message too big. return mtu in this case. 939 **/ 940 941 static int ip6_tnl_xmit2(struct sk_buff *skb, 942 struct net_device *dev, 943 __u8 dsfield, 944 struct flowi6 *fl6, 945 int encap_limit, 946 __u32 *pmtu) 947 { 948 struct ip6_tnl *t = netdev_priv(dev); 949 struct net *net = t->net; 950 struct net_device_stats *stats = &t->dev->stats; 951 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 952 struct ipv6_tel_txoption opt; 953 struct dst_entry *dst = NULL, *ndst = NULL; 954 struct net_device *tdev; 955 int mtu; 956 unsigned int max_headroom = sizeof(struct ipv6hdr); 957 u8 proto; 958 int err = -1; 959 960 if (!fl6->flowi6_mark) 961 dst = ip6_tnl_dst_check(t); 962 if (!dst) { 963 ndst = ip6_route_output(net, NULL, fl6); 964 965 if (ndst->error) 966 goto tx_err_link_failure; 967 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0); 968 if (IS_ERR(ndst)) { 969 err = PTR_ERR(ndst); 970 ndst = NULL; 971 goto tx_err_link_failure; 972 } 973 dst = ndst; 974 } 975 976 tdev = dst->dev; 977 978 if (tdev == dev) { 979 stats->collisions++; 980 net_warn_ratelimited("%s: Local routing loop detected!\n", 981 t->parms.name); 982 goto tx_err_dst_release; 983 } 984 mtu = dst_mtu(dst) - sizeof (*ipv6h); 985 if (encap_limit >= 0) { 986 max_headroom += 8; 987 mtu -= 8; 988 } 989 if (mtu < IPV6_MIN_MTU) 990 mtu = IPV6_MIN_MTU; 991 if (skb_dst(skb)) 992 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 993 if (skb->len > mtu) { 994 *pmtu = mtu; 995 err = -EMSGSIZE; 996 goto tx_err_dst_release; 997 } 998 999 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 1000 1001 /* 1002 * Okay, now see if we can stuff it in the buffer as-is. 1003 */ 1004 max_headroom += LL_RESERVED_SPACE(tdev); 1005 1006 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 1007 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 1008 struct sk_buff *new_skb; 1009 1010 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 1011 goto tx_err_dst_release; 1012 1013 if (skb->sk) 1014 skb_set_owner_w(new_skb, skb->sk); 1015 consume_skb(skb); 1016 skb = new_skb; 1017 } 1018 if (fl6->flowi6_mark) { 1019 skb_dst_set(skb, dst); 1020 ndst = NULL; 1021 } else { 1022 skb_dst_set_noref(skb, dst); 1023 } 1024 skb->transport_header = skb->network_header; 1025 1026 proto = fl6->flowi6_proto; 1027 if (encap_limit >= 0) { 1028 init_tel_txopt(&opt, encap_limit); 1029 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 1030 } 1031 1032 if (likely(!skb->encapsulation)) { 1033 skb_reset_inner_headers(skb); 1034 skb->encapsulation = 1; 1035 } 1036 1037 skb_push(skb, sizeof(struct ipv6hdr)); 1038 skb_reset_network_header(skb); 1039 ipv6h = ipv6_hdr(skb); 1040 ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel); 1041 ipv6h->hop_limit = t->parms.hop_limit; 1042 ipv6h->nexthdr = proto; 1043 ipv6h->saddr = fl6->saddr; 1044 ipv6h->daddr = fl6->daddr; 1045 ip6tunnel_xmit(skb, dev); 1046 if (ndst) 1047 ip6_tnl_dst_store(t, ndst); 1048 return 0; 1049 tx_err_link_failure: 1050 stats->tx_carrier_errors++; 1051 dst_link_failure(skb); 1052 tx_err_dst_release: 1053 dst_release(ndst); 1054 return err; 1055 } 1056 1057 static inline int 1058 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1059 { 1060 struct ip6_tnl *t = netdev_priv(dev); 1061 const struct iphdr *iph = ip_hdr(skb); 1062 int encap_limit = -1; 1063 struct flowi6 fl6; 1064 __u8 dsfield; 1065 __u32 mtu; 1066 int err; 1067 1068 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1069 !ip6_tnl_xmit_ctl(t)) 1070 return -1; 1071 1072 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1073 encap_limit = t->parms.encap_limit; 1074 1075 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1076 fl6.flowi6_proto = IPPROTO_IPIP; 1077 1078 dsfield = ipv4_get_dsfield(iph); 1079 1080 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1081 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1082 & IPV6_TCLASS_MASK; 1083 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1084 fl6.flowi6_mark = skb->mark; 1085 1086 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1087 if (err != 0) { 1088 /* XXX: send ICMP error even if DF is not set. */ 1089 if (err == -EMSGSIZE) 1090 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1091 htonl(mtu)); 1092 return -1; 1093 } 1094 1095 return 0; 1096 } 1097 1098 static inline int 1099 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1100 { 1101 struct ip6_tnl *t = netdev_priv(dev); 1102 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1103 int encap_limit = -1; 1104 __u16 offset; 1105 struct flowi6 fl6; 1106 __u8 dsfield; 1107 __u32 mtu; 1108 int err; 1109 1110 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1111 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1112 return -1; 1113 1114 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb)); 1115 if (offset > 0) { 1116 struct ipv6_tlv_tnl_enc_lim *tel; 1117 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1118 if (tel->encap_limit == 0) { 1119 icmpv6_send(skb, ICMPV6_PARAMPROB, 1120 ICMPV6_HDR_FIELD, offset + 2); 1121 return -1; 1122 } 1123 encap_limit = tel->encap_limit - 1; 1124 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1125 encap_limit = t->parms.encap_limit; 1126 1127 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1128 fl6.flowi6_proto = IPPROTO_IPV6; 1129 1130 dsfield = ipv6_get_dsfield(ipv6h); 1131 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1132 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1133 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) 1134 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1135 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1136 fl6.flowi6_mark = skb->mark; 1137 1138 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1139 if (err != 0) { 1140 if (err == -EMSGSIZE) 1141 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1142 return -1; 1143 } 1144 1145 return 0; 1146 } 1147 1148 static netdev_tx_t 1149 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1150 { 1151 struct ip6_tnl *t = netdev_priv(dev); 1152 struct net_device_stats *stats = &t->dev->stats; 1153 int ret; 1154 1155 switch (skb->protocol) { 1156 case htons(ETH_P_IP): 1157 ret = ip4ip6_tnl_xmit(skb, dev); 1158 break; 1159 case htons(ETH_P_IPV6): 1160 ret = ip6ip6_tnl_xmit(skb, dev); 1161 break; 1162 default: 1163 goto tx_err; 1164 } 1165 1166 if (ret < 0) 1167 goto tx_err; 1168 1169 return NETDEV_TX_OK; 1170 1171 tx_err: 1172 stats->tx_errors++; 1173 stats->tx_dropped++; 1174 kfree_skb(skb); 1175 return NETDEV_TX_OK; 1176 } 1177 1178 static void ip6_tnl_link_config(struct ip6_tnl *t) 1179 { 1180 struct net_device *dev = t->dev; 1181 struct __ip6_tnl_parm *p = &t->parms; 1182 struct flowi6 *fl6 = &t->fl.u.ip6; 1183 1184 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1185 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1186 1187 /* Set up flowi template */ 1188 fl6->saddr = p->laddr; 1189 fl6->daddr = p->raddr; 1190 fl6->flowi6_oif = p->link; 1191 fl6->flowlabel = 0; 1192 1193 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1194 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1195 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1196 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1197 1198 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); 1199 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 1200 1201 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1202 dev->flags |= IFF_POINTOPOINT; 1203 else 1204 dev->flags &= ~IFF_POINTOPOINT; 1205 1206 dev->iflink = p->link; 1207 1208 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1209 int strict = (ipv6_addr_type(&p->raddr) & 1210 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1211 1212 struct rt6_info *rt = rt6_lookup(t->net, 1213 &p->raddr, &p->laddr, 1214 p->link, strict); 1215 1216 if (rt == NULL) 1217 return; 1218 1219 if (rt->dst.dev) { 1220 dev->hard_header_len = rt->dst.dev->hard_header_len + 1221 sizeof (struct ipv6hdr); 1222 1223 dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr); 1224 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1225 dev->mtu-=8; 1226 1227 if (dev->mtu < IPV6_MIN_MTU) 1228 dev->mtu = IPV6_MIN_MTU; 1229 } 1230 ip6_rt_put(rt); 1231 } 1232 } 1233 1234 /** 1235 * ip6_tnl_change - update the tunnel parameters 1236 * @t: tunnel to be changed 1237 * @p: tunnel configuration parameters 1238 * 1239 * Description: 1240 * ip6_tnl_change() updates the tunnel parameters 1241 **/ 1242 1243 static int 1244 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 1245 { 1246 t->parms.laddr = p->laddr; 1247 t->parms.raddr = p->raddr; 1248 t->parms.flags = p->flags; 1249 t->parms.hop_limit = p->hop_limit; 1250 t->parms.encap_limit = p->encap_limit; 1251 t->parms.flowinfo = p->flowinfo; 1252 t->parms.link = p->link; 1253 t->parms.proto = p->proto; 1254 ip6_tnl_dst_reset(t); 1255 ip6_tnl_link_config(t); 1256 return 0; 1257 } 1258 1259 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) 1260 { 1261 struct net *net = t->net; 1262 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1263 int err; 1264 1265 ip6_tnl_unlink(ip6n, t); 1266 synchronize_net(); 1267 err = ip6_tnl_change(t, p); 1268 ip6_tnl_link(ip6n, t); 1269 netdev_state_change(t->dev); 1270 return err; 1271 } 1272 1273 static void 1274 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u) 1275 { 1276 p->laddr = u->laddr; 1277 p->raddr = u->raddr; 1278 p->flags = u->flags; 1279 p->hop_limit = u->hop_limit; 1280 p->encap_limit = u->encap_limit; 1281 p->flowinfo = u->flowinfo; 1282 p->link = u->link; 1283 p->proto = u->proto; 1284 memcpy(p->name, u->name, sizeof(u->name)); 1285 } 1286 1287 static void 1288 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p) 1289 { 1290 u->laddr = p->laddr; 1291 u->raddr = p->raddr; 1292 u->flags = p->flags; 1293 u->hop_limit = p->hop_limit; 1294 u->encap_limit = p->encap_limit; 1295 u->flowinfo = p->flowinfo; 1296 u->link = p->link; 1297 u->proto = p->proto; 1298 memcpy(u->name, p->name, sizeof(u->name)); 1299 } 1300 1301 /** 1302 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1303 * @dev: virtual device associated with tunnel 1304 * @ifr: parameters passed from userspace 1305 * @cmd: command to be performed 1306 * 1307 * Description: 1308 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1309 * from userspace. 1310 * 1311 * The possible commands are the following: 1312 * %SIOCGETTUNNEL: get tunnel parameters for device 1313 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1314 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1315 * %SIOCDELTUNNEL: delete tunnel 1316 * 1317 * The fallback device "ip6tnl0", created during module 1318 * initialization, can be used for creating other tunnel devices. 1319 * 1320 * Return: 1321 * 0 on success, 1322 * %-EFAULT if unable to copy data to or from userspace, 1323 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1324 * %-EINVAL if passed tunnel parameters are invalid, 1325 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1326 * %-ENODEV if attempting to change or delete a nonexisting device 1327 **/ 1328 1329 static int 1330 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1331 { 1332 int err = 0; 1333 struct ip6_tnl_parm p; 1334 struct __ip6_tnl_parm p1; 1335 struct ip6_tnl *t = NULL; 1336 struct net *net = dev_net(dev); 1337 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1338 1339 switch (cmd) { 1340 case SIOCGETTUNNEL: 1341 if (dev == ip6n->fb_tnl_dev) { 1342 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 1343 err = -EFAULT; 1344 break; 1345 } 1346 ip6_tnl_parm_from_user(&p1, &p); 1347 t = ip6_tnl_locate(net, &p1, 0); 1348 } else { 1349 memset(&p, 0, sizeof(p)); 1350 } 1351 if (t == NULL) 1352 t = netdev_priv(dev); 1353 ip6_tnl_parm_to_user(&p, &t->parms); 1354 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 1355 err = -EFAULT; 1356 } 1357 break; 1358 case SIOCADDTUNNEL: 1359 case SIOCCHGTUNNEL: 1360 err = -EPERM; 1361 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1362 break; 1363 err = -EFAULT; 1364 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1365 break; 1366 err = -EINVAL; 1367 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1368 p.proto != 0) 1369 break; 1370 ip6_tnl_parm_from_user(&p1, &p); 1371 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); 1372 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1373 if (t != NULL) { 1374 if (t->dev != dev) { 1375 err = -EEXIST; 1376 break; 1377 } 1378 } else 1379 t = netdev_priv(dev); 1380 1381 err = ip6_tnl_update(t, &p1); 1382 } 1383 if (t) { 1384 err = 0; 1385 ip6_tnl_parm_to_user(&p, &t->parms); 1386 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 1387 err = -EFAULT; 1388 1389 } else 1390 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1391 break; 1392 case SIOCDELTUNNEL: 1393 err = -EPERM; 1394 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1395 break; 1396 1397 if (dev == ip6n->fb_tnl_dev) { 1398 err = -EFAULT; 1399 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1400 break; 1401 err = -ENOENT; 1402 ip6_tnl_parm_from_user(&p1, &p); 1403 t = ip6_tnl_locate(net, &p1, 0); 1404 if (t == NULL) 1405 break; 1406 err = -EPERM; 1407 if (t->dev == ip6n->fb_tnl_dev) 1408 break; 1409 dev = t->dev; 1410 } 1411 err = 0; 1412 unregister_netdevice(dev); 1413 break; 1414 default: 1415 err = -EINVAL; 1416 } 1417 return err; 1418 } 1419 1420 /** 1421 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1422 * @dev: virtual device associated with tunnel 1423 * @new_mtu: the new mtu 1424 * 1425 * Return: 1426 * 0 on success, 1427 * %-EINVAL if mtu too small 1428 **/ 1429 1430 static int 1431 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1432 { 1433 struct ip6_tnl *tnl = netdev_priv(dev); 1434 1435 if (tnl->parms.proto == IPPROTO_IPIP) { 1436 if (new_mtu < 68) 1437 return -EINVAL; 1438 } else { 1439 if (new_mtu < IPV6_MIN_MTU) 1440 return -EINVAL; 1441 } 1442 if (new_mtu > 0xFFF8 - dev->hard_header_len) 1443 return -EINVAL; 1444 dev->mtu = new_mtu; 1445 return 0; 1446 } 1447 1448 1449 static const struct net_device_ops ip6_tnl_netdev_ops = { 1450 .ndo_uninit = ip6_tnl_dev_uninit, 1451 .ndo_start_xmit = ip6_tnl_xmit, 1452 .ndo_do_ioctl = ip6_tnl_ioctl, 1453 .ndo_change_mtu = ip6_tnl_change_mtu, 1454 .ndo_get_stats = ip6_get_stats, 1455 }; 1456 1457 1458 /** 1459 * ip6_tnl_dev_setup - setup virtual tunnel device 1460 * @dev: virtual device associated with tunnel 1461 * 1462 * Description: 1463 * Initialize function pointers and device parameters 1464 **/ 1465 1466 static void ip6_tnl_dev_setup(struct net_device *dev) 1467 { 1468 struct ip6_tnl *t; 1469 1470 dev->netdev_ops = &ip6_tnl_netdev_ops; 1471 dev->destructor = ip6_dev_free; 1472 1473 dev->type = ARPHRD_TUNNEL6; 1474 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1475 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1476 t = netdev_priv(dev); 1477 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1478 dev->mtu-=8; 1479 dev->flags |= IFF_NOARP; 1480 dev->addr_len = sizeof(struct in6_addr); 1481 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1482 /* This perm addr will be used as interface identifier by IPv6 */ 1483 dev->addr_assign_type = NET_ADDR_RANDOM; 1484 eth_random_addr(dev->perm_addr); 1485 } 1486 1487 1488 /** 1489 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1490 * @dev: virtual device associated with tunnel 1491 **/ 1492 1493 static inline int 1494 ip6_tnl_dev_init_gen(struct net_device *dev) 1495 { 1496 struct ip6_tnl *t = netdev_priv(dev); 1497 1498 t->dev = dev; 1499 t->net = dev_net(dev); 1500 dev->tstats = alloc_percpu(struct pcpu_tstats); 1501 if (!dev->tstats) 1502 return -ENOMEM; 1503 return 0; 1504 } 1505 1506 /** 1507 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1508 * @dev: virtual device associated with tunnel 1509 **/ 1510 1511 static int ip6_tnl_dev_init(struct net_device *dev) 1512 { 1513 struct ip6_tnl *t = netdev_priv(dev); 1514 int err = ip6_tnl_dev_init_gen(dev); 1515 1516 if (err) 1517 return err; 1518 ip6_tnl_link_config(t); 1519 return 0; 1520 } 1521 1522 /** 1523 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1524 * @dev: fallback device 1525 * 1526 * Return: 0 1527 **/ 1528 1529 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1530 { 1531 struct ip6_tnl *t = netdev_priv(dev); 1532 struct net *net = dev_net(dev); 1533 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1534 int err = ip6_tnl_dev_init_gen(dev); 1535 1536 if (err) 1537 return err; 1538 1539 t->parms.proto = IPPROTO_IPV6; 1540 dev_hold(dev); 1541 1542 ip6_tnl_link_config(t); 1543 1544 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1545 return 0; 1546 } 1547 1548 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[]) 1549 { 1550 u8 proto; 1551 1552 if (!data) 1553 return 0; 1554 1555 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1556 if (proto != IPPROTO_IPV6 && 1557 proto != IPPROTO_IPIP && 1558 proto != 0) 1559 return -EINVAL; 1560 1561 return 0; 1562 } 1563 1564 static void ip6_tnl_netlink_parms(struct nlattr *data[], 1565 struct __ip6_tnl_parm *parms) 1566 { 1567 memset(parms, 0, sizeof(*parms)); 1568 1569 if (!data) 1570 return; 1571 1572 if (data[IFLA_IPTUN_LINK]) 1573 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1574 1575 if (data[IFLA_IPTUN_LOCAL]) 1576 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL], 1577 sizeof(struct in6_addr)); 1578 1579 if (data[IFLA_IPTUN_REMOTE]) 1580 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE], 1581 sizeof(struct in6_addr)); 1582 1583 if (data[IFLA_IPTUN_TTL]) 1584 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]); 1585 1586 if (data[IFLA_IPTUN_ENCAP_LIMIT]) 1587 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]); 1588 1589 if (data[IFLA_IPTUN_FLOWINFO]) 1590 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]); 1591 1592 if (data[IFLA_IPTUN_FLAGS]) 1593 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]); 1594 1595 if (data[IFLA_IPTUN_PROTO]) 1596 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1597 } 1598 1599 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev, 1600 struct nlattr *tb[], struct nlattr *data[]) 1601 { 1602 struct net *net = dev_net(dev); 1603 struct ip6_tnl *nt; 1604 1605 nt = netdev_priv(dev); 1606 ip6_tnl_netlink_parms(data, &nt->parms); 1607 1608 if (ip6_tnl_locate(net, &nt->parms, 0)) 1609 return -EEXIST; 1610 1611 return ip6_tnl_create2(dev); 1612 } 1613 1614 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[], 1615 struct nlattr *data[]) 1616 { 1617 struct ip6_tnl *t = netdev_priv(dev); 1618 struct __ip6_tnl_parm p; 1619 struct net *net = t->net; 1620 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1621 1622 if (dev == ip6n->fb_tnl_dev) 1623 return -EINVAL; 1624 1625 ip6_tnl_netlink_parms(data, &p); 1626 1627 t = ip6_tnl_locate(net, &p, 0); 1628 1629 if (t) { 1630 if (t->dev != dev) 1631 return -EEXIST; 1632 } else 1633 t = netdev_priv(dev); 1634 1635 return ip6_tnl_update(t, &p); 1636 } 1637 1638 static size_t ip6_tnl_get_size(const struct net_device *dev) 1639 { 1640 return 1641 /* IFLA_IPTUN_LINK */ 1642 nla_total_size(4) + 1643 /* IFLA_IPTUN_LOCAL */ 1644 nla_total_size(sizeof(struct in6_addr)) + 1645 /* IFLA_IPTUN_REMOTE */ 1646 nla_total_size(sizeof(struct in6_addr)) + 1647 /* IFLA_IPTUN_TTL */ 1648 nla_total_size(1) + 1649 /* IFLA_IPTUN_ENCAP_LIMIT */ 1650 nla_total_size(1) + 1651 /* IFLA_IPTUN_FLOWINFO */ 1652 nla_total_size(4) + 1653 /* IFLA_IPTUN_FLAGS */ 1654 nla_total_size(4) + 1655 /* IFLA_IPTUN_PROTO */ 1656 nla_total_size(1) + 1657 0; 1658 } 1659 1660 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1661 { 1662 struct ip6_tnl *tunnel = netdev_priv(dev); 1663 struct __ip6_tnl_parm *parm = &tunnel->parms; 1664 1665 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1666 nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr), 1667 &parm->laddr) || 1668 nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr), 1669 &parm->raddr) || 1670 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) || 1671 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) || 1672 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) || 1673 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) || 1674 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto)) 1675 goto nla_put_failure; 1676 return 0; 1677 1678 nla_put_failure: 1679 return -EMSGSIZE; 1680 } 1681 1682 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = { 1683 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1684 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) }, 1685 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) }, 1686 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1687 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 }, 1688 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 }, 1689 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 }, 1690 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1691 }; 1692 1693 static struct rtnl_link_ops ip6_link_ops __read_mostly = { 1694 .kind = "ip6tnl", 1695 .maxtype = IFLA_IPTUN_MAX, 1696 .policy = ip6_tnl_policy, 1697 .priv_size = sizeof(struct ip6_tnl), 1698 .setup = ip6_tnl_dev_setup, 1699 .validate = ip6_tnl_validate, 1700 .newlink = ip6_tnl_newlink, 1701 .changelink = ip6_tnl_changelink, 1702 .get_size = ip6_tnl_get_size, 1703 .fill_info = ip6_tnl_fill_info, 1704 }; 1705 1706 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1707 .handler = ip4ip6_rcv, 1708 .err_handler = ip4ip6_err, 1709 .priority = 1, 1710 }; 1711 1712 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1713 .handler = ip6ip6_rcv, 1714 .err_handler = ip6ip6_err, 1715 .priority = 1, 1716 }; 1717 1718 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1719 { 1720 struct net *net = dev_net(ip6n->fb_tnl_dev); 1721 struct net_device *dev, *aux; 1722 int h; 1723 struct ip6_tnl *t; 1724 LIST_HEAD(list); 1725 1726 for_each_netdev_safe(net, dev, aux) 1727 if (dev->rtnl_link_ops == &ip6_link_ops) 1728 unregister_netdevice_queue(dev, &list); 1729 1730 for (h = 0; h < HASH_SIZE; h++) { 1731 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1732 while (t != NULL) { 1733 /* If dev is in the same netns, it has already 1734 * been added to the list by the previous loop. 1735 */ 1736 if (!net_eq(dev_net(t->dev), net)) 1737 unregister_netdevice_queue(t->dev, &list); 1738 t = rtnl_dereference(t->next); 1739 } 1740 } 1741 1742 unregister_netdevice_many(&list); 1743 } 1744 1745 static int __net_init ip6_tnl_init_net(struct net *net) 1746 { 1747 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1748 struct ip6_tnl *t = NULL; 1749 int err; 1750 1751 ip6n->tnls[0] = ip6n->tnls_wc; 1752 ip6n->tnls[1] = ip6n->tnls_r_l; 1753 1754 err = -ENOMEM; 1755 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1756 ip6_tnl_dev_setup); 1757 1758 if (!ip6n->fb_tnl_dev) 1759 goto err_alloc_dev; 1760 dev_net_set(ip6n->fb_tnl_dev, net); 1761 ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops; 1762 /* FB netdevice is special: we have one, and only one per netns. 1763 * Allowing to move it to another netns is clearly unsafe. 1764 */ 1765 ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL; 1766 1767 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1768 if (err < 0) 1769 goto err_register; 1770 1771 err = register_netdev(ip6n->fb_tnl_dev); 1772 if (err < 0) 1773 goto err_register; 1774 1775 t = netdev_priv(ip6n->fb_tnl_dev); 1776 1777 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1778 return 0; 1779 1780 err_register: 1781 ip6_dev_free(ip6n->fb_tnl_dev); 1782 err_alloc_dev: 1783 return err; 1784 } 1785 1786 static void __net_exit ip6_tnl_exit_net(struct net *net) 1787 { 1788 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1789 1790 rtnl_lock(); 1791 ip6_tnl_destroy_tunnels(ip6n); 1792 rtnl_unlock(); 1793 } 1794 1795 static struct pernet_operations ip6_tnl_net_ops = { 1796 .init = ip6_tnl_init_net, 1797 .exit = ip6_tnl_exit_net, 1798 .id = &ip6_tnl_net_id, 1799 .size = sizeof(struct ip6_tnl_net), 1800 }; 1801 1802 /** 1803 * ip6_tunnel_init - register protocol and reserve needed resources 1804 * 1805 * Return: 0 on success 1806 **/ 1807 1808 static int __init ip6_tunnel_init(void) 1809 { 1810 int err; 1811 1812 err = register_pernet_device(&ip6_tnl_net_ops); 1813 if (err < 0) 1814 goto out_pernet; 1815 1816 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1817 if (err < 0) { 1818 pr_err("%s: can't register ip4ip6\n", __func__); 1819 goto out_ip4ip6; 1820 } 1821 1822 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1823 if (err < 0) { 1824 pr_err("%s: can't register ip6ip6\n", __func__); 1825 goto out_ip6ip6; 1826 } 1827 err = rtnl_link_register(&ip6_link_ops); 1828 if (err < 0) 1829 goto rtnl_link_failed; 1830 1831 return 0; 1832 1833 rtnl_link_failed: 1834 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); 1835 out_ip6ip6: 1836 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1837 out_ip4ip6: 1838 unregister_pernet_device(&ip6_tnl_net_ops); 1839 out_pernet: 1840 return err; 1841 } 1842 1843 /** 1844 * ip6_tunnel_cleanup - free resources and unregister protocol 1845 **/ 1846 1847 static void __exit ip6_tunnel_cleanup(void) 1848 { 1849 rtnl_link_unregister(&ip6_link_ops); 1850 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1851 pr_info("%s: can't deregister ip4ip6\n", __func__); 1852 1853 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1854 pr_info("%s: can't deregister ip6ip6\n", __func__); 1855 1856 unregister_pernet_device(&ip6_tnl_net_ops); 1857 } 1858 1859 module_init(ip6_tunnel_init); 1860 module_exit(ip6_tunnel_cleanup); 1861