1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPv6 virtual tunneling interface 4 * 5 * Copyright (C) 2013 secunet Security Networks AG 6 * 7 * Author: 8 * Steffen Klassert <steffen.klassert@secunet.com> 9 * 10 * Based on: 11 * net/ipv6/ip6_tunnel.c 12 */ 13 14 #include <linux/module.h> 15 #include <linux/capability.h> 16 #include <linux/errno.h> 17 #include <linux/types.h> 18 #include <linux/sockios.h> 19 #include <linux/icmp.h> 20 #include <linux/if.h> 21 #include <linux/in.h> 22 #include <linux/ip.h> 23 #include <linux/net.h> 24 #include <linux/in6.h> 25 #include <linux/netdevice.h> 26 #include <linux/if_arp.h> 27 #include <linux/icmpv6.h> 28 #include <linux/init.h> 29 #include <linux/route.h> 30 #include <linux/rtnetlink.h> 31 #include <linux/netfilter_ipv6.h> 32 #include <linux/slab.h> 33 #include <linux/hash.h> 34 35 #include <linux/uaccess.h> 36 #include <linux/atomic.h> 37 38 #include <net/icmp.h> 39 #include <net/ip.h> 40 #include <net/ip_tunnels.h> 41 #include <net/ipv6.h> 42 #include <net/ip6_route.h> 43 #include <net/addrconf.h> 44 #include <net/ip6_tunnel.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <net/netdev_lock.h> 49 #include <linux/etherdevice.h> 50 51 #define IP6_VTI_HASH_SIZE_SHIFT 5 52 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT) 53 54 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 55 { 56 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 57 58 return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT); 59 } 60 61 static int vti6_dev_init(struct net_device *dev); 62 static void vti6_dev_setup(struct net_device *dev); 63 static struct rtnl_link_ops vti6_link_ops __read_mostly; 64 65 static unsigned int vti6_net_id __read_mostly; 66 struct vti6_net { 67 /* the vti6 tunnel fallback device */ 68 struct net_device *fb_tnl_dev; 69 /* lists for storing tunnels in use */ 70 struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE]; 71 struct ip6_tnl __rcu *tnls_wc[1]; 72 struct ip6_tnl __rcu **tnls[2]; 73 }; 74 75 #define for_each_vti6_tunnel_rcu(start) \ 76 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 77 78 /** 79 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses 80 * @net: network namespace 81 * @remote: the address of the tunnel exit-point 82 * @local: the address of the tunnel entry-point 83 * 84 * Return: 85 * tunnel matching given end-points if found, 86 * else fallback tunnel if its device is up, 87 * else %NULL 88 **/ 89 static struct ip6_tnl * 90 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote, 91 const struct in6_addr *local) 92 { 93 unsigned int hash = HASH(remote, local); 94 struct ip6_tnl *t; 95 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 96 struct in6_addr any; 97 98 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 99 if (ipv6_addr_equal(local, &t->parms.laddr) && 100 ipv6_addr_equal(remote, &t->parms.raddr) && 101 (t->dev->flags & IFF_UP)) 102 return t; 103 } 104 105 memset(&any, 0, sizeof(any)); 106 hash = HASH(&any, local); 107 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 108 if (ipv6_addr_equal(local, &t->parms.laddr) && 109 ipv6_addr_any(&t->parms.raddr) && 110 (t->dev->flags & IFF_UP)) 111 return t; 112 } 113 114 hash = HASH(remote, &any); 115 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 116 if (ipv6_addr_equal(remote, &t->parms.raddr) && 117 ipv6_addr_any(&t->parms.laddr) && 118 (t->dev->flags & IFF_UP)) 119 return t; 120 } 121 122 t = rcu_dereference(ip6n->tnls_wc[0]); 123 if (t && (t->dev->flags & IFF_UP)) 124 return t; 125 126 return NULL; 127 } 128 129 /** 130 * vti6_tnl_bucket - get head of list matching given tunnel parameters 131 * @ip6n: the private data for ip6_vti in the netns 132 * @p: parameters containing tunnel end-points 133 * 134 * Description: 135 * vti6_tnl_bucket() returns the head of the list matching the 136 * &struct in6_addr entries laddr and raddr in @p. 137 * 138 * Return: head of IPv6 tunnel list 139 **/ 140 static struct ip6_tnl __rcu ** 141 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p) 142 { 143 const struct in6_addr *remote = &p->raddr; 144 const struct in6_addr *local = &p->laddr; 145 unsigned int h = 0; 146 int prio = 0; 147 148 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 149 prio = 1; 150 h = HASH(remote, local); 151 } 152 return &ip6n->tnls[prio][h]; 153 } 154 155 static void 156 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t) 157 { 158 struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms); 159 160 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 161 rcu_assign_pointer(*tp, t); 162 } 163 164 static void 165 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t) 166 { 167 struct ip6_tnl __rcu **tp; 168 struct ip6_tnl *iter; 169 170 for (tp = vti6_tnl_bucket(ip6n, &t->parms); 171 (iter = rtnl_dereference(*tp)) != NULL; 172 tp = &iter->next) { 173 if (t == iter) { 174 rcu_assign_pointer(*tp, t->next); 175 break; 176 } 177 } 178 } 179 180 static int vti6_tnl_create2(struct net_device *dev) 181 { 182 struct ip6_tnl *t = netdev_priv(dev); 183 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 184 int err; 185 186 dev->rtnl_link_ops = &vti6_link_ops; 187 err = register_netdevice(dev); 188 if (err < 0) 189 goto out; 190 191 strcpy(t->parms.name, dev->name); 192 193 vti6_tnl_link(ip6n, t); 194 195 return 0; 196 197 out: 198 return err; 199 } 200 201 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 202 { 203 struct net_device *dev; 204 struct ip6_tnl *t; 205 char name[IFNAMSIZ]; 206 int err; 207 208 if (p->name[0]) { 209 if (!dev_valid_name(p->name)) 210 goto failed; 211 strscpy(name, p->name, IFNAMSIZ); 212 } else { 213 sprintf(name, "ip6_vti%%d"); 214 } 215 216 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup); 217 if (!dev) 218 goto failed; 219 220 dev_net_set(dev, net); 221 222 t = netdev_priv(dev); 223 t->parms = *p; 224 t->net = dev_net(dev); 225 226 err = vti6_tnl_create2(dev); 227 if (err < 0) 228 goto failed_free; 229 230 return t; 231 232 failed_free: 233 free_netdev(dev); 234 failed: 235 return NULL; 236 } 237 238 /** 239 * vti6_locate - find or create tunnel matching given parameters 240 * @net: network namespace 241 * @p: tunnel parameters 242 * @create: != 0 if allowed to create new tunnel if no match found 243 * 244 * Description: 245 * vti6_locate() first tries to locate an existing tunnel 246 * based on @parms. If this is unsuccessful, but @create is set a new 247 * tunnel device is created and registered for use. 248 * 249 * Return: 250 * matching tunnel or NULL 251 **/ 252 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p, 253 int create) 254 { 255 const struct in6_addr *remote = &p->raddr; 256 const struct in6_addr *local = &p->laddr; 257 struct ip6_tnl __rcu **tp; 258 struct ip6_tnl *t; 259 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 260 261 for (tp = vti6_tnl_bucket(ip6n, p); 262 (t = rtnl_dereference(*tp)) != NULL; 263 tp = &t->next) { 264 if (ipv6_addr_equal(local, &t->parms.laddr) && 265 ipv6_addr_equal(remote, &t->parms.raddr)) { 266 if (create) 267 return NULL; 268 269 return t; 270 } 271 } 272 if (!create) 273 return NULL; 274 return vti6_tnl_create(net, p); 275 } 276 277 /** 278 * vti6_dev_uninit - tunnel device uninitializer 279 * @dev: the device to be destroyed 280 * 281 * Description: 282 * vti6_dev_uninit() removes tunnel from its list 283 **/ 284 static void vti6_dev_uninit(struct net_device *dev) 285 { 286 struct ip6_tnl *t = netdev_priv(dev); 287 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 288 289 if (dev == ip6n->fb_tnl_dev) 290 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 291 else 292 vti6_tnl_unlink(ip6n, t); 293 netdev_put(dev, &t->dev_tracker); 294 } 295 296 static int vti6_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi, 297 int encap_type) 298 { 299 struct ip6_tnl *t; 300 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 301 302 rcu_read_lock(); 303 t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); 304 if (t) { 305 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) { 306 rcu_read_unlock(); 307 goto discard; 308 } 309 310 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 311 rcu_read_unlock(); 312 goto discard; 313 } 314 315 ipv6h = ipv6_hdr(skb); 316 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 317 DEV_STATS_INC(t->dev, rx_dropped); 318 rcu_read_unlock(); 319 goto discard; 320 } 321 322 rcu_read_unlock(); 323 324 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t; 325 XFRM_SPI_SKB_CB(skb)->family = AF_INET6; 326 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); 327 return xfrm_input(skb, nexthdr, spi, encap_type); 328 } 329 rcu_read_unlock(); 330 return -EINVAL; 331 discard: 332 kfree_skb(skb); 333 return 0; 334 } 335 336 static int vti6_rcv(struct sk_buff *skb) 337 { 338 int nexthdr = skb_network_header(skb)[IP6CB(skb)->nhoff]; 339 340 return vti6_input_proto(skb, nexthdr, 0, 0); 341 } 342 343 static int vti6_rcv_cb(struct sk_buff *skb, int err) 344 { 345 unsigned short family; 346 struct net_device *dev; 347 struct xfrm_state *x; 348 const struct xfrm_mode *inner_mode; 349 struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6; 350 u32 orig_mark = skb->mark; 351 int ret; 352 353 if (!t) 354 return 1; 355 356 dev = t->dev; 357 358 if (err) { 359 DEV_STATS_INC(dev, rx_errors); 360 DEV_STATS_INC(dev, rx_dropped); 361 362 return 0; 363 } 364 365 x = xfrm_input_state(skb); 366 367 inner_mode = &x->inner_mode; 368 369 if (x->sel.family == AF_UNSPEC) { 370 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 371 if (inner_mode == NULL) { 372 XFRM_INC_STATS(dev_net(skb->dev), 373 LINUX_MIB_XFRMINSTATEMODEERROR); 374 return -EINVAL; 375 } 376 } 377 378 family = inner_mode->family; 379 380 skb->mark = be32_to_cpu(t->parms.i_key); 381 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); 382 skb->mark = orig_mark; 383 384 if (!ret) 385 return -EPERM; 386 387 skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev))); 388 skb->dev = dev; 389 dev_sw_netstats_rx_add(dev, skb->len); 390 391 return 0; 392 } 393 394 /** 395 * vti6_addr_conflict - compare packet addresses to tunnel's own 396 * @t: the outgoing tunnel device 397 * @hdr: IPv6 header from the incoming packet 398 * 399 * Description: 400 * Avoid trivial tunneling loop by checking that tunnel exit-point 401 * doesn't match source of incoming packet. 402 * 403 * Return: 404 * 1 if conflict, 405 * 0 else 406 **/ 407 static inline bool 408 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 409 { 410 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 411 } 412 413 static bool vti6_state_check(const struct xfrm_state *x, 414 const struct in6_addr *dst, 415 const struct in6_addr *src) 416 { 417 xfrm_address_t *daddr = (xfrm_address_t *)dst; 418 xfrm_address_t *saddr = (xfrm_address_t *)src; 419 420 /* if there is no transform then this tunnel is not functional. 421 * Or if the xfrm is not mode tunnel. 422 */ 423 if (!x || x->props.mode != XFRM_MODE_TUNNEL || 424 x->props.family != AF_INET6) 425 return false; 426 427 if (ipv6_addr_any(dst)) 428 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6); 429 430 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6)) 431 return false; 432 433 return true; 434 } 435 436 /** 437 * vti6_xmit - send a packet 438 * @skb: the outgoing socket buffer 439 * @dev: the outgoing tunnel device 440 * @fl: the flow informations for the xfrm_lookup 441 **/ 442 static int 443 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) 444 { 445 struct ip6_tnl *t = netdev_priv(dev); 446 struct dst_entry *dst = skb_dst(skb); 447 struct net_device *tdev; 448 struct xfrm_state *x; 449 int pkt_len = skb->len; 450 int err = -1; 451 int mtu; 452 453 if (!dst) { 454 switch (skb->protocol) { 455 case htons(ETH_P_IP): { 456 struct rtable *rt; 457 458 fl->u.ip4.flowi4_oif = dev->ifindex; 459 fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC; 460 rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4); 461 if (IS_ERR(rt)) 462 goto tx_err_link_failure; 463 dst = &rt->dst; 464 skb_dst_set(skb, dst); 465 break; 466 } 467 case htons(ETH_P_IPV6): 468 fl->u.ip6.flowi6_oif = dev->ifindex; 469 fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC; 470 dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6); 471 if (dst->error) { 472 dst_release(dst); 473 dst = NULL; 474 goto tx_err_link_failure; 475 } 476 skb_dst_set(skb, dst); 477 break; 478 default: 479 goto tx_err_link_failure; 480 } 481 } 482 483 dst_hold(dst); 484 dst = xfrm_lookup_route(t->net, dst, fl, NULL, 0); 485 if (IS_ERR(dst)) { 486 err = PTR_ERR(dst); 487 dst = NULL; 488 goto tx_err_link_failure; 489 } 490 491 if (dst->flags & DST_XFRM_QUEUE) 492 goto xmit; 493 494 x = dst->xfrm; 495 if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) 496 goto tx_err_link_failure; 497 498 if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr, 499 (const struct in6_addr *)&x->id.daddr)) 500 goto tx_err_link_failure; 501 502 tdev = dst_dev(dst); 503 504 if (tdev == dev) { 505 DEV_STATS_INC(dev, collisions); 506 net_warn_ratelimited("%s: Local routing loop detected!\n", 507 t->parms.name); 508 goto tx_err_dst_release; 509 } 510 511 mtu = dst_mtu(dst); 512 if (skb->len > mtu) { 513 skb_dst_update_pmtu_no_confirm(skb, mtu); 514 515 if (skb->protocol == htons(ETH_P_IPV6)) { 516 if (mtu < IPV6_MIN_MTU) 517 mtu = IPV6_MIN_MTU; 518 519 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 520 } else { 521 if (!(ip_hdr(skb)->frag_off & htons(IP_DF))) 522 goto xmit; 523 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 524 htonl(mtu)); 525 } 526 527 err = -EMSGSIZE; 528 goto tx_err_dst_release; 529 } 530 531 xmit: 532 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 533 skb_dst_set(skb, dst); 534 skb->dev = dst_dev(dst); 535 536 err = dst_output(t->net, skb->sk, skb); 537 if (net_xmit_eval(err) == 0) 538 err = pkt_len; 539 iptunnel_xmit_stats(dev, err); 540 541 return 0; 542 tx_err_link_failure: 543 DEV_STATS_INC(dev, tx_carrier_errors); 544 dst_link_failure(skb); 545 tx_err_dst_release: 546 dst_release(dst); 547 return err; 548 } 549 550 static netdev_tx_t 551 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 552 { 553 struct ip6_tnl *t = netdev_priv(dev); 554 struct flowi fl; 555 int ret; 556 557 if (!pskb_inet_may_pull(skb)) 558 goto tx_err; 559 560 memset(&fl, 0, sizeof(fl)); 561 562 switch (skb->protocol) { 563 case htons(ETH_P_IPV6): 564 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 565 vti6_addr_conflict(t, ipv6_hdr(skb))) 566 goto tx_err; 567 568 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 569 xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6); 570 break; 571 case htons(ETH_P_IP): 572 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 573 xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET); 574 break; 575 default: 576 goto tx_err; 577 } 578 579 /* override mark with tunnel output key */ 580 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 581 582 ret = vti6_xmit(skb, dev, &fl); 583 if (ret < 0) 584 goto tx_err; 585 586 return NETDEV_TX_OK; 587 588 tx_err: 589 DEV_STATS_INC(dev, tx_errors); 590 DEV_STATS_INC(dev, tx_dropped); 591 kfree_skb(skb); 592 return NETDEV_TX_OK; 593 } 594 595 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 596 u8 type, u8 code, int offset, __be32 info) 597 { 598 __be32 spi; 599 __u32 mark; 600 struct xfrm_state *x; 601 struct ip6_tnl *t; 602 struct ip_esp_hdr *esph; 603 struct ip_auth_hdr *ah; 604 struct ip_comp_hdr *ipch; 605 struct net *net = dev_net(skb->dev); 606 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 607 int protocol = iph->nexthdr; 608 609 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 610 if (!t) 611 return -1; 612 613 mark = be32_to_cpu(t->parms.o_key); 614 615 switch (protocol) { 616 case IPPROTO_ESP: 617 esph = (struct ip_esp_hdr *)(skb->data + offset); 618 spi = esph->spi; 619 break; 620 case IPPROTO_AH: 621 ah = (struct ip_auth_hdr *)(skb->data + offset); 622 spi = ah->spi; 623 break; 624 case IPPROTO_COMP: 625 ipch = (struct ip_comp_hdr *)(skb->data + offset); 626 spi = htonl(ntohs(ipch->cpi)); 627 break; 628 default: 629 return 0; 630 } 631 632 if (type != ICMPV6_PKT_TOOBIG && 633 type != NDISC_REDIRECT) 634 return 0; 635 636 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 637 spi, protocol, AF_INET6); 638 if (!x) 639 return 0; 640 641 if (type == NDISC_REDIRECT) 642 ip6_redirect(skb, net, skb->dev->ifindex, 0, 643 sock_net_uid(net, NULL)); 644 else 645 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 646 xfrm_state_put(x); 647 648 return 0; 649 } 650 651 static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) 652 { 653 struct net_device *dev = t->dev; 654 struct __ip6_tnl_parm *p = &t->parms; 655 struct net_device *tdev = NULL; 656 int mtu; 657 658 __dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr)); 659 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 660 661 p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV | 662 IP6_TNL_F_CAP_PER_PACKET); 663 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 664 665 if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV) 666 dev->flags |= IFF_POINTOPOINT; 667 else 668 dev->flags &= ~IFF_POINTOPOINT; 669 670 if (keep_mtu && dev->mtu) { 671 WRITE_ONCE(dev->mtu, 672 clamp(dev->mtu, dev->min_mtu, dev->max_mtu)); 673 return; 674 } 675 676 if (p->flags & IP6_TNL_F_CAP_XMIT) { 677 int strict = (ipv6_addr_type(&p->raddr) & 678 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); 679 struct rt6_info *rt = rt6_lookup(t->net, 680 &p->raddr, &p->laddr, 681 p->link, NULL, strict); 682 683 if (rt) 684 tdev = rt->dst.dev; 685 ip6_rt_put(rt); 686 } 687 688 if (!tdev && p->link) 689 tdev = __dev_get_by_index(t->net, p->link); 690 691 if (tdev) 692 mtu = tdev->mtu - sizeof(struct ipv6hdr); 693 else 694 mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr); 695 696 dev->mtu = max_t(int, mtu, IPV4_MIN_MTU); 697 } 698 699 /** 700 * vti6_tnl_change - update the tunnel parameters 701 * @t: tunnel to be changed 702 * @p: tunnel configuration parameters 703 * @keep_mtu: MTU was set from userspace, don't re-compute it 704 * 705 * Description: 706 * vti6_tnl_change() updates the tunnel parameters 707 **/ 708 static int 709 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p, 710 bool keep_mtu) 711 { 712 t->parms.laddr = p->laddr; 713 t->parms.raddr = p->raddr; 714 t->parms.link = p->link; 715 t->parms.i_key = p->i_key; 716 t->parms.o_key = p->o_key; 717 t->parms.proto = p->proto; 718 t->parms.fwmark = p->fwmark; 719 dst_cache_reset(&t->dst_cache); 720 vti6_link_config(t, keep_mtu); 721 return 0; 722 } 723 724 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p, 725 bool keep_mtu) 726 { 727 struct net *net = t->net; 728 struct vti6_net *ip6n; 729 int err; 730 731 ip6n = net_generic(net, vti6_net_id); 732 vti6_tnl_unlink(ip6n, t); 733 synchronize_net(); 734 err = vti6_tnl_change(t, p, keep_mtu); 735 vti6_tnl_link(ip6n, t); 736 netdev_state_change(t->dev); 737 return err; 738 } 739 740 static void 741 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 742 { 743 p->laddr = u->laddr; 744 p->raddr = u->raddr; 745 p->link = u->link; 746 p->i_key = u->i_key; 747 p->o_key = u->o_key; 748 p->proto = u->proto; 749 750 memcpy(p->name, u->name, sizeof(u->name)); 751 } 752 753 static void 754 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 755 { 756 u->laddr = p->laddr; 757 u->raddr = p->raddr; 758 u->link = p->link; 759 u->i_key = p->i_key; 760 u->o_key = p->o_key; 761 if (u->i_key) 762 u->i_flags |= GRE_KEY; 763 if (u->o_key) 764 u->o_flags |= GRE_KEY; 765 u->proto = p->proto; 766 767 memcpy(u->name, p->name, sizeof(u->name)); 768 } 769 770 /** 771 * vti6_siocdevprivate - configure vti6 tunnels from userspace 772 * @dev: virtual device associated with tunnel 773 * @ifr: unused 774 * @data: parameters passed from userspace 775 * @cmd: command to be performed 776 * 777 * Description: 778 * vti6_siocdevprivate() is used for managing vti6 tunnels 779 * from userspace. 780 * 781 * The possible commands are the following: 782 * %SIOCGETTUNNEL: get tunnel parameters for device 783 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 784 * %SIOCCHGTUNNEL: change tunnel parameters to those given 785 * %SIOCDELTUNNEL: delete tunnel 786 * 787 * The fallback device "ip6_vti0", created during module 788 * initialization, can be used for creating other tunnel devices. 789 * 790 * Return: 791 * 0 on success, 792 * %-EFAULT if unable to copy data to or from userspace, 793 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 794 * %-EINVAL if passed tunnel parameters are invalid, 795 * %-EEXIST if changing a tunnel's parameters would cause a conflict 796 * %-ENODEV if attempting to change or delete a nonexisting device 797 **/ 798 static int 799 vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data, int cmd) 800 { 801 int err = 0; 802 struct ip6_tnl_parm2 p; 803 struct __ip6_tnl_parm p1; 804 struct ip6_tnl *t = NULL; 805 struct net *net = dev_net(dev); 806 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 807 808 memset(&p1, 0, sizeof(p1)); 809 810 switch (cmd) { 811 case SIOCGETTUNNEL: 812 if (dev == ip6n->fb_tnl_dev) { 813 if (copy_from_user(&p, data, sizeof(p))) { 814 err = -EFAULT; 815 break; 816 } 817 vti6_parm_from_user(&p1, &p); 818 t = vti6_locate(net, &p1, 0); 819 } else { 820 memset(&p, 0, sizeof(p)); 821 } 822 if (!t) 823 t = netdev_priv(dev); 824 vti6_parm_to_user(&p, &t->parms); 825 if (copy_to_user(data, &p, sizeof(p))) 826 err = -EFAULT; 827 break; 828 case SIOCADDTUNNEL: 829 case SIOCCHGTUNNEL: 830 err = -EPERM; 831 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 832 break; 833 err = -EFAULT; 834 if (copy_from_user(&p, data, sizeof(p))) 835 break; 836 err = -EINVAL; 837 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 838 break; 839 vti6_parm_from_user(&p1, &p); 840 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 841 struct ip6_tnl *self = netdev_priv(dev); 842 843 err = -EPERM; 844 if (!ns_capable(self->net->user_ns, CAP_NET_ADMIN)) 845 break; 846 t = vti6_locate(self->net, &p1, false); 847 if (t) { 848 if (t->dev != dev) { 849 err = -EEXIST; 850 break; 851 } 852 } else 853 t = self; 854 855 err = vti6_update(t, &p1, false); 856 } else { 857 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 858 } 859 if (t) { 860 err = 0; 861 vti6_parm_to_user(&p, &t->parms); 862 if (copy_to_user(data, &p, sizeof(p))) 863 err = -EFAULT; 864 865 } else 866 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 867 break; 868 case SIOCDELTUNNEL: 869 err = -EPERM; 870 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 871 break; 872 873 if (dev == ip6n->fb_tnl_dev) { 874 err = -EFAULT; 875 if (copy_from_user(&p, data, sizeof(p))) 876 break; 877 err = -ENOENT; 878 vti6_parm_from_user(&p1, &p); 879 t = vti6_locate(net, &p1, 0); 880 if (!t) 881 break; 882 err = -EPERM; 883 if (t->dev == ip6n->fb_tnl_dev) 884 break; 885 dev = t->dev; 886 } 887 err = 0; 888 unregister_netdevice(dev); 889 break; 890 default: 891 err = -EINVAL; 892 } 893 return err; 894 } 895 896 static const struct net_device_ops vti6_netdev_ops = { 897 .ndo_init = vti6_dev_init, 898 .ndo_uninit = vti6_dev_uninit, 899 .ndo_start_xmit = vti6_tnl_xmit, 900 .ndo_siocdevprivate = vti6_siocdevprivate, 901 .ndo_get_iflink = ip6_tnl_get_iflink, 902 }; 903 904 /** 905 * vti6_dev_setup - setup virtual tunnel device 906 * @dev: virtual device associated with tunnel 907 * 908 * Description: 909 * Initialize function pointers and device parameters 910 **/ 911 static void vti6_dev_setup(struct net_device *dev) 912 { 913 dev->netdev_ops = &vti6_netdev_ops; 914 dev->header_ops = &ip_tunnel_header_ops; 915 dev->needs_free_netdev = true; 916 917 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 918 dev->type = ARPHRD_TUNNEL6; 919 dev->min_mtu = IPV4_MIN_MTU; 920 dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr); 921 dev->flags |= IFF_NOARP; 922 dev->addr_len = sizeof(struct in6_addr); 923 netif_keep_dst(dev); 924 /* This perm addr will be used as interface identifier by IPv6 */ 925 dev->addr_assign_type = NET_ADDR_RANDOM; 926 eth_random_addr(dev->perm_addr); 927 } 928 929 /** 930 * vti6_dev_init_gen - general initializer for all tunnel devices 931 * @dev: virtual device associated with tunnel 932 **/ 933 static inline int vti6_dev_init_gen(struct net_device *dev) 934 { 935 struct ip6_tnl *t = netdev_priv(dev); 936 937 t->dev = dev; 938 netdev_hold(dev, &t->dev_tracker, GFP_KERNEL); 939 netdev_lockdep_set_classes(dev); 940 return 0; 941 } 942 943 /** 944 * vti6_dev_init - initializer for all non fallback tunnel devices 945 * @dev: virtual device associated with tunnel 946 **/ 947 static int vti6_dev_init(struct net_device *dev) 948 { 949 struct ip6_tnl *t = netdev_priv(dev); 950 int err = vti6_dev_init_gen(dev); 951 952 if (err) 953 return err; 954 vti6_link_config(t, true); 955 return 0; 956 } 957 958 /** 959 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device 960 * @dev: fallback device 961 * 962 * Return: 0 963 **/ 964 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev) 965 { 966 struct ip6_tnl *t = netdev_priv(dev); 967 struct net *net = dev_net(dev); 968 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 969 970 t->net = net; 971 t->parms.proto = IPPROTO_IPV6; 972 973 rcu_assign_pointer(ip6n->tnls_wc[0], t); 974 return 0; 975 } 976 977 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[], 978 struct netlink_ext_ack *extack) 979 { 980 return 0; 981 } 982 983 static void vti6_netlink_parms(struct nlattr *data[], 984 struct __ip6_tnl_parm *parms) 985 { 986 memset(parms, 0, sizeof(*parms)); 987 988 if (!data) 989 return; 990 991 if (data[IFLA_VTI_LINK]) 992 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 993 994 if (data[IFLA_VTI_LOCAL]) 995 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]); 996 997 if (data[IFLA_VTI_REMOTE]) 998 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]); 999 1000 if (data[IFLA_VTI_IKEY]) 1001 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 1002 1003 if (data[IFLA_VTI_OKEY]) 1004 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 1005 1006 if (data[IFLA_VTI_FWMARK]) 1007 parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]); 1008 } 1009 1010 static int vti6_newlink(struct net_device *dev, 1011 struct rtnl_newlink_params *params, 1012 struct netlink_ext_ack *extack) 1013 { 1014 struct nlattr **data = params->data; 1015 struct ip6_tnl *nt; 1016 struct net *net; 1017 1018 net = params->link_net ? : dev_net(dev); 1019 nt = netdev_priv(dev); 1020 vti6_netlink_parms(data, &nt->parms); 1021 1022 nt->parms.proto = IPPROTO_IPV6; 1023 nt->net = net; 1024 1025 if (vti6_locate(net, &nt->parms, 0)) 1026 return -EEXIST; 1027 1028 return vti6_tnl_create2(dev); 1029 } 1030 1031 static void vti6_dellink(struct net_device *dev, struct list_head *head) 1032 { 1033 struct net *net = dev_net(dev); 1034 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1035 1036 if (dev != ip6n->fb_tnl_dev) 1037 unregister_netdevice_queue(dev, head); 1038 } 1039 1040 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 1041 struct nlattr *data[], 1042 struct netlink_ext_ack *extack) 1043 { 1044 struct ip6_tnl *t = netdev_priv(dev); 1045 struct net *net = t->net; 1046 struct __ip6_tnl_parm p; 1047 struct vti6_net *ip6n; 1048 1049 ip6n = net_generic(net, vti6_net_id); 1050 if (dev == ip6n->fb_tnl_dev) 1051 return -EINVAL; 1052 1053 vti6_netlink_parms(data, &p); 1054 1055 t = vti6_locate(net, &p, 0); 1056 1057 if (t) { 1058 if (t->dev != dev) 1059 return -EEXIST; 1060 } else 1061 t = netdev_priv(dev); 1062 1063 return vti6_update(t, &p, tb && tb[IFLA_MTU]); 1064 } 1065 1066 static size_t vti6_get_size(const struct net_device *dev) 1067 { 1068 return 1069 /* IFLA_VTI_LINK */ 1070 nla_total_size(4) + 1071 /* IFLA_VTI_LOCAL */ 1072 nla_total_size(sizeof(struct in6_addr)) + 1073 /* IFLA_VTI_REMOTE */ 1074 nla_total_size(sizeof(struct in6_addr)) + 1075 /* IFLA_VTI_IKEY */ 1076 nla_total_size(4) + 1077 /* IFLA_VTI_OKEY */ 1078 nla_total_size(4) + 1079 /* IFLA_VTI_FWMARK */ 1080 nla_total_size(4) + 1081 0; 1082 } 1083 1084 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1085 { 1086 struct ip6_tnl *tunnel = netdev_priv(dev); 1087 struct __ip6_tnl_parm *parm = &tunnel->parms; 1088 1089 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 1090 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 1091 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1092 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1093 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) || 1094 nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark)) 1095 goto nla_put_failure; 1096 return 0; 1097 1098 nla_put_failure: 1099 return -EMSGSIZE; 1100 } 1101 1102 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1103 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1104 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1105 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1106 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1107 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1108 [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, 1109 }; 1110 1111 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1112 .kind = "vti6", 1113 .maxtype = IFLA_VTI_MAX, 1114 .policy = vti6_policy, 1115 .priv_size = sizeof(struct ip6_tnl), 1116 .setup = vti6_dev_setup, 1117 .validate = vti6_validate, 1118 .newlink = vti6_newlink, 1119 .dellink = vti6_dellink, 1120 .changelink = vti6_changelink, 1121 .get_size = vti6_get_size, 1122 .fill_info = vti6_fill_info, 1123 .get_link_net = ip6_tnl_get_link_net, 1124 }; 1125 1126 static void __net_exit vti6_exit_rtnl_net(struct net *net, struct list_head *list) 1127 { 1128 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1129 struct ip6_tnl *t; 1130 int h; 1131 1132 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1133 t = rtnl_net_dereference(net, ip6n->tnls_r_l[h]); 1134 while (t) { 1135 unregister_netdevice_queue(t->dev, list); 1136 t = rtnl_net_dereference(net, t->next); 1137 } 1138 } 1139 1140 t = rtnl_net_dereference(net, ip6n->tnls_wc[0]); 1141 if (t) 1142 unregister_netdevice_queue(t->dev, list); 1143 } 1144 1145 static int __net_init vti6_init_net(struct net *net) 1146 { 1147 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1148 struct ip6_tnl *t = NULL; 1149 int err; 1150 1151 ip6n->tnls[0] = ip6n->tnls_wc; 1152 ip6n->tnls[1] = ip6n->tnls_r_l; 1153 1154 if (!net_has_fallback_tunnels(net)) 1155 return 0; 1156 err = -ENOMEM; 1157 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1158 NET_NAME_UNKNOWN, vti6_dev_setup); 1159 1160 if (!ip6n->fb_tnl_dev) 1161 goto err_alloc_dev; 1162 dev_net_set(ip6n->fb_tnl_dev, net); 1163 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1164 ip6n->fb_tnl_dev->netns_immutable = true; 1165 1166 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1167 if (err < 0) 1168 goto err_register; 1169 1170 err = register_netdev(ip6n->fb_tnl_dev); 1171 if (err < 0) 1172 goto err_register; 1173 1174 t = netdev_priv(ip6n->fb_tnl_dev); 1175 1176 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1177 return 0; 1178 1179 err_register: 1180 free_netdev(ip6n->fb_tnl_dev); 1181 err_alloc_dev: 1182 return err; 1183 } 1184 1185 static struct pernet_operations vti6_net_ops = { 1186 .init = vti6_init_net, 1187 .exit_rtnl = vti6_exit_rtnl_net, 1188 .id = &vti6_net_id, 1189 .size = sizeof(struct vti6_net), 1190 }; 1191 1192 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1193 .handler = vti6_rcv, 1194 .input_handler = vti6_input_proto, 1195 .cb_handler = vti6_rcv_cb, 1196 .err_handler = vti6_err, 1197 .priority = 100, 1198 }; 1199 1200 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1201 .handler = vti6_rcv, 1202 .input_handler = vti6_input_proto, 1203 .cb_handler = vti6_rcv_cb, 1204 .err_handler = vti6_err, 1205 .priority = 100, 1206 }; 1207 1208 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1209 .handler = vti6_rcv, 1210 .input_handler = vti6_input_proto, 1211 .cb_handler = vti6_rcv_cb, 1212 .err_handler = vti6_err, 1213 .priority = 100, 1214 }; 1215 1216 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1217 static int vti6_rcv_tunnel(struct sk_buff *skb) 1218 { 1219 const xfrm_address_t *saddr; 1220 __be32 spi; 1221 1222 saddr = (const xfrm_address_t *)&ipv6_hdr(skb)->saddr; 1223 spi = xfrm6_tunnel_spi_lookup(dev_net(skb->dev), saddr); 1224 1225 return vti6_input_proto(skb, IPPROTO_IPV6, spi, 0); 1226 } 1227 1228 static struct xfrm6_tunnel vti_ipv6_handler __read_mostly = { 1229 .handler = vti6_rcv_tunnel, 1230 .cb_handler = vti6_rcv_cb, 1231 .err_handler = vti6_err, 1232 .priority = 0, 1233 }; 1234 1235 static struct xfrm6_tunnel vti_ip6ip_handler __read_mostly = { 1236 .handler = vti6_rcv_tunnel, 1237 .cb_handler = vti6_rcv_cb, 1238 .err_handler = vti6_err, 1239 .priority = 0, 1240 }; 1241 #endif 1242 1243 /** 1244 * vti6_tunnel_init - register protocol and reserve needed resources 1245 * 1246 * Return: 0 on success 1247 **/ 1248 static int __init vti6_tunnel_init(void) 1249 { 1250 const char *msg; 1251 int err; 1252 1253 msg = "tunnel device"; 1254 err = register_pernet_device(&vti6_net_ops); 1255 if (err < 0) 1256 goto pernet_dev_failed; 1257 1258 msg = "tunnel protocols"; 1259 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1260 if (err < 0) 1261 goto xfrm_proto_esp_failed; 1262 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1263 if (err < 0) 1264 goto xfrm_proto_ah_failed; 1265 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1266 if (err < 0) 1267 goto xfrm_proto_comp_failed; 1268 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1269 msg = "ipv6 tunnel"; 1270 err = xfrm6_tunnel_register(&vti_ipv6_handler, AF_INET6); 1271 if (err < 0) 1272 goto vti_tunnel_ipv6_failed; 1273 err = xfrm6_tunnel_register(&vti_ip6ip_handler, AF_INET); 1274 if (err < 0) 1275 goto vti_tunnel_ip6ip_failed; 1276 #endif 1277 1278 msg = "netlink interface"; 1279 err = rtnl_link_register(&vti6_link_ops); 1280 if (err < 0) 1281 goto rtnl_link_failed; 1282 1283 return 0; 1284 1285 rtnl_link_failed: 1286 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1287 err = xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET); 1288 vti_tunnel_ip6ip_failed: 1289 err = xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6); 1290 vti_tunnel_ipv6_failed: 1291 #endif 1292 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1293 xfrm_proto_comp_failed: 1294 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1295 xfrm_proto_ah_failed: 1296 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1297 xfrm_proto_esp_failed: 1298 unregister_pernet_device(&vti6_net_ops); 1299 pernet_dev_failed: 1300 pr_err("vti6 init: failed to register %s\n", msg); 1301 return err; 1302 } 1303 1304 /** 1305 * vti6_tunnel_cleanup - free resources and unregister protocol 1306 **/ 1307 static void __exit vti6_tunnel_cleanup(void) 1308 { 1309 rtnl_link_unregister(&vti6_link_ops); 1310 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1311 xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET); 1312 xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6); 1313 #endif 1314 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1315 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1316 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1317 unregister_pernet_device(&vti6_net_ops); 1318 } 1319 1320 module_init(vti6_tunnel_init); 1321 module_exit(vti6_tunnel_cleanup); 1322 MODULE_LICENSE("GPL"); 1323 MODULE_ALIAS_RTNL_LINK("vti6"); 1324 MODULE_ALIAS_NETDEV("ip6_vti0"); 1325 MODULE_AUTHOR("Steffen Klassert"); 1326 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1327