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 <linux/etherdevice.h> 49 50 #define IP6_VTI_HASH_SIZE_SHIFT 5 51 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT) 52 53 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 54 { 55 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 56 57 return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT); 58 } 59 60 static int vti6_dev_init(struct net_device *dev); 61 static void vti6_dev_setup(struct net_device *dev); 62 static struct rtnl_link_ops vti6_link_ops __read_mostly; 63 64 static unsigned int vti6_net_id __read_mostly; 65 struct vti6_net { 66 /* the vti6 tunnel fallback device */ 67 struct net_device *fb_tnl_dev; 68 /* lists for storing tunnels in use */ 69 struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE]; 70 struct ip6_tnl __rcu *tnls_wc[1]; 71 struct ip6_tnl __rcu **tnls[2]; 72 }; 73 74 #define for_each_vti6_tunnel_rcu(start) \ 75 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 76 77 /** 78 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses 79 * @net: network namespace 80 * @remote: the address of the tunnel exit-point 81 * @local: the address of the tunnel entry-point 82 * 83 * Return: 84 * tunnel matching given end-points if found, 85 * else fallback tunnel if its device is up, 86 * else %NULL 87 **/ 88 static struct ip6_tnl * 89 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote, 90 const struct in6_addr *local) 91 { 92 unsigned int hash = HASH(remote, local); 93 struct ip6_tnl *t; 94 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 95 struct in6_addr any; 96 97 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 98 if (ipv6_addr_equal(local, &t->parms.laddr) && 99 ipv6_addr_equal(remote, &t->parms.raddr) && 100 (t->dev->flags & IFF_UP)) 101 return t; 102 } 103 104 memset(&any, 0, sizeof(any)); 105 hash = HASH(&any, local); 106 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 107 if (ipv6_addr_equal(local, &t->parms.laddr) && 108 (t->dev->flags & IFF_UP)) 109 return t; 110 } 111 112 hash = HASH(remote, &any); 113 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 114 if (ipv6_addr_equal(remote, &t->parms.raddr) && 115 (t->dev->flags & IFF_UP)) 116 return t; 117 } 118 119 t = rcu_dereference(ip6n->tnls_wc[0]); 120 if (t && (t->dev->flags & IFF_UP)) 121 return t; 122 123 return NULL; 124 } 125 126 /** 127 * vti6_tnl_bucket - get head of list matching given tunnel parameters 128 * @p: parameters containing tunnel end-points 129 * 130 * Description: 131 * vti6_tnl_bucket() returns the head of the list matching the 132 * &struct in6_addr entries laddr and raddr in @p. 133 * 134 * Return: head of IPv6 tunnel list 135 **/ 136 static struct ip6_tnl __rcu ** 137 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p) 138 { 139 const struct in6_addr *remote = &p->raddr; 140 const struct in6_addr *local = &p->laddr; 141 unsigned int h = 0; 142 int prio = 0; 143 144 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 145 prio = 1; 146 h = HASH(remote, local); 147 } 148 return &ip6n->tnls[prio][h]; 149 } 150 151 static void 152 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t) 153 { 154 struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms); 155 156 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 157 rcu_assign_pointer(*tp, t); 158 } 159 160 static void 161 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t) 162 { 163 struct ip6_tnl __rcu **tp; 164 struct ip6_tnl *iter; 165 166 for (tp = vti6_tnl_bucket(ip6n, &t->parms); 167 (iter = rtnl_dereference(*tp)) != NULL; 168 tp = &iter->next) { 169 if (t == iter) { 170 rcu_assign_pointer(*tp, t->next); 171 break; 172 } 173 } 174 } 175 176 static void vti6_dev_free(struct net_device *dev) 177 { 178 free_percpu(dev->tstats); 179 } 180 181 static int vti6_tnl_create2(struct net_device *dev) 182 { 183 struct ip6_tnl *t = netdev_priv(dev); 184 struct net *net = dev_net(dev); 185 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 186 int err; 187 188 dev->rtnl_link_ops = &vti6_link_ops; 189 err = register_netdevice(dev); 190 if (err < 0) 191 goto out; 192 193 strcpy(t->parms.name, dev->name); 194 195 dev_hold(dev); 196 vti6_tnl_link(ip6n, t); 197 198 return 0; 199 200 out: 201 return err; 202 } 203 204 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 205 { 206 struct net_device *dev; 207 struct ip6_tnl *t; 208 char name[IFNAMSIZ]; 209 int err; 210 211 if (p->name[0]) { 212 if (!dev_valid_name(p->name)) 213 goto failed; 214 strlcpy(name, p->name, IFNAMSIZ); 215 } else { 216 sprintf(name, "ip6_vti%%d"); 217 } 218 219 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup); 220 if (!dev) 221 goto failed; 222 223 dev_net_set(dev, net); 224 225 t = netdev_priv(dev); 226 t->parms = *p; 227 t->net = dev_net(dev); 228 229 err = vti6_tnl_create2(dev); 230 if (err < 0) 231 goto failed_free; 232 233 return t; 234 235 failed_free: 236 free_netdev(dev); 237 failed: 238 return NULL; 239 } 240 241 /** 242 * vti6_locate - find or create tunnel matching given parameters 243 * @net: network namespace 244 * @p: tunnel parameters 245 * @create: != 0 if allowed to create new tunnel if no match found 246 * 247 * Description: 248 * vti6_locate() first tries to locate an existing tunnel 249 * based on @parms. If this is unsuccessful, but @create is set a new 250 * tunnel device is created and registered for use. 251 * 252 * Return: 253 * matching tunnel or NULL 254 **/ 255 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p, 256 int create) 257 { 258 const struct in6_addr *remote = &p->raddr; 259 const struct in6_addr *local = &p->laddr; 260 struct ip6_tnl __rcu **tp; 261 struct ip6_tnl *t; 262 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 263 264 for (tp = vti6_tnl_bucket(ip6n, p); 265 (t = rtnl_dereference(*tp)) != NULL; 266 tp = &t->next) { 267 if (ipv6_addr_equal(local, &t->parms.laddr) && 268 ipv6_addr_equal(remote, &t->parms.raddr)) { 269 if (create) 270 return NULL; 271 272 return t; 273 } 274 } 275 if (!create) 276 return NULL; 277 return vti6_tnl_create(net, p); 278 } 279 280 /** 281 * vti6_dev_uninit - tunnel device uninitializer 282 * @dev: the device to be destroyed 283 * 284 * Description: 285 * vti6_dev_uninit() removes tunnel from its list 286 **/ 287 static void vti6_dev_uninit(struct net_device *dev) 288 { 289 struct ip6_tnl *t = netdev_priv(dev); 290 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 291 292 if (dev == ip6n->fb_tnl_dev) 293 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 294 else 295 vti6_tnl_unlink(ip6n, t); 296 dev_put(dev); 297 } 298 299 static int vti6_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi, 300 int encap_type) 301 { 302 struct ip6_tnl *t; 303 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 304 305 rcu_read_lock(); 306 t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); 307 if (t) { 308 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) { 309 rcu_read_unlock(); 310 goto discard; 311 } 312 313 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 314 rcu_read_unlock(); 315 goto discard; 316 } 317 318 ipv6h = ipv6_hdr(skb); 319 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 320 t->dev->stats.rx_dropped++; 321 rcu_read_unlock(); 322 goto discard; 323 } 324 325 rcu_read_unlock(); 326 327 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t; 328 XFRM_SPI_SKB_CB(skb)->family = AF_INET6; 329 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); 330 return xfrm_input(skb, nexthdr, spi, encap_type); 331 } 332 rcu_read_unlock(); 333 return -EINVAL; 334 discard: 335 kfree_skb(skb); 336 return 0; 337 } 338 339 static int vti6_rcv(struct sk_buff *skb) 340 { 341 int nexthdr = skb_network_header(skb)[IP6CB(skb)->nhoff]; 342 343 return vti6_input_proto(skb, nexthdr, 0, 0); 344 } 345 346 static int vti6_rcv_cb(struct sk_buff *skb, int err) 347 { 348 unsigned short family; 349 struct net_device *dev; 350 struct pcpu_sw_netstats *tstats; 351 struct xfrm_state *x; 352 const struct xfrm_mode *inner_mode; 353 struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6; 354 u32 orig_mark = skb->mark; 355 int ret; 356 357 if (!t) 358 return 1; 359 360 dev = t->dev; 361 362 if (err) { 363 dev->stats.rx_errors++; 364 dev->stats.rx_dropped++; 365 366 return 0; 367 } 368 369 x = xfrm_input_state(skb); 370 371 inner_mode = &x->inner_mode; 372 373 if (x->sel.family == AF_UNSPEC) { 374 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 375 if (inner_mode == NULL) { 376 XFRM_INC_STATS(dev_net(skb->dev), 377 LINUX_MIB_XFRMINSTATEMODEERROR); 378 return -EINVAL; 379 } 380 } 381 382 family = inner_mode->family; 383 384 skb->mark = be32_to_cpu(t->parms.i_key); 385 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); 386 skb->mark = orig_mark; 387 388 if (!ret) 389 return -EPERM; 390 391 skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev))); 392 skb->dev = dev; 393 394 tstats = this_cpu_ptr(dev->tstats); 395 u64_stats_update_begin(&tstats->syncp); 396 tstats->rx_packets++; 397 tstats->rx_bytes += skb->len; 398 u64_stats_update_end(&tstats->syncp); 399 400 return 0; 401 } 402 403 /** 404 * vti6_addr_conflict - compare packet addresses to tunnel's own 405 * @t: the outgoing tunnel device 406 * @hdr: IPv6 header from the incoming packet 407 * 408 * Description: 409 * Avoid trivial tunneling loop by checking that tunnel exit-point 410 * doesn't match source of incoming packet. 411 * 412 * Return: 413 * 1 if conflict, 414 * 0 else 415 **/ 416 static inline bool 417 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 418 { 419 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 420 } 421 422 static bool vti6_state_check(const struct xfrm_state *x, 423 const struct in6_addr *dst, 424 const struct in6_addr *src) 425 { 426 xfrm_address_t *daddr = (xfrm_address_t *)dst; 427 xfrm_address_t *saddr = (xfrm_address_t *)src; 428 429 /* if there is no transform then this tunnel is not functional. 430 * Or if the xfrm is not mode tunnel. 431 */ 432 if (!x || x->props.mode != XFRM_MODE_TUNNEL || 433 x->props.family != AF_INET6) 434 return false; 435 436 if (ipv6_addr_any(dst)) 437 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6); 438 439 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6)) 440 return false; 441 442 return true; 443 } 444 445 /** 446 * vti6_xmit - send a packet 447 * @skb: the outgoing socket buffer 448 * @dev: the outgoing tunnel device 449 * @fl: the flow informations for the xfrm_lookup 450 **/ 451 static int 452 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) 453 { 454 struct ip6_tnl *t = netdev_priv(dev); 455 struct net_device_stats *stats = &t->dev->stats; 456 struct dst_entry *dst = skb_dst(skb); 457 struct net_device *tdev; 458 struct xfrm_state *x; 459 int pkt_len = skb->len; 460 int err = -1; 461 int mtu; 462 463 if (!dst) { 464 switch (skb->protocol) { 465 case htons(ETH_P_IP): { 466 struct rtable *rt; 467 468 fl->u.ip4.flowi4_oif = dev->ifindex; 469 fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC; 470 rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4); 471 if (IS_ERR(rt)) 472 goto tx_err_link_failure; 473 dst = &rt->dst; 474 skb_dst_set(skb, dst); 475 break; 476 } 477 case htons(ETH_P_IPV6): 478 fl->u.ip6.flowi6_oif = dev->ifindex; 479 fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC; 480 dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6); 481 if (dst->error) { 482 dst_release(dst); 483 dst = NULL; 484 goto tx_err_link_failure; 485 } 486 skb_dst_set(skb, dst); 487 break; 488 default: 489 goto tx_err_link_failure; 490 } 491 } 492 493 dst_hold(dst); 494 dst = xfrm_lookup_route(t->net, dst, fl, NULL, 0); 495 if (IS_ERR(dst)) { 496 err = PTR_ERR(dst); 497 dst = NULL; 498 goto tx_err_link_failure; 499 } 500 501 if (dst->flags & DST_XFRM_QUEUE) 502 goto queued; 503 504 x = dst->xfrm; 505 if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) 506 goto tx_err_link_failure; 507 508 if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr, 509 (const struct in6_addr *)&x->id.daddr)) 510 goto tx_err_link_failure; 511 512 tdev = dst->dev; 513 514 if (tdev == dev) { 515 stats->collisions++; 516 net_warn_ratelimited("%s: Local routing loop detected!\n", 517 t->parms.name); 518 goto tx_err_dst_release; 519 } 520 521 mtu = dst_mtu(dst); 522 if (skb->len > mtu) { 523 skb_dst_update_pmtu_no_confirm(skb, mtu); 524 525 if (skb->protocol == htons(ETH_P_IPV6)) { 526 if (mtu < IPV6_MIN_MTU) 527 mtu = IPV6_MIN_MTU; 528 529 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 530 } else { 531 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 532 htonl(mtu)); 533 } 534 535 err = -EMSGSIZE; 536 goto tx_err_dst_release; 537 } 538 539 queued: 540 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 541 skb_dst_set(skb, dst); 542 skb->dev = skb_dst(skb)->dev; 543 544 err = dst_output(t->net, skb->sk, skb); 545 if (net_xmit_eval(err) == 0) 546 err = pkt_len; 547 iptunnel_xmit_stats(dev, err); 548 549 return 0; 550 tx_err_link_failure: 551 stats->tx_carrier_errors++; 552 dst_link_failure(skb); 553 tx_err_dst_release: 554 dst_release(dst); 555 return err; 556 } 557 558 static netdev_tx_t 559 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 560 { 561 struct ip6_tnl *t = netdev_priv(dev); 562 struct net_device_stats *stats = &t->dev->stats; 563 struct flowi fl; 564 int ret; 565 566 if (!pskb_inet_may_pull(skb)) 567 goto tx_err; 568 569 memset(&fl, 0, sizeof(fl)); 570 571 switch (skb->protocol) { 572 case htons(ETH_P_IPV6): 573 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 574 vti6_addr_conflict(t, ipv6_hdr(skb))) 575 goto tx_err; 576 577 xfrm_decode_session(skb, &fl, AF_INET6); 578 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 579 break; 580 case htons(ETH_P_IP): 581 xfrm_decode_session(skb, &fl, AF_INET); 582 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 583 break; 584 default: 585 goto tx_err; 586 } 587 588 /* override mark with tunnel output key */ 589 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 590 591 ret = vti6_xmit(skb, dev, &fl); 592 if (ret < 0) 593 goto tx_err; 594 595 return NETDEV_TX_OK; 596 597 tx_err: 598 stats->tx_errors++; 599 stats->tx_dropped++; 600 kfree_skb(skb); 601 return NETDEV_TX_OK; 602 } 603 604 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 605 u8 type, u8 code, int offset, __be32 info) 606 { 607 __be32 spi; 608 __u32 mark; 609 struct xfrm_state *x; 610 struct ip6_tnl *t; 611 struct ip_esp_hdr *esph; 612 struct ip_auth_hdr *ah; 613 struct ip_comp_hdr *ipch; 614 struct net *net = dev_net(skb->dev); 615 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 616 int protocol = iph->nexthdr; 617 618 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 619 if (!t) 620 return -1; 621 622 mark = be32_to_cpu(t->parms.o_key); 623 624 switch (protocol) { 625 case IPPROTO_ESP: 626 esph = (struct ip_esp_hdr *)(skb->data + offset); 627 spi = esph->spi; 628 break; 629 case IPPROTO_AH: 630 ah = (struct ip_auth_hdr *)(skb->data + offset); 631 spi = ah->spi; 632 break; 633 case IPPROTO_COMP: 634 ipch = (struct ip_comp_hdr *)(skb->data + offset); 635 spi = htonl(ntohs(ipch->cpi)); 636 break; 637 default: 638 return 0; 639 } 640 641 if (type != ICMPV6_PKT_TOOBIG && 642 type != NDISC_REDIRECT) 643 return 0; 644 645 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 646 spi, protocol, AF_INET6); 647 if (!x) 648 return 0; 649 650 if (type == NDISC_REDIRECT) 651 ip6_redirect(skb, net, skb->dev->ifindex, 0, 652 sock_net_uid(net, NULL)); 653 else 654 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 655 xfrm_state_put(x); 656 657 return 0; 658 } 659 660 static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) 661 { 662 struct net_device *dev = t->dev; 663 struct __ip6_tnl_parm *p = &t->parms; 664 struct net_device *tdev = NULL; 665 int mtu; 666 667 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 668 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 669 670 p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV | 671 IP6_TNL_F_CAP_PER_PACKET); 672 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 673 674 if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV) 675 dev->flags |= IFF_POINTOPOINT; 676 else 677 dev->flags &= ~IFF_POINTOPOINT; 678 679 if (keep_mtu && dev->mtu) { 680 dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu); 681 return; 682 } 683 684 if (p->flags & IP6_TNL_F_CAP_XMIT) { 685 int strict = (ipv6_addr_type(&p->raddr) & 686 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); 687 struct rt6_info *rt = rt6_lookup(t->net, 688 &p->raddr, &p->laddr, 689 p->link, NULL, strict); 690 691 if (rt) 692 tdev = rt->dst.dev; 693 ip6_rt_put(rt); 694 } 695 696 if (!tdev && p->link) 697 tdev = __dev_get_by_index(t->net, p->link); 698 699 if (tdev) 700 mtu = tdev->mtu - sizeof(struct ipv6hdr); 701 else 702 mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr); 703 704 dev->mtu = max_t(int, mtu, IPV4_MIN_MTU); 705 } 706 707 /** 708 * vti6_tnl_change - update the tunnel parameters 709 * @t: tunnel to be changed 710 * @p: tunnel configuration parameters 711 * @keep_mtu: MTU was set from userspace, don't re-compute it 712 * 713 * Description: 714 * vti6_tnl_change() updates the tunnel parameters 715 **/ 716 static int 717 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p, 718 bool keep_mtu) 719 { 720 t->parms.laddr = p->laddr; 721 t->parms.raddr = p->raddr; 722 t->parms.link = p->link; 723 t->parms.i_key = p->i_key; 724 t->parms.o_key = p->o_key; 725 t->parms.proto = p->proto; 726 t->parms.fwmark = p->fwmark; 727 dst_cache_reset(&t->dst_cache); 728 vti6_link_config(t, keep_mtu); 729 return 0; 730 } 731 732 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p, 733 bool keep_mtu) 734 { 735 struct net *net = dev_net(t->dev); 736 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 737 int err; 738 739 vti6_tnl_unlink(ip6n, t); 740 synchronize_net(); 741 err = vti6_tnl_change(t, p, keep_mtu); 742 vti6_tnl_link(ip6n, t); 743 netdev_state_change(t->dev); 744 return err; 745 } 746 747 static void 748 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 749 { 750 p->laddr = u->laddr; 751 p->raddr = u->raddr; 752 p->link = u->link; 753 p->i_key = u->i_key; 754 p->o_key = u->o_key; 755 p->proto = u->proto; 756 757 memcpy(p->name, u->name, sizeof(u->name)); 758 } 759 760 static void 761 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 762 { 763 u->laddr = p->laddr; 764 u->raddr = p->raddr; 765 u->link = p->link; 766 u->i_key = p->i_key; 767 u->o_key = p->o_key; 768 if (u->i_key) 769 u->i_flags |= GRE_KEY; 770 if (u->o_key) 771 u->o_flags |= GRE_KEY; 772 u->proto = p->proto; 773 774 memcpy(u->name, p->name, sizeof(u->name)); 775 } 776 777 /** 778 * vti6_ioctl - configure vti6 tunnels from userspace 779 * @dev: virtual device associated with tunnel 780 * @ifr: parameters passed from userspace 781 * @cmd: command to be performed 782 * 783 * Description: 784 * vti6_ioctl() is used for managing vti6 tunnels 785 * from userspace. 786 * 787 * The possible commands are the following: 788 * %SIOCGETTUNNEL: get tunnel parameters for device 789 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 790 * %SIOCCHGTUNNEL: change tunnel parameters to those given 791 * %SIOCDELTUNNEL: delete tunnel 792 * 793 * The fallback device "ip6_vti0", created during module 794 * initialization, can be used for creating other tunnel devices. 795 * 796 * Return: 797 * 0 on success, 798 * %-EFAULT if unable to copy data to or from userspace, 799 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 800 * %-EINVAL if passed tunnel parameters are invalid, 801 * %-EEXIST if changing a tunnel's parameters would cause a conflict 802 * %-ENODEV if attempting to change or delete a nonexisting device 803 **/ 804 static int 805 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 806 { 807 int err = 0; 808 struct ip6_tnl_parm2 p; 809 struct __ip6_tnl_parm p1; 810 struct ip6_tnl *t = NULL; 811 struct net *net = dev_net(dev); 812 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 813 814 switch (cmd) { 815 case SIOCGETTUNNEL: 816 if (dev == ip6n->fb_tnl_dev) { 817 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 818 err = -EFAULT; 819 break; 820 } 821 vti6_parm_from_user(&p1, &p); 822 t = vti6_locate(net, &p1, 0); 823 } else { 824 memset(&p, 0, sizeof(p)); 825 } 826 if (!t) 827 t = netdev_priv(dev); 828 vti6_parm_to_user(&p, &t->parms); 829 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 830 err = -EFAULT; 831 break; 832 case SIOCADDTUNNEL: 833 case SIOCCHGTUNNEL: 834 err = -EPERM; 835 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 836 break; 837 err = -EFAULT; 838 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 839 break; 840 err = -EINVAL; 841 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 842 break; 843 vti6_parm_from_user(&p1, &p); 844 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 845 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 846 if (t) { 847 if (t->dev != dev) { 848 err = -EEXIST; 849 break; 850 } 851 } else 852 t = netdev_priv(dev); 853 854 err = vti6_update(t, &p1, false); 855 } 856 if (t) { 857 err = 0; 858 vti6_parm_to_user(&p, &t->parms); 859 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 860 err = -EFAULT; 861 862 } else 863 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 864 break; 865 case SIOCDELTUNNEL: 866 err = -EPERM; 867 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 868 break; 869 870 if (dev == ip6n->fb_tnl_dev) { 871 err = -EFAULT; 872 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 873 break; 874 err = -ENOENT; 875 vti6_parm_from_user(&p1, &p); 876 t = vti6_locate(net, &p1, 0); 877 if (!t) 878 break; 879 err = -EPERM; 880 if (t->dev == ip6n->fb_tnl_dev) 881 break; 882 dev = t->dev; 883 } 884 err = 0; 885 unregister_netdevice(dev); 886 break; 887 default: 888 err = -EINVAL; 889 } 890 return err; 891 } 892 893 static const struct net_device_ops vti6_netdev_ops = { 894 .ndo_init = vti6_dev_init, 895 .ndo_uninit = vti6_dev_uninit, 896 .ndo_start_xmit = vti6_tnl_xmit, 897 .ndo_do_ioctl = vti6_ioctl, 898 .ndo_get_stats64 = ip_tunnel_get_stats64, 899 .ndo_get_iflink = ip6_tnl_get_iflink, 900 }; 901 902 /** 903 * vti6_dev_setup - setup virtual tunnel device 904 * @dev: virtual device associated with tunnel 905 * 906 * Description: 907 * Initialize function pointers and device parameters 908 **/ 909 static void vti6_dev_setup(struct net_device *dev) 910 { 911 dev->netdev_ops = &vti6_netdev_ops; 912 dev->header_ops = &ip_tunnel_header_ops; 913 dev->needs_free_netdev = true; 914 dev->priv_destructor = vti6_dev_free; 915 916 dev->type = ARPHRD_TUNNEL6; 917 dev->min_mtu = IPV4_MIN_MTU; 918 dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr); 919 dev->flags |= IFF_NOARP; 920 dev->addr_len = sizeof(struct in6_addr); 921 netif_keep_dst(dev); 922 /* This perm addr will be used as interface identifier by IPv6 */ 923 dev->addr_assign_type = NET_ADDR_RANDOM; 924 eth_random_addr(dev->perm_addr); 925 } 926 927 /** 928 * vti6_dev_init_gen - general initializer for all tunnel devices 929 * @dev: virtual device associated with tunnel 930 **/ 931 static inline int vti6_dev_init_gen(struct net_device *dev) 932 { 933 struct ip6_tnl *t = netdev_priv(dev); 934 935 t->dev = dev; 936 t->net = dev_net(dev); 937 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 938 if (!dev->tstats) 939 return -ENOMEM; 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->parms.proto = IPPROTO_IPV6; 971 dev_hold(dev); 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 *src_net, struct net_device *dev, 1011 struct nlattr *tb[], struct nlattr *data[], 1012 struct netlink_ext_ack *extack) 1013 { 1014 struct net *net = dev_net(dev); 1015 struct ip6_tnl *nt; 1016 1017 nt = netdev_priv(dev); 1018 vti6_netlink_parms(data, &nt->parms); 1019 1020 nt->parms.proto = IPPROTO_IPV6; 1021 1022 if (vti6_locate(net, &nt->parms, 0)) 1023 return -EEXIST; 1024 1025 return vti6_tnl_create2(dev); 1026 } 1027 1028 static void vti6_dellink(struct net_device *dev, struct list_head *head) 1029 { 1030 struct net *net = dev_net(dev); 1031 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1032 1033 if (dev != ip6n->fb_tnl_dev) 1034 unregister_netdevice_queue(dev, head); 1035 } 1036 1037 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 1038 struct nlattr *data[], 1039 struct netlink_ext_ack *extack) 1040 { 1041 struct ip6_tnl *t; 1042 struct __ip6_tnl_parm p; 1043 struct net *net = dev_net(dev); 1044 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1045 1046 if (dev == ip6n->fb_tnl_dev) 1047 return -EINVAL; 1048 1049 vti6_netlink_parms(data, &p); 1050 1051 t = vti6_locate(net, &p, 0); 1052 1053 if (t) { 1054 if (t->dev != dev) 1055 return -EEXIST; 1056 } else 1057 t = netdev_priv(dev); 1058 1059 return vti6_update(t, &p, tb && tb[IFLA_MTU]); 1060 } 1061 1062 static size_t vti6_get_size(const struct net_device *dev) 1063 { 1064 return 1065 /* IFLA_VTI_LINK */ 1066 nla_total_size(4) + 1067 /* IFLA_VTI_LOCAL */ 1068 nla_total_size(sizeof(struct in6_addr)) + 1069 /* IFLA_VTI_REMOTE */ 1070 nla_total_size(sizeof(struct in6_addr)) + 1071 /* IFLA_VTI_IKEY */ 1072 nla_total_size(4) + 1073 /* IFLA_VTI_OKEY */ 1074 nla_total_size(4) + 1075 /* IFLA_VTI_FWMARK */ 1076 nla_total_size(4) + 1077 0; 1078 } 1079 1080 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1081 { 1082 struct ip6_tnl *tunnel = netdev_priv(dev); 1083 struct __ip6_tnl_parm *parm = &tunnel->parms; 1084 1085 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 1086 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 1087 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1088 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1089 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) || 1090 nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark)) 1091 goto nla_put_failure; 1092 return 0; 1093 1094 nla_put_failure: 1095 return -EMSGSIZE; 1096 } 1097 1098 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1099 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1100 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1101 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1102 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1103 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1104 [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, 1105 }; 1106 1107 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1108 .kind = "vti6", 1109 .maxtype = IFLA_VTI_MAX, 1110 .policy = vti6_policy, 1111 .priv_size = sizeof(struct ip6_tnl), 1112 .setup = vti6_dev_setup, 1113 .validate = vti6_validate, 1114 .newlink = vti6_newlink, 1115 .dellink = vti6_dellink, 1116 .changelink = vti6_changelink, 1117 .get_size = vti6_get_size, 1118 .fill_info = vti6_fill_info, 1119 .get_link_net = ip6_tnl_get_link_net, 1120 }; 1121 1122 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n, 1123 struct list_head *list) 1124 { 1125 int h; 1126 struct ip6_tnl *t; 1127 1128 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1129 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1130 while (t) { 1131 unregister_netdevice_queue(t->dev, list); 1132 t = rtnl_dereference(t->next); 1133 } 1134 } 1135 1136 t = rtnl_dereference(ip6n->tnls_wc[0]); 1137 if (t) 1138 unregister_netdevice_queue(t->dev, list); 1139 } 1140 1141 static int __net_init vti6_init_net(struct net *net) 1142 { 1143 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1144 struct ip6_tnl *t = NULL; 1145 int err; 1146 1147 ip6n->tnls[0] = ip6n->tnls_wc; 1148 ip6n->tnls[1] = ip6n->tnls_r_l; 1149 1150 if (!net_has_fallback_tunnels(net)) 1151 return 0; 1152 err = -ENOMEM; 1153 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1154 NET_NAME_UNKNOWN, vti6_dev_setup); 1155 1156 if (!ip6n->fb_tnl_dev) 1157 goto err_alloc_dev; 1158 dev_net_set(ip6n->fb_tnl_dev, net); 1159 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1160 1161 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1162 if (err < 0) 1163 goto err_register; 1164 1165 err = register_netdev(ip6n->fb_tnl_dev); 1166 if (err < 0) 1167 goto err_register; 1168 1169 t = netdev_priv(ip6n->fb_tnl_dev); 1170 1171 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1172 return 0; 1173 1174 err_register: 1175 free_netdev(ip6n->fb_tnl_dev); 1176 err_alloc_dev: 1177 return err; 1178 } 1179 1180 static void __net_exit vti6_exit_batch_net(struct list_head *net_list) 1181 { 1182 struct vti6_net *ip6n; 1183 struct net *net; 1184 LIST_HEAD(list); 1185 1186 rtnl_lock(); 1187 list_for_each_entry(net, net_list, exit_list) { 1188 ip6n = net_generic(net, vti6_net_id); 1189 vti6_destroy_tunnels(ip6n, &list); 1190 } 1191 unregister_netdevice_many(&list); 1192 rtnl_unlock(); 1193 } 1194 1195 static struct pernet_operations vti6_net_ops = { 1196 .init = vti6_init_net, 1197 .exit_batch = vti6_exit_batch_net, 1198 .id = &vti6_net_id, 1199 .size = sizeof(struct vti6_net), 1200 }; 1201 1202 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1203 .handler = vti6_rcv, 1204 .input_handler = vti6_input_proto, 1205 .cb_handler = vti6_rcv_cb, 1206 .err_handler = vti6_err, 1207 .priority = 100, 1208 }; 1209 1210 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1211 .handler = vti6_rcv, 1212 .input_handler = vti6_input_proto, 1213 .cb_handler = vti6_rcv_cb, 1214 .err_handler = vti6_err, 1215 .priority = 100, 1216 }; 1217 1218 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1219 .handler = vti6_rcv, 1220 .input_handler = vti6_input_proto, 1221 .cb_handler = vti6_rcv_cb, 1222 .err_handler = vti6_err, 1223 .priority = 100, 1224 }; 1225 1226 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1227 static int vti6_rcv_tunnel(struct sk_buff *skb) 1228 { 1229 const xfrm_address_t *saddr; 1230 __be32 spi; 1231 1232 saddr = (const xfrm_address_t *)&ipv6_hdr(skb)->saddr; 1233 spi = xfrm6_tunnel_spi_lookup(dev_net(skb->dev), saddr); 1234 1235 return vti6_input_proto(skb, IPPROTO_IPV6, spi, 0); 1236 } 1237 1238 static struct xfrm6_tunnel vti_ipv6_handler __read_mostly = { 1239 .handler = vti6_rcv_tunnel, 1240 .cb_handler = vti6_rcv_cb, 1241 .err_handler = vti6_err, 1242 .priority = 0, 1243 }; 1244 1245 static struct xfrm6_tunnel vti_ip6ip_handler __read_mostly = { 1246 .handler = vti6_rcv_tunnel, 1247 .cb_handler = vti6_rcv_cb, 1248 .err_handler = vti6_err, 1249 .priority = 0, 1250 }; 1251 #endif 1252 1253 /** 1254 * vti6_tunnel_init - register protocol and reserve needed resources 1255 * 1256 * Return: 0 on success 1257 **/ 1258 static int __init vti6_tunnel_init(void) 1259 { 1260 const char *msg; 1261 int err; 1262 1263 msg = "tunnel device"; 1264 err = register_pernet_device(&vti6_net_ops); 1265 if (err < 0) 1266 goto pernet_dev_failed; 1267 1268 msg = "tunnel protocols"; 1269 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1270 if (err < 0) 1271 goto xfrm_proto_esp_failed; 1272 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1273 if (err < 0) 1274 goto xfrm_proto_ah_failed; 1275 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1276 if (err < 0) 1277 goto xfrm_proto_comp_failed; 1278 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1279 msg = "ipv6 tunnel"; 1280 err = xfrm6_tunnel_register(&vti_ipv6_handler, AF_INET6); 1281 if (err < 0) 1282 goto vti_tunnel_ipv6_failed; 1283 err = xfrm6_tunnel_register(&vti_ip6ip_handler, AF_INET); 1284 if (err < 0) 1285 goto vti_tunnel_ip6ip_failed; 1286 #endif 1287 1288 msg = "netlink interface"; 1289 err = rtnl_link_register(&vti6_link_ops); 1290 if (err < 0) 1291 goto rtnl_link_failed; 1292 1293 return 0; 1294 1295 rtnl_link_failed: 1296 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1297 err = xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET); 1298 vti_tunnel_ip6ip_failed: 1299 err = xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6); 1300 vti_tunnel_ipv6_failed: 1301 #endif 1302 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1303 xfrm_proto_comp_failed: 1304 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1305 xfrm_proto_ah_failed: 1306 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1307 xfrm_proto_esp_failed: 1308 unregister_pernet_device(&vti6_net_ops); 1309 pernet_dev_failed: 1310 pr_err("vti6 init: failed to register %s\n", msg); 1311 return err; 1312 } 1313 1314 /** 1315 * vti6_tunnel_cleanup - free resources and unregister protocol 1316 **/ 1317 static void __exit vti6_tunnel_cleanup(void) 1318 { 1319 rtnl_link_unregister(&vti6_link_ops); 1320 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL) 1321 xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET); 1322 xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6); 1323 #endif 1324 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1325 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1326 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1327 unregister_pernet_device(&vti6_net_ops); 1328 } 1329 1330 module_init(vti6_tunnel_init); 1331 module_exit(vti6_tunnel_cleanup); 1332 MODULE_LICENSE("GPL"); 1333 MODULE_ALIAS_RTNL_LINK("vti6"); 1334 MODULE_ALIAS_NETDEV("ip6_vti0"); 1335 MODULE_AUTHOR("Steffen Klassert"); 1336 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1337