1 /* 2 * Linux NET3: IP/IP protocol decoder modified to support 3 * virtual tunnel interface 4 * 5 * Authors: 6 * Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 */ 14 15 /* 16 This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c 17 18 For comments look at net/ipv4/ip_gre.c --ANK 19 */ 20 21 22 #include <linux/capability.h> 23 #include <linux/module.h> 24 #include <linux/types.h> 25 #include <linux/kernel.h> 26 #include <linux/uaccess.h> 27 #include <linux/skbuff.h> 28 #include <linux/netdevice.h> 29 #include <linux/in.h> 30 #include <linux/tcp.h> 31 #include <linux/udp.h> 32 #include <linux/if_arp.h> 33 #include <linux/init.h> 34 #include <linux/netfilter_ipv4.h> 35 #include <linux/if_ether.h> 36 #include <linux/icmpv6.h> 37 38 #include <net/sock.h> 39 #include <net/ip.h> 40 #include <net/icmp.h> 41 #include <net/ip_tunnels.h> 42 #include <net/inet_ecn.h> 43 #include <net/xfrm.h> 44 #include <net/net_namespace.h> 45 #include <net/netns/generic.h> 46 47 static struct rtnl_link_ops vti_link_ops __read_mostly; 48 49 static unsigned int vti_net_id __read_mostly; 50 static int vti_tunnel_init(struct net_device *dev); 51 52 static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi, 53 int encap_type, bool update_skb_dev) 54 { 55 struct ip_tunnel *tunnel; 56 const struct iphdr *iph = ip_hdr(skb); 57 struct net *net = dev_net(skb->dev); 58 struct ip_tunnel_net *itn = net_generic(net, vti_net_id); 59 60 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, 61 iph->saddr, iph->daddr, 0); 62 if (tunnel) { 63 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 64 goto drop; 65 66 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel; 67 68 if (update_skb_dev) 69 skb->dev = tunnel->dev; 70 71 return xfrm_input(skb, nexthdr, spi, encap_type); 72 } 73 74 return -EINVAL; 75 drop: 76 kfree_skb(skb); 77 return 0; 78 } 79 80 static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi, 81 int encap_type) 82 { 83 return vti_input(skb, nexthdr, spi, encap_type, false); 84 } 85 86 static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev) 87 { 88 XFRM_SPI_SKB_CB(skb)->family = AF_INET; 89 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); 90 91 return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev); 92 } 93 94 static int vti_rcv_proto(struct sk_buff *skb) 95 { 96 return vti_rcv(skb, 0, false); 97 } 98 99 static int vti_rcv_tunnel(struct sk_buff *skb) 100 { 101 return vti_rcv(skb, ip_hdr(skb)->saddr, true); 102 } 103 104 static int vti_rcv_cb(struct sk_buff *skb, int err) 105 { 106 unsigned short family; 107 struct net_device *dev; 108 struct pcpu_sw_netstats *tstats; 109 struct xfrm_state *x; 110 const struct xfrm_mode *inner_mode; 111 struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4; 112 u32 orig_mark = skb->mark; 113 int ret; 114 115 if (!tunnel) 116 return 1; 117 118 dev = tunnel->dev; 119 120 if (err) { 121 dev->stats.rx_errors++; 122 dev->stats.rx_dropped++; 123 124 return 0; 125 } 126 127 x = xfrm_input_state(skb); 128 129 inner_mode = &x->inner_mode; 130 131 if (x->sel.family == AF_UNSPEC) { 132 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 133 if (inner_mode == NULL) { 134 XFRM_INC_STATS(dev_net(skb->dev), 135 LINUX_MIB_XFRMINSTATEMODEERROR); 136 return -EINVAL; 137 } 138 } 139 140 family = inner_mode->family; 141 142 skb->mark = be32_to_cpu(tunnel->parms.i_key); 143 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); 144 skb->mark = orig_mark; 145 146 if (!ret) 147 return -EPERM; 148 149 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev))); 150 skb->dev = dev; 151 152 tstats = this_cpu_ptr(dev->tstats); 153 154 u64_stats_update_begin(&tstats->syncp); 155 tstats->rx_packets++; 156 tstats->rx_bytes += skb->len; 157 u64_stats_update_end(&tstats->syncp); 158 159 return 0; 160 } 161 162 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src) 163 { 164 xfrm_address_t *daddr = (xfrm_address_t *)&dst; 165 xfrm_address_t *saddr = (xfrm_address_t *)&src; 166 167 /* if there is no transform then this tunnel is not functional. 168 * Or if the xfrm is not mode tunnel. 169 */ 170 if (!x || x->props.mode != XFRM_MODE_TUNNEL || 171 x->props.family != AF_INET) 172 return false; 173 174 if (!dst) 175 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET); 176 177 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET)) 178 return false; 179 180 return true; 181 } 182 183 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev, 184 struct flowi *fl) 185 { 186 struct ip_tunnel *tunnel = netdev_priv(dev); 187 struct ip_tunnel_parm *parms = &tunnel->parms; 188 struct dst_entry *dst = skb_dst(skb); 189 struct net_device *tdev; /* Device to other host */ 190 int pkt_len = skb->len; 191 int err; 192 int mtu; 193 194 if (!dst) { 195 dev->stats.tx_carrier_errors++; 196 goto tx_error_icmp; 197 } 198 199 dst_hold(dst); 200 dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0); 201 if (IS_ERR(dst)) { 202 dev->stats.tx_carrier_errors++; 203 goto tx_error_icmp; 204 } 205 206 if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) { 207 dev->stats.tx_carrier_errors++; 208 dst_release(dst); 209 goto tx_error_icmp; 210 } 211 212 tdev = dst->dev; 213 214 if (tdev == dev) { 215 dst_release(dst); 216 dev->stats.collisions++; 217 goto tx_error; 218 } 219 220 mtu = dst_mtu(dst); 221 if (skb->len > mtu) { 222 skb_dst_update_pmtu(skb, mtu); 223 if (skb->protocol == htons(ETH_P_IP)) { 224 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 225 htonl(mtu)); 226 } else { 227 if (mtu < IPV6_MIN_MTU) 228 mtu = IPV6_MIN_MTU; 229 230 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 231 } 232 233 dst_release(dst); 234 goto tx_error; 235 } 236 237 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev))); 238 skb_dst_set(skb, dst); 239 skb->dev = skb_dst(skb)->dev; 240 241 err = dst_output(tunnel->net, skb->sk, skb); 242 if (net_xmit_eval(err) == 0) 243 err = pkt_len; 244 iptunnel_xmit_stats(dev, err); 245 return NETDEV_TX_OK; 246 247 tx_error_icmp: 248 dst_link_failure(skb); 249 tx_error: 250 dev->stats.tx_errors++; 251 kfree_skb(skb); 252 return NETDEV_TX_OK; 253 } 254 255 /* This function assumes it is being called from dev_queue_xmit() 256 * and that skb is filled properly by that function. 257 */ 258 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 259 { 260 struct ip_tunnel *tunnel = netdev_priv(dev); 261 struct flowi fl; 262 263 if (!pskb_inet_may_pull(skb)) 264 goto tx_err; 265 266 memset(&fl, 0, sizeof(fl)); 267 268 switch (skb->protocol) { 269 case htons(ETH_P_IP): 270 xfrm_decode_session(skb, &fl, AF_INET); 271 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 272 break; 273 case htons(ETH_P_IPV6): 274 xfrm_decode_session(skb, &fl, AF_INET6); 275 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 276 break; 277 default: 278 goto tx_err; 279 } 280 281 /* override mark with tunnel output key */ 282 fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key); 283 284 return vti_xmit(skb, dev, &fl); 285 286 tx_err: 287 dev->stats.tx_errors++; 288 kfree_skb(skb); 289 return NETDEV_TX_OK; 290 } 291 292 static int vti4_err(struct sk_buff *skb, u32 info) 293 { 294 __be32 spi; 295 __u32 mark; 296 struct xfrm_state *x; 297 struct ip_tunnel *tunnel; 298 struct ip_esp_hdr *esph; 299 struct ip_auth_hdr *ah ; 300 struct ip_comp_hdr *ipch; 301 struct net *net = dev_net(skb->dev); 302 const struct iphdr *iph = (const struct iphdr *)skb->data; 303 int protocol = iph->protocol; 304 struct ip_tunnel_net *itn = net_generic(net, vti_net_id); 305 306 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, 307 iph->daddr, iph->saddr, 0); 308 if (!tunnel) 309 return -1; 310 311 mark = be32_to_cpu(tunnel->parms.o_key); 312 313 switch (protocol) { 314 case IPPROTO_ESP: 315 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 316 spi = esph->spi; 317 break; 318 case IPPROTO_AH: 319 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); 320 spi = ah->spi; 321 break; 322 case IPPROTO_COMP: 323 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); 324 spi = htonl(ntohs(ipch->cpi)); 325 break; 326 default: 327 return 0; 328 } 329 330 switch (icmp_hdr(skb)->type) { 331 case ICMP_DEST_UNREACH: 332 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 333 return 0; 334 case ICMP_REDIRECT: 335 break; 336 default: 337 return 0; 338 } 339 340 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 341 spi, protocol, AF_INET); 342 if (!x) 343 return 0; 344 345 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 346 ipv4_update_pmtu(skb, net, info, 0, protocol); 347 else 348 ipv4_redirect(skb, net, 0, protocol); 349 xfrm_state_put(x); 350 351 return 0; 352 } 353 354 static int 355 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 356 { 357 int err = 0; 358 struct ip_tunnel_parm p; 359 360 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 361 return -EFAULT; 362 363 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 364 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 365 p.iph.ihl != 5) 366 return -EINVAL; 367 } 368 369 if (!(p.i_flags & GRE_KEY)) 370 p.i_key = 0; 371 if (!(p.o_flags & GRE_KEY)) 372 p.o_key = 0; 373 374 p.i_flags = VTI_ISVTI; 375 376 err = ip_tunnel_ioctl(dev, &p, cmd); 377 if (err) 378 return err; 379 380 if (cmd != SIOCDELTUNNEL) { 381 p.i_flags |= GRE_KEY; 382 p.o_flags |= GRE_KEY; 383 } 384 385 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 386 return -EFAULT; 387 return 0; 388 } 389 390 static const struct net_device_ops vti_netdev_ops = { 391 .ndo_init = vti_tunnel_init, 392 .ndo_uninit = ip_tunnel_uninit, 393 .ndo_start_xmit = vti_tunnel_xmit, 394 .ndo_do_ioctl = vti_tunnel_ioctl, 395 .ndo_change_mtu = ip_tunnel_change_mtu, 396 .ndo_get_stats64 = ip_tunnel_get_stats64, 397 .ndo_get_iflink = ip_tunnel_get_iflink, 398 }; 399 400 static void vti_tunnel_setup(struct net_device *dev) 401 { 402 dev->netdev_ops = &vti_netdev_ops; 403 dev->type = ARPHRD_TUNNEL; 404 ip_tunnel_setup(dev, vti_net_id); 405 } 406 407 static int vti_tunnel_init(struct net_device *dev) 408 { 409 struct ip_tunnel *tunnel = netdev_priv(dev); 410 struct iphdr *iph = &tunnel->parms.iph; 411 412 memcpy(dev->dev_addr, &iph->saddr, 4); 413 memcpy(dev->broadcast, &iph->daddr, 4); 414 415 dev->flags = IFF_NOARP; 416 dev->addr_len = 4; 417 dev->features |= NETIF_F_LLTX; 418 netif_keep_dst(dev); 419 420 return ip_tunnel_init(dev); 421 } 422 423 static void __net_init vti_fb_tunnel_init(struct net_device *dev) 424 { 425 struct ip_tunnel *tunnel = netdev_priv(dev); 426 struct iphdr *iph = &tunnel->parms.iph; 427 428 iph->version = 4; 429 iph->protocol = IPPROTO_IPIP; 430 iph->ihl = 5; 431 } 432 433 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = { 434 .handler = vti_rcv_proto, 435 .input_handler = vti_input_proto, 436 .cb_handler = vti_rcv_cb, 437 .err_handler = vti4_err, 438 .priority = 100, 439 }; 440 441 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = { 442 .handler = vti_rcv_proto, 443 .input_handler = vti_input_proto, 444 .cb_handler = vti_rcv_cb, 445 .err_handler = vti4_err, 446 .priority = 100, 447 }; 448 449 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = { 450 .handler = vti_rcv_proto, 451 .input_handler = vti_input_proto, 452 .cb_handler = vti_rcv_cb, 453 .err_handler = vti4_err, 454 .priority = 100, 455 }; 456 457 static struct xfrm_tunnel ipip_handler __read_mostly = { 458 .handler = vti_rcv_tunnel, 459 .err_handler = vti4_err, 460 .priority = 0, 461 }; 462 463 static int __net_init vti_init_net(struct net *net) 464 { 465 int err; 466 struct ip_tunnel_net *itn; 467 468 err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0"); 469 if (err) 470 return err; 471 itn = net_generic(net, vti_net_id); 472 if (itn->fb_tunnel_dev) 473 vti_fb_tunnel_init(itn->fb_tunnel_dev); 474 return 0; 475 } 476 477 static void __net_exit vti_exit_batch_net(struct list_head *list_net) 478 { 479 ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops); 480 } 481 482 static struct pernet_operations vti_net_ops = { 483 .init = vti_init_net, 484 .exit_batch = vti_exit_batch_net, 485 .id = &vti_net_id, 486 .size = sizeof(struct ip_tunnel_net), 487 }; 488 489 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 490 struct netlink_ext_ack *extack) 491 { 492 return 0; 493 } 494 495 static void vti_netlink_parms(struct nlattr *data[], 496 struct ip_tunnel_parm *parms, 497 __u32 *fwmark) 498 { 499 memset(parms, 0, sizeof(*parms)); 500 501 parms->iph.protocol = IPPROTO_IPIP; 502 503 if (!data) 504 return; 505 506 parms->i_flags = VTI_ISVTI; 507 508 if (data[IFLA_VTI_LINK]) 509 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 510 511 if (data[IFLA_VTI_IKEY]) 512 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 513 514 if (data[IFLA_VTI_OKEY]) 515 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 516 517 if (data[IFLA_VTI_LOCAL]) 518 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]); 519 520 if (data[IFLA_VTI_REMOTE]) 521 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]); 522 523 if (data[IFLA_VTI_FWMARK]) 524 *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]); 525 } 526 527 static int vti_newlink(struct net *src_net, struct net_device *dev, 528 struct nlattr *tb[], struct nlattr *data[], 529 struct netlink_ext_ack *extack) 530 { 531 struct ip_tunnel_parm parms; 532 __u32 fwmark = 0; 533 534 vti_netlink_parms(data, &parms, &fwmark); 535 return ip_tunnel_newlink(dev, tb, &parms, fwmark); 536 } 537 538 static int vti_changelink(struct net_device *dev, struct nlattr *tb[], 539 struct nlattr *data[], 540 struct netlink_ext_ack *extack) 541 { 542 struct ip_tunnel *t = netdev_priv(dev); 543 __u32 fwmark = t->fwmark; 544 struct ip_tunnel_parm p; 545 546 vti_netlink_parms(data, &p, &fwmark); 547 return ip_tunnel_changelink(dev, tb, &p, fwmark); 548 } 549 550 static size_t vti_get_size(const struct net_device *dev) 551 { 552 return 553 /* IFLA_VTI_LINK */ 554 nla_total_size(4) + 555 /* IFLA_VTI_IKEY */ 556 nla_total_size(4) + 557 /* IFLA_VTI_OKEY */ 558 nla_total_size(4) + 559 /* IFLA_VTI_LOCAL */ 560 nla_total_size(4) + 561 /* IFLA_VTI_REMOTE */ 562 nla_total_size(4) + 563 /* IFLA_VTI_FWMARK */ 564 nla_total_size(4) + 565 0; 566 } 567 568 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev) 569 { 570 struct ip_tunnel *t = netdev_priv(dev); 571 struct ip_tunnel_parm *p = &t->parms; 572 573 if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) || 574 nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) || 575 nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) || 576 nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) || 577 nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) || 578 nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark)) 579 return -EMSGSIZE; 580 581 return 0; 582 } 583 584 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = { 585 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 586 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 587 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 588 [IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 589 [IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 590 [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, 591 }; 592 593 static struct rtnl_link_ops vti_link_ops __read_mostly = { 594 .kind = "vti", 595 .maxtype = IFLA_VTI_MAX, 596 .policy = vti_policy, 597 .priv_size = sizeof(struct ip_tunnel), 598 .setup = vti_tunnel_setup, 599 .validate = vti_tunnel_validate, 600 .newlink = vti_newlink, 601 .changelink = vti_changelink, 602 .dellink = ip_tunnel_dellink, 603 .get_size = vti_get_size, 604 .fill_info = vti_fill_info, 605 .get_link_net = ip_tunnel_get_link_net, 606 }; 607 608 static int __init vti_init(void) 609 { 610 const char *msg; 611 int err; 612 613 pr_info("IPv4 over IPsec tunneling driver\n"); 614 615 msg = "tunnel device"; 616 err = register_pernet_device(&vti_net_ops); 617 if (err < 0) 618 goto pernet_dev_failed; 619 620 msg = "tunnel protocols"; 621 err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP); 622 if (err < 0) 623 goto xfrm_proto_esp_failed; 624 err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH); 625 if (err < 0) 626 goto xfrm_proto_ah_failed; 627 err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP); 628 if (err < 0) 629 goto xfrm_proto_comp_failed; 630 631 msg = "ipip tunnel"; 632 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 633 if (err < 0) 634 goto xfrm_tunnel_failed; 635 636 msg = "netlink interface"; 637 err = rtnl_link_register(&vti_link_ops); 638 if (err < 0) 639 goto rtnl_link_failed; 640 641 return err; 642 643 rtnl_link_failed: 644 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 645 xfrm_tunnel_failed: 646 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP); 647 xfrm_proto_comp_failed: 648 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH); 649 xfrm_proto_ah_failed: 650 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP); 651 xfrm_proto_esp_failed: 652 unregister_pernet_device(&vti_net_ops); 653 pernet_dev_failed: 654 pr_err("vti init: failed to register %s\n", msg); 655 return err; 656 } 657 658 static void __exit vti_fini(void) 659 { 660 rtnl_link_unregister(&vti_link_ops); 661 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 662 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP); 663 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH); 664 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP); 665 unregister_pernet_device(&vti_net_ops); 666 } 667 668 module_init(vti_init); 669 module_exit(vti_fini); 670 MODULE_LICENSE("GPL"); 671 MODULE_ALIAS_RTNL_LINK("vti"); 672 MODULE_ALIAS_NETDEV("ip_vti0"); 673