net/ipv4/ip_vti.c

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