net/ipv4/ip_vti.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux NET3: IP/IP protocol decoder modified to support
   4  *                  virtual tunnel interface
   5  *
   6  *      Authors:
   7  *              Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
   8  */
   9
  10 /*
  11    This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
  12
  13    For comments look at net/ipv4/ip_gre.c --ANK
  14  */
  15
  16
  17 #include <linux/capability.h>
  18 #include <linux/module.h>
  19 #include <linux/types.h>
  20 #include <linux/kernel.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/in.h>
  25 #include <linux/tcp.h>
  26 #include <linux/udp.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/init.h>
  29 #include <linux/netfilter_ipv4.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/icmpv6.h>
  32
  33 #include <net/sock.h>
  34 #include <net/ip.h>
  35 #include <net/icmp.h>
  36 #include <net/ip_tunnels.h>
  37 #include <net/inet_ecn.h>
  38 #include <net/xfrm.h>
  39 #include <net/net_namespace.h>
  40 #include <net/netns/generic.h>
  41
  42 static struct rtnl_link_ops vti_link_ops __read_mostly;
  43
  44 static unsigned int vti_net_id __read_mostly;
  45 static int vti_tunnel_init(struct net_device *dev);
  46
  47 static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
  48                      int encap_type, bool update_skb_dev)
  49 {
  50         struct ip_tunnel *tunnel;
  51         const struct iphdr *iph = ip_hdr(skb);
  52         struct net *net = dev_net(skb->dev);
  53         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
  54
  55         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
  56                                   iph->saddr, iph->daddr, 0);
  57         if (tunnel) {
  58                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
  59                         goto drop;
  60
  61                 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
  62
  63                 if (update_skb_dev)
  64                         skb->dev = tunnel->dev;
  65
  66                 return xfrm_input(skb, nexthdr, spi, encap_type);
  67         }
  68
  69         return -EINVAL;
  70 drop:
  71         kfree_skb(skb);
  72         return 0;
  73 }
  74
  75 static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
  76                            int encap_type)
  77 {
  78         return vti_input(skb, nexthdr, spi, encap_type, false);
  79 }
  80
  81 static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev)
  82 {
  83         XFRM_SPI_SKB_CB(skb)->family = AF_INET;
  84         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
  85
  86         return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev);
  87 }
  88
  89 static int vti_rcv_proto(struct sk_buff *skb)
  90 {
  91         return vti_rcv(skb, 0, false);
  92 }
  93
  94 static int vti_rcv_tunnel(struct sk_buff *skb)
  95 {
  96         return vti_rcv(skb, ip_hdr(skb)->saddr, true);
  97 }
  98
  99 static int vti_rcv_cb(struct sk_buff *skb, int err)
 100 {
 101         unsigned short family;
 102         struct net_device *dev;
 103         struct pcpu_sw_netstats *tstats;
 104         struct xfrm_state *x;
 105         const struct xfrm_mode *inner_mode;
 106         struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
 107         u32 orig_mark = skb->mark;
 108         int ret;
 109
 110         if (!tunnel)
 111                 return 1;
 112
 113         dev = tunnel->dev;
 114
 115         if (err) {
 116                 dev->stats.rx_errors++;
 117                 dev->stats.rx_dropped++;
 118
 119                 return 0;
 120         }
 121
 122         x = xfrm_input_state(skb);
 123
 124         inner_mode = &x->inner_mode;
 125
 126         if (x->sel.family == AF_UNSPEC) {
 127                 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 128                 if (inner_mode == NULL) {
 129                         XFRM_INC_STATS(dev_net(skb->dev),
 130                                        LINUX_MIB_XFRMINSTATEMODEERROR);
 131                         return -EINVAL;
 132                 }
 133         }
 134
 135         family = inner_mode->family;
 136
 137         skb->mark = be32_to_cpu(tunnel->parms.i_key);
 138         ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
 139         skb->mark = orig_mark;
 140
 141         if (!ret)
 142                 return -EPERM;
 143
 144         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
 145         skb->dev = dev;
 146
 147         tstats = this_cpu_ptr(dev->tstats);
 148
 149         u64_stats_update_begin(&tstats->syncp);
 150         tstats->rx_packets++;
 151         tstats->rx_bytes += skb->len;
 152         u64_stats_update_end(&tstats->syncp);
 153
 154         return 0;
 155 }
 156
 157 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
 158 {
 159         xfrm_address_t *daddr = (xfrm_address_t *)&dst;
 160         xfrm_address_t *saddr = (xfrm_address_t *)&src;
 161
 162         /* if there is no transform then this tunnel is not functional.
 163          * Or if the xfrm is not mode tunnel.
 164          */
 165         if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
 166             x->props.family != AF_INET)
 167                 return false;
 168
 169         if (!dst)
 170                 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
 171
 172         if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
 173                 return false;
 174
 175         return true;
 176 }
 177
 178 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 179                             struct flowi *fl)
 180 {
 181         struct ip_tunnel *tunnel = netdev_priv(dev);
 182         struct ip_tunnel_parm *parms = &tunnel->parms;
 183         struct dst_entry *dst = skb_dst(skb);
 184         struct net_device *tdev;        /* Device to other host */
 185         int pkt_len = skb->len;
 186         int err;
 187         int mtu;
 188
 189         if (!dst) {
 190                 struct rtable *rt;
 191
 192                 fl->u.ip4.flowi4_oif = dev->ifindex;
 193                 fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 194                 rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
 195                 if (IS_ERR(rt)) {
 196                         dev->stats.tx_carrier_errors++;
 197                         goto tx_error_icmp;
 198                 }
 199                 dst = &rt->dst;
 200                 skb_dst_set(skb, dst);
 201         }
 202
 203         dst_hold(dst);
 204         dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
 205         if (IS_ERR(dst)) {
 206                 dev->stats.tx_carrier_errors++;
 207                 goto tx_error_icmp;
 208         }
 209
 210         if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
 211                 dev->stats.tx_carrier_errors++;
 212                 dst_release(dst);
 213                 goto tx_error_icmp;
 214         }
 215
 216         tdev = dst->dev;
 217
 218         if (tdev == dev) {
 219                 dst_release(dst);
 220                 dev->stats.collisions++;
 221                 goto tx_error;
 222         }
 223
 224         mtu = dst_mtu(dst);
 225         if (skb->len > mtu) {
 226                 skb_dst_update_pmtu_no_confirm(skb, mtu);
 227                 if (skb->protocol == htons(ETH_P_IP)) {
 228                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 229                                   htonl(mtu));
 230                 } else {
 231                         if (mtu < IPV6_MIN_MTU)
 232                                 mtu = IPV6_MIN_MTU;
 233
 234                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 235                 }
 236
 237                 dst_release(dst);
 238                 goto tx_error;
 239         }
 240
 241         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 242         skb_dst_set(skb, dst);
 243         skb->dev = skb_dst(skb)->dev;
 244
 245         err = dst_output(tunnel->net, skb->sk, skb);
 246         if (net_xmit_eval(err) == 0)
 247                 err = pkt_len;
 248         iptunnel_xmit_stats(dev, err);
 249         return NETDEV_TX_OK;
 250
 251 tx_error_icmp:
 252         dst_link_failure(skb);
 253 tx_error:
 254         dev->stats.tx_errors++;
 255         kfree_skb(skb);
 256         return NETDEV_TX_OK;
 257 }
 258
 259 /* This function assumes it is being called from dev_queue_xmit()
 260  * and that skb is filled properly by that function.
 261  */
 262 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 263 {
 264         struct ip_tunnel *tunnel = netdev_priv(dev);
 265         struct flowi fl;
 266
 267         if (!pskb_inet_may_pull(skb))
 268                 goto tx_err;
 269
 270         memset(&fl, 0, sizeof(fl));
 271
 272         switch (skb->protocol) {
 273         case htons(ETH_P_IP):
 274                 xfrm_decode_session(skb, &fl, AF_INET);
 275                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 276                 break;
 277         case htons(ETH_P_IPV6):
 278                 xfrm_decode_session(skb, &fl, AF_INET6);
 279                 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
 280                 break;
 281         default:
 282                 goto tx_err;
 283         }
 284
 285         /* override mark with tunnel output key */
 286         fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
 287
 288         return vti_xmit(skb, dev, &fl);
 289
 290 tx_err:
 291         dev->stats.tx_errors++;
 292         kfree_skb(skb);
 293         return NETDEV_TX_OK;
 294 }
 295
 296 static int vti4_err(struct sk_buff *skb, u32 info)
 297 {
 298         __be32 spi;
 299         __u32 mark;
 300         struct xfrm_state *x;
 301         struct ip_tunnel *tunnel;
 302         struct ip_esp_hdr *esph;
 303         struct ip_auth_hdr *ah ;
 304         struct ip_comp_hdr *ipch;
 305         struct net *net = dev_net(skb->dev);
 306         const struct iphdr *iph = (const struct iphdr *)skb->data;
 307         int protocol = iph->protocol;
 308         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
 309
 310         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
 311                                   iph->daddr, iph->saddr, 0);
 312         if (!tunnel)
 313                 return -1;
 314
 315         mark = be32_to_cpu(tunnel->parms.o_key);
 316
 317         switch (protocol) {
 318         case IPPROTO_ESP:
 319                 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
 320                 spi = esph->spi;
 321                 break;
 322         case IPPROTO_AH:
 323                 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
 324                 spi = ah->spi;
 325                 break;
 326         case IPPROTO_COMP:
 327                 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
 328                 spi = htonl(ntohs(ipch->cpi));
 329                 break;
 330         default:
 331                 return 0;
 332         }
 333
 334         switch (icmp_hdr(skb)->type) {
 335         case ICMP_DEST_UNREACH:
 336                 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
 337                         return 0;
 338         case ICMP_REDIRECT:
 339                 break;
 340         default:
 341                 return 0;
 342         }
 343
 344         x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 345                               spi, protocol, AF_INET);
 346         if (!x)
 347                 return 0;
 348
 349         if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 350                 ipv4_update_pmtu(skb, net, info, 0, protocol);
 351         else
 352                 ipv4_redirect(skb, net, 0, protocol);
 353         xfrm_state_put(x);
 354
 355         return 0;
 356 }
 357
 358 static int
 359 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 360 {
 361         int err = 0;
 362         struct ip_tunnel_parm p;
 363
 364         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 365                 return -EFAULT;
 366
 367         if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
 368                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
 369                     p.iph.ihl != 5)
 370                         return -EINVAL;
 371         }
 372
 373         if (!(p.i_flags & GRE_KEY))
 374                 p.i_key = 0;
 375         if (!(p.o_flags & GRE_KEY))
 376                 p.o_key = 0;
 377
 378         p.i_flags = VTI_ISVTI;
 379
 380         err = ip_tunnel_ioctl(dev, &p, cmd);
 381         if (err)
 382                 return err;
 383
 384         if (cmd != SIOCDELTUNNEL) {
 385                 p.i_flags |= GRE_KEY;
 386                 p.o_flags |= GRE_KEY;
 387         }
 388
 389         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 390                 return -EFAULT;
 391         return 0;
 392 }
 393
 394 static const struct net_device_ops vti_netdev_ops = {
 395         .ndo_init       = vti_tunnel_init,
 396         .ndo_uninit     = ip_tunnel_uninit,
 397         .ndo_start_xmit = vti_tunnel_xmit,
 398         .ndo_do_ioctl   = vti_tunnel_ioctl,
 399         .ndo_change_mtu = ip_tunnel_change_mtu,
 400         .ndo_get_stats64 = ip_tunnel_get_stats64,
 401         .ndo_get_iflink = ip_tunnel_get_iflink,
 402 };
 403
 404 static void vti_tunnel_setup(struct net_device *dev)
 405 {
 406         dev->netdev_ops         = &vti_netdev_ops;
 407         dev->type               = ARPHRD_TUNNEL;
 408         ip_tunnel_setup(dev, vti_net_id);
 409 }
 410
 411 static int vti_tunnel_init(struct net_device *dev)
 412 {
 413         struct ip_tunnel *tunnel = netdev_priv(dev);
 414         struct iphdr *iph = &tunnel->parms.iph;
 415
 416         memcpy(dev->dev_addr, &iph->saddr, 4);
 417         memcpy(dev->broadcast, &iph->daddr, 4);
 418
 419         dev->flags              = IFF_NOARP;
 420         dev->addr_len           = 4;
 421         dev->features           |= NETIF_F_LLTX;
 422         netif_keep_dst(dev);
 423
 424         return ip_tunnel_init(dev);
 425 }
 426
 427 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
 428 {
 429         struct ip_tunnel *tunnel = netdev_priv(dev);
 430         struct iphdr *iph = &tunnel->parms.iph;
 431
 432         iph->version            = 4;
 433         iph->protocol           = IPPROTO_IPIP;
 434         iph->ihl                = 5;
 435 }
 436
 437 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
 438         .handler        =       vti_rcv_proto,
 439         .input_handler  =       vti_input_proto,
 440         .cb_handler     =       vti_rcv_cb,
 441         .err_handler    =       vti4_err,
 442         .priority       =       100,
 443 };
 444
 445 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
 446         .handler        =       vti_rcv_proto,
 447         .input_handler  =       vti_input_proto,
 448         .cb_handler     =       vti_rcv_cb,
 449         .err_handler    =       vti4_err,
 450         .priority       =       100,
 451 };
 452
 453 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
 454         .handler        =       vti_rcv_proto,
 455         .input_handler  =       vti_input_proto,
 456         .cb_handler     =       vti_rcv_cb,
 457         .err_handler    =       vti4_err,
 458         .priority       =       100,
 459 };
 460
 461 static struct xfrm_tunnel ipip_handler __read_mostly = {
 462         .handler        =       vti_rcv_tunnel,
 463         .err_handler    =       vti4_err,
 464         .priority       =       0,
 465 };
 466
 467 static int __net_init vti_init_net(struct net *net)
 468 {
 469         int err;
 470         struct ip_tunnel_net *itn;
 471
 472         err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
 473         if (err)
 474                 return err;
 475         itn = net_generic(net, vti_net_id);
 476         if (itn->fb_tunnel_dev)
 477                 vti_fb_tunnel_init(itn->fb_tunnel_dev);
 478         return 0;
 479 }
 480
 481 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
 482 {
 483         ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
 484 }
 485
 486 static struct pernet_operations vti_net_ops = {
 487         .init = vti_init_net,
 488         .exit_batch = vti_exit_batch_net,
 489         .id   = &vti_net_id,
 490         .size = sizeof(struct ip_tunnel_net),
 491 };
 492
 493 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
 494                                struct netlink_ext_ack *extack)
 495 {
 496         return 0;
 497 }
 498
 499 static void vti_netlink_parms(struct nlattr *data[],
 500                               struct ip_tunnel_parm *parms,
 501                               __u32 *fwmark)
 502 {
 503         memset(parms, 0, sizeof(*parms));
 504
 505         parms->iph.protocol = IPPROTO_IPIP;
 506
 507         if (!data)
 508                 return;
 509
 510         parms->i_flags = VTI_ISVTI;
 511
 512         if (data[IFLA_VTI_LINK])
 513                 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
 514
 515         if (data[IFLA_VTI_IKEY])
 516                 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
 517
 518         if (data[IFLA_VTI_OKEY])
 519                 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
 520
 521         if (data[IFLA_VTI_LOCAL])
 522                 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
 523
 524         if (data[IFLA_VTI_REMOTE])
 525                 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
 526
 527         if (data[IFLA_VTI_FWMARK])
 528                 *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 529 }
 530
 531 static int vti_newlink(struct net *src_net, struct net_device *dev,
 532                        struct nlattr *tb[], struct nlattr *data[],
 533                        struct netlink_ext_ack *extack)
 534 {
 535         struct ip_tunnel_parm parms;
 536         __u32 fwmark = 0;
 537
 538         vti_netlink_parms(data, &parms, &fwmark);
 539         return ip_tunnel_newlink(dev, tb, &parms, fwmark);
 540 }
 541
 542 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
 543                           struct nlattr *data[],
 544                           struct netlink_ext_ack *extack)
 545 {
 546         struct ip_tunnel *t = netdev_priv(dev);
 547         __u32 fwmark = t->fwmark;
 548         struct ip_tunnel_parm p;
 549
 550         vti_netlink_parms(data, &p, &fwmark);
 551         return ip_tunnel_changelink(dev, tb, &p, fwmark);
 552 }
 553
 554 static size_t vti_get_size(const struct net_device *dev)
 555 {
 556         return
 557                 /* IFLA_VTI_LINK */
 558                 nla_total_size(4) +
 559                 /* IFLA_VTI_IKEY */
 560                 nla_total_size(4) +
 561                 /* IFLA_VTI_OKEY */
 562                 nla_total_size(4) +
 563                 /* IFLA_VTI_LOCAL */
 564                 nla_total_size(4) +
 565                 /* IFLA_VTI_REMOTE */
 566                 nla_total_size(4) +
 567                 /* IFLA_VTI_FWMARK */
 568                 nla_total_size(4) +
 569                 0;
 570 }
 571
 572 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
 573 {
 574         struct ip_tunnel *t = netdev_priv(dev);
 575         struct ip_tunnel_parm *p = &t->parms;
 576
 577         if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
 578             nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
 579             nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
 580             nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
 581             nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
 582             nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
 583                 return -EMSGSIZE;
 584
 585         return 0;
 586 }
 587
 588 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
 589         [IFLA_VTI_LINK]         = { .type = NLA_U32 },
 590         [IFLA_VTI_IKEY]         = { .type = NLA_U32 },
 591         [IFLA_VTI_OKEY]         = { .type = NLA_U32 },
 592         [IFLA_VTI_LOCAL]        = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
 593         [IFLA_VTI_REMOTE]       = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
 594         [IFLA_VTI_FWMARK]       = { .type = NLA_U32 },
 595 };
 596
 597 static struct rtnl_link_ops vti_link_ops __read_mostly = {
 598         .kind           = "vti",
 599         .maxtype        = IFLA_VTI_MAX,
 600         .policy         = vti_policy,
 601         .priv_size      = sizeof(struct ip_tunnel),
 602         .setup          = vti_tunnel_setup,
 603         .validate       = vti_tunnel_validate,
 604         .newlink        = vti_newlink,
 605         .changelink     = vti_changelink,
 606         .dellink        = ip_tunnel_dellink,
 607         .get_size       = vti_get_size,
 608         .fill_info      = vti_fill_info,
 609         .get_link_net   = ip_tunnel_get_link_net,
 610 };
 611
 612 static int __init vti_init(void)
 613 {
 614         const char *msg;
 615         int err;
 616
 617         pr_info("IPv4 over IPsec tunneling driver\n");
 618
 619         msg = "tunnel device";
 620         err = register_pernet_device(&vti_net_ops);
 621         if (err < 0)
 622                 goto pernet_dev_failed;
 623
 624         msg = "tunnel protocols";
 625         err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
 626         if (err < 0)
 627                 goto xfrm_proto_esp_failed;
 628         err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
 629         if (err < 0)
 630                 goto xfrm_proto_ah_failed;
 631         err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
 632         if (err < 0)
 633                 goto xfrm_proto_comp_failed;
 634
 635         msg = "ipip tunnel";
 636         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
 637         if (err < 0)
 638                 goto xfrm_tunnel_failed;
 639
 640         msg = "netlink interface";
 641         err = rtnl_link_register(&vti_link_ops);
 642         if (err < 0)
 643                 goto rtnl_link_failed;
 644
 645         return err;
 646
 647 rtnl_link_failed:
 648         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
 649 xfrm_tunnel_failed:
 650         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 651 xfrm_proto_comp_failed:
 652         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 653 xfrm_proto_ah_failed:
 654         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 655 xfrm_proto_esp_failed:
 656         unregister_pernet_device(&vti_net_ops);
 657 pernet_dev_failed:
 658         pr_err("vti init: failed to register %s\n", msg);
 659         return err;
 660 }
 661
 662 static void __exit vti_fini(void)
 663 {
 664         rtnl_link_unregister(&vti_link_ops);
 665         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
 666         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 667         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 668         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 669         unregister_pernet_device(&vti_net_ops);
 670 }
 671
 672 module_init(vti_init);
 673 module_exit(vti_fini);
 674 MODULE_LICENSE("GPL");
 675 MODULE_ALIAS_RTNL_LINK("vti");
 676 MODULE_ALIAS_NETDEV("ip_vti0");