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_input_ipip(struct sk_buff *skb, int nexthdr, __be32 spi,
  78                      int encap_type)
  79 {
  80         struct ip_tunnel *tunnel;
  81         const struct iphdr *iph = ip_hdr(skb);
  82         struct net *net = dev_net(skb->dev);
  83         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
  84
  85         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
  86                                   iph->saddr, iph->daddr, 0);
  87         if (tunnel) {
  88                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
  89                         goto drop;
  90
  91                 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
  92
  93                 skb->dev = tunnel->dev;
  94
  95                 return xfrm_input(skb, nexthdr, spi, encap_type);
  96         }
  97
  98         return -EINVAL;
  99 drop:
 100         kfree_skb(skb);
 101         return 0;
 102 }
 103
 104 static int vti_rcv(struct sk_buff *skb)
 105 {
 106         XFRM_SPI_SKB_CB(skb)->family = AF_INET;
 107         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
 108
 109         return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
 110 }
 111
 112 static int vti_rcv_ipip(struct sk_buff *skb)
 113 {
 114         XFRM_SPI_SKB_CB(skb)->family = AF_INET;
 115         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
 116
 117         return vti_input_ipip(skb, ip_hdr(skb)->protocol, ip_hdr(skb)->saddr, 0);
 118 }
 119
 120 static int vti_rcv_cb(struct sk_buff *skb, int err)
 121 {
 122         unsigned short family;
 123         struct net_device *dev;
 124         struct pcpu_sw_netstats *tstats;
 125         struct xfrm_state *x;
 126         struct xfrm_mode *inner_mode;
 127         struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
 128         u32 orig_mark = skb->mark;
 129         int ret;
 130
 131         if (!tunnel)
 132                 return 1;
 133
 134         dev = tunnel->dev;
 135
 136         if (err) {
 137                 dev->stats.rx_errors++;
 138                 dev->stats.rx_dropped++;
 139
 140                 return 0;
 141         }
 142
 143         x = xfrm_input_state(skb);
 144
 145         inner_mode = x->inner_mode;
 146
 147         if (x->sel.family == AF_UNSPEC) {
 148                 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 149                 if (inner_mode == NULL) {
 150                         XFRM_INC_STATS(dev_net(skb->dev),
 151                                        LINUX_MIB_XFRMINSTATEMODEERROR);
 152                         return -EINVAL;
 153                 }
 154         }
 155
 156         family = inner_mode->afinfo->family;
 157
 158         skb->mark = be32_to_cpu(tunnel->parms.i_key);
 159         ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
 160         skb->mark = orig_mark;
 161
 162         if (!ret)
 163                 return -EPERM;
 164
 165         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
 166         skb->dev = dev;
 167
 168         tstats = this_cpu_ptr(dev->tstats);
 169
 170         u64_stats_update_begin(&tstats->syncp);
 171         tstats->rx_packets++;
 172         tstats->rx_bytes += skb->len;
 173         u64_stats_update_end(&tstats->syncp);
 174
 175         return 0;
 176 }
 177
 178 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
 179 {
 180         xfrm_address_t *daddr = (xfrm_address_t *)&dst;
 181         xfrm_address_t *saddr = (xfrm_address_t *)&src;
 182
 183         /* if there is no transform then this tunnel is not functional.
 184          * Or if the xfrm is not mode tunnel.
 185          */
 186         if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
 187             x->props.family != AF_INET)
 188                 return false;
 189
 190         if (!dst)
 191                 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
 192
 193         if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
 194                 return false;
 195
 196         return true;
 197 }
 198
 199 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 200                             struct flowi *fl)
 201 {
 202         struct ip_tunnel *tunnel = netdev_priv(dev);
 203         struct ip_tunnel_parm *parms = &tunnel->parms;
 204         struct dst_entry *dst = skb_dst(skb);
 205         struct net_device *tdev;        /* Device to other host */
 206         int pkt_len = skb->len;
 207         int err;
 208         int mtu;
 209
 210         if (!dst) {
 211                 dev->stats.tx_carrier_errors++;
 212                 goto tx_error_icmp;
 213         }
 214
 215         dst_hold(dst);
 216         dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
 217         if (IS_ERR(dst)) {
 218                 dev->stats.tx_carrier_errors++;
 219                 goto tx_error_icmp;
 220         }
 221
 222         if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
 223                 dev->stats.tx_carrier_errors++;
 224                 dst_release(dst);
 225                 goto tx_error_icmp;
 226         }
 227
 228         tdev = dst->dev;
 229
 230         if (tdev == dev) {
 231                 dst_release(dst);
 232                 dev->stats.collisions++;
 233                 goto tx_error;
 234         }
 235
 236         mtu = dst_mtu(dst);
 237         if (skb->len > mtu) {
 238                 skb_dst_update_pmtu(skb, mtu);
 239                 if (skb->protocol == htons(ETH_P_IP)) {
 240                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 241                                   htonl(mtu));
 242                 } else {
 243                         if (mtu < IPV6_MIN_MTU)
 244                                 mtu = IPV6_MIN_MTU;
 245
 246                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 247                 }
 248
 249                 dst_release(dst);
 250                 goto tx_error;
 251         }
 252
 253         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 254         skb_dst_set(skb, dst);
 255         skb->dev = skb_dst(skb)->dev;
 256
 257         err = dst_output(tunnel->net, skb->sk, skb);
 258         if (net_xmit_eval(err) == 0)
 259                 err = pkt_len;
 260         iptunnel_xmit_stats(dev, err);
 261         return NETDEV_TX_OK;
 262
 263 tx_error_icmp:
 264         dst_link_failure(skb);
 265 tx_error:
 266         dev->stats.tx_errors++;
 267         kfree_skb(skb);
 268         return NETDEV_TX_OK;
 269 }
 270
 271 /* This function assumes it is being called from dev_queue_xmit()
 272  * and that skb is filled properly by that function.
 273  */
 274 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 275 {
 276         struct ip_tunnel *tunnel = netdev_priv(dev);
 277         struct flowi fl;
 278
 279         if (!pskb_inet_may_pull(skb))
 280                 goto tx_err;
 281
 282         memset(&fl, 0, sizeof(fl));
 283
 284         switch (skb->protocol) {
 285         case htons(ETH_P_IP):
 286                 xfrm_decode_session(skb, &fl, AF_INET);
 287                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 288                 break;
 289         case htons(ETH_P_IPV6):
 290                 xfrm_decode_session(skb, &fl, AF_INET6);
 291                 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
 292                 break;
 293         default:
 294                 goto tx_err;
 295         }
 296
 297         /* override mark with tunnel output key */
 298         fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
 299
 300         return vti_xmit(skb, dev, &fl);
 301
 302 tx_err:
 303         dev->stats.tx_errors++;
 304         kfree_skb(skb);
 305         return NETDEV_TX_OK;
 306 }
 307
 308 static int vti4_err(struct sk_buff *skb, u32 info)
 309 {
 310         __be32 spi;
 311         __u32 mark;
 312         struct xfrm_state *x;
 313         struct ip_tunnel *tunnel;
 314         struct ip_esp_hdr *esph;
 315         struct ip_auth_hdr *ah ;
 316         struct ip_comp_hdr *ipch;
 317         struct net *net = dev_net(skb->dev);
 318         const struct iphdr *iph = (const struct iphdr *)skb->data;
 319         int protocol = iph->protocol;
 320         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
 321
 322         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
 323                                   iph->daddr, iph->saddr, 0);
 324         if (!tunnel)
 325                 return -1;
 326
 327         mark = be32_to_cpu(tunnel->parms.o_key);
 328
 329         switch (protocol) {
 330         case IPPROTO_ESP:
 331                 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
 332                 spi = esph->spi;
 333                 break;
 334         case IPPROTO_AH:
 335                 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
 336                 spi = ah->spi;
 337                 break;
 338         case IPPROTO_COMP:
 339                 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
 340                 spi = htonl(ntohs(ipch->cpi));
 341                 break;
 342         default:
 343                 return 0;
 344         }
 345
 346         switch (icmp_hdr(skb)->type) {
 347         case ICMP_DEST_UNREACH:
 348                 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
 349                         return 0;
 350         case ICMP_REDIRECT:
 351                 break;
 352         default:
 353                 return 0;
 354         }
 355
 356         x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 357                               spi, protocol, AF_INET);
 358         if (!x)
 359                 return 0;
 360
 361         if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 362                 ipv4_update_pmtu(skb, net, info, 0, protocol);
 363         else
 364                 ipv4_redirect(skb, net, 0, protocol);
 365         xfrm_state_put(x);
 366
 367         return 0;
 368 }
 369
 370 static int
 371 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 372 {
 373         int err = 0;
 374         struct ip_tunnel_parm p;
 375
 376         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 377                 return -EFAULT;
 378
 379         if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
 380                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
 381                     p.iph.ihl != 5)
 382                         return -EINVAL;
 383         }
 384
 385         if (!(p.i_flags & GRE_KEY))
 386                 p.i_key = 0;
 387         if (!(p.o_flags & GRE_KEY))
 388                 p.o_key = 0;
 389
 390         p.i_flags = VTI_ISVTI;
 391
 392         err = ip_tunnel_ioctl(dev, &p, cmd);
 393         if (err)
 394                 return err;
 395
 396         if (cmd != SIOCDELTUNNEL) {
 397                 p.i_flags |= GRE_KEY;
 398                 p.o_flags |= GRE_KEY;
 399         }
 400
 401         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 402                 return -EFAULT;
 403         return 0;
 404 }
 405
 406 static const struct net_device_ops vti_netdev_ops = {
 407         .ndo_init       = vti_tunnel_init,
 408         .ndo_uninit     = ip_tunnel_uninit,
 409         .ndo_start_xmit = vti_tunnel_xmit,
 410         .ndo_do_ioctl   = vti_tunnel_ioctl,
 411         .ndo_change_mtu = ip_tunnel_change_mtu,
 412         .ndo_get_stats64 = ip_tunnel_get_stats64,
 413         .ndo_get_iflink = ip_tunnel_get_iflink,
 414 };
 415
 416 static void vti_tunnel_setup(struct net_device *dev)
 417 {
 418         dev->netdev_ops         = &vti_netdev_ops;
 419         dev->type               = ARPHRD_TUNNEL;
 420         ip_tunnel_setup(dev, vti_net_id);
 421 }
 422
 423 static int vti_tunnel_init(struct net_device *dev)
 424 {
 425         struct ip_tunnel *tunnel = netdev_priv(dev);
 426         struct iphdr *iph = &tunnel->parms.iph;
 427
 428         memcpy(dev->dev_addr, &iph->saddr, 4);
 429         memcpy(dev->broadcast, &iph->daddr, 4);
 430
 431         dev->flags              = IFF_NOARP;
 432         dev->addr_len           = 4;
 433         dev->features           |= NETIF_F_LLTX;
 434         netif_keep_dst(dev);
 435
 436         return ip_tunnel_init(dev);
 437 }
 438
 439 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
 440 {
 441         struct ip_tunnel *tunnel = netdev_priv(dev);
 442         struct iphdr *iph = &tunnel->parms.iph;
 443
 444         iph->version            = 4;
 445         iph->protocol           = IPPROTO_IPIP;
 446         iph->ihl                = 5;
 447 }
 448
 449 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
 450         .handler        =       vti_rcv,
 451         .input_handler  =       vti_input,
 452         .cb_handler     =       vti_rcv_cb,
 453         .err_handler    =       vti4_err,
 454         .priority       =       100,
 455 };
 456
 457 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
 458         .handler        =       vti_rcv,
 459         .input_handler  =       vti_input,
 460         .cb_handler     =       vti_rcv_cb,
 461         .err_handler    =       vti4_err,
 462         .priority       =       100,
 463 };
 464
 465 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
 466         .handler        =       vti_rcv,
 467         .input_handler  =       vti_input,
 468         .cb_handler     =       vti_rcv_cb,
 469         .err_handler    =       vti4_err,
 470         .priority       =       100,
 471 };
 472
 473 static struct xfrm_tunnel ipip_handler __read_mostly = {
 474         .handler        =       vti_rcv_ipip,
 475         .err_handler    =       vti4_err,
 476         .priority       =       0,
 477 };
 478
 479 static int __net_init vti_init_net(struct net *net)
 480 {
 481         int err;
 482         struct ip_tunnel_net *itn;
 483
 484         err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
 485         if (err)
 486                 return err;
 487         itn = net_generic(net, vti_net_id);
 488         if (itn->fb_tunnel_dev)
 489                 vti_fb_tunnel_init(itn->fb_tunnel_dev);
 490         return 0;
 491 }
 492
 493 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
 494 {
 495         ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
 496 }
 497
 498 static struct pernet_operations vti_net_ops = {
 499         .init = vti_init_net,
 500         .exit_batch = vti_exit_batch_net,
 501         .id   = &vti_net_id,
 502         .size = sizeof(struct ip_tunnel_net),
 503 };
 504
 505 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
 506                                struct netlink_ext_ack *extack)
 507 {
 508         return 0;
 509 }
 510
 511 static void vti_netlink_parms(struct nlattr *data[],
 512                               struct ip_tunnel_parm *parms,
 513                               __u32 *fwmark)
 514 {
 515         memset(parms, 0, sizeof(*parms));
 516
 517         parms->iph.protocol = IPPROTO_IPIP;
 518
 519         if (!data)
 520                 return;
 521
 522         parms->i_flags = VTI_ISVTI;
 523
 524         if (data[IFLA_VTI_LINK])
 525                 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
 526
 527         if (data[IFLA_VTI_IKEY])
 528                 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
 529
 530         if (data[IFLA_VTI_OKEY])
 531                 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
 532
 533         if (data[IFLA_VTI_LOCAL])
 534                 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
 535
 536         if (data[IFLA_VTI_REMOTE])
 537                 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
 538
 539         if (data[IFLA_VTI_FWMARK])
 540                 *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 541 }
 542
 543 static int vti_newlink(struct net *src_net, struct net_device *dev,
 544                        struct nlattr *tb[], struct nlattr *data[],
 545                        struct netlink_ext_ack *extack)
 546 {
 547         struct ip_tunnel_parm parms;
 548         __u32 fwmark = 0;
 549
 550         vti_netlink_parms(data, &parms, &fwmark);
 551         return ip_tunnel_newlink(dev, tb, &parms, fwmark);
 552 }
 553
 554 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
 555                           struct nlattr *data[],
 556                           struct netlink_ext_ack *extack)
 557 {
 558         struct ip_tunnel *t = netdev_priv(dev);
 559         __u32 fwmark = t->fwmark;
 560         struct ip_tunnel_parm p;
 561
 562         vti_netlink_parms(data, &p, &fwmark);
 563         return ip_tunnel_changelink(dev, tb, &p, fwmark);
 564 }
 565
 566 static size_t vti_get_size(const struct net_device *dev)
 567 {
 568         return
 569                 /* IFLA_VTI_LINK */
 570                 nla_total_size(4) +
 571                 /* IFLA_VTI_IKEY */
 572                 nla_total_size(4) +
 573                 /* IFLA_VTI_OKEY */
 574                 nla_total_size(4) +
 575                 /* IFLA_VTI_LOCAL */
 576                 nla_total_size(4) +
 577                 /* IFLA_VTI_REMOTE */
 578                 nla_total_size(4) +
 579                 /* IFLA_VTI_FWMARK */
 580                 nla_total_size(4) +
 581                 0;
 582 }
 583
 584 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
 585 {
 586         struct ip_tunnel *t = netdev_priv(dev);
 587         struct ip_tunnel_parm *p = &t->parms;
 588
 589         if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
 590             nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
 591             nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
 592             nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
 593             nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
 594             nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
 595                 return -EMSGSIZE;
 596
 597         return 0;
 598 }
 599
 600 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
 601         [IFLA_VTI_LINK]         = { .type = NLA_U32 },
 602         [IFLA_VTI_IKEY]         = { .type = NLA_U32 },
 603         [IFLA_VTI_OKEY]         = { .type = NLA_U32 },
 604         [IFLA_VTI_LOCAL]        = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
 605         [IFLA_VTI_REMOTE]       = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
 606         [IFLA_VTI_FWMARK]       = { .type = NLA_U32 },
 607 };
 608
 609 static struct rtnl_link_ops vti_link_ops __read_mostly = {
 610         .kind           = "vti",
 611         .maxtype        = IFLA_VTI_MAX,
 612         .policy         = vti_policy,
 613         .priv_size      = sizeof(struct ip_tunnel),
 614         .setup          = vti_tunnel_setup,
 615         .validate       = vti_tunnel_validate,
 616         .newlink        = vti_newlink,
 617         .changelink     = vti_changelink,
 618         .dellink        = ip_tunnel_dellink,
 619         .get_size       = vti_get_size,
 620         .fill_info      = vti_fill_info,
 621         .get_link_net   = ip_tunnel_get_link_net,
 622 };
 623
 624 static int __init vti_init(void)
 625 {
 626         const char *msg;
 627         int err;
 628
 629         pr_info("IPv4 over IPsec tunneling driver\n");
 630
 631         msg = "tunnel device";
 632         err = register_pernet_device(&vti_net_ops);
 633         if (err < 0)
 634                 goto pernet_dev_failed;
 635
 636         msg = "tunnel protocols";
 637         err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
 638         if (err < 0)
 639                 goto xfrm_proto_esp_failed;
 640         err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
 641         if (err < 0)
 642                 goto xfrm_proto_ah_failed;
 643         err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
 644         if (err < 0)
 645                 goto xfrm_proto_comp_failed;
 646
 647         msg = "ipip tunnel";
 648         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
 649         if (err < 0) {
 650                 pr_info("%s: cant't register tunnel\n",__func__);
 651                 goto xfrm_tunnel_failed;
 652         }
 653
 654         msg = "netlink interface";
 655         err = rtnl_link_register(&vti_link_ops);
 656         if (err < 0)
 657                 goto rtnl_link_failed;
 658
 659         return err;
 660
 661 rtnl_link_failed:
 662         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 663 xfrm_tunnel_failed:
 664         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
 665 xfrm_proto_comp_failed:
 666         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 667 xfrm_proto_ah_failed:
 668         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 669 xfrm_proto_esp_failed:
 670         unregister_pernet_device(&vti_net_ops);
 671 pernet_dev_failed:
 672         pr_err("vti init: failed to register %s\n", msg);
 673         return err;
 674 }
 675
 676 static void __exit vti_fini(void)
 677 {
 678         rtnl_link_unregister(&vti_link_ops);
 679         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 680         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 681         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 682         unregister_pernet_device(&vti_net_ops);
 683 }
 684
 685 module_init(vti_init);
 686 module_exit(vti_fini);
 687 MODULE_LICENSE("GPL");
 688 MODULE_ALIAS_RTNL_LINK("vti");
 689 MODULE_ALIAS_NETDEV("ip_vti0");