net/ipv4/ip_gre.c

   1 /*
   2  *      Linux NET3:     GRE over IP protocol decoder.
   3  *
   4  *      Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/capability.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/slab.h>
  20 #include <asm/uaccess.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/in.h>
  24 #include <linux/tcp.h>
  25 #include <linux/udp.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/mroute.h>
  28 #include <linux/init.h>
  29 #include <linux/in6.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/igmp.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/etherdevice.h>
  34 #include <linux/if_ether.h>
  35
  36 #include <net/sock.h>
  37 #include <net/ip.h>
  38 #include <net/icmp.h>
  39 #include <net/protocol.h>
  40 #include <net/ip_tunnels.h>
  41 #include <net/arp.h>
  42 #include <net/checksum.h>
  43 #include <net/dsfield.h>
  44 #include <net/inet_ecn.h>
  45 #include <net/xfrm.h>
  46 #include <net/net_namespace.h>
  47 #include <net/netns/generic.h>
  48 #include <net/rtnetlink.h>
  49 #include <net/gre.h>
  50
  51 #if IS_ENABLED(CONFIG_IPV6)
  52 #include <net/ipv6.h>
  53 #include <net/ip6_fib.h>
  54 #include <net/ip6_route.h>
  55 #endif
  56
  57 /*
  58    Problems & solutions
  59    --------------------
  60
  61    1. The most important issue is detecting local dead loops.
  62    They would cause complete host lockup in transmit, which
  63    would be "resolved" by stack overflow or, if queueing is enabled,
  64    with infinite looping in net_bh.
  65
  66    We cannot track such dead loops during route installation,
  67    it is infeasible task. The most general solutions would be
  68    to keep skb->encapsulation counter (sort of local ttl),
  69    and silently drop packet when it expires. It is a good
  70    solution, but it supposes maintaining new variable in ALL
  71    skb, even if no tunneling is used.
  72
  73    Current solution: xmit_recursion breaks dead loops. This is a percpu
  74    counter, since when we enter the first ndo_xmit(), cpu migration is
  75    forbidden. We force an exit if this counter reaches RECURSION_LIMIT
  76
  77    2. Networking dead loops would not kill routers, but would really
  78    kill network. IP hop limit plays role of "t->recursion" in this case,
  79    if we copy it from packet being encapsulated to upper header.
  80    It is very good solution, but it introduces two problems:
  81
  82    - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
  83      do not work over tunnels.
  84    - traceroute does not work. I planned to relay ICMP from tunnel,
  85      so that this problem would be solved and traceroute output
  86      would even more informative. This idea appeared to be wrong:
  87      only Linux complies to rfc1812 now (yes, guys, Linux is the only
  88      true router now :-)), all routers (at least, in neighbourhood of mine)
  89      return only 8 bytes of payload. It is the end.
  90
  91    Hence, if we want that OSPF worked or traceroute said something reasonable,
  92    we should search for another solution.
  93
  94    One of them is to parse packet trying to detect inner encapsulation
  95    made by our node. It is difficult or even impossible, especially,
  96    taking into account fragmentation. TO be short, ttl is not solution at all.
  97
  98    Current solution: The solution was UNEXPECTEDLY SIMPLE.
  99    We force DF flag on tunnels with preconfigured hop limit,
 100    that is ALL. :-) Well, it does not remove the problem completely,
 101    but exponential growth of network traffic is changed to linear
 102    (branches, that exceed pmtu are pruned) and tunnel mtu
 103    rapidly degrades to value <68, where looping stops.
 104    Yes, it is not good if there exists a router in the loop,
 105    which does not force DF, even when encapsulating packets have DF set.
 106    But it is not our problem! Nobody could accuse us, we made
 107    all that we could make. Even if it is your gated who injected
 108    fatal route to network, even if it were you who configured
 109    fatal static route: you are innocent. :-)
 110
 111    Alexey Kuznetsov.
 112  */
 113
 114 static bool log_ecn_error = true;
 115 module_param(log_ecn_error, bool, 0644);
 116 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 117
 118 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
 119 static int ipgre_tunnel_init(struct net_device *dev);
 120
 121 static int ipgre_net_id __read_mostly;
 122 static int gre_tap_net_id __read_mostly;
 123
 124 static int ipgre_err(struct sk_buff *skb, u32 info,
 125                      const struct tnl_ptk_info *tpi)
 126 {
 127
 128         /* All the routers (except for Linux) return only
 129            8 bytes of packet payload. It means, that precise relaying of
 130            ICMP in the real Internet is absolutely infeasible.
 131
 132            Moreover, Cisco "wise men" put GRE key to the third word
 133            in GRE header. It makes impossible maintaining even soft
 134            state for keyed GRE tunnels with enabled checksum. Tell
 135            them "thank you".
 136
 137            Well, I wonder, rfc1812 was written by Cisco employee,
 138            what the hell these idiots break standards established
 139            by themselves???
 140            */
 141         struct net *net = dev_net(skb->dev);
 142         struct ip_tunnel_net *itn;
 143         const struct iphdr *iph;
 144         const int type = icmp_hdr(skb)->type;
 145         const int code = icmp_hdr(skb)->code;
 146         struct ip_tunnel *t;
 147
 148         switch (type) {
 149         default:
 150         case ICMP_PARAMETERPROB:
 151                 return PACKET_RCVD;
 152
 153         case ICMP_DEST_UNREACH:
 154                 switch (code) {
 155                 case ICMP_SR_FAILED:
 156                 case ICMP_PORT_UNREACH:
 157                         /* Impossible event. */
 158                         return PACKET_RCVD;
 159                 default:
 160                         /* All others are translated to HOST_UNREACH.
 161                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 162                            I believe they are just ether pollution. --ANK
 163                          */
 164                         break;
 165                 }
 166                 break;
 167         case ICMP_TIME_EXCEEDED:
 168                 if (code != ICMP_EXC_TTL)
 169                         return PACKET_RCVD;
 170                 break;
 171
 172         case ICMP_REDIRECT:
 173                 break;
 174         }
 175
 176         if (tpi->proto == htons(ETH_P_TEB))
 177                 itn = net_generic(net, gre_tap_net_id);
 178         else
 179                 itn = net_generic(net, ipgre_net_id);
 180
 181         iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
 182         t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
 183                              iph->daddr, iph->saddr, tpi->key);
 184
 185         if (t == NULL)
 186                 return PACKET_REJECT;
 187
 188         if (t->parms.iph.daddr == 0 ||
 189             ipv4_is_multicast(t->parms.iph.daddr))
 190                 return PACKET_RCVD;
 191
 192         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 193                 return PACKET_RCVD;
 194
 195         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 196                 t->err_count++;
 197         else
 198                 t->err_count = 1;
 199         t->err_time = jiffies;
 200         return PACKET_RCVD;
 201 }
 202
 203 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 204 {
 205         struct net *net = dev_net(skb->dev);
 206         struct ip_tunnel_net *itn;
 207         const struct iphdr *iph;
 208         struct ip_tunnel *tunnel;
 209
 210         if (tpi->proto == htons(ETH_P_TEB))
 211                 itn = net_generic(net, gre_tap_net_id);
 212         else
 213                 itn = net_generic(net, ipgre_net_id);
 214
 215         iph = ip_hdr(skb);
 216         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
 217                                   iph->saddr, iph->daddr, tpi->key);
 218
 219         if (tunnel) {
 220                 skb_pop_mac_header(skb);
 221                 ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);
 222                 return PACKET_RCVD;
 223         }
 224         return PACKET_REJECT;
 225 }
 226
 227 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
 228                        const struct iphdr *tnl_params,
 229                        __be16 proto)
 230 {
 231         struct ip_tunnel *tunnel = netdev_priv(dev);
 232         struct tnl_ptk_info tpi;
 233
 234         tpi.flags = tunnel->parms.o_flags;
 235         tpi.proto = proto;
 236         tpi.key = tunnel->parms.o_key;
 237         if (tunnel->parms.o_flags & TUNNEL_SEQ)
 238                 tunnel->o_seqno++;
 239         tpi.seq = htonl(tunnel->o_seqno);
 240
 241         /* Push GRE header. */
 242         gre_build_header(skb, &tpi, tunnel->hlen);
 243
 244         ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
 245 }
 246
 247 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 248                               struct net_device *dev)
 249 {
 250         struct ip_tunnel *tunnel = netdev_priv(dev);
 251         const struct iphdr *tnl_params;
 252
 253         skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
 254         if (IS_ERR(skb))
 255                 goto out;
 256
 257         if (dev->header_ops) {
 258                 /* Need space for new headers */
 259                 if (skb_cow_head(skb, dev->needed_headroom -
 260                                       (tunnel->hlen + sizeof(struct iphdr))))
 261                         goto free_skb;
 262
 263                 tnl_params = (const struct iphdr *)skb->data;
 264
 265                 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
 266                  * to gre header.
 267                  */
 268                 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
 269         } else {
 270                 if (skb_cow_head(skb, dev->needed_headroom))
 271                         goto free_skb;
 272
 273                 tnl_params = &tunnel->parms.iph;
 274         }
 275
 276         __gre_xmit(skb, dev, tnl_params, skb->protocol);
 277
 278         return NETDEV_TX_OK;
 279
 280 free_skb:
 281         kfree_skb(skb);
 282 out:
 283         dev->stats.tx_dropped++;
 284         return NETDEV_TX_OK;
 285 }
 286
 287 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 288                                 struct net_device *dev)
 289 {
 290         struct ip_tunnel *tunnel = netdev_priv(dev);
 291
 292         skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
 293         if (IS_ERR(skb))
 294                 goto out;
 295
 296         if (skb_cow_head(skb, dev->needed_headroom))
 297                 goto free_skb;
 298
 299         __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
 300
 301         return NETDEV_TX_OK;
 302
 303 free_skb:
 304         kfree_skb(skb);
 305 out:
 306         dev->stats.tx_dropped++;
 307         return NETDEV_TX_OK;
 308 }
 309
 310 static int ipgre_tunnel_ioctl(struct net_device *dev,
 311                               struct ifreq *ifr, int cmd)
 312 {
 313         int err = 0;
 314         struct ip_tunnel_parm p;
 315
 316         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 317                 return -EFAULT;
 318         if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
 319                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
 320                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
 321                     ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
 322                         return -EINVAL;
 323         }
 324         p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
 325         p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
 326
 327         err = ip_tunnel_ioctl(dev, &p, cmd);
 328         if (err)
 329                 return err;
 330
 331         p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
 332         p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
 333
 334         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 335                 return -EFAULT;
 336         return 0;
 337 }
 338
 339 /* Nice toy. Unfortunately, useless in real life :-)
 340    It allows to construct virtual multiprotocol broadcast "LAN"
 341    over the Internet, provided multicast routing is tuned.
 342
 343
 344    I have no idea was this bicycle invented before me,
 345    so that I had to set ARPHRD_IPGRE to a random value.
 346    I have an impression, that Cisco could make something similar,
 347    but this feature is apparently missing in IOS<=11.2(8).
 348
 349    I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
 350    with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
 351
 352    ping -t 255 224.66.66.66
 353
 354    If nobody answers, mbone does not work.
 355
 356    ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
 357    ip addr add 10.66.66.<somewhat>/24 dev Universe
 358    ifconfig Universe up
 359    ifconfig Universe add fe80::<Your_real_addr>/10
 360    ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
 361    ftp 10.66.66.66
 362    ...
 363    ftp fec0:6666:6666::193.233.7.65
 364    ...
 365  */
 366 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
 367                         unsigned short type,
 368                         const void *daddr, const void *saddr, unsigned int len)
 369 {
 370         struct ip_tunnel *t = netdev_priv(dev);
 371         struct iphdr *iph;
 372         struct gre_base_hdr *greh;
 373
 374         iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
 375         greh = (struct gre_base_hdr *)(iph+1);
 376         greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
 377         greh->protocol = htons(type);
 378
 379         memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
 380
 381         /* Set the source hardware address. */
 382         if (saddr)
 383                 memcpy(&iph->saddr, saddr, 4);
 384         if (daddr)
 385                 memcpy(&iph->daddr, daddr, 4);
 386         if (iph->daddr)
 387                 return t->hlen + sizeof(*iph);
 388
 389         return -(t->hlen + sizeof(*iph));
 390 }
 391
 392 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
 393 {
 394         const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
 395         memcpy(haddr, &iph->saddr, 4);
 396         return 4;
 397 }
 398
 399 static const struct header_ops ipgre_header_ops = {
 400         .create = ipgre_header,
 401         .parse  = ipgre_header_parse,
 402 };
 403
 404 #ifdef CONFIG_NET_IPGRE_BROADCAST
 405 static int ipgre_open(struct net_device *dev)
 406 {
 407         struct ip_tunnel *t = netdev_priv(dev);
 408
 409         if (ipv4_is_multicast(t->parms.iph.daddr)) {
 410                 struct flowi4 fl4;
 411                 struct rtable *rt;
 412
 413                 rt = ip_route_output_gre(t->net, &fl4,
 414                                          t->parms.iph.daddr,
 415                                          t->parms.iph.saddr,
 416                                          t->parms.o_key,
 417                                          RT_TOS(t->parms.iph.tos),
 418                                          t->parms.link);
 419                 if (IS_ERR(rt))
 420                         return -EADDRNOTAVAIL;
 421                 dev = rt->dst.dev;
 422                 ip_rt_put(rt);
 423                 if (__in_dev_get_rtnl(dev) == NULL)
 424                         return -EADDRNOTAVAIL;
 425                 t->mlink = dev->ifindex;
 426                 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
 427         }
 428         return 0;
 429 }
 430
 431 static int ipgre_close(struct net_device *dev)
 432 {
 433         struct ip_tunnel *t = netdev_priv(dev);
 434
 435         if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
 436                 struct in_device *in_dev;
 437                 in_dev = inetdev_by_index(t->net, t->mlink);
 438                 if (in_dev)
 439                         ip_mc_dec_group(in_dev, t->parms.iph.daddr);
 440         }
 441         return 0;
 442 }
 443 #endif
 444
 445 static const struct net_device_ops ipgre_netdev_ops = {
 446         .ndo_init               = ipgre_tunnel_init,
 447         .ndo_uninit             = ip_tunnel_uninit,
 448 #ifdef CONFIG_NET_IPGRE_BROADCAST
 449         .ndo_open               = ipgre_open,
 450         .ndo_stop               = ipgre_close,
 451 #endif
 452         .ndo_start_xmit         = ipgre_xmit,
 453         .ndo_do_ioctl           = ipgre_tunnel_ioctl,
 454         .ndo_change_mtu         = ip_tunnel_change_mtu,
 455         .ndo_get_stats64        = ip_tunnel_get_stats64,
 456 };
 457
 458 #define GRE_FEATURES (NETIF_F_SG |              \
 459                       NETIF_F_FRAGLIST |        \
 460                       NETIF_F_HIGHDMA |         \
 461                       NETIF_F_HW_CSUM)
 462
 463 static void ipgre_tunnel_setup(struct net_device *dev)
 464 {
 465         dev->netdev_ops         = &ipgre_netdev_ops;
 466         dev->type               = ARPHRD_IPGRE;
 467         ip_tunnel_setup(dev, ipgre_net_id);
 468 }
 469
 470 static void __gre_tunnel_init(struct net_device *dev)
 471 {
 472         struct ip_tunnel *tunnel;
 473
 474         tunnel = netdev_priv(dev);
 475         tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
 476         tunnel->parms.iph.protocol = IPPROTO_GRE;
 477
 478         dev->needed_headroom    = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
 479         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
 480
 481         dev->features           |= GRE_FEATURES;
 482         dev->hw_features        |= GRE_FEATURES;
 483
 484         if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
 485                 /* TCP offload with GRE SEQ is not supported. */
 486                 dev->features    |= NETIF_F_GSO_SOFTWARE;
 487                 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 488                 /* Can use a lockless transmit, unless we generate
 489                  * output sequences
 490                  */
 491                 dev->features |= NETIF_F_LLTX;
 492         }
 493 }
 494
 495 static int ipgre_tunnel_init(struct net_device *dev)
 496 {
 497         struct ip_tunnel *tunnel = netdev_priv(dev);
 498         struct iphdr *iph = &tunnel->parms.iph;
 499
 500         __gre_tunnel_init(dev);
 501
 502         memcpy(dev->dev_addr, &iph->saddr, 4);
 503         memcpy(dev->broadcast, &iph->daddr, 4);
 504
 505         dev->flags              = IFF_NOARP;
 506         dev->priv_flags         &= ~IFF_XMIT_DST_RELEASE;
 507         dev->addr_len           = 4;
 508
 509         if (iph->daddr) {
 510 #ifdef CONFIG_NET_IPGRE_BROADCAST
 511                 if (ipv4_is_multicast(iph->daddr)) {
 512                         if (!iph->saddr)
 513                                 return -EINVAL;
 514                         dev->flags = IFF_BROADCAST;
 515                         dev->header_ops = &ipgre_header_ops;
 516                 }
 517 #endif
 518         } else
 519                 dev->header_ops = &ipgre_header_ops;
 520
 521         return ip_tunnel_init(dev);
 522 }
 523
 524 static struct gre_cisco_protocol ipgre_protocol = {
 525         .handler        = ipgre_rcv,
 526         .err_handler    = ipgre_err,
 527         .priority       = 0,
 528 };
 529
 530 static int __net_init ipgre_init_net(struct net *net)
 531 {
 532         return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
 533 }
 534
 535 static void __net_exit ipgre_exit_net(struct net *net)
 536 {
 537         struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
 538         ip_tunnel_delete_net(itn, &ipgre_link_ops);
 539 }
 540
 541 static struct pernet_operations ipgre_net_ops = {
 542         .init = ipgre_init_net,
 543         .exit = ipgre_exit_net,
 544         .id   = &ipgre_net_id,
 545         .size = sizeof(struct ip_tunnel_net),
 546 };
 547
 548 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
 549 {
 550         __be16 flags;
 551
 552         if (!data)
 553                 return 0;
 554
 555         flags = 0;
 556         if (data[IFLA_GRE_IFLAGS])
 557                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
 558         if (data[IFLA_GRE_OFLAGS])
 559                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
 560         if (flags & (GRE_VERSION|GRE_ROUTING))
 561                 return -EINVAL;
 562
 563         return 0;
 564 }
 565
 566 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
 567 {
 568         __be32 daddr;
 569
 570         if (tb[IFLA_ADDRESS]) {
 571                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 572                         return -EINVAL;
 573                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 574                         return -EADDRNOTAVAIL;
 575         }
 576
 577         if (!data)
 578                 goto out;
 579
 580         if (data[IFLA_GRE_REMOTE]) {
 581                 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
 582                 if (!daddr)
 583                         return -EINVAL;
 584         }
 585
 586 out:
 587         return ipgre_tunnel_validate(tb, data);
 588 }
 589
 590 static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[],
 591                                struct ip_tunnel_parm *parms)
 592 {
 593         memset(parms, 0, sizeof(*parms));
 594
 595         parms->iph.protocol = IPPROTO_GRE;
 596
 597         if (!data)
 598                 return;
 599
 600         if (data[IFLA_GRE_LINK])
 601                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
 602
 603         if (data[IFLA_GRE_IFLAGS])
 604                 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
 605
 606         if (data[IFLA_GRE_OFLAGS])
 607                 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
 608
 609         if (data[IFLA_GRE_IKEY])
 610                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
 611
 612         if (data[IFLA_GRE_OKEY])
 613                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
 614
 615         if (data[IFLA_GRE_LOCAL])
 616                 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
 617
 618         if (data[IFLA_GRE_REMOTE])
 619                 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
 620
 621         if (data[IFLA_GRE_TTL])
 622                 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
 623
 624         if (data[IFLA_GRE_TOS])
 625                 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
 626
 627         if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
 628                 parms->iph.frag_off = htons(IP_DF);
 629 }
 630
 631 static int gre_tap_init(struct net_device *dev)
 632 {
 633         __gre_tunnel_init(dev);
 634
 635         return ip_tunnel_init(dev);
 636 }
 637
 638 static const struct net_device_ops gre_tap_netdev_ops = {
 639         .ndo_init               = gre_tap_init,
 640         .ndo_uninit             = ip_tunnel_uninit,
 641         .ndo_start_xmit         = gre_tap_xmit,
 642         .ndo_set_mac_address    = eth_mac_addr,
 643         .ndo_validate_addr      = eth_validate_addr,
 644         .ndo_change_mtu         = ip_tunnel_change_mtu,
 645         .ndo_get_stats64        = ip_tunnel_get_stats64,
 646 };
 647
 648 static void ipgre_tap_setup(struct net_device *dev)
 649 {
 650         ether_setup(dev);
 651         dev->netdev_ops         = &gre_tap_netdev_ops;
 652         dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE;
 653         ip_tunnel_setup(dev, gre_tap_net_id);
 654 }
 655
 656 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
 657                          struct nlattr *tb[], struct nlattr *data[])
 658 {
 659         struct ip_tunnel_parm p;
 660
 661         ipgre_netlink_parms(data, tb, &p);
 662         return ip_tunnel_newlink(dev, tb, &p);
 663 }
 664
 665 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
 666                             struct nlattr *data[])
 667 {
 668         struct ip_tunnel_parm p;
 669
 670         ipgre_netlink_parms(data, tb, &p);
 671         return ip_tunnel_changelink(dev, tb, &p);
 672 }
 673
 674 static size_t ipgre_get_size(const struct net_device *dev)
 675 {
 676         return
 677                 /* IFLA_GRE_LINK */
 678                 nla_total_size(4) +
 679                 /* IFLA_GRE_IFLAGS */
 680                 nla_total_size(2) +
 681                 /* IFLA_GRE_OFLAGS */
 682                 nla_total_size(2) +
 683                 /* IFLA_GRE_IKEY */
 684                 nla_total_size(4) +
 685                 /* IFLA_GRE_OKEY */
 686                 nla_total_size(4) +
 687                 /* IFLA_GRE_LOCAL */
 688                 nla_total_size(4) +
 689                 /* IFLA_GRE_REMOTE */
 690                 nla_total_size(4) +
 691                 /* IFLA_GRE_TTL */
 692                 nla_total_size(1) +
 693                 /* IFLA_GRE_TOS */
 694                 nla_total_size(1) +
 695                 /* IFLA_GRE_PMTUDISC */
 696                 nla_total_size(1) +
 697                 0;
 698 }
 699
 700 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
 701 {
 702         struct ip_tunnel *t = netdev_priv(dev);
 703         struct ip_tunnel_parm *p = &t->parms;
 704
 705         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
 706             nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
 707             nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
 708             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
 709             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
 710             nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
 711             nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
 712             nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
 713             nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
 714             nla_put_u8(skb, IFLA_GRE_PMTUDISC,
 715                        !!(p->iph.frag_off & htons(IP_DF))))
 716                 goto nla_put_failure;
 717         return 0;
 718
 719 nla_put_failure:
 720         return -EMSGSIZE;
 721 }
 722
 723 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
 724         [IFLA_GRE_LINK]         = { .type = NLA_U32 },
 725         [IFLA_GRE_IFLAGS]       = { .type = NLA_U16 },
 726         [IFLA_GRE_OFLAGS]       = { .type = NLA_U16 },
 727         [IFLA_GRE_IKEY]         = { .type = NLA_U32 },
 728         [IFLA_GRE_OKEY]         = { .type = NLA_U32 },
 729         [IFLA_GRE_LOCAL]        = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
 730         [IFLA_GRE_REMOTE]       = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
 731         [IFLA_GRE_TTL]          = { .type = NLA_U8 },
 732         [IFLA_GRE_TOS]          = { .type = NLA_U8 },
 733         [IFLA_GRE_PMTUDISC]     = { .type = NLA_U8 },
 734 };
 735
 736 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
 737         .kind           = "gre",
 738         .maxtype        = IFLA_GRE_MAX,
 739         .policy         = ipgre_policy,
 740         .priv_size      = sizeof(struct ip_tunnel),
 741         .setup          = ipgre_tunnel_setup,
 742         .validate       = ipgre_tunnel_validate,
 743         .newlink        = ipgre_newlink,
 744         .changelink     = ipgre_changelink,
 745         .dellink        = ip_tunnel_dellink,
 746         .get_size       = ipgre_get_size,
 747         .fill_info      = ipgre_fill_info,
 748 };
 749
 750 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
 751         .kind           = "gretap",
 752         .maxtype        = IFLA_GRE_MAX,
 753         .policy         = ipgre_policy,
 754         .priv_size      = sizeof(struct ip_tunnel),
 755         .setup          = ipgre_tap_setup,
 756         .validate       = ipgre_tap_validate,
 757         .newlink        = ipgre_newlink,
 758         .changelink     = ipgre_changelink,
 759         .dellink        = ip_tunnel_dellink,
 760         .get_size       = ipgre_get_size,
 761         .fill_info      = ipgre_fill_info,
 762 };
 763
 764 static int __net_init ipgre_tap_init_net(struct net *net)
 765 {
 766         return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL);
 767 }
 768
 769 static void __net_exit ipgre_tap_exit_net(struct net *net)
 770 {
 771         struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
 772         ip_tunnel_delete_net(itn, &ipgre_tap_ops);
 773 }
 774
 775 static struct pernet_operations ipgre_tap_net_ops = {
 776         .init = ipgre_tap_init_net,
 777         .exit = ipgre_tap_exit_net,
 778         .id   = &gre_tap_net_id,
 779         .size = sizeof(struct ip_tunnel_net),
 780 };
 781
 782 static int __init ipgre_init(void)
 783 {
 784         int err;
 785
 786         pr_info("GRE over IPv4 tunneling driver\n");
 787
 788         err = register_pernet_device(&ipgre_net_ops);
 789         if (err < 0)
 790                 return err;
 791
 792         err = register_pernet_device(&ipgre_tap_net_ops);
 793         if (err < 0)
 794                 goto pnet_tap_faied;
 795
 796         err = gre_cisco_register(&ipgre_protocol);
 797         if (err < 0) {
 798                 pr_info("%s: can't add protocol\n", __func__);
 799                 goto add_proto_failed;
 800         }
 801
 802         err = rtnl_link_register(&ipgre_link_ops);
 803         if (err < 0)
 804                 goto rtnl_link_failed;
 805
 806         err = rtnl_link_register(&ipgre_tap_ops);
 807         if (err < 0)
 808                 goto tap_ops_failed;
 809
 810         return 0;
 811
 812 tap_ops_failed:
 813         rtnl_link_unregister(&ipgre_link_ops);
 814 rtnl_link_failed:
 815         gre_cisco_unregister(&ipgre_protocol);
 816 add_proto_failed:
 817         unregister_pernet_device(&ipgre_tap_net_ops);
 818 pnet_tap_faied:
 819         unregister_pernet_device(&ipgre_net_ops);
 820         return err;
 821 }
 822
 823 static void __exit ipgre_fini(void)
 824 {
 825         rtnl_link_unregister(&ipgre_tap_ops);
 826         rtnl_link_unregister(&ipgre_link_ops);
 827         gre_cisco_unregister(&ipgre_protocol);
 828         unregister_pernet_device(&ipgre_tap_net_ops);
 829         unregister_pernet_device(&ipgre_net_ops);
 830 }
 831
 832 module_init(ipgre_init);
 833 module_exit(ipgre_fini);
 834 MODULE_LICENSE("GPL");
 835 MODULE_ALIAS_RTNL_LINK("gre");
 836 MODULE_ALIAS_RTNL_LINK("gretap");
 837 MODULE_ALIAS_NETDEV("gre0");
 838 MODULE_ALIAS_NETDEV("gretap0");