net/ipv4/ip_gre.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux NET3:     GRE over IP protocol decoder.
   4  *
   5  *      Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/capability.h>
  11 #include <linux/module.h>
  12 #include <linux/types.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/in.h>
  19 #include <linux/tcp.h>
  20 #include <linux/udp.h>
  21 #include <linux/if_arp.h>
  22 #include <linux/if_vlan.h>
  23 #include <linux/init.h>
  24 #include <linux/in6.h>
  25 #include <linux/inetdevice.h>
  26 #include <linux/igmp.h>
  27 #include <linux/netfilter_ipv4.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/if_ether.h>
  30
  31 #include <net/sock.h>
  32 #include <net/ip.h>
  33 #include <net/icmp.h>
  34 #include <net/protocol.h>
  35 #include <net/ip_tunnels.h>
  36 #include <net/arp.h>
  37 #include <net/checksum.h>
  38 #include <net/dsfield.h>
  39 #include <net/inet_ecn.h>
  40 #include <net/xfrm.h>
  41 #include <net/net_namespace.h>
  42 #include <net/netns/generic.h>
  43 #include <net/rtnetlink.h>
  44 #include <net/gre.h>
  45 #include <net/dst_metadata.h>
  46 #include <net/erspan.h>
  47
  48 /*
  49    Problems & solutions
  50    --------------------
  51
  52    1. The most important issue is detecting local dead loops.
  53    They would cause complete host lockup in transmit, which
  54    would be "resolved" by stack overflow or, if queueing is enabled,
  55    with infinite looping in net_bh.
  56
  57    We cannot track such dead loops during route installation,
  58    it is infeasible task. The most general solutions would be
  59    to keep skb->encapsulation counter (sort of local ttl),
  60    and silently drop packet when it expires. It is a good
  61    solution, but it supposes maintaining new variable in ALL
  62    skb, even if no tunneling is used.
  63
  64    Current solution: xmit_recursion breaks dead loops. This is a percpu
  65    counter, since when we enter the first ndo_xmit(), cpu migration is
  66    forbidden. We force an exit if this counter reaches RECURSION_LIMIT
  67
  68    2. Networking dead loops would not kill routers, but would really
  69    kill network. IP hop limit plays role of "t->recursion" in this case,
  70    if we copy it from packet being encapsulated to upper header.
  71    It is very good solution, but it introduces two problems:
  72
  73    - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
  74      do not work over tunnels.
  75    - traceroute does not work. I planned to relay ICMP from tunnel,
  76      so that this problem would be solved and traceroute output
  77      would even more informative. This idea appeared to be wrong:
  78      only Linux complies to rfc1812 now (yes, guys, Linux is the only
  79      true router now :-)), all routers (at least, in neighbourhood of mine)
  80      return only 8 bytes of payload. It is the end.
  81
  82    Hence, if we want that OSPF worked or traceroute said something reasonable,
  83    we should search for another solution.
  84
  85    One of them is to parse packet trying to detect inner encapsulation
  86    made by our node. It is difficult or even impossible, especially,
  87    taking into account fragmentation. TO be short, ttl is not solution at all.
  88
  89    Current solution: The solution was UNEXPECTEDLY SIMPLE.
  90    We force DF flag on tunnels with preconfigured hop limit,
  91    that is ALL. :-) Well, it does not remove the problem completely,
  92    but exponential growth of network traffic is changed to linear
  93    (branches, that exceed pmtu are pruned) and tunnel mtu
  94    rapidly degrades to value <68, where looping stops.
  95    Yes, it is not good if there exists a router in the loop,
  96    which does not force DF, even when encapsulating packets have DF set.
  97    But it is not our problem! Nobody could accuse us, we made
  98    all that we could make. Even if it is your gated who injected
  99    fatal route to network, even if it were you who configured
 100    fatal static route: you are innocent. :-)
 101
 102    Alexey Kuznetsov.
 103  */
 104
 105 static bool log_ecn_error = true;
 106 module_param(log_ecn_error, bool, 0644);
 107 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 108
 109 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
 110 static const struct header_ops ipgre_header_ops;
 111
 112 static int ipgre_tunnel_init(struct net_device *dev);
 113 static void erspan_build_header(struct sk_buff *skb,
 114                                 u32 id, u32 index,
 115                                 bool truncate, bool is_ipv4);
 116
 117 static unsigned int ipgre_net_id __read_mostly;
 118 static unsigned int gre_tap_net_id __read_mostly;
 119 static unsigned int erspan_net_id __read_mostly;
 120
 121 static int ipgre_err(struct sk_buff *skb, u32 info,
 122                      const struct tnl_ptk_info *tpi)
 123 {
 124
 125         /* All the routers (except for Linux) return only
 126            8 bytes of packet payload. It means, that precise relaying of
 127            ICMP in the real Internet is absolutely infeasible.
 128
 129            Moreover, Cisco "wise men" put GRE key to the third word
 130            in GRE header. It makes impossible maintaining even soft
 131            state for keyed GRE tunnels with enabled checksum. Tell
 132            them "thank you".
 133
 134            Well, I wonder, rfc1812 was written by Cisco employee,
 135            what the hell these idiots break standards established
 136            by themselves???
 137            */
 138         struct net *net = dev_net(skb->dev);
 139         struct ip_tunnel_net *itn;
 140         const struct iphdr *iph;
 141         const int type = icmp_hdr(skb)->type;
 142         const int code = icmp_hdr(skb)->code;
 143         unsigned int data_len = 0;
 144         struct ip_tunnel *t;
 145
 146         if (tpi->proto == htons(ETH_P_TEB))
 147                 itn = net_generic(net, gre_tap_net_id);
 148         else if (tpi->proto == htons(ETH_P_ERSPAN) ||
 149                  tpi->proto == htons(ETH_P_ERSPAN2))
 150                 itn = net_generic(net, erspan_net_id);
 151         else
 152                 itn = net_generic(net, ipgre_net_id);
 153
 154         iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
 155         t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
 156                              iph->daddr, iph->saddr, tpi->key);
 157
 158         if (!t)
 159                 return -ENOENT;
 160
 161         switch (type) {
 162         default:
 163         case ICMP_PARAMETERPROB:
 164                 return 0;
 165
 166         case ICMP_DEST_UNREACH:
 167                 switch (code) {
 168                 case ICMP_SR_FAILED:
 169                 case ICMP_PORT_UNREACH:
 170                         /* Impossible event. */
 171                         return 0;
 172                 default:
 173                         /* All others are translated to HOST_UNREACH.
 174                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 175                            I believe they are just ether pollution. --ANK
 176                          */
 177                         break;
 178                 }
 179                 break;
 180
 181         case ICMP_TIME_EXCEEDED:
 182                 if (code != ICMP_EXC_TTL)
 183                         return 0;
 184                 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 185                 break;
 186
 187         case ICMP_REDIRECT:
 188                 break;
 189         }
 190
 191 #if IS_ENABLED(CONFIG_IPV6)
 192        if (tpi->proto == htons(ETH_P_IPV6) &&
 193            !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
 194                                        type, data_len))
 195                return 0;
 196 #endif
 197
 198         if (t->parms.iph.daddr == 0 ||
 199             ipv4_is_multicast(t->parms.iph.daddr))
 200                 return 0;
 201
 202         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 203                 return 0;
 204
 205         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 206                 t->err_count++;
 207         else
 208                 t->err_count = 1;
 209         t->err_time = jiffies;
 210
 211         return 0;
 212 }
 213
 214 static void gre_err(struct sk_buff *skb, u32 info)
 215 {
 216         /* All the routers (except for Linux) return only
 217          * 8 bytes of packet payload. It means, that precise relaying of
 218          * ICMP in the real Internet is absolutely infeasible.
 219          *
 220          * Moreover, Cisco "wise men" put GRE key to the third word
 221          * in GRE header. It makes impossible maintaining even soft
 222          * state for keyed
 223          * GRE tunnels with enabled checksum. Tell them "thank you".
 224          *
 225          * Well, I wonder, rfc1812 was written by Cisco employee,
 226          * what the hell these idiots break standards established
 227          * by themselves???
 228          */
 229
 230         const struct iphdr *iph = (struct iphdr *)skb->data;
 231         const int type = icmp_hdr(skb)->type;
 232         const int code = icmp_hdr(skb)->code;
 233         struct tnl_ptk_info tpi;
 234
 235         if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
 236                              iph->ihl * 4) < 0)
 237                 return;
 238
 239         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 240                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 241                                  skb->dev->ifindex, IPPROTO_GRE);
 242                 return;
 243         }
 244         if (type == ICMP_REDIRECT) {
 245                 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
 246                               IPPROTO_GRE);
 247                 return;
 248         }
 249
 250         ipgre_err(skb, info, &tpi);
 251 }
 252
 253 static bool is_erspan_type1(int gre_hdr_len)
 254 {
 255         /* Both ERSPAN type I (version 0) and type II (version 1) use
 256          * protocol 0x88BE, but the type I has only 4-byte GRE header,
 257          * while type II has 8-byte.
 258          */
 259         return gre_hdr_len == 4;
 260 }
 261
 262 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 263                       int gre_hdr_len)
 264 {
 265         struct net *net = dev_net(skb->dev);
 266         struct metadata_dst *tun_dst = NULL;
 267         struct erspan_base_hdr *ershdr;
 268         struct ip_tunnel_net *itn;
 269         struct ip_tunnel *tunnel;
 270         const struct iphdr *iph;
 271         struct erspan_md2 *md2;
 272         int ver;
 273         int len;
 274
 275         itn = net_generic(net, erspan_net_id);
 276         iph = ip_hdr(skb);
 277         if (is_erspan_type1(gre_hdr_len)) {
 278                 ver = 0;
 279                 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
 280                                           tpi->flags | TUNNEL_NO_KEY,
 281                                           iph->saddr, iph->daddr, 0);
 282         } else {
 283                 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
 284                 ver = ershdr->ver;
 285                 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
 286                                           tpi->flags | TUNNEL_KEY,
 287                                           iph->saddr, iph->daddr, tpi->key);
 288         }
 289
 290         if (tunnel) {
 291                 if (is_erspan_type1(gre_hdr_len))
 292                         len = gre_hdr_len;
 293                 else
 294                         len = gre_hdr_len + erspan_hdr_len(ver);
 295
 296                 if (unlikely(!pskb_may_pull(skb, len)))
 297                         return PACKET_REJECT;
 298
 299                 if (__iptunnel_pull_header(skb,
 300                                            len,
 301                                            htons(ETH_P_TEB),
 302                                            false, false) < 0)
 303                         goto drop;
 304
 305                 if (tunnel->collect_md) {
 306                         struct erspan_metadata *pkt_md, *md;
 307                         struct ip_tunnel_info *info;
 308                         unsigned char *gh;
 309                         __be64 tun_id;
 310                         __be16 flags;
 311
 312                         tpi->flags |= TUNNEL_KEY;
 313                         flags = tpi->flags;
 314                         tun_id = key32_to_tunnel_id(tpi->key);
 315
 316                         tun_dst = ip_tun_rx_dst(skb, flags,
 317                                                 tun_id, sizeof(*md));
 318                         if (!tun_dst)
 319                                 return PACKET_REJECT;
 320
 321                         /* skb can be uncloned in __iptunnel_pull_header, so
 322                          * old pkt_md is no longer valid and we need to reset
 323                          * it
 324                          */
 325                         gh = skb_network_header(skb) +
 326                              skb_network_header_len(skb);
 327                         pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
 328                                                             sizeof(*ershdr));
 329                         md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
 330                         md->version = ver;
 331                         md2 = &md->u.md2;
 332                         memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
 333                                                        ERSPAN_V2_MDSIZE);
 334
 335                         info = &tun_dst->u.tun_info;
 336                         info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 337                         info->options_len = sizeof(*md);
 338                 }
 339
 340                 skb_reset_mac_header(skb);
 341                 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
 342                 return PACKET_RCVD;
 343         }
 344         return PACKET_REJECT;
 345
 346 drop:
 347         kfree_skb(skb);
 348         return PACKET_RCVD;
 349 }
 350
 351 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 352                        struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
 353 {
 354         struct metadata_dst *tun_dst = NULL;
 355         const struct iphdr *iph;
 356         struct ip_tunnel *tunnel;
 357
 358         iph = ip_hdr(skb);
 359         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
 360                                   iph->saddr, iph->daddr, tpi->key);
 361
 362         if (tunnel) {
 363                 const struct iphdr *tnl_params;
 364
 365                 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
 366                                            raw_proto, false) < 0)
 367                         goto drop;
 368
 369                 /* Special case for ipgre_header_parse(), which expects the
 370                  * mac_header to point to the outer IP header.
 371                  */
 372                 if (tunnel->dev->header_ops == &ipgre_header_ops)
 373                         skb_pop_mac_header(skb);
 374                 else
 375                         skb_reset_mac_header(skb);
 376
 377                 tnl_params = &tunnel->parms.iph;
 378                 if (tunnel->collect_md || tnl_params->daddr == 0) {
 379                         __be16 flags;
 380                         __be64 tun_id;
 381
 382                         flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
 383                         tun_id = key32_to_tunnel_id(tpi->key);
 384                         tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
 385                         if (!tun_dst)
 386                                 return PACKET_REJECT;
 387                 }
 388
 389                 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
 390                 return PACKET_RCVD;
 391         }
 392         return PACKET_NEXT;
 393
 394 drop:
 395         kfree_skb(skb);
 396         return PACKET_RCVD;
 397 }
 398
 399 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 400                      int hdr_len)
 401 {
 402         struct net *net = dev_net(skb->dev);
 403         struct ip_tunnel_net *itn;
 404         int res;
 405
 406         if (tpi->proto == htons(ETH_P_TEB))
 407                 itn = net_generic(net, gre_tap_net_id);
 408         else
 409                 itn = net_generic(net, ipgre_net_id);
 410
 411         res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
 412         if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
 413                 /* ipgre tunnels in collect metadata mode should receive
 414                  * also ETH_P_TEB traffic.
 415                  */
 416                 itn = net_generic(net, ipgre_net_id);
 417                 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
 418         }
 419         return res;
 420 }
 421
 422 static int gre_rcv(struct sk_buff *skb)
 423 {
 424         struct tnl_ptk_info tpi;
 425         bool csum_err = false;
 426         int hdr_len;
 427
 428 #ifdef CONFIG_NET_IPGRE_BROADCAST
 429         if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
 430                 /* Looped back packet, drop it! */
 431                 if (rt_is_output_route(skb_rtable(skb)))
 432                         goto drop;
 433         }
 434 #endif
 435
 436         hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
 437         if (hdr_len < 0)
 438                 goto drop;
 439
 440         if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
 441                      tpi.proto == htons(ETH_P_ERSPAN2))) {
 442                 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
 443                         return 0;
 444                 goto out;
 445         }
 446
 447         if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
 448                 return 0;
 449
 450 out:
 451         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 452 drop:
 453         kfree_skb(skb);
 454         return 0;
 455 }
 456
 457 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
 458                        const struct iphdr *tnl_params,
 459                        __be16 proto)
 460 {
 461         struct ip_tunnel *tunnel = netdev_priv(dev);
 462
 463         if (tunnel->parms.o_flags & TUNNEL_SEQ)
 464                 tunnel->o_seqno++;
 465
 466         /* Push GRE header. */
 467         gre_build_header(skb, tunnel->tun_hlen,
 468                          tunnel->parms.o_flags, proto, tunnel->parms.o_key,
 469                          htonl(tunnel->o_seqno));
 470
 471         ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
 472 }
 473
 474 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 475 {
 476         if (csum && skb_checksum_start(skb) < skb->data)
 477                 return -EINVAL;
 478         return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 479 }
 480
 481 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 482                         __be16 proto)
 483 {
 484         struct ip_tunnel *tunnel = netdev_priv(dev);
 485         struct ip_tunnel_info *tun_info;
 486         const struct ip_tunnel_key *key;
 487         int tunnel_hlen;
 488         __be16 flags;
 489
 490         tun_info = skb_tunnel_info(skb);
 491         if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
 492                      ip_tunnel_info_af(tun_info) != AF_INET))
 493                 goto err_free_skb;
 494
 495         key = &tun_info->key;
 496         tunnel_hlen = gre_calc_hlen(key->tun_flags);
 497
 498         if (skb_cow_head(skb, dev->needed_headroom))
 499                 goto err_free_skb;
 500
 501         /* Push Tunnel header. */
 502         if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
 503                 goto err_free_skb;
 504
 505         flags = tun_info->key.tun_flags &
 506                 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
 507         gre_build_header(skb, tunnel_hlen, flags, proto,
 508                          tunnel_id_to_key32(tun_info->key.tun_id),
 509                          (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
 510
 511         ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
 512
 513         return;
 514
 515 err_free_skb:
 516         kfree_skb(skb);
 517         dev->stats.tx_dropped++;
 518 }
 519
 520 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 521 {
 522         struct ip_tunnel *tunnel = netdev_priv(dev);
 523         struct ip_tunnel_info *tun_info;
 524         const struct ip_tunnel_key *key;
 525         struct erspan_metadata *md;
 526         bool truncate = false;
 527         __be16 proto;
 528         int tunnel_hlen;
 529         int version;
 530         int nhoff;
 531         int thoff;
 532
 533         tun_info = skb_tunnel_info(skb);
 534         if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
 535                      ip_tunnel_info_af(tun_info) != AF_INET))
 536                 goto err_free_skb;
 537
 538         key = &tun_info->key;
 539         if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
 540                 goto err_free_skb;
 541         if (tun_info->options_len < sizeof(*md))
 542                 goto err_free_skb;
 543         md = ip_tunnel_info_opts(tun_info);
 544
 545         /* ERSPAN has fixed 8 byte GRE header */
 546         version = md->version;
 547         tunnel_hlen = 8 + erspan_hdr_len(version);
 548
 549         if (skb_cow_head(skb, dev->needed_headroom))
 550                 goto err_free_skb;
 551
 552         if (gre_handle_offloads(skb, false))
 553                 goto err_free_skb;
 554
 555         if (skb->len > dev->mtu + dev->hard_header_len) {
 556                 pskb_trim(skb, dev->mtu + dev->hard_header_len);
 557                 truncate = true;
 558         }
 559
 560         nhoff = skb_network_header(skb) - skb_mac_header(skb);
 561         if (skb->protocol == htons(ETH_P_IP) &&
 562             (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
 563                 truncate = true;
 564
 565         thoff = skb_transport_header(skb) - skb_mac_header(skb);
 566         if (skb->protocol == htons(ETH_P_IPV6) &&
 567             (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
 568                 truncate = true;
 569
 570         if (version == 1) {
 571                 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
 572                                     ntohl(md->u.index), truncate, true);
 573                 proto = htons(ETH_P_ERSPAN);
 574         } else if (version == 2) {
 575                 erspan_build_header_v2(skb,
 576                                        ntohl(tunnel_id_to_key32(key->tun_id)),
 577                                        md->u.md2.dir,
 578                                        get_hwid(&md->u.md2),
 579                                        truncate, true);
 580                 proto = htons(ETH_P_ERSPAN2);
 581         } else {
 582                 goto err_free_skb;
 583         }
 584
 585         gre_build_header(skb, 8, TUNNEL_SEQ,
 586                          proto, 0, htonl(tunnel->o_seqno++));
 587
 588         ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
 589
 590         return;
 591
 592 err_free_skb:
 593         kfree_skb(skb);
 594         dev->stats.tx_dropped++;
 595 }
 596
 597 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 598 {
 599         struct ip_tunnel_info *info = skb_tunnel_info(skb);
 600         const struct ip_tunnel_key *key;
 601         struct rtable *rt;
 602         struct flowi4 fl4;
 603
 604         if (ip_tunnel_info_af(info) != AF_INET)
 605                 return -EINVAL;
 606
 607         key = &info->key;
 608         ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
 609                             tunnel_id_to_key32(key->tun_id), key->tos, 0,
 610                             skb->mark, skb_get_hash(skb));
 611         rt = ip_route_output_key(dev_net(dev), &fl4);
 612         if (IS_ERR(rt))
 613                 return PTR_ERR(rt);
 614
 615         ip_rt_put(rt);
 616         info->key.u.ipv4.src = fl4.saddr;
 617         return 0;
 618 }
 619
 620 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 621                               struct net_device *dev)
 622 {
 623         struct ip_tunnel *tunnel = netdev_priv(dev);
 624         const struct iphdr *tnl_params;
 625
 626         if (!pskb_inet_may_pull(skb))
 627                 goto free_skb;
 628
 629         if (tunnel->collect_md) {
 630                 gre_fb_xmit(skb, dev, skb->protocol);
 631                 return NETDEV_TX_OK;
 632         }
 633
 634         if (dev->header_ops) {
 635                 if (skb_cow_head(skb, 0))
 636                         goto free_skb;
 637
 638                 tnl_params = (const struct iphdr *)skb->data;
 639
 640                 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
 641                  * to gre header.
 642                  */
 643                 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
 644                 skb_reset_mac_header(skb);
 645         } else {
 646                 if (skb_cow_head(skb, dev->needed_headroom))
 647                         goto free_skb;
 648
 649                 tnl_params = &tunnel->parms.iph;
 650         }
 651
 652         if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
 653                 goto free_skb;
 654
 655         __gre_xmit(skb, dev, tnl_params, skb->protocol);
 656         return NETDEV_TX_OK;
 657
 658 free_skb:
 659         kfree_skb(skb);
 660         dev->stats.tx_dropped++;
 661         return NETDEV_TX_OK;
 662 }
 663
 664 static netdev_tx_t erspan_xmit(struct sk_buff *skb,
 665                                struct net_device *dev)
 666 {
 667         struct ip_tunnel *tunnel = netdev_priv(dev);
 668         bool truncate = false;
 669         __be16 proto;
 670
 671         if (!pskb_inet_may_pull(skb))
 672                 goto free_skb;
 673
 674         if (tunnel->collect_md) {
 675                 erspan_fb_xmit(skb, dev);
 676                 return NETDEV_TX_OK;
 677         }
 678
 679         if (gre_handle_offloads(skb, false))
 680                 goto free_skb;
 681
 682         if (skb_cow_head(skb, dev->needed_headroom))
 683                 goto free_skb;
 684
 685         if (skb->len > dev->mtu + dev->hard_header_len) {
 686                 pskb_trim(skb, dev->mtu + dev->hard_header_len);
 687                 truncate = true;
 688         }
 689
 690         /* Push ERSPAN header */
 691         if (tunnel->erspan_ver == 0) {
 692                 proto = htons(ETH_P_ERSPAN);
 693                 tunnel->parms.o_flags &= ~TUNNEL_SEQ;
 694         } else if (tunnel->erspan_ver == 1) {
 695                 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
 696                                     tunnel->index,
 697                                     truncate, true);
 698                 proto = htons(ETH_P_ERSPAN);
 699         } else if (tunnel->erspan_ver == 2) {
 700                 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
 701                                        tunnel->dir, tunnel->hwid,
 702                                        truncate, true);
 703                 proto = htons(ETH_P_ERSPAN2);
 704         } else {
 705                 goto free_skb;
 706         }
 707
 708         tunnel->parms.o_flags &= ~TUNNEL_KEY;
 709         __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
 710         return NETDEV_TX_OK;
 711
 712 free_skb:
 713         kfree_skb(skb);
 714         dev->stats.tx_dropped++;
 715         return NETDEV_TX_OK;
 716 }
 717
 718 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 719                                 struct net_device *dev)
 720 {
 721         struct ip_tunnel *tunnel = netdev_priv(dev);
 722
 723         if (!pskb_inet_may_pull(skb))
 724                 goto free_skb;
 725
 726         if (tunnel->collect_md) {
 727                 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
 728                 return NETDEV_TX_OK;
 729         }
 730
 731         if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
 732                 goto free_skb;
 733
 734         if (skb_cow_head(skb, dev->needed_headroom))
 735                 goto free_skb;
 736
 737         __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
 738         return NETDEV_TX_OK;
 739
 740 free_skb:
 741         kfree_skb(skb);
 742         dev->stats.tx_dropped++;
 743         return NETDEV_TX_OK;
 744 }
 745
 746 static void ipgre_link_update(struct net_device *dev, bool set_mtu)
 747 {
 748         struct ip_tunnel *tunnel = netdev_priv(dev);
 749         int len;
 750
 751         len = tunnel->tun_hlen;
 752         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
 753         len = tunnel->tun_hlen - len;
 754         tunnel->hlen = tunnel->hlen + len;
 755
 756         if (dev->header_ops)
 757                 dev->hard_header_len += len;
 758         else
 759                 dev->needed_headroom += len;
 760
 761         if (set_mtu)
 762                 dev->mtu = max_t(int, dev->mtu - len, 68);
 763
 764         if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
 765                 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
 766                     tunnel->encap.type == TUNNEL_ENCAP_NONE) {
 767                         dev->features |= NETIF_F_GSO_SOFTWARE;
 768                         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 769                 } else {
 770                         dev->features &= ~NETIF_F_GSO_SOFTWARE;
 771                         dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
 772                 }
 773                 dev->features |= NETIF_F_LLTX;
 774         } else {
 775                 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
 776                 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE);
 777         }
 778 }
 779
 780 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,
 781                             int cmd)
 782 {
 783         int err;
 784
 785         if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
 786                 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
 787                     p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
 788                     ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING)))
 789                         return -EINVAL;
 790         }
 791
 792         p->i_flags = gre_flags_to_tnl_flags(p->i_flags);
 793         p->o_flags = gre_flags_to_tnl_flags(p->o_flags);
 794
 795         err = ip_tunnel_ctl(dev, p, cmd);
 796         if (err)
 797                 return err;
 798
 799         if (cmd == SIOCCHGTUNNEL) {
 800                 struct ip_tunnel *t = netdev_priv(dev);
 801
 802                 t->parms.i_flags = p->i_flags;
 803                 t->parms.o_flags = p->o_flags;
 804
 805                 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
 806                         ipgre_link_update(dev, true);
 807         }
 808
 809         p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
 810         p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
 811         return 0;
 812 }
 813
 814 /* Nice toy. Unfortunately, useless in real life :-)
 815    It allows to construct virtual multiprotocol broadcast "LAN"
 816    over the Internet, provided multicast routing is tuned.
 817
 818
 819    I have no idea was this bicycle invented before me,
 820    so that I had to set ARPHRD_IPGRE to a random value.
 821    I have an impression, that Cisco could make something similar,
 822    but this feature is apparently missing in IOS<=11.2(8).
 823
 824    I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
 825    with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
 826
 827    ping -t 255 224.66.66.66
 828
 829    If nobody answers, mbone does not work.
 830
 831    ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
 832    ip addr add 10.66.66.<somewhat>/24 dev Universe
 833    ifconfig Universe up
 834    ifconfig Universe add fe80::<Your_real_addr>/10
 835    ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
 836    ftp 10.66.66.66
 837    ...
 838    ftp fec0:6666:6666::193.233.7.65
 839    ...
 840  */
 841 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
 842                         unsigned short type,
 843                         const void *daddr, const void *saddr, unsigned int len)
 844 {
 845         struct ip_tunnel *t = netdev_priv(dev);
 846         struct iphdr *iph;
 847         struct gre_base_hdr *greh;
 848
 849         iph = skb_push(skb, t->hlen + sizeof(*iph));
 850         greh = (struct gre_base_hdr *)(iph+1);
 851         greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
 852         greh->protocol = htons(type);
 853
 854         memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
 855
 856         /* Set the source hardware address. */
 857         if (saddr)
 858                 memcpy(&iph->saddr, saddr, 4);
 859         if (daddr)
 860                 memcpy(&iph->daddr, daddr, 4);
 861         if (iph->daddr)
 862                 return t->hlen + sizeof(*iph);
 863
 864         return -(t->hlen + sizeof(*iph));
 865 }
 866
 867 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
 868 {
 869         const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
 870         memcpy(haddr, &iph->saddr, 4);
 871         return 4;
 872 }
 873
 874 static const struct header_ops ipgre_header_ops = {
 875         .create = ipgre_header,
 876         .parse  = ipgre_header_parse,
 877 };
 878
 879 #ifdef CONFIG_NET_IPGRE_BROADCAST
 880 static int ipgre_open(struct net_device *dev)
 881 {
 882         struct ip_tunnel *t = netdev_priv(dev);
 883
 884         if (ipv4_is_multicast(t->parms.iph.daddr)) {
 885                 struct flowi4 fl4;
 886                 struct rtable *rt;
 887
 888                 rt = ip_route_output_gre(t->net, &fl4,
 889                                          t->parms.iph.daddr,
 890                                          t->parms.iph.saddr,
 891                                          t->parms.o_key,
 892                                          RT_TOS(t->parms.iph.tos),
 893                                          t->parms.link);
 894                 if (IS_ERR(rt))
 895                         return -EADDRNOTAVAIL;
 896                 dev = rt->dst.dev;
 897                 ip_rt_put(rt);
 898                 if (!__in_dev_get_rtnl(dev))
 899                         return -EADDRNOTAVAIL;
 900                 t->mlink = dev->ifindex;
 901                 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
 902         }
 903         return 0;
 904 }
 905
 906 static int ipgre_close(struct net_device *dev)
 907 {
 908         struct ip_tunnel *t = netdev_priv(dev);
 909
 910         if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
 911                 struct in_device *in_dev;
 912                 in_dev = inetdev_by_index(t->net, t->mlink);
 913                 if (in_dev)
 914                         ip_mc_dec_group(in_dev, t->parms.iph.daddr);
 915         }
 916         return 0;
 917 }
 918 #endif
 919
 920 static const struct net_device_ops ipgre_netdev_ops = {
 921         .ndo_init               = ipgre_tunnel_init,
 922         .ndo_uninit             = ip_tunnel_uninit,
 923 #ifdef CONFIG_NET_IPGRE_BROADCAST
 924         .ndo_open               = ipgre_open,
 925         .ndo_stop               = ipgre_close,
 926 #endif
 927         .ndo_start_xmit         = ipgre_xmit,
 928         .ndo_siocdevprivate     = ip_tunnel_siocdevprivate,
 929         .ndo_change_mtu         = ip_tunnel_change_mtu,
 930         .ndo_get_stats64        = dev_get_tstats64,
 931         .ndo_get_iflink         = ip_tunnel_get_iflink,
 932         .ndo_tunnel_ctl         = ipgre_tunnel_ctl,
 933 };
 934
 935 #define GRE_FEATURES (NETIF_F_SG |              \
 936                       NETIF_F_FRAGLIST |        \
 937                       NETIF_F_HIGHDMA |         \
 938                       NETIF_F_HW_CSUM)
 939
 940 static void ipgre_tunnel_setup(struct net_device *dev)
 941 {
 942         dev->netdev_ops         = &ipgre_netdev_ops;
 943         dev->type               = ARPHRD_IPGRE;
 944         ip_tunnel_setup(dev, ipgre_net_id);
 945 }
 946
 947 static void __gre_tunnel_init(struct net_device *dev)
 948 {
 949         struct ip_tunnel *tunnel;
 950
 951         tunnel = netdev_priv(dev);
 952         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
 953         tunnel->parms.iph.protocol = IPPROTO_GRE;
 954
 955         tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
 956         dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
 957
 958         dev->features           |= GRE_FEATURES;
 959         dev->hw_features        |= GRE_FEATURES;
 960
 961         if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
 962                 /* TCP offload with GRE SEQ is not supported, nor
 963                  * can we support 2 levels of outer headers requiring
 964                  * an update.
 965                  */
 966                 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
 967                     (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
 968                         dev->features    |= NETIF_F_GSO_SOFTWARE;
 969                         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 970                 }
 971
 972                 /* Can use a lockless transmit, unless we generate
 973                  * output sequences
 974                  */
 975                 dev->features |= NETIF_F_LLTX;
 976         }
 977 }
 978
 979 static int ipgre_tunnel_init(struct net_device *dev)
 980 {
 981         struct ip_tunnel *tunnel = netdev_priv(dev);
 982         struct iphdr *iph = &tunnel->parms.iph;
 983
 984         __gre_tunnel_init(dev);
 985
 986         memcpy(dev->dev_addr, &iph->saddr, 4);
 987         memcpy(dev->broadcast, &iph->daddr, 4);
 988
 989         dev->flags              = IFF_NOARP;
 990         netif_keep_dst(dev);
 991         dev->addr_len           = 4;
 992
 993         if (iph->daddr && !tunnel->collect_md) {
 994 #ifdef CONFIG_NET_IPGRE_BROADCAST
 995                 if (ipv4_is_multicast(iph->daddr)) {
 996                         if (!iph->saddr)
 997                                 return -EINVAL;
 998                         dev->flags = IFF_BROADCAST;
 999                         dev->header_ops = &ipgre_header_ops;
1000                         dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1001                         dev->needed_headroom = 0;
1002                 }
1003 #endif
1004         } else if (!tunnel->collect_md) {
1005                 dev->header_ops = &ipgre_header_ops;
1006                 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1007                 dev->needed_headroom = 0;
1008         }
1009
1010         return ip_tunnel_init(dev);
1011 }
1012
1013 static const struct gre_protocol ipgre_protocol = {
1014         .handler     = gre_rcv,
1015         .err_handler = gre_err,
1016 };
1017
1018 static int __net_init ipgre_init_net(struct net *net)
1019 {
1020         return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
1021 }
1022
1023 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net)
1024 {
1025         ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops);
1026 }
1027
1028 static struct pernet_operations ipgre_net_ops = {
1029         .init = ipgre_init_net,
1030         .exit_batch = ipgre_exit_batch_net,
1031         .id   = &ipgre_net_id,
1032         .size = sizeof(struct ip_tunnel_net),
1033 };
1034
1035 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1036                                  struct netlink_ext_ack *extack)
1037 {
1038         __be16 flags;
1039
1040         if (!data)
1041                 return 0;
1042
1043         flags = 0;
1044         if (data[IFLA_GRE_IFLAGS])
1045                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1046         if (data[IFLA_GRE_OFLAGS])
1047                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1048         if (flags & (GRE_VERSION|GRE_ROUTING))
1049                 return -EINVAL;
1050
1051         if (data[IFLA_GRE_COLLECT_METADATA] &&
1052             data[IFLA_GRE_ENCAP_TYPE] &&
1053             nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1054                 return -EINVAL;
1055
1056         return 0;
1057 }
1058
1059 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1060                               struct netlink_ext_ack *extack)
1061 {
1062         __be32 daddr;
1063
1064         if (tb[IFLA_ADDRESS]) {
1065                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1066                         return -EINVAL;
1067                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1068                         return -EADDRNOTAVAIL;
1069         }
1070
1071         if (!data)
1072                 goto out;
1073
1074         if (data[IFLA_GRE_REMOTE]) {
1075                 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1076                 if (!daddr)
1077                         return -EINVAL;
1078         }
1079
1080 out:
1081         return ipgre_tunnel_validate(tb, data, extack);
1082 }
1083
1084 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1085                            struct netlink_ext_ack *extack)
1086 {
1087         __be16 flags = 0;
1088         int ret;
1089
1090         if (!data)
1091                 return 0;
1092
1093         ret = ipgre_tap_validate(tb, data, extack);
1094         if (ret)
1095                 return ret;
1096
1097         if (data[IFLA_GRE_ERSPAN_VER] &&
1098             nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
1099                 return 0;
1100
1101         /* ERSPAN type II/III should only have GRE sequence and key flag */
1102         if (data[IFLA_GRE_OFLAGS])
1103                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1104         if (data[IFLA_GRE_IFLAGS])
1105                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1106         if (!data[IFLA_GRE_COLLECT_METADATA] &&
1107             flags != (GRE_SEQ | GRE_KEY))
1108                 return -EINVAL;
1109
1110         /* ERSPAN Session ID only has 10-bit. Since we reuse
1111          * 32-bit key field as ID, check it's range.
1112          */
1113         if (data[IFLA_GRE_IKEY] &&
1114             (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1115                 return -EINVAL;
1116
1117         if (data[IFLA_GRE_OKEY] &&
1118             (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1119                 return -EINVAL;
1120
1121         return 0;
1122 }
1123
1124 static int ipgre_netlink_parms(struct net_device *dev,
1125                                 struct nlattr *data[],
1126                                 struct nlattr *tb[],
1127                                 struct ip_tunnel_parm *parms,
1128                                 __u32 *fwmark)
1129 {
1130         struct ip_tunnel *t = netdev_priv(dev);
1131
1132         memset(parms, 0, sizeof(*parms));
1133
1134         parms->iph.protocol = IPPROTO_GRE;
1135
1136         if (!data)
1137                 return 0;
1138
1139         if (data[IFLA_GRE_LINK])
1140                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1141
1142         if (data[IFLA_GRE_IFLAGS])
1143                 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1144
1145         if (data[IFLA_GRE_OFLAGS])
1146                 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1147
1148         if (data[IFLA_GRE_IKEY])
1149                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1150
1151         if (data[IFLA_GRE_OKEY])
1152                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1153
1154         if (data[IFLA_GRE_LOCAL])
1155                 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1156
1157         if (data[IFLA_GRE_REMOTE])
1158                 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1159
1160         if (data[IFLA_GRE_TTL])
1161                 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1162
1163         if (data[IFLA_GRE_TOS])
1164                 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1165
1166         if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1167                 if (t->ignore_df)
1168                         return -EINVAL;
1169                 parms->iph.frag_off = htons(IP_DF);
1170         }
1171
1172         if (data[IFLA_GRE_COLLECT_METADATA]) {
1173                 t->collect_md = true;
1174                 if (dev->type == ARPHRD_IPGRE)
1175                         dev->type = ARPHRD_NONE;
1176         }
1177
1178         if (data[IFLA_GRE_IGNORE_DF]) {
1179                 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1180                   && (parms->iph.frag_off & htons(IP_DF)))
1181                         return -EINVAL;
1182                 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1183         }
1184
1185         if (data[IFLA_GRE_FWMARK])
1186                 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1187
1188         return 0;
1189 }
1190
1191 static int erspan_netlink_parms(struct net_device *dev,
1192                                 struct nlattr *data[],
1193                                 struct nlattr *tb[],
1194                                 struct ip_tunnel_parm *parms,
1195                                 __u32 *fwmark)
1196 {
1197         struct ip_tunnel *t = netdev_priv(dev);
1198         int err;
1199
1200         err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1201         if (err)
1202                 return err;
1203         if (!data)
1204                 return 0;
1205
1206         if (data[IFLA_GRE_ERSPAN_VER]) {
1207                 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1208
1209                 if (t->erspan_ver > 2)
1210                         return -EINVAL;
1211         }
1212
1213         if (t->erspan_ver == 1) {
1214                 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1215                         t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1216                         if (t->index & ~INDEX_MASK)
1217                                 return -EINVAL;
1218                 }
1219         } else if (t->erspan_ver == 2) {
1220                 if (data[IFLA_GRE_ERSPAN_DIR]) {
1221                         t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1222                         if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1223                                 return -EINVAL;
1224                 }
1225                 if (data[IFLA_GRE_ERSPAN_HWID]) {
1226                         t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1227                         if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1228                                 return -EINVAL;
1229                 }
1230         }
1231
1232         return 0;
1233 }
1234
1235 /* This function returns true when ENCAP attributes are present in the nl msg */
1236 static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1237                                       struct ip_tunnel_encap *ipencap)
1238 {
1239         bool ret = false;
1240
1241         memset(ipencap, 0, sizeof(*ipencap));
1242
1243         if (!data)
1244                 return ret;
1245
1246         if (data[IFLA_GRE_ENCAP_TYPE]) {
1247                 ret = true;
1248                 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1249         }
1250
1251         if (data[IFLA_GRE_ENCAP_FLAGS]) {
1252                 ret = true;
1253                 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1254         }
1255
1256         if (data[IFLA_GRE_ENCAP_SPORT]) {
1257                 ret = true;
1258                 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1259         }
1260
1261         if (data[IFLA_GRE_ENCAP_DPORT]) {
1262                 ret = true;
1263                 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1264         }
1265
1266         return ret;
1267 }
1268
1269 static int gre_tap_init(struct net_device *dev)
1270 {
1271         __gre_tunnel_init(dev);
1272         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1273         netif_keep_dst(dev);
1274
1275         return ip_tunnel_init(dev);
1276 }
1277
1278 static const struct net_device_ops gre_tap_netdev_ops = {
1279         .ndo_init               = gre_tap_init,
1280         .ndo_uninit             = ip_tunnel_uninit,
1281         .ndo_start_xmit         = gre_tap_xmit,
1282         .ndo_set_mac_address    = eth_mac_addr,
1283         .ndo_validate_addr      = eth_validate_addr,
1284         .ndo_change_mtu         = ip_tunnel_change_mtu,
1285         .ndo_get_stats64        = dev_get_tstats64,
1286         .ndo_get_iflink         = ip_tunnel_get_iflink,
1287         .ndo_fill_metadata_dst  = gre_fill_metadata_dst,
1288 };
1289
1290 static int erspan_tunnel_init(struct net_device *dev)
1291 {
1292         struct ip_tunnel *tunnel = netdev_priv(dev);
1293
1294         if (tunnel->erspan_ver == 0)
1295                 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1296         else
1297                 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1298
1299         tunnel->parms.iph.protocol = IPPROTO_GRE;
1300         tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1301                        erspan_hdr_len(tunnel->erspan_ver);
1302
1303         dev->features           |= GRE_FEATURES;
1304         dev->hw_features        |= GRE_FEATURES;
1305         dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE;
1306         netif_keep_dst(dev);
1307
1308         return ip_tunnel_init(dev);
1309 }
1310
1311 static const struct net_device_ops erspan_netdev_ops = {
1312         .ndo_init               = erspan_tunnel_init,
1313         .ndo_uninit             = ip_tunnel_uninit,
1314         .ndo_start_xmit         = erspan_xmit,
1315         .ndo_set_mac_address    = eth_mac_addr,
1316         .ndo_validate_addr      = eth_validate_addr,
1317         .ndo_change_mtu         = ip_tunnel_change_mtu,
1318         .ndo_get_stats64        = dev_get_tstats64,
1319         .ndo_get_iflink         = ip_tunnel_get_iflink,
1320         .ndo_fill_metadata_dst  = gre_fill_metadata_dst,
1321 };
1322
1323 static void ipgre_tap_setup(struct net_device *dev)
1324 {
1325         ether_setup(dev);
1326         dev->max_mtu = 0;
1327         dev->netdev_ops = &gre_tap_netdev_ops;
1328         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1329         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1330         ip_tunnel_setup(dev, gre_tap_net_id);
1331 }
1332
1333 static int
1334 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1335 {
1336         struct ip_tunnel_encap ipencap;
1337
1338         if (ipgre_netlink_encap_parms(data, &ipencap)) {
1339                 struct ip_tunnel *t = netdev_priv(dev);
1340                 int err = ip_tunnel_encap_setup(t, &ipencap);
1341
1342                 if (err < 0)
1343                         return err;
1344         }
1345
1346         return 0;
1347 }
1348
1349 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1350                          struct nlattr *tb[], struct nlattr *data[],
1351                          struct netlink_ext_ack *extack)
1352 {
1353         struct ip_tunnel_parm p;
1354         __u32 fwmark = 0;
1355         int err;
1356
1357         err = ipgre_newlink_encap_setup(dev, data);
1358         if (err)
1359                 return err;
1360
1361         err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1362         if (err < 0)
1363                 return err;
1364         return ip_tunnel_newlink(dev, tb, &p, fwmark);
1365 }
1366
1367 static int erspan_newlink(struct net *src_net, struct net_device *dev,
1368                           struct nlattr *tb[], struct nlattr *data[],
1369                           struct netlink_ext_ack *extack)
1370 {
1371         struct ip_tunnel_parm p;
1372         __u32 fwmark = 0;
1373         int err;
1374
1375         err = ipgre_newlink_encap_setup(dev, data);
1376         if (err)
1377                 return err;
1378
1379         err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1380         if (err)
1381                 return err;
1382         return ip_tunnel_newlink(dev, tb, &p, fwmark);
1383 }
1384
1385 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1386                             struct nlattr *data[],
1387                             struct netlink_ext_ack *extack)
1388 {
1389         struct ip_tunnel *t = netdev_priv(dev);
1390         __u32 fwmark = t->fwmark;
1391         struct ip_tunnel_parm p;
1392         int err;
1393
1394         err = ipgre_newlink_encap_setup(dev, data);
1395         if (err)
1396                 return err;
1397
1398         err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1399         if (err < 0)
1400                 return err;
1401
1402         err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1403         if (err < 0)
1404                 return err;
1405
1406         t->parms.i_flags = p.i_flags;
1407         t->parms.o_flags = p.o_flags;
1408
1409         ipgre_link_update(dev, !tb[IFLA_MTU]);
1410
1411         return 0;
1412 }
1413
1414 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1415                              struct nlattr *data[],
1416                              struct netlink_ext_ack *extack)
1417 {
1418         struct ip_tunnel *t = netdev_priv(dev);
1419         __u32 fwmark = t->fwmark;
1420         struct ip_tunnel_parm p;
1421         int err;
1422
1423         err = ipgre_newlink_encap_setup(dev, data);
1424         if (err)
1425                 return err;
1426
1427         err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1428         if (err < 0)
1429                 return err;
1430
1431         err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1432         if (err < 0)
1433                 return err;
1434
1435         t->parms.i_flags = p.i_flags;
1436         t->parms.o_flags = p.o_flags;
1437
1438         return 0;
1439 }
1440
1441 static size_t ipgre_get_size(const struct net_device *dev)
1442 {
1443         return
1444                 /* IFLA_GRE_LINK */
1445                 nla_total_size(4) +
1446                 /* IFLA_GRE_IFLAGS */
1447                 nla_total_size(2) +
1448                 /* IFLA_GRE_OFLAGS */
1449                 nla_total_size(2) +
1450                 /* IFLA_GRE_IKEY */
1451                 nla_total_size(4) +
1452                 /* IFLA_GRE_OKEY */
1453                 nla_total_size(4) +
1454                 /* IFLA_GRE_LOCAL */
1455                 nla_total_size(4) +
1456                 /* IFLA_GRE_REMOTE */
1457                 nla_total_size(4) +
1458                 /* IFLA_GRE_TTL */
1459                 nla_total_size(1) +
1460                 /* IFLA_GRE_TOS */
1461                 nla_total_size(1) +
1462                 /* IFLA_GRE_PMTUDISC */
1463                 nla_total_size(1) +
1464                 /* IFLA_GRE_ENCAP_TYPE */
1465                 nla_total_size(2) +
1466                 /* IFLA_GRE_ENCAP_FLAGS */
1467                 nla_total_size(2) +
1468                 /* IFLA_GRE_ENCAP_SPORT */
1469                 nla_total_size(2) +
1470                 /* IFLA_GRE_ENCAP_DPORT */
1471                 nla_total_size(2) +
1472                 /* IFLA_GRE_COLLECT_METADATA */
1473                 nla_total_size(0) +
1474                 /* IFLA_GRE_IGNORE_DF */
1475                 nla_total_size(1) +
1476                 /* IFLA_GRE_FWMARK */
1477                 nla_total_size(4) +
1478                 /* IFLA_GRE_ERSPAN_INDEX */
1479                 nla_total_size(4) +
1480                 /* IFLA_GRE_ERSPAN_VER */
1481                 nla_total_size(1) +
1482                 /* IFLA_GRE_ERSPAN_DIR */
1483                 nla_total_size(1) +
1484                 /* IFLA_GRE_ERSPAN_HWID */
1485                 nla_total_size(2) +
1486                 0;
1487 }
1488
1489 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1490 {
1491         struct ip_tunnel *t = netdev_priv(dev);
1492         struct ip_tunnel_parm *p = &t->parms;
1493         __be16 o_flags = p->o_flags;
1494
1495         if (t->erspan_ver <= 2) {
1496                 if (t->erspan_ver != 0 && !t->collect_md)
1497                         o_flags |= TUNNEL_KEY;
1498
1499                 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1500                         goto nla_put_failure;
1501
1502                 if (t->erspan_ver == 1) {
1503                         if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1504                                 goto nla_put_failure;
1505                 } else if (t->erspan_ver == 2) {
1506                         if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1507                                 goto nla_put_failure;
1508                         if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1509                                 goto nla_put_failure;
1510                 }
1511         }
1512
1513         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1514             nla_put_be16(skb, IFLA_GRE_IFLAGS,
1515                          gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1516             nla_put_be16(skb, IFLA_GRE_OFLAGS,
1517                          gre_tnl_flags_to_gre_flags(o_flags)) ||
1518             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1519             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1520             nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1521             nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1522             nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1523             nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1524             nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1525                        !!(p->iph.frag_off & htons(IP_DF))) ||
1526             nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1527                 goto nla_put_failure;
1528
1529         if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1530                         t->encap.type) ||
1531             nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1532                          t->encap.sport) ||
1533             nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1534                          t->encap.dport) ||
1535             nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1536                         t->encap.flags))
1537                 goto nla_put_failure;
1538
1539         if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1540                 goto nla_put_failure;
1541
1542         if (t->collect_md) {
1543                 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1544                         goto nla_put_failure;
1545         }
1546
1547         return 0;
1548
1549 nla_put_failure:
1550         return -EMSGSIZE;
1551 }
1552
1553 static void erspan_setup(struct net_device *dev)
1554 {
1555         struct ip_tunnel *t = netdev_priv(dev);
1556
1557         ether_setup(dev);
1558         dev->max_mtu = 0;
1559         dev->netdev_ops = &erspan_netdev_ops;
1560         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1561         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1562         ip_tunnel_setup(dev, erspan_net_id);
1563         t->erspan_ver = 1;
1564 }
1565
1566 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1567         [IFLA_GRE_LINK]         = { .type = NLA_U32 },
1568         [IFLA_GRE_IFLAGS]       = { .type = NLA_U16 },
1569         [IFLA_GRE_OFLAGS]       = { .type = NLA_U16 },
1570         [IFLA_GRE_IKEY]         = { .type = NLA_U32 },
1571         [IFLA_GRE_OKEY]         = { .type = NLA_U32 },
1572         [IFLA_GRE_LOCAL]        = { .len = sizeof_field(struct iphdr, saddr) },
1573         [IFLA_GRE_REMOTE]       = { .len = sizeof_field(struct iphdr, daddr) },
1574         [IFLA_GRE_TTL]          = { .type = NLA_U8 },
1575         [IFLA_GRE_TOS]          = { .type = NLA_U8 },
1576         [IFLA_GRE_PMTUDISC]     = { .type = NLA_U8 },
1577         [IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1578         [IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1579         [IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1580         [IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1581         [IFLA_GRE_COLLECT_METADATA]     = { .type = NLA_FLAG },
1582         [IFLA_GRE_IGNORE_DF]    = { .type = NLA_U8 },
1583         [IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
1584         [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1585         [IFLA_GRE_ERSPAN_VER]   = { .type = NLA_U8 },
1586         [IFLA_GRE_ERSPAN_DIR]   = { .type = NLA_U8 },
1587         [IFLA_GRE_ERSPAN_HWID]  = { .type = NLA_U16 },
1588 };
1589
1590 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1591         .kind           = "gre",
1592         .maxtype        = IFLA_GRE_MAX,
1593         .policy         = ipgre_policy,
1594         .priv_size      = sizeof(struct ip_tunnel),
1595         .setup          = ipgre_tunnel_setup,
1596         .validate       = ipgre_tunnel_validate,
1597         .newlink        = ipgre_newlink,
1598         .changelink     = ipgre_changelink,
1599         .dellink        = ip_tunnel_dellink,
1600         .get_size       = ipgre_get_size,
1601         .fill_info      = ipgre_fill_info,
1602         .get_link_net   = ip_tunnel_get_link_net,
1603 };
1604
1605 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1606         .kind           = "gretap",
1607         .maxtype        = IFLA_GRE_MAX,
1608         .policy         = ipgre_policy,
1609         .priv_size      = sizeof(struct ip_tunnel),
1610         .setup          = ipgre_tap_setup,
1611         .validate       = ipgre_tap_validate,
1612         .newlink        = ipgre_newlink,
1613         .changelink     = ipgre_changelink,
1614         .dellink        = ip_tunnel_dellink,
1615         .get_size       = ipgre_get_size,
1616         .fill_info      = ipgre_fill_info,
1617         .get_link_net   = ip_tunnel_get_link_net,
1618 };
1619
1620 static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1621         .kind           = "erspan",
1622         .maxtype        = IFLA_GRE_MAX,
1623         .policy         = ipgre_policy,
1624         .priv_size      = sizeof(struct ip_tunnel),
1625         .setup          = erspan_setup,
1626         .validate       = erspan_validate,
1627         .newlink        = erspan_newlink,
1628         .changelink     = erspan_changelink,
1629         .dellink        = ip_tunnel_dellink,
1630         .get_size       = ipgre_get_size,
1631         .fill_info      = ipgre_fill_info,
1632         .get_link_net   = ip_tunnel_get_link_net,
1633 };
1634
1635 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1636                                         u8 name_assign_type)
1637 {
1638         struct nlattr *tb[IFLA_MAX + 1];
1639         struct net_device *dev;
1640         LIST_HEAD(list_kill);
1641         struct ip_tunnel *t;
1642         int err;
1643
1644         memset(&tb, 0, sizeof(tb));
1645
1646         dev = rtnl_create_link(net, name, name_assign_type,
1647                                &ipgre_tap_ops, tb, NULL);
1648         if (IS_ERR(dev))
1649                 return dev;
1650
1651         /* Configure flow based GRE device. */
1652         t = netdev_priv(dev);
1653         t->collect_md = true;
1654
1655         err = ipgre_newlink(net, dev, tb, NULL, NULL);
1656         if (err < 0) {
1657                 free_netdev(dev);
1658                 return ERR_PTR(err);
1659         }
1660
1661         /* openvswitch users expect packet sizes to be unrestricted,
1662          * so set the largest MTU we can.
1663          */
1664         err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1665         if (err)
1666                 goto out;
1667
1668         err = rtnl_configure_link(dev, NULL);
1669         if (err < 0)
1670                 goto out;
1671
1672         return dev;
1673 out:
1674         ip_tunnel_dellink(dev, &list_kill);
1675         unregister_netdevice_many(&list_kill);
1676         return ERR_PTR(err);
1677 }
1678 EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1679
1680 static int __net_init ipgre_tap_init_net(struct net *net)
1681 {
1682         return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1683 }
1684
1685 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
1686 {
1687         ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
1688 }
1689
1690 static struct pernet_operations ipgre_tap_net_ops = {
1691         .init = ipgre_tap_init_net,
1692         .exit_batch = ipgre_tap_exit_batch_net,
1693         .id   = &gre_tap_net_id,
1694         .size = sizeof(struct ip_tunnel_net),
1695 };
1696
1697 static int __net_init erspan_init_net(struct net *net)
1698 {
1699         return ip_tunnel_init_net(net, erspan_net_id,
1700                                   &erspan_link_ops, "erspan0");
1701 }
1702
1703 static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
1704 {
1705         ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
1706 }
1707
1708 static struct pernet_operations erspan_net_ops = {
1709         .init = erspan_init_net,
1710         .exit_batch = erspan_exit_batch_net,
1711         .id   = &erspan_net_id,
1712         .size = sizeof(struct ip_tunnel_net),
1713 };
1714
1715 static int __init ipgre_init(void)
1716 {
1717         int err;
1718
1719         pr_info("GRE over IPv4 tunneling driver\n");
1720
1721         err = register_pernet_device(&ipgre_net_ops);
1722         if (err < 0)
1723                 return err;
1724
1725         err = register_pernet_device(&ipgre_tap_net_ops);
1726         if (err < 0)
1727                 goto pnet_tap_failed;
1728
1729         err = register_pernet_device(&erspan_net_ops);
1730         if (err < 0)
1731                 goto pnet_erspan_failed;
1732
1733         err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1734         if (err < 0) {
1735                 pr_info("%s: can't add protocol\n", __func__);
1736                 goto add_proto_failed;
1737         }
1738
1739         err = rtnl_link_register(&ipgre_link_ops);
1740         if (err < 0)
1741                 goto rtnl_link_failed;
1742
1743         err = rtnl_link_register(&ipgre_tap_ops);
1744         if (err < 0)
1745                 goto tap_ops_failed;
1746
1747         err = rtnl_link_register(&erspan_link_ops);
1748         if (err < 0)
1749                 goto erspan_link_failed;
1750
1751         return 0;
1752
1753 erspan_link_failed:
1754         rtnl_link_unregister(&ipgre_tap_ops);
1755 tap_ops_failed:
1756         rtnl_link_unregister(&ipgre_link_ops);
1757 rtnl_link_failed:
1758         gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1759 add_proto_failed:
1760         unregister_pernet_device(&erspan_net_ops);
1761 pnet_erspan_failed:
1762         unregister_pernet_device(&ipgre_tap_net_ops);
1763 pnet_tap_failed:
1764         unregister_pernet_device(&ipgre_net_ops);
1765         return err;
1766 }
1767
1768 static void __exit ipgre_fini(void)
1769 {
1770         rtnl_link_unregister(&ipgre_tap_ops);
1771         rtnl_link_unregister(&ipgre_link_ops);
1772         rtnl_link_unregister(&erspan_link_ops);
1773         gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1774         unregister_pernet_device(&ipgre_tap_net_ops);
1775         unregister_pernet_device(&ipgre_net_ops);
1776         unregister_pernet_device(&erspan_net_ops);
1777 }
1778
1779 module_init(ipgre_init);
1780 module_exit(ipgre_fini);
1781 MODULE_LICENSE("GPL");
1782 MODULE_ALIAS_RTNL_LINK("gre");
1783 MODULE_ALIAS_RTNL_LINK("gretap");
1784 MODULE_ALIAS_RTNL_LINK("erspan");
1785 MODULE_ALIAS_NETDEV("gre0");
1786 MODULE_ALIAS_NETDEV("gretap0");
1787 MODULE_ALIAS_NETDEV("erspan0");