net/ipv6/ip6_gre.c

   1 /*
   2  *      GRE over IPv6 protocol decoder.
   3  *
   4  *      Authors: Dmitry Kozlov (xeb@mail.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 <linux/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/init.h>
  28 #include <linux/in6.h>
  29 #include <linux/inetdevice.h>
  30 #include <linux/igmp.h>
  31 #include <linux/netfilter_ipv4.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/if_ether.h>
  34 #include <linux/hash.h>
  35 #include <linux/if_tunnel.h>
  36 #include <linux/ip6_tunnel.h>
  37
  38 #include <net/sock.h>
  39 #include <net/ip.h>
  40 #include <net/ip_tunnels.h>
  41 #include <net/icmp.h>
  42 #include <net/protocol.h>
  43 #include <net/addrconf.h>
  44 #include <net/arp.h>
  45 #include <net/checksum.h>
  46 #include <net/dsfield.h>
  47 #include <net/inet_ecn.h>
  48 #include <net/xfrm.h>
  49 #include <net/net_namespace.h>
  50 #include <net/netns/generic.h>
  51 #include <net/rtnetlink.h>
  52
  53 #include <net/ipv6.h>
  54 #include <net/ip6_fib.h>
  55 #include <net/ip6_route.h>
  56 #include <net/ip6_tunnel.h>
  57 #include <net/gre.h>
  58
  59
  60 static bool log_ecn_error = true;
  61 module_param(log_ecn_error, bool, 0644);
  62 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  63
  64 #define IP6_GRE_HASH_SIZE_SHIFT  5
  65 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
  66
  67 static unsigned int ip6gre_net_id __read_mostly;
  68 struct ip6gre_net {
  69         struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
  70
  71         struct net_device *fb_tunnel_dev;
  72 };
  73
  74 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  75 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
  76 static int ip6gre_tunnel_init(struct net_device *dev);
  77 static void ip6gre_tunnel_setup(struct net_device *dev);
  78 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  79 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  80
  81 /* Tunnel hash table */
  82
  83 /*
  84    4 hash tables:
  85
  86    3: (remote,local)
  87    2: (remote,*)
  88    1: (*,local)
  89    0: (*,*)
  90
  91    We require exact key match i.e. if a key is present in packet
  92    it will match only tunnel with the same key; if it is not present,
  93    it will match only keyless tunnel.
  94
  95    All keysless packets, if not matched configured keyless tunnels
  96    will match fallback tunnel.
  97  */
  98
  99 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
 100 static u32 HASH_ADDR(const struct in6_addr *addr)
 101 {
 102         u32 hash = ipv6_addr_hash(addr);
 103
 104         return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
 105 }
 106
 107 #define tunnels_r_l     tunnels[3]
 108 #define tunnels_r       tunnels[2]
 109 #define tunnels_l       tunnels[1]
 110 #define tunnels_wc      tunnels[0]
 111
 112 /* Given src, dst and key, find appropriate for input tunnel. */
 113
 114 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 115                 const struct in6_addr *remote, const struct in6_addr *local,
 116                 __be32 key, __be16 gre_proto)
 117 {
 118         struct net *net = dev_net(dev);
 119         int link = dev->ifindex;
 120         unsigned int h0 = HASH_ADDR(remote);
 121         unsigned int h1 = HASH_KEY(key);
 122         struct ip6_tnl *t, *cand = NULL;
 123         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 124         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 125                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 126         int score, cand_score = 4;
 127
 128         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 129                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 130                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 131                     key != t->parms.i_key ||
 132                     !(t->dev->flags & IFF_UP))
 133                         continue;
 134
 135                 if (t->dev->type != ARPHRD_IP6GRE &&
 136                     t->dev->type != dev_type)
 137                         continue;
 138
 139                 score = 0;
 140                 if (t->parms.link != link)
 141                         score |= 1;
 142                 if (t->dev->type != dev_type)
 143                         score |= 2;
 144                 if (score == 0)
 145                         return t;
 146
 147                 if (score < cand_score) {
 148                         cand = t;
 149                         cand_score = score;
 150                 }
 151         }
 152
 153         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 154                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 155                     key != t->parms.i_key ||
 156                     !(t->dev->flags & IFF_UP))
 157                         continue;
 158
 159                 if (t->dev->type != ARPHRD_IP6GRE &&
 160                     t->dev->type != dev_type)
 161                         continue;
 162
 163                 score = 0;
 164                 if (t->parms.link != link)
 165                         score |= 1;
 166                 if (t->dev->type != dev_type)
 167                         score |= 2;
 168                 if (score == 0)
 169                         return t;
 170
 171                 if (score < cand_score) {
 172                         cand = t;
 173                         cand_score = score;
 174                 }
 175         }
 176
 177         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 178                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 179                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 180                                  !ipv6_addr_is_multicast(local))) ||
 181                     key != t->parms.i_key ||
 182                     !(t->dev->flags & IFF_UP))
 183                         continue;
 184
 185                 if (t->dev->type != ARPHRD_IP6GRE &&
 186                     t->dev->type != dev_type)
 187                         continue;
 188
 189                 score = 0;
 190                 if (t->parms.link != link)
 191                         score |= 1;
 192                 if (t->dev->type != dev_type)
 193                         score |= 2;
 194                 if (score == 0)
 195                         return t;
 196
 197                 if (score < cand_score) {
 198                         cand = t;
 199                         cand_score = score;
 200                 }
 201         }
 202
 203         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 204                 if (t->parms.i_key != key ||
 205                     !(t->dev->flags & IFF_UP))
 206                         continue;
 207
 208                 if (t->dev->type != ARPHRD_IP6GRE &&
 209                     t->dev->type != dev_type)
 210                         continue;
 211
 212                 score = 0;
 213                 if (t->parms.link != link)
 214                         score |= 1;
 215                 if (t->dev->type != dev_type)
 216                         score |= 2;
 217                 if (score == 0)
 218                         return t;
 219
 220                 if (score < cand_score) {
 221                         cand = t;
 222                         cand_score = score;
 223                 }
 224         }
 225
 226         if (cand)
 227                 return cand;
 228
 229         dev = ign->fb_tunnel_dev;
 230         if (dev->flags & IFF_UP)
 231                 return netdev_priv(dev);
 232
 233         return NULL;
 234 }
 235
 236 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 237                 const struct __ip6_tnl_parm *p)
 238 {
 239         const struct in6_addr *remote = &p->raddr;
 240         const struct in6_addr *local = &p->laddr;
 241         unsigned int h = HASH_KEY(p->i_key);
 242         int prio = 0;
 243
 244         if (!ipv6_addr_any(local))
 245                 prio |= 1;
 246         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 247                 prio |= 2;
 248                 h ^= HASH_ADDR(remote);
 249         }
 250
 251         return &ign->tunnels[prio][h];
 252 }
 253
 254 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 255                 const struct ip6_tnl *t)
 256 {
 257         return __ip6gre_bucket(ign, &t->parms);
 258 }
 259
 260 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 261 {
 262         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 263
 264         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 265         rcu_assign_pointer(*tp, t);
 266 }
 267
 268 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 269 {
 270         struct ip6_tnl __rcu **tp;
 271         struct ip6_tnl *iter;
 272
 273         for (tp = ip6gre_bucket(ign, t);
 274              (iter = rtnl_dereference(*tp)) != NULL;
 275              tp = &iter->next) {
 276                 if (t == iter) {
 277                         rcu_assign_pointer(*tp, t->next);
 278                         break;
 279                 }
 280         }
 281 }
 282
 283 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 284                                            const struct __ip6_tnl_parm *parms,
 285                                            int type)
 286 {
 287         const struct in6_addr *remote = &parms->raddr;
 288         const struct in6_addr *local = &parms->laddr;
 289         __be32 key = parms->i_key;
 290         int link = parms->link;
 291         struct ip6_tnl *t;
 292         struct ip6_tnl __rcu **tp;
 293         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 294
 295         for (tp = __ip6gre_bucket(ign, parms);
 296              (t = rtnl_dereference(*tp)) != NULL;
 297              tp = &t->next)
 298                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 299                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 300                     key == t->parms.i_key &&
 301                     link == t->parms.link &&
 302                     type == t->dev->type)
 303                         break;
 304
 305         return t;
 306 }
 307
 308 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 309                 const struct __ip6_tnl_parm *parms, int create)
 310 {
 311         struct ip6_tnl *t, *nt;
 312         struct net_device *dev;
 313         char name[IFNAMSIZ];
 314         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 315
 316         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 317         if (t && create)
 318                 return NULL;
 319         if (t || !create)
 320                 return t;
 321
 322         if (parms->name[0])
 323                 strlcpy(name, parms->name, IFNAMSIZ);
 324         else
 325                 strcpy(name, "ip6gre%d");
 326
 327         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 328                            ip6gre_tunnel_setup);
 329         if (!dev)
 330                 return NULL;
 331
 332         dev_net_set(dev, net);
 333
 334         nt = netdev_priv(dev);
 335         nt->parms = *parms;
 336         dev->rtnl_link_ops = &ip6gre_link_ops;
 337
 338         nt->dev = dev;
 339         nt->net = dev_net(dev);
 340         ip6gre_tnl_link_config(nt, 1);
 341
 342         if (register_netdevice(dev) < 0)
 343                 goto failed_free;
 344
 345         /* Can use a lockless transmit, unless we generate output sequences */
 346         if (!(nt->parms.o_flags & TUNNEL_SEQ))
 347                 dev->features |= NETIF_F_LLTX;
 348
 349         dev_hold(dev);
 350         ip6gre_tunnel_link(ign, nt);
 351         return nt;
 352
 353 failed_free:
 354         free_netdev(dev);
 355         return NULL;
 356 }
 357
 358 static void ip6gre_tunnel_uninit(struct net_device *dev)
 359 {
 360         struct ip6_tnl *t = netdev_priv(dev);
 361         struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 362
 363         ip6gre_tunnel_unlink(ign, t);
 364         dst_cache_reset(&t->dst_cache);
 365         dev_put(dev);
 366 }
 367
 368
 369 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 370                        u8 type, u8 code, int offset, __be32 info)
 371 {
 372         const struct gre_base_hdr *greh;
 373         const struct ipv6hdr *ipv6h;
 374         int grehlen = sizeof(*greh);
 375         struct ip6_tnl *t;
 376         int key_off = 0;
 377         __be16 flags;
 378         __be32 key;
 379
 380         if (!pskb_may_pull(skb, offset + grehlen))
 381                 return;
 382         greh = (const struct gre_base_hdr *)(skb->data + offset);
 383         flags = greh->flags;
 384         if (flags & (GRE_VERSION | GRE_ROUTING))
 385                 return;
 386         if (flags & GRE_CSUM)
 387                 grehlen += 4;
 388         if (flags & GRE_KEY) {
 389                 key_off = grehlen + offset;
 390                 grehlen += 4;
 391         }
 392
 393         if (!pskb_may_pull(skb, offset + grehlen))
 394                 return;
 395         ipv6h = (const struct ipv6hdr *)skb->data;
 396         greh = (const struct gre_base_hdr *)(skb->data + offset);
 397         key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
 398
 399         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 400                                  key, greh->protocol);
 401         if (!t)
 402                 return;
 403
 404         switch (type) {
 405                 __u32 teli;
 406                 struct ipv6_tlv_tnl_enc_lim *tel;
 407                 __u32 mtu;
 408         case ICMPV6_DEST_UNREACH:
 409                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 410                                     t->parms.name);
 411                 break;
 412         case ICMPV6_TIME_EXCEED:
 413                 if (code == ICMPV6_EXC_HOPLIMIT) {
 414                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 415                                             t->parms.name);
 416                 }
 417                 break;
 418         case ICMPV6_PARAMPROB:
 419                 teli = 0;
 420                 if (code == ICMPV6_HDR_FIELD)
 421                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 422
 423                 if (teli && teli == be32_to_cpu(info) - 2) {
 424                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 425                         if (tel->encap_limit == 0) {
 426                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 427                                                     t->parms.name);
 428                         }
 429                 } else {
 430                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 431                                             t->parms.name);
 432                 }
 433                 break;
 434         case ICMPV6_PKT_TOOBIG:
 435                 mtu = be32_to_cpu(info) - offset - t->tun_hlen;
 436                 if (t->dev->type == ARPHRD_ETHER)
 437                         mtu -= ETH_HLEN;
 438                 if (mtu < IPV6_MIN_MTU)
 439                         mtu = IPV6_MIN_MTU;
 440                 t->dev->mtu = mtu;
 441                 break;
 442         }
 443
 444         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 445                 t->err_count++;
 446         else
 447                 t->err_count = 1;
 448         t->err_time = jiffies;
 449 }
 450
 451 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 452 {
 453         const struct ipv6hdr *ipv6h;
 454         struct ip6_tnl *tunnel;
 455
 456         ipv6h = ipv6_hdr(skb);
 457         tunnel = ip6gre_tunnel_lookup(skb->dev,
 458                                       &ipv6h->saddr, &ipv6h->daddr, tpi->key,
 459                                       tpi->proto);
 460         if (tunnel) {
 461                 ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
 462
 463                 return PACKET_RCVD;
 464         }
 465
 466         return PACKET_REJECT;
 467 }
 468
 469 static int gre_rcv(struct sk_buff *skb)
 470 {
 471         struct tnl_ptk_info tpi;
 472         bool csum_err = false;
 473         int hdr_len;
 474
 475         hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
 476         if (hdr_len < 0)
 477                 goto drop;
 478
 479         if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
 480                 goto drop;
 481
 482         if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
 483                 return 0;
 484
 485         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 486 drop:
 487         kfree_skb(skb);
 488         return 0;
 489 }
 490
 491 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 492 {
 493         return iptunnel_handle_offloads(skb,
 494                                         csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 495 }
 496
 497 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 498                                struct net_device *dev, __u8 dsfield,
 499                                struct flowi6 *fl6, int encap_limit,
 500                                __u32 *pmtu, __be16 proto)
 501 {
 502         struct ip6_tnl *tunnel = netdev_priv(dev);
 503         __be16 protocol = (dev->type == ARPHRD_ETHER) ?
 504                           htons(ETH_P_TEB) : proto;
 505
 506         if (dev->type == ARPHRD_ETHER)
 507                 IPCB(skb)->flags = 0;
 508
 509         if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
 510                 fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
 511         else
 512                 fl6->daddr = tunnel->parms.raddr;
 513
 514         if (tunnel->parms.o_flags & TUNNEL_SEQ)
 515                 tunnel->o_seqno++;
 516
 517         /* Push GRE header. */
 518         gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
 519                          protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
 520
 521         return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
 522                             NEXTHDR_GRE);
 523 }
 524
 525 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 526 {
 527         struct ip6_tnl *t = netdev_priv(dev);
 528         const struct iphdr  *iph = ip_hdr(skb);
 529         int encap_limit = -1;
 530         struct flowi6 fl6;
 531         __u8 dsfield;
 532         __u32 mtu;
 533         int err;
 534
 535         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 536
 537         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 538                 encap_limit = t->parms.encap_limit;
 539
 540         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 541
 542         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 543                 dsfield = ipv4_get_dsfield(iph);
 544         else
 545                 dsfield = ip6_tclass(t->parms.flowinfo);
 546         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 547                 fl6.flowi6_mark = skb->mark;
 548         else
 549                 fl6.flowi6_mark = t->parms.fwmark;
 550
 551         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 552
 553         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 554         if (err)
 555                 return -1;
 556
 557         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
 558                           skb->protocol);
 559         if (err != 0) {
 560                 /* XXX: send ICMP error even if DF is not set. */
 561                 if (err == -EMSGSIZE)
 562                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 563                                   htonl(mtu));
 564                 return -1;
 565         }
 566
 567         return 0;
 568 }
 569
 570 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 571 {
 572         struct ip6_tnl *t = netdev_priv(dev);
 573         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 574         int encap_limit = -1;
 575         __u16 offset;
 576         struct flowi6 fl6;
 577         __u8 dsfield;
 578         __u32 mtu;
 579         int err;
 580
 581         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 582                 return -1;
 583
 584         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 585         /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
 586         ipv6h = ipv6_hdr(skb);
 587
 588         if (offset > 0) {
 589                 struct ipv6_tlv_tnl_enc_lim *tel;
 590                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 591                 if (tel->encap_limit == 0) {
 592                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 593                                     ICMPV6_HDR_FIELD, offset + 2);
 594                         return -1;
 595                 }
 596                 encap_limit = tel->encap_limit - 1;
 597         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 598                 encap_limit = t->parms.encap_limit;
 599
 600         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 601
 602         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 603                 dsfield = ipv6_get_dsfield(ipv6h);
 604         else
 605                 dsfield = ip6_tclass(t->parms.flowinfo);
 606
 607         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 608                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 609         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 610                 fl6.flowi6_mark = skb->mark;
 611         else
 612                 fl6.flowi6_mark = t->parms.fwmark;
 613
 614         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 615
 616         if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
 617                 return -1;
 618
 619         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
 620                           &mtu, skb->protocol);
 621         if (err != 0) {
 622                 if (err == -EMSGSIZE)
 623                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 624                 return -1;
 625         }
 626
 627         return 0;
 628 }
 629
 630 /**
 631  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 632  *   @t: the outgoing tunnel device
 633  *   @hdr: IPv6 header from the incoming packet
 634  *
 635  * Description:
 636  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 637  *   doesn't match source of incoming packet.
 638  *
 639  * Return:
 640  *   1 if conflict,
 641  *   0 else
 642  **/
 643
 644 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 645         const struct ipv6hdr *hdr)
 646 {
 647         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 648 }
 649
 650 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 651 {
 652         struct ip6_tnl *t = netdev_priv(dev);
 653         int encap_limit = -1;
 654         struct flowi6 fl6;
 655         __u32 mtu;
 656         int err;
 657
 658         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 659                 encap_limit = t->parms.encap_limit;
 660
 661         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 662
 663         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 664         if (err)
 665                 return err;
 666
 667         err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
 668
 669         return err;
 670 }
 671
 672 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 673         struct net_device *dev)
 674 {
 675         struct ip6_tnl *t = netdev_priv(dev);
 676         struct net_device_stats *stats = &t->dev->stats;
 677         int ret;
 678
 679         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 680                 goto tx_err;
 681
 682         switch (skb->protocol) {
 683         case htons(ETH_P_IP):
 684                 ret = ip6gre_xmit_ipv4(skb, dev);
 685                 break;
 686         case htons(ETH_P_IPV6):
 687                 ret = ip6gre_xmit_ipv6(skb, dev);
 688                 break;
 689         default:
 690                 ret = ip6gre_xmit_other(skb, dev);
 691                 break;
 692         }
 693
 694         if (ret < 0)
 695                 goto tx_err;
 696
 697         return NETDEV_TX_OK;
 698
 699 tx_err:
 700         stats->tx_errors++;
 701         stats->tx_dropped++;
 702         kfree_skb(skb);
 703         return NETDEV_TX_OK;
 704 }
 705
 706 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 707 {
 708         struct net_device *dev = t->dev;
 709         struct __ip6_tnl_parm *p = &t->parms;
 710         struct flowi6 *fl6 = &t->fl.u.ip6;
 711         int t_hlen;
 712
 713         if (dev->type != ARPHRD_ETHER) {
 714                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 715                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 716         }
 717
 718         /* Set up flowi template */
 719         fl6->saddr = p->laddr;
 720         fl6->daddr = p->raddr;
 721         fl6->flowi6_oif = p->link;
 722         fl6->flowlabel = 0;
 723         fl6->flowi6_proto = IPPROTO_GRE;
 724
 725         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 726                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 727         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 728                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 729
 730         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 731         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 732
 733         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 734                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 735                 dev->flags |= IFF_POINTOPOINT;
 736         else
 737                 dev->flags &= ~IFF_POINTOPOINT;
 738
 739         t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
 740
 741         t->hlen = t->encap_hlen + t->tun_hlen;
 742
 743         t_hlen = t->hlen + sizeof(struct ipv6hdr);
 744
 745         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 746                 int strict = (ipv6_addr_type(&p->raddr) &
 747                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 748
 749                 struct rt6_info *rt = rt6_lookup(t->net,
 750                                                  &p->raddr, &p->laddr,
 751                                                  p->link, strict);
 752
 753                 if (!rt)
 754                         return;
 755
 756                 if (rt->dst.dev) {
 757                         dev->hard_header_len = rt->dst.dev->hard_header_len +
 758                                                t_hlen;
 759
 760                         if (set_mtu) {
 761                                 dev->mtu = rt->dst.dev->mtu - t_hlen;
 762                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 763                                         dev->mtu -= 8;
 764                                 if (dev->type == ARPHRD_ETHER)
 765                                         dev->mtu -= ETH_HLEN;
 766
 767                                 if (dev->mtu < IPV6_MIN_MTU)
 768                                         dev->mtu = IPV6_MIN_MTU;
 769                         }
 770                 }
 771                 ip6_rt_put(rt);
 772         }
 773 }
 774
 775 static int ip6gre_tnl_change(struct ip6_tnl *t,
 776         const struct __ip6_tnl_parm *p, int set_mtu)
 777 {
 778         t->parms.laddr = p->laddr;
 779         t->parms.raddr = p->raddr;
 780         t->parms.flags = p->flags;
 781         t->parms.hop_limit = p->hop_limit;
 782         t->parms.encap_limit = p->encap_limit;
 783         t->parms.flowinfo = p->flowinfo;
 784         t->parms.link = p->link;
 785         t->parms.proto = p->proto;
 786         t->parms.i_key = p->i_key;
 787         t->parms.o_key = p->o_key;
 788         t->parms.i_flags = p->i_flags;
 789         t->parms.o_flags = p->o_flags;
 790         t->parms.fwmark = p->fwmark;
 791         dst_cache_reset(&t->dst_cache);
 792         ip6gre_tnl_link_config(t, set_mtu);
 793         return 0;
 794 }
 795
 796 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
 797         const struct ip6_tnl_parm2 *u)
 798 {
 799         p->laddr = u->laddr;
 800         p->raddr = u->raddr;
 801         p->flags = u->flags;
 802         p->hop_limit = u->hop_limit;
 803         p->encap_limit = u->encap_limit;
 804         p->flowinfo = u->flowinfo;
 805         p->link = u->link;
 806         p->i_key = u->i_key;
 807         p->o_key = u->o_key;
 808         p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
 809         p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
 810         memcpy(p->name, u->name, sizeof(u->name));
 811 }
 812
 813 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
 814         const struct __ip6_tnl_parm *p)
 815 {
 816         u->proto = IPPROTO_GRE;
 817         u->laddr = p->laddr;
 818         u->raddr = p->raddr;
 819         u->flags = p->flags;
 820         u->hop_limit = p->hop_limit;
 821         u->encap_limit = p->encap_limit;
 822         u->flowinfo = p->flowinfo;
 823         u->link = p->link;
 824         u->i_key = p->i_key;
 825         u->o_key = p->o_key;
 826         u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
 827         u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
 828         memcpy(u->name, p->name, sizeof(u->name));
 829 }
 830
 831 static int ip6gre_tunnel_ioctl(struct net_device *dev,
 832         struct ifreq *ifr, int cmd)
 833 {
 834         int err = 0;
 835         struct ip6_tnl_parm2 p;
 836         struct __ip6_tnl_parm p1;
 837         struct ip6_tnl *t = netdev_priv(dev);
 838         struct net *net = t->net;
 839         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 840
 841         memset(&p1, 0, sizeof(p1));
 842
 843         switch (cmd) {
 844         case SIOCGETTUNNEL:
 845                 if (dev == ign->fb_tunnel_dev) {
 846                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 847                                 err = -EFAULT;
 848                                 break;
 849                         }
 850                         ip6gre_tnl_parm_from_user(&p1, &p);
 851                         t = ip6gre_tunnel_locate(net, &p1, 0);
 852                         if (!t)
 853                                 t = netdev_priv(dev);
 854                 }
 855                 memset(&p, 0, sizeof(p));
 856                 ip6gre_tnl_parm_to_user(&p, &t->parms);
 857                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 858                         err = -EFAULT;
 859                 break;
 860
 861         case SIOCADDTUNNEL:
 862         case SIOCCHGTUNNEL:
 863                 err = -EPERM;
 864                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 865                         goto done;
 866
 867                 err = -EFAULT;
 868                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 869                         goto done;
 870
 871                 err = -EINVAL;
 872                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
 873                         goto done;
 874
 875                 if (!(p.i_flags&GRE_KEY))
 876                         p.i_key = 0;
 877                 if (!(p.o_flags&GRE_KEY))
 878                         p.o_key = 0;
 879
 880                 ip6gre_tnl_parm_from_user(&p1, &p);
 881                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
 882
 883                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 884                         if (t) {
 885                                 if (t->dev != dev) {
 886                                         err = -EEXIST;
 887                                         break;
 888                                 }
 889                         } else {
 890                                 t = netdev_priv(dev);
 891
 892                                 ip6gre_tunnel_unlink(ign, t);
 893                                 synchronize_net();
 894                                 ip6gre_tnl_change(t, &p1, 1);
 895                                 ip6gre_tunnel_link(ign, t);
 896                                 netdev_state_change(dev);
 897                         }
 898                 }
 899
 900                 if (t) {
 901                         err = 0;
 902
 903                         memset(&p, 0, sizeof(p));
 904                         ip6gre_tnl_parm_to_user(&p, &t->parms);
 905                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 906                                 err = -EFAULT;
 907                 } else
 908                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 909                 break;
 910
 911         case SIOCDELTUNNEL:
 912                 err = -EPERM;
 913                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 914                         goto done;
 915
 916                 if (dev == ign->fb_tunnel_dev) {
 917                         err = -EFAULT;
 918                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 919                                 goto done;
 920                         err = -ENOENT;
 921                         ip6gre_tnl_parm_from_user(&p1, &p);
 922                         t = ip6gre_tunnel_locate(net, &p1, 0);
 923                         if (!t)
 924                                 goto done;
 925                         err = -EPERM;
 926                         if (t == netdev_priv(ign->fb_tunnel_dev))
 927                                 goto done;
 928                         dev = t->dev;
 929                 }
 930                 unregister_netdevice(dev);
 931                 err = 0;
 932                 break;
 933
 934         default:
 935                 err = -EINVAL;
 936         }
 937
 938 done:
 939         return err;
 940 }
 941
 942 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 943                          unsigned short type, const void *daddr,
 944                          const void *saddr, unsigned int len)
 945 {
 946         struct ip6_tnl *t = netdev_priv(dev);
 947         struct ipv6hdr *ipv6h;
 948         __be16 *p;
 949
 950         ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
 951         ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
 952                                                   t->fl.u.ip6.flowlabel,
 953                                                   true, &t->fl.u.ip6));
 954         ipv6h->hop_limit = t->parms.hop_limit;
 955         ipv6h->nexthdr = NEXTHDR_GRE;
 956         ipv6h->saddr = t->parms.laddr;
 957         ipv6h->daddr = t->parms.raddr;
 958
 959         p = (__be16 *)(ipv6h + 1);
 960         p[0] = t->parms.o_flags;
 961         p[1] = htons(type);
 962
 963         /*
 964          *      Set the source hardware address.
 965          */
 966
 967         if (saddr)
 968                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
 969         if (daddr)
 970                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
 971         if (!ipv6_addr_any(&ipv6h->daddr))
 972                 return t->hlen;
 973
 974         return -t->hlen;
 975 }
 976
 977 static const struct header_ops ip6gre_header_ops = {
 978         .create = ip6gre_header,
 979 };
 980
 981 static const struct net_device_ops ip6gre_netdev_ops = {
 982         .ndo_init               = ip6gre_tunnel_init,
 983         .ndo_uninit             = ip6gre_tunnel_uninit,
 984         .ndo_start_xmit         = ip6gre_tunnel_xmit,
 985         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
 986         .ndo_change_mtu         = ip6_tnl_change_mtu,
 987         .ndo_get_stats64        = ip_tunnel_get_stats64,
 988         .ndo_get_iflink         = ip6_tnl_get_iflink,
 989 };
 990
 991 static void ip6gre_dev_free(struct net_device *dev)
 992 {
 993         struct ip6_tnl *t = netdev_priv(dev);
 994
 995         dst_cache_destroy(&t->dst_cache);
 996         free_percpu(dev->tstats);
 997 }
 998
 999 static void ip6gre_tunnel_setup(struct net_device *dev)
1000 {
1001         dev->netdev_ops = &ip6gre_netdev_ops;
1002         dev->needs_free_netdev = true;
1003         dev->priv_destructor = ip6gre_dev_free;
1004
1005         dev->type = ARPHRD_IP6GRE;
1006
1007         dev->flags |= IFF_NOARP;
1008         dev->addr_len = sizeof(struct in6_addr);
1009         netif_keep_dst(dev);
1010         /* This perm addr will be used as interface identifier by IPv6 */
1011         dev->addr_assign_type = NET_ADDR_RANDOM;
1012         eth_random_addr(dev->perm_addr);
1013 }
1014
1015 static int ip6gre_tunnel_init_common(struct net_device *dev)
1016 {
1017         struct ip6_tnl *tunnel;
1018         int ret;
1019         int t_hlen;
1020
1021         tunnel = netdev_priv(dev);
1022
1023         tunnel->dev = dev;
1024         tunnel->net = dev_net(dev);
1025         strcpy(tunnel->parms.name, dev->name);
1026
1027         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1028         if (!dev->tstats)
1029                 return -ENOMEM;
1030
1031         ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1032         if (ret) {
1033                 free_percpu(dev->tstats);
1034                 dev->tstats = NULL;
1035                 return ret;
1036         }
1037
1038         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1039         tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1040         t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1041
1042         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1043         dev->mtu = ETH_DATA_LEN - t_hlen;
1044         if (dev->type == ARPHRD_ETHER)
1045                 dev->mtu -= ETH_HLEN;
1046         if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1047                 dev->mtu -= 8;
1048
1049         return 0;
1050 }
1051
1052 static int ip6gre_tunnel_init(struct net_device *dev)
1053 {
1054         struct ip6_tnl *tunnel;
1055         int ret;
1056
1057         ret = ip6gre_tunnel_init_common(dev);
1058         if (ret)
1059                 return ret;
1060
1061         tunnel = netdev_priv(dev);
1062
1063         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1064         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1065
1066         if (ipv6_addr_any(&tunnel->parms.raddr))
1067                 dev->header_ops = &ip6gre_header_ops;
1068
1069         return 0;
1070 }
1071
1072 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1073 {
1074         struct ip6_tnl *tunnel = netdev_priv(dev);
1075
1076         tunnel->dev = dev;
1077         tunnel->net = dev_net(dev);
1078         strcpy(tunnel->parms.name, dev->name);
1079
1080         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1081
1082         dev_hold(dev);
1083 }
1084
1085
1086 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1087         .handler     = gre_rcv,
1088         .err_handler = ip6gre_err,
1089         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1090 };
1091
1092 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1093 {
1094         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1095         struct net_device *dev, *aux;
1096         int prio;
1097
1098         for_each_netdev_safe(net, dev, aux)
1099                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1100                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1101                         unregister_netdevice_queue(dev, head);
1102
1103         for (prio = 0; prio < 4; prio++) {
1104                 int h;
1105                 for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1106                         struct ip6_tnl *t;
1107
1108                         t = rtnl_dereference(ign->tunnels[prio][h]);
1109
1110                         while (t) {
1111                                 /* If dev is in the same netns, it has already
1112                                  * been added to the list by the previous loop.
1113                                  */
1114                                 if (!net_eq(dev_net(t->dev), net))
1115                                         unregister_netdevice_queue(t->dev,
1116                                                                    head);
1117                                 t = rtnl_dereference(t->next);
1118                         }
1119                 }
1120         }
1121 }
1122
1123 static int __net_init ip6gre_init_net(struct net *net)
1124 {
1125         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1126         int err;
1127
1128         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1129                                           NET_NAME_UNKNOWN,
1130                                           ip6gre_tunnel_setup);
1131         if (!ign->fb_tunnel_dev) {
1132                 err = -ENOMEM;
1133                 goto err_alloc_dev;
1134         }
1135         dev_net_set(ign->fb_tunnel_dev, net);
1136         /* FB netdevice is special: we have one, and only one per netns.
1137          * Allowing to move it to another netns is clearly unsafe.
1138          */
1139         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1140
1141
1142         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1143         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1144
1145         err = register_netdev(ign->fb_tunnel_dev);
1146         if (err)
1147                 goto err_reg_dev;
1148
1149         rcu_assign_pointer(ign->tunnels_wc[0],
1150                            netdev_priv(ign->fb_tunnel_dev));
1151         return 0;
1152
1153 err_reg_dev:
1154         free_netdev(ign->fb_tunnel_dev);
1155 err_alloc_dev:
1156         return err;
1157 }
1158
1159 static void __net_exit ip6gre_exit_net(struct net *net)
1160 {
1161         LIST_HEAD(list);
1162
1163         rtnl_lock();
1164         ip6gre_destroy_tunnels(net, &list);
1165         unregister_netdevice_many(&list);
1166         rtnl_unlock();
1167 }
1168
1169 static struct pernet_operations ip6gre_net_ops = {
1170         .init = ip6gre_init_net,
1171         .exit = ip6gre_exit_net,
1172         .id   = &ip6gre_net_id,
1173         .size = sizeof(struct ip6gre_net),
1174 };
1175
1176 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1177                                   struct netlink_ext_ack *extack)
1178 {
1179         __be16 flags;
1180
1181         if (!data)
1182                 return 0;
1183
1184         flags = 0;
1185         if (data[IFLA_GRE_IFLAGS])
1186                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1187         if (data[IFLA_GRE_OFLAGS])
1188                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1189         if (flags & (GRE_VERSION|GRE_ROUTING))
1190                 return -EINVAL;
1191
1192         return 0;
1193 }
1194
1195 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1196                                struct netlink_ext_ack *extack)
1197 {
1198         struct in6_addr daddr;
1199
1200         if (tb[IFLA_ADDRESS]) {
1201                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1202                         return -EINVAL;
1203                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1204                         return -EADDRNOTAVAIL;
1205         }
1206
1207         if (!data)
1208                 goto out;
1209
1210         if (data[IFLA_GRE_REMOTE]) {
1211                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1212                 if (ipv6_addr_any(&daddr))
1213                         return -EINVAL;
1214         }
1215
1216 out:
1217         return ip6gre_tunnel_validate(tb, data, extack);
1218 }
1219
1220
1221 static void ip6gre_netlink_parms(struct nlattr *data[],
1222                                 struct __ip6_tnl_parm *parms)
1223 {
1224         memset(parms, 0, sizeof(*parms));
1225
1226         if (!data)
1227                 return;
1228
1229         if (data[IFLA_GRE_LINK])
1230                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1231
1232         if (data[IFLA_GRE_IFLAGS])
1233                 parms->i_flags = gre_flags_to_tnl_flags(
1234                                 nla_get_be16(data[IFLA_GRE_IFLAGS]));
1235
1236         if (data[IFLA_GRE_OFLAGS])
1237                 parms->o_flags = gre_flags_to_tnl_flags(
1238                                 nla_get_be16(data[IFLA_GRE_OFLAGS]));
1239
1240         if (data[IFLA_GRE_IKEY])
1241                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1242
1243         if (data[IFLA_GRE_OKEY])
1244                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1245
1246         if (data[IFLA_GRE_LOCAL])
1247                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1248
1249         if (data[IFLA_GRE_REMOTE])
1250                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1251
1252         if (data[IFLA_GRE_TTL])
1253                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1254
1255         if (data[IFLA_GRE_ENCAP_LIMIT])
1256                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1257
1258         if (data[IFLA_GRE_FLOWINFO])
1259                 parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1260
1261         if (data[IFLA_GRE_FLAGS])
1262                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1263
1264         if (data[IFLA_GRE_FWMARK])
1265                 parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1266 }
1267
1268 static int ip6gre_tap_init(struct net_device *dev)
1269 {
1270         struct ip6_tnl *tunnel;
1271         int ret;
1272
1273         ret = ip6gre_tunnel_init_common(dev);
1274         if (ret)
1275                 return ret;
1276
1277         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1278
1279         tunnel = netdev_priv(dev);
1280
1281         ip6gre_tnl_link_config(tunnel, 1);
1282
1283         return 0;
1284 }
1285
1286 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1287         .ndo_init = ip6gre_tap_init,
1288         .ndo_uninit = ip6gre_tunnel_uninit,
1289         .ndo_start_xmit = ip6gre_tunnel_xmit,
1290         .ndo_set_mac_address = eth_mac_addr,
1291         .ndo_validate_addr = eth_validate_addr,
1292         .ndo_change_mtu = ip6_tnl_change_mtu,
1293         .ndo_get_stats64 = ip_tunnel_get_stats64,
1294         .ndo_get_iflink = ip6_tnl_get_iflink,
1295 };
1296
1297 #define GRE6_FEATURES (NETIF_F_SG |             \
1298                        NETIF_F_FRAGLIST |       \
1299                        NETIF_F_HIGHDMA |                \
1300                        NETIF_F_HW_CSUM)
1301
1302 static void ip6gre_tap_setup(struct net_device *dev)
1303 {
1304
1305         ether_setup(dev);
1306
1307         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1308         dev->needs_free_netdev = true;
1309         dev->priv_destructor = ip6gre_dev_free;
1310
1311         dev->features |= NETIF_F_NETNS_LOCAL;
1312         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1313         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1314         netif_keep_dst(dev);
1315 }
1316
1317 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1318                                        struct ip_tunnel_encap *ipencap)
1319 {
1320         bool ret = false;
1321
1322         memset(ipencap, 0, sizeof(*ipencap));
1323
1324         if (!data)
1325                 return ret;
1326
1327         if (data[IFLA_GRE_ENCAP_TYPE]) {
1328                 ret = true;
1329                 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1330         }
1331
1332         if (data[IFLA_GRE_ENCAP_FLAGS]) {
1333                 ret = true;
1334                 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1335         }
1336
1337         if (data[IFLA_GRE_ENCAP_SPORT]) {
1338                 ret = true;
1339                 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1340         }
1341
1342         if (data[IFLA_GRE_ENCAP_DPORT]) {
1343                 ret = true;
1344                 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1345         }
1346
1347         return ret;
1348 }
1349
1350 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1351                           struct nlattr *tb[], struct nlattr *data[],
1352                           struct netlink_ext_ack *extack)
1353 {
1354         struct ip6_tnl *nt;
1355         struct net *net = dev_net(dev);
1356         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1357         struct ip_tunnel_encap ipencap;
1358         int err;
1359
1360         nt = netdev_priv(dev);
1361
1362         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1363                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1364
1365                 if (err < 0)
1366                         return err;
1367         }
1368
1369         ip6gre_netlink_parms(data, &nt->parms);
1370
1371         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1372                 return -EEXIST;
1373
1374         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1375                 eth_hw_addr_random(dev);
1376
1377         nt->dev = dev;
1378         nt->net = dev_net(dev);
1379         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1380
1381         dev->features           |= GRE6_FEATURES;
1382         dev->hw_features        |= GRE6_FEATURES;
1383
1384         if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1385                 /* TCP offload with GRE SEQ is not supported, nor
1386                  * can we support 2 levels of outer headers requiring
1387                  * an update.
1388                  */
1389                 if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1390                     (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1391                         dev->features    |= NETIF_F_GSO_SOFTWARE;
1392                         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1393                 }
1394
1395                 /* Can use a lockless transmit, unless we generate
1396                  * output sequences
1397                  */
1398                 dev->features |= NETIF_F_LLTX;
1399         }
1400
1401         err = register_netdevice(dev);
1402         if (err)
1403                 goto out;
1404
1405         dev_hold(dev);
1406         ip6gre_tunnel_link(ign, nt);
1407
1408 out:
1409         return err;
1410 }
1411
1412 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1413                              struct nlattr *data[],
1414                              struct netlink_ext_ack *extack)
1415 {
1416         struct ip6_tnl *t, *nt = netdev_priv(dev);
1417         struct net *net = nt->net;
1418         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1419         struct __ip6_tnl_parm p;
1420         struct ip_tunnel_encap ipencap;
1421
1422         if (dev == ign->fb_tunnel_dev)
1423                 return -EINVAL;
1424
1425         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1426                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1427
1428                 if (err < 0)
1429                         return err;
1430         }
1431
1432         ip6gre_netlink_parms(data, &p);
1433
1434         t = ip6gre_tunnel_locate(net, &p, 0);
1435
1436         if (t) {
1437                 if (t->dev != dev)
1438                         return -EEXIST;
1439         } else {
1440                 t = nt;
1441         }
1442
1443         ip6gre_tunnel_unlink(ign, t);
1444         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1445         ip6gre_tunnel_link(ign, t);
1446         return 0;
1447 }
1448
1449 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1450 {
1451         struct net *net = dev_net(dev);
1452         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1453
1454         if (dev != ign->fb_tunnel_dev)
1455                 unregister_netdevice_queue(dev, head);
1456 }
1457
1458 static size_t ip6gre_get_size(const struct net_device *dev)
1459 {
1460         return
1461                 /* IFLA_GRE_LINK */
1462                 nla_total_size(4) +
1463                 /* IFLA_GRE_IFLAGS */
1464                 nla_total_size(2) +
1465                 /* IFLA_GRE_OFLAGS */
1466                 nla_total_size(2) +
1467                 /* IFLA_GRE_IKEY */
1468                 nla_total_size(4) +
1469                 /* IFLA_GRE_OKEY */
1470                 nla_total_size(4) +
1471                 /* IFLA_GRE_LOCAL */
1472                 nla_total_size(sizeof(struct in6_addr)) +
1473                 /* IFLA_GRE_REMOTE */
1474                 nla_total_size(sizeof(struct in6_addr)) +
1475                 /* IFLA_GRE_TTL */
1476                 nla_total_size(1) +
1477                 /* IFLA_GRE_ENCAP_LIMIT */
1478                 nla_total_size(1) +
1479                 /* IFLA_GRE_FLOWINFO */
1480                 nla_total_size(4) +
1481                 /* IFLA_GRE_FLAGS */
1482                 nla_total_size(4) +
1483                 /* IFLA_GRE_ENCAP_TYPE */
1484                 nla_total_size(2) +
1485                 /* IFLA_GRE_ENCAP_FLAGS */
1486                 nla_total_size(2) +
1487                 /* IFLA_GRE_ENCAP_SPORT */
1488                 nla_total_size(2) +
1489                 /* IFLA_GRE_ENCAP_DPORT */
1490                 nla_total_size(2) +
1491                 /* IFLA_GRE_FWMARK */
1492                 nla_total_size(4) +
1493                 0;
1494 }
1495
1496 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1497 {
1498         struct ip6_tnl *t = netdev_priv(dev);
1499         struct __ip6_tnl_parm *p = &t->parms;
1500
1501         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1502             nla_put_be16(skb, IFLA_GRE_IFLAGS,
1503                          gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1504             nla_put_be16(skb, IFLA_GRE_OFLAGS,
1505                          gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1506             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1507             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1508             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1509             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1510             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1511             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1512             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1513             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
1514             nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
1515                 goto nla_put_failure;
1516
1517         if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1518                         t->encap.type) ||
1519             nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1520                          t->encap.sport) ||
1521             nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1522                          t->encap.dport) ||
1523             nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1524                         t->encap.flags))
1525                 goto nla_put_failure;
1526
1527         return 0;
1528
1529 nla_put_failure:
1530         return -EMSGSIZE;
1531 }
1532
1533 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1534         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1535         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1536         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1537         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1538         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1539         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1540         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1541         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1542         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1543         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1544         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1545         [IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1546         [IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1547         [IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1548         [IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1549         [IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
1550 };
1551
1552 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1553         .kind           = "ip6gre",
1554         .maxtype        = IFLA_GRE_MAX,
1555         .policy         = ip6gre_policy,
1556         .priv_size      = sizeof(struct ip6_tnl),
1557         .setup          = ip6gre_tunnel_setup,
1558         .validate       = ip6gre_tunnel_validate,
1559         .newlink        = ip6gre_newlink,
1560         .changelink     = ip6gre_changelink,
1561         .dellink        = ip6gre_dellink,
1562         .get_size       = ip6gre_get_size,
1563         .fill_info      = ip6gre_fill_info,
1564         .get_link_net   = ip6_tnl_get_link_net,
1565 };
1566
1567 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1568         .kind           = "ip6gretap",
1569         .maxtype        = IFLA_GRE_MAX,
1570         .policy         = ip6gre_policy,
1571         .priv_size      = sizeof(struct ip6_tnl),
1572         .setup          = ip6gre_tap_setup,
1573         .validate       = ip6gre_tap_validate,
1574         .newlink        = ip6gre_newlink,
1575         .changelink     = ip6gre_changelink,
1576         .get_size       = ip6gre_get_size,
1577         .fill_info      = ip6gre_fill_info,
1578         .get_link_net   = ip6_tnl_get_link_net,
1579 };
1580
1581 /*
1582  *      And now the modules code and kernel interface.
1583  */
1584
1585 static int __init ip6gre_init(void)
1586 {
1587         int err;
1588
1589         pr_info("GRE over IPv6 tunneling driver\n");
1590
1591         err = register_pernet_device(&ip6gre_net_ops);
1592         if (err < 0)
1593                 return err;
1594
1595         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1596         if (err < 0) {
1597                 pr_info("%s: can't add protocol\n", __func__);
1598                 goto add_proto_failed;
1599         }
1600
1601         err = rtnl_link_register(&ip6gre_link_ops);
1602         if (err < 0)
1603                 goto rtnl_link_failed;
1604
1605         err = rtnl_link_register(&ip6gre_tap_ops);
1606         if (err < 0)
1607                 goto tap_ops_failed;
1608
1609 out:
1610         return err;
1611
1612 tap_ops_failed:
1613         rtnl_link_unregister(&ip6gre_link_ops);
1614 rtnl_link_failed:
1615         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1616 add_proto_failed:
1617         unregister_pernet_device(&ip6gre_net_ops);
1618         goto out;
1619 }
1620
1621 static void __exit ip6gre_fini(void)
1622 {
1623         rtnl_link_unregister(&ip6gre_tap_ops);
1624         rtnl_link_unregister(&ip6gre_link_ops);
1625         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1626         unregister_pernet_device(&ip6gre_net_ops);
1627 }
1628
1629 module_init(ip6gre_init);
1630 module_exit(ip6gre_fini);
1631 MODULE_LICENSE("GPL");
1632 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1633 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1634 MODULE_ALIAS_RTNL_LINK("ip6gre");
1635 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1636 MODULE_ALIAS_NETDEV("ip6gre0");