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/mroute.h>
  28 #include <linux/init.h>
  29 #include <linux/in6.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/igmp.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/etherdevice.h>
  34 #include <linux/if_ether.h>
  35 #include <linux/hash.h>
  36 #include <linux/if_tunnel.h>
  37 #include <linux/ip6_tunnel.h>
  38
  39 #include <net/sock.h>
  40 #include <net/ip.h>
  41 #include <net/ip_tunnels.h>
  42 #include <net/icmp.h>
  43 #include <net/protocol.h>
  44 #include <net/addrconf.h>
  45 #include <net/arp.h>
  46 #include <net/checksum.h>
  47 #include <net/dsfield.h>
  48 #include <net/inet_ecn.h>
  49 #include <net/xfrm.h>
  50 #include <net/net_namespace.h>
  51 #include <net/netns/generic.h>
  52 #include <net/rtnetlink.h>
  53
  54 #include <net/ipv6.h>
  55 #include <net/ip6_fib.h>
  56 #include <net/ip6_route.h>
  57 #include <net/ip6_tunnel.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 IPV6_TCLASS_SHIFT 20
  65
  66 #define HASH_SIZE_SHIFT  5
  67 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  68
  69 static int ip6gre_net_id __read_mostly;
  70 struct ip6gre_net {
  71         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  72
  73         struct net_device *fb_tunnel_dev;
  74 };
  75
  76 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  77 static int ip6gre_tunnel_init(struct net_device *dev);
  78 static void ip6gre_tunnel_setup(struct net_device *dev);
  79 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  80 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  81
  82 /* Tunnel hash table */
  83
  84 /*
  85    4 hash tables:
  86
  87    3: (remote,local)
  88    2: (remote,*)
  89    1: (*,local)
  90    0: (*,*)
  91
  92    We require exact key match i.e. if a key is present in packet
  93    it will match only tunnel with the same key; if it is not present,
  94    it will match only keyless tunnel.
  95
  96    All keysless packets, if not matched configured keyless tunnels
  97    will match fallback tunnel.
  98  */
  99
 100 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
 101 static u32 HASH_ADDR(const struct in6_addr *addr)
 102 {
 103         u32 hash = ipv6_addr_hash(addr);
 104
 105         return hash_32(hash, HASH_SIZE_SHIFT);
 106 }
 107
 108 #define tunnels_r_l     tunnels[3]
 109 #define tunnels_r       tunnels[2]
 110 #define tunnels_l       tunnels[1]
 111 #define tunnels_wc      tunnels[0]
 112
 113 /* Given src, dst and key, find appropriate for input tunnel. */
 114
 115 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 116                 const struct in6_addr *remote, const struct in6_addr *local,
 117                 __be32 key, __be16 gre_proto)
 118 {
 119         struct net *net = dev_net(dev);
 120         int link = dev->ifindex;
 121         unsigned int h0 = HASH_ADDR(remote);
 122         unsigned int h1 = HASH_KEY(key);
 123         struct ip6_tnl *t, *cand = NULL;
 124         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 125         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 126                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 127         int score, cand_score = 4;
 128
 129         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 130                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 131                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 132                     key != t->parms.i_key ||
 133                     !(t->dev->flags & IFF_UP))
 134                         continue;
 135
 136                 if (t->dev->type != ARPHRD_IP6GRE &&
 137                     t->dev->type != dev_type)
 138                         continue;
 139
 140                 score = 0;
 141                 if (t->parms.link != link)
 142                         score |= 1;
 143                 if (t->dev->type != dev_type)
 144                         score |= 2;
 145                 if (score == 0)
 146                         return t;
 147
 148                 if (score < cand_score) {
 149                         cand = t;
 150                         cand_score = score;
 151                 }
 152         }
 153
 154         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 155                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 156                     key != t->parms.i_key ||
 157                     !(t->dev->flags & IFF_UP))
 158                         continue;
 159
 160                 if (t->dev->type != ARPHRD_IP6GRE &&
 161                     t->dev->type != dev_type)
 162                         continue;
 163
 164                 score = 0;
 165                 if (t->parms.link != link)
 166                         score |= 1;
 167                 if (t->dev->type != dev_type)
 168                         score |= 2;
 169                 if (score == 0)
 170                         return t;
 171
 172                 if (score < cand_score) {
 173                         cand = t;
 174                         cand_score = score;
 175                 }
 176         }
 177
 178         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 179                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 180                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 181                                  !ipv6_addr_is_multicast(local))) ||
 182                     key != t->parms.i_key ||
 183                     !(t->dev->flags & IFF_UP))
 184                         continue;
 185
 186                 if (t->dev->type != ARPHRD_IP6GRE &&
 187                     t->dev->type != dev_type)
 188                         continue;
 189
 190                 score = 0;
 191                 if (t->parms.link != link)
 192                         score |= 1;
 193                 if (t->dev->type != dev_type)
 194                         score |= 2;
 195                 if (score == 0)
 196                         return t;
 197
 198                 if (score < cand_score) {
 199                         cand = t;
 200                         cand_score = score;
 201                 }
 202         }
 203
 204         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 205                 if (t->parms.i_key != key ||
 206                     !(t->dev->flags & IFF_UP))
 207                         continue;
 208
 209                 if (t->dev->type != ARPHRD_IP6GRE &&
 210                     t->dev->type != dev_type)
 211                         continue;
 212
 213                 score = 0;
 214                 if (t->parms.link != link)
 215                         score |= 1;
 216                 if (t->dev->type != dev_type)
 217                         score |= 2;
 218                 if (score == 0)
 219                         return t;
 220
 221                 if (score < cand_score) {
 222                         cand = t;
 223                         cand_score = score;
 224                 }
 225         }
 226
 227         if (cand != NULL)
 228                 return cand;
 229
 230         dev = ign->fb_tunnel_dev;
 231         if (dev->flags & IFF_UP)
 232                 return netdev_priv(dev);
 233
 234         return NULL;
 235 }
 236
 237 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 238                 const struct __ip6_tnl_parm *p)
 239 {
 240         const struct in6_addr *remote = &p->raddr;
 241         const struct in6_addr *local = &p->laddr;
 242         unsigned int h = HASH_KEY(p->i_key);
 243         int prio = 0;
 244
 245         if (!ipv6_addr_any(local))
 246                 prio |= 1;
 247         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 248                 prio |= 2;
 249                 h ^= HASH_ADDR(remote);
 250         }
 251
 252         return &ign->tunnels[prio][h];
 253 }
 254
 255 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 256                 const struct ip6_tnl *t)
 257 {
 258         return __ip6gre_bucket(ign, &t->parms);
 259 }
 260
 261 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 262 {
 263         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 264
 265         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 266         rcu_assign_pointer(*tp, t);
 267 }
 268
 269 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 270 {
 271         struct ip6_tnl __rcu **tp;
 272         struct ip6_tnl *iter;
 273
 274         for (tp = ip6gre_bucket(ign, t);
 275              (iter = rtnl_dereference(*tp)) != NULL;
 276              tp = &iter->next) {
 277                 if (t == iter) {
 278                         rcu_assign_pointer(*tp, t->next);
 279                         break;
 280                 }
 281         }
 282 }
 283
 284 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 285                                            const struct __ip6_tnl_parm *parms,
 286                                            int type)
 287 {
 288         const struct in6_addr *remote = &parms->raddr;
 289         const struct in6_addr *local = &parms->laddr;
 290         __be32 key = parms->i_key;
 291         int link = parms->link;
 292         struct ip6_tnl *t;
 293         struct ip6_tnl __rcu **tp;
 294         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 295
 296         for (tp = __ip6gre_bucket(ign, parms);
 297              (t = rtnl_dereference(*tp)) != NULL;
 298              tp = &t->next)
 299                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 300                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 301                     key == t->parms.i_key &&
 302                     link == t->parms.link &&
 303                     type == t->dev->type)
 304                         break;
 305
 306         return t;
 307 }
 308
 309 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 310                 const struct __ip6_tnl_parm *parms, int create)
 311 {
 312         struct ip6_tnl *t, *nt;
 313         struct net_device *dev;
 314         char name[IFNAMSIZ];
 315         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 316
 317         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 318         if (t || !create)
 319                 return t;
 320
 321         if (parms->name[0])
 322                 strlcpy(name, parms->name, IFNAMSIZ);
 323         else
 324                 strcpy(name, "ip6gre%d");
 325
 326         dev = alloc_netdev(sizeof(*t), name, ip6gre_tunnel_setup);
 327         if (!dev)
 328                 return NULL;
 329
 330         dev_net_set(dev, net);
 331
 332         nt = netdev_priv(dev);
 333         nt->parms = *parms;
 334         dev->rtnl_link_ops = &ip6gre_link_ops;
 335
 336         nt->dev = dev;
 337         nt->net = dev_net(dev);
 338         ip6gre_tnl_link_config(nt, 1);
 339
 340         if (register_netdevice(dev) < 0)
 341                 goto failed_free;
 342
 343         /* Can use a lockless transmit, unless we generate output sequences */
 344         if (!(nt->parms.o_flags & GRE_SEQ))
 345                 dev->features |= NETIF_F_LLTX;
 346
 347         dev_hold(dev);
 348         ip6gre_tunnel_link(ign, nt);
 349         return nt;
 350
 351 failed_free:
 352         free_netdev(dev);
 353         return NULL;
 354 }
 355
 356 static void ip6gre_tunnel_uninit(struct net_device *dev)
 357 {
 358         struct net *net = dev_net(dev);
 359         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 360
 361         ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 362         dev_put(dev);
 363 }
 364
 365
 366 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 367                 u8 type, u8 code, int offset, __be32 info)
 368 {
 369         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 370         __be16 *p = (__be16 *)(skb->data + offset);
 371         int grehlen = offset + 4;
 372         struct ip6_tnl *t;
 373         __be16 flags;
 374
 375         flags = p[0];
 376         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 377                 if (flags&(GRE_VERSION|GRE_ROUTING))
 378                         return;
 379                 if (flags&GRE_KEY) {
 380                         grehlen += 4;
 381                         if (flags&GRE_CSUM)
 382                                 grehlen += 4;
 383                 }
 384         }
 385
 386         /* If only 8 bytes returned, keyed message will be dropped here */
 387         if (!pskb_may_pull(skb, grehlen))
 388                 return;
 389         ipv6h = (const struct ipv6hdr *)skb->data;
 390         p = (__be16 *)(skb->data + offset);
 391
 392         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 393                                 flags & GRE_KEY ?
 394                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 395                                 p[1]);
 396         if (t == NULL)
 397                 return;
 398
 399         switch (type) {
 400                 __u32 teli;
 401                 struct ipv6_tlv_tnl_enc_lim *tel;
 402                 __u32 mtu;
 403         case ICMPV6_DEST_UNREACH:
 404                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 405                                      t->parms.name);
 406                 break;
 407         case ICMPV6_TIME_EXCEED:
 408                 if (code == ICMPV6_EXC_HOPLIMIT) {
 409                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 410                                              t->parms.name);
 411                 }
 412                 break;
 413         case ICMPV6_PARAMPROB:
 414                 teli = 0;
 415                 if (code == ICMPV6_HDR_FIELD)
 416                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 417
 418                 if (teli && teli == info - 2) {
 419                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 420                         if (tel->encap_limit == 0) {
 421                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 422                                                      t->parms.name);
 423                         }
 424                 } else {
 425                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 426                                              t->parms.name);
 427                 }
 428                 break;
 429         case ICMPV6_PKT_TOOBIG:
 430                 mtu = info - offset;
 431                 if (mtu < IPV6_MIN_MTU)
 432                         mtu = IPV6_MIN_MTU;
 433                 t->dev->mtu = mtu;
 434                 break;
 435         }
 436
 437         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 438                 t->err_count++;
 439         else
 440                 t->err_count = 1;
 441         t->err_time = jiffies;
 442 }
 443
 444 static int ip6gre_rcv(struct sk_buff *skb)
 445 {
 446         const struct ipv6hdr *ipv6h;
 447         u8     *h;
 448         __be16    flags;
 449         __sum16   csum = 0;
 450         __be32 key = 0;
 451         u32    seqno = 0;
 452         struct ip6_tnl *tunnel;
 453         int    offset = 4;
 454         __be16 gre_proto;
 455         int err;
 456
 457         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 458                 goto drop;
 459
 460         ipv6h = ipv6_hdr(skb);
 461         h = skb->data;
 462         flags = *(__be16 *)h;
 463
 464         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 465                 /* - Version must be 0.
 466                    - We do not support routing headers.
 467                  */
 468                 if (flags&(GRE_VERSION|GRE_ROUTING))
 469                         goto drop;
 470
 471                 if (flags&GRE_CSUM) {
 472                         switch (skb->ip_summed) {
 473                         case CHECKSUM_COMPLETE:
 474                                 csum = csum_fold(skb->csum);
 475                                 if (!csum)
 476                                         break;
 477                                 /* fall through */
 478                         case CHECKSUM_NONE:
 479                                 skb->csum = 0;
 480                                 csum = __skb_checksum_complete(skb);
 481                                 skb->ip_summed = CHECKSUM_COMPLETE;
 482                         }
 483                         offset += 4;
 484                 }
 485                 if (flags&GRE_KEY) {
 486                         key = *(__be32 *)(h + offset);
 487                         offset += 4;
 488                 }
 489                 if (flags&GRE_SEQ) {
 490                         seqno = ntohl(*(__be32 *)(h + offset));
 491                         offset += 4;
 492                 }
 493         }
 494
 495         gre_proto = *(__be16 *)(h + 2);
 496
 497         tunnel = ip6gre_tunnel_lookup(skb->dev,
 498                                           &ipv6h->saddr, &ipv6h->daddr, key,
 499                                           gre_proto);
 500         if (tunnel) {
 501                 struct pcpu_tstats *tstats;
 502
 503                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 504                         goto drop;
 505
 506                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 507                         tunnel->dev->stats.rx_dropped++;
 508                         goto drop;
 509                 }
 510
 511                 skb->protocol = gre_proto;
 512                 /* WCCP version 1 and 2 protocol decoding.
 513                  * - Change protocol to IP
 514                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 515                  */
 516                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 517                         skb->protocol = htons(ETH_P_IP);
 518                         if ((*(h + offset) & 0xF0) != 0x40)
 519                                 offset += 4;
 520                 }
 521
 522                 skb->mac_header = skb->network_header;
 523                 __pskb_pull(skb, offset);
 524                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 525
 526                 if (((flags&GRE_CSUM) && csum) ||
 527                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 528                         tunnel->dev->stats.rx_crc_errors++;
 529                         tunnel->dev->stats.rx_errors++;
 530                         goto drop;
 531                 }
 532                 if (tunnel->parms.i_flags&GRE_SEQ) {
 533                         if (!(flags&GRE_SEQ) ||
 534                             (tunnel->i_seqno &&
 535                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 536                                 tunnel->dev->stats.rx_fifo_errors++;
 537                                 tunnel->dev->stats.rx_errors++;
 538                                 goto drop;
 539                         }
 540                         tunnel->i_seqno = seqno + 1;
 541                 }
 542
 543                 /* Warning: All skb pointers will be invalidated! */
 544                 if (tunnel->dev->type == ARPHRD_ETHER) {
 545                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 546                                 tunnel->dev->stats.rx_length_errors++;
 547                                 tunnel->dev->stats.rx_errors++;
 548                                 goto drop;
 549                         }
 550
 551                         ipv6h = ipv6_hdr(skb);
 552                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 553                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 554                 }
 555
 556                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 557
 558                 skb_reset_network_header(skb);
 559
 560                 err = IP6_ECN_decapsulate(ipv6h, skb);
 561                 if (unlikely(err)) {
 562                         if (log_ecn_error)
 563                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 564                                                      &ipv6h->saddr,
 565                                                      ipv6_get_dsfield(ipv6h));
 566                         if (err > 1) {
 567                                 ++tunnel->dev->stats.rx_frame_errors;
 568                                 ++tunnel->dev->stats.rx_errors;
 569                                 goto drop;
 570                         }
 571                 }
 572
 573                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 574                 u64_stats_update_begin(&tstats->syncp);
 575                 tstats->rx_packets++;
 576                 tstats->rx_bytes += skb->len;
 577                 u64_stats_update_end(&tstats->syncp);
 578
 579                 netif_rx(skb);
 580
 581                 return 0;
 582         }
 583         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 584
 585 drop:
 586         kfree_skb(skb);
 587         return 0;
 588 }
 589
 590 struct ipv6_tel_txoption {
 591         struct ipv6_txoptions ops;
 592         __u8 dst_opt[8];
 593 };
 594
 595 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 596 {
 597         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 598
 599         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 600         opt->dst_opt[3] = 1;
 601         opt->dst_opt[4] = encap_limit;
 602         opt->dst_opt[5] = IPV6_TLV_PADN;
 603         opt->dst_opt[6] = 1;
 604
 605         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 606         opt->ops.opt_nflen = 8;
 607 }
 608
 609 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 610                          struct net_device *dev,
 611                          __u8 dsfield,
 612                          struct flowi6 *fl6,
 613                          int encap_limit,
 614                          __u32 *pmtu)
 615 {
 616         struct net *net = dev_net(dev);
 617         struct ip6_tnl *tunnel = netdev_priv(dev);
 618         struct net_device *tdev;    /* Device to other host */
 619         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 620         unsigned int max_headroom = 0; /* The extra header space needed */
 621         int    gre_hlen;
 622         struct ipv6_tel_txoption opt;
 623         int    mtu;
 624         struct dst_entry *dst = NULL, *ndst = NULL;
 625         struct net_device_stats *stats = &tunnel->dev->stats;
 626         int err = -1;
 627         u8 proto;
 628         struct sk_buff *new_skb;
 629
 630         if (dev->type == ARPHRD_ETHER)
 631                 IPCB(skb)->flags = 0;
 632
 633         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 634                 gre_hlen = 0;
 635                 ipv6h = (struct ipv6hdr *)skb->data;
 636                 fl6->daddr = ipv6h->daddr;
 637         } else {
 638                 gre_hlen = tunnel->hlen;
 639                 fl6->daddr = tunnel->parms.raddr;
 640         }
 641
 642         if (!fl6->flowi6_mark)
 643                 dst = ip6_tnl_dst_check(tunnel);
 644
 645         if (!dst) {
 646                 ndst = ip6_route_output(net, NULL, fl6);
 647
 648                 if (ndst->error)
 649                         goto tx_err_link_failure;
 650                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 651                 if (IS_ERR(ndst)) {
 652                         err = PTR_ERR(ndst);
 653                         ndst = NULL;
 654                         goto tx_err_link_failure;
 655                 }
 656                 dst = ndst;
 657         }
 658
 659         tdev = dst->dev;
 660
 661         if (tdev == dev) {
 662                 stats->collisions++;
 663                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 664                                      tunnel->parms.name);
 665                 goto tx_err_dst_release;
 666         }
 667
 668         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 669         if (encap_limit >= 0) {
 670                 max_headroom += 8;
 671                 mtu -= 8;
 672         }
 673         if (mtu < IPV6_MIN_MTU)
 674                 mtu = IPV6_MIN_MTU;
 675         if (skb_dst(skb))
 676                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 677         if (skb->len > mtu) {
 678                 *pmtu = mtu;
 679                 err = -EMSGSIZE;
 680                 goto tx_err_dst_release;
 681         }
 682
 683         if (tunnel->err_count > 0) {
 684                 if (time_before(jiffies,
 685                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 686                         tunnel->err_count--;
 687
 688                         dst_link_failure(skb);
 689                 } else
 690                         tunnel->err_count = 0;
 691         }
 692
 693         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 694
 695         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 696
 697         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 698             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 699                 new_skb = skb_realloc_headroom(skb, max_headroom);
 700                 if (max_headroom > dev->needed_headroom)
 701                         dev->needed_headroom = max_headroom;
 702                 if (!new_skb)
 703                         goto tx_err_dst_release;
 704
 705                 if (skb->sk)
 706                         skb_set_owner_w(new_skb, skb->sk);
 707                 consume_skb(skb);
 708                 skb = new_skb;
 709         }
 710
 711         if (fl6->flowi6_mark) {
 712                 skb_dst_set(skb, dst);
 713                 ndst = NULL;
 714         } else {
 715                 skb_dst_set_noref(skb, dst);
 716         }
 717
 718         proto = NEXTHDR_GRE;
 719         if (encap_limit >= 0) {
 720                 init_tel_txopt(&opt, encap_limit);
 721                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 722         }
 723
 724         if (likely(!skb->encapsulation)) {
 725                 skb_reset_inner_headers(skb);
 726                 skb->encapsulation = 1;
 727         }
 728
 729         skb_push(skb, gre_hlen);
 730         skb_reset_network_header(skb);
 731         skb_set_transport_header(skb, sizeof(*ipv6h));
 732
 733         /*
 734          *      Push down and install the IP header.
 735          */
 736         ipv6h = ipv6_hdr(skb);
 737         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 738         ipv6h->hop_limit = tunnel->parms.hop_limit;
 739         ipv6h->nexthdr = proto;
 740         ipv6h->saddr = fl6->saddr;
 741         ipv6h->daddr = fl6->daddr;
 742
 743         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 744         ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 745                                    htons(ETH_P_TEB) : skb->protocol;
 746
 747         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 748                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 749
 750                 if (tunnel->parms.o_flags&GRE_SEQ) {
 751                         ++tunnel->o_seqno;
 752                         *ptr = htonl(tunnel->o_seqno);
 753                         ptr--;
 754                 }
 755                 if (tunnel->parms.o_flags&GRE_KEY) {
 756                         *ptr = tunnel->parms.o_key;
 757                         ptr--;
 758                 }
 759                 if (tunnel->parms.o_flags&GRE_CSUM) {
 760                         *ptr = 0;
 761                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 762                                 skb->len - sizeof(struct ipv6hdr));
 763                 }
 764         }
 765
 766         ip6tunnel_xmit(skb, dev);
 767         if (ndst)
 768                 ip6_tnl_dst_store(tunnel, ndst);
 769         return 0;
 770 tx_err_link_failure:
 771         stats->tx_carrier_errors++;
 772         dst_link_failure(skb);
 773 tx_err_dst_release:
 774         dst_release(ndst);
 775         return err;
 776 }
 777
 778 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 779 {
 780         struct ip6_tnl *t = netdev_priv(dev);
 781         const struct iphdr  *iph = ip_hdr(skb);
 782         int encap_limit = -1;
 783         struct flowi6 fl6;
 784         __u8 dsfield;
 785         __u32 mtu;
 786         int err;
 787
 788         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 789                 encap_limit = t->parms.encap_limit;
 790
 791         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 792         fl6.flowi6_proto = IPPROTO_IPIP;
 793
 794         dsfield = ipv4_get_dsfield(iph);
 795
 796         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 797                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 798                                           & IPV6_TCLASS_MASK;
 799         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 800                 fl6.flowi6_mark = skb->mark;
 801
 802         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 803         if (err != 0) {
 804                 /* XXX: send ICMP error even if DF is not set. */
 805                 if (err == -EMSGSIZE)
 806                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 807                                   htonl(mtu));
 808                 return -1;
 809         }
 810
 811         return 0;
 812 }
 813
 814 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 815 {
 816         struct ip6_tnl *t = netdev_priv(dev);
 817         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 818         int encap_limit = -1;
 819         __u16 offset;
 820         struct flowi6 fl6;
 821         __u8 dsfield;
 822         __u32 mtu;
 823         int err;
 824
 825         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 826                 return -1;
 827
 828         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 829         if (offset > 0) {
 830                 struct ipv6_tlv_tnl_enc_lim *tel;
 831                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 832                 if (tel->encap_limit == 0) {
 833                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 834                                     ICMPV6_HDR_FIELD, offset + 2);
 835                         return -1;
 836                 }
 837                 encap_limit = tel->encap_limit - 1;
 838         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 839                 encap_limit = t->parms.encap_limit;
 840
 841         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 842         fl6.flowi6_proto = IPPROTO_IPV6;
 843
 844         dsfield = ipv6_get_dsfield(ipv6h);
 845         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 846                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 847         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 848                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 849         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 850                 fl6.flowi6_mark = skb->mark;
 851
 852         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 853         if (err != 0) {
 854                 if (err == -EMSGSIZE)
 855                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 856                 return -1;
 857         }
 858
 859         return 0;
 860 }
 861
 862 /**
 863  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 864  *   @t: the outgoing tunnel device
 865  *   @hdr: IPv6 header from the incoming packet
 866  *
 867  * Description:
 868  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 869  *   doesn't match source of incoming packet.
 870  *
 871  * Return:
 872  *   1 if conflict,
 873  *   0 else
 874  **/
 875
 876 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 877         const struct ipv6hdr *hdr)
 878 {
 879         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 880 }
 881
 882 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 883 {
 884         struct ip6_tnl *t = netdev_priv(dev);
 885         int encap_limit = -1;
 886         struct flowi6 fl6;
 887         __u32 mtu;
 888         int err;
 889
 890         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 891                 encap_limit = t->parms.encap_limit;
 892
 893         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 894         fl6.flowi6_proto = skb->protocol;
 895
 896         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 897
 898         return err;
 899 }
 900
 901 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 902         struct net_device *dev)
 903 {
 904         struct ip6_tnl *t = netdev_priv(dev);
 905         struct net_device_stats *stats = &t->dev->stats;
 906         int ret;
 907
 908         if (!ip6_tnl_xmit_ctl(t))
 909                 goto tx_err;
 910
 911         switch (skb->protocol) {
 912         case htons(ETH_P_IP):
 913                 ret = ip6gre_xmit_ipv4(skb, dev);
 914                 break;
 915         case htons(ETH_P_IPV6):
 916                 ret = ip6gre_xmit_ipv6(skb, dev);
 917                 break;
 918         default:
 919                 ret = ip6gre_xmit_other(skb, dev);
 920                 break;
 921         }
 922
 923         if (ret < 0)
 924                 goto tx_err;
 925
 926         return NETDEV_TX_OK;
 927
 928 tx_err:
 929         stats->tx_errors++;
 930         stats->tx_dropped++;
 931         kfree_skb(skb);
 932         return NETDEV_TX_OK;
 933 }
 934
 935 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 936 {
 937         struct net_device *dev = t->dev;
 938         struct __ip6_tnl_parm *p = &t->parms;
 939         struct flowi6 *fl6 = &t->fl.u.ip6;
 940         int addend = sizeof(struct ipv6hdr) + 4;
 941
 942         if (dev->type != ARPHRD_ETHER) {
 943                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 944                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 945         }
 946
 947         /* Set up flowi template */
 948         fl6->saddr = p->laddr;
 949         fl6->daddr = p->raddr;
 950         fl6->flowi6_oif = p->link;
 951         fl6->flowlabel = 0;
 952
 953         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 954                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 955         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 956                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 957
 958         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 959         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 960
 961         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 962                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 963                 dev->flags |= IFF_POINTOPOINT;
 964         else
 965                 dev->flags &= ~IFF_POINTOPOINT;
 966
 967         dev->iflink = p->link;
 968
 969         /* Precalculate GRE options length */
 970         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 971                 if (t->parms.o_flags&GRE_CSUM)
 972                         addend += 4;
 973                 if (t->parms.o_flags&GRE_KEY)
 974                         addend += 4;
 975                 if (t->parms.o_flags&GRE_SEQ)
 976                         addend += 4;
 977         }
 978         t->hlen = addend;
 979
 980         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 981                 int strict = (ipv6_addr_type(&p->raddr) &
 982                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 983
 984                 struct rt6_info *rt = rt6_lookup(dev_net(dev),
 985                                                  &p->raddr, &p->laddr,
 986                                                  p->link, strict);
 987
 988                 if (rt == NULL)
 989                         return;
 990
 991                 if (rt->dst.dev) {
 992                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 993
 994                         if (set_mtu) {
 995                                 dev->mtu = rt->dst.dev->mtu - addend;
 996                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 997                                         dev->mtu -= 8;
 998
 999                                 if (dev->mtu < IPV6_MIN_MTU)
1000                                         dev->mtu = IPV6_MIN_MTU;
1001                         }
1002                 }
1003                 ip6_rt_put(rt);
1004         }
1005 }
1006
1007 static int ip6gre_tnl_change(struct ip6_tnl *t,
1008         const struct __ip6_tnl_parm *p, int set_mtu)
1009 {
1010         t->parms.laddr = p->laddr;
1011         t->parms.raddr = p->raddr;
1012         t->parms.flags = p->flags;
1013         t->parms.hop_limit = p->hop_limit;
1014         t->parms.encap_limit = p->encap_limit;
1015         t->parms.flowinfo = p->flowinfo;
1016         t->parms.link = p->link;
1017         t->parms.proto = p->proto;
1018         t->parms.i_key = p->i_key;
1019         t->parms.o_key = p->o_key;
1020         t->parms.i_flags = p->i_flags;
1021         t->parms.o_flags = p->o_flags;
1022         ip6_tnl_dst_reset(t);
1023         ip6gre_tnl_link_config(t, set_mtu);
1024         return 0;
1025 }
1026
1027 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1028         const struct ip6_tnl_parm2 *u)
1029 {
1030         p->laddr = u->laddr;
1031         p->raddr = u->raddr;
1032         p->flags = u->flags;
1033         p->hop_limit = u->hop_limit;
1034         p->encap_limit = u->encap_limit;
1035         p->flowinfo = u->flowinfo;
1036         p->link = u->link;
1037         p->i_key = u->i_key;
1038         p->o_key = u->o_key;
1039         p->i_flags = u->i_flags;
1040         p->o_flags = u->o_flags;
1041         memcpy(p->name, u->name, sizeof(u->name));
1042 }
1043
1044 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1045         const struct __ip6_tnl_parm *p)
1046 {
1047         u->proto = IPPROTO_GRE;
1048         u->laddr = p->laddr;
1049         u->raddr = p->raddr;
1050         u->flags = p->flags;
1051         u->hop_limit = p->hop_limit;
1052         u->encap_limit = p->encap_limit;
1053         u->flowinfo = p->flowinfo;
1054         u->link = p->link;
1055         u->i_key = p->i_key;
1056         u->o_key = p->o_key;
1057         u->i_flags = p->i_flags;
1058         u->o_flags = p->o_flags;
1059         memcpy(u->name, p->name, sizeof(u->name));
1060 }
1061
1062 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1063         struct ifreq *ifr, int cmd)
1064 {
1065         int err = 0;
1066         struct ip6_tnl_parm2 p;
1067         struct __ip6_tnl_parm p1;
1068         struct ip6_tnl *t;
1069         struct net *net = dev_net(dev);
1070         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1071
1072         switch (cmd) {
1073         case SIOCGETTUNNEL:
1074                 t = NULL;
1075                 if (dev == ign->fb_tunnel_dev) {
1076                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1077                                 err = -EFAULT;
1078                                 break;
1079                         }
1080                         ip6gre_tnl_parm_from_user(&p1, &p);
1081                         t = ip6gre_tunnel_locate(net, &p1, 0);
1082                 }
1083                 if (t == NULL)
1084                         t = netdev_priv(dev);
1085                 memset(&p, 0, sizeof(p));
1086                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1087                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1088                         err = -EFAULT;
1089                 break;
1090
1091         case SIOCADDTUNNEL:
1092         case SIOCCHGTUNNEL:
1093                 err = -EPERM;
1094                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1095                         goto done;
1096
1097                 err = -EFAULT;
1098                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1099                         goto done;
1100
1101                 err = -EINVAL;
1102                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1103                         goto done;
1104
1105                 if (!(p.i_flags&GRE_KEY))
1106                         p.i_key = 0;
1107                 if (!(p.o_flags&GRE_KEY))
1108                         p.o_key = 0;
1109
1110                 ip6gre_tnl_parm_from_user(&p1, &p);
1111                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1112
1113                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1114                         if (t != NULL) {
1115                                 if (t->dev != dev) {
1116                                         err = -EEXIST;
1117                                         break;
1118                                 }
1119                         } else {
1120                                 t = netdev_priv(dev);
1121
1122                                 ip6gre_tunnel_unlink(ign, t);
1123                                 synchronize_net();
1124                                 ip6gre_tnl_change(t, &p1, 1);
1125                                 ip6gre_tunnel_link(ign, t);
1126                                 netdev_state_change(dev);
1127                         }
1128                 }
1129
1130                 if (t) {
1131                         err = 0;
1132
1133                         memset(&p, 0, sizeof(p));
1134                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1135                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1136                                 err = -EFAULT;
1137                 } else
1138                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1139                 break;
1140
1141         case SIOCDELTUNNEL:
1142                 err = -EPERM;
1143                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1144                         goto done;
1145
1146                 if (dev == ign->fb_tunnel_dev) {
1147                         err = -EFAULT;
1148                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1149                                 goto done;
1150                         err = -ENOENT;
1151                         ip6gre_tnl_parm_from_user(&p1, &p);
1152                         t = ip6gre_tunnel_locate(net, &p1, 0);
1153                         if (t == NULL)
1154                                 goto done;
1155                         err = -EPERM;
1156                         if (t == netdev_priv(ign->fb_tunnel_dev))
1157                                 goto done;
1158                         dev = t->dev;
1159                 }
1160                 unregister_netdevice(dev);
1161                 err = 0;
1162                 break;
1163
1164         default:
1165                 err = -EINVAL;
1166         }
1167
1168 done:
1169         return err;
1170 }
1171
1172 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1173 {
1174         if (new_mtu < 68 ||
1175             new_mtu > 0xFFF8 - dev->hard_header_len)
1176                 return -EINVAL;
1177         dev->mtu = new_mtu;
1178         return 0;
1179 }
1180
1181 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1182                         unsigned short type,
1183                         const void *daddr, const void *saddr, unsigned int len)
1184 {
1185         struct ip6_tnl *t = netdev_priv(dev);
1186         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1187         __be16 *p = (__be16 *)(ipv6h+1);
1188
1189         ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1190         ipv6h->hop_limit = t->parms.hop_limit;
1191         ipv6h->nexthdr = NEXTHDR_GRE;
1192         ipv6h->saddr = t->parms.laddr;
1193         ipv6h->daddr = t->parms.raddr;
1194
1195         p[0]            = t->parms.o_flags;
1196         p[1]            = htons(type);
1197
1198         /*
1199          *      Set the source hardware address.
1200          */
1201
1202         if (saddr)
1203                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1204         if (daddr)
1205                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1206         if (!ipv6_addr_any(&ipv6h->daddr))
1207                 return t->hlen;
1208
1209         return -t->hlen;
1210 }
1211
1212 static const struct header_ops ip6gre_header_ops = {
1213         .create = ip6gre_header,
1214 };
1215
1216 static const struct net_device_ops ip6gre_netdev_ops = {
1217         .ndo_init               = ip6gre_tunnel_init,
1218         .ndo_uninit             = ip6gre_tunnel_uninit,
1219         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1220         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1221         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1222         .ndo_get_stats64        = ip_tunnel_get_stats64,
1223 };
1224
1225 static void ip6gre_dev_free(struct net_device *dev)
1226 {
1227         free_percpu(dev->tstats);
1228         free_netdev(dev);
1229 }
1230
1231 static void ip6gre_tunnel_setup(struct net_device *dev)
1232 {
1233         struct ip6_tnl *t;
1234
1235         dev->netdev_ops = &ip6gre_netdev_ops;
1236         dev->destructor = ip6gre_dev_free;
1237
1238         dev->type = ARPHRD_IP6GRE;
1239         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1240         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1241         t = netdev_priv(dev);
1242         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1243                 dev->mtu -= 8;
1244         dev->flags |= IFF_NOARP;
1245         dev->iflink = 0;
1246         dev->addr_len = sizeof(struct in6_addr);
1247         dev->features |= NETIF_F_NETNS_LOCAL;
1248         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1249 }
1250
1251 static int ip6gre_tunnel_init(struct net_device *dev)
1252 {
1253         struct ip6_tnl *tunnel;
1254         int i;
1255
1256         tunnel = netdev_priv(dev);
1257
1258         tunnel->dev = dev;
1259         tunnel->net = dev_net(dev);
1260         strcpy(tunnel->parms.name, dev->name);
1261
1262         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1263         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1264
1265         if (ipv6_addr_any(&tunnel->parms.raddr))
1266                 dev->header_ops = &ip6gre_header_ops;
1267
1268         dev->tstats = alloc_percpu(struct pcpu_tstats);
1269         if (!dev->tstats)
1270                 return -ENOMEM;
1271
1272         for_each_possible_cpu(i) {
1273                 struct pcpu_tstats *ip6gre_tunnel_stats;
1274                 ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1275                 u64_stats_init(&ip6gre_tunnel_stats->syncp);
1276         }
1277
1278
1279         return 0;
1280 }
1281
1282 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1283 {
1284         struct ip6_tnl *tunnel = netdev_priv(dev);
1285
1286         tunnel->dev = dev;
1287         tunnel->net = dev_net(dev);
1288         strcpy(tunnel->parms.name, dev->name);
1289
1290         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1291
1292         dev_hold(dev);
1293 }
1294
1295
1296 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1297         .handler     = ip6gre_rcv,
1298         .err_handler = ip6gre_err,
1299         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1300 };
1301
1302 static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1303         struct list_head *head)
1304 {
1305         int prio;
1306
1307         for (prio = 0; prio < 4; prio++) {
1308                 int h;
1309                 for (h = 0; h < HASH_SIZE; h++) {
1310                         struct ip6_tnl *t;
1311
1312                         t = rtnl_dereference(ign->tunnels[prio][h]);
1313
1314                         while (t != NULL) {
1315                                 unregister_netdevice_queue(t->dev, head);
1316                                 t = rtnl_dereference(t->next);
1317                         }
1318                 }
1319         }
1320 }
1321
1322 static int __net_init ip6gre_init_net(struct net *net)
1323 {
1324         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1325         int err;
1326
1327         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1328                                            ip6gre_tunnel_setup);
1329         if (!ign->fb_tunnel_dev) {
1330                 err = -ENOMEM;
1331                 goto err_alloc_dev;
1332         }
1333         dev_net_set(ign->fb_tunnel_dev, net);
1334
1335         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1336         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1337
1338         err = register_netdev(ign->fb_tunnel_dev);
1339         if (err)
1340                 goto err_reg_dev;
1341
1342         rcu_assign_pointer(ign->tunnels_wc[0],
1343                            netdev_priv(ign->fb_tunnel_dev));
1344         return 0;
1345
1346 err_reg_dev:
1347         ip6gre_dev_free(ign->fb_tunnel_dev);
1348 err_alloc_dev:
1349         return err;
1350 }
1351
1352 static void __net_exit ip6gre_exit_net(struct net *net)
1353 {
1354         struct ip6gre_net *ign;
1355         LIST_HEAD(list);
1356
1357         ign = net_generic(net, ip6gre_net_id);
1358         rtnl_lock();
1359         ip6gre_destroy_tunnels(ign, &list);
1360         unregister_netdevice_many(&list);
1361         rtnl_unlock();
1362 }
1363
1364 static struct pernet_operations ip6gre_net_ops = {
1365         .init = ip6gre_init_net,
1366         .exit = ip6gre_exit_net,
1367         .id   = &ip6gre_net_id,
1368         .size = sizeof(struct ip6gre_net),
1369 };
1370
1371 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1372 {
1373         __be16 flags;
1374
1375         if (!data)
1376                 return 0;
1377
1378         flags = 0;
1379         if (data[IFLA_GRE_IFLAGS])
1380                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1381         if (data[IFLA_GRE_OFLAGS])
1382                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1383         if (flags & (GRE_VERSION|GRE_ROUTING))
1384                 return -EINVAL;
1385
1386         return 0;
1387 }
1388
1389 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1390 {
1391         struct in6_addr daddr;
1392
1393         if (tb[IFLA_ADDRESS]) {
1394                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1395                         return -EINVAL;
1396                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1397                         return -EADDRNOTAVAIL;
1398         }
1399
1400         if (!data)
1401                 goto out;
1402
1403         if (data[IFLA_GRE_REMOTE]) {
1404                 nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1405                 if (ipv6_addr_any(&daddr))
1406                         return -EINVAL;
1407         }
1408
1409 out:
1410         return ip6gre_tunnel_validate(tb, data);
1411 }
1412
1413
1414 static void ip6gre_netlink_parms(struct nlattr *data[],
1415                                 struct __ip6_tnl_parm *parms)
1416 {
1417         memset(parms, 0, sizeof(*parms));
1418
1419         if (!data)
1420                 return;
1421
1422         if (data[IFLA_GRE_LINK])
1423                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1424
1425         if (data[IFLA_GRE_IFLAGS])
1426                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1427
1428         if (data[IFLA_GRE_OFLAGS])
1429                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1430
1431         if (data[IFLA_GRE_IKEY])
1432                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1433
1434         if (data[IFLA_GRE_OKEY])
1435                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1436
1437         if (data[IFLA_GRE_LOCAL])
1438                 nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1439
1440         if (data[IFLA_GRE_REMOTE])
1441                 nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1442
1443         if (data[IFLA_GRE_TTL])
1444                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1445
1446         if (data[IFLA_GRE_ENCAP_LIMIT])
1447                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1448
1449         if (data[IFLA_GRE_FLOWINFO])
1450                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1451
1452         if (data[IFLA_GRE_FLAGS])
1453                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1454 }
1455
1456 static int ip6gre_tap_init(struct net_device *dev)
1457 {
1458         struct ip6_tnl *tunnel;
1459         int i;
1460
1461         tunnel = netdev_priv(dev);
1462
1463         tunnel->dev = dev;
1464         tunnel->net = dev_net(dev);
1465         strcpy(tunnel->parms.name, dev->name);
1466
1467         ip6gre_tnl_link_config(tunnel, 1);
1468
1469         dev->tstats = alloc_percpu(struct pcpu_tstats);
1470         if (!dev->tstats)
1471                 return -ENOMEM;
1472
1473         for_each_possible_cpu(i) {
1474                 struct pcpu_tstats *ip6gre_tap_stats;
1475                 ip6gre_tap_stats = per_cpu_ptr(dev->tstats, i);
1476                 u64_stats_init(&ip6gre_tap_stats->syncp);
1477         }
1478
1479         return 0;
1480 }
1481
1482 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1483         .ndo_init = ip6gre_tap_init,
1484         .ndo_uninit = ip6gre_tunnel_uninit,
1485         .ndo_start_xmit = ip6gre_tunnel_xmit,
1486         .ndo_set_mac_address = eth_mac_addr,
1487         .ndo_validate_addr = eth_validate_addr,
1488         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1489         .ndo_get_stats64 = ip_tunnel_get_stats64,
1490 };
1491
1492 static void ip6gre_tap_setup(struct net_device *dev)
1493 {
1494
1495         ether_setup(dev);
1496
1497         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1498         dev->destructor = ip6gre_dev_free;
1499
1500         dev->iflink = 0;
1501         dev->features |= NETIF_F_NETNS_LOCAL;
1502 }
1503
1504 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1505         struct nlattr *tb[], struct nlattr *data[])
1506 {
1507         struct ip6_tnl *nt;
1508         struct net *net = dev_net(dev);
1509         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1510         int err;
1511
1512         nt = netdev_priv(dev);
1513         ip6gre_netlink_parms(data, &nt->parms);
1514
1515         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1516                 return -EEXIST;
1517
1518         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1519                 eth_hw_addr_random(dev);
1520
1521         nt->dev = dev;
1522         nt->net = dev_net(dev);
1523         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1524
1525         /* Can use a lockless transmit, unless we generate output sequences */
1526         if (!(nt->parms.o_flags & GRE_SEQ))
1527                 dev->features |= NETIF_F_LLTX;
1528
1529         err = register_netdevice(dev);
1530         if (err)
1531                 goto out;
1532
1533         dev_hold(dev);
1534         ip6gre_tunnel_link(ign, nt);
1535
1536 out:
1537         return err;
1538 }
1539
1540 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1541                             struct nlattr *data[])
1542 {
1543         struct ip6_tnl *t, *nt;
1544         struct net *net = dev_net(dev);
1545         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1546         struct __ip6_tnl_parm p;
1547
1548         if (dev == ign->fb_tunnel_dev)
1549                 return -EINVAL;
1550
1551         nt = netdev_priv(dev);
1552         ip6gre_netlink_parms(data, &p);
1553
1554         t = ip6gre_tunnel_locate(net, &p, 0);
1555
1556         if (t) {
1557                 if (t->dev != dev)
1558                         return -EEXIST;
1559         } else {
1560                 t = nt;
1561
1562                 ip6gre_tunnel_unlink(ign, t);
1563                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1564                 ip6gre_tunnel_link(ign, t);
1565                 netdev_state_change(dev);
1566         }
1567
1568         return 0;
1569 }
1570
1571 static size_t ip6gre_get_size(const struct net_device *dev)
1572 {
1573         return
1574                 /* IFLA_GRE_LINK */
1575                 nla_total_size(4) +
1576                 /* IFLA_GRE_IFLAGS */
1577                 nla_total_size(2) +
1578                 /* IFLA_GRE_OFLAGS */
1579                 nla_total_size(2) +
1580                 /* IFLA_GRE_IKEY */
1581                 nla_total_size(4) +
1582                 /* IFLA_GRE_OKEY */
1583                 nla_total_size(4) +
1584                 /* IFLA_GRE_LOCAL */
1585                 nla_total_size(sizeof(struct in6_addr)) +
1586                 /* IFLA_GRE_REMOTE */
1587                 nla_total_size(sizeof(struct in6_addr)) +
1588                 /* IFLA_GRE_TTL */
1589                 nla_total_size(1) +
1590                 /* IFLA_GRE_TOS */
1591                 nla_total_size(1) +
1592                 /* IFLA_GRE_ENCAP_LIMIT */
1593                 nla_total_size(1) +
1594                 /* IFLA_GRE_FLOWINFO */
1595                 nla_total_size(4) +
1596                 /* IFLA_GRE_FLAGS */
1597                 nla_total_size(4) +
1598                 0;
1599 }
1600
1601 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1602 {
1603         struct ip6_tnl *t = netdev_priv(dev);
1604         struct __ip6_tnl_parm *p = &t->parms;
1605
1606         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1607             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1608             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1609             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1610             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1611             nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1612             nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1613             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1614             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1615             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1616             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1617             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1618                 goto nla_put_failure;
1619         return 0;
1620
1621 nla_put_failure:
1622         return -EMSGSIZE;
1623 }
1624
1625 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1626         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1627         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1628         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1629         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1630         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1631         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1632         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1633         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1634         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1635         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1636         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1637 };
1638
1639 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1640         .kind           = "ip6gre",
1641         .maxtype        = IFLA_GRE_MAX,
1642         .policy         = ip6gre_policy,
1643         .priv_size      = sizeof(struct ip6_tnl),
1644         .setup          = ip6gre_tunnel_setup,
1645         .validate       = ip6gre_tunnel_validate,
1646         .newlink        = ip6gre_newlink,
1647         .changelink     = ip6gre_changelink,
1648         .get_size       = ip6gre_get_size,
1649         .fill_info      = ip6gre_fill_info,
1650 };
1651
1652 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1653         .kind           = "ip6gretap",
1654         .maxtype        = IFLA_GRE_MAX,
1655         .policy         = ip6gre_policy,
1656         .priv_size      = sizeof(struct ip6_tnl),
1657         .setup          = ip6gre_tap_setup,
1658         .validate       = ip6gre_tap_validate,
1659         .newlink        = ip6gre_newlink,
1660         .changelink     = ip6gre_changelink,
1661         .get_size       = ip6gre_get_size,
1662         .fill_info      = ip6gre_fill_info,
1663 };
1664
1665 /*
1666  *      And now the modules code and kernel interface.
1667  */
1668
1669 static int __init ip6gre_init(void)
1670 {
1671         int err;
1672
1673         pr_info("GRE over IPv6 tunneling driver\n");
1674
1675         err = register_pernet_device(&ip6gre_net_ops);
1676         if (err < 0)
1677                 return err;
1678
1679         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1680         if (err < 0) {
1681                 pr_info("%s: can't add protocol\n", __func__);
1682                 goto add_proto_failed;
1683         }
1684
1685         err = rtnl_link_register(&ip6gre_link_ops);
1686         if (err < 0)
1687                 goto rtnl_link_failed;
1688
1689         err = rtnl_link_register(&ip6gre_tap_ops);
1690         if (err < 0)
1691                 goto tap_ops_failed;
1692
1693 out:
1694         return err;
1695
1696 tap_ops_failed:
1697         rtnl_link_unregister(&ip6gre_link_ops);
1698 rtnl_link_failed:
1699         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1700 add_proto_failed:
1701         unregister_pernet_device(&ip6gre_net_ops);
1702         goto out;
1703 }
1704
1705 static void __exit ip6gre_fini(void)
1706 {
1707         rtnl_link_unregister(&ip6gre_tap_ops);
1708         rtnl_link_unregister(&ip6gre_link_ops);
1709         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1710         unregister_pernet_device(&ip6gre_net_ops);
1711 }
1712
1713 module_init(ip6gre_init);
1714 module_exit(ip6gre_fini);
1715 MODULE_LICENSE("GPL");
1716 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1717 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1718 MODULE_ALIAS_RTNL_LINK("ip6gre");
1719 MODULE_ALIAS_NETDEV("ip6gre0");