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
  58
  59 static bool log_ecn_error = true;
  60 module_param(log_ecn_error, bool, 0644);
  61 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  62
  63 #define HASH_SIZE_SHIFT  5
  64 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  65
  66 static int ip6gre_net_id __read_mostly;
  67 struct ip6gre_net {
  68         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  69
  70         struct net_device *fb_tunnel_dev;
  71 };
  72
  73 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  74 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
  75 static int ip6gre_tunnel_init(struct net_device *dev);
  76 static void ip6gre_tunnel_setup(struct net_device *dev);
  77 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  78 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  79
  80 /* Tunnel hash table */
  81
  82 /*
  83    4 hash tables:
  84
  85    3: (remote,local)
  86    2: (remote,*)
  87    1: (*,local)
  88    0: (*,*)
  89
  90    We require exact key match i.e. if a key is present in packet
  91    it will match only tunnel with the same key; if it is not present,
  92    it will match only keyless tunnel.
  93
  94    All keysless packets, if not matched configured keyless tunnels
  95    will match fallback tunnel.
  96  */
  97
  98 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
  99 static u32 HASH_ADDR(const struct in6_addr *addr)
 100 {
 101         u32 hash = ipv6_addr_hash(addr);
 102
 103         return hash_32(hash, HASH_SIZE_SHIFT);
 104 }
 105
 106 #define tunnels_r_l     tunnels[3]
 107 #define tunnels_r       tunnels[2]
 108 #define tunnels_l       tunnels[1]
 109 #define tunnels_wc      tunnels[0]
 110
 111 /* Given src, dst and key, find appropriate for input tunnel. */
 112
 113 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 114                 const struct in6_addr *remote, const struct in6_addr *local,
 115                 __be32 key, __be16 gre_proto)
 116 {
 117         struct net *net = dev_net(dev);
 118         int link = dev->ifindex;
 119         unsigned int h0 = HASH_ADDR(remote);
 120         unsigned int h1 = HASH_KEY(key);
 121         struct ip6_tnl *t, *cand = NULL;
 122         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 123         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 124                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 125         int score, cand_score = 4;
 126
 127         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 128                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 129                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 130                     key != t->parms.i_key ||
 131                     !(t->dev->flags & IFF_UP))
 132                         continue;
 133
 134                 if (t->dev->type != ARPHRD_IP6GRE &&
 135                     t->dev->type != dev_type)
 136                         continue;
 137
 138                 score = 0;
 139                 if (t->parms.link != link)
 140                         score |= 1;
 141                 if (t->dev->type != dev_type)
 142                         score |= 2;
 143                 if (score == 0)
 144                         return t;
 145
 146                 if (score < cand_score) {
 147                         cand = t;
 148                         cand_score = score;
 149                 }
 150         }
 151
 152         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 153                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 154                     key != t->parms.i_key ||
 155                     !(t->dev->flags & IFF_UP))
 156                         continue;
 157
 158                 if (t->dev->type != ARPHRD_IP6GRE &&
 159                     t->dev->type != dev_type)
 160                         continue;
 161
 162                 score = 0;
 163                 if (t->parms.link != link)
 164                         score |= 1;
 165                 if (t->dev->type != dev_type)
 166                         score |= 2;
 167                 if (score == 0)
 168                         return t;
 169
 170                 if (score < cand_score) {
 171                         cand = t;
 172                         cand_score = score;
 173                 }
 174         }
 175
 176         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 177                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 178                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 179                                  !ipv6_addr_is_multicast(local))) ||
 180                     key != t->parms.i_key ||
 181                     !(t->dev->flags & IFF_UP))
 182                         continue;
 183
 184                 if (t->dev->type != ARPHRD_IP6GRE &&
 185                     t->dev->type != dev_type)
 186                         continue;
 187
 188                 score = 0;
 189                 if (t->parms.link != link)
 190                         score |= 1;
 191                 if (t->dev->type != dev_type)
 192                         score |= 2;
 193                 if (score == 0)
 194                         return t;
 195
 196                 if (score < cand_score) {
 197                         cand = t;
 198                         cand_score = score;
 199                 }
 200         }
 201
 202         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 203                 if (t->parms.i_key != key ||
 204                     !(t->dev->flags & IFF_UP))
 205                         continue;
 206
 207                 if (t->dev->type != ARPHRD_IP6GRE &&
 208                     t->dev->type != dev_type)
 209                         continue;
 210
 211                 score = 0;
 212                 if (t->parms.link != link)
 213                         score |= 1;
 214                 if (t->dev->type != dev_type)
 215                         score |= 2;
 216                 if (score == 0)
 217                         return t;
 218
 219                 if (score < cand_score) {
 220                         cand = t;
 221                         cand_score = score;
 222                 }
 223         }
 224
 225         if (cand)
 226                 return cand;
 227
 228         dev = ign->fb_tunnel_dev;
 229         if (dev->flags & IFF_UP)
 230                 return netdev_priv(dev);
 231
 232         return NULL;
 233 }
 234
 235 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 236                 const struct __ip6_tnl_parm *p)
 237 {
 238         const struct in6_addr *remote = &p->raddr;
 239         const struct in6_addr *local = &p->laddr;
 240         unsigned int h = HASH_KEY(p->i_key);
 241         int prio = 0;
 242
 243         if (!ipv6_addr_any(local))
 244                 prio |= 1;
 245         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 246                 prio |= 2;
 247                 h ^= HASH_ADDR(remote);
 248         }
 249
 250         return &ign->tunnels[prio][h];
 251 }
 252
 253 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 254                 const struct ip6_tnl *t)
 255 {
 256         return __ip6gre_bucket(ign, &t->parms);
 257 }
 258
 259 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 260 {
 261         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 262
 263         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 264         rcu_assign_pointer(*tp, t);
 265 }
 266
 267 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 268 {
 269         struct ip6_tnl __rcu **tp;
 270         struct ip6_tnl *iter;
 271
 272         for (tp = ip6gre_bucket(ign, t);
 273              (iter = rtnl_dereference(*tp)) != NULL;
 274              tp = &iter->next) {
 275                 if (t == iter) {
 276                         rcu_assign_pointer(*tp, t->next);
 277                         break;
 278                 }
 279         }
 280 }
 281
 282 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 283                                            const struct __ip6_tnl_parm *parms,
 284                                            int type)
 285 {
 286         const struct in6_addr *remote = &parms->raddr;
 287         const struct in6_addr *local = &parms->laddr;
 288         __be32 key = parms->i_key;
 289         int link = parms->link;
 290         struct ip6_tnl *t;
 291         struct ip6_tnl __rcu **tp;
 292         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 293
 294         for (tp = __ip6gre_bucket(ign, parms);
 295              (t = rtnl_dereference(*tp)) != NULL;
 296              tp = &t->next)
 297                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 298                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 299                     key == t->parms.i_key &&
 300                     link == t->parms.link &&
 301                     type == t->dev->type)
 302                         break;
 303
 304         return t;
 305 }
 306
 307 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 308                 const struct __ip6_tnl_parm *parms, int create)
 309 {
 310         struct ip6_tnl *t, *nt;
 311         struct net_device *dev;
 312         char name[IFNAMSIZ];
 313         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 314
 315         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 316         if (t && create)
 317                 return NULL;
 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, NET_NAME_UNKNOWN,
 327                            ip6gre_tunnel_setup);
 328         if (!dev)
 329                 return NULL;
 330
 331         dev_net_set(dev, net);
 332
 333         nt = netdev_priv(dev);
 334         nt->parms = *parms;
 335         dev->rtnl_link_ops = &ip6gre_link_ops;
 336
 337         nt->dev = dev;
 338         nt->net = dev_net(dev);
 339         ip6gre_tnl_link_config(nt, 1);
 340
 341         if (register_netdevice(dev) < 0)
 342                 goto failed_free;
 343
 344         /* Can use a lockless transmit, unless we generate output sequences */
 345         if (!(nt->parms.o_flags & GRE_SEQ))
 346                 dev->features |= NETIF_F_LLTX;
 347
 348         dev_hold(dev);
 349         ip6gre_tunnel_link(ign, nt);
 350         return nt;
 351
 352 failed_free:
 353         free_netdev(dev);
 354         return NULL;
 355 }
 356
 357 static void ip6gre_tunnel_uninit(struct net_device *dev)
 358 {
 359         struct ip6_tnl *t = netdev_priv(dev);
 360         struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 361
 362         ip6gre_tunnel_unlink(ign, t);
 363         ip6_tnl_dst_reset(t);
 364         dev_put(dev);
 365 }
 366
 367
 368 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 369                 u8 type, u8 code, int offset, __be32 info)
 370 {
 371         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 372         __be16 *p = (__be16 *)(skb->data + offset);
 373         int grehlen = offset + 4;
 374         struct ip6_tnl *t;
 375         __be16 flags;
 376
 377         flags = p[0];
 378         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 379                 if (flags&(GRE_VERSION|GRE_ROUTING))
 380                         return;
 381                 if (flags&GRE_KEY) {
 382                         grehlen += 4;
 383                         if (flags&GRE_CSUM)
 384                                 grehlen += 4;
 385                 }
 386         }
 387
 388         /* If only 8 bytes returned, keyed message will be dropped here */
 389         if (!pskb_may_pull(skb, grehlen))
 390                 return;
 391         ipv6h = (const struct ipv6hdr *)skb->data;
 392         p = (__be16 *)(skb->data + offset);
 393
 394         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 395                                 flags & GRE_KEY ?
 396                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 397                                 p[1]);
 398         if (!t)
 399                 return;
 400
 401         switch (type) {
 402                 __u32 teli;
 403                 struct ipv6_tlv_tnl_enc_lim *tel;
 404                 __u32 mtu;
 405         case ICMPV6_DEST_UNREACH:
 406                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 407                                     t->parms.name);
 408                 break;
 409         case ICMPV6_TIME_EXCEED:
 410                 if (code == ICMPV6_EXC_HOPLIMIT) {
 411                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 412                                             t->parms.name);
 413                 }
 414                 break;
 415         case ICMPV6_PARAMPROB:
 416                 teli = 0;
 417                 if (code == ICMPV6_HDR_FIELD)
 418                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 419
 420                 if (teli && teli == be32_to_cpu(info) - 2) {
 421                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 422                         if (tel->encap_limit == 0) {
 423                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 424                                                     t->parms.name);
 425                         }
 426                 } else {
 427                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 428                                             t->parms.name);
 429                 }
 430                 break;
 431         case ICMPV6_PKT_TOOBIG:
 432                 mtu = be32_to_cpu(info) - offset;
 433                 if (mtu < IPV6_MIN_MTU)
 434                         mtu = IPV6_MIN_MTU;
 435                 t->dev->mtu = mtu;
 436                 break;
 437         }
 438
 439         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 440                 t->err_count++;
 441         else
 442                 t->err_count = 1;
 443         t->err_time = jiffies;
 444 }
 445
 446 static int ip6gre_rcv(struct sk_buff *skb)
 447 {
 448         const struct ipv6hdr *ipv6h;
 449         u8     *h;
 450         __be16    flags;
 451         __sum16   csum = 0;
 452         __be32 key = 0;
 453         u32    seqno = 0;
 454         struct ip6_tnl *tunnel;
 455         int    offset = 4;
 456         __be16 gre_proto;
 457         int err;
 458
 459         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 460                 goto drop;
 461
 462         ipv6h = ipv6_hdr(skb);
 463         h = skb->data;
 464         flags = *(__be16 *)h;
 465
 466         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 467                 /* - Version must be 0.
 468                    - We do not support routing headers.
 469                  */
 470                 if (flags&(GRE_VERSION|GRE_ROUTING))
 471                         goto drop;
 472
 473                 if (flags&GRE_CSUM) {
 474                         csum = skb_checksum_simple_validate(skb);
 475                         offset += 4;
 476                 }
 477                 if (flags&GRE_KEY) {
 478                         key = *(__be32 *)(h + offset);
 479                         offset += 4;
 480                 }
 481                 if (flags&GRE_SEQ) {
 482                         seqno = ntohl(*(__be32 *)(h + offset));
 483                         offset += 4;
 484                 }
 485         }
 486
 487         gre_proto = *(__be16 *)(h + 2);
 488
 489         tunnel = ip6gre_tunnel_lookup(skb->dev,
 490                                           &ipv6h->saddr, &ipv6h->daddr, key,
 491                                           gre_proto);
 492         if (tunnel) {
 493                 struct pcpu_sw_netstats *tstats;
 494
 495                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 496                         goto drop;
 497
 498                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 499                         tunnel->dev->stats.rx_dropped++;
 500                         goto drop;
 501                 }
 502
 503                 skb->protocol = gre_proto;
 504                 /* WCCP version 1 and 2 protocol decoding.
 505                  * - Change protocol to IPv6
 506                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 507                  */
 508                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 509                         skb->protocol = htons(ETH_P_IPV6);
 510                         if ((*(h + offset) & 0xF0) != 0x40)
 511                                 offset += 4;
 512                 }
 513
 514                 skb->mac_header = skb->network_header;
 515                 __pskb_pull(skb, offset);
 516                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 517
 518                 if (((flags&GRE_CSUM) && csum) ||
 519                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 520                         tunnel->dev->stats.rx_crc_errors++;
 521                         tunnel->dev->stats.rx_errors++;
 522                         goto drop;
 523                 }
 524                 if (tunnel->parms.i_flags&GRE_SEQ) {
 525                         if (!(flags&GRE_SEQ) ||
 526                             (tunnel->i_seqno &&
 527                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 528                                 tunnel->dev->stats.rx_fifo_errors++;
 529                                 tunnel->dev->stats.rx_errors++;
 530                                 goto drop;
 531                         }
 532                         tunnel->i_seqno = seqno + 1;
 533                 }
 534
 535                 /* Warning: All skb pointers will be invalidated! */
 536                 if (tunnel->dev->type == ARPHRD_ETHER) {
 537                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 538                                 tunnel->dev->stats.rx_length_errors++;
 539                                 tunnel->dev->stats.rx_errors++;
 540                                 goto drop;
 541                         }
 542
 543                         ipv6h = ipv6_hdr(skb);
 544                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 545                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 546                 }
 547
 548                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 549
 550                 skb_reset_network_header(skb);
 551
 552                 err = IP6_ECN_decapsulate(ipv6h, skb);
 553                 if (unlikely(err)) {
 554                         if (log_ecn_error)
 555                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 556                                                      &ipv6h->saddr,
 557                                                      ipv6_get_dsfield(ipv6h));
 558                         if (err > 1) {
 559                                 ++tunnel->dev->stats.rx_frame_errors;
 560                                 ++tunnel->dev->stats.rx_errors;
 561                                 goto drop;
 562                         }
 563                 }
 564
 565                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 566                 u64_stats_update_begin(&tstats->syncp);
 567                 tstats->rx_packets++;
 568                 tstats->rx_bytes += skb->len;
 569                 u64_stats_update_end(&tstats->syncp);
 570
 571                 netif_rx(skb);
 572
 573                 return 0;
 574         }
 575         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 576
 577 drop:
 578         kfree_skb(skb);
 579         return 0;
 580 }
 581
 582 struct ipv6_tel_txoption {
 583         struct ipv6_txoptions ops;
 584         __u8 dst_opt[8];
 585 };
 586
 587 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 588 {
 589         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 590
 591         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 592         opt->dst_opt[3] = 1;
 593         opt->dst_opt[4] = encap_limit;
 594         opt->dst_opt[5] = IPV6_TLV_PADN;
 595         opt->dst_opt[6] = 1;
 596
 597         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 598         opt->ops.opt_nflen = 8;
 599 }
 600
 601 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 602                          struct net_device *dev,
 603                          __u8 dsfield,
 604                          struct flowi6 *fl6,
 605                          int encap_limit,
 606                          __u32 *pmtu)
 607 {
 608         struct ip6_tnl *tunnel = netdev_priv(dev);
 609         struct net *net = tunnel->net;
 610         struct net_device *tdev;    /* Device to other host */
 611         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 612         unsigned int max_headroom = 0; /* The extra header space needed */
 613         int    gre_hlen;
 614         struct ipv6_tel_txoption opt;
 615         int    mtu;
 616         struct dst_entry *dst = NULL, *ndst = NULL;
 617         struct net_device_stats *stats = &tunnel->dev->stats;
 618         int err = -1;
 619         u8 proto;
 620         struct sk_buff *new_skb;
 621         __be16 protocol;
 622
 623         if (dev->type == ARPHRD_ETHER)
 624                 IPCB(skb)->flags = 0;
 625
 626         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 627                 gre_hlen = 0;
 628                 ipv6h = (struct ipv6hdr *)skb->data;
 629                 fl6->daddr = ipv6h->daddr;
 630         } else {
 631                 gre_hlen = tunnel->hlen;
 632                 fl6->daddr = tunnel->parms.raddr;
 633         }
 634
 635         if (!fl6->flowi6_mark)
 636                 dst = ip6_tnl_dst_get(tunnel);
 637
 638         if (!dst) {
 639                 dst = ip6_route_output(net, NULL, fl6);
 640
 641                 if (dst->error)
 642                         goto tx_err_link_failure;
 643                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
 644                 if (IS_ERR(dst)) {
 645                         err = PTR_ERR(dst);
 646                         dst = NULL;
 647                         goto tx_err_link_failure;
 648                 }
 649                 ndst = dst;
 650         }
 651
 652         tdev = dst->dev;
 653
 654         if (tdev == dev) {
 655                 stats->collisions++;
 656                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 657                                      tunnel->parms.name);
 658                 goto tx_err_dst_release;
 659         }
 660
 661         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 662         if (encap_limit >= 0) {
 663                 max_headroom += 8;
 664                 mtu -= 8;
 665         }
 666         if (mtu < IPV6_MIN_MTU)
 667                 mtu = IPV6_MIN_MTU;
 668         if (skb_dst(skb))
 669                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 670         if (skb->len > mtu) {
 671                 *pmtu = mtu;
 672                 err = -EMSGSIZE;
 673                 goto tx_err_dst_release;
 674         }
 675
 676         if (tunnel->err_count > 0) {
 677                 if (time_before(jiffies,
 678                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 679                         tunnel->err_count--;
 680
 681                         dst_link_failure(skb);
 682                 } else
 683                         tunnel->err_count = 0;
 684         }
 685
 686         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 687
 688         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 689
 690         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 691             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 692                 new_skb = skb_realloc_headroom(skb, max_headroom);
 693                 if (max_headroom > dev->needed_headroom)
 694                         dev->needed_headroom = max_headroom;
 695                 if (!new_skb)
 696                         goto tx_err_dst_release;
 697
 698                 if (skb->sk)
 699                         skb_set_owner_w(new_skb, skb->sk);
 700                 consume_skb(skb);
 701                 skb = new_skb;
 702         }
 703
 704         if (!fl6->flowi6_mark && ndst)
 705                 ip6_tnl_dst_set(tunnel, ndst);
 706         skb_dst_set(skb, dst);
 707
 708         proto = NEXTHDR_GRE;
 709         if (encap_limit >= 0) {
 710                 init_tel_txopt(&opt, encap_limit);
 711                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 712         }
 713
 714         if (likely(!skb->encapsulation)) {
 715                 skb_reset_inner_headers(skb);
 716                 skb->encapsulation = 1;
 717         }
 718
 719         skb_push(skb, gre_hlen);
 720         skb_reset_network_header(skb);
 721         skb_set_transport_header(skb, sizeof(*ipv6h));
 722
 723         /*
 724          *      Push down and install the IP header.
 725          */
 726         ipv6h = ipv6_hdr(skb);
 727         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
 728                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
 729         ipv6h->hop_limit = tunnel->parms.hop_limit;
 730         ipv6h->nexthdr = proto;
 731         ipv6h->saddr = fl6->saddr;
 732         ipv6h->daddr = fl6->daddr;
 733
 734         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 735         protocol = (dev->type == ARPHRD_ETHER) ?
 736                     htons(ETH_P_TEB) : skb->protocol;
 737         ((__be16 *)(ipv6h + 1))[1] = protocol;
 738
 739         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 740                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 741
 742                 if (tunnel->parms.o_flags&GRE_SEQ) {
 743                         ++tunnel->o_seqno;
 744                         *ptr = htonl(tunnel->o_seqno);
 745                         ptr--;
 746                 }
 747                 if (tunnel->parms.o_flags&GRE_KEY) {
 748                         *ptr = tunnel->parms.o_key;
 749                         ptr--;
 750                 }
 751                 if (tunnel->parms.o_flags&GRE_CSUM) {
 752                         *ptr = 0;
 753                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 754                                 skb->len - sizeof(struct ipv6hdr));
 755                 }
 756         }
 757
 758         skb_set_inner_protocol(skb, protocol);
 759
 760         ip6tunnel_xmit(NULL, skb, dev);
 761         return 0;
 762 tx_err_link_failure:
 763         stats->tx_carrier_errors++;
 764         dst_link_failure(skb);
 765 tx_err_dst_release:
 766         dst_release(dst);
 767         return err;
 768 }
 769
 770 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 771 {
 772         struct ip6_tnl *t = netdev_priv(dev);
 773         const struct iphdr  *iph = ip_hdr(skb);
 774         int encap_limit = -1;
 775         struct flowi6 fl6;
 776         __u8 dsfield;
 777         __u32 mtu;
 778         int err;
 779
 780         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 781                 encap_limit = t->parms.encap_limit;
 782
 783         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 784         fl6.flowi6_proto = IPPROTO_GRE;
 785
 786         dsfield = ipv4_get_dsfield(iph);
 787
 788         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 789                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 790                                           & IPV6_TCLASS_MASK;
 791         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 792                 fl6.flowi6_mark = skb->mark;
 793
 794         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 795         if (err != 0) {
 796                 /* XXX: send ICMP error even if DF is not set. */
 797                 if (err == -EMSGSIZE)
 798                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 799                                   htonl(mtu));
 800                 return -1;
 801         }
 802
 803         return 0;
 804 }
 805
 806 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 807 {
 808         struct ip6_tnl *t = netdev_priv(dev);
 809         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 810         int encap_limit = -1;
 811         __u16 offset;
 812         struct flowi6 fl6;
 813         __u8 dsfield;
 814         __u32 mtu;
 815         int err;
 816
 817         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 818                 return -1;
 819
 820         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 821         if (offset > 0) {
 822                 struct ipv6_tlv_tnl_enc_lim *tel;
 823                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 824                 if (tel->encap_limit == 0) {
 825                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 826                                     ICMPV6_HDR_FIELD, offset + 2);
 827                         return -1;
 828                 }
 829                 encap_limit = tel->encap_limit - 1;
 830         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 831                 encap_limit = t->parms.encap_limit;
 832
 833         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 834         fl6.flowi6_proto = IPPROTO_GRE;
 835
 836         dsfield = ipv6_get_dsfield(ipv6h);
 837         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 838                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 839         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 840                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 841         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 842                 fl6.flowi6_mark = skb->mark;
 843
 844         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 845         if (err != 0) {
 846                 if (err == -EMSGSIZE)
 847                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 848                 return -1;
 849         }
 850
 851         return 0;
 852 }
 853
 854 /**
 855  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 856  *   @t: the outgoing tunnel device
 857  *   @hdr: IPv6 header from the incoming packet
 858  *
 859  * Description:
 860  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 861  *   doesn't match source of incoming packet.
 862  *
 863  * Return:
 864  *   1 if conflict,
 865  *   0 else
 866  **/
 867
 868 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 869         const struct ipv6hdr *hdr)
 870 {
 871         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 872 }
 873
 874 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 875 {
 876         struct ip6_tnl *t = netdev_priv(dev);
 877         int encap_limit = -1;
 878         struct flowi6 fl6;
 879         __u32 mtu;
 880         int err;
 881
 882         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 883                 encap_limit = t->parms.encap_limit;
 884
 885         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 886         fl6.flowi6_proto = skb->protocol;
 887
 888         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 889
 890         return err;
 891 }
 892
 893 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 894         struct net_device *dev)
 895 {
 896         struct ip6_tnl *t = netdev_priv(dev);
 897         struct net_device_stats *stats = &t->dev->stats;
 898         int ret;
 899
 900         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 901                 goto tx_err;
 902
 903         switch (skb->protocol) {
 904         case htons(ETH_P_IP):
 905                 ret = ip6gre_xmit_ipv4(skb, dev);
 906                 break;
 907         case htons(ETH_P_IPV6):
 908                 ret = ip6gre_xmit_ipv6(skb, dev);
 909                 break;
 910         default:
 911                 ret = ip6gre_xmit_other(skb, dev);
 912                 break;
 913         }
 914
 915         if (ret < 0)
 916                 goto tx_err;
 917
 918         return NETDEV_TX_OK;
 919
 920 tx_err:
 921         stats->tx_errors++;
 922         stats->tx_dropped++;
 923         kfree_skb(skb);
 924         return NETDEV_TX_OK;
 925 }
 926
 927 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 928 {
 929         struct net_device *dev = t->dev;
 930         struct __ip6_tnl_parm *p = &t->parms;
 931         struct flowi6 *fl6 = &t->fl.u.ip6;
 932         int addend = sizeof(struct ipv6hdr) + 4;
 933
 934         if (dev->type != ARPHRD_ETHER) {
 935                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 936                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 937         }
 938
 939         /* Set up flowi template */
 940         fl6->saddr = p->laddr;
 941         fl6->daddr = p->raddr;
 942         fl6->flowi6_oif = p->link;
 943         fl6->flowlabel = 0;
 944
 945         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 946                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 947         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 948                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 949
 950         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 951         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 952
 953         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 954                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 955                 dev->flags |= IFF_POINTOPOINT;
 956         else
 957                 dev->flags &= ~IFF_POINTOPOINT;
 958
 959         /* Precalculate GRE options length */
 960         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 961                 if (t->parms.o_flags&GRE_CSUM)
 962                         addend += 4;
 963                 if (t->parms.o_flags&GRE_KEY)
 964                         addend += 4;
 965                 if (t->parms.o_flags&GRE_SEQ)
 966                         addend += 4;
 967         }
 968         t->hlen = addend;
 969
 970         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 971                 int strict = (ipv6_addr_type(&p->raddr) &
 972                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 973
 974                 struct rt6_info *rt = rt6_lookup(t->net,
 975                                                  &p->raddr, &p->laddr,
 976                                                  p->link, strict);
 977
 978                 if (!rt)
 979                         return;
 980
 981                 if (rt->dst.dev) {
 982                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 983
 984                         if (set_mtu) {
 985                                 dev->mtu = rt->dst.dev->mtu - addend;
 986                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 987                                         dev->mtu -= 8;
 988
 989                                 if (dev->mtu < IPV6_MIN_MTU)
 990                                         dev->mtu = IPV6_MIN_MTU;
 991                         }
 992                 }
 993                 ip6_rt_put(rt);
 994         }
 995 }
 996
 997 static int ip6gre_tnl_change(struct ip6_tnl *t,
 998         const struct __ip6_tnl_parm *p, int set_mtu)
 999 {
1000         t->parms.laddr = p->laddr;
1001         t->parms.raddr = p->raddr;
1002         t->parms.flags = p->flags;
1003         t->parms.hop_limit = p->hop_limit;
1004         t->parms.encap_limit = p->encap_limit;
1005         t->parms.flowinfo = p->flowinfo;
1006         t->parms.link = p->link;
1007         t->parms.proto = p->proto;
1008         t->parms.i_key = p->i_key;
1009         t->parms.o_key = p->o_key;
1010         t->parms.i_flags = p->i_flags;
1011         t->parms.o_flags = p->o_flags;
1012         ip6_tnl_dst_reset(t);
1013         ip6gre_tnl_link_config(t, set_mtu);
1014         return 0;
1015 }
1016
1017 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1018         const struct ip6_tnl_parm2 *u)
1019 {
1020         p->laddr = u->laddr;
1021         p->raddr = u->raddr;
1022         p->flags = u->flags;
1023         p->hop_limit = u->hop_limit;
1024         p->encap_limit = u->encap_limit;
1025         p->flowinfo = u->flowinfo;
1026         p->link = u->link;
1027         p->i_key = u->i_key;
1028         p->o_key = u->o_key;
1029         p->i_flags = u->i_flags;
1030         p->o_flags = u->o_flags;
1031         memcpy(p->name, u->name, sizeof(u->name));
1032 }
1033
1034 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1035         const struct __ip6_tnl_parm *p)
1036 {
1037         u->proto = IPPROTO_GRE;
1038         u->laddr = p->laddr;
1039         u->raddr = p->raddr;
1040         u->flags = p->flags;
1041         u->hop_limit = p->hop_limit;
1042         u->encap_limit = p->encap_limit;
1043         u->flowinfo = p->flowinfo;
1044         u->link = p->link;
1045         u->i_key = p->i_key;
1046         u->o_key = p->o_key;
1047         u->i_flags = p->i_flags;
1048         u->o_flags = p->o_flags;
1049         memcpy(u->name, p->name, sizeof(u->name));
1050 }
1051
1052 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1053         struct ifreq *ifr, int cmd)
1054 {
1055         int err = 0;
1056         struct ip6_tnl_parm2 p;
1057         struct __ip6_tnl_parm p1;
1058         struct ip6_tnl *t = netdev_priv(dev);
1059         struct net *net = t->net;
1060         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1061
1062         switch (cmd) {
1063         case SIOCGETTUNNEL:
1064                 if (dev == ign->fb_tunnel_dev) {
1065                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1066                                 err = -EFAULT;
1067                                 break;
1068                         }
1069                         ip6gre_tnl_parm_from_user(&p1, &p);
1070                         t = ip6gre_tunnel_locate(net, &p1, 0);
1071                         if (!t)
1072                                 t = netdev_priv(dev);
1073                 }
1074                 memset(&p, 0, sizeof(p));
1075                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1076                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1077                         err = -EFAULT;
1078                 break;
1079
1080         case SIOCADDTUNNEL:
1081         case SIOCCHGTUNNEL:
1082                 err = -EPERM;
1083                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1084                         goto done;
1085
1086                 err = -EFAULT;
1087                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1088                         goto done;
1089
1090                 err = -EINVAL;
1091                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1092                         goto done;
1093
1094                 if (!(p.i_flags&GRE_KEY))
1095                         p.i_key = 0;
1096                 if (!(p.o_flags&GRE_KEY))
1097                         p.o_key = 0;
1098
1099                 ip6gre_tnl_parm_from_user(&p1, &p);
1100                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1101
1102                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1103                         if (t) {
1104                                 if (t->dev != dev) {
1105                                         err = -EEXIST;
1106                                         break;
1107                                 }
1108                         } else {
1109                                 t = netdev_priv(dev);
1110
1111                                 ip6gre_tunnel_unlink(ign, t);
1112                                 synchronize_net();
1113                                 ip6gre_tnl_change(t, &p1, 1);
1114                                 ip6gre_tunnel_link(ign, t);
1115                                 netdev_state_change(dev);
1116                         }
1117                 }
1118
1119                 if (t) {
1120                         err = 0;
1121
1122                         memset(&p, 0, sizeof(p));
1123                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1124                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1125                                 err = -EFAULT;
1126                 } else
1127                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1128                 break;
1129
1130         case SIOCDELTUNNEL:
1131                 err = -EPERM;
1132                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1133                         goto done;
1134
1135                 if (dev == ign->fb_tunnel_dev) {
1136                         err = -EFAULT;
1137                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1138                                 goto done;
1139                         err = -ENOENT;
1140                         ip6gre_tnl_parm_from_user(&p1, &p);
1141                         t = ip6gre_tunnel_locate(net, &p1, 0);
1142                         if (!t)
1143                                 goto done;
1144                         err = -EPERM;
1145                         if (t == netdev_priv(ign->fb_tunnel_dev))
1146                                 goto done;
1147                         dev = t->dev;
1148                 }
1149                 unregister_netdevice(dev);
1150                 err = 0;
1151                 break;
1152
1153         default:
1154                 err = -EINVAL;
1155         }
1156
1157 done:
1158         return err;
1159 }
1160
1161 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1162 {
1163         if (new_mtu < 68 ||
1164             new_mtu > 0xFFF8 - dev->hard_header_len)
1165                 return -EINVAL;
1166         dev->mtu = new_mtu;
1167         return 0;
1168 }
1169
1170 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1171                         unsigned short type,
1172                         const void *daddr, const void *saddr, unsigned int len)
1173 {
1174         struct ip6_tnl *t = netdev_priv(dev);
1175         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1176         __be16 *p = (__be16 *)(ipv6h+1);
1177
1178         ip6_flow_hdr(ipv6h, 0,
1179                      ip6_make_flowlabel(dev_net(dev), skb,
1180                                         t->fl.u.ip6.flowlabel, true,
1181                                         &t->fl.u.ip6));
1182         ipv6h->hop_limit = t->parms.hop_limit;
1183         ipv6h->nexthdr = NEXTHDR_GRE;
1184         ipv6h->saddr = t->parms.laddr;
1185         ipv6h->daddr = t->parms.raddr;
1186
1187         p[0]            = t->parms.o_flags;
1188         p[1]            = htons(type);
1189
1190         /*
1191          *      Set the source hardware address.
1192          */
1193
1194         if (saddr)
1195                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1196         if (daddr)
1197                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1198         if (!ipv6_addr_any(&ipv6h->daddr))
1199                 return t->hlen;
1200
1201         return -t->hlen;
1202 }
1203
1204 static const struct header_ops ip6gre_header_ops = {
1205         .create = ip6gre_header,
1206 };
1207
1208 static const struct net_device_ops ip6gre_netdev_ops = {
1209         .ndo_init               = ip6gre_tunnel_init,
1210         .ndo_uninit             = ip6gre_tunnel_uninit,
1211         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1212         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1213         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1214         .ndo_get_stats64        = ip_tunnel_get_stats64,
1215         .ndo_get_iflink         = ip6_tnl_get_iflink,
1216 };
1217
1218 static void ip6gre_dev_free(struct net_device *dev)
1219 {
1220         struct ip6_tnl *t = netdev_priv(dev);
1221
1222         ip6_tnl_dst_destroy(t);
1223         free_percpu(dev->tstats);
1224         free_netdev(dev);
1225 }
1226
1227 static void ip6gre_tunnel_setup(struct net_device *dev)
1228 {
1229         struct ip6_tnl *t;
1230
1231         dev->netdev_ops = &ip6gre_netdev_ops;
1232         dev->destructor = ip6gre_dev_free;
1233
1234         dev->type = ARPHRD_IP6GRE;
1235         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1236         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1237         t = netdev_priv(dev);
1238         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1239                 dev->mtu -= 8;
1240         dev->flags |= IFF_NOARP;
1241         dev->addr_len = sizeof(struct in6_addr);
1242         netif_keep_dst(dev);
1243 }
1244
1245 static int ip6gre_tunnel_init_common(struct net_device *dev)
1246 {
1247         struct ip6_tnl *tunnel;
1248         int ret;
1249
1250         tunnel = netdev_priv(dev);
1251
1252         tunnel->dev = dev;
1253         tunnel->net = dev_net(dev);
1254         strcpy(tunnel->parms.name, dev->name);
1255
1256         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1257         if (!dev->tstats)
1258                 return -ENOMEM;
1259
1260         ret = ip6_tnl_dst_init(tunnel);
1261         if (ret) {
1262                 free_percpu(dev->tstats);
1263                 dev->tstats = NULL;
1264                 return ret;
1265         }
1266
1267         return 0;
1268 }
1269
1270 static int ip6gre_tunnel_init(struct net_device *dev)
1271 {
1272         struct ip6_tnl *tunnel;
1273         int ret;
1274
1275         ret = ip6gre_tunnel_init_common(dev);
1276         if (ret)
1277                 return ret;
1278
1279         tunnel = netdev_priv(dev);
1280
1281         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1282         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1283
1284         if (ipv6_addr_any(&tunnel->parms.raddr))
1285                 dev->header_ops = &ip6gre_header_ops;
1286
1287         return 0;
1288 }
1289
1290 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1291 {
1292         struct ip6_tnl *tunnel = netdev_priv(dev);
1293
1294         tunnel->dev = dev;
1295         tunnel->net = dev_net(dev);
1296         strcpy(tunnel->parms.name, dev->name);
1297
1298         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1299
1300         dev_hold(dev);
1301 }
1302
1303
1304 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1305         .handler     = ip6gre_rcv,
1306         .err_handler = ip6gre_err,
1307         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1308 };
1309
1310 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1311 {
1312         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1313         struct net_device *dev, *aux;
1314         int prio;
1315
1316         for_each_netdev_safe(net, dev, aux)
1317                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1318                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1319                         unregister_netdevice_queue(dev, head);
1320
1321         for (prio = 0; prio < 4; prio++) {
1322                 int h;
1323                 for (h = 0; h < HASH_SIZE; h++) {
1324                         struct ip6_tnl *t;
1325
1326                         t = rtnl_dereference(ign->tunnels[prio][h]);
1327
1328                         while (t) {
1329                                 /* If dev is in the same netns, it has already
1330                                  * been added to the list by the previous loop.
1331                                  */
1332                                 if (!net_eq(dev_net(t->dev), net))
1333                                         unregister_netdevice_queue(t->dev,
1334                                                                    head);
1335                                 t = rtnl_dereference(t->next);
1336                         }
1337                 }
1338         }
1339 }
1340
1341 static int __net_init ip6gre_init_net(struct net *net)
1342 {
1343         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1344         int err;
1345
1346         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1347                                           NET_NAME_UNKNOWN,
1348                                           ip6gre_tunnel_setup);
1349         if (!ign->fb_tunnel_dev) {
1350                 err = -ENOMEM;
1351                 goto err_alloc_dev;
1352         }
1353         dev_net_set(ign->fb_tunnel_dev, net);
1354         /* FB netdevice is special: we have one, and only one per netns.
1355          * Allowing to move it to another netns is clearly unsafe.
1356          */
1357         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1358
1359
1360         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1361         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1362
1363         err = register_netdev(ign->fb_tunnel_dev);
1364         if (err)
1365                 goto err_reg_dev;
1366
1367         rcu_assign_pointer(ign->tunnels_wc[0],
1368                            netdev_priv(ign->fb_tunnel_dev));
1369         return 0;
1370
1371 err_reg_dev:
1372         ip6gre_dev_free(ign->fb_tunnel_dev);
1373 err_alloc_dev:
1374         return err;
1375 }
1376
1377 static void __net_exit ip6gre_exit_net(struct net *net)
1378 {
1379         LIST_HEAD(list);
1380
1381         rtnl_lock();
1382         ip6gre_destroy_tunnels(net, &list);
1383         unregister_netdevice_many(&list);
1384         rtnl_unlock();
1385 }
1386
1387 static struct pernet_operations ip6gre_net_ops = {
1388         .init = ip6gre_init_net,
1389         .exit = ip6gre_exit_net,
1390         .id   = &ip6gre_net_id,
1391         .size = sizeof(struct ip6gre_net),
1392 };
1393
1394 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1395 {
1396         __be16 flags;
1397
1398         if (!data)
1399                 return 0;
1400
1401         flags = 0;
1402         if (data[IFLA_GRE_IFLAGS])
1403                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1404         if (data[IFLA_GRE_OFLAGS])
1405                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1406         if (flags & (GRE_VERSION|GRE_ROUTING))
1407                 return -EINVAL;
1408
1409         return 0;
1410 }
1411
1412 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1413 {
1414         struct in6_addr daddr;
1415
1416         if (tb[IFLA_ADDRESS]) {
1417                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1418                         return -EINVAL;
1419                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1420                         return -EADDRNOTAVAIL;
1421         }
1422
1423         if (!data)
1424                 goto out;
1425
1426         if (data[IFLA_GRE_REMOTE]) {
1427                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1428                 if (ipv6_addr_any(&daddr))
1429                         return -EINVAL;
1430         }
1431
1432 out:
1433         return ip6gre_tunnel_validate(tb, data);
1434 }
1435
1436
1437 static void ip6gre_netlink_parms(struct nlattr *data[],
1438                                 struct __ip6_tnl_parm *parms)
1439 {
1440         memset(parms, 0, sizeof(*parms));
1441
1442         if (!data)
1443                 return;
1444
1445         if (data[IFLA_GRE_LINK])
1446                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1447
1448         if (data[IFLA_GRE_IFLAGS])
1449                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1450
1451         if (data[IFLA_GRE_OFLAGS])
1452                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1453
1454         if (data[IFLA_GRE_IKEY])
1455                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1456
1457         if (data[IFLA_GRE_OKEY])
1458                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1459
1460         if (data[IFLA_GRE_LOCAL])
1461                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1462
1463         if (data[IFLA_GRE_REMOTE])
1464                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1465
1466         if (data[IFLA_GRE_TTL])
1467                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1468
1469         if (data[IFLA_GRE_ENCAP_LIMIT])
1470                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1471
1472         if (data[IFLA_GRE_FLOWINFO])
1473                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1474
1475         if (data[IFLA_GRE_FLAGS])
1476                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1477 }
1478
1479 static int ip6gre_tap_init(struct net_device *dev)
1480 {
1481         struct ip6_tnl *tunnel;
1482         int ret;
1483
1484         ret = ip6gre_tunnel_init_common(dev);
1485         if (ret)
1486                 return ret;
1487
1488         tunnel = netdev_priv(dev);
1489
1490         ip6gre_tnl_link_config(tunnel, 1);
1491
1492         return 0;
1493 }
1494
1495 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1496         .ndo_init = ip6gre_tap_init,
1497         .ndo_uninit = ip6gre_tunnel_uninit,
1498         .ndo_start_xmit = ip6gre_tunnel_xmit,
1499         .ndo_set_mac_address = eth_mac_addr,
1500         .ndo_validate_addr = eth_validate_addr,
1501         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1502         .ndo_get_stats64 = ip_tunnel_get_stats64,
1503         .ndo_get_iflink = ip6_tnl_get_iflink,
1504 };
1505
1506 static void ip6gre_tap_setup(struct net_device *dev)
1507 {
1508
1509         ether_setup(dev);
1510
1511         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1512         dev->destructor = ip6gre_dev_free;
1513
1514         dev->features |= NETIF_F_NETNS_LOCAL;
1515         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1516 }
1517
1518 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1519         struct nlattr *tb[], struct nlattr *data[])
1520 {
1521         struct ip6_tnl *nt;
1522         struct net *net = dev_net(dev);
1523         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1524         int err;
1525
1526         nt = netdev_priv(dev);
1527         ip6gre_netlink_parms(data, &nt->parms);
1528
1529         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1530                 return -EEXIST;
1531
1532         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1533                 eth_hw_addr_random(dev);
1534
1535         nt->dev = dev;
1536         nt->net = dev_net(dev);
1537         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1538
1539         /* Can use a lockless transmit, unless we generate output sequences */
1540         if (!(nt->parms.o_flags & GRE_SEQ))
1541                 dev->features |= NETIF_F_LLTX;
1542
1543         err = register_netdevice(dev);
1544         if (err)
1545                 goto out;
1546
1547         dev_hold(dev);
1548         ip6gre_tunnel_link(ign, nt);
1549
1550 out:
1551         return err;
1552 }
1553
1554 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1555                             struct nlattr *data[])
1556 {
1557         struct ip6_tnl *t, *nt = netdev_priv(dev);
1558         struct net *net = nt->net;
1559         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1560         struct __ip6_tnl_parm p;
1561
1562         if (dev == ign->fb_tunnel_dev)
1563                 return -EINVAL;
1564
1565         ip6gre_netlink_parms(data, &p);
1566
1567         t = ip6gre_tunnel_locate(net, &p, 0);
1568
1569         if (t) {
1570                 if (t->dev != dev)
1571                         return -EEXIST;
1572         } else {
1573                 t = nt;
1574         }
1575
1576         ip6gre_tunnel_unlink(ign, t);
1577         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1578         ip6gre_tunnel_link(ign, t);
1579         return 0;
1580 }
1581
1582 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1583 {
1584         struct net *net = dev_net(dev);
1585         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1586
1587         if (dev != ign->fb_tunnel_dev)
1588                 unregister_netdevice_queue(dev, head);
1589 }
1590
1591 static size_t ip6gre_get_size(const struct net_device *dev)
1592 {
1593         return
1594                 /* IFLA_GRE_LINK */
1595                 nla_total_size(4) +
1596                 /* IFLA_GRE_IFLAGS */
1597                 nla_total_size(2) +
1598                 /* IFLA_GRE_OFLAGS */
1599                 nla_total_size(2) +
1600                 /* IFLA_GRE_IKEY */
1601                 nla_total_size(4) +
1602                 /* IFLA_GRE_OKEY */
1603                 nla_total_size(4) +
1604                 /* IFLA_GRE_LOCAL */
1605                 nla_total_size(sizeof(struct in6_addr)) +
1606                 /* IFLA_GRE_REMOTE */
1607                 nla_total_size(sizeof(struct in6_addr)) +
1608                 /* IFLA_GRE_TTL */
1609                 nla_total_size(1) +
1610                 /* IFLA_GRE_TOS */
1611                 nla_total_size(1) +
1612                 /* IFLA_GRE_ENCAP_LIMIT */
1613                 nla_total_size(1) +
1614                 /* IFLA_GRE_FLOWINFO */
1615                 nla_total_size(4) +
1616                 /* IFLA_GRE_FLAGS */
1617                 nla_total_size(4) +
1618                 0;
1619 }
1620
1621 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1622 {
1623         struct ip6_tnl *t = netdev_priv(dev);
1624         struct __ip6_tnl_parm *p = &t->parms;
1625
1626         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1627             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1628             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1629             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1630             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1631             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1632             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1633             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1634             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1635             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1636             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1637             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1638                 goto nla_put_failure;
1639         return 0;
1640
1641 nla_put_failure:
1642         return -EMSGSIZE;
1643 }
1644
1645 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1646         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1647         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1648         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1649         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1650         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1651         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1652         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1653         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1654         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1655         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1656         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1657 };
1658
1659 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1660         .kind           = "ip6gre",
1661         .maxtype        = IFLA_GRE_MAX,
1662         .policy         = ip6gre_policy,
1663         .priv_size      = sizeof(struct ip6_tnl),
1664         .setup          = ip6gre_tunnel_setup,
1665         .validate       = ip6gre_tunnel_validate,
1666         .newlink        = ip6gre_newlink,
1667         .changelink     = ip6gre_changelink,
1668         .dellink        = ip6gre_dellink,
1669         .get_size       = ip6gre_get_size,
1670         .fill_info      = ip6gre_fill_info,
1671         .get_link_net   = ip6_tnl_get_link_net,
1672 };
1673
1674 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1675         .kind           = "ip6gretap",
1676         .maxtype        = IFLA_GRE_MAX,
1677         .policy         = ip6gre_policy,
1678         .priv_size      = sizeof(struct ip6_tnl),
1679         .setup          = ip6gre_tap_setup,
1680         .validate       = ip6gre_tap_validate,
1681         .newlink        = ip6gre_newlink,
1682         .changelink     = ip6gre_changelink,
1683         .get_size       = ip6gre_get_size,
1684         .fill_info      = ip6gre_fill_info,
1685         .get_link_net   = ip6_tnl_get_link_net,
1686 };
1687
1688 /*
1689  *      And now the modules code and kernel interface.
1690  */
1691
1692 static int __init ip6gre_init(void)
1693 {
1694         int err;
1695
1696         pr_info("GRE over IPv6 tunneling driver\n");
1697
1698         err = register_pernet_device(&ip6gre_net_ops);
1699         if (err < 0)
1700                 return err;
1701
1702         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1703         if (err < 0) {
1704                 pr_info("%s: can't add protocol\n", __func__);
1705                 goto add_proto_failed;
1706         }
1707
1708         err = rtnl_link_register(&ip6gre_link_ops);
1709         if (err < 0)
1710                 goto rtnl_link_failed;
1711
1712         err = rtnl_link_register(&ip6gre_tap_ops);
1713         if (err < 0)
1714                 goto tap_ops_failed;
1715
1716 out:
1717         return err;
1718
1719 tap_ops_failed:
1720         rtnl_link_unregister(&ip6gre_link_ops);
1721 rtnl_link_failed:
1722         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1723 add_proto_failed:
1724         unregister_pernet_device(&ip6gre_net_ops);
1725         goto out;
1726 }
1727
1728 static void __exit ip6gre_fini(void)
1729 {
1730         rtnl_link_unregister(&ip6gre_tap_ops);
1731         rtnl_link_unregister(&ip6gre_link_ops);
1732         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1733         unregister_pernet_device(&ip6gre_net_ops);
1734 }
1735
1736 module_init(ip6gre_init);
1737 module_exit(ip6gre_fini);
1738 MODULE_LICENSE("GPL");
1739 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1740 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1741 MODULE_ALIAS_RTNL_LINK("ip6gre");
1742 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1743 MODULE_ALIAS_NETDEV("ip6gre0");