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 HASH_SIZE_SHIFT  5
  65 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  66
  67 static int ip6gre_net_id __read_mostly;
  68 struct ip6gre_net {
  69         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  70
  71         struct net_device *fb_tunnel_dev;
  72 };
  73
  74 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  75 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
  76 static int ip6gre_tunnel_init(struct net_device *dev);
  77 static void ip6gre_tunnel_setup(struct net_device *dev);
  78 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  79 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  80
  81 /* Tunnel hash table */
  82
  83 /*
  84    4 hash tables:
  85
  86    3: (remote,local)
  87    2: (remote,*)
  88    1: (*,local)
  89    0: (*,*)
  90
  91    We require exact key match i.e. if a key is present in packet
  92    it will match only tunnel with the same key; if it is not present,
  93    it will match only keyless tunnel.
  94
  95    All keysless packets, if not matched configured keyless tunnels
  96    will match fallback tunnel.
  97  */
  98
  99 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
 100 static u32 HASH_ADDR(const struct in6_addr *addr)
 101 {
 102         u32 hash = ipv6_addr_hash(addr);
 103
 104         return hash_32(hash, HASH_SIZE_SHIFT);
 105 }
 106
 107 #define tunnels_r_l     tunnels[3]
 108 #define tunnels_r       tunnels[2]
 109 #define tunnels_l       tunnels[1]
 110 #define tunnels_wc      tunnels[0]
 111
 112 /* Given src, dst and key, find appropriate for input tunnel. */
 113
 114 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 115                 const struct in6_addr *remote, const struct in6_addr *local,
 116                 __be32 key, __be16 gre_proto)
 117 {
 118         struct net *net = dev_net(dev);
 119         int link = dev->ifindex;
 120         unsigned int h0 = HASH_ADDR(remote);
 121         unsigned int h1 = HASH_KEY(key);
 122         struct ip6_tnl *t, *cand = NULL;
 123         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 124         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 125                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 126         int score, cand_score = 4;
 127
 128         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 129                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 130                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 131                     key != t->parms.i_key ||
 132                     !(t->dev->flags & IFF_UP))
 133                         continue;
 134
 135                 if (t->dev->type != ARPHRD_IP6GRE &&
 136                     t->dev->type != dev_type)
 137                         continue;
 138
 139                 score = 0;
 140                 if (t->parms.link != link)
 141                         score |= 1;
 142                 if (t->dev->type != dev_type)
 143                         score |= 2;
 144                 if (score == 0)
 145                         return t;
 146
 147                 if (score < cand_score) {
 148                         cand = t;
 149                         cand_score = score;
 150                 }
 151         }
 152
 153         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 154                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 155                     key != t->parms.i_key ||
 156                     !(t->dev->flags & IFF_UP))
 157                         continue;
 158
 159                 if (t->dev->type != ARPHRD_IP6GRE &&
 160                     t->dev->type != dev_type)
 161                         continue;
 162
 163                 score = 0;
 164                 if (t->parms.link != link)
 165                         score |= 1;
 166                 if (t->dev->type != dev_type)
 167                         score |= 2;
 168                 if (score == 0)
 169                         return t;
 170
 171                 if (score < cand_score) {
 172                         cand = t;
 173                         cand_score = score;
 174                 }
 175         }
 176
 177         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 178                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 179                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 180                                  !ipv6_addr_is_multicast(local))) ||
 181                     key != t->parms.i_key ||
 182                     !(t->dev->flags & IFF_UP))
 183                         continue;
 184
 185                 if (t->dev->type != ARPHRD_IP6GRE &&
 186                     t->dev->type != dev_type)
 187                         continue;
 188
 189                 score = 0;
 190                 if (t->parms.link != link)
 191                         score |= 1;
 192                 if (t->dev->type != dev_type)
 193                         score |= 2;
 194                 if (score == 0)
 195                         return t;
 196
 197                 if (score < cand_score) {
 198                         cand = t;
 199                         cand_score = score;
 200                 }
 201         }
 202
 203         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 204                 if (t->parms.i_key != key ||
 205                     !(t->dev->flags & IFF_UP))
 206                         continue;
 207
 208                 if (t->dev->type != ARPHRD_IP6GRE &&
 209                     t->dev->type != dev_type)
 210                         continue;
 211
 212                 score = 0;
 213                 if (t->parms.link != link)
 214                         score |= 1;
 215                 if (t->dev->type != dev_type)
 216                         score |= 2;
 217                 if (score == 0)
 218                         return t;
 219
 220                 if (score < cand_score) {
 221                         cand = t;
 222                         cand_score = score;
 223                 }
 224         }
 225
 226         if (cand != NULL)
 227                 return cand;
 228
 229         dev = ign->fb_tunnel_dev;
 230         if (dev->flags & IFF_UP)
 231                 return netdev_priv(dev);
 232
 233         return NULL;
 234 }
 235
 236 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 237                 const struct __ip6_tnl_parm *p)
 238 {
 239         const struct in6_addr *remote = &p->raddr;
 240         const struct in6_addr *local = &p->laddr;
 241         unsigned int h = HASH_KEY(p->i_key);
 242         int prio = 0;
 243
 244         if (!ipv6_addr_any(local))
 245                 prio |= 1;
 246         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 247                 prio |= 2;
 248                 h ^= HASH_ADDR(remote);
 249         }
 250
 251         return &ign->tunnels[prio][h];
 252 }
 253
 254 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 255                 const struct ip6_tnl *t)
 256 {
 257         return __ip6gre_bucket(ign, &t->parms);
 258 }
 259
 260 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 261 {
 262         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 263
 264         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 265         rcu_assign_pointer(*tp, t);
 266 }
 267
 268 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 269 {
 270         struct ip6_tnl __rcu **tp;
 271         struct ip6_tnl *iter;
 272
 273         for (tp = ip6gre_bucket(ign, t);
 274              (iter = rtnl_dereference(*tp)) != NULL;
 275              tp = &iter->next) {
 276                 if (t == iter) {
 277                         rcu_assign_pointer(*tp, t->next);
 278                         break;
 279                 }
 280         }
 281 }
 282
 283 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 284                                            const struct __ip6_tnl_parm *parms,
 285                                            int type)
 286 {
 287         const struct in6_addr *remote = &parms->raddr;
 288         const struct in6_addr *local = &parms->laddr;
 289         __be32 key = parms->i_key;
 290         int link = parms->link;
 291         struct ip6_tnl *t;
 292         struct ip6_tnl __rcu **tp;
 293         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 294
 295         for (tp = __ip6gre_bucket(ign, parms);
 296              (t = rtnl_dereference(*tp)) != NULL;
 297              tp = &t->next)
 298                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 299                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 300                     key == t->parms.i_key &&
 301                     link == t->parms.link &&
 302                     type == t->dev->type)
 303                         break;
 304
 305         return t;
 306 }
 307
 308 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 309                 const struct __ip6_tnl_parm *parms, int create)
 310 {
 311         struct ip6_tnl *t, *nt;
 312         struct net_device *dev;
 313         char name[IFNAMSIZ];
 314         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 315
 316         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 317         if (t || !create)
 318                 return t;
 319
 320         if (parms->name[0])
 321                 strlcpy(name, parms->name, IFNAMSIZ);
 322         else
 323                 strcpy(name, "ip6gre%d");
 324
 325         dev = alloc_netdev(sizeof(*t), name, ip6gre_tunnel_setup);
 326         if (!dev)
 327                 return NULL;
 328
 329         dev_net_set(dev, net);
 330
 331         nt = netdev_priv(dev);
 332         nt->parms = *parms;
 333         dev->rtnl_link_ops = &ip6gre_link_ops;
 334
 335         nt->dev = dev;
 336         nt->net = dev_net(dev);
 337         ip6gre_tnl_link_config(nt, 1);
 338
 339         if (register_netdevice(dev) < 0)
 340                 goto failed_free;
 341
 342         /* Can use a lockless transmit, unless we generate output sequences */
 343         if (!(nt->parms.o_flags & GRE_SEQ))
 344                 dev->features |= NETIF_F_LLTX;
 345
 346         dev_hold(dev);
 347         ip6gre_tunnel_link(ign, nt);
 348         return nt;
 349
 350 failed_free:
 351         free_netdev(dev);
 352         return NULL;
 353 }
 354
 355 static void ip6gre_tunnel_uninit(struct net_device *dev)
 356 {
 357         struct ip6_tnl *t = netdev_priv(dev);
 358         struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 359
 360         ip6gre_tunnel_unlink(ign, t);
 361         dev_put(dev);
 362 }
 363
 364
 365 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 366                 u8 type, u8 code, int offset, __be32 info)
 367 {
 368         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 369         __be16 *p = (__be16 *)(skb->data + offset);
 370         int grehlen = offset + 4;
 371         struct ip6_tnl *t;
 372         __be16 flags;
 373
 374         flags = p[0];
 375         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 376                 if (flags&(GRE_VERSION|GRE_ROUTING))
 377                         return;
 378                 if (flags&GRE_KEY) {
 379                         grehlen += 4;
 380                         if (flags&GRE_CSUM)
 381                                 grehlen += 4;
 382                 }
 383         }
 384
 385         /* If only 8 bytes returned, keyed message will be dropped here */
 386         if (!pskb_may_pull(skb, grehlen))
 387                 return;
 388         ipv6h = (const struct ipv6hdr *)skb->data;
 389         p = (__be16 *)(skb->data + offset);
 390
 391         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 392                                 flags & GRE_KEY ?
 393                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 394                                 p[1]);
 395         if (t == NULL)
 396                 return;
 397
 398         switch (type) {
 399                 __u32 teli;
 400                 struct ipv6_tlv_tnl_enc_lim *tel;
 401                 __u32 mtu;
 402         case ICMPV6_DEST_UNREACH:
 403                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 404                                      t->parms.name);
 405                 break;
 406         case ICMPV6_TIME_EXCEED:
 407                 if (code == ICMPV6_EXC_HOPLIMIT) {
 408                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 409                                              t->parms.name);
 410                 }
 411                 break;
 412         case ICMPV6_PARAMPROB:
 413                 teli = 0;
 414                 if (code == ICMPV6_HDR_FIELD)
 415                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 416
 417                 if (teli && teli == info - 2) {
 418                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 419                         if (tel->encap_limit == 0) {
 420                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 421                                                      t->parms.name);
 422                         }
 423                 } else {
 424                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 425                                              t->parms.name);
 426                 }
 427                 break;
 428         case ICMPV6_PKT_TOOBIG:
 429                 mtu = info - offset;
 430                 if (mtu < IPV6_MIN_MTU)
 431                         mtu = IPV6_MIN_MTU;
 432                 t->dev->mtu = mtu;
 433                 break;
 434         }
 435
 436         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 437                 t->err_count++;
 438         else
 439                 t->err_count = 1;
 440         t->err_time = jiffies;
 441 }
 442
 443 static int ip6gre_rcv(struct sk_buff *skb)
 444 {
 445         const struct ipv6hdr *ipv6h;
 446         u8     *h;
 447         __be16    flags;
 448         __sum16   csum = 0;
 449         __be32 key = 0;
 450         u32    seqno = 0;
 451         struct ip6_tnl *tunnel;
 452         int    offset = 4;
 453         __be16 gre_proto;
 454         int err;
 455
 456         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 457                 goto drop;
 458
 459         ipv6h = ipv6_hdr(skb);
 460         h = skb->data;
 461         flags = *(__be16 *)h;
 462
 463         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 464                 /* - Version must be 0.
 465                    - We do not support routing headers.
 466                  */
 467                 if (flags&(GRE_VERSION|GRE_ROUTING))
 468                         goto drop;
 469
 470                 if (flags&GRE_CSUM) {
 471                         csum = skb_checksum_simple_validate(skb);
 472                         offset += 4;
 473                 }
 474                 if (flags&GRE_KEY) {
 475                         key = *(__be32 *)(h + offset);
 476                         offset += 4;
 477                 }
 478                 if (flags&GRE_SEQ) {
 479                         seqno = ntohl(*(__be32 *)(h + offset));
 480                         offset += 4;
 481                 }
 482         }
 483
 484         gre_proto = *(__be16 *)(h + 2);
 485
 486         tunnel = ip6gre_tunnel_lookup(skb->dev,
 487                                           &ipv6h->saddr, &ipv6h->daddr, key,
 488                                           gre_proto);
 489         if (tunnel) {
 490                 struct pcpu_sw_netstats *tstats;
 491
 492                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 493                         goto drop;
 494
 495                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 496                         tunnel->dev->stats.rx_dropped++;
 497                         goto drop;
 498                 }
 499
 500                 skb->protocol = gre_proto;
 501                 /* WCCP version 1 and 2 protocol decoding.
 502                  * - Change protocol to IP
 503                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 504                  */
 505                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 506                         skb->protocol = htons(ETH_P_IP);
 507                         if ((*(h + offset) & 0xF0) != 0x40)
 508                                 offset += 4;
 509                 }
 510
 511                 skb->mac_header = skb->network_header;
 512                 __pskb_pull(skb, offset);
 513                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 514
 515                 if (((flags&GRE_CSUM) && csum) ||
 516                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 517                         tunnel->dev->stats.rx_crc_errors++;
 518                         tunnel->dev->stats.rx_errors++;
 519                         goto drop;
 520                 }
 521                 if (tunnel->parms.i_flags&GRE_SEQ) {
 522                         if (!(flags&GRE_SEQ) ||
 523                             (tunnel->i_seqno &&
 524                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 525                                 tunnel->dev->stats.rx_fifo_errors++;
 526                                 tunnel->dev->stats.rx_errors++;
 527                                 goto drop;
 528                         }
 529                         tunnel->i_seqno = seqno + 1;
 530                 }
 531
 532                 /* Warning: All skb pointers will be invalidated! */
 533                 if (tunnel->dev->type == ARPHRD_ETHER) {
 534                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 535                                 tunnel->dev->stats.rx_length_errors++;
 536                                 tunnel->dev->stats.rx_errors++;
 537                                 goto drop;
 538                         }
 539
 540                         ipv6h = ipv6_hdr(skb);
 541                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 542                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 543                 }
 544
 545                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 546
 547                 skb_reset_network_header(skb);
 548
 549                 err = IP6_ECN_decapsulate(ipv6h, skb);
 550                 if (unlikely(err)) {
 551                         if (log_ecn_error)
 552                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 553                                                      &ipv6h->saddr,
 554                                                      ipv6_get_dsfield(ipv6h));
 555                         if (err > 1) {
 556                                 ++tunnel->dev->stats.rx_frame_errors;
 557                                 ++tunnel->dev->stats.rx_errors;
 558                                 goto drop;
 559                         }
 560                 }
 561
 562                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 563                 u64_stats_update_begin(&tstats->syncp);
 564                 tstats->rx_packets++;
 565                 tstats->rx_bytes += skb->len;
 566                 u64_stats_update_end(&tstats->syncp);
 567
 568                 netif_rx(skb);
 569
 570                 return 0;
 571         }
 572         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 573
 574 drop:
 575         kfree_skb(skb);
 576         return 0;
 577 }
 578
 579 struct ipv6_tel_txoption {
 580         struct ipv6_txoptions ops;
 581         __u8 dst_opt[8];
 582 };
 583
 584 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 585 {
 586         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 587
 588         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 589         opt->dst_opt[3] = 1;
 590         opt->dst_opt[4] = encap_limit;
 591         opt->dst_opt[5] = IPV6_TLV_PADN;
 592         opt->dst_opt[6] = 1;
 593
 594         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 595         opt->ops.opt_nflen = 8;
 596 }
 597
 598 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 599                          struct net_device *dev,
 600                          __u8 dsfield,
 601                          struct flowi6 *fl6,
 602                          int encap_limit,
 603                          __u32 *pmtu)
 604 {
 605         struct ip6_tnl *tunnel = netdev_priv(dev);
 606         struct net *net = tunnel->net;
 607         struct net_device *tdev;    /* Device to other host */
 608         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 609         unsigned int max_headroom = 0; /* The extra header space needed */
 610         int    gre_hlen;
 611         struct ipv6_tel_txoption opt;
 612         int    mtu;
 613         struct dst_entry *dst = NULL, *ndst = NULL;
 614         struct net_device_stats *stats = &tunnel->dev->stats;
 615         int err = -1;
 616         u8 proto;
 617         struct sk_buff *new_skb;
 618
 619         if (dev->type == ARPHRD_ETHER)
 620                 IPCB(skb)->flags = 0;
 621
 622         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 623                 gre_hlen = 0;
 624                 ipv6h = (struct ipv6hdr *)skb->data;
 625                 fl6->daddr = ipv6h->daddr;
 626         } else {
 627                 gre_hlen = tunnel->hlen;
 628                 fl6->daddr = tunnel->parms.raddr;
 629         }
 630
 631         if (!fl6->flowi6_mark)
 632                 dst = ip6_tnl_dst_check(tunnel);
 633
 634         if (!dst) {
 635                 ndst = ip6_route_output(net, NULL, fl6);
 636
 637                 if (ndst->error)
 638                         goto tx_err_link_failure;
 639                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 640                 if (IS_ERR(ndst)) {
 641                         err = PTR_ERR(ndst);
 642                         ndst = NULL;
 643                         goto tx_err_link_failure;
 644                 }
 645                 dst = ndst;
 646         }
 647
 648         tdev = dst->dev;
 649
 650         if (tdev == dev) {
 651                 stats->collisions++;
 652                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 653                                      tunnel->parms.name);
 654                 goto tx_err_dst_release;
 655         }
 656
 657         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 658         if (encap_limit >= 0) {
 659                 max_headroom += 8;
 660                 mtu -= 8;
 661         }
 662         if (mtu < IPV6_MIN_MTU)
 663                 mtu = IPV6_MIN_MTU;
 664         if (skb_dst(skb))
 665                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 666         if (skb->len > mtu) {
 667                 *pmtu = mtu;
 668                 err = -EMSGSIZE;
 669                 goto tx_err_dst_release;
 670         }
 671
 672         if (tunnel->err_count > 0) {
 673                 if (time_before(jiffies,
 674                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 675                         tunnel->err_count--;
 676
 677                         dst_link_failure(skb);
 678                 } else
 679                         tunnel->err_count = 0;
 680         }
 681
 682         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 683
 684         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 685
 686         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 687             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 688                 new_skb = skb_realloc_headroom(skb, max_headroom);
 689                 if (max_headroom > dev->needed_headroom)
 690                         dev->needed_headroom = max_headroom;
 691                 if (!new_skb)
 692                         goto tx_err_dst_release;
 693
 694                 if (skb->sk)
 695                         skb_set_owner_w(new_skb, skb->sk);
 696                 consume_skb(skb);
 697                 skb = new_skb;
 698         }
 699
 700         if (fl6->flowi6_mark) {
 701                 skb_dst_set(skb, dst);
 702                 ndst = NULL;
 703         } else {
 704                 skb_dst_set_noref(skb, dst);
 705         }
 706
 707         proto = NEXTHDR_GRE;
 708         if (encap_limit >= 0) {
 709                 init_tel_txopt(&opt, encap_limit);
 710                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 711         }
 712
 713         if (likely(!skb->encapsulation)) {
 714                 skb_reset_inner_headers(skb);
 715                 skb->encapsulation = 1;
 716         }
 717
 718         skb_push(skb, gre_hlen);
 719         skb_reset_network_header(skb);
 720         skb_set_transport_header(skb, sizeof(*ipv6h));
 721
 722         /*
 723          *      Push down and install the IP header.
 724          */
 725         ipv6h = ipv6_hdr(skb);
 726         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 727         ipv6h->hop_limit = tunnel->parms.hop_limit;
 728         ipv6h->nexthdr = proto;
 729         ipv6h->saddr = fl6->saddr;
 730         ipv6h->daddr = fl6->daddr;
 731
 732         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 733         ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 734                                    htons(ETH_P_TEB) : skb->protocol;
 735
 736         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 737                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 738
 739                 if (tunnel->parms.o_flags&GRE_SEQ) {
 740                         ++tunnel->o_seqno;
 741                         *ptr = htonl(tunnel->o_seqno);
 742                         ptr--;
 743                 }
 744                 if (tunnel->parms.o_flags&GRE_KEY) {
 745                         *ptr = tunnel->parms.o_key;
 746                         ptr--;
 747                 }
 748                 if (tunnel->parms.o_flags&GRE_CSUM) {
 749                         *ptr = 0;
 750                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 751                                 skb->len - sizeof(struct ipv6hdr));
 752                 }
 753         }
 754
 755         ip6tunnel_xmit(skb, dev);
 756         if (ndst)
 757                 ip6_tnl_dst_store(tunnel, ndst);
 758         return 0;
 759 tx_err_link_failure:
 760         stats->tx_carrier_errors++;
 761         dst_link_failure(skb);
 762 tx_err_dst_release:
 763         dst_release(ndst);
 764         return err;
 765 }
 766
 767 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 768 {
 769         struct ip6_tnl *t = netdev_priv(dev);
 770         const struct iphdr  *iph = ip_hdr(skb);
 771         int encap_limit = -1;
 772         struct flowi6 fl6;
 773         __u8 dsfield;
 774         __u32 mtu;
 775         int err;
 776
 777         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 778                 encap_limit = t->parms.encap_limit;
 779
 780         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 781         fl6.flowi6_proto = IPPROTO_IPIP;
 782
 783         dsfield = ipv4_get_dsfield(iph);
 784
 785         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 786                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 787                                           & IPV6_TCLASS_MASK;
 788         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 789                 fl6.flowi6_mark = skb->mark;
 790
 791         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 792         if (err != 0) {
 793                 /* XXX: send ICMP error even if DF is not set. */
 794                 if (err == -EMSGSIZE)
 795                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 796                                   htonl(mtu));
 797                 return -1;
 798         }
 799
 800         return 0;
 801 }
 802
 803 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 804 {
 805         struct ip6_tnl *t = netdev_priv(dev);
 806         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 807         int encap_limit = -1;
 808         __u16 offset;
 809         struct flowi6 fl6;
 810         __u8 dsfield;
 811         __u32 mtu;
 812         int err;
 813
 814         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 815                 return -1;
 816
 817         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 818         if (offset > 0) {
 819                 struct ipv6_tlv_tnl_enc_lim *tel;
 820                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 821                 if (tel->encap_limit == 0) {
 822                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 823                                     ICMPV6_HDR_FIELD, offset + 2);
 824                         return -1;
 825                 }
 826                 encap_limit = tel->encap_limit - 1;
 827         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 828                 encap_limit = t->parms.encap_limit;
 829
 830         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 831         fl6.flowi6_proto = IPPROTO_IPV6;
 832
 833         dsfield = ipv6_get_dsfield(ipv6h);
 834         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 835                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 836         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 837                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 838         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 839                 fl6.flowi6_mark = skb->mark;
 840
 841         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 842         if (err != 0) {
 843                 if (err == -EMSGSIZE)
 844                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 845                 return -1;
 846         }
 847
 848         return 0;
 849 }
 850
 851 /**
 852  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 853  *   @t: the outgoing tunnel device
 854  *   @hdr: IPv6 header from the incoming packet
 855  *
 856  * Description:
 857  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 858  *   doesn't match source of incoming packet.
 859  *
 860  * Return:
 861  *   1 if conflict,
 862  *   0 else
 863  **/
 864
 865 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 866         const struct ipv6hdr *hdr)
 867 {
 868         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 869 }
 870
 871 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 872 {
 873         struct ip6_tnl *t = netdev_priv(dev);
 874         int encap_limit = -1;
 875         struct flowi6 fl6;
 876         __u32 mtu;
 877         int err;
 878
 879         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 880                 encap_limit = t->parms.encap_limit;
 881
 882         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 883         fl6.flowi6_proto = skb->protocol;
 884
 885         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 886
 887         return err;
 888 }
 889
 890 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 891         struct net_device *dev)
 892 {
 893         struct ip6_tnl *t = netdev_priv(dev);
 894         struct net_device_stats *stats = &t->dev->stats;
 895         int ret;
 896
 897         if (!ip6_tnl_xmit_ctl(t))
 898                 goto tx_err;
 899
 900         switch (skb->protocol) {
 901         case htons(ETH_P_IP):
 902                 ret = ip6gre_xmit_ipv4(skb, dev);
 903                 break;
 904         case htons(ETH_P_IPV6):
 905                 ret = ip6gre_xmit_ipv6(skb, dev);
 906                 break;
 907         default:
 908                 ret = ip6gre_xmit_other(skb, dev);
 909                 break;
 910         }
 911
 912         if (ret < 0)
 913                 goto tx_err;
 914
 915         return NETDEV_TX_OK;
 916
 917 tx_err:
 918         stats->tx_errors++;
 919         stats->tx_dropped++;
 920         kfree_skb(skb);
 921         return NETDEV_TX_OK;
 922 }
 923
 924 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 925 {
 926         struct net_device *dev = t->dev;
 927         struct __ip6_tnl_parm *p = &t->parms;
 928         struct flowi6 *fl6 = &t->fl.u.ip6;
 929         int addend = sizeof(struct ipv6hdr) + 4;
 930
 931         if (dev->type != ARPHRD_ETHER) {
 932                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 933                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 934         }
 935
 936         /* Set up flowi template */
 937         fl6->saddr = p->laddr;
 938         fl6->daddr = p->raddr;
 939         fl6->flowi6_oif = p->link;
 940         fl6->flowlabel = 0;
 941
 942         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 943                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 944         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 945                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 946
 947         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 948         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 949
 950         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 951                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 952                 dev->flags |= IFF_POINTOPOINT;
 953         else
 954                 dev->flags &= ~IFF_POINTOPOINT;
 955
 956         dev->iflink = p->link;
 957
 958         /* Precalculate GRE options length */
 959         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 960                 if (t->parms.o_flags&GRE_CSUM)
 961                         addend += 4;
 962                 if (t->parms.o_flags&GRE_KEY)
 963                         addend += 4;
 964                 if (t->parms.o_flags&GRE_SEQ)
 965                         addend += 4;
 966         }
 967         t->hlen = addend;
 968
 969         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 970                 int strict = (ipv6_addr_type(&p->raddr) &
 971                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 972
 973                 struct rt6_info *rt = rt6_lookup(t->net,
 974                                                  &p->raddr, &p->laddr,
 975                                                  p->link, strict);
 976
 977                 if (rt == NULL)
 978                         return;
 979
 980                 if (rt->dst.dev) {
 981                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 982
 983                         if (set_mtu) {
 984                                 dev->mtu = rt->dst.dev->mtu - addend;
 985                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 986                                         dev->mtu -= 8;
 987
 988                                 if (dev->mtu < IPV6_MIN_MTU)
 989                                         dev->mtu = IPV6_MIN_MTU;
 990                         }
 991                 }
 992                 ip6_rt_put(rt);
 993         }
 994 }
 995
 996 static int ip6gre_tnl_change(struct ip6_tnl *t,
 997         const struct __ip6_tnl_parm *p, int set_mtu)
 998 {
 999         t->parms.laddr = p->laddr;
1000         t->parms.raddr = p->raddr;
1001         t->parms.flags = p->flags;
1002         t->parms.hop_limit = p->hop_limit;
1003         t->parms.encap_limit = p->encap_limit;
1004         t->parms.flowinfo = p->flowinfo;
1005         t->parms.link = p->link;
1006         t->parms.proto = p->proto;
1007         t->parms.i_key = p->i_key;
1008         t->parms.o_key = p->o_key;
1009         t->parms.i_flags = p->i_flags;
1010         t->parms.o_flags = p->o_flags;
1011         ip6_tnl_dst_reset(t);
1012         ip6gre_tnl_link_config(t, set_mtu);
1013         return 0;
1014 }
1015
1016 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1017         const struct ip6_tnl_parm2 *u)
1018 {
1019         p->laddr = u->laddr;
1020         p->raddr = u->raddr;
1021         p->flags = u->flags;
1022         p->hop_limit = u->hop_limit;
1023         p->encap_limit = u->encap_limit;
1024         p->flowinfo = u->flowinfo;
1025         p->link = u->link;
1026         p->i_key = u->i_key;
1027         p->o_key = u->o_key;
1028         p->i_flags = u->i_flags;
1029         p->o_flags = u->o_flags;
1030         memcpy(p->name, u->name, sizeof(u->name));
1031 }
1032
1033 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1034         const struct __ip6_tnl_parm *p)
1035 {
1036         u->proto = IPPROTO_GRE;
1037         u->laddr = p->laddr;
1038         u->raddr = p->raddr;
1039         u->flags = p->flags;
1040         u->hop_limit = p->hop_limit;
1041         u->encap_limit = p->encap_limit;
1042         u->flowinfo = p->flowinfo;
1043         u->link = p->link;
1044         u->i_key = p->i_key;
1045         u->o_key = p->o_key;
1046         u->i_flags = p->i_flags;
1047         u->o_flags = p->o_flags;
1048         memcpy(u->name, p->name, sizeof(u->name));
1049 }
1050
1051 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1052         struct ifreq *ifr, int cmd)
1053 {
1054         int err = 0;
1055         struct ip6_tnl_parm2 p;
1056         struct __ip6_tnl_parm p1;
1057         struct ip6_tnl *t = netdev_priv(dev);
1058         struct net *net = t->net;
1059         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1060
1061         switch (cmd) {
1062         case SIOCGETTUNNEL:
1063                 if (dev == ign->fb_tunnel_dev) {
1064                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1065                                 err = -EFAULT;
1066                                 break;
1067                         }
1068                         ip6gre_tnl_parm_from_user(&p1, &p);
1069                         t = ip6gre_tunnel_locate(net, &p1, 0);
1070                         if (t == NULL)
1071                                 t = netdev_priv(dev);
1072                 }
1073                 memset(&p, 0, sizeof(p));
1074                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1075                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1076                         err = -EFAULT;
1077                 break;
1078
1079         case SIOCADDTUNNEL:
1080         case SIOCCHGTUNNEL:
1081                 err = -EPERM;
1082                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1083                         goto done;
1084
1085                 err = -EFAULT;
1086                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1087                         goto done;
1088
1089                 err = -EINVAL;
1090                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1091                         goto done;
1092
1093                 if (!(p.i_flags&GRE_KEY))
1094                         p.i_key = 0;
1095                 if (!(p.o_flags&GRE_KEY))
1096                         p.o_key = 0;
1097
1098                 ip6gre_tnl_parm_from_user(&p1, &p);
1099                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1100
1101                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1102                         if (t != NULL) {
1103                                 if (t->dev != dev) {
1104                                         err = -EEXIST;
1105                                         break;
1106                                 }
1107                         } else {
1108                                 t = netdev_priv(dev);
1109
1110                                 ip6gre_tunnel_unlink(ign, t);
1111                                 synchronize_net();
1112                                 ip6gre_tnl_change(t, &p1, 1);
1113                                 ip6gre_tunnel_link(ign, t);
1114                                 netdev_state_change(dev);
1115                         }
1116                 }
1117
1118                 if (t) {
1119                         err = 0;
1120
1121                         memset(&p, 0, sizeof(p));
1122                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1123                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1124                                 err = -EFAULT;
1125                 } else
1126                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1127                 break;
1128
1129         case SIOCDELTUNNEL:
1130                 err = -EPERM;
1131                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1132                         goto done;
1133
1134                 if (dev == ign->fb_tunnel_dev) {
1135                         err = -EFAULT;
1136                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1137                                 goto done;
1138                         err = -ENOENT;
1139                         ip6gre_tnl_parm_from_user(&p1, &p);
1140                         t = ip6gre_tunnel_locate(net, &p1, 0);
1141                         if (t == NULL)
1142                                 goto done;
1143                         err = -EPERM;
1144                         if (t == netdev_priv(ign->fb_tunnel_dev))
1145                                 goto done;
1146                         dev = t->dev;
1147                 }
1148                 unregister_netdevice(dev);
1149                 err = 0;
1150                 break;
1151
1152         default:
1153                 err = -EINVAL;
1154         }
1155
1156 done:
1157         return err;
1158 }
1159
1160 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1161 {
1162         if (new_mtu < 68 ||
1163             new_mtu > 0xFFF8 - dev->hard_header_len)
1164                 return -EINVAL;
1165         dev->mtu = new_mtu;
1166         return 0;
1167 }
1168
1169 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1170                         unsigned short type,
1171                         const void *daddr, const void *saddr, unsigned int len)
1172 {
1173         struct ip6_tnl *t = netdev_priv(dev);
1174         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1175         __be16 *p = (__be16 *)(ipv6h+1);
1176
1177         ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1178         ipv6h->hop_limit = t->parms.hop_limit;
1179         ipv6h->nexthdr = NEXTHDR_GRE;
1180         ipv6h->saddr = t->parms.laddr;
1181         ipv6h->daddr = t->parms.raddr;
1182
1183         p[0]            = t->parms.o_flags;
1184         p[1]            = htons(type);
1185
1186         /*
1187          *      Set the source hardware address.
1188          */
1189
1190         if (saddr)
1191                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1192         if (daddr)
1193                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1194         if (!ipv6_addr_any(&ipv6h->daddr))
1195                 return t->hlen;
1196
1197         return -t->hlen;
1198 }
1199
1200 static const struct header_ops ip6gre_header_ops = {
1201         .create = ip6gre_header,
1202 };
1203
1204 static const struct net_device_ops ip6gre_netdev_ops = {
1205         .ndo_init               = ip6gre_tunnel_init,
1206         .ndo_uninit             = ip6gre_tunnel_uninit,
1207         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1208         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1209         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1210         .ndo_get_stats64        = ip_tunnel_get_stats64,
1211 };
1212
1213 static void ip6gre_dev_free(struct net_device *dev)
1214 {
1215         free_percpu(dev->tstats);
1216         free_netdev(dev);
1217 }
1218
1219 static void ip6gre_tunnel_setup(struct net_device *dev)
1220 {
1221         struct ip6_tnl *t;
1222
1223         dev->netdev_ops = &ip6gre_netdev_ops;
1224         dev->destructor = ip6gre_dev_free;
1225
1226         dev->type = ARPHRD_IP6GRE;
1227         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1228         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1229         t = netdev_priv(dev);
1230         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1231                 dev->mtu -= 8;
1232         dev->flags |= IFF_NOARP;
1233         dev->iflink = 0;
1234         dev->addr_len = sizeof(struct in6_addr);
1235         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1236 }
1237
1238 static int ip6gre_tunnel_init(struct net_device *dev)
1239 {
1240         struct ip6_tnl *tunnel;
1241         int i;
1242
1243         tunnel = netdev_priv(dev);
1244
1245         tunnel->dev = dev;
1246         tunnel->net = dev_net(dev);
1247         strcpy(tunnel->parms.name, dev->name);
1248
1249         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1250         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1251
1252         if (ipv6_addr_any(&tunnel->parms.raddr))
1253                 dev->header_ops = &ip6gre_header_ops;
1254
1255         dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1256         if (!dev->tstats)
1257                 return -ENOMEM;
1258
1259         for_each_possible_cpu(i) {
1260                 struct pcpu_sw_netstats *ip6gre_tunnel_stats;
1261                 ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1262                 u64_stats_init(&ip6gre_tunnel_stats->syncp);
1263         }
1264
1265
1266         return 0;
1267 }
1268
1269 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1270 {
1271         struct ip6_tnl *tunnel = netdev_priv(dev);
1272
1273         tunnel->dev = dev;
1274         tunnel->net = dev_net(dev);
1275         strcpy(tunnel->parms.name, dev->name);
1276
1277         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1278
1279         dev_hold(dev);
1280 }
1281
1282
1283 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1284         .handler     = ip6gre_rcv,
1285         .err_handler = ip6gre_err,
1286         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1287 };
1288
1289 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1290 {
1291         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1292         struct net_device *dev, *aux;
1293         int prio;
1294
1295         for_each_netdev_safe(net, dev, aux)
1296                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1297                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1298                         unregister_netdevice_queue(dev, head);
1299
1300         for (prio = 0; prio < 4; prio++) {
1301                 int h;
1302                 for (h = 0; h < HASH_SIZE; h++) {
1303                         struct ip6_tnl *t;
1304
1305                         t = rtnl_dereference(ign->tunnels[prio][h]);
1306
1307                         while (t != NULL) {
1308                                 /* If dev is in the same netns, it has already
1309                                  * been added to the list by the previous loop.
1310                                  */
1311                                 if (!net_eq(dev_net(t->dev), net))
1312                                         unregister_netdevice_queue(t->dev,
1313                                                                    head);
1314                                 t = rtnl_dereference(t->next);
1315                         }
1316                 }
1317         }
1318 }
1319
1320 static int __net_init ip6gre_init_net(struct net *net)
1321 {
1322         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1323         int err;
1324
1325         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1326                                            ip6gre_tunnel_setup);
1327         if (!ign->fb_tunnel_dev) {
1328                 err = -ENOMEM;
1329                 goto err_alloc_dev;
1330         }
1331         dev_net_set(ign->fb_tunnel_dev, net);
1332         /* FB netdevice is special: we have one, and only one per netns.
1333          * Allowing to move it to another netns is clearly unsafe.
1334          */
1335         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1336
1337
1338         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1339         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1340
1341         err = register_netdev(ign->fb_tunnel_dev);
1342         if (err)
1343                 goto err_reg_dev;
1344
1345         rcu_assign_pointer(ign->tunnels_wc[0],
1346                            netdev_priv(ign->fb_tunnel_dev));
1347         return 0;
1348
1349 err_reg_dev:
1350         ip6gre_dev_free(ign->fb_tunnel_dev);
1351 err_alloc_dev:
1352         return err;
1353 }
1354
1355 static void __net_exit ip6gre_exit_net(struct net *net)
1356 {
1357         LIST_HEAD(list);
1358
1359         rtnl_lock();
1360         ip6gre_destroy_tunnels(net, &list);
1361         unregister_netdevice_many(&list);
1362         rtnl_unlock();
1363 }
1364
1365 static struct pernet_operations ip6gre_net_ops = {
1366         .init = ip6gre_init_net,
1367         .exit = ip6gre_exit_net,
1368         .id   = &ip6gre_net_id,
1369         .size = sizeof(struct ip6gre_net),
1370 };
1371
1372 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1373 {
1374         __be16 flags;
1375
1376         if (!data)
1377                 return 0;
1378
1379         flags = 0;
1380         if (data[IFLA_GRE_IFLAGS])
1381                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1382         if (data[IFLA_GRE_OFLAGS])
1383                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1384         if (flags & (GRE_VERSION|GRE_ROUTING))
1385                 return -EINVAL;
1386
1387         return 0;
1388 }
1389
1390 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1391 {
1392         struct in6_addr daddr;
1393
1394         if (tb[IFLA_ADDRESS]) {
1395                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1396                         return -EINVAL;
1397                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1398                         return -EADDRNOTAVAIL;
1399         }
1400
1401         if (!data)
1402                 goto out;
1403
1404         if (data[IFLA_GRE_REMOTE]) {
1405                 nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1406                 if (ipv6_addr_any(&daddr))
1407                         return -EINVAL;
1408         }
1409
1410 out:
1411         return ip6gre_tunnel_validate(tb, data);
1412 }
1413
1414
1415 static void ip6gre_netlink_parms(struct nlattr *data[],
1416                                 struct __ip6_tnl_parm *parms)
1417 {
1418         memset(parms, 0, sizeof(*parms));
1419
1420         if (!data)
1421                 return;
1422
1423         if (data[IFLA_GRE_LINK])
1424                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1425
1426         if (data[IFLA_GRE_IFLAGS])
1427                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1428
1429         if (data[IFLA_GRE_OFLAGS])
1430                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1431
1432         if (data[IFLA_GRE_IKEY])
1433                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1434
1435         if (data[IFLA_GRE_OKEY])
1436                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1437
1438         if (data[IFLA_GRE_LOCAL])
1439                 nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1440
1441         if (data[IFLA_GRE_REMOTE])
1442                 nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1443
1444         if (data[IFLA_GRE_TTL])
1445                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1446
1447         if (data[IFLA_GRE_ENCAP_LIMIT])
1448                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1449
1450         if (data[IFLA_GRE_FLOWINFO])
1451                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1452
1453         if (data[IFLA_GRE_FLAGS])
1454                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1455 }
1456
1457 static int ip6gre_tap_init(struct net_device *dev)
1458 {
1459         struct ip6_tnl *tunnel;
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 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1470         if (!dev->tstats)
1471                 return -ENOMEM;
1472
1473         return 0;
1474 }
1475
1476 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1477         .ndo_init = ip6gre_tap_init,
1478         .ndo_uninit = ip6gre_tunnel_uninit,
1479         .ndo_start_xmit = ip6gre_tunnel_xmit,
1480         .ndo_set_mac_address = eth_mac_addr,
1481         .ndo_validate_addr = eth_validate_addr,
1482         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1483         .ndo_get_stats64 = ip_tunnel_get_stats64,
1484 };
1485
1486 static void ip6gre_tap_setup(struct net_device *dev)
1487 {
1488
1489         ether_setup(dev);
1490
1491         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1492         dev->destructor = ip6gre_dev_free;
1493
1494         dev->iflink = 0;
1495         dev->features |= NETIF_F_NETNS_LOCAL;
1496 }
1497
1498 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1499         struct nlattr *tb[], struct nlattr *data[])
1500 {
1501         struct ip6_tnl *nt;
1502         struct net *net = dev_net(dev);
1503         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1504         int err;
1505
1506         nt = netdev_priv(dev);
1507         ip6gre_netlink_parms(data, &nt->parms);
1508
1509         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1510                 return -EEXIST;
1511
1512         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1513                 eth_hw_addr_random(dev);
1514
1515         nt->dev = dev;
1516         nt->net = dev_net(dev);
1517         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1518
1519         /* Can use a lockless transmit, unless we generate output sequences */
1520         if (!(nt->parms.o_flags & GRE_SEQ))
1521                 dev->features |= NETIF_F_LLTX;
1522
1523         err = register_netdevice(dev);
1524         if (err)
1525                 goto out;
1526
1527         dev_hold(dev);
1528         ip6gre_tunnel_link(ign, nt);
1529
1530 out:
1531         return err;
1532 }
1533
1534 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1535                             struct nlattr *data[])
1536 {
1537         struct ip6_tnl *t, *nt = netdev_priv(dev);
1538         struct net *net = nt->net;
1539         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1540         struct __ip6_tnl_parm p;
1541
1542         if (dev == ign->fb_tunnel_dev)
1543                 return -EINVAL;
1544
1545         ip6gre_netlink_parms(data, &p);
1546
1547         t = ip6gre_tunnel_locate(net, &p, 0);
1548
1549         if (t) {
1550                 if (t->dev != dev)
1551                         return -EEXIST;
1552         } else {
1553                 t = nt;
1554
1555                 ip6gre_tunnel_unlink(ign, t);
1556                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1557                 ip6gre_tunnel_link(ign, t);
1558                 netdev_state_change(dev);
1559         }
1560
1561         return 0;
1562 }
1563
1564 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1565 {
1566         struct net *net = dev_net(dev);
1567         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1568
1569         if (dev != ign->fb_tunnel_dev)
1570                 unregister_netdevice_queue(dev, head);
1571 }
1572
1573 static size_t ip6gre_get_size(const struct net_device *dev)
1574 {
1575         return
1576                 /* IFLA_GRE_LINK */
1577                 nla_total_size(4) +
1578                 /* IFLA_GRE_IFLAGS */
1579                 nla_total_size(2) +
1580                 /* IFLA_GRE_OFLAGS */
1581                 nla_total_size(2) +
1582                 /* IFLA_GRE_IKEY */
1583                 nla_total_size(4) +
1584                 /* IFLA_GRE_OKEY */
1585                 nla_total_size(4) +
1586                 /* IFLA_GRE_LOCAL */
1587                 nla_total_size(sizeof(struct in6_addr)) +
1588                 /* IFLA_GRE_REMOTE */
1589                 nla_total_size(sizeof(struct in6_addr)) +
1590                 /* IFLA_GRE_TTL */
1591                 nla_total_size(1) +
1592                 /* IFLA_GRE_TOS */
1593                 nla_total_size(1) +
1594                 /* IFLA_GRE_ENCAP_LIMIT */
1595                 nla_total_size(1) +
1596                 /* IFLA_GRE_FLOWINFO */
1597                 nla_total_size(4) +
1598                 /* IFLA_GRE_FLAGS */
1599                 nla_total_size(4) +
1600                 0;
1601 }
1602
1603 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1604 {
1605         struct ip6_tnl *t = netdev_priv(dev);
1606         struct __ip6_tnl_parm *p = &t->parms;
1607
1608         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1609             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1610             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1611             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1612             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1613             nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1614             nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1615             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1616             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1617             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1618             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1619             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1620                 goto nla_put_failure;
1621         return 0;
1622
1623 nla_put_failure:
1624         return -EMSGSIZE;
1625 }
1626
1627 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1628         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1629         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1630         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1631         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1632         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1633         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1634         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1635         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1636         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1637         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1638         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1639 };
1640
1641 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1642         .kind           = "ip6gre",
1643         .maxtype        = IFLA_GRE_MAX,
1644         .policy         = ip6gre_policy,
1645         .priv_size      = sizeof(struct ip6_tnl),
1646         .setup          = ip6gre_tunnel_setup,
1647         .validate       = ip6gre_tunnel_validate,
1648         .newlink        = ip6gre_newlink,
1649         .changelink     = ip6gre_changelink,
1650         .dellink        = ip6gre_dellink,
1651         .get_size       = ip6gre_get_size,
1652         .fill_info      = ip6gre_fill_info,
1653 };
1654
1655 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1656         .kind           = "ip6gretap",
1657         .maxtype        = IFLA_GRE_MAX,
1658         .policy         = ip6gre_policy,
1659         .priv_size      = sizeof(struct ip6_tnl),
1660         .setup          = ip6gre_tap_setup,
1661         .validate       = ip6gre_tap_validate,
1662         .newlink        = ip6gre_newlink,
1663         .changelink     = ip6gre_changelink,
1664         .get_size       = ip6gre_get_size,
1665         .fill_info      = ip6gre_fill_info,
1666 };
1667
1668 /*
1669  *      And now the modules code and kernel interface.
1670  */
1671
1672 static int __init ip6gre_init(void)
1673 {
1674         int err;
1675
1676         pr_info("GRE over IPv6 tunneling driver\n");
1677
1678         err = register_pernet_device(&ip6gre_net_ops);
1679         if (err < 0)
1680                 return err;
1681
1682         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1683         if (err < 0) {
1684                 pr_info("%s: can't add protocol\n", __func__);
1685                 goto add_proto_failed;
1686         }
1687
1688         err = rtnl_link_register(&ip6gre_link_ops);
1689         if (err < 0)
1690                 goto rtnl_link_failed;
1691
1692         err = rtnl_link_register(&ip6gre_tap_ops);
1693         if (err < 0)
1694                 goto tap_ops_failed;
1695
1696 out:
1697         return err;
1698
1699 tap_ops_failed:
1700         rtnl_link_unregister(&ip6gre_link_ops);
1701 rtnl_link_failed:
1702         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1703 add_proto_failed:
1704         unregister_pernet_device(&ip6gre_net_ops);
1705         goto out;
1706 }
1707
1708 static void __exit ip6gre_fini(void)
1709 {
1710         rtnl_link_unregister(&ip6gre_tap_ops);
1711         rtnl_link_unregister(&ip6gre_link_ops);
1712         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1713         unregister_pernet_device(&ip6gre_net_ops);
1714 }
1715
1716 module_init(ip6gre_init);
1717 module_exit(ip6gre_fini);
1718 MODULE_LICENSE("GPL");
1719 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1720 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1721 MODULE_ALIAS_RTNL_LINK("ip6gre");
1722 MODULE_ALIAS_NETDEV("ip6gre0");