net/ipv6/ip6_gre.c

   1 /*
   2  *      GRE over IPv6 protocol decoder.
   3  *
   4  *      Authors: Dmitry Kozlov (xeb@mail.ru)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/capability.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/slab.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/in.h>
  24 #include <linux/tcp.h>
  25 #include <linux/udp.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/mroute.h>
  28 #include <linux/init.h>
  29 #include <linux/in6.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/igmp.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/etherdevice.h>
  34 #include <linux/if_ether.h>
  35 #include <linux/hash.h>
  36 #include <linux/if_tunnel.h>
  37 #include <linux/ip6_tunnel.h>
  38
  39 #include <net/sock.h>
  40 #include <net/ip.h>
  41 #include <net/ip_tunnels.h>
  42 #include <net/icmp.h>
  43 #include <net/protocol.h>
  44 #include <net/addrconf.h>
  45 #include <net/arp.h>
  46 #include <net/checksum.h>
  47 #include <net/dsfield.h>
  48 #include <net/inet_ecn.h>
  49 #include <net/xfrm.h>
  50 #include <net/net_namespace.h>
  51 #include <net/netns/generic.h>
  52 #include <net/rtnetlink.h>
  53
  54 #include <net/ipv6.h>
  55 #include <net/ip6_fib.h>
  56 #include <net/ip6_route.h>
  57 #include <net/ip6_tunnel.h>
  58
  59
  60 static bool log_ecn_error = true;
  61 module_param(log_ecn_error, bool, 0644);
  62 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  63
  64 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
  65 #define IPV6_TCLASS_SHIFT 20
  66
  67 #define HASH_SIZE_SHIFT  5
  68 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  69
  70 static int ip6gre_net_id __read_mostly;
  71 struct ip6gre_net {
  72         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  73
  74         struct net_device *fb_tunnel_dev;
  75 };
  76
  77 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  78 static int ip6gre_tunnel_init(struct net_device *dev);
  79 static void ip6gre_tunnel_setup(struct net_device *dev);
  80 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  81 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  82
  83 /* Tunnel hash table */
  84
  85 /*
  86    4 hash tables:
  87
  88    3: (remote,local)
  89    2: (remote,*)
  90    1: (*,local)
  91    0: (*,*)
  92
  93    We require exact key match i.e. if a key is present in packet
  94    it will match only tunnel with the same key; if it is not present,
  95    it will match only keyless tunnel.
  96
  97    All keysless packets, if not matched configured keyless tunnels
  98    will match fallback tunnel.
  99  */
 100
 101 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
 102 static u32 HASH_ADDR(const struct in6_addr *addr)
 103 {
 104         u32 hash = ipv6_addr_hash(addr);
 105
 106         return hash_32(hash, HASH_SIZE_SHIFT);
 107 }
 108
 109 #define tunnels_r_l     tunnels[3]
 110 #define tunnels_r       tunnels[2]
 111 #define tunnels_l       tunnels[1]
 112 #define tunnels_wc      tunnels[0]
 113
 114 /* Given src, dst and key, find appropriate for input tunnel. */
 115
 116 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 117                 const struct in6_addr *remote, const struct in6_addr *local,
 118                 __be32 key, __be16 gre_proto)
 119 {
 120         struct net *net = dev_net(dev);
 121         int link = dev->ifindex;
 122         unsigned int h0 = HASH_ADDR(remote);
 123         unsigned int h1 = HASH_KEY(key);
 124         struct ip6_tnl *t, *cand = NULL;
 125         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 126         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 127                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 128         int score, cand_score = 4;
 129
 130         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 131                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 132                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 133                     key != t->parms.i_key ||
 134                     !(t->dev->flags & IFF_UP))
 135                         continue;
 136
 137                 if (t->dev->type != ARPHRD_IP6GRE &&
 138                     t->dev->type != dev_type)
 139                         continue;
 140
 141                 score = 0;
 142                 if (t->parms.link != link)
 143                         score |= 1;
 144                 if (t->dev->type != dev_type)
 145                         score |= 2;
 146                 if (score == 0)
 147                         return t;
 148
 149                 if (score < cand_score) {
 150                         cand = t;
 151                         cand_score = score;
 152                 }
 153         }
 154
 155         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 156                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 157                     key != t->parms.i_key ||
 158                     !(t->dev->flags & IFF_UP))
 159                         continue;
 160
 161                 if (t->dev->type != ARPHRD_IP6GRE &&
 162                     t->dev->type != dev_type)
 163                         continue;
 164
 165                 score = 0;
 166                 if (t->parms.link != link)
 167                         score |= 1;
 168                 if (t->dev->type != dev_type)
 169                         score |= 2;
 170                 if (score == 0)
 171                         return t;
 172
 173                 if (score < cand_score) {
 174                         cand = t;
 175                         cand_score = score;
 176                 }
 177         }
 178
 179         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 180                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 181                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 182                                  !ipv6_addr_is_multicast(local))) ||
 183                     key != t->parms.i_key ||
 184                     !(t->dev->flags & IFF_UP))
 185                         continue;
 186
 187                 if (t->dev->type != ARPHRD_IP6GRE &&
 188                     t->dev->type != dev_type)
 189                         continue;
 190
 191                 score = 0;
 192                 if (t->parms.link != link)
 193                         score |= 1;
 194                 if (t->dev->type != dev_type)
 195                         score |= 2;
 196                 if (score == 0)
 197                         return t;
 198
 199                 if (score < cand_score) {
 200                         cand = t;
 201                         cand_score = score;
 202                 }
 203         }
 204
 205         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 206                 if (t->parms.i_key != key ||
 207                     !(t->dev->flags & IFF_UP))
 208                         continue;
 209
 210                 if (t->dev->type != ARPHRD_IP6GRE &&
 211                     t->dev->type != dev_type)
 212                         continue;
 213
 214                 score = 0;
 215                 if (t->parms.link != link)
 216                         score |= 1;
 217                 if (t->dev->type != dev_type)
 218                         score |= 2;
 219                 if (score == 0)
 220                         return t;
 221
 222                 if (score < cand_score) {
 223                         cand = t;
 224                         cand_score = score;
 225                 }
 226         }
 227
 228         if (cand != NULL)
 229                 return cand;
 230
 231         dev = ign->fb_tunnel_dev;
 232         if (dev->flags & IFF_UP)
 233                 return netdev_priv(dev);
 234
 235         return NULL;
 236 }
 237
 238 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 239                 const struct __ip6_tnl_parm *p)
 240 {
 241         const struct in6_addr *remote = &p->raddr;
 242         const struct in6_addr *local = &p->laddr;
 243         unsigned int h = HASH_KEY(p->i_key);
 244         int prio = 0;
 245
 246         if (!ipv6_addr_any(local))
 247                 prio |= 1;
 248         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 249                 prio |= 2;
 250                 h ^= HASH_ADDR(remote);
 251         }
 252
 253         return &ign->tunnels[prio][h];
 254 }
 255
 256 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 257                 const struct ip6_tnl *t)
 258 {
 259         return __ip6gre_bucket(ign, &t->parms);
 260 }
 261
 262 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 263 {
 264         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 265
 266         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 267         rcu_assign_pointer(*tp, t);
 268 }
 269
 270 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 271 {
 272         struct ip6_tnl __rcu **tp;
 273         struct ip6_tnl *iter;
 274
 275         for (tp = ip6gre_bucket(ign, t);
 276              (iter = rtnl_dereference(*tp)) != NULL;
 277              tp = &iter->next) {
 278                 if (t == iter) {
 279                         rcu_assign_pointer(*tp, t->next);
 280                         break;
 281                 }
 282         }
 283 }
 284
 285 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 286                                            const struct __ip6_tnl_parm *parms,
 287                                            int type)
 288 {
 289         const struct in6_addr *remote = &parms->raddr;
 290         const struct in6_addr *local = &parms->laddr;
 291         __be32 key = parms->i_key;
 292         int link = parms->link;
 293         struct ip6_tnl *t;
 294         struct ip6_tnl __rcu **tp;
 295         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 296
 297         for (tp = __ip6gre_bucket(ign, parms);
 298              (t = rtnl_dereference(*tp)) != NULL;
 299              tp = &t->next)
 300                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 301                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 302                     key == t->parms.i_key &&
 303                     link == t->parms.link &&
 304                     type == t->dev->type)
 305                         break;
 306
 307         return t;
 308 }
 309
 310 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 311                 const struct __ip6_tnl_parm *parms, int create)
 312 {
 313         struct ip6_tnl *t, *nt;
 314         struct net_device *dev;
 315         char name[IFNAMSIZ];
 316         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 317
 318         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 319         if (t || !create)
 320                 return t;
 321
 322         if (parms->name[0])
 323                 strlcpy(name, parms->name, IFNAMSIZ);
 324         else
 325                 strcpy(name, "ip6gre%d");
 326
 327         dev = alloc_netdev(sizeof(*t), name, 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 net *net = dev_net(dev);
 360         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 361
 362         ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 363         dev_put(dev);
 364 }
 365
 366
 367 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 368                 u8 type, u8 code, int offset, __be32 info)
 369 {
 370         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 371         __be16 *p = (__be16 *)(skb->data + offset);
 372         int grehlen = offset + 4;
 373         struct ip6_tnl *t;
 374         __be16 flags;
 375
 376         flags = p[0];
 377         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 378                 if (flags&(GRE_VERSION|GRE_ROUTING))
 379                         return;
 380                 if (flags&GRE_KEY) {
 381                         grehlen += 4;
 382                         if (flags&GRE_CSUM)
 383                                 grehlen += 4;
 384                 }
 385         }
 386
 387         /* If only 8 bytes returned, keyed message will be dropped here */
 388         if (!pskb_may_pull(skb, grehlen))
 389                 return;
 390         ipv6h = (const struct ipv6hdr *)skb->data;
 391         p = (__be16 *)(skb->data + offset);
 392
 393         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 394                                 flags & GRE_KEY ?
 395                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 396                                 p[1]);
 397         if (t == NULL)
 398                 return;
 399
 400         switch (type) {
 401                 __u32 teli;
 402                 struct ipv6_tlv_tnl_enc_lim *tel;
 403                 __u32 mtu;
 404         case ICMPV6_DEST_UNREACH:
 405                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 406                                      t->parms.name);
 407                 break;
 408         case ICMPV6_TIME_EXCEED:
 409                 if (code == ICMPV6_EXC_HOPLIMIT) {
 410                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 411                                              t->parms.name);
 412                 }
 413                 break;
 414         case ICMPV6_PARAMPROB:
 415                 teli = 0;
 416                 if (code == ICMPV6_HDR_FIELD)
 417                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 418
 419                 if (teli && teli == info - 2) {
 420                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 421                         if (tel->encap_limit == 0) {
 422                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 423                                                      t->parms.name);
 424                         }
 425                 } else {
 426                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 427                                              t->parms.name);
 428                 }
 429                 break;
 430         case ICMPV6_PKT_TOOBIG:
 431                 mtu = info - offset;
 432                 if (mtu < IPV6_MIN_MTU)
 433                         mtu = IPV6_MIN_MTU;
 434                 t->dev->mtu = mtu;
 435                 break;
 436         }
 437
 438         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 439                 t->err_count++;
 440         else
 441                 t->err_count = 1;
 442         t->err_time = jiffies;
 443 }
 444
 445 static int ip6gre_rcv(struct sk_buff *skb)
 446 {
 447         const struct ipv6hdr *ipv6h;
 448         u8     *h;
 449         __be16    flags;
 450         __sum16   csum = 0;
 451         __be32 key = 0;
 452         u32    seqno = 0;
 453         struct ip6_tnl *tunnel;
 454         int    offset = 4;
 455         __be16 gre_proto;
 456         int err;
 457
 458         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 459                 goto drop;
 460
 461         ipv6h = ipv6_hdr(skb);
 462         h = skb->data;
 463         flags = *(__be16 *)h;
 464
 465         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 466                 /* - Version must be 0.
 467                    - We do not support routing headers.
 468                  */
 469                 if (flags&(GRE_VERSION|GRE_ROUTING))
 470                         goto drop;
 471
 472                 if (flags&GRE_CSUM) {
 473                         switch (skb->ip_summed) {
 474                         case CHECKSUM_COMPLETE:
 475                                 csum = csum_fold(skb->csum);
 476                                 if (!csum)
 477                                         break;
 478                                 /* fall through */
 479                         case CHECKSUM_NONE:
 480                                 skb->csum = 0;
 481                                 csum = __skb_checksum_complete(skb);
 482                                 skb->ip_summed = CHECKSUM_COMPLETE;
 483                         }
 484                         offset += 4;
 485                 }
 486                 if (flags&GRE_KEY) {
 487                         key = *(__be32 *)(h + offset);
 488                         offset += 4;
 489                 }
 490                 if (flags&GRE_SEQ) {
 491                         seqno = ntohl(*(__be32 *)(h + offset));
 492                         offset += 4;
 493                 }
 494         }
 495
 496         gre_proto = *(__be16 *)(h + 2);
 497
 498         tunnel = ip6gre_tunnel_lookup(skb->dev,
 499                                           &ipv6h->saddr, &ipv6h->daddr, key,
 500                                           gre_proto);
 501         if (tunnel) {
 502                 struct pcpu_tstats *tstats;
 503
 504                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 505                         goto drop;
 506
 507                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 508                         tunnel->dev->stats.rx_dropped++;
 509                         goto drop;
 510                 }
 511
 512                 skb->protocol = gre_proto;
 513                 /* WCCP version 1 and 2 protocol decoding.
 514                  * - Change protocol to IP
 515                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 516                  */
 517                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 518                         skb->protocol = htons(ETH_P_IP);
 519                         if ((*(h + offset) & 0xF0) != 0x40)
 520                                 offset += 4;
 521                 }
 522
 523                 skb->mac_header = skb->network_header;
 524                 __pskb_pull(skb, offset);
 525                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 526
 527                 if (((flags&GRE_CSUM) && csum) ||
 528                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 529                         tunnel->dev->stats.rx_crc_errors++;
 530                         tunnel->dev->stats.rx_errors++;
 531                         goto drop;
 532                 }
 533                 if (tunnel->parms.i_flags&GRE_SEQ) {
 534                         if (!(flags&GRE_SEQ) ||
 535                             (tunnel->i_seqno &&
 536                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 537                                 tunnel->dev->stats.rx_fifo_errors++;
 538                                 tunnel->dev->stats.rx_errors++;
 539                                 goto drop;
 540                         }
 541                         tunnel->i_seqno = seqno + 1;
 542                 }
 543
 544                 /* Warning: All skb pointers will be invalidated! */
 545                 if (tunnel->dev->type == ARPHRD_ETHER) {
 546                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 547                                 tunnel->dev->stats.rx_length_errors++;
 548                                 tunnel->dev->stats.rx_errors++;
 549                                 goto drop;
 550                         }
 551
 552                         ipv6h = ipv6_hdr(skb);
 553                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 554                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 555                 }
 556
 557                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 558
 559                 skb_reset_network_header(skb);
 560
 561                 err = IP6_ECN_decapsulate(ipv6h, skb);
 562                 if (unlikely(err)) {
 563                         if (log_ecn_error)
 564                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 565                                                      &ipv6h->saddr,
 566                                                      ipv6_get_dsfield(ipv6h));
 567                         if (err > 1) {
 568                                 ++tunnel->dev->stats.rx_frame_errors;
 569                                 ++tunnel->dev->stats.rx_errors;
 570                                 goto drop;
 571                         }
 572                 }
 573
 574                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 575                 u64_stats_update_begin(&tstats->syncp);
 576                 tstats->rx_packets++;
 577                 tstats->rx_bytes += skb->len;
 578                 u64_stats_update_end(&tstats->syncp);
 579
 580                 netif_rx(skb);
 581
 582                 return 0;
 583         }
 584         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 585
 586 drop:
 587         kfree_skb(skb);
 588         return 0;
 589 }
 590
 591 struct ipv6_tel_txoption {
 592         struct ipv6_txoptions ops;
 593         __u8 dst_opt[8];
 594 };
 595
 596 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 597 {
 598         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 599
 600         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 601         opt->dst_opt[3] = 1;
 602         opt->dst_opt[4] = encap_limit;
 603         opt->dst_opt[5] = IPV6_TLV_PADN;
 604         opt->dst_opt[6] = 1;
 605
 606         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 607         opt->ops.opt_nflen = 8;
 608 }
 609
 610 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 611                          struct net_device *dev,
 612                          __u8 dsfield,
 613                          struct flowi6 *fl6,
 614                          int encap_limit,
 615                          __u32 *pmtu)
 616 {
 617         struct net *net = dev_net(dev);
 618         struct ip6_tnl *tunnel = netdev_priv(dev);
 619         struct net_device *tdev;    /* Device to other host */
 620         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 621         unsigned int max_headroom = 0; /* The extra header space needed */
 622         int    gre_hlen;
 623         struct ipv6_tel_txoption opt;
 624         int    mtu;
 625         struct dst_entry *dst = NULL, *ndst = NULL;
 626         struct net_device_stats *stats = &tunnel->dev->stats;
 627         int err = -1;
 628         u8 proto;
 629         struct sk_buff *new_skb;
 630
 631         if (dev->type == ARPHRD_ETHER)
 632                 IPCB(skb)->flags = 0;
 633
 634         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 635                 gre_hlen = 0;
 636                 ipv6h = (struct ipv6hdr *)skb->data;
 637                 fl6->daddr = ipv6h->daddr;
 638         } else {
 639                 gre_hlen = tunnel->hlen;
 640                 fl6->daddr = tunnel->parms.raddr;
 641         }
 642
 643         if (!fl6->flowi6_mark)
 644                 dst = ip6_tnl_dst_check(tunnel);
 645
 646         if (!dst) {
 647                 ndst = ip6_route_output(net, NULL, fl6);
 648
 649                 if (ndst->error)
 650                         goto tx_err_link_failure;
 651                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 652                 if (IS_ERR(ndst)) {
 653                         err = PTR_ERR(ndst);
 654                         ndst = NULL;
 655                         goto tx_err_link_failure;
 656                 }
 657                 dst = ndst;
 658         }
 659
 660         tdev = dst->dev;
 661
 662         if (tdev == dev) {
 663                 stats->collisions++;
 664                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 665                                      tunnel->parms.name);
 666                 goto tx_err_dst_release;
 667         }
 668
 669         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 670         if (encap_limit >= 0) {
 671                 max_headroom += 8;
 672                 mtu -= 8;
 673         }
 674         if (mtu < IPV6_MIN_MTU)
 675                 mtu = IPV6_MIN_MTU;
 676         if (skb_dst(skb))
 677                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 678         if (skb->len > mtu) {
 679                 *pmtu = mtu;
 680                 err = -EMSGSIZE;
 681                 goto tx_err_dst_release;
 682         }
 683
 684         if (tunnel->err_count > 0) {
 685                 if (time_before(jiffies,
 686                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 687                         tunnel->err_count--;
 688
 689                         dst_link_failure(skb);
 690                 } else
 691                         tunnel->err_count = 0;
 692         }
 693
 694         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 695
 696         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 697
 698         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 699             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 700                 new_skb = skb_realloc_headroom(skb, max_headroom);
 701                 if (max_headroom > dev->needed_headroom)
 702                         dev->needed_headroom = max_headroom;
 703                 if (!new_skb)
 704                         goto tx_err_dst_release;
 705
 706                 if (skb->sk)
 707                         skb_set_owner_w(new_skb, skb->sk);
 708                 consume_skb(skb);
 709                 skb = new_skb;
 710         }
 711
 712         if (fl6->flowi6_mark) {
 713                 skb_dst_set(skb, dst);
 714                 ndst = NULL;
 715         } else {
 716                 skb_dst_set_noref(skb, dst);
 717         }
 718
 719         proto = NEXTHDR_GRE;
 720         if (encap_limit >= 0) {
 721                 init_tel_txopt(&opt, encap_limit);
 722                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 723         }
 724
 725         if (likely(!skb->encapsulation)) {
 726                 skb_reset_inner_headers(skb);
 727                 skb->encapsulation = 1;
 728         }
 729
 730         skb_push(skb, gre_hlen);
 731         skb_reset_network_header(skb);
 732         skb_set_transport_header(skb, sizeof(*ipv6h));
 733
 734         /*
 735          *      Push down and install the IP header.
 736          */
 737         ipv6h = ipv6_hdr(skb);
 738         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 739         ipv6h->hop_limit = tunnel->parms.hop_limit;
 740         ipv6h->nexthdr = proto;
 741         ipv6h->saddr = fl6->saddr;
 742         ipv6h->daddr = fl6->daddr;
 743
 744         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 745         ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 746                                    htons(ETH_P_TEB) : skb->protocol;
 747
 748         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 749                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 750
 751                 if (tunnel->parms.o_flags&GRE_SEQ) {
 752                         ++tunnel->o_seqno;
 753                         *ptr = htonl(tunnel->o_seqno);
 754                         ptr--;
 755                 }
 756                 if (tunnel->parms.o_flags&GRE_KEY) {
 757                         *ptr = tunnel->parms.o_key;
 758                         ptr--;
 759                 }
 760                 if (tunnel->parms.o_flags&GRE_CSUM) {
 761                         *ptr = 0;
 762                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 763                                 skb->len - sizeof(struct ipv6hdr));
 764                 }
 765         }
 766
 767         ip6tunnel_xmit(skb, dev);
 768         if (ndst)
 769                 ip6_tnl_dst_store(tunnel, ndst);
 770         return 0;
 771 tx_err_link_failure:
 772         stats->tx_carrier_errors++;
 773         dst_link_failure(skb);
 774 tx_err_dst_release:
 775         dst_release(ndst);
 776         return err;
 777 }
 778
 779 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 780 {
 781         struct ip6_tnl *t = netdev_priv(dev);
 782         const struct iphdr  *iph = ip_hdr(skb);
 783         int encap_limit = -1;
 784         struct flowi6 fl6;
 785         __u8 dsfield;
 786         __u32 mtu;
 787         int err;
 788
 789         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 790                 encap_limit = t->parms.encap_limit;
 791
 792         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 793         fl6.flowi6_proto = IPPROTO_IPIP;
 794
 795         dsfield = ipv4_get_dsfield(iph);
 796
 797         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 798                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 799                                           & IPV6_TCLASS_MASK;
 800         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 801                 fl6.flowi6_mark = skb->mark;
 802
 803         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 804         if (err != 0) {
 805                 /* XXX: send ICMP error even if DF is not set. */
 806                 if (err == -EMSGSIZE)
 807                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 808                                   htonl(mtu));
 809                 return -1;
 810         }
 811
 812         return 0;
 813 }
 814
 815 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 816 {
 817         struct ip6_tnl *t = netdev_priv(dev);
 818         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 819         int encap_limit = -1;
 820         __u16 offset;
 821         struct flowi6 fl6;
 822         __u8 dsfield;
 823         __u32 mtu;
 824         int err;
 825
 826         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 827                 return -1;
 828
 829         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 830         if (offset > 0) {
 831                 struct ipv6_tlv_tnl_enc_lim *tel;
 832                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 833                 if (tel->encap_limit == 0) {
 834                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 835                                     ICMPV6_HDR_FIELD, offset + 2);
 836                         return -1;
 837                 }
 838                 encap_limit = tel->encap_limit - 1;
 839         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 840                 encap_limit = t->parms.encap_limit;
 841
 842         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 843         fl6.flowi6_proto = IPPROTO_IPV6;
 844
 845         dsfield = ipv6_get_dsfield(ipv6h);
 846         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 847                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 848         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 849                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
 850         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 851                 fl6.flowi6_mark = skb->mark;
 852
 853         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 854         if (err != 0) {
 855                 if (err == -EMSGSIZE)
 856                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 857                 return -1;
 858         }
 859
 860         return 0;
 861 }
 862
 863 /**
 864  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 865  *   @t: the outgoing tunnel device
 866  *   @hdr: IPv6 header from the incoming packet
 867  *
 868  * Description:
 869  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 870  *   doesn't match source of incoming packet.
 871  *
 872  * Return:
 873  *   1 if conflict,
 874  *   0 else
 875  **/
 876
 877 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 878         const struct ipv6hdr *hdr)
 879 {
 880         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 881 }
 882
 883 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 884 {
 885         struct ip6_tnl *t = netdev_priv(dev);
 886         int encap_limit = -1;
 887         struct flowi6 fl6;
 888         __u32 mtu;
 889         int err;
 890
 891         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 892                 encap_limit = t->parms.encap_limit;
 893
 894         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 895         fl6.flowi6_proto = skb->protocol;
 896
 897         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 898
 899         return err;
 900 }
 901
 902 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 903         struct net_device *dev)
 904 {
 905         struct ip6_tnl *t = netdev_priv(dev);
 906         struct net_device_stats *stats = &t->dev->stats;
 907         int ret;
 908
 909         if (!ip6_tnl_xmit_ctl(t))
 910                 goto tx_err;
 911
 912         switch (skb->protocol) {
 913         case htons(ETH_P_IP):
 914                 ret = ip6gre_xmit_ipv4(skb, dev);
 915                 break;
 916         case htons(ETH_P_IPV6):
 917                 ret = ip6gre_xmit_ipv6(skb, dev);
 918                 break;
 919         default:
 920                 ret = ip6gre_xmit_other(skb, dev);
 921                 break;
 922         }
 923
 924         if (ret < 0)
 925                 goto tx_err;
 926
 927         return NETDEV_TX_OK;
 928
 929 tx_err:
 930         stats->tx_errors++;
 931         stats->tx_dropped++;
 932         kfree_skb(skb);
 933         return NETDEV_TX_OK;
 934 }
 935
 936 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 937 {
 938         struct net_device *dev = t->dev;
 939         struct __ip6_tnl_parm *p = &t->parms;
 940         struct flowi6 *fl6 = &t->fl.u.ip6;
 941         int addend = sizeof(struct ipv6hdr) + 4;
 942
 943         if (dev->type != ARPHRD_ETHER) {
 944                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 945                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 946         }
 947
 948         /* Set up flowi template */
 949         fl6->saddr = p->laddr;
 950         fl6->daddr = p->raddr;
 951         fl6->flowi6_oif = p->link;
 952         fl6->flowlabel = 0;
 953
 954         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 955                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 956         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 957                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 958
 959         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 960         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 961
 962         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 963                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 964                 dev->flags |= IFF_POINTOPOINT;
 965         else
 966                 dev->flags &= ~IFF_POINTOPOINT;
 967
 968         dev->iflink = p->link;
 969
 970         /* Precalculate GRE options length */
 971         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 972                 if (t->parms.o_flags&GRE_CSUM)
 973                         addend += 4;
 974                 if (t->parms.o_flags&GRE_KEY)
 975                         addend += 4;
 976                 if (t->parms.o_flags&GRE_SEQ)
 977                         addend += 4;
 978         }
 979         t->hlen = addend;
 980
 981         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 982                 int strict = (ipv6_addr_type(&p->raddr) &
 983                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 984
 985                 struct rt6_info *rt = rt6_lookup(dev_net(dev),
 986                                                  &p->raddr, &p->laddr,
 987                                                  p->link, strict);
 988
 989                 if (rt == NULL)
 990                         return;
 991
 992                 if (rt->dst.dev) {
 993                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 994
 995                         if (set_mtu) {
 996                                 dev->mtu = rt->dst.dev->mtu - addend;
 997                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 998                                         dev->mtu -= 8;
 999
1000                                 if (dev->mtu < IPV6_MIN_MTU)
1001                                         dev->mtu = IPV6_MIN_MTU;
1002                         }
1003                 }
1004                 ip6_rt_put(rt);
1005         }
1006 }
1007
1008 static int ip6gre_tnl_change(struct ip6_tnl *t,
1009         const struct __ip6_tnl_parm *p, int set_mtu)
1010 {
1011         t->parms.laddr = p->laddr;
1012         t->parms.raddr = p->raddr;
1013         t->parms.flags = p->flags;
1014         t->parms.hop_limit = p->hop_limit;
1015         t->parms.encap_limit = p->encap_limit;
1016         t->parms.flowinfo = p->flowinfo;
1017         t->parms.link = p->link;
1018         t->parms.proto = p->proto;
1019         t->parms.i_key = p->i_key;
1020         t->parms.o_key = p->o_key;
1021         t->parms.i_flags = p->i_flags;
1022         t->parms.o_flags = p->o_flags;
1023         ip6_tnl_dst_reset(t);
1024         ip6gre_tnl_link_config(t, set_mtu);
1025         return 0;
1026 }
1027
1028 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1029         const struct ip6_tnl_parm2 *u)
1030 {
1031         p->laddr = u->laddr;
1032         p->raddr = u->raddr;
1033         p->flags = u->flags;
1034         p->hop_limit = u->hop_limit;
1035         p->encap_limit = u->encap_limit;
1036         p->flowinfo = u->flowinfo;
1037         p->link = u->link;
1038         p->i_key = u->i_key;
1039         p->o_key = u->o_key;
1040         p->i_flags = u->i_flags;
1041         p->o_flags = u->o_flags;
1042         memcpy(p->name, u->name, sizeof(u->name));
1043 }
1044
1045 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1046         const struct __ip6_tnl_parm *p)
1047 {
1048         u->proto = IPPROTO_GRE;
1049         u->laddr = p->laddr;
1050         u->raddr = p->raddr;
1051         u->flags = p->flags;
1052         u->hop_limit = p->hop_limit;
1053         u->encap_limit = p->encap_limit;
1054         u->flowinfo = p->flowinfo;
1055         u->link = p->link;
1056         u->i_key = p->i_key;
1057         u->o_key = p->o_key;
1058         u->i_flags = p->i_flags;
1059         u->o_flags = p->o_flags;
1060         memcpy(u->name, p->name, sizeof(u->name));
1061 }
1062
1063 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1064         struct ifreq *ifr, int cmd)
1065 {
1066         int err = 0;
1067         struct ip6_tnl_parm2 p;
1068         struct __ip6_tnl_parm p1;
1069         struct ip6_tnl *t;
1070         struct net *net = dev_net(dev);
1071         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1072
1073         switch (cmd) {
1074         case SIOCGETTUNNEL:
1075                 t = NULL;
1076                 if (dev == ign->fb_tunnel_dev) {
1077                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1078                                 err = -EFAULT;
1079                                 break;
1080                         }
1081                         ip6gre_tnl_parm_from_user(&p1, &p);
1082                         t = ip6gre_tunnel_locate(net, &p1, 0);
1083                 }
1084                 if (t == NULL)
1085                         t = netdev_priv(dev);
1086                 memset(&p, 0, sizeof(p));
1087                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1088                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1089                         err = -EFAULT;
1090                 break;
1091
1092         case SIOCADDTUNNEL:
1093         case SIOCCHGTUNNEL:
1094                 err = -EPERM;
1095                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1096                         goto done;
1097
1098                 err = -EFAULT;
1099                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1100                         goto done;
1101
1102                 err = -EINVAL;
1103                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1104                         goto done;
1105
1106                 if (!(p.i_flags&GRE_KEY))
1107                         p.i_key = 0;
1108                 if (!(p.o_flags&GRE_KEY))
1109                         p.o_key = 0;
1110
1111                 ip6gre_tnl_parm_from_user(&p1, &p);
1112                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1113
1114                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1115                         if (t != NULL) {
1116                                 if (t->dev != dev) {
1117                                         err = -EEXIST;
1118                                         break;
1119                                 }
1120                         } else {
1121                                 t = netdev_priv(dev);
1122
1123                                 ip6gre_tunnel_unlink(ign, t);
1124                                 synchronize_net();
1125                                 ip6gre_tnl_change(t, &p1, 1);
1126                                 ip6gre_tunnel_link(ign, t);
1127                                 netdev_state_change(dev);
1128                         }
1129                 }
1130
1131                 if (t) {
1132                         err = 0;
1133
1134                         memset(&p, 0, sizeof(p));
1135                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1136                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1137                                 err = -EFAULT;
1138                 } else
1139                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1140                 break;
1141
1142         case SIOCDELTUNNEL:
1143                 err = -EPERM;
1144                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1145                         goto done;
1146
1147                 if (dev == ign->fb_tunnel_dev) {
1148                         err = -EFAULT;
1149                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1150                                 goto done;
1151                         err = -ENOENT;
1152                         ip6gre_tnl_parm_from_user(&p1, &p);
1153                         t = ip6gre_tunnel_locate(net, &p1, 0);
1154                         if (t == NULL)
1155                                 goto done;
1156                         err = -EPERM;
1157                         if (t == netdev_priv(ign->fb_tunnel_dev))
1158                                 goto done;
1159                         dev = t->dev;
1160                 }
1161                 unregister_netdevice(dev);
1162                 err = 0;
1163                 break;
1164
1165         default:
1166                 err = -EINVAL;
1167         }
1168
1169 done:
1170         return err;
1171 }
1172
1173 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1174 {
1175         if (new_mtu < 68 ||
1176             new_mtu > 0xFFF8 - dev->hard_header_len)
1177                 return -EINVAL;
1178         dev->mtu = new_mtu;
1179         return 0;
1180 }
1181
1182 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1183                         unsigned short type,
1184                         const void *daddr, const void *saddr, unsigned int len)
1185 {
1186         struct ip6_tnl *t = netdev_priv(dev);
1187         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1188         __be16 *p = (__be16 *)(ipv6h+1);
1189
1190         ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1191         ipv6h->hop_limit = t->parms.hop_limit;
1192         ipv6h->nexthdr = NEXTHDR_GRE;
1193         ipv6h->saddr = t->parms.laddr;
1194         ipv6h->daddr = t->parms.raddr;
1195
1196         p[0]            = t->parms.o_flags;
1197         p[1]            = htons(type);
1198
1199         /*
1200          *      Set the source hardware address.
1201          */
1202
1203         if (saddr)
1204                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1205         if (daddr)
1206                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1207         if (!ipv6_addr_any(&ipv6h->daddr))
1208                 return t->hlen;
1209
1210         return -t->hlen;
1211 }
1212
1213 static const struct header_ops ip6gre_header_ops = {
1214         .create = ip6gre_header,
1215 };
1216
1217 static const struct net_device_ops ip6gre_netdev_ops = {
1218         .ndo_init               = ip6gre_tunnel_init,
1219         .ndo_uninit             = ip6gre_tunnel_uninit,
1220         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1221         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1222         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1223         .ndo_get_stats64        = ip_tunnel_get_stats64,
1224 };
1225
1226 static void ip6gre_dev_free(struct net_device *dev)
1227 {
1228         free_percpu(dev->tstats);
1229         free_netdev(dev);
1230 }
1231
1232 static void ip6gre_tunnel_setup(struct net_device *dev)
1233 {
1234         struct ip6_tnl *t;
1235
1236         dev->netdev_ops = &ip6gre_netdev_ops;
1237         dev->destructor = ip6gre_dev_free;
1238
1239         dev->type = ARPHRD_IP6GRE;
1240         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1241         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1242         t = netdev_priv(dev);
1243         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1244                 dev->mtu -= 8;
1245         dev->flags |= IFF_NOARP;
1246         dev->iflink = 0;
1247         dev->addr_len = sizeof(struct in6_addr);
1248         dev->features |= NETIF_F_NETNS_LOCAL;
1249         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1250 }
1251
1252 static int ip6gre_tunnel_init(struct net_device *dev)
1253 {
1254         struct ip6_tnl *tunnel;
1255
1256         tunnel = netdev_priv(dev);
1257
1258         tunnel->dev = dev;
1259         tunnel->net = dev_net(dev);
1260         strcpy(tunnel->parms.name, dev->name);
1261
1262         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1263         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1264
1265         if (ipv6_addr_any(&tunnel->parms.raddr))
1266                 dev->header_ops = &ip6gre_header_ops;
1267
1268         dev->tstats = alloc_percpu(struct pcpu_tstats);
1269         if (!dev->tstats)
1270                 return -ENOMEM;
1271
1272         return 0;
1273 }
1274
1275 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1276 {
1277         struct ip6_tnl *tunnel = netdev_priv(dev);
1278
1279         tunnel->dev = dev;
1280         tunnel->net = dev_net(dev);
1281         strcpy(tunnel->parms.name, dev->name);
1282
1283         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1284
1285         dev_hold(dev);
1286 }
1287
1288
1289 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1290         .handler     = ip6gre_rcv,
1291         .err_handler = ip6gre_err,
1292         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1293 };
1294
1295 static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1296         struct list_head *head)
1297 {
1298         int prio;
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                                 unregister_netdevice_queue(t->dev, head);
1309                                 t = rtnl_dereference(t->next);
1310                         }
1311                 }
1312         }
1313 }
1314
1315 static int __net_init ip6gre_init_net(struct net *net)
1316 {
1317         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1318         int err;
1319
1320         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1321                                            ip6gre_tunnel_setup);
1322         if (!ign->fb_tunnel_dev) {
1323                 err = -ENOMEM;
1324                 goto err_alloc_dev;
1325         }
1326         dev_net_set(ign->fb_tunnel_dev, net);
1327
1328         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1329         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1330
1331         err = register_netdev(ign->fb_tunnel_dev);
1332         if (err)
1333                 goto err_reg_dev;
1334
1335         rcu_assign_pointer(ign->tunnels_wc[0],
1336                            netdev_priv(ign->fb_tunnel_dev));
1337         return 0;
1338
1339 err_reg_dev:
1340         ip6gre_dev_free(ign->fb_tunnel_dev);
1341 err_alloc_dev:
1342         return err;
1343 }
1344
1345 static void __net_exit ip6gre_exit_net(struct net *net)
1346 {
1347         struct ip6gre_net *ign;
1348         LIST_HEAD(list);
1349
1350         ign = net_generic(net, ip6gre_net_id);
1351         rtnl_lock();
1352         ip6gre_destroy_tunnels(ign, &list);
1353         unregister_netdevice_many(&list);
1354         rtnl_unlock();
1355 }
1356
1357 static struct pernet_operations ip6gre_net_ops = {
1358         .init = ip6gre_init_net,
1359         .exit = ip6gre_exit_net,
1360         .id   = &ip6gre_net_id,
1361         .size = sizeof(struct ip6gre_net),
1362 };
1363
1364 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1365 {
1366         __be16 flags;
1367
1368         if (!data)
1369                 return 0;
1370
1371         flags = 0;
1372         if (data[IFLA_GRE_IFLAGS])
1373                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1374         if (data[IFLA_GRE_OFLAGS])
1375                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1376         if (flags & (GRE_VERSION|GRE_ROUTING))
1377                 return -EINVAL;
1378
1379         return 0;
1380 }
1381
1382 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1383 {
1384         struct in6_addr daddr;
1385
1386         if (tb[IFLA_ADDRESS]) {
1387                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1388                         return -EINVAL;
1389                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1390                         return -EADDRNOTAVAIL;
1391         }
1392
1393         if (!data)
1394                 goto out;
1395
1396         if (data[IFLA_GRE_REMOTE]) {
1397                 nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1398                 if (ipv6_addr_any(&daddr))
1399                         return -EINVAL;
1400         }
1401
1402 out:
1403         return ip6gre_tunnel_validate(tb, data);
1404 }
1405
1406
1407 static void ip6gre_netlink_parms(struct nlattr *data[],
1408                                 struct __ip6_tnl_parm *parms)
1409 {
1410         memset(parms, 0, sizeof(*parms));
1411
1412         if (!data)
1413                 return;
1414
1415         if (data[IFLA_GRE_LINK])
1416                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1417
1418         if (data[IFLA_GRE_IFLAGS])
1419                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1420
1421         if (data[IFLA_GRE_OFLAGS])
1422                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1423
1424         if (data[IFLA_GRE_IKEY])
1425                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1426
1427         if (data[IFLA_GRE_OKEY])
1428                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1429
1430         if (data[IFLA_GRE_LOCAL])
1431                 nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1432
1433         if (data[IFLA_GRE_REMOTE])
1434                 nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1435
1436         if (data[IFLA_GRE_TTL])
1437                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1438
1439         if (data[IFLA_GRE_ENCAP_LIMIT])
1440                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1441
1442         if (data[IFLA_GRE_FLOWINFO])
1443                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1444
1445         if (data[IFLA_GRE_FLAGS])
1446                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1447 }
1448
1449 static int ip6gre_tap_init(struct net_device *dev)
1450 {
1451         struct ip6_tnl *tunnel;
1452
1453         tunnel = netdev_priv(dev);
1454
1455         tunnel->dev = dev;
1456         tunnel->net = dev_net(dev);
1457         strcpy(tunnel->parms.name, dev->name);
1458
1459         ip6gre_tnl_link_config(tunnel, 1);
1460
1461         dev->tstats = alloc_percpu(struct pcpu_tstats);
1462         if (!dev->tstats)
1463                 return -ENOMEM;
1464
1465         return 0;
1466 }
1467
1468 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1469         .ndo_init = ip6gre_tap_init,
1470         .ndo_uninit = ip6gre_tunnel_uninit,
1471         .ndo_start_xmit = ip6gre_tunnel_xmit,
1472         .ndo_set_mac_address = eth_mac_addr,
1473         .ndo_validate_addr = eth_validate_addr,
1474         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1475         .ndo_get_stats64 = ip_tunnel_get_stats64,
1476 };
1477
1478 static void ip6gre_tap_setup(struct net_device *dev)
1479 {
1480
1481         ether_setup(dev);
1482
1483         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1484         dev->destructor = ip6gre_dev_free;
1485
1486         dev->iflink = 0;
1487         dev->features |= NETIF_F_NETNS_LOCAL;
1488 }
1489
1490 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1491         struct nlattr *tb[], struct nlattr *data[])
1492 {
1493         struct ip6_tnl *nt;
1494         struct net *net = dev_net(dev);
1495         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1496         int err;
1497
1498         nt = netdev_priv(dev);
1499         ip6gre_netlink_parms(data, &nt->parms);
1500
1501         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1502                 return -EEXIST;
1503
1504         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1505                 eth_hw_addr_random(dev);
1506
1507         nt->dev = dev;
1508         nt->net = dev_net(dev);
1509         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1510
1511         /* Can use a lockless transmit, unless we generate output sequences */
1512         if (!(nt->parms.o_flags & GRE_SEQ))
1513                 dev->features |= NETIF_F_LLTX;
1514
1515         err = register_netdevice(dev);
1516         if (err)
1517                 goto out;
1518
1519         dev_hold(dev);
1520         ip6gre_tunnel_link(ign, nt);
1521
1522 out:
1523         return err;
1524 }
1525
1526 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1527                             struct nlattr *data[])
1528 {
1529         struct ip6_tnl *t, *nt;
1530         struct net *net = dev_net(dev);
1531         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1532         struct __ip6_tnl_parm p;
1533
1534         if (dev == ign->fb_tunnel_dev)
1535                 return -EINVAL;
1536
1537         nt = netdev_priv(dev);
1538         ip6gre_netlink_parms(data, &p);
1539
1540         t = ip6gre_tunnel_locate(net, &p, 0);
1541
1542         if (t) {
1543                 if (t->dev != dev)
1544                         return -EEXIST;
1545         } else {
1546                 t = nt;
1547
1548                 ip6gre_tunnel_unlink(ign, t);
1549                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1550                 ip6gre_tunnel_link(ign, t);
1551                 netdev_state_change(dev);
1552         }
1553
1554         return 0;
1555 }
1556
1557 static size_t ip6gre_get_size(const struct net_device *dev)
1558 {
1559         return
1560                 /* IFLA_GRE_LINK */
1561                 nla_total_size(4) +
1562                 /* IFLA_GRE_IFLAGS */
1563                 nla_total_size(2) +
1564                 /* IFLA_GRE_OFLAGS */
1565                 nla_total_size(2) +
1566                 /* IFLA_GRE_IKEY */
1567                 nla_total_size(4) +
1568                 /* IFLA_GRE_OKEY */
1569                 nla_total_size(4) +
1570                 /* IFLA_GRE_LOCAL */
1571                 nla_total_size(sizeof(struct in6_addr)) +
1572                 /* IFLA_GRE_REMOTE */
1573                 nla_total_size(sizeof(struct in6_addr)) +
1574                 /* IFLA_GRE_TTL */
1575                 nla_total_size(1) +
1576                 /* IFLA_GRE_TOS */
1577                 nla_total_size(1) +
1578                 /* IFLA_GRE_ENCAP_LIMIT */
1579                 nla_total_size(1) +
1580                 /* IFLA_GRE_FLOWINFO */
1581                 nla_total_size(4) +
1582                 /* IFLA_GRE_FLAGS */
1583                 nla_total_size(4) +
1584                 0;
1585 }
1586
1587 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1588 {
1589         struct ip6_tnl *t = netdev_priv(dev);
1590         struct __ip6_tnl_parm *p = &t->parms;
1591
1592         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1593             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1594             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1595             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1596             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1597             nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1598             nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1599             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1600             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1601             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1602             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1603             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1604                 goto nla_put_failure;
1605         return 0;
1606
1607 nla_put_failure:
1608         return -EMSGSIZE;
1609 }
1610
1611 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1612         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1613         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1614         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1615         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1616         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1617         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1618         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1619         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1620         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1621         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1622         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1623 };
1624
1625 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1626         .kind           = "ip6gre",
1627         .maxtype        = IFLA_GRE_MAX,
1628         .policy         = ip6gre_policy,
1629         .priv_size      = sizeof(struct ip6_tnl),
1630         .setup          = ip6gre_tunnel_setup,
1631         .validate       = ip6gre_tunnel_validate,
1632         .newlink        = ip6gre_newlink,
1633         .changelink     = ip6gre_changelink,
1634         .get_size       = ip6gre_get_size,
1635         .fill_info      = ip6gre_fill_info,
1636 };
1637
1638 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1639         .kind           = "ip6gretap",
1640         .maxtype        = IFLA_GRE_MAX,
1641         .policy         = ip6gre_policy,
1642         .priv_size      = sizeof(struct ip6_tnl),
1643         .setup          = ip6gre_tap_setup,
1644         .validate       = ip6gre_tap_validate,
1645         .newlink        = ip6gre_newlink,
1646         .changelink     = ip6gre_changelink,
1647         .get_size       = ip6gre_get_size,
1648         .fill_info      = ip6gre_fill_info,
1649 };
1650
1651 /*
1652  *      And now the modules code and kernel interface.
1653  */
1654
1655 static int __init ip6gre_init(void)
1656 {
1657         int err;
1658
1659         pr_info("GRE over IPv6 tunneling driver\n");
1660
1661         err = register_pernet_device(&ip6gre_net_ops);
1662         if (err < 0)
1663                 return err;
1664
1665         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1666         if (err < 0) {
1667                 pr_info("%s: can't add protocol\n", __func__);
1668                 goto add_proto_failed;
1669         }
1670
1671         err = rtnl_link_register(&ip6gre_link_ops);
1672         if (err < 0)
1673                 goto rtnl_link_failed;
1674
1675         err = rtnl_link_register(&ip6gre_tap_ops);
1676         if (err < 0)
1677                 goto tap_ops_failed;
1678
1679 out:
1680         return err;
1681
1682 tap_ops_failed:
1683         rtnl_link_unregister(&ip6gre_link_ops);
1684 rtnl_link_failed:
1685         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1686 add_proto_failed:
1687         unregister_pernet_device(&ip6gre_net_ops);
1688         goto out;
1689 }
1690
1691 static void __exit ip6gre_fini(void)
1692 {
1693         rtnl_link_unregister(&ip6gre_tap_ops);
1694         rtnl_link_unregister(&ip6gre_link_ops);
1695         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1696         unregister_pernet_device(&ip6gre_net_ops);
1697 }
1698
1699 module_init(ip6gre_init);
1700 module_exit(ip6gre_fini);
1701 MODULE_LICENSE("GPL");
1702 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1703 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1704 MODULE_ALIAS_RTNL_LINK("ip6gre");
1705 MODULE_ALIAS_NETDEV("ip6gre0");