net/ipv6/ip6_gre.c

   1 /*
   2  *      GRE over IPv6 protocol decoder.
   3  *
   4  *      Authors: Dmitry Kozlov ([email protected])
   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)
 227                 return cand;
 228
 229         dev = ign->fb_tunnel_dev;
 230         if (dev->flags & IFF_UP)
 231                 return netdev_priv(dev);
 232
 233         return NULL;
 234 }
 235
 236 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 237                 const struct __ip6_tnl_parm *p)
 238 {
 239         const struct in6_addr *remote = &p->raddr;
 240         const struct in6_addr *local = &p->laddr;
 241         unsigned int h = HASH_KEY(p->i_key);
 242         int prio = 0;
 243
 244         if (!ipv6_addr_any(local))
 245                 prio |= 1;
 246         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 247                 prio |= 2;
 248                 h ^= HASH_ADDR(remote);
 249         }
 250
 251         return &ign->tunnels[prio][h];
 252 }
 253
 254 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 255                 const struct ip6_tnl *t)
 256 {
 257         return __ip6gre_bucket(ign, &t->parms);
 258 }
 259
 260 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 261 {
 262         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 263
 264         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 265         rcu_assign_pointer(*tp, t);
 266 }
 267
 268 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 269 {
 270         struct ip6_tnl __rcu **tp;
 271         struct ip6_tnl *iter;
 272
 273         for (tp = ip6gre_bucket(ign, t);
 274              (iter = rtnl_dereference(*tp)) != NULL;
 275              tp = &iter->next) {
 276                 if (t == iter) {
 277                         rcu_assign_pointer(*tp, t->next);
 278                         break;
 279                 }
 280         }
 281 }
 282
 283 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 284                                            const struct __ip6_tnl_parm *parms,
 285                                            int type)
 286 {
 287         const struct in6_addr *remote = &parms->raddr;
 288         const struct in6_addr *local = &parms->laddr;
 289         __be32 key = parms->i_key;
 290         int link = parms->link;
 291         struct ip6_tnl *t;
 292         struct ip6_tnl __rcu **tp;
 293         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 294
 295         for (tp = __ip6gre_bucket(ign, parms);
 296              (t = rtnl_dereference(*tp)) != NULL;
 297              tp = &t->next)
 298                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 299                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 300                     key == t->parms.i_key &&
 301                     link == t->parms.link &&
 302                     type == t->dev->type)
 303                         break;
 304
 305         return t;
 306 }
 307
 308 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 309                 const struct __ip6_tnl_parm *parms, int create)
 310 {
 311         struct ip6_tnl *t, *nt;
 312         struct net_device *dev;
 313         char name[IFNAMSIZ];
 314         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 315
 316         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 317         if (t && create)
 318                 return NULL;
 319         if (t || !create)
 320                 return t;
 321
 322         if (parms->name[0])
 323                 strlcpy(name, parms->name, IFNAMSIZ);
 324         else
 325                 strcpy(name, "ip6gre%d");
 326
 327         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 328                            ip6gre_tunnel_setup);
 329         if (!dev)
 330                 return NULL;
 331
 332         dev_net_set(dev, net);
 333
 334         nt = netdev_priv(dev);
 335         nt->parms = *parms;
 336         dev->rtnl_link_ops = &ip6gre_link_ops;
 337
 338         nt->dev = dev;
 339         nt->net = dev_net(dev);
 340         ip6gre_tnl_link_config(nt, 1);
 341
 342         if (register_netdevice(dev) < 0)
 343                 goto failed_free;
 344
 345         /* Can use a lockless transmit, unless we generate output sequences */
 346         if (!(nt->parms.o_flags & GRE_SEQ))
 347                 dev->features |= NETIF_F_LLTX;
 348
 349         dev_hold(dev);
 350         ip6gre_tunnel_link(ign, nt);
 351         return nt;
 352
 353 failed_free:
 354         free_netdev(dev);
 355         return NULL;
 356 }
 357
 358 static void ip6gre_tunnel_uninit(struct net_device *dev)
 359 {
 360         struct ip6_tnl *t = netdev_priv(dev);
 361         struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 362
 363         ip6gre_tunnel_unlink(ign, t);
 364         dev_put(dev);
 365 }
 366
 367
 368 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 369                 u8 type, u8 code, int offset, __be32 info)
 370 {
 371         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 372         __be16 *p = (__be16 *)(skb->data + offset);
 373         int grehlen = offset + 4;
 374         struct ip6_tnl *t;
 375         __be16 flags;
 376
 377         flags = p[0];
 378         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 379                 if (flags&(GRE_VERSION|GRE_ROUTING))
 380                         return;
 381                 if (flags&GRE_KEY) {
 382                         grehlen += 4;
 383                         if (flags&GRE_CSUM)
 384                                 grehlen += 4;
 385                 }
 386         }
 387
 388         /* If only 8 bytes returned, keyed message will be dropped here */
 389         if (!pskb_may_pull(skb, grehlen))
 390                 return;
 391         ipv6h = (const struct ipv6hdr *)skb->data;
 392         p = (__be16 *)(skb->data + offset);
 393
 394         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 395                                 flags & GRE_KEY ?
 396                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 397                                 p[1]);
 398         if (!t)
 399                 return;
 400
 401         switch (type) {
 402                 __u32 teli;
 403                 struct ipv6_tlv_tnl_enc_lim *tel;
 404                 __u32 mtu;
 405         case ICMPV6_DEST_UNREACH:
 406                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 407                                      t->parms.name);
 408                 break;
 409         case ICMPV6_TIME_EXCEED:
 410                 if (code == ICMPV6_EXC_HOPLIMIT) {
 411                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 412                                              t->parms.name);
 413                 }
 414                 break;
 415         case ICMPV6_PARAMPROB:
 416                 teli = 0;
 417                 if (code == ICMPV6_HDR_FIELD)
 418                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 419
 420                 if (teli && teli == be32_to_cpu(info) - 2) {
 421                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 422                         if (tel->encap_limit == 0) {
 423                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 424                                                      t->parms.name);
 425                         }
 426                 } else {
 427                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 428                                              t->parms.name);
 429                 }
 430                 break;
 431         case ICMPV6_PKT_TOOBIG:
 432                 mtu = be32_to_cpu(info) - offset;
 433                 if (mtu < IPV6_MIN_MTU)
 434                         mtu = IPV6_MIN_MTU;
 435                 t->dev->mtu = mtu;
 436                 break;
 437         }
 438
 439         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 440                 t->err_count++;
 441         else
 442                 t->err_count = 1;
 443         t->err_time = jiffies;
 444 }
 445
 446 static int ip6gre_rcv(struct sk_buff *skb)
 447 {
 448         const struct ipv6hdr *ipv6h;
 449         u8     *h;
 450         __be16    flags;
 451         __sum16   csum = 0;
 452         __be32 key = 0;
 453         u32    seqno = 0;
 454         struct ip6_tnl *tunnel;
 455         int    offset = 4;
 456         __be16 gre_proto;
 457         int err;
 458
 459         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 460                 goto drop;
 461
 462         ipv6h = ipv6_hdr(skb);
 463         h = skb->data;
 464         flags = *(__be16 *)h;
 465
 466         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 467                 /* - Version must be 0.
 468                    - We do not support routing headers.
 469                  */
 470                 if (flags&(GRE_VERSION|GRE_ROUTING))
 471                         goto drop;
 472
 473                 if (flags&GRE_CSUM) {
 474                         csum = skb_checksum_simple_validate(skb);
 475                         offset += 4;
 476                 }
 477                 if (flags&GRE_KEY) {
 478                         key = *(__be32 *)(h + offset);
 479                         offset += 4;
 480                 }
 481                 if (flags&GRE_SEQ) {
 482                         seqno = ntohl(*(__be32 *)(h + offset));
 483                         offset += 4;
 484                 }
 485         }
 486
 487         gre_proto = *(__be16 *)(h + 2);
 488
 489         tunnel = ip6gre_tunnel_lookup(skb->dev,
 490                                           &ipv6h->saddr, &ipv6h->daddr, key,
 491                                           gre_proto);
 492         if (tunnel) {
 493                 struct pcpu_sw_netstats *tstats;
 494
 495                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 496                         goto drop;
 497
 498                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 499                         tunnel->dev->stats.rx_dropped++;
 500                         goto drop;
 501                 }
 502
 503                 skb->protocol = gre_proto;
 504                 /* WCCP version 1 and 2 protocol decoding.
 505                  * - Change protocol to IPv6
 506                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 507                  */
 508                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 509                         skb->protocol = htons(ETH_P_IPV6);
 510                         if ((*(h + offset) & 0xF0) != 0x40)
 511                                 offset += 4;
 512                 }
 513
 514                 skb->mac_header = skb->network_header;
 515                 __pskb_pull(skb, offset);
 516                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 517
 518                 if (((flags&GRE_CSUM) && csum) ||
 519                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 520                         tunnel->dev->stats.rx_crc_errors++;
 521                         tunnel->dev->stats.rx_errors++;
 522                         goto drop;
 523                 }
 524                 if (tunnel->parms.i_flags&GRE_SEQ) {
 525                         if (!(flags&GRE_SEQ) ||
 526                             (tunnel->i_seqno &&
 527                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 528                                 tunnel->dev->stats.rx_fifo_errors++;
 529                                 tunnel->dev->stats.rx_errors++;
 530                                 goto drop;
 531                         }
 532                         tunnel->i_seqno = seqno + 1;
 533                 }
 534
 535                 /* Warning: All skb pointers will be invalidated! */
 536                 if (tunnel->dev->type == ARPHRD_ETHER) {
 537                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 538                                 tunnel->dev->stats.rx_length_errors++;
 539                                 tunnel->dev->stats.rx_errors++;
 540                                 goto drop;
 541                         }
 542
 543                         ipv6h = ipv6_hdr(skb);
 544                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 545                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 546                 }
 547
 548                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 549
 550                 skb_reset_network_header(skb);
 551
 552                 err = IP6_ECN_decapsulate(ipv6h, skb);
 553                 if (unlikely(err)) {
 554                         if (log_ecn_error)
 555                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 556                                                      &ipv6h->saddr,
 557                                                      ipv6_get_dsfield(ipv6h));
 558                         if (err > 1) {
 559                                 ++tunnel->dev->stats.rx_frame_errors;
 560                                 ++tunnel->dev->stats.rx_errors;
 561                                 goto drop;
 562                         }
 563                 }
 564
 565                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 566                 u64_stats_update_begin(&tstats->syncp);
 567                 tstats->rx_packets++;
 568                 tstats->rx_bytes += skb->len;
 569                 u64_stats_update_end(&tstats->syncp);
 570
 571                 netif_rx(skb);
 572
 573                 return 0;
 574         }
 575         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 576
 577 drop:
 578         kfree_skb(skb);
 579         return 0;
 580 }
 581
 582 struct ipv6_tel_txoption {
 583         struct ipv6_txoptions ops;
 584         __u8 dst_opt[8];
 585 };
 586
 587 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 588 {
 589         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 590
 591         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 592         opt->dst_opt[3] = 1;
 593         opt->dst_opt[4] = encap_limit;
 594         opt->dst_opt[5] = IPV6_TLV_PADN;
 595         opt->dst_opt[6] = 1;
 596
 597         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 598         opt->ops.opt_nflen = 8;
 599 }
 600
 601 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 602                          struct net_device *dev,
 603                          __u8 dsfield,
 604                          struct flowi6 *fl6,
 605                          int encap_limit,
 606                          __u32 *pmtu)
 607 {
 608         struct ip6_tnl *tunnel = netdev_priv(dev);
 609         struct net *net = tunnel->net;
 610         struct net_device *tdev;    /* Device to other host */
 611         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 612         unsigned int max_headroom = 0; /* The extra header space needed */
 613         int    gre_hlen;
 614         struct ipv6_tel_txoption opt;
 615         int    mtu;
 616         struct dst_entry *dst = NULL, *ndst = NULL;
 617         struct net_device_stats *stats = &tunnel->dev->stats;
 618         int err = -1;
 619         u8 proto;
 620         struct sk_buff *new_skb;
 621         __be16 protocol;
 622
 623         if (dev->type == ARPHRD_ETHER)
 624                 IPCB(skb)->flags = 0;
 625
 626         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 627                 gre_hlen = 0;
 628                 ipv6h = (struct ipv6hdr *)skb->data;
 629                 fl6->daddr = ipv6h->daddr;
 630         } else {
 631                 gre_hlen = tunnel->hlen;
 632                 fl6->daddr = tunnel->parms.raddr;
 633         }
 634
 635         if (!fl6->flowi6_mark)
 636                 dst = ip6_tnl_dst_check(tunnel);
 637
 638         if (!dst) {
 639                 ndst = ip6_route_output(net, NULL, fl6);
 640
 641                 if (ndst->error)
 642                         goto tx_err_link_failure;
 643                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 644                 if (IS_ERR(ndst)) {
 645                         err = PTR_ERR(ndst);
 646                         ndst = NULL;
 647                         goto tx_err_link_failure;
 648                 }
 649                 dst = ndst;
 650         }
 651
 652         tdev = dst->dev;
 653
 654         if (tdev == dev) {
 655                 stats->collisions++;
 656                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 657                                      tunnel->parms.name);
 658                 goto tx_err_dst_release;
 659         }
 660
 661         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 662         if (encap_limit >= 0) {
 663                 max_headroom += 8;
 664                 mtu -= 8;
 665         }
 666         if (mtu < IPV6_MIN_MTU)
 667                 mtu = IPV6_MIN_MTU;
 668         if (skb_dst(skb))
 669                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 670         if (skb->len > mtu) {
 671                 *pmtu = mtu;
 672                 err = -EMSGSIZE;
 673                 goto tx_err_dst_release;
 674         }
 675
 676         if (tunnel->err_count > 0) {
 677                 if (time_before(jiffies,
 678                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 679                         tunnel->err_count--;
 680
 681                         dst_link_failure(skb);
 682                 } else
 683                         tunnel->err_count = 0;
 684         }
 685
 686         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 687
 688         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 689
 690         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 691             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 692                 new_skb = skb_realloc_headroom(skb, max_headroom);
 693                 if (max_headroom > dev->needed_headroom)
 694                         dev->needed_headroom = max_headroom;
 695                 if (!new_skb)
 696                         goto tx_err_dst_release;
 697
 698                 if (skb->sk)
 699                         skb_set_owner_w(new_skb, skb->sk);
 700                 consume_skb(skb);
 701                 skb = new_skb;
 702         }
 703
 704         if (fl6->flowi6_mark) {
 705                 skb_dst_set(skb, dst);
 706                 ndst = NULL;
 707         } else {
 708                 skb_dst_set_noref(skb, dst);
 709         }
 710
 711         proto = NEXTHDR_GRE;
 712         if (encap_limit >= 0) {
 713                 init_tel_txopt(&opt, encap_limit);
 714                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 715         }
 716
 717         if (likely(!skb->encapsulation)) {
 718                 skb_reset_inner_headers(skb);
 719                 skb->encapsulation = 1;
 720         }
 721
 722         skb_push(skb, gre_hlen);
 723         skb_reset_network_header(skb);
 724         skb_set_transport_header(skb, sizeof(*ipv6h));
 725
 726         /*
 727          *      Push down and install the IP header.
 728          */
 729         ipv6h = ipv6_hdr(skb);
 730         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
 731                      ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
 732         ipv6h->hop_limit = tunnel->parms.hop_limit;
 733         ipv6h->nexthdr = proto;
 734         ipv6h->saddr = fl6->saddr;
 735         ipv6h->daddr = fl6->daddr;
 736
 737         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 738         protocol = (dev->type == ARPHRD_ETHER) ?
 739                     htons(ETH_P_TEB) : skb->protocol;
 740         ((__be16 *)(ipv6h + 1))[1] = protocol;
 741
 742         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 743                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 744
 745                 if (tunnel->parms.o_flags&GRE_SEQ) {
 746                         ++tunnel->o_seqno;
 747                         *ptr = htonl(tunnel->o_seqno);
 748                         ptr--;
 749                 }
 750                 if (tunnel->parms.o_flags&GRE_KEY) {
 751                         *ptr = tunnel->parms.o_key;
 752                         ptr--;
 753                 }
 754                 if (tunnel->parms.o_flags&GRE_CSUM) {
 755                         *ptr = 0;
 756                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 757                                 skb->len - sizeof(struct ipv6hdr));
 758                 }
 759         }
 760
 761         skb_set_inner_protocol(skb, protocol);
 762
 763         ip6tunnel_xmit(NULL, skb, dev);
 764         if (ndst)
 765                 ip6_tnl_dst_store(tunnel, ndst);
 766         return 0;
 767 tx_err_link_failure:
 768         stats->tx_carrier_errors++;
 769         dst_link_failure(skb);
 770 tx_err_dst_release:
 771         dst_release(ndst);
 772         return err;
 773 }
 774
 775 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 776 {
 777         struct ip6_tnl *t = netdev_priv(dev);
 778         const struct iphdr  *iph = ip_hdr(skb);
 779         int encap_limit = -1;
 780         struct flowi6 fl6;
 781         __u8 dsfield;
 782         __u32 mtu;
 783         int err;
 784
 785         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 786                 encap_limit = t->parms.encap_limit;
 787
 788         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 789         fl6.flowi6_proto = IPPROTO_GRE;
 790
 791         dsfield = ipv4_get_dsfield(iph);
 792
 793         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 794                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 795                                           & IPV6_TCLASS_MASK;
 796         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 797                 fl6.flowi6_mark = skb->mark;
 798
 799         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 800         if (err != 0) {
 801                 /* XXX: send ICMP error even if DF is not set. */
 802                 if (err == -EMSGSIZE)
 803                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 804                                   htonl(mtu));
 805                 return -1;
 806         }
 807
 808         return 0;
 809 }
 810
 811 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 812 {
 813         struct ip6_tnl *t = netdev_priv(dev);
 814         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 815         int encap_limit = -1;
 816         __u16 offset;
 817         struct flowi6 fl6;
 818         __u8 dsfield;
 819         __u32 mtu;
 820         int err;
 821
 822         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 823                 return -1;
 824
 825         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 826         if (offset > 0) {
 827                 struct ipv6_tlv_tnl_enc_lim *tel;
 828                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 829                 if (tel->encap_limit == 0) {
 830                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 831                                     ICMPV6_HDR_FIELD, offset + 2);
 832                         return -1;
 833                 }
 834                 encap_limit = tel->encap_limit - 1;
 835         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 836                 encap_limit = t->parms.encap_limit;
 837
 838         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 839         fl6.flowi6_proto = IPPROTO_GRE;
 840
 841         dsfield = ipv6_get_dsfield(ipv6h);
 842         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 843                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 844         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 845                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 846         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 847                 fl6.flowi6_mark = skb->mark;
 848
 849         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 850         if (err != 0) {
 851                 if (err == -EMSGSIZE)
 852                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 853                 return -1;
 854         }
 855
 856         return 0;
 857 }
 858
 859 /**
 860  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 861  *   @t: the outgoing tunnel device
 862  *   @hdr: IPv6 header from the incoming packet
 863  *
 864  * Description:
 865  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 866  *   doesn't match source of incoming packet.
 867  *
 868  * Return:
 869  *   1 if conflict,
 870  *   0 else
 871  **/
 872
 873 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 874         const struct ipv6hdr *hdr)
 875 {
 876         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 877 }
 878
 879 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 880 {
 881         struct ip6_tnl *t = netdev_priv(dev);
 882         int encap_limit = -1;
 883         struct flowi6 fl6;
 884         __u32 mtu;
 885         int err;
 886
 887         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 888                 encap_limit = t->parms.encap_limit;
 889
 890         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 891         fl6.flowi6_proto = skb->protocol;
 892
 893         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 894
 895         return err;
 896 }
 897
 898 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 899         struct net_device *dev)
 900 {
 901         struct ip6_tnl *t = netdev_priv(dev);
 902         struct net_device_stats *stats = &t->dev->stats;
 903         int ret;
 904
 905         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 906                 goto tx_err;
 907
 908         switch (skb->protocol) {
 909         case htons(ETH_P_IP):
 910                 ret = ip6gre_xmit_ipv4(skb, dev);
 911                 break;
 912         case htons(ETH_P_IPV6):
 913                 ret = ip6gre_xmit_ipv6(skb, dev);
 914                 break;
 915         default:
 916                 ret = ip6gre_xmit_other(skb, dev);
 917                 break;
 918         }
 919
 920         if (ret < 0)
 921                 goto tx_err;
 922
 923         return NETDEV_TX_OK;
 924
 925 tx_err:
 926         stats->tx_errors++;
 927         stats->tx_dropped++;
 928         kfree_skb(skb);
 929         return NETDEV_TX_OK;
 930 }
 931
 932 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 933 {
 934         struct net_device *dev = t->dev;
 935         struct __ip6_tnl_parm *p = &t->parms;
 936         struct flowi6 *fl6 = &t->fl.u.ip6;
 937         int addend = sizeof(struct ipv6hdr) + 4;
 938
 939         if (dev->type != ARPHRD_ETHER) {
 940                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 941                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 942         }
 943
 944         /* Set up flowi template */
 945         fl6->saddr = p->laddr;
 946         fl6->daddr = p->raddr;
 947         fl6->flowi6_oif = p->link;
 948         fl6->flowlabel = 0;
 949
 950         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 951                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 952         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 953                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 954
 955         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 956         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 957
 958         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 959                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 960                 dev->flags |= IFF_POINTOPOINT;
 961         else
 962                 dev->flags &= ~IFF_POINTOPOINT;
 963
 964         /* Precalculate GRE options length */
 965         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 966                 if (t->parms.o_flags&GRE_CSUM)
 967                         addend += 4;
 968                 if (t->parms.o_flags&GRE_KEY)
 969                         addend += 4;
 970                 if (t->parms.o_flags&GRE_SEQ)
 971                         addend += 4;
 972         }
 973         t->hlen = addend;
 974
 975         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 976                 int strict = (ipv6_addr_type(&p->raddr) &
 977                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 978
 979                 struct rt6_info *rt = rt6_lookup(t->net,
 980                                                  &p->raddr, &p->laddr,
 981                                                  p->link, strict);
 982
 983                 if (!rt)
 984                         return;
 985
 986                 if (rt->dst.dev) {
 987                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 988
 989                         if (set_mtu) {
 990                                 dev->mtu = rt->dst.dev->mtu - addend;
 991                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 992                                         dev->mtu -= 8;
 993
 994                                 if (dev->mtu < IPV6_MIN_MTU)
 995                                         dev->mtu = IPV6_MIN_MTU;
 996                         }
 997                 }
 998                 ip6_rt_put(rt);
 999         }
1000 }
1001
1002 static int ip6gre_tnl_change(struct ip6_tnl *t,
1003         const struct __ip6_tnl_parm *p, int set_mtu)
1004 {
1005         t->parms.laddr = p->laddr;
1006         t->parms.raddr = p->raddr;
1007         t->parms.flags = p->flags;
1008         t->parms.hop_limit = p->hop_limit;
1009         t->parms.encap_limit = p->encap_limit;
1010         t->parms.flowinfo = p->flowinfo;
1011         t->parms.link = p->link;
1012         t->parms.proto = p->proto;
1013         t->parms.i_key = p->i_key;
1014         t->parms.o_key = p->o_key;
1015         t->parms.i_flags = p->i_flags;
1016         t->parms.o_flags = p->o_flags;
1017         ip6_tnl_dst_reset(t);
1018         ip6gre_tnl_link_config(t, set_mtu);
1019         return 0;
1020 }
1021
1022 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1023         const struct ip6_tnl_parm2 *u)
1024 {
1025         p->laddr = u->laddr;
1026         p->raddr = u->raddr;
1027         p->flags = u->flags;
1028         p->hop_limit = u->hop_limit;
1029         p->encap_limit = u->encap_limit;
1030         p->flowinfo = u->flowinfo;
1031         p->link = u->link;
1032         p->i_key = u->i_key;
1033         p->o_key = u->o_key;
1034         p->i_flags = u->i_flags;
1035         p->o_flags = u->o_flags;
1036         memcpy(p->name, u->name, sizeof(u->name));
1037 }
1038
1039 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1040         const struct __ip6_tnl_parm *p)
1041 {
1042         u->proto = IPPROTO_GRE;
1043         u->laddr = p->laddr;
1044         u->raddr = p->raddr;
1045         u->flags = p->flags;
1046         u->hop_limit = p->hop_limit;
1047         u->encap_limit = p->encap_limit;
1048         u->flowinfo = p->flowinfo;
1049         u->link = p->link;
1050         u->i_key = p->i_key;
1051         u->o_key = p->o_key;
1052         u->i_flags = p->i_flags;
1053         u->o_flags = p->o_flags;
1054         memcpy(u->name, p->name, sizeof(u->name));
1055 }
1056
1057 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1058         struct ifreq *ifr, int cmd)
1059 {
1060         int err = 0;
1061         struct ip6_tnl_parm2 p;
1062         struct __ip6_tnl_parm p1;
1063         struct ip6_tnl *t = netdev_priv(dev);
1064         struct net *net = t->net;
1065         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1066
1067         switch (cmd) {
1068         case SIOCGETTUNNEL:
1069                 if (dev == ign->fb_tunnel_dev) {
1070                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1071                                 err = -EFAULT;
1072                                 break;
1073                         }
1074                         ip6gre_tnl_parm_from_user(&p1, &p);
1075                         t = ip6gre_tunnel_locate(net, &p1, 0);
1076                         if (!t)
1077                                 t = netdev_priv(dev);
1078                 }
1079                 memset(&p, 0, sizeof(p));
1080                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1081                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1082                         err = -EFAULT;
1083                 break;
1084
1085         case SIOCADDTUNNEL:
1086         case SIOCCHGTUNNEL:
1087                 err = -EPERM;
1088                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1089                         goto done;
1090
1091                 err = -EFAULT;
1092                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1093                         goto done;
1094
1095                 err = -EINVAL;
1096                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1097                         goto done;
1098
1099                 if (!(p.i_flags&GRE_KEY))
1100                         p.i_key = 0;
1101                 if (!(p.o_flags&GRE_KEY))
1102                         p.o_key = 0;
1103
1104                 ip6gre_tnl_parm_from_user(&p1, &p);
1105                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1106
1107                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1108                         if (t) {
1109                                 if (t->dev != dev) {
1110                                         err = -EEXIST;
1111                                         break;
1112                                 }
1113                         } else {
1114                                 t = netdev_priv(dev);
1115
1116                                 ip6gre_tunnel_unlink(ign, t);
1117                                 synchronize_net();
1118                                 ip6gre_tnl_change(t, &p1, 1);
1119                                 ip6gre_tunnel_link(ign, t);
1120                                 netdev_state_change(dev);
1121                         }
1122                 }
1123
1124                 if (t) {
1125                         err = 0;
1126
1127                         memset(&p, 0, sizeof(p));
1128                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1129                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1130                                 err = -EFAULT;
1131                 } else
1132                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1133                 break;
1134
1135         case SIOCDELTUNNEL:
1136                 err = -EPERM;
1137                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1138                         goto done;
1139
1140                 if (dev == ign->fb_tunnel_dev) {
1141                         err = -EFAULT;
1142                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1143                                 goto done;
1144                         err = -ENOENT;
1145                         ip6gre_tnl_parm_from_user(&p1, &p);
1146                         t = ip6gre_tunnel_locate(net, &p1, 0);
1147                         if (!t)
1148                                 goto done;
1149                         err = -EPERM;
1150                         if (t == netdev_priv(ign->fb_tunnel_dev))
1151                                 goto done;
1152                         dev = t->dev;
1153                 }
1154                 unregister_netdevice(dev);
1155                 err = 0;
1156                 break;
1157
1158         default:
1159                 err = -EINVAL;
1160         }
1161
1162 done:
1163         return err;
1164 }
1165
1166 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1167 {
1168         if (new_mtu < 68 ||
1169             new_mtu > 0xFFF8 - dev->hard_header_len)
1170                 return -EINVAL;
1171         dev->mtu = new_mtu;
1172         return 0;
1173 }
1174
1175 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1176                         unsigned short type,
1177                         const void *daddr, const void *saddr, unsigned int len)
1178 {
1179         struct ip6_tnl *t = netdev_priv(dev);
1180         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1181         __be16 *p = (__be16 *)(ipv6h+1);
1182
1183         ip6_flow_hdr(ipv6h, 0,
1184                      ip6_make_flowlabel(dev_net(dev), skb,
1185                                         t->fl.u.ip6.flowlabel, false));
1186         ipv6h->hop_limit = t->parms.hop_limit;
1187         ipv6h->nexthdr = NEXTHDR_GRE;
1188         ipv6h->saddr = t->parms.laddr;
1189         ipv6h->daddr = t->parms.raddr;
1190
1191         p[0]            = t->parms.o_flags;
1192         p[1]            = htons(type);
1193
1194         /*
1195          *      Set the source hardware address.
1196          */
1197
1198         if (saddr)
1199                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1200         if (daddr)
1201                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1202         if (!ipv6_addr_any(&ipv6h->daddr))
1203                 return t->hlen;
1204
1205         return -t->hlen;
1206 }
1207
1208 static const struct header_ops ip6gre_header_ops = {
1209         .create = ip6gre_header,
1210 };
1211
1212 static const struct net_device_ops ip6gre_netdev_ops = {
1213         .ndo_init               = ip6gre_tunnel_init,
1214         .ndo_uninit             = ip6gre_tunnel_uninit,
1215         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1216         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1217         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1218         .ndo_get_stats64        = ip_tunnel_get_stats64,
1219         .ndo_get_iflink         = ip6_tnl_get_iflink,
1220 };
1221
1222 static void ip6gre_dev_free(struct net_device *dev)
1223 {
1224         free_percpu(dev->tstats);
1225         free_netdev(dev);
1226 }
1227
1228 static void ip6gre_tunnel_setup(struct net_device *dev)
1229 {
1230         struct ip6_tnl *t;
1231
1232         dev->netdev_ops = &ip6gre_netdev_ops;
1233         dev->destructor = ip6gre_dev_free;
1234
1235         dev->type = ARPHRD_IP6GRE;
1236         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1237         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1238         t = netdev_priv(dev);
1239         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1240                 dev->mtu -= 8;
1241         dev->flags |= IFF_NOARP;
1242         dev->addr_len = sizeof(struct in6_addr);
1243         netif_keep_dst(dev);
1244 }
1245
1246 static int ip6gre_tunnel_init(struct net_device *dev)
1247 {
1248         struct ip6_tnl *tunnel;
1249
1250         tunnel = netdev_priv(dev);
1251
1252         tunnel->dev = dev;
1253         tunnel->net = dev_net(dev);
1254         strcpy(tunnel->parms.name, dev->name);
1255
1256         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1257         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1258
1259         if (ipv6_addr_any(&tunnel->parms.raddr))
1260                 dev->header_ops = &ip6gre_header_ops;
1261
1262         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1263         if (!dev->tstats)
1264                 return -ENOMEM;
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) {
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                                           NET_NAME_UNKNOWN,
1327                                           ip6gre_tunnel_setup);
1328         if (!ign->fb_tunnel_dev) {
1329                 err = -ENOMEM;
1330                 goto err_alloc_dev;
1331         }
1332         dev_net_set(ign->fb_tunnel_dev, net);
1333         /* FB netdevice is special: we have one, and only one per netns.
1334          * Allowing to move it to another netns is clearly unsafe.
1335          */
1336         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1337
1338
1339         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1340         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1341
1342         err = register_netdev(ign->fb_tunnel_dev);
1343         if (err)
1344                 goto err_reg_dev;
1345
1346         rcu_assign_pointer(ign->tunnels_wc[0],
1347                            netdev_priv(ign->fb_tunnel_dev));
1348         return 0;
1349
1350 err_reg_dev:
1351         ip6gre_dev_free(ign->fb_tunnel_dev);
1352 err_alloc_dev:
1353         return err;
1354 }
1355
1356 static void __net_exit ip6gre_exit_net(struct net *net)
1357 {
1358         LIST_HEAD(list);
1359
1360         rtnl_lock();
1361         ip6gre_destroy_tunnels(net, &list);
1362         unregister_netdevice_many(&list);
1363         rtnl_unlock();
1364 }
1365
1366 static struct pernet_operations ip6gre_net_ops = {
1367         .init = ip6gre_init_net,
1368         .exit = ip6gre_exit_net,
1369         .id   = &ip6gre_net_id,
1370         .size = sizeof(struct ip6gre_net),
1371 };
1372
1373 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1374 {
1375         __be16 flags;
1376
1377         if (!data)
1378                 return 0;
1379
1380         flags = 0;
1381         if (data[IFLA_GRE_IFLAGS])
1382                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1383         if (data[IFLA_GRE_OFLAGS])
1384                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1385         if (flags & (GRE_VERSION|GRE_ROUTING))
1386                 return -EINVAL;
1387
1388         return 0;
1389 }
1390
1391 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1392 {
1393         struct in6_addr daddr;
1394
1395         if (tb[IFLA_ADDRESS]) {
1396                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1397                         return -EINVAL;
1398                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1399                         return -EADDRNOTAVAIL;
1400         }
1401
1402         if (!data)
1403                 goto out;
1404
1405         if (data[IFLA_GRE_REMOTE]) {
1406                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1407                 if (ipv6_addr_any(&daddr))
1408                         return -EINVAL;
1409         }
1410
1411 out:
1412         return ip6gre_tunnel_validate(tb, data);
1413 }
1414
1415
1416 static void ip6gre_netlink_parms(struct nlattr *data[],
1417                                 struct __ip6_tnl_parm *parms)
1418 {
1419         memset(parms, 0, sizeof(*parms));
1420
1421         if (!data)
1422                 return;
1423
1424         if (data[IFLA_GRE_LINK])
1425                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1426
1427         if (data[IFLA_GRE_IFLAGS])
1428                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1429
1430         if (data[IFLA_GRE_OFLAGS])
1431                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1432
1433         if (data[IFLA_GRE_IKEY])
1434                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1435
1436         if (data[IFLA_GRE_OKEY])
1437                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1438
1439         if (data[IFLA_GRE_LOCAL])
1440                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1441
1442         if (data[IFLA_GRE_REMOTE])
1443                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1444
1445         if (data[IFLA_GRE_TTL])
1446                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1447
1448         if (data[IFLA_GRE_ENCAP_LIMIT])
1449                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1450
1451         if (data[IFLA_GRE_FLOWINFO])
1452                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1453
1454         if (data[IFLA_GRE_FLAGS])
1455                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1456 }
1457
1458 static int ip6gre_tap_init(struct net_device *dev)
1459 {
1460         struct ip6_tnl *tunnel;
1461
1462         tunnel = netdev_priv(dev);
1463
1464         tunnel->dev = dev;
1465         tunnel->net = dev_net(dev);
1466         strcpy(tunnel->parms.name, dev->name);
1467
1468         ip6gre_tnl_link_config(tunnel, 1);
1469
1470         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1471         if (!dev->tstats)
1472                 return -ENOMEM;
1473
1474         return 0;
1475 }
1476
1477 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1478         .ndo_init = ip6gre_tap_init,
1479         .ndo_uninit = ip6gre_tunnel_uninit,
1480         .ndo_start_xmit = ip6gre_tunnel_xmit,
1481         .ndo_set_mac_address = eth_mac_addr,
1482         .ndo_validate_addr = eth_validate_addr,
1483         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1484         .ndo_get_stats64 = ip_tunnel_get_stats64,
1485         .ndo_get_iflink = ip6_tnl_get_iflink,
1486 };
1487
1488 static void ip6gre_tap_setup(struct net_device *dev)
1489 {
1490
1491         ether_setup(dev);
1492
1493         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1494         dev->destructor = ip6gre_dev_free;
1495
1496         dev->features |= NETIF_F_NETNS_LOCAL;
1497 }
1498
1499 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1500         struct nlattr *tb[], struct nlattr *data[])
1501 {
1502         struct ip6_tnl *nt;
1503         struct net *net = dev_net(dev);
1504         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1505         int err;
1506
1507         nt = netdev_priv(dev);
1508         ip6gre_netlink_parms(data, &nt->parms);
1509
1510         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1511                 return -EEXIST;
1512
1513         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1514                 eth_hw_addr_random(dev);
1515
1516         nt->dev = dev;
1517         nt->net = dev_net(dev);
1518         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1519
1520         /* Can use a lockless transmit, unless we generate output sequences */
1521         if (!(nt->parms.o_flags & GRE_SEQ))
1522                 dev->features |= NETIF_F_LLTX;
1523
1524         err = register_netdevice(dev);
1525         if (err)
1526                 goto out;
1527
1528         dev_hold(dev);
1529         ip6gre_tunnel_link(ign, nt);
1530
1531 out:
1532         return err;
1533 }
1534
1535 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1536                             struct nlattr *data[])
1537 {
1538         struct ip6_tnl *t, *nt = netdev_priv(dev);
1539         struct net *net = nt->net;
1540         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1541         struct __ip6_tnl_parm p;
1542
1543         if (dev == ign->fb_tunnel_dev)
1544                 return -EINVAL;
1545
1546         ip6gre_netlink_parms(data, &p);
1547
1548         t = ip6gre_tunnel_locate(net, &p, 0);
1549
1550         if (t) {
1551                 if (t->dev != dev)
1552                         return -EEXIST;
1553         } else {
1554                 t = nt;
1555
1556                 ip6gre_tunnel_unlink(ign, t);
1557                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1558                 ip6gre_tunnel_link(ign, t);
1559                 netdev_state_change(dev);
1560         }
1561
1562         return 0;
1563 }
1564
1565 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1566 {
1567         struct net *net = dev_net(dev);
1568         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1569
1570         if (dev != ign->fb_tunnel_dev)
1571                 unregister_netdevice_queue(dev, head);
1572 }
1573
1574 static size_t ip6gre_get_size(const struct net_device *dev)
1575 {
1576         return
1577                 /* IFLA_GRE_LINK */
1578                 nla_total_size(4) +
1579                 /* IFLA_GRE_IFLAGS */
1580                 nla_total_size(2) +
1581                 /* IFLA_GRE_OFLAGS */
1582                 nla_total_size(2) +
1583                 /* IFLA_GRE_IKEY */
1584                 nla_total_size(4) +
1585                 /* IFLA_GRE_OKEY */
1586                 nla_total_size(4) +
1587                 /* IFLA_GRE_LOCAL */
1588                 nla_total_size(sizeof(struct in6_addr)) +
1589                 /* IFLA_GRE_REMOTE */
1590                 nla_total_size(sizeof(struct in6_addr)) +
1591                 /* IFLA_GRE_TTL */
1592                 nla_total_size(1) +
1593                 /* IFLA_GRE_TOS */
1594                 nla_total_size(1) +
1595                 /* IFLA_GRE_ENCAP_LIMIT */
1596                 nla_total_size(1) +
1597                 /* IFLA_GRE_FLOWINFO */
1598                 nla_total_size(4) +
1599                 /* IFLA_GRE_FLAGS */
1600                 nla_total_size(4) +
1601                 0;
1602 }
1603
1604 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1605 {
1606         struct ip6_tnl *t = netdev_priv(dev);
1607         struct __ip6_tnl_parm *p = &t->parms;
1608
1609         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1610             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1611             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1612             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1613             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1614             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1615             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1616             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1617             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1618             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1619             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1620             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1621                 goto nla_put_failure;
1622         return 0;
1623
1624 nla_put_failure:
1625         return -EMSGSIZE;
1626 }
1627
1628 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1629         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1630         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1631         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1632         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1633         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1634         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1635         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1636         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1637         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1638         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1639         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1640 };
1641
1642 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1643         .kind           = "ip6gre",
1644         .maxtype        = IFLA_GRE_MAX,
1645         .policy         = ip6gre_policy,
1646         .priv_size      = sizeof(struct ip6_tnl),
1647         .setup          = ip6gre_tunnel_setup,
1648         .validate       = ip6gre_tunnel_validate,
1649         .newlink        = ip6gre_newlink,
1650         .changelink     = ip6gre_changelink,
1651         .dellink        = ip6gre_dellink,
1652         .get_size       = ip6gre_get_size,
1653         .fill_info      = ip6gre_fill_info,
1654         .get_link_net   = ip6_tnl_get_link_net,
1655 };
1656
1657 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1658         .kind           = "ip6gretap",
1659         .maxtype        = IFLA_GRE_MAX,
1660         .policy         = ip6gre_policy,
1661         .priv_size      = sizeof(struct ip6_tnl),
1662         .setup          = ip6gre_tap_setup,
1663         .validate       = ip6gre_tap_validate,
1664         .newlink        = ip6gre_newlink,
1665         .changelink     = ip6gre_changelink,
1666         .get_size       = ip6gre_get_size,
1667         .fill_info      = ip6gre_fill_info,
1668         .get_link_net   = ip6_tnl_get_link_net,
1669 };
1670
1671 /*
1672  *      And now the modules code and kernel interface.
1673  */
1674
1675 static int __init ip6gre_init(void)
1676 {
1677         int err;
1678
1679         pr_info("GRE over IPv6 tunneling driver\n");
1680
1681         err = register_pernet_device(&ip6gre_net_ops);
1682         if (err < 0)
1683                 return err;
1684
1685         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1686         if (err < 0) {
1687                 pr_info("%s: can't add protocol\n", __func__);
1688                 goto add_proto_failed;
1689         }
1690
1691         err = rtnl_link_register(&ip6gre_link_ops);
1692         if (err < 0)
1693                 goto rtnl_link_failed;
1694
1695         err = rtnl_link_register(&ip6gre_tap_ops);
1696         if (err < 0)
1697                 goto tap_ops_failed;
1698
1699 out:
1700         return err;
1701
1702 tap_ops_failed:
1703         rtnl_link_unregister(&ip6gre_link_ops);
1704 rtnl_link_failed:
1705         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1706 add_proto_failed:
1707         unregister_pernet_device(&ip6gre_net_ops);
1708         goto out;
1709 }
1710
1711 static void __exit ip6gre_fini(void)
1712 {
1713         rtnl_link_unregister(&ip6gre_tap_ops);
1714         rtnl_link_unregister(&ip6gre_link_ops);
1715         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1716         unregister_pernet_device(&ip6gre_net_ops);
1717 }
1718
1719 module_init(ip6gre_init);
1720 module_exit(ip6gre_fini);
1721 MODULE_LICENSE("GPL");
1722 MODULE_AUTHOR("D. Kozlov ([email protected])");
1723 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1724 MODULE_ALIAS_RTNL_LINK("ip6gre");
1725 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1726 MODULE_ALIAS_NETDEV("ip6gre0");