net/ipv6/ip6_gre.c

   1 /*
   2  *      GRE over IPv6 protocol decoder.
   3  *
   4  *      Authors: Dmitry Kozlov (xeb@mail.ru)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/capability.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/slab.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/in.h>
  24 #include <linux/tcp.h>
  25 #include <linux/udp.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/mroute.h>
  28 #include <linux/init.h>
  29 #include <linux/in6.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/igmp.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/etherdevice.h>
  34 #include <linux/if_ether.h>
  35 #include <linux/hash.h>
  36 #include <linux/if_tunnel.h>
  37 #include <linux/ip6_tunnel.h>
  38
  39 #include <net/sock.h>
  40 #include <net/ip.h>
  41 #include <net/ip_tunnels.h>
  42 #include <net/icmp.h>
  43 #include <net/protocol.h>
  44 #include <net/addrconf.h>
  45 #include <net/arp.h>
  46 #include <net/checksum.h>
  47 #include <net/dsfield.h>
  48 #include <net/inet_ecn.h>
  49 #include <net/xfrm.h>
  50 #include <net/net_namespace.h>
  51 #include <net/netns/generic.h>
  52 #include <net/rtnetlink.h>
  53
  54 #include <net/ipv6.h>
  55 #include <net/ip6_fib.h>
  56 #include <net/ip6_route.h>
  57 #include <net/ip6_tunnel.h>
  58
  59
  60 static bool log_ecn_error = true;
  61 module_param(log_ecn_error, bool, 0644);
  62 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  63
  64 #define HASH_SIZE_SHIFT  5
  65 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  66
  67 static int ip6gre_net_id __read_mostly;
  68 struct ip6gre_net {
  69         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  70
  71         struct net_device *fb_tunnel_dev;
  72 };
  73
  74 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  75 static int ip6gre_tunnel_init(struct net_device *dev);
  76 static void ip6gre_tunnel_setup(struct net_device *dev);
  77 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  78 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  79
  80 /* Tunnel hash table */
  81
  82 /*
  83    4 hash tables:
  84
  85    3: (remote,local)
  86    2: (remote,*)
  87    1: (*,local)
  88    0: (*,*)
  89
  90    We require exact key match i.e. if a key is present in packet
  91    it will match only tunnel with the same key; if it is not present,
  92    it will match only keyless tunnel.
  93
  94    All keysless packets, if not matched configured keyless tunnels
  95    will match fallback tunnel.
  96  */
  97
  98 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
  99 static u32 HASH_ADDR(const struct in6_addr *addr)
 100 {
 101         u32 hash = ipv6_addr_hash(addr);
 102
 103         return hash_32(hash, HASH_SIZE_SHIFT);
 104 }
 105
 106 #define tunnels_r_l     tunnels[3]
 107 #define tunnels_r       tunnels[2]
 108 #define tunnels_l       tunnels[1]
 109 #define tunnels_wc      tunnels[0]
 110
 111 /* Given src, dst and key, find appropriate for input tunnel. */
 112
 113 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 114                 const struct in6_addr *remote, const struct in6_addr *local,
 115                 __be32 key, __be16 gre_proto)
 116 {
 117         struct net *net = dev_net(dev);
 118         int link = dev->ifindex;
 119         unsigned int h0 = HASH_ADDR(remote);
 120         unsigned int h1 = HASH_KEY(key);
 121         struct ip6_tnl *t, *cand = NULL;
 122         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 123         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 124                        ARPHRD_ETHER : ARPHRD_IP6GRE;
 125         int score, cand_score = 4;
 126
 127         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 128                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 129                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 130                     key != t->parms.i_key ||
 131                     !(t->dev->flags & IFF_UP))
 132                         continue;
 133
 134                 if (t->dev->type != ARPHRD_IP6GRE &&
 135                     t->dev->type != dev_type)
 136                         continue;
 137
 138                 score = 0;
 139                 if (t->parms.link != link)
 140                         score |= 1;
 141                 if (t->dev->type != dev_type)
 142                         score |= 2;
 143                 if (score == 0)
 144                         return t;
 145
 146                 if (score < cand_score) {
 147                         cand = t;
 148                         cand_score = score;
 149                 }
 150         }
 151
 152         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 153                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 154                     key != t->parms.i_key ||
 155                     !(t->dev->flags & IFF_UP))
 156                         continue;
 157
 158                 if (t->dev->type != ARPHRD_IP6GRE &&
 159                     t->dev->type != dev_type)
 160                         continue;
 161
 162                 score = 0;
 163                 if (t->parms.link != link)
 164                         score |= 1;
 165                 if (t->dev->type != dev_type)
 166                         score |= 2;
 167                 if (score == 0)
 168                         return t;
 169
 170                 if (score < cand_score) {
 171                         cand = t;
 172                         cand_score = score;
 173                 }
 174         }
 175
 176         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 177                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 178                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
 179                                  !ipv6_addr_is_multicast(local))) ||
 180                     key != t->parms.i_key ||
 181                     !(t->dev->flags & IFF_UP))
 182                         continue;
 183
 184                 if (t->dev->type != ARPHRD_IP6GRE &&
 185                     t->dev->type != dev_type)
 186                         continue;
 187
 188                 score = 0;
 189                 if (t->parms.link != link)
 190                         score |= 1;
 191                 if (t->dev->type != dev_type)
 192                         score |= 2;
 193                 if (score == 0)
 194                         return t;
 195
 196                 if (score < cand_score) {
 197                         cand = t;
 198                         cand_score = score;
 199                 }
 200         }
 201
 202         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 203                 if (t->parms.i_key != key ||
 204                     !(t->dev->flags & IFF_UP))
 205                         continue;
 206
 207                 if (t->dev->type != ARPHRD_IP6GRE &&
 208                     t->dev->type != dev_type)
 209                         continue;
 210
 211                 score = 0;
 212                 if (t->parms.link != link)
 213                         score |= 1;
 214                 if (t->dev->type != dev_type)
 215                         score |= 2;
 216                 if (score == 0)
 217                         return t;
 218
 219                 if (score < cand_score) {
 220                         cand = t;
 221                         cand_score = score;
 222                 }
 223         }
 224
 225         if (cand != NULL)
 226                 return cand;
 227
 228         dev = ign->fb_tunnel_dev;
 229         if (dev->flags & IFF_UP)
 230                 return netdev_priv(dev);
 231
 232         return NULL;
 233 }
 234
 235 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 236                 const struct __ip6_tnl_parm *p)
 237 {
 238         const struct in6_addr *remote = &p->raddr;
 239         const struct in6_addr *local = &p->laddr;
 240         unsigned int h = HASH_KEY(p->i_key);
 241         int prio = 0;
 242
 243         if (!ipv6_addr_any(local))
 244                 prio |= 1;
 245         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 246                 prio |= 2;
 247                 h ^= HASH_ADDR(remote);
 248         }
 249
 250         return &ign->tunnels[prio][h];
 251 }
 252
 253 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 254                 const struct ip6_tnl *t)
 255 {
 256         return __ip6gre_bucket(ign, &t->parms);
 257 }
 258
 259 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 260 {
 261         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 262
 263         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 264         rcu_assign_pointer(*tp, t);
 265 }
 266
 267 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 268 {
 269         struct ip6_tnl __rcu **tp;
 270         struct ip6_tnl *iter;
 271
 272         for (tp = ip6gre_bucket(ign, t);
 273              (iter = rtnl_dereference(*tp)) != NULL;
 274              tp = &iter->next) {
 275                 if (t == iter) {
 276                         rcu_assign_pointer(*tp, t->next);
 277                         break;
 278                 }
 279         }
 280 }
 281
 282 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 283                                            const struct __ip6_tnl_parm *parms,
 284                                            int type)
 285 {
 286         const struct in6_addr *remote = &parms->raddr;
 287         const struct in6_addr *local = &parms->laddr;
 288         __be32 key = parms->i_key;
 289         int link = parms->link;
 290         struct ip6_tnl *t;
 291         struct ip6_tnl __rcu **tp;
 292         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 293
 294         for (tp = __ip6gre_bucket(ign, parms);
 295              (t = rtnl_dereference(*tp)) != NULL;
 296              tp = &t->next)
 297                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 298                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 299                     key == t->parms.i_key &&
 300                     link == t->parms.link &&
 301                     type == t->dev->type)
 302                         break;
 303
 304         return t;
 305 }
 306
 307 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 308                 const struct __ip6_tnl_parm *parms, int create)
 309 {
 310         struct ip6_tnl *t, *nt;
 311         struct net_device *dev;
 312         char name[IFNAMSIZ];
 313         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 314
 315         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 316         if (t || !create)
 317                 return t;
 318
 319         if (parms->name[0])
 320                 strlcpy(name, parms->name, IFNAMSIZ);
 321         else
 322                 strcpy(name, "ip6gre%d");
 323
 324         dev = alloc_netdev(sizeof(*t), name, ip6gre_tunnel_setup);
 325         if (!dev)
 326                 return NULL;
 327
 328         dev_net_set(dev, net);
 329
 330         nt = netdev_priv(dev);
 331         nt->parms = *parms;
 332         dev->rtnl_link_ops = &ip6gre_link_ops;
 333
 334         nt->dev = dev;
 335         nt->net = dev_net(dev);
 336         ip6gre_tnl_link_config(nt, 1);
 337
 338         if (register_netdevice(dev) < 0)
 339                 goto failed_free;
 340
 341         /* Can use a lockless transmit, unless we generate output sequences */
 342         if (!(nt->parms.o_flags & GRE_SEQ))
 343                 dev->features |= NETIF_F_LLTX;
 344
 345         dev_hold(dev);
 346         ip6gre_tunnel_link(ign, nt);
 347         return nt;
 348
 349 failed_free:
 350         free_netdev(dev);
 351         return NULL;
 352 }
 353
 354 static void ip6gre_tunnel_uninit(struct net_device *dev)
 355 {
 356         struct net *net = dev_net(dev);
 357         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 358
 359         ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 360         dev_put(dev);
 361 }
 362
 363
 364 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 365                 u8 type, u8 code, int offset, __be32 info)
 366 {
 367         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 368         __be16 *p = (__be16 *)(skb->data + offset);
 369         int grehlen = offset + 4;
 370         struct ip6_tnl *t;
 371         __be16 flags;
 372
 373         flags = p[0];
 374         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 375                 if (flags&(GRE_VERSION|GRE_ROUTING))
 376                         return;
 377                 if (flags&GRE_KEY) {
 378                         grehlen += 4;
 379                         if (flags&GRE_CSUM)
 380                                 grehlen += 4;
 381                 }
 382         }
 383
 384         /* If only 8 bytes returned, keyed message will be dropped here */
 385         if (!pskb_may_pull(skb, grehlen))
 386                 return;
 387         ipv6h = (const struct ipv6hdr *)skb->data;
 388         p = (__be16 *)(skb->data + offset);
 389
 390         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 391                                 flags & GRE_KEY ?
 392                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 393                                 p[1]);
 394         if (t == NULL)
 395                 return;
 396
 397         switch (type) {
 398                 __u32 teli;
 399                 struct ipv6_tlv_tnl_enc_lim *tel;
 400                 __u32 mtu;
 401         case ICMPV6_DEST_UNREACH:
 402                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 403                                      t->parms.name);
 404                 break;
 405         case ICMPV6_TIME_EXCEED:
 406                 if (code == ICMPV6_EXC_HOPLIMIT) {
 407                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 408                                              t->parms.name);
 409                 }
 410                 break;
 411         case ICMPV6_PARAMPROB:
 412                 teli = 0;
 413                 if (code == ICMPV6_HDR_FIELD)
 414                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 415
 416                 if (teli && teli == info - 2) {
 417                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 418                         if (tel->encap_limit == 0) {
 419                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 420                                                      t->parms.name);
 421                         }
 422                 } else {
 423                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 424                                              t->parms.name);
 425                 }
 426                 break;
 427         case ICMPV6_PKT_TOOBIG:
 428                 mtu = info - offset;
 429                 if (mtu < IPV6_MIN_MTU)
 430                         mtu = IPV6_MIN_MTU;
 431                 t->dev->mtu = mtu;
 432                 break;
 433         }
 434
 435         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 436                 t->err_count++;
 437         else
 438                 t->err_count = 1;
 439         t->err_time = jiffies;
 440 }
 441
 442 static int ip6gre_rcv(struct sk_buff *skb)
 443 {
 444         const struct ipv6hdr *ipv6h;
 445         u8     *h;
 446         __be16    flags;
 447         __sum16   csum = 0;
 448         __be32 key = 0;
 449         u32    seqno = 0;
 450         struct ip6_tnl *tunnel;
 451         int    offset = 4;
 452         __be16 gre_proto;
 453         int err;
 454
 455         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 456                 goto drop;
 457
 458         ipv6h = ipv6_hdr(skb);
 459         h = skb->data;
 460         flags = *(__be16 *)h;
 461
 462         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 463                 /* - Version must be 0.
 464                    - We do not support routing headers.
 465                  */
 466                 if (flags&(GRE_VERSION|GRE_ROUTING))
 467                         goto drop;
 468
 469                 if (flags&GRE_CSUM) {
 470                         switch (skb->ip_summed) {
 471                         case CHECKSUM_COMPLETE:
 472                                 csum = csum_fold(skb->csum);
 473                                 if (!csum)
 474                                         break;
 475                                 /* fall through */
 476                         case CHECKSUM_NONE:
 477                                 skb->csum = 0;
 478                                 csum = __skb_checksum_complete(skb);
 479                                 skb->ip_summed = CHECKSUM_COMPLETE;
 480                         }
 481                         offset += 4;
 482                 }
 483                 if (flags&GRE_KEY) {
 484                         key = *(__be32 *)(h + offset);
 485                         offset += 4;
 486                 }
 487                 if (flags&GRE_SEQ) {
 488                         seqno = ntohl(*(__be32 *)(h + offset));
 489                         offset += 4;
 490                 }
 491         }
 492
 493         gre_proto = *(__be16 *)(h + 2);
 494
 495         tunnel = ip6gre_tunnel_lookup(skb->dev,
 496                                           &ipv6h->saddr, &ipv6h->daddr, key,
 497                                           gre_proto);
 498         if (tunnel) {
 499                 struct pcpu_sw_netstats *tstats;
 500
 501                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 502                         goto drop;
 503
 504                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 505                         tunnel->dev->stats.rx_dropped++;
 506                         goto drop;
 507                 }
 508
 509                 skb->protocol = gre_proto;
 510                 /* WCCP version 1 and 2 protocol decoding.
 511                  * - Change protocol to IP
 512                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 513                  */
 514                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 515                         skb->protocol = htons(ETH_P_IP);
 516                         if ((*(h + offset) & 0xF0) != 0x40)
 517                                 offset += 4;
 518                 }
 519
 520                 skb->mac_header = skb->network_header;
 521                 __pskb_pull(skb, offset);
 522                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 523
 524                 if (((flags&GRE_CSUM) && csum) ||
 525                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 526                         tunnel->dev->stats.rx_crc_errors++;
 527                         tunnel->dev->stats.rx_errors++;
 528                         goto drop;
 529                 }
 530                 if (tunnel->parms.i_flags&GRE_SEQ) {
 531                         if (!(flags&GRE_SEQ) ||
 532                             (tunnel->i_seqno &&
 533                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
 534                                 tunnel->dev->stats.rx_fifo_errors++;
 535                                 tunnel->dev->stats.rx_errors++;
 536                                 goto drop;
 537                         }
 538                         tunnel->i_seqno = seqno + 1;
 539                 }
 540
 541                 /* Warning: All skb pointers will be invalidated! */
 542                 if (tunnel->dev->type == ARPHRD_ETHER) {
 543                         if (!pskb_may_pull(skb, ETH_HLEN)) {
 544                                 tunnel->dev->stats.rx_length_errors++;
 545                                 tunnel->dev->stats.rx_errors++;
 546                                 goto drop;
 547                         }
 548
 549                         ipv6h = ipv6_hdr(skb);
 550                         skb->protocol = eth_type_trans(skb, tunnel->dev);
 551                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 552                 }
 553
 554                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 555
 556                 skb_reset_network_header(skb);
 557
 558                 err = IP6_ECN_decapsulate(ipv6h, skb);
 559                 if (unlikely(err)) {
 560                         if (log_ecn_error)
 561                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 562                                                      &ipv6h->saddr,
 563                                                      ipv6_get_dsfield(ipv6h));
 564                         if (err > 1) {
 565                                 ++tunnel->dev->stats.rx_frame_errors;
 566                                 ++tunnel->dev->stats.rx_errors;
 567                                 goto drop;
 568                         }
 569                 }
 570
 571                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 572                 u64_stats_update_begin(&tstats->syncp);
 573                 tstats->rx_packets++;
 574                 tstats->rx_bytes += skb->len;
 575                 u64_stats_update_end(&tstats->syncp);
 576
 577                 netif_rx(skb);
 578
 579                 return 0;
 580         }
 581         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 582
 583 drop:
 584         kfree_skb(skb);
 585         return 0;
 586 }
 587
 588 struct ipv6_tel_txoption {
 589         struct ipv6_txoptions ops;
 590         __u8 dst_opt[8];
 591 };
 592
 593 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 594 {
 595         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 596
 597         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 598         opt->dst_opt[3] = 1;
 599         opt->dst_opt[4] = encap_limit;
 600         opt->dst_opt[5] = IPV6_TLV_PADN;
 601         opt->dst_opt[6] = 1;
 602
 603         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 604         opt->ops.opt_nflen = 8;
 605 }
 606
 607 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 608                          struct net_device *dev,
 609                          __u8 dsfield,
 610                          struct flowi6 *fl6,
 611                          int encap_limit,
 612                          __u32 *pmtu)
 613 {
 614         struct net *net = dev_net(dev);
 615         struct ip6_tnl *tunnel = netdev_priv(dev);
 616         struct net_device *tdev;    /* Device to other host */
 617         struct ipv6hdr  *ipv6h;     /* Our new IP header */
 618         unsigned int max_headroom = 0; /* The extra header space needed */
 619         int    gre_hlen;
 620         struct ipv6_tel_txoption opt;
 621         int    mtu;
 622         struct dst_entry *dst = NULL, *ndst = NULL;
 623         struct net_device_stats *stats = &tunnel->dev->stats;
 624         int err = -1;
 625         u8 proto;
 626         struct sk_buff *new_skb;
 627
 628         if (dev->type == ARPHRD_ETHER)
 629                 IPCB(skb)->flags = 0;
 630
 631         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 632                 gre_hlen = 0;
 633                 ipv6h = (struct ipv6hdr *)skb->data;
 634                 fl6->daddr = ipv6h->daddr;
 635         } else {
 636                 gre_hlen = tunnel->hlen;
 637                 fl6->daddr = tunnel->parms.raddr;
 638         }
 639
 640         if (!fl6->flowi6_mark)
 641                 dst = ip6_tnl_dst_check(tunnel);
 642
 643         if (!dst) {
 644                 ndst = ip6_route_output(net, NULL, fl6);
 645
 646                 if (ndst->error)
 647                         goto tx_err_link_failure;
 648                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 649                 if (IS_ERR(ndst)) {
 650                         err = PTR_ERR(ndst);
 651                         ndst = NULL;
 652                         goto tx_err_link_failure;
 653                 }
 654                 dst = ndst;
 655         }
 656
 657         tdev = dst->dev;
 658
 659         if (tdev == dev) {
 660                 stats->collisions++;
 661                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 662                                      tunnel->parms.name);
 663                 goto tx_err_dst_release;
 664         }
 665
 666         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 667         if (encap_limit >= 0) {
 668                 max_headroom += 8;
 669                 mtu -= 8;
 670         }
 671         if (mtu < IPV6_MIN_MTU)
 672                 mtu = IPV6_MIN_MTU;
 673         if (skb_dst(skb))
 674                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 675         if (skb->len > mtu) {
 676                 *pmtu = mtu;
 677                 err = -EMSGSIZE;
 678                 goto tx_err_dst_release;
 679         }
 680
 681         if (tunnel->err_count > 0) {
 682                 if (time_before(jiffies,
 683                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 684                         tunnel->err_count--;
 685
 686                         dst_link_failure(skb);
 687                 } else
 688                         tunnel->err_count = 0;
 689         }
 690
 691         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 692
 693         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 694
 695         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 696             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 697                 new_skb = skb_realloc_headroom(skb, max_headroom);
 698                 if (max_headroom > dev->needed_headroom)
 699                         dev->needed_headroom = max_headroom;
 700                 if (!new_skb)
 701                         goto tx_err_dst_release;
 702
 703                 if (skb->sk)
 704                         skb_set_owner_w(new_skb, skb->sk);
 705                 consume_skb(skb);
 706                 skb = new_skb;
 707         }
 708
 709         if (fl6->flowi6_mark) {
 710                 skb_dst_set(skb, dst);
 711                 ndst = NULL;
 712         } else {
 713                 skb_dst_set_noref(skb, dst);
 714         }
 715
 716         proto = NEXTHDR_GRE;
 717         if (encap_limit >= 0) {
 718                 init_tel_txopt(&opt, encap_limit);
 719                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 720         }
 721
 722         if (likely(!skb->encapsulation)) {
 723                 skb_reset_inner_headers(skb);
 724                 skb->encapsulation = 1;
 725         }
 726
 727         skb_push(skb, gre_hlen);
 728         skb_reset_network_header(skb);
 729         skb_set_transport_header(skb, sizeof(*ipv6h));
 730
 731         /*
 732          *      Push down and install the IP header.
 733          */
 734         ipv6h = ipv6_hdr(skb);
 735         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 736         ipv6h->hop_limit = tunnel->parms.hop_limit;
 737         ipv6h->nexthdr = proto;
 738         ipv6h->saddr = fl6->saddr;
 739         ipv6h->daddr = fl6->daddr;
 740
 741         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 742         ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 743                                    htons(ETH_P_TEB) : skb->protocol;
 744
 745         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 746                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 747
 748                 if (tunnel->parms.o_flags&GRE_SEQ) {
 749                         ++tunnel->o_seqno;
 750                         *ptr = htonl(tunnel->o_seqno);
 751                         ptr--;
 752                 }
 753                 if (tunnel->parms.o_flags&GRE_KEY) {
 754                         *ptr = tunnel->parms.o_key;
 755                         ptr--;
 756                 }
 757                 if (tunnel->parms.o_flags&GRE_CSUM) {
 758                         *ptr = 0;
 759                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 760                                 skb->len - sizeof(struct ipv6hdr));
 761                 }
 762         }
 763
 764         ip6tunnel_xmit(skb, dev);
 765         if (ndst)
 766                 ip6_tnl_dst_store(tunnel, ndst);
 767         return 0;
 768 tx_err_link_failure:
 769         stats->tx_carrier_errors++;
 770         dst_link_failure(skb);
 771 tx_err_dst_release:
 772         dst_release(ndst);
 773         return err;
 774 }
 775
 776 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 777 {
 778         struct ip6_tnl *t = netdev_priv(dev);
 779         const struct iphdr  *iph = ip_hdr(skb);
 780         int encap_limit = -1;
 781         struct flowi6 fl6;
 782         __u8 dsfield;
 783         __u32 mtu;
 784         int err;
 785
 786         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 787                 encap_limit = t->parms.encap_limit;
 788
 789         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 790         fl6.flowi6_proto = IPPROTO_GRE;
 791
 792         dsfield = ipv4_get_dsfield(iph);
 793
 794         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 795                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 796                                           & IPV6_TCLASS_MASK;
 797         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 798                 fl6.flowi6_mark = skb->mark;
 799
 800         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 801         if (err != 0) {
 802                 /* XXX: send ICMP error even if DF is not set. */
 803                 if (err == -EMSGSIZE)
 804                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 805                                   htonl(mtu));
 806                 return -1;
 807         }
 808
 809         return 0;
 810 }
 811
 812 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 813 {
 814         struct ip6_tnl *t = netdev_priv(dev);
 815         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 816         int encap_limit = -1;
 817         __u16 offset;
 818         struct flowi6 fl6;
 819         __u8 dsfield;
 820         __u32 mtu;
 821         int err;
 822
 823         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 824                 return -1;
 825
 826         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 827         if (offset > 0) {
 828                 struct ipv6_tlv_tnl_enc_lim *tel;
 829                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 830                 if (tel->encap_limit == 0) {
 831                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 832                                     ICMPV6_HDR_FIELD, offset + 2);
 833                         return -1;
 834                 }
 835                 encap_limit = tel->encap_limit - 1;
 836         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 837                 encap_limit = t->parms.encap_limit;
 838
 839         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 840         fl6.flowi6_proto = IPPROTO_GRE;
 841
 842         dsfield = ipv6_get_dsfield(ipv6h);
 843         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 844                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 845         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 846                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 847         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 848                 fl6.flowi6_mark = skb->mark;
 849
 850         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 851         if (err != 0) {
 852                 if (err == -EMSGSIZE)
 853                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 854                 return -1;
 855         }
 856
 857         return 0;
 858 }
 859
 860 /**
 861  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 862  *   @t: the outgoing tunnel device
 863  *   @hdr: IPv6 header from the incoming packet
 864  *
 865  * Description:
 866  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 867  *   doesn't match source of incoming packet.
 868  *
 869  * Return:
 870  *   1 if conflict,
 871  *   0 else
 872  **/
 873
 874 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 875         const struct ipv6hdr *hdr)
 876 {
 877         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 878 }
 879
 880 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 881 {
 882         struct ip6_tnl *t = netdev_priv(dev);
 883         int encap_limit = -1;
 884         struct flowi6 fl6;
 885         __u32 mtu;
 886         int err;
 887
 888         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 889                 encap_limit = t->parms.encap_limit;
 890
 891         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 892         fl6.flowi6_proto = skb->protocol;
 893
 894         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 895
 896         return err;
 897 }
 898
 899 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 900         struct net_device *dev)
 901 {
 902         struct ip6_tnl *t = netdev_priv(dev);
 903         struct net_device_stats *stats = &t->dev->stats;
 904         int ret;
 905
 906         if (!ip6_tnl_xmit_ctl(t))
 907                 goto tx_err;
 908
 909         switch (skb->protocol) {
 910         case htons(ETH_P_IP):
 911                 ret = ip6gre_xmit_ipv4(skb, dev);
 912                 break;
 913         case htons(ETH_P_IPV6):
 914                 ret = ip6gre_xmit_ipv6(skb, dev);
 915                 break;
 916         default:
 917                 ret = ip6gre_xmit_other(skb, dev);
 918                 break;
 919         }
 920
 921         if (ret < 0)
 922                 goto tx_err;
 923
 924         return NETDEV_TX_OK;
 925
 926 tx_err:
 927         stats->tx_errors++;
 928         stats->tx_dropped++;
 929         kfree_skb(skb);
 930         return NETDEV_TX_OK;
 931 }
 932
 933 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 934 {
 935         struct net_device *dev = t->dev;
 936         struct __ip6_tnl_parm *p = &t->parms;
 937         struct flowi6 *fl6 = &t->fl.u.ip6;
 938         int addend = sizeof(struct ipv6hdr) + 4;
 939
 940         if (dev->type != ARPHRD_ETHER) {
 941                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 942                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 943         }
 944
 945         /* Set up flowi template */
 946         fl6->saddr = p->laddr;
 947         fl6->daddr = p->raddr;
 948         fl6->flowi6_oif = p->link;
 949         fl6->flowlabel = 0;
 950
 951         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 952                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 953         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 954                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 955
 956         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 957         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 958
 959         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 960                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 961                 dev->flags |= IFF_POINTOPOINT;
 962         else
 963                 dev->flags &= ~IFF_POINTOPOINT;
 964
 965         /* Precalculate GRE options length */
 966         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 967                 if (t->parms.o_flags&GRE_CSUM)
 968                         addend += 4;
 969                 if (t->parms.o_flags&GRE_KEY)
 970                         addend += 4;
 971                 if (t->parms.o_flags&GRE_SEQ)
 972                         addend += 4;
 973         }
 974         t->hlen = addend;
 975
 976         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 977                 int strict = (ipv6_addr_type(&p->raddr) &
 978                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 979
 980                 struct rt6_info *rt = rt6_lookup(dev_net(dev),
 981                                                  &p->raddr, &p->laddr,
 982                                                  p->link, strict);
 983
 984                 if (rt == NULL)
 985                         return;
 986
 987                 if (rt->dst.dev) {
 988                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 989
 990                         if (set_mtu) {
 991                                 dev->mtu = rt->dst.dev->mtu - addend;
 992                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 993                                         dev->mtu -= 8;
 994
 995                                 if (dev->mtu < IPV6_MIN_MTU)
 996                                         dev->mtu = IPV6_MIN_MTU;
 997                         }
 998                 }
 999                 ip6_rt_put(rt);
1000         }
1001 }
1002
1003 static int ip6gre_tnl_change(struct ip6_tnl *t,
1004         const struct __ip6_tnl_parm *p, int set_mtu)
1005 {
1006         t->parms.laddr = p->laddr;
1007         t->parms.raddr = p->raddr;
1008         t->parms.flags = p->flags;
1009         t->parms.hop_limit = p->hop_limit;
1010         t->parms.encap_limit = p->encap_limit;
1011         t->parms.flowinfo = p->flowinfo;
1012         t->parms.link = p->link;
1013         t->parms.proto = p->proto;
1014         t->parms.i_key = p->i_key;
1015         t->parms.o_key = p->o_key;
1016         t->parms.i_flags = p->i_flags;
1017         t->parms.o_flags = p->o_flags;
1018         ip6_tnl_dst_reset(t);
1019         ip6gre_tnl_link_config(t, set_mtu);
1020         return 0;
1021 }
1022
1023 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1024         const struct ip6_tnl_parm2 *u)
1025 {
1026         p->laddr = u->laddr;
1027         p->raddr = u->raddr;
1028         p->flags = u->flags;
1029         p->hop_limit = u->hop_limit;
1030         p->encap_limit = u->encap_limit;
1031         p->flowinfo = u->flowinfo;
1032         p->link = u->link;
1033         p->i_key = u->i_key;
1034         p->o_key = u->o_key;
1035         p->i_flags = u->i_flags;
1036         p->o_flags = u->o_flags;
1037         memcpy(p->name, u->name, sizeof(u->name));
1038 }
1039
1040 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1041         const struct __ip6_tnl_parm *p)
1042 {
1043         u->proto = IPPROTO_GRE;
1044         u->laddr = p->laddr;
1045         u->raddr = p->raddr;
1046         u->flags = p->flags;
1047         u->hop_limit = p->hop_limit;
1048         u->encap_limit = p->encap_limit;
1049         u->flowinfo = p->flowinfo;
1050         u->link = p->link;
1051         u->i_key = p->i_key;
1052         u->o_key = p->o_key;
1053         u->i_flags = p->i_flags;
1054         u->o_flags = p->o_flags;
1055         memcpy(u->name, p->name, sizeof(u->name));
1056 }
1057
1058 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1059         struct ifreq *ifr, int cmd)
1060 {
1061         int err = 0;
1062         struct ip6_tnl_parm2 p;
1063         struct __ip6_tnl_parm p1;
1064         struct ip6_tnl *t;
1065         struct net *net = dev_net(dev);
1066         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1067
1068         switch (cmd) {
1069         case SIOCGETTUNNEL:
1070                 t = NULL;
1071                 if (dev == ign->fb_tunnel_dev) {
1072                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1073                                 err = -EFAULT;
1074                                 break;
1075                         }
1076                         ip6gre_tnl_parm_from_user(&p1, &p);
1077                         t = ip6gre_tunnel_locate(net, &p1, 0);
1078                 }
1079                 if (t == NULL)
1080                         t = netdev_priv(dev);
1081                 memset(&p, 0, sizeof(p));
1082                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1083                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1084                         err = -EFAULT;
1085                 break;
1086
1087         case SIOCADDTUNNEL:
1088         case SIOCCHGTUNNEL:
1089                 err = -EPERM;
1090                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1091                         goto done;
1092
1093                 err = -EFAULT;
1094                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1095                         goto done;
1096
1097                 err = -EINVAL;
1098                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1099                         goto done;
1100
1101                 if (!(p.i_flags&GRE_KEY))
1102                         p.i_key = 0;
1103                 if (!(p.o_flags&GRE_KEY))
1104                         p.o_key = 0;
1105
1106                 ip6gre_tnl_parm_from_user(&p1, &p);
1107                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1108
1109                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1110                         if (t != NULL) {
1111                                 if (t->dev != dev) {
1112                                         err = -EEXIST;
1113                                         break;
1114                                 }
1115                         } else {
1116                                 t = netdev_priv(dev);
1117
1118                                 ip6gre_tunnel_unlink(ign, t);
1119                                 synchronize_net();
1120                                 ip6gre_tnl_change(t, &p1, 1);
1121                                 ip6gre_tunnel_link(ign, t);
1122                                 netdev_state_change(dev);
1123                         }
1124                 }
1125
1126                 if (t) {
1127                         err = 0;
1128
1129                         memset(&p, 0, sizeof(p));
1130                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1131                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1132                                 err = -EFAULT;
1133                 } else
1134                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1135                 break;
1136
1137         case SIOCDELTUNNEL:
1138                 err = -EPERM;
1139                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1140                         goto done;
1141
1142                 if (dev == ign->fb_tunnel_dev) {
1143                         err = -EFAULT;
1144                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1145                                 goto done;
1146                         err = -ENOENT;
1147                         ip6gre_tnl_parm_from_user(&p1, &p);
1148                         t = ip6gre_tunnel_locate(net, &p1, 0);
1149                         if (t == NULL)
1150                                 goto done;
1151                         err = -EPERM;
1152                         if (t == netdev_priv(ign->fb_tunnel_dev))
1153                                 goto done;
1154                         dev = t->dev;
1155                 }
1156                 unregister_netdevice(dev);
1157                 err = 0;
1158                 break;
1159
1160         default:
1161                 err = -EINVAL;
1162         }
1163
1164 done:
1165         return err;
1166 }
1167
1168 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1169 {
1170         if (new_mtu < 68 ||
1171             new_mtu > 0xFFF8 - dev->hard_header_len)
1172                 return -EINVAL;
1173         dev->mtu = new_mtu;
1174         return 0;
1175 }
1176
1177 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1178                         unsigned short type,
1179                         const void *daddr, const void *saddr, unsigned int len)
1180 {
1181         struct ip6_tnl *t = netdev_priv(dev);
1182         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1183         __be16 *p = (__be16 *)(ipv6h+1);
1184
1185         ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
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 };
1220
1221 static void ip6gre_dev_free(struct net_device *dev)
1222 {
1223         free_percpu(dev->tstats);
1224         free_netdev(dev);
1225 }
1226
1227 static void ip6gre_tunnel_setup(struct net_device *dev)
1228 {
1229         struct ip6_tnl *t;
1230
1231         dev->netdev_ops = &ip6gre_netdev_ops;
1232         dev->destructor = ip6gre_dev_free;
1233
1234         dev->type = ARPHRD_IP6GRE;
1235         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1236         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1237         t = netdev_priv(dev);
1238         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1239                 dev->mtu -= 8;
1240         dev->flags |= IFF_NOARP;
1241         dev->iflink = 0;
1242         dev->addr_len = sizeof(struct in6_addr);
1243         dev->features |= NETIF_F_NETNS_LOCAL;
1244         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1245 }
1246
1247 static int ip6gre_tunnel_init(struct net_device *dev)
1248 {
1249         struct ip6_tnl *tunnel;
1250         int i;
1251
1252         tunnel = netdev_priv(dev);
1253
1254         tunnel->dev = dev;
1255         tunnel->net = dev_net(dev);
1256         strcpy(tunnel->parms.name, dev->name);
1257
1258         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1259         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1260
1261         if (ipv6_addr_any(&tunnel->parms.raddr))
1262                 dev->header_ops = &ip6gre_header_ops;
1263
1264         dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1265         if (!dev->tstats)
1266                 return -ENOMEM;
1267
1268         for_each_possible_cpu(i) {
1269                 struct pcpu_sw_netstats *ip6gre_tunnel_stats;
1270                 ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1271                 u64_stats_init(&ip6gre_tunnel_stats->syncp);
1272         }
1273
1274         dev->iflink = tunnel->parms.link;
1275
1276         return 0;
1277 }
1278
1279 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1280 {
1281         struct ip6_tnl *tunnel = netdev_priv(dev);
1282
1283         tunnel->dev = dev;
1284         tunnel->net = dev_net(dev);
1285         strcpy(tunnel->parms.name, dev->name);
1286
1287         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1288
1289         dev_hold(dev);
1290 }
1291
1292
1293 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1294         .handler     = ip6gre_rcv,
1295         .err_handler = ip6gre_err,
1296         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1297 };
1298
1299 static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1300         struct list_head *head)
1301 {
1302         int prio;
1303
1304         for (prio = 0; prio < 4; prio++) {
1305                 int h;
1306                 for (h = 0; h < HASH_SIZE; h++) {
1307                         struct ip6_tnl *t;
1308
1309                         t = rtnl_dereference(ign->tunnels[prio][h]);
1310
1311                         while (t != NULL) {
1312                                 unregister_netdevice_queue(t->dev, head);
1313                                 t = rtnl_dereference(t->next);
1314                         }
1315                 }
1316         }
1317 }
1318
1319 static int __net_init ip6gre_init_net(struct net *net)
1320 {
1321         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1322         int err;
1323
1324         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1325                                            ip6gre_tunnel_setup);
1326         if (!ign->fb_tunnel_dev) {
1327                 err = -ENOMEM;
1328                 goto err_alloc_dev;
1329         }
1330         dev_net_set(ign->fb_tunnel_dev, net);
1331
1332         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1333         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1334
1335         err = register_netdev(ign->fb_tunnel_dev);
1336         if (err)
1337                 goto err_reg_dev;
1338
1339         rcu_assign_pointer(ign->tunnels_wc[0],
1340                            netdev_priv(ign->fb_tunnel_dev));
1341         return 0;
1342
1343 err_reg_dev:
1344         ip6gre_dev_free(ign->fb_tunnel_dev);
1345 err_alloc_dev:
1346         return err;
1347 }
1348
1349 static void __net_exit ip6gre_exit_net(struct net *net)
1350 {
1351         struct ip6gre_net *ign;
1352         LIST_HEAD(list);
1353
1354         ign = net_generic(net, ip6gre_net_id);
1355         rtnl_lock();
1356         ip6gre_destroy_tunnels(ign, &list);
1357         unregister_netdevice_many(&list);
1358         rtnl_unlock();
1359 }
1360
1361 static struct pernet_operations ip6gre_net_ops = {
1362         .init = ip6gre_init_net,
1363         .exit = ip6gre_exit_net,
1364         .id   = &ip6gre_net_id,
1365         .size = sizeof(struct ip6gre_net),
1366 };
1367
1368 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1369 {
1370         __be16 flags;
1371
1372         if (!data)
1373                 return 0;
1374
1375         flags = 0;
1376         if (data[IFLA_GRE_IFLAGS])
1377                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1378         if (data[IFLA_GRE_OFLAGS])
1379                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1380         if (flags & (GRE_VERSION|GRE_ROUTING))
1381                 return -EINVAL;
1382
1383         return 0;
1384 }
1385
1386 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1387 {
1388         struct in6_addr daddr;
1389
1390         if (tb[IFLA_ADDRESS]) {
1391                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1392                         return -EINVAL;
1393                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1394                         return -EADDRNOTAVAIL;
1395         }
1396
1397         if (!data)
1398                 goto out;
1399
1400         if (data[IFLA_GRE_REMOTE]) {
1401                 nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1402                 if (ipv6_addr_any(&daddr))
1403                         return -EINVAL;
1404         }
1405
1406 out:
1407         return ip6gre_tunnel_validate(tb, data);
1408 }
1409
1410
1411 static void ip6gre_netlink_parms(struct nlattr *data[],
1412                                 struct __ip6_tnl_parm *parms)
1413 {
1414         memset(parms, 0, sizeof(*parms));
1415
1416         if (!data)
1417                 return;
1418
1419         if (data[IFLA_GRE_LINK])
1420                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1421
1422         if (data[IFLA_GRE_IFLAGS])
1423                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1424
1425         if (data[IFLA_GRE_OFLAGS])
1426                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1427
1428         if (data[IFLA_GRE_IKEY])
1429                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1430
1431         if (data[IFLA_GRE_OKEY])
1432                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1433
1434         if (data[IFLA_GRE_LOCAL])
1435                 nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1436
1437         if (data[IFLA_GRE_REMOTE])
1438                 nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1439
1440         if (data[IFLA_GRE_TTL])
1441                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1442
1443         if (data[IFLA_GRE_ENCAP_LIMIT])
1444                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1445
1446         if (data[IFLA_GRE_FLOWINFO])
1447                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1448
1449         if (data[IFLA_GRE_FLAGS])
1450                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1451 }
1452
1453 static int ip6gre_tap_init(struct net_device *dev)
1454 {
1455         struct ip6_tnl *tunnel;
1456         int i;
1457
1458         tunnel = netdev_priv(dev);
1459
1460         tunnel->dev = dev;
1461         tunnel->net = dev_net(dev);
1462         strcpy(tunnel->parms.name, dev->name);
1463
1464         ip6gre_tnl_link_config(tunnel, 1);
1465
1466         dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1467         if (!dev->tstats)
1468                 return -ENOMEM;
1469
1470         for_each_possible_cpu(i) {
1471                 struct pcpu_sw_netstats *ip6gre_tap_stats;
1472                 ip6gre_tap_stats = per_cpu_ptr(dev->tstats, i);
1473                 u64_stats_init(&ip6gre_tap_stats->syncp);
1474         }
1475
1476         dev->iflink = tunnel->parms.link;
1477
1478         return 0;
1479 }
1480
1481 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1482         .ndo_init = ip6gre_tap_init,
1483         .ndo_uninit = ip6gre_tunnel_uninit,
1484         .ndo_start_xmit = ip6gre_tunnel_xmit,
1485         .ndo_set_mac_address = eth_mac_addr,
1486         .ndo_validate_addr = eth_validate_addr,
1487         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1488         .ndo_get_stats64 = ip_tunnel_get_stats64,
1489 };
1490
1491 static void ip6gre_tap_setup(struct net_device *dev)
1492 {
1493
1494         ether_setup(dev);
1495
1496         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1497         dev->destructor = ip6gre_dev_free;
1498
1499         dev->iflink = 0;
1500         dev->features |= NETIF_F_NETNS_LOCAL;
1501 }
1502
1503 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1504         struct nlattr *tb[], struct nlattr *data[])
1505 {
1506         struct ip6_tnl *nt;
1507         struct net *net = dev_net(dev);
1508         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1509         int err;
1510
1511         nt = netdev_priv(dev);
1512         ip6gre_netlink_parms(data, &nt->parms);
1513
1514         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1515                 return -EEXIST;
1516
1517         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1518                 eth_hw_addr_random(dev);
1519
1520         nt->dev = dev;
1521         nt->net = dev_net(dev);
1522         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1523
1524         /* Can use a lockless transmit, unless we generate output sequences */
1525         if (!(nt->parms.o_flags & GRE_SEQ))
1526                 dev->features |= NETIF_F_LLTX;
1527
1528         err = register_netdevice(dev);
1529         if (err)
1530                 goto out;
1531
1532         dev_hold(dev);
1533         ip6gre_tunnel_link(ign, nt);
1534
1535 out:
1536         return err;
1537 }
1538
1539 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1540                             struct nlattr *data[])
1541 {
1542         struct ip6_tnl *t, *nt;
1543         struct net *net = dev_net(dev);
1544         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1545         struct __ip6_tnl_parm p;
1546
1547         if (dev == ign->fb_tunnel_dev)
1548                 return -EINVAL;
1549
1550         nt = netdev_priv(dev);
1551         ip6gre_netlink_parms(data, &p);
1552
1553         t = ip6gre_tunnel_locate(net, &p, 0);
1554
1555         if (t) {
1556                 if (t->dev != dev)
1557                         return -EEXIST;
1558         } else {
1559                 t = nt;
1560
1561                 ip6gre_tunnel_unlink(ign, t);
1562                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1563                 ip6gre_tunnel_link(ign, t);
1564                 netdev_state_change(dev);
1565         }
1566
1567         return 0;
1568 }
1569
1570 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1571 {
1572         struct net *net = dev_net(dev);
1573         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1574
1575         if (dev != ign->fb_tunnel_dev)
1576                 unregister_netdevice_queue(dev, head);
1577 }
1578
1579 static size_t ip6gre_get_size(const struct net_device *dev)
1580 {
1581         return
1582                 /* IFLA_GRE_LINK */
1583                 nla_total_size(4) +
1584                 /* IFLA_GRE_IFLAGS */
1585                 nla_total_size(2) +
1586                 /* IFLA_GRE_OFLAGS */
1587                 nla_total_size(2) +
1588                 /* IFLA_GRE_IKEY */
1589                 nla_total_size(4) +
1590                 /* IFLA_GRE_OKEY */
1591                 nla_total_size(4) +
1592                 /* IFLA_GRE_LOCAL */
1593                 nla_total_size(sizeof(struct in6_addr)) +
1594                 /* IFLA_GRE_REMOTE */
1595                 nla_total_size(sizeof(struct in6_addr)) +
1596                 /* IFLA_GRE_TTL */
1597                 nla_total_size(1) +
1598                 /* IFLA_GRE_TOS */
1599                 nla_total_size(1) +
1600                 /* IFLA_GRE_ENCAP_LIMIT */
1601                 nla_total_size(1) +
1602                 /* IFLA_GRE_FLOWINFO */
1603                 nla_total_size(4) +
1604                 /* IFLA_GRE_FLAGS */
1605                 nla_total_size(4) +
1606                 0;
1607 }
1608
1609 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1610 {
1611         struct ip6_tnl *t = netdev_priv(dev);
1612         struct __ip6_tnl_parm *p = &t->parms;
1613
1614         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1615             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1616             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1617             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1618             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1619             nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1620             nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1621             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1622             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1623             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1624             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1625             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1626                 goto nla_put_failure;
1627         return 0;
1628
1629 nla_put_failure:
1630         return -EMSGSIZE;
1631 }
1632
1633 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1634         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1635         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1636         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1637         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1638         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1639         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1640         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1641         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1642         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1643         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1644         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1645 };
1646
1647 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1648         .kind           = "ip6gre",
1649         .maxtype        = IFLA_GRE_MAX,
1650         .policy         = ip6gre_policy,
1651         .priv_size      = sizeof(struct ip6_tnl),
1652         .setup          = ip6gre_tunnel_setup,
1653         .validate       = ip6gre_tunnel_validate,
1654         .newlink        = ip6gre_newlink,
1655         .changelink     = ip6gre_changelink,
1656         .dellink        = ip6gre_dellink,
1657         .get_size       = ip6gre_get_size,
1658         .fill_info      = ip6gre_fill_info,
1659 };
1660
1661 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1662         .kind           = "ip6gretap",
1663         .maxtype        = IFLA_GRE_MAX,
1664         .policy         = ip6gre_policy,
1665         .priv_size      = sizeof(struct ip6_tnl),
1666         .setup          = ip6gre_tap_setup,
1667         .validate       = ip6gre_tap_validate,
1668         .newlink        = ip6gre_newlink,
1669         .changelink     = ip6gre_changelink,
1670         .get_size       = ip6gre_get_size,
1671         .fill_info      = ip6gre_fill_info,
1672 };
1673
1674 /*
1675  *      And now the modules code and kernel interface.
1676  */
1677
1678 static int __init ip6gre_init(void)
1679 {
1680         int err;
1681
1682         pr_info("GRE over IPv6 tunneling driver\n");
1683
1684         err = register_pernet_device(&ip6gre_net_ops);
1685         if (err < 0)
1686                 return err;
1687
1688         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1689         if (err < 0) {
1690                 pr_info("%s: can't add protocol\n", __func__);
1691                 goto add_proto_failed;
1692         }
1693
1694         err = rtnl_link_register(&ip6gre_link_ops);
1695         if (err < 0)
1696                 goto rtnl_link_failed;
1697
1698         err = rtnl_link_register(&ip6gre_tap_ops);
1699         if (err < 0)
1700                 goto tap_ops_failed;
1701
1702 out:
1703         return err;
1704
1705 tap_ops_failed:
1706         rtnl_link_unregister(&ip6gre_link_ops);
1707 rtnl_link_failed:
1708         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1709 add_proto_failed:
1710         unregister_pernet_device(&ip6gre_net_ops);
1711         goto out;
1712 }
1713
1714 static void __exit ip6gre_fini(void)
1715 {
1716         rtnl_link_unregister(&ip6gre_tap_ops);
1717         rtnl_link_unregister(&ip6gre_link_ops);
1718         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1719         unregister_pernet_device(&ip6gre_net_ops);
1720 }
1721
1722 module_init(ip6gre_init);
1723 module_exit(ip6gre_fini);
1724 MODULE_LICENSE("GPL");
1725 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1726 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1727 MODULE_ALIAS_RTNL_LINK("ip6gre");
1728 MODULE_ALIAS_NETDEV("ip6gre0");