net/ipv6/ip6_gre.c

   1 /*
   2  *      GRE over IPv6 protocol decoder.
   3  *
   4  *      Authors: Dmitry Kozlov (xeb@mail.ru)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/capability.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/slab.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/in.h>
  24 #include <linux/tcp.h>
  25 #include <linux/udp.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/init.h>
  28 #include <linux/in6.h>
  29 #include <linux/inetdevice.h>
  30 #include <linux/igmp.h>
  31 #include <linux/netfilter_ipv4.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/if_ether.h>
  34 #include <linux/hash.h>
  35 #include <linux/if_tunnel.h>
  36 #include <linux/ip6_tunnel.h>
  37
  38 #include <net/sock.h>
  39 #include <net/ip.h>
  40 #include <net/ip_tunnels.h>
  41 #include <net/icmp.h>
  42 #include <net/protocol.h>
  43 #include <net/addrconf.h>
  44 #include <net/arp.h>
  45 #include <net/checksum.h>
  46 #include <net/dsfield.h>
  47 #include <net/inet_ecn.h>
  48 #include <net/xfrm.h>
  49 #include <net/net_namespace.h>
  50 #include <net/netns/generic.h>
  51 #include <net/rtnetlink.h>
  52
  53 #include <net/ipv6.h>
  54 #include <net/ip6_fib.h>
  55 #include <net/ip6_route.h>
  56 #include <net/ip6_tunnel.h>
  57 #include <net/gre.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         dst_cache_reset(&t->dst_cache);
 365         dev_put(dev);
 366 }
 367
 368
 369 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 370                 u8 type, u8 code, int offset, __be32 info)
 371 {
 372         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 373         __be16 *p = (__be16 *)(skb->data + offset);
 374         int grehlen = offset + 4;
 375         struct ip6_tnl *t;
 376         __be16 flags;
 377
 378         flags = p[0];
 379         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 380                 if (flags&(GRE_VERSION|GRE_ROUTING))
 381                         return;
 382                 if (flags&GRE_KEY) {
 383                         grehlen += 4;
 384                         if (flags&GRE_CSUM)
 385                                 grehlen += 4;
 386                 }
 387         }
 388
 389         /* If only 8 bytes returned, keyed message will be dropped here */
 390         if (!pskb_may_pull(skb, grehlen))
 391                 return;
 392         ipv6h = (const struct ipv6hdr *)skb->data;
 393         p = (__be16 *)(skb->data + offset);
 394
 395         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 396                                 flags & GRE_KEY ?
 397                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 398                                 p[1]);
 399         if (!t)
 400                 return;
 401
 402         switch (type) {
 403                 __u32 teli;
 404                 struct ipv6_tlv_tnl_enc_lim *tel;
 405                 __u32 mtu;
 406         case ICMPV6_DEST_UNREACH:
 407                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 408                                     t->parms.name);
 409                 break;
 410         case ICMPV6_TIME_EXCEED:
 411                 if (code == ICMPV6_EXC_HOPLIMIT) {
 412                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 413                                             t->parms.name);
 414                 }
 415                 break;
 416         case ICMPV6_PARAMPROB:
 417                 teli = 0;
 418                 if (code == ICMPV6_HDR_FIELD)
 419                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 420
 421                 if (teli && teli == be32_to_cpu(info) - 2) {
 422                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 423                         if (tel->encap_limit == 0) {
 424                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 425                                                     t->parms.name);
 426                         }
 427                 } else {
 428                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 429                                             t->parms.name);
 430                 }
 431                 break;
 432         case ICMPV6_PKT_TOOBIG:
 433                 mtu = be32_to_cpu(info) - offset;
 434                 if (mtu < IPV6_MIN_MTU)
 435                         mtu = IPV6_MIN_MTU;
 436                 t->dev->mtu = mtu;
 437                 break;
 438         }
 439
 440         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 441                 t->err_count++;
 442         else
 443                 t->err_count = 1;
 444         t->err_time = jiffies;
 445 }
 446
 447 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 448 {
 449         const struct ipv6hdr *ipv6h;
 450         struct ip6_tnl *tunnel;
 451
 452         ipv6h = ipv6_hdr(skb);
 453         tunnel = ip6gre_tunnel_lookup(skb->dev,
 454                                       &ipv6h->saddr, &ipv6h->daddr, tpi->key,
 455                                       tpi->proto);
 456         if (tunnel) {
 457                 ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
 458
 459                 return PACKET_RCVD;
 460         }
 461
 462         return PACKET_REJECT;
 463 }
 464
 465 static int gre_rcv(struct sk_buff *skb)
 466 {
 467         struct tnl_ptk_info tpi;
 468         bool csum_err = false;
 469         int hdr_len;
 470
 471         if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
 472                 goto drop;
 473
 474         if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
 475                 goto drop;
 476
 477         if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
 478                 return 0;
 479
 480         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 481 drop:
 482         kfree_skb(skb);
 483         return 0;
 484 }
 485
 486 struct ipv6_tel_txoption {
 487         struct ipv6_txoptions ops;
 488         __u8 dst_opt[8];
 489 };
 490
 491 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 492 {
 493         return iptunnel_handle_offloads(skb,
 494                                         csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 495 }
 496
 497 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 498                                struct net_device *dev, __u8 dsfield,
 499                                struct flowi6 *fl6, int encap_limit,
 500                                __u32 *pmtu, __be16 proto)
 501 {
 502         struct ip6_tnl *tunnel = netdev_priv(dev);
 503         __be16 protocol = (dev->type == ARPHRD_ETHER) ?
 504                           htons(ETH_P_TEB) : proto;
 505
 506         if (dev->type == ARPHRD_ETHER)
 507                 IPCB(skb)->flags = 0;
 508
 509         if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
 510                 fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
 511         else
 512                 fl6->daddr = tunnel->parms.raddr;
 513
 514         if (tunnel->parms.o_flags & TUNNEL_SEQ)
 515                 tunnel->o_seqno++;
 516
 517         /* Push GRE header. */
 518         gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
 519                          protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
 520
 521         skb_set_inner_protocol(skb, proto);
 522
 523         return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
 524                             NEXTHDR_GRE);
 525 }
 526
 527 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 528 {
 529         struct ip6_tnl *t = netdev_priv(dev);
 530         const struct iphdr  *iph = ip_hdr(skb);
 531         int encap_limit = -1;
 532         struct flowi6 fl6;
 533         __u8 dsfield;
 534         __u32 mtu;
 535         int err;
 536
 537         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 538
 539         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 540                 encap_limit = t->parms.encap_limit;
 541
 542         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 543
 544         dsfield = ipv4_get_dsfield(iph);
 545
 546         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 547                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 548                                           & IPV6_TCLASS_MASK;
 549         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 550                 fl6.flowi6_mark = skb->mark;
 551
 552         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 553         if (err)
 554                 return -1;
 555
 556         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
 557                           skb->protocol);
 558         if (err != 0) {
 559                 /* XXX: send ICMP error even if DF is not set. */
 560                 if (err == -EMSGSIZE)
 561                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 562                                   htonl(mtu));
 563                 return -1;
 564         }
 565
 566         return 0;
 567 }
 568
 569 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 570 {
 571         struct ip6_tnl *t = netdev_priv(dev);
 572         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 573         int encap_limit = -1;
 574         __u16 offset;
 575         struct flowi6 fl6;
 576         __u8 dsfield;
 577         __u32 mtu;
 578         int err;
 579
 580         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 581                 return -1;
 582
 583         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 584         if (offset > 0) {
 585                 struct ipv6_tlv_tnl_enc_lim *tel;
 586                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 587                 if (tel->encap_limit == 0) {
 588                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 589                                     ICMPV6_HDR_FIELD, offset + 2);
 590                         return -1;
 591                 }
 592                 encap_limit = tel->encap_limit - 1;
 593         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 594                 encap_limit = t->parms.encap_limit;
 595
 596         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 597
 598         dsfield = ipv6_get_dsfield(ipv6h);
 599         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 600                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 601         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 602                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 603         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 604                 fl6.flowi6_mark = skb->mark;
 605
 606         if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
 607                 return -1;
 608
 609         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
 610                           &mtu, skb->protocol);
 611         if (err != 0) {
 612                 if (err == -EMSGSIZE)
 613                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 614                 return -1;
 615         }
 616
 617         return 0;
 618 }
 619
 620 /**
 621  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 622  *   @t: the outgoing tunnel device
 623  *   @hdr: IPv6 header from the incoming packet
 624  *
 625  * Description:
 626  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 627  *   doesn't match source of incoming packet.
 628  *
 629  * Return:
 630  *   1 if conflict,
 631  *   0 else
 632  **/
 633
 634 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 635         const struct ipv6hdr *hdr)
 636 {
 637         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 638 }
 639
 640 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 641 {
 642         struct ip6_tnl *t = netdev_priv(dev);
 643         int encap_limit = -1;
 644         struct flowi6 fl6;
 645         __u32 mtu;
 646         int err;
 647
 648         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 649                 encap_limit = t->parms.encap_limit;
 650
 651         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 652         fl6.flowi6_proto = skb->protocol;
 653
 654         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 655         if (err)
 656                 return err;
 657
 658         err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
 659
 660         return err;
 661 }
 662
 663 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 664         struct net_device *dev)
 665 {
 666         struct ip6_tnl *t = netdev_priv(dev);
 667         struct net_device_stats *stats = &t->dev->stats;
 668         int ret;
 669
 670         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 671                 goto tx_err;
 672
 673         switch (skb->protocol) {
 674         case htons(ETH_P_IP):
 675                 ret = ip6gre_xmit_ipv4(skb, dev);
 676                 break;
 677         case htons(ETH_P_IPV6):
 678                 ret = ip6gre_xmit_ipv6(skb, dev);
 679                 break;
 680         default:
 681                 ret = ip6gre_xmit_other(skb, dev);
 682                 break;
 683         }
 684
 685         if (ret < 0)
 686                 goto tx_err;
 687
 688         return NETDEV_TX_OK;
 689
 690 tx_err:
 691         stats->tx_errors++;
 692         stats->tx_dropped++;
 693         kfree_skb(skb);
 694         return NETDEV_TX_OK;
 695 }
 696
 697 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 698 {
 699         struct net_device *dev = t->dev;
 700         struct __ip6_tnl_parm *p = &t->parms;
 701         struct flowi6 *fl6 = &t->fl.u.ip6;
 702         int addend = sizeof(struct ipv6hdr) + 4;
 703
 704         if (dev->type != ARPHRD_ETHER) {
 705                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 706                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 707         }
 708
 709         /* Set up flowi template */
 710         fl6->saddr = p->laddr;
 711         fl6->daddr = p->raddr;
 712         fl6->flowi6_oif = p->link;
 713         fl6->flowlabel = 0;
 714
 715         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 716                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 717         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 718                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 719
 720         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 721         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 722
 723         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 724                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 725                 dev->flags |= IFF_POINTOPOINT;
 726         else
 727                 dev->flags &= ~IFF_POINTOPOINT;
 728
 729         /* Precalculate GRE options length */
 730         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 731                 if (t->parms.o_flags&GRE_CSUM)
 732                         addend += 4;
 733                 if (t->parms.o_flags&GRE_KEY)
 734                         addend += 4;
 735                 if (t->parms.o_flags&GRE_SEQ)
 736                         addend += 4;
 737         }
 738         t->hlen = addend;
 739
 740         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 741                 int strict = (ipv6_addr_type(&p->raddr) &
 742                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 743
 744                 struct rt6_info *rt = rt6_lookup(t->net,
 745                                                  &p->raddr, &p->laddr,
 746                                                  p->link, strict);
 747
 748                 if (!rt)
 749                         return;
 750
 751                 if (rt->dst.dev) {
 752                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 753
 754                         if (set_mtu) {
 755                                 dev->mtu = rt->dst.dev->mtu - addend;
 756                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 757                                         dev->mtu -= 8;
 758                                 if (dev->type == ARPHRD_ETHER)
 759                                         dev->mtu -= ETH_HLEN;
 760
 761                                 if (dev->mtu < IPV6_MIN_MTU)
 762                                         dev->mtu = IPV6_MIN_MTU;
 763                         }
 764                 }
 765                 ip6_rt_put(rt);
 766         }
 767 }
 768
 769 static int ip6gre_tnl_change(struct ip6_tnl *t,
 770         const struct __ip6_tnl_parm *p, int set_mtu)
 771 {
 772         t->parms.laddr = p->laddr;
 773         t->parms.raddr = p->raddr;
 774         t->parms.flags = p->flags;
 775         t->parms.hop_limit = p->hop_limit;
 776         t->parms.encap_limit = p->encap_limit;
 777         t->parms.flowinfo = p->flowinfo;
 778         t->parms.link = p->link;
 779         t->parms.proto = p->proto;
 780         t->parms.i_key = p->i_key;
 781         t->parms.o_key = p->o_key;
 782         t->parms.i_flags = p->i_flags;
 783         t->parms.o_flags = p->o_flags;
 784         dst_cache_reset(&t->dst_cache);
 785         ip6gre_tnl_link_config(t, set_mtu);
 786         return 0;
 787 }
 788
 789 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
 790         const struct ip6_tnl_parm2 *u)
 791 {
 792         p->laddr = u->laddr;
 793         p->raddr = u->raddr;
 794         p->flags = u->flags;
 795         p->hop_limit = u->hop_limit;
 796         p->encap_limit = u->encap_limit;
 797         p->flowinfo = u->flowinfo;
 798         p->link = u->link;
 799         p->i_key = u->i_key;
 800         p->o_key = u->o_key;
 801         p->i_flags = u->i_flags;
 802         p->o_flags = u->o_flags;
 803         memcpy(p->name, u->name, sizeof(u->name));
 804 }
 805
 806 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
 807         const struct __ip6_tnl_parm *p)
 808 {
 809         u->proto = IPPROTO_GRE;
 810         u->laddr = p->laddr;
 811         u->raddr = p->raddr;
 812         u->flags = p->flags;
 813         u->hop_limit = p->hop_limit;
 814         u->encap_limit = p->encap_limit;
 815         u->flowinfo = p->flowinfo;
 816         u->link = p->link;
 817         u->i_key = p->i_key;
 818         u->o_key = p->o_key;
 819         u->i_flags = p->i_flags;
 820         u->o_flags = p->o_flags;
 821         memcpy(u->name, p->name, sizeof(u->name));
 822 }
 823
 824 static int ip6gre_tunnel_ioctl(struct net_device *dev,
 825         struct ifreq *ifr, int cmd)
 826 {
 827         int err = 0;
 828         struct ip6_tnl_parm2 p;
 829         struct __ip6_tnl_parm p1;
 830         struct ip6_tnl *t = netdev_priv(dev);
 831         struct net *net = t->net;
 832         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 833
 834         memset(&p1, 0, sizeof(p1));
 835
 836         switch (cmd) {
 837         case SIOCGETTUNNEL:
 838                 if (dev == ign->fb_tunnel_dev) {
 839                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 840                                 err = -EFAULT;
 841                                 break;
 842                         }
 843                         ip6gre_tnl_parm_from_user(&p1, &p);
 844                         t = ip6gre_tunnel_locate(net, &p1, 0);
 845                         if (!t)
 846                                 t = netdev_priv(dev);
 847                 }
 848                 memset(&p, 0, sizeof(p));
 849                 ip6gre_tnl_parm_to_user(&p, &t->parms);
 850                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 851                         err = -EFAULT;
 852                 break;
 853
 854         case SIOCADDTUNNEL:
 855         case SIOCCHGTUNNEL:
 856                 err = -EPERM;
 857                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 858                         goto done;
 859
 860                 err = -EFAULT;
 861                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 862                         goto done;
 863
 864                 err = -EINVAL;
 865                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
 866                         goto done;
 867
 868                 if (!(p.i_flags&GRE_KEY))
 869                         p.i_key = 0;
 870                 if (!(p.o_flags&GRE_KEY))
 871                         p.o_key = 0;
 872
 873                 ip6gre_tnl_parm_from_user(&p1, &p);
 874                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
 875
 876                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 877                         if (t) {
 878                                 if (t->dev != dev) {
 879                                         err = -EEXIST;
 880                                         break;
 881                                 }
 882                         } else {
 883                                 t = netdev_priv(dev);
 884
 885                                 ip6gre_tunnel_unlink(ign, t);
 886                                 synchronize_net();
 887                                 ip6gre_tnl_change(t, &p1, 1);
 888                                 ip6gre_tunnel_link(ign, t);
 889                                 netdev_state_change(dev);
 890                         }
 891                 }
 892
 893                 if (t) {
 894                         err = 0;
 895
 896                         memset(&p, 0, sizeof(p));
 897                         ip6gre_tnl_parm_to_user(&p, &t->parms);
 898                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 899                                 err = -EFAULT;
 900                 } else
 901                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 902                 break;
 903
 904         case SIOCDELTUNNEL:
 905                 err = -EPERM;
 906                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 907                         goto done;
 908
 909                 if (dev == ign->fb_tunnel_dev) {
 910                         err = -EFAULT;
 911                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 912                                 goto done;
 913                         err = -ENOENT;
 914                         ip6gre_tnl_parm_from_user(&p1, &p);
 915                         t = ip6gre_tunnel_locate(net, &p1, 0);
 916                         if (!t)
 917                                 goto done;
 918                         err = -EPERM;
 919                         if (t == netdev_priv(ign->fb_tunnel_dev))
 920                                 goto done;
 921                         dev = t->dev;
 922                 }
 923                 unregister_netdevice(dev);
 924                 err = 0;
 925                 break;
 926
 927         default:
 928                 err = -EINVAL;
 929         }
 930
 931 done:
 932         return err;
 933 }
 934
 935 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 936                         unsigned short type,
 937                         const void *daddr, const void *saddr, unsigned int len)
 938 {
 939         struct ip6_tnl *t = netdev_priv(dev);
 940         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
 941         __be16 *p = (__be16 *)(ipv6h+1);
 942
 943         ip6_flow_hdr(ipv6h, 0,
 944                      ip6_make_flowlabel(dev_net(dev), skb,
 945                                         t->fl.u.ip6.flowlabel, true,
 946                                         &t->fl.u.ip6));
 947         ipv6h->hop_limit = t->parms.hop_limit;
 948         ipv6h->nexthdr = NEXTHDR_GRE;
 949         ipv6h->saddr = t->parms.laddr;
 950         ipv6h->daddr = t->parms.raddr;
 951
 952         p[0]            = t->parms.o_flags;
 953         p[1]            = htons(type);
 954
 955         /*
 956          *      Set the source hardware address.
 957          */
 958
 959         if (saddr)
 960                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
 961         if (daddr)
 962                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
 963         if (!ipv6_addr_any(&ipv6h->daddr))
 964                 return t->hlen;
 965
 966         return -t->hlen;
 967 }
 968
 969 static const struct header_ops ip6gre_header_ops = {
 970         .create = ip6gre_header,
 971 };
 972
 973 static const struct net_device_ops ip6gre_netdev_ops = {
 974         .ndo_init               = ip6gre_tunnel_init,
 975         .ndo_uninit             = ip6gre_tunnel_uninit,
 976         .ndo_start_xmit         = ip6gre_tunnel_xmit,
 977         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
 978         .ndo_change_mtu         = ip6_tnl_change_mtu,
 979         .ndo_get_stats64        = ip_tunnel_get_stats64,
 980         .ndo_get_iflink         = ip6_tnl_get_iflink,
 981 };
 982
 983 static void ip6gre_dev_free(struct net_device *dev)
 984 {
 985         struct ip6_tnl *t = netdev_priv(dev);
 986
 987         dst_cache_destroy(&t->dst_cache);
 988         free_percpu(dev->tstats);
 989         free_netdev(dev);
 990 }
 991
 992 static void ip6gre_tunnel_setup(struct net_device *dev)
 993 {
 994         dev->netdev_ops = &ip6gre_netdev_ops;
 995         dev->destructor = ip6gre_dev_free;
 996
 997         dev->type = ARPHRD_IP6GRE;
 998
 999         dev->flags |= IFF_NOARP;
1000         dev->addr_len = sizeof(struct in6_addr);
1001         netif_keep_dst(dev);
1002 }
1003
1004 static int ip6gre_tunnel_init_common(struct net_device *dev)
1005 {
1006         struct ip6_tnl *tunnel;
1007         int ret;
1008         int t_hlen;
1009
1010         tunnel = netdev_priv(dev);
1011
1012         tunnel->dev = dev;
1013         tunnel->net = dev_net(dev);
1014         strcpy(tunnel->parms.name, dev->name);
1015
1016         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1017         if (!dev->tstats)
1018                 return -ENOMEM;
1019
1020         ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1021         if (ret) {
1022                 free_percpu(dev->tstats);
1023                 dev->tstats = NULL;
1024                 return ret;
1025         }
1026
1027         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1028
1029         t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1030
1031         dev->needed_headroom    = LL_MAX_HEADER + t_hlen + 4;
1032         dev->mtu                = ETH_DATA_LEN - t_hlen - 4;
1033
1034         if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1035                 dev->mtu -= 8;
1036
1037         return 0;
1038 }
1039
1040 static int ip6gre_tunnel_init(struct net_device *dev)
1041 {
1042         struct ip6_tnl *tunnel;
1043         int ret;
1044
1045         ret = ip6gre_tunnel_init_common(dev);
1046         if (ret)
1047                 return ret;
1048
1049         tunnel = netdev_priv(dev);
1050
1051         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1052         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1053
1054         if (ipv6_addr_any(&tunnel->parms.raddr))
1055                 dev->header_ops = &ip6gre_header_ops;
1056
1057         return 0;
1058 }
1059
1060 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1061 {
1062         struct ip6_tnl *tunnel = netdev_priv(dev);
1063
1064         tunnel->dev = dev;
1065         tunnel->net = dev_net(dev);
1066         strcpy(tunnel->parms.name, dev->name);
1067
1068         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1069
1070         dev_hold(dev);
1071 }
1072
1073
1074 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1075         .handler     = gre_rcv,
1076         .err_handler = ip6gre_err,
1077         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1078 };
1079
1080 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1081 {
1082         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1083         struct net_device *dev, *aux;
1084         int prio;
1085
1086         for_each_netdev_safe(net, dev, aux)
1087                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1088                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1089                         unregister_netdevice_queue(dev, head);
1090
1091         for (prio = 0; prio < 4; prio++) {
1092                 int h;
1093                 for (h = 0; h < HASH_SIZE; h++) {
1094                         struct ip6_tnl *t;
1095
1096                         t = rtnl_dereference(ign->tunnels[prio][h]);
1097
1098                         while (t) {
1099                                 /* If dev is in the same netns, it has already
1100                                  * been added to the list by the previous loop.
1101                                  */
1102                                 if (!net_eq(dev_net(t->dev), net))
1103                                         unregister_netdevice_queue(t->dev,
1104                                                                    head);
1105                                 t = rtnl_dereference(t->next);
1106                         }
1107                 }
1108         }
1109 }
1110
1111 static int __net_init ip6gre_init_net(struct net *net)
1112 {
1113         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1114         int err;
1115
1116         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1117                                           NET_NAME_UNKNOWN,
1118                                           ip6gre_tunnel_setup);
1119         if (!ign->fb_tunnel_dev) {
1120                 err = -ENOMEM;
1121                 goto err_alloc_dev;
1122         }
1123         dev_net_set(ign->fb_tunnel_dev, net);
1124         /* FB netdevice is special: we have one, and only one per netns.
1125          * Allowing to move it to another netns is clearly unsafe.
1126          */
1127         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1128
1129
1130         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1131         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1132
1133         err = register_netdev(ign->fb_tunnel_dev);
1134         if (err)
1135                 goto err_reg_dev;
1136
1137         rcu_assign_pointer(ign->tunnels_wc[0],
1138                            netdev_priv(ign->fb_tunnel_dev));
1139         return 0;
1140
1141 err_reg_dev:
1142         ip6gre_dev_free(ign->fb_tunnel_dev);
1143 err_alloc_dev:
1144         return err;
1145 }
1146
1147 static void __net_exit ip6gre_exit_net(struct net *net)
1148 {
1149         LIST_HEAD(list);
1150
1151         rtnl_lock();
1152         ip6gre_destroy_tunnels(net, &list);
1153         unregister_netdevice_many(&list);
1154         rtnl_unlock();
1155 }
1156
1157 static struct pernet_operations ip6gre_net_ops = {
1158         .init = ip6gre_init_net,
1159         .exit = ip6gre_exit_net,
1160         .id   = &ip6gre_net_id,
1161         .size = sizeof(struct ip6gre_net),
1162 };
1163
1164 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1165 {
1166         __be16 flags;
1167
1168         if (!data)
1169                 return 0;
1170
1171         flags = 0;
1172         if (data[IFLA_GRE_IFLAGS])
1173                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1174         if (data[IFLA_GRE_OFLAGS])
1175                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1176         if (flags & (GRE_VERSION|GRE_ROUTING))
1177                 return -EINVAL;
1178
1179         return 0;
1180 }
1181
1182 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1183 {
1184         struct in6_addr daddr;
1185
1186         if (tb[IFLA_ADDRESS]) {
1187                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1188                         return -EINVAL;
1189                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1190                         return -EADDRNOTAVAIL;
1191         }
1192
1193         if (!data)
1194                 goto out;
1195
1196         if (data[IFLA_GRE_REMOTE]) {
1197                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1198                 if (ipv6_addr_any(&daddr))
1199                         return -EINVAL;
1200         }
1201
1202 out:
1203         return ip6gre_tunnel_validate(tb, data);
1204 }
1205
1206
1207 static void ip6gre_netlink_parms(struct nlattr *data[],
1208                                 struct __ip6_tnl_parm *parms)
1209 {
1210         memset(parms, 0, sizeof(*parms));
1211
1212         if (!data)
1213                 return;
1214
1215         if (data[IFLA_GRE_LINK])
1216                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1217
1218         if (data[IFLA_GRE_IFLAGS])
1219                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1220
1221         if (data[IFLA_GRE_OFLAGS])
1222                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1223
1224         if (data[IFLA_GRE_IKEY])
1225                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1226
1227         if (data[IFLA_GRE_OKEY])
1228                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1229
1230         if (data[IFLA_GRE_LOCAL])
1231                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1232
1233         if (data[IFLA_GRE_REMOTE])
1234                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1235
1236         if (data[IFLA_GRE_TTL])
1237                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1238
1239         if (data[IFLA_GRE_ENCAP_LIMIT])
1240                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1241
1242         if (data[IFLA_GRE_FLOWINFO])
1243                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1244
1245         if (data[IFLA_GRE_FLAGS])
1246                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1247 }
1248
1249 static int ip6gre_tap_init(struct net_device *dev)
1250 {
1251         struct ip6_tnl *tunnel;
1252         int ret;
1253
1254         ret = ip6gre_tunnel_init_common(dev);
1255         if (ret)
1256                 return ret;
1257
1258         tunnel = netdev_priv(dev);
1259
1260         ip6gre_tnl_link_config(tunnel, 1);
1261
1262         return 0;
1263 }
1264
1265 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1266         .ndo_init = ip6gre_tap_init,
1267         .ndo_uninit = ip6gre_tunnel_uninit,
1268         .ndo_start_xmit = ip6gre_tunnel_xmit,
1269         .ndo_set_mac_address = eth_mac_addr,
1270         .ndo_validate_addr = eth_validate_addr,
1271         .ndo_change_mtu = ip6_tnl_change_mtu,
1272         .ndo_get_stats64 = ip_tunnel_get_stats64,
1273         .ndo_get_iflink = ip6_tnl_get_iflink,
1274 };
1275
1276 #define GRE6_FEATURES (NETIF_F_SG |             \
1277                        NETIF_F_FRAGLIST |       \
1278                        NETIF_F_HIGHDMA |                \
1279                        NETIF_F_HW_CSUM)
1280
1281 static void ip6gre_tap_setup(struct net_device *dev)
1282 {
1283
1284         ether_setup(dev);
1285
1286         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1287         dev->destructor = ip6gre_dev_free;
1288
1289         dev->features |= NETIF_F_NETNS_LOCAL;
1290         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1291 }
1292
1293 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1294         struct nlattr *tb[], struct nlattr *data[])
1295 {
1296         struct ip6_tnl *nt;
1297         struct net *net = dev_net(dev);
1298         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1299         int err;
1300
1301         nt = netdev_priv(dev);
1302         ip6gre_netlink_parms(data, &nt->parms);
1303
1304         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1305                 return -EEXIST;
1306
1307         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1308                 eth_hw_addr_random(dev);
1309
1310         nt->dev = dev;
1311         nt->net = dev_net(dev);
1312         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1313
1314         dev->features           |= GRE6_FEATURES;
1315         dev->hw_features        |= GRE6_FEATURES;
1316
1317         if (!(nt->parms.o_flags & GRE_SEQ)) {
1318                 /* TCP segmentation offload is not supported when we
1319                  * generate output sequences.
1320                  */
1321                 dev->features    |= NETIF_F_GSO_SOFTWARE;
1322                 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1323
1324                 /* Can use a lockless transmit, unless we generate
1325                  * output sequences
1326                  */
1327                 dev->features |= NETIF_F_LLTX;
1328         }
1329
1330         err = register_netdevice(dev);
1331         if (err)
1332                 goto out;
1333
1334         dev_hold(dev);
1335         ip6gre_tunnel_link(ign, nt);
1336
1337 out:
1338         return err;
1339 }
1340
1341 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1342                             struct nlattr *data[])
1343 {
1344         struct ip6_tnl *t, *nt = netdev_priv(dev);
1345         struct net *net = nt->net;
1346         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1347         struct __ip6_tnl_parm p;
1348
1349         if (dev == ign->fb_tunnel_dev)
1350                 return -EINVAL;
1351
1352         ip6gre_netlink_parms(data, &p);
1353
1354         t = ip6gre_tunnel_locate(net, &p, 0);
1355
1356         if (t) {
1357                 if (t->dev != dev)
1358                         return -EEXIST;
1359         } else {
1360                 t = nt;
1361         }
1362
1363         ip6gre_tunnel_unlink(ign, t);
1364         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1365         ip6gre_tunnel_link(ign, t);
1366         return 0;
1367 }
1368
1369 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1370 {
1371         struct net *net = dev_net(dev);
1372         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1373
1374         if (dev != ign->fb_tunnel_dev)
1375                 unregister_netdevice_queue(dev, head);
1376 }
1377
1378 static size_t ip6gre_get_size(const struct net_device *dev)
1379 {
1380         return
1381                 /* IFLA_GRE_LINK */
1382                 nla_total_size(4) +
1383                 /* IFLA_GRE_IFLAGS */
1384                 nla_total_size(2) +
1385                 /* IFLA_GRE_OFLAGS */
1386                 nla_total_size(2) +
1387                 /* IFLA_GRE_IKEY */
1388                 nla_total_size(4) +
1389                 /* IFLA_GRE_OKEY */
1390                 nla_total_size(4) +
1391                 /* IFLA_GRE_LOCAL */
1392                 nla_total_size(sizeof(struct in6_addr)) +
1393                 /* IFLA_GRE_REMOTE */
1394                 nla_total_size(sizeof(struct in6_addr)) +
1395                 /* IFLA_GRE_TTL */
1396                 nla_total_size(1) +
1397                 /* IFLA_GRE_TOS */
1398                 nla_total_size(1) +
1399                 /* IFLA_GRE_ENCAP_LIMIT */
1400                 nla_total_size(1) +
1401                 /* IFLA_GRE_FLOWINFO */
1402                 nla_total_size(4) +
1403                 /* IFLA_GRE_FLAGS */
1404                 nla_total_size(4) +
1405                 0;
1406 }
1407
1408 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1409 {
1410         struct ip6_tnl *t = netdev_priv(dev);
1411         struct __ip6_tnl_parm *p = &t->parms;
1412
1413         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1414             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1415             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1416             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1417             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1418             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1419             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1420             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1421             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1422             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1423             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1424             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1425                 goto nla_put_failure;
1426         return 0;
1427
1428 nla_put_failure:
1429         return -EMSGSIZE;
1430 }
1431
1432 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1433         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1434         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1435         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1436         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1437         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1438         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1439         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1440         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1441         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1442         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1443         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1444 };
1445
1446 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1447         .kind           = "ip6gre",
1448         .maxtype        = IFLA_GRE_MAX,
1449         .policy         = ip6gre_policy,
1450         .priv_size      = sizeof(struct ip6_tnl),
1451         .setup          = ip6gre_tunnel_setup,
1452         .validate       = ip6gre_tunnel_validate,
1453         .newlink        = ip6gre_newlink,
1454         .changelink     = ip6gre_changelink,
1455         .dellink        = ip6gre_dellink,
1456         .get_size       = ip6gre_get_size,
1457         .fill_info      = ip6gre_fill_info,
1458         .get_link_net   = ip6_tnl_get_link_net,
1459 };
1460
1461 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1462         .kind           = "ip6gretap",
1463         .maxtype        = IFLA_GRE_MAX,
1464         .policy         = ip6gre_policy,
1465         .priv_size      = sizeof(struct ip6_tnl),
1466         .setup          = ip6gre_tap_setup,
1467         .validate       = ip6gre_tap_validate,
1468         .newlink        = ip6gre_newlink,
1469         .changelink     = ip6gre_changelink,
1470         .get_size       = ip6gre_get_size,
1471         .fill_info      = ip6gre_fill_info,
1472         .get_link_net   = ip6_tnl_get_link_net,
1473 };
1474
1475 /*
1476  *      And now the modules code and kernel interface.
1477  */
1478
1479 static int __init ip6gre_init(void)
1480 {
1481         int err;
1482
1483         pr_info("GRE over IPv6 tunneling driver\n");
1484
1485         err = register_pernet_device(&ip6gre_net_ops);
1486         if (err < 0)
1487                 return err;
1488
1489         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1490         if (err < 0) {
1491                 pr_info("%s: can't add protocol\n", __func__);
1492                 goto add_proto_failed;
1493         }
1494
1495         err = rtnl_link_register(&ip6gre_link_ops);
1496         if (err < 0)
1497                 goto rtnl_link_failed;
1498
1499         err = rtnl_link_register(&ip6gre_tap_ops);
1500         if (err < 0)
1501                 goto tap_ops_failed;
1502
1503 out:
1504         return err;
1505
1506 tap_ops_failed:
1507         rtnl_link_unregister(&ip6gre_link_ops);
1508 rtnl_link_failed:
1509         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1510 add_proto_failed:
1511         unregister_pernet_device(&ip6gre_net_ops);
1512         goto out;
1513 }
1514
1515 static void __exit ip6gre_fini(void)
1516 {
1517         rtnl_link_unregister(&ip6gre_tap_ops);
1518         rtnl_link_unregister(&ip6gre_link_ops);
1519         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1520         unregister_pernet_device(&ip6gre_net_ops);
1521 }
1522
1523 module_init(ip6gre_init);
1524 module_exit(ip6gre_fini);
1525 MODULE_LICENSE("GPL");
1526 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1527 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1528 MODULE_ALIAS_RTNL_LINK("ip6gre");
1529 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1530 MODULE_ALIAS_NETDEV("ip6gre0");