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 IP6_GRE_HASH_SIZE_SHIFT  5
  65 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
  66
  67 static unsigned int ip6gre_net_id __read_mostly;
  68 struct ip6gre_net {
  69         struct ip6_tnl __rcu *tunnels[4][IP6_GRE_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))&(IP6_GRE_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, IP6_GRE_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 & TUNNEL_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         hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
 472         if (hdr_len < 0)
 473                 goto drop;
 474
 475         if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
 476                 goto drop;
 477
 478         if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
 479                 return 0;
 480
 481         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 482 drop:
 483         kfree_skb(skb);
 484         return 0;
 485 }
 486
 487 struct ipv6_tel_txoption {
 488         struct ipv6_txoptions ops;
 489         __u8 dst_opt[8];
 490 };
 491
 492 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 493 {
 494         return iptunnel_handle_offloads(skb,
 495                                         csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 496 }
 497
 498 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 499                                struct net_device *dev, __u8 dsfield,
 500                                struct flowi6 *fl6, int encap_limit,
 501                                __u32 *pmtu, __be16 proto)
 502 {
 503         struct ip6_tnl *tunnel = netdev_priv(dev);
 504         __be16 protocol = (dev->type == ARPHRD_ETHER) ?
 505                           htons(ETH_P_TEB) : proto;
 506
 507         if (dev->type == ARPHRD_ETHER)
 508                 IPCB(skb)->flags = 0;
 509
 510         if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
 511                 fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
 512         else
 513                 fl6->daddr = tunnel->parms.raddr;
 514
 515         if (tunnel->parms.o_flags & TUNNEL_SEQ)
 516                 tunnel->o_seqno++;
 517
 518         /* Push GRE header. */
 519         gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
 520                          protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
 521
 522         return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
 523                             NEXTHDR_GRE);
 524 }
 525
 526 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 527 {
 528         struct ip6_tnl *t = netdev_priv(dev);
 529         const struct iphdr  *iph = ip_hdr(skb);
 530         int encap_limit = -1;
 531         struct flowi6 fl6;
 532         __u8 dsfield;
 533         __u32 mtu;
 534         int err;
 535
 536         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 537
 538         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 539                 encap_limit = t->parms.encap_limit;
 540
 541         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 542
 543         dsfield = ipv4_get_dsfield(iph);
 544
 545         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 546                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 547                                           & IPV6_TCLASS_MASK;
 548         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 549                 fl6.flowi6_mark = skb->mark;
 550
 551         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 552
 553         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 554         if (err)
 555                 return -1;
 556
 557         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
 558                           skb->protocol);
 559         if (err != 0) {
 560                 /* XXX: send ICMP error even if DF is not set. */
 561                 if (err == -EMSGSIZE)
 562                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 563                                   htonl(mtu));
 564                 return -1;
 565         }
 566
 567         return 0;
 568 }
 569
 570 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 571 {
 572         struct ip6_tnl *t = netdev_priv(dev);
 573         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 574         int encap_limit = -1;
 575         __u16 offset;
 576         struct flowi6 fl6;
 577         __u8 dsfield;
 578         __u32 mtu;
 579         int err;
 580
 581         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 582                 return -1;
 583
 584         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 585         if (offset > 0) {
 586                 struct ipv6_tlv_tnl_enc_lim *tel;
 587                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 588                 if (tel->encap_limit == 0) {
 589                         icmpv6_send(skb, ICMPV6_PARAMPROB,
 590                                     ICMPV6_HDR_FIELD, offset + 2);
 591                         return -1;
 592                 }
 593                 encap_limit = tel->encap_limit - 1;
 594         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 595                 encap_limit = t->parms.encap_limit;
 596
 597         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 598
 599         dsfield = ipv6_get_dsfield(ipv6h);
 600         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 601                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 602         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 603                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
 604         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 605                 fl6.flowi6_mark = skb->mark;
 606
 607         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 608
 609         if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
 610                 return -1;
 611
 612         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
 613                           &mtu, skb->protocol);
 614         if (err != 0) {
 615                 if (err == -EMSGSIZE)
 616                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 617                 return -1;
 618         }
 619
 620         return 0;
 621 }
 622
 623 /**
 624  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 625  *   @t: the outgoing tunnel device
 626  *   @hdr: IPv6 header from the incoming packet
 627  *
 628  * Description:
 629  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 630  *   doesn't match source of incoming packet.
 631  *
 632  * Return:
 633  *   1 if conflict,
 634  *   0 else
 635  **/
 636
 637 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 638         const struct ipv6hdr *hdr)
 639 {
 640         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 641 }
 642
 643 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 644 {
 645         struct ip6_tnl *t = netdev_priv(dev);
 646         int encap_limit = -1;
 647         struct flowi6 fl6;
 648         __u32 mtu;
 649         int err;
 650
 651         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 652                 encap_limit = t->parms.encap_limit;
 653
 654         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 655
 656         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
 657         if (err)
 658                 return err;
 659
 660         err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
 661
 662         return err;
 663 }
 664
 665 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 666         struct net_device *dev)
 667 {
 668         struct ip6_tnl *t = netdev_priv(dev);
 669         struct net_device_stats *stats = &t->dev->stats;
 670         int ret;
 671
 672         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 673                 goto tx_err;
 674
 675         switch (skb->protocol) {
 676         case htons(ETH_P_IP):
 677                 ret = ip6gre_xmit_ipv4(skb, dev);
 678                 break;
 679         case htons(ETH_P_IPV6):
 680                 ret = ip6gre_xmit_ipv6(skb, dev);
 681                 break;
 682         default:
 683                 ret = ip6gre_xmit_other(skb, dev);
 684                 break;
 685         }
 686
 687         if (ret < 0)
 688                 goto tx_err;
 689
 690         return NETDEV_TX_OK;
 691
 692 tx_err:
 693         stats->tx_errors++;
 694         stats->tx_dropped++;
 695         kfree_skb(skb);
 696         return NETDEV_TX_OK;
 697 }
 698
 699 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 700 {
 701         struct net_device *dev = t->dev;
 702         struct __ip6_tnl_parm *p = &t->parms;
 703         struct flowi6 *fl6 = &t->fl.u.ip6;
 704         int t_hlen;
 705
 706         if (dev->type != ARPHRD_ETHER) {
 707                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 708                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 709         }
 710
 711         /* Set up flowi template */
 712         fl6->saddr = p->laddr;
 713         fl6->daddr = p->raddr;
 714         fl6->flowi6_oif = p->link;
 715         fl6->flowlabel = 0;
 716         fl6->flowi6_proto = IPPROTO_GRE;
 717
 718         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 719                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 720         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 721                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 722
 723         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 724         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 725
 726         if (p->flags&IP6_TNL_F_CAP_XMIT &&
 727                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 728                 dev->flags |= IFF_POINTOPOINT;
 729         else
 730                 dev->flags &= ~IFF_POINTOPOINT;
 731
 732         t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
 733
 734         t->hlen = t->encap_hlen + t->tun_hlen;
 735
 736         t_hlen = t->hlen + sizeof(struct ipv6hdr);
 737
 738         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 739                 int strict = (ipv6_addr_type(&p->raddr) &
 740                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 741
 742                 struct rt6_info *rt = rt6_lookup(t->net,
 743                                                  &p->raddr, &p->laddr,
 744                                                  p->link, strict);
 745
 746                 if (!rt)
 747                         return;
 748
 749                 if (rt->dst.dev) {
 750                         dev->hard_header_len = rt->dst.dev->hard_header_len +
 751                                                t_hlen;
 752
 753                         if (set_mtu) {
 754                                 dev->mtu = rt->dst.dev->mtu - t_hlen;
 755                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 756                                         dev->mtu -= 8;
 757                                 if (dev->type == ARPHRD_ETHER)
 758                                         dev->mtu -= ETH_HLEN;
 759
 760                                 if (dev->mtu < IPV6_MIN_MTU)
 761                                         dev->mtu = IPV6_MIN_MTU;
 762                         }
 763                 }
 764                 ip6_rt_put(rt);
 765         }
 766 }
 767
 768 static int ip6gre_tnl_change(struct ip6_tnl *t,
 769         const struct __ip6_tnl_parm *p, int set_mtu)
 770 {
 771         t->parms.laddr = p->laddr;
 772         t->parms.raddr = p->raddr;
 773         t->parms.flags = p->flags;
 774         t->parms.hop_limit = p->hop_limit;
 775         t->parms.encap_limit = p->encap_limit;
 776         t->parms.flowinfo = p->flowinfo;
 777         t->parms.link = p->link;
 778         t->parms.proto = p->proto;
 779         t->parms.i_key = p->i_key;
 780         t->parms.o_key = p->o_key;
 781         t->parms.i_flags = p->i_flags;
 782         t->parms.o_flags = p->o_flags;
 783         dst_cache_reset(&t->dst_cache);
 784         ip6gre_tnl_link_config(t, set_mtu);
 785         return 0;
 786 }
 787
 788 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
 789         const struct ip6_tnl_parm2 *u)
 790 {
 791         p->laddr = u->laddr;
 792         p->raddr = u->raddr;
 793         p->flags = u->flags;
 794         p->hop_limit = u->hop_limit;
 795         p->encap_limit = u->encap_limit;
 796         p->flowinfo = u->flowinfo;
 797         p->link = u->link;
 798         p->i_key = u->i_key;
 799         p->o_key = u->o_key;
 800         p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
 801         p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
 802         memcpy(p->name, u->name, sizeof(u->name));
 803 }
 804
 805 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
 806         const struct __ip6_tnl_parm *p)
 807 {
 808         u->proto = IPPROTO_GRE;
 809         u->laddr = p->laddr;
 810         u->raddr = p->raddr;
 811         u->flags = p->flags;
 812         u->hop_limit = p->hop_limit;
 813         u->encap_limit = p->encap_limit;
 814         u->flowinfo = p->flowinfo;
 815         u->link = p->link;
 816         u->i_key = p->i_key;
 817         u->o_key = p->o_key;
 818         u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
 819         u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
 820         memcpy(u->name, p->name, sizeof(u->name));
 821 }
 822
 823 static int ip6gre_tunnel_ioctl(struct net_device *dev,
 824         struct ifreq *ifr, int cmd)
 825 {
 826         int err = 0;
 827         struct ip6_tnl_parm2 p;
 828         struct __ip6_tnl_parm p1;
 829         struct ip6_tnl *t = netdev_priv(dev);
 830         struct net *net = t->net;
 831         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 832
 833         memset(&p1, 0, sizeof(p1));
 834
 835         switch (cmd) {
 836         case SIOCGETTUNNEL:
 837                 if (dev == ign->fb_tunnel_dev) {
 838                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 839                                 err = -EFAULT;
 840                                 break;
 841                         }
 842                         ip6gre_tnl_parm_from_user(&p1, &p);
 843                         t = ip6gre_tunnel_locate(net, &p1, 0);
 844                         if (!t)
 845                                 t = netdev_priv(dev);
 846                 }
 847                 memset(&p, 0, sizeof(p));
 848                 ip6gre_tnl_parm_to_user(&p, &t->parms);
 849                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 850                         err = -EFAULT;
 851                 break;
 852
 853         case SIOCADDTUNNEL:
 854         case SIOCCHGTUNNEL:
 855                 err = -EPERM;
 856                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 857                         goto done;
 858
 859                 err = -EFAULT;
 860                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 861                         goto done;
 862
 863                 err = -EINVAL;
 864                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
 865                         goto done;
 866
 867                 if (!(p.i_flags&GRE_KEY))
 868                         p.i_key = 0;
 869                 if (!(p.o_flags&GRE_KEY))
 870                         p.o_key = 0;
 871
 872                 ip6gre_tnl_parm_from_user(&p1, &p);
 873                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
 874
 875                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 876                         if (t) {
 877                                 if (t->dev != dev) {
 878                                         err = -EEXIST;
 879                                         break;
 880                                 }
 881                         } else {
 882                                 t = netdev_priv(dev);
 883
 884                                 ip6gre_tunnel_unlink(ign, t);
 885                                 synchronize_net();
 886                                 ip6gre_tnl_change(t, &p1, 1);
 887                                 ip6gre_tunnel_link(ign, t);
 888                                 netdev_state_change(dev);
 889                         }
 890                 }
 891
 892                 if (t) {
 893                         err = 0;
 894
 895                         memset(&p, 0, sizeof(p));
 896                         ip6gre_tnl_parm_to_user(&p, &t->parms);
 897                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 898                                 err = -EFAULT;
 899                 } else
 900                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 901                 break;
 902
 903         case SIOCDELTUNNEL:
 904                 err = -EPERM;
 905                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 906                         goto done;
 907
 908                 if (dev == ign->fb_tunnel_dev) {
 909                         err = -EFAULT;
 910                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 911                                 goto done;
 912                         err = -ENOENT;
 913                         ip6gre_tnl_parm_from_user(&p1, &p);
 914                         t = ip6gre_tunnel_locate(net, &p1, 0);
 915                         if (!t)
 916                                 goto done;
 917                         err = -EPERM;
 918                         if (t == netdev_priv(ign->fb_tunnel_dev))
 919                                 goto done;
 920                         dev = t->dev;
 921                 }
 922                 unregister_netdevice(dev);
 923                 err = 0;
 924                 break;
 925
 926         default:
 927                 err = -EINVAL;
 928         }
 929
 930 done:
 931         return err;
 932 }
 933
 934 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 935                         unsigned short type,
 936                         const void *daddr, const void *saddr, unsigned int len)
 937 {
 938         struct ip6_tnl *t = netdev_priv(dev);
 939         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
 940         __be16 *p = (__be16 *)(ipv6h+1);
 941
 942         ip6_flow_hdr(ipv6h, 0,
 943                      ip6_make_flowlabel(dev_net(dev), skb,
 944                                         t->fl.u.ip6.flowlabel, true,
 945                                         &t->fl.u.ip6));
 946         ipv6h->hop_limit = t->parms.hop_limit;
 947         ipv6h->nexthdr = NEXTHDR_GRE;
 948         ipv6h->saddr = t->parms.laddr;
 949         ipv6h->daddr = t->parms.raddr;
 950
 951         p[0]            = t->parms.o_flags;
 952         p[1]            = htons(type);
 953
 954         /*
 955          *      Set the source hardware address.
 956          */
 957
 958         if (saddr)
 959                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
 960         if (daddr)
 961                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
 962         if (!ipv6_addr_any(&ipv6h->daddr))
 963                 return t->hlen;
 964
 965         return -t->hlen;
 966 }
 967
 968 static const struct header_ops ip6gre_header_ops = {
 969         .create = ip6gre_header,
 970 };
 971
 972 static const struct net_device_ops ip6gre_netdev_ops = {
 973         .ndo_init               = ip6gre_tunnel_init,
 974         .ndo_uninit             = ip6gre_tunnel_uninit,
 975         .ndo_start_xmit         = ip6gre_tunnel_xmit,
 976         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
 977         .ndo_change_mtu         = ip6_tnl_change_mtu,
 978         .ndo_get_stats64        = ip_tunnel_get_stats64,
 979         .ndo_get_iflink         = ip6_tnl_get_iflink,
 980 };
 981
 982 static void ip6gre_dev_free(struct net_device *dev)
 983 {
 984         struct ip6_tnl *t = netdev_priv(dev);
 985
 986         dst_cache_destroy(&t->dst_cache);
 987         free_percpu(dev->tstats);
 988         free_netdev(dev);
 989 }
 990
 991 static void ip6gre_tunnel_setup(struct net_device *dev)
 992 {
 993         dev->netdev_ops = &ip6gre_netdev_ops;
 994         dev->destructor = ip6gre_dev_free;
 995
 996         dev->type = ARPHRD_IP6GRE;
 997
 998         dev->flags |= IFF_NOARP;
 999         dev->addr_len = sizeof(struct in6_addr);
1000         netif_keep_dst(dev);
1001 }
1002
1003 static int ip6gre_tunnel_init_common(struct net_device *dev)
1004 {
1005         struct ip6_tnl *tunnel;
1006         int ret;
1007         int t_hlen;
1008
1009         tunnel = netdev_priv(dev);
1010
1011         tunnel->dev = dev;
1012         tunnel->net = dev_net(dev);
1013         strcpy(tunnel->parms.name, dev->name);
1014
1015         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1016         if (!dev->tstats)
1017                 return -ENOMEM;
1018
1019         ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1020         if (ret) {
1021                 free_percpu(dev->tstats);
1022                 dev->tstats = NULL;
1023                 return ret;
1024         }
1025
1026         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1027         tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1028         t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1029
1030         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1031         dev->mtu = ETH_DATA_LEN - t_hlen;
1032         if (dev->type == ARPHRD_ETHER)
1033                 dev->mtu -= ETH_HLEN;
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 < IP6_GRE_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 = gre_flags_to_tnl_flags(
1220                                 nla_get_be16(data[IFLA_GRE_IFLAGS]));
1221
1222         if (data[IFLA_GRE_OFLAGS])
1223                 parms->o_flags = gre_flags_to_tnl_flags(
1224                                 nla_get_be16(data[IFLA_GRE_OFLAGS]));
1225
1226         if (data[IFLA_GRE_IKEY])
1227                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1228
1229         if (data[IFLA_GRE_OKEY])
1230                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1231
1232         if (data[IFLA_GRE_LOCAL])
1233                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1234
1235         if (data[IFLA_GRE_REMOTE])
1236                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1237
1238         if (data[IFLA_GRE_TTL])
1239                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1240
1241         if (data[IFLA_GRE_ENCAP_LIMIT])
1242                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1243
1244         if (data[IFLA_GRE_FLOWINFO])
1245                 parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1246
1247         if (data[IFLA_GRE_FLAGS])
1248                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1249 }
1250
1251 static int ip6gre_tap_init(struct net_device *dev)
1252 {
1253         struct ip6_tnl *tunnel;
1254         int ret;
1255
1256         ret = ip6gre_tunnel_init_common(dev);
1257         if (ret)
1258                 return ret;
1259
1260         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1261
1262         tunnel = netdev_priv(dev);
1263
1264         ip6gre_tnl_link_config(tunnel, 1);
1265
1266         return 0;
1267 }
1268
1269 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1270         .ndo_init = ip6gre_tap_init,
1271         .ndo_uninit = ip6gre_tunnel_uninit,
1272         .ndo_start_xmit = ip6gre_tunnel_xmit,
1273         .ndo_set_mac_address = eth_mac_addr,
1274         .ndo_validate_addr = eth_validate_addr,
1275         .ndo_change_mtu = ip6_tnl_change_mtu,
1276         .ndo_get_stats64 = ip_tunnel_get_stats64,
1277         .ndo_get_iflink = ip6_tnl_get_iflink,
1278 };
1279
1280 #define GRE6_FEATURES (NETIF_F_SG |             \
1281                        NETIF_F_FRAGLIST |       \
1282                        NETIF_F_HIGHDMA |                \
1283                        NETIF_F_HW_CSUM)
1284
1285 static void ip6gre_tap_setup(struct net_device *dev)
1286 {
1287
1288         ether_setup(dev);
1289
1290         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1291         dev->destructor = ip6gre_dev_free;
1292
1293         dev->features |= NETIF_F_NETNS_LOCAL;
1294         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1295         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1296 }
1297
1298 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1299                                        struct ip_tunnel_encap *ipencap)
1300 {
1301         bool ret = false;
1302
1303         memset(ipencap, 0, sizeof(*ipencap));
1304
1305         if (!data)
1306                 return ret;
1307
1308         if (data[IFLA_GRE_ENCAP_TYPE]) {
1309                 ret = true;
1310                 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1311         }
1312
1313         if (data[IFLA_GRE_ENCAP_FLAGS]) {
1314                 ret = true;
1315                 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1316         }
1317
1318         if (data[IFLA_GRE_ENCAP_SPORT]) {
1319                 ret = true;
1320                 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1321         }
1322
1323         if (data[IFLA_GRE_ENCAP_DPORT]) {
1324                 ret = true;
1325                 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1326         }
1327
1328         return ret;
1329 }
1330
1331 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1332         struct nlattr *tb[], struct nlattr *data[])
1333 {
1334         struct ip6_tnl *nt;
1335         struct net *net = dev_net(dev);
1336         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1337         struct ip_tunnel_encap ipencap;
1338         int err;
1339
1340         nt = netdev_priv(dev);
1341
1342         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1343                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1344
1345                 if (err < 0)
1346                         return err;
1347         }
1348
1349         ip6gre_netlink_parms(data, &nt->parms);
1350
1351         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1352                 return -EEXIST;
1353
1354         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1355                 eth_hw_addr_random(dev);
1356
1357         nt->dev = dev;
1358         nt->net = dev_net(dev);
1359         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1360
1361         dev->features           |= GRE6_FEATURES;
1362         dev->hw_features        |= GRE6_FEATURES;
1363
1364         if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1365                 /* TCP offload with GRE SEQ is not supported, nor
1366                  * can we support 2 levels of outer headers requiring
1367                  * an update.
1368                  */
1369                 if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1370                     (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1371                         dev->features    |= NETIF_F_GSO_SOFTWARE;
1372                         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1373                 }
1374
1375                 /* Can use a lockless transmit, unless we generate
1376                  * output sequences
1377                  */
1378                 dev->features |= NETIF_F_LLTX;
1379         }
1380
1381         err = register_netdevice(dev);
1382         if (err)
1383                 goto out;
1384
1385         dev_hold(dev);
1386         ip6gre_tunnel_link(ign, nt);
1387
1388 out:
1389         return err;
1390 }
1391
1392 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1393                             struct nlattr *data[])
1394 {
1395         struct ip6_tnl *t, *nt = netdev_priv(dev);
1396         struct net *net = nt->net;
1397         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1398         struct __ip6_tnl_parm p;
1399         struct ip_tunnel_encap ipencap;
1400
1401         if (dev == ign->fb_tunnel_dev)
1402                 return -EINVAL;
1403
1404         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1405                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1406
1407                 if (err < 0)
1408                         return err;
1409         }
1410
1411         ip6gre_netlink_parms(data, &p);
1412
1413         t = ip6gre_tunnel_locate(net, &p, 0);
1414
1415         if (t) {
1416                 if (t->dev != dev)
1417                         return -EEXIST;
1418         } else {
1419                 t = nt;
1420         }
1421
1422         ip6gre_tunnel_unlink(ign, t);
1423         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1424         ip6gre_tunnel_link(ign, t);
1425         return 0;
1426 }
1427
1428 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1429 {
1430         struct net *net = dev_net(dev);
1431         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1432
1433         if (dev != ign->fb_tunnel_dev)
1434                 unregister_netdevice_queue(dev, head);
1435 }
1436
1437 static size_t ip6gre_get_size(const struct net_device *dev)
1438 {
1439         return
1440                 /* IFLA_GRE_LINK */
1441                 nla_total_size(4) +
1442                 /* IFLA_GRE_IFLAGS */
1443                 nla_total_size(2) +
1444                 /* IFLA_GRE_OFLAGS */
1445                 nla_total_size(2) +
1446                 /* IFLA_GRE_IKEY */
1447                 nla_total_size(4) +
1448                 /* IFLA_GRE_OKEY */
1449                 nla_total_size(4) +
1450                 /* IFLA_GRE_LOCAL */
1451                 nla_total_size(sizeof(struct in6_addr)) +
1452                 /* IFLA_GRE_REMOTE */
1453                 nla_total_size(sizeof(struct in6_addr)) +
1454                 /* IFLA_GRE_TTL */
1455                 nla_total_size(1) +
1456                 /* IFLA_GRE_ENCAP_LIMIT */
1457                 nla_total_size(1) +
1458                 /* IFLA_GRE_FLOWINFO */
1459                 nla_total_size(4) +
1460                 /* IFLA_GRE_FLAGS */
1461                 nla_total_size(4) +
1462                 /* IFLA_GRE_ENCAP_TYPE */
1463                 nla_total_size(2) +
1464                 /* IFLA_GRE_ENCAP_FLAGS */
1465                 nla_total_size(2) +
1466                 /* IFLA_GRE_ENCAP_SPORT */
1467                 nla_total_size(2) +
1468                 /* IFLA_GRE_ENCAP_DPORT */
1469                 nla_total_size(2) +
1470                 0;
1471 }
1472
1473 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1474 {
1475         struct ip6_tnl *t = netdev_priv(dev);
1476         struct __ip6_tnl_parm *p = &t->parms;
1477
1478         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1479             nla_put_be16(skb, IFLA_GRE_IFLAGS,
1480                          gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1481             nla_put_be16(skb, IFLA_GRE_OFLAGS,
1482                          gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1483             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1484             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1485             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1486             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1487             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1488             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1489             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1490             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1491                 goto nla_put_failure;
1492
1493         if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1494                         t->encap.type) ||
1495             nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1496                          t->encap.sport) ||
1497             nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1498                          t->encap.dport) ||
1499             nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1500                         t->encap.flags))
1501                 goto nla_put_failure;
1502
1503         return 0;
1504
1505 nla_put_failure:
1506         return -EMSGSIZE;
1507 }
1508
1509 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1510         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1511         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1512         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1513         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1514         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1515         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1516         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1517         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1518         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1519         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1520         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1521         [IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1522         [IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1523         [IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1524         [IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1525 };
1526
1527 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1528         .kind           = "ip6gre",
1529         .maxtype        = IFLA_GRE_MAX,
1530         .policy         = ip6gre_policy,
1531         .priv_size      = sizeof(struct ip6_tnl),
1532         .setup          = ip6gre_tunnel_setup,
1533         .validate       = ip6gre_tunnel_validate,
1534         .newlink        = ip6gre_newlink,
1535         .changelink     = ip6gre_changelink,
1536         .dellink        = ip6gre_dellink,
1537         .get_size       = ip6gre_get_size,
1538         .fill_info      = ip6gre_fill_info,
1539         .get_link_net   = ip6_tnl_get_link_net,
1540 };
1541
1542 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1543         .kind           = "ip6gretap",
1544         .maxtype        = IFLA_GRE_MAX,
1545         .policy         = ip6gre_policy,
1546         .priv_size      = sizeof(struct ip6_tnl),
1547         .setup          = ip6gre_tap_setup,
1548         .validate       = ip6gre_tap_validate,
1549         .newlink        = ip6gre_newlink,
1550         .changelink     = ip6gre_changelink,
1551         .get_size       = ip6gre_get_size,
1552         .fill_info      = ip6gre_fill_info,
1553         .get_link_net   = ip6_tnl_get_link_net,
1554 };
1555
1556 /*
1557  *      And now the modules code and kernel interface.
1558  */
1559
1560 static int __init ip6gre_init(void)
1561 {
1562         int err;
1563
1564         pr_info("GRE over IPv6 tunneling driver\n");
1565
1566         err = register_pernet_device(&ip6gre_net_ops);
1567         if (err < 0)
1568                 return err;
1569
1570         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1571         if (err < 0) {
1572                 pr_info("%s: can't add protocol\n", __func__);
1573                 goto add_proto_failed;
1574         }
1575
1576         err = rtnl_link_register(&ip6gre_link_ops);
1577         if (err < 0)
1578                 goto rtnl_link_failed;
1579
1580         err = rtnl_link_register(&ip6gre_tap_ops);
1581         if (err < 0)
1582                 goto tap_ops_failed;
1583
1584 out:
1585         return err;
1586
1587 tap_ops_failed:
1588         rtnl_link_unregister(&ip6gre_link_ops);
1589 rtnl_link_failed:
1590         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1591 add_proto_failed:
1592         unregister_pernet_device(&ip6gre_net_ops);
1593         goto out;
1594 }
1595
1596 static void __exit ip6gre_fini(void)
1597 {
1598         rtnl_link_unregister(&ip6gre_tap_ops);
1599         rtnl_link_unregister(&ip6gre_link_ops);
1600         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1601         unregister_pernet_device(&ip6gre_net_ops);
1602 }
1603
1604 module_init(ip6gre_init);
1605 module_exit(ip6gre_fini);
1606 MODULE_LICENSE("GPL");
1607 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1608 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1609 MODULE_ALIAS_RTNL_LINK("ip6gre");
1610 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1611 MODULE_ALIAS_NETDEV("ip6gre0");