net/ipv4/ip_tunnel.c

   1 /*
   2  * Copyright (c) 2013 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301, USA
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/capability.h>
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/in.h>
  30 #include <linux/tcp.h>
  31 #include <linux/udp.h>
  32 #include <linux/if_arp.h>
  33 #include <linux/mroute.h>
  34 #include <linux/init.h>
  35 #include <linux/in6.h>
  36 #include <linux/inetdevice.h>
  37 #include <linux/igmp.h>
  38 #include <linux/netfilter_ipv4.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/if_ether.h>
  41 #include <linux/if_vlan.h>
  42 #include <linux/rculist.h>
  43
  44 #include <net/sock.h>
  45 #include <net/ip.h>
  46 #include <net/icmp.h>
  47 #include <net/protocol.h>
  48 #include <net/ip_tunnels.h>
  49 #include <net/arp.h>
  50 #include <net/checksum.h>
  51 #include <net/dsfield.h>
  52 #include <net/inet_ecn.h>
  53 #include <net/xfrm.h>
  54 #include <net/net_namespace.h>
  55 #include <net/netns/generic.h>
  56 #include <net/rtnetlink.h>
  57
  58 #if IS_ENABLED(CONFIG_IPV6)
  59 #include <net/ipv6.h>
  60 #include <net/ip6_fib.h>
  61 #include <net/ip6_route.h>
  62 #endif
  63
  64 static unsigned int ip_tunnel_hash(struct ip_tunnel_net *itn,
  65                                    __be32 key, __be32 remote)
  66 {
  67         return hash_32((__force u32)key ^ (__force u32)remote,
  68                          IP_TNL_HASH_BITS);
  69 }
  70
  71 /* Often modified stats are per cpu, other are shared (netdev->stats) */
  72 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
  73                                                 struct rtnl_link_stats64 *tot)
  74 {
  75         int i;
  76
  77         for_each_possible_cpu(i) {
  78                 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
  79                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
  80                 unsigned int start;
  81
  82                 do {
  83                         start = u64_stats_fetch_begin_bh(&tstats->syncp);
  84                         rx_packets = tstats->rx_packets;
  85                         tx_packets = tstats->tx_packets;
  86                         rx_bytes = tstats->rx_bytes;
  87                         tx_bytes = tstats->tx_bytes;
  88                 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
  89
  90                 tot->rx_packets += rx_packets;
  91                 tot->tx_packets += tx_packets;
  92                 tot->rx_bytes   += rx_bytes;
  93                 tot->tx_bytes   += tx_bytes;
  94         }
  95
  96         tot->multicast = dev->stats.multicast;
  97
  98         tot->rx_crc_errors = dev->stats.rx_crc_errors;
  99         tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
 100         tot->rx_length_errors = dev->stats.rx_length_errors;
 101         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 102         tot->rx_errors = dev->stats.rx_errors;
 103
 104         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 105         tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
 106         tot->tx_dropped = dev->stats.tx_dropped;
 107         tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
 108         tot->tx_errors = dev->stats.tx_errors;
 109
 110         tot->collisions  = dev->stats.collisions;
 111
 112         return tot;
 113 }
 114 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
 115
 116 static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p,
 117                                 __be16 flags, __be32 key)
 118 {
 119         if (p->i_flags & TUNNEL_KEY) {
 120                 if (flags & TUNNEL_KEY)
 121                         return key == p->i_key;
 122                 else
 123                         /* key expected, none present */
 124                         return false;
 125         } else
 126                 return !(flags & TUNNEL_KEY);
 127 }
 128
 129 /* Fallback tunnel: no source, no destination, no key, no options
 130
 131    Tunnel hash table:
 132    We require exact key match i.e. if a key is present in packet
 133    it will match only tunnel with the same key; if it is not present,
 134    it will match only keyless tunnel.
 135
 136    All keysless packets, if not matched configured keyless tunnels
 137    will match fallback tunnel.
 138    Given src, dst and key, find appropriate for input tunnel.
 139 */
 140 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 141                                    int link, __be16 flags,
 142                                    __be32 remote, __be32 local,
 143                                    __be32 key)
 144 {
 145         unsigned int hash;
 146         struct ip_tunnel *t, *cand = NULL;
 147         struct hlist_head *head;
 148
 149         hash = ip_tunnel_hash(itn, key, remote);
 150         head = &itn->tunnels[hash];
 151
 152         hlist_for_each_entry_rcu(t, head, hash_node) {
 153                 if (local != t->parms.iph.saddr ||
 154                     remote != t->parms.iph.daddr ||
 155                     !(t->dev->flags & IFF_UP))
 156                         continue;
 157
 158                 if (!ip_tunnel_key_match(&t->parms, flags, key))
 159                         continue;
 160
 161                 if (t->parms.link == link)
 162                         return t;
 163                 else
 164                         cand = t;
 165         }
 166
 167         hlist_for_each_entry_rcu(t, head, hash_node) {
 168                 if (remote != t->parms.iph.daddr ||
 169                     !(t->dev->flags & IFF_UP))
 170                         continue;
 171
 172                 if (!ip_tunnel_key_match(&t->parms, flags, key))
 173                         continue;
 174
 175                 if (t->parms.link == link)
 176                         return t;
 177                 else if (!cand)
 178                         cand = t;
 179         }
 180
 181         hash = ip_tunnel_hash(itn, key, 0);
 182         head = &itn->tunnels[hash];
 183
 184         hlist_for_each_entry_rcu(t, head, hash_node) {
 185                 if ((local != t->parms.iph.saddr &&
 186                      (local != t->parms.iph.daddr ||
 187                       !ipv4_is_multicast(local))) ||
 188                     !(t->dev->flags & IFF_UP))
 189                         continue;
 190
 191                 if (!ip_tunnel_key_match(&t->parms, flags, key))
 192                         continue;
 193
 194                 if (t->parms.link == link)
 195                         return t;
 196                 else if (!cand)
 197                         cand = t;
 198         }
 199
 200         if (flags & TUNNEL_NO_KEY)
 201                 goto skip_key_lookup;
 202
 203         hlist_for_each_entry_rcu(t, head, hash_node) {
 204                 if (t->parms.i_key != key ||
 205                     !(t->dev->flags & IFF_UP))
 206                         continue;
 207
 208                 if (t->parms.link == link)
 209                         return t;
 210                 else if (!cand)
 211                         cand = t;
 212         }
 213
 214 skip_key_lookup:
 215         if (cand)
 216                 return cand;
 217
 218         if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)
 219                 return netdev_priv(itn->fb_tunnel_dev);
 220
 221
 222         return NULL;
 223 }
 224 EXPORT_SYMBOL_GPL(ip_tunnel_lookup);
 225
 226 static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn,
 227                                     struct ip_tunnel_parm *parms)
 228 {
 229         unsigned int h;
 230         __be32 remote;
 231
 232         if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr))
 233                 remote = parms->iph.daddr;
 234         else
 235                 remote = 0;
 236
 237         h = ip_tunnel_hash(itn, parms->i_key, remote);
 238         return &itn->tunnels[h];
 239 }
 240
 241 static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t)
 242 {
 243         struct hlist_head *head = ip_bucket(itn, &t->parms);
 244
 245         hlist_add_head_rcu(&t->hash_node, head);
 246 }
 247
 248 static void ip_tunnel_del(struct ip_tunnel *t)
 249 {
 250         hlist_del_init_rcu(&t->hash_node);
 251 }
 252
 253 static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
 254                                         struct ip_tunnel_parm *parms,
 255                                         int type)
 256 {
 257         __be32 remote = parms->iph.daddr;
 258         __be32 local = parms->iph.saddr;
 259         __be32 key = parms->i_key;
 260         int link = parms->link;
 261         struct ip_tunnel *t = NULL;
 262         struct hlist_head *head = ip_bucket(itn, parms);
 263
 264         hlist_for_each_entry_rcu(t, head, hash_node) {
 265                 if (local == t->parms.iph.saddr &&
 266                     remote == t->parms.iph.daddr &&
 267                     key == t->parms.i_key &&
 268                     link == t->parms.link &&
 269                     type == t->dev->type)
 270                         break;
 271         }
 272         return t;
 273 }
 274
 275 static struct net_device *__ip_tunnel_create(struct net *net,
 276                                              const struct rtnl_link_ops *ops,
 277                                              struct ip_tunnel_parm *parms)
 278 {
 279         int err;
 280         struct ip_tunnel *tunnel;
 281         struct net_device *dev;
 282         char name[IFNAMSIZ];
 283
 284         if (parms->name[0])
 285                 strlcpy(name, parms->name, IFNAMSIZ);
 286         else {
 287                 if (strlen(ops->kind) > (IFNAMSIZ - 3)) {
 288                         err = -E2BIG;
 289                         goto failed;
 290                 }
 291                 strlcpy(name, ops->kind, IFNAMSIZ);
 292                 strncat(name, "%d", 2);
 293         }
 294
 295         ASSERT_RTNL();
 296         dev = alloc_netdev(ops->priv_size, name, ops->setup);
 297         if (!dev) {
 298                 err = -ENOMEM;
 299                 goto failed;
 300         }
 301         dev_net_set(dev, net);
 302
 303         dev->rtnl_link_ops = ops;
 304
 305         tunnel = netdev_priv(dev);
 306         tunnel->parms = *parms;
 307         tunnel->net = net;
 308
 309         err = register_netdevice(dev);
 310         if (err)
 311                 goto failed_free;
 312
 313         return dev;
 314
 315 failed_free:
 316         free_netdev(dev);
 317 failed:
 318         return ERR_PTR(err);
 319 }
 320
 321 static inline struct rtable *ip_route_output_tunnel(struct net *net,
 322                                                     struct flowi4 *fl4,
 323                                                     int proto,
 324                                                     __be32 daddr, __be32 saddr,
 325                                                     __be32 key, __u8 tos, int oif)
 326 {
 327         memset(fl4, 0, sizeof(*fl4));
 328         fl4->flowi4_oif = oif;
 329         fl4->daddr = daddr;
 330         fl4->saddr = saddr;
 331         fl4->flowi4_tos = tos;
 332         fl4->flowi4_proto = proto;
 333         fl4->fl4_gre_key = key;
 334         return ip_route_output_key(net, fl4);
 335 }
 336
 337 static int ip_tunnel_bind_dev(struct net_device *dev)
 338 {
 339         struct net_device *tdev = NULL;
 340         struct ip_tunnel *tunnel = netdev_priv(dev);
 341         const struct iphdr *iph;
 342         int hlen = LL_MAX_HEADER;
 343         int mtu = ETH_DATA_LEN;
 344         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 345
 346         iph = &tunnel->parms.iph;
 347
 348         /* Guess output device to choose reasonable mtu and needed_headroom */
 349         if (iph->daddr) {
 350                 struct flowi4 fl4;
 351                 struct rtable *rt;
 352
 353                 rt = ip_route_output_tunnel(dev_net(dev), &fl4,
 354                                             tunnel->parms.iph.protocol,
 355                                             iph->daddr, iph->saddr,
 356                                             tunnel->parms.o_key,
 357                                             RT_TOS(iph->tos),
 358                                             tunnel->parms.link);
 359                 if (!IS_ERR(rt)) {
 360                         tdev = rt->dst.dev;
 361                         ip_rt_put(rt);
 362                 }
 363                 if (dev->type != ARPHRD_ETHER)
 364                         dev->flags |= IFF_POINTOPOINT;
 365         }
 366
 367         if (!tdev && tunnel->parms.link)
 368                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 369
 370         if (tdev) {
 371                 hlen = tdev->hard_header_len + tdev->needed_headroom;
 372                 mtu = tdev->mtu;
 373         }
 374         dev->iflink = tunnel->parms.link;
 375
 376         dev->needed_headroom = t_hlen + hlen;
 377         mtu -= (dev->hard_header_len + t_hlen);
 378
 379         if (mtu < 68)
 380                 mtu = 68;
 381
 382         return mtu;
 383 }
 384
 385 static struct ip_tunnel *ip_tunnel_create(struct net *net,
 386                                           struct ip_tunnel_net *itn,
 387                                           struct ip_tunnel_parm *parms)
 388 {
 389         struct ip_tunnel *nt, *fbt;
 390         struct net_device *dev;
 391
 392         BUG_ON(!itn->fb_tunnel_dev);
 393         fbt = netdev_priv(itn->fb_tunnel_dev);
 394         dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops, parms);
 395         if (IS_ERR(dev))
 396                 return NULL;
 397
 398         dev->mtu = ip_tunnel_bind_dev(dev);
 399
 400         nt = netdev_priv(dev);
 401         ip_tunnel_add(itn, nt);
 402         return nt;
 403 }
 404
 405 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 406                   const struct tnl_ptk_info *tpi, bool log_ecn_error)
 407 {
 408         struct pcpu_tstats *tstats;
 409         const struct iphdr *iph = ip_hdr(skb);
 410         int err;
 411
 412 #ifdef CONFIG_NET_IPGRE_BROADCAST
 413         if (ipv4_is_multicast(iph->daddr)) {
 414                 /* Looped back packet, drop it! */
 415                 if (rt_is_output_route(skb_rtable(skb)))
 416                         goto drop;
 417                 tunnel->dev->stats.multicast++;
 418                 skb->pkt_type = PACKET_BROADCAST;
 419         }
 420 #endif
 421
 422         if ((!(tpi->flags&TUNNEL_CSUM) &&  (tunnel->parms.i_flags&TUNNEL_CSUM)) ||
 423              ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) {
 424                 tunnel->dev->stats.rx_crc_errors++;
 425                 tunnel->dev->stats.rx_errors++;
 426                 goto drop;
 427         }
 428
 429         if (tunnel->parms.i_flags&TUNNEL_SEQ) {
 430                 if (!(tpi->flags&TUNNEL_SEQ) ||
 431                     (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 432                         tunnel->dev->stats.rx_fifo_errors++;
 433                         tunnel->dev->stats.rx_errors++;
 434                         goto drop;
 435                 }
 436                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 437         }
 438
 439         err = IP_ECN_decapsulate(iph, skb);
 440         if (unlikely(err)) {
 441                 if (log_ecn_error)
 442                         net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 443                                         &iph->saddr, iph->tos);
 444                 if (err > 1) {
 445                         ++tunnel->dev->stats.rx_frame_errors;
 446                         ++tunnel->dev->stats.rx_errors;
 447                         goto drop;
 448                 }
 449         }
 450
 451         tstats = this_cpu_ptr(tunnel->dev->tstats);
 452         u64_stats_update_begin(&tstats->syncp);
 453         tstats->rx_packets++;
 454         tstats->rx_bytes += skb->len;
 455         u64_stats_update_end(&tstats->syncp);
 456
 457         if (tunnel->net != dev_net(tunnel->dev))
 458                 skb_scrub_packet(skb);
 459
 460         if (tunnel->dev->type == ARPHRD_ETHER) {
 461                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 462                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 463         } else {
 464                 skb->dev = tunnel->dev;
 465         }
 466         gro_cells_receive(&tunnel->gro_cells, skb);
 467         return 0;
 468
 469 drop:
 470         kfree_skb(skb);
 471         return 0;
 472 }
 473 EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
 474
 475 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
 476                             struct rtable *rt, __be16 df)
 477 {
 478         struct ip_tunnel *tunnel = netdev_priv(dev);
 479         int pkt_size = skb->len - tunnel->hlen;
 480         int mtu;
 481
 482         if (df)
 483                 mtu = dst_mtu(&rt->dst) - dev->hard_header_len
 484                                         - sizeof(struct iphdr) - tunnel->hlen;
 485         else
 486                 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
 487
 488         if (skb_dst(skb))
 489                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 490
 491         if (skb->protocol == htons(ETH_P_IP)) {
 492                 if (!skb_is_gso(skb) &&
 493                     (df & htons(IP_DF)) && mtu < pkt_size) {
 494                         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 495                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
 496                         return -E2BIG;
 497                 }
 498         }
 499 #if IS_ENABLED(CONFIG_IPV6)
 500         else if (skb->protocol == htons(ETH_P_IPV6)) {
 501                 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
 502
 503                 if (rt6 && mtu < dst_mtu(skb_dst(skb)) &&
 504                            mtu >= IPV6_MIN_MTU) {
 505                         if ((tunnel->parms.iph.daddr &&
 506                             !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
 507                             rt6->rt6i_dst.plen == 128) {
 508                                 rt6->rt6i_flags |= RTF_MODIFIED;
 509                                 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
 510                         }
 511                 }
 512
 513                 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU &&
 514                                         mtu < pkt_size) {
 515                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 516                         return -E2BIG;
 517                 }
 518         }
 519 #endif
 520         return 0;
 521 }
 522
 523 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 524                     const struct iphdr *tnl_params, const u8 protocol)
 525 {
 526         struct ip_tunnel *tunnel = netdev_priv(dev);
 527         const struct iphdr *inner_iph;
 528         struct flowi4 fl4;
 529         u8     tos, ttl;
 530         __be16 df;
 531         struct rtable *rt;              /* Route to the other host */
 532         unsigned int max_headroom;      /* The extra header space needed */
 533         __be32 dst;
 534         int err;
 535
 536         inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
 537
 538         dst = tnl_params->daddr;
 539         if (dst == 0) {
 540                 /* NBMA tunnel */
 541
 542                 if (skb_dst(skb) == NULL) {
 543                         dev->stats.tx_fifo_errors++;
 544                         goto tx_error;
 545                 }
 546
 547                 if (skb->protocol == htons(ETH_P_IP)) {
 548                         rt = skb_rtable(skb);
 549                         dst = rt_nexthop(rt, inner_iph->daddr);
 550                 }
 551 #if IS_ENABLED(CONFIG_IPV6)
 552                 else if (skb->protocol == htons(ETH_P_IPV6)) {
 553                         const struct in6_addr *addr6;
 554                         struct neighbour *neigh;
 555                         bool do_tx_error_icmp;
 556                         int addr_type;
 557
 558                         neigh = dst_neigh_lookup(skb_dst(skb),
 559                                                  &ipv6_hdr(skb)->daddr);
 560                         if (neigh == NULL)
 561                                 goto tx_error;
 562
 563                         addr6 = (const struct in6_addr *)&neigh->primary_key;
 564                         addr_type = ipv6_addr_type(addr6);
 565
 566                         if (addr_type == IPV6_ADDR_ANY) {
 567                                 addr6 = &ipv6_hdr(skb)->daddr;
 568                                 addr_type = ipv6_addr_type(addr6);
 569                         }
 570
 571                         if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
 572                                 do_tx_error_icmp = true;
 573                         else {
 574                                 do_tx_error_icmp = false;
 575                                 dst = addr6->s6_addr32[3];
 576                         }
 577                         neigh_release(neigh);
 578                         if (do_tx_error_icmp)
 579                                 goto tx_error_icmp;
 580                 }
 581 #endif
 582                 else
 583                         goto tx_error;
 584         }
 585
 586         tos = tnl_params->tos;
 587         if (tos & 0x1) {
 588                 tos &= ~0x1;
 589                 if (skb->protocol == htons(ETH_P_IP))
 590                         tos = inner_iph->tos;
 591                 else if (skb->protocol == htons(ETH_P_IPV6))
 592                         tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
 593         }
 594
 595         rt = ip_route_output_tunnel(tunnel->net, &fl4,
 596                                     protocol,
 597                                     dst, tnl_params->saddr,
 598                                     tunnel->parms.o_key,
 599                                     RT_TOS(tos),
 600                                     tunnel->parms.link);
 601         if (IS_ERR(rt)) {
 602                 dev->stats.tx_carrier_errors++;
 603                 goto tx_error;
 604         }
 605         if (rt->dst.dev == dev) {
 606                 ip_rt_put(rt);
 607                 dev->stats.collisions++;
 608                 goto tx_error;
 609         }
 610
 611         if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) {
 612                 ip_rt_put(rt);
 613                 goto tx_error;
 614         }
 615
 616         if (tunnel->net != dev_net(dev))
 617                 skb_scrub_packet(skb);
 618
 619         if (tunnel->err_count > 0) {
 620                 if (time_before(jiffies,
 621                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 622                         tunnel->err_count--;
 623
 624                         dst_link_failure(skb);
 625                 } else
 626                         tunnel->err_count = 0;
 627         }
 628
 629         ttl = tnl_params->ttl;
 630         if (ttl == 0) {
 631                 if (skb->protocol == htons(ETH_P_IP))
 632                         ttl = inner_iph->ttl;
 633 #if IS_ENABLED(CONFIG_IPV6)
 634                 else if (skb->protocol == htons(ETH_P_IPV6))
 635                         ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
 636 #endif
 637                 else
 638                         ttl = ip4_dst_hoplimit(&rt->dst);
 639         }
 640
 641         df = tnl_params->frag_off;
 642         if (skb->protocol == htons(ETH_P_IP))
 643                 df |= (inner_iph->frag_off&htons(IP_DF));
 644
 645         max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
 646                         + rt->dst.header_len;
 647         if (max_headroom > dev->needed_headroom) {
 648                 dev->needed_headroom = max_headroom;
 649                 if (skb_cow_head(skb, dev->needed_headroom)) {
 650                         dev->stats.tx_dropped++;
 651                         dev_kfree_skb(skb);
 652                         return;
 653                 }
 654         }
 655
 656         err = iptunnel_xmit(dev_net(dev), rt, skb,
 657                             fl4.saddr, fl4.daddr, protocol,
 658                             ip_tunnel_ecn_encap(tos, inner_iph, skb), ttl, df);
 659         iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 660
 661         return;
 662
 663 #if IS_ENABLED(CONFIG_IPV6)
 664 tx_error_icmp:
 665         dst_link_failure(skb);
 666 #endif
 667 tx_error:
 668         dev->stats.tx_errors++;
 669         dev_kfree_skb(skb);
 670 }
 671 EXPORT_SYMBOL_GPL(ip_tunnel_xmit);
 672
 673 static void ip_tunnel_update(struct ip_tunnel_net *itn,
 674                              struct ip_tunnel *t,
 675                              struct net_device *dev,
 676                              struct ip_tunnel_parm *p,
 677                              bool set_mtu)
 678 {
 679         ip_tunnel_del(t);
 680         t->parms.iph.saddr = p->iph.saddr;
 681         t->parms.iph.daddr = p->iph.daddr;
 682         t->parms.i_key = p->i_key;
 683         t->parms.o_key = p->o_key;
 684         if (dev->type != ARPHRD_ETHER) {
 685                 memcpy(dev->dev_addr, &p->iph.saddr, 4);
 686                 memcpy(dev->broadcast, &p->iph.daddr, 4);
 687         }
 688         ip_tunnel_add(itn, t);
 689
 690         t->parms.iph.ttl = p->iph.ttl;
 691         t->parms.iph.tos = p->iph.tos;
 692         t->parms.iph.frag_off = p->iph.frag_off;
 693
 694         if (t->parms.link != p->link) {
 695                 int mtu;
 696
 697                 t->parms.link = p->link;
 698                 mtu = ip_tunnel_bind_dev(dev);
 699                 if (set_mtu)
 700                         dev->mtu = mtu;
 701         }
 702         netdev_state_change(dev);
 703 }
 704
 705 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
 706 {
 707         int err = 0;
 708         struct ip_tunnel *t;
 709         struct net *net = dev_net(dev);
 710         struct ip_tunnel *tunnel = netdev_priv(dev);
 711         struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
 712
 713         BUG_ON(!itn->fb_tunnel_dev);
 714         switch (cmd) {
 715         case SIOCGETTUNNEL:
 716                 t = NULL;
 717                 if (dev == itn->fb_tunnel_dev)
 718                         t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 719                 if (t == NULL)
 720                         t = netdev_priv(dev);
 721                 memcpy(p, &t->parms, sizeof(*p));
 722                 break;
 723
 724         case SIOCADDTUNNEL:
 725         case SIOCCHGTUNNEL:
 726                 err = -EPERM;
 727                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 728                         goto done;
 729                 if (p->iph.ttl)
 730                         p->iph.frag_off |= htons(IP_DF);
 731                 if (!(p->i_flags&TUNNEL_KEY))
 732                         p->i_key = 0;
 733                 if (!(p->o_flags&TUNNEL_KEY))
 734                         p->o_key = 0;
 735
 736                 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 737
 738                 if (!t && (cmd == SIOCADDTUNNEL))
 739                         t = ip_tunnel_create(net, itn, p);
 740
 741                 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 742                         if (t != NULL) {
 743                                 if (t->dev != dev) {
 744                                         err = -EEXIST;
 745                                         break;
 746                                 }
 747                         } else {
 748                                 unsigned int nflags = 0;
 749
 750                                 if (ipv4_is_multicast(p->iph.daddr))
 751                                         nflags = IFF_BROADCAST;
 752                                 else if (p->iph.daddr)
 753                                         nflags = IFF_POINTOPOINT;
 754
 755                                 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
 756                                         err = -EINVAL;
 757                                         break;
 758                                 }
 759
 760                                 t = netdev_priv(dev);
 761                         }
 762                 }
 763
 764                 if (t) {
 765                         err = 0;
 766                         ip_tunnel_update(itn, t, dev, p, true);
 767                 } else
 768                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 769                 break;
 770
 771         case SIOCDELTUNNEL:
 772                 err = -EPERM;
 773                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 774                         goto done;
 775
 776                 if (dev == itn->fb_tunnel_dev) {
 777                         err = -ENOENT;
 778                         t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 779                         if (t == NULL)
 780                                 goto done;
 781                         err = -EPERM;
 782                         if (t == netdev_priv(itn->fb_tunnel_dev))
 783                                 goto done;
 784                         dev = t->dev;
 785                 }
 786                 unregister_netdevice(dev);
 787                 err = 0;
 788                 break;
 789
 790         default:
 791                 err = -EINVAL;
 792         }
 793
 794 done:
 795         return err;
 796 }
 797 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
 798
 799 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
 800 {
 801         struct ip_tunnel *tunnel = netdev_priv(dev);
 802         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 803
 804         if (new_mtu < 68 ||
 805             new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
 806                 return -EINVAL;
 807         dev->mtu = new_mtu;
 808         return 0;
 809 }
 810 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
 811
 812 static void ip_tunnel_dev_free(struct net_device *dev)
 813 {
 814         struct ip_tunnel *tunnel = netdev_priv(dev);
 815
 816         gro_cells_destroy(&tunnel->gro_cells);
 817         free_percpu(dev->tstats);
 818         free_netdev(dev);
 819 }
 820
 821 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head)
 822 {
 823         struct net *net = dev_net(dev);
 824         struct ip_tunnel *tunnel = netdev_priv(dev);
 825         struct ip_tunnel_net *itn;
 826
 827         itn = net_generic(net, tunnel->ip_tnl_net_id);
 828
 829         if (itn->fb_tunnel_dev != dev) {
 830                 ip_tunnel_del(netdev_priv(dev));
 831                 unregister_netdevice_queue(dev, head);
 832         }
 833 }
 834 EXPORT_SYMBOL_GPL(ip_tunnel_dellink);
 835
 836 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 837                                   struct rtnl_link_ops *ops, char *devname)
 838 {
 839         struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id);
 840         struct ip_tunnel_parm parms;
 841
 842         itn->tunnels = kzalloc(IP_TNL_HASH_SIZE * sizeof(struct hlist_head), GFP_KERNEL);
 843         if (!itn->tunnels)
 844                 return -ENOMEM;
 845
 846         if (!ops) {
 847                 itn->fb_tunnel_dev = NULL;
 848                 return 0;
 849         }
 850         memset(&parms, 0, sizeof(parms));
 851         if (devname)
 852                 strlcpy(parms.name, devname, IFNAMSIZ);
 853
 854         rtnl_lock();
 855         itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms);
 856         rtnl_unlock();
 857         if (IS_ERR(itn->fb_tunnel_dev)) {
 858                 kfree(itn->tunnels);
 859                 return PTR_ERR(itn->fb_tunnel_dev);
 860         }
 861
 862         return 0;
 863 }
 864 EXPORT_SYMBOL_GPL(ip_tunnel_init_net);
 865
 866 static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head)
 867 {
 868         int h;
 869
 870         for (h = 0; h < IP_TNL_HASH_SIZE; h++) {
 871                 struct ip_tunnel *t;
 872                 struct hlist_node *n;
 873                 struct hlist_head *thead = &itn->tunnels[h];
 874
 875                 hlist_for_each_entry_safe(t, n, thead, hash_node)
 876                         unregister_netdevice_queue(t->dev, head);
 877         }
 878         if (itn->fb_tunnel_dev)
 879                 unregister_netdevice_queue(itn->fb_tunnel_dev, head);
 880 }
 881
 882 void ip_tunnel_delete_net(struct ip_tunnel_net *itn)
 883 {
 884         LIST_HEAD(list);
 885
 886         rtnl_lock();
 887         ip_tunnel_destroy(itn, &list);
 888         unregister_netdevice_many(&list);
 889         rtnl_unlock();
 890         kfree(itn->tunnels);
 891 }
 892 EXPORT_SYMBOL_GPL(ip_tunnel_delete_net);
 893
 894 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 895                       struct ip_tunnel_parm *p)
 896 {
 897         struct ip_tunnel *nt;
 898         struct net *net = dev_net(dev);
 899         struct ip_tunnel_net *itn;
 900         int mtu;
 901         int err;
 902
 903         nt = netdev_priv(dev);
 904         itn = net_generic(net, nt->ip_tnl_net_id);
 905
 906         if (ip_tunnel_find(itn, p, dev->type))
 907                 return -EEXIST;
 908
 909         nt->net = net;
 910         nt->parms = *p;
 911         err = register_netdevice(dev);
 912         if (err)
 913                 goto out;
 914
 915         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
 916                 eth_hw_addr_random(dev);
 917
 918         mtu = ip_tunnel_bind_dev(dev);
 919         if (!tb[IFLA_MTU])
 920                 dev->mtu = mtu;
 921
 922         ip_tunnel_add(itn, nt);
 923
 924 out:
 925         return err;
 926 }
 927 EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
 928
 929 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 930                          struct ip_tunnel_parm *p)
 931 {
 932         struct ip_tunnel *t, *nt;
 933         struct net *net = dev_net(dev);
 934         struct ip_tunnel *tunnel = netdev_priv(dev);
 935         struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
 936
 937         if (dev == itn->fb_tunnel_dev)
 938                 return -EINVAL;
 939
 940         nt = netdev_priv(dev);
 941
 942         t = ip_tunnel_find(itn, p, dev->type);
 943
 944         if (t) {
 945                 if (t->dev != dev)
 946                         return -EEXIST;
 947         } else {
 948                 t = nt;
 949
 950                 if (dev->type != ARPHRD_ETHER) {
 951                         unsigned int nflags = 0;
 952
 953                         if (ipv4_is_multicast(p->iph.daddr))
 954                                 nflags = IFF_BROADCAST;
 955                         else if (p->iph.daddr)
 956                                 nflags = IFF_POINTOPOINT;
 957
 958                         if ((dev->flags ^ nflags) &
 959                             (IFF_POINTOPOINT | IFF_BROADCAST))
 960                                 return -EINVAL;
 961                 }
 962         }
 963
 964         ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU]);
 965         return 0;
 966 }
 967 EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
 968
 969 int ip_tunnel_init(struct net_device *dev)
 970 {
 971         struct ip_tunnel *tunnel = netdev_priv(dev);
 972         struct iphdr *iph = &tunnel->parms.iph;
 973         int err;
 974
 975         dev->destructor = ip_tunnel_dev_free;
 976         dev->tstats = alloc_percpu(struct pcpu_tstats);
 977         if (!dev->tstats)
 978                 return -ENOMEM;
 979
 980         err = gro_cells_init(&tunnel->gro_cells, dev);
 981         if (err) {
 982                 free_percpu(dev->tstats);
 983                 return err;
 984         }
 985
 986         tunnel->dev = dev;
 987         strcpy(tunnel->parms.name, dev->name);
 988         iph->version            = 4;
 989         iph->ihl                = 5;
 990
 991         return 0;
 992 }
 993 EXPORT_SYMBOL_GPL(ip_tunnel_init);
 994
 995 void ip_tunnel_uninit(struct net_device *dev)
 996 {
 997         struct net *net = dev_net(dev);
 998         struct ip_tunnel *tunnel = netdev_priv(dev);
 999         struct ip_tunnel_net *itn;
1000
1001         itn = net_generic(net, tunnel->ip_tnl_net_id);
1002         /* fb_tunnel_dev will be unregisted in net-exit call. */
1003         if (itn->fb_tunnel_dev != dev)
1004                 ip_tunnel_del(netdev_priv(dev));
1005 }
1006 EXPORT_SYMBOL_GPL(ip_tunnel_uninit);
1007
1008 /* Do least required initialization, rest of init is done in tunnel_init call */
1009 void ip_tunnel_setup(struct net_device *dev, int net_id)
1010 {
1011         struct ip_tunnel *tunnel = netdev_priv(dev);
1012         tunnel->ip_tnl_net_id = net_id;
1013 }
1014 EXPORT_SYMBOL_GPL(ip_tunnel_setup);
1015
1016 MODULE_LICENSE("GPL");