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
 308         err = register_netdevice(dev);
 309         if (err)
 310                 goto failed_free;
 311
 312         return dev;
 313
 314 failed_free:
 315         free_netdev(dev);
 316 failed:
 317         return ERR_PTR(err);
 318 }
 319
 320 static inline struct rtable *ip_route_output_tunnel(struct net *net,
 321                                                     struct flowi4 *fl4,
 322                                                     int proto,
 323                                                     __be32 daddr, __be32 saddr,
 324                                                     __be32 key, __u8 tos, int oif)
 325 {
 326         memset(fl4, 0, sizeof(*fl4));
 327         fl4->flowi4_oif = oif;
 328         fl4->daddr = daddr;
 329         fl4->saddr = saddr;
 330         fl4->flowi4_tos = tos;
 331         fl4->flowi4_proto = proto;
 332         fl4->fl4_gre_key = key;
 333         return ip_route_output_key(net, fl4);
 334 }
 335
 336 static int ip_tunnel_bind_dev(struct net_device *dev)
 337 {
 338         struct net_device *tdev = NULL;
 339         struct ip_tunnel *tunnel = netdev_priv(dev);
 340         const struct iphdr *iph;
 341         int hlen = LL_MAX_HEADER;
 342         int mtu = ETH_DATA_LEN;
 343         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 344
 345         iph = &tunnel->parms.iph;
 346
 347         /* Guess output device to choose reasonable mtu and needed_headroom */
 348         if (iph->daddr) {
 349                 struct flowi4 fl4;
 350                 struct rtable *rt;
 351
 352                 rt = ip_route_output_tunnel(dev_net(dev), &fl4,
 353                                             tunnel->parms.iph.protocol,
 354                                             iph->daddr, iph->saddr,
 355                                             tunnel->parms.o_key,
 356                                             RT_TOS(iph->tos),
 357                                             tunnel->parms.link);
 358                 if (!IS_ERR(rt)) {
 359                         tdev = rt->dst.dev;
 360                         ip_rt_put(rt);
 361                 }
 362                 if (dev->type != ARPHRD_ETHER)
 363                         dev->flags |= IFF_POINTOPOINT;
 364         }
 365
 366         if (!tdev && tunnel->parms.link)
 367                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 368
 369         if (tdev) {
 370                 hlen = tdev->hard_header_len + tdev->needed_headroom;
 371                 mtu = tdev->mtu;
 372         }
 373         dev->iflink = tunnel->parms.link;
 374
 375         dev->needed_headroom = t_hlen + hlen;
 376         mtu -= (dev->hard_header_len + t_hlen);
 377
 378         if (mtu < 68)
 379                 mtu = 68;
 380
 381         return mtu;
 382 }
 383
 384 static struct ip_tunnel *ip_tunnel_create(struct net *net,
 385                                           struct ip_tunnel_net *itn,
 386                                           struct ip_tunnel_parm *parms)
 387 {
 388         struct ip_tunnel *nt, *fbt;
 389         struct net_device *dev;
 390
 391         BUG_ON(!itn->fb_tunnel_dev);
 392         fbt = netdev_priv(itn->fb_tunnel_dev);
 393         dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops, parms);
 394         if (IS_ERR(dev))
 395                 return NULL;
 396
 397         dev->mtu = ip_tunnel_bind_dev(dev);
 398
 399         nt = netdev_priv(dev);
 400         ip_tunnel_add(itn, nt);
 401         return nt;
 402 }
 403
 404 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 405                   const struct tnl_ptk_info *tpi, bool log_ecn_error)
 406 {
 407         struct pcpu_tstats *tstats;
 408         const struct iphdr *iph = ip_hdr(skb);
 409         int err;
 410
 411         secpath_reset(skb);
 412
 413         skb->protocol = tpi->proto;
 414
 415         skb->mac_header = skb->network_header;
 416         __pskb_pull(skb, tunnel->hlen);
 417         skb_postpull_rcsum(skb, skb_transport_header(skb), tunnel->hlen);
 418 #ifdef CONFIG_NET_IPGRE_BROADCAST
 419         if (ipv4_is_multicast(iph->daddr)) {
 420                 /* Looped back packet, drop it! */
 421                 if (rt_is_output_route(skb_rtable(skb)))
 422                         goto drop;
 423                 tunnel->dev->stats.multicast++;
 424                 skb->pkt_type = PACKET_BROADCAST;
 425         }
 426 #endif
 427
 428         if ((!(tpi->flags&TUNNEL_CSUM) &&  (tunnel->parms.i_flags&TUNNEL_CSUM)) ||
 429              ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) {
 430                 tunnel->dev->stats.rx_crc_errors++;
 431                 tunnel->dev->stats.rx_errors++;
 432                 goto drop;
 433         }
 434
 435         if (tunnel->parms.i_flags&TUNNEL_SEQ) {
 436                 if (!(tpi->flags&TUNNEL_SEQ) ||
 437                     (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 438                         tunnel->dev->stats.rx_fifo_errors++;
 439                         tunnel->dev->stats.rx_errors++;
 440                         goto drop;
 441                 }
 442                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 443         }
 444
 445         /* Warning: All skb pointers will be invalidated! */
 446         if (tunnel->dev->type == ARPHRD_ETHER) {
 447                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 448                         tunnel->dev->stats.rx_length_errors++;
 449                         tunnel->dev->stats.rx_errors++;
 450                         goto drop;
 451                 }
 452
 453                 iph = ip_hdr(skb);
 454                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 455                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 456         }
 457
 458         skb->pkt_type = PACKET_HOST;
 459         __skb_tunnel_rx(skb, tunnel->dev);
 460
 461         skb_reset_network_header(skb);
 462         err = IP_ECN_decapsulate(iph, skb);
 463         if (unlikely(err)) {
 464                 if (log_ecn_error)
 465                         net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 466                                         &iph->saddr, iph->tos);
 467                 if (err > 1) {
 468                         ++tunnel->dev->stats.rx_frame_errors;
 469                         ++tunnel->dev->stats.rx_errors;
 470                         goto drop;
 471                 }
 472         }
 473
 474         tstats = this_cpu_ptr(tunnel->dev->tstats);
 475         u64_stats_update_begin(&tstats->syncp);
 476         tstats->rx_packets++;
 477         tstats->rx_bytes += skb->len;
 478         u64_stats_update_end(&tstats->syncp);
 479
 480         gro_cells_receive(&tunnel->gro_cells, skb);
 481         return 0;
 482
 483 drop:
 484         kfree_skb(skb);
 485         return 0;
 486 }
 487 EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
 488
 489 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
 490                             struct rtable *rt, __be16 df)
 491 {
 492         struct ip_tunnel *tunnel = netdev_priv(dev);
 493         int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len;
 494         int mtu;
 495
 496         if (df)
 497                 mtu = dst_mtu(&rt->dst) - dev->hard_header_len
 498                                         - sizeof(struct iphdr) - tunnel->hlen;
 499         else
 500                 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
 501
 502         if (skb_dst(skb))
 503                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 504
 505         if (skb->protocol == htons(ETH_P_IP)) {
 506                 if (!skb_is_gso(skb) &&
 507                     (df & htons(IP_DF)) && mtu < pkt_size) {
 508                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
 509                         return -E2BIG;
 510                 }
 511         }
 512 #if IS_ENABLED(CONFIG_IPV6)
 513         else if (skb->protocol == htons(ETH_P_IPV6)) {
 514                 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
 515
 516                 if (rt6 && mtu < dst_mtu(skb_dst(skb)) &&
 517                            mtu >= IPV6_MIN_MTU) {
 518                         if ((tunnel->parms.iph.daddr &&
 519                             !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
 520                             rt6->rt6i_dst.plen == 128) {
 521                                 rt6->rt6i_flags |= RTF_MODIFIED;
 522                                 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
 523                         }
 524                 }
 525
 526                 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU &&
 527                                         mtu < pkt_size) {
 528                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 529                         return -E2BIG;
 530                 }
 531         }
 532 #endif
 533         return 0;
 534 }
 535
 536 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 537                     const struct iphdr *tnl_params)
 538 {
 539         struct ip_tunnel *tunnel = netdev_priv(dev);
 540         const struct iphdr *inner_iph;
 541         struct iphdr *iph;
 542         struct flowi4 fl4;
 543         u8     tos, ttl;
 544         __be16 df;
 545         struct rtable *rt;              /* Route to the other host */
 546         struct net_device *tdev;        /* Device to other host */
 547         unsigned int max_headroom;      /* The extra header space needed */
 548         __be32 dst;
 549
 550         inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
 551
 552         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 553         dst = tnl_params->daddr;
 554         if (dst == 0) {
 555                 /* NBMA tunnel */
 556
 557                 if (skb_dst(skb) == NULL) {
 558                         dev->stats.tx_fifo_errors++;
 559                         goto tx_error;
 560                 }
 561
 562                 if (skb->protocol == htons(ETH_P_IP)) {
 563                         rt = skb_rtable(skb);
 564                         dst = rt_nexthop(rt, inner_iph->daddr);
 565                 }
 566 #if IS_ENABLED(CONFIG_IPV6)
 567                 else if (skb->protocol == htons(ETH_P_IPV6)) {
 568                         const struct in6_addr *addr6;
 569                         struct neighbour *neigh;
 570                         bool do_tx_error_icmp;
 571                         int addr_type;
 572
 573                         neigh = dst_neigh_lookup(skb_dst(skb),
 574                                                  &ipv6_hdr(skb)->daddr);
 575                         if (neigh == NULL)
 576                                 goto tx_error;
 577
 578                         addr6 = (const struct in6_addr *)&neigh->primary_key;
 579                         addr_type = ipv6_addr_type(addr6);
 580
 581                         if (addr_type == IPV6_ADDR_ANY) {
 582                                 addr6 = &ipv6_hdr(skb)->daddr;
 583                                 addr_type = ipv6_addr_type(addr6);
 584                         }
 585
 586                         if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
 587                                 do_tx_error_icmp = true;
 588                         else {
 589                                 do_tx_error_icmp = false;
 590                                 dst = addr6->s6_addr32[3];
 591                         }
 592                         neigh_release(neigh);
 593                         if (do_tx_error_icmp)
 594                                 goto tx_error_icmp;
 595                 }
 596 #endif
 597                 else
 598                         goto tx_error;
 599         }
 600
 601         tos = tnl_params->tos;
 602         if (tos & 0x1) {
 603                 tos &= ~0x1;
 604                 if (skb->protocol == htons(ETH_P_IP))
 605                         tos = inner_iph->tos;
 606                 else if (skb->protocol == htons(ETH_P_IPV6))
 607                         tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
 608         }
 609
 610         rt = ip_route_output_tunnel(dev_net(dev), &fl4,
 611                                     tunnel->parms.iph.protocol,
 612                                     dst, tnl_params->saddr,
 613                                     tunnel->parms.o_key,
 614                                     RT_TOS(tos),
 615                                     tunnel->parms.link);
 616         if (IS_ERR(rt)) {
 617                 dev->stats.tx_carrier_errors++;
 618                 goto tx_error;
 619         }
 620         tdev = rt->dst.dev;
 621
 622         if (tdev == dev) {
 623                 ip_rt_put(rt);
 624                 dev->stats.collisions++;
 625                 goto tx_error;
 626         }
 627
 628
 629         if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) {
 630                 ip_rt_put(rt);
 631                 goto tx_error;
 632         }
 633
 634         if (tunnel->err_count > 0) {
 635                 if (time_before(jiffies,
 636                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 637                         tunnel->err_count--;
 638
 639                         dst_link_failure(skb);
 640                 } else
 641                         tunnel->err_count = 0;
 642         }
 643
 644         ttl = tnl_params->ttl;
 645         if (ttl == 0) {
 646                 if (skb->protocol == htons(ETH_P_IP))
 647                         ttl = inner_iph->ttl;
 648 #if IS_ENABLED(CONFIG_IPV6)
 649                 else if (skb->protocol == htons(ETH_P_IPV6))
 650                         ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
 651 #endif
 652                 else
 653                         ttl = ip4_dst_hoplimit(&rt->dst);
 654         }
 655
 656         df = tnl_params->frag_off;
 657         if (skb->protocol == htons(ETH_P_IP))
 658                 df |= (inner_iph->frag_off&htons(IP_DF));
 659
 660         max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr)
 661                                                + rt->dst.header_len;
 662         if (max_headroom > dev->needed_headroom) {
 663                 dev->needed_headroom = max_headroom;
 664                 if (skb_cow_head(skb, dev->needed_headroom)) {
 665                         dev->stats.tx_dropped++;
 666                         dev_kfree_skb(skb);
 667                         return;
 668                 }
 669         }
 670
 671         skb_dst_drop(skb);
 672         skb_dst_set(skb, &rt->dst);
 673
 674         /* Push down and install the IP header. */
 675         skb_push(skb, sizeof(struct iphdr));
 676         skb_reset_network_header(skb);
 677
 678         iph = ip_hdr(skb);
 679         inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
 680
 681         iph->version    =       4;
 682         iph->ihl        =       sizeof(struct iphdr) >> 2;
 683         iph->frag_off   =       df;
 684         iph->protocol   =       tnl_params->protocol;
 685         iph->tos        =       ip_tunnel_ecn_encap(tos, inner_iph, skb);
 686         iph->daddr      =       fl4.daddr;
 687         iph->saddr      =       fl4.saddr;
 688         iph->ttl        =       ttl;
 689         __ip_select_ident(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);
 690
 691         iptunnel_xmit(skb, dev);
 692         return;
 693
 694 #if IS_ENABLED(CONFIG_IPV6)
 695 tx_error_icmp:
 696         dst_link_failure(skb);
 697 #endif
 698 tx_error:
 699         dev->stats.tx_errors++;
 700         dev_kfree_skb(skb);
 701 }
 702 EXPORT_SYMBOL_GPL(ip_tunnel_xmit);
 703
 704 static void ip_tunnel_update(struct ip_tunnel_net *itn,
 705                              struct ip_tunnel *t,
 706                              struct net_device *dev,
 707                              struct ip_tunnel_parm *p,
 708                              bool set_mtu)
 709 {
 710         ip_tunnel_del(t);
 711         t->parms.iph.saddr = p->iph.saddr;
 712         t->parms.iph.daddr = p->iph.daddr;
 713         t->parms.i_key = p->i_key;
 714         t->parms.o_key = p->o_key;
 715         if (dev->type != ARPHRD_ETHER) {
 716                 memcpy(dev->dev_addr, &p->iph.saddr, 4);
 717                 memcpy(dev->broadcast, &p->iph.daddr, 4);
 718         }
 719         ip_tunnel_add(itn, t);
 720
 721         t->parms.iph.ttl = p->iph.ttl;
 722         t->parms.iph.tos = p->iph.tos;
 723         t->parms.iph.frag_off = p->iph.frag_off;
 724
 725         if (t->parms.link != p->link) {
 726                 int mtu;
 727
 728                 t->parms.link = p->link;
 729                 mtu = ip_tunnel_bind_dev(dev);
 730                 if (set_mtu)
 731                         dev->mtu = mtu;
 732         }
 733         netdev_state_change(dev);
 734 }
 735
 736 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
 737 {
 738         int err = 0;
 739         struct ip_tunnel *t;
 740         struct net *net = dev_net(dev);
 741         struct ip_tunnel *tunnel = netdev_priv(dev);
 742         struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
 743
 744         BUG_ON(!itn->fb_tunnel_dev);
 745         switch (cmd) {
 746         case SIOCGETTUNNEL:
 747                 t = NULL;
 748                 if (dev == itn->fb_tunnel_dev)
 749                         t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 750                 if (t == NULL)
 751                         t = netdev_priv(dev);
 752                 memcpy(p, &t->parms, sizeof(*p));
 753                 break;
 754
 755         case SIOCADDTUNNEL:
 756         case SIOCCHGTUNNEL:
 757                 err = -EPERM;
 758                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 759                         goto done;
 760                 if (p->iph.ttl)
 761                         p->iph.frag_off |= htons(IP_DF);
 762                 if (!(p->i_flags&TUNNEL_KEY))
 763                         p->i_key = 0;
 764                 if (!(p->o_flags&TUNNEL_KEY))
 765                         p->o_key = 0;
 766
 767                 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 768
 769                 if (!t && (cmd == SIOCADDTUNNEL))
 770                         t = ip_tunnel_create(net, itn, p);
 771
 772                 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 773                         if (t != NULL) {
 774                                 if (t->dev != dev) {
 775                                         err = -EEXIST;
 776                                         break;
 777                                 }
 778                         } else {
 779                                 unsigned int nflags = 0;
 780
 781                                 if (ipv4_is_multicast(p->iph.daddr))
 782                                         nflags = IFF_BROADCAST;
 783                                 else if (p->iph.daddr)
 784                                         nflags = IFF_POINTOPOINT;
 785
 786                                 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
 787                                         err = -EINVAL;
 788                                         break;
 789                                 }
 790
 791                                 t = netdev_priv(dev);
 792                         }
 793                 }
 794
 795                 if (t) {
 796                         err = 0;
 797                         ip_tunnel_update(itn, t, dev, p, true);
 798                 } else
 799                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 800                 break;
 801
 802         case SIOCDELTUNNEL:
 803                 err = -EPERM;
 804                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 805                         goto done;
 806
 807                 if (dev == itn->fb_tunnel_dev) {
 808                         err = -ENOENT;
 809                         t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 810                         if (t == NULL)
 811                                 goto done;
 812                         err = -EPERM;
 813                         if (t == netdev_priv(itn->fb_tunnel_dev))
 814                                 goto done;
 815                         dev = t->dev;
 816                 }
 817                 unregister_netdevice(dev);
 818                 err = 0;
 819                 break;
 820
 821         default:
 822                 err = -EINVAL;
 823         }
 824
 825 done:
 826         return err;
 827 }
 828 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
 829
 830 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
 831 {
 832         struct ip_tunnel *tunnel = netdev_priv(dev);
 833         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 834
 835         if (new_mtu < 68 ||
 836             new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
 837                 return -EINVAL;
 838         dev->mtu = new_mtu;
 839         return 0;
 840 }
 841 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
 842
 843 static void ip_tunnel_dev_free(struct net_device *dev)
 844 {
 845         struct ip_tunnel *tunnel = netdev_priv(dev);
 846
 847         gro_cells_destroy(&tunnel->gro_cells);
 848         free_percpu(dev->tstats);
 849         free_netdev(dev);
 850 }
 851
 852 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head)
 853 {
 854         struct net *net = dev_net(dev);
 855         struct ip_tunnel *tunnel = netdev_priv(dev);
 856         struct ip_tunnel_net *itn;
 857
 858         itn = net_generic(net, tunnel->ip_tnl_net_id);
 859
 860         if (itn->fb_tunnel_dev != dev) {
 861                 ip_tunnel_del(netdev_priv(dev));
 862                 unregister_netdevice_queue(dev, head);
 863         }
 864 }
 865 EXPORT_SYMBOL_GPL(ip_tunnel_dellink);
 866
 867 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 868                                   struct rtnl_link_ops *ops, char *devname)
 869 {
 870         struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id);
 871         struct ip_tunnel_parm parms;
 872
 873         itn->tunnels = kzalloc(IP_TNL_HASH_SIZE * sizeof(struct hlist_head), GFP_KERNEL);
 874         if (!itn->tunnels)
 875                 return -ENOMEM;
 876
 877         if (!ops) {
 878                 itn->fb_tunnel_dev = NULL;
 879                 return 0;
 880         }
 881         memset(&parms, 0, sizeof(parms));
 882         if (devname)
 883                 strlcpy(parms.name, devname, IFNAMSIZ);
 884
 885         rtnl_lock();
 886         itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms);
 887         rtnl_unlock();
 888         if (IS_ERR(itn->fb_tunnel_dev)) {
 889                 kfree(itn->tunnels);
 890                 return PTR_ERR(itn->fb_tunnel_dev);
 891         }
 892
 893         return 0;
 894 }
 895 EXPORT_SYMBOL_GPL(ip_tunnel_init_net);
 896
 897 static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head)
 898 {
 899         int h;
 900
 901         for (h = 0; h < IP_TNL_HASH_SIZE; h++) {
 902                 struct ip_tunnel *t;
 903                 struct hlist_node *n;
 904                 struct hlist_head *thead = &itn->tunnels[h];
 905
 906                 hlist_for_each_entry_safe(t, n, thead, hash_node)
 907                         unregister_netdevice_queue(t->dev, head);
 908         }
 909         if (itn->fb_tunnel_dev)
 910                 unregister_netdevice_queue(itn->fb_tunnel_dev, head);
 911 }
 912
 913 void ip_tunnel_delete_net(struct ip_tunnel_net *itn)
 914 {
 915         LIST_HEAD(list);
 916
 917         rtnl_lock();
 918         ip_tunnel_destroy(itn, &list);
 919         unregister_netdevice_many(&list);
 920         rtnl_unlock();
 921         kfree(itn->tunnels);
 922 }
 923 EXPORT_SYMBOL_GPL(ip_tunnel_delete_net);
 924
 925 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 926                       struct ip_tunnel_parm *p)
 927 {
 928         struct ip_tunnel *nt;
 929         struct net *net = dev_net(dev);
 930         struct ip_tunnel_net *itn;
 931         int mtu;
 932         int err;
 933
 934         nt = netdev_priv(dev);
 935         itn = net_generic(net, nt->ip_tnl_net_id);
 936
 937         if (ip_tunnel_find(itn, p, dev->type))
 938                 return -EEXIST;
 939
 940         nt->parms = *p;
 941         err = register_netdevice(dev);
 942         if (err)
 943                 goto out;
 944
 945         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
 946                 eth_hw_addr_random(dev);
 947
 948         mtu = ip_tunnel_bind_dev(dev);
 949         if (!tb[IFLA_MTU])
 950                 dev->mtu = mtu;
 951
 952         ip_tunnel_add(itn, nt);
 953
 954 out:
 955         return err;
 956 }
 957 EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
 958
 959 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 960                          struct ip_tunnel_parm *p)
 961 {
 962         struct ip_tunnel *t, *nt;
 963         struct net *net = dev_net(dev);
 964         struct ip_tunnel *tunnel = netdev_priv(dev);
 965         struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
 966
 967         if (dev == itn->fb_tunnel_dev)
 968                 return -EINVAL;
 969
 970         nt = netdev_priv(dev);
 971
 972         t = ip_tunnel_find(itn, p, dev->type);
 973
 974         if (t) {
 975                 if (t->dev != dev)
 976                         return -EEXIST;
 977         } else {
 978                 t = nt;
 979
 980                 if (dev->type != ARPHRD_ETHER) {
 981                         unsigned int nflags = 0;
 982
 983                         if (ipv4_is_multicast(p->iph.daddr))
 984                                 nflags = IFF_BROADCAST;
 985                         else if (p->iph.daddr)
 986                                 nflags = IFF_POINTOPOINT;
 987
 988                         if ((dev->flags ^ nflags) &
 989                             (IFF_POINTOPOINT | IFF_BROADCAST))
 990                                 return -EINVAL;
 991                 }
 992         }
 993
 994         ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU]);
 995         return 0;
 996 }
 997 EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
 998
 999 int ip_tunnel_init(struct net_device *dev)
1000 {
1001         struct ip_tunnel *tunnel = netdev_priv(dev);
1002         struct iphdr *iph = &tunnel->parms.iph;
1003         int err;
1004
1005         dev->destructor = ip_tunnel_dev_free;
1006         dev->tstats = alloc_percpu(struct pcpu_tstats);
1007         if (!dev->tstats)
1008                 return -ENOMEM;
1009
1010         err = gro_cells_init(&tunnel->gro_cells, dev);
1011         if (err) {
1012                 free_percpu(dev->tstats);
1013                 return err;
1014         }
1015
1016         tunnel->dev = dev;
1017         strcpy(tunnel->parms.name, dev->name);
1018         iph->version            = 4;
1019         iph->ihl                = 5;
1020
1021         return 0;
1022 }
1023 EXPORT_SYMBOL_GPL(ip_tunnel_init);
1024
1025 void ip_tunnel_uninit(struct net_device *dev)
1026 {
1027         struct net *net = dev_net(dev);
1028         struct ip_tunnel *tunnel = netdev_priv(dev);
1029         struct ip_tunnel_net *itn;
1030
1031         itn = net_generic(net, tunnel->ip_tnl_net_id);
1032         /* fb_tunnel_dev will be unregisted in net-exit call. */
1033         if (itn->fb_tunnel_dev != dev)
1034                 ip_tunnel_del(netdev_priv(dev));
1035 }
1036 EXPORT_SYMBOL_GPL(ip_tunnel_uninit);
1037
1038 /* Do least required initialization, rest of init is done in tunnel_init call */
1039 void ip_tunnel_setup(struct net_device *dev, int net_id)
1040 {
1041         struct ip_tunnel *tunnel = netdev_priv(dev);
1042         tunnel->ip_tnl_net_id = net_id;
1043 }
1044 EXPORT_SYMBOL_GPL(ip_tunnel_setup);
1045
1046 MODULE_LICENSE("GPL");