Pileus Git - ~andy/linux/blob - 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(tunnel->net, &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(tunnel->net, 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->dev->type == ARPHRD_ETHER) {
 458                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 459                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 460         } else {
 461                 skb->dev = tunnel->dev;
 462         }
 463
 464         if (!net_eq(tunnel->net, dev_net(tunnel->dev)))
 465                 skb_scrub_packet(skb, true);
 466
 467         gro_cells_receive(&tunnel->gro_cells, skb);
 468         return 0;
 469
 470 drop:
 471         kfree_skb(skb);
 472         return 0;
 473 }
 474 EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
 475
 476 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
 477                             struct rtable *rt, __be16 df)
 478 {
 479         struct ip_tunnel *tunnel = netdev_priv(dev);
 480         int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len;
 481         int mtu;
 482
 483         if (df)
 484                 mtu = dst_mtu(&rt->dst) - dev->hard_header_len
 485                                         - sizeof(struct iphdr) - tunnel->hlen;
 486         else
 487                 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
 488
 489         if (skb_dst(skb))
 490                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 491
 492         if (skb->protocol == htons(ETH_P_IP)) {
 493                 if (!skb_is_gso(skb) &&
 494                     (df & htons(IP_DF)) && mtu < pkt_size) {
 495                         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 496                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
 497                         return -E2BIG;
 498                 }
 499         }
 500 #if IS_ENABLED(CONFIG_IPV6)
 501         else if (skb->protocol == htons(ETH_P_IPV6)) {
 502                 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
 503
 504                 if (rt6 && mtu < dst_mtu(skb_dst(skb)) &&
 505                            mtu >= IPV6_MIN_MTU) {
 506                         if ((tunnel->parms.iph.daddr &&
 507                             !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
 508                             rt6->rt6i_dst.plen == 128) {
 509                                 rt6->rt6i_flags |= RTF_MODIFIED;
 510                                 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
 511                         }
 512                 }
 513
 514                 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU &&
 515                                         mtu < pkt_size) {
 516                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 517                         return -E2BIG;
 518                 }
 519         }
 520 #endif
 521         return 0;
 522 }
 523
 524 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 525                     const struct iphdr *tnl_params, const u8 protocol)
 526 {
 527         struct ip_tunnel *tunnel = netdev_priv(dev);
 528         const struct iphdr *inner_iph;
 529         struct flowi4 fl4;
 530         u8     tos, ttl;
 531         __be16 df;
 532         struct rtable *rt;              /* Route to the other host */
 533         unsigned int max_headroom;      /* The extra header space needed */
 534         __be32 dst;
 535         int err;
 536
 537         inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
 538
 539         dst = tnl_params->daddr;
 540         if (dst == 0) {
 541                 /* NBMA tunnel */
 542
 543                 if (skb_dst(skb) == NULL) {
 544                         dev->stats.tx_fifo_errors++;
 545                         goto tx_error;
 546                 }
 547
 548                 if (skb->protocol == htons(ETH_P_IP)) {
 549                         rt = skb_rtable(skb);
 550                         dst = rt_nexthop(rt, inner_iph->daddr);
 551                 }
 552 #if IS_ENABLED(CONFIG_IPV6)
 553                 else if (skb->protocol == htons(ETH_P_IPV6)) {
 554                         const struct in6_addr *addr6;
 555                         struct neighbour *neigh;
 556                         bool do_tx_error_icmp;
 557                         int addr_type;
 558
 559                         neigh = dst_neigh_lookup(skb_dst(skb),
 560                                                  &ipv6_hdr(skb)->daddr);
 561                         if (neigh == NULL)
 562                                 goto tx_error;
 563
 564                         addr6 = (const struct in6_addr *)&neigh->primary_key;
 565                         addr_type = ipv6_addr_type(addr6);
 566
 567                         if (addr_type == IPV6_ADDR_ANY) {
 568                                 addr6 = &ipv6_hdr(skb)->daddr;
 569                                 addr_type = ipv6_addr_type(addr6);
 570                         }
 571
 572                         if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
 573                                 do_tx_error_icmp = true;
 574                         else {
 575                                 do_tx_error_icmp = false;
 576                                 dst = addr6->s6_addr32[3];
 577                         }
 578                         neigh_release(neigh);
 579                         if (do_tx_error_icmp)
 580                                 goto tx_error_icmp;
 581                 }
 582 #endif
 583                 else
 584                         goto tx_error;
 585         }
 586
 587         tos = tnl_params->tos;
 588         if (tos & 0x1) {
 589                 tos &= ~0x1;
 590                 if (skb->protocol == htons(ETH_P_IP))
 591                         tos = inner_iph->tos;
 592                 else if (skb->protocol == htons(ETH_P_IPV6))
 593                         tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
 594         }
 595
 596         rt = ip_route_output_tunnel(tunnel->net, &fl4,
 597                                     protocol,
 598                                     dst, tnl_params->saddr,
 599                                     tunnel->parms.o_key,
 600                                     RT_TOS(tos),
 601                                     tunnel->parms.link);
 602         if (IS_ERR(rt)) {
 603                 dev->stats.tx_carrier_errors++;
 604                 goto tx_error;
 605         }
 606         if (rt->dst.dev == dev) {
 607                 ip_rt_put(rt);
 608                 dev->stats.collisions++;
 609                 goto tx_error;
 610         }
 611
 612         if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) {
 613                 ip_rt_put(rt);
 614                 goto tx_error;
 615         }
 616
 617         if (!net_eq(tunnel->net, dev_net(dev)))
 618                 skb_scrub_packet(skb, true);
 619
 620         if (tunnel->err_count > 0) {
 621                 if (time_before(jiffies,
 622                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 623                         tunnel->err_count--;
 624
 625                         dst_link_failure(skb);
 626                 } else
 627                         tunnel->err_count = 0;
 628         }
 629
 630         ttl = tnl_params->ttl;
 631         if (ttl == 0) {
 632                 if (skb->protocol == htons(ETH_P_IP))
 633                         ttl = inner_iph->ttl;
 634 #if IS_ENABLED(CONFIG_IPV6)
 635                 else if (skb->protocol == htons(ETH_P_IPV6))
 636                         ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
 637 #endif
 638                 else
 639                         ttl = ip4_dst_hoplimit(&rt->dst);
 640         }
 641
 642         df = tnl_params->frag_off;
 643         if (skb->protocol == htons(ETH_P_IP))
 644                 df |= (inner_iph->frag_off&htons(IP_DF));
 645
 646         max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
 647                         + rt->dst.header_len;
 648         if (max_headroom > dev->needed_headroom) {
 649                 dev->needed_headroom = max_headroom;
 650                 if (skb_cow_head(skb, dev->needed_headroom)) {
 651                         dev->stats.tx_dropped++;
 652                         dev_kfree_skb(skb);
 653                         return;
 654                 }
 655         }
 656
 657         err = iptunnel_xmit(rt, skb, 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 ip_tunnel *tunnel = netdev_priv(dev);
 824         struct ip_tunnel_net *itn;
 825
 826         itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id);
 827
 828         if (itn->fb_tunnel_dev != dev) {
 829                 ip_tunnel_del(netdev_priv(dev));
 830                 unregister_netdevice_queue(dev, head);
 831         }
 832 }
 833 EXPORT_SYMBOL_GPL(ip_tunnel_dellink);
 834
 835 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 836                                   struct rtnl_link_ops *ops, char *devname)
 837 {
 838         struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id);
 839         struct ip_tunnel_parm parms;
 840         unsigned int i;
 841
 842         for (i = 0; i < IP_TNL_HASH_SIZE; i++)
 843                 INIT_HLIST_HEAD(&itn->tunnels[i]);
 844
 845         if (!ops) {
 846                 itn->fb_tunnel_dev = NULL;
 847                 return 0;
 848         }
 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         /* FB netdevice is special: we have one, and only one per netns.
 857          * Allowing to move it to another netns is clearly unsafe.
 858          */
 859         if (!IS_ERR(itn->fb_tunnel_dev))
 860                 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
 861         rtnl_unlock();
 862
 863         return PTR_RET(itn->fb_tunnel_dev);
 864 }
 865 EXPORT_SYMBOL_GPL(ip_tunnel_init_net);
 866
 867 static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head,
 868                               struct rtnl_link_ops *ops)
 869 {
 870         struct net *net = dev_net(itn->fb_tunnel_dev);
 871         struct net_device *dev, *aux;
 872         int h;
 873
 874         for_each_netdev_safe(net, dev, aux)
 875                 if (dev->rtnl_link_ops == ops)
 876                         unregister_netdevice_queue(dev, head);
 877
 878         for (h = 0; h < IP_TNL_HASH_SIZE; h++) {
 879                 struct ip_tunnel *t;
 880                 struct hlist_node *n;
 881                 struct hlist_head *thead = &itn->tunnels[h];
 882
 883                 hlist_for_each_entry_safe(t, n, thead, hash_node)
 884                         /* If dev is in the same netns, it has already
 885                          * been added to the list by the previous loop.
 886                          */
 887                         if (!net_eq(dev_net(t->dev), net))
 888                                 unregister_netdevice_queue(t->dev, head);
 889         }
 890         if (itn->fb_tunnel_dev)
 891                 unregister_netdevice_queue(itn->fb_tunnel_dev, head);
 892 }
 893
 894 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops)
 895 {
 896         LIST_HEAD(list);
 897
 898         rtnl_lock();
 899         ip_tunnel_destroy(itn, &list, ops);
 900         unregister_netdevice_many(&list);
 901         rtnl_unlock();
 902 }
 903 EXPORT_SYMBOL_GPL(ip_tunnel_delete_net);
 904
 905 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 906                       struct ip_tunnel_parm *p)
 907 {
 908         struct ip_tunnel *nt;
 909         struct net *net = dev_net(dev);
 910         struct ip_tunnel_net *itn;
 911         int mtu;
 912         int err;
 913
 914         nt = netdev_priv(dev);
 915         itn = net_generic(net, nt->ip_tnl_net_id);
 916
 917         if (ip_tunnel_find(itn, p, dev->type))
 918                 return -EEXIST;
 919
 920         nt->net = net;
 921         nt->parms = *p;
 922         err = register_netdevice(dev);
 923         if (err)
 924                 goto out;
 925
 926         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
 927                 eth_hw_addr_random(dev);
 928
 929         mtu = ip_tunnel_bind_dev(dev);
 930         if (!tb[IFLA_MTU])
 931                 dev->mtu = mtu;
 932
 933         ip_tunnel_add(itn, nt);
 934
 935 out:
 936         return err;
 937 }
 938 EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
 939
 940 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 941                          struct ip_tunnel_parm *p)
 942 {
 943         struct ip_tunnel *t;
 944         struct ip_tunnel *tunnel = netdev_priv(dev);
 945         struct net *net = tunnel->net;
 946         struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
 947
 948         if (dev == itn->fb_tunnel_dev)
 949                 return -EINVAL;
 950
 951         t = ip_tunnel_find(itn, p, dev->type);
 952
 953         if (t) {
 954                 if (t->dev != dev)
 955                         return -EEXIST;
 956         } else {
 957                 t = tunnel;
 958
 959                 if (dev->type != ARPHRD_ETHER) {
 960                         unsigned int nflags = 0;
 961
 962                         if (ipv4_is_multicast(p->iph.daddr))
 963                                 nflags = IFF_BROADCAST;
 964                         else if (p->iph.daddr)
 965                                 nflags = IFF_POINTOPOINT;
 966
 967                         if ((dev->flags ^ nflags) &
 968                             (IFF_POINTOPOINT | IFF_BROADCAST))
 969                                 return -EINVAL;
 970                 }
 971         }
 972
 973         ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU]);
 974         return 0;
 975 }
 976 EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
 977
 978 int ip_tunnel_init(struct net_device *dev)
 979 {
 980         struct ip_tunnel *tunnel = netdev_priv(dev);
 981         struct iphdr *iph = &tunnel->parms.iph;
 982         int err;
 983
 984         dev->destructor = ip_tunnel_dev_free;
 985         dev->tstats = alloc_percpu(struct pcpu_tstats);
 986         if (!dev->tstats)
 987                 return -ENOMEM;
 988
 989         err = gro_cells_init(&tunnel->gro_cells, dev);
 990         if (err) {
 991                 free_percpu(dev->tstats);
 992                 return err;
 993         }
 994
 995         tunnel->dev = dev;
 996         tunnel->net = dev_net(dev);
 997         strcpy(tunnel->parms.name, dev->name);
 998         iph->version            = 4;
 999         iph->ihl                = 5;
1000
1001         return 0;
1002 }
1003 EXPORT_SYMBOL_GPL(ip_tunnel_init);
1004
1005 void ip_tunnel_uninit(struct net_device *dev)
1006 {
1007         struct ip_tunnel *tunnel = netdev_priv(dev);
1008         struct net *net = tunnel->net;
1009         struct ip_tunnel_net *itn;
1010
1011         itn = net_generic(net, tunnel->ip_tnl_net_id);
1012         /* fb_tunnel_dev will be unregisted in net-exit call. */
1013         if (itn->fb_tunnel_dev != dev)
1014                 ip_tunnel_del(netdev_priv(dev));
1015 }
1016 EXPORT_SYMBOL_GPL(ip_tunnel_uninit);
1017
1018 /* Do least required initialization, rest of init is done in tunnel_init call */
1019 void ip_tunnel_setup(struct net_device *dev, int net_id)
1020 {
1021         struct ip_tunnel *tunnel = netdev_priv(dev);
1022         tunnel->ip_tnl_net_id = net_id;
1023 }
1024 EXPORT_SYMBOL_GPL(ip_tunnel_setup);
1025
1026 MODULE_LICENSE("GPL");