net/ipv4/ipip.c

   1 /*
   2  *      Linux NET3:     IP/IP protocol decoder.
   3  *
   4  *      Authors:
   5  *              Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
   6  *
   7  *      Fixes:
   8  *              Alan Cox        :       Merged and made usable non modular (its so tiny its silly as
   9  *                                      a module taking up 2 pages).
  10  *              Alan Cox        :       Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
  11  *                                      to keep ip_forward happy.
  12  *              Alan Cox        :       More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
  13  *              Kai Schulte     :       Fixed #defines for IP_FIREWALL->FIREWALL
  14  *              David Woodhouse :       Perform some basic ICMP handling.
  15  *                                      IPIP Routing without decapsulation.
  16  *              Carlos Picoto   :       GRE over IP support
  17  *              Alexey Kuznetsov:       Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
  18  *                                      I do not want to merge them together.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  *
  25  */
  26
  27 /* tunnel.c: an IP tunnel driver
  28
  29         The purpose of this driver is to provide an IP tunnel through
  30         which you can tunnel network traffic transparently across subnets.
  31
  32         This was written by looking at Nick Holloway's dummy driver
  33         Thanks for the great code!
  34
  35                 -Sam Lantinga   (slouken@cs.ucdavis.edu)  02/01/95
  36
  37         Minor tweaks:
  38                 Cleaned up the code a little and added some pre-1.3.0 tweaks.
  39                 dev->hard_header/hard_header_len changed to use no headers.
  40                 Comments/bracketing tweaked.
  41                 Made the tunnels use dev->name not tunnel: when error reporting.
  42                 Added tx_dropped stat
  43
  44                 -Alan Cox       (alan@lxorguk.ukuu.org.uk) 21 March 95
  45
  46         Reworked:
  47                 Changed to tunnel to destination gateway in addition to the
  48                         tunnel's pointopoint address
  49                 Almost completely rewritten
  50                 Note:  There is currently no firewall or ICMP handling done.
  51
  52                 -Sam Lantinga   (slouken@cs.ucdavis.edu) 02/13/96
  53
  54 */
  55
  56 /* Things I wish I had known when writing the tunnel driver:
  57
  58         When the tunnel_xmit() function is called, the skb contains the
  59         packet to be sent (plus a great deal of extra info), and dev
  60         contains the tunnel device that _we_ are.
  61
  62         When we are passed a packet, we are expected to fill in the
  63         source address with our source IP address.
  64
  65         What is the proper way to allocate, copy and free a buffer?
  66         After you allocate it, it is a "0 length" chunk of memory
  67         starting at zero.  If you want to add headers to the buffer
  68         later, you'll have to call "skb_reserve(skb, amount)" with
  69         the amount of memory you want reserved.  Then, you call
  70         "skb_put(skb, amount)" with the amount of space you want in
  71         the buffer.  skb_put() returns a pointer to the top (#0) of
  72         that buffer.  skb->len is set to the amount of space you have
  73         "allocated" with skb_put().  You can then write up to skb->len
  74         bytes to that buffer.  If you need more, you can call skb_put()
  75         again with the additional amount of space you need.  You can
  76         find out how much more space you can allocate by calling
  77         "skb_tailroom(skb)".
  78         Now, to add header space, call "skb_push(skb, header_len)".
  79         This creates space at the beginning of the buffer and returns
  80         a pointer to this new space.  If later you need to strip a
  81         header from a buffer, call "skb_pull(skb, header_len)".
  82         skb_headroom() will return how much space is left at the top
  83         of the buffer (before the main data).  Remember, this headroom
  84         space must be reserved before the skb_put() function is called.
  85         */
  86
  87 /*
  88    This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
  89
  90    For comments look at net/ipv4/ip_gre.c --ANK
  91  */
  92
  93
  94 #include <linux/capability.h>
  95 #include <linux/module.h>
  96 #include <linux/types.h>
  97 #include <linux/kernel.h>
  98 #include <linux/slab.h>
  99 #include <asm/uaccess.h>
 100 #include <linux/skbuff.h>
 101 #include <linux/netdevice.h>
 102 #include <linux/in.h>
 103 #include <linux/tcp.h>
 104 #include <linux/udp.h>
 105 #include <linux/if_arp.h>
 106 #include <linux/mroute.h>
 107 #include <linux/init.h>
 108 #include <linux/netfilter_ipv4.h>
 109 #include <linux/if_ether.h>
 110
 111 #include <net/sock.h>
 112 #include <net/ip.h>
 113 #include <net/icmp.h>
 114 #include <net/ipip.h>
 115 #include <net/inet_ecn.h>
 116 #include <net/xfrm.h>
 117 #include <net/net_namespace.h>
 118 #include <net/netns/generic.h>
 119
 120 #define HASH_SIZE  16
 121 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
 122
 123 static int ipip_net_id __read_mostly;
 124 struct ipip_net {
 125         struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
 126         struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
 127         struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
 128         struct ip_tunnel __rcu *tunnels_wc[1];
 129         struct ip_tunnel __rcu **tunnels[4];
 130
 131         struct net_device *fb_tunnel_dev;
 132 };
 133
 134 static void ipip_tunnel_init(struct net_device *dev);
 135 static void ipip_tunnel_setup(struct net_device *dev);
 136
 137 /*
 138  * Locking : hash tables are protected by RCU and RTNL
 139  */
 140
 141 #define for_each_ip_tunnel_rcu(start) \
 142         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 143
 144 static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
 145                 __be32 remote, __be32 local)
 146 {
 147         unsigned int h0 = HASH(remote);
 148         unsigned int h1 = HASH(local);
 149         struct ip_tunnel *t;
 150         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 151
 152         for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1])
 153                 if (local == t->parms.iph.saddr &&
 154                     remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
 155                         return t;
 156
 157         for_each_ip_tunnel_rcu(ipn->tunnels_r[h0])
 158                 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
 159                         return t;
 160
 161         for_each_ip_tunnel_rcu(ipn->tunnels_l[h1])
 162                 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
 163                         return t;
 164
 165         t = rcu_dereference(ipn->tunnels_wc[0]);
 166         if (t && (t->dev->flags&IFF_UP))
 167                 return t;
 168         return NULL;
 169 }
 170
 171 static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn,
 172                 struct ip_tunnel_parm *parms)
 173 {
 174         __be32 remote = parms->iph.daddr;
 175         __be32 local = parms->iph.saddr;
 176         unsigned int h = 0;
 177         int prio = 0;
 178
 179         if (remote) {
 180                 prio |= 2;
 181                 h ^= HASH(remote);
 182         }
 183         if (local) {
 184                 prio |= 1;
 185                 h ^= HASH(local);
 186         }
 187         return &ipn->tunnels[prio][h];
 188 }
 189
 190 static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn,
 191                 struct ip_tunnel *t)
 192 {
 193         return __ipip_bucket(ipn, &t->parms);
 194 }
 195
 196 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
 197 {
 198         struct ip_tunnel __rcu **tp;
 199         struct ip_tunnel *iter;
 200
 201         for (tp = ipip_bucket(ipn, t);
 202              (iter = rtnl_dereference(*tp)) != NULL;
 203              tp = &iter->next) {
 204                 if (t == iter) {
 205                         rcu_assign_pointer(*tp, t->next);
 206                         break;
 207                 }
 208         }
 209 }
 210
 211 static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
 212 {
 213         struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t);
 214
 215         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 216         rcu_assign_pointer(*tp, t);
 217 }
 218
 219 static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
 220                 struct ip_tunnel_parm *parms, int create)
 221 {
 222         __be32 remote = parms->iph.daddr;
 223         __be32 local = parms->iph.saddr;
 224         struct ip_tunnel *t, *nt;
 225         struct ip_tunnel __rcu **tp;
 226         struct net_device *dev;
 227         char name[IFNAMSIZ];
 228         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 229
 230         for (tp = __ipip_bucket(ipn, parms);
 231                  (t = rtnl_dereference(*tp)) != NULL;
 232                  tp = &t->next) {
 233                 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
 234                         return t;
 235         }
 236         if (!create)
 237                 return NULL;
 238
 239         if (parms->name[0])
 240                 strlcpy(name, parms->name, IFNAMSIZ);
 241         else
 242                 sprintf(name, "tunl%%d");
 243
 244         dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
 245         if (dev == NULL)
 246                 return NULL;
 247
 248         dev_net_set(dev, net);
 249
 250         if (strchr(name, '%')) {
 251                 if (dev_alloc_name(dev, name) < 0)
 252                         goto failed_free;
 253         }
 254
 255         nt = netdev_priv(dev);
 256         nt->parms = *parms;
 257
 258         ipip_tunnel_init(dev);
 259
 260         if (register_netdevice(dev) < 0)
 261                 goto failed_free;
 262
 263         dev_hold(dev);
 264         ipip_tunnel_link(ipn, nt);
 265         return nt;
 266
 267 failed_free:
 268         free_netdev(dev);
 269         return NULL;
 270 }
 271
 272 /* called with RTNL */
 273 static void ipip_tunnel_uninit(struct net_device *dev)
 274 {
 275         struct net *net = dev_net(dev);
 276         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 277
 278         if (dev == ipn->fb_tunnel_dev)
 279                 rcu_assign_pointer(ipn->tunnels_wc[0], NULL);
 280         else
 281                 ipip_tunnel_unlink(ipn, netdev_priv(dev));
 282         dev_put(dev);
 283 }
 284
 285 static int ipip_err(struct sk_buff *skb, u32 info)
 286 {
 287
 288 /* All the routers (except for Linux) return only
 289    8 bytes of packet payload. It means, that precise relaying of
 290    ICMP in the real Internet is absolutely infeasible.
 291  */
 292         struct iphdr *iph = (struct iphdr *)skb->data;
 293         const int type = icmp_hdr(skb)->type;
 294         const int code = icmp_hdr(skb)->code;
 295         struct ip_tunnel *t;
 296         int err;
 297
 298         switch (type) {
 299         default:
 300         case ICMP_PARAMETERPROB:
 301                 return 0;
 302
 303         case ICMP_DEST_UNREACH:
 304                 switch (code) {
 305                 case ICMP_SR_FAILED:
 306                 case ICMP_PORT_UNREACH:
 307                         /* Impossible event. */
 308                         return 0;
 309                 case ICMP_FRAG_NEEDED:
 310                         /* Soft state for pmtu is maintained by IP core. */
 311                         return 0;
 312                 default:
 313                         /* All others are translated to HOST_UNREACH.
 314                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 315                            I believe they are just ether pollution. --ANK
 316                          */
 317                         break;
 318                 }
 319                 break;
 320         case ICMP_TIME_EXCEEDED:
 321                 if (code != ICMP_EXC_TTL)
 322                         return 0;
 323                 break;
 324         }
 325
 326         err = -ENOENT;
 327
 328         rcu_read_lock();
 329         t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
 330         if (t == NULL || t->parms.iph.daddr == 0)
 331                 goto out;
 332
 333         err = 0;
 334         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 335                 goto out;
 336
 337         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 338                 t->err_count++;
 339         else
 340                 t->err_count = 1;
 341         t->err_time = jiffies;
 342 out:
 343         rcu_read_unlock();
 344         return err;
 345 }
 346
 347 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
 348                                         struct sk_buff *skb)
 349 {
 350         struct iphdr *inner_iph = ip_hdr(skb);
 351
 352         if (INET_ECN_is_ce(outer_iph->tos))
 353                 IP_ECN_set_ce(inner_iph);
 354 }
 355
 356 static int ipip_rcv(struct sk_buff *skb)
 357 {
 358         struct ip_tunnel *tunnel;
 359         const struct iphdr *iph = ip_hdr(skb);
 360
 361         rcu_read_lock();
 362         if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev),
 363                                         iph->saddr, iph->daddr)) != NULL) {
 364                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 365                         rcu_read_unlock();
 366                         kfree_skb(skb);
 367                         return 0;
 368                 }
 369
 370                 secpath_reset(skb);
 371
 372                 skb->mac_header = skb->network_header;
 373                 skb_reset_network_header(skb);
 374                 skb->protocol = htons(ETH_P_IP);
 375                 skb->pkt_type = PACKET_HOST;
 376
 377                 skb_tunnel_rx(skb, tunnel->dev);
 378
 379                 ipip_ecn_decapsulate(iph, skb);
 380                 netif_rx(skb);
 381                 rcu_read_unlock();
 382                 return 0;
 383         }
 384         rcu_read_unlock();
 385
 386         return -1;
 387 }
 388
 389 /*
 390  *      This function assumes it is being called from dev_queue_xmit()
 391  *      and that skb is filled properly by that function.
 392  */
 393
 394 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 395 {
 396         struct ip_tunnel *tunnel = netdev_priv(dev);
 397         struct net_device_stats *stats = &dev->stats;
 398         struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
 399         struct iphdr  *tiph = &tunnel->parms.iph;
 400         u8     tos = tunnel->parms.iph.tos;
 401         __be16 df = tiph->frag_off;
 402         struct rtable *rt;                      /* Route to the other host */
 403         struct net_device *tdev;                        /* Device to other host */
 404         struct iphdr  *old_iph = ip_hdr(skb);
 405         struct iphdr  *iph;                     /* Our new IP header */
 406         unsigned int max_headroom;              /* The extra header space needed */
 407         __be32 dst = tiph->daddr;
 408         int    mtu;
 409
 410         if (skb->protocol != htons(ETH_P_IP))
 411                 goto tx_error;
 412
 413         if (tos&1)
 414                 tos = old_iph->tos;
 415
 416         if (!dst) {
 417                 /* NBMA tunnel */
 418                 if ((rt = skb_rtable(skb)) == NULL) {
 419                         stats->tx_fifo_errors++;
 420                         goto tx_error;
 421                 }
 422                 if ((dst = rt->rt_gateway) == 0)
 423                         goto tx_error_icmp;
 424         }
 425
 426         {
 427                 struct flowi fl = { .oif = tunnel->parms.link,
 428                                     .nl_u = { .ip4_u =
 429                                               { .daddr = dst,
 430                                                 .saddr = tiph->saddr,
 431                                                 .tos = RT_TOS(tos) } },
 432                                     .proto = IPPROTO_IPIP };
 433                 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
 434                         stats->tx_carrier_errors++;
 435                         goto tx_error_icmp;
 436                 }
 437         }
 438         tdev = rt->dst.dev;
 439
 440         if (tdev == dev) {
 441                 ip_rt_put(rt);
 442                 stats->collisions++;
 443                 goto tx_error;
 444         }
 445
 446         df |= old_iph->frag_off & htons(IP_DF);
 447
 448         if (df) {
 449                 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
 450
 451                 if (mtu < 68) {
 452                         stats->collisions++;
 453                         ip_rt_put(rt);
 454                         goto tx_error;
 455                 }
 456
 457                 if (skb_dst(skb))
 458                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
 459
 460                 if ((old_iph->frag_off & htons(IP_DF)) &&
 461                     mtu < ntohs(old_iph->tot_len)) {
 462                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 463                                   htonl(mtu));
 464                         ip_rt_put(rt);
 465                         goto tx_error;
 466                 }
 467         }
 468
 469         if (tunnel->err_count > 0) {
 470                 if (time_before(jiffies,
 471                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 472                         tunnel->err_count--;
 473                         dst_link_failure(skb);
 474                 } else
 475                         tunnel->err_count = 0;
 476         }
 477
 478         /*
 479          * Okay, now see if we can stuff it in the buffer as-is.
 480          */
 481         max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
 482
 483         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 484             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 485                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 486                 if (!new_skb) {
 487                         ip_rt_put(rt);
 488                         txq->tx_dropped++;
 489                         dev_kfree_skb(skb);
 490                         return NETDEV_TX_OK;
 491                 }
 492                 if (skb->sk)
 493                         skb_set_owner_w(new_skb, skb->sk);
 494                 dev_kfree_skb(skb);
 495                 skb = new_skb;
 496                 old_iph = ip_hdr(skb);
 497         }
 498
 499         skb->transport_header = skb->network_header;
 500         skb_push(skb, sizeof(struct iphdr));
 501         skb_reset_network_header(skb);
 502         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 503         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
 504                               IPSKB_REROUTED);
 505         skb_dst_drop(skb);
 506         skb_dst_set(skb, &rt->dst);
 507
 508         /*
 509          *      Push down and install the IPIP header.
 510          */
 511
 512         iph                     =       ip_hdr(skb);
 513         iph->version            =       4;
 514         iph->ihl                =       sizeof(struct iphdr)>>2;
 515         iph->frag_off           =       df;
 516         iph->protocol           =       IPPROTO_IPIP;
 517         iph->tos                =       INET_ECN_encapsulate(tos, old_iph->tos);
 518         iph->daddr              =       rt->rt_dst;
 519         iph->saddr              =       rt->rt_src;
 520
 521         if ((iph->ttl = tiph->ttl) == 0)
 522                 iph->ttl        =       old_iph->ttl;
 523
 524         nf_reset(skb);
 525
 526         IPTUNNEL_XMIT();
 527         return NETDEV_TX_OK;
 528
 529 tx_error_icmp:
 530         dst_link_failure(skb);
 531 tx_error:
 532         stats->tx_errors++;
 533         dev_kfree_skb(skb);
 534         return NETDEV_TX_OK;
 535 }
 536
 537 static void ipip_tunnel_bind_dev(struct net_device *dev)
 538 {
 539         struct net_device *tdev = NULL;
 540         struct ip_tunnel *tunnel;
 541         struct iphdr *iph;
 542
 543         tunnel = netdev_priv(dev);
 544         iph = &tunnel->parms.iph;
 545
 546         if (iph->daddr) {
 547                 struct flowi fl = { .oif = tunnel->parms.link,
 548                                     .nl_u = { .ip4_u =
 549                                               { .daddr = iph->daddr,
 550                                                 .saddr = iph->saddr,
 551                                                 .tos = RT_TOS(iph->tos) } },
 552                                     .proto = IPPROTO_IPIP };
 553                 struct rtable *rt;
 554                 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
 555                         tdev = rt->dst.dev;
 556                         ip_rt_put(rt);
 557                 }
 558                 dev->flags |= IFF_POINTOPOINT;
 559         }
 560
 561         if (!tdev && tunnel->parms.link)
 562                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 563
 564         if (tdev) {
 565                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
 566                 dev->mtu = tdev->mtu - sizeof(struct iphdr);
 567         }
 568         dev->iflink = tunnel->parms.link;
 569 }
 570
 571 static int
 572 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 573 {
 574         int err = 0;
 575         struct ip_tunnel_parm p;
 576         struct ip_tunnel *t;
 577         struct net *net = dev_net(dev);
 578         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 579
 580         switch (cmd) {
 581         case SIOCGETTUNNEL:
 582                 t = NULL;
 583                 if (dev == ipn->fb_tunnel_dev) {
 584                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 585                                 err = -EFAULT;
 586                                 break;
 587                         }
 588                         t = ipip_tunnel_locate(net, &p, 0);
 589                 }
 590                 if (t == NULL)
 591                         t = netdev_priv(dev);
 592                 memcpy(&p, &t->parms, sizeof(p));
 593                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 594                         err = -EFAULT;
 595                 break;
 596
 597         case SIOCADDTUNNEL:
 598         case SIOCCHGTUNNEL:
 599                 err = -EPERM;
 600                 if (!capable(CAP_NET_ADMIN))
 601                         goto done;
 602
 603                 err = -EFAULT;
 604                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 605                         goto done;
 606
 607                 err = -EINVAL;
 608                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
 609                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
 610                         goto done;
 611                 if (p.iph.ttl)
 612                         p.iph.frag_off |= htons(IP_DF);
 613
 614                 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
 615
 616                 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 617                         if (t != NULL) {
 618                                 if (t->dev != dev) {
 619                                         err = -EEXIST;
 620                                         break;
 621                                 }
 622                         } else {
 623                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
 624                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
 625                                         err = -EINVAL;
 626                                         break;
 627                                 }
 628                                 t = netdev_priv(dev);
 629                                 ipip_tunnel_unlink(ipn, t);
 630                                 t->parms.iph.saddr = p.iph.saddr;
 631                                 t->parms.iph.daddr = p.iph.daddr;
 632                                 memcpy(dev->dev_addr, &p.iph.saddr, 4);
 633                                 memcpy(dev->broadcast, &p.iph.daddr, 4);
 634                                 ipip_tunnel_link(ipn, t);
 635                                 netdev_state_change(dev);
 636                         }
 637                 }
 638
 639                 if (t) {
 640                         err = 0;
 641                         if (cmd == SIOCCHGTUNNEL) {
 642                                 t->parms.iph.ttl = p.iph.ttl;
 643                                 t->parms.iph.tos = p.iph.tos;
 644                                 t->parms.iph.frag_off = p.iph.frag_off;
 645                                 if (t->parms.link != p.link) {
 646                                         t->parms.link = p.link;
 647                                         ipip_tunnel_bind_dev(dev);
 648                                         netdev_state_change(dev);
 649                                 }
 650                         }
 651                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
 652                                 err = -EFAULT;
 653                 } else
 654                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 655                 break;
 656
 657         case SIOCDELTUNNEL:
 658                 err = -EPERM;
 659                 if (!capable(CAP_NET_ADMIN))
 660                         goto done;
 661
 662                 if (dev == ipn->fb_tunnel_dev) {
 663                         err = -EFAULT;
 664                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 665                                 goto done;
 666                         err = -ENOENT;
 667                         if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
 668                                 goto done;
 669                         err = -EPERM;
 670                         if (t->dev == ipn->fb_tunnel_dev)
 671                                 goto done;
 672                         dev = t->dev;
 673                 }
 674                 unregister_netdevice(dev);
 675                 err = 0;
 676                 break;
 677
 678         default:
 679                 err = -EINVAL;
 680         }
 681
 682 done:
 683         return err;
 684 }
 685
 686 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
 687 {
 688         if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
 689                 return -EINVAL;
 690         dev->mtu = new_mtu;
 691         return 0;
 692 }
 693
 694 static const struct net_device_ops ipip_netdev_ops = {
 695         .ndo_uninit     = ipip_tunnel_uninit,
 696         .ndo_start_xmit = ipip_tunnel_xmit,
 697         .ndo_do_ioctl   = ipip_tunnel_ioctl,
 698         .ndo_change_mtu = ipip_tunnel_change_mtu,
 699
 700 };
 701
 702 static void ipip_tunnel_setup(struct net_device *dev)
 703 {
 704         dev->netdev_ops         = &ipip_netdev_ops;
 705         dev->destructor         = free_netdev;
 706
 707         dev->type               = ARPHRD_TUNNEL;
 708         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
 709         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
 710         dev->flags              = IFF_NOARP;
 711         dev->iflink             = 0;
 712         dev->addr_len           = 4;
 713         dev->features           |= NETIF_F_NETNS_LOCAL;
 714         dev->priv_flags         &= ~IFF_XMIT_DST_RELEASE;
 715 }
 716
 717 static void ipip_tunnel_init(struct net_device *dev)
 718 {
 719         struct ip_tunnel *tunnel = netdev_priv(dev);
 720
 721         tunnel->dev = dev;
 722         strcpy(tunnel->parms.name, dev->name);
 723
 724         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
 725         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
 726
 727         ipip_tunnel_bind_dev(dev);
 728 }
 729
 730 static void __net_init ipip_fb_tunnel_init(struct net_device *dev)
 731 {
 732         struct ip_tunnel *tunnel = netdev_priv(dev);
 733         struct iphdr *iph = &tunnel->parms.iph;
 734         struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
 735
 736         tunnel->dev = dev;
 737         strcpy(tunnel->parms.name, dev->name);
 738
 739         iph->version            = 4;
 740         iph->protocol           = IPPROTO_IPIP;
 741         iph->ihl                = 5;
 742
 743         dev_hold(dev);
 744         rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
 745 }
 746
 747 static struct xfrm_tunnel ipip_handler __read_mostly = {
 748         .handler        =       ipip_rcv,
 749         .err_handler    =       ipip_err,
 750         .priority       =       1,
 751 };
 752
 753 static const char banner[] __initconst =
 754         KERN_INFO "IPv4 over IPv4 tunneling driver\n";
 755
 756 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
 757 {
 758         int prio;
 759
 760         for (prio = 1; prio < 4; prio++) {
 761                 int h;
 762                 for (h = 0; h < HASH_SIZE; h++) {
 763                         struct ip_tunnel *t;
 764
 765                         t = rtnl_dereference(ipn->tunnels[prio][h]);
 766                         while (t != NULL) {
 767                                 unregister_netdevice_queue(t->dev, head);
 768                                 t = rtnl_dereference(t->next);
 769                         }
 770                 }
 771         }
 772 }
 773
 774 static int __net_init ipip_init_net(struct net *net)
 775 {
 776         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 777         int err;
 778
 779         ipn->tunnels[0] = ipn->tunnels_wc;
 780         ipn->tunnels[1] = ipn->tunnels_l;
 781         ipn->tunnels[2] = ipn->tunnels_r;
 782         ipn->tunnels[3] = ipn->tunnels_r_l;
 783
 784         ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
 785                                            "tunl0",
 786                                            ipip_tunnel_setup);
 787         if (!ipn->fb_tunnel_dev) {
 788                 err = -ENOMEM;
 789                 goto err_alloc_dev;
 790         }
 791         dev_net_set(ipn->fb_tunnel_dev, net);
 792
 793         ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
 794
 795         if ((err = register_netdev(ipn->fb_tunnel_dev)))
 796                 goto err_reg_dev;
 797
 798         return 0;
 799
 800 err_reg_dev:
 801         free_netdev(ipn->fb_tunnel_dev);
 802 err_alloc_dev:
 803         /* nothing */
 804         return err;
 805 }
 806
 807 static void __net_exit ipip_exit_net(struct net *net)
 808 {
 809         struct ipip_net *ipn = net_generic(net, ipip_net_id);
 810         LIST_HEAD(list);
 811
 812         rtnl_lock();
 813         ipip_destroy_tunnels(ipn, &list);
 814         unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
 815         unregister_netdevice_many(&list);
 816         rtnl_unlock();
 817 }
 818
 819 static struct pernet_operations ipip_net_ops = {
 820         .init = ipip_init_net,
 821         .exit = ipip_exit_net,
 822         .id   = &ipip_net_id,
 823         .size = sizeof(struct ipip_net),
 824 };
 825
 826 static int __init ipip_init(void)
 827 {
 828         int err;
 829
 830         printk(banner);
 831
 832         err = register_pernet_device(&ipip_net_ops);
 833         if (err < 0)
 834                 return err;
 835         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
 836         if (err < 0) {
 837                 unregister_pernet_device(&ipip_net_ops);
 838                 printk(KERN_INFO "ipip init: can't register tunnel\n");
 839         }
 840         return err;
 841 }
 842
 843 static void __exit ipip_fini(void)
 844 {
 845         if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
 846                 printk(KERN_INFO "ipip close: can't deregister tunnel\n");
 847
 848         unregister_pernet_device(&ipip_net_ops);
 849 }
 850
 851 module_init(ipip_init);
 852 module_exit(ipip_fini);
 853 MODULE_LICENSE("GPL");