can: fix setting mcp251x bit timing on open
[linux-2.6.git] / 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 <asm/uaccess.h>
99 #include <linux/skbuff.h>
100 #include <linux/netdevice.h>
101 #include <linux/in.h>
102 #include <linux/tcp.h>
103 #include <linux/udp.h>
104 #include <linux/if_arp.h>
105 #include <linux/mroute.h>
106 #include <linux/init.h>
107 #include <linux/netfilter_ipv4.h>
108 #include <linux/if_ether.h>
109
110 #include <net/sock.h>
111 #include <net/ip.h>
112 #include <net/icmp.h>
113 #include <net/ipip.h>
114 #include <net/inet_ecn.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/netns/generic.h>
118
119 #define HASH_SIZE  16
120 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
121
122 static int ipip_net_id;
123 struct ipip_net {
124         struct ip_tunnel *tunnels_r_l[HASH_SIZE];
125         struct ip_tunnel *tunnels_r[HASH_SIZE];
126         struct ip_tunnel *tunnels_l[HASH_SIZE];
127         struct ip_tunnel *tunnels_wc[1];
128         struct ip_tunnel **tunnels[4];
129
130         struct net_device *fb_tunnel_dev;
131 };
132
133 static void ipip_fb_tunnel_init(struct net_device *dev);
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 a spinlock
139  */
140 static DEFINE_SPINLOCK(ipip_lock);
141
142 #define for_each_ip_tunnel_rcu(start) \
143         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
144
145 static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
146                 __be32 remote, __be32 local)
147 {
148         unsigned h0 = HASH(remote);
149         unsigned h1 = HASH(local);
150         struct ip_tunnel *t;
151         struct ipip_net *ipn = net_generic(net, ipip_net_id);
152
153         for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1])
154                 if (local == t->parms.iph.saddr &&
155                     remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
156                         return t;
157
158         for_each_ip_tunnel_rcu(ipn->tunnels_r[h0])
159                 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
160                         return t;
161
162         for_each_ip_tunnel_rcu(ipn->tunnels_l[h1])
163                 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
164                         return t;
165
166         t = rcu_dereference(ipn->tunnels_wc[0]);
167         if (t && (t->dev->flags&IFF_UP))
168                 return t;
169         return NULL;
170 }
171
172 static struct ip_tunnel **__ipip_bucket(struct ipip_net *ipn,
173                 struct ip_tunnel_parm *parms)
174 {
175         __be32 remote = parms->iph.daddr;
176         __be32 local = parms->iph.saddr;
177         unsigned h = 0;
178         int prio = 0;
179
180         if (remote) {
181                 prio |= 2;
182                 h ^= HASH(remote);
183         }
184         if (local) {
185                 prio |= 1;
186                 h ^= HASH(local);
187         }
188         return &ipn->tunnels[prio][h];
189 }
190
191 static inline struct ip_tunnel **ipip_bucket(struct ipip_net *ipn,
192                 struct ip_tunnel *t)
193 {
194         return __ipip_bucket(ipn, &t->parms);
195 }
196
197 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
198 {
199         struct ip_tunnel **tp;
200
201         for (tp = ipip_bucket(ipn, t); *tp; tp = &(*tp)->next) {
202                 if (t == *tp) {
203                         spin_lock_bh(&ipip_lock);
204                         *tp = t->next;
205                         spin_unlock_bh(&ipip_lock);
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 **tp = ipip_bucket(ipn, t);
214
215         spin_lock_bh(&ipip_lock);
216         t->next = *tp;
217         rcu_assign_pointer(*tp, t);
218         spin_unlock_bh(&ipip_lock);
219 }
220
221 static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
222                 struct ip_tunnel_parm *parms, int create)
223 {
224         __be32 remote = parms->iph.daddr;
225         __be32 local = parms->iph.saddr;
226         struct ip_tunnel *t, **tp, *nt;
227         struct net_device *dev;
228         char name[IFNAMSIZ];
229         struct ipip_net *ipn = net_generic(net, ipip_net_id);
230
231         for (tp = __ipip_bucket(ipn, parms); (t = *tp) != NULL; tp = &t->next) {
232                 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
233                         return t;
234         }
235         if (!create)
236                 return NULL;
237
238         if (parms->name[0])
239                 strlcpy(name, parms->name, IFNAMSIZ);
240         else
241                 sprintf(name, "tunl%%d");
242
243         dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
244         if (dev == NULL)
245                 return NULL;
246
247         dev_net_set(dev, net);
248
249         if (strchr(name, '%')) {
250                 if (dev_alloc_name(dev, name) < 0)
251                         goto failed_free;
252         }
253
254         nt = netdev_priv(dev);
255         nt->parms = *parms;
256
257         ipip_tunnel_init(dev);
258
259         if (register_netdevice(dev) < 0)
260                 goto failed_free;
261
262         dev_hold(dev);
263         ipip_tunnel_link(ipn, nt);
264         return nt;
265
266 failed_free:
267         free_netdev(dev);
268         return NULL;
269 }
270
271 static void ipip_tunnel_uninit(struct net_device *dev)
272 {
273         struct net *net = dev_net(dev);
274         struct ipip_net *ipn = net_generic(net, ipip_net_id);
275
276         if (dev == ipn->fb_tunnel_dev) {
277                 spin_lock_bh(&ipip_lock);
278                 ipn->tunnels_wc[0] = NULL;
279                 spin_unlock_bh(&ipip_lock);
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                 tunnel->dev->stats.rx_packets++;
378                 tunnel->dev->stats.rx_bytes += skb->len;
379                 skb->dev = tunnel->dev;
380                 skb_dst_drop(skb);
381                 nf_reset(skb);
382                 ipip_ecn_decapsulate(iph, skb);
383                 netif_rx(skb);
384                 rcu_read_unlock();
385                 return 0;
386         }
387         rcu_read_unlock();
388
389         return -1;
390 }
391
392 /*
393  *      This function assumes it is being called from dev_queue_xmit()
394  *      and that skb is filled properly by that function.
395  */
396
397 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
398 {
399         struct ip_tunnel *tunnel = netdev_priv(dev);
400         struct net_device_stats *stats = &dev->stats;
401         struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
402         struct iphdr  *tiph = &tunnel->parms.iph;
403         u8     tos = tunnel->parms.iph.tos;
404         __be16 df = tiph->frag_off;
405         struct rtable *rt;                      /* Route to the other host */
406         struct net_device *tdev;                        /* Device to other host */
407         struct iphdr  *old_iph = ip_hdr(skb);
408         struct iphdr  *iph;                     /* Our new IP header */
409         unsigned int max_headroom;              /* The extra header space needed */
410         __be32 dst = tiph->daddr;
411         int    mtu;
412
413         if (skb->protocol != htons(ETH_P_IP))
414                 goto tx_error;
415
416         if (tos&1)
417                 tos = old_iph->tos;
418
419         if (!dst) {
420                 /* NBMA tunnel */
421                 if ((rt = skb_rtable(skb)) == NULL) {
422                         stats->tx_fifo_errors++;
423                         goto tx_error;
424                 }
425                 if ((dst = rt->rt_gateway) == 0)
426                         goto tx_error_icmp;
427         }
428
429         {
430                 struct flowi fl = { .oif = tunnel->parms.link,
431                                     .nl_u = { .ip4_u =
432                                               { .daddr = dst,
433                                                 .saddr = tiph->saddr,
434                                                 .tos = RT_TOS(tos) } },
435                                     .proto = IPPROTO_IPIP };
436                 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
437                         stats->tx_carrier_errors++;
438                         goto tx_error_icmp;
439                 }
440         }
441         tdev = rt->u.dst.dev;
442
443         if (tdev == dev) {
444                 ip_rt_put(rt);
445                 stats->collisions++;
446                 goto tx_error;
447         }
448
449         df |= old_iph->frag_off & htons(IP_DF);
450
451         if (df) {
452                 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
453
454                 if (mtu < 68) {
455                         stats->collisions++;
456                         ip_rt_put(rt);
457                         goto tx_error;
458                 }
459
460                 if (skb_dst(skb))
461                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
462
463                 if ((old_iph->frag_off & htons(IP_DF)) &&
464                     mtu < ntohs(old_iph->tot_len)) {
465                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
466                                   htonl(mtu));
467                         ip_rt_put(rt);
468                         goto tx_error;
469                 }
470         }
471
472         if (tunnel->err_count > 0) {
473                 if (time_before(jiffies,
474                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
475                         tunnel->err_count--;
476                         dst_link_failure(skb);
477                 } else
478                         tunnel->err_count = 0;
479         }
480
481         /*
482          * Okay, now see if we can stuff it in the buffer as-is.
483          */
484         max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
485
486         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
487             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
488                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
489                 if (!new_skb) {
490                         ip_rt_put(rt);
491                         txq->tx_dropped++;
492                         dev_kfree_skb(skb);
493                         return NETDEV_TX_OK;
494                 }
495                 if (skb->sk)
496                         skb_set_owner_w(new_skb, skb->sk);
497                 dev_kfree_skb(skb);
498                 skb = new_skb;
499                 old_iph = ip_hdr(skb);
500         }
501
502         skb->transport_header = skb->network_header;
503         skb_push(skb, sizeof(struct iphdr));
504         skb_reset_network_header(skb);
505         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
506         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
507                               IPSKB_REROUTED);
508         skb_dst_drop(skb);
509         skb_dst_set(skb, &rt->u.dst);
510
511         /*
512          *      Push down and install the IPIP header.
513          */
514
515         iph                     =       ip_hdr(skb);
516         iph->version            =       4;
517         iph->ihl                =       sizeof(struct iphdr)>>2;
518         iph->frag_off           =       df;
519         iph->protocol           =       IPPROTO_IPIP;
520         iph->tos                =       INET_ECN_encapsulate(tos, old_iph->tos);
521         iph->daddr              =       rt->rt_dst;
522         iph->saddr              =       rt->rt_src;
523
524         if ((iph->ttl = tiph->ttl) == 0)
525                 iph->ttl        =       old_iph->ttl;
526
527         nf_reset(skb);
528
529         IPTUNNEL_XMIT();
530         return NETDEV_TX_OK;
531
532 tx_error_icmp:
533         dst_link_failure(skb);
534 tx_error:
535         stats->tx_errors++;
536         dev_kfree_skb(skb);
537         return NETDEV_TX_OK;
538 }
539
540 static void ipip_tunnel_bind_dev(struct net_device *dev)
541 {
542         struct net_device *tdev = NULL;
543         struct ip_tunnel *tunnel;
544         struct iphdr *iph;
545
546         tunnel = netdev_priv(dev);
547         iph = &tunnel->parms.iph;
548
549         if (iph->daddr) {
550                 struct flowi fl = { .oif = tunnel->parms.link,
551                                     .nl_u = { .ip4_u =
552                                               { .daddr = iph->daddr,
553                                                 .saddr = iph->saddr,
554                                                 .tos = RT_TOS(iph->tos) } },
555                                     .proto = IPPROTO_IPIP };
556                 struct rtable *rt;
557                 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
558                         tdev = rt->u.dst.dev;
559                         ip_rt_put(rt);
560                 }
561                 dev->flags |= IFF_POINTOPOINT;
562         }
563
564         if (!tdev && tunnel->parms.link)
565                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
566
567         if (tdev) {
568                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
569                 dev->mtu = tdev->mtu - sizeof(struct iphdr);
570         }
571         dev->iflink = tunnel->parms.link;
572 }
573
574 static int
575 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
576 {
577         int err = 0;
578         struct ip_tunnel_parm p;
579         struct ip_tunnel *t;
580         struct net *net = dev_net(dev);
581         struct ipip_net *ipn = net_generic(net, ipip_net_id);
582
583         switch (cmd) {
584         case SIOCGETTUNNEL:
585                 t = NULL;
586                 if (dev == ipn->fb_tunnel_dev) {
587                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
588                                 err = -EFAULT;
589                                 break;
590                         }
591                         t = ipip_tunnel_locate(net, &p, 0);
592                 }
593                 if (t == NULL)
594                         t = netdev_priv(dev);
595                 memcpy(&p, &t->parms, sizeof(p));
596                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
597                         err = -EFAULT;
598                 break;
599
600         case SIOCADDTUNNEL:
601         case SIOCCHGTUNNEL:
602                 err = -EPERM;
603                 if (!capable(CAP_NET_ADMIN))
604                         goto done;
605
606                 err = -EFAULT;
607                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
608                         goto done;
609
610                 err = -EINVAL;
611                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
612                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
613                         goto done;
614                 if (p.iph.ttl)
615                         p.iph.frag_off |= htons(IP_DF);
616
617                 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
618
619                 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
620                         if (t != NULL) {
621                                 if (t->dev != dev) {
622                                         err = -EEXIST;
623                                         break;
624                                 }
625                         } else {
626                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
627                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
628                                         err = -EINVAL;
629                                         break;
630                                 }
631                                 t = netdev_priv(dev);
632                                 ipip_tunnel_unlink(ipn, t);
633                                 t->parms.iph.saddr = p.iph.saddr;
634                                 t->parms.iph.daddr = p.iph.daddr;
635                                 memcpy(dev->dev_addr, &p.iph.saddr, 4);
636                                 memcpy(dev->broadcast, &p.iph.daddr, 4);
637                                 ipip_tunnel_link(ipn, t);
638                                 netdev_state_change(dev);
639                         }
640                 }
641
642                 if (t) {
643                         err = 0;
644                         if (cmd == SIOCCHGTUNNEL) {
645                                 t->parms.iph.ttl = p.iph.ttl;
646                                 t->parms.iph.tos = p.iph.tos;
647                                 t->parms.iph.frag_off = p.iph.frag_off;
648                                 if (t->parms.link != p.link) {
649                                         t->parms.link = p.link;
650                                         ipip_tunnel_bind_dev(dev);
651                                         netdev_state_change(dev);
652                                 }
653                         }
654                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
655                                 err = -EFAULT;
656                 } else
657                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
658                 break;
659
660         case SIOCDELTUNNEL:
661                 err = -EPERM;
662                 if (!capable(CAP_NET_ADMIN))
663                         goto done;
664
665                 if (dev == ipn->fb_tunnel_dev) {
666                         err = -EFAULT;
667                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
668                                 goto done;
669                         err = -ENOENT;
670                         if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
671                                 goto done;
672                         err = -EPERM;
673                         if (t->dev == ipn->fb_tunnel_dev)
674                                 goto done;
675                         dev = t->dev;
676                 }
677                 unregister_netdevice(dev);
678                 err = 0;
679                 break;
680
681         default:
682                 err = -EINVAL;
683         }
684
685 done:
686         return err;
687 }
688
689 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
690 {
691         if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
692                 return -EINVAL;
693         dev->mtu = new_mtu;
694         return 0;
695 }
696
697 static const struct net_device_ops ipip_netdev_ops = {
698         .ndo_uninit     = ipip_tunnel_uninit,
699         .ndo_start_xmit = ipip_tunnel_xmit,
700         .ndo_do_ioctl   = ipip_tunnel_ioctl,
701         .ndo_change_mtu = ipip_tunnel_change_mtu,
702
703 };
704
705 static void ipip_tunnel_setup(struct net_device *dev)
706 {
707         dev->netdev_ops         = &ipip_netdev_ops;
708         dev->destructor         = free_netdev;
709
710         dev->type               = ARPHRD_TUNNEL;
711         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
712         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
713         dev->flags              = IFF_NOARP;
714         dev->iflink             = 0;
715         dev->addr_len           = 4;
716         dev->features           |= NETIF_F_NETNS_LOCAL;
717         dev->priv_flags         &= ~IFF_XMIT_DST_RELEASE;
718 }
719
720 static void ipip_tunnel_init(struct net_device *dev)
721 {
722         struct ip_tunnel *tunnel = netdev_priv(dev);
723
724         tunnel->dev = dev;
725         strcpy(tunnel->parms.name, dev->name);
726
727         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
728         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
729
730         ipip_tunnel_bind_dev(dev);
731 }
732
733 static void ipip_fb_tunnel_init(struct net_device *dev)
734 {
735         struct ip_tunnel *tunnel = netdev_priv(dev);
736         struct iphdr *iph = &tunnel->parms.iph;
737         struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
738
739         tunnel->dev = dev;
740         strcpy(tunnel->parms.name, dev->name);
741
742         iph->version            = 4;
743         iph->protocol           = IPPROTO_IPIP;
744         iph->ihl                = 5;
745
746         dev_hold(dev);
747         ipn->tunnels_wc[0]      = tunnel;
748 }
749
750 static struct xfrm_tunnel ipip_handler = {
751         .handler        =       ipip_rcv,
752         .err_handler    =       ipip_err,
753         .priority       =       1,
754 };
755
756 static const char banner[] __initconst =
757         KERN_INFO "IPv4 over IPv4 tunneling driver\n";
758
759 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
760 {
761         int prio;
762
763         for (prio = 1; prio < 4; prio++) {
764                 int h;
765                 for (h = 0; h < HASH_SIZE; h++) {
766                         struct ip_tunnel *t = ipn->tunnels[prio][h];
767
768                         while (t != NULL) {
769                                 unregister_netdevice_queue(t->dev, head);
770                                 t = t->next;
771                         }
772                 }
773         }
774 }
775
776 static int ipip_init_net(struct net *net)
777 {
778         int err;
779         struct ipip_net *ipn;
780
781         err = -ENOMEM;
782         ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL);
783         if (ipn == NULL)
784                 goto err_alloc;
785
786         err = net_assign_generic(net, ipip_net_id, ipn);
787         if (err < 0)
788                 goto err_assign;
789
790         ipn->tunnels[0] = ipn->tunnels_wc;
791         ipn->tunnels[1] = ipn->tunnels_l;
792         ipn->tunnels[2] = ipn->tunnels_r;
793         ipn->tunnels[3] = ipn->tunnels_r_l;
794
795         ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
796                                            "tunl0",
797                                            ipip_tunnel_setup);
798         if (!ipn->fb_tunnel_dev) {
799                 err = -ENOMEM;
800                 goto err_alloc_dev;
801         }
802         dev_net_set(ipn->fb_tunnel_dev, net);
803
804         ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
805
806         if ((err = register_netdev(ipn->fb_tunnel_dev)))
807                 goto err_reg_dev;
808
809         return 0;
810
811 err_reg_dev:
812         free_netdev(ipn->fb_tunnel_dev);
813 err_alloc_dev:
814         /* nothing */
815 err_assign:
816         kfree(ipn);
817 err_alloc:
818         return err;
819 }
820
821 static void ipip_exit_net(struct net *net)
822 {
823         struct ipip_net *ipn;
824         LIST_HEAD(list);
825
826         ipn = net_generic(net, ipip_net_id);
827         rtnl_lock();
828         ipip_destroy_tunnels(ipn, &list);
829         unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
830         unregister_netdevice_many(&list);
831         rtnl_unlock();
832         kfree(ipn);
833 }
834
835 static struct pernet_operations ipip_net_ops = {
836         .init = ipip_init_net,
837         .exit = ipip_exit_net,
838 };
839
840 static int __init ipip_init(void)
841 {
842         int err;
843
844         printk(banner);
845
846         if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) {
847                 printk(KERN_INFO "ipip init: can't register tunnel\n");
848                 return -EAGAIN;
849         }
850
851         err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops);
852         if (err)
853                 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
854
855         return err;
856 }
857
858 static void __exit ipip_fini(void)
859 {
860         if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
861                 printk(KERN_INFO "ipip close: can't deregister tunnel\n");
862
863         unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops);
864 }
865
866 module_init(ipip_init);
867 module_exit(ipip_fini);
868 MODULE_LICENSE("GPL");