[IP_TUNNEL]: Don't limit the number of tunnels with generic name explicitly.
[linux-2.6.git] / net / ipv6 / ip6_tunnel.c
1 /*
2  *      IPv6 tunneling device
3  *      Linux INET6 implementation
4  *
5  *      Authors:
6  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
7  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
8  *
9  *      $Id$
10  *
11  *      Based on:
12  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
13  *
14  *      RFC 2473
15  *
16  *      This program is free software; you can redistribute it and/or
17  *      modify it under the terms of the GNU General Public License
18  *      as published by the Free Software Foundation; either version
19  *      2 of the License, or (at your option) any later version.
20  *
21  */
22
23 #include <linux/module.h>
24 #include <linux/capability.h>
25 #include <linux/errno.h>
26 #include <linux/types.h>
27 #include <linux/sockios.h>
28 #include <linux/icmp.h>
29 #include <linux/if.h>
30 #include <linux/in.h>
31 #include <linux/ip.h>
32 #include <linux/if_tunnel.h>
33 #include <linux/net.h>
34 #include <linux/in6.h>
35 #include <linux/netdevice.h>
36 #include <linux/if_arp.h>
37 #include <linux/icmpv6.h>
38 #include <linux/init.h>
39 #include <linux/route.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/netfilter_ipv6.h>
42
43 #include <asm/uaccess.h>
44 #include <asm/atomic.h>
45
46 #include <net/icmp.h>
47 #include <net/ip.h>
48 #include <net/ipv6.h>
49 #include <net/ip6_route.h>
50 #include <net/addrconf.h>
51 #include <net/ip6_tunnel.h>
52 #include <net/xfrm.h>
53 #include <net/dsfield.h>
54 #include <net/inet_ecn.h>
55
56 MODULE_AUTHOR("Ville Nuorvala");
57 MODULE_DESCRIPTION("IPv6 tunneling device");
58 MODULE_LICENSE("GPL");
59
60 #define IPV6_TLV_TEL_DST_SIZE 8
61
62 #ifdef IP6_TNL_DEBUG
63 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__)
64 #else
65 #define IP6_TNL_TRACE(x...) do {;} while(0)
66 #endif
67
68 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
69 #define IPV6_TCLASS_SHIFT 20
70
71 #define HASH_SIZE  32
72
73 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \
74                      (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \
75                     (HASH_SIZE - 1))
76
77 static int ip6_fb_tnl_dev_init(struct net_device *dev);
78 static int ip6_tnl_dev_init(struct net_device *dev);
79 static void ip6_tnl_dev_setup(struct net_device *dev);
80
81 /* the IPv6 tunnel fallback device */
82 static struct net_device *ip6_fb_tnl_dev;
83
84
85 /* lists for storing tunnels in use */
86 static struct ip6_tnl *tnls_r_l[HASH_SIZE];
87 static struct ip6_tnl *tnls_wc[1];
88 static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l };
89
90 /* lock for the tunnel lists */
91 static DEFINE_RWLOCK(ip6_tnl_lock);
92
93 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
94 {
95         struct dst_entry *dst = t->dst_cache;
96
97         if (dst && dst->obsolete &&
98             dst->ops->check(dst, t->dst_cookie) == NULL) {
99                 t->dst_cache = NULL;
100                 dst_release(dst);
101                 return NULL;
102         }
103
104         return dst;
105 }
106
107 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t)
108 {
109         dst_release(t->dst_cache);
110         t->dst_cache = NULL;
111 }
112
113 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
114 {
115         struct rt6_info *rt = (struct rt6_info *) dst;
116         t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
117         dst_release(t->dst_cache);
118         t->dst_cache = dst;
119 }
120
121 /**
122  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
123  *   @remote: the address of the tunnel exit-point
124  *   @local: the address of the tunnel entry-point
125  *
126  * Return:
127  *   tunnel matching given end-points if found,
128  *   else fallback tunnel if its device is up,
129  *   else %NULL
130  **/
131
132 static struct ip6_tnl *
133 ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local)
134 {
135         unsigned h0 = HASH(remote);
136         unsigned h1 = HASH(local);
137         struct ip6_tnl *t;
138
139         for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) {
140                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
141                     ipv6_addr_equal(remote, &t->parms.raddr) &&
142                     (t->dev->flags & IFF_UP))
143                         return t;
144         }
145         if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP))
146                 return t;
147
148         return NULL;
149 }
150
151 /**
152  * ip6_tnl_bucket - get head of list matching given tunnel parameters
153  *   @p: parameters containing tunnel end-points
154  *
155  * Description:
156  *   ip6_tnl_bucket() returns the head of the list matching the
157  *   &struct in6_addr entries laddr and raddr in @p.
158  *
159  * Return: head of IPv6 tunnel list
160  **/
161
162 static struct ip6_tnl **
163 ip6_tnl_bucket(struct ip6_tnl_parm *p)
164 {
165         struct in6_addr *remote = &p->raddr;
166         struct in6_addr *local = &p->laddr;
167         unsigned h = 0;
168         int prio = 0;
169
170         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
171                 prio = 1;
172                 h = HASH(remote) ^ HASH(local);
173         }
174         return &tnls[prio][h];
175 }
176
177 /**
178  * ip6_tnl_link - add tunnel to hash table
179  *   @t: tunnel to be added
180  **/
181
182 static void
183 ip6_tnl_link(struct ip6_tnl *t)
184 {
185         struct ip6_tnl **tp = ip6_tnl_bucket(&t->parms);
186
187         t->next = *tp;
188         write_lock_bh(&ip6_tnl_lock);
189         *tp = t;
190         write_unlock_bh(&ip6_tnl_lock);
191 }
192
193 /**
194  * ip6_tnl_unlink - remove tunnel from hash table
195  *   @t: tunnel to be removed
196  **/
197
198 static void
199 ip6_tnl_unlink(struct ip6_tnl *t)
200 {
201         struct ip6_tnl **tp;
202
203         for (tp = ip6_tnl_bucket(&t->parms); *tp; tp = &(*tp)->next) {
204                 if (t == *tp) {
205                         write_lock_bh(&ip6_tnl_lock);
206                         *tp = t->next;
207                         write_unlock_bh(&ip6_tnl_lock);
208                         break;
209                 }
210         }
211 }
212
213 /**
214  * ip6_tnl_create() - create a new tunnel
215  *   @p: tunnel parameters
216  *   @pt: pointer to new tunnel
217  *
218  * Description:
219  *   Create tunnel matching given parameters.
220  *
221  * Return:
222  *   created tunnel or NULL
223  **/
224
225 static struct ip6_tnl *ip6_tnl_create(struct ip6_tnl_parm *p)
226 {
227         struct net_device *dev;
228         struct ip6_tnl *t;
229         char name[IFNAMSIZ];
230         int err;
231
232         if (p->name[0])
233                 strlcpy(name, p->name, IFNAMSIZ);
234         else
235                 sprintf(name, "ip6tnl%%d");
236
237         dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
238         if (dev == NULL)
239                 goto failed;
240
241         t = netdev_priv(dev);
242         dev->init = ip6_tnl_dev_init;
243         t->parms = *p;
244
245         if ((err = register_netdevice(dev)) < 0) {
246                 free_netdev(dev);
247                 goto failed;
248         }
249         dev_hold(dev);
250         ip6_tnl_link(t);
251         return t;
252 failed:
253         return NULL;
254 }
255
256 /**
257  * ip6_tnl_locate - find or create tunnel matching given parameters
258  *   @p: tunnel parameters
259  *   @create: != 0 if allowed to create new tunnel if no match found
260  *
261  * Description:
262  *   ip6_tnl_locate() first tries to locate an existing tunnel
263  *   based on @parms. If this is unsuccessful, but @create is set a new
264  *   tunnel device is created and registered for use.
265  *
266  * Return:
267  *   matching tunnel or NULL
268  **/
269
270 static struct ip6_tnl *ip6_tnl_locate(struct ip6_tnl_parm *p, int create)
271 {
272         struct in6_addr *remote = &p->raddr;
273         struct in6_addr *local = &p->laddr;
274         struct ip6_tnl *t;
275
276         for (t = *ip6_tnl_bucket(p); t; t = t->next) {
277                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
278                     ipv6_addr_equal(remote, &t->parms.raddr))
279                         return t;
280         }
281         if (!create)
282                 return NULL;
283         return ip6_tnl_create(p);
284 }
285
286 /**
287  * ip6_tnl_dev_uninit - tunnel device uninitializer
288  *   @dev: the device to be destroyed
289  *
290  * Description:
291  *   ip6_tnl_dev_uninit() removes tunnel from its list
292  **/
293
294 static void
295 ip6_tnl_dev_uninit(struct net_device *dev)
296 {
297         struct ip6_tnl *t = netdev_priv(dev);
298
299         if (dev == ip6_fb_tnl_dev) {
300                 write_lock_bh(&ip6_tnl_lock);
301                 tnls_wc[0] = NULL;
302                 write_unlock_bh(&ip6_tnl_lock);
303         } else {
304                 ip6_tnl_unlink(t);
305         }
306         ip6_tnl_dst_reset(t);
307         dev_put(dev);
308 }
309
310 /**
311  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
312  *   @skb: received socket buffer
313  *
314  * Return:
315  *   0 if none was found,
316  *   else index to encapsulation limit
317  **/
318
319 static __u16
320 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
321 {
322         struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw;
323         __u8 nexthdr = ipv6h->nexthdr;
324         __u16 off = sizeof (*ipv6h);
325
326         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
327                 __u16 optlen = 0;
328                 struct ipv6_opt_hdr *hdr;
329                 if (raw + off + sizeof (*hdr) > skb->data &&
330                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
331                         break;
332
333                 hdr = (struct ipv6_opt_hdr *) (raw + off);
334                 if (nexthdr == NEXTHDR_FRAGMENT) {
335                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
336                         if (frag_hdr->frag_off)
337                                 break;
338                         optlen = 8;
339                 } else if (nexthdr == NEXTHDR_AUTH) {
340                         optlen = (hdr->hdrlen + 2) << 2;
341                 } else {
342                         optlen = ipv6_optlen(hdr);
343                 }
344                 if (nexthdr == NEXTHDR_DEST) {
345                         __u16 i = off + 2;
346                         while (1) {
347                                 struct ipv6_tlv_tnl_enc_lim *tel;
348
349                                 /* No more room for encapsulation limit */
350                                 if (i + sizeof (*tel) > off + optlen)
351                                         break;
352
353                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
354                                 /* return index of option if found and valid */
355                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
356                                     tel->length == 1)
357                                         return i;
358                                 /* else jump to next option */
359                                 if (tel->type)
360                                         i += tel->length + 2;
361                                 else
362                                         i++;
363                         }
364                 }
365                 nexthdr = hdr->nexthdr;
366                 off += optlen;
367         }
368         return 0;
369 }
370
371 /**
372  * ip6_tnl_err - tunnel error handler
373  *
374  * Description:
375  *   ip6_tnl_err() should handle errors in the tunnel according
376  *   to the specifications in RFC 2473.
377  **/
378
379 static int
380 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
381             int *type, int *code, int *msg, __u32 *info, int offset)
382 {
383         struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data;
384         struct ip6_tnl *t;
385         int rel_msg = 0;
386         int rel_type = ICMPV6_DEST_UNREACH;
387         int rel_code = ICMPV6_ADDR_UNREACH;
388         __u32 rel_info = 0;
389         __u16 len;
390         int err = -ENOENT;
391
392         /* If the packet doesn't contain the original IPv6 header we are
393            in trouble since we might need the source address for further
394            processing of the error. */
395
396         read_lock(&ip6_tnl_lock);
397         if ((t = ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL)
398                 goto out;
399
400         if (t->parms.proto != ipproto && t->parms.proto != 0)
401                 goto out;
402
403         err = 0;
404
405         switch (*type) {
406                 __u32 teli;
407                 struct ipv6_tlv_tnl_enc_lim *tel;
408                 __u32 mtu;
409         case ICMPV6_DEST_UNREACH:
410                 if (net_ratelimit())
411                         printk(KERN_WARNING
412                                "%s: Path to destination invalid "
413                                "or inactive!\n", t->parms.name);
414                 rel_msg = 1;
415                 break;
416         case ICMPV6_TIME_EXCEED:
417                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
418                         if (net_ratelimit())
419                                 printk(KERN_WARNING
420                                        "%s: Too small hop limit or "
421                                        "routing loop in tunnel!\n",
422                                        t->parms.name);
423                         rel_msg = 1;
424                 }
425                 break;
426         case ICMPV6_PARAMPROB:
427                 teli = 0;
428                 if ((*code) == ICMPV6_HDR_FIELD)
429                         teli = parse_tlv_tnl_enc_lim(skb, skb->data);
430
431                 if (teli && teli == *info - 2) {
432                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
433                         if (tel->encap_limit == 0) {
434                                 if (net_ratelimit())
435                                         printk(KERN_WARNING
436                                                "%s: Too small encapsulation "
437                                                "limit or routing loop in "
438                                                "tunnel!\n", t->parms.name);
439                                 rel_msg = 1;
440                         }
441                 } else if (net_ratelimit()) {
442                         printk(KERN_WARNING
443                                "%s: Recipient unable to parse tunneled "
444                                "packet!\n ", t->parms.name);
445                 }
446                 break;
447         case ICMPV6_PKT_TOOBIG:
448                 mtu = *info - offset;
449                 if (mtu < IPV6_MIN_MTU)
450                         mtu = IPV6_MIN_MTU;
451                 t->dev->mtu = mtu;
452
453                 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
454                         rel_type = ICMPV6_PKT_TOOBIG;
455                         rel_code = 0;
456                         rel_info = mtu;
457                         rel_msg = 1;
458                 }
459                 break;
460         }
461
462         *type = rel_type;
463         *code = rel_code;
464         *info = rel_info;
465         *msg = rel_msg;
466
467 out:
468         read_unlock(&ip6_tnl_lock);
469         return err;
470 }
471
472 static int
473 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
474            int type, int code, int offset, __be32 info)
475 {
476         int rel_msg = 0;
477         int rel_type = type;
478         int rel_code = code;
479         __u32 rel_info = ntohl(info);
480         int err;
481         struct sk_buff *skb2;
482         struct iphdr *eiph;
483         struct flowi fl;
484         struct rtable *rt;
485
486         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
487                           &rel_msg, &rel_info, offset);
488         if (err < 0)
489                 return err;
490
491         if (rel_msg == 0)
492                 return 0;
493
494         switch (rel_type) {
495         case ICMPV6_DEST_UNREACH:
496                 if (rel_code != ICMPV6_ADDR_UNREACH)
497                         return 0;
498                 rel_type = ICMP_DEST_UNREACH;
499                 rel_code = ICMP_HOST_UNREACH;
500                 break;
501         case ICMPV6_PKT_TOOBIG:
502                 if (rel_code != 0)
503                         return 0;
504                 rel_type = ICMP_DEST_UNREACH;
505                 rel_code = ICMP_FRAG_NEEDED;
506                 break;
507         default:
508                 return 0;
509         }
510
511         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
512                 return 0;
513
514         skb2 = skb_clone(skb, GFP_ATOMIC);
515         if (!skb2)
516                 return 0;
517
518         dst_release(skb2->dst);
519         skb2->dst = NULL;
520         skb_pull(skb2, offset);
521         skb_reset_network_header(skb2);
522         eiph = ip_hdr(skb2);
523
524         /* Try to guess incoming interface */
525         memset(&fl, 0, sizeof(fl));
526         fl.fl4_dst = eiph->saddr;
527         fl.fl4_tos = RT_TOS(eiph->tos);
528         fl.proto = IPPROTO_IPIP;
529         if (ip_route_output_key(&init_net, &rt, &fl))
530                 goto out;
531
532         skb2->dev = rt->u.dst.dev;
533
534         /* route "incoming" packet */
535         if (rt->rt_flags & RTCF_LOCAL) {
536                 ip_rt_put(rt);
537                 rt = NULL;
538                 fl.fl4_dst = eiph->daddr;
539                 fl.fl4_src = eiph->saddr;
540                 fl.fl4_tos = eiph->tos;
541                 if (ip_route_output_key(&init_net, &rt, &fl) ||
542                     rt->u.dst.dev->type != ARPHRD_TUNNEL) {
543                         ip_rt_put(rt);
544                         goto out;
545                 }
546                 skb2->dst = (struct dst_entry *)rt;
547         } else {
548                 ip_rt_put(rt);
549                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
550                                    skb2->dev) ||
551                     skb2->dst->dev->type != ARPHRD_TUNNEL)
552                         goto out;
553         }
554
555         /* change mtu on this route */
556         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
557                 if (rel_info > dst_mtu(skb2->dst))
558                         goto out;
559
560                 skb2->dst->ops->update_pmtu(skb2->dst, rel_info);
561         }
562
563         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
564
565 out:
566         kfree_skb(skb2);
567         return 0;
568 }
569
570 static int
571 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
572            int type, int code, int offset, __be32 info)
573 {
574         int rel_msg = 0;
575         int rel_type = type;
576         int rel_code = code;
577         __u32 rel_info = ntohl(info);
578         int err;
579
580         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
581                           &rel_msg, &rel_info, offset);
582         if (err < 0)
583                 return err;
584
585         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
586                 struct rt6_info *rt;
587                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
588
589                 if (!skb2)
590                         return 0;
591
592                 dst_release(skb2->dst);
593                 skb2->dst = NULL;
594                 skb_pull(skb2, offset);
595                 skb_reset_network_header(skb2);
596
597                 /* Try to guess incoming interface */
598                 rt = rt6_lookup(&ipv6_hdr(skb2)->saddr, NULL, 0, 0);
599
600                 if (rt && rt->rt6i_dev)
601                         skb2->dev = rt->rt6i_dev;
602
603                 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
604
605                 if (rt)
606                         dst_release(&rt->u.dst);
607
608                 kfree_skb(skb2);
609         }
610
611         return 0;
612 }
613
614 static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
615                                         struct ipv6hdr *ipv6h,
616                                         struct sk_buff *skb)
617 {
618         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
619
620         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
621                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
622
623         if (INET_ECN_is_ce(dsfield))
624                 IP_ECN_set_ce(ip_hdr(skb));
625 }
626
627 static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
628                                         struct ipv6hdr *ipv6h,
629                                         struct sk_buff *skb)
630 {
631         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
632                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
633
634         if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h)))
635                 IP6_ECN_set_ce(ipv6_hdr(skb));
636 }
637
638 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t)
639 {
640         struct ip6_tnl_parm *p = &t->parms;
641         int ret = 0;
642
643         if (p->flags & IP6_TNL_F_CAP_RCV) {
644                 struct net_device *ldev = NULL;
645
646                 if (p->link)
647                         ldev = dev_get_by_index(&init_net, p->link);
648
649                 if ((ipv6_addr_is_multicast(&p->laddr) ||
650                      likely(ipv6_chk_addr(&init_net, &p->laddr, ldev, 0))) &&
651                     likely(!ipv6_chk_addr(&init_net, &p->raddr, NULL, 0)))
652                         ret = 1;
653
654                 if (ldev)
655                         dev_put(ldev);
656         }
657         return ret;
658 }
659
660 /**
661  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
662  *   @skb: received socket buffer
663  *   @protocol: ethernet protocol ID
664  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
665  *
666  * Return: 0
667  **/
668
669 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
670                        __u8 ipproto,
671                        void (*dscp_ecn_decapsulate)(struct ip6_tnl *t,
672                                                     struct ipv6hdr *ipv6h,
673                                                     struct sk_buff *skb))
674 {
675         struct ip6_tnl *t;
676         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
677
678         read_lock(&ip6_tnl_lock);
679
680         if ((t = ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) {
681                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
682                         read_unlock(&ip6_tnl_lock);
683                         goto discard;
684                 }
685
686                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
687                         read_unlock(&ip6_tnl_lock);
688                         goto discard;
689                 }
690
691                 if (!ip6_tnl_rcv_ctl(t)) {
692                         t->stat.rx_dropped++;
693                         read_unlock(&ip6_tnl_lock);
694                         goto discard;
695                 }
696                 secpath_reset(skb);
697                 skb->mac_header = skb->network_header;
698                 skb_reset_network_header(skb);
699                 skb->protocol = htons(protocol);
700                 skb->pkt_type = PACKET_HOST;
701                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
702                 skb->dev = t->dev;
703                 dst_release(skb->dst);
704                 skb->dst = NULL;
705                 nf_reset(skb);
706
707                 dscp_ecn_decapsulate(t, ipv6h, skb);
708
709                 t->stat.rx_packets++;
710                 t->stat.rx_bytes += skb->len;
711                 netif_rx(skb);
712                 read_unlock(&ip6_tnl_lock);
713                 return 0;
714         }
715         read_unlock(&ip6_tnl_lock);
716         return 1;
717
718 discard:
719         kfree_skb(skb);
720         return 0;
721 }
722
723 static int ip4ip6_rcv(struct sk_buff *skb)
724 {
725         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
726                            ip4ip6_dscp_ecn_decapsulate);
727 }
728
729 static int ip6ip6_rcv(struct sk_buff *skb)
730 {
731         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
732                            ip6ip6_dscp_ecn_decapsulate);
733 }
734
735 struct ipv6_tel_txoption {
736         struct ipv6_txoptions ops;
737         __u8 dst_opt[8];
738 };
739
740 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
741 {
742         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
743
744         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
745         opt->dst_opt[3] = 1;
746         opt->dst_opt[4] = encap_limit;
747         opt->dst_opt[5] = IPV6_TLV_PADN;
748         opt->dst_opt[6] = 1;
749
750         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
751         opt->ops.opt_nflen = 8;
752 }
753
754 /**
755  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
756  *   @t: the outgoing tunnel device
757  *   @hdr: IPv6 header from the incoming packet
758  *
759  * Description:
760  *   Avoid trivial tunneling loop by checking that tunnel exit-point
761  *   doesn't match source of incoming packet.
762  *
763  * Return:
764  *   1 if conflict,
765  *   0 else
766  **/
767
768 static inline int
769 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr)
770 {
771         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
772 }
773
774 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
775 {
776         struct ip6_tnl_parm *p = &t->parms;
777         int ret = 0;
778
779         if (p->flags & IP6_TNL_F_CAP_XMIT) {
780                 struct net_device *ldev = NULL;
781
782                 if (p->link)
783                         ldev = dev_get_by_index(&init_net, p->link);
784
785                 if (unlikely(!ipv6_chk_addr(&init_net, &p->laddr, ldev, 0)))
786                         printk(KERN_WARNING
787                                "%s xmit: Local address not yet configured!\n",
788                                p->name);
789                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
790                          unlikely(ipv6_chk_addr(&init_net, &p->raddr, NULL, 0)))
791                         printk(KERN_WARNING
792                                "%s xmit: Routing loop! "
793                                "Remote address found on this node!\n",
794                                p->name);
795                 else
796                         ret = 1;
797                 if (ldev)
798                         dev_put(ldev);
799         }
800         return ret;
801 }
802 /**
803  * ip6_tnl_xmit2 - encapsulate packet and send
804  *   @skb: the outgoing socket buffer
805  *   @dev: the outgoing tunnel device
806  *   @dsfield: dscp code for outer header
807  *   @fl: flow of tunneled packet
808  *   @encap_limit: encapsulation limit
809  *   @pmtu: Path MTU is stored if packet is too big
810  *
811  * Description:
812  *   Build new header and do some sanity checks on the packet before sending
813  *   it.
814  *
815  * Return:
816  *   0 on success
817  *   -1 fail
818  *   %-EMSGSIZE message too big. return mtu in this case.
819  **/
820
821 static int ip6_tnl_xmit2(struct sk_buff *skb,
822                          struct net_device *dev,
823                          __u8 dsfield,
824                          struct flowi *fl,
825                          int encap_limit,
826                          __u32 *pmtu)
827 {
828         struct ip6_tnl *t = netdev_priv(dev);
829         struct net_device_stats *stats = &t->stat;
830         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
831         struct ipv6_tel_txoption opt;
832         struct dst_entry *dst;
833         struct net_device *tdev;
834         int mtu;
835         unsigned int max_headroom = sizeof(struct ipv6hdr);
836         u8 proto;
837         int err = -1;
838         int pkt_len;
839
840         if ((dst = ip6_tnl_dst_check(t)) != NULL)
841                 dst_hold(dst);
842         else {
843                 dst = ip6_route_output(NULL, fl);
844
845                 if (dst->error || xfrm_lookup(&dst, fl, NULL, 0) < 0)
846                         goto tx_err_link_failure;
847         }
848
849         tdev = dst->dev;
850
851         if (tdev == dev) {
852                 stats->collisions++;
853                 if (net_ratelimit())
854                         printk(KERN_WARNING
855                                "%s: Local routing loop detected!\n",
856                                t->parms.name);
857                 goto tx_err_dst_release;
858         }
859         mtu = dst_mtu(dst) - sizeof (*ipv6h);
860         if (encap_limit >= 0) {
861                 max_headroom += 8;
862                 mtu -= 8;
863         }
864         if (mtu < IPV6_MIN_MTU)
865                 mtu = IPV6_MIN_MTU;
866         if (skb->dst)
867                 skb->dst->ops->update_pmtu(skb->dst, mtu);
868         if (skb->len > mtu) {
869                 *pmtu = mtu;
870                 err = -EMSGSIZE;
871                 goto tx_err_dst_release;
872         }
873
874         /*
875          * Okay, now see if we can stuff it in the buffer as-is.
876          */
877         max_headroom += LL_RESERVED_SPACE(tdev);
878
879         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
880             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
881                 struct sk_buff *new_skb;
882
883                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
884                         goto tx_err_dst_release;
885
886                 if (skb->sk)
887                         skb_set_owner_w(new_skb, skb->sk);
888                 kfree_skb(skb);
889                 skb = new_skb;
890         }
891         dst_release(skb->dst);
892         skb->dst = dst_clone(dst);
893
894         skb->transport_header = skb->network_header;
895
896         proto = fl->proto;
897         if (encap_limit >= 0) {
898                 init_tel_txopt(&opt, encap_limit);
899                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
900         }
901         skb_push(skb, sizeof(struct ipv6hdr));
902         skb_reset_network_header(skb);
903         ipv6h = ipv6_hdr(skb);
904         *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000);
905         dsfield = INET_ECN_encapsulate(0, dsfield);
906         ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
907         ipv6h->hop_limit = t->parms.hop_limit;
908         ipv6h->nexthdr = proto;
909         ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src);
910         ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst);
911         nf_reset(skb);
912         pkt_len = skb->len;
913         err = ip6_local_out(skb);
914
915         if (net_xmit_eval(err) == 0) {
916                 stats->tx_bytes += pkt_len;
917                 stats->tx_packets++;
918         } else {
919                 stats->tx_errors++;
920                 stats->tx_aborted_errors++;
921         }
922         ip6_tnl_dst_store(t, dst);
923         return 0;
924 tx_err_link_failure:
925         stats->tx_carrier_errors++;
926         dst_link_failure(skb);
927 tx_err_dst_release:
928         dst_release(dst);
929         return err;
930 }
931
932 static inline int
933 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
934 {
935         struct ip6_tnl *t = netdev_priv(dev);
936         struct iphdr  *iph = ip_hdr(skb);
937         int encap_limit = -1;
938         struct flowi fl;
939         __u8 dsfield;
940         __u32 mtu;
941         int err;
942
943         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
944             !ip6_tnl_xmit_ctl(t))
945                 return -1;
946
947         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
948                 encap_limit = t->parms.encap_limit;
949
950         memcpy(&fl, &t->fl, sizeof (fl));
951         fl.proto = IPPROTO_IPIP;
952
953         dsfield = ipv4_get_dsfield(iph);
954
955         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
956                 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
957                                           & IPV6_TCLASS_MASK;
958
959         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
960         if (err != 0) {
961                 /* XXX: send ICMP error even if DF is not set. */
962                 if (err == -EMSGSIZE)
963                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
964                                   htonl(mtu));
965                 return -1;
966         }
967
968         return 0;
969 }
970
971 static inline int
972 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
973 {
974         struct ip6_tnl *t = netdev_priv(dev);
975         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
976         int encap_limit = -1;
977         __u16 offset;
978         struct flowi fl;
979         __u8 dsfield;
980         __u32 mtu;
981         int err;
982
983         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
984             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
985                 return -1;
986
987         offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb));
988         if (offset > 0) {
989                 struct ipv6_tlv_tnl_enc_lim *tel;
990                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
991                 if (tel->encap_limit == 0) {
992                         icmpv6_send(skb, ICMPV6_PARAMPROB,
993                                     ICMPV6_HDR_FIELD, offset + 2, skb->dev);
994                         return -1;
995                 }
996                 encap_limit = tel->encap_limit - 1;
997         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
998                 encap_limit = t->parms.encap_limit;
999
1000         memcpy(&fl, &t->fl, sizeof (fl));
1001         fl.proto = IPPROTO_IPV6;
1002
1003         dsfield = ipv6_get_dsfield(ipv6h);
1004         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
1005                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1006         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
1007                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1008
1009         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
1010         if (err != 0) {
1011                 if (err == -EMSGSIZE)
1012                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
1013                 return -1;
1014         }
1015
1016         return 0;
1017 }
1018
1019 static int
1020 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1021 {
1022         struct ip6_tnl *t = netdev_priv(dev);
1023         struct net_device_stats *stats = &t->stat;
1024         int ret;
1025
1026         if (t->recursion++) {
1027                 t->stat.collisions++;
1028                 goto tx_err;
1029         }
1030
1031         switch (skb->protocol) {
1032         case __constant_htons(ETH_P_IP):
1033                 ret = ip4ip6_tnl_xmit(skb, dev);
1034                 break;
1035         case __constant_htons(ETH_P_IPV6):
1036                 ret = ip6ip6_tnl_xmit(skb, dev);
1037                 break;
1038         default:
1039                 goto tx_err;
1040         }
1041
1042         if (ret < 0)
1043                 goto tx_err;
1044
1045         t->recursion--;
1046         return 0;
1047
1048 tx_err:
1049         stats->tx_errors++;
1050         stats->tx_dropped++;
1051         kfree_skb(skb);
1052         t->recursion--;
1053         return 0;
1054 }
1055
1056 static void ip6_tnl_set_cap(struct ip6_tnl *t)
1057 {
1058         struct ip6_tnl_parm *p = &t->parms;
1059         int ltype = ipv6_addr_type(&p->laddr);
1060         int rtype = ipv6_addr_type(&p->raddr);
1061
1062         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV);
1063
1064         if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1065             rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1066             !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
1067             (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
1068                 if (ltype&IPV6_ADDR_UNICAST)
1069                         p->flags |= IP6_TNL_F_CAP_XMIT;
1070                 if (rtype&IPV6_ADDR_UNICAST)
1071                         p->flags |= IP6_TNL_F_CAP_RCV;
1072         }
1073 }
1074
1075 static void ip6_tnl_link_config(struct ip6_tnl *t)
1076 {
1077         struct net_device *dev = t->dev;
1078         struct ip6_tnl_parm *p = &t->parms;
1079         struct flowi *fl = &t->fl;
1080
1081         memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1082         memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1083
1084         /* Set up flowi template */
1085         ipv6_addr_copy(&fl->fl6_src, &p->laddr);
1086         ipv6_addr_copy(&fl->fl6_dst, &p->raddr);
1087         fl->oif = p->link;
1088         fl->fl6_flowlabel = 0;
1089
1090         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1091                 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1092         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1093                 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1094
1095         ip6_tnl_set_cap(t);
1096
1097         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1098                 dev->flags |= IFF_POINTOPOINT;
1099         else
1100                 dev->flags &= ~IFF_POINTOPOINT;
1101
1102         dev->iflink = p->link;
1103
1104         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1105                 int strict = (ipv6_addr_type(&p->raddr) &
1106                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1107
1108                 struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr,
1109                                                  p->link, strict);
1110
1111                 if (rt == NULL)
1112                         return;
1113
1114                 if (rt->rt6i_dev) {
1115                         dev->hard_header_len = rt->rt6i_dev->hard_header_len +
1116                                 sizeof (struct ipv6hdr);
1117
1118                         dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr);
1119
1120                         if (dev->mtu < IPV6_MIN_MTU)
1121                                 dev->mtu = IPV6_MIN_MTU;
1122                 }
1123                 dst_release(&rt->u.dst);
1124         }
1125 }
1126
1127 /**
1128  * ip6_tnl_change - update the tunnel parameters
1129  *   @t: tunnel to be changed
1130  *   @p: tunnel configuration parameters
1131  *   @active: != 0 if tunnel is ready for use
1132  *
1133  * Description:
1134  *   ip6_tnl_change() updates the tunnel parameters
1135  **/
1136
1137 static int
1138 ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
1139 {
1140         ipv6_addr_copy(&t->parms.laddr, &p->laddr);
1141         ipv6_addr_copy(&t->parms.raddr, &p->raddr);
1142         t->parms.flags = p->flags;
1143         t->parms.hop_limit = p->hop_limit;
1144         t->parms.encap_limit = p->encap_limit;
1145         t->parms.flowinfo = p->flowinfo;
1146         t->parms.link = p->link;
1147         t->parms.proto = p->proto;
1148         ip6_tnl_dst_reset(t);
1149         ip6_tnl_link_config(t);
1150         return 0;
1151 }
1152
1153 /**
1154  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1155  *   @dev: virtual device associated with tunnel
1156  *   @ifr: parameters passed from userspace
1157  *   @cmd: command to be performed
1158  *
1159  * Description:
1160  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1161  *   from userspace.
1162  *
1163  *   The possible commands are the following:
1164  *     %SIOCGETTUNNEL: get tunnel parameters for device
1165  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1166  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1167  *     %SIOCDELTUNNEL: delete tunnel
1168  *
1169  *   The fallback device "ip6tnl0", created during module
1170  *   initialization, can be used for creating other tunnel devices.
1171  *
1172  * Return:
1173  *   0 on success,
1174  *   %-EFAULT if unable to copy data to or from userspace,
1175  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1176  *   %-EINVAL if passed tunnel parameters are invalid,
1177  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1178  *   %-ENODEV if attempting to change or delete a nonexisting device
1179  **/
1180
1181 static int
1182 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1183 {
1184         int err = 0;
1185         struct ip6_tnl_parm p;
1186         struct ip6_tnl *t = NULL;
1187
1188         switch (cmd) {
1189         case SIOCGETTUNNEL:
1190                 if (dev == ip6_fb_tnl_dev) {
1191                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1192                                 err = -EFAULT;
1193                                 break;
1194                         }
1195                         t = ip6_tnl_locate(&p, 0);
1196                 }
1197                 if (t == NULL)
1198                         t = netdev_priv(dev);
1199                 memcpy(&p, &t->parms, sizeof (p));
1200                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1201                         err = -EFAULT;
1202                 }
1203                 break;
1204         case SIOCADDTUNNEL:
1205         case SIOCCHGTUNNEL:
1206                 err = -EPERM;
1207                 if (!capable(CAP_NET_ADMIN))
1208                         break;
1209                 err = -EFAULT;
1210                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1211                         break;
1212                 err = -EINVAL;
1213                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1214                     p.proto != 0)
1215                         break;
1216                 t = ip6_tnl_locate(&p, cmd == SIOCADDTUNNEL);
1217                 if (dev != ip6_fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1218                         if (t != NULL) {
1219                                 if (t->dev != dev) {
1220                                         err = -EEXIST;
1221                                         break;
1222                                 }
1223                         } else
1224                                 t = netdev_priv(dev);
1225
1226                         ip6_tnl_unlink(t);
1227                         err = ip6_tnl_change(t, &p);
1228                         ip6_tnl_link(t);
1229                         netdev_state_change(dev);
1230                 }
1231                 if (t) {
1232                         err = 0;
1233                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p)))
1234                                 err = -EFAULT;
1235
1236                 } else
1237                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1238                 break;
1239         case SIOCDELTUNNEL:
1240                 err = -EPERM;
1241                 if (!capable(CAP_NET_ADMIN))
1242                         break;
1243
1244                 if (dev == ip6_fb_tnl_dev) {
1245                         err = -EFAULT;
1246                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1247                                 break;
1248                         err = -ENOENT;
1249                         if ((t = ip6_tnl_locate(&p, 0)) == NULL)
1250                                 break;
1251                         err = -EPERM;
1252                         if (t->dev == ip6_fb_tnl_dev)
1253                                 break;
1254                         dev = t->dev;
1255                 }
1256                 err = 0;
1257                 unregister_netdevice(dev);
1258                 break;
1259         default:
1260                 err = -EINVAL;
1261         }
1262         return err;
1263 }
1264
1265 /**
1266  * ip6_tnl_get_stats - return the stats for tunnel device
1267  *   @dev: virtual device associated with tunnel
1268  *
1269  * Return: stats for device
1270  **/
1271
1272 static struct net_device_stats *
1273 ip6_tnl_get_stats(struct net_device *dev)
1274 {
1275         return &(((struct ip6_tnl *)netdev_priv(dev))->stat);
1276 }
1277
1278 /**
1279  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1280  *   @dev: virtual device associated with tunnel
1281  *   @new_mtu: the new mtu
1282  *
1283  * Return:
1284  *   0 on success,
1285  *   %-EINVAL if mtu too small
1286  **/
1287
1288 static int
1289 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1290 {
1291         if (new_mtu < IPV6_MIN_MTU) {
1292                 return -EINVAL;
1293         }
1294         dev->mtu = new_mtu;
1295         return 0;
1296 }
1297
1298 /**
1299  * ip6_tnl_dev_setup - setup virtual tunnel device
1300  *   @dev: virtual device associated with tunnel
1301  *
1302  * Description:
1303  *   Initialize function pointers and device parameters
1304  **/
1305
1306 static void ip6_tnl_dev_setup(struct net_device *dev)
1307 {
1308         dev->uninit = ip6_tnl_dev_uninit;
1309         dev->destructor = free_netdev;
1310         dev->hard_start_xmit = ip6_tnl_xmit;
1311         dev->get_stats = ip6_tnl_get_stats;
1312         dev->do_ioctl = ip6_tnl_ioctl;
1313         dev->change_mtu = ip6_tnl_change_mtu;
1314
1315         dev->type = ARPHRD_TUNNEL6;
1316         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1317         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1318         dev->flags |= IFF_NOARP;
1319         dev->addr_len = sizeof(struct in6_addr);
1320 }
1321
1322
1323 /**
1324  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1325  *   @dev: virtual device associated with tunnel
1326  **/
1327
1328 static inline void
1329 ip6_tnl_dev_init_gen(struct net_device *dev)
1330 {
1331         struct ip6_tnl *t = netdev_priv(dev);
1332         t->dev = dev;
1333         strcpy(t->parms.name, dev->name);
1334 }
1335
1336 /**
1337  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1338  *   @dev: virtual device associated with tunnel
1339  **/
1340
1341 static int
1342 ip6_tnl_dev_init(struct net_device *dev)
1343 {
1344         struct ip6_tnl *t = netdev_priv(dev);
1345         ip6_tnl_dev_init_gen(dev);
1346         ip6_tnl_link_config(t);
1347         return 0;
1348 }
1349
1350 /**
1351  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1352  *   @dev: fallback device
1353  *
1354  * Return: 0
1355  **/
1356
1357 static int
1358 ip6_fb_tnl_dev_init(struct net_device *dev)
1359 {
1360         struct ip6_tnl *t = netdev_priv(dev);
1361         ip6_tnl_dev_init_gen(dev);
1362         t->parms.proto = IPPROTO_IPV6;
1363         dev_hold(dev);
1364         tnls_wc[0] = t;
1365         return 0;
1366 }
1367
1368 static struct xfrm6_tunnel ip4ip6_handler = {
1369         .handler        = ip4ip6_rcv,
1370         .err_handler    = ip4ip6_err,
1371         .priority       =       1,
1372 };
1373
1374 static struct xfrm6_tunnel ip6ip6_handler = {
1375         .handler        = ip6ip6_rcv,
1376         .err_handler    = ip6ip6_err,
1377         .priority       =       1,
1378 };
1379
1380 /**
1381  * ip6_tunnel_init - register protocol and reserve needed resources
1382  *
1383  * Return: 0 on success
1384  **/
1385
1386 static int __init ip6_tunnel_init(void)
1387 {
1388         int  err;
1389
1390         if (xfrm6_tunnel_register(&ip4ip6_handler, AF_INET)) {
1391                 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n");
1392                 err = -EAGAIN;
1393                 goto out;
1394         }
1395
1396         if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) {
1397                 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n");
1398                 err = -EAGAIN;
1399                 goto unreg_ip4ip6;
1400         }
1401         ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1402                                       ip6_tnl_dev_setup);
1403
1404         if (!ip6_fb_tnl_dev) {
1405                 err = -ENOMEM;
1406                 goto fail;
1407         }
1408         ip6_fb_tnl_dev->init = ip6_fb_tnl_dev_init;
1409
1410         if ((err = register_netdev(ip6_fb_tnl_dev))) {
1411                 free_netdev(ip6_fb_tnl_dev);
1412                 goto fail;
1413         }
1414         return 0;
1415 fail:
1416         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1417 unreg_ip4ip6:
1418         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1419 out:
1420         return err;
1421 }
1422
1423 static void __exit ip6_tnl_destroy_tunnels(void)
1424 {
1425         int h;
1426         struct ip6_tnl *t;
1427
1428         for (h = 0; h < HASH_SIZE; h++) {
1429                 while ((t = tnls_r_l[h]) != NULL)
1430                         unregister_netdevice(t->dev);
1431         }
1432
1433         t = tnls_wc[0];
1434         unregister_netdevice(t->dev);
1435 }
1436
1437 /**
1438  * ip6_tunnel_cleanup - free resources and unregister protocol
1439  **/
1440
1441 static void __exit ip6_tunnel_cleanup(void)
1442 {
1443         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1444                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n");
1445
1446         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1447                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n");
1448
1449         rtnl_lock();
1450         ip6_tnl_destroy_tunnels();
1451         rtnl_unlock();
1452 }
1453
1454 module_init(ip6_tunnel_init);
1455 module_exit(ip6_tunnel_cleanup);