]> git.karo-electronics.de Git - karo-tx-linux.git/blob - net/ipv6/ip6_tunnel.c
libceph: take osdc->lock in osdmap_show() and dump flags in hex
[karo-tx-linux.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  *      Based on:
10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
11  *
12  *      RFC 2473
13  *
14  *      This program is free software; you can redistribute it and/or
15  *      modify it under the terms of the GNU General Public License
16  *      as published by the Free Software Foundation; either version
17  *      2 of the License, or (at your option) any later version.
18  *
19  */
20
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/net.h>
33 #include <linux/in6.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/icmpv6.h>
37 #include <linux/init.h>
38 #include <linux/route.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/netfilter_ipv6.h>
41 #include <linux/slab.h>
42 #include <linux/hash.h>
43 #include <linux/etherdevice.h>
44
45 #include <asm/uaccess.h>
46 #include <linux/atomic.h>
47
48 #include <net/icmp.h>
49 #include <net/ip.h>
50 #include <net/ip_tunnels.h>
51 #include <net/ipv6.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_tunnel.h>
55 #include <net/xfrm.h>
56 #include <net/dsfield.h>
57 #include <net/inet_ecn.h>
58 #include <net/net_namespace.h>
59 #include <net/netns/generic.h>
60
61 MODULE_AUTHOR("Ville Nuorvala");
62 MODULE_DESCRIPTION("IPv6 tunneling device");
63 MODULE_LICENSE("GPL");
64 MODULE_ALIAS_RTNL_LINK("ip6tnl");
65 MODULE_ALIAS_NETDEV("ip6tnl0");
66
67 #define HASH_SIZE_SHIFT  5
68 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
69
70 static bool log_ecn_error = true;
71 module_param(log_ecn_error, bool, 0644);
72 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
73
74 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
75 {
76         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
77
78         return hash_32(hash, HASH_SIZE_SHIFT);
79 }
80
81 static int ip6_tnl_dev_init(struct net_device *dev);
82 static void ip6_tnl_dev_setup(struct net_device *dev);
83 static struct rtnl_link_ops ip6_link_ops __read_mostly;
84
85 static int ip6_tnl_net_id __read_mostly;
86 struct ip6_tnl_net {
87         /* the IPv6 tunnel fallback device */
88         struct net_device *fb_tnl_dev;
89         /* lists for storing tunnels in use */
90         struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
91         struct ip6_tnl __rcu *tnls_wc[1];
92         struct ip6_tnl __rcu **tnls[2];
93 };
94
95 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
96 {
97         struct pcpu_sw_netstats tmp, sum = { 0 };
98         int i;
99
100         for_each_possible_cpu(i) {
101                 unsigned int start;
102                 const struct pcpu_sw_netstats *tstats =
103                                                    per_cpu_ptr(dev->tstats, i);
104
105                 do {
106                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
107                         tmp.rx_packets = tstats->rx_packets;
108                         tmp.rx_bytes = tstats->rx_bytes;
109                         tmp.tx_packets = tstats->tx_packets;
110                         tmp.tx_bytes =  tstats->tx_bytes;
111                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
112
113                 sum.rx_packets += tmp.rx_packets;
114                 sum.rx_bytes   += tmp.rx_bytes;
115                 sum.tx_packets += tmp.tx_packets;
116                 sum.tx_bytes   += tmp.tx_bytes;
117         }
118         dev->stats.rx_packets = sum.rx_packets;
119         dev->stats.rx_bytes   = sum.rx_bytes;
120         dev->stats.tx_packets = sum.tx_packets;
121         dev->stats.tx_bytes   = sum.tx_bytes;
122         return &dev->stats;
123 }
124
125 /**
126  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
127  *   @remote: the address of the tunnel exit-point
128  *   @local: the address of the tunnel entry-point
129  *
130  * Return:
131  *   tunnel matching given end-points if found,
132  *   else fallback tunnel if its device is up,
133  *   else %NULL
134  **/
135
136 #define for_each_ip6_tunnel_rcu(start) \
137         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
138
139 static struct ip6_tnl *
140 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
141 {
142         unsigned int hash = HASH(remote, local);
143         struct ip6_tnl *t;
144         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
145         struct in6_addr any;
146
147         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
148                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
149                     ipv6_addr_equal(remote, &t->parms.raddr) &&
150                     (t->dev->flags & IFF_UP))
151                         return t;
152         }
153
154         memset(&any, 0, sizeof(any));
155         hash = HASH(&any, local);
156         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
157                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
158                     (t->dev->flags & IFF_UP))
159                         return t;
160         }
161
162         hash = HASH(remote, &any);
163         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
164                 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
165                     (t->dev->flags & IFF_UP))
166                         return t;
167         }
168
169         t = rcu_dereference(ip6n->tnls_wc[0]);
170         if (t && (t->dev->flags & IFF_UP))
171                 return t;
172
173         return NULL;
174 }
175
176 /**
177  * ip6_tnl_bucket - get head of list matching given tunnel parameters
178  *   @p: parameters containing tunnel end-points
179  *
180  * Description:
181  *   ip6_tnl_bucket() returns the head of the list matching the
182  *   &struct in6_addr entries laddr and raddr in @p.
183  *
184  * Return: head of IPv6 tunnel list
185  **/
186
187 static struct ip6_tnl __rcu **
188 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
189 {
190         const struct in6_addr *remote = &p->raddr;
191         const struct in6_addr *local = &p->laddr;
192         unsigned int h = 0;
193         int prio = 0;
194
195         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
196                 prio = 1;
197                 h = HASH(remote, local);
198         }
199         return &ip6n->tnls[prio][h];
200 }
201
202 /**
203  * ip6_tnl_link - add tunnel to hash table
204  *   @t: tunnel to be added
205  **/
206
207 static void
208 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
209 {
210         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
211
212         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
213         rcu_assign_pointer(*tp, t);
214 }
215
216 /**
217  * ip6_tnl_unlink - remove tunnel from hash table
218  *   @t: tunnel to be removed
219  **/
220
221 static void
222 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
223 {
224         struct ip6_tnl __rcu **tp;
225         struct ip6_tnl *iter;
226
227         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
228              (iter = rtnl_dereference(*tp)) != NULL;
229              tp = &iter->next) {
230                 if (t == iter) {
231                         rcu_assign_pointer(*tp, t->next);
232                         break;
233                 }
234         }
235 }
236
237 static void ip6_dev_free(struct net_device *dev)
238 {
239         struct ip6_tnl *t = netdev_priv(dev);
240
241         dst_cache_destroy(&t->dst_cache);
242         free_percpu(dev->tstats);
243         free_netdev(dev);
244 }
245
246 static int ip6_tnl_create2(struct net_device *dev)
247 {
248         struct ip6_tnl *t = netdev_priv(dev);
249         struct net *net = dev_net(dev);
250         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
251         int err;
252
253         t = netdev_priv(dev);
254
255         dev->rtnl_link_ops = &ip6_link_ops;
256         err = register_netdevice(dev);
257         if (err < 0)
258                 goto out;
259
260         strcpy(t->parms.name, dev->name);
261
262         dev_hold(dev);
263         ip6_tnl_link(ip6n, t);
264         return 0;
265
266 out:
267         return err;
268 }
269
270 /**
271  * ip6_tnl_create - create a new tunnel
272  *   @p: tunnel parameters
273  *   @pt: pointer to new tunnel
274  *
275  * Description:
276  *   Create tunnel matching given parameters.
277  *
278  * Return:
279  *   created tunnel or error pointer
280  **/
281
282 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
283 {
284         struct net_device *dev;
285         struct ip6_tnl *t;
286         char name[IFNAMSIZ];
287         int err = -ENOMEM;
288
289         if (p->name[0])
290                 strlcpy(name, p->name, IFNAMSIZ);
291         else
292                 sprintf(name, "ip6tnl%%d");
293
294         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
295                            ip6_tnl_dev_setup);
296         if (!dev)
297                 goto failed;
298
299         dev_net_set(dev, net);
300
301         t = netdev_priv(dev);
302         t->parms = *p;
303         t->net = dev_net(dev);
304         err = ip6_tnl_create2(dev);
305         if (err < 0)
306                 goto failed_free;
307
308         return t;
309
310 failed_free:
311         ip6_dev_free(dev);
312 failed:
313         return ERR_PTR(err);
314 }
315
316 /**
317  * ip6_tnl_locate - find or create tunnel matching given parameters
318  *   @p: tunnel parameters
319  *   @create: != 0 if allowed to create new tunnel if no match found
320  *
321  * Description:
322  *   ip6_tnl_locate() first tries to locate an existing tunnel
323  *   based on @parms. If this is unsuccessful, but @create is set a new
324  *   tunnel device is created and registered for use.
325  *
326  * Return:
327  *   matching tunnel or error pointer
328  **/
329
330 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
331                 struct __ip6_tnl_parm *p, int create)
332 {
333         const struct in6_addr *remote = &p->raddr;
334         const struct in6_addr *local = &p->laddr;
335         struct ip6_tnl __rcu **tp;
336         struct ip6_tnl *t;
337         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
338
339         for (tp = ip6_tnl_bucket(ip6n, p);
340              (t = rtnl_dereference(*tp)) != NULL;
341              tp = &t->next) {
342                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
343                     ipv6_addr_equal(remote, &t->parms.raddr)) {
344                         if (create)
345                                 return ERR_PTR(-EEXIST);
346
347                         return t;
348                 }
349         }
350         if (!create)
351                 return ERR_PTR(-ENODEV);
352         return ip6_tnl_create(net, p);
353 }
354
355 /**
356  * ip6_tnl_dev_uninit - tunnel device uninitializer
357  *   @dev: the device to be destroyed
358  *
359  * Description:
360  *   ip6_tnl_dev_uninit() removes tunnel from its list
361  **/
362
363 static void
364 ip6_tnl_dev_uninit(struct net_device *dev)
365 {
366         struct ip6_tnl *t = netdev_priv(dev);
367         struct net *net = t->net;
368         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
369
370         if (dev == ip6n->fb_tnl_dev)
371                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
372         else
373                 ip6_tnl_unlink(ip6n, t);
374         dst_cache_reset(&t->dst_cache);
375         dev_put(dev);
376 }
377
378 /**
379  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
380  *   @skb: received socket buffer
381  *
382  * Return:
383  *   0 if none was found,
384  *   else index to encapsulation limit
385  **/
386
387 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
388 {
389         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
390         __u8 nexthdr = ipv6h->nexthdr;
391         __u16 off = sizeof(*ipv6h);
392
393         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
394                 __u16 optlen = 0;
395                 struct ipv6_opt_hdr *hdr;
396                 if (raw + off + sizeof(*hdr) > skb->data &&
397                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
398                         break;
399
400                 hdr = (struct ipv6_opt_hdr *) (raw + off);
401                 if (nexthdr == NEXTHDR_FRAGMENT) {
402                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
403                         if (frag_hdr->frag_off)
404                                 break;
405                         optlen = 8;
406                 } else if (nexthdr == NEXTHDR_AUTH) {
407                         optlen = (hdr->hdrlen + 2) << 2;
408                 } else {
409                         optlen = ipv6_optlen(hdr);
410                 }
411                 if (nexthdr == NEXTHDR_DEST) {
412                         __u16 i = off + 2;
413                         while (1) {
414                                 struct ipv6_tlv_tnl_enc_lim *tel;
415
416                                 /* No more room for encapsulation limit */
417                                 if (i + sizeof (*tel) > off + optlen)
418                                         break;
419
420                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
421                                 /* return index of option if found and valid */
422                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
423                                     tel->length == 1)
424                                         return i;
425                                 /* else jump to next option */
426                                 if (tel->type)
427                                         i += tel->length + 2;
428                                 else
429                                         i++;
430                         }
431                 }
432                 nexthdr = hdr->nexthdr;
433                 off += optlen;
434         }
435         return 0;
436 }
437 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
438
439 /**
440  * ip6_tnl_err - tunnel error handler
441  *
442  * Description:
443  *   ip6_tnl_err() should handle errors in the tunnel according
444  *   to the specifications in RFC 2473.
445  **/
446
447 static int
448 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
449             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
450 {
451         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
452         struct ip6_tnl *t;
453         int rel_msg = 0;
454         u8 rel_type = ICMPV6_DEST_UNREACH;
455         u8 rel_code = ICMPV6_ADDR_UNREACH;
456         u8 tproto;
457         __u32 rel_info = 0;
458         __u16 len;
459         int err = -ENOENT;
460
461         /* If the packet doesn't contain the original IPv6 header we are
462            in trouble since we might need the source address for further
463            processing of the error. */
464
465         rcu_read_lock();
466         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
467         if (!t)
468                 goto out;
469
470         tproto = ACCESS_ONCE(t->parms.proto);
471         if (tproto != ipproto && tproto != 0)
472                 goto out;
473
474         err = 0;
475
476         switch (*type) {
477                 __u32 teli;
478                 struct ipv6_tlv_tnl_enc_lim *tel;
479                 __u32 mtu;
480         case ICMPV6_DEST_UNREACH:
481                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
482                                     t->parms.name);
483                 rel_msg = 1;
484                 break;
485         case ICMPV6_TIME_EXCEED:
486                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
487                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
488                                             t->parms.name);
489                         rel_msg = 1;
490                 }
491                 break;
492         case ICMPV6_PARAMPROB:
493                 teli = 0;
494                 if ((*code) == ICMPV6_HDR_FIELD)
495                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
496
497                 if (teli && teli == *info - 2) {
498                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
499                         if (tel->encap_limit == 0) {
500                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
501                                                     t->parms.name);
502                                 rel_msg = 1;
503                         }
504                 } else {
505                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
506                                             t->parms.name);
507                 }
508                 break;
509         case ICMPV6_PKT_TOOBIG:
510                 mtu = *info - offset;
511                 if (mtu < IPV6_MIN_MTU)
512                         mtu = IPV6_MIN_MTU;
513                 t->dev->mtu = mtu;
514
515                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
516                 if (len > mtu) {
517                         rel_type = ICMPV6_PKT_TOOBIG;
518                         rel_code = 0;
519                         rel_info = mtu;
520                         rel_msg = 1;
521                 }
522                 break;
523         }
524
525         *type = rel_type;
526         *code = rel_code;
527         *info = rel_info;
528         *msg = rel_msg;
529
530 out:
531         rcu_read_unlock();
532         return err;
533 }
534
535 static int
536 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
537            u8 type, u8 code, int offset, __be32 info)
538 {
539         int rel_msg = 0;
540         u8 rel_type = type;
541         u8 rel_code = code;
542         __u32 rel_info = ntohl(info);
543         int err;
544         struct sk_buff *skb2;
545         const struct iphdr *eiph;
546         struct rtable *rt;
547         struct flowi4 fl4;
548
549         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
550                           &rel_msg, &rel_info, offset);
551         if (err < 0)
552                 return err;
553
554         if (rel_msg == 0)
555                 return 0;
556
557         switch (rel_type) {
558         case ICMPV6_DEST_UNREACH:
559                 if (rel_code != ICMPV6_ADDR_UNREACH)
560                         return 0;
561                 rel_type = ICMP_DEST_UNREACH;
562                 rel_code = ICMP_HOST_UNREACH;
563                 break;
564         case ICMPV6_PKT_TOOBIG:
565                 if (rel_code != 0)
566                         return 0;
567                 rel_type = ICMP_DEST_UNREACH;
568                 rel_code = ICMP_FRAG_NEEDED;
569                 break;
570         case NDISC_REDIRECT:
571                 rel_type = ICMP_REDIRECT;
572                 rel_code = ICMP_REDIR_HOST;
573         default:
574                 return 0;
575         }
576
577         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
578                 return 0;
579
580         skb2 = skb_clone(skb, GFP_ATOMIC);
581         if (!skb2)
582                 return 0;
583
584         skb_dst_drop(skb2);
585
586         skb_pull(skb2, offset);
587         skb_reset_network_header(skb2);
588         eiph = ip_hdr(skb2);
589
590         /* Try to guess incoming interface */
591         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
592                                    eiph->saddr, 0,
593                                    0, 0,
594                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
595         if (IS_ERR(rt))
596                 goto out;
597
598         skb2->dev = rt->dst.dev;
599
600         /* route "incoming" packet */
601         if (rt->rt_flags & RTCF_LOCAL) {
602                 ip_rt_put(rt);
603                 rt = NULL;
604                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
605                                            eiph->daddr, eiph->saddr,
606                                            0, 0,
607                                            IPPROTO_IPIP,
608                                            RT_TOS(eiph->tos), 0);
609                 if (IS_ERR(rt) ||
610                     rt->dst.dev->type != ARPHRD_TUNNEL) {
611                         if (!IS_ERR(rt))
612                                 ip_rt_put(rt);
613                         goto out;
614                 }
615                 skb_dst_set(skb2, &rt->dst);
616         } else {
617                 ip_rt_put(rt);
618                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
619                                    skb2->dev) ||
620                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
621                         goto out;
622         }
623
624         /* change mtu on this route */
625         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
626                 if (rel_info > dst_mtu(skb_dst(skb2)))
627                         goto out;
628
629                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
630         }
631         if (rel_type == ICMP_REDIRECT)
632                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
633
634         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
635
636 out:
637         kfree_skb(skb2);
638         return 0;
639 }
640
641 static int
642 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
643            u8 type, u8 code, int offset, __be32 info)
644 {
645         int rel_msg = 0;
646         u8 rel_type = type;
647         u8 rel_code = code;
648         __u32 rel_info = ntohl(info);
649         int err;
650
651         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
652                           &rel_msg, &rel_info, offset);
653         if (err < 0)
654                 return err;
655
656         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
657                 struct rt6_info *rt;
658                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
659
660                 if (!skb2)
661                         return 0;
662
663                 skb_dst_drop(skb2);
664                 skb_pull(skb2, offset);
665                 skb_reset_network_header(skb2);
666
667                 /* Try to guess incoming interface */
668                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
669                                 NULL, 0, 0);
670
671                 if (rt && rt->dst.dev)
672                         skb2->dev = rt->dst.dev;
673
674                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
675
676                 ip6_rt_put(rt);
677
678                 kfree_skb(skb2);
679         }
680
681         return 0;
682 }
683
684 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
685                                        const struct ipv6hdr *ipv6h,
686                                        struct sk_buff *skb)
687 {
688         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
689
690         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
691                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
692
693         return IP6_ECN_decapsulate(ipv6h, skb);
694 }
695
696 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
697                                        const struct ipv6hdr *ipv6h,
698                                        struct sk_buff *skb)
699 {
700         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
701                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
702
703         return IP6_ECN_decapsulate(ipv6h, skb);
704 }
705
706 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
707                              const struct in6_addr *laddr,
708                              const struct in6_addr *raddr)
709 {
710         struct __ip6_tnl_parm *p = &t->parms;
711         int ltype = ipv6_addr_type(laddr);
712         int rtype = ipv6_addr_type(raddr);
713         __u32 flags = 0;
714
715         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
716                 flags = IP6_TNL_F_CAP_PER_PACKET;
717         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
718                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
719                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
720                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
721                 if (ltype&IPV6_ADDR_UNICAST)
722                         flags |= IP6_TNL_F_CAP_XMIT;
723                 if (rtype&IPV6_ADDR_UNICAST)
724                         flags |= IP6_TNL_F_CAP_RCV;
725         }
726         return flags;
727 }
728 EXPORT_SYMBOL(ip6_tnl_get_cap);
729
730 /* called with rcu_read_lock() */
731 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
732                                   const struct in6_addr *laddr,
733                                   const struct in6_addr *raddr)
734 {
735         struct __ip6_tnl_parm *p = &t->parms;
736         int ret = 0;
737         struct net *net = t->net;
738
739         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
740             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
741              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
742                 struct net_device *ldev = NULL;
743
744                 if (p->link)
745                         ldev = dev_get_by_index_rcu(net, p->link);
746
747                 if ((ipv6_addr_is_multicast(laddr) ||
748                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
749                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
750                         ret = 1;
751         }
752         return ret;
753 }
754 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
755
756 /**
757  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
758  *   @skb: received socket buffer
759  *   @protocol: ethernet protocol ID
760  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
761  *
762  * Return: 0
763  **/
764
765 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
766                        __u8 ipproto,
767                        int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
768                                                    const struct ipv6hdr *ipv6h,
769                                                    struct sk_buff *skb))
770 {
771         struct ip6_tnl *t;
772         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
773         u8 tproto;
774         int err;
775
776         rcu_read_lock();
777         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
778         if (t) {
779                 struct pcpu_sw_netstats *tstats;
780
781                 tproto = ACCESS_ONCE(t->parms.proto);
782                 if (tproto != ipproto && tproto != 0) {
783                         rcu_read_unlock();
784                         goto discard;
785                 }
786
787                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
788                         rcu_read_unlock();
789                         goto discard;
790                 }
791
792                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
793                         t->dev->stats.rx_dropped++;
794                         rcu_read_unlock();
795                         goto discard;
796                 }
797                 skb->mac_header = skb->network_header;
798                 skb_reset_network_header(skb);
799                 skb->protocol = htons(protocol);
800                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
801
802                 __skb_tunnel_rx(skb, t->dev, t->net);
803
804                 err = dscp_ecn_decapsulate(t, ipv6h, skb);
805                 if (unlikely(err)) {
806                         if (log_ecn_error)
807                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
808                                                      &ipv6h->saddr,
809                                                      ipv6_get_dsfield(ipv6h));
810                         if (err > 1) {
811                                 ++t->dev->stats.rx_frame_errors;
812                                 ++t->dev->stats.rx_errors;
813                                 rcu_read_unlock();
814                                 goto discard;
815                         }
816                 }
817
818                 tstats = this_cpu_ptr(t->dev->tstats);
819                 u64_stats_update_begin(&tstats->syncp);
820                 tstats->rx_packets++;
821                 tstats->rx_bytes += skb->len;
822                 u64_stats_update_end(&tstats->syncp);
823
824                 netif_rx(skb);
825
826                 rcu_read_unlock();
827                 return 0;
828         }
829         rcu_read_unlock();
830         return 1;
831
832 discard:
833         kfree_skb(skb);
834         return 0;
835 }
836
837 static int ip4ip6_rcv(struct sk_buff *skb)
838 {
839         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
840                            ip4ip6_dscp_ecn_decapsulate);
841 }
842
843 static int ip6ip6_rcv(struct sk_buff *skb)
844 {
845         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
846                            ip6ip6_dscp_ecn_decapsulate);
847 }
848
849 struct ipv6_tel_txoption {
850         struct ipv6_txoptions ops;
851         __u8 dst_opt[8];
852 };
853
854 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
855 {
856         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
857
858         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
859         opt->dst_opt[3] = 1;
860         opt->dst_opt[4] = encap_limit;
861         opt->dst_opt[5] = IPV6_TLV_PADN;
862         opt->dst_opt[6] = 1;
863
864         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
865         opt->ops.opt_nflen = 8;
866 }
867
868 /**
869  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
870  *   @t: the outgoing tunnel device
871  *   @hdr: IPv6 header from the incoming packet
872  *
873  * Description:
874  *   Avoid trivial tunneling loop by checking that tunnel exit-point
875  *   doesn't match source of incoming packet.
876  *
877  * Return:
878  *   1 if conflict,
879  *   0 else
880  **/
881
882 static inline bool
883 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
884 {
885         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
886 }
887
888 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
889                      const struct in6_addr *laddr,
890                      const struct in6_addr *raddr)
891 {
892         struct __ip6_tnl_parm *p = &t->parms;
893         int ret = 0;
894         struct net *net = t->net;
895
896         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
897             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
898              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
899                 struct net_device *ldev = NULL;
900
901                 rcu_read_lock();
902                 if (p->link)
903                         ldev = dev_get_by_index_rcu(net, p->link);
904
905                 if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
906                         pr_warn("%s xmit: Local address not yet configured!\n",
907                                 p->name);
908                 else if (!ipv6_addr_is_multicast(raddr) &&
909                          unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
910                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
911                                 p->name);
912                 else
913                         ret = 1;
914                 rcu_read_unlock();
915         }
916         return ret;
917 }
918 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
919
920 /**
921  * ip6_tnl_xmit2 - encapsulate packet and send
922  *   @skb: the outgoing socket buffer
923  *   @dev: the outgoing tunnel device
924  *   @dsfield: dscp code for outer header
925  *   @fl: flow of tunneled packet
926  *   @encap_limit: encapsulation limit
927  *   @pmtu: Path MTU is stored if packet is too big
928  *
929  * Description:
930  *   Build new header and do some sanity checks on the packet before sending
931  *   it.
932  *
933  * Return:
934  *   0 on success
935  *   -1 fail
936  *   %-EMSGSIZE message too big. return mtu in this case.
937  **/
938
939 static int ip6_tnl_xmit2(struct sk_buff *skb,
940                          struct net_device *dev,
941                          __u8 dsfield,
942                          struct flowi6 *fl6,
943                          int encap_limit,
944                          __u32 *pmtu)
945 {
946         struct ip6_tnl *t = netdev_priv(dev);
947         struct net *net = t->net;
948         struct net_device_stats *stats = &t->dev->stats;
949         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
950         struct ipv6_tel_txoption opt;
951         struct dst_entry *dst = NULL, *ndst = NULL;
952         struct net_device *tdev;
953         int mtu;
954         unsigned int max_headroom = sizeof(struct ipv6hdr);
955         u8 proto;
956         int err = -1;
957
958         /* NBMA tunnel */
959         if (ipv6_addr_any(&t->parms.raddr)) {
960                 struct in6_addr *addr6;
961                 struct neighbour *neigh;
962                 int addr_type;
963
964                 if (!skb_dst(skb))
965                         goto tx_err_link_failure;
966
967                 neigh = dst_neigh_lookup(skb_dst(skb),
968                                          &ipv6_hdr(skb)->daddr);
969                 if (!neigh)
970                         goto tx_err_link_failure;
971
972                 addr6 = (struct in6_addr *)&neigh->primary_key;
973                 addr_type = ipv6_addr_type(addr6);
974
975                 if (addr_type == IPV6_ADDR_ANY)
976                         addr6 = &ipv6_hdr(skb)->daddr;
977
978                 memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
979                 neigh_release(neigh);
980         } else if (!fl6->flowi6_mark)
981                 dst = dst_cache_get(&t->dst_cache);
982
983         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
984                 goto tx_err_link_failure;
985
986         if (!dst) {
987                 dst = ip6_route_output(net, NULL, fl6);
988
989                 if (dst->error)
990                         goto tx_err_link_failure;
991                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
992                 if (IS_ERR(dst)) {
993                         err = PTR_ERR(dst);
994                         dst = NULL;
995                         goto tx_err_link_failure;
996                 }
997                 ndst = dst;
998         }
999
1000         tdev = dst->dev;
1001
1002         if (tdev == dev) {
1003                 stats->collisions++;
1004                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1005                                      t->parms.name);
1006                 goto tx_err_dst_release;
1007         }
1008         mtu = dst_mtu(dst) - sizeof(*ipv6h);
1009         if (encap_limit >= 0) {
1010                 max_headroom += 8;
1011                 mtu -= 8;
1012         }
1013         if (mtu < IPV6_MIN_MTU)
1014                 mtu = IPV6_MIN_MTU;
1015         if (skb_dst(skb))
1016                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1017         if (skb->len > mtu) {
1018                 *pmtu = mtu;
1019                 err = -EMSGSIZE;
1020                 goto tx_err_dst_release;
1021         }
1022
1023         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1024
1025         /*
1026          * Okay, now see if we can stuff it in the buffer as-is.
1027          */
1028         max_headroom += LL_RESERVED_SPACE(tdev);
1029
1030         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1031             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1032                 struct sk_buff *new_skb;
1033
1034                 new_skb = skb_realloc_headroom(skb, max_headroom);
1035                 if (!new_skb)
1036                         goto tx_err_dst_release;
1037
1038                 if (skb->sk)
1039                         skb_set_owner_w(new_skb, skb->sk);
1040                 consume_skb(skb);
1041                 skb = new_skb;
1042         }
1043
1044         if (!fl6->flowi6_mark && ndst)
1045                 dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1046         skb_dst_set(skb, dst);
1047
1048         skb->transport_header = skb->network_header;
1049
1050         proto = fl6->flowi6_proto;
1051         if (encap_limit >= 0) {
1052                 init_tel_txopt(&opt, encap_limit);
1053                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1054         }
1055
1056         if (likely(!skb->encapsulation)) {
1057                 skb_reset_inner_headers(skb);
1058                 skb->encapsulation = 1;
1059         }
1060
1061         skb_push(skb, sizeof(struct ipv6hdr));
1062         skb_reset_network_header(skb);
1063         ipv6h = ipv6_hdr(skb);
1064         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1065                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1066         ipv6h->hop_limit = t->parms.hop_limit;
1067         ipv6h->nexthdr = proto;
1068         ipv6h->saddr = fl6->saddr;
1069         ipv6h->daddr = fl6->daddr;
1070         ip6tunnel_xmit(NULL, skb, dev);
1071         return 0;
1072 tx_err_link_failure:
1073         stats->tx_carrier_errors++;
1074         dst_link_failure(skb);
1075 tx_err_dst_release:
1076         dst_release(dst);
1077         return err;
1078 }
1079
1080 static inline int
1081 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1082 {
1083         struct ip6_tnl *t = netdev_priv(dev);
1084         const struct iphdr  *iph = ip_hdr(skb);
1085         int encap_limit = -1;
1086         struct flowi6 fl6;
1087         __u8 dsfield;
1088         __u32 mtu;
1089         u8 tproto;
1090         int err;
1091
1092         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1093
1094         tproto = ACCESS_ONCE(t->parms.proto);
1095         if (tproto != IPPROTO_IPIP && tproto != 0)
1096                 return -1;
1097
1098         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1099                 encap_limit = t->parms.encap_limit;
1100
1101         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1102         fl6.flowi6_proto = IPPROTO_IPIP;
1103
1104         dsfield = ipv4_get_dsfield(iph);
1105
1106         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1107                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1108                                           & IPV6_TCLASS_MASK;
1109         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1110                 fl6.flowi6_mark = skb->mark;
1111
1112         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1113         if (err != 0) {
1114                 /* XXX: send ICMP error even if DF is not set. */
1115                 if (err == -EMSGSIZE)
1116                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1117                                   htonl(mtu));
1118                 return -1;
1119         }
1120
1121         return 0;
1122 }
1123
1124 static inline int
1125 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1126 {
1127         struct ip6_tnl *t = netdev_priv(dev);
1128         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1129         int encap_limit = -1;
1130         __u16 offset;
1131         struct flowi6 fl6;
1132         __u8 dsfield;
1133         __u32 mtu;
1134         u8 tproto;
1135         int err;
1136
1137         tproto = ACCESS_ONCE(t->parms.proto);
1138         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1139             ip6_tnl_addr_conflict(t, ipv6h))
1140                 return -1;
1141
1142         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1143         if (offset > 0) {
1144                 struct ipv6_tlv_tnl_enc_lim *tel;
1145                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1146                 if (tel->encap_limit == 0) {
1147                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1148                                     ICMPV6_HDR_FIELD, offset + 2);
1149                         return -1;
1150                 }
1151                 encap_limit = tel->encap_limit - 1;
1152         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1153                 encap_limit = t->parms.encap_limit;
1154
1155         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1156         fl6.flowi6_proto = IPPROTO_IPV6;
1157
1158         dsfield = ipv6_get_dsfield(ipv6h);
1159         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1160                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1161         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1162                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1163         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1164                 fl6.flowi6_mark = skb->mark;
1165
1166         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1167         if (err != 0) {
1168                 if (err == -EMSGSIZE)
1169                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1170                 return -1;
1171         }
1172
1173         return 0;
1174 }
1175
1176 static netdev_tx_t
1177 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1178 {
1179         struct ip6_tnl *t = netdev_priv(dev);
1180         struct net_device_stats *stats = &t->dev->stats;
1181         int ret;
1182
1183         switch (skb->protocol) {
1184         case htons(ETH_P_IP):
1185                 ret = ip4ip6_tnl_xmit(skb, dev);
1186                 break;
1187         case htons(ETH_P_IPV6):
1188                 ret = ip6ip6_tnl_xmit(skb, dev);
1189                 break;
1190         default:
1191                 goto tx_err;
1192         }
1193
1194         if (ret < 0)
1195                 goto tx_err;
1196
1197         return NETDEV_TX_OK;
1198
1199 tx_err:
1200         stats->tx_errors++;
1201         stats->tx_dropped++;
1202         kfree_skb(skb);
1203         return NETDEV_TX_OK;
1204 }
1205
1206 static void ip6_tnl_link_config(struct ip6_tnl *t)
1207 {
1208         struct net_device *dev = t->dev;
1209         struct __ip6_tnl_parm *p = &t->parms;
1210         struct flowi6 *fl6 = &t->fl.u.ip6;
1211
1212         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1213         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1214
1215         /* Set up flowi template */
1216         fl6->saddr = p->laddr;
1217         fl6->daddr = p->raddr;
1218         fl6->flowi6_oif = p->link;
1219         fl6->flowlabel = 0;
1220
1221         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1222                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1223         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1224                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1225
1226         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1227         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1228
1229         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1230                 dev->flags |= IFF_POINTOPOINT;
1231         else
1232                 dev->flags &= ~IFF_POINTOPOINT;
1233
1234         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1235                 int strict = (ipv6_addr_type(&p->raddr) &
1236                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1237
1238                 struct rt6_info *rt = rt6_lookup(t->net,
1239                                                  &p->raddr, &p->laddr,
1240                                                  p->link, strict);
1241
1242                 if (!rt)
1243                         return;
1244
1245                 if (rt->dst.dev) {
1246                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1247                                 sizeof(struct ipv6hdr);
1248
1249                         dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr);
1250                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1251                                 dev->mtu -= 8;
1252
1253                         if (dev->mtu < IPV6_MIN_MTU)
1254                                 dev->mtu = IPV6_MIN_MTU;
1255                 }
1256                 ip6_rt_put(rt);
1257         }
1258 }
1259
1260 /**
1261  * ip6_tnl_change - update the tunnel parameters
1262  *   @t: tunnel to be changed
1263  *   @p: tunnel configuration parameters
1264  *
1265  * Description:
1266  *   ip6_tnl_change() updates the tunnel parameters
1267  **/
1268
1269 static int
1270 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1271 {
1272         t->parms.laddr = p->laddr;
1273         t->parms.raddr = p->raddr;
1274         t->parms.flags = p->flags;
1275         t->parms.hop_limit = p->hop_limit;
1276         t->parms.encap_limit = p->encap_limit;
1277         t->parms.flowinfo = p->flowinfo;
1278         t->parms.link = p->link;
1279         t->parms.proto = p->proto;
1280         dst_cache_reset(&t->dst_cache);
1281         ip6_tnl_link_config(t);
1282         return 0;
1283 }
1284
1285 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1286 {
1287         struct net *net = t->net;
1288         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1289         int err;
1290
1291         ip6_tnl_unlink(ip6n, t);
1292         synchronize_net();
1293         err = ip6_tnl_change(t, p);
1294         ip6_tnl_link(ip6n, t);
1295         netdev_state_change(t->dev);
1296         return err;
1297 }
1298
1299 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1300 {
1301         /* for default tnl0 device allow to change only the proto */
1302         t->parms.proto = p->proto;
1303         netdev_state_change(t->dev);
1304         return 0;
1305 }
1306
1307 static void
1308 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1309 {
1310         p->laddr = u->laddr;
1311         p->raddr = u->raddr;
1312         p->flags = u->flags;
1313         p->hop_limit = u->hop_limit;
1314         p->encap_limit = u->encap_limit;
1315         p->flowinfo = u->flowinfo;
1316         p->link = u->link;
1317         p->proto = u->proto;
1318         memcpy(p->name, u->name, sizeof(u->name));
1319 }
1320
1321 static void
1322 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1323 {
1324         u->laddr = p->laddr;
1325         u->raddr = p->raddr;
1326         u->flags = p->flags;
1327         u->hop_limit = p->hop_limit;
1328         u->encap_limit = p->encap_limit;
1329         u->flowinfo = p->flowinfo;
1330         u->link = p->link;
1331         u->proto = p->proto;
1332         memcpy(u->name, p->name, sizeof(u->name));
1333 }
1334
1335 /**
1336  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1337  *   @dev: virtual device associated with tunnel
1338  *   @ifr: parameters passed from userspace
1339  *   @cmd: command to be performed
1340  *
1341  * Description:
1342  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1343  *   from userspace.
1344  *
1345  *   The possible commands are the following:
1346  *     %SIOCGETTUNNEL: get tunnel parameters for device
1347  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1348  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1349  *     %SIOCDELTUNNEL: delete tunnel
1350  *
1351  *   The fallback device "ip6tnl0", created during module
1352  *   initialization, can be used for creating other tunnel devices.
1353  *
1354  * Return:
1355  *   0 on success,
1356  *   %-EFAULT if unable to copy data to or from userspace,
1357  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1358  *   %-EINVAL if passed tunnel parameters are invalid,
1359  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1360  *   %-ENODEV if attempting to change or delete a nonexisting device
1361  **/
1362
1363 static int
1364 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1365 {
1366         int err = 0;
1367         struct ip6_tnl_parm p;
1368         struct __ip6_tnl_parm p1;
1369         struct ip6_tnl *t = netdev_priv(dev);
1370         struct net *net = t->net;
1371         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1372
1373         switch (cmd) {
1374         case SIOCGETTUNNEL:
1375                 if (dev == ip6n->fb_tnl_dev) {
1376                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1377                                 err = -EFAULT;
1378                                 break;
1379                         }
1380                         ip6_tnl_parm_from_user(&p1, &p);
1381                         t = ip6_tnl_locate(net, &p1, 0);
1382                         if (IS_ERR(t))
1383                                 t = netdev_priv(dev);
1384                 } else {
1385                         memset(&p, 0, sizeof(p));
1386                 }
1387                 ip6_tnl_parm_to_user(&p, &t->parms);
1388                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1389                         err = -EFAULT;
1390                 }
1391                 break;
1392         case SIOCADDTUNNEL:
1393         case SIOCCHGTUNNEL:
1394                 err = -EPERM;
1395                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1396                         break;
1397                 err = -EFAULT;
1398                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1399                         break;
1400                 err = -EINVAL;
1401                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1402                     p.proto != 0)
1403                         break;
1404                 ip6_tnl_parm_from_user(&p1, &p);
1405                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1406                 if (cmd == SIOCCHGTUNNEL) {
1407                         if (!IS_ERR(t)) {
1408                                 if (t->dev != dev) {
1409                                         err = -EEXIST;
1410                                         break;
1411                                 }
1412                         } else
1413                                 t = netdev_priv(dev);
1414                         if (dev == ip6n->fb_tnl_dev)
1415                                 err = ip6_tnl0_update(t, &p1);
1416                         else
1417                                 err = ip6_tnl_update(t, &p1);
1418                 }
1419                 if (!IS_ERR(t)) {
1420                         err = 0;
1421                         ip6_tnl_parm_to_user(&p, &t->parms);
1422                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1423                                 err = -EFAULT;
1424
1425                 } else {
1426                         err = PTR_ERR(t);
1427                 }
1428                 break;
1429         case SIOCDELTUNNEL:
1430                 err = -EPERM;
1431                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1432                         break;
1433
1434                 if (dev == ip6n->fb_tnl_dev) {
1435                         err = -EFAULT;
1436                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1437                                 break;
1438                         err = -ENOENT;
1439                         ip6_tnl_parm_from_user(&p1, &p);
1440                         t = ip6_tnl_locate(net, &p1, 0);
1441                         if (IS_ERR(t))
1442                                 break;
1443                         err = -EPERM;
1444                         if (t->dev == ip6n->fb_tnl_dev)
1445                                 break;
1446                         dev = t->dev;
1447                 }
1448                 err = 0;
1449                 unregister_netdevice(dev);
1450                 break;
1451         default:
1452                 err = -EINVAL;
1453         }
1454         return err;
1455 }
1456
1457 /**
1458  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1459  *   @dev: virtual device associated with tunnel
1460  *   @new_mtu: the new mtu
1461  *
1462  * Return:
1463  *   0 on success,
1464  *   %-EINVAL if mtu too small
1465  **/
1466
1467 static int
1468 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1469 {
1470         struct ip6_tnl *tnl = netdev_priv(dev);
1471
1472         if (tnl->parms.proto == IPPROTO_IPIP) {
1473                 if (new_mtu < 68)
1474                         return -EINVAL;
1475         } else {
1476                 if (new_mtu < IPV6_MIN_MTU)
1477                         return -EINVAL;
1478         }
1479         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1480                 return -EINVAL;
1481         dev->mtu = new_mtu;
1482         return 0;
1483 }
1484
1485 int ip6_tnl_get_iflink(const struct net_device *dev)
1486 {
1487         struct ip6_tnl *t = netdev_priv(dev);
1488
1489         return t->parms.link;
1490 }
1491 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1492
1493 static const struct net_device_ops ip6_tnl_netdev_ops = {
1494         .ndo_init       = ip6_tnl_dev_init,
1495         .ndo_uninit     = ip6_tnl_dev_uninit,
1496         .ndo_start_xmit = ip6_tnl_xmit,
1497         .ndo_do_ioctl   = ip6_tnl_ioctl,
1498         .ndo_change_mtu = ip6_tnl_change_mtu,
1499         .ndo_get_stats  = ip6_get_stats,
1500         .ndo_get_iflink = ip6_tnl_get_iflink,
1501 };
1502
1503
1504 /**
1505  * ip6_tnl_dev_setup - setup virtual tunnel device
1506  *   @dev: virtual device associated with tunnel
1507  *
1508  * Description:
1509  *   Initialize function pointers and device parameters
1510  **/
1511
1512 static void ip6_tnl_dev_setup(struct net_device *dev)
1513 {
1514         struct ip6_tnl *t;
1515
1516         dev->netdev_ops = &ip6_tnl_netdev_ops;
1517         dev->destructor = ip6_dev_free;
1518
1519         dev->type = ARPHRD_TUNNEL6;
1520         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
1521         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr);
1522         t = netdev_priv(dev);
1523         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1524                 dev->mtu -= 8;
1525         dev->flags |= IFF_NOARP;
1526         dev->addr_len = sizeof(struct in6_addr);
1527         netif_keep_dst(dev);
1528         /* This perm addr will be used as interface identifier by IPv6 */
1529         dev->addr_assign_type = NET_ADDR_RANDOM;
1530         eth_random_addr(dev->perm_addr);
1531 }
1532
1533
1534 /**
1535  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1536  *   @dev: virtual device associated with tunnel
1537  **/
1538
1539 static inline int
1540 ip6_tnl_dev_init_gen(struct net_device *dev)
1541 {
1542         struct ip6_tnl *t = netdev_priv(dev);
1543         int ret;
1544
1545         t->dev = dev;
1546         t->net = dev_net(dev);
1547         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1548         if (!dev->tstats)
1549                 return -ENOMEM;
1550
1551         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1552         if (ret) {
1553                 free_percpu(dev->tstats);
1554                 dev->tstats = NULL;
1555                 return ret;
1556         }
1557
1558         return 0;
1559 }
1560
1561 /**
1562  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1563  *   @dev: virtual device associated with tunnel
1564  **/
1565
1566 static int ip6_tnl_dev_init(struct net_device *dev)
1567 {
1568         struct ip6_tnl *t = netdev_priv(dev);
1569         int err = ip6_tnl_dev_init_gen(dev);
1570
1571         if (err)
1572                 return err;
1573         ip6_tnl_link_config(t);
1574         return 0;
1575 }
1576
1577 /**
1578  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1579  *   @dev: fallback device
1580  *
1581  * Return: 0
1582  **/
1583
1584 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1585 {
1586         struct ip6_tnl *t = netdev_priv(dev);
1587         struct net *net = dev_net(dev);
1588         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1589
1590         t->parms.proto = IPPROTO_IPV6;
1591         dev_hold(dev);
1592
1593         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1594         return 0;
1595 }
1596
1597 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1598 {
1599         u8 proto;
1600
1601         if (!data || !data[IFLA_IPTUN_PROTO])
1602                 return 0;
1603
1604         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1605         if (proto != IPPROTO_IPV6 &&
1606             proto != IPPROTO_IPIP &&
1607             proto != 0)
1608                 return -EINVAL;
1609
1610         return 0;
1611 }
1612
1613 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1614                                   struct __ip6_tnl_parm *parms)
1615 {
1616         memset(parms, 0, sizeof(*parms));
1617
1618         if (!data)
1619                 return;
1620
1621         if (data[IFLA_IPTUN_LINK])
1622                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1623
1624         if (data[IFLA_IPTUN_LOCAL])
1625                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1626
1627         if (data[IFLA_IPTUN_REMOTE])
1628                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1629
1630         if (data[IFLA_IPTUN_TTL])
1631                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1632
1633         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1634                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1635
1636         if (data[IFLA_IPTUN_FLOWINFO])
1637                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1638
1639         if (data[IFLA_IPTUN_FLAGS])
1640                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1641
1642         if (data[IFLA_IPTUN_PROTO])
1643                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1644 }
1645
1646 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1647                            struct nlattr *tb[], struct nlattr *data[])
1648 {
1649         struct net *net = dev_net(dev);
1650         struct ip6_tnl *nt, *t;
1651
1652         nt = netdev_priv(dev);
1653         ip6_tnl_netlink_parms(data, &nt->parms);
1654
1655         t = ip6_tnl_locate(net, &nt->parms, 0);
1656         if (!IS_ERR(t))
1657                 return -EEXIST;
1658
1659         return ip6_tnl_create2(dev);
1660 }
1661
1662 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1663                               struct nlattr *data[])
1664 {
1665         struct ip6_tnl *t = netdev_priv(dev);
1666         struct __ip6_tnl_parm p;
1667         struct net *net = t->net;
1668         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1669
1670         if (dev == ip6n->fb_tnl_dev)
1671                 return -EINVAL;
1672
1673         ip6_tnl_netlink_parms(data, &p);
1674
1675         t = ip6_tnl_locate(net, &p, 0);
1676         if (!IS_ERR(t)) {
1677                 if (t->dev != dev)
1678                         return -EEXIST;
1679         } else
1680                 t = netdev_priv(dev);
1681
1682         return ip6_tnl_update(t, &p);
1683 }
1684
1685 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1686 {
1687         struct net *net = dev_net(dev);
1688         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1689
1690         if (dev != ip6n->fb_tnl_dev)
1691                 unregister_netdevice_queue(dev, head);
1692 }
1693
1694 static size_t ip6_tnl_get_size(const struct net_device *dev)
1695 {
1696         return
1697                 /* IFLA_IPTUN_LINK */
1698                 nla_total_size(4) +
1699                 /* IFLA_IPTUN_LOCAL */
1700                 nla_total_size(sizeof(struct in6_addr)) +
1701                 /* IFLA_IPTUN_REMOTE */
1702                 nla_total_size(sizeof(struct in6_addr)) +
1703                 /* IFLA_IPTUN_TTL */
1704                 nla_total_size(1) +
1705                 /* IFLA_IPTUN_ENCAP_LIMIT */
1706                 nla_total_size(1) +
1707                 /* IFLA_IPTUN_FLOWINFO */
1708                 nla_total_size(4) +
1709                 /* IFLA_IPTUN_FLAGS */
1710                 nla_total_size(4) +
1711                 /* IFLA_IPTUN_PROTO */
1712                 nla_total_size(1) +
1713                 0;
1714 }
1715
1716 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1717 {
1718         struct ip6_tnl *tunnel = netdev_priv(dev);
1719         struct __ip6_tnl_parm *parm = &tunnel->parms;
1720
1721         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1722             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
1723             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
1724             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1725             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1726             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1727             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1728             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1729                 goto nla_put_failure;
1730         return 0;
1731
1732 nla_put_failure:
1733         return -EMSGSIZE;
1734 }
1735
1736 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
1737 {
1738         struct ip6_tnl *tunnel = netdev_priv(dev);
1739
1740         return tunnel->net;
1741 }
1742 EXPORT_SYMBOL(ip6_tnl_get_link_net);
1743
1744 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1745         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1746         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
1747         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
1748         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1749         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
1750         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
1751         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
1752         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1753 };
1754
1755 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1756         .kind           = "ip6tnl",
1757         .maxtype        = IFLA_IPTUN_MAX,
1758         .policy         = ip6_tnl_policy,
1759         .priv_size      = sizeof(struct ip6_tnl),
1760         .setup          = ip6_tnl_dev_setup,
1761         .validate       = ip6_tnl_validate,
1762         .newlink        = ip6_tnl_newlink,
1763         .changelink     = ip6_tnl_changelink,
1764         .dellink        = ip6_tnl_dellink,
1765         .get_size       = ip6_tnl_get_size,
1766         .fill_info      = ip6_tnl_fill_info,
1767         .get_link_net   = ip6_tnl_get_link_net,
1768 };
1769
1770 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1771         .handler        = ip4ip6_rcv,
1772         .err_handler    = ip4ip6_err,
1773         .priority       =       1,
1774 };
1775
1776 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1777         .handler        = ip6ip6_rcv,
1778         .err_handler    = ip6ip6_err,
1779         .priority       =       1,
1780 };
1781
1782 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1783 {
1784         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1785         struct net_device *dev, *aux;
1786         int h;
1787         struct ip6_tnl *t;
1788         LIST_HEAD(list);
1789
1790         for_each_netdev_safe(net, dev, aux)
1791                 if (dev->rtnl_link_ops == &ip6_link_ops)
1792                         unregister_netdevice_queue(dev, &list);
1793
1794         for (h = 0; h < HASH_SIZE; h++) {
1795                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1796                 while (t) {
1797                         /* If dev is in the same netns, it has already
1798                          * been added to the list by the previous loop.
1799                          */
1800                         if (!net_eq(dev_net(t->dev), net))
1801                                 unregister_netdevice_queue(t->dev, &list);
1802                         t = rtnl_dereference(t->next);
1803                 }
1804         }
1805
1806         unregister_netdevice_many(&list);
1807 }
1808
1809 static int __net_init ip6_tnl_init_net(struct net *net)
1810 {
1811         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1812         struct ip6_tnl *t = NULL;
1813         int err;
1814
1815         ip6n->tnls[0] = ip6n->tnls_wc;
1816         ip6n->tnls[1] = ip6n->tnls_r_l;
1817
1818         err = -ENOMEM;
1819         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1820                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
1821
1822         if (!ip6n->fb_tnl_dev)
1823                 goto err_alloc_dev;
1824         dev_net_set(ip6n->fb_tnl_dev, net);
1825         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1826         /* FB netdevice is special: we have one, and only one per netns.
1827          * Allowing to move it to another netns is clearly unsafe.
1828          */
1829         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1830
1831         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1832         if (err < 0)
1833                 goto err_register;
1834
1835         err = register_netdev(ip6n->fb_tnl_dev);
1836         if (err < 0)
1837                 goto err_register;
1838
1839         t = netdev_priv(ip6n->fb_tnl_dev);
1840
1841         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1842         return 0;
1843
1844 err_register:
1845         ip6_dev_free(ip6n->fb_tnl_dev);
1846 err_alloc_dev:
1847         return err;
1848 }
1849
1850 static void __net_exit ip6_tnl_exit_net(struct net *net)
1851 {
1852         rtnl_lock();
1853         ip6_tnl_destroy_tunnels(net);
1854         rtnl_unlock();
1855 }
1856
1857 static struct pernet_operations ip6_tnl_net_ops = {
1858         .init = ip6_tnl_init_net,
1859         .exit = ip6_tnl_exit_net,
1860         .id   = &ip6_tnl_net_id,
1861         .size = sizeof(struct ip6_tnl_net),
1862 };
1863
1864 /**
1865  * ip6_tunnel_init - register protocol and reserve needed resources
1866  *
1867  * Return: 0 on success
1868  **/
1869
1870 static int __init ip6_tunnel_init(void)
1871 {
1872         int  err;
1873
1874         err = register_pernet_device(&ip6_tnl_net_ops);
1875         if (err < 0)
1876                 goto out_pernet;
1877
1878         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1879         if (err < 0) {
1880                 pr_err("%s: can't register ip4ip6\n", __func__);
1881                 goto out_ip4ip6;
1882         }
1883
1884         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1885         if (err < 0) {
1886                 pr_err("%s: can't register ip6ip6\n", __func__);
1887                 goto out_ip6ip6;
1888         }
1889         err = rtnl_link_register(&ip6_link_ops);
1890         if (err < 0)
1891                 goto rtnl_link_failed;
1892
1893         return 0;
1894
1895 rtnl_link_failed:
1896         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1897 out_ip6ip6:
1898         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1899 out_ip4ip6:
1900         unregister_pernet_device(&ip6_tnl_net_ops);
1901 out_pernet:
1902         return err;
1903 }
1904
1905 /**
1906  * ip6_tunnel_cleanup - free resources and unregister protocol
1907  **/
1908
1909 static void __exit ip6_tunnel_cleanup(void)
1910 {
1911         rtnl_link_unregister(&ip6_link_ops);
1912         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1913                 pr_info("%s: can't deregister ip4ip6\n", __func__);
1914
1915         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1916                 pr_info("%s: can't deregister ip6ip6\n", __func__);
1917
1918         unregister_pernet_device(&ip6_tnl_net_ops);
1919 }
1920
1921 module_init(ip6_tunnel_init);
1922 module_exit(ip6_tunnel_cleanup);