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Linux 3.8-rc7
[cris-mirror.git] / net / ipv6 / ip6_tunnel.c
bloba14f28b280f57a040e3d499955419f6c949c5c93
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/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 #include <linux/slab.h>
43 #include <linux/hash.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/ipv6.h>
51 #include <net/ip6_route.h>
52 #include <net/addrconf.h>
53 #include <net/ip6_tunnel.h>
54 #include <net/xfrm.h>
55 #include <net/dsfield.h>
56 #include <net/inet_ecn.h>
57 #include <net/net_namespace.h>
58 #include <net/netns/generic.h>
59
60 MODULE_AUTHOR("Ville Nuorvala");
61 MODULE_DESCRIPTION("IPv6 tunneling device");
62 MODULE_LICENSE("GPL");
63 MODULE_ALIAS_NETDEV("ip6tnl0");
64
65 #ifdef IP6_TNL_DEBUG
66 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
67 #else
68 #define IP6_TNL_TRACE(x...) do {;} while(0)
69 #endif
70
71 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
72 #define IPV6_TCLASS_SHIFT 20
73
74 #define HASH_SIZE_SHIFT 5
75 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
76
77 static bool log_ecn_error = true;
78 module_param(log_ecn_error, bool, 0644);
79 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
80
81 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
82 {
83 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
84
85 return hash_32(hash, HASH_SIZE_SHIFT);
86 }
87
88 static int ip6_tnl_dev_init(struct net_device *dev);
89 static void ip6_tnl_dev_setup(struct net_device *dev);
90 static struct rtnl_link_ops ip6_link_ops __read_mostly;
91
92 static int ip6_tnl_net_id __read_mostly;
93 struct ip6_tnl_net {
94 /* the IPv6 tunnel fallback device */
95 struct net_device *fb_tnl_dev;
96 /* lists for storing tunnels in use */
97 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
98 struct ip6_tnl __rcu *tnls_wc[1];
99 struct ip6_tnl __rcu **tnls[2];
100 };
101
102 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
103 {
104 struct pcpu_tstats sum = { 0 };
105 int i;
106
107 for_each_possible_cpu(i) {
108 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
109
110 sum.rx_packets += tstats->rx_packets;
111 sum.rx_bytes += tstats->rx_bytes;
112 sum.tx_packets += tstats->tx_packets;
113 sum.tx_bytes += tstats->tx_bytes;
114 }
115 dev->stats.rx_packets = sum.rx_packets;
116 dev->stats.rx_bytes = sum.rx_bytes;
117 dev->stats.tx_packets = sum.tx_packets;
118 dev->stats.tx_bytes = sum.tx_bytes;
119 return &dev->stats;
120 }
121
122 /*
123 * Locking : hash tables are protected by RCU and RTNL
124 */
125
126 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
127 {
128 struct dst_entry *dst = t->dst_cache;
129
130 if (dst && dst->obsolete &&
131 dst->ops->check(dst, t->dst_cookie) == NULL) {
132 t->dst_cache = NULL;
133 dst_release(dst);
134 return NULL;
135 }
136
137 return dst;
138 }
139 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
140
141 void ip6_tnl_dst_reset(struct ip6_tnl *t)
142 {
143 dst_release(t->dst_cache);
144 t->dst_cache = NULL;
145 }
146 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
147
148 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
149 {
150 struct rt6_info *rt = (struct rt6_info *) dst;
151 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
152 dst_release(t->dst_cache);
153 t->dst_cache = dst;
154 }
155 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
156
157 /**
158 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
159 * @remote: the address of the tunnel exit-point
160 * @local: the address of the tunnel entry-point
161 *
162 * Return:
163 * tunnel matching given end-points if found,
164 * else fallback tunnel if its device is up,
165 * else %NULL
166 **/
167
168 #define for_each_ip6_tunnel_rcu(start) \
169 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
170
171 static struct ip6_tnl *
172 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
173 {
174 unsigned int hash = HASH(remote, local);
175 struct ip6_tnl *t;
176 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
177
178 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
179 if (ipv6_addr_equal(local, &t->parms.laddr) &&
180 ipv6_addr_equal(remote, &t->parms.raddr) &&
181 (t->dev->flags & IFF_UP))
182 return t;
183 }
184 t = rcu_dereference(ip6n->tnls_wc[0]);
185 if (t && (t->dev->flags & IFF_UP))
186 return t;
187
188 return NULL;
189 }
190
191 /**
192 * ip6_tnl_bucket - get head of list matching given tunnel parameters
193 * @p: parameters containing tunnel end-points
194 *
195 * Description:
196 * ip6_tnl_bucket() returns the head of the list matching the
197 * &struct in6_addr entries laddr and raddr in @p.
198 *
199 * Return: head of IPv6 tunnel list
200 **/
201
202 static struct ip6_tnl __rcu **
203 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
204 {
205 const struct in6_addr *remote = &p->raddr;
206 const struct in6_addr *local = &p->laddr;
207 unsigned int h = 0;
208 int prio = 0;
209
210 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
211 prio = 1;
212 h = HASH(remote, local);
213 }
214 return &ip6n->tnls[prio][h];
215 }
216
217 /**
218 * ip6_tnl_link - add tunnel to hash table
219 * @t: tunnel to be added
220 **/
221
222 static void
223 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
224 {
225 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
226
227 rcu_assign_pointer(t->next , rtnl_dereference(*tp));
228 rcu_assign_pointer(*tp, t);
229 }
230
231 /**
232 * ip6_tnl_unlink - remove tunnel from hash table
233 * @t: tunnel to be removed
234 **/
235
236 static void
237 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
238 {
239 struct ip6_tnl __rcu **tp;
240 struct ip6_tnl *iter;
241
242 for (tp = ip6_tnl_bucket(ip6n, &t->parms);
243 (iter = rtnl_dereference(*tp)) != NULL;
244 tp = &iter->next) {
245 if (t == iter) {
246 rcu_assign_pointer(*tp, t->next);
247 break;
248 }
249 }
250 }
251
252 static void ip6_dev_free(struct net_device *dev)
253 {
254 free_percpu(dev->tstats);
255 free_netdev(dev);
256 }
257
258 static int ip6_tnl_create2(struct net_device *dev)
259 {
260 struct ip6_tnl *t = netdev_priv(dev);
261 struct net *net = dev_net(dev);
262 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
263 int err;
264
265 t = netdev_priv(dev);
266 err = ip6_tnl_dev_init(dev);
267 if (err < 0)
268 goto out;
269
270 err = register_netdevice(dev);
271 if (err < 0)
272 goto out;
273
274 strcpy(t->parms.name, dev->name);
275 dev->rtnl_link_ops = &ip6_link_ops;
276
277 dev_hold(dev);
278 ip6_tnl_link(ip6n, t);
279 return 0;
280
281 out:
282 return err;
283 }
284
285 /**
286 * ip6_tnl_create - create a new tunnel
287 * @p: tunnel parameters
288 * @pt: pointer to new tunnel
289 *
290 * Description:
291 * Create tunnel matching given parameters.
292 *
293 * Return:
294 * created tunnel or NULL
295 **/
296
297 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
298 {
299 struct net_device *dev;
300 struct ip6_tnl *t;
301 char name[IFNAMSIZ];
302 int err;
303
304 if (p->name[0])
305 strlcpy(name, p->name, IFNAMSIZ);
306 else
307 sprintf(name, "ip6tnl%%d");
308
309 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
310 if (dev == NULL)
311 goto failed;
312
313 dev_net_set(dev, net);
314
315 t = netdev_priv(dev);
316 t->parms = *p;
317 err = ip6_tnl_create2(dev);
318 if (err < 0)
319 goto failed_free;
320
321 return t;
322
323 failed_free:
324 ip6_dev_free(dev);
325 failed:
326 return NULL;
327 }
328
329 /**
330 * ip6_tnl_locate - find or create tunnel matching given parameters
331 * @p: tunnel parameters
332 * @create: != 0 if allowed to create new tunnel if no match found
333 *
334 * Description:
335 * ip6_tnl_locate() first tries to locate an existing tunnel
336 * based on @parms. If this is unsuccessful, but @create is set a new
337 * tunnel device is created and registered for use.
338 *
339 * Return:
340 * matching tunnel or NULL
341 **/
342
343 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
344 struct __ip6_tnl_parm *p, int create)
345 {
346 const struct in6_addr *remote = &p->raddr;
347 const struct in6_addr *local = &p->laddr;
348 struct ip6_tnl __rcu **tp;
349 struct ip6_tnl *t;
350 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
351
352 for (tp = ip6_tnl_bucket(ip6n, p);
353 (t = rtnl_dereference(*tp)) != NULL;
354 tp = &t->next) {
355 if (ipv6_addr_equal(local, &t->parms.laddr) &&
356 ipv6_addr_equal(remote, &t->parms.raddr))
357 return t;
358 }
359 if (!create)
360 return NULL;
361 return ip6_tnl_create(net, p);
362 }
363
364 /**
365 * ip6_tnl_dev_uninit - tunnel device uninitializer
366 * @dev: the device to be destroyed
367 *
368 * Description:
369 * ip6_tnl_dev_uninit() removes tunnel from its list
370 **/
371
372 static void
373 ip6_tnl_dev_uninit(struct net_device *dev)
374 {
375 struct ip6_tnl *t = netdev_priv(dev);
376 struct net *net = dev_net(dev);
377 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
378
379 if (dev == ip6n->fb_tnl_dev)
380 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
381 else
382 ip6_tnl_unlink(ip6n, t);
383 ip6_tnl_dst_reset(t);
384 dev_put(dev);
385 }
386
387 /**
388 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
389 * @skb: received socket buffer
390 *
391 * Return:
392 * 0 if none was found,
393 * else index to encapsulation limit
394 **/
395
396 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
397 {
398 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
399 __u8 nexthdr = ipv6h->nexthdr;
400 __u16 off = sizeof (*ipv6h);
401
402 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
403 __u16 optlen = 0;
404 struct ipv6_opt_hdr *hdr;
405 if (raw + off + sizeof (*hdr) > skb->data &&
406 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
407 break;
408
409 hdr = (struct ipv6_opt_hdr *) (raw + off);
410 if (nexthdr == NEXTHDR_FRAGMENT) {
411 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
412 if (frag_hdr->frag_off)
413 break;
414 optlen = 8;
415 } else if (nexthdr == NEXTHDR_AUTH) {
416 optlen = (hdr->hdrlen + 2) << 2;
417 } else {
418 optlen = ipv6_optlen(hdr);
419 }
420 if (nexthdr == NEXTHDR_DEST) {
421 __u16 i = off + 2;
422 while (1) {
423 struct ipv6_tlv_tnl_enc_lim *tel;
424
425 /* No more room for encapsulation limit */
426 if (i + sizeof (*tel) > off + optlen)
427 break;
428
429 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
430 /* return index of option if found and valid */
431 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
432 tel->length == 1)
433 return i;
434 /* else jump to next option */
435 if (tel->type)
436 i += tel->length + 2;
437 else
438 i++;
439 }
440 }
441 nexthdr = hdr->nexthdr;
442 off += optlen;
443 }
444 return 0;
445 }
446 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
447
448 /**
449 * ip6_tnl_err - tunnel error handler
450 *
451 * Description:
452 * ip6_tnl_err() should handle errors in the tunnel according
453 * to the specifications in RFC 2473.
454 **/
455
456 static int
457 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
458 u8 *type, u8 *code, int *msg, __u32 *info, int offset)
459 {
460 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
461 struct ip6_tnl *t;
462 int rel_msg = 0;
463 u8 rel_type = ICMPV6_DEST_UNREACH;
464 u8 rel_code = ICMPV6_ADDR_UNREACH;
465 __u32 rel_info = 0;
466 __u16 len;
467 int err = -ENOENT;
468
469 /* If the packet doesn't contain the original IPv6 header we are
470 in trouble since we might need the source address for further
471 processing of the error. */
472
473 rcu_read_lock();
474 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
475 &ipv6h->saddr)) == NULL)
476 goto out;
477
478 if (t->parms.proto != ipproto && t->parms.proto != 0)
479 goto out;
480
481 err = 0;
482
483 switch (*type) {
484 __u32 teli;
485 struct ipv6_tlv_tnl_enc_lim *tel;
486 __u32 mtu;
487 case ICMPV6_DEST_UNREACH:
488 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
489 t->parms.name);
490 rel_msg = 1;
491 break;
492 case ICMPV6_TIME_EXCEED:
493 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
494 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
495 t->parms.name);
496 rel_msg = 1;
497 }
498 break;
499 case ICMPV6_PARAMPROB:
500 teli = 0;
501 if ((*code) == ICMPV6_HDR_FIELD)
502 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
503
504 if (teli && teli == *info - 2) {
505 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
506 if (tel->encap_limit == 0) {
507 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
508 t->parms.name);
509 rel_msg = 1;
510 }
511 } else {
512 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
513 t->parms.name);
514 }
515 break;
516 case ICMPV6_PKT_TOOBIG:
517 mtu = *info - offset;
518 if (mtu < IPV6_MIN_MTU)
519 mtu = IPV6_MIN_MTU;
520 t->dev->mtu = mtu;
521
522 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
523 rel_type = ICMPV6_PKT_TOOBIG;
524 rel_code = 0;
525 rel_info = mtu;
526 rel_msg = 1;
527 }
528 break;
529 }
530
531 *type = rel_type;
532 *code = rel_code;
533 *info = rel_info;
534 *msg = rel_msg;
535
536 out:
537 rcu_read_unlock();
538 return err;
539 }
540
541 static int
542 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
543 u8 type, u8 code, int offset, __be32 info)
544 {
545 int rel_msg = 0;
546 u8 rel_type = type;
547 u8 rel_code = code;
548 __u32 rel_info = ntohl(info);
549 int err;
550 struct sk_buff *skb2;
551 const struct iphdr *eiph;
552 struct rtable *rt;
553 struct flowi4 fl4;
554
555 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
556 &rel_msg, &rel_info, offset);
557 if (err < 0)
558 return err;
559
560 if (rel_msg == 0)
561 return 0;
562
563 switch (rel_type) {
564 case ICMPV6_DEST_UNREACH:
565 if (rel_code != ICMPV6_ADDR_UNREACH)
566 return 0;
567 rel_type = ICMP_DEST_UNREACH;
568 rel_code = ICMP_HOST_UNREACH;
569 break;
570 case ICMPV6_PKT_TOOBIG:
571 if (rel_code != 0)
572 return 0;
573 rel_type = ICMP_DEST_UNREACH;
574 rel_code = ICMP_FRAG_NEEDED;
575 break;
576 case NDISC_REDIRECT:
577 rel_type = ICMP_REDIRECT;
578 rel_code = ICMP_REDIR_HOST;
579 default:
580 return 0;
581 }
582
583 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
584 return 0;
585
586 skb2 = skb_clone(skb, GFP_ATOMIC);
587 if (!skb2)
588 return 0;
589
590 skb_dst_drop(skb2);
591
592 skb_pull(skb2, offset);
593 skb_reset_network_header(skb2);
594 eiph = ip_hdr(skb2);
595
596 /* Try to guess incoming interface */
597 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
598 eiph->saddr, 0,
599 0, 0,
600 IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
601 if (IS_ERR(rt))
602 goto out;
603
604 skb2->dev = rt->dst.dev;
605
606 /* route "incoming" packet */
607 if (rt->rt_flags & RTCF_LOCAL) {
608 ip_rt_put(rt);
609 rt = NULL;
610 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
611 eiph->daddr, eiph->saddr,
612 0, 0,
613 IPPROTO_IPIP,
614 RT_TOS(eiph->tos), 0);
615 if (IS_ERR(rt) ||
616 rt->dst.dev->type != ARPHRD_TUNNEL) {
617 if (!IS_ERR(rt))
618 ip_rt_put(rt);
619 goto out;
620 }
621 skb_dst_set(skb2, &rt->dst);
622 } else {
623 ip_rt_put(rt);
624 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
625 skb2->dev) ||
626 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
627 goto out;
628 }
629
630 /* change mtu on this route */
631 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
632 if (rel_info > dst_mtu(skb_dst(skb2)))
633 goto out;
634
635 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
636 }
637 if (rel_type == ICMP_REDIRECT)
638 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
639
640 icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
641
642 out:
643 kfree_skb(skb2);
644 return 0;
645 }
646
647 static int
648 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
649 u8 type, u8 code, int offset, __be32 info)
650 {
651 int rel_msg = 0;
652 u8 rel_type = type;
653 u8 rel_code = code;
654 __u32 rel_info = ntohl(info);
655 int err;
656
657 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
658 &rel_msg, &rel_info, offset);
659 if (err < 0)
660 return err;
661
662 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
663 struct rt6_info *rt;
664 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
665
666 if (!skb2)
667 return 0;
668
669 skb_dst_drop(skb2);
670 skb_pull(skb2, offset);
671 skb_reset_network_header(skb2);
672
673 /* Try to guess incoming interface */
674 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
675 NULL, 0, 0);
676
677 if (rt && rt->dst.dev)
678 skb2->dev = rt->dst.dev;
679
680 icmpv6_send(skb2, rel_type, rel_code, rel_info);
681
682 ip6_rt_put(rt);
683
684 kfree_skb(skb2);
685 }
686
687 return 0;
688 }
689
690 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
691 const struct ipv6hdr *ipv6h,
692 struct sk_buff *skb)
693 {
694 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
695
696 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
697 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
698
699 return IP6_ECN_decapsulate(ipv6h, skb);
700 }
701
702 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
703 const struct ipv6hdr *ipv6h,
704 struct sk_buff *skb)
705 {
706 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
707 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
708
709 return IP6_ECN_decapsulate(ipv6h, skb);
710 }
711
712 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
713 const struct in6_addr *laddr,
714 const struct in6_addr *raddr)
715 {
716 struct __ip6_tnl_parm *p = &t->parms;
717 int ltype = ipv6_addr_type(laddr);
718 int rtype = ipv6_addr_type(raddr);
719 __u32 flags = 0;
720
721 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
722 flags = IP6_TNL_F_CAP_PER_PACKET;
723 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
724 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
725 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
726 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
727 if (ltype&IPV6_ADDR_UNICAST)
728 flags |= IP6_TNL_F_CAP_XMIT;
729 if (rtype&IPV6_ADDR_UNICAST)
730 flags |= IP6_TNL_F_CAP_RCV;
731 }
732 return flags;
733 }
734 EXPORT_SYMBOL(ip6_tnl_get_cap);
735
736 /* called with rcu_read_lock() */
737 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
738 const struct in6_addr *laddr,
739 const struct in6_addr *raddr)
740 {
741 struct __ip6_tnl_parm *p = &t->parms;
742 int ret = 0;
743 struct net *net = dev_net(t->dev);
744
745 if ((p->flags & IP6_TNL_F_CAP_RCV) ||
746 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
747 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
748 struct net_device *ldev = NULL;
749
750 if (p->link)
751 ldev = dev_get_by_index_rcu(net, p->link);
752
753 if ((ipv6_addr_is_multicast(laddr) ||
754 likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
755 likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
756 ret = 1;
757 }
758 return ret;
759 }
760 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
761
762 /**
763 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
764 * @skb: received socket buffer
765 * @protocol: ethernet protocol ID
766 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
767 *
768 * Return: 0
769 **/
770
771 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
772 __u8 ipproto,
773 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
774 const struct ipv6hdr *ipv6h,
775 struct sk_buff *skb))
776 {
777 struct ip6_tnl *t;
778 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
779 int err;
780
781 rcu_read_lock();
782
783 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
784 &ipv6h->daddr)) != NULL) {
785 struct pcpu_tstats *tstats;
786
787 if (t->parms.proto != ipproto && t->parms.proto != 0) {
788 rcu_read_unlock();
789 goto discard;
790 }
791
792 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
793 rcu_read_unlock();
794 goto discard;
795 }
796
797 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
798 t->dev->stats.rx_dropped++;
799 rcu_read_unlock();
800 goto discard;
801 }
802 secpath_reset(skb);
803 skb->mac_header = skb->network_header;
804 skb_reset_network_header(skb);
805 skb->protocol = htons(protocol);
806 skb->pkt_type = PACKET_HOST;
807 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
808
809 __skb_tunnel_rx(skb, t->dev);
810
811 err = dscp_ecn_decapsulate(t, ipv6h, skb);
812 if (unlikely(err)) {
813 if (log_ecn_error)
814 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
815 &ipv6h->saddr,
816 ipv6_get_dsfield(ipv6h));
817 if (err > 1) {
818 ++t->dev->stats.rx_frame_errors;
819 ++t->dev->stats.rx_errors;
820 rcu_read_unlock();
821 goto discard;
822 }
823 }
824
825 tstats = this_cpu_ptr(t->dev->tstats);
826 tstats->rx_packets++;
827 tstats->rx_bytes += skb->len;
828
829 netif_rx(skb);
830
831 rcu_read_unlock();
832 return 0;
833 }
834 rcu_read_unlock();
835 return 1;
836
837 discard:
838 kfree_skb(skb);
839 return 0;
840 }
841
842 static int ip4ip6_rcv(struct sk_buff *skb)
843 {
844 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
845 ip4ip6_dscp_ecn_decapsulate);
846 }
847
848 static int ip6ip6_rcv(struct sk_buff *skb)
849 {
850 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
851 ip6ip6_dscp_ecn_decapsulate);
852 }
853
854 struct ipv6_tel_txoption {
855 struct ipv6_txoptions ops;
856 __u8 dst_opt[8];
857 };
858
859 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
860 {
861 memset(opt, 0, sizeof(struct ipv6_tel_txoption));
862
863 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
864 opt->dst_opt[3] = 1;
865 opt->dst_opt[4] = encap_limit;
866 opt->dst_opt[5] = IPV6_TLV_PADN;
867 opt->dst_opt[6] = 1;
868
869 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
870 opt->ops.opt_nflen = 8;
871 }
872
873 /**
874 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
875 * @t: the outgoing tunnel device
876 * @hdr: IPv6 header from the incoming packet
877 *
878 * Description:
879 * Avoid trivial tunneling loop by checking that tunnel exit-point
880 * doesn't match source of incoming packet.
881 *
882 * Return:
883 * 1 if conflict,
884 * 0 else
885 **/
886
887 static inline bool
888 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
889 {
890 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
891 }
892
893 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
894 {
895 struct __ip6_tnl_parm *p = &t->parms;
896 int ret = 0;
897 struct net *net = dev_net(t->dev);
898
899 if (p->flags & IP6_TNL_F_CAP_XMIT) {
900 struct net_device *ldev = NULL;
901
902 rcu_read_lock();
903 if (p->link)
904 ldev = dev_get_by_index_rcu(net, p->link);
905
906 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
907 pr_warn("%s xmit: Local address not yet configured!\n",
908 p->name);
909 else if (!ipv6_addr_is_multicast(&p->raddr) &&
910 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
911 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
912 p->name);
913 else
914 ret = 1;
915 rcu_read_unlock();
916 }
917 return ret;
918 }
919 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
920
921 /**
922 * ip6_tnl_xmit2 - encapsulate packet and send
923 * @skb: the outgoing socket buffer
924 * @dev: the outgoing tunnel device
925 * @dsfield: dscp code for outer header
926 * @fl: flow of tunneled packet
927 * @encap_limit: encapsulation limit
928 * @pmtu: Path MTU is stored if packet is too big
929 *
930 * Description:
931 * Build new header and do some sanity checks on the packet before sending
932 * it.
933 *
934 * Return:
935 * 0 on success
936 * -1 fail
937 * %-EMSGSIZE message too big. return mtu in this case.
938 **/
939
940 static int ip6_tnl_xmit2(struct sk_buff *skb,
941 struct net_device *dev,
942 __u8 dsfield,
943 struct flowi6 *fl6,
944 int encap_limit,
945 __u32 *pmtu)
946 {
947 struct net *net = dev_net(dev);
948 struct ip6_tnl *t = netdev_priv(dev);
949 struct net_device_stats *stats = &t->dev->stats;
950 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
951 struct ipv6_tel_txoption opt;
952 struct dst_entry *dst = NULL, *ndst = NULL;
953 struct net_device *tdev;
954 int mtu;
955 unsigned int max_headroom = sizeof(struct ipv6hdr);
956 u8 proto;
957 int err = -1;
958 int pkt_len;
959
960 if (!fl6->flowi6_mark)
961 dst = ip6_tnl_dst_check(t);
962 if (!dst) {
963 ndst = ip6_route_output(net, NULL, fl6);
964
965 if (ndst->error)
966 goto tx_err_link_failure;
967 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
968 if (IS_ERR(ndst)) {
969 err = PTR_ERR(ndst);
970 ndst = NULL;
971 goto tx_err_link_failure;
972 }
973 dst = ndst;
974 }
975
976 tdev = dst->dev;
977
978 if (tdev == dev) {
979 stats->collisions++;
980 net_warn_ratelimited("%s: Local routing loop detected!\n",
981 t->parms.name);
982 goto tx_err_dst_release;
983 }
984 mtu = dst_mtu(dst) - sizeof (*ipv6h);
985 if (encap_limit >= 0) {
986 max_headroom += 8;
987 mtu -= 8;
988 }
989 if (mtu < IPV6_MIN_MTU)
990 mtu = IPV6_MIN_MTU;
991 if (skb_dst(skb))
992 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
993 if (skb->len > mtu) {
994 *pmtu = mtu;
995 err = -EMSGSIZE;
996 goto tx_err_dst_release;
997 }
998
999 /*
1000 * Okay, now see if we can stuff it in the buffer as-is.
1001 */
1002 max_headroom += LL_RESERVED_SPACE(tdev);
1003
1004 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1005 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1006 struct sk_buff *new_skb;
1007
1008 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1009 goto tx_err_dst_release;
1010
1011 if (skb->sk)
1012 skb_set_owner_w(new_skb, skb->sk);
1013 consume_skb(skb);
1014 skb = new_skb;
1015 }
1016 skb_dst_drop(skb);
1017 if (fl6->flowi6_mark) {
1018 skb_dst_set(skb, dst);
1019 ndst = NULL;
1020 } else {
1021 skb_dst_set_noref(skb, dst);
1022 }
1023 skb->transport_header = skb->network_header;
1024
1025 proto = fl6->flowi6_proto;
1026 if (encap_limit >= 0) {
1027 init_tel_txopt(&opt, encap_limit);
1028 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1029 }
1030 skb_push(skb, sizeof(struct ipv6hdr));
1031 skb_reset_network_header(skb);
1032 ipv6h = ipv6_hdr(skb);
1033 *(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000);
1034 dsfield = INET_ECN_encapsulate(0, dsfield);
1035 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
1036 ipv6h->hop_limit = t->parms.hop_limit;
1037 ipv6h->nexthdr = proto;
1038 ipv6h->saddr = fl6->saddr;
1039 ipv6h->daddr = fl6->daddr;
1040 nf_reset(skb);
1041 pkt_len = skb->len;
1042 err = ip6_local_out(skb);
1043
1044 if (net_xmit_eval(err) == 0) {
1045 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats);
1046
1047 tstats->tx_bytes += pkt_len;
1048 tstats->tx_packets++;
1049 } else {
1050 stats->tx_errors++;
1051 stats->tx_aborted_errors++;
1052 }
1053 if (ndst)
1054 ip6_tnl_dst_store(t, ndst);
1055 return 0;
1056 tx_err_link_failure:
1057 stats->tx_carrier_errors++;
1058 dst_link_failure(skb);
1059 tx_err_dst_release:
1060 dst_release(ndst);
1061 return err;
1062 }
1063
1064 static inline int
1065 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1066 {
1067 struct ip6_tnl *t = netdev_priv(dev);
1068 const struct iphdr *iph = ip_hdr(skb);
1069 int encap_limit = -1;
1070 struct flowi6 fl6;
1071 __u8 dsfield;
1072 __u32 mtu;
1073 int err;
1074
1075 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1076 !ip6_tnl_xmit_ctl(t))
1077 return -1;
1078
1079 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1080 encap_limit = t->parms.encap_limit;
1081
1082 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1083 fl6.flowi6_proto = IPPROTO_IPIP;
1084
1085 dsfield = ipv4_get_dsfield(iph);
1086
1087 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1088 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1089 & IPV6_TCLASS_MASK;
1090 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1091 fl6.flowi6_mark = skb->mark;
1092
1093 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1094 if (err != 0) {
1095 /* XXX: send ICMP error even if DF is not set. */
1096 if (err == -EMSGSIZE)
1097 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1098 htonl(mtu));
1099 return -1;
1100 }
1101
1102 return 0;
1103 }
1104
1105 static inline int
1106 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1107 {
1108 struct ip6_tnl *t = netdev_priv(dev);
1109 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1110 int encap_limit = -1;
1111 __u16 offset;
1112 struct flowi6 fl6;
1113 __u8 dsfield;
1114 __u32 mtu;
1115 int err;
1116
1117 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1118 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1119 return -1;
1120
1121 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1122 if (offset > 0) {
1123 struct ipv6_tlv_tnl_enc_lim *tel;
1124 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1125 if (tel->encap_limit == 0) {
1126 icmpv6_send(skb, ICMPV6_PARAMPROB,
1127 ICMPV6_HDR_FIELD, offset + 2);
1128 return -1;
1129 }
1130 encap_limit = tel->encap_limit - 1;
1131 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1132 encap_limit = t->parms.encap_limit;
1133
1134 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1135 fl6.flowi6_proto = IPPROTO_IPV6;
1136
1137 dsfield = ipv6_get_dsfield(ipv6h);
1138 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1139 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1140 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1141 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1142 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1143 fl6.flowi6_mark = skb->mark;
1144
1145 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1146 if (err != 0) {
1147 if (err == -EMSGSIZE)
1148 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1149 return -1;
1150 }
1151
1152 return 0;
1153 }
1154
1155 static netdev_tx_t
1156 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1157 {
1158 struct ip6_tnl *t = netdev_priv(dev);
1159 struct net_device_stats *stats = &t->dev->stats;
1160 int ret;
1161
1162 switch (skb->protocol) {
1163 case htons(ETH_P_IP):
1164 ret = ip4ip6_tnl_xmit(skb, dev);
1165 break;
1166 case htons(ETH_P_IPV6):
1167 ret = ip6ip6_tnl_xmit(skb, dev);
1168 break;
1169 default:
1170 goto tx_err;
1171 }
1172
1173 if (ret < 0)
1174 goto tx_err;
1175
1176 return NETDEV_TX_OK;
1177
1178 tx_err:
1179 stats->tx_errors++;
1180 stats->tx_dropped++;
1181 kfree_skb(skb);
1182 return NETDEV_TX_OK;
1183 }
1184
1185 static void ip6_tnl_link_config(struct ip6_tnl *t)
1186 {
1187 struct net_device *dev = t->dev;
1188 struct __ip6_tnl_parm *p = &t->parms;
1189 struct flowi6 *fl6 = &t->fl.u.ip6;
1190
1191 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1192 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1193
1194 /* Set up flowi template */
1195 fl6->saddr = p->laddr;
1196 fl6->daddr = p->raddr;
1197 fl6->flowi6_oif = p->link;
1198 fl6->flowlabel = 0;
1199
1200 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1201 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1202 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1203 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1204
1205 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1206 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1207
1208 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1209 dev->flags |= IFF_POINTOPOINT;
1210 else
1211 dev->flags &= ~IFF_POINTOPOINT;
1212
1213 dev->iflink = p->link;
1214
1215 if (p->flags & IP6_TNL_F_CAP_XMIT) {
1216 int strict = (ipv6_addr_type(&p->raddr) &
1217 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1218
1219 struct rt6_info *rt = rt6_lookup(dev_net(dev),
1220 &p->raddr, &p->laddr,
1221 p->link, strict);
1222
1223 if (rt == NULL)
1224 return;
1225
1226 if (rt->dst.dev) {
1227 dev->hard_header_len = rt->dst.dev->hard_header_len +
1228 sizeof (struct ipv6hdr);
1229
1230 dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1231 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1232 dev->mtu-=8;
1233
1234 if (dev->mtu < IPV6_MIN_MTU)
1235 dev->mtu = IPV6_MIN_MTU;
1236 }
1237 ip6_rt_put(rt);
1238 }
1239 }
1240
1241 /**
1242 * ip6_tnl_change - update the tunnel parameters
1243 * @t: tunnel to be changed
1244 * @p: tunnel configuration parameters
1245 *
1246 * Description:
1247 * ip6_tnl_change() updates the tunnel parameters
1248 **/
1249
1250 static int
1251 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1252 {
1253 t->parms.laddr = p->laddr;
1254 t->parms.raddr = p->raddr;
1255 t->parms.flags = p->flags;
1256 t->parms.hop_limit = p->hop_limit;
1257 t->parms.encap_limit = p->encap_limit;
1258 t->parms.flowinfo = p->flowinfo;
1259 t->parms.link = p->link;
1260 t->parms.proto = p->proto;
1261 ip6_tnl_dst_reset(t);
1262 ip6_tnl_link_config(t);
1263 return 0;
1264 }
1265
1266 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1267 {
1268 struct net *net = dev_net(t->dev);
1269 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1270 int err;
1271
1272 ip6_tnl_unlink(ip6n, t);
1273 synchronize_net();
1274 err = ip6_tnl_change(t, p);
1275 ip6_tnl_link(ip6n, t);
1276 netdev_state_change(t->dev);
1277 return err;
1278 }
1279
1280 static void
1281 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1282 {
1283 p->laddr = u->laddr;
1284 p->raddr = u->raddr;
1285 p->flags = u->flags;
1286 p->hop_limit = u->hop_limit;
1287 p->encap_limit = u->encap_limit;
1288 p->flowinfo = u->flowinfo;
1289 p->link = u->link;
1290 p->proto = u->proto;
1291 memcpy(p->name, u->name, sizeof(u->name));
1292 }
1293
1294 static void
1295 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1296 {
1297 u->laddr = p->laddr;
1298 u->raddr = p->raddr;
1299 u->flags = p->flags;
1300 u->hop_limit = p->hop_limit;
1301 u->encap_limit = p->encap_limit;
1302 u->flowinfo = p->flowinfo;
1303 u->link = p->link;
1304 u->proto = p->proto;
1305 memcpy(u->name, p->name, sizeof(u->name));
1306 }
1307
1308 /**
1309 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1310 * @dev: virtual device associated with tunnel
1311 * @ifr: parameters passed from userspace
1312 * @cmd: command to be performed
1313 *
1314 * Description:
1315 * ip6_tnl_ioctl() is used for managing IPv6 tunnels
1316 * from userspace.
1317 *
1318 * The possible commands are the following:
1319 * %SIOCGETTUNNEL: get tunnel parameters for device
1320 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1321 * %SIOCCHGTUNNEL: change tunnel parameters to those given
1322 * %SIOCDELTUNNEL: delete tunnel
1323 *
1324 * The fallback device "ip6tnl0", created during module
1325 * initialization, can be used for creating other tunnel devices.
1326 *
1327 * Return:
1328 * 0 on success,
1329 * %-EFAULT if unable to copy data to or from userspace,
1330 * %-EPERM if current process hasn't %CAP_NET_ADMIN set
1331 * %-EINVAL if passed tunnel parameters are invalid,
1332 * %-EEXIST if changing a tunnel's parameters would cause a conflict
1333 * %-ENODEV if attempting to change or delete a nonexisting device
1334 **/
1335
1336 static int
1337 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1338 {
1339 int err = 0;
1340 struct ip6_tnl_parm p;
1341 struct __ip6_tnl_parm p1;
1342 struct ip6_tnl *t = NULL;
1343 struct net *net = dev_net(dev);
1344 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1345
1346 switch (cmd) {
1347 case SIOCGETTUNNEL:
1348 if (dev == ip6n->fb_tnl_dev) {
1349 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1350 err = -EFAULT;
1351 break;
1352 }
1353 ip6_tnl_parm_from_user(&p1, &p);
1354 t = ip6_tnl_locate(net, &p1, 0);
1355 } else {
1356 memset(&p, 0, sizeof(p));
1357 }
1358 if (t == NULL)
1359 t = netdev_priv(dev);
1360 ip6_tnl_parm_to_user(&p, &t->parms);
1361 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1362 err = -EFAULT;
1363 }
1364 break;
1365 case SIOCADDTUNNEL:
1366 case SIOCCHGTUNNEL:
1367 err = -EPERM;
1368 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1369 break;
1370 err = -EFAULT;
1371 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1372 break;
1373 err = -EINVAL;
1374 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1375 p.proto != 0)
1376 break;
1377 ip6_tnl_parm_from_user(&p1, &p);
1378 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1379 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1380 if (t != NULL) {
1381 if (t->dev != dev) {
1382 err = -EEXIST;
1383 break;
1384 }
1385 } else
1386 t = netdev_priv(dev);
1387
1388 err = ip6_tnl_update(t, &p1);
1389 }
1390 if (t) {
1391 err = 0;
1392 ip6_tnl_parm_to_user(&p, &t->parms);
1393 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1394 err = -EFAULT;
1395
1396 } else
1397 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1398 break;
1399 case SIOCDELTUNNEL:
1400 err = -EPERM;
1401 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1402 break;
1403
1404 if (dev == ip6n->fb_tnl_dev) {
1405 err = -EFAULT;
1406 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1407 break;
1408 err = -ENOENT;
1409 ip6_tnl_parm_from_user(&p1, &p);
1410 t = ip6_tnl_locate(net, &p1, 0);
1411 if (t == NULL)
1412 break;
1413 err = -EPERM;
1414 if (t->dev == ip6n->fb_tnl_dev)
1415 break;
1416 dev = t->dev;
1417 }
1418 err = 0;
1419 unregister_netdevice(dev);
1420 break;
1421 default:
1422 err = -EINVAL;
1423 }
1424 return err;
1425 }
1426
1427 /**
1428 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1429 * @dev: virtual device associated with tunnel
1430 * @new_mtu: the new mtu
1431 *
1432 * Return:
1433 * 0 on success,
1434 * %-EINVAL if mtu too small
1435 **/
1436
1437 static int
1438 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1439 {
1440 if (new_mtu < IPV6_MIN_MTU) {
1441 return -EINVAL;
1442 }
1443 dev->mtu = new_mtu;
1444 return 0;
1445 }
1446
1447
1448 static const struct net_device_ops ip6_tnl_netdev_ops = {
1449 .ndo_uninit = ip6_tnl_dev_uninit,
1450 .ndo_start_xmit = ip6_tnl_xmit,
1451 .ndo_do_ioctl = ip6_tnl_ioctl,
1452 .ndo_change_mtu = ip6_tnl_change_mtu,
1453 .ndo_get_stats = ip6_get_stats,
1454 };
1455
1456
1457 /**
1458 * ip6_tnl_dev_setup - setup virtual tunnel device
1459 * @dev: virtual device associated with tunnel
1460 *
1461 * Description:
1462 * Initialize function pointers and device parameters
1463 **/
1464
1465 static void ip6_tnl_dev_setup(struct net_device *dev)
1466 {
1467 struct ip6_tnl *t;
1468
1469 dev->netdev_ops = &ip6_tnl_netdev_ops;
1470 dev->destructor = ip6_dev_free;
1471
1472 dev->type = ARPHRD_TUNNEL6;
1473 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1474 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1475 t = netdev_priv(dev);
1476 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1477 dev->mtu-=8;
1478 dev->flags |= IFF_NOARP;
1479 dev->addr_len = sizeof(struct in6_addr);
1480 dev->features |= NETIF_F_NETNS_LOCAL;
1481 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1482 }
1483
1484
1485 /**
1486 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1487 * @dev: virtual device associated with tunnel
1488 **/
1489
1490 static inline int
1491 ip6_tnl_dev_init_gen(struct net_device *dev)
1492 {
1493 struct ip6_tnl *t = netdev_priv(dev);
1494
1495 t->dev = dev;
1496 dev->tstats = alloc_percpu(struct pcpu_tstats);
1497 if (!dev->tstats)
1498 return -ENOMEM;
1499 return 0;
1500 }
1501
1502 /**
1503 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1504 * @dev: virtual device associated with tunnel
1505 **/
1506
1507 static int ip6_tnl_dev_init(struct net_device *dev)
1508 {
1509 struct ip6_tnl *t = netdev_priv(dev);
1510 int err = ip6_tnl_dev_init_gen(dev);
1511
1512 if (err)
1513 return err;
1514 ip6_tnl_link_config(t);
1515 return 0;
1516 }
1517
1518 /**
1519 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1520 * @dev: fallback device
1521 *
1522 * Return: 0
1523 **/
1524
1525 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1526 {
1527 struct ip6_tnl *t = netdev_priv(dev);
1528 struct net *net = dev_net(dev);
1529 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1530 int err = ip6_tnl_dev_init_gen(dev);
1531
1532 if (err)
1533 return err;
1534
1535 t->parms.proto = IPPROTO_IPV6;
1536 dev_hold(dev);
1537
1538 ip6_tnl_link_config(t);
1539
1540 rcu_assign_pointer(ip6n->tnls_wc[0], t);
1541 return 0;
1542 }
1543
1544 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1545 {
1546 u8 proto;
1547
1548 if (!data)
1549 return 0;
1550
1551 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1552 if (proto != IPPROTO_IPV6 &&
1553 proto != IPPROTO_IPIP &&
1554 proto != 0)
1555 return -EINVAL;
1556
1557 return 0;
1558 }
1559
1560 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1561 struct __ip6_tnl_parm *parms)
1562 {
1563 memset(parms, 0, sizeof(*parms));
1564
1565 if (!data)
1566 return;
1567
1568 if (data[IFLA_IPTUN_LINK])
1569 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1570
1571 if (data[IFLA_IPTUN_LOCAL])
1572 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1573 sizeof(struct in6_addr));
1574
1575 if (data[IFLA_IPTUN_REMOTE])
1576 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1577 sizeof(struct in6_addr));
1578
1579 if (data[IFLA_IPTUN_TTL])
1580 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1581
1582 if (data[IFLA_IPTUN_ENCAP_LIMIT])
1583 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1584
1585 if (data[IFLA_IPTUN_FLOWINFO])
1586 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1587
1588 if (data[IFLA_IPTUN_FLAGS])
1589 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1590
1591 if (data[IFLA_IPTUN_PROTO])
1592 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1593 }
1594
1595 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1596 struct nlattr *tb[], struct nlattr *data[])
1597 {
1598 struct net *net = dev_net(dev);
1599 struct ip6_tnl *nt;
1600
1601 nt = netdev_priv(dev);
1602 ip6_tnl_netlink_parms(data, &nt->parms);
1603
1604 if (ip6_tnl_locate(net, &nt->parms, 0))
1605 return -EEXIST;
1606
1607 return ip6_tnl_create2(dev);
1608 }
1609
1610 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1611 struct nlattr *data[])
1612 {
1613 struct ip6_tnl *t;
1614 struct __ip6_tnl_parm p;
1615 struct net *net = dev_net(dev);
1616 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1617
1618 if (dev == ip6n->fb_tnl_dev)
1619 return -EINVAL;
1620
1621 ip6_tnl_netlink_parms(data, &p);
1622
1623 t = ip6_tnl_locate(net, &p, 0);
1624
1625 if (t) {
1626 if (t->dev != dev)
1627 return -EEXIST;
1628 } else
1629 t = netdev_priv(dev);
1630
1631 return ip6_tnl_update(t, &p);
1632 }
1633
1634 static size_t ip6_tnl_get_size(const struct net_device *dev)
1635 {
1636 return
1637 /* IFLA_IPTUN_LINK */
1638 nla_total_size(4) +
1639 /* IFLA_IPTUN_LOCAL */
1640 nla_total_size(sizeof(struct in6_addr)) +
1641 /* IFLA_IPTUN_REMOTE */
1642 nla_total_size(sizeof(struct in6_addr)) +
1643 /* IFLA_IPTUN_TTL */
1644 nla_total_size(1) +
1645 /* IFLA_IPTUN_ENCAP_LIMIT */
1646 nla_total_size(1) +
1647 /* IFLA_IPTUN_FLOWINFO */
1648 nla_total_size(4) +
1649 /* IFLA_IPTUN_FLAGS */
1650 nla_total_size(4) +
1651 /* IFLA_IPTUN_PROTO */
1652 nla_total_size(1) +
1653 0;
1654 }
1655
1656 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1657 {
1658 struct ip6_tnl *tunnel = netdev_priv(dev);
1659 struct __ip6_tnl_parm *parm = &tunnel->parms;
1660
1661 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1662 nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1663 &parm->raddr) ||
1664 nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1665 &parm->laddr) ||
1666 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1667 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1668 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1669 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1670 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1671 goto nla_put_failure;
1672 return 0;
1673
1674 nla_put_failure:
1675 return -EMSGSIZE;
1676 }
1677
1678 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1679 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1680 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) },
1681 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) },
1682 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1683 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 },
1684 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 },
1685 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 },
1686 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1687 };
1688
1689 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1690 .kind = "ip6tnl",
1691 .maxtype = IFLA_IPTUN_MAX,
1692 .policy = ip6_tnl_policy,
1693 .priv_size = sizeof(struct ip6_tnl),
1694 .setup = ip6_tnl_dev_setup,
1695 .validate = ip6_tnl_validate,
1696 .newlink = ip6_tnl_newlink,
1697 .changelink = ip6_tnl_changelink,
1698 .get_size = ip6_tnl_get_size,
1699 .fill_info = ip6_tnl_fill_info,
1700 };
1701
1702 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1703 .handler = ip4ip6_rcv,
1704 .err_handler = ip4ip6_err,
1705 .priority = 1,
1706 };
1707
1708 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1709 .handler = ip6ip6_rcv,
1710 .err_handler = ip6ip6_err,
1711 .priority = 1,
1712 };
1713
1714 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
1715 {
1716 int h;
1717 struct ip6_tnl *t;
1718 LIST_HEAD(list);
1719
1720 for (h = 0; h < HASH_SIZE; h++) {
1721 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1722 while (t != NULL) {
1723 unregister_netdevice_queue(t->dev, &list);
1724 t = rtnl_dereference(t->next);
1725 }
1726 }
1727
1728 t = rtnl_dereference(ip6n->tnls_wc[0]);
1729 unregister_netdevice_queue(t->dev, &list);
1730 unregister_netdevice_many(&list);
1731 }
1732
1733 static int __net_init ip6_tnl_init_net(struct net *net)
1734 {
1735 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1736 struct ip6_tnl *t = NULL;
1737 int err;
1738
1739 ip6n->tnls[0] = ip6n->tnls_wc;
1740 ip6n->tnls[1] = ip6n->tnls_r_l;
1741
1742 err = -ENOMEM;
1743 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1744 ip6_tnl_dev_setup);
1745
1746 if (!ip6n->fb_tnl_dev)
1747 goto err_alloc_dev;
1748 dev_net_set(ip6n->fb_tnl_dev, net);
1749
1750 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1751 if (err < 0)
1752 goto err_register;
1753
1754 err = register_netdev(ip6n->fb_tnl_dev);
1755 if (err < 0)
1756 goto err_register;
1757
1758 t = netdev_priv(ip6n->fb_tnl_dev);
1759
1760 strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1761 return 0;
1762
1763 err_register:
1764 ip6_dev_free(ip6n->fb_tnl_dev);
1765 err_alloc_dev:
1766 return err;
1767 }
1768
1769 static void __net_exit ip6_tnl_exit_net(struct net *net)
1770 {
1771 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1772
1773 rtnl_lock();
1774 ip6_tnl_destroy_tunnels(ip6n);
1775 rtnl_unlock();
1776 }
1777
1778 static struct pernet_operations ip6_tnl_net_ops = {
1779 .init = ip6_tnl_init_net,
1780 .exit = ip6_tnl_exit_net,
1781 .id = &ip6_tnl_net_id,
1782 .size = sizeof(struct ip6_tnl_net),
1783 };
1784
1785 /**
1786 * ip6_tunnel_init - register protocol and reserve needed resources
1787 *
1788 * Return: 0 on success
1789 **/
1790
1791 static int __init ip6_tunnel_init(void)
1792 {
1793 int err;
1794
1795 err = register_pernet_device(&ip6_tnl_net_ops);
1796 if (err < 0)
1797 goto out_pernet;
1798
1799 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1800 if (err < 0) {
1801 pr_err("%s: can't register ip4ip6\n", __func__);
1802 goto out_ip4ip6;
1803 }
1804
1805 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1806 if (err < 0) {
1807 pr_err("%s: can't register ip6ip6\n", __func__);
1808 goto out_ip6ip6;
1809 }
1810 err = rtnl_link_register(&ip6_link_ops);
1811 if (err < 0)
1812 goto rtnl_link_failed;
1813
1814 return 0;
1815
1816 rtnl_link_failed:
1817 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1818 out_ip6ip6:
1819 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1820 out_ip4ip6:
1821 unregister_pernet_device(&ip6_tnl_net_ops);
1822 out_pernet:
1823 return err;
1824 }
1825
1826 /**
1827 * ip6_tunnel_cleanup - free resources and unregister protocol
1828 **/
1829
1830 static void __exit ip6_tunnel_cleanup(void)
1831 {
1832 rtnl_link_unregister(&ip6_link_ops);
1833 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1834 pr_info("%s: can't deregister ip4ip6\n", __func__);
1835
1836 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1837 pr_info("%s: can't deregister ip6ip6\n", __func__);
1838
1839 unregister_pernet_device(&ip6_tnl_net_ops);
1840 }
1841
1842 module_init(ip6_tunnel_init);
1843 module_exit(ip6_tunnel_cleanup);
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