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Merge branch 'for-linville' of git://github.com/kvalo/ath
[deliverable/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 #ifdef IP6_TNL_DEBUG
68 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
69 #else
70 #define IP6_TNL_TRACE(x...) do {;} while(0)
71 #endif
72
73 #define HASH_SIZE_SHIFT 5
74 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
75
76 static bool log_ecn_error = true;
77 module_param(log_ecn_error, bool, 0644);
78 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
79
80 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
81 {
82 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
83
84 return hash_32(hash, HASH_SIZE_SHIFT);
85 }
86
87 static int ip6_tnl_dev_init(struct net_device *dev);
88 static void ip6_tnl_dev_setup(struct net_device *dev);
89 static struct rtnl_link_ops ip6_link_ops __read_mostly;
90
91 static int ip6_tnl_net_id __read_mostly;
92 struct ip6_tnl_net {
93 /* the IPv6 tunnel fallback device */
94 struct net_device *fb_tnl_dev;
95 /* lists for storing tunnels in use */
96 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
97 struct ip6_tnl __rcu *tnls_wc[1];
98 struct ip6_tnl __rcu **tnls[2];
99 };
100
101 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
102 {
103 struct pcpu_sw_netstats tmp, sum = { 0 };
104 int i;
105
106 for_each_possible_cpu(i) {
107 unsigned int start;
108 const struct pcpu_sw_netstats *tstats =
109 per_cpu_ptr(dev->tstats, i);
110
111 do {
112 start = u64_stats_fetch_begin_irq(&tstats->syncp);
113 tmp.rx_packets = tstats->rx_packets;
114 tmp.rx_bytes = tstats->rx_bytes;
115 tmp.tx_packets = tstats->tx_packets;
116 tmp.tx_bytes = tstats->tx_bytes;
117 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
118
119 sum.rx_packets += tmp.rx_packets;
120 sum.rx_bytes += tmp.rx_bytes;
121 sum.tx_packets += tmp.tx_packets;
122 sum.tx_bytes += tmp.tx_bytes;
123 }
124 dev->stats.rx_packets = sum.rx_packets;
125 dev->stats.rx_bytes = sum.rx_bytes;
126 dev->stats.tx_packets = sum.tx_packets;
127 dev->stats.tx_bytes = sum.tx_bytes;
128 return &dev->stats;
129 }
130
131 /*
132 * Locking : hash tables are protected by RCU and RTNL
133 */
134
135 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
136 {
137 struct dst_entry *dst = t->dst_cache;
138
139 if (dst && dst->obsolete &&
140 dst->ops->check(dst, t->dst_cookie) == NULL) {
141 t->dst_cache = NULL;
142 dst_release(dst);
143 return NULL;
144 }
145
146 return dst;
147 }
148 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
149
150 void ip6_tnl_dst_reset(struct ip6_tnl *t)
151 {
152 dst_release(t->dst_cache);
153 t->dst_cache = NULL;
154 }
155 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
156
157 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
158 {
159 struct rt6_info *rt = (struct rt6_info *) dst;
160 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
161 dst_release(t->dst_cache);
162 t->dst_cache = dst;
163 }
164 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
165
166 /**
167 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
168 * @remote: the address of the tunnel exit-point
169 * @local: the address of the tunnel entry-point
170 *
171 * Return:
172 * tunnel matching given end-points if found,
173 * else fallback tunnel if its device is up,
174 * else %NULL
175 **/
176
177 #define for_each_ip6_tunnel_rcu(start) \
178 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
179
180 static struct ip6_tnl *
181 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
182 {
183 unsigned int hash = HASH(remote, local);
184 struct ip6_tnl *t;
185 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
186
187 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
188 if (ipv6_addr_equal(local, &t->parms.laddr) &&
189 ipv6_addr_equal(remote, &t->parms.raddr) &&
190 (t->dev->flags & IFF_UP))
191 return t;
192 }
193 t = rcu_dereference(ip6n->tnls_wc[0]);
194 if (t && (t->dev->flags & IFF_UP))
195 return t;
196
197 return NULL;
198 }
199
200 /**
201 * ip6_tnl_bucket - get head of list matching given tunnel parameters
202 * @p: parameters containing tunnel end-points
203 *
204 * Description:
205 * ip6_tnl_bucket() returns the head of the list matching the
206 * &struct in6_addr entries laddr and raddr in @p.
207 *
208 * Return: head of IPv6 tunnel list
209 **/
210
211 static struct ip6_tnl __rcu **
212 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
213 {
214 const struct in6_addr *remote = &p->raddr;
215 const struct in6_addr *local = &p->laddr;
216 unsigned int h = 0;
217 int prio = 0;
218
219 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
220 prio = 1;
221 h = HASH(remote, local);
222 }
223 return &ip6n->tnls[prio][h];
224 }
225
226 /**
227 * ip6_tnl_link - add tunnel to hash table
228 * @t: tunnel to be added
229 **/
230
231 static void
232 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
233 {
234 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
235
236 rcu_assign_pointer(t->next , rtnl_dereference(*tp));
237 rcu_assign_pointer(*tp, t);
238 }
239
240 /**
241 * ip6_tnl_unlink - remove tunnel from hash table
242 * @t: tunnel to be removed
243 **/
244
245 static void
246 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
247 {
248 struct ip6_tnl __rcu **tp;
249 struct ip6_tnl *iter;
250
251 for (tp = ip6_tnl_bucket(ip6n, &t->parms);
252 (iter = rtnl_dereference(*tp)) != NULL;
253 tp = &iter->next) {
254 if (t == iter) {
255 rcu_assign_pointer(*tp, t->next);
256 break;
257 }
258 }
259 }
260
261 static void ip6_dev_free(struct net_device *dev)
262 {
263 free_percpu(dev->tstats);
264 free_netdev(dev);
265 }
266
267 static int ip6_tnl_create2(struct net_device *dev)
268 {
269 struct ip6_tnl *t = netdev_priv(dev);
270 struct net *net = dev_net(dev);
271 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
272 int err;
273
274 t = netdev_priv(dev);
275 err = ip6_tnl_dev_init(dev);
276 if (err < 0)
277 goto out;
278
279 err = register_netdevice(dev);
280 if (err < 0)
281 goto out;
282
283 strcpy(t->parms.name, dev->name);
284 dev->rtnl_link_ops = &ip6_link_ops;
285
286 dev_hold(dev);
287 ip6_tnl_link(ip6n, t);
288 return 0;
289
290 out:
291 return err;
292 }
293
294 /**
295 * ip6_tnl_create - create a new tunnel
296 * @p: tunnel parameters
297 * @pt: pointer to new tunnel
298 *
299 * Description:
300 * Create tunnel matching given parameters.
301 *
302 * Return:
303 * created tunnel or NULL
304 **/
305
306 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
307 {
308 struct net_device *dev;
309 struct ip6_tnl *t;
310 char name[IFNAMSIZ];
311 int err;
312
313 if (p->name[0])
314 strlcpy(name, p->name, IFNAMSIZ);
315 else
316 sprintf(name, "ip6tnl%%d");
317
318 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
319 ip6_tnl_dev_setup);
320 if (dev == NULL)
321 goto failed;
322
323 dev_net_set(dev, net);
324
325 t = netdev_priv(dev);
326 t->parms = *p;
327 t->net = dev_net(dev);
328 err = ip6_tnl_create2(dev);
329 if (err < 0)
330 goto failed_free;
331
332 return t;
333
334 failed_free:
335 ip6_dev_free(dev);
336 failed:
337 return NULL;
338 }
339
340 /**
341 * ip6_tnl_locate - find or create tunnel matching given parameters
342 * @p: tunnel parameters
343 * @create: != 0 if allowed to create new tunnel if no match found
344 *
345 * Description:
346 * ip6_tnl_locate() first tries to locate an existing tunnel
347 * based on @parms. If this is unsuccessful, but @create is set a new
348 * tunnel device is created and registered for use.
349 *
350 * Return:
351 * matching tunnel or NULL
352 **/
353
354 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
355 struct __ip6_tnl_parm *p, int create)
356 {
357 const struct in6_addr *remote = &p->raddr;
358 const struct in6_addr *local = &p->laddr;
359 struct ip6_tnl __rcu **tp;
360 struct ip6_tnl *t;
361 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
362
363 for (tp = ip6_tnl_bucket(ip6n, p);
364 (t = rtnl_dereference(*tp)) != NULL;
365 tp = &t->next) {
366 if (ipv6_addr_equal(local, &t->parms.laddr) &&
367 ipv6_addr_equal(remote, &t->parms.raddr)) {
368 if (create)
369 return NULL;
370
371 return t;
372 }
373 }
374 if (!create)
375 return NULL;
376 return ip6_tnl_create(net, p);
377 }
378
379 /**
380 * ip6_tnl_dev_uninit - tunnel device uninitializer
381 * @dev: the device to be destroyed
382 *
383 * Description:
384 * ip6_tnl_dev_uninit() removes tunnel from its list
385 **/
386
387 static void
388 ip6_tnl_dev_uninit(struct net_device *dev)
389 {
390 struct ip6_tnl *t = netdev_priv(dev);
391 struct net *net = t->net;
392 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
393
394 if (dev == ip6n->fb_tnl_dev)
395 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
396 else
397 ip6_tnl_unlink(ip6n, t);
398 ip6_tnl_dst_reset(t);
399 dev_put(dev);
400 }
401
402 /**
403 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
404 * @skb: received socket buffer
405 *
406 * Return:
407 * 0 if none was found,
408 * else index to encapsulation limit
409 **/
410
411 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
412 {
413 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
414 __u8 nexthdr = ipv6h->nexthdr;
415 __u16 off = sizeof(*ipv6h);
416
417 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
418 __u16 optlen = 0;
419 struct ipv6_opt_hdr *hdr;
420 if (raw + off + sizeof(*hdr) > skb->data &&
421 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
422 break;
423
424 hdr = (struct ipv6_opt_hdr *) (raw + off);
425 if (nexthdr == NEXTHDR_FRAGMENT) {
426 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
427 if (frag_hdr->frag_off)
428 break;
429 optlen = 8;
430 } else if (nexthdr == NEXTHDR_AUTH) {
431 optlen = (hdr->hdrlen + 2) << 2;
432 } else {
433 optlen = ipv6_optlen(hdr);
434 }
435 if (nexthdr == NEXTHDR_DEST) {
436 __u16 i = off + 2;
437 while (1) {
438 struct ipv6_tlv_tnl_enc_lim *tel;
439
440 /* No more room for encapsulation limit */
441 if (i + sizeof (*tel) > off + optlen)
442 break;
443
444 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
445 /* return index of option if found and valid */
446 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
447 tel->length == 1)
448 return i;
449 /* else jump to next option */
450 if (tel->type)
451 i += tel->length + 2;
452 else
453 i++;
454 }
455 }
456 nexthdr = hdr->nexthdr;
457 off += optlen;
458 }
459 return 0;
460 }
461 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
462
463 /**
464 * ip6_tnl_err - tunnel error handler
465 *
466 * Description:
467 * ip6_tnl_err() should handle errors in the tunnel according
468 * to the specifications in RFC 2473.
469 **/
470
471 static int
472 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
473 u8 *type, u8 *code, int *msg, __u32 *info, int offset)
474 {
475 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
476 struct ip6_tnl *t;
477 int rel_msg = 0;
478 u8 rel_type = ICMPV6_DEST_UNREACH;
479 u8 rel_code = ICMPV6_ADDR_UNREACH;
480 __u32 rel_info = 0;
481 __u16 len;
482 int err = -ENOENT;
483
484 /* If the packet doesn't contain the original IPv6 header we are
485 in trouble since we might need the source address for further
486 processing of the error. */
487
488 rcu_read_lock();
489 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
490 &ipv6h->saddr)) == NULL)
491 goto out;
492
493 if (t->parms.proto != ipproto && t->parms.proto != 0)
494 goto out;
495
496 err = 0;
497
498 switch (*type) {
499 __u32 teli;
500 struct ipv6_tlv_tnl_enc_lim *tel;
501 __u32 mtu;
502 case ICMPV6_DEST_UNREACH:
503 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
504 t->parms.name);
505 rel_msg = 1;
506 break;
507 case ICMPV6_TIME_EXCEED:
508 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
509 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
510 t->parms.name);
511 rel_msg = 1;
512 }
513 break;
514 case ICMPV6_PARAMPROB:
515 teli = 0;
516 if ((*code) == ICMPV6_HDR_FIELD)
517 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
518
519 if (teli && teli == *info - 2) {
520 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
521 if (tel->encap_limit == 0) {
522 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
523 t->parms.name);
524 rel_msg = 1;
525 }
526 } else {
527 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
528 t->parms.name);
529 }
530 break;
531 case ICMPV6_PKT_TOOBIG:
532 mtu = *info - offset;
533 if (mtu < IPV6_MIN_MTU)
534 mtu = IPV6_MIN_MTU;
535 t->dev->mtu = mtu;
536
537 if ((len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
538 rel_type = ICMPV6_PKT_TOOBIG;
539 rel_code = 0;
540 rel_info = mtu;
541 rel_msg = 1;
542 }
543 break;
544 }
545
546 *type = rel_type;
547 *code = rel_code;
548 *info = rel_info;
549 *msg = rel_msg;
550
551 out:
552 rcu_read_unlock();
553 return err;
554 }
555
556 static int
557 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
558 u8 type, u8 code, int offset, __be32 info)
559 {
560 int rel_msg = 0;
561 u8 rel_type = type;
562 u8 rel_code = code;
563 __u32 rel_info = ntohl(info);
564 int err;
565 struct sk_buff *skb2;
566 const struct iphdr *eiph;
567 struct rtable *rt;
568 struct flowi4 fl4;
569
570 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
571 &rel_msg, &rel_info, offset);
572 if (err < 0)
573 return err;
574
575 if (rel_msg == 0)
576 return 0;
577
578 switch (rel_type) {
579 case ICMPV6_DEST_UNREACH:
580 if (rel_code != ICMPV6_ADDR_UNREACH)
581 return 0;
582 rel_type = ICMP_DEST_UNREACH;
583 rel_code = ICMP_HOST_UNREACH;
584 break;
585 case ICMPV6_PKT_TOOBIG:
586 if (rel_code != 0)
587 return 0;
588 rel_type = ICMP_DEST_UNREACH;
589 rel_code = ICMP_FRAG_NEEDED;
590 break;
591 case NDISC_REDIRECT:
592 rel_type = ICMP_REDIRECT;
593 rel_code = ICMP_REDIR_HOST;
594 default:
595 return 0;
596 }
597
598 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
599 return 0;
600
601 skb2 = skb_clone(skb, GFP_ATOMIC);
602 if (!skb2)
603 return 0;
604
605 skb_dst_drop(skb2);
606
607 skb_pull(skb2, offset);
608 skb_reset_network_header(skb2);
609 eiph = ip_hdr(skb2);
610
611 /* Try to guess incoming interface */
612 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
613 eiph->saddr, 0,
614 0, 0,
615 IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
616 if (IS_ERR(rt))
617 goto out;
618
619 skb2->dev = rt->dst.dev;
620
621 /* route "incoming" packet */
622 if (rt->rt_flags & RTCF_LOCAL) {
623 ip_rt_put(rt);
624 rt = NULL;
625 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
626 eiph->daddr, eiph->saddr,
627 0, 0,
628 IPPROTO_IPIP,
629 RT_TOS(eiph->tos), 0);
630 if (IS_ERR(rt) ||
631 rt->dst.dev->type != ARPHRD_TUNNEL) {
632 if (!IS_ERR(rt))
633 ip_rt_put(rt);
634 goto out;
635 }
636 skb_dst_set(skb2, &rt->dst);
637 } else {
638 ip_rt_put(rt);
639 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
640 skb2->dev) ||
641 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
642 goto out;
643 }
644
645 /* change mtu on this route */
646 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
647 if (rel_info > dst_mtu(skb_dst(skb2)))
648 goto out;
649
650 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
651 }
652 if (rel_type == ICMP_REDIRECT)
653 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
654
655 icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
656
657 out:
658 kfree_skb(skb2);
659 return 0;
660 }
661
662 static int
663 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
664 u8 type, u8 code, int offset, __be32 info)
665 {
666 int rel_msg = 0;
667 u8 rel_type = type;
668 u8 rel_code = code;
669 __u32 rel_info = ntohl(info);
670 int err;
671
672 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
673 &rel_msg, &rel_info, offset);
674 if (err < 0)
675 return err;
676
677 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
678 struct rt6_info *rt;
679 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
680
681 if (!skb2)
682 return 0;
683
684 skb_dst_drop(skb2);
685 skb_pull(skb2, offset);
686 skb_reset_network_header(skb2);
687
688 /* Try to guess incoming interface */
689 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
690 NULL, 0, 0);
691
692 if (rt && rt->dst.dev)
693 skb2->dev = rt->dst.dev;
694
695 icmpv6_send(skb2, rel_type, rel_code, rel_info);
696
697 ip6_rt_put(rt);
698
699 kfree_skb(skb2);
700 }
701
702 return 0;
703 }
704
705 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
706 const struct ipv6hdr *ipv6h,
707 struct sk_buff *skb)
708 {
709 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
710
711 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
712 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
713
714 return IP6_ECN_decapsulate(ipv6h, skb);
715 }
716
717 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
718 const struct ipv6hdr *ipv6h,
719 struct sk_buff *skb)
720 {
721 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
722 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
723
724 return IP6_ECN_decapsulate(ipv6h, skb);
725 }
726
727 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
728 const struct in6_addr *laddr,
729 const struct in6_addr *raddr)
730 {
731 struct __ip6_tnl_parm *p = &t->parms;
732 int ltype = ipv6_addr_type(laddr);
733 int rtype = ipv6_addr_type(raddr);
734 __u32 flags = 0;
735
736 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
737 flags = IP6_TNL_F_CAP_PER_PACKET;
738 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
739 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
740 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
741 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
742 if (ltype&IPV6_ADDR_UNICAST)
743 flags |= IP6_TNL_F_CAP_XMIT;
744 if (rtype&IPV6_ADDR_UNICAST)
745 flags |= IP6_TNL_F_CAP_RCV;
746 }
747 return flags;
748 }
749 EXPORT_SYMBOL(ip6_tnl_get_cap);
750
751 /* called with rcu_read_lock() */
752 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
753 const struct in6_addr *laddr,
754 const struct in6_addr *raddr)
755 {
756 struct __ip6_tnl_parm *p = &t->parms;
757 int ret = 0;
758 struct net *net = t->net;
759
760 if ((p->flags & IP6_TNL_F_CAP_RCV) ||
761 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
762 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
763 struct net_device *ldev = NULL;
764
765 if (p->link)
766 ldev = dev_get_by_index_rcu(net, p->link);
767
768 if ((ipv6_addr_is_multicast(laddr) ||
769 likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
770 likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
771 ret = 1;
772 }
773 return ret;
774 }
775 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
776
777 /**
778 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
779 * @skb: received socket buffer
780 * @protocol: ethernet protocol ID
781 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
782 *
783 * Return: 0
784 **/
785
786 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
787 __u8 ipproto,
788 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
789 const struct ipv6hdr *ipv6h,
790 struct sk_buff *skb))
791 {
792 struct ip6_tnl *t;
793 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
794 int err;
795
796 rcu_read_lock();
797
798 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
799 &ipv6h->daddr)) != NULL) {
800 struct pcpu_sw_netstats *tstats;
801
802 if (t->parms.proto != ipproto && t->parms.proto != 0) {
803 rcu_read_unlock();
804 goto discard;
805 }
806
807 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
808 rcu_read_unlock();
809 goto discard;
810 }
811
812 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
813 t->dev->stats.rx_dropped++;
814 rcu_read_unlock();
815 goto discard;
816 }
817 skb->mac_header = skb->network_header;
818 skb_reset_network_header(skb);
819 skb->protocol = htons(protocol);
820 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
821
822 __skb_tunnel_rx(skb, t->dev, t->net);
823
824 err = dscp_ecn_decapsulate(t, ipv6h, skb);
825 if (unlikely(err)) {
826 if (log_ecn_error)
827 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
828 &ipv6h->saddr,
829 ipv6_get_dsfield(ipv6h));
830 if (err > 1) {
831 ++t->dev->stats.rx_frame_errors;
832 ++t->dev->stats.rx_errors;
833 rcu_read_unlock();
834 goto discard;
835 }
836 }
837
838 tstats = this_cpu_ptr(t->dev->tstats);
839 u64_stats_update_begin(&tstats->syncp);
840 tstats->rx_packets++;
841 tstats->rx_bytes += skb->len;
842 u64_stats_update_end(&tstats->syncp);
843
844 netif_rx(skb);
845
846 rcu_read_unlock();
847 return 0;
848 }
849 rcu_read_unlock();
850 return 1;
851
852 discard:
853 kfree_skb(skb);
854 return 0;
855 }
856
857 static int ip4ip6_rcv(struct sk_buff *skb)
858 {
859 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
860 ip4ip6_dscp_ecn_decapsulate);
861 }
862
863 static int ip6ip6_rcv(struct sk_buff *skb)
864 {
865 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
866 ip6ip6_dscp_ecn_decapsulate);
867 }
868
869 struct ipv6_tel_txoption {
870 struct ipv6_txoptions ops;
871 __u8 dst_opt[8];
872 };
873
874 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
875 {
876 memset(opt, 0, sizeof(struct ipv6_tel_txoption));
877
878 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
879 opt->dst_opt[3] = 1;
880 opt->dst_opt[4] = encap_limit;
881 opt->dst_opt[5] = IPV6_TLV_PADN;
882 opt->dst_opt[6] = 1;
883
884 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
885 opt->ops.opt_nflen = 8;
886 }
887
888 /**
889 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
890 * @t: the outgoing tunnel device
891 * @hdr: IPv6 header from the incoming packet
892 *
893 * Description:
894 * Avoid trivial tunneling loop by checking that tunnel exit-point
895 * doesn't match source of incoming packet.
896 *
897 * Return:
898 * 1 if conflict,
899 * 0 else
900 **/
901
902 static inline bool
903 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
904 {
905 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
906 }
907
908 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
909 {
910 struct __ip6_tnl_parm *p = &t->parms;
911 int ret = 0;
912 struct net *net = t->net;
913
914 if (p->flags & IP6_TNL_F_CAP_XMIT) {
915 struct net_device *ldev = NULL;
916
917 rcu_read_lock();
918 if (p->link)
919 ldev = dev_get_by_index_rcu(net, p->link);
920
921 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
922 pr_warn("%s xmit: Local address not yet configured!\n",
923 p->name);
924 else if (!ipv6_addr_is_multicast(&p->raddr) &&
925 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
926 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
927 p->name);
928 else
929 ret = 1;
930 rcu_read_unlock();
931 }
932 return ret;
933 }
934 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
935
936 /**
937 * ip6_tnl_xmit2 - encapsulate packet and send
938 * @skb: the outgoing socket buffer
939 * @dev: the outgoing tunnel device
940 * @dsfield: dscp code for outer header
941 * @fl: flow of tunneled packet
942 * @encap_limit: encapsulation limit
943 * @pmtu: Path MTU is stored if packet is too big
944 *
945 * Description:
946 * Build new header and do some sanity checks on the packet before sending
947 * it.
948 *
949 * Return:
950 * 0 on success
951 * -1 fail
952 * %-EMSGSIZE message too big. return mtu in this case.
953 **/
954
955 static int ip6_tnl_xmit2(struct sk_buff *skb,
956 struct net_device *dev,
957 __u8 dsfield,
958 struct flowi6 *fl6,
959 int encap_limit,
960 __u32 *pmtu)
961 {
962 struct ip6_tnl *t = netdev_priv(dev);
963 struct net *net = t->net;
964 struct net_device_stats *stats = &t->dev->stats;
965 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
966 struct ipv6_tel_txoption opt;
967 struct dst_entry *dst = NULL, *ndst = NULL;
968 struct net_device *tdev;
969 int mtu;
970 unsigned int max_headroom = sizeof(struct ipv6hdr);
971 u8 proto;
972 int err = -1;
973
974 if (!fl6->flowi6_mark)
975 dst = ip6_tnl_dst_check(t);
976 if (!dst) {
977 ndst = ip6_route_output(net, NULL, fl6);
978
979 if (ndst->error)
980 goto tx_err_link_failure;
981 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
982 if (IS_ERR(ndst)) {
983 err = PTR_ERR(ndst);
984 ndst = NULL;
985 goto tx_err_link_failure;
986 }
987 dst = ndst;
988 }
989
990 tdev = dst->dev;
991
992 if (tdev == dev) {
993 stats->collisions++;
994 net_warn_ratelimited("%s: Local routing loop detected!\n",
995 t->parms.name);
996 goto tx_err_dst_release;
997 }
998 mtu = dst_mtu(dst) - sizeof(*ipv6h);
999 if (encap_limit >= 0) {
1000 max_headroom += 8;
1001 mtu -= 8;
1002 }
1003 if (mtu < IPV6_MIN_MTU)
1004 mtu = IPV6_MIN_MTU;
1005 if (skb_dst(skb))
1006 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1007 if (skb->len > mtu) {
1008 *pmtu = mtu;
1009 err = -EMSGSIZE;
1010 goto tx_err_dst_release;
1011 }
1012
1013 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1014
1015 /*
1016 * Okay, now see if we can stuff it in the buffer as-is.
1017 */
1018 max_headroom += LL_RESERVED_SPACE(tdev);
1019
1020 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1021 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1022 struct sk_buff *new_skb;
1023
1024 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1025 goto tx_err_dst_release;
1026
1027 if (skb->sk)
1028 skb_set_owner_w(new_skb, skb->sk);
1029 consume_skb(skb);
1030 skb = new_skb;
1031 }
1032 if (fl6->flowi6_mark) {
1033 skb_dst_set(skb, dst);
1034 ndst = NULL;
1035 } else {
1036 skb_dst_set_noref(skb, dst);
1037 }
1038 skb->transport_header = skb->network_header;
1039
1040 proto = fl6->flowi6_proto;
1041 if (encap_limit >= 0) {
1042 init_tel_txopt(&opt, encap_limit);
1043 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1044 }
1045
1046 if (likely(!skb->encapsulation)) {
1047 skb_reset_inner_headers(skb);
1048 skb->encapsulation = 1;
1049 }
1050
1051 skb_push(skb, sizeof(struct ipv6hdr));
1052 skb_reset_network_header(skb);
1053 ipv6h = ipv6_hdr(skb);
1054 ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1055 ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
1056 ipv6h->hop_limit = t->parms.hop_limit;
1057 ipv6h->nexthdr = proto;
1058 ipv6h->saddr = fl6->saddr;
1059 ipv6h->daddr = fl6->daddr;
1060 ip6tunnel_xmit(skb, dev);
1061 if (ndst)
1062 ip6_tnl_dst_store(t, ndst);
1063 return 0;
1064 tx_err_link_failure:
1065 stats->tx_carrier_errors++;
1066 dst_link_failure(skb);
1067 tx_err_dst_release:
1068 dst_release(ndst);
1069 return err;
1070 }
1071
1072 static inline int
1073 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1074 {
1075 struct ip6_tnl *t = netdev_priv(dev);
1076 const struct iphdr *iph = ip_hdr(skb);
1077 int encap_limit = -1;
1078 struct flowi6 fl6;
1079 __u8 dsfield;
1080 __u32 mtu;
1081 int err;
1082
1083 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1084 !ip6_tnl_xmit_ctl(t))
1085 return -1;
1086
1087 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1088 encap_limit = t->parms.encap_limit;
1089
1090 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1091 fl6.flowi6_proto = IPPROTO_IPIP;
1092
1093 dsfield = ipv4_get_dsfield(iph);
1094
1095 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1096 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1097 & IPV6_TCLASS_MASK;
1098 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1099 fl6.flowi6_mark = skb->mark;
1100
1101 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1102 if (err != 0) {
1103 /* XXX: send ICMP error even if DF is not set. */
1104 if (err == -EMSGSIZE)
1105 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1106 htonl(mtu));
1107 return -1;
1108 }
1109
1110 return 0;
1111 }
1112
1113 static inline int
1114 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1115 {
1116 struct ip6_tnl *t = netdev_priv(dev);
1117 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1118 int encap_limit = -1;
1119 __u16 offset;
1120 struct flowi6 fl6;
1121 __u8 dsfield;
1122 __u32 mtu;
1123 int err;
1124
1125 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1126 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1127 return -1;
1128
1129 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1130 if (offset > 0) {
1131 struct ipv6_tlv_tnl_enc_lim *tel;
1132 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1133 if (tel->encap_limit == 0) {
1134 icmpv6_send(skb, ICMPV6_PARAMPROB,
1135 ICMPV6_HDR_FIELD, offset + 2);
1136 return -1;
1137 }
1138 encap_limit = tel->encap_limit - 1;
1139 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1140 encap_limit = t->parms.encap_limit;
1141
1142 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1143 fl6.flowi6_proto = IPPROTO_IPV6;
1144
1145 dsfield = ipv6_get_dsfield(ipv6h);
1146 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1147 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1148 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1149 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1150 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1151 fl6.flowi6_mark = skb->mark;
1152
1153 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1154 if (err != 0) {
1155 if (err == -EMSGSIZE)
1156 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1157 return -1;
1158 }
1159
1160 return 0;
1161 }
1162
1163 static netdev_tx_t
1164 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1165 {
1166 struct ip6_tnl *t = netdev_priv(dev);
1167 struct net_device_stats *stats = &t->dev->stats;
1168 int ret;
1169
1170 switch (skb->protocol) {
1171 case htons(ETH_P_IP):
1172 ret = ip4ip6_tnl_xmit(skb, dev);
1173 break;
1174 case htons(ETH_P_IPV6):
1175 ret = ip6ip6_tnl_xmit(skb, dev);
1176 break;
1177 default:
1178 goto tx_err;
1179 }
1180
1181 if (ret < 0)
1182 goto tx_err;
1183
1184 return NETDEV_TX_OK;
1185
1186 tx_err:
1187 stats->tx_errors++;
1188 stats->tx_dropped++;
1189 kfree_skb(skb);
1190 return NETDEV_TX_OK;
1191 }
1192
1193 static void ip6_tnl_link_config(struct ip6_tnl *t)
1194 {
1195 struct net_device *dev = t->dev;
1196 struct __ip6_tnl_parm *p = &t->parms;
1197 struct flowi6 *fl6 = &t->fl.u.ip6;
1198
1199 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1200 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1201
1202 /* Set up flowi template */
1203 fl6->saddr = p->laddr;
1204 fl6->daddr = p->raddr;
1205 fl6->flowi6_oif = p->link;
1206 fl6->flowlabel = 0;
1207
1208 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1209 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1210 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1211 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1212
1213 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1214 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1215
1216 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1217 dev->flags |= IFF_POINTOPOINT;
1218 else
1219 dev->flags &= ~IFF_POINTOPOINT;
1220
1221 dev->iflink = p->link;
1222
1223 if (p->flags & IP6_TNL_F_CAP_XMIT) {
1224 int strict = (ipv6_addr_type(&p->raddr) &
1225 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1226
1227 struct rt6_info *rt = rt6_lookup(t->net,
1228 &p->raddr, &p->laddr,
1229 p->link, strict);
1230
1231 if (rt == NULL)
1232 return;
1233
1234 if (rt->dst.dev) {
1235 dev->hard_header_len = rt->dst.dev->hard_header_len +
1236 sizeof(struct ipv6hdr);
1237
1238 dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr);
1239 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1240 dev->mtu -= 8;
1241
1242 if (dev->mtu < IPV6_MIN_MTU)
1243 dev->mtu = IPV6_MIN_MTU;
1244 }
1245 ip6_rt_put(rt);
1246 }
1247 }
1248
1249 /**
1250 * ip6_tnl_change - update the tunnel parameters
1251 * @t: tunnel to be changed
1252 * @p: tunnel configuration parameters
1253 *
1254 * Description:
1255 * ip6_tnl_change() updates the tunnel parameters
1256 **/
1257
1258 static int
1259 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1260 {
1261 t->parms.laddr = p->laddr;
1262 t->parms.raddr = p->raddr;
1263 t->parms.flags = p->flags;
1264 t->parms.hop_limit = p->hop_limit;
1265 t->parms.encap_limit = p->encap_limit;
1266 t->parms.flowinfo = p->flowinfo;
1267 t->parms.link = p->link;
1268 t->parms.proto = p->proto;
1269 ip6_tnl_dst_reset(t);
1270 ip6_tnl_link_config(t);
1271 return 0;
1272 }
1273
1274 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1275 {
1276 struct net *net = t->net;
1277 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1278 int err;
1279
1280 ip6_tnl_unlink(ip6n, t);
1281 synchronize_net();
1282 err = ip6_tnl_change(t, p);
1283 ip6_tnl_link(ip6n, t);
1284 netdev_state_change(t->dev);
1285 return err;
1286 }
1287
1288 static void
1289 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1290 {
1291 p->laddr = u->laddr;
1292 p->raddr = u->raddr;
1293 p->flags = u->flags;
1294 p->hop_limit = u->hop_limit;
1295 p->encap_limit = u->encap_limit;
1296 p->flowinfo = u->flowinfo;
1297 p->link = u->link;
1298 p->proto = u->proto;
1299 memcpy(p->name, u->name, sizeof(u->name));
1300 }
1301
1302 static void
1303 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1304 {
1305 u->laddr = p->laddr;
1306 u->raddr = p->raddr;
1307 u->flags = p->flags;
1308 u->hop_limit = p->hop_limit;
1309 u->encap_limit = p->encap_limit;
1310 u->flowinfo = p->flowinfo;
1311 u->link = p->link;
1312 u->proto = p->proto;
1313 memcpy(u->name, p->name, sizeof(u->name));
1314 }
1315
1316 /**
1317 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1318 * @dev: virtual device associated with tunnel
1319 * @ifr: parameters passed from userspace
1320 * @cmd: command to be performed
1321 *
1322 * Description:
1323 * ip6_tnl_ioctl() is used for managing IPv6 tunnels
1324 * from userspace.
1325 *
1326 * The possible commands are the following:
1327 * %SIOCGETTUNNEL: get tunnel parameters for device
1328 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1329 * %SIOCCHGTUNNEL: change tunnel parameters to those given
1330 * %SIOCDELTUNNEL: delete tunnel
1331 *
1332 * The fallback device "ip6tnl0", created during module
1333 * initialization, can be used for creating other tunnel devices.
1334 *
1335 * Return:
1336 * 0 on success,
1337 * %-EFAULT if unable to copy data to or from userspace,
1338 * %-EPERM if current process hasn't %CAP_NET_ADMIN set
1339 * %-EINVAL if passed tunnel parameters are invalid,
1340 * %-EEXIST if changing a tunnel's parameters would cause a conflict
1341 * %-ENODEV if attempting to change or delete a nonexisting device
1342 **/
1343
1344 static int
1345 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1346 {
1347 int err = 0;
1348 struct ip6_tnl_parm p;
1349 struct __ip6_tnl_parm p1;
1350 struct ip6_tnl *t = netdev_priv(dev);
1351 struct net *net = t->net;
1352 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1353
1354 switch (cmd) {
1355 case SIOCGETTUNNEL:
1356 if (dev == ip6n->fb_tnl_dev) {
1357 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1358 err = -EFAULT;
1359 break;
1360 }
1361 ip6_tnl_parm_from_user(&p1, &p);
1362 t = ip6_tnl_locate(net, &p1, 0);
1363 if (t == NULL)
1364 t = netdev_priv(dev);
1365 } else {
1366 memset(&p, 0, sizeof(p));
1367 }
1368 ip6_tnl_parm_to_user(&p, &t->parms);
1369 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1370 err = -EFAULT;
1371 }
1372 break;
1373 case SIOCADDTUNNEL:
1374 case SIOCCHGTUNNEL:
1375 err = -EPERM;
1376 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1377 break;
1378 err = -EFAULT;
1379 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1380 break;
1381 err = -EINVAL;
1382 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1383 p.proto != 0)
1384 break;
1385 ip6_tnl_parm_from_user(&p1, &p);
1386 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1387 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1388 if (t != NULL) {
1389 if (t->dev != dev) {
1390 err = -EEXIST;
1391 break;
1392 }
1393 } else
1394 t = netdev_priv(dev);
1395
1396 err = ip6_tnl_update(t, &p1);
1397 }
1398 if (t) {
1399 err = 0;
1400 ip6_tnl_parm_to_user(&p, &t->parms);
1401 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1402 err = -EFAULT;
1403
1404 } else
1405 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1406 break;
1407 case SIOCDELTUNNEL:
1408 err = -EPERM;
1409 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1410 break;
1411
1412 if (dev == ip6n->fb_tnl_dev) {
1413 err = -EFAULT;
1414 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1415 break;
1416 err = -ENOENT;
1417 ip6_tnl_parm_from_user(&p1, &p);
1418 t = ip6_tnl_locate(net, &p1, 0);
1419 if (t == NULL)
1420 break;
1421 err = -EPERM;
1422 if (t->dev == ip6n->fb_tnl_dev)
1423 break;
1424 dev = t->dev;
1425 }
1426 err = 0;
1427 unregister_netdevice(dev);
1428 break;
1429 default:
1430 err = -EINVAL;
1431 }
1432 return err;
1433 }
1434
1435 /**
1436 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1437 * @dev: virtual device associated with tunnel
1438 * @new_mtu: the new mtu
1439 *
1440 * Return:
1441 * 0 on success,
1442 * %-EINVAL if mtu too small
1443 **/
1444
1445 static int
1446 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1447 {
1448 struct ip6_tnl *tnl = netdev_priv(dev);
1449
1450 if (tnl->parms.proto == IPPROTO_IPIP) {
1451 if (new_mtu < 68)
1452 return -EINVAL;
1453 } else {
1454 if (new_mtu < IPV6_MIN_MTU)
1455 return -EINVAL;
1456 }
1457 if (new_mtu > 0xFFF8 - dev->hard_header_len)
1458 return -EINVAL;
1459 dev->mtu = new_mtu;
1460 return 0;
1461 }
1462
1463
1464 static const struct net_device_ops ip6_tnl_netdev_ops = {
1465 .ndo_uninit = ip6_tnl_dev_uninit,
1466 .ndo_start_xmit = ip6_tnl_xmit,
1467 .ndo_do_ioctl = ip6_tnl_ioctl,
1468 .ndo_change_mtu = ip6_tnl_change_mtu,
1469 .ndo_get_stats = ip6_get_stats,
1470 };
1471
1472
1473 /**
1474 * ip6_tnl_dev_setup - setup virtual tunnel device
1475 * @dev: virtual device associated with tunnel
1476 *
1477 * Description:
1478 * Initialize function pointers and device parameters
1479 **/
1480
1481 static void ip6_tnl_dev_setup(struct net_device *dev)
1482 {
1483 struct ip6_tnl *t;
1484
1485 dev->netdev_ops = &ip6_tnl_netdev_ops;
1486 dev->destructor = ip6_dev_free;
1487
1488 dev->type = ARPHRD_TUNNEL6;
1489 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
1490 dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr);
1491 t = netdev_priv(dev);
1492 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1493 dev->mtu -= 8;
1494 dev->flags |= IFF_NOARP;
1495 dev->addr_len = sizeof(struct in6_addr);
1496 netif_keep_dst(dev);
1497 /* This perm addr will be used as interface identifier by IPv6 */
1498 dev->addr_assign_type = NET_ADDR_RANDOM;
1499 eth_random_addr(dev->perm_addr);
1500 }
1501
1502
1503 /**
1504 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1505 * @dev: virtual device associated with tunnel
1506 **/
1507
1508 static inline int
1509 ip6_tnl_dev_init_gen(struct net_device *dev)
1510 {
1511 struct ip6_tnl *t = netdev_priv(dev);
1512
1513 t->dev = dev;
1514 t->net = dev_net(dev);
1515 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1516 if (!dev->tstats)
1517 return -ENOMEM;
1518 return 0;
1519 }
1520
1521 /**
1522 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1523 * @dev: virtual device associated with tunnel
1524 **/
1525
1526 static int ip6_tnl_dev_init(struct net_device *dev)
1527 {
1528 struct ip6_tnl *t = netdev_priv(dev);
1529 int err = ip6_tnl_dev_init_gen(dev);
1530
1531 if (err)
1532 return err;
1533 ip6_tnl_link_config(t);
1534 return 0;
1535 }
1536
1537 /**
1538 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1539 * @dev: fallback device
1540 *
1541 * Return: 0
1542 **/
1543
1544 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1545 {
1546 struct ip6_tnl *t = netdev_priv(dev);
1547 struct net *net = dev_net(dev);
1548 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1549 int err = ip6_tnl_dev_init_gen(dev);
1550
1551 if (err)
1552 return err;
1553
1554 t->parms.proto = IPPROTO_IPV6;
1555 dev_hold(dev);
1556
1557 ip6_tnl_link_config(t);
1558
1559 rcu_assign_pointer(ip6n->tnls_wc[0], t);
1560 return 0;
1561 }
1562
1563 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1564 {
1565 u8 proto;
1566
1567 if (!data || !data[IFLA_IPTUN_PROTO])
1568 return 0;
1569
1570 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1571 if (proto != IPPROTO_IPV6 &&
1572 proto != IPPROTO_IPIP &&
1573 proto != 0)
1574 return -EINVAL;
1575
1576 return 0;
1577 }
1578
1579 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1580 struct __ip6_tnl_parm *parms)
1581 {
1582 memset(parms, 0, sizeof(*parms));
1583
1584 if (!data)
1585 return;
1586
1587 if (data[IFLA_IPTUN_LINK])
1588 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1589
1590 if (data[IFLA_IPTUN_LOCAL])
1591 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1592 sizeof(struct in6_addr));
1593
1594 if (data[IFLA_IPTUN_REMOTE])
1595 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1596 sizeof(struct in6_addr));
1597
1598 if (data[IFLA_IPTUN_TTL])
1599 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1600
1601 if (data[IFLA_IPTUN_ENCAP_LIMIT])
1602 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1603
1604 if (data[IFLA_IPTUN_FLOWINFO])
1605 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1606
1607 if (data[IFLA_IPTUN_FLAGS])
1608 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1609
1610 if (data[IFLA_IPTUN_PROTO])
1611 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1612 }
1613
1614 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1615 struct nlattr *tb[], struct nlattr *data[])
1616 {
1617 struct net *net = dev_net(dev);
1618 struct ip6_tnl *nt;
1619
1620 nt = netdev_priv(dev);
1621 ip6_tnl_netlink_parms(data, &nt->parms);
1622
1623 if (ip6_tnl_locate(net, &nt->parms, 0))
1624 return -EEXIST;
1625
1626 return ip6_tnl_create2(dev);
1627 }
1628
1629 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1630 struct nlattr *data[])
1631 {
1632 struct ip6_tnl *t = netdev_priv(dev);
1633 struct __ip6_tnl_parm p;
1634 struct net *net = t->net;
1635 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1636
1637 if (dev == ip6n->fb_tnl_dev)
1638 return -EINVAL;
1639
1640 ip6_tnl_netlink_parms(data, &p);
1641
1642 t = ip6_tnl_locate(net, &p, 0);
1643
1644 if (t) {
1645 if (t->dev != dev)
1646 return -EEXIST;
1647 } else
1648 t = netdev_priv(dev);
1649
1650 return ip6_tnl_update(t, &p);
1651 }
1652
1653 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1654 {
1655 struct net *net = dev_net(dev);
1656 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1657
1658 if (dev != ip6n->fb_tnl_dev)
1659 unregister_netdevice_queue(dev, head);
1660 }
1661
1662 static size_t ip6_tnl_get_size(const struct net_device *dev)
1663 {
1664 return
1665 /* IFLA_IPTUN_LINK */
1666 nla_total_size(4) +
1667 /* IFLA_IPTUN_LOCAL */
1668 nla_total_size(sizeof(struct in6_addr)) +
1669 /* IFLA_IPTUN_REMOTE */
1670 nla_total_size(sizeof(struct in6_addr)) +
1671 /* IFLA_IPTUN_TTL */
1672 nla_total_size(1) +
1673 /* IFLA_IPTUN_ENCAP_LIMIT */
1674 nla_total_size(1) +
1675 /* IFLA_IPTUN_FLOWINFO */
1676 nla_total_size(4) +
1677 /* IFLA_IPTUN_FLAGS */
1678 nla_total_size(4) +
1679 /* IFLA_IPTUN_PROTO */
1680 nla_total_size(1) +
1681 0;
1682 }
1683
1684 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1685 {
1686 struct ip6_tnl *tunnel = netdev_priv(dev);
1687 struct __ip6_tnl_parm *parm = &tunnel->parms;
1688
1689 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1690 nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1691 &parm->laddr) ||
1692 nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1693 &parm->raddr) ||
1694 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1695 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1696 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1697 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1698 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1699 goto nla_put_failure;
1700 return 0;
1701
1702 nla_put_failure:
1703 return -EMSGSIZE;
1704 }
1705
1706 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1707 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1708 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) },
1709 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) },
1710 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1711 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 },
1712 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 },
1713 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 },
1714 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1715 };
1716
1717 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1718 .kind = "ip6tnl",
1719 .maxtype = IFLA_IPTUN_MAX,
1720 .policy = ip6_tnl_policy,
1721 .priv_size = sizeof(struct ip6_tnl),
1722 .setup = ip6_tnl_dev_setup,
1723 .validate = ip6_tnl_validate,
1724 .newlink = ip6_tnl_newlink,
1725 .changelink = ip6_tnl_changelink,
1726 .dellink = ip6_tnl_dellink,
1727 .get_size = ip6_tnl_get_size,
1728 .fill_info = ip6_tnl_fill_info,
1729 };
1730
1731 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1732 .handler = ip4ip6_rcv,
1733 .err_handler = ip4ip6_err,
1734 .priority = 1,
1735 };
1736
1737 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1738 .handler = ip6ip6_rcv,
1739 .err_handler = ip6ip6_err,
1740 .priority = 1,
1741 };
1742
1743 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1744 {
1745 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1746 struct net_device *dev, *aux;
1747 int h;
1748 struct ip6_tnl *t;
1749 LIST_HEAD(list);
1750
1751 for_each_netdev_safe(net, dev, aux)
1752 if (dev->rtnl_link_ops == &ip6_link_ops)
1753 unregister_netdevice_queue(dev, &list);
1754
1755 for (h = 0; h < HASH_SIZE; h++) {
1756 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1757 while (t != NULL) {
1758 /* If dev is in the same netns, it has already
1759 * been added to the list by the previous loop.
1760 */
1761 if (!net_eq(dev_net(t->dev), net))
1762 unregister_netdevice_queue(t->dev, &list);
1763 t = rtnl_dereference(t->next);
1764 }
1765 }
1766
1767 unregister_netdevice_many(&list);
1768 }
1769
1770 static int __net_init ip6_tnl_init_net(struct net *net)
1771 {
1772 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1773 struct ip6_tnl *t = NULL;
1774 int err;
1775
1776 ip6n->tnls[0] = ip6n->tnls_wc;
1777 ip6n->tnls[1] = ip6n->tnls_r_l;
1778
1779 err = -ENOMEM;
1780 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1781 NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
1782
1783 if (!ip6n->fb_tnl_dev)
1784 goto err_alloc_dev;
1785 dev_net_set(ip6n->fb_tnl_dev, net);
1786 ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1787 /* FB netdevice is special: we have one, and only one per netns.
1788 * Allowing to move it to another netns is clearly unsafe.
1789 */
1790 ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1791
1792 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1793 if (err < 0)
1794 goto err_register;
1795
1796 err = register_netdev(ip6n->fb_tnl_dev);
1797 if (err < 0)
1798 goto err_register;
1799
1800 t = netdev_priv(ip6n->fb_tnl_dev);
1801
1802 strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1803 return 0;
1804
1805 err_register:
1806 ip6_dev_free(ip6n->fb_tnl_dev);
1807 err_alloc_dev:
1808 return err;
1809 }
1810
1811 static void __net_exit ip6_tnl_exit_net(struct net *net)
1812 {
1813 rtnl_lock();
1814 ip6_tnl_destroy_tunnels(net);
1815 rtnl_unlock();
1816 }
1817
1818 static struct pernet_operations ip6_tnl_net_ops = {
1819 .init = ip6_tnl_init_net,
1820 .exit = ip6_tnl_exit_net,
1821 .id = &ip6_tnl_net_id,
1822 .size = sizeof(struct ip6_tnl_net),
1823 };
1824
1825 /**
1826 * ip6_tunnel_init - register protocol and reserve needed resources
1827 *
1828 * Return: 0 on success
1829 **/
1830
1831 static int __init ip6_tunnel_init(void)
1832 {
1833 int err;
1834
1835 err = register_pernet_device(&ip6_tnl_net_ops);
1836 if (err < 0)
1837 goto out_pernet;
1838
1839 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1840 if (err < 0) {
1841 pr_err("%s: can't register ip4ip6\n", __func__);
1842 goto out_ip4ip6;
1843 }
1844
1845 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1846 if (err < 0) {
1847 pr_err("%s: can't register ip6ip6\n", __func__);
1848 goto out_ip6ip6;
1849 }
1850 err = rtnl_link_register(&ip6_link_ops);
1851 if (err < 0)
1852 goto rtnl_link_failed;
1853
1854 return 0;
1855
1856 rtnl_link_failed:
1857 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1858 out_ip6ip6:
1859 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1860 out_ip4ip6:
1861 unregister_pernet_device(&ip6_tnl_net_ops);
1862 out_pernet:
1863 return err;
1864 }
1865
1866 /**
1867 * ip6_tunnel_cleanup - free resources and unregister protocol
1868 **/
1869
1870 static void __exit ip6_tunnel_cleanup(void)
1871 {
1872 rtnl_link_unregister(&ip6_link_ops);
1873 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1874 pr_info("%s: can't deregister ip4ip6\n", __func__);
1875
1876 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1877 pr_info("%s: can't deregister ip6ip6\n", __func__);
1878
1879 unregister_pernet_device(&ip6_tnl_net_ops);
1880 }
1881
1882 module_init(ip6_tunnel_init);
1883 module_exit(ip6_tunnel_cleanup);
Linux kernel - Deliverables
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