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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
44#include <asm/uaccess.h>
45#include <linux/atomic.h>
46
47#include <net/icmp.h>
48#include <net/ip.h>
49#include <net/ipv6.h>
50#include <net/ip6_route.h>
51#include <net/addrconf.h>
52#include <net/ip6_tunnel.h>
53#include <net/xfrm.h>
54#include <net/dsfield.h>
55#include <net/inet_ecn.h>
56#include <net/net_namespace.h>
57#include <net/netns/generic.h>
58
59MODULE_AUTHOR("Ville Nuorvala");
60MODULE_DESCRIPTION("IPv6 tunneling device");
61MODULE_LICENSE("GPL");
62MODULE_ALIAS_NETDEV("ip6tnl0");
63
64#ifdef IP6_TNL_DEBUG
65#define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
66#else
67#define IP6_TNL_TRACE(x...) do {;} while(0)
68#endif
69
70#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
71#define IPV6_TCLASS_SHIFT 20
72
73#define HASH_SIZE 32
74
75#define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \
76 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \
77 (HASH_SIZE - 1))
78
79static int ip6_tnl_dev_init(struct net_device *dev);
80static void ip6_tnl_dev_setup(struct net_device *dev);
81
82static int ip6_tnl_net_id __read_mostly;
83struct ip6_tnl_net {
84 /* the IPv6 tunnel fallback device */
85 struct net_device *fb_tnl_dev;
86 /* lists for storing tunnels in use */
87 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
88 struct ip6_tnl __rcu *tnls_wc[1];
89 struct ip6_tnl __rcu **tnls[2];
90};
91
92/* often modified stats are per cpu, other are shared (netdev->stats) */
93struct pcpu_tstats {
94 unsigned long rx_packets;
95 unsigned long rx_bytes;
96 unsigned long tx_packets;
97 unsigned long tx_bytes;
98} __attribute__((aligned(4*sizeof(unsigned long))));
99
100static struct net_device_stats *ip6_get_stats(struct net_device *dev)
101{
102 struct pcpu_tstats sum = { 0 };
103 int i;
104
105 for_each_possible_cpu(i) {
106 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
107
108 sum.rx_packets += tstats->rx_packets;
109 sum.rx_bytes += tstats->rx_bytes;
110 sum.tx_packets += tstats->tx_packets;
111 sum.tx_bytes += tstats->tx_bytes;
112 }
113 dev->stats.rx_packets = sum.rx_packets;
114 dev->stats.rx_bytes = sum.rx_bytes;
115 dev->stats.tx_packets = sum.tx_packets;
116 dev->stats.tx_bytes = sum.tx_bytes;
117 return &dev->stats;
118}
119
120/*
121 * Locking : hash tables are protected by RCU and RTNL
122 */
123
124static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
125{
126 struct dst_entry *dst = t->dst_cache;
127
128 if (dst && dst->obsolete &&
129 dst->ops->check(dst, t->dst_cookie) == NULL) {
130 t->dst_cache = NULL;
131 dst_release(dst);
132 return NULL;
133 }
134
135 return dst;
136}
137
138static inline void ip6_tnl_dst_reset(struct ip6_tnl *t)
139{
140 dst_release(t->dst_cache);
141 t->dst_cache = NULL;
142}
143
144static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
145{
146 struct rt6_info *rt = (struct rt6_info *) dst;
147 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
148 dst_release(t->dst_cache);
149 t->dst_cache = dst;
150}
151
152/**
153 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
154 * @remote: the address of the tunnel exit-point
155 * @local: the address of the tunnel entry-point
156 *
157 * Return:
158 * tunnel matching given end-points if found,
159 * else fallback tunnel if its device is up,
160 * else %NULL
161 **/
162
163#define for_each_ip6_tunnel_rcu(start) \
164 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
165
166static struct ip6_tnl *
167ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
168{
169 unsigned int h0 = HASH(remote);
170 unsigned int h1 = HASH(local);
171 struct ip6_tnl *t;
172 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
173
174 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) {
175 if (ipv6_addr_equal(local, &t->parms.laddr) &&
176 ipv6_addr_equal(remote, &t->parms.raddr) &&
177 (t->dev->flags & IFF_UP))
178 return t;
179 }
180 t = rcu_dereference(ip6n->tnls_wc[0]);
181 if (t && (t->dev->flags & IFF_UP))
182 return t;
183
184 return NULL;
185}
186
187/**
188 * ip6_tnl_bucket - get head of list matching given tunnel parameters
189 * @p: parameters containing tunnel end-points
190 *
191 * Description:
192 * ip6_tnl_bucket() returns the head of the list matching the
193 * &struct in6_addr entries laddr and raddr in @p.
194 *
195 * Return: head of IPv6 tunnel list
196 **/
197
198static struct ip6_tnl __rcu **
199ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct ip6_tnl_parm *p)
200{
201 const struct in6_addr *remote = &p->raddr;
202 const struct in6_addr *local = &p->laddr;
203 unsigned int h = 0;
204 int prio = 0;
205
206 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
207 prio = 1;
208 h = HASH(remote) ^ HASH(local);
209 }
210 return &ip6n->tnls[prio][h];
211}
212
213/**
214 * ip6_tnl_link - add tunnel to hash table
215 * @t: tunnel to be added
216 **/
217
218static void
219ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
220{
221 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
222
223 rcu_assign_pointer(t->next , rtnl_dereference(*tp));
224 rcu_assign_pointer(*tp, t);
225}
226
227/**
228 * ip6_tnl_unlink - remove tunnel from hash table
229 * @t: tunnel to be removed
230 **/
231
232static void
233ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
234{
235 struct ip6_tnl __rcu **tp;
236 struct ip6_tnl *iter;
237
238 for (tp = ip6_tnl_bucket(ip6n, &t->parms);
239 (iter = rtnl_dereference(*tp)) != NULL;
240 tp = &iter->next) {
241 if (t == iter) {
242 rcu_assign_pointer(*tp, t->next);
243 break;
244 }
245 }
246}
247
248static void ip6_dev_free(struct net_device *dev)
249{
250 free_percpu(dev->tstats);
251 free_netdev(dev);
252}
253
254/**
255 * ip6_tnl_create() - create a new tunnel
256 * @p: tunnel parameters
257 * @pt: pointer to new tunnel
258 *
259 * Description:
260 * Create tunnel matching given parameters.
261 *
262 * Return:
263 * created tunnel or NULL
264 **/
265
266static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p)
267{
268 struct net_device *dev;
269 struct ip6_tnl *t;
270 char name[IFNAMSIZ];
271 int err;
272 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
273
274 if (p->name[0])
275 strlcpy(name, p->name, IFNAMSIZ);
276 else
277 sprintf(name, "ip6tnl%%d");
278
279 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
280 if (dev == NULL)
281 goto failed;
282
283 dev_net_set(dev, net);
284
285 t = netdev_priv(dev);
286 t->parms = *p;
287 err = ip6_tnl_dev_init(dev);
288 if (err < 0)
289 goto failed_free;
290
291 if ((err = register_netdevice(dev)) < 0)
292 goto failed_free;
293
294 strcpy(t->parms.name, dev->name);
295
296 dev_hold(dev);
297 ip6_tnl_link(ip6n, t);
298 return t;
299
300failed_free:
301 ip6_dev_free(dev);
302failed:
303 return NULL;
304}
305
306/**
307 * ip6_tnl_locate - find or create tunnel matching given parameters
308 * @p: tunnel parameters
309 * @create: != 0 if allowed to create new tunnel if no match found
310 *
311 * Description:
312 * ip6_tnl_locate() first tries to locate an existing tunnel
313 * based on @parms. If this is unsuccessful, but @create is set a new
314 * tunnel device is created and registered for use.
315 *
316 * Return:
317 * matching tunnel or NULL
318 **/
319
320static struct ip6_tnl *ip6_tnl_locate(struct net *net,
321 struct ip6_tnl_parm *p, int create)
322{
323 const struct in6_addr *remote = &p->raddr;
324 const struct in6_addr *local = &p->laddr;
325 struct ip6_tnl __rcu **tp;
326 struct ip6_tnl *t;
327 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
328
329 for (tp = ip6_tnl_bucket(ip6n, p);
330 (t = rtnl_dereference(*tp)) != NULL;
331 tp = &t->next) {
332 if (ipv6_addr_equal(local, &t->parms.laddr) &&
333 ipv6_addr_equal(remote, &t->parms.raddr))
334 return t;
335 }
336 if (!create)
337 return NULL;
338 return ip6_tnl_create(net, p);
339}
340
341/**
342 * ip6_tnl_dev_uninit - tunnel device uninitializer
343 * @dev: the device to be destroyed
344 *
345 * Description:
346 * ip6_tnl_dev_uninit() removes tunnel from its list
347 **/
348
349static void
350ip6_tnl_dev_uninit(struct net_device *dev)
351{
352 struct ip6_tnl *t = netdev_priv(dev);
353 struct net *net = dev_net(dev);
354 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
355
356 if (dev == ip6n->fb_tnl_dev)
357 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
358 else
359 ip6_tnl_unlink(ip6n, t);
360 ip6_tnl_dst_reset(t);
361 dev_put(dev);
362}
363
364/**
365 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
366 * @skb: received socket buffer
367 *
368 * Return:
369 * 0 if none was found,
370 * else index to encapsulation limit
371 **/
372
373static __u16
374parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
375{
376 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
377 __u8 nexthdr = ipv6h->nexthdr;
378 __u16 off = sizeof (*ipv6h);
379
380 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
381 __u16 optlen = 0;
382 struct ipv6_opt_hdr *hdr;
383 if (raw + off + sizeof (*hdr) > skb->data &&
384 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
385 break;
386
387 hdr = (struct ipv6_opt_hdr *) (raw + off);
388 if (nexthdr == NEXTHDR_FRAGMENT) {
389 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
390 if (frag_hdr->frag_off)
391 break;
392 optlen = 8;
393 } else if (nexthdr == NEXTHDR_AUTH) {
394 optlen = (hdr->hdrlen + 2) << 2;
395 } else {
396 optlen = ipv6_optlen(hdr);
397 }
398 if (nexthdr == NEXTHDR_DEST) {
399 __u16 i = off + 2;
400 while (1) {
401 struct ipv6_tlv_tnl_enc_lim *tel;
402
403 /* No more room for encapsulation limit */
404 if (i + sizeof (*tel) > off + optlen)
405 break;
406
407 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
408 /* return index of option if found and valid */
409 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
410 tel->length == 1)
411 return i;
412 /* else jump to next option */
413 if (tel->type)
414 i += tel->length + 2;
415 else
416 i++;
417 }
418 }
419 nexthdr = hdr->nexthdr;
420 off += optlen;
421 }
422 return 0;
423}
424
425/**
426 * ip6_tnl_err - tunnel error handler
427 *
428 * Description:
429 * ip6_tnl_err() should handle errors in the tunnel according
430 * to the specifications in RFC 2473.
431 **/
432
433static int
434ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
435 u8 *type, u8 *code, int *msg, __u32 *info, int offset)
436{
437 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
438 struct ip6_tnl *t;
439 int rel_msg = 0;
440 u8 rel_type = ICMPV6_DEST_UNREACH;
441 u8 rel_code = ICMPV6_ADDR_UNREACH;
442 __u32 rel_info = 0;
443 __u16 len;
444 int err = -ENOENT;
445
446 /* If the packet doesn't contain the original IPv6 header we are
447 in trouble since we might need the source address for further
448 processing of the error. */
449
450 rcu_read_lock();
451 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
452 &ipv6h->saddr)) == NULL)
453 goto out;
454
455 if (t->parms.proto != ipproto && t->parms.proto != 0)
456 goto out;
457
458 err = 0;
459
460 switch (*type) {
461 __u32 teli;
462 struct ipv6_tlv_tnl_enc_lim *tel;
463 __u32 mtu;
464 case ICMPV6_DEST_UNREACH:
465 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
466 t->parms.name);
467 rel_msg = 1;
468 break;
469 case ICMPV6_TIME_EXCEED:
470 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
471 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
472 t->parms.name);
473 rel_msg = 1;
474 }
475 break;
476 case ICMPV6_PARAMPROB:
477 teli = 0;
478 if ((*code) == ICMPV6_HDR_FIELD)
479 teli = parse_tlv_tnl_enc_lim(skb, skb->data);
480
481 if (teli && teli == *info - 2) {
482 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
483 if (tel->encap_limit == 0) {
484 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
485 t->parms.name);
486 rel_msg = 1;
487 }
488 } else {
489 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
490 t->parms.name);
491 }
492 break;
493 case ICMPV6_PKT_TOOBIG:
494 mtu = *info - offset;
495 if (mtu < IPV6_MIN_MTU)
496 mtu = IPV6_MIN_MTU;
497 t->dev->mtu = mtu;
498
499 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
500 rel_type = ICMPV6_PKT_TOOBIG;
501 rel_code = 0;
502 rel_info = mtu;
503 rel_msg = 1;
504 }
505 break;
506 }
507
508 *type = rel_type;
509 *code = rel_code;
510 *info = rel_info;
511 *msg = rel_msg;
512
513out:
514 rcu_read_unlock();
515 return err;
516}
517
518static int
519ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
520 u8 type, u8 code, int offset, __be32 info)
521{
522 int rel_msg = 0;
523 u8 rel_type = type;
524 u8 rel_code = code;
525 __u32 rel_info = ntohl(info);
526 int err;
527 struct sk_buff *skb2;
528 const struct iphdr *eiph;
529 struct rtable *rt;
530 struct flowi4 fl4;
531
532 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
533 &rel_msg, &rel_info, offset);
534 if (err < 0)
535 return err;
536
537 if (rel_msg == 0)
538 return 0;
539
540 switch (rel_type) {
541 case ICMPV6_DEST_UNREACH:
542 if (rel_code != ICMPV6_ADDR_UNREACH)
543 return 0;
544 rel_type = ICMP_DEST_UNREACH;
545 rel_code = ICMP_HOST_UNREACH;
546 break;
547 case ICMPV6_PKT_TOOBIG:
548 if (rel_code != 0)
549 return 0;
550 rel_type = ICMP_DEST_UNREACH;
551 rel_code = ICMP_FRAG_NEEDED;
552 break;
553 default:
554 return 0;
555 }
556
557 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
558 return 0;
559
560 skb2 = skb_clone(skb, GFP_ATOMIC);
561 if (!skb2)
562 return 0;
563
564 skb_dst_drop(skb2);
565
566 skb_pull(skb2, offset);
567 skb_reset_network_header(skb2);
568 eiph = ip_hdr(skb2);
569
570 /* Try to guess incoming interface */
571 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
572 eiph->saddr, 0,
573 0, 0,
574 IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
575 if (IS_ERR(rt))
576 goto out;
577
578 skb2->dev = rt->dst.dev;
579
580 /* route "incoming" packet */
581 if (rt->rt_flags & RTCF_LOCAL) {
582 ip_rt_put(rt);
583 rt = NULL;
584 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
585 eiph->daddr, eiph->saddr,
586 0, 0,
587 IPPROTO_IPIP,
588 RT_TOS(eiph->tos), 0);
589 if (IS_ERR(rt) ||
590 rt->dst.dev->type != ARPHRD_TUNNEL) {
591 if (!IS_ERR(rt))
592 ip_rt_put(rt);
593 goto out;
594 }
595 skb_dst_set(skb2, &rt->dst);
596 } else {
597 ip_rt_put(rt);
598 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
599 skb2->dev) ||
600 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
601 goto out;
602 }
603
604 /* change mtu on this route */
605 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
606 if (rel_info > dst_mtu(skb_dst(skb2)))
607 goto out;
608
609 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info);
610 }
611
612 icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
613
614out:
615 kfree_skb(skb2);
616 return 0;
617}
618
619static int
620ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
621 u8 type, u8 code, int offset, __be32 info)
622{
623 int rel_msg = 0;
624 u8 rel_type = type;
625 u8 rel_code = code;
626 __u32 rel_info = ntohl(info);
627 int err;
628
629 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
630 &rel_msg, &rel_info, offset);
631 if (err < 0)
632 return err;
633
634 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
635 struct rt6_info *rt;
636 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
637
638 if (!skb2)
639 return 0;
640
641 skb_dst_drop(skb2);
642 skb_pull(skb2, offset);
643 skb_reset_network_header(skb2);
644
645 /* Try to guess incoming interface */
646 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
647 NULL, 0, 0);
648
649 if (rt && rt->dst.dev)
650 skb2->dev = rt->dst.dev;
651
652 icmpv6_send(skb2, rel_type, rel_code, rel_info);
653
654 if (rt)
655 dst_release(&rt->dst);
656
657 kfree_skb(skb2);
658 }
659
660 return 0;
661}
662
663static void ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
664 const struct ipv6hdr *ipv6h,
665 struct sk_buff *skb)
666{
667 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
668
669 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
670 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
671
672 if (INET_ECN_is_ce(dsfield))
673 IP_ECN_set_ce(ip_hdr(skb));
674}
675
676static void ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
677 const struct ipv6hdr *ipv6h,
678 struct sk_buff *skb)
679{
680 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
681 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
682
683 if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h)))
684 IP6_ECN_set_ce(ipv6_hdr(skb));
685}
686
687/* called with rcu_read_lock() */
688static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t)
689{
690 struct ip6_tnl_parm *p = &t->parms;
691 int ret = 0;
692 struct net *net = dev_net(t->dev);
693
694 if (p->flags & IP6_TNL_F_CAP_RCV) {
695 struct net_device *ldev = NULL;
696
697 if (p->link)
698 ldev = dev_get_by_index_rcu(net, p->link);
699
700 if ((ipv6_addr_is_multicast(&p->laddr) ||
701 likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) &&
702 likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0)))
703 ret = 1;
704
705 }
706 return ret;
707}
708
709/**
710 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
711 * @skb: received socket buffer
712 * @protocol: ethernet protocol ID
713 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
714 *
715 * Return: 0
716 **/
717
718static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
719 __u8 ipproto,
720 void (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
721 const struct ipv6hdr *ipv6h,
722 struct sk_buff *skb))
723{
724 struct ip6_tnl *t;
725 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
726
727 rcu_read_lock();
728
729 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
730 &ipv6h->daddr)) != NULL) {
731 struct pcpu_tstats *tstats;
732
733 if (t->parms.proto != ipproto && t->parms.proto != 0) {
734 rcu_read_unlock();
735 goto discard;
736 }
737
738 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
739 rcu_read_unlock();
740 goto discard;
741 }
742
743 if (!ip6_tnl_rcv_ctl(t)) {
744 t->dev->stats.rx_dropped++;
745 rcu_read_unlock();
746 goto discard;
747 }
748 secpath_reset(skb);
749 skb->mac_header = skb->network_header;
750 skb_reset_network_header(skb);
751 skb->protocol = htons(protocol);
752 skb->pkt_type = PACKET_HOST;
753 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
754
755 tstats = this_cpu_ptr(t->dev->tstats);
756 tstats->rx_packets++;
757 tstats->rx_bytes += skb->len;
758
759 __skb_tunnel_rx(skb, t->dev);
760
761 dscp_ecn_decapsulate(t, ipv6h, skb);
762
763 netif_rx(skb);
764
765 rcu_read_unlock();
766 return 0;
767 }
768 rcu_read_unlock();
769 return 1;
770
771discard:
772 kfree_skb(skb);
773 return 0;
774}
775
776static int ip4ip6_rcv(struct sk_buff *skb)
777{
778 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
779 ip4ip6_dscp_ecn_decapsulate);
780}
781
782static int ip6ip6_rcv(struct sk_buff *skb)
783{
784 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
785 ip6ip6_dscp_ecn_decapsulate);
786}
787
788struct ipv6_tel_txoption {
789 struct ipv6_txoptions ops;
790 __u8 dst_opt[8];
791};
792
793static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
794{
795 memset(opt, 0, sizeof(struct ipv6_tel_txoption));
796
797 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
798 opt->dst_opt[3] = 1;
799 opt->dst_opt[4] = encap_limit;
800 opt->dst_opt[5] = IPV6_TLV_PADN;
801 opt->dst_opt[6] = 1;
802
803 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
804 opt->ops.opt_nflen = 8;
805}
806
807/**
808 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
809 * @t: the outgoing tunnel device
810 * @hdr: IPv6 header from the incoming packet
811 *
812 * Description:
813 * Avoid trivial tunneling loop by checking that tunnel exit-point
814 * doesn't match source of incoming packet.
815 *
816 * Return:
817 * 1 if conflict,
818 * 0 else
819 **/
820
821static inline bool
822ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
823{
824 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
825}
826
827static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
828{
829 struct ip6_tnl_parm *p = &t->parms;
830 int ret = 0;
831 struct net *net = dev_net(t->dev);
832
833 if (p->flags & IP6_TNL_F_CAP_XMIT) {
834 struct net_device *ldev = NULL;
835
836 rcu_read_lock();
837 if (p->link)
838 ldev = dev_get_by_index_rcu(net, p->link);
839
840 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
841 pr_warn("%s xmit: Local address not yet configured!\n",
842 p->name);
843 else if (!ipv6_addr_is_multicast(&p->raddr) &&
844 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
845 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
846 p->name);
847 else
848 ret = 1;
849 rcu_read_unlock();
850 }
851 return ret;
852}
853/**
854 * ip6_tnl_xmit2 - encapsulate packet and send
855 * @skb: the outgoing socket buffer
856 * @dev: the outgoing tunnel device
857 * @dsfield: dscp code for outer header
858 * @fl: flow of tunneled packet
859 * @encap_limit: encapsulation limit
860 * @pmtu: Path MTU is stored if packet is too big
861 *
862 * Description:
863 * Build new header and do some sanity checks on the packet before sending
864 * it.
865 *
866 * Return:
867 * 0 on success
868 * -1 fail
869 * %-EMSGSIZE message too big. return mtu in this case.
870 **/
871
872static int ip6_tnl_xmit2(struct sk_buff *skb,
873 struct net_device *dev,
874 __u8 dsfield,
875 struct flowi6 *fl6,
876 int encap_limit,
877 __u32 *pmtu)
878{
879 struct net *net = dev_net(dev);
880 struct ip6_tnl *t = netdev_priv(dev);
881 struct net_device_stats *stats = &t->dev->stats;
882 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
883 struct ipv6_tel_txoption opt;
884 struct dst_entry *dst = NULL, *ndst = NULL;
885 struct net_device *tdev;
886 int mtu;
887 unsigned int max_headroom = sizeof(struct ipv6hdr);
888 u8 proto;
889 int err = -1;
890 int pkt_len;
891
892 if (!fl6->flowi6_mark)
893 dst = ip6_tnl_dst_check(t);
894 if (!dst) {
895 ndst = ip6_route_output(net, NULL, fl6);
896
897 if (ndst->error)
898 goto tx_err_link_failure;
899 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
900 if (IS_ERR(ndst)) {
901 err = PTR_ERR(ndst);
902 ndst = NULL;
903 goto tx_err_link_failure;
904 }
905 dst = ndst;
906 }
907
908 tdev = dst->dev;
909
910 if (tdev == dev) {
911 stats->collisions++;
912 net_warn_ratelimited("%s: Local routing loop detected!\n",
913 t->parms.name);
914 goto tx_err_dst_release;
915 }
916 mtu = dst_mtu(dst) - sizeof (*ipv6h);
917 if (encap_limit >= 0) {
918 max_headroom += 8;
919 mtu -= 8;
920 }
921 if (mtu < IPV6_MIN_MTU)
922 mtu = IPV6_MIN_MTU;
923 if (skb_dst(skb))
924 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
925 if (skb->len > mtu) {
926 *pmtu = mtu;
927 err = -EMSGSIZE;
928 goto tx_err_dst_release;
929 }
930
931 /*
932 * Okay, now see if we can stuff it in the buffer as-is.
933 */
934 max_headroom += LL_RESERVED_SPACE(tdev);
935
936 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
937 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
938 struct sk_buff *new_skb;
939
940 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
941 goto tx_err_dst_release;
942
943 if (skb->sk)
944 skb_set_owner_w(new_skb, skb->sk);
945 consume_skb(skb);
946 skb = new_skb;
947 }
948 skb_dst_drop(skb);
949 if (fl6->flowi6_mark) {
950 skb_dst_set(skb, dst);
951 ndst = NULL;
952 } else {
953 skb_dst_set_noref(skb, dst);
954 }
955 skb->transport_header = skb->network_header;
956
957 proto = fl6->flowi6_proto;
958 if (encap_limit >= 0) {
959 init_tel_txopt(&opt, encap_limit);
960 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
961 }
962 skb_push(skb, sizeof(struct ipv6hdr));
963 skb_reset_network_header(skb);
964 ipv6h = ipv6_hdr(skb);
965 *(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000);
966 dsfield = INET_ECN_encapsulate(0, dsfield);
967 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
968 ipv6h->hop_limit = t->parms.hop_limit;
969 ipv6h->nexthdr = proto;
970 ipv6h->saddr = fl6->saddr;
971 ipv6h->daddr = fl6->daddr;
972 nf_reset(skb);
973 pkt_len = skb->len;
974 err = ip6_local_out(skb);
975
976 if (net_xmit_eval(err) == 0) {
977 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats);
978
979 tstats->tx_bytes += pkt_len;
980 tstats->tx_packets++;
981 } else {
982 stats->tx_errors++;
983 stats->tx_aborted_errors++;
984 }
985 if (ndst)
986 ip6_tnl_dst_store(t, ndst);
987 return 0;
988tx_err_link_failure:
989 stats->tx_carrier_errors++;
990 dst_link_failure(skb);
991tx_err_dst_release:
992 dst_release(ndst);
993 return err;
994}
995
996static inline int
997ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
998{
999 struct ip6_tnl *t = netdev_priv(dev);
1000 const struct iphdr *iph = ip_hdr(skb);
1001 int encap_limit = -1;
1002 struct flowi6 fl6;
1003 __u8 dsfield;
1004 __u32 mtu;
1005 int err;
1006
1007 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1008 !ip6_tnl_xmit_ctl(t))
1009 return -1;
1010
1011 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1012 encap_limit = t->parms.encap_limit;
1013
1014 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1015 fl6.flowi6_proto = IPPROTO_IPIP;
1016
1017 dsfield = ipv4_get_dsfield(iph);
1018
1019 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1020 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1021 & IPV6_TCLASS_MASK;
1022 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1023 fl6.flowi6_mark = skb->mark;
1024
1025 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1026 if (err != 0) {
1027 /* XXX: send ICMP error even if DF is not set. */
1028 if (err == -EMSGSIZE)
1029 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1030 htonl(mtu));
1031 return -1;
1032 }
1033
1034 return 0;
1035}
1036
1037static inline int
1038ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1039{
1040 struct ip6_tnl *t = netdev_priv(dev);
1041 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1042 int encap_limit = -1;
1043 __u16 offset;
1044 struct flowi6 fl6;
1045 __u8 dsfield;
1046 __u32 mtu;
1047 int err;
1048
1049 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1050 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1051 return -1;
1052
1053 offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb));
1054 if (offset > 0) {
1055 struct ipv6_tlv_tnl_enc_lim *tel;
1056 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1057 if (tel->encap_limit == 0) {
1058 icmpv6_send(skb, ICMPV6_PARAMPROB,
1059 ICMPV6_HDR_FIELD, offset + 2);
1060 return -1;
1061 }
1062 encap_limit = tel->encap_limit - 1;
1063 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1064 encap_limit = t->parms.encap_limit;
1065
1066 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1067 fl6.flowi6_proto = IPPROTO_IPV6;
1068
1069 dsfield = ipv6_get_dsfield(ipv6h);
1070 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1071 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1072 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1073 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1074 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1075 fl6.flowi6_mark = skb->mark;
1076
1077 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1078 if (err != 0) {
1079 if (err == -EMSGSIZE)
1080 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1081 return -1;
1082 }
1083
1084 return 0;
1085}
1086
1087static netdev_tx_t
1088ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1089{
1090 struct ip6_tnl *t = netdev_priv(dev);
1091 struct net_device_stats *stats = &t->dev->stats;
1092 int ret;
1093
1094 switch (skb->protocol) {
1095 case htons(ETH_P_IP):
1096 ret = ip4ip6_tnl_xmit(skb, dev);
1097 break;
1098 case htons(ETH_P_IPV6):
1099 ret = ip6ip6_tnl_xmit(skb, dev);
1100 break;
1101 default:
1102 goto tx_err;
1103 }
1104
1105 if (ret < 0)
1106 goto tx_err;
1107
1108 return NETDEV_TX_OK;
1109
1110tx_err:
1111 stats->tx_errors++;
1112 stats->tx_dropped++;
1113 kfree_skb(skb);
1114 return NETDEV_TX_OK;
1115}
1116
1117static void ip6_tnl_set_cap(struct ip6_tnl *t)
1118{
1119 struct ip6_tnl_parm *p = &t->parms;
1120 int ltype = ipv6_addr_type(&p->laddr);
1121 int rtype = ipv6_addr_type(&p->raddr);
1122
1123 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV);
1124
1125 if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1126 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1127 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
1128 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
1129 if (ltype&IPV6_ADDR_UNICAST)
1130 p->flags |= IP6_TNL_F_CAP_XMIT;
1131 if (rtype&IPV6_ADDR_UNICAST)
1132 p->flags |= IP6_TNL_F_CAP_RCV;
1133 }
1134}
1135
1136static void ip6_tnl_link_config(struct ip6_tnl *t)
1137{
1138 struct net_device *dev = t->dev;
1139 struct ip6_tnl_parm *p = &t->parms;
1140 struct flowi6 *fl6 = &t->fl.u.ip6;
1141
1142 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1143 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1144
1145 /* Set up flowi template */
1146 fl6->saddr = p->laddr;
1147 fl6->daddr = p->raddr;
1148 fl6->flowi6_oif = p->link;
1149 fl6->flowlabel = 0;
1150
1151 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1152 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1153 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1154 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1155
1156 ip6_tnl_set_cap(t);
1157
1158 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1159 dev->flags |= IFF_POINTOPOINT;
1160 else
1161 dev->flags &= ~IFF_POINTOPOINT;
1162
1163 dev->iflink = p->link;
1164
1165 if (p->flags & IP6_TNL_F_CAP_XMIT) {
1166 int strict = (ipv6_addr_type(&p->raddr) &
1167 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1168
1169 struct rt6_info *rt = rt6_lookup(dev_net(dev),
1170 &p->raddr, &p->laddr,
1171 p->link, strict);
1172
1173 if (rt == NULL)
1174 return;
1175
1176 if (rt->dst.dev) {
1177 dev->hard_header_len = rt->dst.dev->hard_header_len +
1178 sizeof (struct ipv6hdr);
1179
1180 dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1181 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1182 dev->mtu-=8;
1183
1184 if (dev->mtu < IPV6_MIN_MTU)
1185 dev->mtu = IPV6_MIN_MTU;
1186 }
1187 dst_release(&rt->dst);
1188 }
1189}
1190
1191/**
1192 * ip6_tnl_change - update the tunnel parameters
1193 * @t: tunnel to be changed
1194 * @p: tunnel configuration parameters
1195 *
1196 * Description:
1197 * ip6_tnl_change() updates the tunnel parameters
1198 **/
1199
1200static int
1201ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
1202{
1203 t->parms.laddr = p->laddr;
1204 t->parms.raddr = p->raddr;
1205 t->parms.flags = p->flags;
1206 t->parms.hop_limit = p->hop_limit;
1207 t->parms.encap_limit = p->encap_limit;
1208 t->parms.flowinfo = p->flowinfo;
1209 t->parms.link = p->link;
1210 t->parms.proto = p->proto;
1211 ip6_tnl_dst_reset(t);
1212 ip6_tnl_link_config(t);
1213 return 0;
1214}
1215
1216/**
1217 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1218 * @dev: virtual device associated with tunnel
1219 * @ifr: parameters passed from userspace
1220 * @cmd: command to be performed
1221 *
1222 * Description:
1223 * ip6_tnl_ioctl() is used for managing IPv6 tunnels
1224 * from userspace.
1225 *
1226 * The possible commands are the following:
1227 * %SIOCGETTUNNEL: get tunnel parameters for device
1228 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1229 * %SIOCCHGTUNNEL: change tunnel parameters to those given
1230 * %SIOCDELTUNNEL: delete tunnel
1231 *
1232 * The fallback device "ip6tnl0", created during module
1233 * initialization, can be used for creating other tunnel devices.
1234 *
1235 * Return:
1236 * 0 on success,
1237 * %-EFAULT if unable to copy data to or from userspace,
1238 * %-EPERM if current process hasn't %CAP_NET_ADMIN set
1239 * %-EINVAL if passed tunnel parameters are invalid,
1240 * %-EEXIST if changing a tunnel's parameters would cause a conflict
1241 * %-ENODEV if attempting to change or delete a nonexisting device
1242 **/
1243
1244static int
1245ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1246{
1247 int err = 0;
1248 struct ip6_tnl_parm p;
1249 struct ip6_tnl *t = NULL;
1250 struct net *net = dev_net(dev);
1251 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1252
1253 switch (cmd) {
1254 case SIOCGETTUNNEL:
1255 if (dev == ip6n->fb_tnl_dev) {
1256 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1257 err = -EFAULT;
1258 break;
1259 }
1260 t = ip6_tnl_locate(net, &p, 0);
1261 }
1262 if (t == NULL)
1263 t = netdev_priv(dev);
1264 memcpy(&p, &t->parms, sizeof (p));
1265 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1266 err = -EFAULT;
1267 }
1268 break;
1269 case SIOCADDTUNNEL:
1270 case SIOCCHGTUNNEL:
1271 err = -EPERM;
1272 if (!capable(CAP_NET_ADMIN))
1273 break;
1274 err = -EFAULT;
1275 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1276 break;
1277 err = -EINVAL;
1278 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1279 p.proto != 0)
1280 break;
1281 t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL);
1282 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1283 if (t != NULL) {
1284 if (t->dev != dev) {
1285 err = -EEXIST;
1286 break;
1287 }
1288 } else
1289 t = netdev_priv(dev);
1290
1291 ip6_tnl_unlink(ip6n, t);
1292 synchronize_net();
1293 err = ip6_tnl_change(t, &p);
1294 ip6_tnl_link(ip6n, t);
1295 netdev_state_change(dev);
1296 }
1297 if (t) {
1298 err = 0;
1299 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p)))
1300 err = -EFAULT;
1301
1302 } else
1303 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1304 break;
1305 case SIOCDELTUNNEL:
1306 err = -EPERM;
1307 if (!capable(CAP_NET_ADMIN))
1308 break;
1309
1310 if (dev == ip6n->fb_tnl_dev) {
1311 err = -EFAULT;
1312 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1313 break;
1314 err = -ENOENT;
1315 if ((t = ip6_tnl_locate(net, &p, 0)) == NULL)
1316 break;
1317 err = -EPERM;
1318 if (t->dev == ip6n->fb_tnl_dev)
1319 break;
1320 dev = t->dev;
1321 }
1322 err = 0;
1323 unregister_netdevice(dev);
1324 break;
1325 default:
1326 err = -EINVAL;
1327 }
1328 return err;
1329}
1330
1331/**
1332 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1333 * @dev: virtual device associated with tunnel
1334 * @new_mtu: the new mtu
1335 *
1336 * Return:
1337 * 0 on success,
1338 * %-EINVAL if mtu too small
1339 **/
1340
1341static int
1342ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1343{
1344 if (new_mtu < IPV6_MIN_MTU) {
1345 return -EINVAL;
1346 }
1347 dev->mtu = new_mtu;
1348 return 0;
1349}
1350
1351
1352static const struct net_device_ops ip6_tnl_netdev_ops = {
1353 .ndo_uninit = ip6_tnl_dev_uninit,
1354 .ndo_start_xmit = ip6_tnl_xmit,
1355 .ndo_do_ioctl = ip6_tnl_ioctl,
1356 .ndo_change_mtu = ip6_tnl_change_mtu,
1357 .ndo_get_stats = ip6_get_stats,
1358};
1359
1360
1361/**
1362 * ip6_tnl_dev_setup - setup virtual tunnel device
1363 * @dev: virtual device associated with tunnel
1364 *
1365 * Description:
1366 * Initialize function pointers and device parameters
1367 **/
1368
1369static void ip6_tnl_dev_setup(struct net_device *dev)
1370{
1371 struct ip6_tnl *t;
1372
1373 dev->netdev_ops = &ip6_tnl_netdev_ops;
1374 dev->destructor = ip6_dev_free;
1375
1376 dev->type = ARPHRD_TUNNEL6;
1377 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1378 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1379 t = netdev_priv(dev);
1380 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1381 dev->mtu-=8;
1382 dev->flags |= IFF_NOARP;
1383 dev->addr_len = sizeof(struct in6_addr);
1384 dev->features |= NETIF_F_NETNS_LOCAL;
1385 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1386}
1387
1388
1389/**
1390 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1391 * @dev: virtual device associated with tunnel
1392 **/
1393
1394static inline int
1395ip6_tnl_dev_init_gen(struct net_device *dev)
1396{
1397 struct ip6_tnl *t = netdev_priv(dev);
1398
1399 t->dev = dev;
1400 dev->tstats = alloc_percpu(struct pcpu_tstats);
1401 if (!dev->tstats)
1402 return -ENOMEM;
1403 return 0;
1404}
1405
1406/**
1407 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1408 * @dev: virtual device associated with tunnel
1409 **/
1410
1411static int ip6_tnl_dev_init(struct net_device *dev)
1412{
1413 struct ip6_tnl *t = netdev_priv(dev);
1414 int err = ip6_tnl_dev_init_gen(dev);
1415
1416 if (err)
1417 return err;
1418 ip6_tnl_link_config(t);
1419 return 0;
1420}
1421
1422/**
1423 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1424 * @dev: fallback device
1425 *
1426 * Return: 0
1427 **/
1428
1429static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1430{
1431 struct ip6_tnl *t = netdev_priv(dev);
1432 struct net *net = dev_net(dev);
1433 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1434 int err = ip6_tnl_dev_init_gen(dev);
1435
1436 if (err)
1437 return err;
1438
1439 t->parms.proto = IPPROTO_IPV6;
1440 dev_hold(dev);
1441 rcu_assign_pointer(ip6n->tnls_wc[0], t);
1442 return 0;
1443}
1444
1445static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1446 .handler = ip4ip6_rcv,
1447 .err_handler = ip4ip6_err,
1448 .priority = 1,
1449};
1450
1451static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1452 .handler = ip6ip6_rcv,
1453 .err_handler = ip6ip6_err,
1454 .priority = 1,
1455};
1456
1457static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
1458{
1459 int h;
1460 struct ip6_tnl *t;
1461 LIST_HEAD(list);
1462
1463 for (h = 0; h < HASH_SIZE; h++) {
1464 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1465 while (t != NULL) {
1466 unregister_netdevice_queue(t->dev, &list);
1467 t = rtnl_dereference(t->next);
1468 }
1469 }
1470
1471 t = rtnl_dereference(ip6n->tnls_wc[0]);
1472 unregister_netdevice_queue(t->dev, &list);
1473 unregister_netdevice_many(&list);
1474}
1475
1476static int __net_init ip6_tnl_init_net(struct net *net)
1477{
1478 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1479 struct ip6_tnl *t = NULL;
1480 int err;
1481
1482 ip6n->tnls[0] = ip6n->tnls_wc;
1483 ip6n->tnls[1] = ip6n->tnls_r_l;
1484
1485 err = -ENOMEM;
1486 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1487 ip6_tnl_dev_setup);
1488
1489 if (!ip6n->fb_tnl_dev)
1490 goto err_alloc_dev;
1491 dev_net_set(ip6n->fb_tnl_dev, net);
1492
1493 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1494 if (err < 0)
1495 goto err_register;
1496
1497 err = register_netdev(ip6n->fb_tnl_dev);
1498 if (err < 0)
1499 goto err_register;
1500
1501 t = netdev_priv(ip6n->fb_tnl_dev);
1502
1503 strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1504 return 0;
1505
1506err_register:
1507 ip6_dev_free(ip6n->fb_tnl_dev);
1508err_alloc_dev:
1509 return err;
1510}
1511
1512static void __net_exit ip6_tnl_exit_net(struct net *net)
1513{
1514 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1515
1516 rtnl_lock();
1517 ip6_tnl_destroy_tunnels(ip6n);
1518 rtnl_unlock();
1519}
1520
1521static struct pernet_operations ip6_tnl_net_ops = {
1522 .init = ip6_tnl_init_net,
1523 .exit = ip6_tnl_exit_net,
1524 .id = &ip6_tnl_net_id,
1525 .size = sizeof(struct ip6_tnl_net),
1526};
1527
1528/**
1529 * ip6_tunnel_init - register protocol and reserve needed resources
1530 *
1531 * Return: 0 on success
1532 **/
1533
1534static int __init ip6_tunnel_init(void)
1535{
1536 int err;
1537
1538 err = register_pernet_device(&ip6_tnl_net_ops);
1539 if (err < 0)
1540 goto out_pernet;
1541
1542 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1543 if (err < 0) {
1544 pr_err("%s: can't register ip4ip6\n", __func__);
1545 goto out_ip4ip6;
1546 }
1547
1548 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1549 if (err < 0) {
1550 pr_err("%s: can't register ip6ip6\n", __func__);
1551 goto out_ip6ip6;
1552 }
1553
1554 return 0;
1555
1556out_ip6ip6:
1557 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1558out_ip4ip6:
1559 unregister_pernet_device(&ip6_tnl_net_ops);
1560out_pernet:
1561 return err;
1562}
1563
1564/**
1565 * ip6_tunnel_cleanup - free resources and unregister protocol
1566 **/
1567
1568static void __exit ip6_tunnel_cleanup(void)
1569{
1570 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1571 pr_info("%s: can't deregister ip4ip6\n", __func__);
1572
1573 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1574 pr_info("%s: can't deregister ip6ip6\n", __func__);
1575
1576 unregister_pernet_device(&ip6_tnl_net_ops);
1577}
1578
1579module_init(ip6_tunnel_init);
1580module_exit(ip6_tunnel_cleanup);