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Merge branch 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux/fpc-iii.git] / net / ipv6 / sit.c
blob976e68244b998fd2a7f78536f0042fc504b083eb
1 /*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * Changes:
15 * Roger Venning <r.venning@telstra.com>: 6to4 support
16 * Nate Thompson <nate@thebog.net>: 6to4 support
17 * Fred Templin <fred.l.templin@boeing.com>: isatap support
18 */
19
20 #include <linux/module.h>
21 #include <linux/capability.h>
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/net.h>
27 #include <linux/in6.h>
28 #include <linux/netdevice.h>
29 #include <linux/if_arp.h>
30 #include <linux/icmp.h>
31 #include <asm/uaccess.h>
32 #include <linux/init.h>
33 #include <linux/netfilter_ipv4.h>
34 #include <linux/if_ether.h>
35
36 #include <net/sock.h>
37 #include <net/snmp.h>
38
39 #include <net/ipv6.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/ip6_fib.h>
43 #include <net/ip6_route.h>
44 #include <net/ndisc.h>
45 #include <net/addrconf.h>
46 #include <net/ip.h>
47 #include <net/udp.h>
48 #include <net/icmp.h>
49 #include <net/ipip.h>
50 #include <net/inet_ecn.h>
51 #include <net/xfrm.h>
52 #include <net/dsfield.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 /*
57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
58
59 For comments look at net/ipv4/ip_gre.c --ANK
60 */
61
62 #define HASH_SIZE 16
63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
64
65 static void ipip6_fb_tunnel_init(struct net_device *dev);
66 static void ipip6_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_setup(struct net_device *dev);
68
69 static int sit_net_id __read_mostly;
70 struct sit_net {
71 struct ip_tunnel *tunnels_r_l[HASH_SIZE];
72 struct ip_tunnel *tunnels_r[HASH_SIZE];
73 struct ip_tunnel *tunnels_l[HASH_SIZE];
74 struct ip_tunnel *tunnels_wc[1];
75 struct ip_tunnel **tunnels[4];
76
77 struct net_device *fb_tunnel_dev;
78 };
79
80 /*
81 * Locking : hash tables are protected by RCU and a spinlock
82 */
83 static DEFINE_SPINLOCK(ipip6_lock);
84
85 #define for_each_ip_tunnel_rcu(start) \
86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
87
88 /*
89 * Must be invoked with rcu_read_lock
90 */
91 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
92 struct net_device *dev, __be32 remote, __be32 local)
93 {
94 unsigned h0 = HASH(remote);
95 unsigned h1 = HASH(local);
96 struct ip_tunnel *t;
97 struct sit_net *sitn = net_generic(net, sit_net_id);
98
99 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
100 if (local == t->parms.iph.saddr &&
101 remote == t->parms.iph.daddr &&
102 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
103 (t->dev->flags & IFF_UP))
104 return t;
105 }
106 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
107 if (remote == t->parms.iph.daddr &&
108 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
109 (t->dev->flags & IFF_UP))
110 return t;
111 }
112 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
113 if (local == t->parms.iph.saddr &&
114 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
115 (t->dev->flags & IFF_UP))
116 return t;
117 }
118 t = rcu_dereference(sitn->tunnels_wc[0]);
119 if ((t != NULL) && (t->dev->flags & IFF_UP))
120 return t;
121 return NULL;
122 }
123
124 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn,
125 struct ip_tunnel_parm *parms)
126 {
127 __be32 remote = parms->iph.daddr;
128 __be32 local = parms->iph.saddr;
129 unsigned h = 0;
130 int prio = 0;
131
132 if (remote) {
133 prio |= 2;
134 h ^= HASH(remote);
135 }
136 if (local) {
137 prio |= 1;
138 h ^= HASH(local);
139 }
140 return &sitn->tunnels[prio][h];
141 }
142
143 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn,
144 struct ip_tunnel *t)
145 {
146 return __ipip6_bucket(sitn, &t->parms);
147 }
148
149 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
150 {
151 struct ip_tunnel **tp;
152
153 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) {
154 if (t == *tp) {
155 spin_lock_bh(&ipip6_lock);
156 *tp = t->next;
157 spin_unlock_bh(&ipip6_lock);
158 break;
159 }
160 }
161 }
162
163 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
164 {
165 struct ip_tunnel **tp = ipip6_bucket(sitn, t);
166
167 spin_lock_bh(&ipip6_lock);
168 t->next = *tp;
169 rcu_assign_pointer(*tp, t);
170 spin_unlock_bh(&ipip6_lock);
171 }
172
173 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
174 {
175 #ifdef CONFIG_IPV6_SIT_6RD
176 struct ip_tunnel *t = netdev_priv(dev);
177
178 if (t->dev == sitn->fb_tunnel_dev) {
179 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
180 t->ip6rd.relay_prefix = 0;
181 t->ip6rd.prefixlen = 16;
182 t->ip6rd.relay_prefixlen = 0;
183 } else {
184 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
185 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
186 }
187 #endif
188 }
189
190 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
191 struct ip_tunnel_parm *parms, int create)
192 {
193 __be32 remote = parms->iph.daddr;
194 __be32 local = parms->iph.saddr;
195 struct ip_tunnel *t, **tp, *nt;
196 struct net_device *dev;
197 char name[IFNAMSIZ];
198 struct sit_net *sitn = net_generic(net, sit_net_id);
199
200 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) {
201 if (local == t->parms.iph.saddr &&
202 remote == t->parms.iph.daddr &&
203 parms->link == t->parms.link) {
204 if (create)
205 return NULL;
206 else
207 return t;
208 }
209 }
210 if (!create)
211 goto failed;
212
213 if (parms->name[0])
214 strlcpy(name, parms->name, IFNAMSIZ);
215 else
216 sprintf(name, "sit%%d");
217
218 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
219 if (dev == NULL)
220 return NULL;
221
222 dev_net_set(dev, net);
223
224 if (strchr(name, '%')) {
225 if (dev_alloc_name(dev, name) < 0)
226 goto failed_free;
227 }
228
229 nt = netdev_priv(dev);
230
231 nt->parms = *parms;
232 ipip6_tunnel_init(dev);
233 ipip6_tunnel_clone_6rd(dev, sitn);
234
235 if (parms->i_flags & SIT_ISATAP)
236 dev->priv_flags |= IFF_ISATAP;
237
238 if (register_netdevice(dev) < 0)
239 goto failed_free;
240
241 dev_hold(dev);
242
243 ipip6_tunnel_link(sitn, nt);
244 return nt;
245
246 failed_free:
247 free_netdev(dev);
248 failed:
249 return NULL;
250 }
251
252 static DEFINE_SPINLOCK(ipip6_prl_lock);
253
254 #define for_each_prl_rcu(start) \
255 for (prl = rcu_dereference(start); \
256 prl; \
257 prl = rcu_dereference(prl->next))
258
259 static struct ip_tunnel_prl_entry *
260 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
261 {
262 struct ip_tunnel_prl_entry *prl;
263
264 for_each_prl_rcu(t->prl)
265 if (prl->addr == addr)
266 break;
267 return prl;
268
269 }
270
271 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
272 struct ip_tunnel_prl __user *a)
273 {
274 struct ip_tunnel_prl kprl, *kp;
275 struct ip_tunnel_prl_entry *prl;
276 unsigned int cmax, c = 0, ca, len;
277 int ret = 0;
278
279 if (copy_from_user(&kprl, a, sizeof(kprl)))
280 return -EFAULT;
281 cmax = kprl.datalen / sizeof(kprl);
282 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
283 cmax = 1;
284
285 /* For simple GET or for root users,
286 * we try harder to allocate.
287 */
288 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
289 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
290 NULL;
291
292 rcu_read_lock();
293
294 ca = t->prl_count < cmax ? t->prl_count : cmax;
295
296 if (!kp) {
297 /* We don't try hard to allocate much memory for
298 * non-root users.
299 * For root users, retry allocating enough memory for
300 * the answer.
301 */
302 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
303 if (!kp) {
304 ret = -ENOMEM;
305 goto out;
306 }
307 }
308
309 c = 0;
310 for_each_prl_rcu(t->prl) {
311 if (c >= cmax)
312 break;
313 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
314 continue;
315 kp[c].addr = prl->addr;
316 kp[c].flags = prl->flags;
317 c++;
318 if (kprl.addr != htonl(INADDR_ANY))
319 break;
320 }
321 out:
322 rcu_read_unlock();
323
324 len = sizeof(*kp) * c;
325 ret = 0;
326 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
327 ret = -EFAULT;
328
329 kfree(kp);
330
331 return ret;
332 }
333
334 static int
335 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
336 {
337 struct ip_tunnel_prl_entry *p;
338 int err = 0;
339
340 if (a->addr == htonl(INADDR_ANY))
341 return -EINVAL;
342
343 spin_lock(&ipip6_prl_lock);
344
345 for (p = t->prl; p; p = p->next) {
346 if (p->addr == a->addr) {
347 if (chg) {
348 p->flags = a->flags;
349 goto out;
350 }
351 err = -EEXIST;
352 goto out;
353 }
354 }
355
356 if (chg) {
357 err = -ENXIO;
358 goto out;
359 }
360
361 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
362 if (!p) {
363 err = -ENOBUFS;
364 goto out;
365 }
366
367 INIT_RCU_HEAD(&p->rcu_head);
368 p->next = t->prl;
369 p->addr = a->addr;
370 p->flags = a->flags;
371 t->prl_count++;
372 rcu_assign_pointer(t->prl, p);
373 out:
374 spin_unlock(&ipip6_prl_lock);
375 return err;
376 }
377
378 static void prl_entry_destroy_rcu(struct rcu_head *head)
379 {
380 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head));
381 }
382
383 static void prl_list_destroy_rcu(struct rcu_head *head)
384 {
385 struct ip_tunnel_prl_entry *p, *n;
386
387 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
388 do {
389 n = p->next;
390 kfree(p);
391 p = n;
392 } while (p);
393 }
394
395 static int
396 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
397 {
398 struct ip_tunnel_prl_entry *x, **p;
399 int err = 0;
400
401 spin_lock(&ipip6_prl_lock);
402
403 if (a && a->addr != htonl(INADDR_ANY)) {
404 for (p = &t->prl; *p; p = &(*p)->next) {
405 if ((*p)->addr == a->addr) {
406 x = *p;
407 *p = x->next;
408 call_rcu(&x->rcu_head, prl_entry_destroy_rcu);
409 t->prl_count--;
410 goto out;
411 }
412 }
413 err = -ENXIO;
414 } else {
415 if (t->prl) {
416 t->prl_count = 0;
417 x = t->prl;
418 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
419 t->prl = NULL;
420 }
421 }
422 out:
423 spin_unlock(&ipip6_prl_lock);
424 return err;
425 }
426
427 static int
428 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
429 {
430 struct ip_tunnel_prl_entry *p;
431 int ok = 1;
432
433 rcu_read_lock();
434 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
435 if (p) {
436 if (p->flags & PRL_DEFAULT)
437 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
438 else
439 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
440 } else {
441 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
442 if (ipv6_addr_is_isatap(addr6) &&
443 (addr6->s6_addr32[3] == iph->saddr) &&
444 ipv6_chk_prefix(addr6, t->dev))
445 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
446 else
447 ok = 0;
448 }
449 rcu_read_unlock();
450 return ok;
451 }
452
453 static void ipip6_tunnel_uninit(struct net_device *dev)
454 {
455 struct net *net = dev_net(dev);
456 struct sit_net *sitn = net_generic(net, sit_net_id);
457
458 if (dev == sitn->fb_tunnel_dev) {
459 spin_lock_bh(&ipip6_lock);
460 sitn->tunnels_wc[0] = NULL;
461 spin_unlock_bh(&ipip6_lock);
462 dev_put(dev);
463 } else {
464 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
465 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
466 dev_put(dev);
467 }
468 }
469
470
471 static int ipip6_err(struct sk_buff *skb, u32 info)
472 {
473
474 /* All the routers (except for Linux) return only
475 8 bytes of packet payload. It means, that precise relaying of
476 ICMP in the real Internet is absolutely infeasible.
477 */
478 struct iphdr *iph = (struct iphdr*)skb->data;
479 const int type = icmp_hdr(skb)->type;
480 const int code = icmp_hdr(skb)->code;
481 struct ip_tunnel *t;
482 int err;
483
484 switch (type) {
485 default:
486 case ICMP_PARAMETERPROB:
487 return 0;
488
489 case ICMP_DEST_UNREACH:
490 switch (code) {
491 case ICMP_SR_FAILED:
492 case ICMP_PORT_UNREACH:
493 /* Impossible event. */
494 return 0;
495 case ICMP_FRAG_NEEDED:
496 /* Soft state for pmtu is maintained by IP core. */
497 return 0;
498 default:
499 /* All others are translated to HOST_UNREACH.
500 rfc2003 contains "deep thoughts" about NET_UNREACH,
501 I believe they are just ether pollution. --ANK
502 */
503 break;
504 }
505 break;
506 case ICMP_TIME_EXCEEDED:
507 if (code != ICMP_EXC_TTL)
508 return 0;
509 break;
510 }
511
512 err = -ENOENT;
513
514 rcu_read_lock();
515 t = ipip6_tunnel_lookup(dev_net(skb->dev),
516 skb->dev,
517 iph->daddr,
518 iph->saddr);
519 if (t == NULL || t->parms.iph.daddr == 0)
520 goto out;
521
522 err = 0;
523 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
524 goto out;
525
526 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
527 t->err_count++;
528 else
529 t->err_count = 1;
530 t->err_time = jiffies;
531 out:
532 rcu_read_unlock();
533 return err;
534 }
535
536 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
537 {
538 if (INET_ECN_is_ce(iph->tos))
539 IP6_ECN_set_ce(ipv6_hdr(skb));
540 }
541
542 static int ipip6_rcv(struct sk_buff *skb)
543 {
544 struct iphdr *iph;
545 struct ip_tunnel *tunnel;
546
547 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
548 goto out;
549
550 iph = ip_hdr(skb);
551
552 rcu_read_lock();
553 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
554 iph->saddr, iph->daddr);
555 if (tunnel != NULL) {
556 secpath_reset(skb);
557 skb->mac_header = skb->network_header;
558 skb_reset_network_header(skb);
559 IPCB(skb)->flags = 0;
560 skb->protocol = htons(ETH_P_IPV6);
561 skb->pkt_type = PACKET_HOST;
562
563 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
564 !isatap_chksrc(skb, iph, tunnel)) {
565 tunnel->dev->stats.rx_errors++;
566 rcu_read_unlock();
567 kfree_skb(skb);
568 return 0;
569 }
570 tunnel->dev->stats.rx_packets++;
571 tunnel->dev->stats.rx_bytes += skb->len;
572 skb->dev = tunnel->dev;
573 skb_dst_drop(skb);
574 nf_reset(skb);
575 ipip6_ecn_decapsulate(iph, skb);
576 netif_rx(skb);
577 rcu_read_unlock();
578 return 0;
579 }
580
581 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
582 rcu_read_unlock();
583 out:
584 kfree_skb(skb);
585 return 0;
586 }
587
588 /*
589 * Returns the embedded IPv4 address if the IPv6 address
590 * comes from 6rd / 6to4 (RFC 3056) addr space.
591 */
592 static inline
593 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
594 {
595 __be32 dst = 0;
596
597 #ifdef CONFIG_IPV6_SIT_6RD
598 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
599 tunnel->ip6rd.prefixlen)) {
600 unsigned pbw0, pbi0;
601 int pbi1;
602 u32 d;
603
604 pbw0 = tunnel->ip6rd.prefixlen >> 5;
605 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
606
607 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
608 tunnel->ip6rd.relay_prefixlen;
609
610 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
611 if (pbi1 > 0)
612 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
613 (32 - pbi1);
614
615 dst = tunnel->ip6rd.relay_prefix | htonl(d);
616 }
617 #else
618 if (v6dst->s6_addr16[0] == htons(0x2002)) {
619 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
620 memcpy(&dst, &v6dst->s6_addr16[1], 4);
621 }
622 #endif
623 return dst;
624 }
625
626 /*
627 * This function assumes it is being called from dev_queue_xmit()
628 * and that skb is filled properly by that function.
629 */
630
631 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
632 struct net_device *dev)
633 {
634 struct ip_tunnel *tunnel = netdev_priv(dev);
635 struct net_device_stats *stats = &dev->stats;
636 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
637 struct iphdr *tiph = &tunnel->parms.iph;
638 struct ipv6hdr *iph6 = ipv6_hdr(skb);
639 u8 tos = tunnel->parms.iph.tos;
640 __be16 df = tiph->frag_off;
641 struct rtable *rt; /* Route to the other host */
642 struct net_device *tdev; /* Device to other host */
643 struct iphdr *iph; /* Our new IP header */
644 unsigned int max_headroom; /* The extra header space needed */
645 __be32 dst = tiph->daddr;
646 int mtu;
647 struct in6_addr *addr6;
648 int addr_type;
649
650 if (skb->protocol != htons(ETH_P_IPV6))
651 goto tx_error;
652
653 /* ISATAP (RFC4214) - must come before 6to4 */
654 if (dev->priv_flags & IFF_ISATAP) {
655 struct neighbour *neigh = NULL;
656
657 if (skb_dst(skb))
658 neigh = skb_dst(skb)->neighbour;
659
660 if (neigh == NULL) {
661 if (net_ratelimit())
662 printk(KERN_DEBUG "sit: nexthop == NULL\n");
663 goto tx_error;
664 }
665
666 addr6 = (struct in6_addr*)&neigh->primary_key;
667 addr_type = ipv6_addr_type(addr6);
668
669 if ((addr_type & IPV6_ADDR_UNICAST) &&
670 ipv6_addr_is_isatap(addr6))
671 dst = addr6->s6_addr32[3];
672 else
673 goto tx_error;
674 }
675
676 if (!dst)
677 dst = try_6rd(&iph6->daddr, tunnel);
678
679 if (!dst) {
680 struct neighbour *neigh = NULL;
681
682 if (skb_dst(skb))
683 neigh = skb_dst(skb)->neighbour;
684
685 if (neigh == NULL) {
686 if (net_ratelimit())
687 printk(KERN_DEBUG "sit: nexthop == NULL\n");
688 goto tx_error;
689 }
690
691 addr6 = (struct in6_addr*)&neigh->primary_key;
692 addr_type = ipv6_addr_type(addr6);
693
694 if (addr_type == IPV6_ADDR_ANY) {
695 addr6 = &ipv6_hdr(skb)->daddr;
696 addr_type = ipv6_addr_type(addr6);
697 }
698
699 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
700 goto tx_error_icmp;
701
702 dst = addr6->s6_addr32[3];
703 }
704
705 {
706 struct flowi fl = { .nl_u = { .ip4_u =
707 { .daddr = dst,
708 .saddr = tiph->saddr,
709 .tos = RT_TOS(tos) } },
710 .oif = tunnel->parms.link,
711 .proto = IPPROTO_IPV6 };
712 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
713 stats->tx_carrier_errors++;
714 goto tx_error_icmp;
715 }
716 }
717 if (rt->rt_type != RTN_UNICAST) {
718 ip_rt_put(rt);
719 stats->tx_carrier_errors++;
720 goto tx_error_icmp;
721 }
722 tdev = rt->u.dst.dev;
723
724 if (tdev == dev) {
725 ip_rt_put(rt);
726 stats->collisions++;
727 goto tx_error;
728 }
729
730 if (df) {
731 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
732
733 if (mtu < 68) {
734 stats->collisions++;
735 ip_rt_put(rt);
736 goto tx_error;
737 }
738
739 if (mtu < IPV6_MIN_MTU) {
740 mtu = IPV6_MIN_MTU;
741 df = 0;
742 }
743
744 if (tunnel->parms.iph.daddr && skb_dst(skb))
745 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
746
747 if (skb->len > mtu) {
748 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
749 ip_rt_put(rt);
750 goto tx_error;
751 }
752 }
753
754 if (tunnel->err_count > 0) {
755 if (time_before(jiffies,
756 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
757 tunnel->err_count--;
758 dst_link_failure(skb);
759 } else
760 tunnel->err_count = 0;
761 }
762
763 /*
764 * Okay, now see if we can stuff it in the buffer as-is.
765 */
766 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
767
768 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
769 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
770 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
771 if (!new_skb) {
772 ip_rt_put(rt);
773 txq->tx_dropped++;
774 dev_kfree_skb(skb);
775 return NETDEV_TX_OK;
776 }
777 if (skb->sk)
778 skb_set_owner_w(new_skb, skb->sk);
779 dev_kfree_skb(skb);
780 skb = new_skb;
781 iph6 = ipv6_hdr(skb);
782 }
783
784 skb->transport_header = skb->network_header;
785 skb_push(skb, sizeof(struct iphdr));
786 skb_reset_network_header(skb);
787 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
788 IPCB(skb)->flags = 0;
789 skb_dst_drop(skb);
790 skb_dst_set(skb, &rt->u.dst);
791
792 /*
793 * Push down and install the IPIP header.
794 */
795
796 iph = ip_hdr(skb);
797 iph->version = 4;
798 iph->ihl = sizeof(struct iphdr)>>2;
799 iph->frag_off = df;
800 iph->protocol = IPPROTO_IPV6;
801 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
802 iph->daddr = rt->rt_dst;
803 iph->saddr = rt->rt_src;
804
805 if ((iph->ttl = tiph->ttl) == 0)
806 iph->ttl = iph6->hop_limit;
807
808 nf_reset(skb);
809
810 IPTUNNEL_XMIT();
811 return NETDEV_TX_OK;
812
813 tx_error_icmp:
814 dst_link_failure(skb);
815 tx_error:
816 stats->tx_errors++;
817 dev_kfree_skb(skb);
818 return NETDEV_TX_OK;
819 }
820
821 static void ipip6_tunnel_bind_dev(struct net_device *dev)
822 {
823 struct net_device *tdev = NULL;
824 struct ip_tunnel *tunnel;
825 struct iphdr *iph;
826
827 tunnel = netdev_priv(dev);
828 iph = &tunnel->parms.iph;
829
830 if (iph->daddr) {
831 struct flowi fl = { .nl_u = { .ip4_u =
832 { .daddr = iph->daddr,
833 .saddr = iph->saddr,
834 .tos = RT_TOS(iph->tos) } },
835 .oif = tunnel->parms.link,
836 .proto = IPPROTO_IPV6 };
837 struct rtable *rt;
838 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
839 tdev = rt->u.dst.dev;
840 ip_rt_put(rt);
841 }
842 dev->flags |= IFF_POINTOPOINT;
843 }
844
845 if (!tdev && tunnel->parms.link)
846 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
847
848 if (tdev) {
849 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
850 dev->mtu = tdev->mtu - sizeof(struct iphdr);
851 if (dev->mtu < IPV6_MIN_MTU)
852 dev->mtu = IPV6_MIN_MTU;
853 }
854 dev->iflink = tunnel->parms.link;
855 }
856
857 static int
858 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
859 {
860 int err = 0;
861 struct ip_tunnel_parm p;
862 struct ip_tunnel_prl prl;
863 struct ip_tunnel *t;
864 struct net *net = dev_net(dev);
865 struct sit_net *sitn = net_generic(net, sit_net_id);
866 #ifdef CONFIG_IPV6_SIT_6RD
867 struct ip_tunnel_6rd ip6rd;
868 #endif
869
870 switch (cmd) {
871 case SIOCGETTUNNEL:
872 #ifdef CONFIG_IPV6_SIT_6RD
873 case SIOCGET6RD:
874 #endif
875 t = NULL;
876 if (dev == sitn->fb_tunnel_dev) {
877 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
878 err = -EFAULT;
879 break;
880 }
881 t = ipip6_tunnel_locate(net, &p, 0);
882 }
883 if (t == NULL)
884 t = netdev_priv(dev);
885
886 err = -EFAULT;
887 if (cmd == SIOCGETTUNNEL) {
888 memcpy(&p, &t->parms, sizeof(p));
889 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
890 sizeof(p)))
891 goto done;
892 #ifdef CONFIG_IPV6_SIT_6RD
893 } else {
894 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
895 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
896 ip6rd.prefixlen = t->ip6rd.prefixlen;
897 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
898 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
899 sizeof(ip6rd)))
900 goto done;
901 #endif
902 }
903 err = 0;
904 break;
905
906 case SIOCADDTUNNEL:
907 case SIOCCHGTUNNEL:
908 err = -EPERM;
909 if (!capable(CAP_NET_ADMIN))
910 goto done;
911
912 err = -EFAULT;
913 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
914 goto done;
915
916 err = -EINVAL;
917 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
918 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
919 goto done;
920 if (p.iph.ttl)
921 p.iph.frag_off |= htons(IP_DF);
922
923 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
924
925 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
926 if (t != NULL) {
927 if (t->dev != dev) {
928 err = -EEXIST;
929 break;
930 }
931 } else {
932 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
933 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
934 err = -EINVAL;
935 break;
936 }
937 t = netdev_priv(dev);
938 ipip6_tunnel_unlink(sitn, t);
939 t->parms.iph.saddr = p.iph.saddr;
940 t->parms.iph.daddr = p.iph.daddr;
941 memcpy(dev->dev_addr, &p.iph.saddr, 4);
942 memcpy(dev->broadcast, &p.iph.daddr, 4);
943 ipip6_tunnel_link(sitn, t);
944 netdev_state_change(dev);
945 }
946 }
947
948 if (t) {
949 err = 0;
950 if (cmd == SIOCCHGTUNNEL) {
951 t->parms.iph.ttl = p.iph.ttl;
952 t->parms.iph.tos = p.iph.tos;
953 if (t->parms.link != p.link) {
954 t->parms.link = p.link;
955 ipip6_tunnel_bind_dev(dev);
956 netdev_state_change(dev);
957 }
958 }
959 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
960 err = -EFAULT;
961 } else
962 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
963 break;
964
965 case SIOCDELTUNNEL:
966 err = -EPERM;
967 if (!capable(CAP_NET_ADMIN))
968 goto done;
969
970 if (dev == sitn->fb_tunnel_dev) {
971 err = -EFAULT;
972 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
973 goto done;
974 err = -ENOENT;
975 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
976 goto done;
977 err = -EPERM;
978 if (t == netdev_priv(sitn->fb_tunnel_dev))
979 goto done;
980 dev = t->dev;
981 }
982 unregister_netdevice(dev);
983 err = 0;
984 break;
985
986 case SIOCGETPRL:
987 err = -EINVAL;
988 if (dev == sitn->fb_tunnel_dev)
989 goto done;
990 err = -ENOENT;
991 if (!(t = netdev_priv(dev)))
992 goto done;
993 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
994 break;
995
996 case SIOCADDPRL:
997 case SIOCDELPRL:
998 case SIOCCHGPRL:
999 err = -EPERM;
1000 if (!capable(CAP_NET_ADMIN))
1001 goto done;
1002 err = -EINVAL;
1003 if (dev == sitn->fb_tunnel_dev)
1004 goto done;
1005 err = -EFAULT;
1006 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1007 goto done;
1008 err = -ENOENT;
1009 if (!(t = netdev_priv(dev)))
1010 goto done;
1011
1012 switch (cmd) {
1013 case SIOCDELPRL:
1014 err = ipip6_tunnel_del_prl(t, &prl);
1015 break;
1016 case SIOCADDPRL:
1017 case SIOCCHGPRL:
1018 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1019 break;
1020 }
1021 netdev_state_change(dev);
1022 break;
1023
1024 #ifdef CONFIG_IPV6_SIT_6RD
1025 case SIOCADD6RD:
1026 case SIOCCHG6RD:
1027 case SIOCDEL6RD:
1028 err = -EPERM;
1029 if (!capable(CAP_NET_ADMIN))
1030 goto done;
1031
1032 err = -EFAULT;
1033 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1034 sizeof(ip6rd)))
1035 goto done;
1036
1037 t = netdev_priv(dev);
1038
1039 if (cmd != SIOCDEL6RD) {
1040 struct in6_addr prefix;
1041 __be32 relay_prefix;
1042
1043 err = -EINVAL;
1044 if (ip6rd.relay_prefixlen > 32 ||
1045 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1046 goto done;
1047
1048 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1049 ip6rd.prefixlen);
1050 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1051 goto done;
1052 if (ip6rd.relay_prefixlen)
1053 relay_prefix = ip6rd.relay_prefix &
1054 htonl(0xffffffffUL <<
1055 (32 - ip6rd.relay_prefixlen));
1056 else
1057 relay_prefix = 0;
1058 if (relay_prefix != ip6rd.relay_prefix)
1059 goto done;
1060
1061 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1062 t->ip6rd.relay_prefix = relay_prefix;
1063 t->ip6rd.prefixlen = ip6rd.prefixlen;
1064 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1065 } else
1066 ipip6_tunnel_clone_6rd(dev, sitn);
1067
1068 err = 0;
1069 break;
1070 #endif
1071
1072 default:
1073 err = -EINVAL;
1074 }
1075
1076 done:
1077 return err;
1078 }
1079
1080 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1081 {
1082 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1083 return -EINVAL;
1084 dev->mtu = new_mtu;
1085 return 0;
1086 }
1087
1088 static const struct net_device_ops ipip6_netdev_ops = {
1089 .ndo_uninit = ipip6_tunnel_uninit,
1090 .ndo_start_xmit = ipip6_tunnel_xmit,
1091 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1092 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1093 };
1094
1095 static void ipip6_tunnel_setup(struct net_device *dev)
1096 {
1097 dev->netdev_ops = &ipip6_netdev_ops;
1098 dev->destructor = free_netdev;
1099
1100 dev->type = ARPHRD_SIT;
1101 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1102 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1103 dev->flags = IFF_NOARP;
1104 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1105 dev->iflink = 0;
1106 dev->addr_len = 4;
1107 dev->features |= NETIF_F_NETNS_LOCAL;
1108 }
1109
1110 static void ipip6_tunnel_init(struct net_device *dev)
1111 {
1112 struct ip_tunnel *tunnel = netdev_priv(dev);
1113
1114 tunnel->dev = dev;
1115 strcpy(tunnel->parms.name, dev->name);
1116
1117 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1118 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1119
1120 ipip6_tunnel_bind_dev(dev);
1121 }
1122
1123 static void ipip6_fb_tunnel_init(struct net_device *dev)
1124 {
1125 struct ip_tunnel *tunnel = netdev_priv(dev);
1126 struct iphdr *iph = &tunnel->parms.iph;
1127 struct net *net = dev_net(dev);
1128 struct sit_net *sitn = net_generic(net, sit_net_id);
1129
1130 tunnel->dev = dev;
1131 strcpy(tunnel->parms.name, dev->name);
1132
1133 iph->version = 4;
1134 iph->protocol = IPPROTO_IPV6;
1135 iph->ihl = 5;
1136 iph->ttl = 64;
1137
1138 dev_hold(dev);
1139 sitn->tunnels_wc[0] = tunnel;
1140 }
1141
1142 static struct xfrm_tunnel sit_handler = {
1143 .handler = ipip6_rcv,
1144 .err_handler = ipip6_err,
1145 .priority = 1,
1146 };
1147
1148 static void sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1149 {
1150 int prio;
1151
1152 for (prio = 1; prio < 4; prio++) {
1153 int h;
1154 for (h = 0; h < HASH_SIZE; h++) {
1155 struct ip_tunnel *t = sitn->tunnels[prio][h];
1156
1157 while (t != NULL) {
1158 unregister_netdevice_queue(t->dev, head);
1159 t = t->next;
1160 }
1161 }
1162 }
1163 }
1164
1165 static int sit_init_net(struct net *net)
1166 {
1167 struct sit_net *sitn = net_generic(net, sit_net_id);
1168 int err;
1169
1170 sitn->tunnels[0] = sitn->tunnels_wc;
1171 sitn->tunnels[1] = sitn->tunnels_l;
1172 sitn->tunnels[2] = sitn->tunnels_r;
1173 sitn->tunnels[3] = sitn->tunnels_r_l;
1174
1175 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1176 ipip6_tunnel_setup);
1177 if (!sitn->fb_tunnel_dev) {
1178 err = -ENOMEM;
1179 goto err_alloc_dev;
1180 }
1181 dev_net_set(sitn->fb_tunnel_dev, net);
1182
1183 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1184 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1185
1186 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1187 goto err_reg_dev;
1188
1189 return 0;
1190
1191 err_reg_dev:
1192 dev_put(sitn->fb_tunnel_dev);
1193 free_netdev(sitn->fb_tunnel_dev);
1194 err_alloc_dev:
1195 return err;
1196 }
1197
1198 static void sit_exit_net(struct net *net)
1199 {
1200 struct sit_net *sitn = net_generic(net, sit_net_id);
1201 LIST_HEAD(list);
1202
1203 rtnl_lock();
1204 sit_destroy_tunnels(sitn, &list);
1205 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1206 unregister_netdevice_many(&list);
1207 rtnl_unlock();
1208 }
1209
1210 static struct pernet_operations sit_net_ops = {
1211 .init = sit_init_net,
1212 .exit = sit_exit_net,
1213 .id = &sit_net_id,
1214 .size = sizeof(struct sit_net),
1215 };
1216
1217 static void __exit sit_cleanup(void)
1218 {
1219 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1220
1221 unregister_pernet_device(&sit_net_ops);
1222 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1223 }
1224
1225 static int __init sit_init(void)
1226 {
1227 int err;
1228
1229 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1230
1231 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1232 printk(KERN_INFO "sit init: Can't add protocol\n");
1233 return -EAGAIN;
1234 }
1235
1236 err = register_pernet_device(&sit_net_ops);
1237 if (err < 0)
1238 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1239
1240 return err;
1241 }
1242
1243 module_init(sit_init);
1244 module_exit(sit_cleanup);
1245 MODULE_LICENSE("GPL");
1246 MODULE_ALIAS("sit0");
Linux with added FPC-III support