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um, x86: Cast to (u64 *) inside set_64bit()
[linux-2.6.git] / net / ipv6 / sit.c
blobe51e650ea80be7e4e2e0e0fe8514e3f14f0f1890
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 <linux/slab.h>
32 #include <asm/uaccess.h>
33 #include <linux/init.h>
34 #include <linux/netfilter_ipv4.h>
35 #include <linux/if_ether.h>
36
37 #include <net/sock.h>
38 #include <net/snmp.h>
39
40 #include <net/ipv6.h>
41 #include <net/protocol.h>
42 #include <net/transp_v6.h>
43 #include <net/ip6_fib.h>
44 #include <net/ip6_route.h>
45 #include <net/ndisc.h>
46 #include <net/addrconf.h>
47 #include <net/ip.h>
48 #include <net/udp.h>
49 #include <net/icmp.h>
50 #include <net/ipip.h>
51 #include <net/inet_ecn.h>
52 #include <net/xfrm.h>
53 #include <net/dsfield.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 /*
58 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
59
60 For comments look at net/ipv4/ip_gre.c --ANK
61 */
62
63 #define HASH_SIZE 16
64 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
65
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 p->next = t->prl;
368 p->addr = a->addr;
369 p->flags = a->flags;
370 t->prl_count++;
371 rcu_assign_pointer(t->prl, p);
372 out:
373 spin_unlock(&ipip6_prl_lock);
374 return err;
375 }
376
377 static void prl_entry_destroy_rcu(struct rcu_head *head)
378 {
379 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head));
380 }
381
382 static void prl_list_destroy_rcu(struct rcu_head *head)
383 {
384 struct ip_tunnel_prl_entry *p, *n;
385
386 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
387 do {
388 n = p->next;
389 kfree(p);
390 p = n;
391 } while (p);
392 }
393
394 static int
395 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
396 {
397 struct ip_tunnel_prl_entry *x, **p;
398 int err = 0;
399
400 spin_lock(&ipip6_prl_lock);
401
402 if (a && a->addr != htonl(INADDR_ANY)) {
403 for (p = &t->prl; *p; p = &(*p)->next) {
404 if ((*p)->addr == a->addr) {
405 x = *p;
406 *p = x->next;
407 call_rcu(&x->rcu_head, prl_entry_destroy_rcu);
408 t->prl_count--;
409 goto out;
410 }
411 }
412 err = -ENXIO;
413 } else {
414 if (t->prl) {
415 t->prl_count = 0;
416 x = t->prl;
417 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
418 t->prl = NULL;
419 }
420 }
421 out:
422 spin_unlock(&ipip6_prl_lock);
423 return err;
424 }
425
426 static int
427 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
428 {
429 struct ip_tunnel_prl_entry *p;
430 int ok = 1;
431
432 rcu_read_lock();
433 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
434 if (p) {
435 if (p->flags & PRL_DEFAULT)
436 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
437 else
438 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
439 } else {
440 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
441 if (ipv6_addr_is_isatap(addr6) &&
442 (addr6->s6_addr32[3] == iph->saddr) &&
443 ipv6_chk_prefix(addr6, t->dev))
444 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
445 else
446 ok = 0;
447 }
448 rcu_read_unlock();
449 return ok;
450 }
451
452 static void ipip6_tunnel_uninit(struct net_device *dev)
453 {
454 struct net *net = dev_net(dev);
455 struct sit_net *sitn = net_generic(net, sit_net_id);
456
457 if (dev == sitn->fb_tunnel_dev) {
458 spin_lock_bh(&ipip6_lock);
459 sitn->tunnels_wc[0] = NULL;
460 spin_unlock_bh(&ipip6_lock);
461 dev_put(dev);
462 } else {
463 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
464 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
465 dev_put(dev);
466 }
467 }
468
469
470 static int ipip6_err(struct sk_buff *skb, u32 info)
471 {
472
473 /* All the routers (except for Linux) return only
474 8 bytes of packet payload. It means, that precise relaying of
475 ICMP in the real Internet is absolutely infeasible.
476 */
477 struct iphdr *iph = (struct iphdr*)skb->data;
478 const int type = icmp_hdr(skb)->type;
479 const int code = icmp_hdr(skb)->code;
480 struct ip_tunnel *t;
481 int err;
482
483 switch (type) {
484 default:
485 case ICMP_PARAMETERPROB:
486 return 0;
487
488 case ICMP_DEST_UNREACH:
489 switch (code) {
490 case ICMP_SR_FAILED:
491 case ICMP_PORT_UNREACH:
492 /* Impossible event. */
493 return 0;
494 case ICMP_FRAG_NEEDED:
495 /* Soft state for pmtu is maintained by IP core. */
496 return 0;
497 default:
498 /* All others are translated to HOST_UNREACH.
499 rfc2003 contains "deep thoughts" about NET_UNREACH,
500 I believe they are just ether pollution. --ANK
501 */
502 break;
503 }
504 break;
505 case ICMP_TIME_EXCEEDED:
506 if (code != ICMP_EXC_TTL)
507 return 0;
508 break;
509 }
510
511 err = -ENOENT;
512
513 rcu_read_lock();
514 t = ipip6_tunnel_lookup(dev_net(skb->dev),
515 skb->dev,
516 iph->daddr,
517 iph->saddr);
518 if (t == NULL || t->parms.iph.daddr == 0)
519 goto out;
520
521 err = 0;
522 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
523 goto out;
524
525 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
526 t->err_count++;
527 else
528 t->err_count = 1;
529 t->err_time = jiffies;
530 out:
531 rcu_read_unlock();
532 return err;
533 }
534
535 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
536 {
537 if (INET_ECN_is_ce(iph->tos))
538 IP6_ECN_set_ce(ipv6_hdr(skb));
539 }
540
541 static int ipip6_rcv(struct sk_buff *skb)
542 {
543 struct iphdr *iph;
544 struct ip_tunnel *tunnel;
545
546 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
547 goto out;
548
549 iph = ip_hdr(skb);
550
551 rcu_read_lock();
552 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
553 iph->saddr, iph->daddr);
554 if (tunnel != NULL) {
555 secpath_reset(skb);
556 skb->mac_header = skb->network_header;
557 skb_reset_network_header(skb);
558 IPCB(skb)->flags = 0;
559 skb->protocol = htons(ETH_P_IPV6);
560 skb->pkt_type = PACKET_HOST;
561
562 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
563 !isatap_chksrc(skb, iph, tunnel)) {
564 tunnel->dev->stats.rx_errors++;
565 rcu_read_unlock();
566 kfree_skb(skb);
567 return 0;
568 }
569
570 skb_tunnel_rx(skb, tunnel->dev);
571
572 ipip6_ecn_decapsulate(iph, skb);
573 netif_rx(skb);
574 rcu_read_unlock();
575 return 0;
576 }
577
578 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
579 rcu_read_unlock();
580 out:
581 kfree_skb(skb);
582 return 0;
583 }
584
585 /*
586 * Returns the embedded IPv4 address if the IPv6 address
587 * comes from 6rd / 6to4 (RFC 3056) addr space.
588 */
589 static inline
590 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
591 {
592 __be32 dst = 0;
593
594 #ifdef CONFIG_IPV6_SIT_6RD
595 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
596 tunnel->ip6rd.prefixlen)) {
597 unsigned pbw0, pbi0;
598 int pbi1;
599 u32 d;
600
601 pbw0 = tunnel->ip6rd.prefixlen >> 5;
602 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
603
604 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
605 tunnel->ip6rd.relay_prefixlen;
606
607 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
608 if (pbi1 > 0)
609 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
610 (32 - pbi1);
611
612 dst = tunnel->ip6rd.relay_prefix | htonl(d);
613 }
614 #else
615 if (v6dst->s6_addr16[0] == htons(0x2002)) {
616 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
617 memcpy(&dst, &v6dst->s6_addr16[1], 4);
618 }
619 #endif
620 return dst;
621 }
622
623 /*
624 * This function assumes it is being called from dev_queue_xmit()
625 * and that skb is filled properly by that function.
626 */
627
628 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
629 struct net_device *dev)
630 {
631 struct ip_tunnel *tunnel = netdev_priv(dev);
632 struct net_device_stats *stats = &dev->stats;
633 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
634 struct iphdr *tiph = &tunnel->parms.iph;
635 struct ipv6hdr *iph6 = ipv6_hdr(skb);
636 u8 tos = tunnel->parms.iph.tos;
637 __be16 df = tiph->frag_off;
638 struct rtable *rt; /* Route to the other host */
639 struct net_device *tdev; /* Device to other host */
640 struct iphdr *iph; /* Our new IP header */
641 unsigned int max_headroom; /* The extra header space needed */
642 __be32 dst = tiph->daddr;
643 int mtu;
644 struct in6_addr *addr6;
645 int addr_type;
646
647 if (skb->protocol != htons(ETH_P_IPV6))
648 goto tx_error;
649
650 /* ISATAP (RFC4214) - must come before 6to4 */
651 if (dev->priv_flags & IFF_ISATAP) {
652 struct neighbour *neigh = NULL;
653
654 if (skb_dst(skb))
655 neigh = skb_dst(skb)->neighbour;
656
657 if (neigh == NULL) {
658 if (net_ratelimit())
659 printk(KERN_DEBUG "sit: nexthop == NULL\n");
660 goto tx_error;
661 }
662
663 addr6 = (struct in6_addr*)&neigh->primary_key;
664 addr_type = ipv6_addr_type(addr6);
665
666 if ((addr_type & IPV6_ADDR_UNICAST) &&
667 ipv6_addr_is_isatap(addr6))
668 dst = addr6->s6_addr32[3];
669 else
670 goto tx_error;
671 }
672
673 if (!dst)
674 dst = try_6rd(&iph6->daddr, tunnel);
675
676 if (!dst) {
677 struct neighbour *neigh = NULL;
678
679 if (skb_dst(skb))
680 neigh = skb_dst(skb)->neighbour;
681
682 if (neigh == NULL) {
683 if (net_ratelimit())
684 printk(KERN_DEBUG "sit: nexthop == NULL\n");
685 goto tx_error;
686 }
687
688 addr6 = (struct in6_addr*)&neigh->primary_key;
689 addr_type = ipv6_addr_type(addr6);
690
691 if (addr_type == IPV6_ADDR_ANY) {
692 addr6 = &ipv6_hdr(skb)->daddr;
693 addr_type = ipv6_addr_type(addr6);
694 }
695
696 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
697 goto tx_error_icmp;
698
699 dst = addr6->s6_addr32[3];
700 }
701
702 {
703 struct flowi fl = { .nl_u = { .ip4_u =
704 { .daddr = dst,
705 .saddr = tiph->saddr,
706 .tos = RT_TOS(tos) } },
707 .oif = tunnel->parms.link,
708 .proto = IPPROTO_IPV6 };
709 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
710 stats->tx_carrier_errors++;
711 goto tx_error_icmp;
712 }
713 }
714 if (rt->rt_type != RTN_UNICAST) {
715 ip_rt_put(rt);
716 stats->tx_carrier_errors++;
717 goto tx_error_icmp;
718 }
719 tdev = rt->u.dst.dev;
720
721 if (tdev == dev) {
722 ip_rt_put(rt);
723 stats->collisions++;
724 goto tx_error;
725 }
726
727 if (df) {
728 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
729
730 if (mtu < 68) {
731 stats->collisions++;
732 ip_rt_put(rt);
733 goto tx_error;
734 }
735
736 if (mtu < IPV6_MIN_MTU) {
737 mtu = IPV6_MIN_MTU;
738 df = 0;
739 }
740
741 if (tunnel->parms.iph.daddr && skb_dst(skb))
742 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
743
744 if (skb->len > mtu) {
745 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
746 ip_rt_put(rt);
747 goto tx_error;
748 }
749 }
750
751 if (tunnel->err_count > 0) {
752 if (time_before(jiffies,
753 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
754 tunnel->err_count--;
755 dst_link_failure(skb);
756 } else
757 tunnel->err_count = 0;
758 }
759
760 /*
761 * Okay, now see if we can stuff it in the buffer as-is.
762 */
763 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
764
765 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
766 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
767 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
768 if (!new_skb) {
769 ip_rt_put(rt);
770 txq->tx_dropped++;
771 dev_kfree_skb(skb);
772 return NETDEV_TX_OK;
773 }
774 if (skb->sk)
775 skb_set_owner_w(new_skb, skb->sk);
776 dev_kfree_skb(skb);
777 skb = new_skb;
778 iph6 = ipv6_hdr(skb);
779 }
780
781 skb->transport_header = skb->network_header;
782 skb_push(skb, sizeof(struct iphdr));
783 skb_reset_network_header(skb);
784 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
785 IPCB(skb)->flags = 0;
786 skb_dst_drop(skb);
787 skb_dst_set(skb, &rt->u.dst);
788
789 /*
790 * Push down and install the IPIP header.
791 */
792
793 iph = ip_hdr(skb);
794 iph->version = 4;
795 iph->ihl = sizeof(struct iphdr)>>2;
796 iph->frag_off = df;
797 iph->protocol = IPPROTO_IPV6;
798 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
799 iph->daddr = rt->rt_dst;
800 iph->saddr = rt->rt_src;
801
802 if ((iph->ttl = tiph->ttl) == 0)
803 iph->ttl = iph6->hop_limit;
804
805 nf_reset(skb);
806
807 IPTUNNEL_XMIT();
808 return NETDEV_TX_OK;
809
810 tx_error_icmp:
811 dst_link_failure(skb);
812 tx_error:
813 stats->tx_errors++;
814 dev_kfree_skb(skb);
815 return NETDEV_TX_OK;
816 }
817
818 static void ipip6_tunnel_bind_dev(struct net_device *dev)
819 {
820 struct net_device *tdev = NULL;
821 struct ip_tunnel *tunnel;
822 struct iphdr *iph;
823
824 tunnel = netdev_priv(dev);
825 iph = &tunnel->parms.iph;
826
827 if (iph->daddr) {
828 struct flowi fl = { .nl_u = { .ip4_u =
829 { .daddr = iph->daddr,
830 .saddr = iph->saddr,
831 .tos = RT_TOS(iph->tos) } },
832 .oif = tunnel->parms.link,
833 .proto = IPPROTO_IPV6 };
834 struct rtable *rt;
835 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
836 tdev = rt->u.dst.dev;
837 ip_rt_put(rt);
838 }
839 dev->flags |= IFF_POINTOPOINT;
840 }
841
842 if (!tdev && tunnel->parms.link)
843 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
844
845 if (tdev) {
846 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
847 dev->mtu = tdev->mtu - sizeof(struct iphdr);
848 if (dev->mtu < IPV6_MIN_MTU)
849 dev->mtu = IPV6_MIN_MTU;
850 }
851 dev->iflink = tunnel->parms.link;
852 }
853
854 static int
855 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
856 {
857 int err = 0;
858 struct ip_tunnel_parm p;
859 struct ip_tunnel_prl prl;
860 struct ip_tunnel *t;
861 struct net *net = dev_net(dev);
862 struct sit_net *sitn = net_generic(net, sit_net_id);
863 #ifdef CONFIG_IPV6_SIT_6RD
864 struct ip_tunnel_6rd ip6rd;
865 #endif
866
867 switch (cmd) {
868 case SIOCGETTUNNEL:
869 #ifdef CONFIG_IPV6_SIT_6RD
870 case SIOCGET6RD:
871 #endif
872 t = NULL;
873 if (dev == sitn->fb_tunnel_dev) {
874 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
875 err = -EFAULT;
876 break;
877 }
878 t = ipip6_tunnel_locate(net, &p, 0);
879 }
880 if (t == NULL)
881 t = netdev_priv(dev);
882
883 err = -EFAULT;
884 if (cmd == SIOCGETTUNNEL) {
885 memcpy(&p, &t->parms, sizeof(p));
886 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
887 sizeof(p)))
888 goto done;
889 #ifdef CONFIG_IPV6_SIT_6RD
890 } else {
891 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
892 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
893 ip6rd.prefixlen = t->ip6rd.prefixlen;
894 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
895 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
896 sizeof(ip6rd)))
897 goto done;
898 #endif
899 }
900 err = 0;
901 break;
902
903 case SIOCADDTUNNEL:
904 case SIOCCHGTUNNEL:
905 err = -EPERM;
906 if (!capable(CAP_NET_ADMIN))
907 goto done;
908
909 err = -EFAULT;
910 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
911 goto done;
912
913 err = -EINVAL;
914 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
915 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
916 goto done;
917 if (p.iph.ttl)
918 p.iph.frag_off |= htons(IP_DF);
919
920 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
921
922 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
923 if (t != NULL) {
924 if (t->dev != dev) {
925 err = -EEXIST;
926 break;
927 }
928 } else {
929 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
930 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
931 err = -EINVAL;
932 break;
933 }
934 t = netdev_priv(dev);
935 ipip6_tunnel_unlink(sitn, t);
936 t->parms.iph.saddr = p.iph.saddr;
937 t->parms.iph.daddr = p.iph.daddr;
938 memcpy(dev->dev_addr, &p.iph.saddr, 4);
939 memcpy(dev->broadcast, &p.iph.daddr, 4);
940 ipip6_tunnel_link(sitn, t);
941 netdev_state_change(dev);
942 }
943 }
944
945 if (t) {
946 err = 0;
947 if (cmd == SIOCCHGTUNNEL) {
948 t->parms.iph.ttl = p.iph.ttl;
949 t->parms.iph.tos = p.iph.tos;
950 if (t->parms.link != p.link) {
951 t->parms.link = p.link;
952 ipip6_tunnel_bind_dev(dev);
953 netdev_state_change(dev);
954 }
955 }
956 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
957 err = -EFAULT;
958 } else
959 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
960 break;
961
962 case SIOCDELTUNNEL:
963 err = -EPERM;
964 if (!capable(CAP_NET_ADMIN))
965 goto done;
966
967 if (dev == sitn->fb_tunnel_dev) {
968 err = -EFAULT;
969 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
970 goto done;
971 err = -ENOENT;
972 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
973 goto done;
974 err = -EPERM;
975 if (t == netdev_priv(sitn->fb_tunnel_dev))
976 goto done;
977 dev = t->dev;
978 }
979 unregister_netdevice(dev);
980 err = 0;
981 break;
982
983 case SIOCGETPRL:
984 err = -EINVAL;
985 if (dev == sitn->fb_tunnel_dev)
986 goto done;
987 err = -ENOENT;
988 if (!(t = netdev_priv(dev)))
989 goto done;
990 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
991 break;
992
993 case SIOCADDPRL:
994 case SIOCDELPRL:
995 case SIOCCHGPRL:
996 err = -EPERM;
997 if (!capable(CAP_NET_ADMIN))
998 goto done;
999 err = -EINVAL;
1000 if (dev == sitn->fb_tunnel_dev)
1001 goto done;
1002 err = -EFAULT;
1003 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1004 goto done;
1005 err = -ENOENT;
1006 if (!(t = netdev_priv(dev)))
1007 goto done;
1008
1009 switch (cmd) {
1010 case SIOCDELPRL:
1011 err = ipip6_tunnel_del_prl(t, &prl);
1012 break;
1013 case SIOCADDPRL:
1014 case SIOCCHGPRL:
1015 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1016 break;
1017 }
1018 netdev_state_change(dev);
1019 break;
1020
1021 #ifdef CONFIG_IPV6_SIT_6RD
1022 case SIOCADD6RD:
1023 case SIOCCHG6RD:
1024 case SIOCDEL6RD:
1025 err = -EPERM;
1026 if (!capable(CAP_NET_ADMIN))
1027 goto done;
1028
1029 err = -EFAULT;
1030 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1031 sizeof(ip6rd)))
1032 goto done;
1033
1034 t = netdev_priv(dev);
1035
1036 if (cmd != SIOCDEL6RD) {
1037 struct in6_addr prefix;
1038 __be32 relay_prefix;
1039
1040 err = -EINVAL;
1041 if (ip6rd.relay_prefixlen > 32 ||
1042 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1043 goto done;
1044
1045 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1046 ip6rd.prefixlen);
1047 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1048 goto done;
1049 if (ip6rd.relay_prefixlen)
1050 relay_prefix = ip6rd.relay_prefix &
1051 htonl(0xffffffffUL <<
1052 (32 - ip6rd.relay_prefixlen));
1053 else
1054 relay_prefix = 0;
1055 if (relay_prefix != ip6rd.relay_prefix)
1056 goto done;
1057
1058 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1059 t->ip6rd.relay_prefix = relay_prefix;
1060 t->ip6rd.prefixlen = ip6rd.prefixlen;
1061 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1062 } else
1063 ipip6_tunnel_clone_6rd(dev, sitn);
1064
1065 err = 0;
1066 break;
1067 #endif
1068
1069 default:
1070 err = -EINVAL;
1071 }
1072
1073 done:
1074 return err;
1075 }
1076
1077 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1078 {
1079 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1080 return -EINVAL;
1081 dev->mtu = new_mtu;
1082 return 0;
1083 }
1084
1085 static const struct net_device_ops ipip6_netdev_ops = {
1086 .ndo_uninit = ipip6_tunnel_uninit,
1087 .ndo_start_xmit = ipip6_tunnel_xmit,
1088 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1089 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1090 };
1091
1092 static void ipip6_tunnel_setup(struct net_device *dev)
1093 {
1094 dev->netdev_ops = &ipip6_netdev_ops;
1095 dev->destructor = free_netdev;
1096
1097 dev->type = ARPHRD_SIT;
1098 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1099 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1100 dev->flags = IFF_NOARP;
1101 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1102 dev->iflink = 0;
1103 dev->addr_len = 4;
1104 dev->features |= NETIF_F_NETNS_LOCAL;
1105 }
1106
1107 static void ipip6_tunnel_init(struct net_device *dev)
1108 {
1109 struct ip_tunnel *tunnel = netdev_priv(dev);
1110
1111 tunnel->dev = dev;
1112 strcpy(tunnel->parms.name, dev->name);
1113
1114 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1115 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1116
1117 ipip6_tunnel_bind_dev(dev);
1118 }
1119
1120 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1121 {
1122 struct ip_tunnel *tunnel = netdev_priv(dev);
1123 struct iphdr *iph = &tunnel->parms.iph;
1124 struct net *net = dev_net(dev);
1125 struct sit_net *sitn = net_generic(net, sit_net_id);
1126
1127 tunnel->dev = dev;
1128 strcpy(tunnel->parms.name, dev->name);
1129
1130 iph->version = 4;
1131 iph->protocol = IPPROTO_IPV6;
1132 iph->ihl = 5;
1133 iph->ttl = 64;
1134
1135 dev_hold(dev);
1136 sitn->tunnels_wc[0] = tunnel;
1137 }
1138
1139 static struct xfrm_tunnel sit_handler = {
1140 .handler = ipip6_rcv,
1141 .err_handler = ipip6_err,
1142 .priority = 1,
1143 };
1144
1145 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1146 {
1147 int prio;
1148
1149 for (prio = 1; prio < 4; prio++) {
1150 int h;
1151 for (h = 0; h < HASH_SIZE; h++) {
1152 struct ip_tunnel *t = sitn->tunnels[prio][h];
1153
1154 while (t != NULL) {
1155 unregister_netdevice_queue(t->dev, head);
1156 t = t->next;
1157 }
1158 }
1159 }
1160 }
1161
1162 static int __net_init sit_init_net(struct net *net)
1163 {
1164 struct sit_net *sitn = net_generic(net, sit_net_id);
1165 int err;
1166
1167 sitn->tunnels[0] = sitn->tunnels_wc;
1168 sitn->tunnels[1] = sitn->tunnels_l;
1169 sitn->tunnels[2] = sitn->tunnels_r;
1170 sitn->tunnels[3] = sitn->tunnels_r_l;
1171
1172 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1173 ipip6_tunnel_setup);
1174 if (!sitn->fb_tunnel_dev) {
1175 err = -ENOMEM;
1176 goto err_alloc_dev;
1177 }
1178 dev_net_set(sitn->fb_tunnel_dev, net);
1179
1180 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1181 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1182
1183 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1184 goto err_reg_dev;
1185
1186 return 0;
1187
1188 err_reg_dev:
1189 dev_put(sitn->fb_tunnel_dev);
1190 free_netdev(sitn->fb_tunnel_dev);
1191 err_alloc_dev:
1192 return err;
1193 }
1194
1195 static void __net_exit sit_exit_net(struct net *net)
1196 {
1197 struct sit_net *sitn = net_generic(net, sit_net_id);
1198 LIST_HEAD(list);
1199
1200 rtnl_lock();
1201 sit_destroy_tunnels(sitn, &list);
1202 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1203 unregister_netdevice_many(&list);
1204 rtnl_unlock();
1205 }
1206
1207 static struct pernet_operations sit_net_ops = {
1208 .init = sit_init_net,
1209 .exit = sit_exit_net,
1210 .id = &sit_net_id,
1211 .size = sizeof(struct sit_net),
1212 };
1213
1214 static void __exit sit_cleanup(void)
1215 {
1216 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1217
1218 unregister_pernet_device(&sit_net_ops);
1219 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1220 }
1221
1222 static int __init sit_init(void)
1223 {
1224 int err;
1225
1226 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1227
1228 err = register_pernet_device(&sit_net_ops);
1229 if (err < 0)
1230 return err;
1231 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1232 if (err < 0) {
1233 unregister_pernet_device(&sit_net_ops);
1234 printk(KERN_INFO "sit init: Can't add protocol\n");
1235 }
1236 return err;
1237 }
1238
1239 module_init(sit_init);
1240 module_exit(sit_cleanup);
1241 MODULE_LICENSE("GPL");
1242 MODULE_ALIAS("sit0");
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