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[linux-2.6/next.git] / net / ipv6 / sit.c
blob1cca5761aea9709e39302c82df57acd777676d7d
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 int ipip6_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_setup(struct net_device *dev);
68 static void ipip6_dev_free(struct net_device *dev);
69
70 static int sit_net_id __read_mostly;
71 struct sit_net {
72 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
73 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
74 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
75 struct ip_tunnel __rcu *tunnels_wc[1];
76 struct ip_tunnel __rcu **tunnels[4];
77
78 struct net_device *fb_tunnel_dev;
79 };
80
81 /*
82 * Locking : hash tables are protected by RCU and RTNL
83 */
84
85 #define for_each_ip_tunnel_rcu(start) \
86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
87
88 /* often modified stats are per cpu, other are shared (netdev->stats) */
89 struct pcpu_tstats {
90 unsigned long rx_packets;
91 unsigned long rx_bytes;
92 unsigned long tx_packets;
93 unsigned long tx_bytes;
94 };
95
96 static struct net_device_stats *ipip6_get_stats(struct net_device *dev)
97 {
98 struct pcpu_tstats sum = { 0 };
99 int i;
100
101 for_each_possible_cpu(i) {
102 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
103
104 sum.rx_packets += tstats->rx_packets;
105 sum.rx_bytes += tstats->rx_bytes;
106 sum.tx_packets += tstats->tx_packets;
107 sum.tx_bytes += tstats->tx_bytes;
108 }
109 dev->stats.rx_packets = sum.rx_packets;
110 dev->stats.rx_bytes = sum.rx_bytes;
111 dev->stats.tx_packets = sum.tx_packets;
112 dev->stats.tx_bytes = sum.tx_bytes;
113 return &dev->stats;
114 }
115 /*
116 * Must be invoked with rcu_read_lock
117 */
118 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
119 struct net_device *dev, __be32 remote, __be32 local)
120 {
121 unsigned int h0 = HASH(remote);
122 unsigned int h1 = HASH(local);
123 struct ip_tunnel *t;
124 struct sit_net *sitn = net_generic(net, sit_net_id);
125
126 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
127 if (local == t->parms.iph.saddr &&
128 remote == t->parms.iph.daddr &&
129 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
130 (t->dev->flags & IFF_UP))
131 return t;
132 }
133 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
134 if (remote == t->parms.iph.daddr &&
135 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
136 (t->dev->flags & IFF_UP))
137 return t;
138 }
139 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
140 if (local == t->parms.iph.saddr &&
141 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
142 (t->dev->flags & IFF_UP))
143 return t;
144 }
145 t = rcu_dereference(sitn->tunnels_wc[0]);
146 if ((t != NULL) && (t->dev->flags & IFF_UP))
147 return t;
148 return NULL;
149 }
150
151 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
152 struct ip_tunnel_parm *parms)
153 {
154 __be32 remote = parms->iph.daddr;
155 __be32 local = parms->iph.saddr;
156 unsigned int h = 0;
157 int prio = 0;
158
159 if (remote) {
160 prio |= 2;
161 h ^= HASH(remote);
162 }
163 if (local) {
164 prio |= 1;
165 h ^= HASH(local);
166 }
167 return &sitn->tunnels[prio][h];
168 }
169
170 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
171 struct ip_tunnel *t)
172 {
173 return __ipip6_bucket(sitn, &t->parms);
174 }
175
176 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
177 {
178 struct ip_tunnel __rcu **tp;
179 struct ip_tunnel *iter;
180
181 for (tp = ipip6_bucket(sitn, t);
182 (iter = rtnl_dereference(*tp)) != NULL;
183 tp = &iter->next) {
184 if (t == iter) {
185 rcu_assign_pointer(*tp, t->next);
186 break;
187 }
188 }
189 }
190
191 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
192 {
193 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
194
195 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
196 rcu_assign_pointer(*tp, t);
197 }
198
199 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
200 {
201 #ifdef CONFIG_IPV6_SIT_6RD
202 struct ip_tunnel *t = netdev_priv(dev);
203
204 if (t->dev == sitn->fb_tunnel_dev) {
205 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
206 t->ip6rd.relay_prefix = 0;
207 t->ip6rd.prefixlen = 16;
208 t->ip6rd.relay_prefixlen = 0;
209 } else {
210 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
211 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
212 }
213 #endif
214 }
215
216 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
217 struct ip_tunnel_parm *parms, int create)
218 {
219 __be32 remote = parms->iph.daddr;
220 __be32 local = parms->iph.saddr;
221 struct ip_tunnel *t, *nt;
222 struct ip_tunnel __rcu **tp;
223 struct net_device *dev;
224 char name[IFNAMSIZ];
225 struct sit_net *sitn = net_generic(net, sit_net_id);
226
227 for (tp = __ipip6_bucket(sitn, parms);
228 (t = rtnl_dereference(*tp)) != NULL;
229 tp = &t->next) {
230 if (local == t->parms.iph.saddr &&
231 remote == t->parms.iph.daddr &&
232 parms->link == t->parms.link) {
233 if (create)
234 return NULL;
235 else
236 return t;
237 }
238 }
239 if (!create)
240 goto failed;
241
242 if (parms->name[0])
243 strlcpy(name, parms->name, IFNAMSIZ);
244 else
245 strcpy(name, "sit%d");
246
247 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
248 if (dev == NULL)
249 return NULL;
250
251 dev_net_set(dev, net);
252
253 nt = netdev_priv(dev);
254
255 nt->parms = *parms;
256 if (ipip6_tunnel_init(dev) < 0)
257 goto failed_free;
258 ipip6_tunnel_clone_6rd(dev, sitn);
259
260 if (parms->i_flags & SIT_ISATAP)
261 dev->priv_flags |= IFF_ISATAP;
262
263 if (register_netdevice(dev) < 0)
264 goto failed_free;
265
266 dev_hold(dev);
267
268 ipip6_tunnel_link(sitn, nt);
269 return nt;
270
271 failed_free:
272 ipip6_dev_free(dev);
273 failed:
274 return NULL;
275 }
276
277 #define for_each_prl_rcu(start) \
278 for (prl = rcu_dereference(start); \
279 prl; \
280 prl = rcu_dereference(prl->next))
281
282 static struct ip_tunnel_prl_entry *
283 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
284 {
285 struct ip_tunnel_prl_entry *prl;
286
287 for_each_prl_rcu(t->prl)
288 if (prl->addr == addr)
289 break;
290 return prl;
291
292 }
293
294 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
295 struct ip_tunnel_prl __user *a)
296 {
297 struct ip_tunnel_prl kprl, *kp;
298 struct ip_tunnel_prl_entry *prl;
299 unsigned int cmax, c = 0, ca, len;
300 int ret = 0;
301
302 if (copy_from_user(&kprl, a, sizeof(kprl)))
303 return -EFAULT;
304 cmax = kprl.datalen / sizeof(kprl);
305 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
306 cmax = 1;
307
308 /* For simple GET or for root users,
309 * we try harder to allocate.
310 */
311 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
312 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
313 NULL;
314
315 rcu_read_lock();
316
317 ca = t->prl_count < cmax ? t->prl_count : cmax;
318
319 if (!kp) {
320 /* We don't try hard to allocate much memory for
321 * non-root users.
322 * For root users, retry allocating enough memory for
323 * the answer.
324 */
325 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
326 if (!kp) {
327 ret = -ENOMEM;
328 goto out;
329 }
330 }
331
332 c = 0;
333 for_each_prl_rcu(t->prl) {
334 if (c >= cmax)
335 break;
336 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
337 continue;
338 kp[c].addr = prl->addr;
339 kp[c].flags = prl->flags;
340 c++;
341 if (kprl.addr != htonl(INADDR_ANY))
342 break;
343 }
344 out:
345 rcu_read_unlock();
346
347 len = sizeof(*kp) * c;
348 ret = 0;
349 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
350 ret = -EFAULT;
351
352 kfree(kp);
353
354 return ret;
355 }
356
357 static int
358 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
359 {
360 struct ip_tunnel_prl_entry *p;
361 int err = 0;
362
363 if (a->addr == htonl(INADDR_ANY))
364 return -EINVAL;
365
366 ASSERT_RTNL();
367
368 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
369 if (p->addr == a->addr) {
370 if (chg) {
371 p->flags = a->flags;
372 goto out;
373 }
374 err = -EEXIST;
375 goto out;
376 }
377 }
378
379 if (chg) {
380 err = -ENXIO;
381 goto out;
382 }
383
384 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
385 if (!p) {
386 err = -ENOBUFS;
387 goto out;
388 }
389
390 p->next = t->prl;
391 p->addr = a->addr;
392 p->flags = a->flags;
393 t->prl_count++;
394 rcu_assign_pointer(t->prl, p);
395 out:
396 return err;
397 }
398
399 static void prl_list_destroy_rcu(struct rcu_head *head)
400 {
401 struct ip_tunnel_prl_entry *p, *n;
402
403 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
404 do {
405 n = rcu_dereference_protected(p->next, 1);
406 kfree(p);
407 p = n;
408 } while (p);
409 }
410
411 static int
412 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
413 {
414 struct ip_tunnel_prl_entry *x;
415 struct ip_tunnel_prl_entry __rcu **p;
416 int err = 0;
417
418 ASSERT_RTNL();
419
420 if (a && a->addr != htonl(INADDR_ANY)) {
421 for (p = &t->prl;
422 (x = rtnl_dereference(*p)) != NULL;
423 p = &x->next) {
424 if (x->addr == a->addr) {
425 *p = x->next;
426 kfree_rcu(x, rcu_head);
427 t->prl_count--;
428 goto out;
429 }
430 }
431 err = -ENXIO;
432 } else {
433 x = rtnl_dereference(t->prl);
434 if (x) {
435 t->prl_count = 0;
436 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
437 t->prl = NULL;
438 }
439 }
440 out:
441 return err;
442 }
443
444 static int
445 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
446 {
447 struct ip_tunnel_prl_entry *p;
448 int ok = 1;
449
450 rcu_read_lock();
451 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
452 if (p) {
453 if (p->flags & PRL_DEFAULT)
454 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
455 else
456 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
457 } else {
458 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
459
460 if (ipv6_addr_is_isatap(addr6) &&
461 (addr6->s6_addr32[3] == iph->saddr) &&
462 ipv6_chk_prefix(addr6, t->dev))
463 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
464 else
465 ok = 0;
466 }
467 rcu_read_unlock();
468 return ok;
469 }
470
471 static void ipip6_tunnel_uninit(struct net_device *dev)
472 {
473 struct net *net = dev_net(dev);
474 struct sit_net *sitn = net_generic(net, sit_net_id);
475
476 if (dev == sitn->fb_tunnel_dev) {
477 rcu_assign_pointer(sitn->tunnels_wc[0], NULL);
478 } else {
479 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
480 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
481 }
482 dev_put(dev);
483 }
484
485
486 static int ipip6_err(struct sk_buff *skb, u32 info)
487 {
488
489 /* All the routers (except for Linux) return only
490 8 bytes of packet payload. It means, that precise relaying of
491 ICMP in the real Internet is absolutely infeasible.
492 */
493 const struct iphdr *iph = (const struct iphdr *)skb->data;
494 const int type = icmp_hdr(skb)->type;
495 const int code = icmp_hdr(skb)->code;
496 struct ip_tunnel *t;
497 int err;
498
499 switch (type) {
500 default:
501 case ICMP_PARAMETERPROB:
502 return 0;
503
504 case ICMP_DEST_UNREACH:
505 switch (code) {
506 case ICMP_SR_FAILED:
507 case ICMP_PORT_UNREACH:
508 /* Impossible event. */
509 return 0;
510 case ICMP_FRAG_NEEDED:
511 /* Soft state for pmtu is maintained by IP core. */
512 return 0;
513 default:
514 /* All others are translated to HOST_UNREACH.
515 rfc2003 contains "deep thoughts" about NET_UNREACH,
516 I believe they are just ether pollution. --ANK
517 */
518 break;
519 }
520 break;
521 case ICMP_TIME_EXCEEDED:
522 if (code != ICMP_EXC_TTL)
523 return 0;
524 break;
525 }
526
527 err = -ENOENT;
528
529 rcu_read_lock();
530 t = ipip6_tunnel_lookup(dev_net(skb->dev),
531 skb->dev,
532 iph->daddr,
533 iph->saddr);
534 if (t == NULL || t->parms.iph.daddr == 0)
535 goto out;
536
537 err = 0;
538 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
539 goto out;
540
541 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
542 t->err_count++;
543 else
544 t->err_count = 1;
545 t->err_time = jiffies;
546 out:
547 rcu_read_unlock();
548 return err;
549 }
550
551 static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
552 {
553 if (INET_ECN_is_ce(iph->tos))
554 IP6_ECN_set_ce(ipv6_hdr(skb));
555 }
556
557 static int ipip6_rcv(struct sk_buff *skb)
558 {
559 const struct iphdr *iph;
560 struct ip_tunnel *tunnel;
561
562 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
563 goto out;
564
565 iph = ip_hdr(skb);
566
567 rcu_read_lock();
568 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
569 iph->saddr, iph->daddr);
570 if (tunnel != NULL) {
571 struct pcpu_tstats *tstats;
572
573 secpath_reset(skb);
574 skb->mac_header = skb->network_header;
575 skb_reset_network_header(skb);
576 IPCB(skb)->flags = 0;
577 skb->protocol = htons(ETH_P_IPV6);
578 skb->pkt_type = PACKET_HOST;
579
580 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
581 !isatap_chksrc(skb, iph, tunnel)) {
582 tunnel->dev->stats.rx_errors++;
583 rcu_read_unlock();
584 kfree_skb(skb);
585 return 0;
586 }
587
588 tstats = this_cpu_ptr(tunnel->dev->tstats);
589 tstats->rx_packets++;
590 tstats->rx_bytes += skb->len;
591
592 __skb_tunnel_rx(skb, tunnel->dev);
593
594 ipip6_ecn_decapsulate(iph, skb);
595
596 netif_rx(skb);
597
598 rcu_read_unlock();
599 return 0;
600 }
601
602 /* no tunnel matched, let upstream know, ipsec may handle it */
603 rcu_read_unlock();
604 return 1;
605 out:
606 kfree_skb(skb);
607 return 0;
608 }
609
610 /*
611 * Returns the embedded IPv4 address if the IPv6 address
612 * comes from 6rd / 6to4 (RFC 3056) addr space.
613 */
614 static inline
615 __be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel)
616 {
617 __be32 dst = 0;
618
619 #ifdef CONFIG_IPV6_SIT_6RD
620 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
621 tunnel->ip6rd.prefixlen)) {
622 unsigned int pbw0, pbi0;
623 int pbi1;
624 u32 d;
625
626 pbw0 = tunnel->ip6rd.prefixlen >> 5;
627 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
628
629 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
630 tunnel->ip6rd.relay_prefixlen;
631
632 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
633 if (pbi1 > 0)
634 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
635 (32 - pbi1);
636
637 dst = tunnel->ip6rd.relay_prefix | htonl(d);
638 }
639 #else
640 if (v6dst->s6_addr16[0] == htons(0x2002)) {
641 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
642 memcpy(&dst, &v6dst->s6_addr16[1], 4);
643 }
644 #endif
645 return dst;
646 }
647
648 /*
649 * This function assumes it is being called from dev_queue_xmit()
650 * and that skb is filled properly by that function.
651 */
652
653 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
654 struct net_device *dev)
655 {
656 struct ip_tunnel *tunnel = netdev_priv(dev);
657 struct pcpu_tstats *tstats;
658 const struct iphdr *tiph = &tunnel->parms.iph;
659 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
660 u8 tos = tunnel->parms.iph.tos;
661 __be16 df = tiph->frag_off;
662 struct rtable *rt; /* Route to the other host */
663 struct net_device *tdev; /* Device to other host */
664 struct iphdr *iph; /* Our new IP header */
665 unsigned int max_headroom; /* The extra header space needed */
666 __be32 dst = tiph->daddr;
667 struct flowi4 fl4;
668 int mtu;
669 const struct in6_addr *addr6;
670 int addr_type;
671
672 if (skb->protocol != htons(ETH_P_IPV6))
673 goto tx_error;
674
675 /* ISATAP (RFC4214) - must come before 6to4 */
676 if (dev->priv_flags & IFF_ISATAP) {
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 = (const struct in6_addr*)&neigh->primary_key;
689 addr_type = ipv6_addr_type(addr6);
690
691 if ((addr_type & IPV6_ADDR_UNICAST) &&
692 ipv6_addr_is_isatap(addr6))
693 dst = addr6->s6_addr32[3];
694 else
695 goto tx_error;
696 }
697
698 if (!dst)
699 dst = try_6rd(&iph6->daddr, tunnel);
700
701 if (!dst) {
702 struct neighbour *neigh = NULL;
703
704 if (skb_dst(skb))
705 neigh = skb_dst(skb)->neighbour;
706
707 if (neigh == NULL) {
708 if (net_ratelimit())
709 printk(KERN_DEBUG "sit: nexthop == NULL\n");
710 goto tx_error;
711 }
712
713 addr6 = (const struct in6_addr*)&neigh->primary_key;
714 addr_type = ipv6_addr_type(addr6);
715
716 if (addr_type == IPV6_ADDR_ANY) {
717 addr6 = &ipv6_hdr(skb)->daddr;
718 addr_type = ipv6_addr_type(addr6);
719 }
720
721 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
722 goto tx_error_icmp;
723
724 dst = addr6->s6_addr32[3];
725 }
726
727 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
728 dst, tiph->saddr,
729 0, 0,
730 IPPROTO_IPV6, RT_TOS(tos),
731 tunnel->parms.link);
732 if (IS_ERR(rt)) {
733 dev->stats.tx_carrier_errors++;
734 goto tx_error_icmp;
735 }
736 if (rt->rt_type != RTN_UNICAST) {
737 ip_rt_put(rt);
738 dev->stats.tx_carrier_errors++;
739 goto tx_error_icmp;
740 }
741 tdev = rt->dst.dev;
742
743 if (tdev == dev) {
744 ip_rt_put(rt);
745 dev->stats.collisions++;
746 goto tx_error;
747 }
748
749 if (df) {
750 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
751
752 if (mtu < 68) {
753 dev->stats.collisions++;
754 ip_rt_put(rt);
755 goto tx_error;
756 }
757
758 if (mtu < IPV6_MIN_MTU) {
759 mtu = IPV6_MIN_MTU;
760 df = 0;
761 }
762
763 if (tunnel->parms.iph.daddr && skb_dst(skb))
764 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
765
766 if (skb->len > mtu) {
767 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
768 ip_rt_put(rt);
769 goto tx_error;
770 }
771 }
772
773 if (tunnel->err_count > 0) {
774 if (time_before(jiffies,
775 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
776 tunnel->err_count--;
777 dst_link_failure(skb);
778 } else
779 tunnel->err_count = 0;
780 }
781
782 /*
783 * Okay, now see if we can stuff it in the buffer as-is.
784 */
785 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
786
787 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
788 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
789 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
790 if (!new_skb) {
791 ip_rt_put(rt);
792 dev->stats.tx_dropped++;
793 dev_kfree_skb(skb);
794 return NETDEV_TX_OK;
795 }
796 if (skb->sk)
797 skb_set_owner_w(new_skb, skb->sk);
798 dev_kfree_skb(skb);
799 skb = new_skb;
800 iph6 = ipv6_hdr(skb);
801 }
802
803 skb->transport_header = skb->network_header;
804 skb_push(skb, sizeof(struct iphdr));
805 skb_reset_network_header(skb);
806 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
807 IPCB(skb)->flags = 0;
808 skb_dst_drop(skb);
809 skb_dst_set(skb, &rt->dst);
810
811 /*
812 * Push down and install the IPIP header.
813 */
814
815 iph = ip_hdr(skb);
816 iph->version = 4;
817 iph->ihl = sizeof(struct iphdr)>>2;
818 iph->frag_off = df;
819 iph->protocol = IPPROTO_IPV6;
820 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
821 iph->daddr = fl4.daddr;
822 iph->saddr = fl4.saddr;
823
824 if ((iph->ttl = tiph->ttl) == 0)
825 iph->ttl = iph6->hop_limit;
826
827 nf_reset(skb);
828 tstats = this_cpu_ptr(dev->tstats);
829 __IPTUNNEL_XMIT(tstats, &dev->stats);
830 return NETDEV_TX_OK;
831
832 tx_error_icmp:
833 dst_link_failure(skb);
834 tx_error:
835 dev->stats.tx_errors++;
836 dev_kfree_skb(skb);
837 return NETDEV_TX_OK;
838 }
839
840 static void ipip6_tunnel_bind_dev(struct net_device *dev)
841 {
842 struct net_device *tdev = NULL;
843 struct ip_tunnel *tunnel;
844 const struct iphdr *iph;
845 struct flowi4 fl4;
846
847 tunnel = netdev_priv(dev);
848 iph = &tunnel->parms.iph;
849
850 if (iph->daddr) {
851 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
852 iph->daddr, iph->saddr,
853 0, 0,
854 IPPROTO_IPV6,
855 RT_TOS(iph->tos),
856 tunnel->parms.link);
857
858 if (!IS_ERR(rt)) {
859 tdev = rt->dst.dev;
860 ip_rt_put(rt);
861 }
862 dev->flags |= IFF_POINTOPOINT;
863 }
864
865 if (!tdev && tunnel->parms.link)
866 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
867
868 if (tdev) {
869 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
870 dev->mtu = tdev->mtu - sizeof(struct iphdr);
871 if (dev->mtu < IPV6_MIN_MTU)
872 dev->mtu = IPV6_MIN_MTU;
873 }
874 dev->iflink = tunnel->parms.link;
875 }
876
877 static int
878 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
879 {
880 int err = 0;
881 struct ip_tunnel_parm p;
882 struct ip_tunnel_prl prl;
883 struct ip_tunnel *t;
884 struct net *net = dev_net(dev);
885 struct sit_net *sitn = net_generic(net, sit_net_id);
886 #ifdef CONFIG_IPV6_SIT_6RD
887 struct ip_tunnel_6rd ip6rd;
888 #endif
889
890 switch (cmd) {
891 case SIOCGETTUNNEL:
892 #ifdef CONFIG_IPV6_SIT_6RD
893 case SIOCGET6RD:
894 #endif
895 t = NULL;
896 if (dev == sitn->fb_tunnel_dev) {
897 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
898 err = -EFAULT;
899 break;
900 }
901 t = ipip6_tunnel_locate(net, &p, 0);
902 }
903 if (t == NULL)
904 t = netdev_priv(dev);
905
906 err = -EFAULT;
907 if (cmd == SIOCGETTUNNEL) {
908 memcpy(&p, &t->parms, sizeof(p));
909 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
910 sizeof(p)))
911 goto done;
912 #ifdef CONFIG_IPV6_SIT_6RD
913 } else {
914 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
915 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
916 ip6rd.prefixlen = t->ip6rd.prefixlen;
917 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
918 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
919 sizeof(ip6rd)))
920 goto done;
921 #endif
922 }
923 err = 0;
924 break;
925
926 case SIOCADDTUNNEL:
927 case SIOCCHGTUNNEL:
928 err = -EPERM;
929 if (!capable(CAP_NET_ADMIN))
930 goto done;
931
932 err = -EFAULT;
933 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
934 goto done;
935
936 err = -EINVAL;
937 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
938 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
939 goto done;
940 if (p.iph.ttl)
941 p.iph.frag_off |= htons(IP_DF);
942
943 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
944
945 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
946 if (t != NULL) {
947 if (t->dev != dev) {
948 err = -EEXIST;
949 break;
950 }
951 } else {
952 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
953 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
954 err = -EINVAL;
955 break;
956 }
957 t = netdev_priv(dev);
958 ipip6_tunnel_unlink(sitn, t);
959 synchronize_net();
960 t->parms.iph.saddr = p.iph.saddr;
961 t->parms.iph.daddr = p.iph.daddr;
962 memcpy(dev->dev_addr, &p.iph.saddr, 4);
963 memcpy(dev->broadcast, &p.iph.daddr, 4);
964 ipip6_tunnel_link(sitn, t);
965 netdev_state_change(dev);
966 }
967 }
968
969 if (t) {
970 err = 0;
971 if (cmd == SIOCCHGTUNNEL) {
972 t->parms.iph.ttl = p.iph.ttl;
973 t->parms.iph.tos = p.iph.tos;
974 if (t->parms.link != p.link) {
975 t->parms.link = p.link;
976 ipip6_tunnel_bind_dev(dev);
977 netdev_state_change(dev);
978 }
979 }
980 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
981 err = -EFAULT;
982 } else
983 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
984 break;
985
986 case SIOCDELTUNNEL:
987 err = -EPERM;
988 if (!capable(CAP_NET_ADMIN))
989 goto done;
990
991 if (dev == sitn->fb_tunnel_dev) {
992 err = -EFAULT;
993 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
994 goto done;
995 err = -ENOENT;
996 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
997 goto done;
998 err = -EPERM;
999 if (t == netdev_priv(sitn->fb_tunnel_dev))
1000 goto done;
1001 dev = t->dev;
1002 }
1003 unregister_netdevice(dev);
1004 err = 0;
1005 break;
1006
1007 case SIOCGETPRL:
1008 err = -EINVAL;
1009 if (dev == sitn->fb_tunnel_dev)
1010 goto done;
1011 err = -ENOENT;
1012 if (!(t = netdev_priv(dev)))
1013 goto done;
1014 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1015 break;
1016
1017 case SIOCADDPRL:
1018 case SIOCDELPRL:
1019 case SIOCCHGPRL:
1020 err = -EPERM;
1021 if (!capable(CAP_NET_ADMIN))
1022 goto done;
1023 err = -EINVAL;
1024 if (dev == sitn->fb_tunnel_dev)
1025 goto done;
1026 err = -EFAULT;
1027 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1028 goto done;
1029 err = -ENOENT;
1030 if (!(t = netdev_priv(dev)))
1031 goto done;
1032
1033 switch (cmd) {
1034 case SIOCDELPRL:
1035 err = ipip6_tunnel_del_prl(t, &prl);
1036 break;
1037 case SIOCADDPRL:
1038 case SIOCCHGPRL:
1039 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1040 break;
1041 }
1042 netdev_state_change(dev);
1043 break;
1044
1045 #ifdef CONFIG_IPV6_SIT_6RD
1046 case SIOCADD6RD:
1047 case SIOCCHG6RD:
1048 case SIOCDEL6RD:
1049 err = -EPERM;
1050 if (!capable(CAP_NET_ADMIN))
1051 goto done;
1052
1053 err = -EFAULT;
1054 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1055 sizeof(ip6rd)))
1056 goto done;
1057
1058 t = netdev_priv(dev);
1059
1060 if (cmd != SIOCDEL6RD) {
1061 struct in6_addr prefix;
1062 __be32 relay_prefix;
1063
1064 err = -EINVAL;
1065 if (ip6rd.relay_prefixlen > 32 ||
1066 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1067 goto done;
1068
1069 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1070 ip6rd.prefixlen);
1071 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1072 goto done;
1073 if (ip6rd.relay_prefixlen)
1074 relay_prefix = ip6rd.relay_prefix &
1075 htonl(0xffffffffUL <<
1076 (32 - ip6rd.relay_prefixlen));
1077 else
1078 relay_prefix = 0;
1079 if (relay_prefix != ip6rd.relay_prefix)
1080 goto done;
1081
1082 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1083 t->ip6rd.relay_prefix = relay_prefix;
1084 t->ip6rd.prefixlen = ip6rd.prefixlen;
1085 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1086 } else
1087 ipip6_tunnel_clone_6rd(dev, sitn);
1088
1089 err = 0;
1090 break;
1091 #endif
1092
1093 default:
1094 err = -EINVAL;
1095 }
1096
1097 done:
1098 return err;
1099 }
1100
1101 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1102 {
1103 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1104 return -EINVAL;
1105 dev->mtu = new_mtu;
1106 return 0;
1107 }
1108
1109 static const struct net_device_ops ipip6_netdev_ops = {
1110 .ndo_uninit = ipip6_tunnel_uninit,
1111 .ndo_start_xmit = ipip6_tunnel_xmit,
1112 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1113 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1114 .ndo_get_stats = ipip6_get_stats,
1115 };
1116
1117 static void ipip6_dev_free(struct net_device *dev)
1118 {
1119 free_percpu(dev->tstats);
1120 free_netdev(dev);
1121 }
1122
1123 static void ipip6_tunnel_setup(struct net_device *dev)
1124 {
1125 dev->netdev_ops = &ipip6_netdev_ops;
1126 dev->destructor = ipip6_dev_free;
1127
1128 dev->type = ARPHRD_SIT;
1129 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1130 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1131 dev->flags = IFF_NOARP;
1132 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1133 dev->iflink = 0;
1134 dev->addr_len = 4;
1135 dev->features |= NETIF_F_NETNS_LOCAL;
1136 dev->features |= NETIF_F_LLTX;
1137 }
1138
1139 static int ipip6_tunnel_init(struct net_device *dev)
1140 {
1141 struct ip_tunnel *tunnel = netdev_priv(dev);
1142
1143 tunnel->dev = dev;
1144 strcpy(tunnel->parms.name, dev->name);
1145
1146 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1147 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1148
1149 ipip6_tunnel_bind_dev(dev);
1150 dev->tstats = alloc_percpu(struct pcpu_tstats);
1151 if (!dev->tstats)
1152 return -ENOMEM;
1153
1154 return 0;
1155 }
1156
1157 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1158 {
1159 struct ip_tunnel *tunnel = netdev_priv(dev);
1160 struct iphdr *iph = &tunnel->parms.iph;
1161 struct net *net = dev_net(dev);
1162 struct sit_net *sitn = net_generic(net, sit_net_id);
1163
1164 tunnel->dev = dev;
1165 strcpy(tunnel->parms.name, dev->name);
1166
1167 iph->version = 4;
1168 iph->protocol = IPPROTO_IPV6;
1169 iph->ihl = 5;
1170 iph->ttl = 64;
1171
1172 dev->tstats = alloc_percpu(struct pcpu_tstats);
1173 if (!dev->tstats)
1174 return -ENOMEM;
1175 dev_hold(dev);
1176 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1177 return 0;
1178 }
1179
1180 static struct xfrm_tunnel sit_handler __read_mostly = {
1181 .handler = ipip6_rcv,
1182 .err_handler = ipip6_err,
1183 .priority = 1,
1184 };
1185
1186 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1187 {
1188 int prio;
1189
1190 for (prio = 1; prio < 4; prio++) {
1191 int h;
1192 for (h = 0; h < HASH_SIZE; h++) {
1193 struct ip_tunnel *t;
1194
1195 t = rtnl_dereference(sitn->tunnels[prio][h]);
1196 while (t != NULL) {
1197 unregister_netdevice_queue(t->dev, head);
1198 t = rtnl_dereference(t->next);
1199 }
1200 }
1201 }
1202 }
1203
1204 static int __net_init sit_init_net(struct net *net)
1205 {
1206 struct sit_net *sitn = net_generic(net, sit_net_id);
1207 int err;
1208
1209 sitn->tunnels[0] = sitn->tunnels_wc;
1210 sitn->tunnels[1] = sitn->tunnels_l;
1211 sitn->tunnels[2] = sitn->tunnels_r;
1212 sitn->tunnels[3] = sitn->tunnels_r_l;
1213
1214 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1215 ipip6_tunnel_setup);
1216 if (!sitn->fb_tunnel_dev) {
1217 err = -ENOMEM;
1218 goto err_alloc_dev;
1219 }
1220 dev_net_set(sitn->fb_tunnel_dev, net);
1221
1222 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1223 if (err)
1224 goto err_dev_free;
1225
1226 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1227
1228 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1229 goto err_reg_dev;
1230
1231 return 0;
1232
1233 err_reg_dev:
1234 dev_put(sitn->fb_tunnel_dev);
1235 err_dev_free:
1236 ipip6_dev_free(sitn->fb_tunnel_dev);
1237 err_alloc_dev:
1238 return err;
1239 }
1240
1241 static void __net_exit sit_exit_net(struct net *net)
1242 {
1243 struct sit_net *sitn = net_generic(net, sit_net_id);
1244 LIST_HEAD(list);
1245
1246 rtnl_lock();
1247 sit_destroy_tunnels(sitn, &list);
1248 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1249 unregister_netdevice_many(&list);
1250 rtnl_unlock();
1251 }
1252
1253 static struct pernet_operations sit_net_ops = {
1254 .init = sit_init_net,
1255 .exit = sit_exit_net,
1256 .id = &sit_net_id,
1257 .size = sizeof(struct sit_net),
1258 };
1259
1260 static void __exit sit_cleanup(void)
1261 {
1262 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1263
1264 unregister_pernet_device(&sit_net_ops);
1265 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1266 }
1267
1268 static int __init sit_init(void)
1269 {
1270 int err;
1271
1272 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1273
1274 err = register_pernet_device(&sit_net_ops);
1275 if (err < 0)
1276 return err;
1277 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1278 if (err < 0) {
1279 unregister_pernet_device(&sit_net_ops);
1280 printk(KERN_INFO "sit init: Can't add protocol\n");
1281 }
1282 return err;
1283 }
1284
1285 module_init(sit_init);
1286 module_exit(sit_cleanup);
1287 MODULE_LICENSE("GPL");
1288 MODULE_ALIAS_NETDEV("sit0");
linux-next