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Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
[zen-stable.git] / net / ipv6 / sit.c
bloba7a18602a046e1ffe5f0f00883844459802f4a25
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_INIT_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_INIT_POINTER(t->next, rtnl_dereference(*tp));
196 RCU_INIT_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_INIT_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_INIT_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 if (tos == 1)
676 tos = ipv6_get_dsfield(iph6);
677
678 /* ISATAP (RFC4214) - must come before 6to4 */
679 if (dev->priv_flags & IFF_ISATAP) {
680 struct neighbour *neigh = NULL;
681
682 if (skb_dst(skb))
683 neigh = dst_get_neighbour(skb_dst(skb));
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 = (const struct in6_addr*)&neigh->primary_key;
692 addr_type = ipv6_addr_type(addr6);
693
694 if ((addr_type & IPV6_ADDR_UNICAST) &&
695 ipv6_addr_is_isatap(addr6))
696 dst = addr6->s6_addr32[3];
697 else
698 goto tx_error;
699 }
700
701 if (!dst)
702 dst = try_6rd(&iph6->daddr, tunnel);
703
704 if (!dst) {
705 struct neighbour *neigh = NULL;
706
707 if (skb_dst(skb))
708 neigh = dst_get_neighbour(skb_dst(skb));
709
710 if (neigh == NULL) {
711 if (net_ratelimit())
712 printk(KERN_DEBUG "sit: nexthop == NULL\n");
713 goto tx_error;
714 }
715
716 addr6 = (const struct in6_addr*)&neigh->primary_key;
717 addr_type = ipv6_addr_type(addr6);
718
719 if (addr_type == IPV6_ADDR_ANY) {
720 addr6 = &ipv6_hdr(skb)->daddr;
721 addr_type = ipv6_addr_type(addr6);
722 }
723
724 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
725 goto tx_error_icmp;
726
727 dst = addr6->s6_addr32[3];
728 }
729
730 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
731 dst, tiph->saddr,
732 0, 0,
733 IPPROTO_IPV6, RT_TOS(tos),
734 tunnel->parms.link);
735 if (IS_ERR(rt)) {
736 dev->stats.tx_carrier_errors++;
737 goto tx_error_icmp;
738 }
739 if (rt->rt_type != RTN_UNICAST) {
740 ip_rt_put(rt);
741 dev->stats.tx_carrier_errors++;
742 goto tx_error_icmp;
743 }
744 tdev = rt->dst.dev;
745
746 if (tdev == dev) {
747 ip_rt_put(rt);
748 dev->stats.collisions++;
749 goto tx_error;
750 }
751
752 if (df) {
753 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
754
755 if (mtu < 68) {
756 dev->stats.collisions++;
757 ip_rt_put(rt);
758 goto tx_error;
759 }
760
761 if (mtu < IPV6_MIN_MTU) {
762 mtu = IPV6_MIN_MTU;
763 df = 0;
764 }
765
766 if (tunnel->parms.iph.daddr && skb_dst(skb))
767 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
768
769 if (skb->len > mtu) {
770 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
771 ip_rt_put(rt);
772 goto tx_error;
773 }
774 }
775
776 if (tunnel->err_count > 0) {
777 if (time_before(jiffies,
778 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
779 tunnel->err_count--;
780 dst_link_failure(skb);
781 } else
782 tunnel->err_count = 0;
783 }
784
785 /*
786 * Okay, now see if we can stuff it in the buffer as-is.
787 */
788 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
789
790 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
791 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
792 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
793 if (!new_skb) {
794 ip_rt_put(rt);
795 dev->stats.tx_dropped++;
796 dev_kfree_skb(skb);
797 return NETDEV_TX_OK;
798 }
799 if (skb->sk)
800 skb_set_owner_w(new_skb, skb->sk);
801 dev_kfree_skb(skb);
802 skb = new_skb;
803 iph6 = ipv6_hdr(skb);
804 }
805
806 skb->transport_header = skb->network_header;
807 skb_push(skb, sizeof(struct iphdr));
808 skb_reset_network_header(skb);
809 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
810 IPCB(skb)->flags = 0;
811 skb_dst_drop(skb);
812 skb_dst_set(skb, &rt->dst);
813
814 /*
815 * Push down and install the IPIP header.
816 */
817
818 iph = ip_hdr(skb);
819 iph->version = 4;
820 iph->ihl = sizeof(struct iphdr)>>2;
821 iph->frag_off = df;
822 iph->protocol = IPPROTO_IPV6;
823 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
824 iph->daddr = fl4.daddr;
825 iph->saddr = fl4.saddr;
826
827 if ((iph->ttl = tiph->ttl) == 0)
828 iph->ttl = iph6->hop_limit;
829
830 nf_reset(skb);
831 tstats = this_cpu_ptr(dev->tstats);
832 __IPTUNNEL_XMIT(tstats, &dev->stats);
833 return NETDEV_TX_OK;
834
835 tx_error_icmp:
836 dst_link_failure(skb);
837 tx_error:
838 dev->stats.tx_errors++;
839 dev_kfree_skb(skb);
840 return NETDEV_TX_OK;
841 }
842
843 static void ipip6_tunnel_bind_dev(struct net_device *dev)
844 {
845 struct net_device *tdev = NULL;
846 struct ip_tunnel *tunnel;
847 const struct iphdr *iph;
848 struct flowi4 fl4;
849
850 tunnel = netdev_priv(dev);
851 iph = &tunnel->parms.iph;
852
853 if (iph->daddr) {
854 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
855 iph->daddr, iph->saddr,
856 0, 0,
857 IPPROTO_IPV6,
858 RT_TOS(iph->tos),
859 tunnel->parms.link);
860
861 if (!IS_ERR(rt)) {
862 tdev = rt->dst.dev;
863 ip_rt_put(rt);
864 }
865 dev->flags |= IFF_POINTOPOINT;
866 }
867
868 if (!tdev && tunnel->parms.link)
869 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
870
871 if (tdev) {
872 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
873 dev->mtu = tdev->mtu - sizeof(struct iphdr);
874 if (dev->mtu < IPV6_MIN_MTU)
875 dev->mtu = IPV6_MIN_MTU;
876 }
877 dev->iflink = tunnel->parms.link;
878 }
879
880 static int
881 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
882 {
883 int err = 0;
884 struct ip_tunnel_parm p;
885 struct ip_tunnel_prl prl;
886 struct ip_tunnel *t;
887 struct net *net = dev_net(dev);
888 struct sit_net *sitn = net_generic(net, sit_net_id);
889 #ifdef CONFIG_IPV6_SIT_6RD
890 struct ip_tunnel_6rd ip6rd;
891 #endif
892
893 switch (cmd) {
894 case SIOCGETTUNNEL:
895 #ifdef CONFIG_IPV6_SIT_6RD
896 case SIOCGET6RD:
897 #endif
898 t = NULL;
899 if (dev == sitn->fb_tunnel_dev) {
900 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
901 err = -EFAULT;
902 break;
903 }
904 t = ipip6_tunnel_locate(net, &p, 0);
905 }
906 if (t == NULL)
907 t = netdev_priv(dev);
908
909 err = -EFAULT;
910 if (cmd == SIOCGETTUNNEL) {
911 memcpy(&p, &t->parms, sizeof(p));
912 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
913 sizeof(p)))
914 goto done;
915 #ifdef CONFIG_IPV6_SIT_6RD
916 } else {
917 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
918 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
919 ip6rd.prefixlen = t->ip6rd.prefixlen;
920 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
921 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
922 sizeof(ip6rd)))
923 goto done;
924 #endif
925 }
926 err = 0;
927 break;
928
929 case SIOCADDTUNNEL:
930 case SIOCCHGTUNNEL:
931 err = -EPERM;
932 if (!capable(CAP_NET_ADMIN))
933 goto done;
934
935 err = -EFAULT;
936 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
937 goto done;
938
939 err = -EINVAL;
940 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
941 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
942 goto done;
943 if (p.iph.ttl)
944 p.iph.frag_off |= htons(IP_DF);
945
946 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
947
948 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
949 if (t != NULL) {
950 if (t->dev != dev) {
951 err = -EEXIST;
952 break;
953 }
954 } else {
955 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
956 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
957 err = -EINVAL;
958 break;
959 }
960 t = netdev_priv(dev);
961 ipip6_tunnel_unlink(sitn, t);
962 synchronize_net();
963 t->parms.iph.saddr = p.iph.saddr;
964 t->parms.iph.daddr = p.iph.daddr;
965 memcpy(dev->dev_addr, &p.iph.saddr, 4);
966 memcpy(dev->broadcast, &p.iph.daddr, 4);
967 ipip6_tunnel_link(sitn, t);
968 netdev_state_change(dev);
969 }
970 }
971
972 if (t) {
973 err = 0;
974 if (cmd == SIOCCHGTUNNEL) {
975 t->parms.iph.ttl = p.iph.ttl;
976 t->parms.iph.tos = p.iph.tos;
977 if (t->parms.link != p.link) {
978 t->parms.link = p.link;
979 ipip6_tunnel_bind_dev(dev);
980 netdev_state_change(dev);
981 }
982 }
983 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
984 err = -EFAULT;
985 } else
986 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
987 break;
988
989 case SIOCDELTUNNEL:
990 err = -EPERM;
991 if (!capable(CAP_NET_ADMIN))
992 goto done;
993
994 if (dev == sitn->fb_tunnel_dev) {
995 err = -EFAULT;
996 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
997 goto done;
998 err = -ENOENT;
999 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1000 goto done;
1001 err = -EPERM;
1002 if (t == netdev_priv(sitn->fb_tunnel_dev))
1003 goto done;
1004 dev = t->dev;
1005 }
1006 unregister_netdevice(dev);
1007 err = 0;
1008 break;
1009
1010 case SIOCGETPRL:
1011 err = -EINVAL;
1012 if (dev == sitn->fb_tunnel_dev)
1013 goto done;
1014 err = -ENOENT;
1015 if (!(t = netdev_priv(dev)))
1016 goto done;
1017 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1018 break;
1019
1020 case SIOCADDPRL:
1021 case SIOCDELPRL:
1022 case SIOCCHGPRL:
1023 err = -EPERM;
1024 if (!capable(CAP_NET_ADMIN))
1025 goto done;
1026 err = -EINVAL;
1027 if (dev == sitn->fb_tunnel_dev)
1028 goto done;
1029 err = -EFAULT;
1030 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1031 goto done;
1032 err = -ENOENT;
1033 if (!(t = netdev_priv(dev)))
1034 goto done;
1035
1036 switch (cmd) {
1037 case SIOCDELPRL:
1038 err = ipip6_tunnel_del_prl(t, &prl);
1039 break;
1040 case SIOCADDPRL:
1041 case SIOCCHGPRL:
1042 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1043 break;
1044 }
1045 netdev_state_change(dev);
1046 break;
1047
1048 #ifdef CONFIG_IPV6_SIT_6RD
1049 case SIOCADD6RD:
1050 case SIOCCHG6RD:
1051 case SIOCDEL6RD:
1052 err = -EPERM;
1053 if (!capable(CAP_NET_ADMIN))
1054 goto done;
1055
1056 err = -EFAULT;
1057 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1058 sizeof(ip6rd)))
1059 goto done;
1060
1061 t = netdev_priv(dev);
1062
1063 if (cmd != SIOCDEL6RD) {
1064 struct in6_addr prefix;
1065 __be32 relay_prefix;
1066
1067 err = -EINVAL;
1068 if (ip6rd.relay_prefixlen > 32 ||
1069 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1070 goto done;
1071
1072 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1073 ip6rd.prefixlen);
1074 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1075 goto done;
1076 if (ip6rd.relay_prefixlen)
1077 relay_prefix = ip6rd.relay_prefix &
1078 htonl(0xffffffffUL <<
1079 (32 - ip6rd.relay_prefixlen));
1080 else
1081 relay_prefix = 0;
1082 if (relay_prefix != ip6rd.relay_prefix)
1083 goto done;
1084
1085 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1086 t->ip6rd.relay_prefix = relay_prefix;
1087 t->ip6rd.prefixlen = ip6rd.prefixlen;
1088 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1089 } else
1090 ipip6_tunnel_clone_6rd(dev, sitn);
1091
1092 err = 0;
1093 break;
1094 #endif
1095
1096 default:
1097 err = -EINVAL;
1098 }
1099
1100 done:
1101 return err;
1102 }
1103
1104 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1105 {
1106 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1107 return -EINVAL;
1108 dev->mtu = new_mtu;
1109 return 0;
1110 }
1111
1112 static const struct net_device_ops ipip6_netdev_ops = {
1113 .ndo_uninit = ipip6_tunnel_uninit,
1114 .ndo_start_xmit = ipip6_tunnel_xmit,
1115 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1116 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1117 .ndo_get_stats = ipip6_get_stats,
1118 };
1119
1120 static void ipip6_dev_free(struct net_device *dev)
1121 {
1122 free_percpu(dev->tstats);
1123 free_netdev(dev);
1124 }
1125
1126 static void ipip6_tunnel_setup(struct net_device *dev)
1127 {
1128 dev->netdev_ops = &ipip6_netdev_ops;
1129 dev->destructor = ipip6_dev_free;
1130
1131 dev->type = ARPHRD_SIT;
1132 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1133 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1134 dev->flags = IFF_NOARP;
1135 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1136 dev->iflink = 0;
1137 dev->addr_len = 4;
1138 dev->features |= NETIF_F_NETNS_LOCAL;
1139 dev->features |= NETIF_F_LLTX;
1140 }
1141
1142 static int ipip6_tunnel_init(struct net_device *dev)
1143 {
1144 struct ip_tunnel *tunnel = netdev_priv(dev);
1145
1146 tunnel->dev = dev;
1147 strcpy(tunnel->parms.name, dev->name);
1148
1149 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1150 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1151
1152 ipip6_tunnel_bind_dev(dev);
1153 dev->tstats = alloc_percpu(struct pcpu_tstats);
1154 if (!dev->tstats)
1155 return -ENOMEM;
1156
1157 return 0;
1158 }
1159
1160 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1161 {
1162 struct ip_tunnel *tunnel = netdev_priv(dev);
1163 struct iphdr *iph = &tunnel->parms.iph;
1164 struct net *net = dev_net(dev);
1165 struct sit_net *sitn = net_generic(net, sit_net_id);
1166
1167 tunnel->dev = dev;
1168 strcpy(tunnel->parms.name, dev->name);
1169
1170 iph->version = 4;
1171 iph->protocol = IPPROTO_IPV6;
1172 iph->ihl = 5;
1173 iph->ttl = 64;
1174
1175 dev->tstats = alloc_percpu(struct pcpu_tstats);
1176 if (!dev->tstats)
1177 return -ENOMEM;
1178 dev_hold(dev);
1179 RCU_INIT_POINTER(sitn->tunnels_wc[0], tunnel);
1180 return 0;
1181 }
1182
1183 static struct xfrm_tunnel sit_handler __read_mostly = {
1184 .handler = ipip6_rcv,
1185 .err_handler = ipip6_err,
1186 .priority = 1,
1187 };
1188
1189 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1190 {
1191 int prio;
1192
1193 for (prio = 1; prio < 4; prio++) {
1194 int h;
1195 for (h = 0; h < HASH_SIZE; h++) {
1196 struct ip_tunnel *t;
1197
1198 t = rtnl_dereference(sitn->tunnels[prio][h]);
1199 while (t != NULL) {
1200 unregister_netdevice_queue(t->dev, head);
1201 t = rtnl_dereference(t->next);
1202 }
1203 }
1204 }
1205 }
1206
1207 static int __net_init sit_init_net(struct net *net)
1208 {
1209 struct sit_net *sitn = net_generic(net, sit_net_id);
1210 int err;
1211
1212 sitn->tunnels[0] = sitn->tunnels_wc;
1213 sitn->tunnels[1] = sitn->tunnels_l;
1214 sitn->tunnels[2] = sitn->tunnels_r;
1215 sitn->tunnels[3] = sitn->tunnels_r_l;
1216
1217 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1218 ipip6_tunnel_setup);
1219 if (!sitn->fb_tunnel_dev) {
1220 err = -ENOMEM;
1221 goto err_alloc_dev;
1222 }
1223 dev_net_set(sitn->fb_tunnel_dev, net);
1224
1225 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1226 if (err)
1227 goto err_dev_free;
1228
1229 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1230
1231 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1232 goto err_reg_dev;
1233
1234 return 0;
1235
1236 err_reg_dev:
1237 dev_put(sitn->fb_tunnel_dev);
1238 err_dev_free:
1239 ipip6_dev_free(sitn->fb_tunnel_dev);
1240 err_alloc_dev:
1241 return err;
1242 }
1243
1244 static void __net_exit sit_exit_net(struct net *net)
1245 {
1246 struct sit_net *sitn = net_generic(net, sit_net_id);
1247 LIST_HEAD(list);
1248
1249 rtnl_lock();
1250 sit_destroy_tunnels(sitn, &list);
1251 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1252 unregister_netdevice_many(&list);
1253 rtnl_unlock();
1254 }
1255
1256 static struct pernet_operations sit_net_ops = {
1257 .init = sit_init_net,
1258 .exit = sit_exit_net,
1259 .id = &sit_net_id,
1260 .size = sizeof(struct sit_net),
1261 };
1262
1263 static void __exit sit_cleanup(void)
1264 {
1265 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1266
1267 unregister_pernet_device(&sit_net_ops);
1268 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1269 }
1270
1271 static int __init sit_init(void)
1272 {
1273 int err;
1274
1275 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1276
1277 err = register_pernet_device(&sit_net_ops);
1278 if (err < 0)
1279 return err;
1280 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1281 if (err < 0) {
1282 unregister_pernet_device(&sit_net_ops);
1283 printk(KERN_INFO "sit init: Can't add protocol\n");
1284 }
1285 return err;
1286 }
1287
1288 module_init(sit_init);
1289 module_exit(sit_cleanup);
1290 MODULE_LICENSE("GPL");
1291 MODULE_ALIAS_NETDEV("sit0");