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Use dentry_path() to create full path to inode object
[pohmelfs.git] / net / ipv6 / sit.c
blob133768e52912bd561930736f36c0085c594000b4
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 } __attribute__((aligned(4*sizeof(unsigned long))));
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 strcpy(nt->parms.name, dev->name);
267
268 dev_hold(dev);
269
270 ipip6_tunnel_link(sitn, nt);
271 return nt;
272
273 failed_free:
274 ipip6_dev_free(dev);
275 failed:
276 return NULL;
277 }
278
279 #define for_each_prl_rcu(start) \
280 for (prl = rcu_dereference(start); \
281 prl; \
282 prl = rcu_dereference(prl->next))
283
284 static struct ip_tunnel_prl_entry *
285 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
286 {
287 struct ip_tunnel_prl_entry *prl;
288
289 for_each_prl_rcu(t->prl)
290 if (prl->addr == addr)
291 break;
292 return prl;
293
294 }
295
296 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
297 struct ip_tunnel_prl __user *a)
298 {
299 struct ip_tunnel_prl kprl, *kp;
300 struct ip_tunnel_prl_entry *prl;
301 unsigned int cmax, c = 0, ca, len;
302 int ret = 0;
303
304 if (copy_from_user(&kprl, a, sizeof(kprl)))
305 return -EFAULT;
306 cmax = kprl.datalen / sizeof(kprl);
307 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
308 cmax = 1;
309
310 /* For simple GET or for root users,
311 * we try harder to allocate.
312 */
313 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
314 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
315 NULL;
316
317 rcu_read_lock();
318
319 ca = t->prl_count < cmax ? t->prl_count : cmax;
320
321 if (!kp) {
322 /* We don't try hard to allocate much memory for
323 * non-root users.
324 * For root users, retry allocating enough memory for
325 * the answer.
326 */
327 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
328 if (!kp) {
329 ret = -ENOMEM;
330 goto out;
331 }
332 }
333
334 c = 0;
335 for_each_prl_rcu(t->prl) {
336 if (c >= cmax)
337 break;
338 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
339 continue;
340 kp[c].addr = prl->addr;
341 kp[c].flags = prl->flags;
342 c++;
343 if (kprl.addr != htonl(INADDR_ANY))
344 break;
345 }
346 out:
347 rcu_read_unlock();
348
349 len = sizeof(*kp) * c;
350 ret = 0;
351 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
352 ret = -EFAULT;
353
354 kfree(kp);
355
356 return ret;
357 }
358
359 static int
360 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
361 {
362 struct ip_tunnel_prl_entry *p;
363 int err = 0;
364
365 if (a->addr == htonl(INADDR_ANY))
366 return -EINVAL;
367
368 ASSERT_RTNL();
369
370 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
371 if (p->addr == a->addr) {
372 if (chg) {
373 p->flags = a->flags;
374 goto out;
375 }
376 err = -EEXIST;
377 goto out;
378 }
379 }
380
381 if (chg) {
382 err = -ENXIO;
383 goto out;
384 }
385
386 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
387 if (!p) {
388 err = -ENOBUFS;
389 goto out;
390 }
391
392 p->next = t->prl;
393 p->addr = a->addr;
394 p->flags = a->flags;
395 t->prl_count++;
396 rcu_assign_pointer(t->prl, p);
397 out:
398 return err;
399 }
400
401 static void prl_list_destroy_rcu(struct rcu_head *head)
402 {
403 struct ip_tunnel_prl_entry *p, *n;
404
405 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
406 do {
407 n = rcu_dereference_protected(p->next, 1);
408 kfree(p);
409 p = n;
410 } while (p);
411 }
412
413 static int
414 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
415 {
416 struct ip_tunnel_prl_entry *x;
417 struct ip_tunnel_prl_entry __rcu **p;
418 int err = 0;
419
420 ASSERT_RTNL();
421
422 if (a && a->addr != htonl(INADDR_ANY)) {
423 for (p = &t->prl;
424 (x = rtnl_dereference(*p)) != NULL;
425 p = &x->next) {
426 if (x->addr == a->addr) {
427 *p = x->next;
428 kfree_rcu(x, rcu_head);
429 t->prl_count--;
430 goto out;
431 }
432 }
433 err = -ENXIO;
434 } else {
435 x = rtnl_dereference(t->prl);
436 if (x) {
437 t->prl_count = 0;
438 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
439 t->prl = NULL;
440 }
441 }
442 out:
443 return err;
444 }
445
446 static int
447 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
448 {
449 struct ip_tunnel_prl_entry *p;
450 int ok = 1;
451
452 rcu_read_lock();
453 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
454 if (p) {
455 if (p->flags & PRL_DEFAULT)
456 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
457 else
458 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
459 } else {
460 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
461
462 if (ipv6_addr_is_isatap(addr6) &&
463 (addr6->s6_addr32[3] == iph->saddr) &&
464 ipv6_chk_prefix(addr6, t->dev))
465 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
466 else
467 ok = 0;
468 }
469 rcu_read_unlock();
470 return ok;
471 }
472
473 static void ipip6_tunnel_uninit(struct net_device *dev)
474 {
475 struct net *net = dev_net(dev);
476 struct sit_net *sitn = net_generic(net, sit_net_id);
477
478 if (dev == sitn->fb_tunnel_dev) {
479 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
480 } else {
481 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
482 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
483 }
484 dev_put(dev);
485 }
486
487
488 static int ipip6_err(struct sk_buff *skb, u32 info)
489 {
490
491 /* All the routers (except for Linux) return only
492 8 bytes of packet payload. It means, that precise relaying of
493 ICMP in the real Internet is absolutely infeasible.
494 */
495 const struct iphdr *iph = (const struct iphdr *)skb->data;
496 const int type = icmp_hdr(skb)->type;
497 const int code = icmp_hdr(skb)->code;
498 struct ip_tunnel *t;
499 int err;
500
501 switch (type) {
502 default:
503 case ICMP_PARAMETERPROB:
504 return 0;
505
506 case ICMP_DEST_UNREACH:
507 switch (code) {
508 case ICMP_SR_FAILED:
509 case ICMP_PORT_UNREACH:
510 /* Impossible event. */
511 return 0;
512 case ICMP_FRAG_NEEDED:
513 /* Soft state for pmtu is maintained by IP core. */
514 return 0;
515 default:
516 /* All others are translated to HOST_UNREACH.
517 rfc2003 contains "deep thoughts" about NET_UNREACH,
518 I believe they are just ether pollution. --ANK
519 */
520 break;
521 }
522 break;
523 case ICMP_TIME_EXCEEDED:
524 if (code != ICMP_EXC_TTL)
525 return 0;
526 break;
527 }
528
529 err = -ENOENT;
530
531 rcu_read_lock();
532 t = ipip6_tunnel_lookup(dev_net(skb->dev),
533 skb->dev,
534 iph->daddr,
535 iph->saddr);
536 if (t == NULL || t->parms.iph.daddr == 0)
537 goto out;
538
539 err = 0;
540 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
541 goto out;
542
543 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
544 t->err_count++;
545 else
546 t->err_count = 1;
547 t->err_time = jiffies;
548 out:
549 rcu_read_unlock();
550 return err;
551 }
552
553 static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
554 {
555 if (INET_ECN_is_ce(iph->tos))
556 IP6_ECN_set_ce(ipv6_hdr(skb));
557 }
558
559 static int ipip6_rcv(struct sk_buff *skb)
560 {
561 const struct iphdr *iph;
562 struct ip_tunnel *tunnel;
563
564 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
565 goto out;
566
567 iph = ip_hdr(skb);
568
569 rcu_read_lock();
570 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
571 iph->saddr, iph->daddr);
572 if (tunnel != NULL) {
573 struct pcpu_tstats *tstats;
574
575 secpath_reset(skb);
576 skb->mac_header = skb->network_header;
577 skb_reset_network_header(skb);
578 IPCB(skb)->flags = 0;
579 skb->protocol = htons(ETH_P_IPV6);
580 skb->pkt_type = PACKET_HOST;
581
582 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
583 !isatap_chksrc(skb, iph, tunnel)) {
584 tunnel->dev->stats.rx_errors++;
585 rcu_read_unlock();
586 kfree_skb(skb);
587 return 0;
588 }
589
590 tstats = this_cpu_ptr(tunnel->dev->tstats);
591 tstats->rx_packets++;
592 tstats->rx_bytes += skb->len;
593
594 __skb_tunnel_rx(skb, tunnel->dev);
595
596 ipip6_ecn_decapsulate(iph, skb);
597
598 netif_rx(skb);
599
600 rcu_read_unlock();
601 return 0;
602 }
603
604 /* no tunnel matched, let upstream know, ipsec may handle it */
605 rcu_read_unlock();
606 return 1;
607 out:
608 kfree_skb(skb);
609 return 0;
610 }
611
612 /*
613 * Returns the embedded IPv4 address if the IPv6 address
614 * comes from 6rd / 6to4 (RFC 3056) addr space.
615 */
616 static inline
617 __be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel)
618 {
619 __be32 dst = 0;
620
621 #ifdef CONFIG_IPV6_SIT_6RD
622 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
623 tunnel->ip6rd.prefixlen)) {
624 unsigned int pbw0, pbi0;
625 int pbi1;
626 u32 d;
627
628 pbw0 = tunnel->ip6rd.prefixlen >> 5;
629 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
630
631 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
632 tunnel->ip6rd.relay_prefixlen;
633
634 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
635 if (pbi1 > 0)
636 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
637 (32 - pbi1);
638
639 dst = tunnel->ip6rd.relay_prefix | htonl(d);
640 }
641 #else
642 if (v6dst->s6_addr16[0] == htons(0x2002)) {
643 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
644 memcpy(&dst, &v6dst->s6_addr16[1], 4);
645 }
646 #endif
647 return dst;
648 }
649
650 /*
651 * This function assumes it is being called from dev_queue_xmit()
652 * and that skb is filled properly by that function.
653 */
654
655 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
656 struct net_device *dev)
657 {
658 struct ip_tunnel *tunnel = netdev_priv(dev);
659 struct pcpu_tstats *tstats;
660 const struct iphdr *tiph = &tunnel->parms.iph;
661 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
662 u8 tos = tunnel->parms.iph.tos;
663 __be16 df = tiph->frag_off;
664 struct rtable *rt; /* Route to the other host */
665 struct net_device *tdev; /* Device to other host */
666 struct iphdr *iph; /* Our new IP header */
667 unsigned int max_headroom; /* The extra header space needed */
668 __be32 dst = tiph->daddr;
669 struct flowi4 fl4;
670 int mtu;
671 const struct in6_addr *addr6;
672 int addr_type;
673
674 if (skb->protocol != htons(ETH_P_IPV6))
675 goto tx_error;
676
677 if (tos == 1)
678 tos = ipv6_get_dsfield(iph6);
679
680 /* ISATAP (RFC4214) - must come before 6to4 */
681 if (dev->priv_flags & IFF_ISATAP) {
682 struct neighbour *neigh = NULL;
683
684 if (skb_dst(skb))
685 neigh = dst_get_neighbour_noref(skb_dst(skb));
686
687 if (neigh == NULL) {
688 if (net_ratelimit())
689 printk(KERN_DEBUG "sit: nexthop == NULL\n");
690 goto tx_error;
691 }
692
693 addr6 = (const struct in6_addr*)&neigh->primary_key;
694 addr_type = ipv6_addr_type(addr6);
695
696 if ((addr_type & IPV6_ADDR_UNICAST) &&
697 ipv6_addr_is_isatap(addr6))
698 dst = addr6->s6_addr32[3];
699 else
700 goto tx_error;
701 }
702
703 if (!dst)
704 dst = try_6rd(&iph6->daddr, tunnel);
705
706 if (!dst) {
707 struct neighbour *neigh = NULL;
708
709 if (skb_dst(skb))
710 neigh = dst_get_neighbour_noref(skb_dst(skb));
711
712 if (neigh == NULL) {
713 if (net_ratelimit())
714 printk(KERN_DEBUG "sit: nexthop == NULL\n");
715 goto tx_error;
716 }
717
718 addr6 = (const struct in6_addr*)&neigh->primary_key;
719 addr_type = ipv6_addr_type(addr6);
720
721 if (addr_type == IPV6_ADDR_ANY) {
722 addr6 = &ipv6_hdr(skb)->daddr;
723 addr_type = ipv6_addr_type(addr6);
724 }
725
726 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
727 goto tx_error_icmp;
728
729 dst = addr6->s6_addr32[3];
730 }
731
732 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
733 dst, tiph->saddr,
734 0, 0,
735 IPPROTO_IPV6, RT_TOS(tos),
736 tunnel->parms.link);
737 if (IS_ERR(rt)) {
738 dev->stats.tx_carrier_errors++;
739 goto tx_error_icmp;
740 }
741 if (rt->rt_type != RTN_UNICAST) {
742 ip_rt_put(rt);
743 dev->stats.tx_carrier_errors++;
744 goto tx_error_icmp;
745 }
746 tdev = rt->dst.dev;
747
748 if (tdev == dev) {
749 ip_rt_put(rt);
750 dev->stats.collisions++;
751 goto tx_error;
752 }
753
754 if (df) {
755 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
756
757 if (mtu < 68) {
758 dev->stats.collisions++;
759 ip_rt_put(rt);
760 goto tx_error;
761 }
762
763 if (mtu < IPV6_MIN_MTU) {
764 mtu = IPV6_MIN_MTU;
765 df = 0;
766 }
767
768 if (tunnel->parms.iph.daddr && skb_dst(skb))
769 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
770
771 if (skb->len > mtu) {
772 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
773 ip_rt_put(rt);
774 goto tx_error;
775 }
776 }
777
778 if (tunnel->err_count > 0) {
779 if (time_before(jiffies,
780 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
781 tunnel->err_count--;
782 dst_link_failure(skb);
783 } else
784 tunnel->err_count = 0;
785 }
786
787 /*
788 * Okay, now see if we can stuff it in the buffer as-is.
789 */
790 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
791
792 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
793 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
794 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
795 if (!new_skb) {
796 ip_rt_put(rt);
797 dev->stats.tx_dropped++;
798 dev_kfree_skb(skb);
799 return NETDEV_TX_OK;
800 }
801 if (skb->sk)
802 skb_set_owner_w(new_skb, skb->sk);
803 dev_kfree_skb(skb);
804 skb = new_skb;
805 iph6 = ipv6_hdr(skb);
806 }
807
808 skb->transport_header = skb->network_header;
809 skb_push(skb, sizeof(struct iphdr));
810 skb_reset_network_header(skb);
811 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
812 IPCB(skb)->flags = 0;
813 skb_dst_drop(skb);
814 skb_dst_set(skb, &rt->dst);
815
816 /*
817 * Push down and install the IPIP header.
818 */
819
820 iph = ip_hdr(skb);
821 iph->version = 4;
822 iph->ihl = sizeof(struct iphdr)>>2;
823 iph->frag_off = df;
824 iph->protocol = IPPROTO_IPV6;
825 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
826 iph->daddr = fl4.daddr;
827 iph->saddr = fl4.saddr;
828
829 if ((iph->ttl = tiph->ttl) == 0)
830 iph->ttl = iph6->hop_limit;
831
832 nf_reset(skb);
833 tstats = this_cpu_ptr(dev->tstats);
834 __IPTUNNEL_XMIT(tstats, &dev->stats);
835 return NETDEV_TX_OK;
836
837 tx_error_icmp:
838 dst_link_failure(skb);
839 tx_error:
840 dev->stats.tx_errors++;
841 dev_kfree_skb(skb);
842 return NETDEV_TX_OK;
843 }
844
845 static void ipip6_tunnel_bind_dev(struct net_device *dev)
846 {
847 struct net_device *tdev = NULL;
848 struct ip_tunnel *tunnel;
849 const struct iphdr *iph;
850 struct flowi4 fl4;
851
852 tunnel = netdev_priv(dev);
853 iph = &tunnel->parms.iph;
854
855 if (iph->daddr) {
856 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
857 iph->daddr, iph->saddr,
858 0, 0,
859 IPPROTO_IPV6,
860 RT_TOS(iph->tos),
861 tunnel->parms.link);
862
863 if (!IS_ERR(rt)) {
864 tdev = rt->dst.dev;
865 ip_rt_put(rt);
866 }
867 dev->flags |= IFF_POINTOPOINT;
868 }
869
870 if (!tdev && tunnel->parms.link)
871 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
872
873 if (tdev) {
874 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
875 dev->mtu = tdev->mtu - sizeof(struct iphdr);
876 if (dev->mtu < IPV6_MIN_MTU)
877 dev->mtu = IPV6_MIN_MTU;
878 }
879 dev->iflink = tunnel->parms.link;
880 }
881
882 static int
883 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
884 {
885 int err = 0;
886 struct ip_tunnel_parm p;
887 struct ip_tunnel_prl prl;
888 struct ip_tunnel *t;
889 struct net *net = dev_net(dev);
890 struct sit_net *sitn = net_generic(net, sit_net_id);
891 #ifdef CONFIG_IPV6_SIT_6RD
892 struct ip_tunnel_6rd ip6rd;
893 #endif
894
895 switch (cmd) {
896 case SIOCGETTUNNEL:
897 #ifdef CONFIG_IPV6_SIT_6RD
898 case SIOCGET6RD:
899 #endif
900 t = NULL;
901 if (dev == sitn->fb_tunnel_dev) {
902 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
903 err = -EFAULT;
904 break;
905 }
906 t = ipip6_tunnel_locate(net, &p, 0);
907 }
908 if (t == NULL)
909 t = netdev_priv(dev);
910
911 err = -EFAULT;
912 if (cmd == SIOCGETTUNNEL) {
913 memcpy(&p, &t->parms, sizeof(p));
914 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
915 sizeof(p)))
916 goto done;
917 #ifdef CONFIG_IPV6_SIT_6RD
918 } else {
919 ip6rd.prefix = t->ip6rd.prefix;
920 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
921 ip6rd.prefixlen = t->ip6rd.prefixlen;
922 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
923 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
924 sizeof(ip6rd)))
925 goto done;
926 #endif
927 }
928 err = 0;
929 break;
930
931 case SIOCADDTUNNEL:
932 case SIOCCHGTUNNEL:
933 err = -EPERM;
934 if (!capable(CAP_NET_ADMIN))
935 goto done;
936
937 err = -EFAULT;
938 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
939 goto done;
940
941 err = -EINVAL;
942 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
943 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
944 goto done;
945 if (p.iph.ttl)
946 p.iph.frag_off |= htons(IP_DF);
947
948 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
949
950 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
951 if (t != NULL) {
952 if (t->dev != dev) {
953 err = -EEXIST;
954 break;
955 }
956 } else {
957 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
958 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
959 err = -EINVAL;
960 break;
961 }
962 t = netdev_priv(dev);
963 ipip6_tunnel_unlink(sitn, t);
964 synchronize_net();
965 t->parms.iph.saddr = p.iph.saddr;
966 t->parms.iph.daddr = p.iph.daddr;
967 memcpy(dev->dev_addr, &p.iph.saddr, 4);
968 memcpy(dev->broadcast, &p.iph.daddr, 4);
969 ipip6_tunnel_link(sitn, t);
970 netdev_state_change(dev);
971 }
972 }
973
974 if (t) {
975 err = 0;
976 if (cmd == SIOCCHGTUNNEL) {
977 t->parms.iph.ttl = p.iph.ttl;
978 t->parms.iph.tos = p.iph.tos;
979 if (t->parms.link != p.link) {
980 t->parms.link = p.link;
981 ipip6_tunnel_bind_dev(dev);
982 netdev_state_change(dev);
983 }
984 }
985 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
986 err = -EFAULT;
987 } else
988 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
989 break;
990
991 case SIOCDELTUNNEL:
992 err = -EPERM;
993 if (!capable(CAP_NET_ADMIN))
994 goto done;
995
996 if (dev == sitn->fb_tunnel_dev) {
997 err = -EFAULT;
998 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
999 goto done;
1000 err = -ENOENT;
1001 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1002 goto done;
1003 err = -EPERM;
1004 if (t == netdev_priv(sitn->fb_tunnel_dev))
1005 goto done;
1006 dev = t->dev;
1007 }
1008 unregister_netdevice(dev);
1009 err = 0;
1010 break;
1011
1012 case SIOCGETPRL:
1013 err = -EINVAL;
1014 if (dev == sitn->fb_tunnel_dev)
1015 goto done;
1016 err = -ENOENT;
1017 if (!(t = netdev_priv(dev)))
1018 goto done;
1019 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1020 break;
1021
1022 case SIOCADDPRL:
1023 case SIOCDELPRL:
1024 case SIOCCHGPRL:
1025 err = -EPERM;
1026 if (!capable(CAP_NET_ADMIN))
1027 goto done;
1028 err = -EINVAL;
1029 if (dev == sitn->fb_tunnel_dev)
1030 goto done;
1031 err = -EFAULT;
1032 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1033 goto done;
1034 err = -ENOENT;
1035 if (!(t = netdev_priv(dev)))
1036 goto done;
1037
1038 switch (cmd) {
1039 case SIOCDELPRL:
1040 err = ipip6_tunnel_del_prl(t, &prl);
1041 break;
1042 case SIOCADDPRL:
1043 case SIOCCHGPRL:
1044 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1045 break;
1046 }
1047 netdev_state_change(dev);
1048 break;
1049
1050 #ifdef CONFIG_IPV6_SIT_6RD
1051 case SIOCADD6RD:
1052 case SIOCCHG6RD:
1053 case SIOCDEL6RD:
1054 err = -EPERM;
1055 if (!capable(CAP_NET_ADMIN))
1056 goto done;
1057
1058 err = -EFAULT;
1059 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1060 sizeof(ip6rd)))
1061 goto done;
1062
1063 t = netdev_priv(dev);
1064
1065 if (cmd != SIOCDEL6RD) {
1066 struct in6_addr prefix;
1067 __be32 relay_prefix;
1068
1069 err = -EINVAL;
1070 if (ip6rd.relay_prefixlen > 32 ||
1071 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1072 goto done;
1073
1074 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1075 ip6rd.prefixlen);
1076 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1077 goto done;
1078 if (ip6rd.relay_prefixlen)
1079 relay_prefix = ip6rd.relay_prefix &
1080 htonl(0xffffffffUL <<
1081 (32 - ip6rd.relay_prefixlen));
1082 else
1083 relay_prefix = 0;
1084 if (relay_prefix != ip6rd.relay_prefix)
1085 goto done;
1086
1087 t->ip6rd.prefix = prefix;
1088 t->ip6rd.relay_prefix = relay_prefix;
1089 t->ip6rd.prefixlen = ip6rd.prefixlen;
1090 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1091 } else
1092 ipip6_tunnel_clone_6rd(dev, sitn);
1093
1094 err = 0;
1095 break;
1096 #endif
1097
1098 default:
1099 err = -EINVAL;
1100 }
1101
1102 done:
1103 return err;
1104 }
1105
1106 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1107 {
1108 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1109 return -EINVAL;
1110 dev->mtu = new_mtu;
1111 return 0;
1112 }
1113
1114 static const struct net_device_ops ipip6_netdev_ops = {
1115 .ndo_uninit = ipip6_tunnel_uninit,
1116 .ndo_start_xmit = ipip6_tunnel_xmit,
1117 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1118 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1119 .ndo_get_stats = ipip6_get_stats,
1120 };
1121
1122 static void ipip6_dev_free(struct net_device *dev)
1123 {
1124 free_percpu(dev->tstats);
1125 free_netdev(dev);
1126 }
1127
1128 static void ipip6_tunnel_setup(struct net_device *dev)
1129 {
1130 dev->netdev_ops = &ipip6_netdev_ops;
1131 dev->destructor = ipip6_dev_free;
1132
1133 dev->type = ARPHRD_SIT;
1134 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1135 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1136 dev->flags = IFF_NOARP;
1137 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1138 dev->iflink = 0;
1139 dev->addr_len = 4;
1140 dev->features |= NETIF_F_NETNS_LOCAL;
1141 dev->features |= NETIF_F_LLTX;
1142 }
1143
1144 static int ipip6_tunnel_init(struct net_device *dev)
1145 {
1146 struct ip_tunnel *tunnel = netdev_priv(dev);
1147
1148 tunnel->dev = dev;
1149
1150 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1151 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1152
1153 ipip6_tunnel_bind_dev(dev);
1154 dev->tstats = alloc_percpu(struct pcpu_tstats);
1155 if (!dev->tstats)
1156 return -ENOMEM;
1157
1158 return 0;
1159 }
1160
1161 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1162 {
1163 struct ip_tunnel *tunnel = netdev_priv(dev);
1164 struct iphdr *iph = &tunnel->parms.iph;
1165 struct net *net = dev_net(dev);
1166 struct sit_net *sitn = net_generic(net, sit_net_id);
1167
1168 tunnel->dev = dev;
1169 strcpy(tunnel->parms.name, dev->name);
1170
1171 iph->version = 4;
1172 iph->protocol = IPPROTO_IPV6;
1173 iph->ihl = 5;
1174 iph->ttl = 64;
1175
1176 dev->tstats = alloc_percpu(struct pcpu_tstats);
1177 if (!dev->tstats)
1178 return -ENOMEM;
1179 dev_hold(dev);
1180 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1181 return 0;
1182 }
1183
1184 static struct xfrm_tunnel sit_handler __read_mostly = {
1185 .handler = ipip6_rcv,
1186 .err_handler = ipip6_err,
1187 .priority = 1,
1188 };
1189
1190 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1191 {
1192 int prio;
1193
1194 for (prio = 1; prio < 4; prio++) {
1195 int h;
1196 for (h = 0; h < HASH_SIZE; h++) {
1197 struct ip_tunnel *t;
1198
1199 t = rtnl_dereference(sitn->tunnels[prio][h]);
1200 while (t != NULL) {
1201 unregister_netdevice_queue(t->dev, head);
1202 t = rtnl_dereference(t->next);
1203 }
1204 }
1205 }
1206 }
1207
1208 static int __net_init sit_init_net(struct net *net)
1209 {
1210 struct sit_net *sitn = net_generic(net, sit_net_id);
1211 struct ip_tunnel *t;
1212 int err;
1213
1214 sitn->tunnels[0] = sitn->tunnels_wc;
1215 sitn->tunnels[1] = sitn->tunnels_l;
1216 sitn->tunnels[2] = sitn->tunnels_r;
1217 sitn->tunnels[3] = sitn->tunnels_r_l;
1218
1219 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1220 ipip6_tunnel_setup);
1221 if (!sitn->fb_tunnel_dev) {
1222 err = -ENOMEM;
1223 goto err_alloc_dev;
1224 }
1225 dev_net_set(sitn->fb_tunnel_dev, net);
1226
1227 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1228 if (err)
1229 goto err_dev_free;
1230
1231 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1232
1233 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1234 goto err_reg_dev;
1235
1236 t = netdev_priv(sitn->fb_tunnel_dev);
1237
1238 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1239 return 0;
1240
1241 err_reg_dev:
1242 dev_put(sitn->fb_tunnel_dev);
1243 err_dev_free:
1244 ipip6_dev_free(sitn->fb_tunnel_dev);
1245 err_alloc_dev:
1246 return err;
1247 }
1248
1249 static void __net_exit sit_exit_net(struct net *net)
1250 {
1251 struct sit_net *sitn = net_generic(net, sit_net_id);
1252 LIST_HEAD(list);
1253
1254 rtnl_lock();
1255 sit_destroy_tunnels(sitn, &list);
1256 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1257 unregister_netdevice_many(&list);
1258 rtnl_unlock();
1259 }
1260
1261 static struct pernet_operations sit_net_ops = {
1262 .init = sit_init_net,
1263 .exit = sit_exit_net,
1264 .id = &sit_net_id,
1265 .size = sizeof(struct sit_net),
1266 };
1267
1268 static void __exit sit_cleanup(void)
1269 {
1270 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1271
1272 unregister_pernet_device(&sit_net_ops);
1273 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1274 }
1275
1276 static int __init sit_init(void)
1277 {
1278 int err;
1279
1280 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1281
1282 err = register_pernet_device(&sit_net_ops);
1283 if (err < 0)
1284 return err;
1285 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1286 if (err < 0) {
1287 unregister_pernet_device(&sit_net_ops);
1288 printk(KERN_INFO "sit init: Can't add protocol\n");
1289 }
1290 return err;
1291 }
1292
1293 module_init(sit_init);
1294 module_exit(sit_cleanup);
1295 MODULE_LICENSE("GPL");
1296 MODULE_ALIAS_NETDEV("sit0");