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Initial commit
[wrt350n-kernel.git] / net / ipv6 / sit.c
blobe77239d02bf5323e014e8757f459c2505898431b
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 * $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 * Changes:
17 * Roger Venning <r.venning@telstra.com>: 6to4 support
18 * Nate Thompson <nate@thebog.net>: 6to4 support
19 * Fred L. Templin <fltemplin@acm.org>: isatap support
20 */
21
22 #include <linux/module.h>
23 #include <linux/capability.h>
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/icmp.h>
33 #include <asm/uaccess.h>
34 #include <linux/init.h>
35 #include <linux/netfilter_ipv4.h>
36 #include <linux/if_ether.h>
37
38 #include <net/sock.h>
39 #include <net/snmp.h>
40
41 #include <net/ipv6.h>
42 #include <net/protocol.h>
43 #include <net/transp_v6.h>
44 #include <net/ip6_fib.h>
45 #include <net/ip6_route.h>
46 #include <net/ndisc.h>
47 #include <net/addrconf.h>
48 #include <net/ip.h>
49 #include <net/udp.h>
50 #include <net/icmp.h>
51 #include <net/ipip.h>
52 #include <net/inet_ecn.h>
53 #include <net/xfrm.h>
54 #include <net/dsfield.h>
55
56 /*
57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
58
59 For comments look at net/ipv4/ip_gre.c --ANK
60 */
61
62 #define HASH_SIZE 16
63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
64
65 static int ipip6_fb_tunnel_init(struct net_device *dev);
66 static int ipip6_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_setup(struct net_device *dev);
68
69 static struct net_device *ipip6_fb_tunnel_dev;
70
71 static struct ip_tunnel *tunnels_r_l[HASH_SIZE];
72 static struct ip_tunnel *tunnels_r[HASH_SIZE];
73 static struct ip_tunnel *tunnels_l[HASH_SIZE];
74 static struct ip_tunnel *tunnels_wc[1];
75 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l };
76
77 static DEFINE_RWLOCK(ipip6_lock);
78
79 static struct ip_tunnel * ipip6_tunnel_lookup(__be32 remote, __be32 local)
80 {
81 unsigned h0 = HASH(remote);
82 unsigned h1 = HASH(local);
83 struct ip_tunnel *t;
84
85 for (t = tunnels_r_l[h0^h1]; t; t = t->next) {
86 if (local == t->parms.iph.saddr &&
87 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
88 return t;
89 }
90 for (t = tunnels_r[h0]; t; t = t->next) {
91 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
92 return t;
93 }
94 for (t = tunnels_l[h1]; t; t = t->next) {
95 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
96 return t;
97 }
98 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
99 return t;
100 return NULL;
101 }
102
103 static struct ip_tunnel **__ipip6_bucket(struct ip_tunnel_parm *parms)
104 {
105 __be32 remote = parms->iph.daddr;
106 __be32 local = parms->iph.saddr;
107 unsigned h = 0;
108 int prio = 0;
109
110 if (remote) {
111 prio |= 2;
112 h ^= HASH(remote);
113 }
114 if (local) {
115 prio |= 1;
116 h ^= HASH(local);
117 }
118 return &tunnels[prio][h];
119 }
120
121 static inline struct ip_tunnel **ipip6_bucket(struct ip_tunnel *t)
122 {
123 return __ipip6_bucket(&t->parms);
124 }
125
126 static void ipip6_tunnel_unlink(struct ip_tunnel *t)
127 {
128 struct ip_tunnel **tp;
129
130 for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) {
131 if (t == *tp) {
132 write_lock_bh(&ipip6_lock);
133 *tp = t->next;
134 write_unlock_bh(&ipip6_lock);
135 break;
136 }
137 }
138 }
139
140 static void ipip6_tunnel_link(struct ip_tunnel *t)
141 {
142 struct ip_tunnel **tp = ipip6_bucket(t);
143
144 t->next = *tp;
145 write_lock_bh(&ipip6_lock);
146 *tp = t;
147 write_unlock_bh(&ipip6_lock);
148 }
149
150 static struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create)
151 {
152 __be32 remote = parms->iph.daddr;
153 __be32 local = parms->iph.saddr;
154 struct ip_tunnel *t, **tp, *nt;
155 struct net_device *dev;
156 char name[IFNAMSIZ];
157
158 for (tp = __ipip6_bucket(parms); (t = *tp) != NULL; tp = &t->next) {
159 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
160 return t;
161 }
162 if (!create)
163 goto failed;
164
165 if (parms->name[0])
166 strlcpy(name, parms->name, IFNAMSIZ);
167 else {
168 int i;
169 for (i=1; i<100; i++) {
170 sprintf(name, "sit%d", i);
171 if (__dev_get_by_name(&init_net, name) == NULL)
172 break;
173 }
174 if (i==100)
175 goto failed;
176 }
177
178 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
179 if (dev == NULL)
180 return NULL;
181
182 nt = netdev_priv(dev);
183 dev->init = ipip6_tunnel_init;
184 nt->parms = *parms;
185
186 if (parms->i_flags & SIT_ISATAP)
187 dev->priv_flags |= IFF_ISATAP;
188
189 if (register_netdevice(dev) < 0) {
190 free_netdev(dev);
191 goto failed;
192 }
193
194 dev_hold(dev);
195
196 ipip6_tunnel_link(nt);
197 return nt;
198
199 failed:
200 return NULL;
201 }
202
203 static void ipip6_tunnel_uninit(struct net_device *dev)
204 {
205 if (dev == ipip6_fb_tunnel_dev) {
206 write_lock_bh(&ipip6_lock);
207 tunnels_wc[0] = NULL;
208 write_unlock_bh(&ipip6_lock);
209 dev_put(dev);
210 } else {
211 ipip6_tunnel_unlink(netdev_priv(dev));
212 dev_put(dev);
213 }
214 }
215
216
217 static int ipip6_err(struct sk_buff *skb, u32 info)
218 {
219 #ifndef I_WISH_WORLD_WERE_PERFECT
220
221 /* It is not :-( All the routers (except for Linux) return only
222 8 bytes of packet payload. It means, that precise relaying of
223 ICMP in the real Internet is absolutely infeasible.
224 */
225 struct iphdr *iph = (struct iphdr*)skb->data;
226 const int type = icmp_hdr(skb)->type;
227 const int code = icmp_hdr(skb)->code;
228 struct ip_tunnel *t;
229 int err;
230
231 switch (type) {
232 default:
233 case ICMP_PARAMETERPROB:
234 return 0;
235
236 case ICMP_DEST_UNREACH:
237 switch (code) {
238 case ICMP_SR_FAILED:
239 case ICMP_PORT_UNREACH:
240 /* Impossible event. */
241 return 0;
242 case ICMP_FRAG_NEEDED:
243 /* Soft state for pmtu is maintained by IP core. */
244 return 0;
245 default:
246 /* All others are translated to HOST_UNREACH.
247 rfc2003 contains "deep thoughts" about NET_UNREACH,
248 I believe they are just ether pollution. --ANK
249 */
250 break;
251 }
252 break;
253 case ICMP_TIME_EXCEEDED:
254 if (code != ICMP_EXC_TTL)
255 return 0;
256 break;
257 }
258
259 err = -ENOENT;
260
261 read_lock(&ipip6_lock);
262 t = ipip6_tunnel_lookup(iph->daddr, iph->saddr);
263 if (t == NULL || t->parms.iph.daddr == 0)
264 goto out;
265
266 err = 0;
267 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
268 goto out;
269
270 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
271 t->err_count++;
272 else
273 t->err_count = 1;
274 t->err_time = jiffies;
275 out:
276 read_unlock(&ipip6_lock);
277 return err;
278 #else
279 struct iphdr *iph = (struct iphdr*)dp;
280 int hlen = iph->ihl<<2;
281 struct ipv6hdr *iph6;
282 const int type = icmp_hdr(skb)->type;
283 const int code = icmp_hdr(skb)->code;
284 int rel_type = 0;
285 int rel_code = 0;
286 int rel_info = 0;
287 struct sk_buff *skb2;
288 struct rt6_info *rt6i;
289
290 if (len < hlen + sizeof(struct ipv6hdr))
291 return;
292 iph6 = (struct ipv6hdr*)(dp + hlen);
293
294 switch (type) {
295 default:
296 return;
297 case ICMP_PARAMETERPROB:
298 if (icmp_hdr(skb)->un.gateway < hlen)
299 return;
300
301 /* So... This guy found something strange INSIDE encapsulated
302 packet. Well, he is fool, but what can we do ?
303 */
304 rel_type = ICMPV6_PARAMPROB;
305 rel_info = icmp_hdr(skb)->un.gateway - hlen;
306 break;
307
308 case ICMP_DEST_UNREACH:
309 switch (code) {
310 case ICMP_SR_FAILED:
311 case ICMP_PORT_UNREACH:
312 /* Impossible event. */
313 return;
314 case ICMP_FRAG_NEEDED:
315 /* Too complicated case ... */
316 return;
317 default:
318 /* All others are translated to HOST_UNREACH.
319 rfc2003 contains "deep thoughts" about NET_UNREACH,
320 I believe, it is just ether pollution. --ANK
321 */
322 rel_type = ICMPV6_DEST_UNREACH;
323 rel_code = ICMPV6_ADDR_UNREACH;
324 break;
325 }
326 break;
327 case ICMP_TIME_EXCEEDED:
328 if (code != ICMP_EXC_TTL)
329 return;
330 rel_type = ICMPV6_TIME_EXCEED;
331 rel_code = ICMPV6_EXC_HOPLIMIT;
332 break;
333 }
334
335 /* Prepare fake skb to feed it to icmpv6_send */
336 skb2 = skb_clone(skb, GFP_ATOMIC);
337 if (skb2 == NULL)
338 return 0;
339 dst_release(skb2->dst);
340 skb2->dst = NULL;
341 skb_pull(skb2, skb->data - (u8*)iph6);
342 skb_reset_network_header(skb2);
343
344 /* Try to guess incoming interface */
345 rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0);
346 if (rt6i && rt6i->rt6i_dev) {
347 skb2->dev = rt6i->rt6i_dev;
348
349 rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0);
350
351 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
352 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev);
353 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
354 rel_type = ICMPV6_DEST_UNREACH;
355 rel_code = ICMPV6_ADDR_UNREACH;
356 }
357 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
358 }
359 }
360 kfree_skb(skb2);
361 return 0;
362 #endif
363 }
364
365 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
366 {
367 if (INET_ECN_is_ce(iph->tos))
368 IP6_ECN_set_ce(ipv6_hdr(skb));
369 }
370
371 /* ISATAP (RFC4214) - check source address */
372 static int
373 isatap_srcok(struct sk_buff *skb, struct iphdr *iph, struct net_device *dev)
374 {
375 struct neighbour *neigh;
376 struct dst_entry *dst;
377 struct rt6_info *rt;
378 struct flowi fl;
379 struct in6_addr *addr6;
380 struct in6_addr rtr;
381 struct ipv6hdr *iph6;
382 int ok = 0;
383
384 /* from onlink default router */
385 ipv6_addr_set(&rtr, htonl(0xFE800000), 0, 0, 0);
386 ipv6_isatap_eui64(rtr.s6_addr + 8, iph->saddr);
387 if ((rt = rt6_get_dflt_router(&rtr, dev))) {
388 dst_release(&rt->u.dst);
389 return 1;
390 }
391
392 iph6 = ipv6_hdr(skb);
393 memset(&fl, 0, sizeof(fl));
394 fl.proto = iph6->nexthdr;
395 ipv6_addr_copy(&fl.fl6_dst, &iph6->saddr);
396 fl.oif = dev->ifindex;
397 security_skb_classify_flow(skb, &fl);
398
399 dst = ip6_route_output(NULL, &fl);
400 if (!dst->error && (dst->dev == dev) && (neigh = dst->neighbour)) {
401
402 addr6 = (struct in6_addr*)&neigh->primary_key;
403
404 /* from correct previous hop */
405 if (ipv6_addr_is_isatap(addr6) &&
406 (addr6->s6_addr32[3] == iph->saddr))
407 ok = 1;
408 }
409 dst_release(dst);
410 return ok;
411 }
412
413 static int ipip6_rcv(struct sk_buff *skb)
414 {
415 struct iphdr *iph;
416 struct ip_tunnel *tunnel;
417
418 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
419 goto out;
420
421 iph = ip_hdr(skb);
422
423 read_lock(&ipip6_lock);
424 if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) {
425 secpath_reset(skb);
426 skb->mac_header = skb->network_header;
427 skb_reset_network_header(skb);
428 IPCB(skb)->flags = 0;
429 skb->protocol = htons(ETH_P_IPV6);
430 skb->pkt_type = PACKET_HOST;
431
432 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
433 !isatap_srcok(skb, iph, tunnel->dev)) {
434 tunnel->stat.rx_errors++;
435 read_unlock(&ipip6_lock);
436 kfree_skb(skb);
437 return 0;
438 }
439 tunnel->stat.rx_packets++;
440 tunnel->stat.rx_bytes += skb->len;
441 skb->dev = tunnel->dev;
442 dst_release(skb->dst);
443 skb->dst = NULL;
444 nf_reset(skb);
445 ipip6_ecn_decapsulate(iph, skb);
446 netif_rx(skb);
447 read_unlock(&ipip6_lock);
448 return 0;
449 }
450
451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
452 kfree_skb(skb);
453 read_unlock(&ipip6_lock);
454 out:
455 return 0;
456 }
457
458 /* Returns the embedded IPv4 address if the IPv6 address
459 comes from 6to4 (RFC 3056) addr space */
460
461 static inline __be32 try_6to4(struct in6_addr *v6dst)
462 {
463 __be32 dst = 0;
464
465 if (v6dst->s6_addr16[0] == htons(0x2002)) {
466 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
467 memcpy(&dst, &v6dst->s6_addr16[1], 4);
468 }
469 return dst;
470 }
471
472 /*
473 * This function assumes it is being called from dev_queue_xmit()
474 * and that skb is filled properly by that function.
475 */
476
477 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
478 {
479 struct ip_tunnel *tunnel = netdev_priv(dev);
480 struct net_device_stats *stats = &tunnel->stat;
481 struct iphdr *tiph = &tunnel->parms.iph;
482 struct ipv6hdr *iph6 = ipv6_hdr(skb);
483 u8 tos = tunnel->parms.iph.tos;
484 struct rtable *rt; /* Route to the other host */
485 struct net_device *tdev; /* Device to other host */
486 struct iphdr *iph; /* Our new IP header */
487 unsigned int max_headroom; /* The extra header space needed */
488 __be32 dst = tiph->daddr;
489 int mtu;
490 struct in6_addr *addr6;
491 int addr_type;
492
493 if (tunnel->recursion++) {
494 tunnel->stat.collisions++;
495 goto tx_error;
496 }
497
498 if (skb->protocol != htons(ETH_P_IPV6))
499 goto tx_error;
500
501 /* ISATAP (RFC4214) - must come before 6to4 */
502 if (dev->priv_flags & IFF_ISATAP) {
503 struct neighbour *neigh = NULL;
504
505 if (skb->dst)
506 neigh = skb->dst->neighbour;
507
508 if (neigh == NULL) {
509 if (net_ratelimit())
510 printk(KERN_DEBUG "sit: nexthop == NULL\n");
511 goto tx_error;
512 }
513
514 addr6 = (struct in6_addr*)&neigh->primary_key;
515 addr_type = ipv6_addr_type(addr6);
516
517 if ((addr_type & IPV6_ADDR_UNICAST) &&
518 ipv6_addr_is_isatap(addr6))
519 dst = addr6->s6_addr32[3];
520 else
521 goto tx_error;
522 }
523
524 if (!dst)
525 dst = try_6to4(&iph6->daddr);
526
527 if (!dst) {
528 struct neighbour *neigh = NULL;
529
530 if (skb->dst)
531 neigh = skb->dst->neighbour;
532
533 if (neigh == NULL) {
534 if (net_ratelimit())
535 printk(KERN_DEBUG "sit: nexthop == NULL\n");
536 goto tx_error;
537 }
538
539 addr6 = (struct in6_addr*)&neigh->primary_key;
540 addr_type = ipv6_addr_type(addr6);
541
542 if (addr_type == IPV6_ADDR_ANY) {
543 addr6 = &ipv6_hdr(skb)->daddr;
544 addr_type = ipv6_addr_type(addr6);
545 }
546
547 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
548 goto tx_error_icmp;
549
550 dst = addr6->s6_addr32[3];
551 }
552
553 {
554 struct flowi fl = { .nl_u = { .ip4_u =
555 { .daddr = dst,
556 .saddr = tiph->saddr,
557 .tos = RT_TOS(tos) } },
558 .oif = tunnel->parms.link,
559 .proto = IPPROTO_IPV6 };
560 if (ip_route_output_key(&init_net, &rt, &fl)) {
561 tunnel->stat.tx_carrier_errors++;
562 goto tx_error_icmp;
563 }
564 }
565 if (rt->rt_type != RTN_UNICAST) {
566 ip_rt_put(rt);
567 tunnel->stat.tx_carrier_errors++;
568 goto tx_error_icmp;
569 }
570 tdev = rt->u.dst.dev;
571
572 if (tdev == dev) {
573 ip_rt_put(rt);
574 tunnel->stat.collisions++;
575 goto tx_error;
576 }
577
578 if (tiph->frag_off)
579 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
580 else
581 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
582
583 if (mtu < 68) {
584 tunnel->stat.collisions++;
585 ip_rt_put(rt);
586 goto tx_error;
587 }
588 if (mtu < IPV6_MIN_MTU)
589 mtu = IPV6_MIN_MTU;
590 if (tunnel->parms.iph.daddr && skb->dst)
591 skb->dst->ops->update_pmtu(skb->dst, mtu);
592
593 if (skb->len > mtu) {
594 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
595 ip_rt_put(rt);
596 goto tx_error;
597 }
598
599 if (tunnel->err_count > 0) {
600 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
601 tunnel->err_count--;
602 dst_link_failure(skb);
603 } else
604 tunnel->err_count = 0;
605 }
606
607 /*
608 * Okay, now see if we can stuff it in the buffer as-is.
609 */
610 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
611
612 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
613 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
614 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
615 if (!new_skb) {
616 ip_rt_put(rt);
617 stats->tx_dropped++;
618 dev_kfree_skb(skb);
619 tunnel->recursion--;
620 return 0;
621 }
622 if (skb->sk)
623 skb_set_owner_w(new_skb, skb->sk);
624 dev_kfree_skb(skb);
625 skb = new_skb;
626 iph6 = ipv6_hdr(skb);
627 }
628
629 skb->transport_header = skb->network_header;
630 skb_push(skb, sizeof(struct iphdr));
631 skb_reset_network_header(skb);
632 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
633 IPCB(skb)->flags = 0;
634 dst_release(skb->dst);
635 skb->dst = &rt->u.dst;
636
637 /*
638 * Push down and install the IPIP header.
639 */
640
641 iph = ip_hdr(skb);
642 iph->version = 4;
643 iph->ihl = sizeof(struct iphdr)>>2;
644 if (mtu > IPV6_MIN_MTU)
645 iph->frag_off = htons(IP_DF);
646 else
647 iph->frag_off = 0;
648
649 iph->protocol = IPPROTO_IPV6;
650 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
651 iph->daddr = rt->rt_dst;
652 iph->saddr = rt->rt_src;
653
654 if ((iph->ttl = tiph->ttl) == 0)
655 iph->ttl = iph6->hop_limit;
656
657 nf_reset(skb);
658
659 IPTUNNEL_XMIT();
660 tunnel->recursion--;
661 return 0;
662
663 tx_error_icmp:
664 dst_link_failure(skb);
665 tx_error:
666 stats->tx_errors++;
667 dev_kfree_skb(skb);
668 tunnel->recursion--;
669 return 0;
670 }
671
672 static void ipip6_tunnel_bind_dev(struct net_device *dev)
673 {
674 struct net_device *tdev = NULL;
675 struct ip_tunnel *tunnel;
676 struct iphdr *iph;
677
678 tunnel = netdev_priv(dev);
679 iph = &tunnel->parms.iph;
680
681 if (iph->daddr) {
682 struct flowi fl = { .nl_u = { .ip4_u =
683 { .daddr = iph->daddr,
684 .saddr = iph->saddr,
685 .tos = RT_TOS(iph->tos) } },
686 .oif = tunnel->parms.link,
687 .proto = IPPROTO_IPV6 };
688 struct rtable *rt;
689 if (!ip_route_output_key(&init_net, &rt, &fl)) {
690 tdev = rt->u.dst.dev;
691 ip_rt_put(rt);
692 }
693 dev->flags |= IFF_POINTOPOINT;
694 }
695
696 if (!tdev && tunnel->parms.link)
697 tdev = __dev_get_by_index(&init_net, tunnel->parms.link);
698
699 if (tdev) {
700 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
701 dev->mtu = tdev->mtu - sizeof(struct iphdr);
702 if (dev->mtu < IPV6_MIN_MTU)
703 dev->mtu = IPV6_MIN_MTU;
704 }
705 dev->iflink = tunnel->parms.link;
706 }
707
708 static int
709 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
710 {
711 int err = 0;
712 struct ip_tunnel_parm p;
713 struct ip_tunnel *t;
714
715 switch (cmd) {
716 case SIOCGETTUNNEL:
717 t = NULL;
718 if (dev == ipip6_fb_tunnel_dev) {
719 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
720 err = -EFAULT;
721 break;
722 }
723 t = ipip6_tunnel_locate(&p, 0);
724 }
725 if (t == NULL)
726 t = netdev_priv(dev);
727 memcpy(&p, &t->parms, sizeof(p));
728 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
729 err = -EFAULT;
730 break;
731
732 case SIOCADDTUNNEL:
733 case SIOCCHGTUNNEL:
734 err = -EPERM;
735 if (!capable(CAP_NET_ADMIN))
736 goto done;
737
738 err = -EFAULT;
739 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
740 goto done;
741
742 err = -EINVAL;
743 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
744 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
745 goto done;
746 if (p.iph.ttl)
747 p.iph.frag_off |= htons(IP_DF);
748
749 t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL);
750
751 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
752 if (t != NULL) {
753 if (t->dev != dev) {
754 err = -EEXIST;
755 break;
756 }
757 } else {
758 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
759 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
760 err = -EINVAL;
761 break;
762 }
763 t = netdev_priv(dev);
764 ipip6_tunnel_unlink(t);
765 t->parms.iph.saddr = p.iph.saddr;
766 t->parms.iph.daddr = p.iph.daddr;
767 memcpy(dev->dev_addr, &p.iph.saddr, 4);
768 memcpy(dev->broadcast, &p.iph.daddr, 4);
769 ipip6_tunnel_link(t);
770 netdev_state_change(dev);
771 }
772 }
773
774 if (t) {
775 err = 0;
776 if (cmd == SIOCCHGTUNNEL) {
777 t->parms.iph.ttl = p.iph.ttl;
778 t->parms.iph.tos = p.iph.tos;
779 if (t->parms.link != p.link) {
780 t->parms.link = p.link;
781 ipip6_tunnel_bind_dev(dev);
782 netdev_state_change(dev);
783 }
784 }
785 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
786 err = -EFAULT;
787 } else
788 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
789 break;
790
791 case SIOCDELTUNNEL:
792 err = -EPERM;
793 if (!capable(CAP_NET_ADMIN))
794 goto done;
795
796 if (dev == ipip6_fb_tunnel_dev) {
797 err = -EFAULT;
798 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
799 goto done;
800 err = -ENOENT;
801 if ((t = ipip6_tunnel_locate(&p, 0)) == NULL)
802 goto done;
803 err = -EPERM;
804 if (t == netdev_priv(ipip6_fb_tunnel_dev))
805 goto done;
806 dev = t->dev;
807 }
808 unregister_netdevice(dev);
809 err = 0;
810 break;
811
812 default:
813 err = -EINVAL;
814 }
815
816 done:
817 return err;
818 }
819
820 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev)
821 {
822 return &(((struct ip_tunnel*)netdev_priv(dev))->stat);
823 }
824
825 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
826 {
827 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
828 return -EINVAL;
829 dev->mtu = new_mtu;
830 return 0;
831 }
832
833 static void ipip6_tunnel_setup(struct net_device *dev)
834 {
835 dev->uninit = ipip6_tunnel_uninit;
836 dev->destructor = free_netdev;
837 dev->hard_start_xmit = ipip6_tunnel_xmit;
838 dev->get_stats = ipip6_tunnel_get_stats;
839 dev->do_ioctl = ipip6_tunnel_ioctl;
840 dev->change_mtu = ipip6_tunnel_change_mtu;
841
842 dev->type = ARPHRD_SIT;
843 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
844 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
845 dev->flags = IFF_NOARP;
846 dev->iflink = 0;
847 dev->addr_len = 4;
848 }
849
850 static int ipip6_tunnel_init(struct net_device *dev)
851 {
852 struct ip_tunnel *tunnel;
853
854 tunnel = netdev_priv(dev);
855
856 tunnel->dev = dev;
857 strcpy(tunnel->parms.name, dev->name);
858
859 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
860 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
861
862 ipip6_tunnel_bind_dev(dev);
863
864 return 0;
865 }
866
867 static int __init ipip6_fb_tunnel_init(struct net_device *dev)
868 {
869 struct ip_tunnel *tunnel = netdev_priv(dev);
870 struct iphdr *iph = &tunnel->parms.iph;
871
872 tunnel->dev = dev;
873 strcpy(tunnel->parms.name, dev->name);
874
875 iph->version = 4;
876 iph->protocol = IPPROTO_IPV6;
877 iph->ihl = 5;
878 iph->ttl = 64;
879
880 dev_hold(dev);
881 tunnels_wc[0] = tunnel;
882 return 0;
883 }
884
885 static struct xfrm_tunnel sit_handler = {
886 .handler = ipip6_rcv,
887 .err_handler = ipip6_err,
888 .priority = 1,
889 };
890
891 static void __exit sit_destroy_tunnels(void)
892 {
893 int prio;
894
895 for (prio = 1; prio < 4; prio++) {
896 int h;
897 for (h = 0; h < HASH_SIZE; h++) {
898 struct ip_tunnel *t;
899 while ((t = tunnels[prio][h]) != NULL)
900 unregister_netdevice(t->dev);
901 }
902 }
903 }
904
905 static void __exit sit_cleanup(void)
906 {
907 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
908
909 rtnl_lock();
910 sit_destroy_tunnels();
911 unregister_netdevice(ipip6_fb_tunnel_dev);
912 rtnl_unlock();
913 }
914
915 static int __init sit_init(void)
916 {
917 int err;
918
919 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
920
921 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
922 printk(KERN_INFO "sit init: Can't add protocol\n");
923 return -EAGAIN;
924 }
925
926 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
927 ipip6_tunnel_setup);
928 if (!ipip6_fb_tunnel_dev) {
929 err = -ENOMEM;
930 goto err1;
931 }
932
933 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init;
934
935 if ((err = register_netdev(ipip6_fb_tunnel_dev)))
936 goto err2;
937
938 out:
939 return err;
940 err2:
941 free_netdev(ipip6_fb_tunnel_dev);
942 err1:
943 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
944 goto out;
945 }
946
947 module_init(sit_init);
948 module_exit(sit_cleanup);
949 MODULE_LICENSE("GPL");
950 MODULE_ALIAS("sit0");
WRT350N Kernel Patches