blob: eb20bb690abd736e6699f1af7987cb8a1287d3c3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09006 * Pedro Roque <roque@di.fc.ul.pt>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * 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 */
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/module.h>
Randy Dunlap4fc268d2006-01-11 12:17:47 -080022#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/errno.h>
24#include <linux/types.h>
25#include <linux/socket.h>
26#include <linux/sockios.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/net.h>
28#include <linux/in6.h>
29#include <linux/netdevice.h>
30#include <linux/if_arp.h>
31#include <linux/icmp.h>
32#include <asm/uaccess.h>
33#include <linux/init.h>
34#include <linux/netfilter_ipv4.h>
Kris Katterjohn46f25df2006-01-05 16:35:42 -080035#include <linux/if_ether.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
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
55/*
56 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
57
58 For comments look at net/ipv4/ip_gre.c --ANK
59 */
60
61#define HASH_SIZE 16
Al Viroe69a4ad2006-11-14 20:56:00 -080062#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64static int ipip6_fb_tunnel_init(struct net_device *dev);
65static int ipip6_tunnel_init(struct net_device *dev);
66static void ipip6_tunnel_setup(struct net_device *dev);
67
68static struct net_device *ipip6_fb_tunnel_dev;
69
70static struct ip_tunnel *tunnels_r_l[HASH_SIZE];
71static struct ip_tunnel *tunnels_r[HASH_SIZE];
72static struct ip_tunnel *tunnels_l[HASH_SIZE];
73static struct ip_tunnel *tunnels_wc[1];
74static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l };
75
76static DEFINE_RWLOCK(ipip6_lock);
77
Al Viroe69a4ad2006-11-14 20:56:00 -080078static struct ip_tunnel * ipip6_tunnel_lookup(__be32 remote, __be32 local)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
80 unsigned h0 = HASH(remote);
81 unsigned h1 = HASH(local);
82 struct ip_tunnel *t;
83
84 for (t = tunnels_r_l[h0^h1]; t; t = t->next) {
85 if (local == t->parms.iph.saddr &&
86 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
87 return t;
88 }
89 for (t = tunnels_r[h0]; t; t = t->next) {
90 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
91 return t;
92 }
93 for (t = tunnels_l[h1]; t; t = t->next) {
94 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
95 return t;
96 }
97 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
98 return t;
99 return NULL;
100}
101
YOSHIFUJI Hideaki420fe232007-04-24 20:44:47 +0900102static struct ip_tunnel **__ipip6_bucket(struct ip_tunnel_parm *parms)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
YOSHIFUJI Hideaki420fe232007-04-24 20:44:47 +0900104 __be32 remote = parms->iph.daddr;
105 __be32 local = parms->iph.saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 unsigned h = 0;
107 int prio = 0;
108
109 if (remote) {
110 prio |= 2;
111 h ^= HASH(remote);
112 }
113 if (local) {
114 prio |= 1;
115 h ^= HASH(local);
116 }
117 return &tunnels[prio][h];
118}
119
YOSHIFUJI Hideaki420fe232007-04-24 20:44:47 +0900120static inline struct ip_tunnel **ipip6_bucket(struct ip_tunnel *t)
121{
122 return __ipip6_bucket(&t->parms);
123}
124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125static void ipip6_tunnel_unlink(struct ip_tunnel *t)
126{
127 struct ip_tunnel **tp;
128
129 for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) {
130 if (t == *tp) {
131 write_lock_bh(&ipip6_lock);
132 *tp = t->next;
133 write_unlock_bh(&ipip6_lock);
134 break;
135 }
136 }
137}
138
139static void ipip6_tunnel_link(struct ip_tunnel *t)
140{
141 struct ip_tunnel **tp = ipip6_bucket(t);
142
143 t->next = *tp;
144 write_lock_bh(&ipip6_lock);
145 *tp = t;
146 write_unlock_bh(&ipip6_lock);
147}
148
149static struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create)
150{
Al Viroe69a4ad2006-11-14 20:56:00 -0800151 __be32 remote = parms->iph.daddr;
152 __be32 local = parms->iph.saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 struct ip_tunnel *t, **tp, *nt;
154 struct net_device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 char name[IFNAMSIZ];
156
YOSHIFUJI Hideaki420fe232007-04-24 20:44:47 +0900157 for (tp = __ipip6_bucket(parms); (t = *tp) != NULL; tp = &t->next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
159 return t;
160 }
161 if (!create)
162 goto failed;
163
164 if (parms->name[0])
165 strlcpy(name, parms->name, IFNAMSIZ);
166 else {
167 int i;
168 for (i=1; i<100; i++) {
169 sprintf(name, "sit%d", i);
170 if (__dev_get_by_name(name) == NULL)
171 break;
172 }
173 if (i==100)
174 goto failed;
175 }
176
177 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
178 if (dev == NULL)
179 return NULL;
180
Patrick McHardy2941a482006-01-08 22:05:26 -0800181 nt = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 dev->init = ipip6_tunnel_init;
183 nt->parms = *parms;
184
185 if (register_netdevice(dev) < 0) {
186 free_netdev(dev);
187 goto failed;
188 }
189
190 dev_hold(dev);
191
192 ipip6_tunnel_link(nt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 return nt;
194
195failed:
196 return NULL;
197}
198
199static void ipip6_tunnel_uninit(struct net_device *dev)
200{
201 if (dev == ipip6_fb_tunnel_dev) {
202 write_lock_bh(&ipip6_lock);
203 tunnels_wc[0] = NULL;
204 write_unlock_bh(&ipip6_lock);
205 dev_put(dev);
206 } else {
Patrick McHardy2941a482006-01-08 22:05:26 -0800207 ipip6_tunnel_unlink(netdev_priv(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 dev_put(dev);
209 }
210}
211
212
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800213static int ipip6_err(struct sk_buff *skb, u32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
215#ifndef I_WISH_WORLD_WERE_PERFECT
216
217/* It is not :-( All the routers (except for Linux) return only
218 8 bytes of packet payload. It means, that precise relaying of
219 ICMP in the real Internet is absolutely infeasible.
220 */
221 struct iphdr *iph = (struct iphdr*)skb->data;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300222 const int type = icmp_hdr(skb)->type;
223 const int code = icmp_hdr(skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 struct ip_tunnel *t;
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800225 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 switch (type) {
228 default:
229 case ICMP_PARAMETERPROB:
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800230 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232 case ICMP_DEST_UNREACH:
233 switch (code) {
234 case ICMP_SR_FAILED:
235 case ICMP_PORT_UNREACH:
236 /* Impossible event. */
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800237 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 case ICMP_FRAG_NEEDED:
239 /* Soft state for pmtu is maintained by IP core. */
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800240 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 default:
242 /* All others are translated to HOST_UNREACH.
243 rfc2003 contains "deep thoughts" about NET_UNREACH,
244 I believe they are just ether pollution. --ANK
245 */
246 break;
247 }
248 break;
249 case ICMP_TIME_EXCEEDED:
250 if (code != ICMP_EXC_TTL)
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800251 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 break;
253 }
254
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800255 err = -ENOENT;
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 read_lock(&ipip6_lock);
258 t = ipip6_tunnel_lookup(iph->daddr, iph->saddr);
259 if (t == NULL || t->parms.iph.daddr == 0)
260 goto out;
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800261
262 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
264 goto out;
265
266 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
267 t->err_count++;
268 else
269 t->err_count = 1;
270 t->err_time = jiffies;
271out:
272 read_unlock(&ipip6_lock);
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800273 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274#else
275 struct iphdr *iph = (struct iphdr*)dp;
276 int hlen = iph->ihl<<2;
277 struct ipv6hdr *iph6;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300278 const int type = icmp_hdr(skb)->type;
279 const int code = icmp_hdr(skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 int rel_type = 0;
281 int rel_code = 0;
282 int rel_info = 0;
283 struct sk_buff *skb2;
284 struct rt6_info *rt6i;
285
286 if (len < hlen + sizeof(struct ipv6hdr))
287 return;
288 iph6 = (struct ipv6hdr*)(dp + hlen);
289
290 switch (type) {
291 default:
292 return;
293 case ICMP_PARAMETERPROB:
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300294 if (icmp_hdr(skb)->un.gateway < hlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 return;
296
297 /* So... This guy found something strange INSIDE encapsulated
298 packet. Well, he is fool, but what can we do ?
299 */
300 rel_type = ICMPV6_PARAMPROB;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300301 rel_info = icmp_hdr(skb)->un.gateway - hlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 break;
303
304 case ICMP_DEST_UNREACH:
305 switch (code) {
306 case ICMP_SR_FAILED:
307 case ICMP_PORT_UNREACH:
308 /* Impossible event. */
309 return;
310 case ICMP_FRAG_NEEDED:
311 /* Too complicated case ... */
312 return;
313 default:
314 /* All others are translated to HOST_UNREACH.
315 rfc2003 contains "deep thoughts" about NET_UNREACH,
316 I believe, it is just ether pollution. --ANK
317 */
318 rel_type = ICMPV6_DEST_UNREACH;
319 rel_code = ICMPV6_ADDR_UNREACH;
320 break;
321 }
322 break;
323 case ICMP_TIME_EXCEEDED:
324 if (code != ICMP_EXC_TTL)
325 return;
326 rel_type = ICMPV6_TIME_EXCEED;
327 rel_code = ICMPV6_EXC_HOPLIMIT;
328 break;
329 }
330
331 /* Prepare fake skb to feed it to icmpv6_send */
332 skb2 = skb_clone(skb, GFP_ATOMIC);
333 if (skb2 == NULL)
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800334 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 dst_release(skb2->dst);
336 skb2->dst = NULL;
337 skb_pull(skb2, skb->data - (u8*)iph6);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700338 skb_reset_network_header(skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
340 /* Try to guess incoming interface */
341 rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0);
342 if (rt6i && rt6i->rt6i_dev) {
343 skb2->dev = rt6i->rt6i_dev;
344
345 rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0);
346
347 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
Patrick McHardy2941a482006-01-08 22:05:26 -0800348 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
350 rel_type = ICMPV6_DEST_UNREACH;
351 rel_code = ICMPV6_ADDR_UNREACH;
352 }
353 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
354 }
355 }
356 kfree_skb(skb2);
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800357 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358#endif
359}
360
361static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
362{
363 if (INET_ECN_is_ce(iph->tos))
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700364 IP6_ECN_set_ce(ipv6_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365}
366
367static int ipip6_rcv(struct sk_buff *skb)
368{
369 struct iphdr *iph;
370 struct ip_tunnel *tunnel;
371
372 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
373 goto out;
374
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700375 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
377 read_lock(&ipip6_lock);
378 if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) {
379 secpath_reset(skb);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700380 skb->mac_header = skb->network_header;
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700381 skb_reset_network_header(skb);
Patrick McHardy8cdfab82006-01-06 23:04:01 -0800382 IPCB(skb)->flags = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 skb->protocol = htons(ETH_P_IPV6);
384 skb->pkt_type = PACKET_HOST;
385 tunnel->stat.rx_packets++;
386 tunnel->stat.rx_bytes += skb->len;
387 skb->dev = tunnel->dev;
388 dst_release(skb->dst);
389 skb->dst = NULL;
390 nf_reset(skb);
391 ipip6_ecn_decapsulate(iph, skb);
392 netif_rx(skb);
393 read_unlock(&ipip6_lock);
394 return 0;
395 }
396
Herbert Xu45af08b2006-04-05 22:31:19 -0700397 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 kfree_skb(skb);
399 read_unlock(&ipip6_lock);
400out:
401 return 0;
402}
403
404/* Returns the embedded IPv4 address if the IPv6 address
405 comes from 6to4 (RFC 3056) addr space */
406
Al Viroe69a4ad2006-11-14 20:56:00 -0800407static inline __be32 try_6to4(struct in6_addr *v6dst)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
Al Viroe69a4ad2006-11-14 20:56:00 -0800409 __be32 dst = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410
411 if (v6dst->s6_addr16[0] == htons(0x2002)) {
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900412 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 memcpy(&dst, &v6dst->s6_addr16[1], 4);
414 }
415 return dst;
416}
417
418/*
419 * This function assumes it is being called from dev_queue_xmit()
420 * and that skb is filled properly by that function.
421 */
422
423static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
424{
Patrick McHardy2941a482006-01-08 22:05:26 -0800425 struct ip_tunnel *tunnel = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 struct net_device_stats *stats = &tunnel->stat;
427 struct iphdr *tiph = &tunnel->parms.iph;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700428 struct ipv6hdr *iph6 = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 u8 tos = tunnel->parms.iph.tos;
430 struct rtable *rt; /* Route to the other host */
431 struct net_device *tdev; /* Device to other host */
432 struct iphdr *iph; /* Our new IP header */
433 int max_headroom; /* The extra header space needed */
Al Viroe69a4ad2006-11-14 20:56:00 -0800434 __be32 dst = tiph->daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 int mtu;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900436 struct in6_addr *addr6;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 int addr_type;
438
439 if (tunnel->recursion++) {
440 tunnel->stat.collisions++;
441 goto tx_error;
442 }
443
444 if (skb->protocol != htons(ETH_P_IPV6))
445 goto tx_error;
446
447 if (!dst)
448 dst = try_6to4(&iph6->daddr);
449
450 if (!dst) {
451 struct neighbour *neigh = NULL;
452
453 if (skb->dst)
454 neigh = skb->dst->neighbour;
455
456 if (neigh == NULL) {
457 if (net_ratelimit())
458 printk(KERN_DEBUG "sit: nexthop == NULL\n");
459 goto tx_error;
460 }
461
462 addr6 = (struct in6_addr*)&neigh->primary_key;
463 addr_type = ipv6_addr_type(addr6);
464
465 if (addr_type == IPV6_ADDR_ANY) {
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700466 addr6 = &ipv6_hdr(skb)->daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 addr_type = ipv6_addr_type(addr6);
468 }
469
470 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
471 goto tx_error_icmp;
472
473 dst = addr6->s6_addr32[3];
474 }
475
476 {
477 struct flowi fl = { .nl_u = { .ip4_u =
478 { .daddr = dst,
479 .saddr = tiph->saddr,
480 .tos = RT_TOS(tos) } },
481 .oif = tunnel->parms.link,
482 .proto = IPPROTO_IPV6 };
483 if (ip_route_output_key(&rt, &fl)) {
484 tunnel->stat.tx_carrier_errors++;
485 goto tx_error_icmp;
486 }
487 }
488 if (rt->rt_type != RTN_UNICAST) {
489 ip_rt_put(rt);
490 tunnel->stat.tx_carrier_errors++;
491 goto tx_error_icmp;
492 }
493 tdev = rt->u.dst.dev;
494
495 if (tdev == dev) {
496 ip_rt_put(rt);
497 tunnel->stat.collisions++;
498 goto tx_error;
499 }
500
501 if (tiph->frag_off)
502 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
503 else
504 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
505
506 if (mtu < 68) {
507 tunnel->stat.collisions++;
508 ip_rt_put(rt);
509 goto tx_error;
510 }
511 if (mtu < IPV6_MIN_MTU)
512 mtu = IPV6_MIN_MTU;
513 if (tunnel->parms.iph.daddr && skb->dst)
514 skb->dst->ops->update_pmtu(skb->dst, mtu);
515
516 if (skb->len > mtu) {
517 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
518 ip_rt_put(rt);
519 goto tx_error;
520 }
521
522 if (tunnel->err_count > 0) {
523 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
524 tunnel->err_count--;
525 dst_link_failure(skb);
526 } else
527 tunnel->err_count = 0;
528 }
529
530 /*
531 * Okay, now see if we can stuff it in the buffer as-is.
532 */
533 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
534
Patrick McHardycfbba492007-07-09 15:33:40 -0700535 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
536 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
538 if (!new_skb) {
539 ip_rt_put(rt);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900540 stats->tx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 dev_kfree_skb(skb);
542 tunnel->recursion--;
543 return 0;
544 }
545 if (skb->sk)
546 skb_set_owner_w(new_skb, skb->sk);
547 dev_kfree_skb(skb);
548 skb = new_skb;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700549 iph6 = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 }
551
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700552 skb->transport_header = skb->network_header;
Arnaldo Carvalho de Meloe2d1bca2007-04-10 20:46:21 -0700553 skb_push(skb, sizeof(struct iphdr));
554 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
Patrick McHardy8cdfab82006-01-06 23:04:01 -0800556 IPCB(skb)->flags = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 dst_release(skb->dst);
558 skb->dst = &rt->u.dst;
559
560 /*
561 * Push down and install the IPIP header.
562 */
563
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700564 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 iph->version = 4;
566 iph->ihl = sizeof(struct iphdr)>>2;
567 if (mtu > IPV6_MIN_MTU)
568 iph->frag_off = htons(IP_DF);
569 else
570 iph->frag_off = 0;
571
572 iph->protocol = IPPROTO_IPV6;
573 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
574 iph->daddr = rt->rt_dst;
575 iph->saddr = rt->rt_src;
576
577 if ((iph->ttl = tiph->ttl) == 0)
578 iph->ttl = iph6->hop_limit;
579
580 nf_reset(skb);
581
582 IPTUNNEL_XMIT();
583 tunnel->recursion--;
584 return 0;
585
586tx_error_icmp:
587 dst_link_failure(skb);
588tx_error:
589 stats->tx_errors++;
590 dev_kfree_skb(skb);
591 tunnel->recursion--;
592 return 0;
593}
594
595static int
596ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
597{
598 int err = 0;
599 struct ip_tunnel_parm p;
600 struct ip_tunnel *t;
601
602 switch (cmd) {
603 case SIOCGETTUNNEL:
604 t = NULL;
605 if (dev == ipip6_fb_tunnel_dev) {
606 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
607 err = -EFAULT;
608 break;
609 }
610 t = ipip6_tunnel_locate(&p, 0);
611 }
612 if (t == NULL)
Patrick McHardy2941a482006-01-08 22:05:26 -0800613 t = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 memcpy(&p, &t->parms, sizeof(p));
615 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
616 err = -EFAULT;
617 break;
618
619 case SIOCADDTUNNEL:
620 case SIOCCHGTUNNEL:
621 err = -EPERM;
622 if (!capable(CAP_NET_ADMIN))
623 goto done;
624
625 err = -EFAULT;
626 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
627 goto done;
628
629 err = -EINVAL;
630 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
631 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
632 goto done;
633 if (p.iph.ttl)
634 p.iph.frag_off |= htons(IP_DF);
635
636 t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL);
637
638 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
639 if (t != NULL) {
640 if (t->dev != dev) {
641 err = -EEXIST;
642 break;
643 }
644 } else {
645 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
646 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
647 err = -EINVAL;
648 break;
649 }
Patrick McHardy2941a482006-01-08 22:05:26 -0800650 t = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 ipip6_tunnel_unlink(t);
652 t->parms.iph.saddr = p.iph.saddr;
653 t->parms.iph.daddr = p.iph.daddr;
654 memcpy(dev->dev_addr, &p.iph.saddr, 4);
655 memcpy(dev->broadcast, &p.iph.daddr, 4);
656 ipip6_tunnel_link(t);
657 netdev_state_change(dev);
658 }
659 }
660
661 if (t) {
662 err = 0;
663 if (cmd == SIOCCHGTUNNEL) {
664 t->parms.iph.ttl = p.iph.ttl;
665 t->parms.iph.tos = p.iph.tos;
666 }
667 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
668 err = -EFAULT;
669 } else
670 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
671 break;
672
673 case SIOCDELTUNNEL:
674 err = -EPERM;
675 if (!capable(CAP_NET_ADMIN))
676 goto done;
677
678 if (dev == ipip6_fb_tunnel_dev) {
679 err = -EFAULT;
680 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
681 goto done;
682 err = -ENOENT;
683 if ((t = ipip6_tunnel_locate(&p, 0)) == NULL)
684 goto done;
685 err = -EPERM;
Patrick McHardy2941a482006-01-08 22:05:26 -0800686 if (t == netdev_priv(ipip6_fb_tunnel_dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 goto done;
688 dev = t->dev;
689 }
Stephen Hemminger22f8cde2007-02-07 00:09:58 -0800690 unregister_netdevice(dev);
691 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 break;
693
694 default:
695 err = -EINVAL;
696 }
697
698done:
699 return err;
700}
701
702static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev)
703{
Patrick McHardy2941a482006-01-08 22:05:26 -0800704 return &(((struct ip_tunnel*)netdev_priv(dev))->stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705}
706
707static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
708{
709 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
710 return -EINVAL;
711 dev->mtu = new_mtu;
712 return 0;
713}
714
715static void ipip6_tunnel_setup(struct net_device *dev)
716{
717 SET_MODULE_OWNER(dev);
718 dev->uninit = ipip6_tunnel_uninit;
719 dev->destructor = free_netdev;
720 dev->hard_start_xmit = ipip6_tunnel_xmit;
721 dev->get_stats = ipip6_tunnel_get_stats;
722 dev->do_ioctl = ipip6_tunnel_ioctl;
723 dev->change_mtu = ipip6_tunnel_change_mtu;
724
725 dev->type = ARPHRD_SIT;
726 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
Kris Katterjohn46f25df2006-01-05 16:35:42 -0800727 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 dev->flags = IFF_NOARP;
729 dev->iflink = 0;
730 dev->addr_len = 4;
731}
732
733static int ipip6_tunnel_init(struct net_device *dev)
734{
735 struct net_device *tdev = NULL;
736 struct ip_tunnel *tunnel;
737 struct iphdr *iph;
738
Patrick McHardy2941a482006-01-08 22:05:26 -0800739 tunnel = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 iph = &tunnel->parms.iph;
741
742 tunnel->dev = dev;
743 strcpy(tunnel->parms.name, dev->name);
744
745 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
746 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
747
748 if (iph->daddr) {
749 struct flowi fl = { .nl_u = { .ip4_u =
750 { .daddr = iph->daddr,
751 .saddr = iph->saddr,
752 .tos = RT_TOS(iph->tos) } },
753 .oif = tunnel->parms.link,
754 .proto = IPPROTO_IPV6 };
755 struct rtable *rt;
756 if (!ip_route_output_key(&rt, &fl)) {
757 tdev = rt->u.dst.dev;
758 ip_rt_put(rt);
759 }
760 dev->flags |= IFF_POINTOPOINT;
761 }
762
763 if (!tdev && tunnel->parms.link)
764 tdev = __dev_get_by_index(tunnel->parms.link);
765
766 if (tdev) {
767 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
768 dev->mtu = tdev->mtu - sizeof(struct iphdr);
769 if (dev->mtu < IPV6_MIN_MTU)
770 dev->mtu = IPV6_MIN_MTU;
771 }
772 dev->iflink = tunnel->parms.link;
773
774 return 0;
775}
776
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300777static int __init ipip6_fb_tunnel_init(struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778{
Patrick McHardy2941a482006-01-08 22:05:26 -0800779 struct ip_tunnel *tunnel = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 struct iphdr *iph = &tunnel->parms.iph;
781
782 tunnel->dev = dev;
783 strcpy(tunnel->parms.name, dev->name);
784
785 iph->version = 4;
786 iph->protocol = IPPROTO_IPV6;
787 iph->ihl = 5;
788 iph->ttl = 64;
789
790 dev_hold(dev);
791 tunnels_wc[0] = tunnel;
792 return 0;
793}
794
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800795static struct xfrm_tunnel sit_handler = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 .handler = ipip6_rcv,
797 .err_handler = ipip6_err,
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800798 .priority = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799};
800
Alexey Kuznetsovdb445752005-07-30 17:46:44 -0700801static void __exit sit_destroy_tunnels(void)
802{
803 int prio;
804
805 for (prio = 1; prio < 4; prio++) {
806 int h;
807 for (h = 0; h < HASH_SIZE; h++) {
808 struct ip_tunnel *t;
809 while ((t = tunnels[prio][h]) != NULL)
810 unregister_netdevice(t->dev);
811 }
812 }
813}
814
Adrian Bunk89c89452006-11-20 16:56:48 -0800815static void __exit sit_cleanup(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800817 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
Alexey Kuznetsovdb445752005-07-30 17:46:44 -0700818
819 rtnl_lock();
820 sit_destroy_tunnels();
821 unregister_netdevice(ipip6_fb_tunnel_dev);
822 rtnl_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823}
824
Adrian Bunk89c89452006-11-20 16:56:48 -0800825static int __init sit_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826{
827 int err;
828
829 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
830
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800831 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 printk(KERN_INFO "sit init: Can't add protocol\n");
833 return -EAGAIN;
834 }
835
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900836 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 ipip6_tunnel_setup);
838 if (!ipip6_fb_tunnel_dev) {
839 err = -ENOMEM;
840 goto err1;
841 }
842
843 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init;
844
845 if ((err = register_netdev(ipip6_fb_tunnel_dev)))
846 goto err2;
847
848 out:
849 return err;
850 err2:
851 free_netdev(ipip6_fb_tunnel_dev);
852 err1:
Kazunori MIYAZAWAc73cb5a2007-02-13 12:55:25 -0800853 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 goto out;
855}
Joerg Roedel989e5b92006-10-10 14:47:44 -0700856
857module_init(sit_init);
858module_exit(sit_cleanup);
Jan Dittmer39c85082006-10-13 15:05:53 -0700859MODULE_LICENSE("GPL");
Patrick McHardydaccff02006-11-05 15:47:04 -0800860MODULE_ALIAS("sit0");