Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Linux NET3: IP/IP protocol decoder. | |
3 | * | |
4 | * Version: $Id: ipip.c,v 1.50 2001/10/02 02:22:36 davem Exp $ | |
5 | * | |
6 | * Authors: | |
7 | * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 | |
8 | * | |
9 | * Fixes: | |
10 | * Alan Cox : Merged and made usable non modular (its so tiny its silly as | |
11 | * a module taking up 2 pages). | |
12 | * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph) | |
13 | * to keep ip_forward happy. | |
14 | * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8). | |
15 | * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL | |
16 | * David Woodhouse : Perform some basic ICMP handling. | |
17 | * IPIP Routing without decapsulation. | |
18 | * Carlos Picoto : GRE over IP support | |
19 | * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c. | |
20 | * I do not want to merge them together. | |
21 | * | |
22 | * This program is free software; you can redistribute it and/or | |
23 | * modify it under the terms of the GNU General Public License | |
24 | * as published by the Free Software Foundation; either version | |
25 | * 2 of the License, or (at your option) any later version. | |
26 | * | |
27 | */ | |
28 | ||
29 | /* tunnel.c: an IP tunnel driver | |
30 | ||
31 | The purpose of this driver is to provide an IP tunnel through | |
32 | which you can tunnel network traffic transparently across subnets. | |
33 | ||
34 | This was written by looking at Nick Holloway's dummy driver | |
35 | Thanks for the great code! | |
36 | ||
37 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 | |
38 | ||
39 | Minor tweaks: | |
40 | Cleaned up the code a little and added some pre-1.3.0 tweaks. | |
41 | dev->hard_header/hard_header_len changed to use no headers. | |
42 | Comments/bracketing tweaked. | |
43 | Made the tunnels use dev->name not tunnel: when error reporting. | |
44 | Added tx_dropped stat | |
45 | ||
46 | -Alan Cox (Alan.Cox@linux.org) 21 March 95 | |
47 | ||
48 | Reworked: | |
49 | Changed to tunnel to destination gateway in addition to the | |
50 | tunnel's pointopoint address | |
51 | Almost completely rewritten | |
52 | Note: There is currently no firewall or ICMP handling done. | |
53 | ||
54 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96 | |
55 | ||
56 | */ | |
57 | ||
58 | /* Things I wish I had known when writing the tunnel driver: | |
59 | ||
60 | When the tunnel_xmit() function is called, the skb contains the | |
61 | packet to be sent (plus a great deal of extra info), and dev | |
62 | contains the tunnel device that _we_ are. | |
63 | ||
64 | When we are passed a packet, we are expected to fill in the | |
65 | source address with our source IP address. | |
66 | ||
67 | What is the proper way to allocate, copy and free a buffer? | |
68 | After you allocate it, it is a "0 length" chunk of memory | |
69 | starting at zero. If you want to add headers to the buffer | |
70 | later, you'll have to call "skb_reserve(skb, amount)" with | |
71 | the amount of memory you want reserved. Then, you call | |
72 | "skb_put(skb, amount)" with the amount of space you want in | |
73 | the buffer. skb_put() returns a pointer to the top (#0) of | |
74 | that buffer. skb->len is set to the amount of space you have | |
75 | "allocated" with skb_put(). You can then write up to skb->len | |
76 | bytes to that buffer. If you need more, you can call skb_put() | |
77 | again with the additional amount of space you need. You can | |
78 | find out how much more space you can allocate by calling | |
79 | "skb_tailroom(skb)". | |
80 | Now, to add header space, call "skb_push(skb, header_len)". | |
81 | This creates space at the beginning of the buffer and returns | |
82 | a pointer to this new space. If later you need to strip a | |
83 | header from a buffer, call "skb_pull(skb, header_len)". | |
84 | skb_headroom() will return how much space is left at the top | |
85 | of the buffer (before the main data). Remember, this headroom | |
86 | space must be reserved before the skb_put() function is called. | |
87 | */ | |
88 | ||
89 | /* | |
90 | This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c | |
91 | ||
92 | For comments look at net/ipv4/ip_gre.c --ANK | |
93 | */ | |
94 | ||
95 | ||
96 | #include <linux/config.h> | |
97 | #include <linux/module.h> | |
98 | #include <linux/types.h> | |
99 | #include <linux/sched.h> | |
100 | #include <linux/kernel.h> | |
101 | #include <asm/uaccess.h> | |
102 | #include <linux/skbuff.h> | |
103 | #include <linux/netdevice.h> | |
104 | #include <linux/in.h> | |
105 | #include <linux/tcp.h> | |
106 | #include <linux/udp.h> | |
107 | #include <linux/if_arp.h> | |
108 | #include <linux/mroute.h> | |
109 | #include <linux/init.h> | |
110 | #include <linux/netfilter_ipv4.h> | |
111 | ||
112 | #include <net/sock.h> | |
113 | #include <net/ip.h> | |
114 | #include <net/icmp.h> | |
115 | #include <net/protocol.h> | |
116 | #include <net/ipip.h> | |
117 | #include <net/inet_ecn.h> | |
118 | #include <net/xfrm.h> | |
119 | ||
120 | #define HASH_SIZE 16 | |
121 | #define HASH(addr) ((addr^(addr>>4))&0xF) | |
122 | ||
123 | static int ipip_fb_tunnel_init(struct net_device *dev); | |
124 | static int ipip_tunnel_init(struct net_device *dev); | |
125 | static void ipip_tunnel_setup(struct net_device *dev); | |
126 | ||
127 | static struct net_device *ipip_fb_tunnel_dev; | |
128 | ||
129 | static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; | |
130 | static struct ip_tunnel *tunnels_r[HASH_SIZE]; | |
131 | static struct ip_tunnel *tunnels_l[HASH_SIZE]; | |
132 | static struct ip_tunnel *tunnels_wc[1]; | |
133 | static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; | |
134 | ||
135 | static DEFINE_RWLOCK(ipip_lock); | |
136 | ||
137 | static struct ip_tunnel * ipip_tunnel_lookup(u32 remote, u32 local) | |
138 | { | |
139 | unsigned h0 = HASH(remote); | |
140 | unsigned h1 = HASH(local); | |
141 | struct ip_tunnel *t; | |
142 | ||
143 | for (t = tunnels_r_l[h0^h1]; t; t = t->next) { | |
144 | if (local == t->parms.iph.saddr && | |
145 | remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) | |
146 | return t; | |
147 | } | |
148 | for (t = tunnels_r[h0]; t; t = t->next) { | |
149 | if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) | |
150 | return t; | |
151 | } | |
152 | for (t = tunnels_l[h1]; t; t = t->next) { | |
153 | if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) | |
154 | return t; | |
155 | } | |
156 | if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) | |
157 | return t; | |
158 | return NULL; | |
159 | } | |
160 | ||
161 | static struct ip_tunnel **ipip_bucket(struct ip_tunnel *t) | |
162 | { | |
163 | u32 remote = t->parms.iph.daddr; | |
164 | u32 local = t->parms.iph.saddr; | |
165 | unsigned h = 0; | |
166 | int prio = 0; | |
167 | ||
168 | if (remote) { | |
169 | prio |= 2; | |
170 | h ^= HASH(remote); | |
171 | } | |
172 | if (local) { | |
173 | prio |= 1; | |
174 | h ^= HASH(local); | |
175 | } | |
176 | return &tunnels[prio][h]; | |
177 | } | |
178 | ||
179 | ||
180 | static void ipip_tunnel_unlink(struct ip_tunnel *t) | |
181 | { | |
182 | struct ip_tunnel **tp; | |
183 | ||
184 | for (tp = ipip_bucket(t); *tp; tp = &(*tp)->next) { | |
185 | if (t == *tp) { | |
186 | write_lock_bh(&ipip_lock); | |
187 | *tp = t->next; | |
188 | write_unlock_bh(&ipip_lock); | |
189 | break; | |
190 | } | |
191 | } | |
192 | } | |
193 | ||
194 | static void ipip_tunnel_link(struct ip_tunnel *t) | |
195 | { | |
196 | struct ip_tunnel **tp = ipip_bucket(t); | |
197 | ||
198 | t->next = *tp; | |
199 | write_lock_bh(&ipip_lock); | |
200 | *tp = t; | |
201 | write_unlock_bh(&ipip_lock); | |
202 | } | |
203 | ||
204 | static struct ip_tunnel * ipip_tunnel_locate(struct ip_tunnel_parm *parms, int create) | |
205 | { | |
206 | u32 remote = parms->iph.daddr; | |
207 | u32 local = parms->iph.saddr; | |
208 | struct ip_tunnel *t, **tp, *nt; | |
209 | struct net_device *dev; | |
210 | unsigned h = 0; | |
211 | int prio = 0; | |
212 | char name[IFNAMSIZ]; | |
213 | ||
214 | if (remote) { | |
215 | prio |= 2; | |
216 | h ^= HASH(remote); | |
217 | } | |
218 | if (local) { | |
219 | prio |= 1; | |
220 | h ^= HASH(local); | |
221 | } | |
222 | for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { | |
223 | if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) | |
224 | return t; | |
225 | } | |
226 | if (!create) | |
227 | return NULL; | |
228 | ||
229 | if (parms->name[0]) | |
230 | strlcpy(name, parms->name, IFNAMSIZ); | |
231 | else { | |
232 | int i; | |
233 | for (i=1; i<100; i++) { | |
234 | sprintf(name, "tunl%d", i); | |
235 | if (__dev_get_by_name(name) == NULL) | |
236 | break; | |
237 | } | |
238 | if (i==100) | |
239 | goto failed; | |
240 | } | |
241 | ||
242 | dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); | |
243 | if (dev == NULL) | |
244 | return NULL; | |
245 | ||
246 | nt = dev->priv; | |
247 | SET_MODULE_OWNER(dev); | |
248 | dev->init = ipip_tunnel_init; | |
249 | nt->parms = *parms; | |
250 | ||
251 | if (register_netdevice(dev) < 0) { | |
252 | free_netdev(dev); | |
253 | goto failed; | |
254 | } | |
255 | ||
256 | dev_hold(dev); | |
257 | ipip_tunnel_link(nt); | |
1da177e4 LT |
258 | return nt; |
259 | ||
260 | failed: | |
261 | return NULL; | |
262 | } | |
263 | ||
264 | static void ipip_tunnel_uninit(struct net_device *dev) | |
265 | { | |
266 | if (dev == ipip_fb_tunnel_dev) { | |
267 | write_lock_bh(&ipip_lock); | |
268 | tunnels_wc[0] = NULL; | |
269 | write_unlock_bh(&ipip_lock); | |
270 | } else | |
271 | ipip_tunnel_unlink((struct ip_tunnel*)dev->priv); | |
272 | dev_put(dev); | |
273 | } | |
274 | ||
0303770d | 275 | static void ipip_err(struct sk_buff *skb, u32 info) |
1da177e4 LT |
276 | { |
277 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
278 | ||
279 | /* It is not :-( All the routers (except for Linux) return only | |
280 | 8 bytes of packet payload. It means, that precise relaying of | |
281 | ICMP in the real Internet is absolutely infeasible. | |
282 | */ | |
283 | struct iphdr *iph = (struct iphdr*)skb->data; | |
284 | int type = skb->h.icmph->type; | |
285 | int code = skb->h.icmph->code; | |
286 | struct ip_tunnel *t; | |
287 | ||
288 | switch (type) { | |
289 | default: | |
290 | case ICMP_PARAMETERPROB: | |
291 | return; | |
292 | ||
293 | case ICMP_DEST_UNREACH: | |
294 | switch (code) { | |
295 | case ICMP_SR_FAILED: | |
296 | case ICMP_PORT_UNREACH: | |
297 | /* Impossible event. */ | |
298 | return; | |
299 | case ICMP_FRAG_NEEDED: | |
300 | /* Soft state for pmtu is maintained by IP core. */ | |
301 | return; | |
302 | default: | |
303 | /* All others are translated to HOST_UNREACH. | |
304 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
305 | I believe they are just ether pollution. --ANK | |
306 | */ | |
307 | break; | |
308 | } | |
309 | break; | |
310 | case ICMP_TIME_EXCEEDED: | |
311 | if (code != ICMP_EXC_TTL) | |
312 | return; | |
313 | break; | |
314 | } | |
315 | ||
316 | read_lock(&ipip_lock); | |
317 | t = ipip_tunnel_lookup(iph->daddr, iph->saddr); | |
318 | if (t == NULL || t->parms.iph.daddr == 0) | |
319 | goto out; | |
320 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) | |
321 | goto out; | |
322 | ||
323 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
324 | t->err_count++; | |
325 | else | |
326 | t->err_count = 1; | |
327 | t->err_time = jiffies; | |
328 | out: | |
329 | read_unlock(&ipip_lock); | |
330 | return; | |
331 | #else | |
332 | struct iphdr *iph = (struct iphdr*)dp; | |
333 | int hlen = iph->ihl<<2; | |
334 | struct iphdr *eiph; | |
335 | int type = skb->h.icmph->type; | |
336 | int code = skb->h.icmph->code; | |
337 | int rel_type = 0; | |
338 | int rel_code = 0; | |
339 | int rel_info = 0; | |
340 | struct sk_buff *skb2; | |
341 | struct flowi fl; | |
342 | struct rtable *rt; | |
343 | ||
344 | if (len < hlen + sizeof(struct iphdr)) | |
345 | return; | |
346 | eiph = (struct iphdr*)(dp + hlen); | |
347 | ||
348 | switch (type) { | |
349 | default: | |
350 | return; | |
351 | case ICMP_PARAMETERPROB: | |
352 | if (skb->h.icmph->un.gateway < hlen) | |
353 | return; | |
354 | ||
355 | /* So... This guy found something strange INSIDE encapsulated | |
356 | packet. Well, he is fool, but what can we do ? | |
357 | */ | |
358 | rel_type = ICMP_PARAMETERPROB; | |
359 | rel_info = skb->h.icmph->un.gateway - hlen; | |
360 | break; | |
361 | ||
362 | case ICMP_DEST_UNREACH: | |
363 | switch (code) { | |
364 | case ICMP_SR_FAILED: | |
365 | case ICMP_PORT_UNREACH: | |
366 | /* Impossible event. */ | |
367 | return; | |
368 | case ICMP_FRAG_NEEDED: | |
369 | /* And it is the only really necessary thing :-) */ | |
370 | rel_info = ntohs(skb->h.icmph->un.frag.mtu); | |
371 | if (rel_info < hlen+68) | |
372 | return; | |
373 | rel_info -= hlen; | |
374 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ | |
375 | if (rel_info > ntohs(eiph->tot_len)) | |
376 | return; | |
377 | break; | |
378 | default: | |
379 | /* All others are translated to HOST_UNREACH. | |
380 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
381 | I believe, it is just ether pollution. --ANK | |
382 | */ | |
383 | rel_type = ICMP_DEST_UNREACH; | |
384 | rel_code = ICMP_HOST_UNREACH; | |
385 | break; | |
386 | } | |
387 | break; | |
388 | case ICMP_TIME_EXCEEDED: | |
389 | if (code != ICMP_EXC_TTL) | |
390 | return; | |
391 | break; | |
392 | } | |
393 | ||
394 | /* Prepare fake skb to feed it to icmp_send */ | |
395 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
396 | if (skb2 == NULL) | |
397 | return; | |
398 | dst_release(skb2->dst); | |
399 | skb2->dst = NULL; | |
400 | skb_pull(skb2, skb->data - (u8*)eiph); | |
401 | skb2->nh.raw = skb2->data; | |
402 | ||
403 | /* Try to guess incoming interface */ | |
404 | memset(&fl, 0, sizeof(fl)); | |
405 | fl.fl4_daddr = eiph->saddr; | |
406 | fl.fl4_tos = RT_TOS(eiph->tos); | |
407 | fl.proto = IPPROTO_IPIP; | |
408 | if (ip_route_output_key(&rt, &key)) { | |
409 | kfree_skb(skb2); | |
410 | return; | |
411 | } | |
412 | skb2->dev = rt->u.dst.dev; | |
413 | ||
414 | /* route "incoming" packet */ | |
415 | if (rt->rt_flags&RTCF_LOCAL) { | |
416 | ip_rt_put(rt); | |
417 | rt = NULL; | |
418 | fl.fl4_daddr = eiph->daddr; | |
419 | fl.fl4_src = eiph->saddr; | |
420 | fl.fl4_tos = eiph->tos; | |
421 | if (ip_route_output_key(&rt, &fl) || | |
422 | rt->u.dst.dev->type != ARPHRD_TUNNEL) { | |
423 | ip_rt_put(rt); | |
424 | kfree_skb(skb2); | |
425 | return; | |
426 | } | |
427 | } else { | |
428 | ip_rt_put(rt); | |
429 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || | |
430 | skb2->dst->dev->type != ARPHRD_TUNNEL) { | |
431 | kfree_skb(skb2); | |
432 | return; | |
433 | } | |
434 | } | |
435 | ||
436 | /* change mtu on this route */ | |
437 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
438 | if (rel_info > dst_mtu(skb2->dst)) { | |
439 | kfree_skb(skb2); | |
440 | return; | |
441 | } | |
442 | skb2->dst->ops->update_pmtu(skb2->dst, rel_info); | |
443 | rel_info = htonl(rel_info); | |
444 | } else if (type == ICMP_TIME_EXCEEDED) { | |
445 | struct ip_tunnel *t = (struct ip_tunnel*)skb2->dev->priv; | |
446 | if (t->parms.iph.ttl) { | |
447 | rel_type = ICMP_DEST_UNREACH; | |
448 | rel_code = ICMP_HOST_UNREACH; | |
449 | } | |
450 | } | |
451 | ||
452 | icmp_send(skb2, rel_type, rel_code, rel_info); | |
453 | kfree_skb(skb2); | |
454 | return; | |
455 | #endif | |
456 | } | |
457 | ||
458 | static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb) | |
459 | { | |
460 | struct iphdr *inner_iph = skb->nh.iph; | |
461 | ||
462 | if (INET_ECN_is_ce(outer_iph->tos)) | |
463 | IP_ECN_set_ce(inner_iph); | |
464 | } | |
465 | ||
466 | static int ipip_rcv(struct sk_buff *skb) | |
467 | { | |
468 | struct iphdr *iph; | |
469 | struct ip_tunnel *tunnel; | |
470 | ||
471 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
472 | goto out; | |
473 | ||
474 | iph = skb->nh.iph; | |
475 | ||
476 | read_lock(&ipip_lock); | |
477 | if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { | |
478 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
479 | read_unlock(&ipip_lock); | |
480 | kfree_skb(skb); | |
481 | return 0; | |
482 | } | |
483 | ||
484 | secpath_reset(skb); | |
485 | ||
486 | skb->mac.raw = skb->nh.raw; | |
487 | skb->nh.raw = skb->data; | |
488 | memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); | |
489 | skb->protocol = htons(ETH_P_IP); | |
490 | skb->pkt_type = PACKET_HOST; | |
491 | ||
492 | tunnel->stat.rx_packets++; | |
493 | tunnel->stat.rx_bytes += skb->len; | |
494 | skb->dev = tunnel->dev; | |
495 | dst_release(skb->dst); | |
496 | skb->dst = NULL; | |
497 | nf_reset(skb); | |
498 | ipip_ecn_decapsulate(iph, skb); | |
499 | netif_rx(skb); | |
500 | read_unlock(&ipip_lock); | |
501 | return 0; | |
502 | } | |
503 | read_unlock(&ipip_lock); | |
504 | ||
505 | out: | |
506 | return -1; | |
507 | } | |
508 | ||
509 | /* | |
510 | * This function assumes it is being called from dev_queue_xmit() | |
511 | * and that skb is filled properly by that function. | |
512 | */ | |
513 | ||
514 | static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
515 | { | |
516 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; | |
517 | struct net_device_stats *stats = &tunnel->stat; | |
518 | struct iphdr *tiph = &tunnel->parms.iph; | |
519 | u8 tos = tunnel->parms.iph.tos; | |
520 | u16 df = tiph->frag_off; | |
521 | struct rtable *rt; /* Route to the other host */ | |
522 | struct net_device *tdev; /* Device to other host */ | |
523 | struct iphdr *old_iph = skb->nh.iph; | |
524 | struct iphdr *iph; /* Our new IP header */ | |
525 | int max_headroom; /* The extra header space needed */ | |
526 | u32 dst = tiph->daddr; | |
527 | int mtu; | |
528 | ||
529 | if (tunnel->recursion++) { | |
530 | tunnel->stat.collisions++; | |
531 | goto tx_error; | |
532 | } | |
533 | ||
534 | if (skb->protocol != htons(ETH_P_IP)) | |
535 | goto tx_error; | |
536 | ||
537 | if (tos&1) | |
538 | tos = old_iph->tos; | |
539 | ||
540 | if (!dst) { | |
541 | /* NBMA tunnel */ | |
542 | if ((rt = (struct rtable*)skb->dst) == NULL) { | |
543 | tunnel->stat.tx_fifo_errors++; | |
544 | goto tx_error; | |
545 | } | |
546 | if ((dst = rt->rt_gateway) == 0) | |
547 | goto tx_error_icmp; | |
548 | } | |
549 | ||
550 | { | |
551 | struct flowi fl = { .oif = tunnel->parms.link, | |
552 | .nl_u = { .ip4_u = | |
553 | { .daddr = dst, | |
554 | .saddr = tiph->saddr, | |
555 | .tos = RT_TOS(tos) } }, | |
556 | .proto = IPPROTO_IPIP }; | |
557 | if (ip_route_output_key(&rt, &fl)) { | |
558 | tunnel->stat.tx_carrier_errors++; | |
559 | goto tx_error_icmp; | |
560 | } | |
561 | } | |
562 | tdev = rt->u.dst.dev; | |
563 | ||
564 | if (tdev == dev) { | |
565 | ip_rt_put(rt); | |
566 | tunnel->stat.collisions++; | |
567 | goto tx_error; | |
568 | } | |
569 | ||
570 | if (tiph->frag_off) | |
571 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); | |
572 | else | |
573 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
574 | ||
575 | if (mtu < 68) { | |
576 | tunnel->stat.collisions++; | |
577 | ip_rt_put(rt); | |
578 | goto tx_error; | |
579 | } | |
580 | if (skb->dst) | |
581 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
582 | ||
583 | df |= (old_iph->frag_off&htons(IP_DF)); | |
584 | ||
585 | if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { | |
586 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
587 | ip_rt_put(rt); | |
588 | goto tx_error; | |
589 | } | |
590 | ||
591 | if (tunnel->err_count > 0) { | |
592 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
593 | tunnel->err_count--; | |
594 | dst_link_failure(skb); | |
595 | } else | |
596 | tunnel->err_count = 0; | |
597 | } | |
598 | ||
599 | /* | |
600 | * Okay, now see if we can stuff it in the buffer as-is. | |
601 | */ | |
602 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); | |
603 | ||
604 | if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { | |
605 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
606 | if (!new_skb) { | |
607 | ip_rt_put(rt); | |
608 | stats->tx_dropped++; | |
609 | dev_kfree_skb(skb); | |
610 | tunnel->recursion--; | |
611 | return 0; | |
612 | } | |
613 | if (skb->sk) | |
614 | skb_set_owner_w(new_skb, skb->sk); | |
615 | dev_kfree_skb(skb); | |
616 | skb = new_skb; | |
617 | old_iph = skb->nh.iph; | |
618 | } | |
619 | ||
620 | skb->h.raw = skb->nh.raw; | |
621 | skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); | |
622 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
623 | dst_release(skb->dst); | |
624 | skb->dst = &rt->u.dst; | |
625 | ||
626 | /* | |
627 | * Push down and install the IPIP header. | |
628 | */ | |
629 | ||
630 | iph = skb->nh.iph; | |
631 | iph->version = 4; | |
632 | iph->ihl = sizeof(struct iphdr)>>2; | |
633 | iph->frag_off = df; | |
634 | iph->protocol = IPPROTO_IPIP; | |
635 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); | |
636 | iph->daddr = rt->rt_dst; | |
637 | iph->saddr = rt->rt_src; | |
638 | ||
639 | if ((iph->ttl = tiph->ttl) == 0) | |
640 | iph->ttl = old_iph->ttl; | |
641 | ||
642 | nf_reset(skb); | |
643 | ||
644 | IPTUNNEL_XMIT(); | |
645 | tunnel->recursion--; | |
646 | return 0; | |
647 | ||
648 | tx_error_icmp: | |
649 | dst_link_failure(skb); | |
650 | tx_error: | |
651 | stats->tx_errors++; | |
652 | dev_kfree_skb(skb); | |
653 | tunnel->recursion--; | |
654 | return 0; | |
655 | } | |
656 | ||
657 | static int | |
658 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
659 | { | |
660 | int err = 0; | |
661 | struct ip_tunnel_parm p; | |
662 | struct ip_tunnel *t; | |
663 | ||
664 | switch (cmd) { | |
665 | case SIOCGETTUNNEL: | |
666 | t = NULL; | |
667 | if (dev == ipip_fb_tunnel_dev) { | |
668 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
669 | err = -EFAULT; | |
670 | break; | |
671 | } | |
672 | t = ipip_tunnel_locate(&p, 0); | |
673 | } | |
674 | if (t == NULL) | |
675 | t = (struct ip_tunnel*)dev->priv; | |
676 | memcpy(&p, &t->parms, sizeof(p)); | |
677 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
678 | err = -EFAULT; | |
679 | break; | |
680 | ||
681 | case SIOCADDTUNNEL: | |
682 | case SIOCCHGTUNNEL: | |
683 | err = -EPERM; | |
684 | if (!capable(CAP_NET_ADMIN)) | |
685 | goto done; | |
686 | ||
687 | err = -EFAULT; | |
688 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
689 | goto done; | |
690 | ||
691 | err = -EINVAL; | |
692 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || | |
693 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
694 | goto done; | |
695 | if (p.iph.ttl) | |
696 | p.iph.frag_off |= htons(IP_DF); | |
697 | ||
698 | t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
699 | ||
700 | if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
701 | if (t != NULL) { | |
702 | if (t->dev != dev) { | |
703 | err = -EEXIST; | |
704 | break; | |
705 | } | |
706 | } else { | |
707 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
708 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
709 | err = -EINVAL; | |
710 | break; | |
711 | } | |
712 | t = (struct ip_tunnel*)dev->priv; | |
713 | ipip_tunnel_unlink(t); | |
714 | t->parms.iph.saddr = p.iph.saddr; | |
715 | t->parms.iph.daddr = p.iph.daddr; | |
716 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
717 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
718 | ipip_tunnel_link(t); | |
719 | netdev_state_change(dev); | |
720 | } | |
721 | } | |
722 | ||
723 | if (t) { | |
724 | err = 0; | |
725 | if (cmd == SIOCCHGTUNNEL) { | |
726 | t->parms.iph.ttl = p.iph.ttl; | |
727 | t->parms.iph.tos = p.iph.tos; | |
728 | t->parms.iph.frag_off = p.iph.frag_off; | |
729 | } | |
730 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
731 | err = -EFAULT; | |
732 | } else | |
733 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
734 | break; | |
735 | ||
736 | case SIOCDELTUNNEL: | |
737 | err = -EPERM; | |
738 | if (!capable(CAP_NET_ADMIN)) | |
739 | goto done; | |
740 | ||
741 | if (dev == ipip_fb_tunnel_dev) { | |
742 | err = -EFAULT; | |
743 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
744 | goto done; | |
745 | err = -ENOENT; | |
746 | if ((t = ipip_tunnel_locate(&p, 0)) == NULL) | |
747 | goto done; | |
748 | err = -EPERM; | |
749 | if (t->dev == ipip_fb_tunnel_dev) | |
750 | goto done; | |
751 | dev = t->dev; | |
752 | } | |
753 | err = unregister_netdevice(dev); | |
754 | break; | |
755 | ||
756 | default: | |
757 | err = -EINVAL; | |
758 | } | |
759 | ||
760 | done: | |
761 | return err; | |
762 | } | |
763 | ||
764 | static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) | |
765 | { | |
766 | return &(((struct ip_tunnel*)dev->priv)->stat); | |
767 | } | |
768 | ||
769 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
770 | { | |
771 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
772 | return -EINVAL; | |
773 | dev->mtu = new_mtu; | |
774 | return 0; | |
775 | } | |
776 | ||
777 | static void ipip_tunnel_setup(struct net_device *dev) | |
778 | { | |
779 | SET_MODULE_OWNER(dev); | |
780 | dev->uninit = ipip_tunnel_uninit; | |
781 | dev->hard_start_xmit = ipip_tunnel_xmit; | |
782 | dev->get_stats = ipip_tunnel_get_stats; | |
783 | dev->do_ioctl = ipip_tunnel_ioctl; | |
784 | dev->change_mtu = ipip_tunnel_change_mtu; | |
785 | dev->destructor = free_netdev; | |
786 | ||
787 | dev->type = ARPHRD_TUNNEL; | |
788 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
789 | dev->mtu = 1500 - sizeof(struct iphdr); | |
790 | dev->flags = IFF_NOARP; | |
791 | dev->iflink = 0; | |
792 | dev->addr_len = 4; | |
793 | } | |
794 | ||
795 | static int ipip_tunnel_init(struct net_device *dev) | |
796 | { | |
797 | struct net_device *tdev = NULL; | |
798 | struct ip_tunnel *tunnel; | |
799 | struct iphdr *iph; | |
800 | ||
801 | tunnel = (struct ip_tunnel*)dev->priv; | |
802 | iph = &tunnel->parms.iph; | |
803 | ||
804 | tunnel->dev = dev; | |
805 | strcpy(tunnel->parms.name, dev->name); | |
806 | ||
807 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
808 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
809 | ||
810 | if (iph->daddr) { | |
811 | struct flowi fl = { .oif = tunnel->parms.link, | |
812 | .nl_u = { .ip4_u = | |
813 | { .daddr = iph->daddr, | |
814 | .saddr = iph->saddr, | |
815 | .tos = RT_TOS(iph->tos) } }, | |
816 | .proto = IPPROTO_IPIP }; | |
817 | struct rtable *rt; | |
818 | if (!ip_route_output_key(&rt, &fl)) { | |
819 | tdev = rt->u.dst.dev; | |
820 | ip_rt_put(rt); | |
821 | } | |
822 | dev->flags |= IFF_POINTOPOINT; | |
823 | } | |
824 | ||
825 | if (!tdev && tunnel->parms.link) | |
826 | tdev = __dev_get_by_index(tunnel->parms.link); | |
827 | ||
828 | if (tdev) { | |
829 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
830 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
831 | } | |
832 | dev->iflink = tunnel->parms.link; | |
833 | ||
834 | return 0; | |
835 | } | |
836 | ||
837 | static int __init ipip_fb_tunnel_init(struct net_device *dev) | |
838 | { | |
839 | struct ip_tunnel *tunnel = dev->priv; | |
840 | struct iphdr *iph = &tunnel->parms.iph; | |
841 | ||
842 | tunnel->dev = dev; | |
843 | strcpy(tunnel->parms.name, dev->name); | |
844 | ||
845 | iph->version = 4; | |
846 | iph->protocol = IPPROTO_IPIP; | |
847 | iph->ihl = 5; | |
848 | ||
849 | dev_hold(dev); | |
850 | tunnels_wc[0] = tunnel; | |
851 | return 0; | |
852 | } | |
853 | ||
0303770d | 854 | #ifdef CONFIG_INET_TUNNEL |
1da177e4 LT |
855 | static struct xfrm_tunnel ipip_handler = { |
856 | .handler = ipip_rcv, | |
857 | .err_handler = ipip_err, | |
858 | }; | |
859 | ||
0303770d PM |
860 | static inline int ipip_register(void) |
861 | { | |
862 | return xfrm4_tunnel_register(&ipip_handler); | |
863 | } | |
864 | ||
865 | static inline int ipip_unregister(void) | |
866 | { | |
867 | return xfrm4_tunnel_deregister(&ipip_handler); | |
868 | } | |
869 | #else | |
870 | static struct net_protocol ipip_protocol = { | |
871 | .handler = ipip_rcv, | |
872 | .err_handler = ipip_err, | |
873 | .no_policy = 1, | |
874 | }; | |
875 | ||
876 | static inline int ipip_register(void) | |
877 | { | |
878 | return inet_add_protocol(&ipip_protocol, IPPROTO_IPIP); | |
879 | } | |
880 | ||
881 | static inline int ipip_unregister(void) | |
882 | { | |
883 | return inet_del_protocol(&ipip_protocol, IPPROTO_IPIP); | |
884 | } | |
885 | #endif | |
886 | ||
1da177e4 LT |
887 | static char banner[] __initdata = |
888 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; | |
889 | ||
890 | static int __init ipip_init(void) | |
891 | { | |
892 | int err; | |
893 | ||
894 | printk(banner); | |
895 | ||
0303770d | 896 | if (ipip_register() < 0) { |
1da177e4 LT |
897 | printk(KERN_INFO "ipip init: can't register tunnel\n"); |
898 | return -EAGAIN; | |
899 | } | |
900 | ||
901 | ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), | |
902 | "tunl0", | |
903 | ipip_tunnel_setup); | |
904 | if (!ipip_fb_tunnel_dev) { | |
905 | err = -ENOMEM; | |
906 | goto err1; | |
907 | } | |
908 | ||
909 | ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; | |
910 | ||
911 | if ((err = register_netdev(ipip_fb_tunnel_dev))) | |
912 | goto err2; | |
913 | out: | |
914 | return err; | |
915 | err2: | |
916 | free_netdev(ipip_fb_tunnel_dev); | |
917 | err1: | |
0303770d | 918 | ipip_unregister(); |
1da177e4 LT |
919 | goto out; |
920 | } | |
921 | ||
db44575f AK |
922 | static void __exit ipip_destroy_tunnels(void) |
923 | { | |
924 | int prio; | |
925 | ||
926 | for (prio = 1; prio < 4; prio++) { | |
927 | int h; | |
928 | for (h = 0; h < HASH_SIZE; h++) { | |
929 | struct ip_tunnel *t; | |
930 | while ((t = tunnels[prio][h]) != NULL) | |
931 | unregister_netdevice(t->dev); | |
932 | } | |
933 | } | |
934 | } | |
935 | ||
1da177e4 LT |
936 | static void __exit ipip_fini(void) |
937 | { | |
0303770d | 938 | if (ipip_unregister() < 0) |
1da177e4 LT |
939 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); |
940 | ||
db44575f AK |
941 | rtnl_lock(); |
942 | ipip_destroy_tunnels(); | |
943 | unregister_netdevice(ipip_fb_tunnel_dev); | |
944 | rtnl_unlock(); | |
1da177e4 LT |
945 | } |
946 | ||
947 | module_init(ipip_init); | |
948 | module_exit(ipip_fini); | |
949 | MODULE_LICENSE("GPL"); |