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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); | |
258 | /* Do not decrement MOD_USE_COUNT here. */ | |
259 | return nt; | |
260 | ||
261 | failed: | |
262 | return NULL; | |
263 | } | |
264 | ||
265 | static void ipip_tunnel_uninit(struct net_device *dev) | |
266 | { | |
267 | if (dev == ipip_fb_tunnel_dev) { | |
268 | write_lock_bh(&ipip_lock); | |
269 | tunnels_wc[0] = NULL; | |
270 | write_unlock_bh(&ipip_lock); | |
271 | } else | |
272 | ipip_tunnel_unlink((struct ip_tunnel*)dev->priv); | |
273 | dev_put(dev); | |
274 | } | |
275 | ||
276 | static void ipip_err(struct sk_buff *skb, void *__unused) | |
277 | { | |
278 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
279 | ||
280 | /* It is not :-( All the routers (except for Linux) return only | |
281 | 8 bytes of packet payload. It means, that precise relaying of | |
282 | ICMP in the real Internet is absolutely infeasible. | |
283 | */ | |
284 | struct iphdr *iph = (struct iphdr*)skb->data; | |
285 | int type = skb->h.icmph->type; | |
286 | int code = skb->h.icmph->code; | |
287 | struct ip_tunnel *t; | |
288 | ||
289 | switch (type) { | |
290 | default: | |
291 | case ICMP_PARAMETERPROB: | |
292 | return; | |
293 | ||
294 | case ICMP_DEST_UNREACH: | |
295 | switch (code) { | |
296 | case ICMP_SR_FAILED: | |
297 | case ICMP_PORT_UNREACH: | |
298 | /* Impossible event. */ | |
299 | return; | |
300 | case ICMP_FRAG_NEEDED: | |
301 | /* Soft state for pmtu is maintained by IP core. */ | |
302 | return; | |
303 | default: | |
304 | /* All others are translated to HOST_UNREACH. | |
305 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
306 | I believe they are just ether pollution. --ANK | |
307 | */ | |
308 | break; | |
309 | } | |
310 | break; | |
311 | case ICMP_TIME_EXCEEDED: | |
312 | if (code != ICMP_EXC_TTL) | |
313 | return; | |
314 | break; | |
315 | } | |
316 | ||
317 | read_lock(&ipip_lock); | |
318 | t = ipip_tunnel_lookup(iph->daddr, iph->saddr); | |
319 | if (t == NULL || t->parms.iph.daddr == 0) | |
320 | goto out; | |
321 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) | |
322 | goto out; | |
323 | ||
324 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
325 | t->err_count++; | |
326 | else | |
327 | t->err_count = 1; | |
328 | t->err_time = jiffies; | |
329 | out: | |
330 | read_unlock(&ipip_lock); | |
331 | return; | |
332 | #else | |
333 | struct iphdr *iph = (struct iphdr*)dp; | |
334 | int hlen = iph->ihl<<2; | |
335 | struct iphdr *eiph; | |
336 | int type = skb->h.icmph->type; | |
337 | int code = skb->h.icmph->code; | |
338 | int rel_type = 0; | |
339 | int rel_code = 0; | |
340 | int rel_info = 0; | |
341 | struct sk_buff *skb2; | |
342 | struct flowi fl; | |
343 | struct rtable *rt; | |
344 | ||
345 | if (len < hlen + sizeof(struct iphdr)) | |
346 | return; | |
347 | eiph = (struct iphdr*)(dp + hlen); | |
348 | ||
349 | switch (type) { | |
350 | default: | |
351 | return; | |
352 | case ICMP_PARAMETERPROB: | |
353 | if (skb->h.icmph->un.gateway < hlen) | |
354 | return; | |
355 | ||
356 | /* So... This guy found something strange INSIDE encapsulated | |
357 | packet. Well, he is fool, but what can we do ? | |
358 | */ | |
359 | rel_type = ICMP_PARAMETERPROB; | |
360 | rel_info = skb->h.icmph->un.gateway - hlen; | |
361 | break; | |
362 | ||
363 | case ICMP_DEST_UNREACH: | |
364 | switch (code) { | |
365 | case ICMP_SR_FAILED: | |
366 | case ICMP_PORT_UNREACH: | |
367 | /* Impossible event. */ | |
368 | return; | |
369 | case ICMP_FRAG_NEEDED: | |
370 | /* And it is the only really necessary thing :-) */ | |
371 | rel_info = ntohs(skb->h.icmph->un.frag.mtu); | |
372 | if (rel_info < hlen+68) | |
373 | return; | |
374 | rel_info -= hlen; | |
375 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ | |
376 | if (rel_info > ntohs(eiph->tot_len)) | |
377 | return; | |
378 | break; | |
379 | default: | |
380 | /* All others are translated to HOST_UNREACH. | |
381 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
382 | I believe, it is just ether pollution. --ANK | |
383 | */ | |
384 | rel_type = ICMP_DEST_UNREACH; | |
385 | rel_code = ICMP_HOST_UNREACH; | |
386 | break; | |
387 | } | |
388 | break; | |
389 | case ICMP_TIME_EXCEEDED: | |
390 | if (code != ICMP_EXC_TTL) | |
391 | return; | |
392 | break; | |
393 | } | |
394 | ||
395 | /* Prepare fake skb to feed it to icmp_send */ | |
396 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
397 | if (skb2 == NULL) | |
398 | return; | |
399 | dst_release(skb2->dst); | |
400 | skb2->dst = NULL; | |
401 | skb_pull(skb2, skb->data - (u8*)eiph); | |
402 | skb2->nh.raw = skb2->data; | |
403 | ||
404 | /* Try to guess incoming interface */ | |
405 | memset(&fl, 0, sizeof(fl)); | |
406 | fl.fl4_daddr = eiph->saddr; | |
407 | fl.fl4_tos = RT_TOS(eiph->tos); | |
408 | fl.proto = IPPROTO_IPIP; | |
409 | if (ip_route_output_key(&rt, &key)) { | |
410 | kfree_skb(skb2); | |
411 | return; | |
412 | } | |
413 | skb2->dev = rt->u.dst.dev; | |
414 | ||
415 | /* route "incoming" packet */ | |
416 | if (rt->rt_flags&RTCF_LOCAL) { | |
417 | ip_rt_put(rt); | |
418 | rt = NULL; | |
419 | fl.fl4_daddr = eiph->daddr; | |
420 | fl.fl4_src = eiph->saddr; | |
421 | fl.fl4_tos = eiph->tos; | |
422 | if (ip_route_output_key(&rt, &fl) || | |
423 | rt->u.dst.dev->type != ARPHRD_TUNNEL) { | |
424 | ip_rt_put(rt); | |
425 | kfree_skb(skb2); | |
426 | return; | |
427 | } | |
428 | } else { | |
429 | ip_rt_put(rt); | |
430 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || | |
431 | skb2->dst->dev->type != ARPHRD_TUNNEL) { | |
432 | kfree_skb(skb2); | |
433 | return; | |
434 | } | |
435 | } | |
436 | ||
437 | /* change mtu on this route */ | |
438 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
439 | if (rel_info > dst_mtu(skb2->dst)) { | |
440 | kfree_skb(skb2); | |
441 | return; | |
442 | } | |
443 | skb2->dst->ops->update_pmtu(skb2->dst, rel_info); | |
444 | rel_info = htonl(rel_info); | |
445 | } else if (type == ICMP_TIME_EXCEEDED) { | |
446 | struct ip_tunnel *t = (struct ip_tunnel*)skb2->dev->priv; | |
447 | if (t->parms.iph.ttl) { | |
448 | rel_type = ICMP_DEST_UNREACH; | |
449 | rel_code = ICMP_HOST_UNREACH; | |
450 | } | |
451 | } | |
452 | ||
453 | icmp_send(skb2, rel_type, rel_code, rel_info); | |
454 | kfree_skb(skb2); | |
455 | return; | |
456 | #endif | |
457 | } | |
458 | ||
459 | static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb) | |
460 | { | |
461 | struct iphdr *inner_iph = skb->nh.iph; | |
462 | ||
463 | if (INET_ECN_is_ce(outer_iph->tos)) | |
464 | IP_ECN_set_ce(inner_iph); | |
465 | } | |
466 | ||
467 | static int ipip_rcv(struct sk_buff *skb) | |
468 | { | |
469 | struct iphdr *iph; | |
470 | struct ip_tunnel *tunnel; | |
471 | ||
472 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
473 | goto out; | |
474 | ||
475 | iph = skb->nh.iph; | |
476 | ||
477 | read_lock(&ipip_lock); | |
478 | if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { | |
479 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
480 | read_unlock(&ipip_lock); | |
481 | kfree_skb(skb); | |
482 | return 0; | |
483 | } | |
484 | ||
485 | secpath_reset(skb); | |
486 | ||
487 | skb->mac.raw = skb->nh.raw; | |
488 | skb->nh.raw = skb->data; | |
489 | memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); | |
490 | skb->protocol = htons(ETH_P_IP); | |
491 | skb->pkt_type = PACKET_HOST; | |
492 | ||
493 | tunnel->stat.rx_packets++; | |
494 | tunnel->stat.rx_bytes += skb->len; | |
495 | skb->dev = tunnel->dev; | |
496 | dst_release(skb->dst); | |
497 | skb->dst = NULL; | |
498 | nf_reset(skb); | |
499 | ipip_ecn_decapsulate(iph, skb); | |
500 | netif_rx(skb); | |
501 | read_unlock(&ipip_lock); | |
502 | return 0; | |
503 | } | |
504 | read_unlock(&ipip_lock); | |
505 | ||
506 | out: | |
507 | return -1; | |
508 | } | |
509 | ||
510 | /* | |
511 | * This function assumes it is being called from dev_queue_xmit() | |
512 | * and that skb is filled properly by that function. | |
513 | */ | |
514 | ||
515 | static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
516 | { | |
517 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; | |
518 | struct net_device_stats *stats = &tunnel->stat; | |
519 | struct iphdr *tiph = &tunnel->parms.iph; | |
520 | u8 tos = tunnel->parms.iph.tos; | |
521 | u16 df = tiph->frag_off; | |
522 | struct rtable *rt; /* Route to the other host */ | |
523 | struct net_device *tdev; /* Device to other host */ | |
524 | struct iphdr *old_iph = skb->nh.iph; | |
525 | struct iphdr *iph; /* Our new IP header */ | |
526 | int max_headroom; /* The extra header space needed */ | |
527 | u32 dst = tiph->daddr; | |
528 | int mtu; | |
529 | ||
530 | if (tunnel->recursion++) { | |
531 | tunnel->stat.collisions++; | |
532 | goto tx_error; | |
533 | } | |
534 | ||
535 | if (skb->protocol != htons(ETH_P_IP)) | |
536 | goto tx_error; | |
537 | ||
538 | if (tos&1) | |
539 | tos = old_iph->tos; | |
540 | ||
541 | if (!dst) { | |
542 | /* NBMA tunnel */ | |
543 | if ((rt = (struct rtable*)skb->dst) == NULL) { | |
544 | tunnel->stat.tx_fifo_errors++; | |
545 | goto tx_error; | |
546 | } | |
547 | if ((dst = rt->rt_gateway) == 0) | |
548 | goto tx_error_icmp; | |
549 | } | |
550 | ||
551 | { | |
552 | struct flowi fl = { .oif = tunnel->parms.link, | |
553 | .nl_u = { .ip4_u = | |
554 | { .daddr = dst, | |
555 | .saddr = tiph->saddr, | |
556 | .tos = RT_TOS(tos) } }, | |
557 | .proto = IPPROTO_IPIP }; | |
558 | if (ip_route_output_key(&rt, &fl)) { | |
559 | tunnel->stat.tx_carrier_errors++; | |
560 | goto tx_error_icmp; | |
561 | } | |
562 | } | |
563 | tdev = rt->u.dst.dev; | |
564 | ||
565 | if (tdev == dev) { | |
566 | ip_rt_put(rt); | |
567 | tunnel->stat.collisions++; | |
568 | goto tx_error; | |
569 | } | |
570 | ||
571 | if (tiph->frag_off) | |
572 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); | |
573 | else | |
574 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
575 | ||
576 | if (mtu < 68) { | |
577 | tunnel->stat.collisions++; | |
578 | ip_rt_put(rt); | |
579 | goto tx_error; | |
580 | } | |
581 | if (skb->dst) | |
582 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
583 | ||
584 | df |= (old_iph->frag_off&htons(IP_DF)); | |
585 | ||
586 | if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { | |
587 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
588 | ip_rt_put(rt); | |
589 | goto tx_error; | |
590 | } | |
591 | ||
592 | if (tunnel->err_count > 0) { | |
593 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
594 | tunnel->err_count--; | |
595 | dst_link_failure(skb); | |
596 | } else | |
597 | tunnel->err_count = 0; | |
598 | } | |
599 | ||
600 | /* | |
601 | * Okay, now see if we can stuff it in the buffer as-is. | |
602 | */ | |
603 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); | |
604 | ||
605 | if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { | |
606 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
607 | if (!new_skb) { | |
608 | ip_rt_put(rt); | |
609 | stats->tx_dropped++; | |
610 | dev_kfree_skb(skb); | |
611 | tunnel->recursion--; | |
612 | return 0; | |
613 | } | |
614 | if (skb->sk) | |
615 | skb_set_owner_w(new_skb, skb->sk); | |
616 | dev_kfree_skb(skb); | |
617 | skb = new_skb; | |
618 | old_iph = skb->nh.iph; | |
619 | } | |
620 | ||
621 | skb->h.raw = skb->nh.raw; | |
622 | skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); | |
623 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
624 | dst_release(skb->dst); | |
625 | skb->dst = &rt->u.dst; | |
626 | ||
627 | /* | |
628 | * Push down and install the IPIP header. | |
629 | */ | |
630 | ||
631 | iph = skb->nh.iph; | |
632 | iph->version = 4; | |
633 | iph->ihl = sizeof(struct iphdr)>>2; | |
634 | iph->frag_off = df; | |
635 | iph->protocol = IPPROTO_IPIP; | |
636 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); | |
637 | iph->daddr = rt->rt_dst; | |
638 | iph->saddr = rt->rt_src; | |
639 | ||
640 | if ((iph->ttl = tiph->ttl) == 0) | |
641 | iph->ttl = old_iph->ttl; | |
642 | ||
643 | nf_reset(skb); | |
644 | ||
645 | IPTUNNEL_XMIT(); | |
646 | tunnel->recursion--; | |
647 | return 0; | |
648 | ||
649 | tx_error_icmp: | |
650 | dst_link_failure(skb); | |
651 | tx_error: | |
652 | stats->tx_errors++; | |
653 | dev_kfree_skb(skb); | |
654 | tunnel->recursion--; | |
655 | return 0; | |
656 | } | |
657 | ||
658 | static int | |
659 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
660 | { | |
661 | int err = 0; | |
662 | struct ip_tunnel_parm p; | |
663 | struct ip_tunnel *t; | |
664 | ||
665 | switch (cmd) { | |
666 | case SIOCGETTUNNEL: | |
667 | t = NULL; | |
668 | if (dev == ipip_fb_tunnel_dev) { | |
669 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
670 | err = -EFAULT; | |
671 | break; | |
672 | } | |
673 | t = ipip_tunnel_locate(&p, 0); | |
674 | } | |
675 | if (t == NULL) | |
676 | t = (struct ip_tunnel*)dev->priv; | |
677 | memcpy(&p, &t->parms, sizeof(p)); | |
678 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
679 | err = -EFAULT; | |
680 | break; | |
681 | ||
682 | case SIOCADDTUNNEL: | |
683 | case SIOCCHGTUNNEL: | |
684 | err = -EPERM; | |
685 | if (!capable(CAP_NET_ADMIN)) | |
686 | goto done; | |
687 | ||
688 | err = -EFAULT; | |
689 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
690 | goto done; | |
691 | ||
692 | err = -EINVAL; | |
693 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || | |
694 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
695 | goto done; | |
696 | if (p.iph.ttl) | |
697 | p.iph.frag_off |= htons(IP_DF); | |
698 | ||
699 | t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
700 | ||
701 | if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
702 | if (t != NULL) { | |
703 | if (t->dev != dev) { | |
704 | err = -EEXIST; | |
705 | break; | |
706 | } | |
707 | } else { | |
708 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
709 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
710 | err = -EINVAL; | |
711 | break; | |
712 | } | |
713 | t = (struct ip_tunnel*)dev->priv; | |
714 | ipip_tunnel_unlink(t); | |
715 | t->parms.iph.saddr = p.iph.saddr; | |
716 | t->parms.iph.daddr = p.iph.daddr; | |
717 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
718 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
719 | ipip_tunnel_link(t); | |
720 | netdev_state_change(dev); | |
721 | } | |
722 | } | |
723 | ||
724 | if (t) { | |
725 | err = 0; | |
726 | if (cmd == SIOCCHGTUNNEL) { | |
727 | t->parms.iph.ttl = p.iph.ttl; | |
728 | t->parms.iph.tos = p.iph.tos; | |
729 | t->parms.iph.frag_off = p.iph.frag_off; | |
730 | } | |
731 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
732 | err = -EFAULT; | |
733 | } else | |
734 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
735 | break; | |
736 | ||
737 | case SIOCDELTUNNEL: | |
738 | err = -EPERM; | |
739 | if (!capable(CAP_NET_ADMIN)) | |
740 | goto done; | |
741 | ||
742 | if (dev == ipip_fb_tunnel_dev) { | |
743 | err = -EFAULT; | |
744 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
745 | goto done; | |
746 | err = -ENOENT; | |
747 | if ((t = ipip_tunnel_locate(&p, 0)) == NULL) | |
748 | goto done; | |
749 | err = -EPERM; | |
750 | if (t->dev == ipip_fb_tunnel_dev) | |
751 | goto done; | |
752 | dev = t->dev; | |
753 | } | |
754 | err = unregister_netdevice(dev); | |
755 | break; | |
756 | ||
757 | default: | |
758 | err = -EINVAL; | |
759 | } | |
760 | ||
761 | done: | |
762 | return err; | |
763 | } | |
764 | ||
765 | static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) | |
766 | { | |
767 | return &(((struct ip_tunnel*)dev->priv)->stat); | |
768 | } | |
769 | ||
770 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
771 | { | |
772 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
773 | return -EINVAL; | |
774 | dev->mtu = new_mtu; | |
775 | return 0; | |
776 | } | |
777 | ||
778 | static void ipip_tunnel_setup(struct net_device *dev) | |
779 | { | |
780 | SET_MODULE_OWNER(dev); | |
781 | dev->uninit = ipip_tunnel_uninit; | |
782 | dev->hard_start_xmit = ipip_tunnel_xmit; | |
783 | dev->get_stats = ipip_tunnel_get_stats; | |
784 | dev->do_ioctl = ipip_tunnel_ioctl; | |
785 | dev->change_mtu = ipip_tunnel_change_mtu; | |
786 | dev->destructor = free_netdev; | |
787 | ||
788 | dev->type = ARPHRD_TUNNEL; | |
789 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
790 | dev->mtu = 1500 - sizeof(struct iphdr); | |
791 | dev->flags = IFF_NOARP; | |
792 | dev->iflink = 0; | |
793 | dev->addr_len = 4; | |
794 | } | |
795 | ||
796 | static int ipip_tunnel_init(struct net_device *dev) | |
797 | { | |
798 | struct net_device *tdev = NULL; | |
799 | struct ip_tunnel *tunnel; | |
800 | struct iphdr *iph; | |
801 | ||
802 | tunnel = (struct ip_tunnel*)dev->priv; | |
803 | iph = &tunnel->parms.iph; | |
804 | ||
805 | tunnel->dev = dev; | |
806 | strcpy(tunnel->parms.name, dev->name); | |
807 | ||
808 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
809 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
810 | ||
811 | if (iph->daddr) { | |
812 | struct flowi fl = { .oif = tunnel->parms.link, | |
813 | .nl_u = { .ip4_u = | |
814 | { .daddr = iph->daddr, | |
815 | .saddr = iph->saddr, | |
816 | .tos = RT_TOS(iph->tos) } }, | |
817 | .proto = IPPROTO_IPIP }; | |
818 | struct rtable *rt; | |
819 | if (!ip_route_output_key(&rt, &fl)) { | |
820 | tdev = rt->u.dst.dev; | |
821 | ip_rt_put(rt); | |
822 | } | |
823 | dev->flags |= IFF_POINTOPOINT; | |
824 | } | |
825 | ||
826 | if (!tdev && tunnel->parms.link) | |
827 | tdev = __dev_get_by_index(tunnel->parms.link); | |
828 | ||
829 | if (tdev) { | |
830 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
831 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
832 | } | |
833 | dev->iflink = tunnel->parms.link; | |
834 | ||
835 | return 0; | |
836 | } | |
837 | ||
838 | static int __init ipip_fb_tunnel_init(struct net_device *dev) | |
839 | { | |
840 | struct ip_tunnel *tunnel = dev->priv; | |
841 | struct iphdr *iph = &tunnel->parms.iph; | |
842 | ||
843 | tunnel->dev = dev; | |
844 | strcpy(tunnel->parms.name, dev->name); | |
845 | ||
846 | iph->version = 4; | |
847 | iph->protocol = IPPROTO_IPIP; | |
848 | iph->ihl = 5; | |
849 | ||
850 | dev_hold(dev); | |
851 | tunnels_wc[0] = tunnel; | |
852 | return 0; | |
853 | } | |
854 | ||
855 | static struct xfrm_tunnel ipip_handler = { | |
856 | .handler = ipip_rcv, | |
857 | .err_handler = ipip_err, | |
858 | }; | |
859 | ||
860 | static char banner[] __initdata = | |
861 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; | |
862 | ||
863 | static int __init ipip_init(void) | |
864 | { | |
865 | int err; | |
866 | ||
867 | printk(banner); | |
868 | ||
869 | if (xfrm4_tunnel_register(&ipip_handler) < 0) { | |
870 | printk(KERN_INFO "ipip init: can't register tunnel\n"); | |
871 | return -EAGAIN; | |
872 | } | |
873 | ||
874 | ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), | |
875 | "tunl0", | |
876 | ipip_tunnel_setup); | |
877 | if (!ipip_fb_tunnel_dev) { | |
878 | err = -ENOMEM; | |
879 | goto err1; | |
880 | } | |
881 | ||
882 | ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; | |
883 | ||
884 | if ((err = register_netdev(ipip_fb_tunnel_dev))) | |
885 | goto err2; | |
886 | out: | |
887 | return err; | |
888 | err2: | |
889 | free_netdev(ipip_fb_tunnel_dev); | |
890 | err1: | |
891 | xfrm4_tunnel_deregister(&ipip_handler); | |
892 | goto out; | |
893 | } | |
894 | ||
895 | static void __exit ipip_fini(void) | |
896 | { | |
897 | if (xfrm4_tunnel_deregister(&ipip_handler) < 0) | |
898 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); | |
899 | ||
900 | unregister_netdev(ipip_fb_tunnel_dev); | |
901 | } | |
902 | ||
903 | module_init(ipip_init); | |
904 | module_exit(ipip_fini); | |
905 | MODULE_LICENSE("GPL"); |