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1da177e4 LT |
1 | /* |
2 | * Linux NET3: GRE over IP protocol decoder. | |
3 | * | |
4 | * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <linux/config.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <asm/uaccess.h> | |
19 | #include <linux/skbuff.h> | |
20 | #include <linux/netdevice.h> | |
21 | #include <linux/in.h> | |
22 | #include <linux/tcp.h> | |
23 | #include <linux/udp.h> | |
24 | #include <linux/if_arp.h> | |
25 | #include <linux/mroute.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/in6.h> | |
28 | #include <linux/inetdevice.h> | |
29 | #include <linux/igmp.h> | |
30 | #include <linux/netfilter_ipv4.h> | |
31 | ||
32 | #include <net/sock.h> | |
33 | #include <net/ip.h> | |
34 | #include <net/icmp.h> | |
35 | #include <net/protocol.h> | |
36 | #include <net/ipip.h> | |
37 | #include <net/arp.h> | |
38 | #include <net/checksum.h> | |
39 | #include <net/dsfield.h> | |
40 | #include <net/inet_ecn.h> | |
41 | #include <net/xfrm.h> | |
42 | ||
43 | #ifdef CONFIG_IPV6 | |
44 | #include <net/ipv6.h> | |
45 | #include <net/ip6_fib.h> | |
46 | #include <net/ip6_route.h> | |
47 | #endif | |
48 | ||
49 | /* | |
50 | Problems & solutions | |
51 | -------------------- | |
52 | ||
53 | 1. The most important issue is detecting local dead loops. | |
54 | They would cause complete host lockup in transmit, which | |
55 | would be "resolved" by stack overflow or, if queueing is enabled, | |
56 | with infinite looping in net_bh. | |
57 | ||
58 | We cannot track such dead loops during route installation, | |
59 | it is infeasible task. The most general solutions would be | |
60 | to keep skb->encapsulation counter (sort of local ttl), | |
61 | and silently drop packet when it expires. It is the best | |
62 | solution, but it supposes maintaing new variable in ALL | |
63 | skb, even if no tunneling is used. | |
64 | ||
65 | Current solution: t->recursion lock breaks dead loops. It looks | |
66 | like dev->tbusy flag, but I preferred new variable, because | |
67 | the semantics is different. One day, when hard_start_xmit | |
68 | will be multithreaded we will have to use skb->encapsulation. | |
69 | ||
70 | ||
71 | ||
72 | 2. Networking dead loops would not kill routers, but would really | |
73 | kill network. IP hop limit plays role of "t->recursion" in this case, | |
74 | if we copy it from packet being encapsulated to upper header. | |
75 | It is very good solution, but it introduces two problems: | |
76 | ||
77 | - Routing protocols, using packets with ttl=1 (OSPF, RIP2), | |
78 | do not work over tunnels. | |
79 | - traceroute does not work. I planned to relay ICMP from tunnel, | |
80 | so that this problem would be solved and traceroute output | |
81 | would even more informative. This idea appeared to be wrong: | |
82 | only Linux complies to rfc1812 now (yes, guys, Linux is the only | |
83 | true router now :-)), all routers (at least, in neighbourhood of mine) | |
84 | return only 8 bytes of payload. It is the end. | |
85 | ||
86 | Hence, if we want that OSPF worked or traceroute said something reasonable, | |
87 | we should search for another solution. | |
88 | ||
89 | One of them is to parse packet trying to detect inner encapsulation | |
90 | made by our node. It is difficult or even impossible, especially, | |
91 | taking into account fragmentation. TO be short, tt is not solution at all. | |
92 | ||
93 | Current solution: The solution was UNEXPECTEDLY SIMPLE. | |
94 | We force DF flag on tunnels with preconfigured hop limit, | |
95 | that is ALL. :-) Well, it does not remove the problem completely, | |
96 | but exponential growth of network traffic is changed to linear | |
97 | (branches, that exceed pmtu are pruned) and tunnel mtu | |
98 | fastly degrades to value <68, where looping stops. | |
99 | Yes, it is not good if there exists a router in the loop, | |
100 | which does not force DF, even when encapsulating packets have DF set. | |
101 | But it is not our problem! Nobody could accuse us, we made | |
102 | all that we could make. Even if it is your gated who injected | |
103 | fatal route to network, even if it were you who configured | |
104 | fatal static route: you are innocent. :-) | |
105 | ||
106 | ||
107 | ||
108 | 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain | |
109 | practically identical code. It would be good to glue them | |
110 | together, but it is not very evident, how to make them modular. | |
111 | sit is integral part of IPv6, ipip and gre are naturally modular. | |
112 | We could extract common parts (hash table, ioctl etc) | |
113 | to a separate module (ip_tunnel.c). | |
114 | ||
115 | Alexey Kuznetsov. | |
116 | */ | |
117 | ||
118 | static int ipgre_tunnel_init(struct net_device *dev); | |
119 | static void ipgre_tunnel_setup(struct net_device *dev); | |
120 | ||
121 | /* Fallback tunnel: no source, no destination, no key, no options */ | |
122 | ||
123 | static int ipgre_fb_tunnel_init(struct net_device *dev); | |
124 | ||
125 | static struct net_device *ipgre_fb_tunnel_dev; | |
126 | ||
127 | /* Tunnel hash table */ | |
128 | ||
129 | /* | |
130 | 4 hash tables: | |
131 | ||
132 | 3: (remote,local) | |
133 | 2: (remote,*) | |
134 | 1: (*,local) | |
135 | 0: (*,*) | |
136 | ||
137 | We require exact key match i.e. if a key is present in packet | |
138 | it will match only tunnel with the same key; if it is not present, | |
139 | it will match only keyless tunnel. | |
140 | ||
141 | All keysless packets, if not matched configured keyless tunnels | |
142 | will match fallback tunnel. | |
143 | */ | |
144 | ||
145 | #define HASH_SIZE 16 | |
146 | #define HASH(addr) ((addr^(addr>>4))&0xF) | |
147 | ||
148 | static struct ip_tunnel *tunnels[4][HASH_SIZE]; | |
149 | ||
150 | #define tunnels_r_l (tunnels[3]) | |
151 | #define tunnels_r (tunnels[2]) | |
152 | #define tunnels_l (tunnels[1]) | |
153 | #define tunnels_wc (tunnels[0]) | |
154 | ||
155 | static DEFINE_RWLOCK(ipgre_lock); | |
156 | ||
157 | /* Given src, dst and key, find appropriate for input tunnel. */ | |
158 | ||
159 | static struct ip_tunnel * ipgre_tunnel_lookup(u32 remote, u32 local, u32 key) | |
160 | { | |
161 | unsigned h0 = HASH(remote); | |
162 | unsigned h1 = HASH(key); | |
163 | struct ip_tunnel *t; | |
164 | ||
165 | for (t = tunnels_r_l[h0^h1]; t; t = t->next) { | |
166 | if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) { | |
167 | if (t->parms.i_key == key && (t->dev->flags&IFF_UP)) | |
168 | return t; | |
169 | } | |
170 | } | |
171 | for (t = tunnels_r[h0^h1]; t; t = t->next) { | |
172 | if (remote == t->parms.iph.daddr) { | |
173 | if (t->parms.i_key == key && (t->dev->flags&IFF_UP)) | |
174 | return t; | |
175 | } | |
176 | } | |
177 | for (t = tunnels_l[h1]; t; t = t->next) { | |
178 | if (local == t->parms.iph.saddr || | |
179 | (local == t->parms.iph.daddr && MULTICAST(local))) { | |
180 | if (t->parms.i_key == key && (t->dev->flags&IFF_UP)) | |
181 | return t; | |
182 | } | |
183 | } | |
184 | for (t = tunnels_wc[h1]; t; t = t->next) { | |
185 | if (t->parms.i_key == key && (t->dev->flags&IFF_UP)) | |
186 | return t; | |
187 | } | |
188 | ||
189 | if (ipgre_fb_tunnel_dev->flags&IFF_UP) | |
190 | return ipgre_fb_tunnel_dev->priv; | |
191 | return NULL; | |
192 | } | |
193 | ||
194 | static struct ip_tunnel **ipgre_bucket(struct ip_tunnel *t) | |
195 | { | |
196 | u32 remote = t->parms.iph.daddr; | |
197 | u32 local = t->parms.iph.saddr; | |
198 | u32 key = t->parms.i_key; | |
199 | unsigned h = HASH(key); | |
200 | int prio = 0; | |
201 | ||
202 | if (local) | |
203 | prio |= 1; | |
204 | if (remote && !MULTICAST(remote)) { | |
205 | prio |= 2; | |
206 | h ^= HASH(remote); | |
207 | } | |
208 | ||
209 | return &tunnels[prio][h]; | |
210 | } | |
211 | ||
212 | static void ipgre_tunnel_link(struct ip_tunnel *t) | |
213 | { | |
214 | struct ip_tunnel **tp = ipgre_bucket(t); | |
215 | ||
216 | t->next = *tp; | |
217 | write_lock_bh(&ipgre_lock); | |
218 | *tp = t; | |
219 | write_unlock_bh(&ipgre_lock); | |
220 | } | |
221 | ||
222 | static void ipgre_tunnel_unlink(struct ip_tunnel *t) | |
223 | { | |
224 | struct ip_tunnel **tp; | |
225 | ||
226 | for (tp = ipgre_bucket(t); *tp; tp = &(*tp)->next) { | |
227 | if (t == *tp) { | |
228 | write_lock_bh(&ipgre_lock); | |
229 | *tp = t->next; | |
230 | write_unlock_bh(&ipgre_lock); | |
231 | break; | |
232 | } | |
233 | } | |
234 | } | |
235 | ||
236 | static struct ip_tunnel * ipgre_tunnel_locate(struct ip_tunnel_parm *parms, int create) | |
237 | { | |
238 | u32 remote = parms->iph.daddr; | |
239 | u32 local = parms->iph.saddr; | |
240 | u32 key = parms->i_key; | |
241 | struct ip_tunnel *t, **tp, *nt; | |
242 | struct net_device *dev; | |
243 | unsigned h = HASH(key); | |
244 | int prio = 0; | |
245 | char name[IFNAMSIZ]; | |
246 | ||
247 | if (local) | |
248 | prio |= 1; | |
249 | if (remote && !MULTICAST(remote)) { | |
250 | prio |= 2; | |
251 | h ^= HASH(remote); | |
252 | } | |
253 | for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { | |
254 | if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) { | |
255 | if (key == t->parms.i_key) | |
256 | return t; | |
257 | } | |
258 | } | |
259 | if (!create) | |
260 | return NULL; | |
261 | ||
262 | if (parms->name[0]) | |
263 | strlcpy(name, parms->name, IFNAMSIZ); | |
264 | else { | |
265 | int i; | |
266 | for (i=1; i<100; i++) { | |
267 | sprintf(name, "gre%d", i); | |
268 | if (__dev_get_by_name(name) == NULL) | |
269 | break; | |
270 | } | |
271 | if (i==100) | |
272 | goto failed; | |
273 | } | |
274 | ||
275 | dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup); | |
276 | if (!dev) | |
277 | return NULL; | |
278 | ||
279 | dev->init = ipgre_tunnel_init; | |
280 | nt = dev->priv; | |
281 | nt->parms = *parms; | |
282 | ||
283 | if (register_netdevice(dev) < 0) { | |
284 | free_netdev(dev); | |
285 | goto failed; | |
286 | } | |
287 | ||
288 | nt = dev->priv; | |
289 | nt->parms = *parms; | |
290 | ||
291 | dev_hold(dev); | |
292 | ipgre_tunnel_link(nt); | |
1da177e4 LT |
293 | return nt; |
294 | ||
295 | failed: | |
296 | return NULL; | |
297 | } | |
298 | ||
299 | static void ipgre_tunnel_uninit(struct net_device *dev) | |
300 | { | |
301 | ipgre_tunnel_unlink((struct ip_tunnel*)dev->priv); | |
302 | dev_put(dev); | |
303 | } | |
304 | ||
305 | ||
306 | static void ipgre_err(struct sk_buff *skb, u32 info) | |
307 | { | |
308 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
309 | ||
310 | /* It is not :-( All the routers (except for Linux) return only | |
311 | 8 bytes of packet payload. It means, that precise relaying of | |
312 | ICMP in the real Internet is absolutely infeasible. | |
313 | ||
314 | Moreover, Cisco "wise men" put GRE key to the third word | |
315 | in GRE header. It makes impossible maintaining even soft state for keyed | |
316 | GRE tunnels with enabled checksum. Tell them "thank you". | |
317 | ||
318 | Well, I wonder, rfc1812 was written by Cisco employee, | |
319 | what the hell these idiots break standrads established | |
320 | by themself??? | |
321 | */ | |
322 | ||
323 | struct iphdr *iph = (struct iphdr*)skb->data; | |
324 | u16 *p = (u16*)(skb->data+(iph->ihl<<2)); | |
325 | int grehlen = (iph->ihl<<2) + 4; | |
326 | int type = skb->h.icmph->type; | |
327 | int code = skb->h.icmph->code; | |
328 | struct ip_tunnel *t; | |
329 | u16 flags; | |
330 | ||
331 | flags = p[0]; | |
332 | if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) { | |
333 | if (flags&(GRE_VERSION|GRE_ROUTING)) | |
334 | return; | |
335 | if (flags&GRE_KEY) { | |
336 | grehlen += 4; | |
337 | if (flags&GRE_CSUM) | |
338 | grehlen += 4; | |
339 | } | |
340 | } | |
341 | ||
342 | /* If only 8 bytes returned, keyed message will be dropped here */ | |
343 | if (skb_headlen(skb) < grehlen) | |
344 | return; | |
345 | ||
346 | switch (type) { | |
347 | default: | |
348 | case ICMP_PARAMETERPROB: | |
349 | return; | |
350 | ||
351 | case ICMP_DEST_UNREACH: | |
352 | switch (code) { | |
353 | case ICMP_SR_FAILED: | |
354 | case ICMP_PORT_UNREACH: | |
355 | /* Impossible event. */ | |
356 | return; | |
357 | case ICMP_FRAG_NEEDED: | |
358 | /* Soft state for pmtu is maintained by IP core. */ | |
359 | return; | |
360 | default: | |
361 | /* All others are translated to HOST_UNREACH. | |
362 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
363 | I believe they are just ether pollution. --ANK | |
364 | */ | |
365 | break; | |
366 | } | |
367 | break; | |
368 | case ICMP_TIME_EXCEEDED: | |
369 | if (code != ICMP_EXC_TTL) | |
370 | return; | |
371 | break; | |
372 | } | |
373 | ||
374 | read_lock(&ipgre_lock); | |
375 | t = ipgre_tunnel_lookup(iph->daddr, iph->saddr, (flags&GRE_KEY) ? *(((u32*)p) + (grehlen>>2) - 1) : 0); | |
376 | if (t == NULL || t->parms.iph.daddr == 0 || MULTICAST(t->parms.iph.daddr)) | |
377 | goto out; | |
378 | ||
379 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) | |
380 | goto out; | |
381 | ||
382 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
383 | t->err_count++; | |
384 | else | |
385 | t->err_count = 1; | |
386 | t->err_time = jiffies; | |
387 | out: | |
388 | read_unlock(&ipgre_lock); | |
389 | return; | |
390 | #else | |
391 | struct iphdr *iph = (struct iphdr*)dp; | |
392 | struct iphdr *eiph; | |
393 | u16 *p = (u16*)(dp+(iph->ihl<<2)); | |
394 | int type = skb->h.icmph->type; | |
395 | int code = skb->h.icmph->code; | |
396 | int rel_type = 0; | |
397 | int rel_code = 0; | |
398 | int rel_info = 0; | |
399 | u16 flags; | |
400 | int grehlen = (iph->ihl<<2) + 4; | |
401 | struct sk_buff *skb2; | |
402 | struct flowi fl; | |
403 | struct rtable *rt; | |
404 | ||
405 | if (p[1] != htons(ETH_P_IP)) | |
406 | return; | |
407 | ||
408 | flags = p[0]; | |
409 | if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) { | |
410 | if (flags&(GRE_VERSION|GRE_ROUTING)) | |
411 | return; | |
412 | if (flags&GRE_CSUM) | |
413 | grehlen += 4; | |
414 | if (flags&GRE_KEY) | |
415 | grehlen += 4; | |
416 | if (flags&GRE_SEQ) | |
417 | grehlen += 4; | |
418 | } | |
419 | if (len < grehlen + sizeof(struct iphdr)) | |
420 | return; | |
421 | eiph = (struct iphdr*)(dp + grehlen); | |
422 | ||
423 | switch (type) { | |
424 | default: | |
425 | return; | |
426 | case ICMP_PARAMETERPROB: | |
427 | if (skb->h.icmph->un.gateway < (iph->ihl<<2)) | |
428 | return; | |
429 | ||
430 | /* So... This guy found something strange INSIDE encapsulated | |
431 | packet. Well, he is fool, but what can we do ? | |
432 | */ | |
433 | rel_type = ICMP_PARAMETERPROB; | |
434 | rel_info = skb->h.icmph->un.gateway - grehlen; | |
435 | break; | |
436 | ||
437 | case ICMP_DEST_UNREACH: | |
438 | switch (code) { | |
439 | case ICMP_SR_FAILED: | |
440 | case ICMP_PORT_UNREACH: | |
441 | /* Impossible event. */ | |
442 | return; | |
443 | case ICMP_FRAG_NEEDED: | |
444 | /* And it is the only really necessary thing :-) */ | |
445 | rel_info = ntohs(skb->h.icmph->un.frag.mtu); | |
446 | if (rel_info < grehlen+68) | |
447 | return; | |
448 | rel_info -= grehlen; | |
449 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ | |
450 | if (rel_info > ntohs(eiph->tot_len)) | |
451 | return; | |
452 | break; | |
453 | default: | |
454 | /* All others are translated to HOST_UNREACH. | |
455 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
456 | I believe, it is just ether pollution. --ANK | |
457 | */ | |
458 | rel_type = ICMP_DEST_UNREACH; | |
459 | rel_code = ICMP_HOST_UNREACH; | |
460 | break; | |
461 | } | |
462 | break; | |
463 | case ICMP_TIME_EXCEEDED: | |
464 | if (code != ICMP_EXC_TTL) | |
465 | return; | |
466 | break; | |
467 | } | |
468 | ||
469 | /* Prepare fake skb to feed it to icmp_send */ | |
470 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
471 | if (skb2 == NULL) | |
472 | return; | |
473 | dst_release(skb2->dst); | |
474 | skb2->dst = NULL; | |
475 | skb_pull(skb2, skb->data - (u8*)eiph); | |
476 | skb2->nh.raw = skb2->data; | |
477 | ||
478 | /* Try to guess incoming interface */ | |
479 | memset(&fl, 0, sizeof(fl)); | |
480 | fl.fl4_dst = eiph->saddr; | |
481 | fl.fl4_tos = RT_TOS(eiph->tos); | |
482 | fl.proto = IPPROTO_GRE; | |
483 | if (ip_route_output_key(&rt, &fl)) { | |
484 | kfree_skb(skb2); | |
485 | return; | |
486 | } | |
487 | skb2->dev = rt->u.dst.dev; | |
488 | ||
489 | /* route "incoming" packet */ | |
490 | if (rt->rt_flags&RTCF_LOCAL) { | |
491 | ip_rt_put(rt); | |
492 | rt = NULL; | |
493 | fl.fl4_dst = eiph->daddr; | |
494 | fl.fl4_src = eiph->saddr; | |
495 | fl.fl4_tos = eiph->tos; | |
496 | if (ip_route_output_key(&rt, &fl) || | |
497 | rt->u.dst.dev->type != ARPHRD_IPGRE) { | |
498 | ip_rt_put(rt); | |
499 | kfree_skb(skb2); | |
500 | return; | |
501 | } | |
502 | } else { | |
503 | ip_rt_put(rt); | |
504 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || | |
505 | skb2->dst->dev->type != ARPHRD_IPGRE) { | |
506 | kfree_skb(skb2); | |
507 | return; | |
508 | } | |
509 | } | |
510 | ||
511 | /* change mtu on this route */ | |
512 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
513 | if (rel_info > dst_mtu(skb2->dst)) { | |
514 | kfree_skb(skb2); | |
515 | return; | |
516 | } | |
517 | skb2->dst->ops->update_pmtu(skb2->dst, rel_info); | |
518 | rel_info = htonl(rel_info); | |
519 | } else if (type == ICMP_TIME_EXCEEDED) { | |
520 | struct ip_tunnel *t = (struct ip_tunnel*)skb2->dev->priv; | |
521 | if (t->parms.iph.ttl) { | |
522 | rel_type = ICMP_DEST_UNREACH; | |
523 | rel_code = ICMP_HOST_UNREACH; | |
524 | } | |
525 | } | |
526 | ||
527 | icmp_send(skb2, rel_type, rel_code, rel_info); | |
528 | kfree_skb(skb2); | |
529 | #endif | |
530 | } | |
531 | ||
532 | static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) | |
533 | { | |
534 | if (INET_ECN_is_ce(iph->tos)) { | |
535 | if (skb->protocol == htons(ETH_P_IP)) { | |
536 | IP_ECN_set_ce(skb->nh.iph); | |
537 | } else if (skb->protocol == htons(ETH_P_IPV6)) { | |
538 | IP6_ECN_set_ce(skb->nh.ipv6h); | |
539 | } | |
540 | } | |
541 | } | |
542 | ||
543 | static inline u8 | |
544 | ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb) | |
545 | { | |
546 | u8 inner = 0; | |
547 | if (skb->protocol == htons(ETH_P_IP)) | |
548 | inner = old_iph->tos; | |
549 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
550 | inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph); | |
551 | return INET_ECN_encapsulate(tos, inner); | |
552 | } | |
553 | ||
554 | static int ipgre_rcv(struct sk_buff *skb) | |
555 | { | |
556 | struct iphdr *iph; | |
557 | u8 *h; | |
558 | u16 flags; | |
559 | u16 csum = 0; | |
560 | u32 key = 0; | |
561 | u32 seqno = 0; | |
562 | struct ip_tunnel *tunnel; | |
563 | int offset = 4; | |
564 | ||
565 | if (!pskb_may_pull(skb, 16)) | |
566 | goto drop_nolock; | |
567 | ||
568 | iph = skb->nh.iph; | |
569 | h = skb->data; | |
570 | flags = *(u16*)h; | |
571 | ||
572 | if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) { | |
573 | /* - Version must be 0. | |
574 | - We do not support routing headers. | |
575 | */ | |
576 | if (flags&(GRE_VERSION|GRE_ROUTING)) | |
577 | goto drop_nolock; | |
578 | ||
579 | if (flags&GRE_CSUM) { | |
580 | if (skb->ip_summed == CHECKSUM_HW) { | |
581 | csum = (u16)csum_fold(skb->csum); | |
582 | if (csum) | |
583 | skb->ip_summed = CHECKSUM_NONE; | |
584 | } | |
585 | if (skb->ip_summed == CHECKSUM_NONE) { | |
586 | skb->csum = skb_checksum(skb, 0, skb->len, 0); | |
587 | skb->ip_summed = CHECKSUM_HW; | |
588 | csum = (u16)csum_fold(skb->csum); | |
589 | } | |
590 | offset += 4; | |
591 | } | |
592 | if (flags&GRE_KEY) { | |
593 | key = *(u32*)(h + offset); | |
594 | offset += 4; | |
595 | } | |
596 | if (flags&GRE_SEQ) { | |
597 | seqno = ntohl(*(u32*)(h + offset)); | |
598 | offset += 4; | |
599 | } | |
600 | } | |
601 | ||
602 | read_lock(&ipgre_lock); | |
603 | if ((tunnel = ipgre_tunnel_lookup(iph->saddr, iph->daddr, key)) != NULL) { | |
604 | secpath_reset(skb); | |
605 | ||
606 | skb->protocol = *(u16*)(h + 2); | |
607 | /* WCCP version 1 and 2 protocol decoding. | |
608 | * - Change protocol to IP | |
609 | * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header | |
610 | */ | |
611 | if (flags == 0 && | |
612 | skb->protocol == __constant_htons(ETH_P_WCCP)) { | |
613 | skb->protocol = __constant_htons(ETH_P_IP); | |
614 | if ((*(h + offset) & 0xF0) != 0x40) | |
615 | offset += 4; | |
616 | } | |
617 | ||
618 | skb->mac.raw = skb->nh.raw; | |
619 | skb->nh.raw = __pskb_pull(skb, offset); | |
620 | skb_postpull_rcsum(skb, skb->mac.raw, offset); | |
621 | memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); | |
622 | skb->pkt_type = PACKET_HOST; | |
623 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
624 | if (MULTICAST(iph->daddr)) { | |
625 | /* Looped back packet, drop it! */ | |
626 | if (((struct rtable*)skb->dst)->fl.iif == 0) | |
627 | goto drop; | |
628 | tunnel->stat.multicast++; | |
629 | skb->pkt_type = PACKET_BROADCAST; | |
630 | } | |
631 | #endif | |
632 | ||
633 | if (((flags&GRE_CSUM) && csum) || | |
634 | (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) { | |
635 | tunnel->stat.rx_crc_errors++; | |
636 | tunnel->stat.rx_errors++; | |
637 | goto drop; | |
638 | } | |
639 | if (tunnel->parms.i_flags&GRE_SEQ) { | |
640 | if (!(flags&GRE_SEQ) || | |
641 | (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) { | |
642 | tunnel->stat.rx_fifo_errors++; | |
643 | tunnel->stat.rx_errors++; | |
644 | goto drop; | |
645 | } | |
646 | tunnel->i_seqno = seqno + 1; | |
647 | } | |
648 | tunnel->stat.rx_packets++; | |
649 | tunnel->stat.rx_bytes += skb->len; | |
650 | skb->dev = tunnel->dev; | |
651 | dst_release(skb->dst); | |
652 | skb->dst = NULL; | |
653 | nf_reset(skb); | |
654 | ipgre_ecn_decapsulate(iph, skb); | |
655 | netif_rx(skb); | |
656 | read_unlock(&ipgre_lock); | |
657 | return(0); | |
658 | } | |
659 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0); | |
660 | ||
661 | drop: | |
662 | read_unlock(&ipgre_lock); | |
663 | drop_nolock: | |
664 | kfree_skb(skb); | |
665 | return(0); | |
666 | } | |
667 | ||
668 | static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
669 | { | |
670 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; | |
671 | struct net_device_stats *stats = &tunnel->stat; | |
672 | struct iphdr *old_iph = skb->nh.iph; | |
673 | struct iphdr *tiph; | |
674 | u8 tos; | |
675 | u16 df; | |
676 | struct rtable *rt; /* Route to the other host */ | |
677 | struct net_device *tdev; /* Device to other host */ | |
678 | struct iphdr *iph; /* Our new IP header */ | |
679 | int max_headroom; /* The extra header space needed */ | |
680 | int gre_hlen; | |
681 | u32 dst; | |
682 | int mtu; | |
683 | ||
684 | if (tunnel->recursion++) { | |
685 | tunnel->stat.collisions++; | |
686 | goto tx_error; | |
687 | } | |
688 | ||
689 | if (dev->hard_header) { | |
690 | gre_hlen = 0; | |
691 | tiph = (struct iphdr*)skb->data; | |
692 | } else { | |
693 | gre_hlen = tunnel->hlen; | |
694 | tiph = &tunnel->parms.iph; | |
695 | } | |
696 | ||
697 | if ((dst = tiph->daddr) == 0) { | |
698 | /* NBMA tunnel */ | |
699 | ||
700 | if (skb->dst == NULL) { | |
701 | tunnel->stat.tx_fifo_errors++; | |
702 | goto tx_error; | |
703 | } | |
704 | ||
705 | if (skb->protocol == htons(ETH_P_IP)) { | |
706 | rt = (struct rtable*)skb->dst; | |
707 | if ((dst = rt->rt_gateway) == 0) | |
708 | goto tx_error_icmp; | |
709 | } | |
710 | #ifdef CONFIG_IPV6 | |
711 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
712 | struct in6_addr *addr6; | |
713 | int addr_type; | |
714 | struct neighbour *neigh = skb->dst->neighbour; | |
715 | ||
716 | if (neigh == NULL) | |
717 | goto tx_error; | |
718 | ||
719 | addr6 = (struct in6_addr*)&neigh->primary_key; | |
720 | addr_type = ipv6_addr_type(addr6); | |
721 | ||
722 | if (addr_type == IPV6_ADDR_ANY) { | |
723 | addr6 = &skb->nh.ipv6h->daddr; | |
724 | addr_type = ipv6_addr_type(addr6); | |
725 | } | |
726 | ||
727 | if ((addr_type & IPV6_ADDR_COMPATv4) == 0) | |
728 | goto tx_error_icmp; | |
729 | ||
730 | dst = addr6->s6_addr32[3]; | |
731 | } | |
732 | #endif | |
733 | else | |
734 | goto tx_error; | |
735 | } | |
736 | ||
737 | tos = tiph->tos; | |
738 | if (tos&1) { | |
739 | if (skb->protocol == htons(ETH_P_IP)) | |
740 | tos = old_iph->tos; | |
741 | tos &= ~1; | |
742 | } | |
743 | ||
744 | { | |
745 | struct flowi fl = { .oif = tunnel->parms.link, | |
746 | .nl_u = { .ip4_u = | |
747 | { .daddr = dst, | |
748 | .saddr = tiph->saddr, | |
749 | .tos = RT_TOS(tos) } }, | |
750 | .proto = IPPROTO_GRE }; | |
751 | if (ip_route_output_key(&rt, &fl)) { | |
752 | tunnel->stat.tx_carrier_errors++; | |
753 | goto tx_error; | |
754 | } | |
755 | } | |
756 | tdev = rt->u.dst.dev; | |
757 | ||
758 | if (tdev == dev) { | |
759 | ip_rt_put(rt); | |
760 | tunnel->stat.collisions++; | |
761 | goto tx_error; | |
762 | } | |
763 | ||
764 | df = tiph->frag_off; | |
765 | if (df) | |
766 | mtu = dst_mtu(&rt->u.dst) - tunnel->hlen; | |
767 | else | |
768 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
769 | ||
770 | if (skb->dst) | |
771 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
772 | ||
773 | if (skb->protocol == htons(ETH_P_IP)) { | |
774 | df |= (old_iph->frag_off&htons(IP_DF)); | |
775 | ||
776 | if ((old_iph->frag_off&htons(IP_DF)) && | |
777 | mtu < ntohs(old_iph->tot_len)) { | |
778 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
779 | ip_rt_put(rt); | |
780 | goto tx_error; | |
781 | } | |
782 | } | |
783 | #ifdef CONFIG_IPV6 | |
784 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
785 | struct rt6_info *rt6 = (struct rt6_info*)skb->dst; | |
786 | ||
787 | if (rt6 && mtu < dst_mtu(skb->dst) && mtu >= IPV6_MIN_MTU) { | |
788 | if ((tunnel->parms.iph.daddr && !MULTICAST(tunnel->parms.iph.daddr)) || | |
789 | rt6->rt6i_dst.plen == 128) { | |
790 | rt6->rt6i_flags |= RTF_MODIFIED; | |
791 | skb->dst->metrics[RTAX_MTU-1] = mtu; | |
792 | } | |
793 | } | |
794 | ||
795 | if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) { | |
796 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); | |
797 | ip_rt_put(rt); | |
798 | goto tx_error; | |
799 | } | |
800 | } | |
801 | #endif | |
802 | ||
803 | if (tunnel->err_count > 0) { | |
804 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
805 | tunnel->err_count--; | |
806 | ||
807 | dst_link_failure(skb); | |
808 | } else | |
809 | tunnel->err_count = 0; | |
810 | } | |
811 | ||
812 | max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen; | |
813 | ||
814 | if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { | |
815 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
816 | if (!new_skb) { | |
817 | ip_rt_put(rt); | |
818 | stats->tx_dropped++; | |
819 | dev_kfree_skb(skb); | |
820 | tunnel->recursion--; | |
821 | return 0; | |
822 | } | |
823 | if (skb->sk) | |
824 | skb_set_owner_w(new_skb, skb->sk); | |
825 | dev_kfree_skb(skb); | |
826 | skb = new_skb; | |
827 | old_iph = skb->nh.iph; | |
828 | } | |
829 | ||
830 | skb->h.raw = skb->nh.raw; | |
831 | skb->nh.raw = skb_push(skb, gre_hlen); | |
832 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
833 | dst_release(skb->dst); | |
834 | skb->dst = &rt->u.dst; | |
835 | ||
836 | /* | |
837 | * Push down and install the IPIP header. | |
838 | */ | |
839 | ||
840 | iph = skb->nh.iph; | |
841 | iph->version = 4; | |
842 | iph->ihl = sizeof(struct iphdr) >> 2; | |
843 | iph->frag_off = df; | |
844 | iph->protocol = IPPROTO_GRE; | |
845 | iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb); | |
846 | iph->daddr = rt->rt_dst; | |
847 | iph->saddr = rt->rt_src; | |
848 | ||
849 | if ((iph->ttl = tiph->ttl) == 0) { | |
850 | if (skb->protocol == htons(ETH_P_IP)) | |
851 | iph->ttl = old_iph->ttl; | |
852 | #ifdef CONFIG_IPV6 | |
853 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
854 | iph->ttl = ((struct ipv6hdr*)old_iph)->hop_limit; | |
855 | #endif | |
856 | else | |
857 | iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT); | |
858 | } | |
859 | ||
860 | ((u16*)(iph+1))[0] = tunnel->parms.o_flags; | |
861 | ((u16*)(iph+1))[1] = skb->protocol; | |
862 | ||
863 | if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) { | |
864 | u32 *ptr = (u32*)(((u8*)iph) + tunnel->hlen - 4); | |
865 | ||
866 | if (tunnel->parms.o_flags&GRE_SEQ) { | |
867 | ++tunnel->o_seqno; | |
868 | *ptr = htonl(tunnel->o_seqno); | |
869 | ptr--; | |
870 | } | |
871 | if (tunnel->parms.o_flags&GRE_KEY) { | |
872 | *ptr = tunnel->parms.o_key; | |
873 | ptr--; | |
874 | } | |
875 | if (tunnel->parms.o_flags&GRE_CSUM) { | |
876 | *ptr = 0; | |
877 | *(__u16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr)); | |
878 | } | |
879 | } | |
880 | ||
881 | nf_reset(skb); | |
882 | ||
883 | IPTUNNEL_XMIT(); | |
884 | tunnel->recursion--; | |
885 | return 0; | |
886 | ||
887 | tx_error_icmp: | |
888 | dst_link_failure(skb); | |
889 | ||
890 | tx_error: | |
891 | stats->tx_errors++; | |
892 | dev_kfree_skb(skb); | |
893 | tunnel->recursion--; | |
894 | return 0; | |
895 | } | |
896 | ||
897 | static int | |
898 | ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
899 | { | |
900 | int err = 0; | |
901 | struct ip_tunnel_parm p; | |
902 | struct ip_tunnel *t; | |
903 | ||
904 | switch (cmd) { | |
905 | case SIOCGETTUNNEL: | |
906 | t = NULL; | |
907 | if (dev == ipgre_fb_tunnel_dev) { | |
908 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
909 | err = -EFAULT; | |
910 | break; | |
911 | } | |
912 | t = ipgre_tunnel_locate(&p, 0); | |
913 | } | |
914 | if (t == NULL) | |
915 | t = (struct ip_tunnel*)dev->priv; | |
916 | memcpy(&p, &t->parms, sizeof(p)); | |
917 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
918 | err = -EFAULT; | |
919 | break; | |
920 | ||
921 | case SIOCADDTUNNEL: | |
922 | case SIOCCHGTUNNEL: | |
923 | err = -EPERM; | |
924 | if (!capable(CAP_NET_ADMIN)) | |
925 | goto done; | |
926 | ||
927 | err = -EFAULT; | |
928 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
929 | goto done; | |
930 | ||
931 | err = -EINVAL; | |
932 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || | |
933 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || | |
934 | ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) | |
935 | goto done; | |
936 | if (p.iph.ttl) | |
937 | p.iph.frag_off |= htons(IP_DF); | |
938 | ||
939 | if (!(p.i_flags&GRE_KEY)) | |
940 | p.i_key = 0; | |
941 | if (!(p.o_flags&GRE_KEY)) | |
942 | p.o_key = 0; | |
943 | ||
944 | t = ipgre_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
945 | ||
946 | if (dev != ipgre_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
947 | if (t != NULL) { | |
948 | if (t->dev != dev) { | |
949 | err = -EEXIST; | |
950 | break; | |
951 | } | |
952 | } else { | |
953 | unsigned nflags=0; | |
954 | ||
955 | t = (struct ip_tunnel*)dev->priv; | |
956 | ||
957 | if (MULTICAST(p.iph.daddr)) | |
958 | nflags = IFF_BROADCAST; | |
959 | else if (p.iph.daddr) | |
960 | nflags = IFF_POINTOPOINT; | |
961 | ||
962 | if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { | |
963 | err = -EINVAL; | |
964 | break; | |
965 | } | |
966 | ipgre_tunnel_unlink(t); | |
967 | t->parms.iph.saddr = p.iph.saddr; | |
968 | t->parms.iph.daddr = p.iph.daddr; | |
969 | t->parms.i_key = p.i_key; | |
970 | t->parms.o_key = p.o_key; | |
971 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
972 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
973 | ipgre_tunnel_link(t); | |
974 | netdev_state_change(dev); | |
975 | } | |
976 | } | |
977 | ||
978 | if (t) { | |
979 | err = 0; | |
980 | if (cmd == SIOCCHGTUNNEL) { | |
981 | t->parms.iph.ttl = p.iph.ttl; | |
982 | t->parms.iph.tos = p.iph.tos; | |
983 | t->parms.iph.frag_off = p.iph.frag_off; | |
984 | } | |
985 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
986 | err = -EFAULT; | |
987 | } else | |
988 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
989 | break; | |
990 | ||
991 | case SIOCDELTUNNEL: | |
992 | err = -EPERM; | |
993 | if (!capable(CAP_NET_ADMIN)) | |
994 | goto done; | |
995 | ||
996 | if (dev == ipgre_fb_tunnel_dev) { | |
997 | err = -EFAULT; | |
998 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
999 | goto done; | |
1000 | err = -ENOENT; | |
1001 | if ((t = ipgre_tunnel_locate(&p, 0)) == NULL) | |
1002 | goto done; | |
1003 | err = -EPERM; | |
1004 | if (t == ipgre_fb_tunnel_dev->priv) | |
1005 | goto done; | |
1006 | dev = t->dev; | |
1007 | } | |
1008 | err = unregister_netdevice(dev); | |
1009 | break; | |
1010 | ||
1011 | default: | |
1012 | err = -EINVAL; | |
1013 | } | |
1014 | ||
1015 | done: | |
1016 | return err; | |
1017 | } | |
1018 | ||
1019 | static struct net_device_stats *ipgre_tunnel_get_stats(struct net_device *dev) | |
1020 | { | |
1021 | return &(((struct ip_tunnel*)dev->priv)->stat); | |
1022 | } | |
1023 | ||
1024 | static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
1025 | { | |
1026 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; | |
1027 | if (new_mtu < 68 || new_mtu > 0xFFF8 - tunnel->hlen) | |
1028 | return -EINVAL; | |
1029 | dev->mtu = new_mtu; | |
1030 | return 0; | |
1031 | } | |
1032 | ||
1033 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
1034 | /* Nice toy. Unfortunately, useless in real life :-) | |
1035 | It allows to construct virtual multiprotocol broadcast "LAN" | |
1036 | over the Internet, provided multicast routing is tuned. | |
1037 | ||
1038 | ||
1039 | I have no idea was this bicycle invented before me, | |
1040 | so that I had to set ARPHRD_IPGRE to a random value. | |
1041 | I have an impression, that Cisco could make something similar, | |
1042 | but this feature is apparently missing in IOS<=11.2(8). | |
1043 | ||
1044 | I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks | |
1045 | with broadcast 224.66.66.66. If you have access to mbone, play with me :-) | |
1046 | ||
1047 | ping -t 255 224.66.66.66 | |
1048 | ||
1049 | If nobody answers, mbone does not work. | |
1050 | ||
1051 | ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 | |
1052 | ip addr add 10.66.66.<somewhat>/24 dev Universe | |
1053 | ifconfig Universe up | |
1054 | ifconfig Universe add fe80::<Your_real_addr>/10 | |
1055 | ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 | |
1056 | ftp 10.66.66.66 | |
1057 | ... | |
1058 | ftp fec0:6666:6666::193.233.7.65 | |
1059 | ... | |
1060 | ||
1061 | */ | |
1062 | ||
1063 | static int ipgre_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, | |
1064 | void *daddr, void *saddr, unsigned len) | |
1065 | { | |
1066 | struct ip_tunnel *t = (struct ip_tunnel*)dev->priv; | |
1067 | struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen); | |
1068 | u16 *p = (u16*)(iph+1); | |
1069 | ||
1070 | memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); | |
1071 | p[0] = t->parms.o_flags; | |
1072 | p[1] = htons(type); | |
1073 | ||
1074 | /* | |
1075 | * Set the source hardware address. | |
1076 | */ | |
1077 | ||
1078 | if (saddr) | |
1079 | memcpy(&iph->saddr, saddr, 4); | |
1080 | ||
1081 | if (daddr) { | |
1082 | memcpy(&iph->daddr, daddr, 4); | |
1083 | return t->hlen; | |
1084 | } | |
1085 | if (iph->daddr && !MULTICAST(iph->daddr)) | |
1086 | return t->hlen; | |
1087 | ||
1088 | return -t->hlen; | |
1089 | } | |
1090 | ||
1091 | static int ipgre_open(struct net_device *dev) | |
1092 | { | |
1093 | struct ip_tunnel *t = (struct ip_tunnel*)dev->priv; | |
1094 | ||
1095 | if (MULTICAST(t->parms.iph.daddr)) { | |
1096 | struct flowi fl = { .oif = t->parms.link, | |
1097 | .nl_u = { .ip4_u = | |
1098 | { .daddr = t->parms.iph.daddr, | |
1099 | .saddr = t->parms.iph.saddr, | |
1100 | .tos = RT_TOS(t->parms.iph.tos) } }, | |
1101 | .proto = IPPROTO_GRE }; | |
1102 | struct rtable *rt; | |
1103 | if (ip_route_output_key(&rt, &fl)) | |
1104 | return -EADDRNOTAVAIL; | |
1105 | dev = rt->u.dst.dev; | |
1106 | ip_rt_put(rt); | |
1107 | if (__in_dev_get(dev) == NULL) | |
1108 | return -EADDRNOTAVAIL; | |
1109 | t->mlink = dev->ifindex; | |
1110 | ip_mc_inc_group(__in_dev_get(dev), t->parms.iph.daddr); | |
1111 | } | |
1112 | return 0; | |
1113 | } | |
1114 | ||
1115 | static int ipgre_close(struct net_device *dev) | |
1116 | { | |
1117 | struct ip_tunnel *t = (struct ip_tunnel*)dev->priv; | |
1118 | if (MULTICAST(t->parms.iph.daddr) && t->mlink) { | |
1119 | struct in_device *in_dev = inetdev_by_index(t->mlink); | |
1120 | if (in_dev) { | |
1121 | ip_mc_dec_group(in_dev, t->parms.iph.daddr); | |
1122 | in_dev_put(in_dev); | |
1123 | } | |
1124 | } | |
1125 | return 0; | |
1126 | } | |
1127 | ||
1128 | #endif | |
1129 | ||
1130 | static void ipgre_tunnel_setup(struct net_device *dev) | |
1131 | { | |
1132 | SET_MODULE_OWNER(dev); | |
1133 | dev->uninit = ipgre_tunnel_uninit; | |
1134 | dev->destructor = free_netdev; | |
1135 | dev->hard_start_xmit = ipgre_tunnel_xmit; | |
1136 | dev->get_stats = ipgre_tunnel_get_stats; | |
1137 | dev->do_ioctl = ipgre_tunnel_ioctl; | |
1138 | dev->change_mtu = ipgre_tunnel_change_mtu; | |
1139 | ||
1140 | dev->type = ARPHRD_IPGRE; | |
1141 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr) + 4; | |
1142 | dev->mtu = 1500 - sizeof(struct iphdr) - 4; | |
1143 | dev->flags = IFF_NOARP; | |
1144 | dev->iflink = 0; | |
1145 | dev->addr_len = 4; | |
1146 | } | |
1147 | ||
1148 | static int ipgre_tunnel_init(struct net_device *dev) | |
1149 | { | |
1150 | struct net_device *tdev = NULL; | |
1151 | struct ip_tunnel *tunnel; | |
1152 | struct iphdr *iph; | |
1153 | int hlen = LL_MAX_HEADER; | |
1154 | int mtu = 1500; | |
1155 | int addend = sizeof(struct iphdr) + 4; | |
1156 | ||
1157 | tunnel = (struct ip_tunnel*)dev->priv; | |
1158 | iph = &tunnel->parms.iph; | |
1159 | ||
1160 | tunnel->dev = dev; | |
1161 | strcpy(tunnel->parms.name, dev->name); | |
1162 | ||
1163 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
1164 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
1165 | ||
1166 | /* Guess output device to choose reasonable mtu and hard_header_len */ | |
1167 | ||
1168 | if (iph->daddr) { | |
1169 | struct flowi fl = { .oif = tunnel->parms.link, | |
1170 | .nl_u = { .ip4_u = | |
1171 | { .daddr = iph->daddr, | |
1172 | .saddr = iph->saddr, | |
1173 | .tos = RT_TOS(iph->tos) } }, | |
1174 | .proto = IPPROTO_GRE }; | |
1175 | struct rtable *rt; | |
1176 | if (!ip_route_output_key(&rt, &fl)) { | |
1177 | tdev = rt->u.dst.dev; | |
1178 | ip_rt_put(rt); | |
1179 | } | |
1180 | ||
1181 | dev->flags |= IFF_POINTOPOINT; | |
1182 | ||
1183 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
1184 | if (MULTICAST(iph->daddr)) { | |
1185 | if (!iph->saddr) | |
1186 | return -EINVAL; | |
1187 | dev->flags = IFF_BROADCAST; | |
1188 | dev->hard_header = ipgre_header; | |
1189 | dev->open = ipgre_open; | |
1190 | dev->stop = ipgre_close; | |
1191 | } | |
1192 | #endif | |
1193 | } | |
1194 | ||
1195 | if (!tdev && tunnel->parms.link) | |
1196 | tdev = __dev_get_by_index(tunnel->parms.link); | |
1197 | ||
1198 | if (tdev) { | |
1199 | hlen = tdev->hard_header_len; | |
1200 | mtu = tdev->mtu; | |
1201 | } | |
1202 | dev->iflink = tunnel->parms.link; | |
1203 | ||
1204 | /* Precalculate GRE options length */ | |
1205 | if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) { | |
1206 | if (tunnel->parms.o_flags&GRE_CSUM) | |
1207 | addend += 4; | |
1208 | if (tunnel->parms.o_flags&GRE_KEY) | |
1209 | addend += 4; | |
1210 | if (tunnel->parms.o_flags&GRE_SEQ) | |
1211 | addend += 4; | |
1212 | } | |
1213 | dev->hard_header_len = hlen + addend; | |
1214 | dev->mtu = mtu - addend; | |
1215 | tunnel->hlen = addend; | |
1216 | return 0; | |
1217 | } | |
1218 | ||
1219 | int __init ipgre_fb_tunnel_init(struct net_device *dev) | |
1220 | { | |
1221 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; | |
1222 | struct iphdr *iph = &tunnel->parms.iph; | |
1223 | ||
1224 | tunnel->dev = dev; | |
1225 | strcpy(tunnel->parms.name, dev->name); | |
1226 | ||
1227 | iph->version = 4; | |
1228 | iph->protocol = IPPROTO_GRE; | |
1229 | iph->ihl = 5; | |
1230 | tunnel->hlen = sizeof(struct iphdr) + 4; | |
1231 | ||
1232 | dev_hold(dev); | |
1233 | tunnels_wc[0] = tunnel; | |
1234 | return 0; | |
1235 | } | |
1236 | ||
1237 | ||
1238 | static struct net_protocol ipgre_protocol = { | |
1239 | .handler = ipgre_rcv, | |
1240 | .err_handler = ipgre_err, | |
1241 | }; | |
1242 | ||
1243 | ||
1244 | /* | |
1245 | * And now the modules code and kernel interface. | |
1246 | */ | |
1247 | ||
1248 | static int __init ipgre_init(void) | |
1249 | { | |
1250 | int err; | |
1251 | ||
1252 | printk(KERN_INFO "GRE over IPv4 tunneling driver\n"); | |
1253 | ||
1254 | if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) { | |
1255 | printk(KERN_INFO "ipgre init: can't add protocol\n"); | |
1256 | return -EAGAIN; | |
1257 | } | |
1258 | ||
1259 | ipgre_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0", | |
1260 | ipgre_tunnel_setup); | |
1261 | if (!ipgre_fb_tunnel_dev) { | |
1262 | err = -ENOMEM; | |
1263 | goto err1; | |
1264 | } | |
1265 | ||
1266 | ipgre_fb_tunnel_dev->init = ipgre_fb_tunnel_init; | |
1267 | ||
1268 | if ((err = register_netdev(ipgre_fb_tunnel_dev))) | |
1269 | goto err2; | |
1270 | out: | |
1271 | return err; | |
1272 | err2: | |
1273 | free_netdev(ipgre_fb_tunnel_dev); | |
1274 | err1: | |
1275 | inet_del_protocol(&ipgre_protocol, IPPROTO_GRE); | |
1276 | goto out; | |
1277 | } | |
1278 | ||
db44575f AK |
1279 | static void __exit ipgre_destroy_tunnels(void) |
1280 | { | |
1281 | int prio; | |
1282 | ||
1283 | for (prio = 0; prio < 4; prio++) { | |
1284 | int h; | |
1285 | for (h = 0; h < HASH_SIZE; h++) { | |
1286 | struct ip_tunnel *t; | |
1287 | while ((t = tunnels[prio][h]) != NULL) | |
1288 | unregister_netdevice(t->dev); | |
1289 | } | |
1290 | } | |
1291 | } | |
1292 | ||
1293 | static void __exit ipgre_fini(void) | |
1da177e4 LT |
1294 | { |
1295 | if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) | |
1296 | printk(KERN_INFO "ipgre close: can't remove protocol\n"); | |
1297 | ||
db44575f AK |
1298 | rtnl_lock(); |
1299 | ipgre_destroy_tunnels(); | |
1300 | rtnl_unlock(); | |
1da177e4 LT |
1301 | } |
1302 | ||
1303 | module_init(ipgre_init); | |
1304 | module_exit(ipgre_fini); | |
1305 | MODULE_LICENSE("GPL"); |