Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
e905a9ed | 2 | * Linux NET3: GRE over IP protocol decoder. |
1da177e4 LT |
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 | ||
4fc268d2 | 13 | #include <linux/capability.h> |
1da177e4 LT |
14 | #include <linux/module.h> |
15 | #include <linux/types.h> | |
1da177e4 LT |
16 | #include <linux/kernel.h> |
17 | #include <asm/uaccess.h> | |
18 | #include <linux/skbuff.h> | |
19 | #include <linux/netdevice.h> | |
20 | #include <linux/in.h> | |
21 | #include <linux/tcp.h> | |
22 | #include <linux/udp.h> | |
23 | #include <linux/if_arp.h> | |
24 | #include <linux/mroute.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/in6.h> | |
27 | #include <linux/inetdevice.h> | |
28 | #include <linux/igmp.h> | |
29 | #include <linux/netfilter_ipv4.h> | |
46f25dff | 30 | #include <linux/if_ether.h> |
1da177e4 LT |
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 | ||
e905a9ed | 65 | Current solution: t->recursion lock breaks dead loops. It looks |
1da177e4 LT |
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 | |
d5a0a1e3 | 146 | #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) |
1da177e4 LT |
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 | ||
d5a0a1e3 | 159 | static struct ip_tunnel * ipgre_tunnel_lookup(__be32 remote, __be32 local, __be32 key) |
1da177e4 LT |
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) | |
2941a486 | 190 | return netdev_priv(ipgre_fb_tunnel_dev); |
1da177e4 LT |
191 | return NULL; |
192 | } | |
193 | ||
194 | static struct ip_tunnel **ipgre_bucket(struct ip_tunnel *t) | |
195 | { | |
d5a0a1e3 AV |
196 | __be32 remote = t->parms.iph.daddr; |
197 | __be32 local = t->parms.iph.saddr; | |
198 | __be32 key = t->parms.i_key; | |
1da177e4 LT |
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 | { | |
d5a0a1e3 AV |
238 | __be32 remote = parms->iph.daddr; |
239 | __be32 local = parms->iph.saddr; | |
240 | __be32 key = parms->i_key; | |
1da177e4 LT |
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; | |
2941a486 | 280 | nt = netdev_priv(dev); |
1da177e4 LT |
281 | nt->parms = *parms; |
282 | ||
283 | if (register_netdevice(dev) < 0) { | |
284 | free_netdev(dev); | |
285 | goto failed; | |
286 | } | |
287 | ||
1da177e4 LT |
288 | dev_hold(dev); |
289 | ipgre_tunnel_link(nt); | |
1da177e4 LT |
290 | return nt; |
291 | ||
292 | failed: | |
293 | return NULL; | |
294 | } | |
295 | ||
296 | static void ipgre_tunnel_uninit(struct net_device *dev) | |
297 | { | |
2941a486 | 298 | ipgre_tunnel_unlink(netdev_priv(dev)); |
1da177e4 LT |
299 | dev_put(dev); |
300 | } | |
301 | ||
302 | ||
303 | static void ipgre_err(struct sk_buff *skb, u32 info) | |
304 | { | |
305 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
306 | ||
307 | /* It is not :-( All the routers (except for Linux) return only | |
308 | 8 bytes of packet payload. It means, that precise relaying of | |
309 | ICMP in the real Internet is absolutely infeasible. | |
310 | ||
311 | Moreover, Cisco "wise men" put GRE key to the third word | |
312 | in GRE header. It makes impossible maintaining even soft state for keyed | |
313 | GRE tunnels with enabled checksum. Tell them "thank you". | |
314 | ||
315 | Well, I wonder, rfc1812 was written by Cisco employee, | |
316 | what the hell these idiots break standrads established | |
317 | by themself??? | |
318 | */ | |
319 | ||
320 | struct iphdr *iph = (struct iphdr*)skb->data; | |
d5a0a1e3 | 321 | __be16 *p = (__be16*)(skb->data+(iph->ihl<<2)); |
1da177e4 LT |
322 | int grehlen = (iph->ihl<<2) + 4; |
323 | int type = skb->h.icmph->type; | |
324 | int code = skb->h.icmph->code; | |
325 | struct ip_tunnel *t; | |
d5a0a1e3 | 326 | __be16 flags; |
1da177e4 LT |
327 | |
328 | flags = p[0]; | |
329 | if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) { | |
330 | if (flags&(GRE_VERSION|GRE_ROUTING)) | |
331 | return; | |
332 | if (flags&GRE_KEY) { | |
333 | grehlen += 4; | |
334 | if (flags&GRE_CSUM) | |
335 | grehlen += 4; | |
336 | } | |
337 | } | |
338 | ||
339 | /* If only 8 bytes returned, keyed message will be dropped here */ | |
340 | if (skb_headlen(skb) < grehlen) | |
341 | return; | |
342 | ||
343 | switch (type) { | |
344 | default: | |
345 | case ICMP_PARAMETERPROB: | |
346 | return; | |
347 | ||
348 | case ICMP_DEST_UNREACH: | |
349 | switch (code) { | |
350 | case ICMP_SR_FAILED: | |
351 | case ICMP_PORT_UNREACH: | |
352 | /* Impossible event. */ | |
353 | return; | |
354 | case ICMP_FRAG_NEEDED: | |
355 | /* Soft state for pmtu is maintained by IP core. */ | |
356 | return; | |
357 | default: | |
358 | /* All others are translated to HOST_UNREACH. | |
359 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
360 | I believe they are just ether pollution. --ANK | |
361 | */ | |
362 | break; | |
363 | } | |
364 | break; | |
365 | case ICMP_TIME_EXCEEDED: | |
366 | if (code != ICMP_EXC_TTL) | |
367 | return; | |
368 | break; | |
369 | } | |
370 | ||
371 | read_lock(&ipgre_lock); | |
d5a0a1e3 | 372 | t = ipgre_tunnel_lookup(iph->daddr, iph->saddr, (flags&GRE_KEY) ? *(((__be32*)p) + (grehlen>>2) - 1) : 0); |
1da177e4 LT |
373 | if (t == NULL || t->parms.iph.daddr == 0 || MULTICAST(t->parms.iph.daddr)) |
374 | goto out; | |
375 | ||
376 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) | |
377 | goto out; | |
378 | ||
379 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
380 | t->err_count++; | |
381 | else | |
382 | t->err_count = 1; | |
383 | t->err_time = jiffies; | |
384 | out: | |
385 | read_unlock(&ipgre_lock); | |
386 | return; | |
387 | #else | |
388 | struct iphdr *iph = (struct iphdr*)dp; | |
389 | struct iphdr *eiph; | |
d5a0a1e3 | 390 | __be16 *p = (__be16*)(dp+(iph->ihl<<2)); |
1da177e4 LT |
391 | int type = skb->h.icmph->type; |
392 | int code = skb->h.icmph->code; | |
393 | int rel_type = 0; | |
394 | int rel_code = 0; | |
c55e2f49 AV |
395 | __be32 rel_info = 0; |
396 | __u32 n = 0; | |
d5a0a1e3 | 397 | __be16 flags; |
1da177e4 LT |
398 | int grehlen = (iph->ihl<<2) + 4; |
399 | struct sk_buff *skb2; | |
400 | struct flowi fl; | |
401 | struct rtable *rt; | |
402 | ||
403 | if (p[1] != htons(ETH_P_IP)) | |
404 | return; | |
405 | ||
406 | flags = p[0]; | |
407 | if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) { | |
408 | if (flags&(GRE_VERSION|GRE_ROUTING)) | |
409 | return; | |
410 | if (flags&GRE_CSUM) | |
411 | grehlen += 4; | |
412 | if (flags&GRE_KEY) | |
413 | grehlen += 4; | |
414 | if (flags&GRE_SEQ) | |
415 | grehlen += 4; | |
416 | } | |
417 | if (len < grehlen + sizeof(struct iphdr)) | |
418 | return; | |
419 | eiph = (struct iphdr*)(dp + grehlen); | |
420 | ||
421 | switch (type) { | |
422 | default: | |
423 | return; | |
424 | case ICMP_PARAMETERPROB: | |
c55e2f49 AV |
425 | n = ntohl(skb->h.icmph->un.gateway) >> 24; |
426 | if (n < (iph->ihl<<2)) | |
1da177e4 LT |
427 | return; |
428 | ||
429 | /* So... This guy found something strange INSIDE encapsulated | |
430 | packet. Well, he is fool, but what can we do ? | |
431 | */ | |
432 | rel_type = ICMP_PARAMETERPROB; | |
c55e2f49 AV |
433 | n -= grehlen; |
434 | rel_info = htonl(n << 24); | |
1da177e4 LT |
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 :-) */ | |
c55e2f49 AV |
445 | n = ntohs(skb->h.icmph->un.frag.mtu); |
446 | if (n < grehlen+68) | |
1da177e4 | 447 | return; |
c55e2f49 | 448 | n -= grehlen; |
1da177e4 | 449 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ |
c55e2f49 | 450 | if (n > ntohs(eiph->tot_len)) |
1da177e4 | 451 | return; |
c55e2f49 | 452 | rel_info = htonl(n); |
1da177e4 LT |
453 | break; |
454 | default: | |
455 | /* All others are translated to HOST_UNREACH. | |
456 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
457 | I believe, it is just ether pollution. --ANK | |
458 | */ | |
459 | rel_type = ICMP_DEST_UNREACH; | |
460 | rel_code = ICMP_HOST_UNREACH; | |
461 | break; | |
462 | } | |
463 | break; | |
464 | case ICMP_TIME_EXCEEDED: | |
465 | if (code != ICMP_EXC_TTL) | |
466 | return; | |
467 | break; | |
468 | } | |
469 | ||
470 | /* Prepare fake skb to feed it to icmp_send */ | |
471 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
472 | if (skb2 == NULL) | |
473 | return; | |
474 | dst_release(skb2->dst); | |
475 | skb2->dst = NULL; | |
476 | skb_pull(skb2, skb->data - (u8*)eiph); | |
c1d2bbe1 | 477 | skb_reset_network_header(skb2); |
1da177e4 LT |
478 | |
479 | /* Try to guess incoming interface */ | |
480 | memset(&fl, 0, sizeof(fl)); | |
481 | fl.fl4_dst = eiph->saddr; | |
482 | fl.fl4_tos = RT_TOS(eiph->tos); | |
483 | fl.proto = IPPROTO_GRE; | |
484 | if (ip_route_output_key(&rt, &fl)) { | |
485 | kfree_skb(skb2); | |
486 | return; | |
487 | } | |
488 | skb2->dev = rt->u.dst.dev; | |
489 | ||
490 | /* route "incoming" packet */ | |
491 | if (rt->rt_flags&RTCF_LOCAL) { | |
492 | ip_rt_put(rt); | |
493 | rt = NULL; | |
494 | fl.fl4_dst = eiph->daddr; | |
495 | fl.fl4_src = eiph->saddr; | |
496 | fl.fl4_tos = eiph->tos; | |
497 | if (ip_route_output_key(&rt, &fl) || | |
498 | rt->u.dst.dev->type != ARPHRD_IPGRE) { | |
499 | ip_rt_put(rt); | |
500 | kfree_skb(skb2); | |
501 | return; | |
502 | } | |
503 | } else { | |
504 | ip_rt_put(rt); | |
505 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || | |
506 | skb2->dst->dev->type != ARPHRD_IPGRE) { | |
507 | kfree_skb(skb2); | |
508 | return; | |
509 | } | |
510 | } | |
511 | ||
512 | /* change mtu on this route */ | |
513 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
c55e2f49 | 514 | if (n > dst_mtu(skb2->dst)) { |
1da177e4 LT |
515 | kfree_skb(skb2); |
516 | return; | |
517 | } | |
c55e2f49 | 518 | skb2->dst->ops->update_pmtu(skb2->dst, n); |
1da177e4 | 519 | } else if (type == ICMP_TIME_EXCEEDED) { |
2941a486 | 520 | struct ip_tunnel *t = netdev_priv(skb2->dev); |
1da177e4 LT |
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)) { | |
eddc9ec5 | 536 | IP_ECN_set_ce(ip_hdr(skb)); |
1da177e4 | 537 | } else if (skb->protocol == htons(ETH_P_IPV6)) { |
0660e03f | 538 | IP6_ECN_set_ce(ipv6_hdr(skb)); |
1da177e4 LT |
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; | |
d5a0a1e3 | 558 | __be16 flags; |
d3bc23e7 | 559 | __sum16 csum = 0; |
d5a0a1e3 | 560 | __be32 key = 0; |
1da177e4 LT |
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 | ||
eddc9ec5 | 568 | iph = ip_hdr(skb); |
1da177e4 | 569 | h = skb->data; |
d5a0a1e3 | 570 | flags = *(__be16*)h; |
1da177e4 LT |
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) { | |
fb286bb2 | 580 | switch (skb->ip_summed) { |
84fa7933 | 581 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 582 | csum = csum_fold(skb->csum); |
fb286bb2 HX |
583 | if (!csum) |
584 | break; | |
585 | /* fall through */ | |
586 | case CHECKSUM_NONE: | |
587 | skb->csum = 0; | |
588 | csum = __skb_checksum_complete(skb); | |
84fa7933 | 589 | skb->ip_summed = CHECKSUM_COMPLETE; |
1da177e4 LT |
590 | } |
591 | offset += 4; | |
592 | } | |
593 | if (flags&GRE_KEY) { | |
d5a0a1e3 | 594 | key = *(__be32*)(h + offset); |
1da177e4 LT |
595 | offset += 4; |
596 | } | |
597 | if (flags&GRE_SEQ) { | |
d5a0a1e3 | 598 | seqno = ntohl(*(__be32*)(h + offset)); |
1da177e4 LT |
599 | offset += 4; |
600 | } | |
601 | } | |
602 | ||
603 | read_lock(&ipgre_lock); | |
604 | if ((tunnel = ipgre_tunnel_lookup(iph->saddr, iph->daddr, key)) != NULL) { | |
605 | secpath_reset(skb); | |
606 | ||
d5a0a1e3 | 607 | skb->protocol = *(__be16*)(h + 2); |
1da177e4 LT |
608 | /* WCCP version 1 and 2 protocol decoding. |
609 | * - Change protocol to IP | |
610 | * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header | |
611 | */ | |
612 | if (flags == 0 && | |
496c98df YH |
613 | skb->protocol == htons(ETH_P_WCCP)) { |
614 | skb->protocol = htons(ETH_P_IP); | |
e905a9ed | 615 | if ((*(h + offset) & 0xF0) != 0x40) |
1da177e4 LT |
616 | offset += 4; |
617 | } | |
618 | ||
459a98ed | 619 | skb_reset_mac_header(skb); |
4209fb60 ACM |
620 | __pskb_pull(skb, offset); |
621 | skb_reset_network_header(skb); | |
1542272a | 622 | skb_postpull_rcsum(skb, skb->h.raw, offset); |
1da177e4 LT |
623 | skb->pkt_type = PACKET_HOST; |
624 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
625 | if (MULTICAST(iph->daddr)) { | |
626 | /* Looped back packet, drop it! */ | |
627 | if (((struct rtable*)skb->dst)->fl.iif == 0) | |
628 | goto drop; | |
629 | tunnel->stat.multicast++; | |
630 | skb->pkt_type = PACKET_BROADCAST; | |
631 | } | |
632 | #endif | |
633 | ||
634 | if (((flags&GRE_CSUM) && csum) || | |
635 | (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) { | |
636 | tunnel->stat.rx_crc_errors++; | |
637 | tunnel->stat.rx_errors++; | |
638 | goto drop; | |
639 | } | |
640 | if (tunnel->parms.i_flags&GRE_SEQ) { | |
641 | if (!(flags&GRE_SEQ) || | |
642 | (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) { | |
643 | tunnel->stat.rx_fifo_errors++; | |
644 | tunnel->stat.rx_errors++; | |
645 | goto drop; | |
646 | } | |
647 | tunnel->i_seqno = seqno + 1; | |
648 | } | |
649 | tunnel->stat.rx_packets++; | |
650 | tunnel->stat.rx_bytes += skb->len; | |
651 | skb->dev = tunnel->dev; | |
652 | dst_release(skb->dst); | |
653 | skb->dst = NULL; | |
654 | nf_reset(skb); | |
655 | ipgre_ecn_decapsulate(iph, skb); | |
656 | netif_rx(skb); | |
657 | read_unlock(&ipgre_lock); | |
658 | return(0); | |
659 | } | |
45af08be | 660 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); |
1da177e4 LT |
661 | |
662 | drop: | |
663 | read_unlock(&ipgre_lock); | |
664 | drop_nolock: | |
665 | kfree_skb(skb); | |
666 | return(0); | |
667 | } | |
668 | ||
669 | static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
670 | { | |
2941a486 | 671 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 | 672 | struct net_device_stats *stats = &tunnel->stat; |
eddc9ec5 | 673 | struct iphdr *old_iph = ip_hdr(skb); |
1da177e4 LT |
674 | struct iphdr *tiph; |
675 | u8 tos; | |
d5a0a1e3 | 676 | __be16 df; |
1da177e4 LT |
677 | struct rtable *rt; /* Route to the other host */ |
678 | struct net_device *tdev; /* Device to other host */ | |
679 | struct iphdr *iph; /* Our new IP header */ | |
680 | int max_headroom; /* The extra header space needed */ | |
681 | int gre_hlen; | |
d5a0a1e3 | 682 | __be32 dst; |
1da177e4 LT |
683 | int mtu; |
684 | ||
685 | if (tunnel->recursion++) { | |
686 | tunnel->stat.collisions++; | |
687 | goto tx_error; | |
688 | } | |
689 | ||
690 | if (dev->hard_header) { | |
691 | gre_hlen = 0; | |
692 | tiph = (struct iphdr*)skb->data; | |
693 | } else { | |
694 | gre_hlen = tunnel->hlen; | |
695 | tiph = &tunnel->parms.iph; | |
696 | } | |
697 | ||
698 | if ((dst = tiph->daddr) == 0) { | |
699 | /* NBMA tunnel */ | |
700 | ||
701 | if (skb->dst == NULL) { | |
702 | tunnel->stat.tx_fifo_errors++; | |
703 | goto tx_error; | |
704 | } | |
705 | ||
706 | if (skb->protocol == htons(ETH_P_IP)) { | |
707 | rt = (struct rtable*)skb->dst; | |
708 | if ((dst = rt->rt_gateway) == 0) | |
709 | goto tx_error_icmp; | |
710 | } | |
711 | #ifdef CONFIG_IPV6 | |
712 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
713 | struct in6_addr *addr6; | |
714 | int addr_type; | |
715 | struct neighbour *neigh = skb->dst->neighbour; | |
716 | ||
717 | if (neigh == NULL) | |
718 | goto tx_error; | |
719 | ||
720 | addr6 = (struct in6_addr*)&neigh->primary_key; | |
721 | addr_type = ipv6_addr_type(addr6); | |
722 | ||
723 | if (addr_type == IPV6_ADDR_ANY) { | |
0660e03f | 724 | addr6 = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
725 | addr_type = ipv6_addr_type(addr6); |
726 | } | |
727 | ||
728 | if ((addr_type & IPV6_ADDR_COMPATv4) == 0) | |
729 | goto tx_error_icmp; | |
730 | ||
731 | dst = addr6->s6_addr32[3]; | |
732 | } | |
733 | #endif | |
734 | else | |
735 | goto tx_error; | |
736 | } | |
737 | ||
738 | tos = tiph->tos; | |
739 | if (tos&1) { | |
740 | if (skb->protocol == htons(ETH_P_IP)) | |
741 | tos = old_iph->tos; | |
742 | tos &= ~1; | |
743 | } | |
744 | ||
745 | { | |
746 | struct flowi fl = { .oif = tunnel->parms.link, | |
747 | .nl_u = { .ip4_u = | |
748 | { .daddr = dst, | |
749 | .saddr = tiph->saddr, | |
750 | .tos = RT_TOS(tos) } }, | |
751 | .proto = IPPROTO_GRE }; | |
752 | if (ip_route_output_key(&rt, &fl)) { | |
753 | tunnel->stat.tx_carrier_errors++; | |
754 | goto tx_error; | |
755 | } | |
756 | } | |
757 | tdev = rt->u.dst.dev; | |
758 | ||
759 | if (tdev == dev) { | |
760 | ip_rt_put(rt); | |
761 | tunnel->stat.collisions++; | |
762 | goto tx_error; | |
763 | } | |
764 | ||
765 | df = tiph->frag_off; | |
766 | if (df) | |
767 | mtu = dst_mtu(&rt->u.dst) - tunnel->hlen; | |
768 | else | |
769 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
770 | ||
771 | if (skb->dst) | |
772 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
773 | ||
774 | if (skb->protocol == htons(ETH_P_IP)) { | |
775 | df |= (old_iph->frag_off&htons(IP_DF)); | |
776 | ||
777 | if ((old_iph->frag_off&htons(IP_DF)) && | |
778 | mtu < ntohs(old_iph->tot_len)) { | |
779 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
780 | ip_rt_put(rt); | |
781 | goto tx_error; | |
782 | } | |
783 | } | |
784 | #ifdef CONFIG_IPV6 | |
785 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
786 | struct rt6_info *rt6 = (struct rt6_info*)skb->dst; | |
787 | ||
788 | if (rt6 && mtu < dst_mtu(skb->dst) && mtu >= IPV6_MIN_MTU) { | |
789 | if ((tunnel->parms.iph.daddr && !MULTICAST(tunnel->parms.iph.daddr)) || | |
790 | rt6->rt6i_dst.plen == 128) { | |
791 | rt6->rt6i_flags |= RTF_MODIFIED; | |
792 | skb->dst->metrics[RTAX_MTU-1] = mtu; | |
793 | } | |
794 | } | |
795 | ||
796 | if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) { | |
797 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); | |
798 | ip_rt_put(rt); | |
799 | goto tx_error; | |
800 | } | |
801 | } | |
802 | #endif | |
803 | ||
804 | if (tunnel->err_count > 0) { | |
805 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
806 | tunnel->err_count--; | |
807 | ||
808 | dst_link_failure(skb); | |
809 | } else | |
810 | tunnel->err_count = 0; | |
811 | } | |
812 | ||
813 | max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen; | |
814 | ||
815 | if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { | |
816 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
817 | if (!new_skb) { | |
818 | ip_rt_put(rt); | |
e905a9ed | 819 | stats->tx_dropped++; |
1da177e4 LT |
820 | dev_kfree_skb(skb); |
821 | tunnel->recursion--; | |
822 | return 0; | |
823 | } | |
824 | if (skb->sk) | |
825 | skb_set_owner_w(new_skb, skb->sk); | |
826 | dev_kfree_skb(skb); | |
827 | skb = new_skb; | |
eddc9ec5 | 828 | old_iph = ip_hdr(skb); |
1da177e4 LT |
829 | } |
830 | ||
831 | skb->h.raw = skb->nh.raw; | |
e2d1bca7 ACM |
832 | skb_push(skb, gre_hlen); |
833 | skb_reset_network_header(skb); | |
1da177e4 | 834 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
48d5cad8 PM |
835 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
836 | IPSKB_REROUTED); | |
1da177e4 LT |
837 | dst_release(skb->dst); |
838 | skb->dst = &rt->u.dst; | |
839 | ||
840 | /* | |
841 | * Push down and install the IPIP header. | |
842 | */ | |
843 | ||
eddc9ec5 | 844 | iph = ip_hdr(skb); |
1da177e4 LT |
845 | iph->version = 4; |
846 | iph->ihl = sizeof(struct iphdr) >> 2; | |
847 | iph->frag_off = df; | |
848 | iph->protocol = IPPROTO_GRE; | |
849 | iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb); | |
850 | iph->daddr = rt->rt_dst; | |
851 | iph->saddr = rt->rt_src; | |
852 | ||
853 | if ((iph->ttl = tiph->ttl) == 0) { | |
854 | if (skb->protocol == htons(ETH_P_IP)) | |
855 | iph->ttl = old_iph->ttl; | |
856 | #ifdef CONFIG_IPV6 | |
857 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
858 | iph->ttl = ((struct ipv6hdr*)old_iph)->hop_limit; | |
859 | #endif | |
860 | else | |
861 | iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT); | |
862 | } | |
863 | ||
d5a0a1e3 AV |
864 | ((__be16*)(iph+1))[0] = tunnel->parms.o_flags; |
865 | ((__be16*)(iph+1))[1] = skb->protocol; | |
1da177e4 LT |
866 | |
867 | if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) { | |
d5a0a1e3 | 868 | __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4); |
1da177e4 LT |
869 | |
870 | if (tunnel->parms.o_flags&GRE_SEQ) { | |
871 | ++tunnel->o_seqno; | |
872 | *ptr = htonl(tunnel->o_seqno); | |
873 | ptr--; | |
874 | } | |
875 | if (tunnel->parms.o_flags&GRE_KEY) { | |
876 | *ptr = tunnel->parms.o_key; | |
877 | ptr--; | |
878 | } | |
879 | if (tunnel->parms.o_flags&GRE_CSUM) { | |
880 | *ptr = 0; | |
5f92a738 | 881 | *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr)); |
1da177e4 LT |
882 | } |
883 | } | |
884 | ||
885 | nf_reset(skb); | |
886 | ||
887 | IPTUNNEL_XMIT(); | |
888 | tunnel->recursion--; | |
889 | return 0; | |
890 | ||
891 | tx_error_icmp: | |
892 | dst_link_failure(skb); | |
893 | ||
894 | tx_error: | |
895 | stats->tx_errors++; | |
896 | dev_kfree_skb(skb); | |
897 | tunnel->recursion--; | |
898 | return 0; | |
899 | } | |
900 | ||
901 | static int | |
902 | ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
903 | { | |
904 | int err = 0; | |
905 | struct ip_tunnel_parm p; | |
906 | struct ip_tunnel *t; | |
907 | ||
908 | switch (cmd) { | |
909 | case SIOCGETTUNNEL: | |
910 | t = NULL; | |
911 | if (dev == ipgre_fb_tunnel_dev) { | |
912 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
913 | err = -EFAULT; | |
914 | break; | |
915 | } | |
916 | t = ipgre_tunnel_locate(&p, 0); | |
917 | } | |
918 | if (t == NULL) | |
2941a486 | 919 | t = netdev_priv(dev); |
1da177e4 LT |
920 | memcpy(&p, &t->parms, sizeof(p)); |
921 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
922 | err = -EFAULT; | |
923 | break; | |
924 | ||
925 | case SIOCADDTUNNEL: | |
926 | case SIOCCHGTUNNEL: | |
927 | err = -EPERM; | |
928 | if (!capable(CAP_NET_ADMIN)) | |
929 | goto done; | |
930 | ||
931 | err = -EFAULT; | |
932 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
933 | goto done; | |
934 | ||
935 | err = -EINVAL; | |
936 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || | |
937 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || | |
938 | ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) | |
939 | goto done; | |
940 | if (p.iph.ttl) | |
941 | p.iph.frag_off |= htons(IP_DF); | |
942 | ||
943 | if (!(p.i_flags&GRE_KEY)) | |
944 | p.i_key = 0; | |
945 | if (!(p.o_flags&GRE_KEY)) | |
946 | p.o_key = 0; | |
947 | ||
948 | t = ipgre_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
949 | ||
950 | if (dev != ipgre_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
951 | if (t != NULL) { | |
952 | if (t->dev != dev) { | |
953 | err = -EEXIST; | |
954 | break; | |
955 | } | |
956 | } else { | |
957 | unsigned nflags=0; | |
958 | ||
2941a486 | 959 | t = netdev_priv(dev); |
1da177e4 LT |
960 | |
961 | if (MULTICAST(p.iph.daddr)) | |
962 | nflags = IFF_BROADCAST; | |
963 | else if (p.iph.daddr) | |
964 | nflags = IFF_POINTOPOINT; | |
965 | ||
966 | if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { | |
967 | err = -EINVAL; | |
968 | break; | |
969 | } | |
970 | ipgre_tunnel_unlink(t); | |
971 | t->parms.iph.saddr = p.iph.saddr; | |
972 | t->parms.iph.daddr = p.iph.daddr; | |
973 | t->parms.i_key = p.i_key; | |
974 | t->parms.o_key = p.o_key; | |
975 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
976 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
977 | ipgre_tunnel_link(t); | |
978 | netdev_state_change(dev); | |
979 | } | |
980 | } | |
981 | ||
982 | if (t) { | |
983 | err = 0; | |
984 | if (cmd == SIOCCHGTUNNEL) { | |
985 | t->parms.iph.ttl = p.iph.ttl; | |
986 | t->parms.iph.tos = p.iph.tos; | |
987 | t->parms.iph.frag_off = p.iph.frag_off; | |
988 | } | |
989 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
990 | err = -EFAULT; | |
991 | } else | |
992 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
993 | break; | |
994 | ||
995 | case SIOCDELTUNNEL: | |
996 | err = -EPERM; | |
997 | if (!capable(CAP_NET_ADMIN)) | |
998 | goto done; | |
999 | ||
1000 | if (dev == ipgre_fb_tunnel_dev) { | |
1001 | err = -EFAULT; | |
1002 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
1003 | goto done; | |
1004 | err = -ENOENT; | |
1005 | if ((t = ipgre_tunnel_locate(&p, 0)) == NULL) | |
1006 | goto done; | |
1007 | err = -EPERM; | |
2941a486 | 1008 | if (t == netdev_priv(ipgre_fb_tunnel_dev)) |
1da177e4 LT |
1009 | goto done; |
1010 | dev = t->dev; | |
1011 | } | |
22f8cde5 SH |
1012 | unregister_netdevice(dev); |
1013 | err = 0; | |
1da177e4 LT |
1014 | break; |
1015 | ||
1016 | default: | |
1017 | err = -EINVAL; | |
1018 | } | |
1019 | ||
1020 | done: | |
1021 | return err; | |
1022 | } | |
1023 | ||
1024 | static struct net_device_stats *ipgre_tunnel_get_stats(struct net_device *dev) | |
1025 | { | |
2941a486 | 1026 | return &(((struct ip_tunnel*)netdev_priv(dev))->stat); |
1da177e4 LT |
1027 | } |
1028 | ||
1029 | static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
1030 | { | |
2941a486 | 1031 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
1032 | if (new_mtu < 68 || new_mtu > 0xFFF8 - tunnel->hlen) |
1033 | return -EINVAL; | |
1034 | dev->mtu = new_mtu; | |
1035 | return 0; | |
1036 | } | |
1037 | ||
1038 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
1039 | /* Nice toy. Unfortunately, useless in real life :-) | |
1040 | It allows to construct virtual multiprotocol broadcast "LAN" | |
1041 | over the Internet, provided multicast routing is tuned. | |
1042 | ||
1043 | ||
1044 | I have no idea was this bicycle invented before me, | |
1045 | so that I had to set ARPHRD_IPGRE to a random value. | |
1046 | I have an impression, that Cisco could make something similar, | |
1047 | but this feature is apparently missing in IOS<=11.2(8). | |
e905a9ed | 1048 | |
1da177e4 LT |
1049 | I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks |
1050 | with broadcast 224.66.66.66. If you have access to mbone, play with me :-) | |
1051 | ||
1052 | ping -t 255 224.66.66.66 | |
1053 | ||
1054 | If nobody answers, mbone does not work. | |
1055 | ||
1056 | ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 | |
1057 | ip addr add 10.66.66.<somewhat>/24 dev Universe | |
1058 | ifconfig Universe up | |
1059 | ifconfig Universe add fe80::<Your_real_addr>/10 | |
1060 | ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 | |
1061 | ftp 10.66.66.66 | |
1062 | ... | |
1063 | ftp fec0:6666:6666::193.233.7.65 | |
1064 | ... | |
1065 | ||
1066 | */ | |
1067 | ||
1068 | static int ipgre_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, | |
1069 | void *daddr, void *saddr, unsigned len) | |
1070 | { | |
2941a486 | 1071 | struct ip_tunnel *t = netdev_priv(dev); |
1da177e4 | 1072 | struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen); |
d5a0a1e3 | 1073 | __be16 *p = (__be16*)(iph+1); |
1da177e4 LT |
1074 | |
1075 | memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); | |
1076 | p[0] = t->parms.o_flags; | |
1077 | p[1] = htons(type); | |
1078 | ||
1079 | /* | |
e905a9ed | 1080 | * Set the source hardware address. |
1da177e4 | 1081 | */ |
e905a9ed | 1082 | |
1da177e4 LT |
1083 | if (saddr) |
1084 | memcpy(&iph->saddr, saddr, 4); | |
1085 | ||
1086 | if (daddr) { | |
1087 | memcpy(&iph->daddr, daddr, 4); | |
1088 | return t->hlen; | |
1089 | } | |
1090 | if (iph->daddr && !MULTICAST(iph->daddr)) | |
1091 | return t->hlen; | |
e905a9ed | 1092 | |
1da177e4 LT |
1093 | return -t->hlen; |
1094 | } | |
1095 | ||
1096 | static int ipgre_open(struct net_device *dev) | |
1097 | { | |
2941a486 | 1098 | struct ip_tunnel *t = netdev_priv(dev); |
1da177e4 LT |
1099 | |
1100 | if (MULTICAST(t->parms.iph.daddr)) { | |
1101 | struct flowi fl = { .oif = t->parms.link, | |
1102 | .nl_u = { .ip4_u = | |
1103 | { .daddr = t->parms.iph.daddr, | |
1104 | .saddr = t->parms.iph.saddr, | |
1105 | .tos = RT_TOS(t->parms.iph.tos) } }, | |
1106 | .proto = IPPROTO_GRE }; | |
1107 | struct rtable *rt; | |
1108 | if (ip_route_output_key(&rt, &fl)) | |
1109 | return -EADDRNOTAVAIL; | |
1110 | dev = rt->u.dst.dev; | |
1111 | ip_rt_put(rt); | |
e5ed6399 | 1112 | if (__in_dev_get_rtnl(dev) == NULL) |
1da177e4 LT |
1113 | return -EADDRNOTAVAIL; |
1114 | t->mlink = dev->ifindex; | |
e5ed6399 | 1115 | ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); |
1da177e4 LT |
1116 | } |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | static int ipgre_close(struct net_device *dev) | |
1121 | { | |
2941a486 | 1122 | struct ip_tunnel *t = netdev_priv(dev); |
1da177e4 LT |
1123 | if (MULTICAST(t->parms.iph.daddr) && t->mlink) { |
1124 | struct in_device *in_dev = inetdev_by_index(t->mlink); | |
1125 | if (in_dev) { | |
1126 | ip_mc_dec_group(in_dev, t->parms.iph.daddr); | |
1127 | in_dev_put(in_dev); | |
1128 | } | |
1129 | } | |
1130 | return 0; | |
1131 | } | |
1132 | ||
1133 | #endif | |
1134 | ||
1135 | static void ipgre_tunnel_setup(struct net_device *dev) | |
1136 | { | |
1137 | SET_MODULE_OWNER(dev); | |
1138 | dev->uninit = ipgre_tunnel_uninit; | |
1139 | dev->destructor = free_netdev; | |
1140 | dev->hard_start_xmit = ipgre_tunnel_xmit; | |
1141 | dev->get_stats = ipgre_tunnel_get_stats; | |
1142 | dev->do_ioctl = ipgre_tunnel_ioctl; | |
1143 | dev->change_mtu = ipgre_tunnel_change_mtu; | |
1144 | ||
1145 | dev->type = ARPHRD_IPGRE; | |
1146 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr) + 4; | |
46f25dff | 1147 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4; |
1da177e4 LT |
1148 | dev->flags = IFF_NOARP; |
1149 | dev->iflink = 0; | |
1150 | dev->addr_len = 4; | |
1151 | } | |
1152 | ||
1153 | static int ipgre_tunnel_init(struct net_device *dev) | |
1154 | { | |
1155 | struct net_device *tdev = NULL; | |
1156 | struct ip_tunnel *tunnel; | |
1157 | struct iphdr *iph; | |
1158 | int hlen = LL_MAX_HEADER; | |
46f25dff | 1159 | int mtu = ETH_DATA_LEN; |
1da177e4 LT |
1160 | int addend = sizeof(struct iphdr) + 4; |
1161 | ||
2941a486 | 1162 | tunnel = netdev_priv(dev); |
1da177e4 LT |
1163 | iph = &tunnel->parms.iph; |
1164 | ||
1165 | tunnel->dev = dev; | |
1166 | strcpy(tunnel->parms.name, dev->name); | |
1167 | ||
1168 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
1169 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
1170 | ||
1171 | /* Guess output device to choose reasonable mtu and hard_header_len */ | |
1172 | ||
1173 | if (iph->daddr) { | |
1174 | struct flowi fl = { .oif = tunnel->parms.link, | |
1175 | .nl_u = { .ip4_u = | |
1176 | { .daddr = iph->daddr, | |
1177 | .saddr = iph->saddr, | |
1178 | .tos = RT_TOS(iph->tos) } }, | |
1179 | .proto = IPPROTO_GRE }; | |
1180 | struct rtable *rt; | |
1181 | if (!ip_route_output_key(&rt, &fl)) { | |
1182 | tdev = rt->u.dst.dev; | |
1183 | ip_rt_put(rt); | |
1184 | } | |
1185 | ||
1186 | dev->flags |= IFF_POINTOPOINT; | |
1187 | ||
1188 | #ifdef CONFIG_NET_IPGRE_BROADCAST | |
1189 | if (MULTICAST(iph->daddr)) { | |
1190 | if (!iph->saddr) | |
1191 | return -EINVAL; | |
1192 | dev->flags = IFF_BROADCAST; | |
1193 | dev->hard_header = ipgre_header; | |
1194 | dev->open = ipgre_open; | |
1195 | dev->stop = ipgre_close; | |
1196 | } | |
1197 | #endif | |
1198 | } | |
1199 | ||
1200 | if (!tdev && tunnel->parms.link) | |
1201 | tdev = __dev_get_by_index(tunnel->parms.link); | |
1202 | ||
1203 | if (tdev) { | |
1204 | hlen = tdev->hard_header_len; | |
1205 | mtu = tdev->mtu; | |
1206 | } | |
1207 | dev->iflink = tunnel->parms.link; | |
1208 | ||
1209 | /* Precalculate GRE options length */ | |
1210 | if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) { | |
1211 | if (tunnel->parms.o_flags&GRE_CSUM) | |
1212 | addend += 4; | |
1213 | if (tunnel->parms.o_flags&GRE_KEY) | |
1214 | addend += 4; | |
1215 | if (tunnel->parms.o_flags&GRE_SEQ) | |
1216 | addend += 4; | |
1217 | } | |
1218 | dev->hard_header_len = hlen + addend; | |
1219 | dev->mtu = mtu - addend; | |
1220 | tunnel->hlen = addend; | |
1221 | return 0; | |
1222 | } | |
1223 | ||
4b30b1c6 | 1224 | static int __init ipgre_fb_tunnel_init(struct net_device *dev) |
1da177e4 | 1225 | { |
2941a486 | 1226 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
1227 | struct iphdr *iph = &tunnel->parms.iph; |
1228 | ||
1229 | tunnel->dev = dev; | |
1230 | strcpy(tunnel->parms.name, dev->name); | |
1231 | ||
1232 | iph->version = 4; | |
1233 | iph->protocol = IPPROTO_GRE; | |
1234 | iph->ihl = 5; | |
1235 | tunnel->hlen = sizeof(struct iphdr) + 4; | |
1236 | ||
1237 | dev_hold(dev); | |
1238 | tunnels_wc[0] = tunnel; | |
1239 | return 0; | |
1240 | } | |
1241 | ||
1242 | ||
1243 | static struct net_protocol ipgre_protocol = { | |
1244 | .handler = ipgre_rcv, | |
1245 | .err_handler = ipgre_err, | |
1246 | }; | |
1247 | ||
1248 | ||
1249 | /* | |
1250 | * And now the modules code and kernel interface. | |
1251 | */ | |
1252 | ||
1253 | static int __init ipgre_init(void) | |
1254 | { | |
1255 | int err; | |
1256 | ||
1257 | printk(KERN_INFO "GRE over IPv4 tunneling driver\n"); | |
1258 | ||
1259 | if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) { | |
1260 | printk(KERN_INFO "ipgre init: can't add protocol\n"); | |
1261 | return -EAGAIN; | |
1262 | } | |
1263 | ||
1264 | ipgre_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0", | |
1265 | ipgre_tunnel_setup); | |
1266 | if (!ipgre_fb_tunnel_dev) { | |
1267 | err = -ENOMEM; | |
1268 | goto err1; | |
1269 | } | |
1270 | ||
1271 | ipgre_fb_tunnel_dev->init = ipgre_fb_tunnel_init; | |
1272 | ||
1273 | if ((err = register_netdev(ipgre_fb_tunnel_dev))) | |
1274 | goto err2; | |
1275 | out: | |
1276 | return err; | |
1277 | err2: | |
1278 | free_netdev(ipgre_fb_tunnel_dev); | |
1279 | err1: | |
1280 | inet_del_protocol(&ipgre_protocol, IPPROTO_GRE); | |
1281 | goto out; | |
1282 | } | |
1283 | ||
db44575f AK |
1284 | static void __exit ipgre_destroy_tunnels(void) |
1285 | { | |
1286 | int prio; | |
1287 | ||
1288 | for (prio = 0; prio < 4; prio++) { | |
1289 | int h; | |
1290 | for (h = 0; h < HASH_SIZE; h++) { | |
1291 | struct ip_tunnel *t; | |
1292 | while ((t = tunnels[prio][h]) != NULL) | |
1293 | unregister_netdevice(t->dev); | |
1294 | } | |
1295 | } | |
1296 | } | |
1297 | ||
1298 | static void __exit ipgre_fini(void) | |
1da177e4 LT |
1299 | { |
1300 | if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) | |
1301 | printk(KERN_INFO "ipgre close: can't remove protocol\n"); | |
1302 | ||
db44575f AK |
1303 | rtnl_lock(); |
1304 | ipgre_destroy_tunnels(); | |
1305 | rtnl_unlock(); | |
1da177e4 LT |
1306 | } |
1307 | ||
1308 | module_init(ipgre_init); | |
1309 | module_exit(ipgre_fini); | |
1310 | MODULE_LICENSE("GPL"); |