Commit | Line | Data |
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1da177e4 | 1 | /* |
e905a9ed | 2 | * Linux NET3: IP/IP protocol decoder. |
1da177e4 LT |
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 | |
e905a9ed | 38 | |
1da177e4 LT |
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 | |
e905a9ed | 45 | |
1da177e4 LT |
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 | |
e905a9ed | 55 | |
1da177e4 LT |
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 | |
e905a9ed | 78 | find out how much more space you can allocate by calling |
1da177e4 LT |
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 | ||
e905a9ed | 95 | |
4fc268d2 | 96 | #include <linux/capability.h> |
1da177e4 LT |
97 | #include <linux/module.h> |
98 | #include <linux/types.h> | |
1da177e4 LT |
99 | #include <linux/kernel.h> |
100 | #include <asm/uaccess.h> | |
101 | #include <linux/skbuff.h> | |
102 | #include <linux/netdevice.h> | |
103 | #include <linux/in.h> | |
104 | #include <linux/tcp.h> | |
105 | #include <linux/udp.h> | |
106 | #include <linux/if_arp.h> | |
107 | #include <linux/mroute.h> | |
108 | #include <linux/init.h> | |
109 | #include <linux/netfilter_ipv4.h> | |
46f25dff | 110 | #include <linux/if_ether.h> |
1da177e4 LT |
111 | |
112 | #include <net/sock.h> | |
113 | #include <net/ip.h> | |
114 | #include <net/icmp.h> | |
1da177e4 LT |
115 | #include <net/ipip.h> |
116 | #include <net/inet_ecn.h> | |
117 | #include <net/xfrm.h> | |
118 | ||
119 | #define HASH_SIZE 16 | |
d5a0a1e3 | 120 | #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) |
1da177e4 LT |
121 | |
122 | static int ipip_fb_tunnel_init(struct net_device *dev); | |
123 | static int ipip_tunnel_init(struct net_device *dev); | |
124 | static void ipip_tunnel_setup(struct net_device *dev); | |
125 | ||
126 | static struct net_device *ipip_fb_tunnel_dev; | |
127 | ||
128 | static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; | |
129 | static struct ip_tunnel *tunnels_r[HASH_SIZE]; | |
130 | static struct ip_tunnel *tunnels_l[HASH_SIZE]; | |
131 | static struct ip_tunnel *tunnels_wc[1]; | |
132 | static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; | |
133 | ||
134 | static DEFINE_RWLOCK(ipip_lock); | |
135 | ||
d5a0a1e3 | 136 | static struct ip_tunnel * ipip_tunnel_lookup(__be32 remote, __be32 local) |
1da177e4 LT |
137 | { |
138 | unsigned h0 = HASH(remote); | |
139 | unsigned h1 = HASH(local); | |
140 | struct ip_tunnel *t; | |
141 | ||
142 | for (t = tunnels_r_l[h0^h1]; t; t = t->next) { | |
143 | if (local == t->parms.iph.saddr && | |
144 | remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) | |
145 | return t; | |
146 | } | |
147 | for (t = tunnels_r[h0]; t; t = t->next) { | |
148 | if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) | |
149 | return t; | |
150 | } | |
151 | for (t = tunnels_l[h1]; t; t = t->next) { | |
152 | if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) | |
153 | return t; | |
154 | } | |
155 | if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) | |
156 | return t; | |
157 | return NULL; | |
158 | } | |
159 | ||
87d1a164 | 160 | static struct ip_tunnel **__ipip_bucket(struct ip_tunnel_parm *parms) |
1da177e4 | 161 | { |
87d1a164 YH |
162 | __be32 remote = parms->iph.daddr; |
163 | __be32 local = parms->iph.saddr; | |
1da177e4 LT |
164 | unsigned h = 0; |
165 | int prio = 0; | |
166 | ||
167 | if (remote) { | |
168 | prio |= 2; | |
169 | h ^= HASH(remote); | |
170 | } | |
171 | if (local) { | |
172 | prio |= 1; | |
173 | h ^= HASH(local); | |
174 | } | |
175 | return &tunnels[prio][h]; | |
176 | } | |
177 | ||
87d1a164 YH |
178 | static inline struct ip_tunnel **ipip_bucket(struct ip_tunnel *t) |
179 | { | |
180 | return __ipip_bucket(&t->parms); | |
181 | } | |
1da177e4 LT |
182 | |
183 | static void ipip_tunnel_unlink(struct ip_tunnel *t) | |
184 | { | |
185 | struct ip_tunnel **tp; | |
186 | ||
187 | for (tp = ipip_bucket(t); *tp; tp = &(*tp)->next) { | |
188 | if (t == *tp) { | |
189 | write_lock_bh(&ipip_lock); | |
190 | *tp = t->next; | |
191 | write_unlock_bh(&ipip_lock); | |
192 | break; | |
193 | } | |
194 | } | |
195 | } | |
196 | ||
197 | static void ipip_tunnel_link(struct ip_tunnel *t) | |
198 | { | |
199 | struct ip_tunnel **tp = ipip_bucket(t); | |
200 | ||
201 | t->next = *tp; | |
202 | write_lock_bh(&ipip_lock); | |
203 | *tp = t; | |
204 | write_unlock_bh(&ipip_lock); | |
205 | } | |
206 | ||
207 | static struct ip_tunnel * ipip_tunnel_locate(struct ip_tunnel_parm *parms, int create) | |
208 | { | |
d5a0a1e3 AV |
209 | __be32 remote = parms->iph.daddr; |
210 | __be32 local = parms->iph.saddr; | |
1da177e4 LT |
211 | struct ip_tunnel *t, **tp, *nt; |
212 | struct net_device *dev; | |
1da177e4 LT |
213 | char name[IFNAMSIZ]; |
214 | ||
87d1a164 | 215 | for (tp = __ipip_bucket(parms); (t = *tp) != NULL; tp = &t->next) { |
1da177e4 LT |
216 | if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) |
217 | return t; | |
218 | } | |
219 | if (!create) | |
220 | return NULL; | |
221 | ||
222 | if (parms->name[0]) | |
223 | strlcpy(name, parms->name, IFNAMSIZ); | |
224 | else { | |
225 | int i; | |
226 | for (i=1; i<100; i++) { | |
227 | sprintf(name, "tunl%d", i); | |
228 | if (__dev_get_by_name(name) == NULL) | |
229 | break; | |
230 | } | |
231 | if (i==100) | |
232 | goto failed; | |
233 | } | |
234 | ||
235 | dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); | |
236 | if (dev == NULL) | |
237 | return NULL; | |
238 | ||
2941a486 | 239 | nt = netdev_priv(dev); |
1da177e4 LT |
240 | SET_MODULE_OWNER(dev); |
241 | dev->init = ipip_tunnel_init; | |
242 | nt->parms = *parms; | |
243 | ||
244 | if (register_netdevice(dev) < 0) { | |
245 | free_netdev(dev); | |
246 | goto failed; | |
247 | } | |
248 | ||
249 | dev_hold(dev); | |
250 | ipip_tunnel_link(nt); | |
1da177e4 LT |
251 | return nt; |
252 | ||
253 | failed: | |
254 | return NULL; | |
255 | } | |
256 | ||
257 | static void ipip_tunnel_uninit(struct net_device *dev) | |
258 | { | |
259 | if (dev == ipip_fb_tunnel_dev) { | |
260 | write_lock_bh(&ipip_lock); | |
261 | tunnels_wc[0] = NULL; | |
262 | write_unlock_bh(&ipip_lock); | |
263 | } else | |
2941a486 | 264 | ipip_tunnel_unlink(netdev_priv(dev)); |
1da177e4 LT |
265 | dev_put(dev); |
266 | } | |
267 | ||
d2acc347 | 268 | static int ipip_err(struct sk_buff *skb, u32 info) |
1da177e4 LT |
269 | { |
270 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
271 | ||
272 | /* It is not :-( All the routers (except for Linux) return only | |
273 | 8 bytes of packet payload. It means, that precise relaying of | |
274 | ICMP in the real Internet is absolutely infeasible. | |
275 | */ | |
276 | struct iphdr *iph = (struct iphdr*)skb->data; | |
88c7664f ACM |
277 | const int type = icmp_hdr(skb)->type; |
278 | const int code = icmp_hdr(skb)->code; | |
1da177e4 | 279 | struct ip_tunnel *t; |
d2acc347 | 280 | int err; |
1da177e4 LT |
281 | |
282 | switch (type) { | |
283 | default: | |
284 | case ICMP_PARAMETERPROB: | |
d2acc347 | 285 | return 0; |
1da177e4 LT |
286 | |
287 | case ICMP_DEST_UNREACH: | |
288 | switch (code) { | |
289 | case ICMP_SR_FAILED: | |
290 | case ICMP_PORT_UNREACH: | |
291 | /* Impossible event. */ | |
d2acc347 | 292 | return 0; |
1da177e4 LT |
293 | case ICMP_FRAG_NEEDED: |
294 | /* Soft state for pmtu is maintained by IP core. */ | |
d2acc347 | 295 | return 0; |
1da177e4 LT |
296 | default: |
297 | /* All others are translated to HOST_UNREACH. | |
298 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
299 | I believe they are just ether pollution. --ANK | |
300 | */ | |
301 | break; | |
302 | } | |
303 | break; | |
304 | case ICMP_TIME_EXCEEDED: | |
305 | if (code != ICMP_EXC_TTL) | |
d2acc347 | 306 | return 0; |
1da177e4 LT |
307 | break; |
308 | } | |
309 | ||
d2acc347 HX |
310 | err = -ENOENT; |
311 | ||
1da177e4 LT |
312 | read_lock(&ipip_lock); |
313 | t = ipip_tunnel_lookup(iph->daddr, iph->saddr); | |
314 | if (t == NULL || t->parms.iph.daddr == 0) | |
315 | goto out; | |
d2acc347 HX |
316 | |
317 | err = 0; | |
1da177e4 LT |
318 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) |
319 | goto out; | |
320 | ||
321 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
322 | t->err_count++; | |
323 | else | |
324 | t->err_count = 1; | |
325 | t->err_time = jiffies; | |
326 | out: | |
327 | read_unlock(&ipip_lock); | |
d2acc347 | 328 | return err; |
1da177e4 LT |
329 | #else |
330 | struct iphdr *iph = (struct iphdr*)dp; | |
331 | int hlen = iph->ihl<<2; | |
332 | struct iphdr *eiph; | |
88c7664f ACM |
333 | const int type = icmp_hdr(skb)->type; |
334 | const int code = icmp_hdr(skb)->code; | |
1da177e4 LT |
335 | int rel_type = 0; |
336 | int rel_code = 0; | |
c55e2f49 AV |
337 | __be32 rel_info = 0; |
338 | __u32 n = 0; | |
1da177e4 LT |
339 | struct sk_buff *skb2; |
340 | struct flowi fl; | |
341 | struct rtable *rt; | |
342 | ||
343 | if (len < hlen + sizeof(struct iphdr)) | |
d2acc347 | 344 | return 0; |
1da177e4 LT |
345 | eiph = (struct iphdr*)(dp + hlen); |
346 | ||
347 | switch (type) { | |
348 | default: | |
d2acc347 | 349 | return 0; |
1da177e4 | 350 | case ICMP_PARAMETERPROB: |
88c7664f | 351 | n = ntohl(icmp_hdr(skb)->un.gateway) >> 24; |
c55e2f49 | 352 | if (n < hlen) |
d2acc347 | 353 | return 0; |
1da177e4 LT |
354 | |
355 | /* So... This guy found something strange INSIDE encapsulated | |
356 | packet. Well, he is fool, but what can we do ? | |
357 | */ | |
358 | rel_type = ICMP_PARAMETERPROB; | |
c55e2f49 | 359 | rel_info = htonl((n - hlen) << 24); |
1da177e4 LT |
360 | break; |
361 | ||
362 | case ICMP_DEST_UNREACH: | |
363 | switch (code) { | |
364 | case ICMP_SR_FAILED: | |
365 | case ICMP_PORT_UNREACH: | |
366 | /* Impossible event. */ | |
d2acc347 | 367 | return 0; |
1da177e4 LT |
368 | case ICMP_FRAG_NEEDED: |
369 | /* And it is the only really necessary thing :-) */ | |
88c7664f | 370 | n = ntohs(icmp_hdr(skb)->un.frag.mtu); |
c55e2f49 | 371 | if (n < hlen+68) |
d2acc347 | 372 | return 0; |
c55e2f49 | 373 | n -= hlen; |
1da177e4 | 374 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ |
c55e2f49 | 375 | if (n > ntohs(eiph->tot_len)) |
d2acc347 | 376 | return 0; |
c55e2f49 | 377 | rel_info = htonl(n); |
1da177e4 LT |
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) | |
d2acc347 | 391 | return 0; |
1da177e4 LT |
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) | |
d2acc347 | 398 | return 0; |
1da177e4 LT |
399 | dst_release(skb2->dst); |
400 | skb2->dst = NULL; | |
401 | skb_pull(skb2, skb->data - (u8*)eiph); | |
c1d2bbe1 | 402 | skb_reset_network_header(skb2); |
1da177e4 LT |
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); | |
d2acc347 | 411 | return 0; |
1da177e4 LT |
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); | |
d2acc347 | 426 | return 0; |
1da177e4 LT |
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); | |
d2acc347 | 433 | return 0; |
1da177e4 LT |
434 | } |
435 | } | |
436 | ||
437 | /* change mtu on this route */ | |
438 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
c55e2f49 | 439 | if (n > dst_mtu(skb2->dst)) { |
1da177e4 | 440 | kfree_skb(skb2); |
d2acc347 | 441 | return 0; |
1da177e4 | 442 | } |
c55e2f49 | 443 | skb2->dst->ops->update_pmtu(skb2->dst, n); |
1da177e4 | 444 | } else if (type == ICMP_TIME_EXCEEDED) { |
2941a486 | 445 | struct ip_tunnel *t = netdev_priv(skb2->dev); |
1da177e4 LT |
446 | if (t->parms.iph.ttl) { |
447 | rel_type = ICMP_DEST_UNREACH; | |
448 | rel_code = ICMP_HOST_UNREACH; | |
449 | } | |
450 | } | |
451 | ||
452 | icmp_send(skb2, rel_type, rel_code, rel_info); | |
453 | kfree_skb(skb2); | |
d2acc347 | 454 | return 0; |
1da177e4 LT |
455 | #endif |
456 | } | |
457 | ||
eddc9ec5 ACM |
458 | static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, |
459 | struct sk_buff *skb) | |
1da177e4 | 460 | { |
eddc9ec5 | 461 | struct iphdr *inner_iph = ip_hdr(skb); |
1da177e4 LT |
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 | { | |
1da177e4 | 469 | struct ip_tunnel *tunnel; |
eddc9ec5 | 470 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 LT |
471 | |
472 | read_lock(&ipip_lock); | |
473 | if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { | |
474 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
475 | read_unlock(&ipip_lock); | |
476 | kfree_skb(skb); | |
477 | return 0; | |
478 | } | |
479 | ||
480 | secpath_reset(skb); | |
481 | ||
b0e380b1 | 482 | skb->mac_header = skb->network_header; |
c1d2bbe1 | 483 | skb_reset_network_header(skb); |
1da177e4 LT |
484 | skb->protocol = htons(ETH_P_IP); |
485 | skb->pkt_type = PACKET_HOST; | |
486 | ||
487 | tunnel->stat.rx_packets++; | |
488 | tunnel->stat.rx_bytes += skb->len; | |
489 | skb->dev = tunnel->dev; | |
490 | dst_release(skb->dst); | |
491 | skb->dst = NULL; | |
492 | nf_reset(skb); | |
493 | ipip_ecn_decapsulate(iph, skb); | |
494 | netif_rx(skb); | |
495 | read_unlock(&ipip_lock); | |
496 | return 0; | |
497 | } | |
498 | read_unlock(&ipip_lock); | |
499 | ||
1da177e4 LT |
500 | return -1; |
501 | } | |
502 | ||
503 | /* | |
504 | * This function assumes it is being called from dev_queue_xmit() | |
505 | * and that skb is filled properly by that function. | |
506 | */ | |
507 | ||
508 | static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
509 | { | |
2941a486 | 510 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
511 | struct net_device_stats *stats = &tunnel->stat; |
512 | struct iphdr *tiph = &tunnel->parms.iph; | |
513 | u8 tos = tunnel->parms.iph.tos; | |
d5a0a1e3 | 514 | __be16 df = tiph->frag_off; |
1da177e4 LT |
515 | struct rtable *rt; /* Route to the other host */ |
516 | struct net_device *tdev; /* Device to other host */ | |
eddc9ec5 | 517 | struct iphdr *old_iph = ip_hdr(skb); |
1da177e4 LT |
518 | struct iphdr *iph; /* Our new IP header */ |
519 | int max_headroom; /* The extra header space needed */ | |
d5a0a1e3 | 520 | __be32 dst = tiph->daddr; |
1da177e4 LT |
521 | int mtu; |
522 | ||
523 | if (tunnel->recursion++) { | |
524 | tunnel->stat.collisions++; | |
525 | goto tx_error; | |
526 | } | |
527 | ||
528 | if (skb->protocol != htons(ETH_P_IP)) | |
529 | goto tx_error; | |
530 | ||
531 | if (tos&1) | |
532 | tos = old_iph->tos; | |
533 | ||
534 | if (!dst) { | |
535 | /* NBMA tunnel */ | |
536 | if ((rt = (struct rtable*)skb->dst) == NULL) { | |
537 | tunnel->stat.tx_fifo_errors++; | |
538 | goto tx_error; | |
539 | } | |
540 | if ((dst = rt->rt_gateway) == 0) | |
541 | goto tx_error_icmp; | |
542 | } | |
543 | ||
544 | { | |
545 | struct flowi fl = { .oif = tunnel->parms.link, | |
546 | .nl_u = { .ip4_u = | |
547 | { .daddr = dst, | |
548 | .saddr = tiph->saddr, | |
549 | .tos = RT_TOS(tos) } }, | |
550 | .proto = IPPROTO_IPIP }; | |
551 | if (ip_route_output_key(&rt, &fl)) { | |
552 | tunnel->stat.tx_carrier_errors++; | |
553 | goto tx_error_icmp; | |
554 | } | |
555 | } | |
556 | tdev = rt->u.dst.dev; | |
557 | ||
558 | if (tdev == dev) { | |
559 | ip_rt_put(rt); | |
560 | tunnel->stat.collisions++; | |
561 | goto tx_error; | |
562 | } | |
563 | ||
564 | if (tiph->frag_off) | |
565 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); | |
566 | else | |
567 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
568 | ||
569 | if (mtu < 68) { | |
570 | tunnel->stat.collisions++; | |
571 | ip_rt_put(rt); | |
572 | goto tx_error; | |
573 | } | |
574 | if (skb->dst) | |
575 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
576 | ||
577 | df |= (old_iph->frag_off&htons(IP_DF)); | |
578 | ||
579 | if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { | |
580 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
581 | ip_rt_put(rt); | |
582 | goto tx_error; | |
583 | } | |
584 | ||
585 | if (tunnel->err_count > 0) { | |
586 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
587 | tunnel->err_count--; | |
588 | dst_link_failure(skb); | |
589 | } else | |
590 | tunnel->err_count = 0; | |
591 | } | |
592 | ||
593 | /* | |
594 | * Okay, now see if we can stuff it in the buffer as-is. | |
595 | */ | |
596 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); | |
597 | ||
cfbba49d PM |
598 | if (skb_headroom(skb) < max_headroom || skb_shared(skb) || |
599 | (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { | |
1da177e4 LT |
600 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); |
601 | if (!new_skb) { | |
602 | ip_rt_put(rt); | |
e905a9ed | 603 | stats->tx_dropped++; |
1da177e4 LT |
604 | dev_kfree_skb(skb); |
605 | tunnel->recursion--; | |
606 | return 0; | |
607 | } | |
608 | if (skb->sk) | |
609 | skb_set_owner_w(new_skb, skb->sk); | |
610 | dev_kfree_skb(skb); | |
611 | skb = new_skb; | |
eddc9ec5 | 612 | old_iph = ip_hdr(skb); |
1da177e4 LT |
613 | } |
614 | ||
b0e380b1 | 615 | skb->transport_header = skb->network_header; |
e2d1bca7 ACM |
616 | skb_push(skb, sizeof(struct iphdr)); |
617 | skb_reset_network_header(skb); | |
1da177e4 | 618 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
48d5cad8 PM |
619 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
620 | IPSKB_REROUTED); | |
1da177e4 LT |
621 | dst_release(skb->dst); |
622 | skb->dst = &rt->u.dst; | |
623 | ||
624 | /* | |
625 | * Push down and install the IPIP header. | |
626 | */ | |
627 | ||
eddc9ec5 | 628 | iph = ip_hdr(skb); |
1da177e4 LT |
629 | iph->version = 4; |
630 | iph->ihl = sizeof(struct iphdr)>>2; | |
631 | iph->frag_off = df; | |
632 | iph->protocol = IPPROTO_IPIP; | |
633 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); | |
634 | iph->daddr = rt->rt_dst; | |
635 | iph->saddr = rt->rt_src; | |
636 | ||
637 | if ((iph->ttl = tiph->ttl) == 0) | |
638 | iph->ttl = old_iph->ttl; | |
639 | ||
640 | nf_reset(skb); | |
641 | ||
642 | IPTUNNEL_XMIT(); | |
643 | tunnel->recursion--; | |
644 | return 0; | |
645 | ||
646 | tx_error_icmp: | |
647 | dst_link_failure(skb); | |
648 | tx_error: | |
649 | stats->tx_errors++; | |
650 | dev_kfree_skb(skb); | |
651 | tunnel->recursion--; | |
652 | return 0; | |
653 | } | |
654 | ||
655 | static int | |
656 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
657 | { | |
658 | int err = 0; | |
659 | struct ip_tunnel_parm p; | |
660 | struct ip_tunnel *t; | |
661 | ||
662 | switch (cmd) { | |
663 | case SIOCGETTUNNEL: | |
664 | t = NULL; | |
665 | if (dev == ipip_fb_tunnel_dev) { | |
666 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
667 | err = -EFAULT; | |
668 | break; | |
669 | } | |
670 | t = ipip_tunnel_locate(&p, 0); | |
671 | } | |
672 | if (t == NULL) | |
2941a486 | 673 | t = netdev_priv(dev); |
1da177e4 LT |
674 | memcpy(&p, &t->parms, sizeof(p)); |
675 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
676 | err = -EFAULT; | |
677 | break; | |
678 | ||
679 | case SIOCADDTUNNEL: | |
680 | case SIOCCHGTUNNEL: | |
681 | err = -EPERM; | |
682 | if (!capable(CAP_NET_ADMIN)) | |
683 | goto done; | |
684 | ||
685 | err = -EFAULT; | |
686 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
687 | goto done; | |
688 | ||
689 | err = -EINVAL; | |
690 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || | |
691 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
692 | goto done; | |
693 | if (p.iph.ttl) | |
694 | p.iph.frag_off |= htons(IP_DF); | |
695 | ||
696 | t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
697 | ||
698 | if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
699 | if (t != NULL) { | |
700 | if (t->dev != dev) { | |
701 | err = -EEXIST; | |
702 | break; | |
703 | } | |
704 | } else { | |
705 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
706 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
707 | err = -EINVAL; | |
708 | break; | |
709 | } | |
2941a486 | 710 | t = netdev_priv(dev); |
1da177e4 LT |
711 | ipip_tunnel_unlink(t); |
712 | t->parms.iph.saddr = p.iph.saddr; | |
713 | t->parms.iph.daddr = p.iph.daddr; | |
714 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
715 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
716 | ipip_tunnel_link(t); | |
717 | netdev_state_change(dev); | |
718 | } | |
719 | } | |
720 | ||
721 | if (t) { | |
722 | err = 0; | |
723 | if (cmd == SIOCCHGTUNNEL) { | |
724 | t->parms.iph.ttl = p.iph.ttl; | |
725 | t->parms.iph.tos = p.iph.tos; | |
726 | t->parms.iph.frag_off = p.iph.frag_off; | |
727 | } | |
728 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
729 | err = -EFAULT; | |
730 | } else | |
731 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
732 | break; | |
733 | ||
734 | case SIOCDELTUNNEL: | |
735 | err = -EPERM; | |
736 | if (!capable(CAP_NET_ADMIN)) | |
737 | goto done; | |
738 | ||
739 | if (dev == ipip_fb_tunnel_dev) { | |
740 | err = -EFAULT; | |
741 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
742 | goto done; | |
743 | err = -ENOENT; | |
744 | if ((t = ipip_tunnel_locate(&p, 0)) == NULL) | |
745 | goto done; | |
746 | err = -EPERM; | |
747 | if (t->dev == ipip_fb_tunnel_dev) | |
748 | goto done; | |
749 | dev = t->dev; | |
750 | } | |
22f8cde5 SH |
751 | unregister_netdevice(dev); |
752 | err = 0; | |
1da177e4 LT |
753 | break; |
754 | ||
755 | default: | |
756 | err = -EINVAL; | |
757 | } | |
758 | ||
759 | done: | |
760 | return err; | |
761 | } | |
762 | ||
763 | static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) | |
764 | { | |
2941a486 | 765 | return &(((struct ip_tunnel*)netdev_priv(dev))->stat); |
1da177e4 LT |
766 | } |
767 | ||
768 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
769 | { | |
770 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
771 | return -EINVAL; | |
772 | dev->mtu = new_mtu; | |
773 | return 0; | |
774 | } | |
775 | ||
776 | static void ipip_tunnel_setup(struct net_device *dev) | |
777 | { | |
778 | SET_MODULE_OWNER(dev); | |
779 | dev->uninit = ipip_tunnel_uninit; | |
780 | dev->hard_start_xmit = ipip_tunnel_xmit; | |
781 | dev->get_stats = ipip_tunnel_get_stats; | |
782 | dev->do_ioctl = ipip_tunnel_ioctl; | |
783 | dev->change_mtu = ipip_tunnel_change_mtu; | |
784 | dev->destructor = free_netdev; | |
785 | ||
786 | dev->type = ARPHRD_TUNNEL; | |
787 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
46f25dff | 788 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); |
1da177e4 LT |
789 | dev->flags = IFF_NOARP; |
790 | dev->iflink = 0; | |
791 | dev->addr_len = 4; | |
792 | } | |
793 | ||
794 | static int ipip_tunnel_init(struct net_device *dev) | |
795 | { | |
796 | struct net_device *tdev = NULL; | |
797 | struct ip_tunnel *tunnel; | |
798 | struct iphdr *iph; | |
799 | ||
2941a486 | 800 | tunnel = netdev_priv(dev); |
1da177e4 LT |
801 | iph = &tunnel->parms.iph; |
802 | ||
803 | tunnel->dev = dev; | |
804 | strcpy(tunnel->parms.name, dev->name); | |
805 | ||
806 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
807 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
808 | ||
809 | if (iph->daddr) { | |
810 | struct flowi fl = { .oif = tunnel->parms.link, | |
811 | .nl_u = { .ip4_u = | |
812 | { .daddr = iph->daddr, | |
813 | .saddr = iph->saddr, | |
814 | .tos = RT_TOS(iph->tos) } }, | |
815 | .proto = IPPROTO_IPIP }; | |
816 | struct rtable *rt; | |
817 | if (!ip_route_output_key(&rt, &fl)) { | |
818 | tdev = rt->u.dst.dev; | |
819 | ip_rt_put(rt); | |
820 | } | |
821 | dev->flags |= IFF_POINTOPOINT; | |
822 | } | |
823 | ||
824 | if (!tdev && tunnel->parms.link) | |
825 | tdev = __dev_get_by_index(tunnel->parms.link); | |
826 | ||
827 | if (tdev) { | |
828 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
829 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
830 | } | |
831 | dev->iflink = tunnel->parms.link; | |
832 | ||
833 | return 0; | |
834 | } | |
835 | ||
836 | static int __init ipip_fb_tunnel_init(struct net_device *dev) | |
837 | { | |
2941a486 | 838 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
839 | struct iphdr *iph = &tunnel->parms.iph; |
840 | ||
841 | tunnel->dev = dev; | |
842 | strcpy(tunnel->parms.name, dev->name); | |
843 | ||
844 | iph->version = 4; | |
845 | iph->protocol = IPPROTO_IPIP; | |
846 | iph->ihl = 5; | |
847 | ||
848 | dev_hold(dev); | |
849 | tunnels_wc[0] = tunnel; | |
850 | return 0; | |
851 | } | |
852 | ||
853 | static struct xfrm_tunnel ipip_handler = { | |
854 | .handler = ipip_rcv, | |
855 | .err_handler = ipip_err, | |
d2acc347 | 856 | .priority = 1, |
1da177e4 LT |
857 | }; |
858 | ||
859 | static char banner[] __initdata = | |
860 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; | |
861 | ||
862 | static int __init ipip_init(void) | |
863 | { | |
864 | int err; | |
865 | ||
866 | printk(banner); | |
867 | ||
c0d56408 | 868 | if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) { |
1da177e4 LT |
869 | printk(KERN_INFO "ipip init: can't register tunnel\n"); |
870 | return -EAGAIN; | |
871 | } | |
872 | ||
873 | ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), | |
874 | "tunl0", | |
875 | ipip_tunnel_setup); | |
876 | if (!ipip_fb_tunnel_dev) { | |
877 | err = -ENOMEM; | |
878 | goto err1; | |
879 | } | |
880 | ||
881 | ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; | |
882 | ||
883 | if ((err = register_netdev(ipip_fb_tunnel_dev))) | |
884 | goto err2; | |
885 | out: | |
886 | return err; | |
887 | err2: | |
888 | free_netdev(ipip_fb_tunnel_dev); | |
889 | err1: | |
c0d56408 | 890 | xfrm4_tunnel_deregister(&ipip_handler, AF_INET); |
1da177e4 LT |
891 | goto out; |
892 | } | |
893 | ||
db44575f AK |
894 | static void __exit ipip_destroy_tunnels(void) |
895 | { | |
896 | int prio; | |
897 | ||
898 | for (prio = 1; prio < 4; prio++) { | |
899 | int h; | |
900 | for (h = 0; h < HASH_SIZE; h++) { | |
901 | struct ip_tunnel *t; | |
902 | while ((t = tunnels[prio][h]) != NULL) | |
903 | unregister_netdevice(t->dev); | |
904 | } | |
905 | } | |
906 | } | |
907 | ||
1da177e4 LT |
908 | static void __exit ipip_fini(void) |
909 | { | |
c0d56408 | 910 | if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) |
1da177e4 LT |
911 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); |
912 | ||
db44575f AK |
913 | rtnl_lock(); |
914 | ipip_destroy_tunnels(); | |
915 | unregister_netdevice(ipip_fb_tunnel_dev); | |
916 | rtnl_unlock(); | |
1da177e4 LT |
917 | } |
918 | ||
919 | module_init(ipip_init); | |
920 | module_exit(ipip_fini); | |
921 | MODULE_LICENSE("GPL"); |