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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); | |
34cc7ba6 PE |
224 | else |
225 | sprintf(name, "tunl%%d"); | |
1da177e4 LT |
226 | |
227 | dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); | |
228 | if (dev == NULL) | |
229 | return NULL; | |
230 | ||
2941a486 | 231 | nt = netdev_priv(dev); |
1da177e4 LT |
232 | dev->init = ipip_tunnel_init; |
233 | nt->parms = *parms; | |
234 | ||
235 | if (register_netdevice(dev) < 0) { | |
236 | free_netdev(dev); | |
237 | goto failed; | |
238 | } | |
239 | ||
240 | dev_hold(dev); | |
241 | ipip_tunnel_link(nt); | |
1da177e4 LT |
242 | return nt; |
243 | ||
244 | failed: | |
245 | return NULL; | |
246 | } | |
247 | ||
248 | static void ipip_tunnel_uninit(struct net_device *dev) | |
249 | { | |
250 | if (dev == ipip_fb_tunnel_dev) { | |
251 | write_lock_bh(&ipip_lock); | |
252 | tunnels_wc[0] = NULL; | |
253 | write_unlock_bh(&ipip_lock); | |
254 | } else | |
2941a486 | 255 | ipip_tunnel_unlink(netdev_priv(dev)); |
1da177e4 LT |
256 | dev_put(dev); |
257 | } | |
258 | ||
d2acc347 | 259 | static int ipip_err(struct sk_buff *skb, u32 info) |
1da177e4 LT |
260 | { |
261 | #ifndef I_WISH_WORLD_WERE_PERFECT | |
262 | ||
263 | /* It is not :-( All the routers (except for Linux) return only | |
264 | 8 bytes of packet payload. It means, that precise relaying of | |
265 | ICMP in the real Internet is absolutely infeasible. | |
266 | */ | |
267 | struct iphdr *iph = (struct iphdr*)skb->data; | |
88c7664f ACM |
268 | const int type = icmp_hdr(skb)->type; |
269 | const int code = icmp_hdr(skb)->code; | |
1da177e4 | 270 | struct ip_tunnel *t; |
d2acc347 | 271 | int err; |
1da177e4 LT |
272 | |
273 | switch (type) { | |
274 | default: | |
275 | case ICMP_PARAMETERPROB: | |
d2acc347 | 276 | return 0; |
1da177e4 LT |
277 | |
278 | case ICMP_DEST_UNREACH: | |
279 | switch (code) { | |
280 | case ICMP_SR_FAILED: | |
281 | case ICMP_PORT_UNREACH: | |
282 | /* Impossible event. */ | |
d2acc347 | 283 | return 0; |
1da177e4 LT |
284 | case ICMP_FRAG_NEEDED: |
285 | /* Soft state for pmtu is maintained by IP core. */ | |
d2acc347 | 286 | return 0; |
1da177e4 LT |
287 | default: |
288 | /* All others are translated to HOST_UNREACH. | |
289 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
290 | I believe they are just ether pollution. --ANK | |
291 | */ | |
292 | break; | |
293 | } | |
294 | break; | |
295 | case ICMP_TIME_EXCEEDED: | |
296 | if (code != ICMP_EXC_TTL) | |
d2acc347 | 297 | return 0; |
1da177e4 LT |
298 | break; |
299 | } | |
300 | ||
d2acc347 HX |
301 | err = -ENOENT; |
302 | ||
1da177e4 LT |
303 | read_lock(&ipip_lock); |
304 | t = ipip_tunnel_lookup(iph->daddr, iph->saddr); | |
305 | if (t == NULL || t->parms.iph.daddr == 0) | |
306 | goto out; | |
d2acc347 HX |
307 | |
308 | err = 0; | |
1da177e4 LT |
309 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) |
310 | goto out; | |
311 | ||
312 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) | |
313 | t->err_count++; | |
314 | else | |
315 | t->err_count = 1; | |
316 | t->err_time = jiffies; | |
317 | out: | |
318 | read_unlock(&ipip_lock); | |
d2acc347 | 319 | return err; |
1da177e4 LT |
320 | #else |
321 | struct iphdr *iph = (struct iphdr*)dp; | |
322 | int hlen = iph->ihl<<2; | |
323 | struct iphdr *eiph; | |
88c7664f ACM |
324 | const int type = icmp_hdr(skb)->type; |
325 | const int code = icmp_hdr(skb)->code; | |
1da177e4 LT |
326 | int rel_type = 0; |
327 | int rel_code = 0; | |
c55e2f49 AV |
328 | __be32 rel_info = 0; |
329 | __u32 n = 0; | |
1da177e4 LT |
330 | struct sk_buff *skb2; |
331 | struct flowi fl; | |
332 | struct rtable *rt; | |
333 | ||
334 | if (len < hlen + sizeof(struct iphdr)) | |
d2acc347 | 335 | return 0; |
1da177e4 LT |
336 | eiph = (struct iphdr*)(dp + hlen); |
337 | ||
338 | switch (type) { | |
339 | default: | |
d2acc347 | 340 | return 0; |
1da177e4 | 341 | case ICMP_PARAMETERPROB: |
88c7664f | 342 | n = ntohl(icmp_hdr(skb)->un.gateway) >> 24; |
c55e2f49 | 343 | if (n < hlen) |
d2acc347 | 344 | return 0; |
1da177e4 LT |
345 | |
346 | /* So... This guy found something strange INSIDE encapsulated | |
347 | packet. Well, he is fool, but what can we do ? | |
348 | */ | |
349 | rel_type = ICMP_PARAMETERPROB; | |
c55e2f49 | 350 | rel_info = htonl((n - hlen) << 24); |
1da177e4 LT |
351 | break; |
352 | ||
353 | case ICMP_DEST_UNREACH: | |
354 | switch (code) { | |
355 | case ICMP_SR_FAILED: | |
356 | case ICMP_PORT_UNREACH: | |
357 | /* Impossible event. */ | |
d2acc347 | 358 | return 0; |
1da177e4 LT |
359 | case ICMP_FRAG_NEEDED: |
360 | /* And it is the only really necessary thing :-) */ | |
88c7664f | 361 | n = ntohs(icmp_hdr(skb)->un.frag.mtu); |
c55e2f49 | 362 | if (n < hlen+68) |
d2acc347 | 363 | return 0; |
c55e2f49 | 364 | n -= hlen; |
1da177e4 | 365 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ |
c55e2f49 | 366 | if (n > ntohs(eiph->tot_len)) |
d2acc347 | 367 | return 0; |
c55e2f49 | 368 | rel_info = htonl(n); |
1da177e4 LT |
369 | break; |
370 | default: | |
371 | /* All others are translated to HOST_UNREACH. | |
372 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
373 | I believe, it is just ether pollution. --ANK | |
374 | */ | |
375 | rel_type = ICMP_DEST_UNREACH; | |
376 | rel_code = ICMP_HOST_UNREACH; | |
377 | break; | |
378 | } | |
379 | break; | |
380 | case ICMP_TIME_EXCEEDED: | |
381 | if (code != ICMP_EXC_TTL) | |
d2acc347 | 382 | return 0; |
1da177e4 LT |
383 | break; |
384 | } | |
385 | ||
386 | /* Prepare fake skb to feed it to icmp_send */ | |
387 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
388 | if (skb2 == NULL) | |
d2acc347 | 389 | return 0; |
1da177e4 LT |
390 | dst_release(skb2->dst); |
391 | skb2->dst = NULL; | |
392 | skb_pull(skb2, skb->data - (u8*)eiph); | |
c1d2bbe1 | 393 | skb_reset_network_header(skb2); |
1da177e4 LT |
394 | |
395 | /* Try to guess incoming interface */ | |
396 | memset(&fl, 0, sizeof(fl)); | |
397 | fl.fl4_daddr = eiph->saddr; | |
398 | fl.fl4_tos = RT_TOS(eiph->tos); | |
399 | fl.proto = IPPROTO_IPIP; | |
f206351a | 400 | if (ip_route_output_key(&init_net, &rt, &key)) { |
1da177e4 | 401 | kfree_skb(skb2); |
d2acc347 | 402 | return 0; |
1da177e4 LT |
403 | } |
404 | skb2->dev = rt->u.dst.dev; | |
405 | ||
406 | /* route "incoming" packet */ | |
407 | if (rt->rt_flags&RTCF_LOCAL) { | |
408 | ip_rt_put(rt); | |
409 | rt = NULL; | |
410 | fl.fl4_daddr = eiph->daddr; | |
411 | fl.fl4_src = eiph->saddr; | |
412 | fl.fl4_tos = eiph->tos; | |
f206351a | 413 | if (ip_route_output_key(&init_net, &rt, &fl) || |
1da177e4 LT |
414 | rt->u.dst.dev->type != ARPHRD_TUNNEL) { |
415 | ip_rt_put(rt); | |
416 | kfree_skb(skb2); | |
d2acc347 | 417 | return 0; |
1da177e4 LT |
418 | } |
419 | } else { | |
420 | ip_rt_put(rt); | |
421 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || | |
422 | skb2->dst->dev->type != ARPHRD_TUNNEL) { | |
423 | kfree_skb(skb2); | |
d2acc347 | 424 | return 0; |
1da177e4 LT |
425 | } |
426 | } | |
427 | ||
428 | /* change mtu on this route */ | |
429 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | |
c55e2f49 | 430 | if (n > dst_mtu(skb2->dst)) { |
1da177e4 | 431 | kfree_skb(skb2); |
d2acc347 | 432 | return 0; |
1da177e4 | 433 | } |
c55e2f49 | 434 | skb2->dst->ops->update_pmtu(skb2->dst, n); |
1da177e4 | 435 | } else if (type == ICMP_TIME_EXCEEDED) { |
2941a486 | 436 | struct ip_tunnel *t = netdev_priv(skb2->dev); |
1da177e4 LT |
437 | if (t->parms.iph.ttl) { |
438 | rel_type = ICMP_DEST_UNREACH; | |
439 | rel_code = ICMP_HOST_UNREACH; | |
440 | } | |
441 | } | |
442 | ||
443 | icmp_send(skb2, rel_type, rel_code, rel_info); | |
444 | kfree_skb(skb2); | |
d2acc347 | 445 | return 0; |
1da177e4 LT |
446 | #endif |
447 | } | |
448 | ||
eddc9ec5 ACM |
449 | static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, |
450 | struct sk_buff *skb) | |
1da177e4 | 451 | { |
eddc9ec5 | 452 | struct iphdr *inner_iph = ip_hdr(skb); |
1da177e4 LT |
453 | |
454 | if (INET_ECN_is_ce(outer_iph->tos)) | |
455 | IP_ECN_set_ce(inner_iph); | |
456 | } | |
457 | ||
458 | static int ipip_rcv(struct sk_buff *skb) | |
459 | { | |
1da177e4 | 460 | struct ip_tunnel *tunnel; |
eddc9ec5 | 461 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 LT |
462 | |
463 | read_lock(&ipip_lock); | |
464 | if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { | |
465 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
466 | read_unlock(&ipip_lock); | |
467 | kfree_skb(skb); | |
468 | return 0; | |
469 | } | |
470 | ||
471 | secpath_reset(skb); | |
472 | ||
b0e380b1 | 473 | skb->mac_header = skb->network_header; |
c1d2bbe1 | 474 | skb_reset_network_header(skb); |
1da177e4 LT |
475 | skb->protocol = htons(ETH_P_IP); |
476 | skb->pkt_type = PACKET_HOST; | |
477 | ||
478 | tunnel->stat.rx_packets++; | |
479 | tunnel->stat.rx_bytes += skb->len; | |
480 | skb->dev = tunnel->dev; | |
481 | dst_release(skb->dst); | |
482 | skb->dst = NULL; | |
483 | nf_reset(skb); | |
484 | ipip_ecn_decapsulate(iph, skb); | |
485 | netif_rx(skb); | |
486 | read_unlock(&ipip_lock); | |
487 | return 0; | |
488 | } | |
489 | read_unlock(&ipip_lock); | |
490 | ||
1da177e4 LT |
491 | return -1; |
492 | } | |
493 | ||
494 | /* | |
495 | * This function assumes it is being called from dev_queue_xmit() | |
496 | * and that skb is filled properly by that function. | |
497 | */ | |
498 | ||
499 | static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) | |
500 | { | |
2941a486 | 501 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
502 | struct net_device_stats *stats = &tunnel->stat; |
503 | struct iphdr *tiph = &tunnel->parms.iph; | |
504 | u8 tos = tunnel->parms.iph.tos; | |
d5a0a1e3 | 505 | __be16 df = tiph->frag_off; |
1da177e4 LT |
506 | struct rtable *rt; /* Route to the other host */ |
507 | struct net_device *tdev; /* Device to other host */ | |
eddc9ec5 | 508 | struct iphdr *old_iph = ip_hdr(skb); |
1da177e4 | 509 | struct iphdr *iph; /* Our new IP header */ |
c2636b4d | 510 | unsigned int max_headroom; /* The extra header space needed */ |
d5a0a1e3 | 511 | __be32 dst = tiph->daddr; |
1da177e4 LT |
512 | int mtu; |
513 | ||
514 | if (tunnel->recursion++) { | |
515 | tunnel->stat.collisions++; | |
516 | goto tx_error; | |
517 | } | |
518 | ||
519 | if (skb->protocol != htons(ETH_P_IP)) | |
520 | goto tx_error; | |
521 | ||
522 | if (tos&1) | |
523 | tos = old_iph->tos; | |
524 | ||
525 | if (!dst) { | |
526 | /* NBMA tunnel */ | |
527 | if ((rt = (struct rtable*)skb->dst) == NULL) { | |
528 | tunnel->stat.tx_fifo_errors++; | |
529 | goto tx_error; | |
530 | } | |
531 | if ((dst = rt->rt_gateway) == 0) | |
532 | goto tx_error_icmp; | |
533 | } | |
534 | ||
535 | { | |
536 | struct flowi fl = { .oif = tunnel->parms.link, | |
537 | .nl_u = { .ip4_u = | |
538 | { .daddr = dst, | |
539 | .saddr = tiph->saddr, | |
540 | .tos = RT_TOS(tos) } }, | |
541 | .proto = IPPROTO_IPIP }; | |
f206351a | 542 | if (ip_route_output_key(&init_net, &rt, &fl)) { |
1da177e4 LT |
543 | tunnel->stat.tx_carrier_errors++; |
544 | goto tx_error_icmp; | |
545 | } | |
546 | } | |
547 | tdev = rt->u.dst.dev; | |
548 | ||
549 | if (tdev == dev) { | |
550 | ip_rt_put(rt); | |
551 | tunnel->stat.collisions++; | |
552 | goto tx_error; | |
553 | } | |
554 | ||
555 | if (tiph->frag_off) | |
556 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); | |
557 | else | |
558 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; | |
559 | ||
560 | if (mtu < 68) { | |
561 | tunnel->stat.collisions++; | |
562 | ip_rt_put(rt); | |
563 | goto tx_error; | |
564 | } | |
565 | if (skb->dst) | |
566 | skb->dst->ops->update_pmtu(skb->dst, mtu); | |
567 | ||
568 | df |= (old_iph->frag_off&htons(IP_DF)); | |
569 | ||
570 | if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { | |
571 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); | |
572 | ip_rt_put(rt); | |
573 | goto tx_error; | |
574 | } | |
575 | ||
576 | if (tunnel->err_count > 0) { | |
577 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { | |
578 | tunnel->err_count--; | |
579 | dst_link_failure(skb); | |
580 | } else | |
581 | tunnel->err_count = 0; | |
582 | } | |
583 | ||
584 | /* | |
585 | * Okay, now see if we can stuff it in the buffer as-is. | |
586 | */ | |
587 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); | |
588 | ||
cfbba49d PM |
589 | if (skb_headroom(skb) < max_headroom || skb_shared(skb) || |
590 | (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { | |
1da177e4 LT |
591 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); |
592 | if (!new_skb) { | |
593 | ip_rt_put(rt); | |
e905a9ed | 594 | stats->tx_dropped++; |
1da177e4 LT |
595 | dev_kfree_skb(skb); |
596 | tunnel->recursion--; | |
597 | return 0; | |
598 | } | |
599 | if (skb->sk) | |
600 | skb_set_owner_w(new_skb, skb->sk); | |
601 | dev_kfree_skb(skb); | |
602 | skb = new_skb; | |
eddc9ec5 | 603 | old_iph = ip_hdr(skb); |
1da177e4 LT |
604 | } |
605 | ||
b0e380b1 | 606 | skb->transport_header = skb->network_header; |
e2d1bca7 ACM |
607 | skb_push(skb, sizeof(struct iphdr)); |
608 | skb_reset_network_header(skb); | |
1da177e4 | 609 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
48d5cad8 PM |
610 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
611 | IPSKB_REROUTED); | |
1da177e4 LT |
612 | dst_release(skb->dst); |
613 | skb->dst = &rt->u.dst; | |
614 | ||
615 | /* | |
616 | * Push down and install the IPIP header. | |
617 | */ | |
618 | ||
eddc9ec5 | 619 | iph = ip_hdr(skb); |
1da177e4 LT |
620 | iph->version = 4; |
621 | iph->ihl = sizeof(struct iphdr)>>2; | |
622 | iph->frag_off = df; | |
623 | iph->protocol = IPPROTO_IPIP; | |
624 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); | |
625 | iph->daddr = rt->rt_dst; | |
626 | iph->saddr = rt->rt_src; | |
627 | ||
628 | if ((iph->ttl = tiph->ttl) == 0) | |
629 | iph->ttl = old_iph->ttl; | |
630 | ||
631 | nf_reset(skb); | |
632 | ||
633 | IPTUNNEL_XMIT(); | |
634 | tunnel->recursion--; | |
635 | return 0; | |
636 | ||
637 | tx_error_icmp: | |
638 | dst_link_failure(skb); | |
639 | tx_error: | |
640 | stats->tx_errors++; | |
641 | dev_kfree_skb(skb); | |
642 | tunnel->recursion--; | |
643 | return 0; | |
644 | } | |
645 | ||
5533995b MS |
646 | static void ipip_tunnel_bind_dev(struct net_device *dev) |
647 | { | |
648 | struct net_device *tdev = NULL; | |
649 | struct ip_tunnel *tunnel; | |
650 | struct iphdr *iph; | |
651 | ||
652 | tunnel = netdev_priv(dev); | |
653 | iph = &tunnel->parms.iph; | |
654 | ||
655 | if (iph->daddr) { | |
656 | struct flowi fl = { .oif = tunnel->parms.link, | |
657 | .nl_u = { .ip4_u = | |
658 | { .daddr = iph->daddr, | |
659 | .saddr = iph->saddr, | |
660 | .tos = RT_TOS(iph->tos) } }, | |
661 | .proto = IPPROTO_IPIP }; | |
662 | struct rtable *rt; | |
f206351a | 663 | if (!ip_route_output_key(&init_net, &rt, &fl)) { |
5533995b MS |
664 | tdev = rt->u.dst.dev; |
665 | ip_rt_put(rt); | |
666 | } | |
667 | dev->flags |= IFF_POINTOPOINT; | |
668 | } | |
669 | ||
670 | if (!tdev && tunnel->parms.link) | |
671 | tdev = __dev_get_by_index(&init_net, tunnel->parms.link); | |
672 | ||
673 | if (tdev) { | |
674 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
675 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
676 | } | |
677 | dev->iflink = tunnel->parms.link; | |
678 | } | |
679 | ||
1da177e4 LT |
680 | static int |
681 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
682 | { | |
683 | int err = 0; | |
684 | struct ip_tunnel_parm p; | |
685 | struct ip_tunnel *t; | |
686 | ||
687 | switch (cmd) { | |
688 | case SIOCGETTUNNEL: | |
689 | t = NULL; | |
690 | if (dev == ipip_fb_tunnel_dev) { | |
691 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
692 | err = -EFAULT; | |
693 | break; | |
694 | } | |
695 | t = ipip_tunnel_locate(&p, 0); | |
696 | } | |
697 | if (t == NULL) | |
2941a486 | 698 | t = netdev_priv(dev); |
1da177e4 LT |
699 | memcpy(&p, &t->parms, sizeof(p)); |
700 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
701 | err = -EFAULT; | |
702 | break; | |
703 | ||
704 | case SIOCADDTUNNEL: | |
705 | case SIOCCHGTUNNEL: | |
706 | err = -EPERM; | |
707 | if (!capable(CAP_NET_ADMIN)) | |
708 | goto done; | |
709 | ||
710 | err = -EFAULT; | |
711 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
712 | goto done; | |
713 | ||
714 | err = -EINVAL; | |
715 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || | |
716 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
717 | goto done; | |
718 | if (p.iph.ttl) | |
719 | p.iph.frag_off |= htons(IP_DF); | |
720 | ||
721 | t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); | |
722 | ||
723 | if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
724 | if (t != NULL) { | |
725 | if (t->dev != dev) { | |
726 | err = -EEXIST; | |
727 | break; | |
728 | } | |
729 | } else { | |
730 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
731 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
732 | err = -EINVAL; | |
733 | break; | |
734 | } | |
2941a486 | 735 | t = netdev_priv(dev); |
1da177e4 LT |
736 | ipip_tunnel_unlink(t); |
737 | t->parms.iph.saddr = p.iph.saddr; | |
738 | t->parms.iph.daddr = p.iph.daddr; | |
739 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
740 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
741 | ipip_tunnel_link(t); | |
742 | netdev_state_change(dev); | |
743 | } | |
744 | } | |
745 | ||
746 | if (t) { | |
747 | err = 0; | |
748 | if (cmd == SIOCCHGTUNNEL) { | |
749 | t->parms.iph.ttl = p.iph.ttl; | |
750 | t->parms.iph.tos = p.iph.tos; | |
751 | t->parms.iph.frag_off = p.iph.frag_off; | |
5533995b MS |
752 | if (t->parms.link != p.link) { |
753 | t->parms.link = p.link; | |
754 | ipip_tunnel_bind_dev(dev); | |
755 | netdev_state_change(dev); | |
756 | } | |
1da177e4 LT |
757 | } |
758 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
759 | err = -EFAULT; | |
760 | } else | |
761 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
762 | break; | |
763 | ||
764 | case SIOCDELTUNNEL: | |
765 | err = -EPERM; | |
766 | if (!capable(CAP_NET_ADMIN)) | |
767 | goto done; | |
768 | ||
769 | if (dev == ipip_fb_tunnel_dev) { | |
770 | err = -EFAULT; | |
771 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
772 | goto done; | |
773 | err = -ENOENT; | |
774 | if ((t = ipip_tunnel_locate(&p, 0)) == NULL) | |
775 | goto done; | |
776 | err = -EPERM; | |
777 | if (t->dev == ipip_fb_tunnel_dev) | |
778 | goto done; | |
779 | dev = t->dev; | |
780 | } | |
22f8cde5 SH |
781 | unregister_netdevice(dev); |
782 | err = 0; | |
1da177e4 LT |
783 | break; |
784 | ||
785 | default: | |
786 | err = -EINVAL; | |
787 | } | |
788 | ||
789 | done: | |
790 | return err; | |
791 | } | |
792 | ||
793 | static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) | |
794 | { | |
2941a486 | 795 | return &(((struct ip_tunnel*)netdev_priv(dev))->stat); |
1da177e4 LT |
796 | } |
797 | ||
798 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
799 | { | |
800 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
801 | return -EINVAL; | |
802 | dev->mtu = new_mtu; | |
803 | return 0; | |
804 | } | |
805 | ||
806 | static void ipip_tunnel_setup(struct net_device *dev) | |
807 | { | |
1da177e4 LT |
808 | dev->uninit = ipip_tunnel_uninit; |
809 | dev->hard_start_xmit = ipip_tunnel_xmit; | |
810 | dev->get_stats = ipip_tunnel_get_stats; | |
811 | dev->do_ioctl = ipip_tunnel_ioctl; | |
812 | dev->change_mtu = ipip_tunnel_change_mtu; | |
813 | dev->destructor = free_netdev; | |
814 | ||
815 | dev->type = ARPHRD_TUNNEL; | |
816 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
46f25dff | 817 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); |
1da177e4 LT |
818 | dev->flags = IFF_NOARP; |
819 | dev->iflink = 0; | |
820 | dev->addr_len = 4; | |
821 | } | |
822 | ||
823 | static int ipip_tunnel_init(struct net_device *dev) | |
824 | { | |
1da177e4 | 825 | struct ip_tunnel *tunnel; |
1da177e4 | 826 | |
2941a486 | 827 | tunnel = netdev_priv(dev); |
1da177e4 LT |
828 | |
829 | tunnel->dev = dev; | |
830 | strcpy(tunnel->parms.name, dev->name); | |
831 | ||
832 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
833 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
834 | ||
5533995b | 835 | ipip_tunnel_bind_dev(dev); |
1da177e4 LT |
836 | |
837 | return 0; | |
838 | } | |
839 | ||
840 | static int __init ipip_fb_tunnel_init(struct net_device *dev) | |
841 | { | |
2941a486 | 842 | struct ip_tunnel *tunnel = netdev_priv(dev); |
1da177e4 LT |
843 | struct iphdr *iph = &tunnel->parms.iph; |
844 | ||
845 | tunnel->dev = dev; | |
846 | strcpy(tunnel->parms.name, dev->name); | |
847 | ||
848 | iph->version = 4; | |
849 | iph->protocol = IPPROTO_IPIP; | |
850 | iph->ihl = 5; | |
851 | ||
852 | dev_hold(dev); | |
853 | tunnels_wc[0] = tunnel; | |
854 | return 0; | |
855 | } | |
856 | ||
857 | static struct xfrm_tunnel ipip_handler = { | |
858 | .handler = ipip_rcv, | |
859 | .err_handler = ipip_err, | |
d2acc347 | 860 | .priority = 1, |
1da177e4 LT |
861 | }; |
862 | ||
863 | static char banner[] __initdata = | |
864 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; | |
865 | ||
866 | static int __init ipip_init(void) | |
867 | { | |
868 | int err; | |
869 | ||
870 | printk(banner); | |
871 | ||
c0d56408 | 872 | if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) { |
1da177e4 LT |
873 | printk(KERN_INFO "ipip init: can't register tunnel\n"); |
874 | return -EAGAIN; | |
875 | } | |
876 | ||
877 | ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), | |
878 | "tunl0", | |
879 | ipip_tunnel_setup); | |
880 | if (!ipip_fb_tunnel_dev) { | |
881 | err = -ENOMEM; | |
882 | goto err1; | |
883 | } | |
884 | ||
885 | ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; | |
886 | ||
887 | if ((err = register_netdev(ipip_fb_tunnel_dev))) | |
888 | goto err2; | |
889 | out: | |
890 | return err; | |
891 | err2: | |
892 | free_netdev(ipip_fb_tunnel_dev); | |
893 | err1: | |
c0d56408 | 894 | xfrm4_tunnel_deregister(&ipip_handler, AF_INET); |
1da177e4 LT |
895 | goto out; |
896 | } | |
897 | ||
db44575f AK |
898 | static void __exit ipip_destroy_tunnels(void) |
899 | { | |
900 | int prio; | |
901 | ||
902 | for (prio = 1; prio < 4; prio++) { | |
903 | int h; | |
904 | for (h = 0; h < HASH_SIZE; h++) { | |
905 | struct ip_tunnel *t; | |
906 | while ((t = tunnels[prio][h]) != NULL) | |
907 | unregister_netdevice(t->dev); | |
908 | } | |
909 | } | |
910 | } | |
911 | ||
1da177e4 LT |
912 | static void __exit ipip_fini(void) |
913 | { | |
c0d56408 | 914 | if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) |
1da177e4 LT |
915 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); |
916 | ||
db44575f AK |
917 | rtnl_lock(); |
918 | ipip_destroy_tunnels(); | |
919 | unregister_netdevice(ipip_fb_tunnel_dev); | |
920 | rtnl_unlock(); | |
1da177e4 LT |
921 | } |
922 | ||
923 | module_init(ipip_init); | |
924 | module_exit(ipip_fini); | |
925 | MODULE_LICENSE("GPL"); |