Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173 | |
3 | * | |
4 | * Copyright (C)2003 USAGI/WIDE Project | |
5 | * | |
6 | * Author Mitsuru KANDA <mk@linux-ipv6.org> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
1ab1457c | 12 | * |
1da177e4 LT |
13 | * This program is distributed in the hope that it will be useful, |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
1ab1457c | 17 | * |
1da177e4 LT |
18 | * You should have received a copy of the GNU General Public License |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | */ | |
1ab1457c | 22 | /* |
1da177e4 LT |
23 | * [Memo] |
24 | * | |
25 | * Outbound: | |
1ab1457c YH |
26 | * The compression of IP datagram MUST be done before AH/ESP processing, |
27 | * fragmentation, and the addition of Hop-by-Hop/Routing header. | |
1da177e4 LT |
28 | * |
29 | * Inbound: | |
1ab1457c | 30 | * The decompression of IP datagram MUST be done after the reassembly, |
1da177e4 LT |
31 | * AH/ESP processing. |
32 | */ | |
1da177e4 LT |
33 | #include <linux/module.h> |
34 | #include <net/ip.h> | |
35 | #include <net/xfrm.h> | |
36 | #include <net/ipcomp.h> | |
1da177e4 LT |
37 | #include <asm/semaphore.h> |
38 | #include <linux/crypto.h> | |
39 | #include <linux/pfkeyv2.h> | |
40 | #include <linux/random.h> | |
41 | #include <linux/percpu.h> | |
42 | #include <linux/smp.h> | |
43 | #include <linux/list.h> | |
44 | #include <linux/vmalloc.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <net/icmp.h> | |
47 | #include <net/ipv6.h> | |
14c85021 | 48 | #include <net/protocol.h> |
1da177e4 LT |
49 | #include <linux/ipv6.h> |
50 | #include <linux/icmpv6.h> | |
4a3e2f71 | 51 | #include <linux/mutex.h> |
1da177e4 LT |
52 | |
53 | struct ipcomp6_tfms { | |
54 | struct list_head list; | |
e4d5b79c | 55 | struct crypto_comp **tfms; |
1da177e4 LT |
56 | int users; |
57 | }; | |
58 | ||
4a3e2f71 | 59 | static DEFINE_MUTEX(ipcomp6_resource_mutex); |
1da177e4 LT |
60 | static void **ipcomp6_scratches; |
61 | static int ipcomp6_scratch_users; | |
62 | static LIST_HEAD(ipcomp6_tfms_list); | |
63 | ||
e695633e | 64 | static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 | 65 | { |
364c6bad | 66 | int err = -ENOMEM; |
87bdc48d | 67 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
68 | int plen, dlen; |
69 | struct ipcomp_data *ipcd = x->data; | |
70 | u8 *start, *scratch; | |
e4d5b79c | 71 | struct crypto_comp *tfm; |
1da177e4 LT |
72 | int cpu; |
73 | ||
364c6bad | 74 | if (skb_linearize_cow(skb)) |
1da177e4 | 75 | goto out; |
1da177e4 LT |
76 | |
77 | skb->ip_summed = CHECKSUM_NONE; | |
78 | ||
79 | /* Remove ipcomp header and decompress original payload */ | |
31a4ab93 | 80 | ipch = (void *)skb->data; |
b0e380b1 | 81 | skb->transport_header = skb->network_header + sizeof(*ipch); |
31a4ab93 | 82 | __skb_pull(skb, sizeof(*ipch)); |
1da177e4 LT |
83 | |
84 | /* decompression */ | |
85 | plen = skb->len; | |
86 | dlen = IPCOMP_SCRATCH_SIZE; | |
87 | start = skb->data; | |
88 | ||
89 | cpu = get_cpu(); | |
90 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
91 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
92 | ||
93 | err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen); | |
87bdc48d | 94 | if (err) |
1da177e4 | 95 | goto out_put_cpu; |
1da177e4 | 96 | |
87bdc48d | 97 | if (dlen < (plen + sizeof(*ipch))) { |
1da177e4 LT |
98 | err = -EINVAL; |
99 | goto out_put_cpu; | |
100 | } | |
101 | ||
102 | err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC); | |
103 | if (err) { | |
104 | goto out_put_cpu; | |
105 | } | |
106 | ||
da952315 HX |
107 | skb->truesize += dlen - plen; |
108 | __skb_put(skb, dlen - plen); | |
27d7ff46 | 109 | skb_copy_to_linear_data(skb, scratch, dlen); |
31a4ab93 | 110 | err = ipch->nexthdr; |
1da177e4 | 111 | |
1da177e4 LT |
112 | out_put_cpu: |
113 | put_cpu(); | |
114 | out: | |
1da177e4 LT |
115 | return err; |
116 | } | |
117 | ||
118 | static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb) | |
119 | { | |
120 | int err; | |
87bdc48d | 121 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
122 | struct ipcomp_data *ipcd = x->data; |
123 | int plen, dlen; | |
124 | u8 *start, *scratch; | |
e4d5b79c | 125 | struct crypto_comp *tfm; |
1da177e4 | 126 | int cpu; |
1da177e4 LT |
127 | |
128 | /* check whether datagram len is larger than threshold */ | |
ceb1eec8 | 129 | if (skb->len < ipcd->threshold) { |
1da177e4 LT |
130 | goto out_ok; |
131 | } | |
132 | ||
364c6bad | 133 | if (skb_linearize_cow(skb)) |
1da177e4 | 134 | goto out_ok; |
1da177e4 LT |
135 | |
136 | /* compression */ | |
ceb1eec8 | 137 | plen = skb->len; |
1da177e4 | 138 | dlen = IPCOMP_SCRATCH_SIZE; |
ceb1eec8 | 139 | start = skb->data; |
1da177e4 LT |
140 | |
141 | cpu = get_cpu(); | |
142 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
143 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
144 | ||
145 | err = crypto_comp_compress(tfm, start, plen, scratch, &dlen); | |
87bdc48d | 146 | if (err || (dlen + sizeof(*ipch)) >= plen) { |
1da177e4 LT |
147 | put_cpu(); |
148 | goto out_ok; | |
149 | } | |
150 | memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen); | |
151 | put_cpu(); | |
ceb1eec8 | 152 | pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr)); |
1da177e4 LT |
153 | |
154 | /* insert ipcomp header and replace datagram */ | |
87bdc48d | 155 | ipch = ip_comp_hdr(skb); |
007f0211 | 156 | ipch->nexthdr = *skb_mac_header(skb); |
1da177e4 LT |
157 | ipch->flags = 0; |
158 | ipch->cpi = htons((u16 )ntohl(x->id.spi)); | |
007f0211 | 159 | *skb_mac_header(skb) = IPPROTO_COMP; |
1da177e4 LT |
160 | |
161 | out_ok: | |
ceb1eec8 HX |
162 | skb_push(skb, -skb_network_offset(skb)); |
163 | ||
1da177e4 LT |
164 | return 0; |
165 | } | |
166 | ||
167 | static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, | |
1ab1457c | 168 | int type, int code, int offset, __be32 info) |
1da177e4 | 169 | { |
a94cfd19 | 170 | __be32 spi; |
1da177e4 | 171 | struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; |
87bdc48d HX |
172 | struct ip_comp_hdr *ipcomph = |
173 | (struct ip_comp_hdr *)(skb->data + offset); | |
1da177e4 LT |
174 | struct xfrm_state *x; |
175 | ||
176 | if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG) | |
177 | return; | |
178 | ||
4195f814 | 179 | spi = htonl(ntohs(ipcomph->cpi)); |
1da177e4 LT |
180 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6); |
181 | if (!x) | |
182 | return; | |
183 | ||
46b86a2d | 184 | printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n", |
1da177e4 LT |
185 | spi, NIP6(iph->daddr)); |
186 | xfrm_state_put(x); | |
187 | } | |
188 | ||
189 | static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) | |
190 | { | |
191 | struct xfrm_state *t = NULL; | |
0a69452c | 192 | u8 mode = XFRM_MODE_TUNNEL; |
1da177e4 LT |
193 | |
194 | t = xfrm_state_alloc(); | |
195 | if (!t) | |
196 | goto out; | |
197 | ||
198 | t->id.proto = IPPROTO_IPV6; | |
199 | t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr); | |
6abaaaae HX |
200 | if (!t->id.spi) |
201 | goto error; | |
202 | ||
1da177e4 LT |
203 | memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); |
204 | memcpy(&t->sel, &x->sel, sizeof(t->sel)); | |
205 | t->props.family = AF_INET6; | |
0a69452c DB |
206 | if (x->props.mode == XFRM_MODE_BEET) |
207 | mode = x->props.mode; | |
208 | t->props.mode = mode; | |
1da177e4 LT |
209 | memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); |
210 | ||
72cb6962 | 211 | if (xfrm_init_state(t)) |
1da177e4 LT |
212 | goto error; |
213 | ||
1da177e4 LT |
214 | atomic_set(&t->tunnel_users, 1); |
215 | ||
216 | out: | |
217 | return t; | |
218 | ||
219 | error: | |
6abaaaae | 220 | t->km.state = XFRM_STATE_DEAD; |
1da177e4 | 221 | xfrm_state_put(t); |
6abaaaae | 222 | t = NULL; |
1da177e4 LT |
223 | goto out; |
224 | } | |
225 | ||
226 | static int ipcomp6_tunnel_attach(struct xfrm_state *x) | |
227 | { | |
228 | int err = 0; | |
229 | struct xfrm_state *t = NULL; | |
a94cfd19 | 230 | __be32 spi; |
1da177e4 LT |
231 | |
232 | spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr); | |
233 | if (spi) | |
234 | t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr, | |
235 | spi, IPPROTO_IPV6, AF_INET6); | |
236 | if (!t) { | |
237 | t = ipcomp6_tunnel_create(x); | |
238 | if (!t) { | |
239 | err = -EINVAL; | |
240 | goto out; | |
241 | } | |
242 | xfrm_state_insert(t); | |
243 | xfrm_state_hold(t); | |
244 | } | |
245 | x->tunnel = t; | |
246 | atomic_inc(&t->tunnel_users); | |
247 | ||
248 | out: | |
249 | return err; | |
250 | } | |
251 | ||
252 | static void ipcomp6_free_scratches(void) | |
253 | { | |
254 | int i; | |
255 | void **scratches; | |
256 | ||
257 | if (--ipcomp6_scratch_users) | |
258 | return; | |
259 | ||
260 | scratches = ipcomp6_scratches; | |
261 | if (!scratches) | |
262 | return; | |
263 | ||
6f912042 | 264 | for_each_possible_cpu(i) { |
1da177e4 | 265 | void *scratch = *per_cpu_ptr(scratches, i); |
2b191bef JJ |
266 | |
267 | vfree(scratch); | |
1da177e4 LT |
268 | } |
269 | ||
270 | free_percpu(scratches); | |
271 | } | |
272 | ||
273 | static void **ipcomp6_alloc_scratches(void) | |
274 | { | |
275 | int i; | |
276 | void **scratches; | |
277 | ||
278 | if (ipcomp6_scratch_users++) | |
279 | return ipcomp6_scratches; | |
280 | ||
281 | scratches = alloc_percpu(void *); | |
282 | if (!scratches) | |
283 | return NULL; | |
284 | ||
285 | ipcomp6_scratches = scratches; | |
286 | ||
6f912042 | 287 | for_each_possible_cpu(i) { |
1da177e4 LT |
288 | void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE); |
289 | if (!scratch) | |
290 | return NULL; | |
291 | *per_cpu_ptr(scratches, i) = scratch; | |
292 | } | |
293 | ||
294 | return scratches; | |
295 | } | |
296 | ||
e4d5b79c | 297 | static void ipcomp6_free_tfms(struct crypto_comp **tfms) |
1da177e4 LT |
298 | { |
299 | struct ipcomp6_tfms *pos; | |
300 | int cpu; | |
301 | ||
302 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
303 | if (pos->tfms == tfms) | |
304 | break; | |
305 | } | |
306 | ||
307 | BUG_TRAP(pos); | |
308 | ||
309 | if (--pos->users) | |
310 | return; | |
311 | ||
312 | list_del(&pos->list); | |
313 | kfree(pos); | |
314 | ||
315 | if (!tfms) | |
316 | return; | |
317 | ||
6f912042 | 318 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
319 | struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu); |
320 | crypto_free_comp(tfm); | |
1da177e4 LT |
321 | } |
322 | free_percpu(tfms); | |
323 | } | |
324 | ||
e4d5b79c | 325 | static struct crypto_comp **ipcomp6_alloc_tfms(const char *alg_name) |
1da177e4 LT |
326 | { |
327 | struct ipcomp6_tfms *pos; | |
e4d5b79c | 328 | struct crypto_comp **tfms; |
1da177e4 LT |
329 | int cpu; |
330 | ||
331 | /* This can be any valid CPU ID so we don't need locking. */ | |
6fc8b9e7 | 332 | cpu = raw_smp_processor_id(); |
1da177e4 LT |
333 | |
334 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
e4d5b79c | 335 | struct crypto_comp *tfm; |
1da177e4 LT |
336 | |
337 | tfms = pos->tfms; | |
338 | tfm = *per_cpu_ptr(tfms, cpu); | |
339 | ||
e4d5b79c | 340 | if (!strcmp(crypto_comp_name(tfm), alg_name)) { |
1da177e4 LT |
341 | pos->users++; |
342 | return tfms; | |
343 | } | |
344 | } | |
345 | ||
346 | pos = kmalloc(sizeof(*pos), GFP_KERNEL); | |
347 | if (!pos) | |
348 | return NULL; | |
349 | ||
350 | pos->users = 1; | |
351 | INIT_LIST_HEAD(&pos->list); | |
352 | list_add(&pos->list, &ipcomp6_tfms_list); | |
353 | ||
e4d5b79c | 354 | pos->tfms = tfms = alloc_percpu(struct crypto_comp *); |
1da177e4 LT |
355 | if (!tfms) |
356 | goto error; | |
357 | ||
6f912042 | 358 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
359 | struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0, |
360 | CRYPTO_ALG_ASYNC); | |
1da177e4 LT |
361 | if (!tfm) |
362 | goto error; | |
363 | *per_cpu_ptr(tfms, cpu) = tfm; | |
364 | } | |
365 | ||
366 | return tfms; | |
367 | ||
368 | error: | |
369 | ipcomp6_free_tfms(tfms); | |
370 | return NULL; | |
371 | } | |
372 | ||
373 | static void ipcomp6_free_data(struct ipcomp_data *ipcd) | |
374 | { | |
375 | if (ipcd->tfms) | |
376 | ipcomp6_free_tfms(ipcd->tfms); | |
377 | ipcomp6_free_scratches(); | |
378 | } | |
379 | ||
380 | static void ipcomp6_destroy(struct xfrm_state *x) | |
381 | { | |
382 | struct ipcomp_data *ipcd = x->data; | |
383 | if (!ipcd) | |
384 | return; | |
385 | xfrm_state_delete_tunnel(x); | |
4a3e2f71 | 386 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 | 387 | ipcomp6_free_data(ipcd); |
4a3e2f71 | 388 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
389 | kfree(ipcd); |
390 | ||
391 | xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr); | |
392 | } | |
393 | ||
72cb6962 | 394 | static int ipcomp6_init_state(struct xfrm_state *x) |
1da177e4 LT |
395 | { |
396 | int err; | |
397 | struct ipcomp_data *ipcd; | |
398 | struct xfrm_algo_desc *calg_desc; | |
399 | ||
400 | err = -EINVAL; | |
401 | if (!x->calg) | |
402 | goto out; | |
403 | ||
404 | if (x->encap) | |
405 | goto out; | |
406 | ||
407 | err = -ENOMEM; | |
0c600eda | 408 | ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL); |
1da177e4 LT |
409 | if (!ipcd) |
410 | goto out; | |
411 | ||
1da177e4 | 412 | x->props.header_len = 0; |
ca68145f HX |
413 | switch (x->props.mode) { |
414 | case XFRM_MODE_BEET: | |
415 | case XFRM_MODE_TRANSPORT: | |
416 | break; | |
417 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 418 | x->props.header_len += sizeof(struct ipv6hdr); |
ca68145f HX |
419 | default: |
420 | goto error; | |
421 | } | |
1ab1457c | 422 | |
4a3e2f71 | 423 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
424 | if (!ipcomp6_alloc_scratches()) |
425 | goto error; | |
426 | ||
427 | ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name); | |
428 | if (!ipcd->tfms) | |
429 | goto error; | |
4a3e2f71 | 430 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 | 431 | |
7e49e6de | 432 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
1da177e4 LT |
433 | err = ipcomp6_tunnel_attach(x); |
434 | if (err) | |
435 | goto error_tunnel; | |
436 | } | |
437 | ||
438 | calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0); | |
439 | BUG_ON(!calg_desc); | |
440 | ipcd->threshold = calg_desc->uinfo.comp.threshold; | |
441 | x->data = ipcd; | |
442 | err = 0; | |
443 | out: | |
444 | return err; | |
445 | error_tunnel: | |
4a3e2f71 | 446 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
447 | error: |
448 | ipcomp6_free_data(ipcd); | |
4a3e2f71 | 449 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
450 | kfree(ipcd); |
451 | ||
452 | goto out; | |
453 | } | |
454 | ||
1ab1457c | 455 | static struct xfrm_type ipcomp6_type = |
1da177e4 LT |
456 | { |
457 | .description = "IPCOMP6", | |
458 | .owner = THIS_MODULE, | |
459 | .proto = IPPROTO_COMP, | |
460 | .init_state = ipcomp6_init_state, | |
461 | .destructor = ipcomp6_destroy, | |
462 | .input = ipcomp6_input, | |
463 | .output = ipcomp6_output, | |
aee5adb4 | 464 | .hdr_offset = xfrm6_find_1stfragopt, |
1da177e4 LT |
465 | }; |
466 | ||
1ab1457c | 467 | static struct inet6_protocol ipcomp6_protocol = |
1da177e4 LT |
468 | { |
469 | .handler = xfrm6_rcv, | |
470 | .err_handler = ipcomp6_err, | |
471 | .flags = INET6_PROTO_NOPOLICY, | |
472 | }; | |
473 | ||
474 | static int __init ipcomp6_init(void) | |
475 | { | |
476 | if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { | |
477 | printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); | |
478 | return -EAGAIN; | |
479 | } | |
480 | if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { | |
481 | printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); | |
482 | xfrm_unregister_type(&ipcomp6_type, AF_INET6); | |
483 | return -EAGAIN; | |
484 | } | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static void __exit ipcomp6_fini(void) | |
489 | { | |
1ab1457c | 490 | if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) |
1da177e4 LT |
491 | printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); |
492 | if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) | |
493 | printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); | |
494 | } | |
495 | ||
496 | module_init(ipcomp6_init); | |
497 | module_exit(ipcomp6_fini); | |
498 | MODULE_LICENSE("GPL"); | |
499 | MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); | |
500 | MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); | |
501 | ||
d3d6dd3a | 502 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); |