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> | |
4999f362 | 39 | #include <linux/err.h> |
1da177e4 LT |
40 | #include <linux/pfkeyv2.h> |
41 | #include <linux/random.h> | |
42 | #include <linux/percpu.h> | |
43 | #include <linux/smp.h> | |
44 | #include <linux/list.h> | |
45 | #include <linux/vmalloc.h> | |
46 | #include <linux/rtnetlink.h> | |
47 | #include <net/icmp.h> | |
48 | #include <net/ipv6.h> | |
14c85021 | 49 | #include <net/protocol.h> |
1da177e4 LT |
50 | #include <linux/ipv6.h> |
51 | #include <linux/icmpv6.h> | |
4a3e2f71 | 52 | #include <linux/mutex.h> |
1da177e4 LT |
53 | |
54 | struct ipcomp6_tfms { | |
55 | struct list_head list; | |
e4d5b79c | 56 | struct crypto_comp **tfms; |
1da177e4 LT |
57 | int users; |
58 | }; | |
59 | ||
4a3e2f71 | 60 | static DEFINE_MUTEX(ipcomp6_resource_mutex); |
1da177e4 LT |
61 | static void **ipcomp6_scratches; |
62 | static int ipcomp6_scratch_users; | |
63 | static LIST_HEAD(ipcomp6_tfms_list); | |
64 | ||
e695633e | 65 | static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 | 66 | { |
364c6bad | 67 | int err = -ENOMEM; |
87bdc48d | 68 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
69 | int plen, dlen; |
70 | struct ipcomp_data *ipcd = x->data; | |
71 | u8 *start, *scratch; | |
e4d5b79c | 72 | struct crypto_comp *tfm; |
1da177e4 LT |
73 | int cpu; |
74 | ||
364c6bad | 75 | if (skb_linearize_cow(skb)) |
1da177e4 | 76 | goto out; |
1da177e4 LT |
77 | |
78 | skb->ip_summed = CHECKSUM_NONE; | |
79 | ||
80 | /* Remove ipcomp header and decompress original payload */ | |
31a4ab93 | 81 | ipch = (void *)skb->data; |
b0e380b1 | 82 | skb->transport_header = skb->network_header + sizeof(*ipch); |
31a4ab93 | 83 | __skb_pull(skb, sizeof(*ipch)); |
1da177e4 LT |
84 | |
85 | /* decompression */ | |
86 | plen = skb->len; | |
87 | dlen = IPCOMP_SCRATCH_SIZE; | |
88 | start = skb->data; | |
89 | ||
90 | cpu = get_cpu(); | |
91 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
92 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
93 | ||
94 | err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen); | |
87bdc48d | 95 | if (err) |
1da177e4 | 96 | goto out_put_cpu; |
1da177e4 | 97 | |
87bdc48d | 98 | if (dlen < (plen + sizeof(*ipch))) { |
1da177e4 LT |
99 | err = -EINVAL; |
100 | goto out_put_cpu; | |
101 | } | |
102 | ||
103 | err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC); | |
104 | if (err) { | |
105 | goto out_put_cpu; | |
106 | } | |
107 | ||
da952315 HX |
108 | skb->truesize += dlen - plen; |
109 | __skb_put(skb, dlen - plen); | |
27d7ff46 | 110 | skb_copy_to_linear_data(skb, scratch, dlen); |
31a4ab93 | 111 | err = ipch->nexthdr; |
1da177e4 | 112 | |
1da177e4 LT |
113 | out_put_cpu: |
114 | put_cpu(); | |
115 | out: | |
1da177e4 LT |
116 | return err; |
117 | } | |
118 | ||
119 | static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb) | |
120 | { | |
121 | int err; | |
87bdc48d | 122 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
123 | struct ipcomp_data *ipcd = x->data; |
124 | int plen, dlen; | |
125 | u8 *start, *scratch; | |
e4d5b79c | 126 | struct crypto_comp *tfm; |
1da177e4 | 127 | int cpu; |
1da177e4 LT |
128 | |
129 | /* check whether datagram len is larger than threshold */ | |
ceb1eec8 | 130 | if (skb->len < ipcd->threshold) { |
1da177e4 LT |
131 | goto out_ok; |
132 | } | |
133 | ||
364c6bad | 134 | if (skb_linearize_cow(skb)) |
1da177e4 | 135 | goto out_ok; |
1da177e4 LT |
136 | |
137 | /* compression */ | |
ceb1eec8 | 138 | plen = skb->len; |
1da177e4 | 139 | dlen = IPCOMP_SCRATCH_SIZE; |
ceb1eec8 | 140 | start = skb->data; |
1da177e4 LT |
141 | |
142 | cpu = get_cpu(); | |
143 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
144 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
145 | ||
146 | err = crypto_comp_compress(tfm, start, plen, scratch, &dlen); | |
87bdc48d | 147 | if (err || (dlen + sizeof(*ipch)) >= plen) { |
1da177e4 LT |
148 | put_cpu(); |
149 | goto out_ok; | |
150 | } | |
151 | memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen); | |
152 | put_cpu(); | |
ceb1eec8 | 153 | pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr)); |
1da177e4 LT |
154 | |
155 | /* insert ipcomp header and replace datagram */ | |
87bdc48d | 156 | ipch = ip_comp_hdr(skb); |
007f0211 | 157 | ipch->nexthdr = *skb_mac_header(skb); |
1da177e4 LT |
158 | ipch->flags = 0; |
159 | ipch->cpi = htons((u16 )ntohl(x->id.spi)); | |
007f0211 | 160 | *skb_mac_header(skb) = IPPROTO_COMP; |
1da177e4 LT |
161 | |
162 | out_ok: | |
ceb1eec8 HX |
163 | skb_push(skb, -skb_network_offset(skb)); |
164 | ||
1da177e4 LT |
165 | return 0; |
166 | } | |
167 | ||
168 | static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, | |
1ab1457c | 169 | int type, int code, int offset, __be32 info) |
1da177e4 | 170 | { |
a94cfd19 | 171 | __be32 spi; |
1da177e4 | 172 | struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; |
87bdc48d HX |
173 | struct ip_comp_hdr *ipcomph = |
174 | (struct ip_comp_hdr *)(skb->data + offset); | |
1da177e4 LT |
175 | struct xfrm_state *x; |
176 | ||
177 | if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG) | |
178 | return; | |
179 | ||
4195f814 | 180 | spi = htonl(ntohs(ipcomph->cpi)); |
1da177e4 LT |
181 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6); |
182 | if (!x) | |
183 | return; | |
184 | ||
46b86a2d | 185 | printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n", |
1da177e4 LT |
186 | spi, NIP6(iph->daddr)); |
187 | xfrm_state_put(x); | |
188 | } | |
189 | ||
190 | static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) | |
191 | { | |
192 | struct xfrm_state *t = NULL; | |
0a69452c | 193 | u8 mode = XFRM_MODE_TUNNEL; |
1da177e4 LT |
194 | |
195 | t = xfrm_state_alloc(); | |
196 | if (!t) | |
197 | goto out; | |
198 | ||
199 | t->id.proto = IPPROTO_IPV6; | |
200 | t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr); | |
6abaaaae HX |
201 | if (!t->id.spi) |
202 | goto error; | |
203 | ||
1da177e4 LT |
204 | memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); |
205 | memcpy(&t->sel, &x->sel, sizeof(t->sel)); | |
206 | t->props.family = AF_INET6; | |
0a69452c DB |
207 | if (x->props.mode == XFRM_MODE_BEET) |
208 | mode = x->props.mode; | |
209 | t->props.mode = mode; | |
1da177e4 LT |
210 | memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); |
211 | ||
72cb6962 | 212 | if (xfrm_init_state(t)) |
1da177e4 LT |
213 | goto error; |
214 | ||
1da177e4 LT |
215 | atomic_set(&t->tunnel_users, 1); |
216 | ||
217 | out: | |
218 | return t; | |
219 | ||
220 | error: | |
6abaaaae | 221 | t->km.state = XFRM_STATE_DEAD; |
1da177e4 | 222 | xfrm_state_put(t); |
6abaaaae | 223 | t = NULL; |
1da177e4 LT |
224 | goto out; |
225 | } | |
226 | ||
227 | static int ipcomp6_tunnel_attach(struct xfrm_state *x) | |
228 | { | |
229 | int err = 0; | |
230 | struct xfrm_state *t = NULL; | |
a94cfd19 | 231 | __be32 spi; |
1da177e4 LT |
232 | |
233 | spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr); | |
234 | if (spi) | |
235 | t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr, | |
236 | spi, IPPROTO_IPV6, AF_INET6); | |
237 | if (!t) { | |
238 | t = ipcomp6_tunnel_create(x); | |
239 | if (!t) { | |
240 | err = -EINVAL; | |
241 | goto out; | |
242 | } | |
243 | xfrm_state_insert(t); | |
244 | xfrm_state_hold(t); | |
245 | } | |
246 | x->tunnel = t; | |
247 | atomic_inc(&t->tunnel_users); | |
248 | ||
249 | out: | |
250 | return err; | |
251 | } | |
252 | ||
253 | static void ipcomp6_free_scratches(void) | |
254 | { | |
255 | int i; | |
256 | void **scratches; | |
257 | ||
258 | if (--ipcomp6_scratch_users) | |
259 | return; | |
260 | ||
261 | scratches = ipcomp6_scratches; | |
262 | if (!scratches) | |
263 | return; | |
264 | ||
6f912042 | 265 | for_each_possible_cpu(i) { |
1da177e4 | 266 | void *scratch = *per_cpu_ptr(scratches, i); |
2b191bef JJ |
267 | |
268 | vfree(scratch); | |
1da177e4 LT |
269 | } |
270 | ||
271 | free_percpu(scratches); | |
272 | } | |
273 | ||
274 | static void **ipcomp6_alloc_scratches(void) | |
275 | { | |
276 | int i; | |
277 | void **scratches; | |
278 | ||
279 | if (ipcomp6_scratch_users++) | |
280 | return ipcomp6_scratches; | |
281 | ||
282 | scratches = alloc_percpu(void *); | |
283 | if (!scratches) | |
284 | return NULL; | |
285 | ||
286 | ipcomp6_scratches = scratches; | |
287 | ||
6f912042 | 288 | for_each_possible_cpu(i) { |
1da177e4 LT |
289 | void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE); |
290 | if (!scratch) | |
291 | return NULL; | |
292 | *per_cpu_ptr(scratches, i) = scratch; | |
293 | } | |
294 | ||
295 | return scratches; | |
296 | } | |
297 | ||
e4d5b79c | 298 | static void ipcomp6_free_tfms(struct crypto_comp **tfms) |
1da177e4 LT |
299 | { |
300 | struct ipcomp6_tfms *pos; | |
301 | int cpu; | |
302 | ||
303 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
304 | if (pos->tfms == tfms) | |
305 | break; | |
306 | } | |
307 | ||
308 | BUG_TRAP(pos); | |
309 | ||
310 | if (--pos->users) | |
311 | return; | |
312 | ||
313 | list_del(&pos->list); | |
314 | kfree(pos); | |
315 | ||
316 | if (!tfms) | |
317 | return; | |
318 | ||
6f912042 | 319 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
320 | struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu); |
321 | crypto_free_comp(tfm); | |
1da177e4 LT |
322 | } |
323 | free_percpu(tfms); | |
324 | } | |
325 | ||
e4d5b79c | 326 | static struct crypto_comp **ipcomp6_alloc_tfms(const char *alg_name) |
1da177e4 LT |
327 | { |
328 | struct ipcomp6_tfms *pos; | |
e4d5b79c | 329 | struct crypto_comp **tfms; |
1da177e4 LT |
330 | int cpu; |
331 | ||
332 | /* This can be any valid CPU ID so we don't need locking. */ | |
6fc8b9e7 | 333 | cpu = raw_smp_processor_id(); |
1da177e4 LT |
334 | |
335 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
e4d5b79c | 336 | struct crypto_comp *tfm; |
1da177e4 LT |
337 | |
338 | tfms = pos->tfms; | |
339 | tfm = *per_cpu_ptr(tfms, cpu); | |
340 | ||
e4d5b79c | 341 | if (!strcmp(crypto_comp_name(tfm), alg_name)) { |
1da177e4 LT |
342 | pos->users++; |
343 | return tfms; | |
344 | } | |
345 | } | |
346 | ||
347 | pos = kmalloc(sizeof(*pos), GFP_KERNEL); | |
348 | if (!pos) | |
349 | return NULL; | |
350 | ||
351 | pos->users = 1; | |
352 | INIT_LIST_HEAD(&pos->list); | |
353 | list_add(&pos->list, &ipcomp6_tfms_list); | |
354 | ||
e4d5b79c | 355 | pos->tfms = tfms = alloc_percpu(struct crypto_comp *); |
1da177e4 LT |
356 | if (!tfms) |
357 | goto error; | |
358 | ||
6f912042 | 359 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
360 | struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0, |
361 | CRYPTO_ALG_ASYNC); | |
4999f362 | 362 | if (IS_ERR(tfm)) |
1da177e4 LT |
363 | goto error; |
364 | *per_cpu_ptr(tfms, cpu) = tfm; | |
365 | } | |
366 | ||
367 | return tfms; | |
368 | ||
369 | error: | |
370 | ipcomp6_free_tfms(tfms); | |
371 | return NULL; | |
372 | } | |
373 | ||
374 | static void ipcomp6_free_data(struct ipcomp_data *ipcd) | |
375 | { | |
376 | if (ipcd->tfms) | |
377 | ipcomp6_free_tfms(ipcd->tfms); | |
378 | ipcomp6_free_scratches(); | |
379 | } | |
380 | ||
381 | static void ipcomp6_destroy(struct xfrm_state *x) | |
382 | { | |
383 | struct ipcomp_data *ipcd = x->data; | |
384 | if (!ipcd) | |
385 | return; | |
386 | xfrm_state_delete_tunnel(x); | |
4a3e2f71 | 387 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 | 388 | ipcomp6_free_data(ipcd); |
4a3e2f71 | 389 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
390 | kfree(ipcd); |
391 | ||
392 | xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr); | |
393 | } | |
394 | ||
72cb6962 | 395 | static int ipcomp6_init_state(struct xfrm_state *x) |
1da177e4 LT |
396 | { |
397 | int err; | |
398 | struct ipcomp_data *ipcd; | |
399 | struct xfrm_algo_desc *calg_desc; | |
400 | ||
401 | err = -EINVAL; | |
402 | if (!x->calg) | |
403 | goto out; | |
404 | ||
405 | if (x->encap) | |
406 | goto out; | |
407 | ||
408 | err = -ENOMEM; | |
0c600eda | 409 | ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL); |
1da177e4 LT |
410 | if (!ipcd) |
411 | goto out; | |
412 | ||
1da177e4 | 413 | x->props.header_len = 0; |
ca68145f HX |
414 | switch (x->props.mode) { |
415 | case XFRM_MODE_BEET: | |
416 | case XFRM_MODE_TRANSPORT: | |
417 | break; | |
418 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 419 | x->props.header_len += sizeof(struct ipv6hdr); |
ca68145f HX |
420 | default: |
421 | goto error; | |
422 | } | |
1ab1457c | 423 | |
4a3e2f71 | 424 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
425 | if (!ipcomp6_alloc_scratches()) |
426 | goto error; | |
427 | ||
428 | ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name); | |
429 | if (!ipcd->tfms) | |
430 | goto error; | |
4a3e2f71 | 431 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 | 432 | |
7e49e6de | 433 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
1da177e4 LT |
434 | err = ipcomp6_tunnel_attach(x); |
435 | if (err) | |
436 | goto error_tunnel; | |
437 | } | |
438 | ||
439 | calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0); | |
440 | BUG_ON(!calg_desc); | |
441 | ipcd->threshold = calg_desc->uinfo.comp.threshold; | |
442 | x->data = ipcd; | |
443 | err = 0; | |
444 | out: | |
445 | return err; | |
446 | error_tunnel: | |
4a3e2f71 | 447 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
448 | error: |
449 | ipcomp6_free_data(ipcd); | |
4a3e2f71 | 450 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
451 | kfree(ipcd); |
452 | ||
453 | goto out; | |
454 | } | |
455 | ||
1ab1457c | 456 | static struct xfrm_type ipcomp6_type = |
1da177e4 LT |
457 | { |
458 | .description = "IPCOMP6", | |
459 | .owner = THIS_MODULE, | |
460 | .proto = IPPROTO_COMP, | |
461 | .init_state = ipcomp6_init_state, | |
462 | .destructor = ipcomp6_destroy, | |
463 | .input = ipcomp6_input, | |
464 | .output = ipcomp6_output, | |
aee5adb4 | 465 | .hdr_offset = xfrm6_find_1stfragopt, |
1da177e4 LT |
466 | }; |
467 | ||
1ab1457c | 468 | static struct inet6_protocol ipcomp6_protocol = |
1da177e4 LT |
469 | { |
470 | .handler = xfrm6_rcv, | |
471 | .err_handler = ipcomp6_err, | |
472 | .flags = INET6_PROTO_NOPOLICY, | |
473 | }; | |
474 | ||
475 | static int __init ipcomp6_init(void) | |
476 | { | |
477 | if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { | |
478 | printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); | |
479 | return -EAGAIN; | |
480 | } | |
481 | if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { | |
482 | printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); | |
483 | xfrm_unregister_type(&ipcomp6_type, AF_INET6); | |
484 | return -EAGAIN; | |
485 | } | |
486 | return 0; | |
487 | } | |
488 | ||
489 | static void __exit ipcomp6_fini(void) | |
490 | { | |
1ab1457c | 491 | if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) |
1da177e4 LT |
492 | printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); |
493 | if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) | |
494 | printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); | |
495 | } | |
496 | ||
497 | module_init(ipcomp6_init); | |
498 | module_exit(ipcomp6_fini); | |
499 | MODULE_LICENSE("GPL"); | |
500 | MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); | |
501 | MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); | |
502 | ||
d3d6dd3a | 503 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); |