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 | { |
2614fa59 | 67 | int nexthdr; |
364c6bad | 68 | int err = -ENOMEM; |
87bdc48d | 69 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
70 | int plen, dlen; |
71 | struct ipcomp_data *ipcd = x->data; | |
72 | u8 *start, *scratch; | |
e4d5b79c | 73 | struct crypto_comp *tfm; |
1da177e4 LT |
74 | int cpu; |
75 | ||
364c6bad | 76 | if (skb_linearize_cow(skb)) |
1da177e4 | 77 | goto out; |
1da177e4 LT |
78 | |
79 | skb->ip_summed = CHECKSUM_NONE; | |
80 | ||
81 | /* Remove ipcomp header and decompress original payload */ | |
31a4ab93 | 82 | ipch = (void *)skb->data; |
2614fa59 HX |
83 | nexthdr = ipch->nexthdr; |
84 | ||
b0e380b1 | 85 | skb->transport_header = skb->network_header + sizeof(*ipch); |
31a4ab93 | 86 | __skb_pull(skb, sizeof(*ipch)); |
1da177e4 LT |
87 | |
88 | /* decompression */ | |
89 | plen = skb->len; | |
90 | dlen = IPCOMP_SCRATCH_SIZE; | |
91 | start = skb->data; | |
92 | ||
93 | cpu = get_cpu(); | |
94 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
95 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
96 | ||
97 | err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen); | |
87bdc48d | 98 | if (err) |
1da177e4 | 99 | goto out_put_cpu; |
1da177e4 | 100 | |
87bdc48d | 101 | if (dlen < (plen + sizeof(*ipch))) { |
1da177e4 LT |
102 | err = -EINVAL; |
103 | goto out_put_cpu; | |
104 | } | |
105 | ||
106 | err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC); | |
107 | if (err) { | |
108 | goto out_put_cpu; | |
109 | } | |
110 | ||
da952315 HX |
111 | skb->truesize += dlen - plen; |
112 | __skb_put(skb, dlen - plen); | |
27d7ff46 | 113 | skb_copy_to_linear_data(skb, scratch, dlen); |
2614fa59 | 114 | err = nexthdr; |
1da177e4 | 115 | |
1da177e4 LT |
116 | out_put_cpu: |
117 | put_cpu(); | |
118 | out: | |
1da177e4 LT |
119 | return err; |
120 | } | |
121 | ||
122 | static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb) | |
123 | { | |
124 | int err; | |
87bdc48d | 125 | struct ip_comp_hdr *ipch; |
1da177e4 LT |
126 | struct ipcomp_data *ipcd = x->data; |
127 | int plen, dlen; | |
128 | u8 *start, *scratch; | |
e4d5b79c | 129 | struct crypto_comp *tfm; |
1da177e4 | 130 | int cpu; |
1da177e4 LT |
131 | |
132 | /* check whether datagram len is larger than threshold */ | |
ceb1eec8 | 133 | if (skb->len < ipcd->threshold) { |
1da177e4 LT |
134 | goto out_ok; |
135 | } | |
136 | ||
364c6bad | 137 | if (skb_linearize_cow(skb)) |
1da177e4 | 138 | goto out_ok; |
1da177e4 LT |
139 | |
140 | /* compression */ | |
ceb1eec8 | 141 | plen = skb->len; |
1da177e4 | 142 | dlen = IPCOMP_SCRATCH_SIZE; |
ceb1eec8 | 143 | start = skb->data; |
1da177e4 LT |
144 | |
145 | cpu = get_cpu(); | |
146 | scratch = *per_cpu_ptr(ipcomp6_scratches, cpu); | |
147 | tfm = *per_cpu_ptr(ipcd->tfms, cpu); | |
148 | ||
21e43188 | 149 | local_bh_disable(); |
1da177e4 | 150 | err = crypto_comp_compress(tfm, start, plen, scratch, &dlen); |
21e43188 | 151 | local_bh_enable(); |
87bdc48d | 152 | if (err || (dlen + sizeof(*ipch)) >= plen) { |
1da177e4 LT |
153 | put_cpu(); |
154 | goto out_ok; | |
155 | } | |
156 | memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen); | |
157 | put_cpu(); | |
ceb1eec8 | 158 | pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr)); |
1da177e4 LT |
159 | |
160 | /* insert ipcomp header and replace datagram */ | |
87bdc48d | 161 | ipch = ip_comp_hdr(skb); |
007f0211 | 162 | ipch->nexthdr = *skb_mac_header(skb); |
1da177e4 LT |
163 | ipch->flags = 0; |
164 | ipch->cpi = htons((u16 )ntohl(x->id.spi)); | |
007f0211 | 165 | *skb_mac_header(skb) = IPPROTO_COMP; |
1da177e4 LT |
166 | |
167 | out_ok: | |
ceb1eec8 HX |
168 | skb_push(skb, -skb_network_offset(skb)); |
169 | ||
1da177e4 LT |
170 | return 0; |
171 | } | |
172 | ||
173 | static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, | |
1ab1457c | 174 | int type, int code, int offset, __be32 info) |
1da177e4 | 175 | { |
a94cfd19 | 176 | __be32 spi; |
1da177e4 | 177 | struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; |
87bdc48d HX |
178 | struct ip_comp_hdr *ipcomph = |
179 | (struct ip_comp_hdr *)(skb->data + offset); | |
1da177e4 LT |
180 | struct xfrm_state *x; |
181 | ||
182 | if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG) | |
183 | return; | |
184 | ||
4195f814 | 185 | spi = htonl(ntohs(ipcomph->cpi)); |
1da177e4 LT |
186 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6); |
187 | if (!x) | |
188 | return; | |
189 | ||
46b86a2d | 190 | printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n", |
1da177e4 LT |
191 | spi, NIP6(iph->daddr)); |
192 | xfrm_state_put(x); | |
193 | } | |
194 | ||
195 | static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) | |
196 | { | |
197 | struct xfrm_state *t = NULL; | |
198 | ||
199 | t = xfrm_state_alloc(); | |
200 | if (!t) | |
201 | goto out; | |
202 | ||
203 | t->id.proto = IPPROTO_IPV6; | |
204 | t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr); | |
6abaaaae HX |
205 | if (!t->id.spi) |
206 | goto error; | |
207 | ||
1da177e4 LT |
208 | memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); |
209 | memcpy(&t->sel, &x->sel, sizeof(t->sel)); | |
210 | t->props.family = AF_INET6; | |
e40b3286 | 211 | t->props.mode = x->props.mode; |
1da177e4 LT |
212 | memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); |
213 | ||
72cb6962 | 214 | if (xfrm_init_state(t)) |
1da177e4 LT |
215 | goto error; |
216 | ||
1da177e4 LT |
217 | atomic_set(&t->tunnel_users, 1); |
218 | ||
219 | out: | |
220 | return t; | |
221 | ||
222 | error: | |
6abaaaae | 223 | t->km.state = XFRM_STATE_DEAD; |
1da177e4 | 224 | xfrm_state_put(t); |
6abaaaae | 225 | t = NULL; |
1da177e4 LT |
226 | goto out; |
227 | } | |
228 | ||
229 | static int ipcomp6_tunnel_attach(struct xfrm_state *x) | |
230 | { | |
231 | int err = 0; | |
232 | struct xfrm_state *t = NULL; | |
a94cfd19 | 233 | __be32 spi; |
1da177e4 LT |
234 | |
235 | spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr); | |
236 | if (spi) | |
237 | t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr, | |
238 | spi, IPPROTO_IPV6, AF_INET6); | |
239 | if (!t) { | |
240 | t = ipcomp6_tunnel_create(x); | |
241 | if (!t) { | |
242 | err = -EINVAL; | |
243 | goto out; | |
244 | } | |
245 | xfrm_state_insert(t); | |
246 | xfrm_state_hold(t); | |
247 | } | |
248 | x->tunnel = t; | |
249 | atomic_inc(&t->tunnel_users); | |
250 | ||
251 | out: | |
252 | return err; | |
253 | } | |
254 | ||
255 | static void ipcomp6_free_scratches(void) | |
256 | { | |
257 | int i; | |
258 | void **scratches; | |
259 | ||
260 | if (--ipcomp6_scratch_users) | |
261 | return; | |
262 | ||
263 | scratches = ipcomp6_scratches; | |
264 | if (!scratches) | |
265 | return; | |
266 | ||
6f912042 | 267 | for_each_possible_cpu(i) { |
1da177e4 | 268 | void *scratch = *per_cpu_ptr(scratches, i); |
2b191bef JJ |
269 | |
270 | vfree(scratch); | |
1da177e4 LT |
271 | } |
272 | ||
273 | free_percpu(scratches); | |
274 | } | |
275 | ||
276 | static void **ipcomp6_alloc_scratches(void) | |
277 | { | |
278 | int i; | |
279 | void **scratches; | |
280 | ||
281 | if (ipcomp6_scratch_users++) | |
282 | return ipcomp6_scratches; | |
283 | ||
284 | scratches = alloc_percpu(void *); | |
285 | if (!scratches) | |
286 | return NULL; | |
287 | ||
288 | ipcomp6_scratches = scratches; | |
289 | ||
6f912042 | 290 | for_each_possible_cpu(i) { |
1da177e4 LT |
291 | void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE); |
292 | if (!scratch) | |
293 | return NULL; | |
294 | *per_cpu_ptr(scratches, i) = scratch; | |
295 | } | |
296 | ||
297 | return scratches; | |
298 | } | |
299 | ||
e4d5b79c | 300 | static void ipcomp6_free_tfms(struct crypto_comp **tfms) |
1da177e4 LT |
301 | { |
302 | struct ipcomp6_tfms *pos; | |
303 | int cpu; | |
304 | ||
305 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
306 | if (pos->tfms == tfms) | |
307 | break; | |
308 | } | |
309 | ||
310 | BUG_TRAP(pos); | |
311 | ||
312 | if (--pos->users) | |
313 | return; | |
314 | ||
315 | list_del(&pos->list); | |
316 | kfree(pos); | |
317 | ||
318 | if (!tfms) | |
319 | return; | |
320 | ||
6f912042 | 321 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
322 | struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu); |
323 | crypto_free_comp(tfm); | |
1da177e4 LT |
324 | } |
325 | free_percpu(tfms); | |
326 | } | |
327 | ||
e4d5b79c | 328 | static struct crypto_comp **ipcomp6_alloc_tfms(const char *alg_name) |
1da177e4 LT |
329 | { |
330 | struct ipcomp6_tfms *pos; | |
e4d5b79c | 331 | struct crypto_comp **tfms; |
1da177e4 LT |
332 | int cpu; |
333 | ||
334 | /* This can be any valid CPU ID so we don't need locking. */ | |
6fc8b9e7 | 335 | cpu = raw_smp_processor_id(); |
1da177e4 LT |
336 | |
337 | list_for_each_entry(pos, &ipcomp6_tfms_list, list) { | |
e4d5b79c | 338 | struct crypto_comp *tfm; |
1da177e4 LT |
339 | |
340 | tfms = pos->tfms; | |
341 | tfm = *per_cpu_ptr(tfms, cpu); | |
342 | ||
e4d5b79c | 343 | if (!strcmp(crypto_comp_name(tfm), alg_name)) { |
1da177e4 LT |
344 | pos->users++; |
345 | return tfms; | |
346 | } | |
347 | } | |
348 | ||
349 | pos = kmalloc(sizeof(*pos), GFP_KERNEL); | |
350 | if (!pos) | |
351 | return NULL; | |
352 | ||
353 | pos->users = 1; | |
354 | INIT_LIST_HEAD(&pos->list); | |
355 | list_add(&pos->list, &ipcomp6_tfms_list); | |
356 | ||
e4d5b79c | 357 | pos->tfms = tfms = alloc_percpu(struct crypto_comp *); |
1da177e4 LT |
358 | if (!tfms) |
359 | goto error; | |
360 | ||
6f912042 | 361 | for_each_possible_cpu(cpu) { |
e4d5b79c HX |
362 | struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0, |
363 | CRYPTO_ALG_ASYNC); | |
4999f362 | 364 | if (IS_ERR(tfm)) |
1da177e4 LT |
365 | goto error; |
366 | *per_cpu_ptr(tfms, cpu) = tfm; | |
367 | } | |
368 | ||
369 | return tfms; | |
370 | ||
371 | error: | |
372 | ipcomp6_free_tfms(tfms); | |
373 | return NULL; | |
374 | } | |
375 | ||
376 | static void ipcomp6_free_data(struct ipcomp_data *ipcd) | |
377 | { | |
378 | if (ipcd->tfms) | |
379 | ipcomp6_free_tfms(ipcd->tfms); | |
380 | ipcomp6_free_scratches(); | |
381 | } | |
382 | ||
383 | static void ipcomp6_destroy(struct xfrm_state *x) | |
384 | { | |
385 | struct ipcomp_data *ipcd = x->data; | |
386 | if (!ipcd) | |
387 | return; | |
388 | xfrm_state_delete_tunnel(x); | |
4a3e2f71 | 389 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 | 390 | ipcomp6_free_data(ipcd); |
4a3e2f71 | 391 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
392 | kfree(ipcd); |
393 | ||
394 | xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr); | |
395 | } | |
396 | ||
72cb6962 | 397 | static int ipcomp6_init_state(struct xfrm_state *x) |
1da177e4 LT |
398 | { |
399 | int err; | |
400 | struct ipcomp_data *ipcd; | |
401 | struct xfrm_algo_desc *calg_desc; | |
402 | ||
403 | err = -EINVAL; | |
404 | if (!x->calg) | |
405 | goto out; | |
406 | ||
407 | if (x->encap) | |
408 | goto out; | |
409 | ||
1da177e4 | 410 | x->props.header_len = 0; |
ca68145f | 411 | switch (x->props.mode) { |
ca68145f HX |
412 | case XFRM_MODE_TRANSPORT: |
413 | break; | |
414 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 415 | x->props.header_len += sizeof(struct ipv6hdr); |
e40b3286 | 416 | break; |
ca68145f | 417 | default: |
e40b3286 | 418 | goto out; |
ca68145f | 419 | } |
1ab1457c | 420 | |
e40b3286 HX |
421 | err = -ENOMEM; |
422 | ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL); | |
423 | if (!ipcd) | |
424 | goto out; | |
425 | ||
4a3e2f71 | 426 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
427 | if (!ipcomp6_alloc_scratches()) |
428 | goto error; | |
429 | ||
430 | ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name); | |
431 | if (!ipcd->tfms) | |
432 | goto error; | |
4a3e2f71 | 433 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 | 434 | |
7e49e6de | 435 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
1da177e4 LT |
436 | err = ipcomp6_tunnel_attach(x); |
437 | if (err) | |
438 | goto error_tunnel; | |
439 | } | |
440 | ||
441 | calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0); | |
442 | BUG_ON(!calg_desc); | |
443 | ipcd->threshold = calg_desc->uinfo.comp.threshold; | |
444 | x->data = ipcd; | |
445 | err = 0; | |
446 | out: | |
447 | return err; | |
448 | error_tunnel: | |
4a3e2f71 | 449 | mutex_lock(&ipcomp6_resource_mutex); |
1da177e4 LT |
450 | error: |
451 | ipcomp6_free_data(ipcd); | |
4a3e2f71 | 452 | mutex_unlock(&ipcomp6_resource_mutex); |
1da177e4 LT |
453 | kfree(ipcd); |
454 | ||
455 | goto out; | |
456 | } | |
457 | ||
533cb5b0 | 458 | static const struct xfrm_type ipcomp6_type = |
1da177e4 LT |
459 | { |
460 | .description = "IPCOMP6", | |
461 | .owner = THIS_MODULE, | |
462 | .proto = IPPROTO_COMP, | |
463 | .init_state = ipcomp6_init_state, | |
464 | .destructor = ipcomp6_destroy, | |
465 | .input = ipcomp6_input, | |
466 | .output = ipcomp6_output, | |
aee5adb4 | 467 | .hdr_offset = xfrm6_find_1stfragopt, |
1da177e4 LT |
468 | }; |
469 | ||
1ab1457c | 470 | static struct inet6_protocol ipcomp6_protocol = |
1da177e4 LT |
471 | { |
472 | .handler = xfrm6_rcv, | |
473 | .err_handler = ipcomp6_err, | |
474 | .flags = INET6_PROTO_NOPOLICY, | |
475 | }; | |
476 | ||
477 | static int __init ipcomp6_init(void) | |
478 | { | |
479 | if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { | |
480 | printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); | |
481 | return -EAGAIN; | |
482 | } | |
483 | if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { | |
484 | printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); | |
485 | xfrm_unregister_type(&ipcomp6_type, AF_INET6); | |
486 | return -EAGAIN; | |
487 | } | |
488 | return 0; | |
489 | } | |
490 | ||
491 | static void __exit ipcomp6_fini(void) | |
492 | { | |
1ab1457c | 493 | if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) |
1da177e4 LT |
494 | printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); |
495 | if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) | |
496 | printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); | |
497 | } | |
498 | ||
499 | module_init(ipcomp6_init); | |
500 | module_exit(ipcomp6_fini); | |
501 | MODULE_LICENSE("GPL"); | |
502 | MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); | |
503 | MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); | |
504 | ||
d3d6dd3a | 505 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); |