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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv6/ipcomp6.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv6/ipcomp6.c')
-rw-r--r--net/ipv6/ipcomp6.c524
1 files changed, 524 insertions, 0 deletions
diff --git a/net/ipv6/ipcomp6.c b/net/ipv6/ipcomp6.c
new file mode 100644
index 000000000000..6cde5310cd76
--- /dev/null
+++ b/net/ipv6/ipcomp6.c
@@ -0,0 +1,524 @@
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.
12 *
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.
17 *
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 */
22/*
23 * [Memo]
24 *
25 * Outbound:
26 * The compression of IP datagram MUST be done before AH/ESP processing,
27 * fragmentation, and the addition of Hop-by-Hop/Routing header.
28 *
29 * Inbound:
30 * The decompression of IP datagram MUST be done after the reassembly,
31 * AH/ESP processing.
32 */
33#include <linux/config.h>
34#include <linux/module.h>
35#include <net/ip.h>
36#include <net/xfrm.h>
37#include <net/ipcomp.h>
38#include <asm/scatterlist.h>
39#include <asm/semaphore.h>
40#include <linux/crypto.h>
41#include <linux/pfkeyv2.h>
42#include <linux/random.h>
43#include <linux/percpu.h>
44#include <linux/smp.h>
45#include <linux/list.h>
46#include <linux/vmalloc.h>
47#include <linux/rtnetlink.h>
48#include <net/icmp.h>
49#include <net/ipv6.h>
50#include <linux/ipv6.h>
51#include <linux/icmpv6.h>
52
53struct ipcomp6_tfms {
54 struct list_head list;
55 struct crypto_tfm **tfms;
56 int users;
57};
58
59static DECLARE_MUTEX(ipcomp6_resource_sem);
60static void **ipcomp6_scratches;
61static int ipcomp6_scratch_users;
62static LIST_HEAD(ipcomp6_tfms_list);
63
64static int ipcomp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
65{
66 int err = 0;
67 u8 nexthdr = 0;
68 int hdr_len = skb->h.raw - skb->nh.raw;
69 unsigned char *tmp_hdr = NULL;
70 struct ipv6hdr *iph;
71 int plen, dlen;
72 struct ipcomp_data *ipcd = x->data;
73 u8 *start, *scratch;
74 struct crypto_tfm *tfm;
75 int cpu;
76
77 if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
78 skb_linearize(skb, GFP_ATOMIC) != 0) {
79 err = -ENOMEM;
80 goto out;
81 }
82
83 skb->ip_summed = CHECKSUM_NONE;
84
85 /* Remove ipcomp header and decompress original payload */
86 iph = skb->nh.ipv6h;
87 tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
88 if (!tmp_hdr)
89 goto out;
90 memcpy(tmp_hdr, iph, hdr_len);
91 nexthdr = *(u8 *)skb->data;
92 skb_pull(skb, sizeof(struct ipv6_comp_hdr));
93 skb->nh.raw += sizeof(struct ipv6_comp_hdr);
94 memcpy(skb->nh.raw, tmp_hdr, hdr_len);
95 iph = skb->nh.ipv6h;
96 iph->payload_len = htons(ntohs(iph->payload_len) - sizeof(struct ipv6_comp_hdr));
97 skb->h.raw = skb->data;
98
99 /* decompression */
100 plen = skb->len;
101 dlen = IPCOMP_SCRATCH_SIZE;
102 start = skb->data;
103
104 cpu = get_cpu();
105 scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
106 tfm = *per_cpu_ptr(ipcd->tfms, cpu);
107
108 err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
109 if (err) {
110 err = -EINVAL;
111 goto out_put_cpu;
112 }
113
114 if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
115 err = -EINVAL;
116 goto out_put_cpu;
117 }
118
119 err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
120 if (err) {
121 goto out_put_cpu;
122 }
123
124 skb_put(skb, dlen - plen);
125 memcpy(skb->data, scratch, dlen);
126
127 iph = skb->nh.ipv6h;
128 iph->payload_len = htons(skb->len);
129
130out_put_cpu:
131 put_cpu();
132out:
133 if (tmp_hdr)
134 kfree(tmp_hdr);
135 if (err)
136 goto error_out;
137 return nexthdr;
138error_out:
139 return err;
140}
141
142static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
143{
144 int err;
145 struct ipv6hdr *top_iph;
146 int hdr_len;
147 struct ipv6_comp_hdr *ipch;
148 struct ipcomp_data *ipcd = x->data;
149 int plen, dlen;
150 u8 *start, *scratch;
151 struct crypto_tfm *tfm;
152 int cpu;
153
154 hdr_len = skb->h.raw - skb->data;
155
156 /* check whether datagram len is larger than threshold */
157 if ((skb->len - hdr_len) < ipcd->threshold) {
158 goto out_ok;
159 }
160
161 if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
162 skb_linearize(skb, GFP_ATOMIC) != 0) {
163 goto out_ok;
164 }
165
166 /* compression */
167 plen = skb->len - hdr_len;
168 dlen = IPCOMP_SCRATCH_SIZE;
169 start = skb->h.raw;
170
171 cpu = get_cpu();
172 scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
173 tfm = *per_cpu_ptr(ipcd->tfms, cpu);
174
175 err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
176 if (err || (dlen + sizeof(struct ipv6_comp_hdr)) >= plen) {
177 put_cpu();
178 goto out_ok;
179 }
180 memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
181 put_cpu();
182 pskb_trim(skb, hdr_len + dlen + sizeof(struct ip_comp_hdr));
183
184 /* insert ipcomp header and replace datagram */
185 top_iph = (struct ipv6hdr *)skb->data;
186
187 top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
188
189 ipch = (struct ipv6_comp_hdr *)start;
190 ipch->nexthdr = *skb->nh.raw;
191 ipch->flags = 0;
192 ipch->cpi = htons((u16 )ntohl(x->id.spi));
193 *skb->nh.raw = IPPROTO_COMP;
194
195out_ok:
196 return 0;
197}
198
199static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
200 int type, int code, int offset, __u32 info)
201{
202 u32 spi;
203 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
204 struct ipv6_comp_hdr *ipcomph = (struct ipv6_comp_hdr*)(skb->data+offset);
205 struct xfrm_state *x;
206
207 if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
208 return;
209
210 spi = ntohl(ntohs(ipcomph->cpi));
211 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
212 if (!x)
213 return;
214
215 printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/"
216 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
217 spi, NIP6(iph->daddr));
218 xfrm_state_put(x);
219}
220
221static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
222{
223 struct xfrm_state *t = NULL;
224
225 t = xfrm_state_alloc();
226 if (!t)
227 goto out;
228
229 t->id.proto = IPPROTO_IPV6;
230 t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
231 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
232 memcpy(&t->sel, &x->sel, sizeof(t->sel));
233 t->props.family = AF_INET6;
234 t->props.mode = 1;
235 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
236
237 t->type = xfrm_get_type(IPPROTO_IPV6, t->props.family);
238 if (t->type == NULL)
239 goto error;
240
241 if (t->type->init_state(t, NULL))
242 goto error;
243
244 t->km.state = XFRM_STATE_VALID;
245 atomic_set(&t->tunnel_users, 1);
246
247out:
248 return t;
249
250error:
251 xfrm_state_put(t);
252 goto out;
253}
254
255static int ipcomp6_tunnel_attach(struct xfrm_state *x)
256{
257 int err = 0;
258 struct xfrm_state *t = NULL;
259 u32 spi;
260
261 spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
262 if (spi)
263 t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
264 spi, IPPROTO_IPV6, AF_INET6);
265 if (!t) {
266 t = ipcomp6_tunnel_create(x);
267 if (!t) {
268 err = -EINVAL;
269 goto out;
270 }
271 xfrm_state_insert(t);
272 xfrm_state_hold(t);
273 }
274 x->tunnel = t;
275 atomic_inc(&t->tunnel_users);
276
277out:
278 return err;
279}
280
281static void ipcomp6_free_scratches(void)
282{
283 int i;
284 void **scratches;
285
286 if (--ipcomp6_scratch_users)
287 return;
288
289 scratches = ipcomp6_scratches;
290 if (!scratches)
291 return;
292
293 for_each_cpu(i) {
294 void *scratch = *per_cpu_ptr(scratches, i);
295 if (scratch)
296 vfree(scratch);
297 }
298
299 free_percpu(scratches);
300}
301
302static void **ipcomp6_alloc_scratches(void)
303{
304 int i;
305 void **scratches;
306
307 if (ipcomp6_scratch_users++)
308 return ipcomp6_scratches;
309
310 scratches = alloc_percpu(void *);
311 if (!scratches)
312 return NULL;
313
314 ipcomp6_scratches = scratches;
315
316 for_each_cpu(i) {
317 void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
318 if (!scratch)
319 return NULL;
320 *per_cpu_ptr(scratches, i) = scratch;
321 }
322
323 return scratches;
324}
325
326static void ipcomp6_free_tfms(struct crypto_tfm **tfms)
327{
328 struct ipcomp6_tfms *pos;
329 int cpu;
330
331 list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
332 if (pos->tfms == tfms)
333 break;
334 }
335
336 BUG_TRAP(pos);
337
338 if (--pos->users)
339 return;
340
341 list_del(&pos->list);
342 kfree(pos);
343
344 if (!tfms)
345 return;
346
347 for_each_cpu(cpu) {
348 struct crypto_tfm *tfm = *per_cpu_ptr(tfms, cpu);
349 if (tfm)
350 crypto_free_tfm(tfm);
351 }
352 free_percpu(tfms);
353}
354
355static struct crypto_tfm **ipcomp6_alloc_tfms(const char *alg_name)
356{
357 struct ipcomp6_tfms *pos;
358 struct crypto_tfm **tfms;
359 int cpu;
360
361 /* This can be any valid CPU ID so we don't need locking. */
362 cpu = smp_processor_id();
363
364 list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
365 struct crypto_tfm *tfm;
366
367 tfms = pos->tfms;
368 tfm = *per_cpu_ptr(tfms, cpu);
369
370 if (!strcmp(crypto_tfm_alg_name(tfm), alg_name)) {
371 pos->users++;
372 return tfms;
373 }
374 }
375
376 pos = kmalloc(sizeof(*pos), GFP_KERNEL);
377 if (!pos)
378 return NULL;
379
380 pos->users = 1;
381 INIT_LIST_HEAD(&pos->list);
382 list_add(&pos->list, &ipcomp6_tfms_list);
383
384 pos->tfms = tfms = alloc_percpu(struct crypto_tfm *);
385 if (!tfms)
386 goto error;
387
388 for_each_cpu(cpu) {
389 struct crypto_tfm *tfm = crypto_alloc_tfm(alg_name, 0);
390 if (!tfm)
391 goto error;
392 *per_cpu_ptr(tfms, cpu) = tfm;
393 }
394
395 return tfms;
396
397error:
398 ipcomp6_free_tfms(tfms);
399 return NULL;
400}
401
402static void ipcomp6_free_data(struct ipcomp_data *ipcd)
403{
404 if (ipcd->tfms)
405 ipcomp6_free_tfms(ipcd->tfms);
406 ipcomp6_free_scratches();
407}
408
409static void ipcomp6_destroy(struct xfrm_state *x)
410{
411 struct ipcomp_data *ipcd = x->data;
412 if (!ipcd)
413 return;
414 xfrm_state_delete_tunnel(x);
415 down(&ipcomp6_resource_sem);
416 ipcomp6_free_data(ipcd);
417 up(&ipcomp6_resource_sem);
418 kfree(ipcd);
419
420 xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
421}
422
423static int ipcomp6_init_state(struct xfrm_state *x, void *args)
424{
425 int err;
426 struct ipcomp_data *ipcd;
427 struct xfrm_algo_desc *calg_desc;
428
429 err = -EINVAL;
430 if (!x->calg)
431 goto out;
432
433 if (x->encap)
434 goto out;
435
436 err = -ENOMEM;
437 ipcd = kmalloc(sizeof(*ipcd), GFP_KERNEL);
438 if (!ipcd)
439 goto out;
440
441 memset(ipcd, 0, sizeof(*ipcd));
442 x->props.header_len = 0;
443 if (x->props.mode)
444 x->props.header_len += sizeof(struct ipv6hdr);
445
446 down(&ipcomp6_resource_sem);
447 if (!ipcomp6_alloc_scratches())
448 goto error;
449
450 ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
451 if (!ipcd->tfms)
452 goto error;
453 up(&ipcomp6_resource_sem);
454
455 if (x->props.mode) {
456 err = ipcomp6_tunnel_attach(x);
457 if (err)
458 goto error_tunnel;
459 }
460
461 calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
462 BUG_ON(!calg_desc);
463 ipcd->threshold = calg_desc->uinfo.comp.threshold;
464 x->data = ipcd;
465 err = 0;
466out:
467 return err;
468error_tunnel:
469 down(&ipcomp6_resource_sem);
470error:
471 ipcomp6_free_data(ipcd);
472 up(&ipcomp6_resource_sem);
473 kfree(ipcd);
474
475 goto out;
476}
477
478static struct xfrm_type ipcomp6_type =
479{
480 .description = "IPCOMP6",
481 .owner = THIS_MODULE,
482 .proto = IPPROTO_COMP,
483 .init_state = ipcomp6_init_state,
484 .destructor = ipcomp6_destroy,
485 .input = ipcomp6_input,
486 .output = ipcomp6_output,
487};
488
489static struct inet6_protocol ipcomp6_protocol =
490{
491 .handler = xfrm6_rcv,
492 .err_handler = ipcomp6_err,
493 .flags = INET6_PROTO_NOPOLICY,
494};
495
496static int __init ipcomp6_init(void)
497{
498 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
499 printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
500 return -EAGAIN;
501 }
502 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
503 printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
504 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
505 return -EAGAIN;
506 }
507 return 0;
508}
509
510static void __exit ipcomp6_fini(void)
511{
512 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
513 printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
514 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
515 printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
516}
517
518module_init(ipcomp6_init);
519module_exit(ipcomp6_fini);
520MODULE_LICENSE("GPL");
521MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
522MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
523
524