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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/esp6.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/esp6.c')
-rw-r--r--net/ipv6/esp6.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
new file mode 100644
index 000000000000..be7095d6babe
--- /dev/null
+++ b/net/ipv6/esp6.c
@@ -0,0 +1,424 @@
1/*
2 * Copyright (C)2002 USAGI/WIDE Project
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Authors
19 *
20 * Mitsuru KANDA @USAGI : IPv6 Support
21 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
23 *
24 * This file is derived from net/ipv4/esp.c
25 */
26
27#include <linux/config.h>
28#include <linux/module.h>
29#include <net/ip.h>
30#include <net/xfrm.h>
31#include <net/esp.h>
32#include <asm/scatterlist.h>
33#include <linux/crypto.h>
34#include <linux/pfkeyv2.h>
35#include <linux/random.h>
36#include <net/icmp.h>
37#include <net/ipv6.h>
38#include <linux/icmpv6.h>
39
40static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
41{
42 int err;
43 int hdr_len;
44 struct ipv6hdr *top_iph;
45 struct ipv6_esp_hdr *esph;
46 struct crypto_tfm *tfm;
47 struct esp_data *esp;
48 struct sk_buff *trailer;
49 int blksize;
50 int clen;
51 int alen;
52 int nfrags;
53
54 esp = x->data;
55 hdr_len = skb->h.raw - skb->data +
56 sizeof(*esph) + esp->conf.ivlen;
57
58 /* Strip IP+ESP header. */
59 __skb_pull(skb, hdr_len);
60
61 /* Now skb is pure payload to encrypt */
62 err = -ENOMEM;
63
64 /* Round to block size */
65 clen = skb->len;
66
67 alen = esp->auth.icv_trunc_len;
68 tfm = esp->conf.tfm;
69 blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
70 clen = (clen + 2 + blksize-1)&~(blksize-1);
71 if (esp->conf.padlen)
72 clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
73
74 if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
75 goto error;
76 }
77
78 /* Fill padding... */
79 do {
80 int i;
81 for (i=0; i<clen-skb->len - 2; i++)
82 *(u8*)(trailer->tail + i) = i+1;
83 } while (0);
84 *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
85 pskb_put(skb, trailer, clen - skb->len);
86
87 top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
88 esph = (struct ipv6_esp_hdr *)skb->h.raw;
89 top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
90 *(u8*)(trailer->tail - 1) = *skb->nh.raw;
91 *skb->nh.raw = IPPROTO_ESP;
92
93 esph->spi = x->id.spi;
94 esph->seq_no = htonl(++x->replay.oseq);
95
96 if (esp->conf.ivlen)
97 crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
98
99 do {
100 struct scatterlist *sg = &esp->sgbuf[0];
101
102 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
103 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
104 if (!sg)
105 goto error;
106 }
107 skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
108 crypto_cipher_encrypt(tfm, sg, sg, clen);
109 if (unlikely(sg != &esp->sgbuf[0]))
110 kfree(sg);
111 } while (0);
112
113 if (esp->conf.ivlen) {
114 memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
115 crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
116 }
117
118 if (esp->auth.icv_full_len) {
119 esp->auth.icv(esp, skb, (u8*)esph-skb->data,
120 sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
121 pskb_put(skb, trailer, alen);
122 }
123
124 err = 0;
125
126error:
127 return err;
128}
129
130static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
131{
132 struct ipv6hdr *iph;
133 struct ipv6_esp_hdr *esph;
134 struct esp_data *esp = x->data;
135 struct sk_buff *trailer;
136 int blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
137 int alen = esp->auth.icv_trunc_len;
138 int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
139
140 int hdr_len = skb->h.raw - skb->nh.raw;
141 int nfrags;
142 unsigned char *tmp_hdr = NULL;
143 int ret = 0;
144
145 if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
146 ret = -EINVAL;
147 goto out_nofree;
148 }
149
150 if (elen <= 0 || (elen & (blksize-1))) {
151 ret = -EINVAL;
152 goto out_nofree;
153 }
154
155 tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
156 if (!tmp_hdr) {
157 ret = -ENOMEM;
158 goto out_nofree;
159 }
160 memcpy(tmp_hdr, skb->nh.raw, hdr_len);
161
162 /* If integrity check is required, do this. */
163 if (esp->auth.icv_full_len) {
164 u8 sum[esp->auth.icv_full_len];
165 u8 sum1[alen];
166
167 esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
168
169 if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
170 BUG();
171
172 if (unlikely(memcmp(sum, sum1, alen))) {
173 x->stats.integrity_failed++;
174 ret = -EINVAL;
175 goto out;
176 }
177 }
178
179 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
180 ret = -EINVAL;
181 goto out;
182 }
183
184 skb->ip_summed = CHECKSUM_NONE;
185
186 esph = (struct ipv6_esp_hdr*)skb->data;
187 iph = skb->nh.ipv6h;
188
189 /* Get ivec. This can be wrong, check against another impls. */
190 if (esp->conf.ivlen)
191 crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
192
193 {
194 u8 nexthdr[2];
195 struct scatterlist *sg = &esp->sgbuf[0];
196 u8 padlen;
197
198 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
199 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
200 if (!sg) {
201 ret = -ENOMEM;
202 goto out;
203 }
204 }
205 skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
206 crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
207 if (unlikely(sg != &esp->sgbuf[0]))
208 kfree(sg);
209
210 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
211 BUG();
212
213 padlen = nexthdr[0];
214 if (padlen+2 >= elen) {
215 LIMIT_NETDEBUG(
216 printk(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen));
217 ret = -EINVAL;
218 goto out;
219 }
220 /* ... check padding bits here. Silly. :-) */
221
222 pskb_trim(skb, skb->len - alen - padlen - 2);
223 skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
224 skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
225 memcpy(skb->nh.raw, tmp_hdr, hdr_len);
226 skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
227 ret = nexthdr[1];
228 }
229
230out:
231 kfree(tmp_hdr);
232out_nofree:
233 return ret;
234}
235
236static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
237{
238 struct esp_data *esp = x->data;
239 u32 blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
240
241 if (x->props.mode) {
242 mtu = (mtu + 2 + blksize-1)&~(blksize-1);
243 } else {
244 /* The worst case. */
245 mtu += 2 + blksize;
246 }
247 if (esp->conf.padlen)
248 mtu = (mtu + esp->conf.padlen-1)&~(esp->conf.padlen-1);
249
250 return mtu + x->props.header_len + esp->auth.icv_full_len;
251}
252
253static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
254 int type, int code, int offset, __u32 info)
255{
256 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
257 struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
258 struct xfrm_state *x;
259
260 if (type != ICMPV6_DEST_UNREACH &&
261 type != ICMPV6_PKT_TOOBIG)
262 return;
263
264 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
265 if (!x)
266 return;
267 printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
268 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
269 ntohl(esph->spi), NIP6(iph->daddr));
270 xfrm_state_put(x);
271}
272
273static void esp6_destroy(struct xfrm_state *x)
274{
275 struct esp_data *esp = x->data;
276
277 if (!esp)
278 return;
279
280 if (esp->conf.tfm) {
281 crypto_free_tfm(esp->conf.tfm);
282 esp->conf.tfm = NULL;
283 }
284 if (esp->conf.ivec) {
285 kfree(esp->conf.ivec);
286 esp->conf.ivec = NULL;
287 }
288 if (esp->auth.tfm) {
289 crypto_free_tfm(esp->auth.tfm);
290 esp->auth.tfm = NULL;
291 }
292 if (esp->auth.work_icv) {
293 kfree(esp->auth.work_icv);
294 esp->auth.work_icv = NULL;
295 }
296 kfree(esp);
297}
298
299static int esp6_init_state(struct xfrm_state *x, void *args)
300{
301 struct esp_data *esp = NULL;
302
303 /* null auth and encryption can have zero length keys */
304 if (x->aalg) {
305 if (x->aalg->alg_key_len > 512)
306 goto error;
307 }
308 if (x->ealg == NULL)
309 goto error;
310
311 if (x->encap)
312 goto error;
313
314 esp = kmalloc(sizeof(*esp), GFP_KERNEL);
315 if (esp == NULL)
316 return -ENOMEM;
317
318 memset(esp, 0, sizeof(*esp));
319
320 if (x->aalg) {
321 struct xfrm_algo_desc *aalg_desc;
322
323 esp->auth.key = x->aalg->alg_key;
324 esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
325 esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
326 if (esp->auth.tfm == NULL)
327 goto error;
328 esp->auth.icv = esp_hmac_digest;
329
330 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
331 BUG_ON(!aalg_desc);
332
333 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
334 crypto_tfm_alg_digestsize(esp->auth.tfm)) {
335 printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
336 x->aalg->alg_name,
337 crypto_tfm_alg_digestsize(esp->auth.tfm),
338 aalg_desc->uinfo.auth.icv_fullbits/8);
339 goto error;
340 }
341
342 esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
343 esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
344
345 esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
346 if (!esp->auth.work_icv)
347 goto error;
348 }
349 esp->conf.key = x->ealg->alg_key;
350 esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
351 if (x->props.ealgo == SADB_EALG_NULL)
352 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
353 else
354 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
355 if (esp->conf.tfm == NULL)
356 goto error;
357 esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
358 esp->conf.padlen = 0;
359 if (esp->conf.ivlen) {
360 esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
361 if (unlikely(esp->conf.ivec == NULL))
362 goto error;
363 get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
364 }
365 if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
366 goto error;
367 x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
368 if (x->props.mode)
369 x->props.header_len += sizeof(struct ipv6hdr);
370 x->data = esp;
371 return 0;
372
373error:
374 x->data = esp;
375 esp6_destroy(x);
376 x->data = NULL;
377 return -EINVAL;
378}
379
380static struct xfrm_type esp6_type =
381{
382 .description = "ESP6",
383 .owner = THIS_MODULE,
384 .proto = IPPROTO_ESP,
385 .init_state = esp6_init_state,
386 .destructor = esp6_destroy,
387 .get_max_size = esp6_get_max_size,
388 .input = esp6_input,
389 .output = esp6_output
390};
391
392static struct inet6_protocol esp6_protocol = {
393 .handler = xfrm6_rcv,
394 .err_handler = esp6_err,
395 .flags = INET6_PROTO_NOPOLICY,
396};
397
398static int __init esp6_init(void)
399{
400 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
401 printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
402 return -EAGAIN;
403 }
404 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
405 printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
406 xfrm_unregister_type(&esp6_type, AF_INET6);
407 return -EAGAIN;
408 }
409
410 return 0;
411}
412
413static void __exit esp6_fini(void)
414{
415 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
416 printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
417 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
418 printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
419}
420
421module_init(esp6_init);
422module_exit(esp6_fini);
423
424MODULE_LICENSE("GPL");