[ARM] 3704/1: format IOP Kconfig with tabs, create more consistency
[linux-2.6/kvm.git] / net / ipv6 / esp6.c
bloba15a6f320f7000c5b512ff3f6f3085a33016c3df
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.
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
18 * Authors
20 * Mitsuru KANDA @USAGI : IPv6 Support
21 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
24 * This file is derived from net/ipv4/esp.c
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/kernel.h>
35 #include <linux/pfkeyv2.h>
36 #include <linux/random.h>
37 #include <net/icmp.h>
38 #include <net/ipv6.h>
39 #include <net/protocol.h>
40 #include <linux/icmpv6.h>
42 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
44 int err;
45 int hdr_len;
46 struct ipv6hdr *top_iph;
47 struct ipv6_esp_hdr *esph;
48 struct crypto_tfm *tfm;
49 struct esp_data *esp;
50 struct sk_buff *trailer;
51 int blksize;
52 int clen;
53 int alen;
54 int nfrags;
56 esp = x->data;
57 hdr_len = skb->h.raw - skb->data +
58 sizeof(*esph) + esp->conf.ivlen;
60 /* Strip IP+ESP header. */
61 __skb_pull(skb, hdr_len);
63 /* Now skb is pure payload to encrypt */
64 err = -ENOMEM;
66 /* Round to block size */
67 clen = skb->len;
69 alen = esp->auth.icv_trunc_len;
70 tfm = esp->conf.tfm;
71 blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
72 clen = ALIGN(clen + 2, blksize);
73 if (esp->conf.padlen)
74 clen = ALIGN(clen, esp->conf.padlen);
76 if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
77 goto error;
80 /* Fill padding... */
81 do {
82 int i;
83 for (i=0; i<clen-skb->len - 2; i++)
84 *(u8*)(trailer->tail + i) = i+1;
85 } while (0);
86 *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
87 pskb_put(skb, trailer, clen - skb->len);
89 top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
90 esph = (struct ipv6_esp_hdr *)skb->h.raw;
91 top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
92 *(u8*)(trailer->tail - 1) = *skb->nh.raw;
93 *skb->nh.raw = IPPROTO_ESP;
95 esph->spi = x->id.spi;
96 esph->seq_no = htonl(++x->replay.oseq);
97 xfrm_aevent_doreplay(x);
99 if (esp->conf.ivlen)
100 crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
102 do {
103 struct scatterlist *sg = &esp->sgbuf[0];
105 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
106 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
107 if (!sg)
108 goto error;
110 skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
111 crypto_cipher_encrypt(tfm, sg, sg, clen);
112 if (unlikely(sg != &esp->sgbuf[0]))
113 kfree(sg);
114 } while (0);
116 if (esp->conf.ivlen) {
117 memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
118 crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
121 if (esp->auth.icv_full_len) {
122 esp->auth.icv(esp, skb, (u8*)esph-skb->data,
123 sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
124 pskb_put(skb, trailer, alen);
127 err = 0;
129 error:
130 return err;
133 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
135 struct ipv6hdr *iph;
136 struct ipv6_esp_hdr *esph;
137 struct esp_data *esp = x->data;
138 struct sk_buff *trailer;
139 int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
140 int alen = esp->auth.icv_trunc_len;
141 int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
143 int hdr_len = skb->h.raw - skb->nh.raw;
144 int nfrags;
145 int ret = 0;
147 if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
148 ret = -EINVAL;
149 goto out;
152 if (elen <= 0 || (elen & (blksize-1))) {
153 ret = -EINVAL;
154 goto out;
157 /* If integrity check is required, do this. */
158 if (esp->auth.icv_full_len) {
159 u8 sum[esp->auth.icv_full_len];
160 u8 sum1[alen];
162 esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
164 if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
165 BUG();
167 if (unlikely(memcmp(sum, sum1, alen))) {
168 x->stats.integrity_failed++;
169 ret = -EINVAL;
170 goto out;
174 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
175 ret = -EINVAL;
176 goto out;
179 skb->ip_summed = CHECKSUM_NONE;
181 esph = (struct ipv6_esp_hdr*)skb->data;
182 iph = skb->nh.ipv6h;
184 /* Get ivec. This can be wrong, check against another impls. */
185 if (esp->conf.ivlen)
186 crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
189 u8 nexthdr[2];
190 struct scatterlist *sg = &esp->sgbuf[0];
191 u8 padlen;
193 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
194 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
195 if (!sg) {
196 ret = -ENOMEM;
197 goto out;
200 skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
201 crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
202 if (unlikely(sg != &esp->sgbuf[0]))
203 kfree(sg);
205 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
206 BUG();
208 padlen = nexthdr[0];
209 if (padlen+2 >= elen) {
210 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
211 ret = -EINVAL;
212 goto out;
214 /* ... check padding bits here. Silly. :-) */
216 pskb_trim(skb, skb->len - alen - padlen - 2);
217 ret = nexthdr[1];
220 skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - hdr_len;
222 out:
223 return ret;
226 static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
228 struct esp_data *esp = x->data;
229 u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
231 if (x->props.mode) {
232 mtu = ALIGN(mtu + 2, blksize);
233 } else {
234 /* The worst case. */
235 u32 padsize = ((blksize - 1) & 7) + 1;
236 mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
238 if (esp->conf.padlen)
239 mtu = ALIGN(mtu, esp->conf.padlen);
241 return mtu + x->props.header_len + esp->auth.icv_trunc_len;
244 static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
245 int type, int code, int offset, __u32 info)
247 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
248 struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
249 struct xfrm_state *x;
251 if (type != ICMPV6_DEST_UNREACH &&
252 type != ICMPV6_PKT_TOOBIG)
253 return;
255 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
256 if (!x)
257 return;
258 printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/" NIP6_FMT "\n",
259 ntohl(esph->spi), NIP6(iph->daddr));
260 xfrm_state_put(x);
263 static void esp6_destroy(struct xfrm_state *x)
265 struct esp_data *esp = x->data;
267 if (!esp)
268 return;
270 crypto_free_tfm(esp->conf.tfm);
271 esp->conf.tfm = NULL;
272 kfree(esp->conf.ivec);
273 esp->conf.ivec = NULL;
274 crypto_free_tfm(esp->auth.tfm);
275 esp->auth.tfm = NULL;
276 kfree(esp->auth.work_icv);
277 esp->auth.work_icv = NULL;
278 kfree(esp);
281 static int esp6_init_state(struct xfrm_state *x)
283 struct esp_data *esp = NULL;
285 /* null auth and encryption can have zero length keys */
286 if (x->aalg) {
287 if (x->aalg->alg_key_len > 512)
288 goto error;
290 if (x->ealg == NULL)
291 goto error;
293 if (x->encap)
294 goto error;
296 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
297 if (esp == NULL)
298 return -ENOMEM;
300 if (x->aalg) {
301 struct xfrm_algo_desc *aalg_desc;
303 esp->auth.key = x->aalg->alg_key;
304 esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
305 esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
306 if (esp->auth.tfm == NULL)
307 goto error;
308 esp->auth.icv = esp_hmac_digest;
310 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
311 BUG_ON(!aalg_desc);
313 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
314 crypto_tfm_alg_digestsize(esp->auth.tfm)) {
315 printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
316 x->aalg->alg_name,
317 crypto_tfm_alg_digestsize(esp->auth.tfm),
318 aalg_desc->uinfo.auth.icv_fullbits/8);
319 goto error;
322 esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
323 esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
325 esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
326 if (!esp->auth.work_icv)
327 goto error;
329 esp->conf.key = x->ealg->alg_key;
330 esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
331 if (x->props.ealgo == SADB_EALG_NULL)
332 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
333 else
334 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
335 if (esp->conf.tfm == NULL)
336 goto error;
337 esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
338 esp->conf.padlen = 0;
339 if (esp->conf.ivlen) {
340 esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
341 if (unlikely(esp->conf.ivec == NULL))
342 goto error;
343 get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
345 if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
346 goto error;
347 x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
348 if (x->props.mode)
349 x->props.header_len += sizeof(struct ipv6hdr);
350 x->data = esp;
351 return 0;
353 error:
354 x->data = esp;
355 esp6_destroy(x);
356 x->data = NULL;
357 return -EINVAL;
360 static struct xfrm_type esp6_type =
362 .description = "ESP6",
363 .owner = THIS_MODULE,
364 .proto = IPPROTO_ESP,
365 .init_state = esp6_init_state,
366 .destructor = esp6_destroy,
367 .get_max_size = esp6_get_max_size,
368 .input = esp6_input,
369 .output = esp6_output
372 static struct inet6_protocol esp6_protocol = {
373 .handler = xfrm6_rcv,
374 .err_handler = esp6_err,
375 .flags = INET6_PROTO_NOPOLICY,
378 static int __init esp6_init(void)
380 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
381 printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
382 return -EAGAIN;
384 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
385 printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
386 xfrm_unregister_type(&esp6_type, AF_INET6);
387 return -EAGAIN;
390 return 0;
393 static void __exit esp6_fini(void)
395 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
396 printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
397 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
398 printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
401 module_init(esp6_init);
402 module_exit(esp6_fini);
404 MODULE_LICENSE("GPL");