2 * Copyright (C)2002 USAGI/WIDE Project
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.
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
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>
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>
39 #include <linux/icmpv6.h>
41 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
45 struct ipv6hdr *top_iph;
46 struct ipv6_esp_hdr *esph;
47 struct crypto_tfm *tfm;
49 struct sk_buff *trailer;
56 hdr_len = skb->h.raw - skb->data +
57 sizeof(*esph) + esp->conf.ivlen;
59 /* Strip IP+ESP header. */
60 __skb_pull(skb, hdr_len);
62 /* Now skb is pure payload to encrypt */
65 /* Round to block size */
68 alen = esp->auth.icv_trunc_len;
70 blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
71 clen = ALIGN(clen + 2, blksize);
73 clen = ALIGN(clen, esp->conf.padlen);
75 if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
82 for (i=0; i<clen-skb->len - 2; i++)
83 *(u8*)(trailer->tail + i) = i+1;
85 *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
86 pskb_put(skb, trailer, clen - skb->len);
88 top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
89 esph = (struct ipv6_esp_hdr *)skb->h.raw;
90 top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
91 *(u8*)(trailer->tail - 1) = *skb->nh.raw;
92 *skb->nh.raw = IPPROTO_ESP;
94 esph->spi = x->id.spi;
95 esph->seq_no = htonl(++x->replay.oseq);
98 crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
101 struct scatterlist *sg = &esp->sgbuf[0];
103 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
104 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
108 skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
109 crypto_cipher_encrypt(tfm, sg, sg, clen);
110 if (unlikely(sg != &esp->sgbuf[0]))
114 if (esp->conf.ivlen) {
115 memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
116 crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
119 if (esp->auth.icv_full_len) {
120 esp->auth.icv(esp, skb, (u8*)esph-skb->data,
121 sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
122 pskb_put(skb, trailer, alen);
131 static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
134 struct ipv6_esp_hdr *esph;
135 struct esp_data *esp = x->data;
136 struct sk_buff *trailer;
137 int blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
138 int alen = esp->auth.icv_trunc_len;
139 int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
141 int hdr_len = skb->h.raw - skb->nh.raw;
143 unsigned char *tmp_hdr = NULL;
146 if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
151 if (elen <= 0 || (elen & (blksize-1))) {
156 tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
161 memcpy(tmp_hdr, skb->nh.raw, hdr_len);
163 /* If integrity check is required, do this. */
164 if (esp->auth.icv_full_len) {
165 u8 sum[esp->auth.icv_full_len];
168 esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
170 if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
173 if (unlikely(memcmp(sum, sum1, alen))) {
174 x->stats.integrity_failed++;
180 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
185 skb->ip_summed = CHECKSUM_NONE;
187 esph = (struct ipv6_esp_hdr*)skb->data;
190 /* Get ivec. This can be wrong, check against another impls. */
192 crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
196 struct scatterlist *sg = &esp->sgbuf[0];
199 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
200 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
206 skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
207 crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
208 if (unlikely(sg != &esp->sgbuf[0]))
211 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
215 if (padlen+2 >= elen) {
216 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
220 /* ... check padding bits here. Silly. :-) */
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));
236 static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
238 struct esp_data *esp = x->data;
239 u32 blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
242 mtu = ALIGN(mtu + 2, blksize);
244 /* The worst case. */
247 if (esp->conf.padlen)
248 mtu = ALIGN(mtu, esp->conf.padlen);
250 return mtu + x->props.header_len + esp->auth.icv_full_len;
253 static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
254 int type, int code, int offset, __u32 info)
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;
260 if (type != ICMPV6_DEST_UNREACH &&
261 type != ICMPV6_PKT_TOOBIG)
264 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
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));
273 static void esp6_destroy(struct xfrm_state *x)
275 struct esp_data *esp = x->data;
280 crypto_free_tfm(esp->conf.tfm);
281 esp->conf.tfm = NULL;
282 kfree(esp->conf.ivec);
283 esp->conf.ivec = NULL;
284 crypto_free_tfm(esp->auth.tfm);
285 esp->auth.tfm = NULL;
286 kfree(esp->auth.work_icv);
287 esp->auth.work_icv = NULL;
291 static int esp6_init_state(struct xfrm_state *x)
293 struct esp_data *esp = NULL;
295 /* null auth and encryption can have zero length keys */
297 if (x->aalg->alg_key_len > 512)
306 esp = kmalloc(sizeof(*esp), GFP_KERNEL);
310 memset(esp, 0, sizeof(*esp));
313 struct xfrm_algo_desc *aalg_desc;
315 esp->auth.key = x->aalg->alg_key;
316 esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
317 esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
318 if (esp->auth.tfm == NULL)
320 esp->auth.icv = esp_hmac_digest;
322 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
325 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
326 crypto_tfm_alg_digestsize(esp->auth.tfm)) {
327 printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
329 crypto_tfm_alg_digestsize(esp->auth.tfm),
330 aalg_desc->uinfo.auth.icv_fullbits/8);
334 esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
335 esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
337 esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
338 if (!esp->auth.work_icv)
341 esp->conf.key = x->ealg->alg_key;
342 esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
343 if (x->props.ealgo == SADB_EALG_NULL)
344 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
346 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
347 if (esp->conf.tfm == NULL)
349 esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
350 esp->conf.padlen = 0;
351 if (esp->conf.ivlen) {
352 esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
353 if (unlikely(esp->conf.ivec == NULL))
355 get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
357 if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
359 x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
361 x->props.header_len += sizeof(struct ipv6hdr);
372 static struct xfrm_type esp6_type =
374 .description = "ESP6",
375 .owner = THIS_MODULE,
376 .proto = IPPROTO_ESP,
377 .init_state = esp6_init_state,
378 .destructor = esp6_destroy,
379 .get_max_size = esp6_get_max_size,
381 .output = esp6_output
384 static struct inet6_protocol esp6_protocol = {
385 .handler = xfrm6_rcv,
386 .err_handler = esp6_err,
387 .flags = INET6_PROTO_NOPOLICY,
390 static int __init esp6_init(void)
392 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
393 printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
396 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
397 printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
398 xfrm_unregister_type(&esp6_type, AF_INET6);
405 static void __exit esp6_fini(void)
407 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
408 printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
409 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
410 printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
413 module_init(esp6_init);
414 module_exit(esp6_fini);
416 MODULE_LICENSE("GPL");