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/pfkeyv2.h>
35 #include <linux/random.h>
38 #include <linux/icmpv6.h>
40 int esp6_output(struct sk_buff **pskb)
44 struct dst_entry *dst = (*pskb)->dst;
45 struct xfrm_state *x = dst->xfrm;
46 struct ipv6hdr *top_iph;
47 struct ipv6_esp_hdr *esph;
48 struct crypto_tfm *tfm;
50 struct sk_buff *trailer;
57 hdr_len = (*pskb)->h.raw - (*pskb)->data +
58 sizeof(*esph) + esp->conf.ivlen;
60 /* Strip IP+ESP header. */
61 __skb_pull(*pskb, hdr_len);
63 /* Now skb is pure payload to encrypt */
66 /* Round to block size */
69 alen = esp->auth.icv_trunc_len;
71 blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
72 clen = (clen + 2 + blksize-1)&~(blksize-1);
74 clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
76 if ((nfrags = skb_cow_data(*pskb, clen-(*pskb)->len+alen, &trailer)) < 0) {
83 for (i=0; i<clen-(*pskb)->len - 2; i++)
84 *(u8*)(trailer->tail + i) = i+1;
86 *(u8*)(trailer->tail + clen-(*pskb)->len - 2) = (clen - (*pskb)->len)-2;
87 pskb_put(*pskb, trailer, clen - (*pskb)->len);
89 top_iph = (struct ipv6hdr *)__skb_push(*pskb, hdr_len);
90 esph = (struct ipv6_esp_hdr *)(*pskb)->h.raw;
91 top_iph->payload_len = htons((*pskb)->len + alen - sizeof(*top_iph));
92 *(u8*)(trailer->tail - 1) = *(*pskb)->nh.raw;
93 *(*pskb)->nh.raw = IPPROTO_ESP;
95 esph->spi = x->id.spi;
96 esph->seq_no = htonl(++x->replay.oseq);
99 crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
102 struct scatterlist *sg = &esp->sgbuf[0];
104 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
105 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
109 skb_to_sgvec(*pskb, sg, esph->enc_data+esp->conf.ivlen-(*pskb)->data, clen);
110 crypto_cipher_encrypt(tfm, sg, sg, clen);
111 if (unlikely(sg != &esp->sgbuf[0]))
115 if (esp->conf.ivlen) {
116 memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
117 crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
120 if (esp->auth.icv_full_len) {
121 esp->auth.icv(esp, *pskb, (u8*)esph-(*pskb)->data,
122 sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
123 pskb_put(*pskb, trailer, alen);
132 int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
135 struct ipv6_esp_hdr *esph;
136 struct esp_data *esp = x->data;
137 struct sk_buff *trailer;
138 int blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
139 int alen = esp->auth.icv_trunc_len;
140 int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
142 int hdr_len = skb->h.raw - skb->nh.raw;
144 unsigned char *tmp_hdr = NULL;
147 if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
152 if (elen <= 0 || (elen & (blksize-1))) {
157 tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
162 memcpy(tmp_hdr, skb->nh.raw, hdr_len);
164 /* If integrity check is required, do this. */
165 if (esp->auth.icv_full_len) {
166 u8 sum[esp->auth.icv_full_len];
169 esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
171 if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
174 if (unlikely(memcmp(sum, sum1, alen))) {
175 x->stats.integrity_failed++;
181 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
186 skb->ip_summed = CHECKSUM_NONE;
188 esph = (struct ipv6_esp_hdr*)skb->data;
191 /* Get ivec. This can be wrong, check against another impls. */
193 crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
197 struct scatterlist *sg = &esp->sgbuf[0];
200 if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
201 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
207 skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
208 crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
209 if (unlikely(sg != &esp->sgbuf[0]))
212 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
216 if (padlen+2 >= elen) {
218 printk(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen));
222 /* ... check padding bits here. Silly. :-) */
224 pskb_trim(skb, skb->len - alen - padlen - 2);
225 skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
226 skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
227 memcpy(skb->nh.raw, tmp_hdr, hdr_len);
228 skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
238 static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
240 struct esp_data *esp = x->data;
241 u32 blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
244 mtu = (mtu + 2 + blksize-1)&~(blksize-1);
246 /* The worst case. */
249 if (esp->conf.padlen)
250 mtu = (mtu + esp->conf.padlen-1)&~(esp->conf.padlen-1);
252 return mtu + x->props.header_len + esp->auth.icv_full_len;
255 void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
256 int type, int code, int offset, __u32 info)
258 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
259 struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
260 struct xfrm_state *x;
262 if (type != ICMPV6_DEST_UNREACH &&
263 type != ICMPV6_PKT_TOOBIG)
266 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
269 printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
270 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
271 ntohl(esph->spi), NIP6(iph->daddr));
275 void esp6_destroy(struct xfrm_state *x)
277 struct esp_data *esp = x->data;
283 crypto_free_tfm(esp->conf.tfm);
284 esp->conf.tfm = NULL;
286 if (esp->conf.ivec) {
287 kfree(esp->conf.ivec);
288 esp->conf.ivec = NULL;
291 crypto_free_tfm(esp->auth.tfm);
292 esp->auth.tfm = NULL;
294 if (esp->auth.work_icv) {
295 kfree(esp->auth.work_icv);
296 esp->auth.work_icv = NULL;
301 int esp6_init_state(struct xfrm_state *x, void *args)
303 struct esp_data *esp = NULL;
306 if (x->aalg->alg_key_len == 0 || x->aalg->alg_key_len > 512)
312 esp = kmalloc(sizeof(*esp), GFP_KERNEL);
316 memset(esp, 0, sizeof(*esp));
319 struct xfrm_algo_desc *aalg_desc;
321 esp->auth.key = x->aalg->alg_key;
322 esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
323 esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
324 if (esp->auth.tfm == NULL)
326 esp->auth.icv = esp_hmac_digest;
328 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name);
331 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
332 crypto_tfm_alg_digestsize(esp->auth.tfm)) {
333 printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
335 crypto_tfm_alg_digestsize(esp->auth.tfm),
336 aalg_desc->uinfo.auth.icv_fullbits/8);
340 esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
341 esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
343 esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
344 if (!esp->auth.work_icv)
347 esp->conf.key = x->ealg->alg_key;
348 esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
349 if (x->props.ealgo == SADB_EALG_NULL)
350 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
352 esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
353 if (esp->conf.tfm == NULL)
355 esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
356 esp->conf.padlen = 0;
357 if (esp->conf.ivlen) {
358 esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
359 if (unlikely(esp->conf.ivec == NULL))
361 get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
363 crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len);
364 x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
366 x->props.header_len += sizeof(struct ipv6hdr);
373 crypto_free_tfm(esp->auth.tfm);
374 if (esp->auth.work_icv)
375 kfree(esp->auth.work_icv);
377 crypto_free_tfm(esp->conf.tfm);
383 static struct xfrm_type esp6_type =
385 .description = "ESP6",
386 .owner = THIS_MODULE,
387 .proto = IPPROTO_ESP,
388 .init_state = esp6_init_state,
389 .destructor = esp6_destroy,
390 .get_max_size = esp6_get_max_size,
392 .output = esp6_output
395 static struct inet6_protocol esp6_protocol = {
396 .handler = xfrm6_rcv,
397 .err_handler = esp6_err,
398 .flags = INET6_PROTO_NOPOLICY,
401 int __init esp6_init(void)
403 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
404 printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
407 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
408 printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
409 xfrm_unregister_type(&esp6_type, AF_INET6);
416 static void __exit esp6_fini(void)
418 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
419 printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
420 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
421 printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
424 module_init(esp6_init);
425 module_exit(esp6_fini);
427 MODULE_LICENSE("GPL");