linux/net/ipv6/esp6.c
Arnaldo Carvalho de Melo 14c850212e [INET_SOCK]: Move struct inet_sock & helper functions to net/inet_sock.h
To help in reducing the number of include dependencies, several files were
touched as they were getting needed headers indirectly for stuff they use.

Thanks also to Alan Menegotto for pointing out that net/dccp/proto.c had
linux/dccp.h include twice.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:21 -08:00

419 lines
11 KiB
C

/*
* Copyright (C)2002 USAGI/WIDE Project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Authors
*
* Mitsuru KANDA @USAGI : IPv6 Support
* Kazunori MIYAZAWA @USAGI :
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
*
* This file is derived from net/ipv4/esp.c
*/
#include <linux/config.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <asm/scatterlist.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/icmpv6.h>
static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
int hdr_len;
struct ipv6hdr *top_iph;
struct ipv6_esp_hdr *esph;
struct crypto_tfm *tfm;
struct esp_data *esp;
struct sk_buff *trailer;
int blksize;
int clen;
int alen;
int nfrags;
esp = x->data;
hdr_len = skb->h.raw - skb->data +
sizeof(*esph) + esp->conf.ivlen;
/* Strip IP+ESP header. */
__skb_pull(skb, hdr_len);
/* Now skb is pure payload to encrypt */
err = -ENOMEM;
/* Round to block size */
clen = skb->len;
alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
clen = ALIGN(clen + 2, blksize);
if (esp->conf.padlen)
clen = ALIGN(clen, esp->conf.padlen);
if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
goto error;
}
/* Fill padding... */
do {
int i;
for (i=0; i<clen-skb->len - 2; i++)
*(u8*)(trailer->tail + i) = i+1;
} while (0);
*(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
pskb_put(skb, trailer, clen - skb->len);
top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
esph = (struct ipv6_esp_hdr *)skb->h.raw;
top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
*(u8*)(trailer->tail - 1) = *skb->nh.raw;
*skb->nh.raw = IPPROTO_ESP;
esph->spi = x->id.spi;
esph->seq_no = htonl(++x->replay.oseq);
if (esp->conf.ivlen)
crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
do {
struct scatterlist *sg = &esp->sgbuf[0];
if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
if (!sg)
goto error;
}
skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
crypto_cipher_encrypt(tfm, sg, sg, clen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
} while (0);
if (esp->conf.ivlen) {
memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
}
if (esp->auth.icv_full_len) {
esp->auth.icv(esp, skb, (u8*)esph-skb->data,
sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
pskb_put(skb, trailer, alen);
}
err = 0;
error:
return err;
}
static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
struct ipv6hdr *iph;
struct ipv6_esp_hdr *esph;
struct esp_data *esp = x->data;
struct sk_buff *trailer;
int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
int alen = esp->auth.icv_trunc_len;
int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
int hdr_len = skb->h.raw - skb->nh.raw;
int nfrags;
unsigned char *tmp_hdr = NULL;
int ret = 0;
if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
ret = -EINVAL;
goto out_nofree;
}
if (elen <= 0 || (elen & (blksize-1))) {
ret = -EINVAL;
goto out_nofree;
}
tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
if (!tmp_hdr) {
ret = -ENOMEM;
goto out_nofree;
}
memcpy(tmp_hdr, skb->nh.raw, hdr_len);
/* If integrity check is required, do this. */
if (esp->auth.icv_full_len) {
u8 sum[esp->auth.icv_full_len];
u8 sum1[alen];
esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
BUG();
if (unlikely(memcmp(sum, sum1, alen))) {
x->stats.integrity_failed++;
ret = -EINVAL;
goto out;
}
}
if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
ret = -EINVAL;
goto out;
}
skb->ip_summed = CHECKSUM_NONE;
esph = (struct ipv6_esp_hdr*)skb->data;
iph = skb->nh.ipv6h;
/* Get ivec. This can be wrong, check against another impls. */
if (esp->conf.ivlen)
crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
{
u8 nexthdr[2];
struct scatterlist *sg = &esp->sgbuf[0];
u8 padlen;
if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
if (!sg) {
ret = -ENOMEM;
goto out;
}
}
skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
BUG();
padlen = nexthdr[0];
if (padlen+2 >= elen) {
LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
ret = -EINVAL;
goto out;
}
/* ... check padding bits here. Silly. :-) */
pskb_trim(skb, skb->len - alen - padlen - 2);
skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
memcpy(skb->nh.raw, tmp_hdr, hdr_len);
skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
ret = nexthdr[1];
}
out:
kfree(tmp_hdr);
out_nofree:
return ret;
}
static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
{
struct esp_data *esp = x->data;
u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
if (x->props.mode) {
mtu = ALIGN(mtu + 2, blksize);
} else {
/* The worst case. */
u32 padsize = ((blksize - 1) & 7) + 1;
mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
}
if (esp->conf.padlen)
mtu = ALIGN(mtu, esp->conf.padlen);
return mtu + x->props.header_len + esp->auth.icv_trunc_len;
}
static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __u32 info)
{
struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
struct xfrm_state *x;
if (type != ICMPV6_DEST_UNREACH &&
type != ICMPV6_PKT_TOOBIG)
return;
x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
if (!x)
return;
printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
"%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
ntohl(esph->spi), NIP6(iph->daddr));
xfrm_state_put(x);
}
static void esp6_destroy(struct xfrm_state *x)
{
struct esp_data *esp = x->data;
if (!esp)
return;
crypto_free_tfm(esp->conf.tfm);
esp->conf.tfm = NULL;
kfree(esp->conf.ivec);
esp->conf.ivec = NULL;
crypto_free_tfm(esp->auth.tfm);
esp->auth.tfm = NULL;
kfree(esp->auth.work_icv);
esp->auth.work_icv = NULL;
kfree(esp);
}
static int esp6_init_state(struct xfrm_state *x)
{
struct esp_data *esp = NULL;
/* null auth and encryption can have zero length keys */
if (x->aalg) {
if (x->aalg->alg_key_len > 512)
goto error;
}
if (x->ealg == NULL)
goto error;
if (x->encap)
goto error;
esp = kmalloc(sizeof(*esp), GFP_KERNEL);
if (esp == NULL)
return -ENOMEM;
memset(esp, 0, sizeof(*esp));
if (x->aalg) {
struct xfrm_algo_desc *aalg_desc;
esp->auth.key = x->aalg->alg_key;
esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
if (esp->auth.tfm == NULL)
goto error;
esp->auth.icv = esp_hmac_digest;
aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
BUG_ON(!aalg_desc);
if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
crypto_tfm_alg_digestsize(esp->auth.tfm)) {
printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
x->aalg->alg_name,
crypto_tfm_alg_digestsize(esp->auth.tfm),
aalg_desc->uinfo.auth.icv_fullbits/8);
goto error;
}
esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
if (!esp->auth.work_icv)
goto error;
}
esp->conf.key = x->ealg->alg_key;
esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
if (x->props.ealgo == SADB_EALG_NULL)
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
else
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
if (esp->conf.tfm == NULL)
goto error;
esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
esp->conf.padlen = 0;
if (esp->conf.ivlen) {
esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
if (unlikely(esp->conf.ivec == NULL))
goto error;
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
}
if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
goto error;
x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
if (x->props.mode)
x->props.header_len += sizeof(struct ipv6hdr);
x->data = esp;
return 0;
error:
x->data = esp;
esp6_destroy(x);
x->data = NULL;
return -EINVAL;
}
static struct xfrm_type esp6_type =
{
.description = "ESP6",
.owner = THIS_MODULE,
.proto = IPPROTO_ESP,
.init_state = esp6_init_state,
.destructor = esp6_destroy,
.get_max_size = esp6_get_max_size,
.input = esp6_input,
.output = esp6_output
};
static struct inet6_protocol esp6_protocol = {
.handler = xfrm6_rcv,
.err_handler = esp6_err,
.flags = INET6_PROTO_NOPOLICY,
};
static int __init esp6_init(void)
{
if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
return -EAGAIN;
}
if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
xfrm_unregister_type(&esp6_type, AF_INET6);
return -EAGAIN;
}
return 0;
}
static void __exit esp6_fini(void)
{
if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
}
module_init(esp6_init);
module_exit(esp6_fini);
MODULE_LICENSE("GPL");