kernel_optimize_test/net/ipv4/esp4.c
Herbert Xu 87bdc48d30 [IPSEC]: Get rid of ipv6_{auth,esp,comp}_hdr
This patch removes the duplicate ipv6_{auth,esp,comp}_hdr structures since
they're identical to the IPv4 versions.  Duplicating them would only create
problems for ourselves later when we need to add things like extended
sequence numbers.

I've also added transport header type conversion headers for these types
which are now used by the transforms.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:55:55 -07:00

481 lines
11 KiB
C

#include <linux/err.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 <linux/spinlock.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/udp.h>
static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
struct iphdr *top_iph;
struct ip_esp_hdr *esph;
struct crypto_blkcipher *tfm;
struct blkcipher_desc desc;
struct esp_data *esp;
struct sk_buff *trailer;
u8 *tail;
int blksize;
int clen;
int alen;
int nfrags;
/* skb is pure payload to encrypt */
err = -ENOMEM;
/* Round to block size */
clen = skb->len;
esp = x->data;
alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
desc.tfm = tfm;
desc.flags = 0;
blksize = ALIGN(crypto_blkcipher_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... */
tail = skb_tail_pointer(trailer);
do {
int i;
for (i=0; i<clen-skb->len - 2; i++)
tail[i] = i + 1;
} while (0);
tail[clen - skb->len - 2] = (clen - skb->len) - 2;
pskb_put(skb, trailer, clen - skb->len);
skb_push(skb, -skb_network_offset(skb));
top_iph = ip_hdr(skb);
esph = ip_esp_hdr(skb);
top_iph->tot_len = htons(skb->len + alen);
*(skb_tail_pointer(trailer) - 1) = *skb_mac_header(skb);
*skb_mac_header(skb) = IPPROTO_ESP;
spin_lock_bh(&x->lock);
/* this is non-NULL only with UDP Encapsulation */
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh;
__be32 *udpdata32;
uh = (struct udphdr *)esph;
uh->source = encap->encap_sport;
uh->dest = encap->encap_dport;
uh->len = htons(skb->len + alen - top_iph->ihl*4);
uh->check = 0;
switch (encap->encap_type) {
default:
case UDP_ENCAP_ESPINUDP:
esph = (struct ip_esp_hdr *)(uh + 1);
break;
case UDP_ENCAP_ESPINUDP_NON_IKE:
udpdata32 = (__be32 *)(uh + 1);
udpdata32[0] = udpdata32[1] = 0;
esph = (struct ip_esp_hdr *)(udpdata32 + 2);
break;
}
*skb_mac_header(skb) = IPPROTO_UDP;
}
esph->spi = x->id.spi;
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq);
if (esp->conf.ivlen) {
if (unlikely(!esp->conf.ivinitted)) {
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
esp->conf.ivinitted = 1;
}
crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen);
}
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 unlock;
}
skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
err = crypto_blkcipher_encrypt(&desc, sg, sg, clen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
} while (0);
if (unlikely(err))
goto unlock;
if (esp->conf.ivlen) {
memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen);
crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen);
}
if (esp->auth.icv_full_len) {
err = esp_mac_digest(esp, skb, (u8 *)esph - skb->data,
sizeof(*esph) + esp->conf.ivlen + clen);
memcpy(pskb_put(skb, trailer, alen), esp->auth.work_icv, alen);
}
unlock:
spin_unlock_bh(&x->lock);
ip_send_check(top_iph);
error:
return err;
}
/*
* Note: detecting truncated vs. non-truncated authentication data is very
* expensive, so we only support truncated data, which is the recommended
* and common case.
*/
static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct iphdr *iph;
struct ip_esp_hdr *esph;
struct esp_data *esp = x->data;
struct crypto_blkcipher *tfm = esp->conf.tfm;
struct blkcipher_desc desc = { .tfm = tfm };
struct sk_buff *trailer;
int blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4);
int alen = esp->auth.icv_trunc_len;
int elen = skb->len - sizeof(*esph) - esp->conf.ivlen - alen;
int nfrags;
int ihl;
u8 nexthdr[2];
struct scatterlist *sg;
int padlen;
int err;
if (!pskb_may_pull(skb, sizeof(*esph)))
goto out;
if (elen <= 0 || (elen & (blksize-1)))
goto out;
/* If integrity check is required, do this. */
if (esp->auth.icv_full_len) {
u8 sum[alen];
err = esp_mac_digest(esp, skb, 0, skb->len - alen);
if (err)
goto out;
if (skb_copy_bits(skb, skb->len - alen, sum, alen))
BUG();
if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) {
x->stats.integrity_failed++;
goto out;
}
}
if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0)
goto out;
skb->ip_summed = CHECKSUM_NONE;
esph = (struct ip_esp_hdr *)skb->data;
/* Get ivec. This can be wrong, check against another impls. */
if (esp->conf.ivlen)
crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen);
sg = &esp->sgbuf[0];
if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
if (!sg)
goto out;
}
skb_to_sgvec(skb, sg, sizeof(*esph) + esp->conf.ivlen, elen);
err = crypto_blkcipher_decrypt(&desc, sg, sg, elen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
if (unlikely(err))
return err;
if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
BUG();
padlen = nexthdr[0];
if (padlen+2 >= elen)
goto out;
/* ... check padding bits here. Silly. :-) */
iph = ip_hdr(skb);
ihl = iph->ihl * 4;
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
/*
* 1) if the NAT-T peer's IP or port changed then
* advertize the change to the keying daemon.
* This is an inbound SA, so just compare
* SRC ports.
*/
if (iph->saddr != x->props.saddr.a4 ||
uh->source != encap->encap_sport) {
xfrm_address_t ipaddr;
ipaddr.a4 = iph->saddr;
km_new_mapping(x, &ipaddr, uh->source);
/* XXX: perhaps add an extra
* policy check here, to see
* if we should allow or
* reject a packet from a
* different source
* address/port.
*/
}
/*
* 2) ignore UDP/TCP checksums in case
* of NAT-T in Transport Mode, or
* perform other post-processing fixes
* as per draft-ietf-ipsec-udp-encaps-06,
* section 3.1.2
*/
if (x->props.mode == XFRM_MODE_TRANSPORT)
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
iph->protocol = nexthdr[1];
pskb_trim(skb, skb->len - alen - padlen - 2);
__skb_pull(skb, sizeof(*esph) + esp->conf.ivlen);
skb_set_transport_header(skb, -ihl);
return 0;
out:
return -EINVAL;
}
static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
{
struct esp_data *esp = x->data;
u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
u32 align = max_t(u32, blksize, esp->conf.padlen);
u32 rem;
mtu -= x->props.header_len + esp->auth.icv_trunc_len;
rem = mtu & (align - 1);
mtu &= ~(align - 1);
switch (x->props.mode) {
case XFRM_MODE_TUNNEL:
break;
default:
case XFRM_MODE_TRANSPORT:
/* The worst case */
mtu -= blksize - 4;
mtu += min_t(u32, blksize - 4, rem);
break;
case XFRM_MODE_BEET:
/* The worst case. */
mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
break;
}
return mtu - 2;
}
static void esp4_err(struct sk_buff *skb, u32 info)
{
struct iphdr *iph = (struct iphdr*)skb->data;
struct ip_esp_hdr *esph = (struct ip_esp_hdr*)(skb->data+(iph->ihl<<2));
struct xfrm_state *x;
if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
return;
x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET);
if (!x)
return;
NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
ntohl(esph->spi), ntohl(iph->daddr));
xfrm_state_put(x);
}
static void esp_destroy(struct xfrm_state *x)
{
struct esp_data *esp = x->data;
if (!esp)
return;
crypto_free_blkcipher(esp->conf.tfm);
esp->conf.tfm = NULL;
kfree(esp->conf.ivec);
esp->conf.ivec = NULL;
crypto_free_hash(esp->auth.tfm);
esp->auth.tfm = NULL;
kfree(esp->auth.work_icv);
esp->auth.work_icv = NULL;
kfree(esp);
}
static int esp_init_state(struct xfrm_state *x)
{
struct esp_data *esp = NULL;
struct crypto_blkcipher *tfm;
u32 align;
if (x->ealg == NULL)
goto error;
esp = kzalloc(sizeof(*esp), GFP_KERNEL);
if (esp == NULL)
return -ENOMEM;
if (x->aalg) {
struct xfrm_algo_desc *aalg_desc;
struct crypto_hash *hash;
hash = crypto_alloc_hash(x->aalg->alg_name, 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(hash))
goto error;
esp->auth.tfm = hash;
if (crypto_hash_setkey(hash, x->aalg->alg_key,
(x->aalg->alg_key_len + 7) / 8))
goto error;
aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
BUG_ON(!aalg_desc);
if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
crypto_hash_digestsize(hash)) {
NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
x->aalg->alg_name,
crypto_hash_digestsize(hash),
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;
}
tfm = crypto_alloc_blkcipher(x->ealg->alg_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm))
goto error;
esp->conf.tfm = tfm;
esp->conf.ivlen = crypto_blkcipher_ivsize(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;
esp->conf.ivinitted = 0;
}
if (crypto_blkcipher_setkey(tfm, x->ealg->alg_key,
(x->ealg->alg_key_len + 7) / 8))
goto error;
x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
if (x->props.mode == XFRM_MODE_TUNNEL)
x->props.header_len += sizeof(struct iphdr);
else if (x->props.mode == XFRM_MODE_BEET)
x->props.header_len += IPV4_BEET_PHMAXLEN;
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
switch (encap->encap_type) {
default:
goto error;
case UDP_ENCAP_ESPINUDP:
x->props.header_len += sizeof(struct udphdr);
break;
case UDP_ENCAP_ESPINUDP_NON_IKE:
x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
break;
}
}
x->data = esp;
align = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
if (esp->conf.padlen)
align = max_t(u32, align, esp->conf.padlen);
x->props.trailer_len = align + 1 + esp->auth.icv_trunc_len;
return 0;
error:
x->data = esp;
esp_destroy(x);
x->data = NULL;
return -EINVAL;
}
static struct xfrm_type esp_type =
{
.description = "ESP4",
.owner = THIS_MODULE,
.proto = IPPROTO_ESP,
.flags = XFRM_TYPE_REPLAY_PROT,
.init_state = esp_init_state,
.destructor = esp_destroy,
.get_mtu = esp4_get_mtu,
.input = esp_input,
.output = esp_output
};
static struct net_protocol esp4_protocol = {
.handler = xfrm4_rcv,
.err_handler = esp4_err,
.no_policy = 1,
};
static int __init esp4_init(void)
{
if (xfrm_register_type(&esp_type, AF_INET) < 0) {
printk(KERN_INFO "ip esp init: can't add xfrm type\n");
return -EAGAIN;
}
if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
printk(KERN_INFO "ip esp init: can't add protocol\n");
xfrm_unregister_type(&esp_type, AF_INET);
return -EAGAIN;
}
return 0;
}
static void __exit esp4_fini(void)
{
if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
printk(KERN_INFO "ip esp close: can't remove protocol\n");
if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
printk(KERN_INFO "ip esp close: can't remove xfrm type\n");
}
module_init(esp4_init);
module_exit(esp4_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);