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_blkcipher *tfm;
struct blkcipher_desc desc;
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;
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... */
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);
xfrm_aevent_doreplay(x);
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 error;
}
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 error;
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);
}
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(struct ip_esp_hdr) - esp->conf.ivlen - alen;
int nfrags;
int ihl;
u8 nexthdr[2];
struct scatterlist *sg;
int padlen;
int err;
if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr)))
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(struct ip_esp_hdr) + 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 = skb->nh.iph;
ihl = iph->ihl * 4;
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh = (void *)(skb->nh.raw + 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 ||
x->props.mode == XFRM_MODE_BEET)
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
iph->protocol = nexthdr[1];
pskb_trim(skb, skb->len - alen - padlen - 2);
skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - ihl;
return 0;
out:
return -EINVAL;
}
static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *iph;
struct ipv6_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(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
int hdr_len = skb->h.raw - skb->nh.raw;
int nfrags;
int ret = 0;
if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
ret = -EINVAL;
goto out;
}
if (elen <= 0 || (elen & (blksize-1))) {
ret = -EINVAL;
goto out;
}
/* If integrity check is required, do this. */
if (esp->auth.icv_full_len) {
u8 sum[alen];
ret = esp_mac_digest(esp, skb, 0, skb->len - alen);
if (ret)
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++;
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_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen);
{
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);
ret = crypto_blkcipher_decrypt(&desc, sg, sg, elen);
if (unlikely(sg != &esp->sgbuf[0]))
kfree(sg);
if (unlikely(ret))
goto out;
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);
ret = nexthdr[1];
}
skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - hdr_len;
out:
return ret;
}
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;
int blksize;
int clen;
int alen;
int nfrags;
/* Strip IP+ESP header. */
__skb_pull(skb, skb->h.raw - skb->data);
/* Now 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... */
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);
__skb_push(skb, skb->data - skb->nh.raw);
top_iph = skb->nh.iph;
esph = (struct ip_esp_hdr *)(skb->nh.raw + top_iph->ihl*4);
top_iph->tot_len = htons(skb->len + alen);
*(u8*)(trailer->tail - 1) = top_iph->protocol;
/* this is non-NULL only with UDP Encapsulation */
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh;
u32 *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 = (u32 *)(uh + 1);
udpdata32[0] = udpdata32[1] = 0;
esph = (struct ip_esp_hdr *)(udpdata32 + 2);
break;
}
top_iph->protocol = IPPROTO_UDP;
} else
top_iph->protocol = IPPROTO_ESP;
esph->spi = x->id.spi;
esph->seq_no = htonl(++x->replay.oseq);
xfrm_aevent_doreplay(x);
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 error;
}
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 error;
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);
}
ip_send_check(top_iph);
error:
return err;
}
