int esp_output(struct sk_buff *skb)
{
int err;
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
struct iphdr *iph, *top_iph;
struct ip_esp_hdr *esph;
struct crypto_tfm *tfm;
struct esp_data *esp;
struct sk_buff *trailer;
struct udphdr *uh = NULL;
struct xfrm_encap_tmpl *encap = NULL;
int blksize;
int clen;
int alen;
int nfrags;
union {
struct iphdr iph;
char buf[60];
} tmp_iph;
/* First, if the skb is not checksummed, complete checksum. */
if (skb->ip_summed == CHECKSUM_HW && skb_checksum_help(skb) == NULL) {
err = -EINVAL;
goto error_nolock;
}
spin_lock_bh(&x->lock);
err = xfrm_check_output(x, skb, AF_INET);
if (err)
goto error;
err = -ENOMEM;
/* Strip IP header in transport mode. Save it. */
if (!x->props.mode) {
iph = skb->nh.iph;
memcpy(&tmp_iph, iph, iph->ihl*4);
__skb_pull(skb, iph->ihl*4);
}
/* Now skb is pure payload to encrypt */
/* Round to block size */
clen = skb->len;
esp = x->data;
alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
clen = (clen + 2 + blksize-1)&~(blksize-1);
if (esp->conf.padlen)
clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
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);
encap = x->encap;
iph = skb->nh.iph;
if (x->props.mode) {
top_iph = (struct iphdr*)skb_push(skb, x->props.header_len);
esph = (struct ip_esp_hdr*)(top_iph+1);
if (encap && encap->encap_type) {
switch (encap->encap_type) {
case UDP_ENCAP_ESPINUDP:
uh = (struct udphdr*) esph;
esph = (struct ip_esp_hdr*)(uh+1);
top_iph->protocol = IPPROTO_UDP;
break;
default:
printk(KERN_INFO
"esp_output(): Unhandled encap: %u\n",
encap->encap_type);
top_iph->protocol = IPPROTO_ESP;
break;
}
} else
top_iph->protocol = IPPROTO_ESP;
*(u8*)(trailer->tail - 1) = IPPROTO_IPIP;
top_iph->ihl = 5;
top_iph->version = 4;
top_iph->tos = iph->tos; /* DS disclosed */
if (x->props.flags & XFRM_STATE_NOECN)
IP_ECN_clear(top_iph);
top_iph->tot_len = htons(skb->len + alen);
top_iph->frag_off = iph->frag_off&htons(IP_DF);
if (!(top_iph->frag_off))
ip_select_ident(top_iph, dst, 0);
top_iph->ttl = iph->ttl; /* TTL disclosed */
top_iph->check = 0;
top_iph->saddr = x->props.saddr.a4;
top_iph->daddr = x->id.daddr.a4;
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
} else {
esph = (struct ip_esp_hdr*)skb_push(skb, x->props.header_len);
top_iph = (struct iphdr*)skb_push(skb, iph->ihl*4);
memcpy(top_iph, &tmp_iph, iph->ihl*4);
if (encap && encap->encap_type) {
switch (encap->encap_type) {
case UDP_ENCAP_ESPINUDP:
uh = (struct udphdr*) esph;
esph = (struct ip_esp_hdr*)(uh+1);
top_iph->protocol = IPPROTO_UDP;
break;
default:
printk(KERN_INFO
"esp_output(): Unhandled encap: %u\n",
encap->encap_type);
top_iph->protocol = IPPROTO_ESP;
break;
}
} else
top_iph->protocol = IPPROTO_ESP;
iph = &tmp_iph.iph;
top_iph->tot_len = htons(skb->len + alen);
top_iph->check = 0;
top_iph->frag_off = iph->frag_off;
*(u8*)(trailer->tail - 1) = iph->protocol;
}
/* this is non-NULL only with UDP Encapsulation */
if (encap && uh) {
uh->source = encap->encap_sport;
uh->dest = encap->encap_dport;
uh->len = htons(skb->len + alen - sizeof(struct iphdr));
uh->check = 0;
}
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 sgbuf[nfrags>MAX_SG_ONSTACK ? 0 : nfrags];
struct scatterlist *sg = sgbuf;
if (unlikely(nfrags > MAX_SG_ONSTACK)) {
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 != sgbuf))
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 ip_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
pskb_put(skb, trailer, alen);
}
ip_send_check(top_iph);
skb->nh.raw = skb->data;
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock_bh(&x->lock);
if ((skb->dst = dst_pop(dst)) == NULL) {
err = -EHOSTUNREACH;
goto error_nolock;
}
return NET_XMIT_BYPASS;
error:
spin_unlock_bh(&x->lock);
error_nolock:
kfree_skb(skb);
return err;
}
int esp_init_state(struct xfrm_state *x, void *args)
{
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;
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);
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);
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
}
crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len);
x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
if (x->props.mode)
x->props.header_len += sizeof(struct iphdr);
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
if (encap->encap_type) {
switch (encap->encap_type) {
case UDP_ENCAP_ESPINUDP:
x->props.header_len += sizeof(struct udphdr);
break;
default:
printk (KERN_INFO
"esp_init_state(): Unhandled encap type: %u\n",
encap->encap_type);
break;
}
}
}
x->data = esp;
x->props.trailer_len = esp4_get_max_size(x, 0) - x->props.header_len;
return 0;
error:
if (esp) {
if (esp->auth.tfm)
crypto_free_tfm(esp->auth.tfm);
if (esp->auth.work_icv)
kfree(esp->auth.work_icv);
if (esp->conf.tfm)
crypto_free_tfm(esp->conf.tfm);
kfree(esp);
}
return -EINVAL;
}
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;
}
/*
* Note: detecting truncated vs. non-truncated authentication data is very
* expensive, so we only support truncated data, which is the recommended
* and common case.
*/
int esp_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
struct iphdr *iph;
struct ip_esp_hdr *esph;
struct esp_data *esp = x->data;
struct sk_buff *trailer;
int blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
int alen = esp->auth.icv_trunc_len;
int elen = skb->len - sizeof(struct ip_esp_hdr) - esp->conf.ivlen - alen;
int nfrags;
int encap_len = 0;
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[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++;
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;
iph = skb->nh.iph;
/* 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 sgbuf[nfrags>MAX_SG_ONSTACK ? 0 : nfrags];
struct scatterlist *sg = sgbuf;
u8 workbuf[60];
int padlen;
if (unlikely(nfrags > MAX_SG_ONSTACK)) {
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);
crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
if (unlikely(sg != sgbuf))
kfree(sg);
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. :-) */
if (x->encap && decap && decap->decap_type) {
struct esp_decap_data *encap_data;
struct udphdr *uh = (struct udphdr *) (iph+1);
encap_data = (struct esp_decap_data *) (decap->decap_data);
encap_data->proto = 0;
switch (decap->decap_type) {
case UDP_ENCAP_ESPINUDP:
if ((void*)uh == (void*)esph) {
printk(KERN_DEBUG
"esp_input(): Got ESP; expecting ESPinUDP\n");
break;
}
encap_data->proto = AF_INET;
encap_data->saddr.a4 = iph->saddr;
encap_data->sport = uh->source;
encap_len = (void*)esph - (void*)uh;
if (encap_len != sizeof(*uh))
printk(KERN_DEBUG
"esp_input(): UDP -> ESP: too much room: %d\n",
encap_len);
break;
default:
printk(KERN_INFO
"esp_input(): processing unknown encap type: %u\n",
decap->decap_type);
break;
}
}
iph->protocol = nexthdr[1];
pskb_trim(skb, skb->len - alen - padlen - 2);
memcpy(workbuf, skb->nh.raw, iph->ihl*4);
skb->h.raw = skb_pull(skb, sizeof(struct ip_esp_hdr) + esp->conf.ivlen);
skb->nh.raw += encap_len + sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
memcpy(skb->nh.raw, workbuf, iph->ihl*4);
skb->nh.iph->tot_len = htons(skb->len);
}
return 0;
out:
return -EINVAL;
}
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;
}
esph = (struct ipv6_esp_hdr*)skb->data;
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];
if (x->props.replay_window && xfrm_replay_check(x, esph->seq_no)) {
ret = -EINVAL;
goto out;
}
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 (x->props.replay_window)
xfrm_replay_advance(x, esph->seq_no);
}
if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
ret = -EINVAL;
goto out;
}
skb->ip_summed = CHECKSUM_NONE;
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 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 || (x->ealg->alg_key_len == 0 && x->props.ealgo != SADB_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;
unsigned int digestsize;
u32 mode = 0;
aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
BUG_ON(!aalg_desc);
#ifdef CONFIG_CRYPTO_XCBC
mode = aalg_desc->desc.sadb_alg_id == SADB_X_AALG_AES_XCBC_MAC ?
CRYPTO_TFM_MODE_CBC : 0;
#endif
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, mode);
if (esp->auth.tfm == NULL)
goto error;
#ifdef CONFIG_CRYPTO_XCBC
esp->auth.icv = !mode ? esp_hmac_digest : esp_xcbc_digest;
#else
esp->auth.icv = esp_hmac_digest;
#endif
digestsize = !mode ? crypto_tfm_alg_digestsize(esp->auth.tfm) :
crypto_tfm_alg_blocksize(esp->auth.tfm);
if (aalg_desc->uinfo.auth.icv_fullbits/8 != digestsize) {
printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
x->aalg->alg_name,
digestsize,
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;
if (x->props.ealgo == SADB_EALG_NULL) {
esp->conf.key_len = 0;
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
} else {
esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
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 int esp_output(struct sk_buff *skb)
{
int err;
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
struct iphdr *top_iph;
struct ip_esp_hdr *esph;
struct crypto_tfm *tfm;
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;
blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
clen = (clen + 2 + blksize-1)&~(blksize-1);
if (esp->conf.padlen)
clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
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);
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 ip_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
pskb_put(skb, trailer, alen);
}
ip_send_check(top_iph);
err = 0;
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 xfrm_decap_state *decap, struct sk_buff *skb)
{
struct iphdr *iph;
struct ip_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 ip_esp_hdr) - esp->conf.ivlen - alen;
int nfrags;
int encap_len = 0;
u8 nexthdr[2];
struct scatterlist *sg;
u8 workbuf[60];
int padlen;
if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr)))
goto out;
esph = (struct ip_esp_hdr*)skb->data;
if (elen <= 0 || (elen & (blksize-1)))
goto out;
/* If integrity check is required, do this. */
if (esp->auth.icv_full_len) {
u8 sum[esp->auth.icv_full_len];
u8 sum1[alen];
if (x->props.replay_window && xfrm_replay_check(x, esph->seq_no))
goto out;
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++;
goto out;
}
if (x->props.replay_window)
xfrm_replay_advance(x, esph->seq_no);
}
if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0)
goto out;
skb->ip_summed = CHECKSUM_NONE;
iph = skb->nh.iph;
/* 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));
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);
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)
goto out;
/* ... check padding bits here. Silly. :-) */
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh;
if (encap->encap_type != decap->decap_type)
goto out;
uh = (struct udphdr *)(iph + 1);
encap_len = (void*)esph - (void*)uh;
/*
* 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)
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
iph->protocol = nexthdr[1];
pskb_trim(skb, skb->len - alen - padlen - 2);
memcpy(workbuf, skb->nh.raw, iph->ihl*4);
skb->h.raw = skb_pull(skb, sizeof(struct ip_esp_hdr) + esp->conf.ivlen);
skb->nh.raw += encap_len + sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
memcpy(skb->nh.raw, workbuf, iph->ihl*4);
skb->nh.iph->tot_len = htons(skb->len);
return 0;
out:
return -EINVAL;
}
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;
#if defined (CONFIG_OCTEON_NATIVE_IPSEC)
esp->oct_data = cavium_alloc_n_fill(x);
#endif
return 0;
error:
x->data = esp;
esp6_destroy(x);
x->data = NULL;
return -EINVAL;
}
int esp6_output(struct sk_buff *skb)
{
int err;
int hdr_len = 0;
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
struct ipv6hdr *iph = NULL, *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;
u8 *prevhdr;
u8 nexthdr = 0;
/* First, if the skb is not checksummed, complete checksum. */
if (skb->ip_summed == CHECKSUM_HW && skb_checksum_help(skb) == NULL) {
err = -EINVAL;
goto error_nolock;
}
spin_lock_bh(&x->lock);
err = xfrm_check_output(x, skb, AF_INET6);
if (err)
goto error;
err = -ENOMEM;
/* Strip IP header in transport mode. Save it. */
if (!x->props.mode) {
hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
nexthdr = *prevhdr;
*prevhdr = IPPROTO_ESP;
iph = kmalloc(hdr_len, GFP_ATOMIC);
if (!iph) {
err = -ENOMEM;
goto error;
}
memcpy(iph, skb->nh.raw, hdr_len);
__skb_pull(skb, hdr_len);
}
/* Now skb is pure payload to encrypt */
/* Round to block size */
clen = skb->len;
esp = x->data;
alen = esp->auth.icv_trunc_len;
tfm = esp->conf.tfm;
blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
clen = (clen + 2 + blksize-1)&~(blksize-1);
if (esp->conf.padlen)
clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
if (!x->props.mode && iph) kfree(iph);
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);
if (x->props.mode) {
iph = skb->nh.ipv6h;
top_iph = (struct ipv6hdr*)skb_push(skb, x->props.header_len);
esph = (struct ipv6_esp_hdr*)(top_iph+1);
*(u8*)(trailer->tail - 1) = IPPROTO_IPV6;
top_iph->version = 6;
top_iph->priority = iph->priority;
top_iph->flow_lbl[0] = iph->flow_lbl[0];
top_iph->flow_lbl[1] = iph->flow_lbl[1];
top_iph->flow_lbl[2] = iph->flow_lbl[2];
if (x->props.flags & XFRM_STATE_NOECN)
IP6_ECN_clear(top_iph);
top_iph->nexthdr = IPPROTO_ESP;
top_iph->payload_len = htons(skb->len + alen - sizeof(struct ipv6hdr));
top_iph->hop_limit = iph->hop_limit;
ipv6_addr_copy(&top_iph->saddr,
(struct in6_addr *)&x->props.saddr);
ipv6_addr_copy(&top_iph->daddr,
(struct in6_addr *)&x->id.daddr);
} else {
esph = (struct ipv6_esp_hdr*)skb_push(skb, x->props.header_len);
skb->h.raw = (unsigned char*)esph;
top_iph = (struct ipv6hdr*)skb_push(skb, hdr_len);
memcpy(top_iph, iph, hdr_len);
kfree(iph);
top_iph->payload_len = htons(skb->len + alen - sizeof(struct ipv6hdr));
*(u8*)(trailer->tail - 1) = nexthdr;
}
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 sgbuf[nfrags>MAX_SG_ONSTACK ? 0 : nfrags];
struct scatterlist *sg = sgbuf;
if (unlikely(nfrags > MAX_SG_ONSTACK)) {
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 != sgbuf))
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);
}
skb->nh.raw = skb->data;
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock_bh(&x->lock);
if ((skb->dst = dst_pop(dst)) == NULL) {
err = -EHOSTUNREACH;
goto error_nolock;
}
return NET_XMIT_BYPASS;
error:
spin_unlock_bh(&x->lock);
error_nolock:
kfree_skb(skb);
return err;
}
int esp6_init_state(struct xfrm_state *x, void *args)
{
struct esp_data *esp = NULL;
if (x->aalg) {
if (x->aalg->alg_key_len == 0 || x->aalg->alg_key_len > 512)
goto error;
}
if (x->ealg == NULL)
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);
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);
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
}
crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len);
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:
if (esp) {
if (esp->auth.tfm)
crypto_free_tfm(esp->auth.tfm);
if (esp->auth.work_icv)
kfree(esp->auth.work_icv);
if (esp->conf.tfm)
crypto_free_tfm(esp->conf.tfm);
kfree(esp);
}
return -EINVAL;
}
