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;
}
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;
}
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;
}
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;
}