-
-struct ipcomp_tfms {
- struct list_head list;
- struct crypto_comp **tfms;
- int users;
-};
-
-static DEFINE_MUTEX(ipcomp_resource_mutex);
-static void **ipcomp_scratches;
-static int ipcomp_scratch_users;
-static LIST_HEAD(ipcomp_tfms_list);
-
-static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
-{
- struct ipcomp_data *ipcd = x->data;
- const int plen = skb->len;
- int dlen = IPCOMP_SCRATCH_SIZE;
- const u8 *start = skb->data;
- const int cpu = get_cpu();
- u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
- struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
- int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
-
- if (err)
- goto out;
-
- if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
- err = -EINVAL;
- goto out;
- }
-
- err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
- if (err)
- goto out;
-
- skb->truesize += dlen - plen;
- __skb_put(skb, dlen - plen);
- skb_copy_to_linear_data(skb, scratch, dlen);
-out:
- put_cpu();
- return err;
-}
-
-static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
-{
- int nexthdr;
- int err = -ENOMEM;
- struct ip_comp_hdr *ipch;
-
- if (skb_linearize_cow(skb))
- goto out;
-
- skb->ip_summed = CHECKSUM_NONE;
-
- /* Remove ipcomp header and decompress original payload */
- ipch = (void *)skb->data;
- nexthdr = ipch->nexthdr;
-
- skb->transport_header = skb->network_header + sizeof(*ipch);
- __skb_pull(skb, sizeof(*ipch));
- err = ipcomp_decompress(x, skb);
- if (err)
- goto out;
-
- err = nexthdr;
-
-out:
- return err;
-}
-
-static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
-{
- struct ipcomp_data *ipcd = x->data;
- const int plen = skb->len;
- int dlen = IPCOMP_SCRATCH_SIZE;
- u8 *start = skb->data;
- const int cpu = get_cpu();
- u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
- struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
- int err;
-
- local_bh_disable();
- err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
- local_bh_enable();
- if (err)
- goto out;
-
- if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
- err = -EMSGSIZE;
- goto out;
- }
-
- memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
- put_cpu();
-
- pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
- return 0;
-
-out:
- put_cpu();
- return err;
-}
-
-static int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
-{
- int err;
- struct ip_comp_hdr *ipch;
- struct ipcomp_data *ipcd = x->data;
-
- if (skb->len < ipcd->threshold) {
- /* Don't bother compressing */
- goto out_ok;
- }
-
- if (skb_linearize_cow(skb))
- goto out_ok;
-
- err = ipcomp_compress(x, skb);
-
- if (err) {
- goto out_ok;
- }
-
- /* Install ipcomp header, convert into ipcomp datagram. */
- ipch = ip_comp_hdr(skb);
- ipch->nexthdr = *skb_mac_header(skb);
- ipch->flags = 0;
- ipch->cpi = htons((u16 )ntohl(x->id.spi));
- *skb_mac_header(skb) = IPPROTO_COMP;
-out_ok:
- skb_push(skb, -skb_network_offset(skb));
- return 0;
-}