[IPSEC]: Set skb->data to payload in x->mode->output

This patch changes the calling convention so that on entry from
x->mode->output and before entry into x->type->output skb->data
will point to the payload instead of the IP header.

This is essentially a redistribution of skb_push/skb_pull calls
with the aim of minimising them on the common path of tunnel +
ESP.

It'll also let us use the same calling convention between IPv4
and IPv6 with the next patch.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu
2007-10-10 15:44:06 -07:00
committed by David S. Miller
parent bee0b40c06
commit 7b277b1a5f
16 changed files with 47 additions and 42 deletions

View File

@@ -41,8 +41,8 @@ static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
* filled in by x->type->output and the mac header will be set to the
* nextheader field of the extension header directly preceding the
* encapsulation header, or in its absence, that of the top IP header.
* The value of skb->data and the network header will always point to the
* top IP header.
* The value of the network header will always point to the top IP header
* while skb->data will point to the payload.
*/
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
@@ -51,12 +51,13 @@ static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
struct ipv6hdr *iph, *top_iph;
int dsfield;
skb_push(skb, x->props.header_len);
iph = ipv6_hdr(skb);
skb_set_mac_header(skb, offsetof(struct ipv6hdr, nexthdr));
skb_reset_network_header(skb);
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
skb_set_mac_header(skb, offsetof(struct ipv6hdr, nexthdr) -
x->props.header_len);
skb_set_network_header(skb, -x->props.header_len);
skb_set_transport_header(skb, sizeof(struct ipv6hdr) -
x->props.header_len);
top_iph = ipv6_hdr(skb);
top_iph->version = 6;