[IPSEC]: Use IPv6 calling convention as the convention for x->mode->output

The IPv6 calling convention for x->mode->output is more general and could
help an eventual protocol-generic x->type->output implementation.  This
patch adopts it for IPv4 as well and modifies the IPv4 type output functions
accordingly.

It also rewrites the IPv6 mac/transport header calculation to be based off
the network header where practical.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 6 insertions, 35 deletions

diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c
index bca018d19ec6..42c6ef839e59 100644
--- a/net/ipv6/xfrm6_mode_beet.c
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -24,13 +24,6 @@
  * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
  * The following fields in it shall be filled in by x->type->output:
  *	payload_len
- *
- * On exit, skb->h will be set to the start of the encapsulation header to be
- * 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 the network header will always point to the top IP header
- * while skb->data will point to the payload.
  */
 static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
 {
@@ -44,7 +37,7 @@ static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
 	skb_set_network_header(skb, -x->props.header_len);
-	skb_set_transport_header(skb, hdr_len - x->props.header_len);
+	skb->transport_header = skb->network_header + hdr_len;
 	__skb_pull(skb, hdr_len);
 
 	top_iph = ipv6_hdr(skb);
diff --git a/net/ipv6/xfrm6_mode_ro.c b/net/ipv6/xfrm6_mode_ro.c
index 5c29b367b432..957ae36b6695 100644
--- a/net/ipv6/xfrm6_mode_ro.c
+++ b/net/ipv6/xfrm6_mode_ro.c
@@ -37,13 +37,6 @@
  *
  * The IP header and mutable extension headers will be moved forward to make
  * space for the route optimization header.
- *
- * On exit, skb->h will be set to the start of the encapsulation header to be
- * 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 the network header will always point to the top IP header
- * while skb->data will point to the payload.
  */
 static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
 {
@@ -56,7 +49,7 @@ static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
 	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
 	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
 	skb_set_network_header(skb, -x->props.header_len);
-	skb_set_transport_header(skb, hdr_len - x->props.header_len);
+	skb->transport_header = skb->network_header + hdr_len;
 	__skb_pull(skb, hdr_len);
 	memmove(ipv6_hdr(skb), iph, hdr_len);
 
diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
index f2ee186494ed..4e344105b3fd 100644
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -18,13 +18,6 @@
  *
  * The IP header and mutable extension headers will be moved forward to make
  * space for the encapsulation header.
- *
- * On exit, skb->h will be set to the start of the encapsulation header to be
- * 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 the network header will always point to the top IP header
- * while skb->data will point to the payload.
  */
 static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 {
@@ -37,7 +30,7 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
 	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
 	skb_set_network_header(skb, -x->props.header_len);
-	skb_set_transport_header(skb, hdr_len - x->props.header_len);
+	skb->transport_header = skb->network_header + hdr_len;
 	__skb_pull(skb, hdr_len);
 	memmove(ipv6_hdr(skb), iph, hdr_len);
 	return 0;
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 01bd7d11ea1b..e79c6bdf71c1 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -36,13 +36,6 @@ static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
  * The top IP header will be constructed per RFC 2401.  The following fields
  * in it shall be filled in by x->type->output:
  *	payload_len
- *
- * On exit, skb->h will be set to the start of the encapsulation header to be
- * 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 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)
 {
@@ -53,11 +46,10 @@ static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	iph = ipv6_hdr(skb);
 
-	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);
+	skb->mac_header = skb->network_header +
+			  offsetof(struct ipv6hdr, nexthdr);
+	skb->transport_header = skb->network_header + sizeof(*iph);
 	top_iph = ipv6_hdr(skb);
 
 	top_iph->version = 6;