[IPSEC]: Move IP length/checksum setting out of transforms

This patch moves the setting of the IP length and checksum fields out of
the transforms and into the xfrmX_output functions.  This would help future
efforts in merging the transforms themselves.

It also adds an optimisation to ipcomp due to the fact that the transport
offset is guaranteed to be zero.

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

1 files changed, 1 insertions, 6 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 66eb4968b910..8377bedf3f66 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -16,7 +16,6 @@
 static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 {
         int err;
-        struct iphdr *top_iph;
         struct ip_esp_hdr *esph;
         struct crypto_blkcipher *tfm;
         struct blkcipher_desc desc;
@@ -59,9 +58,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
         pskb_put(skb, trailer, clen - skb->len);
 
         skb_push(skb, -skb_network_offset(skb));
-        top_iph = ip_hdr(skb);
         esph = ip_esp_hdr(skb);
-        top_iph->tot_len = htons(skb->len + alen);
         *(skb_tail_pointer(trailer) - 1) = *skb_mac_header(skb);
         *skb_mac_header(skb) = IPPROTO_ESP;
 
@@ -76,7 +73,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
                 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->len = htons(skb->len + alen - skb_transport_offset(skb));
                 uh->check = 0;
 
                 switch (encap->encap_type) {
@@ -136,8 +133,6 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 unlock:
         spin_unlock_bh(&x->lock);
 
-        ip_send_check(top_iph);
-
 error:
         return err;
 }