[SK_BUFF]: Introduce skb_reset_mac_header(skb)

For the common, open coded 'skb->mac.raw = skb->data' operation, so that we can
later turn skb->mac.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple case, next will handle the slightly more
"complex" cases.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 4 insertions, 3 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 9151da642318..88f8aae873f4 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -616,7 +616,7 @@ static int ipgre_rcv(struct sk_buff *skb)
                                 offset += 4;
                 }
 
-                skb->mac.raw = skb->nh.raw;
+                skb_reset_mac_header(skb);
                 skb->nh.raw = __pskb_pull(skb, offset);
                 skb_postpull_rcsum(skb, skb->h.raw, offset);
                 skb->pkt_type = PACKET_HOST;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 5db301b33372..ddba857bd243 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -95,7 +95,7 @@ __inline__ void ip_send_check(struct iphdr *iph)
 /* dev_loopback_xmit for use with netfilter. */
 static int ip_dev_loopback_xmit(struct sk_buff *newskb)
 {
-        newskb->mac.raw = newskb->data;
+        skb_reset_mac_header(newskb);
         __skb_pull(newskb, newskb->nh.raw - newskb->data);
         newskb->pkt_type = PACKET_LOOPBACK;
         newskb->ip_summed = CHECKSUM_UNNECESSARY;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0b3d7bf40f4e..29ee7be45aa6 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2747,7 +2747,8 @@ int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
         /* Reserve room for dummy headers, this skb can pass
            through good chunk of routing engine.
          */
-        skb->mac.raw = skb->nh.raw = skb->data;
+        skb_reset_mac_header(skb);
+        skb->nh.raw = skb->data;
 
         /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
         skb->nh.iph->protocol = IPPROTO_ICMP;