[SK_BUFF]: Introduce skb_reset_transport_header(skb)

For the common, open coded 'skb->h.raw = skb->data' operation, so that we can
later turn skb->h.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 cases:

skb->h.raw = skb->data;
skb->h.raw = {skb_push|[__]skb_pull}()

The next ones 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>

7 files changed, 12 insertions, 8 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e7720c72a6e..f011390f19c 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1120,7 +1120,8 @@ static int inet_gso_send_check(struct sk_buff *skb)
 	if (unlikely(!pskb_may_pull(skb, ihl)))
 		goto out;
 
-	skb->h.raw = __skb_pull(skb, ihl);
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
 	iph = ip_hdr(skb);
 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
 	err = -EPROTONOSUPPORT;
@@ -1163,7 +1164,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
 	if (unlikely(!pskb_may_pull(skb, ihl)))
 		goto out;
 
-	skb->h.raw = __skb_pull(skb, ihl);
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
 	iph = ip_hdr(skb);
 	id = ntohs(iph->id);
 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 00fd31da252..ebcc797e1c1 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -182,7 +182,8 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 	}
 	((struct iphdr*)work_buf)->protocol = ah->nexthdr;
 	skb->nh.raw += ah_hlen;
-	skb->h.raw = memcpy(skb_network_header(skb), work_buf, ihl);
+	memcpy(skb_network_header(skb), work_buf, ihl);
+	skb->h.raw = skb->nh.raw;
 	__skb_pull(skb, ah_hlen + ihl);
 
 	return 0;
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 237880a8043..324e7e0fdb2 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -201,7 +201,7 @@ static inline int ip_local_deliver_finish(struct sk_buff *skb)
 	__skb_pull(skb, ip_hdrlen(skb));
 
 	/* Point into the IP datagram, just past the header. */
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	rcu_read_lock();
 	{
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 1abc48899f2..63c05be0764 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -500,7 +500,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
 			 * before previous one went down. */
 			if (frag) {
 				frag->ip_summed = CHECKSUM_NONE;
-				frag->h.raw = frag->data;
+				skb_reset_transport_header(frag);
 				__skb_push(frag, hlen);
 				skb_reset_network_header(frag);
 				memcpy(skb_network_header(frag), iph, hlen);
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index e0021499093..03869d91f6f 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -563,7 +563,7 @@ static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
 		 */
 		skb_push(skb, sizeof(struct iphdr));
 		skb_reset_network_header(skb);
-		skb->h.raw = skb->data;
+		skb_reset_transport_header(skb);
 		msg = (struct igmpmsg *)skb_network_header(skb);
 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index b4cad50c18e..13739cd8206 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1002,7 +1002,8 @@ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
 	 * transport header to point to ESP.  Keep UDP on the stack
 	 * for later.
 	 */
-	skb->h.raw = __skb_pull(skb, len);
+	__skb_pull(skb, len);
+	skb_reset_transport_header(skb);
 
 	/* modify the protocol (it's ESP!) */
 	iph->protocol = IPPROTO_ESP;
diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c
index 124f24bc4db..2c46cbb3bbb 100644
--- a/net/ipv4/xfrm4_mode_transport.c
+++ b/net/ipv4/xfrm4_mode_transport.c
@@ -52,7 +52,7 @@ static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 		skb->nh.raw = skb->h.raw;
 	}
 	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	return 0;
 }