[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 e7720c72a6e2..f011390f19c9 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 00fd31da252e..ebcc797e1c13 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 237880a80432..324e7e0fdb2a 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 1abc48899f2d..63c05be0764d 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 e0021499093f..03869d91f6f0 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 b4cad50c18e9..13739cd8206f 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 124f24bc4dbc..2c46cbb3bbb5 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;
 }