[SK_BUFF]: Introduce skb_transport_offset()

For the quite common 'skb->h.raw - skb->data' sequence.

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

1 files changed, 7 insertions, 5 deletions

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index dab069b0b3f..1bda0299890 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -146,7 +146,7 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp)
         int off = skb->h.raw - skb->nh.raw;
         int len = ((skb->h.raw[1]+1)<<3);
 
-        if ((skb->h.raw + len) - skb->data > skb_headlen(skb))
+        if (skb_transport_offset(skb) + len > skb_headlen(skb))
                 goto bad;
 
         off += 2;
@@ -288,8 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
 #endif
         struct dst_entry *dst;
 
-        if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
-            !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
+        if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
+            !pskb_may_pull(skb, (skb_transport_offset(skb) +
+                                 ((skb->h.raw[1] + 1) << 3)))) {
                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
                                  IPSTATS_MIB_INHDRERRORS);
                 kfree_skb(skb);
@@ -387,8 +388,9 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 
         in6_dev_put(idev);
 
-        if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
-            !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
+        if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
+            !pskb_may_pull(skb, (skb_transport_offset(skb) +
+                                 ((skb->h.raw[1] + 1) << 3)))) {
                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
                                  IPSTATS_MIB_INHDRERRORS);
                 kfree_skb(skb);