[NETFILTER]: Avoid skb_copy/pskb_copy/skb_realloc_headroom

This patch replaces unnecessary uses of skb_copy, pskb_copy and
skb_realloc_headroom by functions such as skb_make_writable and
pskb_expand_head.

This allows us to remove the double pointers later.

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

1 files changed, 3 insertions, 7 deletions

diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index 31b6f9d0982..f111edf5f77 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -105,14 +105,10 @@ tcpmss_mangle_packet(struct sk_buff **pskb,
          * MSS Option not found ?! add it..
          */
         if (skb_tailroom((*pskb)) < TCPOLEN_MSS) {
-                struct sk_buff *newskb;
-
-                newskb = skb_copy_expand(*pskb, skb_headroom(*pskb),
-                                         TCPOLEN_MSS, GFP_ATOMIC);
-                if (!newskb)
+                if (pskb_expand_head(*pskb, 0,
+                                     TCPOLEN_MSS - skb_tailroom(*pskb),
+                                     GFP_ATOMIC))
                         return -1;
-                kfree_skb(*pskb);
-                *pskb = newskb;
                 tcph = (struct tcphdr *)(skb_network_header(*pskb) + tcphoff);
         }