[NET]: Fix zero-size datagram reception

The recent rewrite of skb_copy_datagram_iovec broke the reception of
zero-size datagrams.  This patch fixes it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 81987df536eb..d219435d086c 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -213,6 +213,10 @@ int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset,
 {
         int i, err, fraglen, end = 0;
         struct sk_buff *next = skb_shinfo(skb)->frag_list;
+
+        if (!len)
+                return 0;
+
 next_skb:
         fraglen = skb_headlen(skb);
         i = -1;