ip6_output: fragment outgoing reassembled skb properly

[ Upstream commit 9037c3579a277f3a23ba476664629fda8c35f7c4 ]

If reassembled packet would fit into outdev MTU, it is not fragmented
according the original frag size and it is send as single big packet.

The second case is if skb is gso. In that case fragmentation does not happen
according to the original frag size.

This patch fixes these.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 878f8027ebf6..53630d0d0f43 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -150,7 +150,8 @@ static int ip6_finish_output2(struct sk_buff *skb)
 static int ip6_finish_output(struct sk_buff *skb)
 {
         if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
-            dst_allfrag(skb_dst(skb)))
+            dst_allfrag(skb_dst(skb)) ||
+            (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
                 return ip6_fragment(skb, ip6_finish_output2);
         else
                 return ip6_finish_output2(skb);