From: zheng li <james.z.li@xxxxxxxxxxxx>
There is an inconsitent conditional judgement in __ip_append_data and
ip_finish_output functions, the variable length in __ip_append_data just
include the length of applicatoin's payload and udp header, don't include
the length of ip header, but in ip_finish_output use
(skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the
length of ip header.
That cuase some particular applicatoin's udp payload whose length is
between (MTU - IP Header) and MTU were framented by ip_fragment even
though the rst->dev support UFO feature.[...]
Add the length of ip header to length in __ip_append_data to keep
consistent conditional judgement as ip_finish_output for ip fragment.
Signed-off-by: Zheng Li <james.z.li@xxxxxxxxxxxx>