ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data...
authorzheng li <james.z.li@ericsson.com>
Mon, 12 Dec 2016 01:56:05 +0000 (09:56 +0800)
committerDavid S. Miller <davem@davemloft.net>
Tue, 20 Dec 2016 15:45:22 +0000 (10:45 -0500)
commit0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38
treed287b44d8adb46fdf802ee45d7945e6d41c33125
parentad688cdbb076833ba17fc65591cd0fe01900a5cf
ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output

There is an inconsistent conditional judgement in __ip_append_data and
ip_finish_output functions, the variable length in __ip_append_data just
include the length of application'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 causes some particular application's udp payload whose length is
between (MTU - IP Header) and MTU were fragmented 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@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/ip_output.c