On 17-05-05 08:47 AM, Simon Horman wrote:
Return an error from __skb_flow_dissect() if insufficient packet data is
present when dissecting icmp type and code.
Without this patch the absence of the ICMP type and code in truncated
ICMPv4 or IPVPv6 packets is treated the way same as the presence of a code
and type of value of zero. And without this patch the flower classifier is
unable to differentiate between these two cases which may lead to
unexpected matching of truncated packets.
With this patch the flow dissector and in turn the flower classifier can
differentiate between packets with zero ICMP type and code, and truncated
packets.
The approach taken here is to return an error if the IP protocol indicates
ICMP but the type and code data is not present in the packet - an error
return value from __skb_header_pointer().
This should only effect the flower classifier as it is the only user of
W_DISSECTOR_KEY_ICMP. The behavioural update for flower only takes effect
with a separate patch to have it refuse to match if dissection fails.
Signed-off-by: Simon Horman <simon.hor...@netronome.com>
Reviewed-by: Benjamin LaHaise <benjamin.laha...@netronome.com>
Reviewed-by: Jamal Hadi Salim <j...@mojatatu.com>
cheers,
jamal
