net/sched: act_pedit: Parse L3 Header for L4 offset

Instead of relying on skb->transport_header being set correctly, opt
instead to parse the L3 header length out of the L3 headers for both
IPv4/IPv6 when the Extended Layer Op for tcp/udp is used. This fixes a
bug if GRO is disabled, when GRO is disabled skb->transport_header is
set by __netif_receive_skb_core() to point to the L3 header, it's later
fixed by the upper protocol layers, but act_pedit will receive the SKB
before the fixups are completed. The existing behavior causes the
following to edit the L3 header if GRO is disabled instead of the UDP
header:

    tc filter add dev eth0 ingress protocol ip flower ip_proto udp \
 dst_ip 192.168.1.3 action pedit ex munge udp set dport 18053

Also re-introduce a rate-limited warning if we were unable to extract
the header offset when using the 'ex' interface.

Fixes: 71d0ed7079df ("net/act_pedit: Support using offset relative to
the conventional network headers")
Signed-off-by: Max Tottenham <[email protected]>
Reviewed-by: Josh Hunt <[email protected]>
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Reviewed-by: Pedro Tammela <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions