On Tue, Feb 10, 2026 at 06:51:29PM +0000, Aleksei Oladko wrote:
> The tests use the tc pedit action to modify the IPv4 source address
> ("pedit ex munge ip src set"), but the IP header checksum is not
> recalculated after the modification. As a result, the modified packet
> fails sanity checks in br_netfilter after bridging and is dropped,
> which causes the test to fail.
>
> Fix this by adding an explicit checksum recalculation using the
> "csum ip" action, so the modified packet contains a valid IPv4
> checksum.
>
> Note on IPv6:
> The tests in pedit_ip.sh also cover IPv6 (test_ip6_src, test_ip6_dst).
> The csum ip action is harmless for IPv6 packets since IPv6 has no
> header checksum — it will be a no-op.
>
> Signed-off-by: Aleksei Oladko <[email protected]>
> ---
> tools/testing/selftests/net/forwarding/pedit_dsfield.sh | 5 +++--
> tools/testing/selftests/net/forwarding/pedit_ip.sh | 2 +-
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
> b/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
> index af008fbf2725..310f96fb2274 100755
> --- a/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
> +++ b/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
> @@ -156,7 +156,7 @@ do_test_pedit_dsfield()
> local daddr=$1; shift
>
> tc filter add $pedit_locus handle 101 pref 1 \
> - flower action pedit ex munge $pedit_action
> + flower action pedit ex munge $pedit_action pipe action csum ip
I believe that this is going to be a problem when running the test over
a device that does not support "action csum" offload.
Can you instead set "net.bridge.bridge-nf-call-iptables" to "0"
(assuming it exists) and restore its original value at the end?
> tc filter add dev $h2 ingress handle 101 pref 1 prot $match_prot \
> flower skip_hw $match_flower action pass
>
> @@ -229,7 +229,8 @@ do_test_ip_dscp_ecn()
>
> tc filter add $locus handle 101 pref 1 \
> flower action pedit ex munge ip dsfield set 124 retain 0xfc \
> - action pedit ex munge ip dsfield set 1 retain 0x03
> + action pedit ex munge ip dsfield set 1 retain 0x03 \
> + pipe action csum ip
> tc filter add dev $h2 ingress handle 101 pref 1 prot ip \
> flower skip_hw ip_tos 125 action pass
>
> diff --git a/tools/testing/selftests/net/forwarding/pedit_ip.sh
> b/tools/testing/selftests/net/forwarding/pedit_ip.sh
> index d14efb2d23b2..a53ee3b1ef67 100755
> --- a/tools/testing/selftests/net/forwarding/pedit_ip.sh
> +++ b/tools/testing/selftests/net/forwarding/pedit_ip.sh
> @@ -122,7 +122,7 @@ do_test_pedit_ip()
> local mz_flags=$1; shift
>
> tc filter add $pedit_locus handle 101 pref 1 \
> - flower action pedit ex munge $pedit_action
> + flower action pedit ex munge $pedit_action pipe action csum ip
> tc filter add dev $h2 ingress handle 101 pref 1 prot $match_prot \
> flower skip_hw $match_flower action pass
>
> --
> 2.43.0
>
