[PATCH 3/3] selftests: forwarding: fix pedit tests failure with br_netfilter enabled
From: Aleksei Oladko <hidden>
Date: 2026-02-10 18:51:58
Also in:
linux-kselftest, lkml
Subsystem:
kernel selftest framework, networking [general], networking [ipv4/ipv6], the rest · Maintainers:
Shuah Khan, Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted>
---
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 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