[PATCH net v2 3/3] selftests: forwarding: fix pedit tests failure with br_netfilter enabled

[Aleksei Oladko]

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 ensuring net.bridge.bridge-nf-call-iptables is set to 0
during the test execution. This prevents the bridge from passing
L2 traffic to netfilter, bypasing the checksum validation that
causes the test failure.

Fixes: 92ad3828944e ("selftests: forwarding: Add a test for pedit munge SIP and 
DIP")
Fixes: 226657ba2389 ("selftests: forwarding: Add a forwarding test for pedit 
munge dsfield")
Signed-off-by: Aleksei Oladko <aleksey.ola...@virtuozzo.com>
---
 tools/testing/selftests/net/forwarding/pedit_dsfield.sh | 8 ++++++++
 tools/testing/selftests/net/forwarding/pedit_ip.sh      | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/tools/testing/selftests/net/forwarding/pedit_dsfield.sh 
b/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
index af008fbf2725..eb2d8034de9c 100755
--- a/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
+++ b/tools/testing/selftests/net/forwarding/pedit_dsfield.sh
@@ -98,12 +98,20 @@ setup_prepare()
        h1_create
        h2_create
        switch_create
+
+       if [ -f /proc/sys/net/bridge/bridge-nf-call-iptables ]; then
+               sysctl_set net.bridge.bridge-nf-call-iptables 0
+       fi
 }
 
 cleanup()
 {
        pre_cleanup
 
+       if [ -f /proc/sys/net/bridge/bridge-nf-call-iptables ]; then
+               sysctl_restore net.bridge.bridge-nf-call-iptables
+       fi
+
        switch_destroy
        h2_destroy
        h1_destroy
diff --git a/tools/testing/selftests/net/forwarding/pedit_ip.sh 
b/tools/testing/selftests/net/forwarding/pedit_ip.sh
index d14efb2d23b2..9235674627ab 100755
--- a/tools/testing/selftests/net/forwarding/pedit_ip.sh
+++ b/tools/testing/selftests/net/forwarding/pedit_ip.sh
@@ -91,12 +91,20 @@ setup_prepare()
        h1_create
        h2_create
        switch_create
+
+       if [ -f /proc/sys/net/bridge/bridge-nf-call-iptables ]; then
+               sysctl_set net.bridge.bridge-nf-call-iptables 0
+       fi
 }
 
 cleanup()
 {
        pre_cleanup
 
+       if [ -f /proc/sys/net/bridge/bridge-nf-call-iptables ]; then
+               sysctl_restore net.bridge.bridge-nf-call-iptables
+       fi
+
        switch_destroy
        h2_destroy
        h1_destroy
-- 
2.43.0