[Devel] [PATCH RHEL10 COMMIT] selftests: forwarding: vxlan_bridge_1d_ipv6: fix test failure with br_netfilter enabled

[Konstantin Khorenko]

The commit is pushed to "branch-rh10-6.12.0-55.52.1.5.x.vz10-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh10-6.12.0-55.52.1.5.5.vz10
------>
commit 46595537126bbec63a5dd90906d29a7f630fd028
Author: Aleksei Oladko <aleksey.oladko at virtuozzo.com>
Date:   Sat Jan 31 23:19:37 2026 +0000

    selftests: forwarding: vxlan_bridge_1d_ipv6: fix test failure with br_netfilter enabled
    
    The test generates VXLAN traffic using mausezahn, where the encapsulated
    inner IPv6 packet an incorrect payload length set in the IPv6 header.
    After VXLAN decapsulation, such packets do not pass sanity checks in
    br_netfilter and are dropped, which causes the test to fail.
    
    Fix this by setting the correct IPv6 payload length for the encapsulated
    packet generated by mausezahn, so that the packet is accepted
    by br_netfilter.
    
    khorenko@ note:
      ICMPv6 payload after IPv6 header:
    
       tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh lines 698-706
    
                  )"00:03:"$(           : Payload length
                  )"3a:"$(              : Next header
                  )"04:"$(              : Hop limit
                  )"$saddr:"$(          : IP saddr
                  )"$daddr:"$(          : IP daddr
                  )"80:"$(              : ICMPv6.type
                  )"00:"$(              : ICMPv6.code
                  )"00:"$(              : ICMPv6.checksum
                  )
    
      Data after IPv6 header:
      • 80: — 1 byte (ICMPv6 type)
      • 00: — 1 byte (ICMPv6 code)
      • 00: — 1 byte (ICMPv6 checksum, truncated)
    
      Total: 3 bytes → 00:03 is correct. The old value 00:08 did not match the actual payload size.
    
      Note (non-blocker)
    
      The ICMPv6 packet is technically incomplete:
      • Checksum should be 2 bytes, only 1 byte is present
      • Missing Identifier and Sequence Number fields
    
      However, for the purpose of this test (verifying traffic passes through VXLAN), this is likely not critical.
    
    https://virtuozzo.atlassian.net/browse/VSTOR-123249
    
    Signed-off-by: Aleksei Oladko <aleksey.oladko at virtuozzo.com>
    
    Feature: fix selftests
---
 tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh b/tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh
index a603f7b0a08f0..e642feeada0e7 100755
--- a/tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh
+++ b/tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh
@@ -695,7 +695,7 @@ vxlan_encapped_ping_do()
 		    )"6"$(			  : IP version
 		    )"$inner_tos"$(               : Traffic class
 		    )"0:00:00:"$(                 : Flow label
-		    )"00:08:"$(                   : Payload length
+		    )"00:03:"$(                   : Payload length
 		    )"3a:"$(                      : Next header
 		    )"04:"$(                      : Hop limit
 		    )"$saddr:"$(		  : IP saddr