selftests: vxlan_mdb: Fix failures with old libnet

Locally generated IP multicast packets (such as the ones used in the
test) do not perform routing and simply egress the bound device.

However, as explained in commit 8bcfb4ae4d97 ("selftests: forwarding:
Fix failing tests with old libnet"), old versions of libnet (used by
mausezahn) do not use the "SO_BINDTODEVICE" socket option. Specifically,
the library started using the option for IPv6 sockets in version 1.1.6
and for IPv4 sockets in version 1.2. This explains why on Ubuntu - which
uses version 1.1.6 - the IPv4 overlay tests are failing whereas the IPv6
ones are passing.

Fix by specifying the source and destination MAC of the packets which
will cause mausezahn to use a packet socket instead of an IP socket.

Fixes: 62199e3f1658 ("selftests: net: Add VXLAN MDB test")
Reported-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Closes: https://lore.kernel.org/netdev/5bb50349-196d-4892-8ed2-f37543aa863f@alu.unizg.hr/
Tested-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240325075030.2379513-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

selftests: vxlan_mdb: Avoid duplicate test names

Rename some test cases to avoid overlapping test names which is
problematic for the kernel test robot. No changes in the test's logic.

Suggested-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240227170418.491442-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

selftests: vxlan_mdb: Add MDB bulk deletion test

Add test cases to verify the behavior of the MDB bulk deletion
functionality in the VXLAN driver.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests/net: convert test_vxlan_mdb.sh to run it in unique namespace

Here is the test result after conversion.

]# ./test_vxlan_mdb.sh

Control path: Basic (*, G) operations - IPv4 overlay / IPv4 underlay
--------------------------------------------------------------------
TEST: MDB entry addition [ OK ]

...

Data path: MDB torture test - IPv6 overlay / IPv6 underlay
----------------------------------------------------------
TEST: Torture test [ OK ]

Tests passed: 620
Tests failed: 0

Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: vxlan_mdb: Use MDB get instead of dump

Test the new MDB get functionality by converting dump and grep to MDB
get.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: net: Add VXLAN MDB test

Add test cases for VXLAN MDB, testing the control and data paths. Two
different sets of namespaces (i.e., ns{1,2}_v4 and ns{1,2}_v6) are used
in order to test VXLAN MDB with both IPv4 and IPv6 underlays,
respectively.

Example truncated output:

# ./test_vxlan_mdb.sh
[...]
Tests passed: 620
Tests failed: 0

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>