# Unpatched (linux-7.1-rc1 vanilla)

$ rmmod hsr; insmod /root/hsr.ko; /root/poc_hsr_pernet 15
[child] bringing up vethA1, vethB1, hsr0
[child] HSR family_id=37 mcgrp_id=15
[child] hsr0 up
[child] listening on HSR mcast in child namespace for 15s...
[child] received 0 HSR notifications in child namespace
[parent] creating veth pairs vethA0<->vethA1, vethB0<->vethB1
[parent] moving vethA1, vethB1 into the child namespace
[parent] creating hsr1 on vethA0+vethB0 in init_net
[parent] HSR family_id=37 mcgrp_id=15 (init_net)
[parent] soak 4s
[parent] bringing vethA0, vethB0 down
[parent] listening 11s for nodedown
[parent(init_net)] HSR notification cmd=2 len=32
[parent(init_net)] HSR notification cmd=2 len=32

========== RESULT ==========
init_net   received 2 HSR notifications
child namespace  received 0 HSR notifications
UNPATCHED: init_net got events that belong to the child namespace.


# Patched (linux-7.1-rc1 + the two-line genlmsg_multicast_netns conversion)

$ rmmod hsr; insmod /root/hsr.ko; /root/poc_hsr_pernet 15
[child] bringing up vethA1, vethB1, hsr0
[child] HSR family_id=38 mcgrp_id=15
[child] hsr0 up
[child] listening on HSR mcast in child namespace for 15s...
[child] HSR notification cmd=2 len=32
[child] received 1 HSR notifications in child namespace
[parent] creating veth pairs vethA0<->vethA1, vethB0<->vethB1
[parent] moving vethA1, vethB1 into the child namespace
[parent] creating hsr1 on vethA0+vethB0 in init_net
[parent] HSR family_id=38 mcgrp_id=15 (init_net)
[parent] soak 4s
[parent] bringing vethA0, vethB0 down
[parent] listening 11s for nodedown
[parent(init_net)] HSR notification cmd=2 len=32

========== RESULT ==========
init_net   received 1 HSR notifications
child namespace  received >=1 HSR notifications
PATCHED: each namespace receives only its own events.