The previous patch added IFA_MC_USERS and emits it for IPv4 multicast
groups. Add the same snapshot attribute to IPv6 RTM_GETMULTICAST
replies and entry-lifecycle notifications, carrying
ifmcaddr6::mca_users.
This makes the multicast rtnetlink ABI symmetric across IPv4 and IPv6
and gives userspace the same user count that /proc/net/igmp6 exposes.
Signed-off-by: Yuyang Huang <sigefriedhyy@gmail.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260630110207.37841-3-sigefriedhyy@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
e1d0f3f083