Record why the kernel deletes an IPv6 route on its own:
- RT_DEL_REASON_EXPIRED for routes reaped by the FIB6 garbage
collector after their RTF_EXPIRES lifetime ran out.
- RT_DEL_REASON_RA_WITHDRAWN for default routes, prefix routes and
RFC 4191 route information routes withdrawn by a zero-lifetime
Router Advertisement.
Deleting a default route because its metric changed is not a
withdrawal, so it keeps RT_DEL_REASON_UNSPEC.
Signed-off-by: Yuyang Huang <sigefriedhyy@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260808005642.26901-4-sigefriedhyy@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>