If some table with a list of tuples (interface name, ip prefix) has ip prefixes without a mask length, it will cause issues in SONiC. For example quagga and frr will treat ipv4 address without a mask, so "10.20.30.40" address will be treated as "10.0.0.0/8", which is dangerous.
The fix here is that when pfx_filter get a tuple (interface name, ip prefix), where the ip prefix doesn't have prefix mask length, add a mask by default: "/32 for ipv4 addresses, /128 for ipv6 addresses".
Co-authored-by: Pavel Shirshov <pavel.contrib@gmail.com>
