Fix error in IPv6 prefix calculation.

Error with prefixed address assignment. When it is calculating number of
addresses from prefixlen, it rotates only 32bit int instead of 64b uint.
Only result is assigned to 64b variable.

Two examples:

dhcp-host=[2000::1230:0:0/92],correct-prefix
dhcp-host=[2000::1234:5678:0/92],incorrect-prefix

If prefix length is lower than 96, the result is zero. It means
incorrect-prefix is not refused as it should. Fix is simple, attaching
patch with it. Just rotate 64b int.
2 files changed