reverse zone: fix Normalize (#4621)

Make normalize return multiple "hosts" (= reverse zones) when a
non-octet boundary cidr is given.

Added pkg/cidr package that holds the cidr calculation routines; felt
they didn't really fit dnsutil.

This change means the IPNet return parameter isn't needed, the hosts are
all correct. The tests that tests this is also removed: TestSplitHostPortReverse
The fallout was that zoneAddr _also_ doesn't need the IPNet member, that
in turn make it visible that zoneAddr in address.go duplicated a bunch
of stuff from register.go; removed/refactored that too.

Created a plugin.OriginsFromArgsOrServerBlock to help plugins do the
right things, by consuming ZONE arguments; this now expands reverse
zones correctly. This is mostly mechanical.

Remove the reverse test in plugin/kubernetes which is a copy-paste from
a core test (which has since been fixed).

Remove MustNormalize as it has no plugin users.

This change is not backwards compatible to plugins that have a ZONE
argument that they parse in the setup util.

All in-tree plugins have been updated.

Signed-off-by: Miek Gieben <miek@miek.nl>

1 files changed, 1 insertions, 13 deletions

diff --git a/plugin/kubernetes/setup.go b/plugin/kubernetes/setup.go
index 8b9bd2c42..c85170d9b 100644
--- a/plugin/kubernetes/setup.go
+++ b/plugin/kubernetes/setup.go
@@ -96,19 +96,7 @@ func ParseStanza(c *caddy.Controller) (*Kubernetes, error) {
 	}
 	k8s.opts = opts
 
-	zones := c.RemainingArgs()
-
-	if len(zones) != 0 {
-		k8s.Zones = zones
-		for i := 0; i < len(k8s.Zones); i++ {
-			k8s.Zones[i] = plugin.Host(k8s.Zones[i]).Normalize()
-		}
-	} else {
-		k8s.Zones = make([]string, len(c.ServerBlockKeys))
-		for i := 0; i < len(c.ServerBlockKeys); i++ {
-			k8s.Zones[i] = plugin.Host(c.ServerBlockKeys[i]).Normalize()
-		}
-	}
+	k8s.Zones = plugin.OriginsFromArgsOrServerBlock(c.RemainingArgs(), c.ServerBlockKeys)
 
 	k8s.primaryZoneIndex = -1
 	for i, z := range k8s.Zones {