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, 7 deletions

diff --git a/plugin/secondary/setup.go b/plugin/secondary/setup.go
index 83d8e56ef..c09147276 100644
--- a/plugin/secondary/setup.go
+++ b/plugin/secondary/setup.go
@@ -47,14 +47,8 @@ func secondaryParse(c *caddy.Controller) (file.Zones, error) {
 
 		if c.Val() == "secondary" {
 			// secondary [origin]
-			origins := make([]string, len(c.ServerBlockKeys))
-			copy(origins, c.ServerBlockKeys)
-			args := c.RemainingArgs()
-			if len(args) > 0 {
-				origins = args
-			}
+			origins := plugin.OriginsFromArgsOrServerBlock(c.RemainingArgs(), c.ServerBlockKeys)
 			for i := range origins {
-				origins[i] = plugin.Host(origins[i]).Normalize()
 				z[origins[i]] = file.NewZone(origins[i], "stdin")
 				names = append(names, origins[i])
 			}