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, 2 insertions, 3 deletions

diff --git a/plugin/forward/setup.go b/plugin/forward/setup.go
index 7504e9409..b183044a8 100644
--- a/plugin/forward/setup.go
+++ b/plugin/forward/setup.go
@@ -92,7 +92,7 @@ func parseStanza(c *caddy.Controller) (*Forward, error) {
 	if !c.Args(&f.from) {
 		return f, c.ArgErr()
 	}
-	f.from = plugin.Host(f.from).Normalize()
+	f.from = plugin.Host(f.from).Normalize()[0] // there can only be one here, won't work with non-octet reverse
 
 	to := c.RemainingArgs()
 	if len(to) == 0 {
@@ -151,9 +151,8 @@ func parseBlock(c *caddy.Controller, f *Forward) error {
 			return c.ArgErr()
 		}
 		for i := 0; i < len(ignore); i++ {
-			ignore[i] = plugin.Host(ignore[i]).Normalize()
+			f.ignored = append(f.ignored, plugin.Host(ignore[i]).Normalize()...)
 		}
-		f.ignored = ignore
 	case "max_fails":
 		if !c.NextArg() {
 			return c.ArgErr()