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>

2 files changed, 3 insertions, 10 deletions

diff --git a/plugin/acl/acl_test.go b/plugin/acl/acl_test.go
index 4c6df95e5..0ab6c1d77 100644
--- a/plugin/acl/acl_test.go
+++ b/plugin/acl/acl_test.go
@@ -233,7 +233,7 @@ func TestACLServeDNS(t *testing.T) {
 		},
 		{
 			"Fine-Grained 2 REFUSED",
-			`acl {
+			`acl example.org {
 				block net 192.168.1.0/24
 			}`,
 			[]string{"example.org"},
diff --git a/plugin/acl/setup.go b/plugin/acl/setup.go
index 1a688a485..3adde0aec 100644
--- a/plugin/acl/setup.go
+++ b/plugin/acl/setup.go
@@ -43,15 +43,8 @@ func parse(c *caddy.Controller) (ACL, error) {
 	a := ACL{}
 	for c.Next() {
 		r := rule{}
-		r.zones = c.RemainingArgs()
-		if len(r.zones) == 0 {
-			// if empty, the zones from the configuration block are used.
-			r.zones = make([]string, len(c.ServerBlockKeys))
-			copy(r.zones, c.ServerBlockKeys)
-		}
-		for i := range r.zones {
-			r.zones[i] = plugin.Host(r.zones[i]).Normalize()
-		}
+		args := c.RemainingArgs()
+		r.zones = plugin.OriginsFromArgsOrServerBlock(args, c.ServerBlockKeys)
 
 		for c.NextBlock() {
 			p := policy{}