Add secondary support

Allow specifying a primary server and retrieve the zone's content.

Add tests and an Expired bool to zone struct, to stop server zones

that are expired. The zone is retrieved on Startup, no updates of

changed content are done. We also don't respond to notifies yet.

middleware/file/zone.go

@@ -7,23 +7,22 @@ import (
 	"github.com/miekg/dns"
 )
 
-type Transfer struct {
-	Out bool
-	In  bool
-}
-
 type Zone struct {
 	SOA  *dns.SOA
 	SIG  []dns.RR
 	name string
 	*tree.Tree
-	Peers    []string
-	Transfer *Transfer
+
+	TransferTo   []string
+	TransferFrom []string
+	Expired      *bool
 }
 
 // NewZone returns a new zone.
 func NewZone(name string) *Zone {
-	return &Zone{name: dns.Fqdn(name), Tree: &tree.Tree{}, Transfer: &Transfer{}}
+	z := &Zone{name: dns.Fqdn(name), Tree: &tree.Tree{}, Expired: new(bool)}
+	*z.Expired = false
+	return z
 }
 
 // Insert inserts r into z.
@@ -32,12 +31,14 @@ func (z *Zone) Insert(r dns.RR) { z.Tree.Insert(r) }
 // Delete deletes r from z.
 func (z *Zone) Delete(r dns.RR) { z.Tree.Delete(r) }
 
-// It the transfer request allowed.
+// TransferAllowed checks if incoming request for transferring the zone is allowed according to the ACLs.
 func (z *Zone) TransferAllowed(state middleware.State) bool {
-	if z.Transfer == nil {
-		return false
+	for _, t := range z.TransferTo {
+		if t == "*" {
+			return true
+		}
 	}
-	return z.Transfer.Out
+	return false
 }
 
 // All returns all records from the zone, the first record will be the SOA record,
@@ -54,5 +55,3 @@ func (z *Zone) All() []dns.RR {
 	}
 	return append([]dns.RR{z.SOA}, records...)
 }
-
-// Apex function?