Add AXFR test

Test shouldTransfer by upping a testserver and sending the SOA query.

Remove state from DefaultErrorHandler and just get it from the request.

Add more logging to show what is going on.



This also adds the infrastructure for future tests.

middleware/file/secondary.go

@@ -57,6 +57,8 @@ Transfer:
 	}
 
 	z.Tree = z1.Tree
+	z.SOA = z1.SOA
+	z.SIG = z1.SIG
 	*z.Expired = false
 	log.Printf("[INFO] Transferred: %s", z.name)
 	return nil
@@ -73,6 +75,7 @@ func (z *Zone) shouldTransfer() (bool, error) {
 	var Err error
 	serial := -1
 
+Transfer:
 	for _, tr := range z.TransferFrom {
 		Err = nil
 		ret, err := middleware.Exchange(c, m, tr)
@@ -83,6 +86,7 @@ func (z *Zone) shouldTransfer() (bool, error) {
 		for _, a := range ret.Answer {
 			if a.Header().Rrtype == dns.TypeSOA {
 				serial = int(a.(*dns.SOA).Serial)
+				break Transfer
 			}
 		}
 	}
@@ -94,8 +98,10 @@ func (z *Zone) shouldTransfer() (bool, error) {
 
 // less return true of a is smaller than b when taking RFC 1982 serial arithmetic into account.
 func less(a, b uint32) bool {
-	// TODO(miek): implement!
-	return a < b
+	if a < b {
+		return (b - a) <= MaxSerialIncrement
+	}
+	return (a - b) > MaxSerialIncrement
 }
 
 // Update updates the secondary zone according to its SOA. It will run for the life time of the server
@@ -103,24 +109,29 @@ func less(a, b uint32) bool {
 // server) it wil retry every retry interval. If the zone failed to transfer before the expire, the zone
 // will be marked expired.
 func (z *Zone) Update() error {
-	// TODO(miek): if SOA changes we need to redo this with possible different timer values.
-	// TODO(miek): yeah...
+	// If we don't have a SOA, we don't have a zone, wait for it to appear.
 	for z.SOA == nil {
 		time.Sleep(1 * time.Second)
 	}
+	retryActive := false
 
+Restart:
 	refresh := time.Second * time.Duration(z.SOA.Refresh)
 	retry := time.Second * time.Duration(z.SOA.Retry)
 	expire := time.Second * time.Duration(z.SOA.Expire)
-	retryActive := false
 
-	// TODO(miek): check max as well?
 	if refresh < time.Hour {
 		refresh = time.Hour
 	}
 	if retry < time.Hour {
 		retry = time.Hour
 	}
+	if refresh > 24*time.Hour {
+		refresh = 24 * time.Hour
+	}
+	if retry > 12*time.Hour {
+		retry = 12 * time.Hour
+	}
 
 	refreshTicker := time.NewTicker(refresh)
 	retryTicker := time.NewTicker(retry)
@@ -132,7 +143,6 @@ func (z *Zone) Update() error {
 			if !retryActive {
 				break
 			}
-			// TODO(miek): should actually keep track of last succesfull transfer
 			*z.Expired = true
 
 		case <-retryTicker.C:
@@ -141,23 +151,40 @@ func (z *Zone) Update() error {
 			}
 			ok, err := z.shouldTransfer()
 			if err != nil && ok {
-				log.Printf("[INFO] Refreshing zone: %s: initiating transfer", z.name)
-				z.TransferIn()
+				if err := z.TransferIn(); err != nil {
+					// transfer failed, leave retryActive true
+					break
+				}
 				retryActive = false
+				// transfer OK, possible new SOA, stop timers and redo
+				refreshTicker.Stop()
+				retryTicker.Stop()
+				expireTicker.Stop()
+				goto Restart
 			}
 
 		case <-refreshTicker.C:
 			ok, err := z.shouldTransfer()
 			retryActive = err != nil
 			if err != nil && ok {
-				log.Printf("[INFO] Refreshing zone: %s: initiating transfer", z.name)
-				z.TransferIn()
+				if err := z.TransferIn(); err != nil {
+					// transfer failed
+					retryActive = true
+					break
+				}
+				retryActive = false
+				// transfer OK, possible new SOA, stop timers and redo
+				refreshTicker.Stop()
+				retryTicker.Stop()
+				expireTicker.Stop()
+				goto Restart
 			}
 		}
 	}
-
-	refreshTicker.Stop()
-	retryTicker.Stop()
-	expireTicker.Stop()
 	return nil
 }
+
+// The maximum difference between two serial numbers. If the difference between
+// two serials is greater than this number, the smaller one is considered
+// greater.
+const MaxSerialIncrement uint32 = 2147483647