Refactored Backend

backend.go

@@ -8,47 +8,54 @@ import (
 	"strings"
 )
 
+// This function implements the PowerDNS-Pipe-Backend protocol and generates
+// the response data it possible
 func RunBackend(conn *connection.RedisConnection) {
 
+    // handshake with PowerDNS
 	fmt.Printf("OK\tDDNS Go Backend\n")
 
 	bio := bufio.NewReader(os.Stdin)
 
 	for {
 		line, _, err := bio.ReadLine()
+
 		HandleErr(err)
-
+		HandleRequest(string(line), conn)
-		parts := strings.Split(string(line), "\t")
-		if len(parts) == 6 {
-			query_name := parts[1]
-
-			// get the host part of the fqdn
-			// pi.d.example.org -> pi
-			hostname := ""
-			if strings.HasSuffix(query_name, DdnsDomain) {
-				hostname = query_name[:len(query_name)-len(DdnsDomain)]
-			}
-
-			query_class := parts[2]
-			// query_type := parts[3]
-			query_id := parts[4]
-
-			if hostname != "" {
-				// check for existance and create response
-				if conn.HostExist(hostname) {
-					host := conn.GetHost(hostname)
-
-					record := "A"
-					if !host.IsIPv4() {
-						record = "AAAA"
-					}
-
-					fmt.Printf("DATA\t%s\t%s\t%s\t10\t%s\t%s\n",
-						query_name, query_class, record, query_id, host.Ip)
-				}
-			}
-		}
-
-		fmt.Printf("END\n")
 	}
 }
+
+func HandleRequest(line string, conn *connection.RedisConnection) {
+	defer fmt.Printf("END\n")
+
+    parts := strings.Split(line, "\t")
+    if len(parts) != 6 {
+        return
+    }
+
+    query_name  := parts[1]
+    query_class := parts[2]
+    // query_type  := parts[3] // TODO Handle SOA Requests
+    query_id    := parts[4]
+
+    // get the host part of the fqdn
+    // pi.d.example.org -> pi
+    hostname := ""
+    if strings.HasSuffix(query_name, DdnsDomain) {
+        hostname = query_name[:len(query_name)-len(DdnsDomain)]
+    }
+
+    if hostname == "" || ! conn.HostExist(hostname) {
+        return
+    }
+
+    host := conn.GetHost(hostname)
+
+    record := "A"
+    if !host.IsIPv4() {
+        record = "AAAA"
+    }
+
+    fmt.Printf("DATA\t%s\t%s\t%s\t10\t%s\t%s\n",
+        query_name, query_class, record, query_id, host.Ip)
+}

ddns.go

@@ -44,7 +44,7 @@ func PrepareForExecution() string {
 }
 
 func main() {
-	cmd = PrepareForExecution()
+    cmd := PrepareForExecution()
 
 	conn := connection.OpenConnection()
 	defer conn.Close()