DNSAgent - parsing NAPTR and E164 from within

agents/dnsagent.go

@@ -20,7 +20,6 @@ package agents
 
 import (
 	"fmt"
-	"net"
 	"strings"
 
 	"github.com/cgrates/cgrates/config"
@@ -73,7 +72,7 @@ func (da *DNSAgent) ListenAndServe() error {
 // requests are reaching here asynchronously
 func (da *DNSAgent) handleMessage(w dns.ResponseWriter, req *dns.Msg) {
 	fmt.Printf("got message: %+v\n", req)
-	rply := new(dns.Msg)
+	/*rply := new(dns.Msg)
 	rply.SetReply(req)
 	switch req.Question[0].Qtype {
 	case dns.TypeA:
@@ -90,7 +89,17 @@ func (da *DNSAgent) handleMessage(w dns.ResponseWriter, req *dns.Msg) {
 			)
 		}
 	}
-
-	fmt.Printf("send reply message: %+v\n", rply)
 	w.WriteMsg(rply)
+	*/
+	reqVars := make(map[string]interface{})
+	reqVars[QueryType] = dns.TypeToString[req.Question[0].Qtype]
+	if req.Question[0].Qtype == dns.TypeNAPTR {
+		e164, err := e164FromNAPTR(req.Question[0].Name)
+		if err != nil {
+			utils.Logger.Warning(
+				fmt.Sprintf("<%s> decoding NAPTR query: <%s>, err: %s",
+					utils.DNSAgent, req.Question[0].Name, err.Error()))
+		}
+		reqVars[E164Address] = e164
+	}
 }

agents/libdns.go

@@ -0,0 +1,42 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package agents
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/cgrates/cgrates/utils"
+)
+
+const (
+	QueryType   = "QueryType"
+	E164Address = "E164"
+)
+
+// e164FromNAPTR extracts the E164 address out of a NAPTR name record
+func e164FromNAPTR(name string) (e164 string, err error) {
+	i := strings.Index(name, ".e164.arpa")
+	if i == -1 {
+		return "", errors.New("unknown format")
+	}
+	e164 = utils.ReverseString(
+		strings.Replace(name[:i], ".", "", -1))
+	return
+}

agents/libdns_test.go

@@ -0,0 +1,29 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package agents
+
+import "testing"
+
+func TestE164FromNAPTR(t *testing.T) {
+	if e164, err := e164FromNAPTR("8.7.6.5.4.3.2.1.0.1.6.e164.arpa."); err != nil {
+		t.Error(err)
+	} else if e164 != "61012345678" {
+		t.Errorf("received: <%s>", e164)
+	}
+}

utils/coreutils.go

@@ -937,3 +937,11 @@ type CachedRPCResponse struct {
 	Result interface{}
 	Error  error
 }
+
+func ReverseString(s string) string {
+	r := []rune(s)
+	for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
+		r[i], r[j] = r[j], r[i]
+	}
+	return string(r)
+}