support PRIVATE_VOIP_NETWORK_CIDR for SDP negotiation (#124)

* support PRIVATE_VOIP_NETWORK_CIDR for SDP negotiation

* support multi PRIVATE_VOIP_NETWORK_CIDR

lib/call-session.js

@@ -6,7 +6,8 @@ const {
   SdpWantsSDES,
   nudgeCallCounts,
   roundTripTime,
-  parseConnectionIp
+  parseConnectionIp,
+  isPrivateVoipNetwork
 } = require('./utils');
 
 const {forwardInDialogRequests} = require('drachtio-fn-b2b-sugar');
@@ -177,7 +178,7 @@ class CallSession extends Emitter {
         ...this.rtpEngineOpts.common,
         ...this.rtpEngineOpts.uac.mediaOpts,
         'from-tag': this.rtpEngineOpts.uas.tag,
-        direction:  ['public', 'private'],
+        direction:  [isPrivateVoipNetwork(this.req.source_address) ? 'private' : 'public', 'private'],
         sdp
       };
       const startAt = process.hrtime();
@@ -248,7 +249,8 @@ class CallSession extends Emitter {
           '-Max-Forwards',
           '-Record-Route',
           '-Session-Expires',
-          '-X-Subspace-Forwarded-For'
+          '-X-Application-Sid',
+          '-X-Authenticated-User'
         ],
         proxyResponseHeaders: ['all', '-X-Trace-ID'],
         localSdpB: spdOfferB,

lib/utils.js

@@ -195,6 +195,14 @@ const isMSTeamsCIDR = (ip) => {
   return matcher.contains(ip);
 };
 
+const isPrivateVoipNetwork = (ip) => {
+  if (process.env.PRIVATE_VOIP_NETWORK_CIDR) {
+    const matcher = new CIDRMatcher(process.env.PRIVATE_VOIP_NETWORK_CIDR.split(','));
+    return matcher.contains(ip);
+  }
+  return false;
+};
+
 module.exports = {
   isWSS,
   SdpWantsSrtp,
@@ -211,5 +219,6 @@ module.exports = {
   nudgeCallCounts,
   roundTripTime,
   parseConnectionIp,
-  isMSTeamsCIDR
+  isMSTeamsCIDR,
+  isPrivateVoipNetwork
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sbc-inbound",
-  "version": "0.8.4",
+  "version": "0.8.5",
   "main": "app.js",
   "engines": {
     "node": ">= 12.0.0"
@@ -39,7 +39,7 @@
     "cidr-matcher": "^2.1.1",
     "debug": "^4.3.4",
     "drachtio-fn-b2b-sugar": "0.0.12",
-    "drachtio-srf": "^4.5.21",
+    "drachtio-srf": "^4.5.31",
     "express": "^4.18.1",
     "pino": "^7.11.0",
     "verify-aws-sns-signature": "^0.1.0",

test/scenarios/uac-pcap-pbx-success.xml

@@ -36,6 +36,8 @@
       Subject: uac-pcap-carrier-success
       Content-Type: application/sdp
       Content-Length: [len]
+      X-Authenticated-User: xhoaluu@jambonz.org
+      X-Application-Sid: APP_ID_1
 
       v=0
       o=user1 53655765 2353687637 IN IP[local_ip_type] [local_ip]