Feat/3pcc invite (#187)

* wip

* wip

* wip

* add test for late media / 3pcc invite, which should now work

lib/call-session.js

@@ -108,7 +108,8 @@ class CallSession extends Emitter {
 
   async connect() {
     const {sdp} = this.req.locals;
-    this.logger.info('inbound call accepted for routing');
+    const is3pcc = this.req.body?.length === 0;
+    this.logger.info(`inbound ${is3pcc ? '3pcc ' : ''}call accepted for routing`);
     const engine = this.getRtpEngine();
     if (!engine) {
       this.logger.info('No available rtpengines, rejecting call!');
@@ -183,13 +184,13 @@ class CallSession extends Emitter {
     else uri = `${scheme}:${host}`;
     this.logger.info(`uri will be: ${uri}, proxy ${proxy}`);
 
-    try {
+    const sendOfferToRtpEngine = async(remoteSdp) => {
       const opts = {
         ...this.rtpEngineOpts.common,
         ...this.rtpEngineOpts.uac.mediaOpts,
         'from-tag': this.rtpEngineOpts.uas.tag,
         direction:  [isPrivateVoipNetwork(this.req.source_address) ? 'private' : 'public', 'private'],
-        sdp
+        sdp: remoteSdp
       };
       const startAt = process.hrtime();
       const response = await this.offer(opts);
@@ -202,7 +203,11 @@ class CallSession extends Emitter {
         this.logger.error({}, `rtpengine offer failed with ${JSON.stringify(response)}`);
         throw new Error('rtpengine failed: answer');
       }
+      return response;
+    };
 
+    try {
+      const response = await sendOfferToRtpEngine(sdp);
       let headers = {
         'From': createBLegFromHeader(this.req),
         'To': this.req.get('To'),
@@ -212,9 +217,13 @@ class CallSession extends Emitter {
       };
       if (this.privateSipAddress) headers = {...headers, Contact: `<sip:${this.privateSipAddress}>`};
 
-      const spdOfferB = this.siprec && this.xml ?
-        createSiprecBody(headers, response.sdp, this.xml.type, this.xml.content) :
-        response.sdp;
+      let spdOfferB;
+      if (this.siprec && this.xml) {
+        spdOfferB = createSiprecBody(headers, response.sdp, this.xml.type, this.xml.content);
+      }
+      else if (!is3pcc) {
+        spdOfferB = response.sdp;
+      }
 
       if (this.req.locals.carrier) {
         Object.assign(headers, {
@@ -281,7 +290,10 @@ class CallSession extends Emitter {
           '-X-Authenticated-User'
         ],
         proxyResponseHeaders: ['all', '-X-Trace-ID'],
-        localSdpB: spdOfferB,
+        localSdpB: spdOfferB ? spdOfferB : async(ackBody) => {
+          const response = await sendOfferToRtpEngine(ackBody);
+          return response.sdp;
+        },
         localSdpA: async(sdp, res) => {
           this.rtpEngineOpts.uac.tag = res.getParsedHeader('To').params.tag;
           const opts = {
@@ -292,8 +304,12 @@ class CallSession extends Emitter {
             sdp
           };
           const startAt = process.hrtime();
-          const response = await this.answer(opts);
-          this.logger.debug({response, opts}, 'response from rtpengine to answer');
+          const aOpts = {
+            ...opts,
+            ...(is3pcc && {direction: ['private', 'public']})
+          };
+          const response = await this.answer(aOpts);
+          this.logger.debug({response, opts: aOpts}, 'response from rtpengine to answer');
           const rtt = roundTripTime(startAt);
           this.stats.histogram('app.rtpengine.response_time', rtt, [
             'direction:inbound', 'command:answer', `rtpengine:${this.rtpengineIp}`]);
@@ -313,7 +329,7 @@ class CallSession extends Emitter {
           }
 
           return response.sdp;
-        }
+        },
       });
 
       // successfully connected