initial support for siprec recording (#36)

* initial support for siprec recording

* handle pause/resume siprec recording

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:slim
+FROM node:lts-slim
 WORKDIR /opt/app/
 COPY package.json package-lock.json ./
 RUN npm ci

lib/call-session.js

@@ -1,4 +1,5 @@
 const Emitter = require('events');
+const SrsClient = require('./srs-client');
 const {makeRtpEngineOpts, SdpWantsSrtp, makeCallCountKey} = require('./utils');
 const {forwardInDialogRequests} = require('drachtio-fn-b2b-sugar');
 const {parseUri, stringifyUri, SipError} = require('drachtio-srf');
@@ -62,7 +63,10 @@ class CallSession extends Emitter {
       blockDTMF,
       unblockDTMF,
       subscribeDTMF,
-      unsubscribeDTMF
+      unsubscribeDTMF,
+      subscribeRequest,
+      subscribeAnswer,
+      unsubscribe
     } = engine;
     this.offer = offer;
     this.answer = answer;
@@ -73,6 +77,9 @@ class CallSession extends Emitter {
     this.unblockDTMF = unblockDTMF;
     this.subscribeDTMF = subscribeDTMF;
     this.unsubscribeDTMF = unsubscribeDTMF;
+    this.subscribeRequest = subscribeRequest;
+    this.subscribeAnswer = subscribeAnswer;
+    this.unsubscribe = unsubscribe;
 
     const featureServer = await this.getFeatureServer();
     if (!featureServer) {
@@ -224,6 +231,12 @@ class CallSession extends Emitter {
       this.rtpEngineResource.destroy().catch((err) => {});
       this.activeCallIds.delete(callId);
       if (dlg.other && dlg.other.connected) dlg.other.destroy().catch((e) => {});
+
+      if (this.srsClient) {
+        this.srsClient.stop();
+        this.srsClient = null;
+      }
+
       this.srf.endSession(this.req);
     });
 
@@ -288,6 +301,11 @@ class CallSession extends Emitter {
         dlg.other = null;
         other.other = null;
 
+        if (this.srsClient) {
+          this.srsClient.stop();
+          this.srsClient = null;
+        }
+
         this.logger.info(`call ended with normal termination, there are ${this.activeCallIds.size} active`);
         this.srf.endSession(this.req);
       });
@@ -449,6 +467,7 @@ Duration=${payload.duration} `
 
   async _onInfo(dlg, req, res) {
     const fromTag = dlg.type === 'uas' ? this.rtpEngineOpts.uas.tag : this.rtpEngineOpts.uac.tag;
+    const toTag = dlg.type === 'uas' ? this.rtpEngineOpts.uac.tag : this.rtpEngineOpts.uas.tag;
     try {
       if (dlg.type === 'uac' && req.has('X-Reason')) {
         const reason = req.get('X-Reason');
@@ -458,16 +477,100 @@ Duration=${payload.duration} `
           'from-tag': fromTag
         };
         this.logger.info(`_onInfo: got request ${reason}`);
-        res.send(200);
 
         if (reason.startsWith('mute')) {
           const response = Promise.all([this.blockMedia(opts), this.blockDTMF(opts)]);
+          res.send(200);
           this.logger.info({response}, `_onInfo: response to rtpengine command for ${reason}`);
         }
         else if (reason.startsWith('unmute')) {
           const response = Promise.all([this.unblockMedia(opts), this.unblockDTMF(opts)]);
+          res.send(200);
           this.logger.info({response}, `_onInfo: response to rtpengine command for ${reason}`);
         }
+        else if (reason.includes('CallRecording')) {
+          let succeeded = false;
+          if (reason === 'startCallRecording') {
+            const from = this.req.getParsedHeader('From');
+            const to = this.req.getParsedHeader('To');
+            const aorFrom = from.uri;
+            const aorTo = to.uri;
+            this.logger.info({to, from}, 'startCallRecording request for a call');
+
+            const srsUrl = req.get('X-Srs-Url');
+            const srsRecordingId = req.get('X-Srs-Recording-ID');
+            const callSid = req.get('X-Call-Sid');
+            const accountSid = req.get('X-Account-Sid');
+            const applicationSid = req.get('X-Application-Sid');
+            if (this.srsClient) {
+              res.send(400);
+              this.logger.info('discarding duplicate startCallRecording request for a call');
+              return;
+            }
+            if (!srsUrl) {
+              this.logger.info('startCallRecording request is missing X-Srs-Url header');
+              res.send(400);
+              return;
+            }
+            this.srsClient = new SrsClient(this.logger, {
+              srf: dlg.srf,
+              originalInvite: this.req,
+              callingNumber: this.req.callingNumber,
+              calledNumber: this.req.calledNumber,
+              srsUrl,
+              srsRecordingId,
+              callSid,
+              accountSid,
+              applicationSid,
+              rtpEngineOpts: this.rtpEngineOpts,
+              fromTag,
+              toTag,
+              aorFrom,
+              aorTo,
+              subscribeRequest: this.subscribeRequest,
+              subscribeAnswer: this.subscribeAnswer,
+              del: this.del,
+              blockMedia: this.blockMedia,
+              unblockMedia: this.unblockMedia,
+              unsubscribe: this.unsubscribe
+            });
+            try {
+              succeeded = await this.srsClient.start();
+            } catch (err) {
+              this.logger.error({err}, 'Error starting SipRec call recording');
+            }
+          }
+          else if (reason === 'stopCallRecording') {
+            if (!this.srsClient) {
+              res.send(400);
+              this.logger.info('discarding stopCallRecording request because we are not recording');
+              return;
+            }
+            try {
+              succeeded = await this.srsClient.stop();
+            } catch (err) {
+              this.logger.error({err}, 'Error stopping SipRec call recording');
+            }
+            this.srsClient = null;
+          }
+          else if (reason === 'pauseCallRecording') {
+            if (!this.srsClient || this.srsClient.paused) {
+              this.logger.info('discarding invalid pauseCallRecording request');
+              res.send(400);
+              return;
+            }
+            succeeded = await this.srsClient.pause();
+          }
+          else if (reason === 'resumeCallRecording') {
+            if (!this.srsClient || !this.srsClient.paused) {
+              res.send(400);
+              this.logger.info('discarding invalid resumeCallRecording request');
+              return;
+            }
+            succeeded = await this.srsClient.resume();
+          }
+          res.send(succeeded ? 200 : 503);
+        }
       }
       else {
         const immutableHdrs = ['via', 'from', 'to', 'call-id', 'cseq', 'max-forwards', 'content-length'];
@@ -483,6 +586,10 @@ Duration=${payload.duration} `
         res.send(response.status, {headers: responseHeaders, body: response.body});
       }
     } catch (err) {
+      if (this.srsClient) {
+        this.srsClient = null;
+      }
+      res.send(500);
       this.logger.info({err}, `Error handing INFO request on ${dlg.type} leg`);
     }
   }

lib/srs-client.js

@@ -0,0 +1,249 @@
+const Emitter = require('events');
+const assert = require('assert');
+const transform = require('sdp-transform');
+const { v4: uuidv4 } = require('uuid');
+
+const createMultipartSdp = (sdp, {
+  originalInvite,
+  srsRecordingId,
+  callSid,
+  accountSid,
+  applicationSid,
+  sipCallId,
+  aorFrom,
+  aorTo,
+  callingNumber,
+  calledNumber
+}) => {
+  const sessionId = uuidv4();
+  const uuidStream1 = uuidv4();
+  const uuidStream2 = uuidv4();
+  const participant1 = uuidv4();
+  const participant2 = uuidv4();
+  const sipSessionId = originalInvite.get('Call-ID');
+  const {originator = 'unknown', carrier = 'unknown'} = originalInvite.locals;
+
+  const x = `--uniqueBoundary
+Content-Disposition: session;handling=required
+Content-Type: application/sdp
+
+--sdp-placeholder--
+--uniqueBoundary
+Content-Disposition: recording-session
+Content-Type: application/rs-metadata+xml
+
+<?xml version="1.0" encoding="UTF-8"?>
+<recording xmlns="urn:ietf:params:xml:ns:recording:1">
+  <datamode>complete</datamode>
+  <session session_id="${sessionId}">
+    <sipSessionID>${sipSessionId}</sipSessionID>
+  </session>
+  <extensiondata xmlns:jb="http://jambonz.org/siprec">
+    <jb:callsid>${callSid}</jb:callsid>
+    <jb:accountsid>${accountSid}</jb:accountsid>
+    <jb:applicationsid>${applicationSid}</jb:applicationsid>
+    <jb:recordingid>${srsRecordingId}</jb:recordingid>
+    <jb:originationsource>${originator}</jb:originationsource>
+    <jb:carrier>${carrier}</jb:carrier>
+  </extensiondata>
+  <participant participant_id="${participant1}">
+    <nameID aor="${aorFrom}">
+      <name>${callingNumber}</name>
+    </nameID>
+  </participant>
+  <participantsessionassoc participant_id="${participant1}" session_id="${sessionId}">
+  </participantsessionassoc>
+  <stream stream_id="${uuidStream1}" session_id="${sessionId}">
+    <label>1</label>
+  </stream>
+  <participant participant_id="${participant2}">
+    <nameID aor="${aorTo}">
+      <name>${calledNumber}</name>
+    </nameID>
+  </participant>
+  <participantsessionassoc participant_id="${participant2}" session_id="${sessionId}">
+  </participantsessionassoc>
+  <stream stream_id="${uuidStream2}" session_id="${sessionId}">
+    <label>2</label>
+  </stream>
+  <participantstreamassoc participant_id="${participant1}">
+    <send>${uuidStream1}</send>
+    <recv>${uuidStream2}</recv>
+  </participantstreamassoc>
+  <participantstreamassoc participant_id="${participant2}">
+    <send>${uuidStream2}</send>
+    <recv>${uuidStream1}</recv>
+  </participantstreamassoc>
+</recording>`
+    .replace(/\n/g, '\r\n')
+    .replace('--sdp-placeholder--', sdp);
+
+  return `${x}\r\n`;
+};
+
+class SrsClient extends Emitter {
+  constructor(logger, opts) {
+    super();
+    const {
+      srf,
+      originalInvite,
+      calledNumber,
+      callingNumber,
+      srsUrl,
+      srsRecordingId,
+      callSid,
+      accountSid,
+      applicationSid,
+      srsDestUserName,
+      rtpEngineOpts,
+      //fromTag,
+      toTag,
+      aorFrom,
+      aorTo,
+      subscribeRequest,
+      subscribeAnswer,
+      del,
+      blockMedia,
+      unblockMedia,
+      unsubscribe
+    } = opts;
+    this.logger = logger;
+    this.srf = srf;
+    this.originalInvite = originalInvite;
+    this.callingNumber = callingNumber;
+    this.calledNumber = calledNumber;
+    this.subscribeRequest = subscribeRequest;
+    this.subscribeAnswer = subscribeAnswer;
+    this.del = del;
+    this.blockMedia = blockMedia;
+    this.unblockMedia = unblockMedia;
+    this.unsubscribe = unsubscribe;
+    this.srsUrl = srsUrl;
+    this.srsRecordingId = srsRecordingId;
+    this.callSid = callSid;
+    this.accountSid = accountSid;
+    this.applicationSid = applicationSid;
+    this.srsDestUserName = srsDestUserName;
+    this.rtpEngineOpts = rtpEngineOpts;
+    this.sipRecFromTag = toTag;
+    this.aorFrom = aorFrom;
+    this.aorTo = aorTo;
+
+    /* state */
+    this.activated = false;
+    this.paused = false;
+  }
+
+  async start() {
+    assert(!this.activated);
+
+    const opts = {
+      'call-id': this.rtpEngineOpts.common['call-id'],
+      'from-tag': this.sipRecFromTag
+    };
+
+    let response = await this.subscribeRequest({...opts, label: '1', flags: ['all'], interface: 'public'});
+    if (response.result !== 'ok') {
+      this.logger.error({response}, 'SrsClient:start error calling subscribe request');
+      throw new Error('error calling subscribe request');
+    }
+    this.siprecToTag = response['to-tag'];
+
+    const parsed = transform.parse(response.sdp);
+    parsed.name = 'jambonz SRS';
+    parsed.media[0].label = '1';
+    parsed.media[1].label = '2';
+    this.sdpOffer = transform.write(parsed);
+    const sdp = createMultipartSdp(this.sdpOffer, {
+      originalInvite: this.originalInvite,
+      srsRecordingId: this.srsRecordingId,
+      callSid: this.callSid,
+      accountSid: this.accountSid,
+      applicationSid: this.applicationSid,
+      calledNumber: this.calledNumber,
+      callingNumber: this.callingNumber,
+      aorFrom: this.aorFrom,
+      aorTo: this.aorTo
+    });
+
+    this.logger.info({response}, `SrsClient: sending SDP ${sdp}`);
+
+    /* */
+    try {
+      this.uac = await this.srf.createUAC(this.srsUrl, {
+        headers: {
+          'Content-Type': 'multipart/mixed;boundary=uniqueBoundary',
+        },
+        localSdp: sdp
+      });
+    } catch (err) {
+      this.logger.info({err}, `Error sending SIPREC INVITE to ${this.srsUrl}`);
+      throw err;
+    }
+
+    this.logger.info({sdp: this.uac.remote.sdp}, `SrsClient:start - successfully connected to SRS ${this.srsUrl}`);
+    response = await this.subscribeAnswer({
+      ...opts,
+      sdp: this.uac.remote.sdp,
+      'to-tag': response['to-tag'],
+      label: '2'
+    });
+    if (response.result !== 'ok') {
+      this.logger.error({response}, 'SrsClient:start error calling subscribe answer');
+      throw new Error('error calling subscribe answer');
+    }
+
+    this.activated = true;
+    this.logger.info('successfully established siprec connection');
+    return true;
+  }
+
+  async stop() {
+    assert(this.activated);
+    const opts = {
+      'call-id': this.rtpEngineOpts.common['call-id'],
+      'from-tag': this.sipRecFromTag
+    };
+
+    this.del(opts)
+      //.then((response) => this.logger.debug({response}, 'Successfully stopped siprec media'))
+      .catch((err) => this.logger.info({err}, 'Error deleting siprec media session'));
+    this.uac.destroy().catch(() => {});
+    this.activated = false;
+    return true;
+  }
+
+  async pause() {
+    assert(!this.paused);
+    const opts = {
+      'call-id': this.rtpEngineOpts.common['call-id'],
+      'from-tag': this.sipRecFromTag
+    };
+    try {
+      await this.blockMedia(opts);
+      await this.uac.modify(this.sdpOffer.replace(/sendonly/g, 'inactive'));
+      this.paused = true;
+      return true;
+    } catch (err) {
+      this.logger.info({err}, 'Error pausing siprec media session');
+    }
+    return false;
+  }
+
+  async resume() {
+    assert(this.paused);
+    const opts = {
+      'call-id': this.rtpEngineOpts.common['call-id'],
+      'from-tag': this.sipRecFromTag
+    };
+    try {
+      await this.blockMedia(opts);
+      await this.uac.modify(this.sdpOffer);
+    } catch (err) {
+      this.logger.info({err}, 'Error resuming siprec media session');
+    }
+    return true;
+  }
+}
+
+module.exports = SrsClient;

package.json

@@ -40,6 +40,8 @@
     "drachtio-srf": "^4.5.0",
     "express": "^4.18.1",
     "pino": "^7.11.0",
+    "sdp-transform": "^2.14.1",
+    "uuid": "^8.3.2",
     "verify-aws-sns-signature": "^0.0.6",
     "xml2js": "^0.4.23"
   },