Feature/sip refer (#44)

* changes to support sip REFER

* implement actionhook

* changes from testing

* minor logging

lib/tasks/make_task.js

@@ -17,8 +17,10 @@ function makeTask(logger, obj, parent) {
     case TaskName.SipDecline:
       const TaskSipDecline = require('./sip_decline');
       return new TaskSipDecline(logger, data, parent);
+    case TaskName.SipRefer:
+      const TaskSipRefer = require('./sip_refer');
+      return new TaskSipRefer(logger, data, parent);
     case TaskName.Conference:
-      logger.debug({data}, 'Conference verb');
       const TaskConference = require('./conference');
       return new TaskConference(logger, data, parent);
     case TaskName.Dial:

lib/tasks/sip_refer.js

@@ -0,0 +1,101 @@
+const Task = require('./task');
+const {TaskName, TaskPreconditions} = require('../utils/constants');
+const {parseUri} = require('drachtio-srf');
+
+/**
+ * sends a sip REFER to transfer the existing call
+ */
+class TaskSipRefer extends Task {
+  constructor(logger, opts) {
+    super(logger, opts);
+    this.preconditions = TaskPreconditions.StableCall;
+
+    this.referTo = this.data.referTo;
+    this.referredBy = this.data.referredBy;
+    this.headers = this.data.headers || {};
+    this.eventHook = this.data.eventHook;
+  }
+
+  get name() { return TaskName.SipRefer; }
+
+  async exec(cs) {
+    super.exec(cs);
+    const {dlg} = cs;
+    const {referTo, referredBy} = this._normalizeReferHeaders(cs, dlg);
+
+    try {
+      this.notifyHandler = this._handleNotify.bind(this, cs, dlg);
+      dlg.on('notify', this.notifyHandler);
+      const response = await dlg.request({
+        method: 'REFER',
+        headers: {
+          ...this.headers,
+          'Refer-To': referTo,
+          'Referred-By': referredBy
+        }
+      });
+      this.referStatus = response.status;
+      this.logger.info(`TaskSipRefer:exec - received ${this.referStatus} to REFER`);
+
+      /* if we fail, fall through to next verb.  If success, we should get BYE from far end */
+      if (this.referStatus === 202) {
+        await this.awaitTaskDone();
+      }
+      else await this.performAction({refer_status: this.referStatus});
+    } catch (err) {
+      this.logger.info({err}, 'TaskSipRefer:exec - error sending REFER');
+    }
+  }
+
+  async kill(cs) {
+    super.kill(cs);
+    const {dlg} = cs;
+    dlg.off('notify', this.notifyHandler);
+  }
+
+  async _handleNotify(cs, dlg, req, res) {
+    res.send(200);
+
+    const contentType = req.get('Content-Type');
+    this.logger.debug({body: req.body}, `TaskSipRefer:_handleNotify got ${contentType}`);
+
+    if (contentType === 'message/sipfrag') {
+      const arr = /SIP\/2\.0\s+(\d+)/.exec(req.body);
+      if (arr) {
+        const status = arr[1];
+        this.logger.debug(`TaskSipRefer:_handleNotify: call got status ${status}`);
+        if (this.eventHook) {
+          await cs.requestor.request(this.eventHook, {event: 'transfer-status', call_status: status});
+        }
+        if (status >= 200) {
+          await this.performAction({refer_status: 202, final_referred_call_status: status});
+          this.notifyTaskDone();
+        }
+      }
+    }
+  }
+
+  _normalizeReferHeaders(cs, dlg) {
+    let {referTo, referredBy} = this;
+
+    /* get IP address of the SBC to use as hostname if needed */
+    const {host} = parseUri(dlg.remote.uri);
+
+    if (!referTo.startsWith('<') && !referTo.startsWith('sip') && !referTo.startsWith('"')) {
+      /* they may have only provided a phone number/user */
+      referTo = `sip:${referTo}@${host}`;
+    }
+    if (!referredBy) {
+      /* default */
+      referredBy = cs.req?.callingNumber || dlg.local.uri;
+      this.logger.info({referredBy}, 'setting referredby');
+    }
+    if (!referredBy.startsWith('<') && !referredBy.startsWith('sip') && !referredBy.startsWith('"')) {
+      /* they may have only provided a phone number/user */
+      referredBy = `sip:${referredBy}@${host}`;
+    }
+    return {referTo, referredBy};
+  }
+}
+
+module.exports = TaskSipRefer;

lib/tasks/specs.json

@@ -9,6 +9,18 @@
       "status"
     ]
   },
+  "sip:refer": {
+    "properties": {
+      "referTo": "string",
+      "referredBy": "string",
+      "headers": "object",
+      "actionHook": "object|string",
+      "eventHook": "object|string"
+    },
+    "required": [
+      "referTo"
+    ]
+  },
   "dequeue": {
     "properties": {
       "name": "string",

lib/utils/constants.json

@@ -18,6 +18,7 @@
     "Redirect": "redirect",
     "RestDial": "rest:dial",
     "SipDecline": "sip:decline",
+    "SipRefer": "sip:refer",
     "SipNotify": "sip:notify",
     "SipRedirect": "sip:redirect",
     "Say": "say",