First commit merge

routes/invite.js

@@ -0,0 +1,188 @@
+const logger = require('../utils/logger');
+const config = require('config');
+
+/**
+ * INVITE Handler - Equivalent to Kamailio's INCOMING_INVITE route
+ * Handles SIP INVITE requests and manages call routing
+ */
+class InviteHandler {
+  constructor(srf) {
+    this.srf = srf;
+    this.specialNumbers = config.get('security.specialNumbers');
+    this.asteriskServers = config.get('dispatcher.asteriskServers');
+    this.currentServerIndex = 0; // For round-robin dispatching
+  }
+
+  /**
+   * Record routing for dialog-forming requests (equivalent to kamailio.cfg:766-767)
+   */
+  recordRoute(req) {
+    // Add Record-Route header
+    const recordRoute = `Record-Route: <sip:${req.source_address}:${req.source_port};lr>`;
+    req.set('Record-Route', recordRoute);
+  }
+
+  /**
+   * Enable RTP proxy for media relay (equivalent to kamailio.cfg:774)
+   */
+  enableRtpProxy(req, res) {
+    if (config.get('rtpProxy.enabled')) {
+      logger.info('[INVITE] Enabling RTPProxy media relay | Call-ID: %s', req.get('Call-ID'));
+      // RTP proxy integration will be handled in the SDP processing
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Check if it's a special number (equivalent to kamailio.cfg:778-782)
+   */
+  isSpecialNumber(number) {
+    return this.specialNumbers.includes(number);
+  }
+
+  /**
+   * Route to Asterisk servers (equivalent to kamailio.cfg:696-720)
+   */
+  async routeToAsterisk(req, res) {
+    logger.info('[INVITE] Routing to Asterisk servers | Call-ID: %s', req.get('Call-ID'));
+
+    // Select Asterisk server using round-robin
+    const server = this.asteriskServers[this.currentServerIndex];
+    this.currentServerIndex = (this.currentServerIndex + 1) % this.asteriskServers.length;
+
+    if (!server) {
+      logger.error('[INVITE] No available Asterisk servers | Call-ID: %s', req.get('Call-ID'));
+      res.send(404, 'No destination');
+      return;
+    }
+
+    logger.info('[INVITE] Selected destination: %s:%s | Call-ID: %s', server.host, server.port, req.get('Call-ID'));
+
+    try {
+      // Create new INVITE to Asterisk
+      const targetUri = `sip:${req.uri.user}@${server.host}:${server.port}`;
+
+      const dlg = await this.srf.createUacInvite(targetUri, {
+        headers: {
+          'From': req.get('From'),
+          'To': req.get('To'),
+          'Call-ID': req.get('Call-ID'),
+          'CSeq': req.get('CSeq'),
+          'Contact': req.get('Contact'),
+          'Content-Type': req.get('Content-Type'),
+          'Via': req.get('Via'),
+          'Route': req.get('Route'),
+          'Max-Forwards': req.get('Max-Forwards')
+        },
+        body: req.body
+      });
+
+      logger.info('[INVITE] Successfully routed to Asterisk: %s | Call-ID: %s', targetUri, req.get('Call-ID'));
+
+      // Send 100 Trying response
+      res.send(100, 'Trying');
+
+      // Relay responses between endpoints
+      this.relayResponses(dlg, req, res);
+
+    } catch (error) {
+      logger.error('[INVITE] Failed to route to Asterisk: %s | Call-ID: %s', error.message, req.get('Call-ID'));
+      res.send(500, 'Server Error');
+    }
+  }
+
+  /**
+   * Route to local user (equivalent to kamailio.cfg:786-791)
+   */
+  async routeToLocalUser(req, res, registration) {
+    logger.info('[INVITE] User %s found locally - routing directly | Call-ID: %s',
+      req.uri.user, req.get('Call-ID'));
+
+    try {
+      // Create INVITE to local user's contact
+      const targetUri = registration.contact;
+
+      const dlg = await this.srf.createUacInvite(targetUri, {
+        headers: {
+          'From': req.get('From'),
+          'To': req.get('To'),
+          'Call-ID': req.get('Call-ID'),
+          'CSeq': req.get('CSeq'),
+          'Contact': req.get('Contact'),
+          'Content-Type': req.get('Content-Type'),
+          'Via': req.get('Via'),
+          'Route': req.get('Route'),
+          'Max-Forwards': req.get('Max-Forwards')
+        },
+        body: req.body
+      });
+
+      logger.info('[INVITE] Successfully routed to local user: %s | Call-ID: %s', targetUri, req.get('Call-ID'));
+
+      // Send 100 Trying response
+      res.send(100, 'Trying');
+
+      // Relay responses between endpoints
+      this.relayResponses(dlg, req, res);
+
+    } catch (error) {
+      logger.error('[INVITE] Failed to route to local user: %s | Call-ID: %s', error.message, req.get('Call-ID'));
+      res.send(500, 'Server Error');
+    }
+  }
+
+  /**
+   * Relay responses between dialogs
+   */
+  relayResponses(uacDialog, uasReq, uasRes) {
+    // Relay UAC responses back to UAS
+    uacDialog.on('response', (response) => {
+      uasRes.send(response.status, response.reason, response.headers);
+    });
+
+    // Handle UAS responses to UAC
+    uasRes.on('response', (response) => {
+      uacDialog.send(response.status, response.reason, response.headers);
+    });
+  }
+
+  /**
+   * Handle INVITE request (equivalent to kamailio.cfg:762-856)
+   */
+  async handleInvite(req, res) {
+    const callId = req.get('Call-ID');
+    const fromUser = req.getParsedHeader('from').uri.user;
+    const toUser = req.uri.user;
+
+    logger.info('[INVITE] Call setup: %s -> %s | Call-ID: %s', fromUser, toUser, callId);
+
+    // Record routing
+    this.recordRoute(req);
+
+    // Enable RTP proxy
+    this.enableRtpProxy(req, res);
+
+    // Step 1: Check if it's a special number
+    if (this.isSpecialNumber(toUser)) {
+      logger.info('[INVITE] Special service call to %s, routing to Asterisk | Call-ID: %s', toUser, callId);
+      await this.routeToAsterisk(req, res);
+      return;
+    }
+
+    // Step 2: Check if user is registered locally
+    const aor = `${toUser}@${req.uri.host}`;
+    const registration = this.srf.registrationHandler?.lookup(aor);
+
+    if (registration) {
+      await this.routeToLocalUser(req, res, registration);
+      return;
+    }
+
+    // Step 3: No route found - send error
+    logger.info('[INVITE] User %s not found locally, no route available | Call-ID: %s', toUser, callId);
+    res.send(480, 'Temporarily Unavailable - User not found');
+  }
+}
+
+module.exports = InviteHandler;