From 5b88065925da5d316951556d0348776c4b2ba120 Mon Sep 17 00:00:00 2001
From: Dave Horton <daveh@beachdognet.com>
Date: Wed, 30 Nov 2022 12:55:15 -0500
Subject: [PATCH] bugfix: allow users to fully specify a Refer-To uri without
 us overiding it

---
 lib/call-session.js | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/lib/call-session.js b/lib/call-session.js
index 6df1ec2..5655712 100644
--- a/lib/call-session.js
+++ b/lib/call-session.js
@@ -774,30 +774,38 @@ Duration=${payload.duration} `
         const referredBy = req.getParsedHeader('Referred-By');
         if (!referredBy) return res.send(400);
         const u = parseUri(referredBy.uri);
-        const isDotDecimal = /^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/.test(uri.host);
-        let selectedGateway = false;
-        let e164 = false;
-        if (gateway && isDotDecimal) {
-          /* host of Refer-to to an outbound gateway */
-          const gw = await this.srf.locals.getOutboundGatewayForRefer(gateway.voip_carrier_sid);
-          if (gw) {
-            selectedGateway = true;
-            e164 = gw.e164_leading_plus;
-            uri.host = gw.ipv4;
-            uri.port = gw.port;
+        const leaveReferToAlone = req.has('X-Refer-To-Leave-Untouched');
+        if (leaveReferToAlone) {
+          this.logger.debug(`passing Refer-To header through untouched: ${referTo}`);
+        }
+        else {
+          const isDotDecimal = /^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/.test(uri.host);
+          let selectedGateway = false;
+          let e164 = false;
+          if (gateway && isDotDecimal) {
+            /* host of Refer-to to an outbound gateway */
+            const gw = await this.srf.locals.getOutboundGatewayForRefer(gateway.voip_carrier_sid);
+            if (gw) {
+              selectedGateway = true;
+              e164 = gw.e164_leading_plus;
+              uri.host = gw.ipv4;
+              uri.port = gw.port;
+            }
+          }
+          if (!selectedGateway && isDotDecimal) {
+            uri.host = this.req.source_address;
+            uri.port = this.req.source_port;
+          }
+          if (e164 && !uri.user.startsWith('+')) {
+            uri.user = `+${uri.user}`;
           }
-        }
-        if (!selectedGateway && isDotDecimal) {
-          uri.host = this.req.source_address;
-          uri.port = this.req.source_port;
-        }
-        if (e164 && !uri.user.startsWith('+')) {
-          uri.user = `+${uri.user}`;
         }
         // eslint-disable-next-line no-unused-vars
         const {via, from, to, 'call-id':callid, cseq, 'max-forwards':maxforwards,
           // eslint-disable-next-line no-unused-vars
           'content-length':contentlength, 'refer-to':_referto, 'referred-by':_referredby,
+          // eslint-disable-next-line no-unused-vars
+          'x-refer-to-leave-untouched': _leave,
           ...customHeaders
         } = req.headers;