use redirect for challenged invites by media servers

* ensures that challenged INVITE goes to same media server

kamailio/default.cfg

@@ -168,6 +168,7 @@ loadmodule "sdpops.so"
 ######## Generic Hash Table container in shared memory ########
 loadmodule "htable.so"
 modparam("htable", "htable", "associations=>size=16;autoexpire=7200")
+modparam("htable", "htable", "redirects=>size=16;autoexpire=5")
 modparam("htable", "db_url", "KAZOO_DB_URL")
 
 ####### RTIMER module ##########
@@ -762,6 +763,13 @@ onreply_route[INTERNAL_REPLY]
         ) {
         xlog("L_INFO", "$ci|log|call setup, now ignoring abnormal termination\n");
         setflag(FLAG_SESSION_PROGRESS);
+
+        # clear the redirect
+        if ($avp(AVP_REDIRECT_KEY) != $null && $sht(redirects=>$avp(AVP_REDIRECT_KEY)) != $null) {
+            xlog("L_INFO", "$ci|log|removing redirect mapping $avp(AVP_REDIRECT_KEY)\n");
+            $sht(redirects=>$avp(AVP_REDIRECT_KEY)) = $null;
+        }
+
     }
 
     if ($rs < 300) {
@@ -795,8 +803,14 @@ failure_route[INTERNAL_FAULT]
 
     remove_hf_re("^X-.*");
 
+    # handle challenges replies from media server, we want to route to same media server
+    if (t_check_status("407")) {
+        xlog("L_INFO", "$ci|log|media $xavp(ds_dst=>uri) challenged the invite, creating redirect\n");
+        $var(redirect) = @from.uri.user + "@" + @from.uri.host + "->" + @ruri.user + "@" + @ruri.host;
+        $sht(redirects=>$var(redirect)) = $xavp(ds_dst=>uri);
+
     # change 6xx to 4xx
-    if (t_check_status("6[0-9][0-9]") && !t_check_status("600|603|604|606")) {
+    } else if (t_check_status("6[0-9][0-9]") && !t_check_status("600|603|604|606")) {
         $var(new_code) = "4" + $(T_reply_code{s.substr,1,0});
         xlog("L_INFO", "$ci|failure|sending $T_reply_code reply as $var(new_code) $T_reply_reason\n");
             t_reply("$(var(new_code){s.int})", "$T_reply_reason");
@@ -809,7 +823,7 @@ failure_route[INTERNAL_FAULT]
         xlog("L_INFO", "$ci|failure|ignoring failure after session progress\n");
     } else if (t_check_status("403") && $T_reply_reason=="Forbidden") {
         xlog("L_WARNING", "$ci|failure|Failed auth from IP $si\n");
-    } else if (t_check_status("(401)|(407)|(486)")) {
+    } else if (t_check_status("(401)|(486)")) {
         xlog("L_INFO", "$ci|failure|auth reply $T_reply_code $T_reply_reason\n");
     } else if (t_check_status("402")) {
         xlog("L_INFO", "$ci|failure|overriding reply code 402 with 486\n");

kamailio/dispatcher-role-5.2.cfg

@@ -146,13 +146,9 @@ route[DISPATCHER_FIND_ROUTES]
         + @ruri.user + "@" + @ruri.host;
     if ($sht(redirects=>$var(redirect)) != $null) {
         $var(prefered_route) = $sht(redirects=>$var(redirect));
-        xlog("L_INFO", "$ci|route|found redirect for $var(redirect)\n");
-        if (route(DISPATCHER_PREFERRED_ROUTE)) {
-            $avp(AVP_REDIRECT_KEY) = $var(redirect);
-            xlog("L_INFO", "$ci|route|REORDER OK $var(redirect)\n");
-        } else {
-            xlog("L_INFO", "$ci|route|REORDER KO $var(redirect)\n");
-        }
+        xlog("L_INFO", "$ci|route|found redirect for $var(redirect) to $var(prefered_route)\n");
+        $avp(AVP_REDIRECT_KEY) = $var(redirect);
+        route(DISPATCHER_PREFERRED_ROUTE);
     } else if ($sht(associations=>$var(user_source)) != $null) {
         if($sel(cfg_get.kazoo.dispatcher_route_to_associated_media) == 1) {
             $var(prefered_route) = $sht(associations=>$var(user_source));
@@ -180,7 +176,6 @@ route[DISPATCHER_PREFERRED_ROUTE]
     $var(i) = 0;
     while($var(i) < $xavp(ds_ctx=>cnt)) {
        if($xavp(ds_dst[$var(i)]=>uri) == $var(prefered_route)) {
-          xlog("L_INFO", "$ci|route|removing preferred route $xavp(ds_dst[$var(i)]=>uri) from list\n");
           $xavp(ds_dst[$var(i)]=>*) = $null;
        }
        $var(i) = $var(i) + 1;