feat: support external callers

When receiving calls from external callers (usually from PSTN) the
endpoint won't be found, this would previously result in calls not being
allowed. The logic has been changed to support this use case.

internal/service/bouncer.go

@@ -32,9 +32,16 @@ func (b *Bouncer) Check(ctx context.Context, endpoint, dialed string) model.Boun
 		return result
 	}
 
+	var callerId string
+	if row.Callerid.Valid {
+		callerId = row.Callerid.String
+	} else {
+		callerId = endpoint
+	}
+
 	return model.BouncerResponse{
 		Allow:       true,
 		Destination: row.ID,
-		CallerID:    row.Callerid.String,
+		CallerID:    callerId,
 	}
 }

queries.sql

@@ -63,7 +63,7 @@ FROM
     ps_endpoints dest
 INNER JOIN
     ery_extension ee ON dest.sid = ee.endpoint_id
-INNER JOIN
+LEFT JOIN
     ps_endpoints src ON src.id = $1
 WHERE
     ee.extension = $2;