Add safeguard against infinite routing loops

CHANGES.md

@@ -1,3 +1,9 @@
+### v1.3.0
+- Allow Routers to dispatch additional Routers.
+
+### v1.2.2
+- Fix issue with 100 Continue status codes, etc. where r\n\r\n appears within the list of headers
+
 ### v1.2.1
 - Allow Request to read request headers without apache_request_headers().
 

src/pjdietz/WellRESTed/Router.php

@@ -10,7 +10,6 @@
 
 namespace pjdietz\WellRESTed;
 
-use pjdietz\WellRESTed\Interfaces\HandlerInterface;
 use pjdietz\WellRESTed\Interfaces\RequestInterface;
 use pjdietz\WellRESTed\Interfaces\ResponseInterface;
 use pjdietz\WellRESTed\Interfaces\RouteInterface;
@@ -26,8 +25,14 @@ class Router extends RouteTarget implements RouterInterface
 {
     /** @var string  Fully qualified name for the interface for handlers */
     const ROUTE_TARGET_INTERFACE = '\\pjdietz\\WellRESTed\\Interfaces\\RouteTargetInterface';
+    /** @var int  Default maximum number of levels of routing. */
+    const MAX_DEPTH = 10;
+    /** @var int maximum levels of routing before the router raises an error. */
+    protected $maxDepth = self::MAX_DEPTH;
     /** @var array  Array of Route objects */
     private $routes;
+    /** @var int counter incrememted each time a router dispatches a route target. */
+    private $depth = 0;
 
     /** Create a new Router. */
     public function __construct()
@@ -53,10 +58,16 @@ class Router extends RouteTarget implements RouterInterface
      */
     public function getResponse(RequestInterface $request = null)
     {
-        if (is_null($request)) {
-            $request = Request::getRequest();
+        // Set the instance's request, if the called passed one.
+        if (!is_null($request)) {
+            $this->request = $request;
         }
-
+        // If the instance does not have a request, use the singleton.
+        if (is_null($this->request)) {
+            $this->request = Request::getRequest();
+        }
+        // Reference the request and path.
+        $request = $this->request;
         $path = $request->getPath();
 
         foreach ($this->routes as $route) {
@@ -79,8 +90,10 @@ class Router extends RouteTarget implements RouterInterface
                     // If this instance already had a top-level router, pass it along.
                     // Otherwise, pass itself as the top-level router.
                     if (isset($this->router)) {
+                        $this->router->incrementDepth();
                         $target->setRouter($this->router);
                     } else {
+                        $this->incrementDepth();
                         $target->setRouter($this);
                     }
 
@@ -95,6 +108,19 @@ class Router extends RouteTarget implements RouterInterface
         return $this->getNoRouteResponse($request);
     }
 
+    public function incrementDepth()
+    {
+        $this->depth++;
+        if ($this->depth >= $this->maxDepth) {
+            $response = $this->getInternalServerErrorResponse(
+                $this->getRequest(),
+                'Maximum recursion level reached.'
+            );
+            $response->respond();
+            exit;
+        }
+    }
+
     /**
      * Prepare a resonse indicating a 404 Not Found error
      *
@@ -109,10 +135,10 @@ class Router extends RouteTarget implements RouterInterface
     }
 
     /** Prepare a response indicating a 500 Internal Server Error */
-    protected function getInternalServerErrorResponse(RequestInterface $request)
+    protected function getInternalServerErrorResponse(RequestInterface $request, $message = '')
     {
         $response = new Response(500);
-        $response->body = 'Server error at ' . $request->getPath();
+        $response->setBody('Server error at ' . $request->getPath() . "\n" . $message);
         return $response;
     }