Python: Simplify getARouteHandler for Django

RasmusWL · RasmusWL · commit ffdbecfbb752 · 2020-12-04T11:29:52.000+01:00
diff --git a/python/ql/src/semmle/python/frameworks/Django.qll b/python/ql/src/semmle/python/frameworks/Django.qll
@@ -1549,8 +1549,16 @@ private module Django {
     Parameter getRequestParam() { result = this.getArg(this.getRequestParamIndex()) }
   }
 
+  /** A data-flow node that sets up a route on a server, using the django framework. */
   abstract private class DjangoRouteSetup extends HTTP::Server::RouteSetup::Range, DataFlow::CfgNode {
-    abstract override DjangoRouteHandler getARouteHandler();
+    /** Gets the data-flow node that is used as the argument for the view handler. */
+    abstract DataFlow::Node getViewArg();
+
+    final override DjangoRouteHandler getARouteHandler() {
+      exists(DataFlow::Node viewArg | viewArg = getViewArg() |
+        djangoRouteHandlerFunctionTracker(result) = viewArg
+      )
+    }
   }
 
   /**
@@ -1576,11 +1584,8 @@ private module Django {
       result.asCfgNode() = [node.getArg(0), node.getArgByName("route")]
     }
 
-    override DjangoRouteHandler getARouteHandler() {
-      exists(DataFlow::Node viewArg |
-        viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and
-        djangoRouteHandlerFunctionTracker(result) = viewArg
-      )
+    override DataFlow::Node getViewArg() {
+      result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]
     }
 
     override Parameter getARoutedParameter() {
@@ -1661,11 +1666,8 @@ private module Django {
       result.asCfgNode() = [node.getArg(0), node.getArgByName("route")]
     }
 
-    override DjangoRouteHandler getARouteHandler() {
-      exists(DataFlow::Node viewArg |
-        viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and
-        djangoRouteHandlerFunctionTracker(result) = viewArg
-      )
+    override DataFlow::Node getViewArg() {
+      result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]
     }
   }
 
@@ -1683,11 +1685,8 @@ private module Django {
       result.asCfgNode() = [node.getArg(0), node.getArgByName("regex")]
     }
 
-    override DjangoRouteHandler getARouteHandler() {
-      exists(DataFlow::Node viewArg |
-        viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and
-        djangoRouteHandlerFunctionTracker(result) = viewArg
-      )
+    override DataFlow::Node getViewArg() {
+      result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]
     }
   }
 

Original file line number	Diff line number	Diff line change
`@@ -1549,8 +1549,16 @@ private module Django {`
`1549`	`1549`	`Parameter getRequestParam() { result = this.getArg(this.getRequestParamIndex()) }`
`1550`	`1550`	`}`
`1551`	`1551`
	`1552`	`+ /** A data-flow node that sets up a route on a server, using the django framework. */`
`1552`	`1553`	`abstract private class DjangoRouteSetup extends HTTP::Server::RouteSetup::Range, DataFlow::CfgNode {`
`1553`		`- abstract override DjangoRouteHandler getARouteHandler();`
	`1554`	`+ /** Gets the data-flow node that is used as the argument for the view handler. */`
	`1555`	`+ abstract DataFlow::Node getViewArg();`
	`1556`	`+`
	`1557`	`+ final override DjangoRouteHandler getARouteHandler() {`
	`1558`	`+ exists(DataFlow::Node viewArg \| viewArg = getViewArg() \|`
	`1559`	`+ djangoRouteHandlerFunctionTracker(result) = viewArg`
	`1560`	`+ )`
	`1561`	`+ }`
`1554`	`1562`	`}`
`1555`	`1563`
`1556`	`1564`	`/**`
`@@ -1576,11 +1584,8 @@ private module Django {`
`1576`	`1584`	`result.asCfgNode() = [node.getArg(0), node.getArgByName("route")]`
`1577`	`1585`	`}`
`1578`	`1586`
`1579`		`- override DjangoRouteHandler getARouteHandler() {`
`1580`		`- exists(DataFlow::Node viewArg \|`
`1581`		`- viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and`
`1582`		`- djangoRouteHandlerFunctionTracker(result) = viewArg`
`1583`		`- )`
	`1587`	`+ override DataFlow::Node getViewArg() {`
	`1588`	`+ result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]`
`1584`	`1589`	`}`
`1585`	`1590`
`1586`	`1591`	`override Parameter getARoutedParameter() {`
`@@ -1661,11 +1666,8 @@ private module Django {`
`1661`	`1666`	`result.asCfgNode() = [node.getArg(0), node.getArgByName("route")]`
`1662`	`1667`	`}`
`1663`	`1668`
`1664`		`- override DjangoRouteHandler getARouteHandler() {`
`1665`		`- exists(DataFlow::Node viewArg \|`
`1666`		`- viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and`
`1667`		`- djangoRouteHandlerFunctionTracker(result) = viewArg`
`1668`		`- )`
	`1669`	`+ override DataFlow::Node getViewArg() {`
	`1670`	`+ result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]`
`1669`	`1671`	`}`
`1670`	`1672`	`}`
`1671`	`1673`
`@@ -1683,11 +1685,8 @@ private module Django {`
`1683`	`1685`	`result.asCfgNode() = [node.getArg(0), node.getArgByName("regex")]`
`1684`	`1686`	`}`
`1685`	`1687`
`1686`		`- override DjangoRouteHandler getARouteHandler() {`
`1687`		`- exists(DataFlow::Node viewArg \|`
`1688`		`- viewArg.asCfgNode() in [node.getArg(1), node.getArgByName("view")] and`
`1689`		`- djangoRouteHandlerFunctionTracker(result) = viewArg`
`1690`		`- )`
	`1688`	`+ override DataFlow::Node getViewArg() {`
	`1689`	`+ result.asCfgNode() in [node.getArg(1), node.getArgByName("view")]`
`1691`	`1690`	`}`
`1692`	`1691`	`}`
`1693`	`1692`