fix: Add coordinator validation interface for Python UDF security

presto-analyzer/src/main/java/com/facebook/presto/sql/analyzer/FunctionAndTypeResolver.java

@@ -52,4 +52,13 @@ FunctionHandle resolveFunction(
     FunctionHandle lookupCast(String castType, Type fromType, Type toType);
 
     QualifiedObjectName qualifyObjectName(QualifiedName name);
+
+    /**
+     * Validate a function call during analysis phase on the coordinator.
+     * Delegates to the FunctionNamespaceManager for custom validation logic.
+     *
+     * @param functionHandle The function handle being validated
+     * @param arguments Raw argument expressions (not yet evaluated)
+     */
+    void validateFunctionCall(FunctionHandle functionHandle, List<?> arguments);
 }

presto-main-base/src/main/java/com/facebook/presto/metadata/FunctionAndTypeManager.java

@@ -319,6 +319,12 @@ public FunctionHandle lookupCast(String castType, Type fromType, Type toType)
                 return FunctionAndTypeManager.this.lookupCast(CastType.valueOf(castType), fromType, toType);
             }
 
+            @Override
+            public void validateFunctionCall(FunctionHandle functionHandle, List<?> arguments)
+            {
+                FunctionAndTypeManager.this.validateFunctionCall(functionHandle, arguments);
+            }
+
             public QualifiedObjectName qualifyObjectName(QualifiedName name)
             {
                 if (name.getSuffix().startsWith("$internal")) {
@@ -719,6 +725,19 @@ public CompletableFuture<SqlFunctionResult> executeFunction(String source, Funct
         return functionNamespaceManager.get().executeFunction(source, functionHandle, inputPage, channels, this);
     }
 
+    public void validateFunctionCall(FunctionHandle functionHandle, List<?> arguments)
+    {
+        // Built-in functions don't need validation
+        if (functionHandle instanceof BuiltInFunctionHandle) {
+            return;
+        }
+
+        Optional<FunctionNamespaceManager<?>> functionNamespaceManager = getServingFunctionNamespaceManager(functionHandle.getCatalogSchemaName());
+        if (functionNamespaceManager.isPresent()) {
+            functionNamespaceManager.get().validateFunctionCall(functionHandle, arguments);
+        }
+    }
+
     public WindowFunctionSupplier getWindowFunctionImplementation(FunctionHandle functionHandle)
     {
         return builtInTypeAndFunctionNamespaceManager.getWindowFunctionImplementation(functionHandle);

presto-main-base/src/main/java/com/facebook/presto/sql/analyzer/ExpressionAnalyzer.java

@@ -1120,6 +1120,10 @@ else if (frame.getType() == GROUPS) {
             FunctionHandle function = resolveFunction(sessionFunctions, transactionId, node, argumentTypes, functionAndTypeResolver);
             FunctionMetadata functionMetadata = functionAndTypeResolver.getFunctionMetadata(function);
 
+            // Delegate function-specific validation to the FunctionNamespaceManager
+            // This allows function namespaces to perform custom validation
+            functionAndTypeResolver.validateFunctionCall(function, node.getArguments());
+
             if (node.getOrderBy().isPresent()) {
                 for (SortItem sortItem : node.getOrderBy().get().getSortItems()) {
                     Type sortKeyType = process(sortItem.getSortKey(), context);

presto-spi/src/main/java/com/facebook/presto/spi/function/FunctionNamespaceManager.java

@@ -122,4 +122,18 @@ default AggregationFunctionImplementation getAggregateFunctionImplementation(Fun
     {
         throw new UnsupportedOperationException("Does not support get aggregation function");
     }
+
+    /**
+     * Validate a function call during analysis phase on the coordinator.
+     * This allows function namespace managers to perform custom validation logic
+     * such as security checks, argument validation, etc.
+     *
+     * @param functionHandle The function handle being validated
+     * @param arguments Raw argument expressions (not yet evaluated) - type is Object to avoid SPI module dependencies
+     * @throws RuntimeException if validation fails
+     */
+    default void validateFunctionCall(FunctionHandle functionHandle, List<?> arguments)
+    {
+        // Default implementation: no validation
+    }
 }