| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.guacamole.rest; |
| |
| import com.google.inject.Inject; |
| import java.lang.annotation.Annotation; |
| import java.lang.reflect.Method; |
| import javax.ws.rs.FormParam; |
| import javax.ws.rs.QueryParam; |
| import javax.ws.rs.WebApplicationException; |
| import javax.ws.rs.core.Response; |
| import org.aopalliance.intercept.MethodInterceptor; |
| import org.aopalliance.intercept.MethodInvocation; |
| import org.apache.guacamole.GuacamoleClientException; |
| import org.apache.guacamole.GuacamoleException; |
| import org.apache.guacamole.GuacamoleResourceNotFoundException; |
| import org.apache.guacamole.GuacamoleSecurityException; |
| import org.apache.guacamole.GuacamoleUnauthorizedException; |
| import org.apache.guacamole.rest.auth.AuthenticationService; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A method interceptor which wraps custom exception handling around methods |
| * which can throw GuacamoleExceptions and which are exposed through the REST |
| * interface. The various types of GuacamoleExceptions are automatically |
| * translated into appropriate HTTP responses, including JSON describing the |
| * error that occurred. |
| */ |
| public class RESTExceptionWrapper implements MethodInterceptor { |
| |
| /** |
| * Logger for this class. |
| */ |
| private final Logger logger = LoggerFactory.getLogger(RESTExceptionWrapper.class); |
| |
| /** |
| * Service for authenticating users and managing their Guacamole sessions. |
| */ |
| @Inject |
| private AuthenticationService authenticationService; |
| |
| /** |
| * Determines whether the given set of annotations describes an HTTP |
| * request parameter of the given name. For a parameter to be associated |
| * with an HTTP request parameter, it must be annotated with either the |
| * <code>@QueryParam</code> or <code>@FormParam</code> annotations. |
| * |
| * @param annotations |
| * The annotations associated with the Java parameter being checked. |
| * |
| * @param name |
| * The name of the HTTP request parameter. |
| * |
| * @return |
| * true if the given set of annotations describes an HTTP request |
| * parameter having the given name, false otherwise. |
| */ |
| private boolean isRequestParameter(Annotation[] annotations, String name) { |
| |
| // Search annotations for associated HTTP parameters |
| for (Annotation annotation : annotations) { |
| |
| // Check if parameter is associated with the HTTP query string |
| if (annotation instanceof QueryParam && name.equals(((QueryParam) annotation).value())) |
| return true; |
| |
| // Failing that, check whether the parameter is associated with the |
| // HTTP request body |
| if (annotation instanceof FormParam && name.equals(((FormParam) annotation).value())) |
| return true; |
| |
| } |
| |
| // No parameter annotations are present |
| return false; |
| |
| } |
| |
| /** |
| * Returns the authentication token that was passed in the given method |
| * invocation. If the given method invocation is not associated with an |
| * HTTP request (it lacks the appropriate JAX-RS annotations) or there is |
| * no authentication token, null is returned. |
| * |
| * @param invocation |
| * The method invocation whose corresponding authentication token |
| * should be determined. |
| * |
| * @return |
| * The authentication token passed in the given method invocation, or |
| * null if there is no such token. |
| */ |
| private String getAuthenticationToken(MethodInvocation invocation) { |
| |
| Method method = invocation.getMethod(); |
| |
| // Get the types and annotations associated with each parameter |
| Annotation[][] parameterAnnotations = method.getParameterAnnotations(); |
| Class<?>[] parameterTypes = method.getParameterTypes(); |
| |
| // The Java standards require these to be parallel arrays |
| assert(parameterAnnotations.length == parameterTypes.length); |
| |
| // Iterate through all parameters, looking for the authentication token |
| for (int i = 0; i < parameterTypes.length; i++) { |
| |
| // Only inspect String parameters |
| Class<?> parameterType = parameterTypes[i]; |
| if (parameterType != String.class) |
| continue; |
| |
| // Parameter must be declared as a REST service parameter |
| Annotation[] annotations = parameterAnnotations[i]; |
| if (!isRequestParameter(annotations, "token")) |
| continue; |
| |
| // The token parameter has been found - return its value |
| Object[] args = invocation.getArguments(); |
| return (String) args[i]; |
| |
| } |
| |
| // No token parameter is defined |
| return null; |
| |
| } |
| |
| @Override |
| public Object invoke(MethodInvocation invocation) throws WebApplicationException { |
| |
| try { |
| |
| // Invoke wrapped method |
| try { |
| return invocation.proceed(); |
| } |
| |
| // Ensure any associated session is invalidated if unauthorized |
| catch (GuacamoleUnauthorizedException e) { |
| |
| // Pull authentication token from request |
| String token = getAuthenticationToken(invocation); |
| |
| // If there is an associated auth token, invalidate it |
| if (authenticationService.destroyGuacamoleSession(token)) |
| logger.debug("Implicitly invalidated session for token \"{}\".", token); |
| |
| // Continue with exception processing |
| throw e; |
| |
| } |
| |
| } |
| |
| // Translate GuacamoleException subclasses to HTTP error codes |
| catch (GuacamoleException e) { |
| throw new APIException( |
| Response.Status.fromStatusCode(e.getHttpStatusCode()), |
| e |
| ); |
| } |
| |
| // Rethrow unchecked exceptions such that they are properly wrapped |
| catch (Throwable t) { |
| |
| // Log all reasonable details of error |
| String message = t.getMessage(); |
| if (message != null) |
| logger.error("Unexpected internal error: {}", message); |
| else |
| logger.error("An internal error occurred, but did not contain " |
| + "an error message. Enable debug-level logging for " |
| + "details."); |
| |
| // Ensure internal errors are fully logged at the debug level |
| logger.debug("Unexpected error in REST endpoint.", t); |
| |
| throw new APIException(Response.Status.INTERNAL_SERVER_ERROR, |
| new GuacamoleException("Unexpected internal error.", t)); |
| |
| } |
| |
| } |
| |
| } |