#!/usr/bin/env python # # Copyright 2007 Google Inc. # # Licensed 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. # """Directly processes text of web.xml. WebXmlParser is called with Xml string to produce a WebXml object containing the data from that string. WebXmlParser: Converts xml to AppEngineWebXml object. WebXml: Contains relevant information from web.xml. SecurityConstraint: Contains information about specified security constraints. """ import logging from xml.etree import ElementTree from google.appengine.tools import xml_parser_utils from google.appengine.tools.app_engine_config_exception import AppEngineConfigException from google.appengine.tools.value_mixin import ValueMixin class WebXmlParser(object): """Provides logic for walking down XML tree and pulling data.""" def ProcessXml(self, xml_str, has_jsps=False): """Parses XML string and returns object representation of relevant info. Uses ElementTree parser to return a tree representation of XML. Then walks down that tree and extracts important info and adds it to the object. Args: xml_str: The XML string itself. has_jsps: True if the application has *.jsp files. Returns: If there is well-formed but illegal XML, returns a list of errors. Otherwise, returns an AppEngineWebXml object containing information from XML. Raises: AppEngineConfigException: In case of malformed XML or illegal inputs. """ try: self.web_xml = WebXml() self.web_xml.has_jsps = has_jsps self.errors = [] xml_root = ElementTree.fromstring(xml_str) for node in xml_root.getchildren(): self.ProcessSecondLevelNode(node) if self.errors: raise AppEngineConfigException('\n'.join(self.errors)) return self.web_xml except ElementTree.ParseError: raise AppEngineConfigException('Bad input -- not valid XML') _IGNORED_NODES = frozenset([ 'context-param', 'description', 'display-name', 'distributable', 'ejb-local-ref', 'ejb-ref', 'env-entry', 'filter', 'icon', 'jsp-config', 'listener', 'locale-encoding-mapping-list', 'login-config', 'message-destination', 'message-destination-ref', 'persistence-context-ref', 'persistence-unit-ref', 'post-construct', 'pre-destroy', 'resource-env-ref', 'resource-ref', 'security-role', 'service-ref', 'servlet', 'session-config', 'taglib', ]) def ProcessSecondLevelNode(self, node): element_name = xml_parser_utils.GetTag(node) if element_name in self._IGNORED_NODES: return camel_case_name = ''.join(part.title() for part in element_name.split('-')) method_name = 'Process%sNode' % camel_case_name if (hasattr(self, method_name) and method_name is not 'ProcessSecondLevelNode'): getattr(self, method_name)(node) else: logging.warning('Second-level tag not recognized: %s', element_name) def ProcessServletMappingNode(self, node): self._ProcessUrlMappingNode(node) def ProcessFilterMappingNode(self, node): self._ProcessUrlMappingNode(node) def _ProcessUrlMappingNode(self, node): """Parses out URL and possible ID for filter-mapping and servlet-mapping. Pulls url-pattern text out of node and adds to WebXml object. If url-pattern has an id attribute, adds that as well. This is done for and nodes. Args: node: An ElementTreeNode which looks something like the following: redteam /red/* """ url_pattern_node = xml_parser_utils.GetChild(node, 'url-pattern') if url_pattern_node is not None: self.web_xml.patterns.append(url_pattern_node.text) id_attr = xml_parser_utils.GetAttribute(url_pattern_node, 'id') if id_attr: self.web_xml.pattern_to_id[url_pattern_node.text] = id_attr def ProcessErrorPageNode(self, node): """Process error page specifications. If one of the supplied error codes is 404, allow fall through to runtime. Args: node: An ElementTreeNode which looks something like the following. 500 /errors/servererror.jsp """ error_code = xml_parser_utils.GetChildNodeText(node, 'error-code') if error_code == '404': self.web_xml.fall_through_to_runtime = True def ProcessWelcomeFileListNode(self, node): for welcome_node in xml_parser_utils.GetNodes(node, 'welcome-file'): welcome_file = welcome_node.text if welcome_file and welcome_file[0] == '/': self.errors.append('Welcome files must be relative paths: %s' % welcome_file) continue self.web_xml.welcome_files.append(welcome_file) def ProcessMimeMappingNode(self, node): extension = xml_parser_utils.GetChildNodeText(node, 'extension') mime_type = xml_parser_utils.GetChildNodeText(node, 'mime-type') if not extension: self.errors.append(' without extension') return self.web_xml.mime_mappings[extension] = mime_type def ProcessSecurityConstraintNode(self, node): """Pulls data from the security constraint node and adds to WebXml object. Args: node: An ElementTree Xml node that looks something like the following: /profile/* CONFIDENTIAL """ security_constraint = SecurityConstraint() resources_node = xml_parser_utils.GetChild(node, 'web-resource-collection') security_constraint.patterns = [ sub_node.text for sub_node in xml_parser_utils.GetNodes( resources_node, 'url-pattern')] constraint = xml_parser_utils.GetChild(node, 'auth-constraint') if constraint is not None: role_name = xml_parser_utils.GetChildNodeText( constraint, 'role-name').lower() if role_name: if role_name not in ('none', '*', 'admin'): self.errors.append('Bad value for (%s), must be none, ' '*, or admin' % role_name) security_constraint.required_role = role_name user_constraint = xml_parser_utils.GetChild(node, 'user-data-constraint') if user_constraint is not None: guarantee = xml_parser_utils.GetChildNodeText( user_constraint, 'transport-guarantee').lower() if guarantee not in ('none', 'integral', 'confidential'): self.errors.append('Bad value for (%s), must be' ' none, integral, or confidential' % guarantee) security_constraint.transport_guarantee = guarantee self.web_xml.security_constraints.append(security_constraint) class WebXml(ValueMixin): """Contains information about web.xml relevant for translation to app.yaml.""" def __init__(self): self.patterns = [] self.security_constraints = [] self.welcome_files = [] self.mime_mappings = {} self.pattern_to_id = {} self.fall_through_to_runtime = False self.has_jsps = False def GetMimeTypeForPath(self, path): if '.' not in path: return None return self.mime_mappings.get(path.split('.')[-1], None) class SecurityConstraint(ValueMixin): """Contains information about security constraints in web.xml.""" def __init__(self): self.patterns = [] self.transport_guarantee = 'none' self.required_role = 'none'