cgiprocessenvironment.java

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/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * 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.
 */


package org.apache.catalina.util;

import java.io.File;
import java.net.URLEncoder;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.StringTokenizer;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;


/**
 * Encapsulates the CGI Process' environment and rules to derive
 * that environment from the servlet container and request information.
 * @author   Martin Dengler [[e-mail]]
 * @version  $Revision: 303237 $, $Date: 2004-09-16 19:23:37 -0400 (Thu, 16 Sep 2004) $
 * @since    Tomcat 4.0
 */

public class CGIProcessEnvironment extends ProcessEnvironment {
    
    
    private static org.apache.commons.logging.Log log=
        org.apache.commons.logging.LogFactory.getLog( CGIProcessEnvironment.class );
    
    /** cgi command's query parameters */
    private Hashtable queryParameters = null;

    /**
     *  The CGI search path will start at
     *    webAppRootDir + File.separator + cgiPathPrefix
     *    (or webAppRootDir alone if cgiPathPrefix is
     *    null)
     */
    private String cgiPathPrefix = null;


    /**
     * Creates a ProcessEnvironment and derives the necessary environment,
     * working directory, command, etc.  The cgi path prefix is initialized
     * to "" (the empty string).
     *
     * @param  req       HttpServletRequest for information provided by
     *                   the Servlet API
     * @param  context   ServletContext for information provided by
     *                   the Servlet API
     */
    public CGIProcessEnvironment(HttpServletRequest req,
        ServletContext context) {
            this(req, context, "");
    }



    /**
     * Creates a ProcessEnvironment and derives the necessary environment,
     * working directory, command, etc.
     * @param req             HttpServletRequest for information provided by
     *                        the Servlet API
     * @param context         ServletContext for information provided by
     *                        the Servlet API
     * @param cgiPathPrefix   subdirectory of webAppRootDir below which the
     *                        web app's CGIs may be stored; can be null or "".
     */
    public CGIProcessEnvironment(HttpServletRequest req,
        ServletContext context, String cgiPathPrefix) {
            this(req, context, cgiPathPrefix, 0);
    }



    /**
     * Creates a ProcessEnvironment and derives the necessary environment,
     * working directory, command, etc.
     * @param req             HttpServletRequest for information provided by
     *                        the Servlet API
     * @param context         ServletContext for information provided by
     *                        the Servlet API
     * @param  debug          int debug level (0 == none, 6 == lots)
     */
    public CGIProcessEnvironment(HttpServletRequest req,
        ServletContext context, int debug) {
            this(req, context, "", 0);
    }




    /**
     * Creates a ProcessEnvironment and derives the necessary environment,
     * working directory, command, etc.
     * @param req             HttpServletRequest for information provided by
     *                        the Servlet API
     * @param context         ServletContext for information provided by
     *                        the Servlet API
     * @param cgiPathPrefix   subdirectory of webAppRootDir below which the
     *                        web app's CGIs may be stored; can be null or "".
     * @param  debug          int debug level (0 == none, 6 == lots)
     */
    public CGIProcessEnvironment(HttpServletRequest req,
        ServletContext context, String cgiPathPrefix, int debug) {
            super(req, context, debug);
            this.cgiPathPrefix = cgiPathPrefix;
            queryParameters = new Hashtable();
            Enumeration paramNames = req.getParameterNames();
            while (paramNames != null && paramNames.hasMoreElements()) {
                String param = paramNames.nextElement().toString();
                if (param != null) {
                    queryParameters.put(param,
                        URLEncoder.encode(req.getParameter(param)));
                }
            }
            this.valid = deriveProcessEnvironment(req);
    }



    /**
     * Constructs the CGI environment to be supplied to the invoked CGI
     * script; relies heavliy on Servlet API methods and findCGI
     * @param    req request associated with the CGI invokation
     * @return   true if environment was set OK, false if there was a problem
     *           and no environment was set
     */
    protected boolean deriveProcessEnvironment(HttpServletRequest req) {
        /*
         * This method is slightly ugly; c'est la vie.
         * "You cannot stop [ugliness], you can only hope to contain [it]"
         * (apologies to Marv Albert regarding MJ)
         */

        Hashtable envp;
        super.deriveProcessEnvironment(req);
        envp = getEnvironment();

        String sPathInfoOrig = null;
        String sPathTranslatedOrig = null;
        String sPathInfoCGI = null;
        String sPathTranslatedCGI = null;
        String sCGIFullPath = null;
        String sCGIScriptName = null;
        String sCGIFullName = null;
        String sCGIName = null;
        String[] sCGINames;
        sPathInfoOrig = this.pathInfo;
        sPathInfoOrig = sPathInfoOrig == null ? "" : sPathInfoOrig;
        sPathTranslatedOrig = req.getPathTranslated();
        sPathTranslatedOrig = sPathTranslatedOrig == null ? "" :
            sPathTranslatedOrig;
            sCGINames =
                findCGI(sPathInfoOrig, getWebAppRootDir(), getContextPath(),
                getServletPath(), cgiPathPrefix);
        sCGIFullPath = sCGINames[0];
        sCGIScriptName = sCGINames[1];
        sCGIFullName = sCGINames[2];
        sCGIName = sCGINames[3];
        if (sCGIFullPath == null || sCGIScriptName == null
            || sCGIFullName == null || sCGIName == null) {
                return false;
        }
        envp.put("SERVER_SOFTWARE", "TOMCAT");
        envp.put("SERVER_NAME", nullsToBlanks(req.getServerName()));
        envp.put("GATEWAY_INTERFACE", "CGI/1.1");
        envp.put("SERVER_PROTOCOL", nullsToBlanks(req.getProtocol()));
        int port = req.getServerPort();
        Integer iPort = (port == 0 ? new Integer(-1) : new Integer(port));
        envp.put("SERVER_PORT", iPort.toString());
        envp.put("REQUEST_METHOD", nullsToBlanks(req.getMethod()));

        /*-
        * PATH_INFO should be determined by using sCGIFullName:
        * 1) Let sCGIFullName not end in a "/" (see method findCGI)
        * 2) Let sCGIFullName equal the pathInfo fragment which
        *    corresponds to the actual cgi script.
        * 3) Thus, PATH_INFO = request.getPathInfo().substring(
        *                      sCGIFullName.length())
        *
        * (see method findCGI, where the real work is done)
        *
        */

        if (pathInfo == null ||
            (pathInfo.substring(sCGIFullName.length()).length() <= 0)) {
                sPathInfoCGI = "";
        } else {
            sPathInfoCGI = pathInfo.substring(sCGIFullName.length());
        }
        envp.put("PATH_INFO", sPathInfoCGI);

        /*-
        * PATH_TRANSLATED must be determined after PATH_INFO (and the
        * implied real cgi-script) has been taken into account.
        *
        * The following example demonstrates:
        *
        * servlet info   = /servlet/cgigw/dir1/dir2/cgi1/trans1/trans2
        * cgifullpath    = /servlet/cgigw/dir1/dir2/cgi1
        * path_info      = /trans1/trans2
        * webAppRootDir  = servletContext.getRealPath("/")
        *
        * path_translated = servletContext.getRealPath("/trans1/trans2")
        *
        * That is, PATH_TRANSLATED = webAppRootDir + sPathInfoCGI
        * (unless sPathInfoCGI is null or blank, then the CGI
        * specification dictates that the PATH_TRANSLATED metavariable
        * SHOULD NOT be defined.
        *