opensim/OpenSim/Framework/Servers/OSHttpHandler.cs

/*
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 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
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 * modification, are permitted provided that the following conditions are met:
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 *       notice, this list of conditions and the following disclaimer.
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 *       notice, this list of conditions and the following disclaimer in the
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 *       derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;

namespace OpenSim.Framework.Servers
{
    /// <sumary>
    /// Any OSHttpHandler must return one of the following results:
    /// <list type = "table">
    ///   <listheader>
    ///     <term>result code</term>
    ///     <description>meaning</description>
    ///   </listheader>
    ///   <item>
    ///     <term>Pass</term>
    ///     <description>handler did not process the request</request>
    ///   </item>
    ///   <item>
    ///     <term>Done</term>
    ///     <description>handler did process the request, OSHttpServer
    ///       can clean up and close the request</request>
    ///   </item>
    /// </list>
    /// </summary>
    public enum OSHttpHandlerResult
    {
        Unprocessed,
        Pass,
        Done,
    }

    /// <summary>
    /// An OSHttpHandler that matches on the "content-type" header can
    /// supply an OSHttpContentTypeChecker delegate which will be
    /// invoked by the request matcher in OSHttpRequestPump.
    /// </summary>
    /// <returns>true if the handler is interested in the content;
    /// false otherwise</returns>
    public delegate bool OSHttpContentTypeChecker(OSHttpRequest req);

    public abstract class OSHttpHandler
    {
        /// <summary>
        /// Regular expression used to match against method of
        /// the incoming HTTP request. If you want to match any string
        /// either use '.*' or null. To match on the empty string use
        /// '^$'. 
        /// </summary>
        public virtual Regex Method
        {
            get { return _method; }
        }
        protected Regex _method;
        
        /// <summary>
        /// Regular expression used to match against path of the
        /// incoming HTTP request. If you want to match any string
        /// either use '.*' or null. To match on the emtpy string use
        /// '^$'.
        /// </summary>
        public virtual Regex Path 
        {
            get { return _path; }
        }
        protected Regex _path;

        /// <summary>
        /// Dictionary of (header name, regular expression) tuples,
        /// allowing us to match on HTTP header fields.
        /// </summary>
        public virtual Dictionary<string, Regex> Headers
        { 
            get { return _headers; }
        }
        protected Dictionary<string, Regex> _headers;

        /// <summary>
        /// Dictionary of (header name, regular expression) tuples,
        /// allowing us to match on HTTP header fields.
        /// </summary>
        /// <remarks>
        /// This feature is currently not implemented as it requires
        /// (trivial) changes to HttpServer.HttpListener that have not
        /// been implemented.
        /// </remarks>
        public virtual Regex IPEndPointWhitelist
        {
            get { return _ipEndPointRegex; }
        }
        protected Regex _ipEndPointRegex;


        /// <summary>
        /// An OSHttpHandler that matches on the "content-type" header can
        /// supply an OSHttpContentTypeChecker delegate which will be
        /// invoked by the request matcher in OSHttpRequestPump.
        /// </summary>
        /// <returns>true if the handler is interested in the content;
        /// false otherwise</returns>
        internal virtual OSHttpContentTypeChecker ContentTypeChecker
        { 
            get { return null; }
        }

        /// <summary>
        /// Base class constructor.
        /// </summary>
        /// <param name="path">null or path regex</param>
        /// <param name="headers">null or dictionary of header
        /// regexs</param>
        /// <param name="contentType">null or content type
        /// regex</param>
        /// <param name="whitelist">null or IP address regex</param>
        public OSHttpHandler(Regex method, Regex path, Dictionary<string, Regex> headers, Regex contentType, Regex whitelist)
        {
            _method = method;
            _path = path;
            _ipEndPointRegex = whitelist;

            if (null == _headers && null != contentType)
            {
                _headers = new Dictionary<string, Regex>();
                _headers.Add("content-type", contentType);
            }
        }


        /// <summary>
        /// Process an incoming OSHttpRequest that matched our
        /// requirements. 
        /// </summary>
        /// <returns>
        /// OSHttpHandlerResult.Pass if we are after all not
        /// interested in the request; OSHttpHandlerResult.Done if we
        /// did process the request.
        /// </returns>
        public abstract OSHttpHandlerResult Process(OSHttpRequest request);

        public override string ToString()
        {
            StringWriter sw = new StringWriter();
            sw.WriteLine("{0}", base.ToString());
            sw.WriteLine("    method regex     {0}", null == Method ? "null" : Method.ToString());
            sw.WriteLine("    path regex       {0}", null == Path ? "null": Path.ToString());
            foreach (string tag in Headers.Keys)
            {
                sw.WriteLine("    header           {0} : {1}", tag, Headers[tag].ToString());
            }
            sw.WriteLine("    IP whitelist     {0}", null == IPEndPointWhitelist ? "null" : IPEndPointWhitelist.ToString());
            sw.WriteLine();
            sw.Close();
            return sw.ToString();
        }
    }
}