mcs/class/System.Web/System.Web.SessionState/SessionStateModule.cs

   1 //
   2 // System.Web.SessionState.SesionStateModule
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //      Stefan Görling (stefan@gorling.se)
   7 //      Jackson Harper (jackson@ximian.com)
   8 //
   9 // (C) 2002,2003,2004,2005 Novell, Inc (http://www.novell.com)
  10 // (C) 2003 Stefan Görling (http://www.gorling.se)
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Web;
  34 using System.Web.Caching;
  35 using System.Web.Util;
  36 using System.Security.Cryptography;
  37
  38 namespace System.Web.SessionState
  39 {
  40         public sealed class SessionStateModule : IHttpModule
  41         {
  42                 internal static readonly string CookieName = "ASPSESSION";
  43                 internal static readonly string HeaderName = "AspFilterSessionId";
  44
  45                 static SessionConfig config;
  46                 static Type handlerType;
  47                 ISessionHandler handler;
  48                 bool sessionForStaticFiles;
  49
  50                 static RandomNumberGenerator rng = new RNGCryptoServiceProvider ();
  51
  52                 public SessionStateModule ()
  53                 {
  54                 }
  55
  56                 internal RandomNumberGenerator Rng {
  57                         get { return rng; }
  58                 }
  59
  60                 public void Dispose ()
  61                 {
  62                     if (handler!=null)
  63                         handler.Dispose();
  64                 }
  65
  66                 public void Init (HttpApplication app)
  67                 {
  68                         sessionForStaticFiles = (Environment.GetEnvironmentVariable ("MONO_XSP_STATIC_SESSION") != null);
  69                         if (config == null) {
  70                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
  71                                 if (config ==  null)
  72                                         config = new SessionConfig (null);
  73
  74                                 if (config.Mode == SessionStateMode.StateServer)
  75                                         handlerType = typeof (SessionStateServerHandler);
  76
  77                                 if (config.Mode == SessionStateMode.SQLServer)
  78                                         handlerType = typeof (SessionSQLServerHandler);
  79
  80                                 if (config.Mode == SessionStateMode.InProc)
  81                                         handlerType = typeof (SessionInProcHandler);
  82
  83                                 if (config.Mode == SessionStateMode.Off)
  84                                         return;
  85                         }
  86
  87                         if (config.CookieLess)
  88                                 app.BeginRequest += new EventHandler (OnBeginRequest);
  89
  90                         app.AddOnAcquireRequestStateAsync (
  91                                 new BeginEventHandler (OnBeginAcquireState),
  92                                 new EndEventHandler (OnEndAcquireState));
  93
  94                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
  95                         app.EndRequest += new EventHandler (OnEndRequest);
  96
  97                         if (handlerType != null && handler == null) {
  98                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
  99                                 handler.Init (this, app, config); //initialize
 100                         }
 101                 }
 102
 103                 void OnBeginRequest (object o, EventArgs args)
 104                 {
 105                         HttpApplication application = (HttpApplication) o;
 106                         HttpContext context = application.Context;
 107                         string base_path = context.Request.BaseVirtualDir;
 108                         string id = UrlUtils.GetSessionId (base_path);
 109
 110                         if (id == null)
 111                                 return;
 112
 113                         context.Request.SetCurrentExePath (UrlUtils.RemoveSessionId (base_path,
 114                                                                      context.Request.FilePath));
 115                         context.Request.SetHeader (HeaderName, id);
 116                         context.Response.SetAppPathModifier (String.Format ("({0})", id));
 117                 }
 118
 119                 void OnReleaseRequestState (object o, EventArgs args)
 120                 {
 121                         if (handler == null)
 122                                 return;
 123
 124                         HttpApplication application = (HttpApplication) o;
 125                         HttpContext context = application.Context;
 126                         handler.UpdateHandler (context, this);
 127                 }
 128
 129                 void OnEndRequest (object o, EventArgs args)
 130                 {
 131                 }
 132
 133                 IAsyncResult OnBeginAcquireState (object o, EventArgs args, AsyncCallback cb, object data)
 134                 {
 135                         HttpApplication application = (HttpApplication) o;
 136                         HttpContext context = application.Context;
 137
 138                         bool required = (context.Handler is IRequiresSessionState);
 139
 140                         // This is a hack. Sites that use Session in global.asax event handling code
 141                         // are not supposed to get a Session object for static files, but seems that
 142                         // IIS handles those files before getting there and thus they are served without
 143                         // error.
 144                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 145                         // on mono, but you lose performance when serving static files.
 146                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 147                                 required = true;
 148                         // hack end
 149
 150                         bool read_only = (context.Handler is IReadOnlySessionState);
 151
 152                         bool isNew = false;
 153                         HttpSessionState session = null;
 154                         if (handler != null)
 155                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 156
 157                         if (session != null) {
 158                                 if (isNew)
 159                                         session.SetNewSession (true);
 160
 161                                 if (read_only)
 162                                         session = session.Clone ();
 163
 164                                 context.SetSession (session);
 165
 166                                 if (isNew && config.CookieLess) {
 167                                         string id = context.Session.SessionID;
 168                                         context.Request.SetHeader (HeaderName, id);
 169                                         context.Response.Redirect (UrlUtils.InsertSessionId (id,
 170                                                                    context.Request.FilePath));
 171                                 } else if (isNew) {
 172                                         string id = context.Session.SessionID;
 173                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 174                                         cookie.Path = UrlUtils.GetDirectory (context.Request.ApplicationPath);
 175                                         context.Response.AppendCookie (cookie);
 176                                 }
 177                         }
 178
 179                         // In the future, we might want to move the Async stuff down to
 180                         // the interface level, if we're going to support other than
 181                         // InProc, we might actually want to do things async, now we
 182                         // simply fake it.
 183                         HttpAsyncResult result=new HttpAsyncResult (cb,this);
 184                         result.Complete (true, o, null);
 185                         if (isNew && Start != null)
 186                                 Start (this, args);
 187
 188                         return result;
 189                 }
 190
 191                 void OnEndAcquireState (IAsyncResult result) { }
 192
 193                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 194                 {
 195                         OnEnd ();
 196                 }
 197
 198                 internal void OnEnd ()
 199                 {
 200                         if (End != null)
 201                                 End (this, EventArgs.Empty);
 202                 }
 203
 204                 public event EventHandler Start;
 205                 public event EventHandler End;
 206         }
 207 }
 208