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 #if !TARGET_J2EE
  46                 static SessionConfig config;
  47                 static Type handlerType;
  48 #else
  49                 static private SessionConfig config {
  50                         get {
  51                                 return (SessionConfig)AppDomain.CurrentDomain.GetData("SessionStateModule.config");
  52                         }
  53                         set {
  54                                 AppDomain.CurrentDomain.SetData("SessionStateModule.config", value);
  55                         }
  56                 }
  57                 static private Type handlerType {
  58                         get {
  59                                 return (Type)AppDomain.CurrentDomain.GetData("SessionStateModule.handlerType");
  60                         }
  61                         set {
  62                                 AppDomain.CurrentDomain.SetData("SessionStateModule.handlerType", value);
  63                         }
  64                 }
  65 #endif
  66                 ISessionHandler handler;
  67                 bool sessionForStaticFiles;
  68
  69                 static RandomNumberGenerator rng = new RNGCryptoServiceProvider ();
  70
  71                 public SessionStateModule ()
  72                 {
  73                 }
  74
  75                 internal RandomNumberGenerator Rng {
  76                         get { return rng; }
  77                 }
  78
  79                 public void Dispose ()
  80                 {
  81                     if (handler!=null)
  82                         handler.Dispose();
  83                 }
  84
  85                 public void Init (HttpApplication app)
  86                 {
  87                         sessionForStaticFiles = (Environment.GetEnvironmentVariable ("MONO_XSP_STATIC_SESSION") != null);
  88                         if (config == null) {
  89                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
  90                                 if (config ==  null)
  91                                         config = new SessionConfig (null);
  92
  93                                 if (config.Mode == SessionStateMode.StateServer)
  94                                         handlerType = typeof (SessionStateServerHandler);
  95
  96                                 if (config.Mode == SessionStateMode.SQLServer)
  97                                         handlerType = typeof (SessionSQLServerHandler);
  98
  99                                 if (config.Mode == SessionStateMode.InProc)
 100                                         handlerType = typeof (SessionInProcHandler);
 101
 102                                 if (config.Mode == SessionStateMode.Off)
 103                                         return;
 104                         }
 105
 106                         if (config.CookieLess)
 107                                 app.BeginRequest += new EventHandler (OnBeginRequest);
 108
 109                         app.AddOnAcquireRequestStateAsync (
 110                                 new BeginEventHandler (OnBeginAcquireState),
 111                                 new EndEventHandler (OnEndAcquireState));
 112
 113                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 114                         app.EndRequest += new EventHandler (OnEndRequest);
 115
 116                         if (handlerType != null && handler == null) {
 117                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
 118                                 handler.Init (this, app, config); //initialize
 119                         }
 120                 }
 121
 122                 void OnBeginRequest (object o, EventArgs args)
 123                 {
 124                         HttpApplication application = (HttpApplication) o;
 125                         HttpContext context = application.Context;
 126                         string base_path = context.Request.BaseVirtualDir;
 127                         string id = UrlUtils.GetSessionId (base_path);
 128
 129                         if (id == null)
 130                                 return;
 131
 132                         context.Request.SetCurrentExePath (UrlUtils.RemoveSessionId (base_path,
 133                                                                      context.Request.FilePath));
 134                         context.Request.SetHeader (HeaderName, id);
 135                         context.Response.SetAppPathModifier (String.Format ("({0})", id));
 136                 }
 137
 138                 void OnReleaseRequestState (object o, EventArgs args)
 139                 {
 140                         if (handler == null)
 141                                 return;
 142
 143                         HttpApplication application = (HttpApplication) o;
 144                         HttpContext context = application.Context;
 145                         handler.UpdateHandler (context, this);
 146                 }
 147
 148                 void OnEndRequest (object o, EventArgs args)
 149                 {
 150                 }
 151
 152                 IAsyncResult OnBeginAcquireState (object o, EventArgs args, AsyncCallback cb, object data)
 153                 {
 154                         HttpApplication application = (HttpApplication) o;
 155                         HttpContext context = application.Context;
 156
 157                         bool required = (context.Handler is IRequiresSessionState);
 158
 159                         // This is a hack. Sites that use Session in global.asax event handling code
 160                         // are not supposed to get a Session object for static files, but seems that
 161                         // IIS handles those files before getting there and thus they are served without
 162                         // error.
 163                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 164                         // on mono, but you lose performance when serving static files.
 165                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 166                                 required = true;
 167                         // hack end
 168
 169                         bool read_only = (context.Handler is IReadOnlySessionState);
 170
 171                         bool isNew = false;
 172                         HttpSessionState session = null;
 173                         if (handler != null)
 174                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 175
 176                         if (session != null) {
 177                                 if (isNew)
 178                                         session.SetNewSession (true);
 179
 180                                 if (read_only)
 181                                         session = session.Clone ();
 182
 183                                 context.SetSession (session);
 184
 185                                 if (isNew && config.CookieLess) {
 186                                         string id = context.Session.SessionID;
 187                                         context.Request.SetHeader (HeaderName, id);
 188                                         context.Response.Redirect (UrlUtils.InsertSessionId (id,
 189                                                                    context.Request.FilePath));
 190                                 } else if (isNew) {
 191                                         string id = context.Session.SessionID;
 192                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 193                                         cookie.Path = UrlUtils.GetDirectory (context.Request.ApplicationPath);
 194                                         context.Response.AppendCookie (cookie);
 195                                 }
 196                         }
 197
 198                         // In the future, we might want to move the Async stuff down to
 199                         // the interface level, if we're going to support other than
 200                         // InProc, we might actually want to do things async, now we
 201                         // simply fake it.
 202                         HttpAsyncResult result=new HttpAsyncResult (cb,this);
 203                         result.Complete (true, o, null);
 204                         if (isNew && Start != null)
 205                                 Start (this, args);
 206
 207                         return result;
 208                 }
 209
 210                 void OnEndAcquireState (IAsyncResult result) { }
 211
 212                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 213                 {
 214                         OnEnd ();
 215                 }
 216
 217                 internal void OnEnd ()
 218                 {
 219 #if !TARGET_J2EE
 220                         if (End != null)
 221                                 End (this, EventArgs.Empty);
 222 #endif
 223                 }
 224
 225                 public event EventHandler Start;
 226                 public event EventHandler End;
 227         }
 228 }
 229