mcs/class/System.Web/System.Web.SessionState_2.0/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 //      Marek Habersack (grendello@gmail.com)
   9 //
  10 // Copyright (C) 2002-2006 Novell, Inc (http://www.novell.com)
  11 // (C) 2003 Stefan Görling (http://www.gorling.se)
  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 #if NET_2_0
  34 using System.Collections.Specialized;
  35 using System.Web.Configuration;
  36 using System.Web.Caching;
  37 using System.Web.Util;
  38 using System.Security.Cryptography;
  39 using System.Security.Permissions;
  40 using System.Threading;
  41
  42 namespace System.Web.SessionState
  43 {
  44         class CallbackState
  45         {
  46                 public HttpContext Context;
  47                 public AutoResetEvent AutoEvent;
  48
  49                 public CallbackState (HttpContext context, AutoResetEvent e)
  50                 {
  51                         this.Context = context;
  52                         this.AutoEvent = e;
  53                 }
  54         }
  55
  56         // CAS - no InheritanceDemand here as the class is sealed
  57         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  58         public sealed class SessionStateModule : IHttpModule
  59         {
  60                 internal const string HeaderName = "AspFilterSessionId";
  61                 internal const string CookielessFlagName = "_SessionIDManager_IsCookieLess";
  62
  63                 static object locker = new object ();
  64
  65                 internal static string CookieName {
  66                         get {
  67                                 config = GetConfig ();
  68                                 if (config == null)
  69                                         return null;
  70                                 return config.CookieName;
  71                         }
  72                 }
  73
  74 #if TARGET_J2EE
  75                 static private SessionStateSection config {
  76                         get {
  77                                 return (SessionStateSection) AppDomain.CurrentDomain.GetData ("SessionStateModule.config");
  78                         }
  79                         set {
  80                                 AppDomain.CurrentDomain.SetData ("SessionStateModule.config", value);
  81                         }
  82                 }
  83
  84                 static private Type handlerType
  85                 {
  86                         get {
  87                                 return (Type) AppDomain.CurrentDomain.GetData ("SessionStateModule.handlerType");
  88                         }
  89                         set {
  90                                 AppDomain.CurrentDomain.SetData ("SessionStateModule.handlerType", value);
  91                         }
  92                 }
  93
  94                 static private Type idManagerType
  95                 {
  96                         get {
  97                                 return (Type) AppDomain.CurrentDomain.GetData ("SessionStateModule.idManagerType");
  98                         }
  99                         set {
 100                                 AppDomain.CurrentDomain.SetData ("SessionStateModule.idManagerType", value);
 101                         }
 102                 }
 103 #else
 104                 static SessionStateSection config;
 105                 static Type handlerType;
 106                 static Type idManagerType;
 107 #endif
 108                 SessionStateStoreProviderBase handler;
 109                 ISessionIDManager idManager;
 110                 HttpApplication app;
 111
 112                 // Store state
 113                 bool storeLocked;
 114                 TimeSpan storeLockAge;
 115                 object storeLockId = new object();
 116                 SessionStateActions storeSessionAction;
 117                 SessionStateStoreData storeData;
 118
 119                 // Session state
 120                 bool isReadOnly;
 121                 bool isNew;
 122                 bool supportSessionIDReissue;
 123                 bool supportsExpiration;
 124                 string sessionId;
 125                 HttpSessionStateContainer container;
 126
 127                 // config
 128                 static TimeSpan executionTimeout;
 129                 static int executionTimeoutMS;
 130
 131                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
 132                 public SessionStateModule ()
 133                 {
 134                 }
 135
 136                 public void Dispose ()
 137                 {
 138                     if (handler!=null)
 139                         handler.Dispose();
 140                 }
 141
 142                 static SessionStateSection GetConfig ()
 143                 {
 144                         lock (locker) {
 145                                 if (config != null)
 146                                         return config;
 147
 148                                 config = (SessionStateSection) WebConfigurationManager.GetSection ("system.web/sessionState");
 149                                 SessionStateMode handlerMode = config.Mode;
 150
 151 #if TARGET_J2EE
 152                                 if (handlerMode == SessionStateMode.SQLServer || handlerMode == SessionStateMode.StateServer)
 153                                         throw new NotImplementedException("You must use web.xml to specify session state handling");
 154 #endif
 155                                 InitTypesFromConfig (config, handlerMode);
 156                                 HttpRuntimeSection runtime = WebConfigurationManager.GetSection ("system.web/httpruntime") as HttpRuntimeSection;
 157                                 if (runtime != null) {
 158                                         executionTimeout = runtime.ExecutionTimeout;
 159                                         executionTimeoutMS = executionTimeout.Milliseconds;
 160                                 }
 161
 162                                 return config;
 163                         }
 164                 }
 165
 166                 static void InitTypesFromConfig (SessionStateSection config, SessionStateMode handlerMode)
 167                 {
 168                         if (handlerMode == SessionStateMode.StateServer)
 169                                 handlerType = typeof (SessionStateServerHandler);
 170
 171 //                      if (handlerMode == SessionStateMode.SQLServer)
 172 //                              handlerType = typeof (SessionSQLServerHandler);
 173
 174                         if (handlerMode == SessionStateMode.InProc)
 175                                 handlerType = typeof (SessionInProcHandler);
 176
 177                         if (handlerMode == SessionStateMode.Custom)
 178                                 handlerType = GetCustomHandlerType (config);
 179
 180                         try {
 181                                 idManagerType = Type.GetType (config.SessionIDManagerType, true);
 182                         } catch {
 183                                 idManagerType = typeof (SessionIDManager);
 184                         }
 185                 }
 186
 187                 static Type GetCustomHandlerType (SessionStateSection config)
 188                 {
 189                         return null;
 190                 }
 191
 192                 [EnvironmentPermission (SecurityAction.Assert, Read = "MONO_XSP_STATIC_SESSION")]
 193                 public void Init (HttpApplication app)
 194                 {
 195                         SessionStateSection cfg = GetConfig ();
 196                         this.app = app;
 197                         if (handlerType == null || idManagerType == null)
 198                                 throw new HttpException ("Cannot initialize the session state module. Missing handler or ID manager types.");
 199                         app.BeginRequest += new EventHandler (OnBeginRequest);
 200                         app.AcquireRequestState += new EventHandler (OnAcquireRequestState);
 201                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 202                         app.EndRequest += new EventHandler (OnEndRequest);
 203
 204                         if (handler == null) {
 205                                 try {
 206                                         handler = Activator.CreateInstance (handlerType, new object [] {cfg}) as SessionStateStoreProviderBase;
 207                                         handler.Initialize (GetHandlerName (), GetHandlerConfig ());
 208                                 } catch (Exception ex) {
 209                                         throw new HttpException ("Failed to initialize session storage provider.", ex);
 210                                 }
 211                         }
 212
 213                         if (idManager == null) {
 214                                 try {
 215                                         idManager = Activator.CreateInstance (idManagerType) as ISessionIDManager;
 216                                         idManager.Initialize ();
 217                                 } catch (Exception ex) {
 218                                         throw new HttpException ("Failed to initialize session ID manager.", ex);
 219                                 }
 220                         }
 221                 }
 222
 223                 string GetHandlerName ()
 224                 {
 225                         switch (config.Mode) {
 226                                 case SessionStateMode.InProc:
 227                                 case SessionStateMode.StateServer:
 228                                 case SessionStateMode.SQLServer:
 229                                         return null; // set by the handler
 230
 231                                 case SessionStateMode.Custom:
 232                                         return "Custom Session State Handler";
 233
 234                                 default:
 235                                         throw new HttpException ("Unknown session handler mode.");
 236                         }
 237                 }
 238
 239                 NameValueCollection GetHandlerConfig ()
 240                 {
 241                         switch (config.Mode) {
 242                                 case SessionStateMode.InProc:
 243                                 case SessionStateMode.StateServer:
 244                                 case SessionStateMode.SQLServer:
 245                                         return new NameValueCollection ();
 246
 247                                 // TODO: implement
 248                                 case SessionStateMode.Custom:
 249                                         return new NameValueCollection ();
 250
 251                                 default:
 252                                         throw new HttpException ("Unknown session handler mode.");
 253                         }
 254                 }
 255
 256                 internal static bool IsCookieLess (HttpContext context)
 257                 {
 258                         if (config.Cookieless == HttpCookieMode.UseCookies)
 259                                 return false;
 260                         if (config.Cookieless == HttpCookieMode.UseUri)
 261                                 return true;
 262                         object cookieless = context.Items [CookielessFlagName];
 263                         if (cookieless == null)
 264                                 return false;
 265                         return (bool)cookieless;
 266                 }
 267
 268                 void OnBeginRequest (object o, EventArgs args)
 269                 {
 270                         HttpApplication application = (HttpApplication) o;
 271                         HttpContext context = application.Context;
 272                         string base_path = context.Request.BaseVirtualDir;
 273                         string id = UrlUtils.GetSessionId (base_path);
 274
 275                         if (id == null)
 276                                 return;
 277
 278                         string new_path = UrlUtils.RemoveSessionId (base_path, context.Request.FilePath);
 279                         context.Request.SetFilePath (new_path);
 280                         context.Request.SetHeader (HeaderName, id);
 281                         context.Response.SetAppPathModifier (String.Concat ("(", id, ")"));
 282                 }
 283
 284                 void OnAcquireRequestState (object o, EventArgs args)
 285                 {
 286                         Console.WriteLine ("SessionStateModule.OnAcquireRequestState (hash {0})", this.GetHashCode ().ToString ("x"));
 287                         HttpApplication application = (HttpApplication) o;
 288                         HttpContext context = application.Context;
 289
 290                         if (!(context.Handler is IRequiresSessionState)) {
 291                                 Console.WriteLine ("Handler ({0}) does not require session state", context.Handler);
 292                                 return;
 293                         }
 294                         isReadOnly = (context.Handler is IReadOnlySessionState);
 295
 296                         if (idManager != null) {
 297                                 if (idManager.InitializeRequest (context, false, out supportSessionIDReissue))
 298                                         return; // Redirected, will come back here in a while
 299                                 sessionId = idManager.GetSessionID (context);
 300                         }
 301
 302                         if (handler != null) {
 303                                 handler.InitializeRequest (context);
 304                                 GetStoreData (context);
 305                                 if (storeData == null && !storeLocked) {
 306                                         isNew = true;
 307                                         sessionId = idManager.CreateSessionID (context);
 308                                         Console.WriteLine ("New session ID allocated: {0}", sessionId);
 309                                         bool redirected = false;
 310                                         bool cookieAdded = false;
 311                                         idManager.SaveSessionID (context, sessionId, out redirected, out cookieAdded);
 312                                         if (redirected) {
 313                                                 if (supportSessionIDReissue)
 314                                                         handler.CreateUninitializedItem (context, sessionId, config.Timeout.Minutes);
 315                                                 context.Response.End();
 316                                                 return;
 317                                         } else
 318                                                 storeData = handler.CreateNewStoreData (context, config.Timeout.Minutes);
 319                                 } else if (storeData == null && storeLocked) {
 320                                         WaitForStoreUnlock (context);
 321                                 } else if (storeData != null &&
 322                                            !storeLocked &&
 323                                            storeSessionAction == SessionStateActions.InitializeItem &&
 324                                            IsCookieLess (context)) {
 325                                         storeData = handler.CreateNewStoreData (context, config.Timeout.Minutes);
 326                                 }
 327
 328                                 SessionSetup (context, isNew);
 329                         }
 330                 }
 331
 332                 void OnReleaseRequestState (object o, EventArgs args)
 333                 {
 334                         Console.WriteLine ("SessionStateModule.OnReleaseRequestState (hash {0})", this.GetHashCode ().ToString ("x"));
 335                         Console.WriteLine ("\tsessionId == {0}", sessionId);
 336                         if (handler == null)
 337                                 return;
 338
 339                         HttpApplication application = (HttpApplication) o;
 340                         HttpContext context = application.Context;
 341                         if (!(context.Handler is IRequiresSessionState))
 342                                 return;
 343                         Console.WriteLine ("\trequest path == {0}", context.Request.FilePath);
 344                         Console.WriteLine ("\tHandler ({0}) requires session state", context.Handler);
 345
 346                         if (!container.IsAbandoned) {
 347                                 Console.WriteLine ("\tnot abandoned");
 348                                 if (!isReadOnly) {
 349                                         Console.WriteLine ("\tnot read only, storing and releasing");
 350                                         handler.SetAndReleaseItemExclusive (context, sessionId, storeData, storeLockId, false);
 351                                 } else {
 352                                         Console.WriteLine ("\tread only, releasing");
 353                                         handler.ReleaseItemExclusive (context, sessionId, storeLockId);
 354                                 }
 355                                 handler.ResetItemTimeout (context, sessionId);
 356                         } else {
 357                                 handler.ReleaseItemExclusive (context, sessionId, storeLockId);
 358                                 handler.RemoveItem (context, sessionId, storeLockId, storeData);
 359                         }
 360                         SessionStateUtility.RemoveHttpSessionStateFromContext (context);
 361                         if (supportsExpiration)
 362                                 SessionStateUtility.RaiseSessionEnd (container, o, args);
 363                 }
 364
 365                 void OnEndRequest (object o, EventArgs args)
 366                 {
 367                         if (handler == null)
 368                                 return;
 369
 370                         HttpApplication application = o as HttpApplication;
 371                         if (application == null)
 372                                 return;
 373                         if (handler != null)
 374                                 handler.EndRequest (application.Context);
 375                 }
 376
 377                 void GetStoreData (HttpContext context)
 378                 {
 379                         if (sessionId == null)
 380                                 return;
 381
 382                         if (isReadOnly)
 383                                 storeData = handler.GetItem (context,
 384                                                              sessionId,
 385                                                              out storeLocked,
 386                                                              out storeLockAge,
 387                                                              out storeLockId,
 388                                                              out storeSessionAction);
 389                         else
 390                                 storeData = handler.GetItemExclusive (context,
 391                                                                       sessionId,
 392                                                                       out storeLocked,
 393                                                                       out storeLockAge,
 394                                                                       out storeLockId,
 395                                                                       out storeSessionAction);
 396                 }
 397
 398                 void WaitForStoreUnlock (HttpContext context)
 399                 {
 400                         AutoResetEvent are = new AutoResetEvent (false);
 401                         TimerCallback tc = new TimerCallback (this.StoreUnlockWaitCallback);
 402                         CallbackState cs = new CallbackState (context, are);
 403                         using (Timer timer = new Timer (tc, cs, 500, 500)) {
 404                                 try {
 405                                         are.WaitOne (executionTimeout, false);
 406                                 } catch {
 407                                         storeData = null;
 408                                 }
 409                         }
 410                 }
 411
 412                 void StoreUnlockWaitCallback (object s)
 413                 {
 414                         CallbackState state = s as CallbackState;
 415                         GetStoreData (state.Context);
 416                         if (storeData == null && storeLocked && (storeLockAge > executionTimeout)) {
 417                                 handler.ReleaseItemExclusive (state.Context, sessionId, storeLockId);
 418                                 state.AutoEvent.Set ();
 419                         } else if (storeData != null && !storeLocked)
 420                                 state.AutoEvent.Set ();
 421                 }
 422
 423                 void SessionSetup (HttpContext context, bool isNew)
 424                 {
 425                         if (storeData != null && sessionId != null) {
 426                                 container = new HttpSessionStateContainer (
 427                                         sessionId,
 428                                         storeData.Items,
 429                                         storeData.StaticObjects,
 430                                         storeData.Timeout,
 431                                         isNew,
 432                                         config.Cookieless,
 433                                         config.Mode,
 434                                         isReadOnly);
 435                                 SessionStateUtility.AddHttpSessionStateToContext (context, container);
 436                                 if (isNew) {
 437                                         supportsExpiration = handler.SetItemExpireCallback (OnSessionExpired);
 438                                         OnSessionStart ();
 439                                 }
 440                         }
 441                 }
 442
 443                 void OnSessionExpired (string id, SessionStateStoreData item)
 444                 {
 445                 }
 446
 447                 void OnSessionStart ()
 448                 {
 449                         if (Start != null)
 450                                 Start (this, EventArgs.Empty);
 451                 }
 452
 453                 public event EventHandler Start;
 454
 455                 // This event is public, but only Session_[On]End in global.asax will be invoked if present.
 456                 public event EventHandler End;
 457         }
 458 }
 459 #endif