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 // Copyright (C) 2002,2003,2004,2005 Novell, Inc (http://www.novell.com)
  10 // (C) 2003 Stefan Görling (http://www.gorling.se)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32
  33 using System.Web.Configuration;
  34 using System.Web.Caching;
  35 using System.Web.Util;
  36 using System.Security.Cryptography;
  37 using System.Security.Permissions;
  38
  39 namespace System.Web.SessionState
  40 {
  41         // CAS - no InheritanceDemand here as the class is sealed
  42         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  43         public sealed class SessionStateModule : IHttpModule
  44         {
  45                 internal static readonly string CookieName = "ASPSESSION";
  46                 internal static readonly string HeaderName = "AspFilterSessionId";
  47                 static object locker = new object ();
  48
  49 #if TARGET_J2EE
  50                 static private SessionConfig config {
  51                         get {
  52                                 return (SessionConfig)AppDomain.CurrentDomain.GetData("SessionStateModule.config");
  53                         }
  54                         set {
  55                                 AppDomain.CurrentDomain.SetData("SessionStateModule.config", value);
  56                         }
  57                 }
  58                 static private Type handlerType {
  59                         get {
  60                                 return (Type)AppDomain.CurrentDomain.GetData("SessionStateModule.handlerType");
  61                         }
  62                         set {
  63                                 AppDomain.CurrentDomain.SetData("SessionStateModule.handlerType", value);
  64                         }
  65                 }
  66 #else
  67 #if NET_2_0
  68                 static SessionStateSection config;
  69 #else
  70                 static SessionConfig config;
  71 #endif
  72                 static Type handlerType;
  73 #endif
  74                 ISessionHandler handler;
  75                 bool sessionForStaticFiles;
  76
  77                 static RandomNumberGenerator rng = RandomNumberGenerator.Create ();
  78
  79                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
  80                 public SessionStateModule ()
  81                 {
  82                 }
  83
  84                 internal RandomNumberGenerator Rng {
  85                         get { return rng; }
  86                 }
  87
  88                 public void Dispose ()
  89                 {
  90                     if (handler!=null)
  91                         handler.Dispose();
  92                 }
  93
  94 #if NET_2_0
  95                 SessionStateSection GetConfig ()
  96 #else
  97                 SessionConfig GetConfig ()
  98 #endif
  99                 {
 100                         lock (locker) {
 101                                 if (config != null)
 102                                         return config;
 103
 104 #if NET_2_0
 105                                 config = (SessionStateSection) WebConfigurationManager.GetSection ("system.web/sessionState");
 106 #else
 107                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
 108                                 if (config ==  null)
 109                                         config = new SessionConfig (null);
 110 #endif
 111
 112 #if TARGET_J2EE
 113                                 if (config.Mode == SessionStateMode.SQLServer || config.Mode == SessionStateMode.StateServer)
 114                                         throw new NotImplementedException("You must use web.xml to specify session state handling");
 115 #else
 116                                 if (config.Mode == SessionStateMode.StateServer)
 117                                         handlerType = typeof (SessionStateServerHandler);
 118
 119                                 if (config.Mode == SessionStateMode.SQLServer)
 120                                         handlerType = typeof (SessionSQLServerHandler);
 121 #endif
 122                                 if (config.Mode == SessionStateMode.InProc)
 123                                         handlerType = typeof (SessionInProcHandler);
 124
 125                                 return config;
 126                         }
 127                 }
 128
 129                 [EnvironmentPermission (SecurityAction.Assert, Read = "MONO_XSP_STATIC_SESSION")]
 130                 public void Init (HttpApplication app)
 131                 {
 132                         sessionForStaticFiles = (Environment.GetEnvironmentVariable ("MONO_XSP_STATIC_SESSION") != null);
 133 #if NET_2_0
 134                         SessionStateSection cfg = GetConfig ();
 135 #else
 136                         SessionConfig cfg = GetConfig ();
 137 #endif
 138                         if (handlerType == null)
 139                                 return;
 140
 141                         if (cfg.CookieLess)
 142                                 app.BeginRequest += new EventHandler (OnBeginRequest);
 143
 144                         app.AcquireRequestState += new EventHandler (OnAcquireState);
 145                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 146                         app.EndRequest += new EventHandler (OnEndRequest);
 147
 148                         if (handlerType != null && handler == null) {
 149                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
 150                                 handler.Init (this, app, cfg); //initialize
 151                         }
 152                 }
 153
 154                 void OnBeginRequest (object o, EventArgs args)
 155                 {
 156                         HttpApplication application = (HttpApplication) o;
 157                         HttpContext context = application.Context;
 158                         string base_path = context.Request.BaseVirtualDir;
 159                         string id = UrlUtils.GetSessionId (base_path);
 160
 161                         if (id == null)
 162                                 return;
 163
 164                         string new_path = UrlUtils.RemoveSessionId (base_path, context.Request.FilePath);
 165                         context.Request.SetFilePath (new_path);
 166                         context.Request.SetHeader (HeaderName, id);
 167                         context.Response.SetAppPathModifier (String.Concat ("(", id, ")"));
 168                 }
 169
 170                 void OnReleaseRequestState (object o, EventArgs args)
 171                 {
 172                         if (handler == null)
 173                                 return;
 174
 175                         HttpApplication application = (HttpApplication) o;
 176                         HttpContext context = application.Context;
 177                         handler.UpdateHandler (context, this);
 178                 }
 179
 180                 void OnEndRequest (object o, EventArgs args)
 181                 {
 182                 }
 183
 184                 void OnAcquireState (object o, EventArgs args)
 185                 {
 186                         HttpApplication application = (HttpApplication) o;
 187                         HttpContext context = application.Context;
 188
 189                         bool required = (context.Handler is IRequiresSessionState);
 190
 191                         // This is a hack. Sites that use Session in global.asax event handling code
 192                         // are not supposed to get a Session object for static files, but seems that
 193                         // IIS handles those files before getting there and thus they are served without
 194                         // error.
 195                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 196                         // on mono, but you lose performance when serving static files.
 197                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 198                                 required = true;
 199                         // hack end
 200
 201                         bool read_only = (context.Handler is IReadOnlySessionState);
 202
 203                         bool isNew = false;
 204                         HttpSessionState session = null;
 205                         if (handler != null)
 206                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 207
 208                         if (session != null) {
 209                                 if (isNew)
 210                                         session.SetNewSession (true);
 211
 212                                 if (read_only)
 213                                         session = session.Clone ();
 214
 215                                 context.SetSession (session);
 216
 217                                 HttpRequest request = context.Request;
 218                                 HttpResponse response = context.Response;
 219                                 string id = context.Session.SessionID;
 220                                 if (isNew && config.CookieLess) {
 221                                         request.SetHeader (HeaderName, id);
 222                                         response.Redirect (UrlUtils.InsertSessionId (id, request.FilePath));
 223                                 } else if (isNew) {
 224                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 225                                         cookie.Path = request.ApplicationPath;
 226                                         context.Response.AppendCookie (cookie);
 227                                 }
 228
 229                                 if (isNew)
 230                                         OnSessionStart ();
 231                         }
 232                 }
 233
 234                 void OnSessionStart ()
 235                 {
 236                         if (Start != null)
 237                                 Start (this, EventArgs.Empty);
 238                 }
 239
 240                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 241                 {
 242 #if NET_2_0
 243                         SessionStateSection cfg = GetConfig ();
 244 #else
 245                         SessionConfig cfg = GetConfig ();
 246 #endif
 247
 248                         // Only invoked for InProc (see msdn2 docs on SessionStateModule.End)
 249                         if (cfg.Mode == SessionStateMode.InProc)
 250                                 HttpApplicationFactory.InvokeSessionEnd (value);
 251                 }
 252
 253                 public event EventHandler Start;
 254
 255                 // This event is public, but only Session_[On]End in global.asax will be invoked if present.
 256                 public event EventHandler End;
 257         }
 258 }
 259