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) 2002-2006 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 #if !NET_2_0
  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 const string CookieName = "ASPSESSION";
  46                 internal const 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                 static SessionConfig config;
  68                 static Type handlerType;
  69 #endif
  70                 ISessionHandler handler;
  71                 bool sessionForStaticFiles;
  72
  73                 static RandomNumberGenerator rng = RandomNumberGenerator.Create ();
  74
  75                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
  76                 public SessionStateModule ()
  77                 {
  78                 }
  79
  80                 internal RandomNumberGenerator Rng {
  81                         get { return rng; }
  82                 }
  83
  84                 public void Dispose ()
  85                 {
  86                     if (handler!=null)
  87                         handler.Dispose();
  88                 }
  89
  90                 SessionConfig GetConfig ()
  91                 {
  92                         lock (locker) {
  93                                 if (config != null)
  94                                         return config;
  95
  96                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
  97                                 if (config ==  null)
  98                                         config = new SessionConfig (null);
  99
 100 #if TARGET_J2EE
 101                                 if (config.Mode == SessionStateMode.SQLServer || config.Mode == SessionStateMode.StateServer)
 102                                         throw new NotImplementedException("You must use web.xml to specify session state handling");
 103 #else
 104                                 if (config.Mode == SessionStateMode.StateServer)
 105                                         handlerType = typeof (SessionStateServerHandler);
 106
 107                                 if (config.Mode == SessionStateMode.SQLServer)
 108                                         handlerType = typeof (SessionSQLServerHandler);
 109 #endif
 110                                 if (config.Mode == SessionStateMode.InProc)
 111                                         handlerType = typeof (SessionInProcHandler);
 112
 113                                 return config;
 114                         }
 115                 }
 116
 117                 [EnvironmentPermission (SecurityAction.Assert, Read = "MONO_XSP_STATIC_SESSION")]
 118                 public void Init (HttpApplication app)
 119                 {
 120                         sessionForStaticFiles = (Environment.GetEnvironmentVariable ("MONO_XSP_STATIC_SESSION") != null);
 121                         SessionConfig cfg = GetConfig ();
 122                         if (handlerType == null)
 123                                 return;
 124
 125                         if (cfg.CookieLess)
 126                                 app.BeginRequest += new EventHandler (OnBeginRequest);
 127
 128                         app.AcquireRequestState += new EventHandler (OnAcquireState);
 129                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 130                         app.EndRequest += new EventHandler (OnEndRequest);
 131
 132                         if (handlerType != null && handler == null) {
 133                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
 134                                 handler.Init (this, app, cfg); //initialize
 135                         }
 136                 }
 137
 138                 void OnBeginRequest (object o, EventArgs args)
 139                 {
 140                         HttpApplication application = (HttpApplication) o;
 141                         HttpContext context = application.Context;
 142                         string base_path = context.Request.BaseVirtualDir;
 143                         string id = UrlUtils.GetSessionId (base_path);
 144
 145                         if (id == null)
 146                                 return;
 147
 148                         string new_path = UrlUtils.RemoveSessionId (base_path, context.Request.FilePath);
 149                         context.Request.SetFilePath (new_path);
 150                         context.Request.SetHeader (HeaderName, id);
 151                         context.Response.SetAppPathModifier (String.Concat ("(", id, ")"));
 152                 }
 153
 154                 void OnReleaseRequestState (object o, EventArgs args)
 155                 {
 156                         if (handler == null)
 157                                 return;
 158
 159                         HttpApplication application = (HttpApplication) o;
 160                         HttpContext context = application.Context;
 161                         handler.UpdateHandler (context, this);
 162                 }
 163
 164                 void OnEndRequest (object o, EventArgs args)
 165                 {
 166                 }
 167
 168                 void OnAcquireState (object o, EventArgs args)
 169                 {
 170                         HttpApplication application = (HttpApplication) o;
 171                         HttpContext context = application.Context;
 172
 173                         bool required = (context.Handler is IRequiresSessionState);
 174
 175                         // This is a hack. Sites that use Session in global.asax event handling code
 176                         // are not supposed to get a Session object for static files, but seems that
 177                         // IIS handles those files before getting there and thus they are served without
 178                         // error.
 179                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 180                         // on mono, but you lose performance when serving static files.
 181                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 182                                 required = true;
 183                         // hack end
 184
 185                         bool read_only = (context.Handler is IReadOnlySessionState);
 186
 187                         bool isNew = false;
 188                         HttpSessionState session = null;
 189                         if (handler != null)
 190                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 191
 192                         if (session != null) {
 193                                 if (isNew)
 194                                         session.SetNewSession (true);
 195
 196                                 if (read_only)
 197                                         session = session.Clone ();
 198
 199                                 context.SetSession (session);
 200
 201                                 HttpRequest request = context.Request;
 202                                 HttpResponse response = context.Response;
 203                                 string id = context.Session.SessionID;
 204                                 if (isNew && config.CookieLess) {
 205                                         request.SetHeader (HeaderName, id);
 206                                         response.Redirect (UrlUtils.InsertSessionId (id, request.FilePath));
 207                                 } else if (isNew) {
 208                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 209                                         cookie.Path = request.ApplicationPath;
 210                                         context.Response.AppendCookie (cookie);
 211                                 }
 212
 213                                 if (isNew)
 214                                         OnSessionStart ();
 215                         }
 216                 }
 217
 218                 void OnSessionStart ()
 219                 {
 220                         if (Start != null)
 221                                 Start (this, EventArgs.Empty);
 222                 }
 223
 224                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 225                 {
 226                         SessionConfig cfg = GetConfig ();
 227
 228                         // Only invoked for InProc (see msdn2 docs on SessionStateModule.End)
 229                         if (cfg.Mode == SessionStateMode.InProc)
 230                                 HttpApplicationFactory.InvokeSessionEnd (value);
 231                 }
 232
 233                 public event EventHandler Start;
 234
 235                 // This event is public, but only Session_[On]End in global.asax will be invoked if present.
 236                 public event EventHandler End;
 237         }
 238 }
 239
 240 #endif