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 using System.Web.Caching;
  33 using System.Web.Util;
  34 using System.Security.Cryptography;
  35 using System.Security.Permissions;
  36
  37 namespace System.Web.SessionState
  38 {
  39         // CAS - no InheritanceDemand here as the class is sealed
  40         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  41         public sealed class SessionStateModule : IHttpModule
  42         {
  43                 internal static readonly string CookieName = "ASPSESSION";
  44                 internal static readonly string HeaderName = "AspFilterSessionId";
  45                 static object locker = new object ();
  46
  47 #if TARGET_J2EE
  48                 static private SessionConfig config {
  49                         get {
  50                                 return (SessionConfig)AppDomain.CurrentDomain.GetData("SessionStateModule.config");
  51                         }
  52                         set {
  53                                 AppDomain.CurrentDomain.SetData("SessionStateModule.config", value);
  54                         }
  55                 }
  56                 static private Type handlerType {
  57                         get {
  58                                 return (Type)AppDomain.CurrentDomain.GetData("SessionStateModule.handlerType");
  59                         }
  60                         set {
  61                                 AppDomain.CurrentDomain.SetData("SessionStateModule.handlerType", value);
  62                         }
  63                 }
  64 #else
  65                 static SessionConfig config;
  66                 static Type handlerType;
  67 #endif
  68                 ISessionHandler handler;
  69                 bool sessionForStaticFiles;
  70
  71                 static RandomNumberGenerator rng = RandomNumberGenerator.Create ();
  72
  73                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
  74                 public SessionStateModule ()
  75                 {
  76                 }
  77
  78                 internal RandomNumberGenerator Rng {
  79                         get { return rng; }
  80                 }
  81
  82                 public void Dispose ()
  83                 {
  84                     if (handler!=null)
  85                         handler.Dispose();
  86                 }
  87
  88                 SessionConfig GetConfig ()
  89                 {
  90                         lock (locker) {
  91                                 if (config != null)
  92                                         return config;
  93
  94                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
  95                                 if (config ==  null)
  96                                         config = new SessionConfig (null);
  97
  98 #if TARGET_J2EE
  99                                 if (config.Mode == SessionStateMode.SQLServer || config.Mode == SessionStateMode.StateServer)
 100                                         throw new NotImplementedException("You must use web.xml to specify session state handling");
 101 #else
 102                                 if (config.Mode == SessionStateMode.StateServer)
 103                                         handlerType = typeof (SessionStateServerHandler);
 104
 105                                 if (config.Mode == SessionStateMode.SQLServer)
 106                                         handlerType = typeof (SessionSQLServerHandler);
 107 #endif
 108                                 if (config.Mode == SessionStateMode.InProc)
 109                                         handlerType = typeof (SessionInProcHandler);
 110
 111                                 return config;
 112                         }
 113                 }
 114
 115                 [EnvironmentPermission (SecurityAction.Assert, Read = "MONO_XSP_STATIC_SESSION")]
 116                 public void Init (HttpApplication app)
 117                 {
 118                         sessionForStaticFiles = (Environment.GetEnvironmentVariable ("MONO_XSP_STATIC_SESSION") != null);
 119                         SessionConfig cfg = GetConfig ();
 120                         if (handlerType == null)
 121                                 return;
 122
 123                         if (cfg.CookieLess)
 124                                 app.BeginRequest += new EventHandler (OnBeginRequest);
 125
 126                         app.AcquireRequestState += new EventHandler (OnAcquireState);
 127                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 128                         app.EndRequest += new EventHandler (OnEndRequest);
 129
 130                         if (handlerType != null && handler == null) {
 131                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
 132                                 handler.Init (this, app, cfg); //initialize
 133                         }
 134                 }
 135
 136                 void OnBeginRequest (object o, EventArgs args)
 137                 {
 138                         HttpApplication application = (HttpApplication) o;
 139                         HttpContext context = application.Context;
 140                         string base_path = context.Request.BaseVirtualDir;
 141                         string id = UrlUtils.GetSessionId (base_path);
 142
 143                         if (id == null)
 144                                 return;
 145
 146                         string new_path = UrlUtils.RemoveSessionId (base_path, context.Request.FilePath);
 147                         context.Request.SetFilePath (new_path);
 148                         context.Request.SetHeader (HeaderName, id);
 149                         context.Response.SetAppPathModifier (String.Concat ("(", id, ")"));
 150                 }
 151
 152                 void OnReleaseRequestState (object o, EventArgs args)
 153                 {
 154                         if (handler == null)
 155                                 return;
 156
 157                         HttpApplication application = (HttpApplication) o;
 158                         HttpContext context = application.Context;
 159                         handler.UpdateHandler (context, this);
 160                 }
 161
 162                 void OnEndRequest (object o, EventArgs args)
 163                 {
 164                 }
 165
 166                 void OnAcquireState (object o, EventArgs args)
 167                 {
 168                         HttpApplication application = (HttpApplication) o;
 169                         HttpContext context = application.Context;
 170
 171                         bool required = (context.Handler is IRequiresSessionState);
 172
 173                         // This is a hack. Sites that use Session in global.asax event handling code
 174                         // are not supposed to get a Session object for static files, but seems that
 175                         // IIS handles those files before getting there and thus they are served without
 176                         // error.
 177                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 178                         // on mono, but you lose performance when serving static files.
 179                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 180                                 required = true;
 181                         // hack end
 182
 183                         bool read_only = (context.Handler is IReadOnlySessionState);
 184
 185                         bool isNew = false;
 186                         HttpSessionState session = null;
 187                         if (handler != null)
 188                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 189
 190                         if (session != null) {
 191                                 if (isNew)
 192                                         session.SetNewSession (true);
 193
 194                                 if (read_only)
 195                                         session = session.Clone ();
 196
 197                                 context.SetSession (session);
 198
 199                                 HttpRequest request = context.Request;
 200                                 HttpResponse response = context.Response;
 201                                 string id = context.Session.SessionID;
 202                                 if (isNew && config.CookieLess) {
 203                                         request.SetHeader (HeaderName, id);
 204                                         response.Redirect (UrlUtils.InsertSessionId (id, request.FilePath));
 205                                 } else if (isNew) {
 206                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 207                                         cookie.Path = request.ApplicationPath;
 208                                         context.Response.AppendCookie (cookie);
 209                                 }
 210
 211                                 if (isNew)
 212                                         OnSessionStart ();
 213                         }
 214                 }
 215
 216                 void OnSessionStart ()
 217                 {
 218                         if (Start != null)
 219                                 Start (this, EventArgs.Empty);
 220                 }
 221
 222                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 223                 {
 224                         // Only invoked for InProc (see msdn2 docs on SessionStateModule.End)
 225                         if (GetConfig ().Mode == SessionStateMode.InProc)
 226                                 HttpApplicationFactory.InvokeSessionEnd (value);
 227                 }
 228
 229                 public event EventHandler Start;
 230
 231                 // This event is public, but only Session_[On]End in global.asax will be invoked if present.
 232                 public event EventHandler End;
 233         }
 234 }
 235