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 private SessionConfig config {
  47                         get {
  48                                 return (SessionConfig)AppDomain.CurrentDomain.GetData("SessionStateModule.config");
  49                         }
  50                         set {
  51                                 AppDomain.CurrentDomain.SetData("SessionStateModule.config", value);
  52                         }
  53                 }
  54                 static private Type handlerType {
  55                         get {
  56                                 return (Type)AppDomain.CurrentDomain.GetData("SessionStateModule.handlerType");
  57                         }
  58                         set {
  59                                 AppDomain.CurrentDomain.SetData("SessionStateModule.handlerType", value);
  60                         }
  61                 }
  62 #else
  63                 static SessionConfig config;
  64                 static Type handlerType;
  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 TARGET_J2EE
  94                                 if (config.Mode == SessionStateMode.SQLServer || config.Mode == SessionStateMode.StateServer)
  95                                         throw new NotImplementedException("You must use web.xml to specify session state handling");
  96 #else
  97                                 if (config.Mode == SessionStateMode.StateServer)
  98                                         handlerType = typeof (SessionStateServerHandler);
  99
 100                                 if (config.Mode == SessionStateMode.SQLServer)
 101                                         handlerType = typeof (SessionSQLServerHandler);
 102 #endif
 103
 104                                 if (config.Mode == SessionStateMode.InProc)
 105                                         handlerType = typeof (SessionInProcHandler);
 106
 107                                 if (config.Mode == SessionStateMode.Off)
 108                                         return;
 109                         }
 110
 111                         if (config.CookieLess)
 112                                 app.BeginRequest += new EventHandler (OnBeginRequest);
 113
 114                         app.AddOnAcquireRequestStateAsync (
 115                                 new BeginEventHandler (OnBeginAcquireState),
 116                                 new EndEventHandler (OnEndAcquireState));
 117
 118                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
 119                         app.EndRequest += new EventHandler (OnEndRequest);
 120
 121                         if (handlerType != null && handler == null) {
 122                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
 123                                 handler.Init (this, app, config); //initialize
 124                         }
 125                 }
 126
 127                 void OnBeginRequest (object o, EventArgs args)
 128                 {
 129                         HttpApplication application = (HttpApplication) o;
 130                         HttpContext context = application.Context;
 131                         string base_path = context.Request.BaseVirtualDir;
 132                         string id = UrlUtils.GetSessionId (base_path);
 133
 134                         if (id == null)
 135                                 return;
 136
 137                         context.Request.SetCurrentExePath (UrlUtils.RemoveSessionId (base_path,
 138                                                                      context.Request.FilePath));
 139                         context.Request.SetHeader (HeaderName, id);
 140                         context.Response.SetAppPathModifier (String.Format ("({0})", id));
 141                 }
 142
 143                 void OnReleaseRequestState (object o, EventArgs args)
 144                 {
 145                         if (handler == null)
 146                                 return;
 147
 148                         HttpApplication application = (HttpApplication) o;
 149                         HttpContext context = application.Context;
 150                         handler.UpdateHandler (context, this);
 151                 }
 152
 153                 void OnEndRequest (object o, EventArgs args)
 154                 {
 155                 }
 156
 157                 IAsyncResult OnBeginAcquireState (object o, EventArgs args, AsyncCallback cb, object data)
 158                 {
 159                         HttpApplication application = (HttpApplication) o;
 160                         HttpContext context = application.Context;
 161
 162                         bool required = (context.Handler is IRequiresSessionState);
 163
 164                         // This is a hack. Sites that use Session in global.asax event handling code
 165                         // are not supposed to get a Session object for static files, but seems that
 166                         // IIS handles those files before getting there and thus they are served without
 167                         // error.
 168                         // As a workaround, setting MONO_XSP_STATIC_SESSION variable make this work
 169                         // on mono, but you lose performance when serving static files.
 170                         if (sessionForStaticFiles && context.Handler is StaticFileHandler)
 171                                 required = true;
 172                         // hack end
 173
 174                         bool read_only = (context.Handler is IReadOnlySessionState);
 175
 176                         bool isNew = false;
 177                         HttpSessionState session = null;
 178                         if (handler != null)
 179                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 180
 181                         if (session != null) {
 182                                 if (isNew)
 183                                         session.SetNewSession (true);
 184
 185                                 if (read_only)
 186                                         session = session.Clone ();
 187
 188                                 context.SetSession (session);
 189
 190                                 if (isNew && config.CookieLess) {
 191                                         string id = context.Session.SessionID;
 192                                         context.Request.SetHeader (HeaderName, id);
 193                                         context.Response.Redirect (UrlUtils.InsertSessionId (id,
 194                                                                    context.Request.FilePath));
 195                                 } else if (isNew) {
 196                                         string id = context.Session.SessionID;
 197                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 198                                         cookie.Path = UrlUtils.GetDirectory (context.Request.ApplicationPath);
 199                                         context.Response.AppendCookie (cookie);
 200                                 }
 201                         }
 202
 203                         // In the future, we might want to move the Async stuff down to
 204                         // the interface level, if we're going to support other than
 205                         // InProc, we might actually want to do things async, now we
 206                         // simply fake it.
 207                         HttpAsyncResult result=new HttpAsyncResult (cb,this);
 208                         result.Complete (true, o, null);
 209                         if (isNew && Start != null)
 210                                 Start (this, args);
 211
 212                         return result;
 213                 }
 214
 215                 void OnEndAcquireState (IAsyncResult result) { }
 216
 217                 internal void OnSessionRemoved (string key, object value, CacheItemRemovedReason reason)
 218                 {
 219                         OnEnd ();
 220                 }
 221
 222                 internal void OnEnd ()
 223                 {
 224 #if !TARGET_J2EE
 225                         if (End != null)
 226                                 End (this, EventArgs.Empty);
 227 #endif
 228                 }
 229
 230                 public event EventHandler Start;
 231                 public event EventHandler End;
 232         }
 233 }
 234