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 Ximian, Inc (http://www.ximian.com)
  10 // (C) 2003 Stefan Görling (http://www.gorling.se)
  11
  12 using System.Web;
  13 using System.Web.Util;
  14 using System.Security.Cryptography;
  15
  16 namespace System.Web.SessionState
  17 {
  18         public sealed class SessionStateModule : IHttpModule
  19         {
  20                 internal static readonly string CookieName = "ASPSESSION";
  21                 internal static readonly string HeaderName = "AspFilterSessionId";
  22
  23                 static SessionConfig config;
  24                 static Type handlerType;
  25                 ISessionHandler handler;
  26
  27                 private RandomNumberGenerator rng;
  28
  29                 public SessionStateModule ()
  30                 {
  31                         rng = new RNGCryptoServiceProvider ();
  32                 }
  33
  34                 internal RandomNumberGenerator Rng {
  35                         get { return rng; }
  36                 }
  37
  38                 public void Dispose ()
  39                 {
  40                     if (handler!=null)
  41                         handler.Dispose();
  42                 }
  43
  44                 public void Init (HttpApplication app)
  45                 {
  46                         if (config == null) {
  47                                 config = (SessionConfig) HttpContext.GetAppConfig ("system.web/sessionState");
  48                                 if (config ==  null)
  49                                         config = new SessionConfig (null);
  50
  51                                 if (config.Mode == SessionStateMode.StateServer)
  52                                         handlerType = typeof (SessionStateServerHandler);
  53
  54                                 if (config.Mode == SessionStateMode.SQLServer)
  55                                         handlerType = typeof (SessionSQLServerHandler);
  56
  57                                 if (config.Mode == SessionStateMode.InProc)
  58                                         handlerType = typeof (SessionInProcHandler);
  59
  60                                 if (config.Mode == SessionStateMode.Off)
  61                                         return;
  62                         }
  63
  64                         if (config.CookieLess)
  65                                 app.BeginRequest += new EventHandler (OnBeginRequest);
  66
  67                         app.AddOnAcquireRequestStateAsync (
  68                                 new BeginEventHandler (OnBeginAcquireState),
  69                                 new EndEventHandler (OnEndAcquireState));
  70
  71                         app.ReleaseRequestState += new EventHandler (OnReleaseRequestState);
  72                         app.EndRequest += new EventHandler (OnEndRequest);
  73
  74                         if (handlerType != null && handler == null) {
  75                                 handler = (ISessionHandler) Activator.CreateInstance (handlerType);
  76                                 handler.Init(app, config); //initialize
  77                         }
  78                 }
  79
  80                 void OnBeginRequest (object o, EventArgs args)
  81                 {
  82                         HttpApplication application = (HttpApplication) o;
  83                         HttpContext context = application.Context;
  84                         string base_path = context.Request.BaseVirtualDir;
  85                         string id = UrlUtils.GetSessionId (base_path);
  86
  87                         if (id == null)
  88                                 return;
  89
  90                         context.Request.SetFilePath (UrlUtils.RemoveSessionId (base_path,
  91                                                                      context.Request.FilePath));
  92                         context.Request.SetHeader (HeaderName, id);
  93                 }
  94
  95                 void OnReleaseRequestState (object o, EventArgs args)
  96                 {
  97                         if (handler == null)
  98                                 return;
  99
 100                         HttpApplication application = (HttpApplication) o;
 101                         HttpContext context = application.Context;
 102                         handler.UpdateHandler (context, this);
 103                 }
 104
 105                 void OnEndRequest (object o, EventArgs args)
 106                 {
 107                 }
 108
 109                 IAsyncResult OnBeginAcquireState (object o, EventArgs args, AsyncCallback cb, object data)
 110                 {
 111                         HttpApplication application = (HttpApplication) o;
 112                         HttpContext context = application.Context;
 113
 114                         bool required = (context.Handler is IRequiresSessionState);
 115                         bool read_only = (context.Handler is IReadOnlySessionState);
 116
 117                         bool isNew = false;
 118                         HttpSessionState session = null;
 119                         if (handler != null)
 120                                 session = handler.UpdateContext (context, this, required, read_only, ref isNew);
 121
 122                         if (session != null) {
 123                                 if (isNew)
 124                                         session.SetNewSession (true);
 125
 126                                 if (read_only)
 127                                         session = session.Clone ();
 128
 129                                 context.SetSession (session);
 130
 131                                 if (isNew && config.CookieLess) {
 132                                         string id = context.Session.SessionID;
 133                                         context.Request.SetHeader (HeaderName, id);
 134                                         context.Response.Redirect (UrlUtils.InsertSessionId (id,
 135                                                                    context.Request.FilePath));
 136                                 } else if (isNew) {
 137                                         string id = context.Session.SessionID;
 138                                         HttpCookie cookie = new HttpCookie (CookieName, id);
 139                                         cookie.Path = UrlUtils.GetDirectory (context.Request.Path);
 140                                         context.Response.AppendCookie (cookie);
 141                                 }
 142                         }
 143
 144                         // In the future, we might want to move the Async stuff down to
 145                         // the interface level, if we're going to support other than
 146                         // InProc, we might actually want to do things async, now we
 147                         // simply fake it.
 148                         HttpAsyncResult result=new HttpAsyncResult (cb,this);
 149                         result.Complete (true, o, null);
 150                         if (isNew && Start != null)
 151                                 Start (this, args);
 152
 153                         return result;
 154                 }
 155
 156                 void OnEndAcquireState (IAsyncResult result)
 157                 {
 158                 }
 159
 160                 internal void OnEnd ()
 161                 {
 162                         if (End != null)
 163                                 End (this, EventArgs.Empty);
 164                 }
 165
 166                 public event EventHandler Start;
 167                 public event EventHandler End;
 168         }
 169 }
 170