My goal is to call a native DLL via P/Invoke from an ASP.NET application. So far, I can successfully call the DLL from a Console app, or even from an OWIN server running on HttpListener, hosted in an Azure WorkerRole.
Troubles arise when I try to host the exact same code in ASP.NET/IIS, either in a simple ASP.NET app or in an Azure WebRole. In such a context, the call to the DLL throws an AccessViolationException.
From my research, it looks like the issue could come from the fact that the native DLL is not thread-safe - and a test trying to call it from concurrent threads even in a Console app throws the AVE, which shows that it's not thread-safe indeed. So I'm checking with the DLL's author on that.
But in the meantime, I'm still wondering if that's really the root cause of the crash on ASP.NET/IIS, because during my tests I only do one request at a time. So waiting for the thread-safety to be fixed, I wanted to know if you guys would be aware of other specificites that could cause the P/Invoke to fail in ASP.NET/IIS.
UPDATE
Based on my numerous tests, it turned out that the crash was caused by the DLL trying to load external files. In a non-IIS application, placing these files at the same folder level as the DLL just works; but on my dev machine for example, the same code running on IIS tries to look for the files in "C:\Program Files (x86)\IIS Express".
So my question now is: is there a way to control the path where a simple File.Open would look for and if not, is there a way to get the default path so that I can copy the required files there at startup?
Thanks
What you observe simply indicates that you use relative paths. That means when running under IIS Express (not IIS) the process tries to search under C:\Program Files (x86)\IIS Express as it assumes that's the base directory to use when interpreting the relative paths.
You should always use absolute paths instead of relative paths, and then this issue won't happen.
http://msdn.microsoft.com/en-us/library/ms178116(v=vs.100).aspx
Please don't muck around with copying files on every app startup, that can only go south.
A better solution would be to get the provider of the DLL to add some code that checks the Windows Registry for a path value. If that value exists in the Registry, the DLL will attempt to load its associated libraries from the path in that value; otherwise it will fall back to attempting to load them from the DLL's current directory.
I have a legacy ASP application that I support. By support I mean that I haven't touched it since about 2005 because its just worked.
However there were a couple of data issues in the Access database that the ASP application uses. So like a fool I opened the database directly over a fileshare (using MS Access 2007), fixed the data and saved it down (in Access 2000 format).
Now the application will retrieve and display the data OK, but any updates fail with the error 3705: Operation is not allowed when the object is open. I have not changed the code in any way, the only change was the data update and database save.
I've found plenty of examples of this error, but they all relate to fairly simple issues like ensuring the recordset is closed before opening it, changing the CursorLocation enum, etc. I've tried most of these in the vain hope that something will work, but nothing has.
Any ideas how can I fix this?
Thanks.
UPDATE
I've installed a web based access database management system, and have tried to compact and repair the database. I received the error:
The Microsoft Jet database engine cannot open the file '<snip>'. It is
already opened exclusively by another user, or you need permission to view
its data. (-2147217911)
I have run the macro detailed here to determine who is logged onto the database, and just showed the admin user (which was me - while running it)
Those errors mean one thing: the database file is opened by some other process and thus is being locked.
Most likely that "web based access database management system" is the culprit, try to find how you can configure it to not lock the file, or get rid of it.
As a work around or way to verify the real problem, you can copy the .mdb file into different location and change the classic ASP connection string to check if you can update the database in its new location.
#Remou's comment above about checking the file and folder permissions was correct.
I had our server admin check the permissions, and it seems that the write access had dropped off the folder (and the files also inherit their permissions from the folder). He said that this has happened before when saving directly over the fileshare.
(accepting in lieu of an answer from #Remou)
Needed to write a server text file as the output of a business process initiated by ASP.net app.
The text file writing code is in a library file using standard stream code
All worked OK in IDE.
Publish and it falls over trying to write file. IIS is reluctant to write to the file system.
Much rummaging around and hair pulling finally led to a solution. It is not pretty and only applicable in a situation where you have control over the Webserver.
Just saw your answer.
It doesn't need to be inside your inetpub or wwwroot directory for that matter, it could be anywhere, as long as security permissions are set correctly for the user under which the application is running as.
But this is actually desired. If not just imagine the consequences of allowing write access anywhere.
Also, there's no need for the virtual directory. You could create a directory like C:\ProcessOutput, and grant permissions accordingly and it should work just fine.
Another option, would be to have a service account created, and impersonate as that user within your application only for when you need to write that output file.
Solution was:
Create a physical directory on the webserver with the physical path of:
c:\inetpub\wwwroot\mywebapp\myOutputFileDirectory
Make a virtual directory that points at the directory.
Using windows explorer give write permission to the physical directory to IIS_IUSRS.
Use a physical path of c:\inetpub\wwwroot\mywebapp\myOutputFileDirectory in your Streamwriter code
Maybe the virtual path could point to somewhere more sensible across the LAN if you get the security sorted but I am sufficiently battered to accept this small crumb with gratitude.
I’m working on trying to port an ASP.NET app from Server 2003 (and IIS6) to Server 2008 (IIS7).
When I try and visit the page on the browser I get this:
Server Error in ‘/’ Application.
Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application’s trust level in the configuration file.
Exception Details: System.Security.SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and the location of the exception can be identified using the exception stack trace below.
Stack Trace:
[SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.]
System.Diagnostics.EventLog.FindSourceRegistration(String source, String machineName, Boolean readOnly) +562
System.Diagnostics.EventLog.SourceExists(String source, String machineName) +251
[snip]
These are the things I’ve done to try and solve it:
Give “Everyone” full access permission to the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Security. This worked. But naturally I can’t do this in production. So I deleted the “Everyone” permission after running the app for a few minutes and the error re-appeared.
I created the source in the Application log and the Security log (and I verified it exists via regedit) during installation with elevated permissions but the error remained.
I gave the app a full trust level in the web.config file (and using appcmd.exe) but to no avail.
Does anyone have an insight as to what could be done here?
PS: This is a follow up to this question. I followed the given answers but to no avail (see #2 above).
To give Network Service read permission on the EventLog/Security key (as suggested by Firenzi and royrules22) follow instructions from http://geekswithblogs.net/timh/archive/2005/10/05/56029.aspx
Open the Registry Editor:
Select Start then Run. Enter regedt32 or regedit
Navigate/expand to the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security
3. Right click on this entry and select Permissions
Add the Network Service user
Give it Read permission
UPDATE: The steps above are ok on developer machines, where you do not use deployment process to install application.
However if you deploy your application to other machine(s), consider to register event log sources during installation as suggested in SailAvid's and Nicole Calinoiu's answers.
I am using PowerShell function (calling in Octopus Deploy.ps1)
function Create-EventSources() {
$eventSources = #("MySource1","MySource2" )
foreach ($source in $eventSources) {
if ([System.Diagnostics.EventLog]::SourceExists($source) -eq $false) {
[System.Diagnostics.EventLog]::CreateEventSource($source, "Application")
}
}
}
See also Microsoft KB 2028427 Fail to write to the Windows event log from an ASP.NET or ASP application
The problem is that the EventLog.SourceExists tries to access the EventLog\Security key, access which is only permitted for an administrator.
A common example for a C# Program logging into EventLog is:
string sSource;
string sLog;
string sEvent;
sSource = "dotNET Sample App";
sLog = "Application";
sEvent = "Sample Event";
if (!EventLog.SourceExists(sSource))
EventLog.CreateEventSource(sSource, sLog);
EventLog.WriteEntry(sSource, sEvent);
EventLog.WriteEntry(sSource, sEvent, EventLogEntryType.Warning, 234);
However, the following lines fail if the program hasn't administrator permissions and the key is not found under EventLog\Application as EventLog.SourceExists will then try to access EventLog\Security.
if (!EventLog.SourceExists(sSource))
EventLog.CreateEventSource(sSource, sLog);
Therefore the recommended way is to create an install script, which creates the corresponding key, namely:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\dotNET Sample App
One can then remove those two lines.
You can also create a .reg file to create the registry key. Simply save the following text into a file create.reg:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\dotNET Sample App]
The solution was to give the "Network Service" account read permission on the EventLog/Security key.
For me ony granting 'Read' permissions for 'NetworkService' to the whole 'EventLog' branch worked.
I had a very similar problem with a console program I develop under VS2010 (upgraded from VS2008 under XP)
My prog uses EnLib to do some logging.
The error was fired because EntLib had not the permission to register a new event source.
So I started once my compiled prog as an Administrator : it registered the event source.
Then I went back developping and debugging from inside VS without problem.
(you may also refer to http://www.blackwasp.co.uk/EventLog_3.aspx, it helped me
This exception was occurring for me from a .NET console app running as a scheduled task, and I was trying to do basically the same thing - create a new Event Source and write to the event log.
In the end, setting full permissions for the user under which the task was running on the following keys did the trick for me:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Security
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog
I try almost everything in here to solve this problem... I share here the answer that help me:
Another way to resolve the issue :
in IIS console, go to application pool managing your site, and note the identity running it (usually Network Service)
make sure this identity can read KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog (rigth-click, authorisations)
now change the identity of this application pool to Local System, apply, and switch back to Network Service
Credentials will be reloaded and EventLog reacheable
in http://geekswithblogs.net/timh/archive/2005/10/05/56029.aspx , thanks Michael Freidgeim
A new key with source name used need to be created under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application in the regEdit when you use System.Diagnostics.EventLog.WriteEntry("SourceName", "ErrorMessage", EventLogEntryType.Error);
So basically your user does not have permission to create the key. The can do the following depending of the user that you are using from the Identity value in the Application Pool Advanced settings:
Run RegEdit and go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog
Right click in EventLog key and the select Permissions... option
3.Add your user with full Control access.
-If you are using "NetworkService" add NETWORK SERVICE user
-If you are usinf "ApplicationPoolIdentity" add IIS APPPOL{name of your app pool} (use local machine location when search the user).
-If you are using "LocalSystem" make sure that the user has Administrator permissions. It is not recommend for vulnerabilities.
Repeat the steps from 1 to 3 for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Security
For debugging with Visual Studio I use "NetworkService" (it is ASP.NET user) and when the site is published I used "AppicationPoolIdentity".
I ran into the same issue, but I had to go up one level and give full access to everyone to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\ key, instead of going down to security, that cleared up the issue for me.
Same issue on Windows 7 64bits.
Run as administrator solved the problem.
There does appear to be a glaringly obvious solution to this that I've yet to see a huge downside, at least where it's not practical to obtain administrative rights in order to create your own event source: Use one that's already there.
The two which I've started to make use of are ".Net Runtime" and "Application Error", both of which seem like they will be present on most machines.
Main disadvantages are inability to group by that event, and that you probably don't have an associated Event ID, which means the log entry may very well be prefixed with something to the effect of "The description for Event ID 0 from source .Net Runtime cannot be found...." if you omit it, but the log goes in, and the output looks broadly sensible.
The resultant code ends up looking like:
EventLog.WriteEntry(
".Net Runtime",
"Some message text here, maybe an exception you want to log",
EventLogEntryType.Error
);
Of course, since there's always a chance you're on a machine that doesn't have those event sources for whatever reason, you probably want to try {} catch{} wrap it in case it fails and makes things worse, but events are now saveable.
FYI...my problem was that accidently selected "Local Service" as the Account on properties of the ProcessInstaller instead of "Local System". Just mentioning for anyone else who followed the MSDN tutorial as the Local Service selection shows first and I wasn't paying close attention....
I'm not working on IIS, but I do have an application that throws the same error on a 2K8 box. It works just fine on a 2K3 box, go figure.
My resolution was to "Run as administrator" to give the application elevated rights and everything works happily. I hope this helps lead you in the right direction.
Windows 2008 is rights/permissions/elevation is really different from Windows 2003, gar.
Hi I ran into the same problem when I was developing an application and wanted to install it on a remote PC, I fixed it by doing the following:
1) Goto your registry, locate: HKLM\System\CurrentControlSet\Services\EventLog\Application(???YOUR_SERVICE_OR_APP_NAME???)
Note that "(???YOUR_SERVICE_OR_APP_NAME???)" is your application service name as you defined it when you created your .NET deployment, for example, if you named your new application "My new App" then the key would be: HKLM\System\CurrentControlSet\Services\EventLog\Application\My New app
Note2: Depending on which eventLog you are writing into, you may find on your DEV box, \Application\ (as noted above), or also (\System) or (\Security) depending on what event your application is writing into, mostly, (\Application) should be fine all the times.
2) Being on the key above, From the menu; Select "FILE" -> "Export", and then save the file. (Note: This would create your necessary registry settings when the application would need to access this key to write into the Event Viewer), the new file will be a .REG file, for the argument sake, call it "My New App.REG"
3) When deploying on PRODuction, consult the Server's System's administrator (SA), hand over the "My New App.REG" file along with the application, and ask the SA to install this REG file, once done (as admin) this would create the key for your applicaion.
4) Run your application, it should not need to access anything else other than this key.
Problem should be resolved by now.
Cause:
When developing an application that writes anything into the EventLog, it would require a KEY for it under the Eventlog registry if this key isn't found, it would try to create it, which then fails for having no permissions to do so. The above process, is similar to deploying an application (manually) whereas we are creating this ourselves, and no need to have a headache since you are not tweaking the registry by adding permissions to EVERYONE which is a securty risk on production servers.
I hope this helps resolving it.
Though the installer answer is a good answer, it is not always practical when dealing with software you did not write. A simple answer is to create the log and the event source using the PowerShell command New-EventLog (http://technet.microsoft.com/en-us/library/hh849768.aspx)
Run PowerShell as an Administrator and run the following command changing out the log name and source that you need.
New-EventLog -LogName Application -Source TFSAggregator
I used it to solve the Event Log Exception when Aggregator runs issue from codeplex.
Had a similar issue with all of our 2008 servers. The security log stopped working altogether because of a GPO that took the group Authenticated Users and read permission away from the key HKLM\System\CurrentControlSet\Services\EventLog\security
Putting this back per Microsoft's recommendation corrected the issue. I suspect giving all authenticated users read at a higher level will also correct your problem.
I hit similar issue - in my case Source contained <, > characters. 64 bit machines are using new even log - xml base I would say and these characters (set from string) create invalid xml which causes exception. Arguably this should be consider Microsoft issue - not handling the Source (name/string) correctly.
My app gets installed on client web servers. Rather than fiddling with Network Service permissions and the registry, I opted to check SourceExists and run CreateEventSource in my installer.
I also added a try/catch around log.source = "xx" in the app to set it to a known source if my event source wasn't created (This would only come up if I hot swapped a .dll instead of re-installing).
Solution is very simple - Run Visual Studio Application in Admin mode !
I had a console application where I also had done a "Publish" to create an Install disk.
I was getting the same error at the OP:
The solution was right click setup.exe and click Run as Administrator
This enabled the install process the necessary privilege's.
I had this issue when running an app within VS. All I had to do was run the program as Administrator once, then I could run from within VS.
To run as Administrator, just navigate to your debug folder in windows explorer. Right-click on the program and choose Run as administrator.
try below in web.config
<system.web>
<trust level="Full"/>
</system.web>
Rebuilding the solution worked for me