CODEWITHSUNDEEP
c++vb.netvbac#-4.0visual-c++
user3228249
user3228249

Reputation: 109

intercept messages between VBA applications

I have an application developed in VB 6.0. I don't have access to its code. This application also exposes its functionality through certain API provided in its dlls. Is there a way for me to check what methods of the API the consumers of this application's API are calling across anywhere the API is deployed. I want a C# program to just sit in that target environment and intercept the calls made to that API and report it back to my service via a service. I wont be modifying the API or the code calling the API. Is this possible in C# or would I need to go with C++?

Update

Lets say for sake of simplicity, that its a simple VB application developed in VB 6 called SimpleAPP, and it has a button that displays records in a grid. It does this by calling a component CMPA.dll with a public method GetRecords(string ID) which returns an Array of records. I have another few applications called CustomerApp.exe and AnotherCustomerApp.exe which also have a reference to CMPA.dll and they both calls this same method to get the records. Now, I want to develop a program called Interceptor.exe that will actually sit in the environment where CustomerApp and AnotherCustomerApp is deployed and will log internally which of these two applications called that CMPA dll's public method GetRecords and also log what parameter it sent in and what results were retrieved.

Upvotes: 0

Views: 204

Answers (1)

Cheers and hth. - Alf
Cheers and hth. - Alf

Reputation: 145204

I had to google to find the library that was on the tip of my tongue.

That googling turned up some interesting articles: a new to me 1999 Microsoft Research article called “Intercepting and Instrumenting COM Applications” and an Microsoft Systems Journal article from january 1999 that I do remember, “Building a Lightweight COM Interception Framework”.

The library you want is probably Microsoft Detours. I have only used it from C++, not from C#, and I have only used it for intercepting calls to Windows API functions, not COM methods, so I can’t guarantee that it’s well suited. But it's not exactly rocket science to interface these two languages, if needed.

If Detours doesn’t turn out to fill your needs, then look at the articles cited. Quite possibly they resulted in some framework you can use. And otherwise they have the information you need to build your own. You might then also check out if ParkPlace ever made what you want. There was once great interest in “cross concern“ functionality, and ParcPlace did some of the most interesting research, as I recall.

Upvotes: 5

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