Declaring and calling exported functions for DLL's, declaring and using exported Dynamic Link Library functions with assembler

I'm working on DLL EXPORTS and failing to export variable!
Code snippet is how I do in C

Note: above does not require DLL H or DEF files

Code snippet how I'm trying in Masm32

I have found bits and pieces from all over!
Link below:
DLL Definition file

I would appreciate any help with this!
Would like to have corrected/detailed generic example put in
Snippets/DLL section for others to reference.

William,

In the attachment you'll find an example of how to declare and use dll exports (both by name and ordinal). Also, you 'll see how you can put a function in a PE segment of your choice, (remember, PE segment names can only be 8 characters long!) as in the code you attached.

Generally speaking, you can directly export data from a dll, but it's a best practice to code a stub that returns a pointer to your data as in the third exported function of this example.
Directly accessing a variable within a DLL, requires knowledge of the Import Address Table - related structures. More on that on the next post...

Attached File ( Number of downloads: 11 )
 DLL.Example.zip

And here is the other method to directly access a variable within a dll.
To understand the code, you need to read the following article, and also use the debugger to figure out what happens and why.

Understanding the Import Address Table.

These methods, especially the second and third ones, should work with the vast majority of DLLs produced with MS compilers, but not with all DLLs, because compilers from other vendors may handle imported functions differently (i.e. not via the jmp thunk_address method).

Also, the variable must be exported from the dll, exactly the way an exported function is (by ordinal, or by name).

To summarize: Do not use this method, instead write a stub that exports a pointer for the variable you want to access, as in the example in the above post.
This method is presented here only for the sake of conversation.

Attached File ( Number of downloads: 11 )
 DIRECTLY.ACCESSING.A.VARIABLE.WITHIN.A.DLL.zip

Nice work samael,

I have been working on this for 5 days, reading alot, hoping
I would'nt have to use Import Address Table. Calling Dll function
to find bool state is not practical for what I'm doing.
Am going to set DLL hook state in INI file for now, until I gain
futher knowledge on this.

I have no issues with functions, I've tested Hook procedure start, stop
and at app exit, all works fine. Dll Exports are being exported, just need
to be able to access variable value. All examples I've seen export a
static/non-changing variables.

I attached a tool to check DLL exports "DLL Export Viewer 1.11".


Attached File ( Number of downloads: 14 )
 dllexp.zip

Was it something like that you had in mind?



Attached File ( Number of downloads: 16 )
 DLL.Example_3.zip