[Question] Sending a packet

[IceFire32]

Hey mmowned ^^

I have a question about sending a packet with the WoW-internal function "SendPacket", which does the encryption for me.

All I know about this topic, is the information I was able to get from this thread: http://www.mmowned.com/forums/world-...nd-packet.html

I reversed a bit and found SendPacket at 0x0088E530 and g_clientConnection at 0x00BB43F0. I tried to use the CDataStore class from the "Help Send Packet" thread, but if i try to put some data into it with the "<<" operator, mysteriously my DLL unloads itself / stops execution.

That's my code:

void loadUp()
{
	addChatMessage("|cff00ff00Loaded!") ;
	
	CDataStore dataStore ;
	dataStore << 0x123 ;

	__asm { 
		mov edx, dataStore
		push edx // push the pointer to dataStore

		mov ecx, 0x00BB43F0 // move g_clientConnection to ecx
		
		mov eax, 0x0088E530 
		call eax // call SendPacket
	}

	addChatMessage("|cff00ff00Finished!") ;
}

I hope you are able to help me

Greetings,
IceFire32

PS:
Sorry for my bad english :>

[Bananenbrot]

CDataStore dataStore ;
...
__asm
{
    mov edx, &dataStore
    push edx // push the pointer to dataStore
    ...
}
...

I'm not at all familiar with the inline assembler, but I think you need to pass the pointer to your stackallocated CDataStore.

[IceFire32]

CDataStore dataStore ;
...
__asm
{
    mov edx, &dataStore
    push edx // push the pointer to dataStore
    ...
}
...

I'm not at all familiar with the inline assembler, but I think you need to pass the pointer to your stackallocated CDataStore.

Thanks for the quick answer!

The inline assembler isn't the problem, if I execute the following code, "dataStore << 0x123 ; | <- was executed" isn't written into the chat, so the problem seems to be in the CDataStore class :/

void loadUp()
{
	addChatMessage("|cff00ff00Loaded!") ;
	
	CDataStore dataStore ;
	dataStore << 0x123 ;
	addChatMessage("dataStore << 0x123 ; | <- was executed") ;
	__asm { 
		mov edx, dataStore
		push edx // push the pointer to dataStore

		mov ecx, 0x00BB43F0 // move g_clientConnection to ecx
		
		mov eax, 0x0088E530 
		call eax // call SendPacket
	}

	addChatMessage("|cff00ff00Finished!") ;
}

It's not necessary to use the "&" operator in inline ASM (not just not necessary, it's not able).

[namreeb]

Have you tried catching an exception and writing it out?

[caytchen]

You probably have to assign your dataStore a buffer to store data in. Though if its trying to write to bad memory thats easily detectable with a debugger. If thats not the case and your CDataStore works as expected, check if the stack is sane and get rid of these engine calls to do your logging.

[lanman92]

Try

CDataStore* ds = new CDataStore();

I think that will work. I'd give typedef's a try too, instead of inline asm.

[caytchen]

Try

CDataStore* ds = new CDataStore();

I think that will work. I'd give typedef's a try too, instead of inline asm.

The only difference to creating the dataStore locally is that the object will persist beyond the function scope, but that is obviously not the issue here.

[xcyanx]

you could prolly use:

void loadUp()
{
	addChatMessage("|cff00ff00Loaded!") ;
	
	CDataStore *dataStore ;
	*dataStore << 0x123 ; //so you will get the pointer to the dataStore inside your  
                                       //asm block of code.

	__asm { 
		mov edx, dataStore
		push edx // push the pointer to dataStore

		mov ecx, 0x00BB43F0 // move g_clientConnection to ecx
		
		mov eax, 0x0088E530 
		call eax // call SendPacket
                add esp, 0x4 //based on lanman92 from the thread that you got the info from
	}

	addChatMessage("|cff00ff00Finished!") ;
}

It's not necessary to use the "&" operator in inline ASM (not just not necessary, it's not able).

You can use the "&" operator in the inline ASM but not with that symbol. You could use [dataStore](or something like that, i don't remember exactly) to get the address of your object.