Making a Packet Sniffer that Modifies Incomming Packets

[cplusplusFtw]

Hey, I want to make a program that can intercept packets your client receives from the server and modify a specific packet to something you want your client to receive. For example, if the packet I want the program to modify contains the string of hex (I'm not quite sure what its called) "10 15 1B 32" and I want to modify it to "10 15 1D 35" how exactly would this be done? A basic source code of this happening would be REALLY helpful, if no one's not bored enough to write one for me can anyone at least link me sites or threads or anything that can help me achieve this? Thanks.

By the way, how much harder would it be to get the packet editor to find and modify a specific packet that changes a little each time you receive it? For example, the packet can contain the bytes "AA AC AC AA" one time then contain "BB AC AC BB" the next time. I want it to find the packet containing the "AC AC" between the 2 bytes that always change and modify it

[cplusplusFtw]

Also, I want to program to focus on a specific service such as a web browser like firefox.exe. How do you make it so you can "attach" a packet editor to a specific service to capture packets it receives/sends? A basic source code or tutorial on another site/thread would be very helpful again :/.

[cplusplusFtw]

Any help?...

[cplusplusFtw]

...

[Skizmo]

I think that nobody is reacting on your post, because of your request. It sounds a bit 'shady', and we don't support 'shady' things. What are you trying to build ?

[Doron Moraz]

Hey, I want to make a program that can intercept packets your client receives from the server and modify a specific packet to something you want your client to receive.

You can use an existing library like Winpcap (http://www.winpcap.org/),
or API's like LSP (http://en.wikipedia.org/wiki/Layered_Service_Provider) /
NDIS (http://en.wikipedia.org/wiki/Network..._Specification).


[EDIT]
I agree with Skizmo, your post can come across as a bit 'shady',
I'm sure that wasn’t your intention, so I suggest you to specify what you’re trying to achieve when asking questions of this type.
In addition you should have posted this thread in the 'network programming' forum.


Regards
Doron Moraz