Re: Interfacing mac802154 stack with userspace applications

[Alexander Aring <alex.aring@gmail.com>]

Hi,

On Mon, Mar 09, 2020 at 09:25:08PM -0300, Victhor Foster wrote:
> I have resumed work on this project, and I decided to implement a few
> changes. I abandoned the socat approach and came up with a different
> implementation, modifying the linux-wpan example programs.
> 

aha, which one?

> I made two programs, one that receives packets from a wpan interface
> and outputs them to a UDP port, while the other program receives
> packets from a UDP port and sends them to a wpan interface. It seems
> to work well enough, but there's a problem with my approach.
> 

You telling me something about UDP to a wpan interface. This makes no
sense except you also building some IP layer in user space.

> I need to get outgoing packets from the wpan interface. Is there a way
> to filter packets coming through a raw socket, such that only outgoing
> packets come out of the socket?
> 

Now you saying something about RAW sockets, what kind of raw sockets?

> Right now, I'm not filtering for outgoing packets, so when packets are
> received through my program and sent to the wpan interface, the same
> packets come out of the interface, as there's no filtering being done,
> causing a loop.
> 
> I tried using the sll_pkttype field in the raw socket structure, but
> all packets received by the socket have the same value, so it's not
> useful, unfortunately.
> 

No, it smells for me you want to do something with traffic control and
egress path.

- Alex