help decoding vendor specific attributes

[ralberto]

Hi.
(Sorry if this is not a right place to ask this type of question. I'm also not familiarized with radius protocol)

I'm creating an utility that will receive radius packets (via UDP socket) and decode some A/V pairs to a human readable format. With the help of this project I'm currently able to read the packages and retrieve A/V pairs using rfc2865.<attr_GetString(packet)>.

However, I really need to decode a vendor specific attribute, namely 3GPP User-Location-Info. Can someone point me in the right direction how to do that?

Thanks for any help you could provide.

[ghost]

You'll want to use radius-dict-gen for this. It takes in a FreeRadius dictionary file and outputs Go helper code for working with those dictionary's attributes on a packet. Once installed, you can run it like this:

radius-dict-gen -output generated.go -package threegpp /usr/share/freeradius/dictionary.3gpp

I just tried running that command on my machine, and I get errors because I have not implemented the "byte" attribute, which that dictionary apparently uses. You can either use the -ignore flag (e.g. -ignore 3GPP-Session-Stop-Indicator) if those particular attributes are of no interest to you, or open another ticket requesting that the byte attribute be supported.

[ralberto]

Thanks @bontibon.
That's really helpful. I don't need those attributes, however I think the -ignore flag is not being applied during the parse phase. So the parser fails with the error:

... unknown attribute type "byte`

[ralberto]

As a workaround I just commented those attributes directly on the 3gpp dictionary!