[Olsr-users] Missing mandatory TLV 25 in extension 256

[Mika Rajala]

Hi

Yes I'm trying to implement a DLEP radio, or DLEP modem.

It’s kind of hard for me to copy any data or code here, since I have to do it by hand.

I get the UDP peer discovery signal and I reply to it with the valid message.

Then the dlep_router opens a connection to my tcp server and sends a session initialization message. all ok.

I respond by sending a session initialization response, but then the dlep_router doesn't respond or sends a termination message.

Looking at the dlep_router with a debugger reveals the following.

dlep_session.c : 742 
checks that I gave all mandatory TLVs in my session initialization response.
dlep_session.c : 933
fails when it doesn't find the TLV 25 for extension 256.

My session initialization message doesn't have the Supported extensions TLV in it, here's my packet in octet form: ( I copied this from a hexdump of the traffic)

00 04 00 42			// HEADER
00 05 00 02 00 0a 		// Heartbeat
00 0c 00 08 00 00 00 00 00 01 c2 00	// max recv
00 0d 00 08 00 00 00 00 00 01 c2 00 	// max send
00 0e 00 08 00 00 00 00 00 00 00 00 	// current recv
00 0f 00 08 00 00 00 00 00 00 00 00 	// current send
00 10 00 08 00 00 00 00 00 0f 42 40 	// latency

It should say

message code 4, length 66 octets
heartbeat interval 10 seconds
max recv bitrate 115200
max send bitrate 115200
current recv bitrate 0
current send bitrate 0
latency 1000000 microseconds

according to the documentation 
https://tools.ietf.org/html/draft-ietf-manet-dlep-19#section-10.4

That should be enough.

-mika

-----Original Message-----
From: Henning Rogge [mailto:(spam-protected)] 
Sent: 19. helmikuuta 2016 11:08
To: Mika Rajala <(spam-protected)>
Cc: (spam-protected)
Subject: Re: [Olsr-users] Missing mandatory TLV 25 in extension 256

On Fri, Feb 19, 2016 at 9:45 AM, Mika Rajala <(spam-protected)> wrote:
> Hi
>
> I’m trying to send a Dlep session init response message to 
> dlep_router_static.

so you are trying to implement a DLEP radio, right?

> But it won’t accept it since it’s missing a mandatory tlv 25? This 
> results in dlep_router sending dlep session terminate message.
>
> There is no mandatory tlv 25 for dlep session init response, the 
> mandatory tlv codes are 
> (https://tools.ietf.org/html/draft-ietf-manet-dlep-19)
>
> 5, 12, 13, 14, 15 and 16
>
> tlv code 25 is reserved for future extensions.

TLV 25 is part of one of the two extensions (in this case "extension
256") I have added to DLEP...

it SHOULD negotiate about the valid extensions and switch them of if necessary.

> Also I don’t give any supported extensions in my dlep session init response.

so you are going through the UDP exchange and the OONF DLEP router drops the connection when it gets your message...

could you post the byte string your radio sends as the "Session Initialization Response Message" ?

Henning