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Why aren't ITS messages supported yet? [closed]

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Hi there!

Hopefully someone can help me.

In the development builds I can dissect ITS messages to see the message id, which protocol is used (eg. 2 for CAM).

But I cannot see further than that. Higher protocols aren't supported and the data remains a pile of rubbish.

When looking in the source code I would find that there is at least intended support for CAM and DENM.

So my question is: What's the hold up? Why isn't it working yet?

Best regards

PS: I tried several builds on two machines and no configuration could dissect said messages properly.

Edit (27.03.19): I believe I wasn't bringing my point across very well. It's about Wireshark build 3.1.0rc0-190-g41c566b4. The file in question is "epan/dissectors/packet-its.c"

The code reads as if all the dissectors were implemented. Though I can only recognize the lowest level of those ITS messages when running said build. Since I am new to dissector development I have no clue as to why it isn't working.

My idea was to implement them myself using an ASN.1 compiler for wireshark (which name I forgot). When I noticed that there already were all the necessary ASN.1 definitions present. A look in the code surprised me with lots of DENM and CAM (between other) references. Though they wouldn't appear in the build.

Does anybody know what's wrong with the code? Is there an issue tracker where I could follow certain dissectors?

Thanks

Edit (28.03.19): I thank Anders for clearing things up during the exchange of comments. Though while my original question wasn't answered, I'm satisfied with the result. Therefore I close this question.

totogo's avatar
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totogo
asked 2019-02-28 16:56:40 +0000, updated 2019-03-28 10:39:41 +0000
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Closed for the following reason "the question is answered, right answer was accepted" by totogo 2019-03-28 10:40:34 +0000

Comments

What's an "ITS message"?

Guy Harris's avatar Guy Harris (2019-02-28 18:11:04 +0000) edit

(ITS) Intelligent Transport Systems It's all about vehicular communications. https://www.etsi.org/committee/1402-its

totogo's avatar totogo (2019-03-27 13:20:22 +0000) edit
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1 Answer

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So my question is: What's the hold up? Why isn't it working yet?

The short answer to that is: You haven't written the dissector code yet. As this is a community project volunteers provide code, which the core developers will try to integrate.

PS: It could be anyone writing this code, it seems no-one has invested their (spare) time yet.

Jaap's avatar
13.7k
Jaap
answered 2019-03-01 07:40:00 +0000
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Comments

It looks like it might be "Intelligent Transport Systems (ITS); Vehicular Communications" (packet-geonw.c)

You coud raise a bug report attaching a trace and reference the apropriate standards so someone can take a look.

Anders's avatar Anders (2019-03-01 11:32:14 +0000) edit

So this is either a bug, or it is about to be integrated. Did I understand that correctly?

I was thinking about just waiting a bit and check whether or not it works in newer builds.

totogo's avatar totogo (2019-03-27 13:23:23 +0000) edit

Somewhat confusingly, the Wireshark Bugzilla is also used for enhancement requests, i.e. to add further dissection functions.

There is no "plan" of what's about to be added, the nearest equivalent is checking for pending changes undergoing review on the Wireshark Gerrit review site.

grahamb's avatar grahamb (2019-03-27 13:40:46 +0000) edit

It seems like some ITS stuff IS supported and some got fixed in https://code.wireshark.org/review/#/c... so you would have to let us know what you think is not working.

Anders's avatar Anders (2019-03-27 14:09:21 +0000) edit

Hey, that's great news! So I built version 3.1.0rc0-393-g303ccbe4. But what I found was that there is a new sub tree saying there was "No subdissector found for this Message id/protocol version combination" when looking at a CAM message.

totogo's avatar totogo (2019-03-27 14:26:18 +0000) edit
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