Wireshark mailing list archives
Making sure a dissector correctly interprets the extra data passed to it
From: Guy Harris <guy () alum mit edu>
Date: Mon, 18 Apr 2016 17:23:32 -0700
On Apr 17, 2016, at 5:33 AM, Peter Wu (Code Review) <code-review-do-not-reply () wireshark org> wrote:
Peter Wu has posted comments on this change. Change subject: Don't assume the HTTP dissector is being called from the TCP dissector. ...................................................................... Patch Set 2: This internal detail unnecessarily changes the external interface. Can't we just check for the parent protocol in the dissect_http? Change Ib5138d3a082f1017b7ef190e5128a21eb9a49e92 is an example of a test that was adjusted, but I believe that is the wrong fix as it will break all existing configurations.
There is a problem with the current "extra data" mechanism - there's no enforcement. Nothing in the Wireshark core checks whether dissector A is getting the extra data it expects to be passed. If we decide not to support polymorphism, we need to have some way to ensure that, if dissector A expects to be handled the sort of extra data that dissector B passes to its subdissectors, dissector A is *not* called by any dissectors that *don't* do that. If we *do* decide to support polymorphism, we should have a standard and convenient way to allow dissector A to determine what type of extra data is being passed to it. It sounds as if you're advocating polymorphism here. Are you saying that a standard and convenient way to allow a dissector to determine what sort of extra data is being passed to it, by checking the parent protocol? If so, what is it? ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
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- Making sure a dissector correctly interprets the extra data passed to it Guy Harris (Apr 18)