Wireshark · Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 53489: /trunk/epan/ /trunk/epan/dissectors/: packet-ethe

[Evan Huus <eapache@xxxxxxxxx>]

On Thu, Nov 21, 2013 at 3:44 PM, Guy Harris <guy@xxxxxxxxxxxx> wrote:
>
> On Nov 21, 2013, at 12:08 PM, mmann@xxxxxxxxxxxxx wrote:
>
>> http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=53489
>>
>> User: mmann
>> Date: 2013/11/21 08:08 PM
>>
>> Log:
>> Remove ethertype, mpls_label and ppids from packet_info structure.
>
>>
>> The information was converted to "proto" data within their respective dissectors strictly for use in "Decode As".
>
> "proto" data is persistent, so you're allocating a chunk of data for every packet in an Ethernet capture, for example, which remains around until the capture is closed.  That might amount to a significant additional amount of memory for a large capture.
>
> Perhaps what's needed here is a way for dissectors to attach arbitrary data to a packet_info structure, with the data being freed when the packet_info structure is freed (for example, when the epan_dissect_t containing a packet_info structure is freed).

Memory allocated in the pinfo wmem allocator (pinfo->pool) will
automatically be freed when the packet_info struct is freed. It would
be pretty easy to do an analogue of p_add_proto_data using pinfo and
this wmem pool.