Re: [dpdk-dev] [RFC 2/2] net/tap: add eBPF instructions

[Pascal Mazon <pascal.mazon@6wind.com>]

Indeed, the spirit of the initial work was to publish source code,
compiled BPF bytecode, and Makefile for re-generating the latter.
I have no clue regarding licensing, I'll trust you guys on that.

On 30/11/2017 18:39, Thomas Monjalon wrote:
> 30/11/2017 18:20, Stephen Hemminger:
>> On Thu, 30 Nov 2017 18:05:22 +0100
>> Thomas Monjalon <thomas@monjalon.net> wrote:
>>
>>> 30/11/2017 17:54, Stephen Hemminger:
>>>> Loading BPF is a could solution to doing dynamic flow matching.
>>>> It needs to be done differently to be accepted.
>>>>
>>>> Putting raw machine instructions in source code is as bad as binary
>>>> blobs. You need to provide original source of program and then have
>>>> build instructions to create any needed code.  
>>> The source program is provided in this patch: tap_bpf_program.c
>>> It is pre-compiled to avoid requiring too many dependencies when building DPDK.
>> But the "freedom to modify" comes into play here. If a *evil* vendor builds
>> an application based on DPDK and does not provide source. Then user still deserves
>> the right to modify the eBPF program that it loads as GPL.  The best solution
>> is to make the TAP PMD loader routine load the program from a file.
>> Although I am certainly not a FSF legal scholar, putting GPL'd object code in
>> TAP PMD risks accusations of being a derived or combined work.
> Good point.
> The compiled BPF may be provided as a plugin file.
> So we would be free to not package this GPL file.