From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@gmail.com>
Subject: Re: [RFC v2 6/7] net/af_xdp: load BPF file
Date: Wed, 9 May 2018 09:02:22 +0200
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References: <20180308135249.28187-1-qi.z.zhang@intel.com>
 <20180308135249.28187-7-qi.z.zhang@intel.com>
 <20180308151500.2365b677@xeon-e3>
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Cc: Qi Zhang <qi.z.zhang@intel.com>, dev@dpdk.org,
 "Karlsson, Magnus" <magnus.karlsson@intel.com>,
 =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@intel.com>,
 Jesper Dangaard Brouer <brouer@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
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2018-03-09 0:15 GMT+01:00 Stephen Hemminger <stephen@networkplumber.org>:
> On Thu,  8 Mar 2018 21:52:48 +0800
> Qi Zhang <qi.z.zhang@intel.com> wrote:
>
>> +struct bpf_insn prog[] =3D {
>> +     {
>> +             .code =3D 0x85, //call imm
>> +             .dst_reg =3D 0,
>> +             .src_reg =3D 0,
>> +             .off =3D 0,
>> +             .imm =3D BPF_FUNC_xdpsk_redirect,
>> +     },
>> +     {
>> +             .code =3D 0x95, //exit
>> +             .dst_reg =3D 0,
>> +             .src_reg =3D 0,
>> +             .off =3D 0,
>> +             .imm =3D 0,
>> +     },
>> +};
>> +
>> +int load_bpf_file(void)
>> +{
>> +     int fd;
>> +
>> +     fd =3D bpf_load_program(BPF_PROG_TYPE_XDP, prog,
>> +                           ARRAY_SIZE(prog),
>> +                           "GPL", 0,
>> +                           bpf_log_buf, BPF_LOG_BUF_SIZE);
>
> Still have license conflict here. The short bpf program is in BSD code an=
d therefore
> is BSD, not GPL. But kernel won't let you load non-GPL programs.
>

Raising a dead thread! Loading a bpf program that's *not* gpl is not
an issue. The only think to keep in mind is that some bpf helpers are
gpl only -- still -- loading non-gpl bpf code is perfectly ok. So, the
issue here is that bpf_load_program passes "GPL" and therefore making
the program gpl.


Bj=C3=B6rn

> Please check with Intel open source compliance to find a GPL solution.
>
> A possible license safe solution is more complex. You need to provide ori=
ginal program
> source for the BPF program under dual clause (GPL-2/BSD-3); then read in =
that object
> file and load it.  A user wishing to exercise their GPL rights can then t=
ake your
> source file and modify and create new file to load.
>
> Doing this also creates additional GPL issues for appliance vendors using=
 AF_XDP.
> They need to make available the source of all these XDP BPF programs.
>
> Complying with mixed licenses is hard.