RE: [PATCH v5 0/2] Add config file support for l3fwd

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> > This patchset introduces config file support for l3fwd
> > and its lookup methods LPM, FIB, and EM, similar to
> > that of l3fwd-acl. This allows for route rules to be
> > defined in configuration files and edited there instead
> > of in each of the lookup methods hardcoded route tables.
> >
> > V4:
> > * Fix nondeterministic bug of segfault on termination of
> >   sample app.
> > V5:
> > * Reintroduce hardcoded tables as to not break dts and
> >   allow for hardcoded tables to be used if no config
> >   files presented.
> >
> > Sean Morrissey (2):
> >   examples/l3fwd: add config file support for LPM/FIB
> >   examples/l3fwd: add config file support for EM
> >
> >  doc/guides/sample_app_ug/l3_forward.rst |  89 +++--
> >  examples/l3fwd/em_default_v4.cfg        |  17 +
> >  examples/l3fwd/em_default_v6.cfg        |  17 +
> >  examples/l3fwd/l3fwd.h                  |  41 +++
> >  examples/l3fwd/l3fwd_em.c               | 471 +++++++++++++++++-------
> >  examples/l3fwd/l3fwd_fib.c              |  50 +--
> >  examples/l3fwd/l3fwd_lpm.c              | 315 +++++++++++++++-
> >  examples/l3fwd/l3fwd_route.h            |  41 +++
> >  examples/l3fwd/lpm_default_v4.cfg       |  17 +
> >  examples/l3fwd/lpm_default_v6.cfg       |  17 +
> >  examples/l3fwd/main.c                   |  68 +++-
> >  11 files changed, 949 insertions(+), 194 deletions(-)
> >  create mode 100644 examples/l3fwd/em_default_v4.cfg
> >  create mode 100644 examples/l3fwd/em_default_v6.cfg
> >  create mode 100644 examples/l3fwd/lpm_default_v4.cfg
> >  create mode 100644 examples/l3fwd/lpm_default_v6.cfg
> >
> 
> Why not use the DPDK cfgfile library and format?
> It is model after standard INI format.

It is probably some sort of misunderstanding:
This patch doesn't add configuration file for some l3fwd run-time parameters
(number of ports/queues, queue/cpu mappings, etc.).
It allows user to specify he's own routing table instead of hard-coded ones.
For routing table .ini file format is not really suitable.
Instead we follow format similar to what is used in other DPDK apps
(l3fwd-acl, ipsec-secgw, test-acl, test-fib,  test-sad, etc.) for these purposes:
list of route entries, each entry occupies exactly one line.
As an example:
/examples/l3fwd/lpm_default_v4.cfg
#Copy of hard-coded IPv4 FWD table for L3FWD LPM
R198.18.0.0/24 0
R198.18.1.0/24 1
R198.18.2.0/24 2
R198.18.3.0/24 3
....
I suppose it is self-explanatory, intuitive and close enough 
to what user used for with unix-like route config tools.
Konstantin