Re: [PATCH net-next v1 5/9] net: devmem: ksft: add ipv4 support

[Stanislav Fomichev <stfomichev@gmail.com>]

On 05/19, Mina Almasry wrote:
> On Mon, May 19, 2025 at 8:32 AM Stanislav Fomichev <stfomichev@gmail.com> wrote:
> >
> > On 05/19, Mina Almasry wrote:
> > > ncdevmem supports both ipv4 and ipv6, but the ksft is currently
> > > ipv6-only. Propagate the ipv4 support to the ksft, so that folks that
> > > are limited to these networks can also test.
> > >
> > > Signed-off-by: Mina Almasry <almasrymina@google.com>
> > >
> > > ---
> > >  .../selftests/drivers/net/hw/devmem.py        | 33 ++++++++++++-------
> > >  1 file changed, 22 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/drivers/net/hw/devmem.py b/tools/testing/selftests/drivers/net/hw/devmem.py
> > > index f5d7809400ea..850381e14d9e 100755
> > > --- a/tools/testing/selftests/drivers/net/hw/devmem.py
> > > +++ b/tools/testing/selftests/drivers/net/hw/devmem.py
> > > @@ -18,30 +18,36 @@ def require_devmem(cfg):
> > >          raise KsftSkipEx("Test requires devmem support")
> > >
> > >
> > > -def check_rx(cfg) -> None:
> > > -    cfg.require_ipver("6")
> > > +def check_rx(cfg, ipver) -> None:
> > >      require_devmem(cfg)
> > >
> > > +    addr = cfg.addr_v[ipver]
> > > +    if ipver == "6":
> > > +        addr = "[" + addr + "]"
> >
> > I think you can add [] unconditionally, no need to special case v6.
> >
> 
> I'll double check, but IIRC the [] were v6-only.
> 
> > > +
> > > +    socat = f"socat -u - TCP{ipver}:{addr}:{port}"
> > > +
> > >      port = rand_port()
> > >      listen_cmd = f"{cfg.bin_local} -l -f {cfg.ifname} -s {cfg.addr_v['6']} -p {port}"
> > >
> > > -    with bkg(listen_cmd) as socat:
> > > +    with bkg(listen_cmd) as ncdevmem:
> > >          wait_port_listen(port)
> > > -        cmd(f"echo -e \"hello\\nworld\"| socat -u - TCP6:[{cfg.addr_v['6']}]:{port}", host=cfg.remote, shell=True)
> > > +        cmd(f"echo -e \"hello\\nworld\"| {socat}", host=cfg.remote, shell=True)
> > >
> > > -    ksft_eq(socat.stdout.strip(), "hello\nworld")
> > > +    ksft_eq(ncdevmem.stdout.strip(), "hello\nworld")
> > >
> > >
> > > -def check_tx(cfg) -> None:
> > > -    cfg.require_ipver("6")
> > > +def check_tx(cfg, ipver) -> None:
> > >      require_devmem(cfg)
> > >
> > >      port = rand_port()
> > > -    listen_cmd = f"socat -U - TCP6-LISTEN:{port}"
> > > +    listen_cmd = f"socat -U - TCP{ipver}-LISTEN:{port}"
> > >
> > > -    with bkg(listen_cmd, exit_wait=True) as socat:
> > > +    addr = cfg.addr_v[ipver]
> > > +
> > > +    with bkg(listen_cmd) as socat:
> > >          wait_port_listen(port)
> > > -        cmd(f"echo -e \"hello\\nworld\"| {cfg.bin_remote} -f {cfg.ifname} -s {cfg.addr_v['6']} -p {port}", host=cfg.remote, shell=True)
> > > +        cmd(f"echo -e \"hello\\nworld\"| {cfg.bin_remote} -f {cfg.ifname} -s {addr} -p {port}", host=cfg.remote, shell=True)
> > >
> > >      ksft_eq(socat.stdout.strip(), "hello\nworld")
> > >
> > > @@ -51,8 +57,13 @@ def main() -> None:
> > >          cfg.bin_local = path.abspath(path.dirname(__file__) + "/ncdevmem")
> > >          cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
> > >
> > > +        if "4" in cfg.addr_v:
> > > +            ipver = "4"
> > > +        else:
> > > +            ipver = "6"
> >
> > If we have both, we prefer v4, can we do the opposite?
> 
> Sure, but why? Just curious.

We want to be in the v6-only world at some point (unlikely to get there
though), and having dualstack deployments prefer v6 is the way to go.