linux-kernel - Re: [PATCH net-next v4 9/9] selftests: ncdevmem: Implement devmem TCP TX

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Z7eKHlA0rCF2Wgxb@mini-arch>
Date: Thu, 20 Feb 2025 12:01:34 -0800
From: Stanislav Fomichev <stfomichev@...il.com>
To: Mina Almasry <almasrymina@...gle.com>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org, virtualization@...ts.linux.dev,
	kvm@...r.kernel.org, linux-kselftest@...r.kernel.org,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Donald Hunter <donald.hunter@...il.com>,
	Jonathan Corbet <corbet@....net>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	Jeroen de Borst <jeroendb@...gle.com>,
	Praveen Kaligineedi <pkaligineedi@...gle.com>,
	Shailend Chand <shailend@...gle.com>,
	Kuniyuki Iwashima <kuniyu@...zon.com>,
	Willem de Bruijn <willemb@...gle.com>,
	David Ahern <dsahern@...nel.org>,
	Neal Cardwell <ncardwell@...gle.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Jason Wang <jasowang@...hat.com>,
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
	Eugenio Pérez <eperezma@...hat.com>,
	Stefan Hajnoczi <stefanha@...hat.com>,
	Stefano Garzarella <sgarzare@...hat.com>,
	Shuah Khan <shuah@...nel.org>, sdf@...ichev.me,
	asml.silence@...il.com, dw@...idwei.uk,
	Jamal Hadi Salim <jhs@...atatu.com>,
	Victor Nogueira <victor@...atatu.com>,
	Pedro Tammela <pctammela@...atatu.com>,
	Samiullah Khawaja <skhawaja@...gle.com>
Subject: Re: [PATCH net-next v4 9/9] selftests: ncdevmem: Implement devmem
 TCP TX

On 02/20, Mina Almasry wrote:
> Add support for devmem TX in ncdevmem.
> 
> This is a combination of the ncdevmem from the devmem TCP series RFCv1
> which included the TX path, and work by Stan to include the netlink API
> and refactored on top of his generic memory_provider support.
> 
> Signed-off-by: Mina Almasry <almasrymina@...gle.com>
> Signed-off-by: Stanislav Fomichev <sdf@...ichev.me>
> 
> ---
> 
> v4:
> - Add TX test to devmem.py (Paolo).
> 
> v3:
> - Update ncdevmem docs to run validation with RX-only and RX-with-TX.
> - Fix build warnings (Stan).
> - Make the validation expect new lines in the pattern so we can have the
>   TX path behave like netcat (Stan).
> - Change ret to errno in error() calls (Stan).
> - Handle the case where client_ip is not provided (Stan).
> - Don't assume mid is <= 2000 (Stan).
> 
> v2:
> - make errors a static variable so that we catch instances where there
>   are less than 20 errors across different buffers.
> - Fix the issue where the seed is reset to 0 instead of its starting
>   value 1.
> - Use 1000ULL instead of 1000 to guard against overflow (Willem).
> - Do not set POLLERR (Willem).
> - Update the test to use the new interface where iov_base is the
>   dmabuf_offset.
> - Update the test to send 2 iov instead of 1, so we get some test
>   coverage over sending multiple iovs at once.
> - Print the ifindex the test is using, useful for debugging issues where
>   maybe the test may fail because the ifindex of the socket is different
>   from the dmabuf binding.
> 
> ---
>  .../selftests/drivers/net/hw/devmem.py        |  28 +-
>  .../selftests/drivers/net/hw/ncdevmem.c       | 300 +++++++++++++++++-
>  2 files changed, 312 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/devmem.py b/tools/testing/selftests/drivers/net/hw/devmem.py
> index 1223f0f5c10c..3d4f7fc5e63f 100755
> --- a/tools/testing/selftests/drivers/net/hw/devmem.py
> +++ b/tools/testing/selftests/drivers/net/hw/devmem.py
> @@ -1,6 +1,7 @@
>  #!/usr/bin/env python3
>  # SPDX-License-Identifier: GPL-2.0
>  
> +from os import path
>  from lib.py import ksft_run, ksft_exit
>  from lib.py import ksft_eq, KsftSkipEx
>  from lib.py import NetDrvEpEnv
> @@ -10,8 +11,7 @@ from lib.py import ksft_disruptive
>  
>  def require_devmem(cfg):
>      if not hasattr(cfg, "_devmem_probed"):
> -        port = rand_port()
> -        probe_command = f"./ncdevmem -f {cfg.ifname}"
> +        probe_command = f"{cfg.bin_local} -f {cfg.ifname}"
>          cfg._devmem_supported = cmd(probe_command, fail=False, shell=True).ret == 0
>          cfg._devmem_probed = True
>  
> @@ -25,18 +25,36 @@ def check_rx(cfg) -> None:
>      require_devmem(cfg)
>  
>      port = rand_port()
> -    listen_cmd = f"./ncdevmem -l -f {cfg.ifname} -s {cfg.v6} -p {port}"
> +    listen_cmd = f"{cfg.bin_local} -l -f {cfg.ifname} -s {cfg.v6} -p {port}"
>  
>      with bkg(listen_cmd) as socat:
>          wait_port_listen(port)
> -        cmd(f"echo -e \"hello\\nworld\"| socat -u - TCP6:[{cfg.v6}]:{port}", host=cfg.remote, shell=True)
> +        cmd(f"echo -e \"hello\\nworld\"| socat -u - TCP6:{cfg.v6}:{port},bind={cfg.remote_v6}:{port}", host=cfg.remote, shell=True)

IPv6 address need to be wrapped into [], so has to be at least:
	socat -u - TCP6:[{cfg.v6}]:{port},bind=[{cfg.remote_v6}]:{port}

But not sure why we care here about bind address here, let the kernel
figure out the routing.

Also, seems like "bkg(listen_cmd)" needs to be "bkg(listen_cmd,
exit_wait=True)", otherwise sometimes I see racy empty result.