[PATCH v2 1/2] net/mlx5: enhance socket file path

[Stephen Hemminger]

On Fri, 21 Mar 2025 21:27:49 +0800
Yang Ming <ming.1.yang at nokia-sbell.com> wrote:

> The directory /var/tmp may not be writable in a container's
> read-only mode. To address this issue, use the DPDK runtime
> directory as an alternative when /var/tmp is not writable.
> 
> Cc: bingz at nvidia.com
> Cc: dsosnowski at nvidia.com
> Cc: stephen at networkplumber.org
> Cc: julien.meunier at nokia.com
> 
> Signed-off-by: Yang Ming <ming.1.yang at nokia-sbell.com>
> ---
>  drivers/net/mlx5/linux/mlx5_socket.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/mlx5/linux/mlx5_socket.c b/drivers/net/mlx5/linux/mlx5_socket.c
> index 6ce0e59643..270a105f1d 100644
> --- a/drivers/net/mlx5/linux/mlx5_socket.c
> +++ b/drivers/net/mlx5/linux/mlx5_socket.c
> @@ -20,7 +20,8 @@
>  
>  /* PMD socket service for tools. */
>  
> -#define MLX5_SOCKET_PATH "/var/tmp/dpdk_net_mlx5_%d"
> +#define MLX5_SOCKET_DPATH "/var/tmp"
> +#define MLX5_SOCKET_FNAME "dpdk_net_mlx5"
>  #define MLX5_ALL_PORT_IDS 0xffff

Using /tmp or /var/tmp is non-standard on modern Linux distros.
Systemd based systems use /run for this.
Would be better to use abstract sockets, but that might break some containers.

Example:
$ ss -x | awk '{ print $5}' | grep -v '^@' | grep -v '*' | sort -u
/home/shemminger/.cache/ibus/dbus-d8xKr3Ya
Local
/run/dbus/system_bus_socket
/run/gdm3/dbus/dbus-6Kd7KbFO
/run/gdm3/dbus/dbus-RNBHo0m9
/run/systemd/io.systemd.ManagedOOM
/run/systemd/journal/dev-log
/run/systemd/journal/socket
/run/systemd/journal/stdout
/run/systemd/notify
/run/systemd/oom/io.systemd.ManagedOOM
/run/user/1000/at-spi/bus
/run/user/1000/bus
/run/user/1000/.dbus-proxy/a11y-bus-proxy-HBPCF3
/run/user/1000/.dbus-proxy/session-bus-proxy-1HPCF3
/run/user/1000/.dbus-proxy/system-bus-proxy-HIPCF3
/run/user/1000/emacs/server
/run/user/1000/.flatpak-helper/pkcs11-flatpak-16622
/run/user/1000/gvfsd/socket-r1TYSmLV
/run/user/1000/gvfsd/socket-Rk6Pe47X
/run/user/1000/pipewire-0
/run/user/1000/pipewire-0-manager
/run/user/1000/pulse/native
/run/user/1000/speech-dispatcher/speechd.sock
/run/user/1000/wayland-0
/run/user/1000/wayland-proxy-4315