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Message-ID: <c3b29cc0-f352-468d-8030-00ed6de3e319@hartkopp.net>
Date: Sat, 20 Jan 2024 09:18:50 +0100
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Subject: Re: [PATCH v2] can: bcm: add recvmsg flags for own, local and remote
 traffic
To: Nicolas Maier <nicolas.maier.dev@gmail.com>,
 Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
 Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>,
 Paolo Abeni <pabeni@redhat.com>, Jonathan Corbet <corbet@lwn.net>,
 netdev@vger.kernel.org, linux-doc@vger.kernel.org,
 linux-kernel@vger.kernel.org
References: <4f433c14-94d5-493d-96b1-8a0180026ad5@gmail.com>
Content-Language: en-US
From: Oliver Hartkopp <socketcan@hartkopp.net>
In-Reply-To: <4f433c14-94d5-493d-96b1-8a0180026ad5@gmail.com>
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Hi Nicolas,

On 2024-01-14 15:08, Nicolas Maier wrote:
> v2:
> * add 'traffic_flags' parameter to bcm_rx_update_and_send and
>    bcm_rx_cmp_to_index, to put the flags in the can frame after its data
>    has been copied

That looks great now!

> @@ -344,8 +360,16 @@ static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
>   		 * relevant for updates that are generated by the
>   		 * BCM, where nframes is 1
>   		 */
> -		if (head->nframes == 1)
> +		if (head->nframes == 1) {
> +			pflags = bcm_flags(skb);
> +			*pflags = 0;

This initialization of the msg flags always has to be done.

I've sent a 'v3' patch that also simplifies the sock_skb_cb_check_size() 
usage:

https://lore.kernel.org/linux-can/20240120081018.2319-1-socketcan@hartkopp.net/

Please check if the changes fit for you.

I also created some user space testing code in my can-tests repo to 
prove the correct msg flags implementation:

https://github.com/hartkopp/can-tests/commit/67957def0b0035d79000f5baad93f8764ec11fc4

Works fine ;-)

Best regards,
Oliver