Re: [EXTERNAL] [PATCH] netpoll: support sending over raw IP interfaces

From: Mark <mark@yotsuba.nl>
To: Ratheesh Kannoth <rkannoth@marvell.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Hans de Goede <hdegoede@redhat.com>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Breno Leitao <leitao@debian.org>, Ingo Molnar <mingo@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Paolo Abeni <pabeni@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [EXTERNAL] [PATCH] netpoll: support sending over raw IP interfaces
Date: Thu, 21 Mar 2024 13:33:17 +0100	[thread overview]
Message-ID: <4ACBB9C7-EFF5-47CA-9A8A-114209AE7953@yotsuba.nl> (raw)
In-Reply-To: <MWHPR1801MB191845C94DD80E4CD6C8C962D32D2@MWHPR1801MB1918.namprd18.prod.outlook.com>

Hi Ratheesh,

> Op 18 mrt 6 Reiwa, om 15:06 heeft Ratheesh Kannoth <rkannoth@marvell.com> het volgende geschreven:
> 
>> […]
> Is below network topology possible ?  
> Netpoll()- ------> netdev A ----> raw interface 
> Where netdev A's  netdev->header_ops != NULL

I believe so, this is not uncommon in tunnel devices like gretap.
However, those fully encapsulate the link layer header in the packet
to the lower interface. I am not aware of a interface driver that removes
a header upon xmit, so to speak. However, I have just posted a v2 that
instead uses the documented `dev_has_header()` API, which seems to fit the
check exactly, here:

https://lore.kernel.org/netdev/20240321122003.20089-1-mark@yotsuba.nl/T/

I hope this change manages to mitigate your concerns. :-)

> […]

Thanks and regards,
Mark