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Message-ID: <d645f6e1-d977-e2ea-1f8e-0b5458c9438e@openvpn.net>
Date:   Thu, 28 Jul 2022 09:44:18 +0200
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Subject: Re: [RFC 1/1] net: introduce OpenVPN Data Channel Offload (ovpn-dco)
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To:     Andrew Lunn <andrew@lunn.ch>
Cc:     netdev@vger.kernel.org, David Miller <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org
References: <20220719014704.21346-1-antonio@openvpn.net>
 <20220719014704.21346-2-antonio@openvpn.net> <YtbPtkF1Ah9xrBam@lunn.ch>
From:   Antonio Quartulli <antonio@openvpn.net>
Organization: OpenVPN Inc.
In-Reply-To: <YtbPtkF1Ah9xrBam@lunn.ch>
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Hi,

On 19/07/2022 17:37, Andrew Lunn wrote:
>> +static int ovpn_net_change_mtu(struct net_device *dev, int new_mtu)
>> +{
>> +	if (new_mtu < IPV4_MIN_MTU ||
>> +	    new_mtu + dev->hard_header_len > IP_MAX_MTU)
>> +		return -EINVAL;
> 
> If you set dev->min_mtu and dev->max_mtu, the core will validate this
> for you, see dev_validate_mtu().

Yeah, thanks for the pointer.

> 
>> +static int ovpn_get_link_ksettings(struct net_device *dev,
>> +				   struct ethtool_link_ksettings *cmd)
>> +{
>> +	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported, 0);
>> +	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising, 0);
> 
> These two should not be needed. Look at tun, veth etc, they don't set
> them.

I found this in tun.c:

3512         ethtool_link_ksettings_zero_link_mode(cmd, supported);
3513         ethtool_link_ksettings_zero_link_mode(cmd, advertising);

Which seems a more appropriate version of my code, no?

Regards,

-- 
Antonio Quartulli
OpenVPN Inc.