Commit d154cd07 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Jakub Kicinski
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mctp: serial: enforce fixed MTU 



The current serial driver requires a maximum MTU of 68, and it doesn't
make sense to set a MTU below the MCTP-required baseline (of 68) either.

This change sets the min_mtu & max_mtu of the mctp netdev, essentially
disallowing changes. By using these instead of a ndo_change_mtu op, we
get the netlink extacks reported too.

Signed-off-by: default avatarJeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7bd9890f

drivers/net/mctp/mctp-serial.c

+7 −0
Original line number Diff line number Diff line
@@ -410,7 +410,14 @@ static const struct net_device_ops mctp_serial_netdev_ops = { 
static void mctp_serial_setup(struct net_device *ndev)

{

	ndev->type = ARPHRD_MCTP;



	/* we limit at the fixed MTU, which is also the MCTP-standard

	 * baseline MTU, so is also our minimum

	 */

	ndev->mtu = MCTP_SERIAL_MTU;

	ndev->max_mtu = MCTP_SERIAL_MTU;

	ndev->min_mtu = MCTP_SERIAL_MTU;



	ndev->hard_header_len = 0;

	ndev->addr_len = 0;

	ndev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;