Re: [PATCH] net: macsec: use TX SCI as MAC address

From: Sabrina Dubroca
Date: Tue Aug 08 2023 - 12:44:33 EST


2023-08-08, 17:14:29 +0300, Radu Pirea (NXP OSS) wrote:
> According to IEEE 802.1AE the SCI comprises the MAC address and the port
> identifier.

I don't think the SCI needs to be composed of the actual device's MAC
address. 8.2.1 says that the MAC address *can* be used to compose the
SCI, but doesn't mandate it.

If you want the SCI to match the device's MAC address, why not use
IFLA_MACSEC_PORT instead?

> If a new MACsec interface is created with a specific TX SCI, use that
> SCI to set the MAC address of the new interface.
>
> Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@xxxxxxxxxxx>
> ---
> drivers/net/macsec.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
> index 984dfa5d6c11..6db69daf880d 100644
> --- a/drivers/net/macsec.c
> +++ b/drivers/net/macsec.c
> @@ -4103,12 +4103,14 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
> /* need to be already registered so that ->init has run and
> * the MAC addr is set
> */
> - if (data && data[IFLA_MACSEC_SCI])
> + if (data && data[IFLA_MACSEC_SCI]) {
> sci = nla_get_sci(data[IFLA_MACSEC_SCI]);
> - else if (data && data[IFLA_MACSEC_PORT])
> + eth_hw_addr_set(dev, (u8 *)&sci);
> + } else if (data && data[IFLA_MACSEC_PORT]) {
> sci = dev_to_sci(dev, nla_get_be16(data[IFLA_MACSEC_PORT]));
> - else
> + } else {
> sci = dev_to_sci(dev, MACSEC_PORT_ES);
> + }
>
> if (rx_handler && sci_exists(real_dev, sci)) {
> err = -EBUSY;
> --
> 2.34.1
>

--
Sabrina