On Fri, 19 Apr, 2024 17:05:52 +0200 Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> wrote:
> 2024-04-18, 18:17:16 -0700, Rahul Rameshbabu wrote:
<snip>
>> + /* This datapath is insecure because it is unable to
>> + * enforce isolation of broadcast/multicast traffic and
>> + * unicast traffic with promiscuous mode on the macsec
>> + * netdev. Since the core stack has no mechanism to
>> + * check that the hardware did indeed receive MACsec
>> + * traffic, it is possible that the response handling
>> + * done by the MACsec port was to a plaintext packet.
>> + * This violates the MACsec protocol standard.
>> + */
>> + DEBUG_NET_WARN_ON_ONCE(true);
>
> If you insist on this warning (and I'm not convinced it's useful,
> since if the HW is already built and cannot inform the driver, there's
> nothing the driver implementer can do), I would move it somewhere into
> the config path. macsec_update_offload would be a better location for
> this kind of warning (maybe with a pr_warn (not limited to debug
> configs) saying something like "MACsec offload on devices that don't
> support md_dst are insecure: they do not provide proper isolation of
> traffic"). The comment can stay here.
>
I do not like the warning either. I left it mainly if it needed further
discussion on the mailing list. Will remove it in my next revision. That
said, it may make sense to advertise rx_uses_md_dst over netlink to
annotate what macsec offload path a device uses? Just throwing out an
idea here.
>> if (ether_addr_equal_64bits(hdr->h_dest,
>> ndev->dev_addr)) {
>> /* exact match, divert skb to this port */
--
Thanks,
Rahul Rameshbabu
