[PATCH v4 4/7] net/handshake: Support KeyUpdate message types

[Hannes Reinecke]

On 10/22/25 06:40, Alistair Francis wrote:
> On Tue, Oct 21, 2025 at 1:19 PM Alistair Francis <alistair23 at gmail.com> wrote:
>>
>> On Mon, Oct 20, 2025 at 4:09 PM Hannes Reinecke <hare at suse.de> wrote:
>>>
>>> On 10/17/25 06:23, alistair23 at gmail.com wrote:
>>>> From: Alistair Francis <alistair.francis at wdc.com>
>>>>
[ .. ]>>>> @@ -372,6 +384,44 @@ int tls_client_hello_psk(const struct 
tls_handshake_args *args, gfp_t flags)
>>>>    }
>>>>    EXPORT_SYMBOL(tls_client_hello_psk);
>>>>
>>>> +/**
>>>> + * tls_client_keyupdate_psk - request a PSK-based TLS handshake on a socket
>>>> + * @args: socket and handshake parameters for this request
>>>> + * @flags: memory allocation control flags
>>>> + * @keyupdate: specifies the type of KeyUpdate operation
>>>> + *
>>>> + * Return values:
>>>> + *   %0: Handshake request enqueue; ->done will be called when complete
>>>> + *   %-EINVAL: Wrong number of local peer IDs
>>>> + *   %-ESRCH: No user agent is available
>>>> + *   %-ENOMEM: Memory allocation failed
>>>> + */
>>>> +int tls_client_keyupdate_psk(const struct tls_handshake_args *args, gfp_t flags,
>>>> +                          handshake_key_update_type keyupdate)
>>>> +{
>>>> +     struct tls_handshake_req *treq;
>>>> +     struct handshake_req *req;
>>>> +     unsigned int i;
>>>> +
>>>> +     if (!args->ta_num_peerids ||
>>>> +         args->ta_num_peerids > ARRAY_SIZE(treq->th_peerid))
>>>> +             return -EINVAL;
>>>> +
>>>> +     req = handshake_req_alloc(&tls_handshake_proto, flags);
>>>> +     if (!req)
>>>> +             return -ENOMEM;
>>>> +     treq = tls_handshake_req_init(req, args);
>>>> +     treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTKEYUPDATE;
>>>> +     treq->th_key_update_request = keyupdate;
>>>> +     treq->th_auth_mode = HANDSHAKE_AUTH_PSK;
>>>> +     treq->th_num_peerids = args->ta_num_peerids;
>>>> +     for (i = 0; i < args->ta_num_peerids; i++)
>>>> +             treq->th_peerid[i] = args->ta_my_peerids[i];
>>> Hmm?
>>> Do we use the 'peerids'?
>>
>> We don't, this is just copied from the
>> tls_client_hello_psk()/tls_server_hello_psk() to provide the same
>> information to keep things more consistent.
>>
>> I can remove setting these
> 
> Actually, ktls-utils (tlshd) expects these to be set, so I think we
> should leave them as is
> 

Can't we rather fix up tlshd?
It feels really pointless, erroring out on values which are completely
irrelevant for the operation...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare at suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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