Re: [RFC v2 1/1] net/tls: allow limiting maximum record size

[Hannes Reinecke <hare@suse.de>]

On 8/21/25 08:18, Wilfred Mallawa wrote:
> On Mon, 2025-08-18 at 08:31 +0200, Hannes Reinecke wrote:
>>
> [snip]
>>> --- a/include/uapi/linux/handshake.h
>>> +++ b/include/uapi/linux/handshake.h
>>> @@ -54,6 +54,7 @@ enum {
>>>    	HANDSHAKE_A_DONE_STATUS = 1,
>>>    	HANDSHAKE_A_DONE_SOCKFD,
>>>    	HANDSHAKE_A_DONE_REMOTE_AUTH,
>>> +	HANDSHAKE_A_DONE_RECORD_SIZE_LIMIT,
>>>    
>>>    	__HANDSHAKE_A_DONE_MAX,
>>>    	HANDSHAKE_A_DONE_MAX = (__HANDSHAKE_A_DONE_MAX - 1)
>>> diff --git a/net/handshake/genl.c b/net/handshake/genl.c
>>> index f55d14d7b726..44c43ce18361 100644
>>> --- a/net/handshake/genl.c
>>> +++ b/net/handshake/genl.c
>>> @@ -16,10 +16,11 @@ static const struct nla_policy
>>> handshake_accept_nl_policy[HANDSHAKE_A_ACCEPT_HAN
>>>    };
>>>    
>>>    /* HANDSHAKE_CMD_DONE - do */
>>> -static const struct nla_policy
>>> handshake_done_nl_policy[HANDSHAKE_A_DONE_REMOTE_AUTH + 1] = {
>>> +static const struct nla_policy
>>> handshake_done_nl_policy[HANDSHAKE_A_DONE_RECORD_SIZE_LIMIT + 1] =
>>> {
>>
> Hey Hannes,
> 
> I did consider using HANDSHAKE_A_DONE_MAX, but wasn't sure if the
> existing convention is there for some reason. But I can switch over if
> you think that is best.
> 
I guess, no reason, just an oversight.

>> Shouldn't that be 'HANDSHAKE_A_DONE_MAX'?
>>
>>>    	[HANDSHAKE_A_DONE_STATUS] = { .type = NLA_U32, },
>>>    	[HANDSHAKE_A_DONE_SOCKFD] = { .type = NLA_S32, },
>>>    	[HANDSHAKE_A_DONE_REMOTE_AUTH] = { .type = NLA_U32, },
>>> +	[HANDSHAKE_A_DONE_RECORD_SIZE_LIMIT] = { .type = NLA_U32,
>>> },
>>>    };
>>>    
>>>    /* Ops table for handshake */
>>> @@ -35,7 +36,7 @@ static const struct genl_split_ops
>>> handshake_nl_ops[] = {
>>>    		.cmd		= HANDSHAKE_CMD_DONE,
>>>    		.doit		= handshake_nl_done_doit,
>>>    		.policy		=
>>> handshake_done_nl_policy,
>>> -		.maxattr	= HANDSHAKE_A_DONE_REMOTE_AUTH,
>>> +		.maxattr	=
>>> HANDSHAKE_A_DONE_RECORD_SIZE_LIMIT,
>>
>> HANDSHAKE_A_DONE_MAX - 1?
> 
> Shouldn't it be `HANDSHAKE_A_DONE_MAX`? Unless the existing
> `HANDSHAKE_A_DONE_REMOTE_AUTH` is incorrect?
> 
Yes, you are right.

Cheers,
Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich