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

[Hannes Reinecke]

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@xxxxxxx                                +49 911 74053 688
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