Re: [PATCH net-next 2/3] ipv6: sr: Use HMAC-SHA1 and HMAC-SHA256 library functions

[Eric Biggers <ebiggers@kernel.org>]

On Sat, Aug 16, 2025 at 07:01:28AM +0000, Kuniyuki Iwashima wrote:
> From: Eric Biggers <ebiggers@kernel.org>
> Date: Fri, 15 Aug 2025 20:11:35 -0700
> > @@ -106,79 +95,17 @@ static struct sr6_tlv_hmac *seg6_get_tlv_hmac(struct ipv6_sr_hdr *srh)
> >  		return NULL;
> >  
> >  	return tlv;
> >  }
> >  
> > -static struct seg6_hmac_algo *__hmac_get_algo(u8 alg_id)
> > -{
> > -	struct seg6_hmac_algo *algo;
> > -	int i, alg_count;
> > -
> > -	alg_count = ARRAY_SIZE(hmac_algos);
> > -	for (i = 0; i < alg_count; i++) {
> > -		algo = &hmac_algos[i];
> > -		if (algo->alg_id == alg_id)
> > -			return algo;
> > -	}
> > -
> > -	return NULL;
> > -}
> 
> This chunk will cause build failure when net.git is merged
> to net-next due to the patch below.  You may want to respin
> the series after this lands to net-next.
> 
> https://lore.kernel.org/netdev/20250815063845.85426-1-heminhong@kylinos.cn/

Thanks for pointing that out.  I hadn't seen that patch.  Patch 3 in my
series actually fixes the exact same problem, though in my patch it's
more of a side effect of preparing the HMAC key rather than the main
point of the patch.  If that patch lands first, I'll rebase my series.

We do need to decide whether the algorithm ID validation and key
preparation should be done in seg6_hmac_info_add() as in that patch, or
in seg6_genl_sethmac() as in my patch.  seg6_hmac_info_add() is fine I
guess, but let me know if you have a preference.

- Eric