Re: [PATCH net] l2tp: ppp: use max L2TP header size for PPP channel hdrlen

[Jakub Kicinski]

On Fri, 13 Mar 2026 11:47:31 +0800 Qingfang Deng wrote:
> chan.hdrlen is read once at channel registration by
> ppp_register_net_channel(), and used to set the PPP net device's
> hard_header_len. It was set to PPPOL2TP_L2TP_HDR_SIZE_NOSEQ (6), which
> is 4 bytes too small if sequence numbers are later enabled via
> setsockopt(PPPOL2TP_SO_SENDSEQ), causing unnecessary skb reallocations
> on the TX path.

If the main effect of this patch is that we avoid reallocations I think
this is an optimization and should go to net-next? If there's more to
it please explain in the commit msg a bit more.
-- 
pw-bot: cr