On Tue, 25 Feb 2025 07:20:08 +0800 Jiayuan Chen wrote: > I apologize for the mistake, I've investigated the original maintainer's > user-space PPP implementation and libpcap's behavior, and found that > initializing the first byte to 0 or 1 is necessary, it indicates > direction, which is used in libpcap to distinguish between inbound and > outbound traffic. > For more details, please refer to the cover letter of my v3 patch. > > https://lore.kernel.org/linux-ppp/20250222092556.274267-1-jiayuan.chen@xxxxxxxxx/T/#t You can still use the htons() there, it's cleaner.