Hi Guillaume, On Sun, Dec 16, 2018 at 6:30 PM Guillaume Nault <g.na...@alphalink.fr> wrote: > > On Fri, Dec 14, 2018 at 11:12:42PM +0200, Sam Protsenko wrote: > > When Protocol Field Compression (PFC) is enabled, the "Protocol" field > > in PPP packet should be transmitted without leading 0x00. See section > > 6.5 in RFC 1661 for details. Let's compress protocol field if needed, > > the same way it's done in drivers/net/ppp/pptp.c. > > > > To actually enable PFC, one should issue corresponding ioctl to L2TP > > driver from user-space, like this: > > > > ioctl(fd, PPPIOCGFLAGS, &flags); > > flags |= SC_COMP_PROT; > > ioctl(fd, PPPIOCSFLAGS, &flags); > > > > It can be done e.g. from pppol2tp plugin (pppd), when pcomp option was > > negotiated with peer. > > > > Of course, we don't compress Protocol field when sending LCP packets. As > > stated in RFC 1661, section 6.5: > > > > The Protocol field is never compressed when sending any LCP > > packet. This rule guarantees unambiguous recognition of LCP > > packets. > > > Again, I'm sorry, but I must oppose this change. Although I'm lacking > time to keep sanitising L2TP, at least I'd like to avoid making the > situation worse. > > L2TP's uapi is already messy enough. Please don't add non-L2TP features > there. > > Activating PFC should be done on PPP file descriptors, not no L2TP > sockets. We certainly don't want L2TP to snoop on PPP data, much less > modify them.
Makes sense. I thought about this, too, just found that it's done that way in PPTP code and decided not to be too smart about this. Let me try and re-work this one. Will send v2 soon. Thanks.
