From owner-freebsd-hackers Thu Jan 1 10:22:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.7/8.8.7) id KAA27570 for hackers-outgoing; Thu, 1 Jan 1998 10:22:05 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from awfulhak.demon.co.uk (awfulhak.demon.co.uk [158.152.17.1]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id KAA27559; Thu, 1 Jan 1998 10:21:45 -0800 (PST) (envelope-from brian@awfulhak.org) Received: from gate.lan.awfulhak.org (localhost [127.0.0.1]) by awfulhak.demon.co.uk (8.8.7/8.8.7) with ESMTP id SAA19774; Thu, 1 Jan 1998 18:19:50 GMT (envelope-from brian@gate.lan.awfulhak.org) Message-Id: <199801011819.SAA19774@awfulhak.demon.co.uk> X-Mailer: exmh version 2.0.1 12/23/97 To: Joerg Wunsch cc: Brian Somers , John-Mark Gurney , freebsd-bugs@hub.freebsd.org, freebsd-hackers@FreeBSD.ORG Subject: Re: kern/5404: slXX slip (tun & ppp) interfaces always point to point In-reply-to: Your message of "Thu, 01 Jan 1998 18:50:07 +0100." <19980101185007.59283@uriah.heep.sax.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 01 Jan 1998 18:19:50 +0000 From: Brian Somers Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk > As Brian Somers wrote: > > > I intended to remove the possibility of netmasks and broadcast > > addresses for pointopoint links, but retrospectively, this will break > > the ability to attach to a peer that proxy arps for you (well, it's > > already broken). > > Why? Proxyarping is done on the Ethernet interface, and this one > still has a netmask. I mean in the sense that the client cannot broadcast on the network at the other end of the pointopoint link, or can it ? I guess you could set up a static route for the broadcast address. That should work. I haven't tried. > > I would suggest (and I'm willing to do it) adding the ability to use > > SIOCSIFPOINTOPOINT and SIOCGIFPOINTOPOINT on sl* ppp* and tun*. The > > default is that these interfaces are pointopoint, but you can change > > that by issuing the `S' ioctl. > > Nope, you can't. `p2p' is an unchangeable attribute of an interface, > see IFF_CANTCHANGE in /sys/net/if.h. Perhaps IFF_POINTOPOINT should be settable while the interface is down only. In the `tun' case (I'm not sure about pppX & slX) it could be done at the ioctl(TUNSIFINFO) stage - the `dummy' part of the struct tuninfo could be changed to specify the interface flags. But this would break existing code that never initialises `dummy' to zero (which, it really should, although ppp doesn't :-(). OpenBSD already has this requirement. The `dummy' part is replaced by `flags' and those flags must specify IFF_POINTOPOINT if you want that. I'm not actually sure what happens there if you don't specify IFF_POINTOPOINT. > -- > cheers, J"org > > joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE > Never trust an operating system you don't have sources for. ;-) -- Brian , , Don't _EVER_ lose your sense of humour....