> From: Mike Belopuhov <m...@belopuhov.com> > Date: Wed, 28 Nov 2012 22:21:07 +0100 > > On Wed, Nov 28, 2012 at 8:21 PM, Mark Kettenis <mark.kette...@xs4all.nl> > wrote: > >> Date: Wed, 28 Nov 2012 17:39:24 +0100 > >> From: Reyk Floeter <r...@openbsd.org> > >> > >> Hi, > >> > >> inspired by mikeb@'s clonable bpf patch, this slightly more complex > >> diff implements clonable interface support to tun(4). > >> > >> The idea is to split the fixed relation between device minor number > >> (/dev/tunX) and interface unit (ifconfig tunY). In difference to the > >> current tun(4) implementation, opening /dev/tun0 will first do nothing > >> and return an unuseable device. You first have to call the new > >> TUNSIFUNIT to assign/request a specified interface unit. > > > > Why? Because people don't realize they need to run MAKEDEV to get > > more than four tun(4) devices? > > > >> Drawback: This diff would require to patch all the existing users of > >> /dev/tun* in ports and the tree to add the TUNSIFUNIT ioctl. The > >> benefit is that you don't have to MAKEDEV all the tuns anymore and can > >> open up to around 1024 active tun(4) interfaces (with the specinfo > >> patch). > > > > That's a pretty big drawback. > > > > third party software has to be patched anyways, since tun is not > standard.
But currently /dev/tunN is usable from any programming language that that can do reads and writes. With Reyk's changes you need to do an ioctl even for basic usage, which is at best quirky in languages other than C/C++. That feels like a step backward to me.
