On Thu, Nov 29, 2012 at 10:59 AM, Mike Belopuhov <m...@belopuhov.com> wrote:
>> 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.
>
> sure, we can totally leave tun for legacy use in the shell scripts.
> so i guess reyk should go ahead and implement a dynamic tun interface
> (dun?) with whatever semantics we need and want.
Or even better duh? ;-) I wrote this diff because I wanted to
experiment with clonable device nodes, I still don't like the fact
that you have to MAKEDEV a device per dynamic interface, and because
it adds some extra flexibility. But it doesn't have to go anywhere, I
didn't even waste much time with writing it yesterday in the
afternoon.
btw., I like C and it is still my favorite language (sorry, CS
people). But it shouldn't be a problem to do simple ioctls with most
other languages except shell scripts.
#!/usr/bin/perl
require "sys/ioctl.ph";
$TUNSIFUNIT = _IOC(&IOC_INOUT, ord('t'), 90, 4);
open(TUN0, "+</dev/tun0") or die "open";
ioctl(TUN0, $TUNSIFUNIT, $unit = pack("i", -1)) or die "ioctl $!";
print "Returned: tun".unpack("i", $unit)."\n";
close(TUN0);
reyk
