Qemu tun/tap networking and problem with 2.6.18

Question

Kernel 2.6.18 introduced some security restrictions so that tun devices can't be created by normal users (see: http://www.friedhoff.org/fscaps.html#Qemu)
So if you start qemu now you will get the following error:
warning: could not configure /dev/net/tun: no virtual network emulation
Could not initialize device 'tap'
According to this post you have to use tunctl in order to fix that (or run qemu as root, or patch the kernel, I think neither of these options are a real solution)
I have the following wrapper script for qemu (called qemu.sh) (I have also tried the full script from the post mentioned above):
#!/bin/sh
sudo tunctl -u enrique
qemu $@ -net nic -net tap
sudo tunctl -d tap0
enrique is my user name. The tun module has been loaded. It still fails with the above error when I run qemu like this:
qemu.sh -m 128 -hda hda.img -boot c

Answer 1

Hm, I'm glad that it works for you, but it still does not work for me. And as I said in my initial post, I have tried the full script from that qemu forum, and it did not work either.
Mayby I have made a stupid mistake somewhere, so here is my complete current setup:
my qemu wrapper script (qemu.sh):
#!/bin/sh
echo "Loading kqemu"
sudo modprobe kqemu major=0
echo "Loading tun"
sudo modprobe tun
sudo chgrp users /dev/kqemu
sudo chmod g+rw /dev/kqemu
USERID=`whoami`
iface=`sudo tunctl -b -u $USERID`
sudo tunctl -u $USERID -t $iface
qemu $@ -net nic -net tap,ifname=$iface
sudo tunctl -d $iface
/etc/qemu-ifup:
#!/bin/sh
echo "Executing /etc/qemu-ifup"
sudo ifconfig eth0 down
sudo brctl addbr br0
sudo ifconfig eth0 0.0.0.0 up
sudo ifconfig br0 192.168.0.2
sudo brctl stp br0 off
sudo brctl setfd br0 1
sudo brctl sethello br0 1
sudo brctl addif br0 eth0
sudo route add default gw 192.168.0.1
echo "Bringing up $1 for bridged mode..."
sudo ifconfig $1 up
sudo brctl addif br0 $1
when I run qemu.sh I use the following parameters:
qemu.sh -kernel-kqemu -m 128 -hda debian-hda.img -boot c
I get the following output: (please notice that qemu never reaches /etc/qemu-ifup)
Loading kqemu
Loading tun
Set 'tap0' persistent and owned by uid 1001
warning: could not open /dev/net/tun: no virtual network emulation
Could not initialize device 'tap'
Set 'tap0' nonpersistent
(uid 1001 is my correct uid)
ls -l /dev/net/tun:
crw-rw---- 1 root root 10, 200 29 nov 20:18 /dev/net/tun
Last part of my dmest:
QEMU Accelerator Module version 1.3.0, Copyright (c) 2005-2006 Fabrice Bellard
This is a proprietary product. Read the LICENSE file for more information
Redistribution of this module is prohibited without authorization
KQEMU installed, max_locked_mem=517912kB.
tun: Universal TUN/TAP device driver, 1.6
tun: (C) 1999-2004 Max Krasnyansky <maxk>