Open("/dev/net/tun"): Permission denied

[stamerf]

Hello,

I tried to follow your "usage" tutorial but get a permission denied when trying to run "slirp4netns --configure --mtu=65520 --disable-host-loopback $(cat /tmp/pid) tap0 starting slirp, MTU=65520" as a non root user

It works when executed as root. The rights to "tun" are already chmod 666. Do you have any advice?

Thanks in advance

[ljluestc]

#!/bin/bash

# Ensure /dev/net/tun exists and has correct permissions
if [ ! -e /dev/net/tun ]; then
    sudo mkdir -p /dev/net
    sudo mknod /dev/net/tun c 10 200
fi
sudo chmod 666 /dev/net/tun

# Add user to the tun group (if it exists)
if grep -q tun /etc/group; then
    sudo usermod -aG tun $USER
    sudo chown root:tun /dev/net/tun
    echo "Added user to the 'tun' group. Please log out and log back in."
else
    echo "The 'tun' group does not exist. Creating it..."
    sudo groupadd tun
    sudo usermod -aG tun $USER
    sudo chown root:tun /dev/net/tun
    echo "Added user to the 'tun' group. Please log out and log back in."
fi

# Grant CAP_NET_ADMIN capability to slirp4netns
sudo setcap cap_net_admin+ep /usr/bin/slirp4netns

# Run slirp4netns
slirp4netns --configure --mtu=65520 --disable-host-loopback $(cat /tmp/pid) tap0