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novpn: Bypass VPN for specific apps [Linux / OpenVPN]
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| #!/bin/bash | |
| # === INFO === | |
| # NoVPN | |
| # Description: Bypass VPN tunnel for applications run through this tool. | |
| VERSION="3.0.0" | |
| # Author: KrisWebDev | |
| # Requirements: Linux with kernel > 2.6.4 (released in 2008). | |
| # This version is tested on Ubuntu 14.04 and 19.10 with bash. | |
| # Main dependencies are automatically installed. | |
| # Script will guide you for iptables upgrade if needed. | |
| # Note: For security, this script will disable IPv6, even after --clean. | |
| # === LICENSE === | |
| # This program is free software: you can redistribute it and/or modify | |
| # it under the terms of the GNU General Public License as published by | |
| # the Free Software Foundation, either version 3 of the License, or | |
| # (at your option) any later version. | |
| # | |
| # This program is distributed in the hope that it will be useful, | |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| # GNU General Public License for more details. | |
| # | |
| # You should have received a copy of the GNU General Public License | |
| # along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| # === CONFIGURATION === | |
| # Find your real (non-VPN) interface manually with: ip route | |
| # Guess with: ip route | grep "default via " | sed -n '/^.* dev \([-_[:alnum:]]\{1,\}\).*$/s//\1/p' | grep -v tun | |
| real_interface="enp0s3" | |
| # Warn if real interface guessed at startup doesn't match above setting | |
| real_interface_check_warn=true | |
| # === ADVANCED CONFIGURATION === | |
| cgroup_name="novpn" # Better keep it with purely lowercase alphabetic & underscore | |
| net_cls_classid="0x00110011" # Anything from 0x00000001 to 0xFFFFFFFF | |
| ip_table_fwmark="11" # Anything from 1 to 2147483647 | |
| ip_table_number="11" # Anything from 1 to 252 | |
| # === CODE === | |
| real_interface_gateway=`ip route | grep "dev ${real_interface}" | awk '/^default/ { print $3 }'` | |
| # Handle options | |
| action="command" | |
| background=false | |
| skip=false | |
| check_sudo_conf=false | |
| init_nb_args="$#" | |
| cgroup_version=1 | |
| while [ "$#" -gt 0 ]; do | |
| case "$1" in | |
| -b|--background) background=true; shift 1;; | |
| -o|--outside) action="outside"; shift 1;; | |
| -i|--inside) action="inside"; shift 1;; | |
| -l|--list) action="list"; shift 1;; | |
| -s|--skip) skip=true; shift 1;; | |
| -f|--force) check_sudo_conf=true; shift 1;; | |
| --sudok) sudok=true; shift 1;; | |
| -g|--cgroup) cgroup_name="$2"; shift 1; shift 1;; | |
| -2|--cgv2) cgroup_version=2; shift 1;; | |
| -I|--info) action="info"; shift 1;; | |
| -c|--clean) action="clean"; shift 1;; | |
| -h|--help) action="help"; shift 1;; | |
| -v|--version) echo "novpn v$VERSION"; exit 0;; | |
| -*) echo "Unknown option: $1. Try --help." >&2; exit 1;; | |
| *) break;; # Start of COMMAND or LIST | |
| esac | |
| done | |
| if { [ "$#" -lt 1 ] && [ "$action" == "command" ]; } || [ "$action" = "help" ] ; then | |
| me=`basename "$0"` | |
| echo -e "Usage : \e[1m$me [\e[4mOPTIONS\e[24m] [\e[4mCOMMAND\e[24m [\e[4mCOMMAND PARAMETERS\e[24m]]\e[0m" | |
| echo -e " or : \e[1m$me [\e[4mOPTIONS\e[24m] { --outside | --inside } \e[4mLIST\e[24m\e[0m" | |
| echo -e "Run command outside the VPN tunnel interface." | |
| echo | |
| echo -e "\e[1m\e[4mOPTIONS\e[0m:" | |
| echo -e "\e[1m-b, --background\e[0m Start \e[4mCOMMAND\e[24m as background process (release the shell)." | |
| echo -e "\e[1m-o, --outside \e[4mLIST\e[24m\e[0m Move running process \e[4mLIST\e[24m outside tunnel. \e[1mBROKEN!\e[0m" | |
| echo -e "\e[1m-i, --inside \e[4mLIST\e[24m\e[0m Move back running process \e[4mLIST\e[24m inside tunnel." | |
| echo -e "\e[1m-l, --list\e[0m List processes going outside tunnel." | |
| echo -e "\e[1m-s, --skip\e[0m Don't setup system config (never ask for root);\n just perform public routing test and run \e[4mCOMMAND\e[24m." | |
| echo -e "\e[1m--sudok\e[0m Drop sudo rights with \"sudo -K\" before executing \e[4mCOMMAND\e[24m." | |
| echo -e "\e[1m-f, --force\e[0m Force setup of system config (always ask for root)." | |
| echo -e "\e[1m-g, --cgroup \e[4mNAME\e[24m\e[0m Specify cgroup name (cgroup v1) or relative path (cgroup v2). Default: \"$cgroup_name\"." | |
| echo -e "\e[1m-2, --cgv2\e[0m Use Control Groups version 2 if supported." | |
| echo -e "\e[1m-I, --info\e[0m Display debug information and exit." | |
| echo -e "\e[1m-c, --clean\e[0m Move back all proceses to initial routing settings and remove system config." | |
| echo -e "\e[1m-v, --version\e[0m Print this program version." | |
| echo -e "\e[1m-h, --help\e[0m This help." | |
| echo | |
| echo -e "\e[1m\e[4mLIST\e[0m: List o f process ID or names separated by spaces." | |
| exit 1 | |
| fi | |
| ip_table_name="$cgroup_name" | |
| # This program can't ask for root outside terminal | |
| if [ ! -t 1 ] && [ "$(id -u)" -ne 0 ]; then | |
| skip=true | |
| fi | |
| if [ "$skip" = true ]; then | |
| if [ "$action" = "clean" ]; then | |
| echo -e "\e[31mCan't use --skip with --clean. Aborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| if [ "$check_sudo_conf" = true ]; then | |
| echo -e "\e[31mCan't use --skip with --force. Aborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| fi | |
| # Interface check | |
| if [ "$real_interface_check_warn" = true ]; then | |
| real_interface_guess="$(ip route | grep "default via " | sed -n '/^.* dev \([-_[:alnum:]]\{1,\}\).*$/s//\1/p' | grep -v tun)" | |
| if [ ! -z "$real_interface_guess" ] && [ "$real_interface" != "$real_interface_guess" ]; then | |
| echo -e "\e[93mWarning: Guessed real interface is \"$real_interface_guess\" but this script is configured to use \"$real_interface\"." | |
| echo -e "Manually edit the script settings if needed.\e[0m" >&2 | |
| fi | |
| fi | |
| # Find/Check cgroup system folders | |
| cgroup_v1_net_cls="/sys/fs/cgroup/net_cls" | |
| cgroup_v2_root="/sys/fs/cgroup" | |
| cgroup_base="/sys/fs/cgroup" | |
| find_root(){ | |
| # Find cgroup v2 root filesystem | |
| if [ "$cgroup_version" = 2 ]; then | |
| [ -f "$cgroup_v2_root""/cgroup.procs" ] || cgroup_v2_root="/sys/fs/cgroup/unified" | |
| [ -f "$cgroup_v2_root""/cgroup.procs" ] || cgroup_v2_root="$(mount -t cgroup2 | head -n1 | grep -oP '^cgroup2 on \K\S+')" | |
| if [ ! -f "$cgroup_v2_root""/cgroup.procs" ]; then | |
| echo -e "\e[31mCan't find a valid cgroup v2 mounted filesystem. Aborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| echo "Using cgroups v2. Found valid cgroup v2 filesystem at $cgroup_v2_root" | |
| cgroup_base="$cgroup_v2_root" | |
| else | |
| # Find cgroup v1 net_cls folder | |
| [ -f "$cgroup_v1_net_cls""/cgroup.procs" ] || cgroup_v1_net_cls="$(mount -t cgroup | grep net_cls | head -n1 | grep -oP '^cgroup on \K\S+')" | |
| if [ ! -f "$cgroup_v1_net_cls""/cgroup.procs" ]; then | |
| echo -e "\e[31mCan't find a valid cgroup v1 net_cls folder. Aborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| echo "Using cgroups v1. Found valid cgroup v1 net_cls folder at $cgroup_v1_net_cls" | |
| cgroup_base="$cgroup_v1_net_cls" | |
| fi | |
| } | |
| # Prepare variables | |
| if [ "$cgroup_version" = 2 ]; then | |
| iptables_arg="--path $cgroup_name" | |
| else | |
| iptables_arg="--cgroup $net_cls_classid" | |
| fi | |
| # Helper functions | |
| # Check the presence of required system packages | |
| check_install_package(){ | |
| nothing_installed=1 | |
| for package_name in "$@" | |
| do | |
| if ! dpkg -s "$package_name" &> /dev/null; then | |
| if [ "$package_name" = "cgroup-tools" ]; then | |
| if [ -x "$(command -v cgexec)" ]; then | |
| continue | |
| fi | |
| if [ "$(apt-cache search --names-only '^cgroup-tools$' | wc -l)" -eq 0 ]; then | |
| echo "cgroups-tools is not available in apt cache, falling back to cgroup-bin install" | |
| package_name="cgroup-bin" | |
| fi | |
| fi | |
| echo "Installing $package_name" | |
| read -p "Press enter to continue or Ctrl+C to cancel" | |
| sudo apt-get install "$package_name" | |
| nothing_installed=0 | |
| fi | |
| done | |
| return $nothing_installed | |
| } | |
| check_package(){ | |
| for package_name in "$@" | |
| do | |
| if ! dpkg -s "$package_name" &> /dev/null; then | |
| if [ "$package_name" = "cgroup-tools" ]; then | |
| # Ignore if cgexec is available (e.g. through cgroup-bin) | |
| if [ ! -x "$(command -v cgexec)" ]; then | |
| true | |
| return | |
| fi | |
| else | |
| true | |
| return | |
| fi | |
| fi | |
| done | |
| false | |
| } | |
| # Main functions | |
| # Check/Install dependencies | |
| install_dependencies(){ | |
| if check_install_package cgroup-lite traceroute; then # Removed cgroup-tools | |
| if check_package cgroup-lite traceroute; then # Removed cgroup-tools | |
| echo "Required packages not properly installed. Aborting." >&2 | |
| exit 1 | |
| fi | |
| fi | |
| iptables_version=$(iptables --version | grep -oP "iptables v\K[0-9.]+") | |
| if dpkg --compare-versions "$iptables_version" "lt" "1.6"; then | |
| echo -e "\e[31mYou need iptables 1.6.0+. Please install manually. Aborting.\e[0m" >&2 | |
| echo "Find latest iptables at http://www.netfilter.org/projects/iptables/downloads.html" >&2 | |
| echo "Commands to install iptables 1.8.4:" >&2 | |
| echo -e "\e[34msudo apt-get install dh-autoreconf bison flex | |
| cd /tmp | |
| curl https://netfilter.org/projects/iptables/files/iptables-1.8.4.tar.bz2 | tar xj | |
| cd iptables-1.8.4 | |
| ./configure --prefix=/usr \\ | |
| --sbindir=/sbin \\ | |
| --disable-nftables \\ | |
| --enable-libipq \\ | |
| --with-xtlibdir=/lib/xtables \\ | |
| && make \\ | |
| && sudo make install | |
| iptables --version\e[0m" >&2 | |
| exit 1 | |
| fi | |
| } | |
| # Check and setup iptables - requires root even for check | |
| iptable_checked=false | |
| setup_config(){ | |
| #if [ "$cgroup_version" = 1 ]; then | |
| if [ ! -d "$cgroup_base/$cgroup_name" ]; then | |
| echo "Creating control group at \"$cgroup_base/$cgroup_name\"" >&2 | |
| sudo mkdir -p "$cgroup_base/$cgroup_name" | |
| sudo chown -R "$USER":"`id -g -n "$USER"`" "$cgroup_base/$cgroup_name" | |
| check_sudo_conf=true | |
| fi | |
| cgroup_owner=`stat -c "%U" "$cgroup_base/$cgroup_name/cgroup.procs"` | |
| if [ "$cgroup_owner" != "`id -g -n "$USER"`" ] && [ "$EUID" -ne 0 ]; then | |
| echo -e "\e[93mWARNING: Folder \"$cgroup_base/$cgroup_name/cgroup.procs\" already exists, it is owned by someone else ($cgroup_owner) and you are not root.\e[0m" >&2 | |
| fi | |
| # Redundant | |
| #if [ -z "`lscgroup net_cls:$cgroup_name`" ] || [ `stat -c "%U" "$cgroup_v1_net_cls/${cgroup_name}/tasks"` != "$USER" ]; then | |
| # echo "Creating cgroup net_cls:${cgroup_name}. User $USER will be able to move tasks in it without root permissions." >&2 | |
| # sudo cgcreate -t "$USER":"$USER" -a `id -g -n "$USER"`:`id -g -n "$USER"` -g net_cls:"$cgroup_name" | |
| # check_sudo_conf=true | |
| #fi | |
| if [ "$cgroup_version" = 1 ] && [ `cat "$cgroup_v1_net_cls/$cgroup_name/net_cls.classid" | xargs -n 1 printf "0x%08x"` != "$net_cls_classid" ]; then | |
| echo "Applying net_cls class identifier $net_cls_classid to cgroup $cgroup_name" >&2 | |
| echo "$net_cls_classid" | sudo tee "$cgroup_v1_net_cls/$cgroup_name/net_cls.classid" > /dev/null | |
| check_sudo_conf=true | |
| fi | |
| if ! grep -E "^${ip_table_number}\s+$ip_table_name" /etc/iproute2/rt_tables &>/dev/null; then | |
| if grep -E "^${ip_table_number}\s+" /etc/iproute2/rt_tables; then | |
| echo -e "\e[31mERROR: Table ${ip_table_number} already exists in /etc/iproute2/rt_tables with a different name than $ip_table_name.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| echo "Creating ip routing table: number=$ip_table_number name=$ip_table_name" >&2 | |
| echo "$ip_table_number $ip_table_name" | sudo tee -a /etc/iproute2/rt_tables > /dev/null | |
| check_sudo_conf=true | |
| fi | |
| if ! ip rule list | grep " lookup $ip_table_name" | grep " fwmark " &>/dev/null; then | |
| echo "Adding rule to use ip routing table $ip_table_name for packets with firewall mark $ip_table_fwmark" >&2 | |
| sudo ip rule add fwmark "$ip_table_fwmark" table "$ip_table_name" | |
| check_sudo_conf=true | |
| fi | |
| if [ -z "`ip route list table "$ip_table_name" default via $real_interface_gateway dev ${real_interface} 2>/dev/null`" ]; then | |
| echo "Adding default route in ip routing table $ip_table_name via $real_interface_gateway dev $real_interface" >&2 | |
| sudo ip route add default via "$real_interface_gateway" dev "$real_interface" table "$ip_table_name" | |
| # Useless? | |
| echo "Flushing ip route cache" >&2 | |
| sudo ip route flush cache | |
| check_sudo_conf=true | |
| fi | |
| if [ "`cat /proc/sys/net/ipv4/conf/all/rp_filter`" != "0" ] && [ "`cat /proc/sys/net/ipv4/conf/all/rp_filter`" != "2" ]; then | |
| echo "Unset reverse path filtering for interface \"all\"" >&2 | |
| echo 2 | sudo tee "/proc/sys/net/ipv4/conf/all/rp_filter" > /dev/null | |
| check_sudo_conf=true | |
| fi | |
| if [ "`cat /proc/sys/net/ipv4/conf/${real_interface}/rp_filter`" != "0" ] && [ "`cat /proc/sys/net/ipv4/conf/${real_interface}/rp_filter`" != "2" ]; then | |
| echo "Unset reverse path filtering for interface \"${real_interface}\"" >&2 | |
| echo 2 | sudo tee "/proc/sys/net/ipv4/conf/${real_interface}/rp_filter" > /dev/null | |
| check_sudo_conf=true | |
| fi | |
| # Only check iptables configuration if another configuration item was missing or if the test fails, as it requires root rights | |
| if [ "$check_sudo_conf" = true ]; then | |
| if ! sudo iptables -t mangle -C OUTPUT -m cgroup $iptables_arg -j MARK --set-mark "$ip_table_fwmark" 2>/dev/null; then | |
| echo "Adding iptables MANGLE rule to set firewall mark $ip_table_fwmark on packets with class identifier $net_cls_classid" >&2 | |
| sudo iptables -t mangle -A OUTPUT -m cgroup $iptables_arg -j MARK --set-mark "$ip_table_fwmark" | |
| fi | |
| if ! sudo iptables -t nat -C POSTROUTING -m cgroup $iptables_arg -o "$real_interface" -j MASQUERADE 2>/dev/null; then | |
| echo "Adding iptables NAT rule to force the packets with class identifier $net_cls_classid to exit through $real_interface" >&2 | |
| sudo iptables -t nat -A POSTROUTING -m cgroup $iptables_arg -o "$real_interface" -j MASQUERADE | |
| fi | |
| iptable_checked=true | |
| fi | |
| if [ "`cat /proc/sys/net/ipv6/conf/all/disable_ipv6`" != "1" ] || [ "`cat /proc/sys/net/ipv6/conf/""$real_interface""/disable_ipv6`" != "1" ] || [ "$check_sudo_conf" = true ]; then | |
| echo "Disabling IPv6 (not supported/implemented)" | |
| sudo ip -6 route add blackhole default metric 1 | |
| echo 1 | sudo tee "/proc/sys/net/ipv6/conf/all/disable_ipv6" > /dev/null | |
| fi | |
| } | |
| fcgexec() { | |
| "$@" | |
| } | |
| # Test if config is working, IPv4 only | |
| test_routing(){ | |
| #exit_ip="$(fcgexec -g net_cls:"$cgroup_name" traceroute -n -m 1 8.8.8.8 | sed -n '2{p;q}' | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)" | |
| exit_ip="$(fcgexec traceroute -n -m 1 8.8.8.8 | sed -n '2{p;q}' | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)" | |
| if [ -z "$exit_ip" ]; then | |
| # Old traceroute | |
| #exit_ip="$(fcgexec -g net_cls:"$cgroup_name" traceroute -m 1 8.8.8.8 | sed -n '2{p;q}' | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)" | |
| exit_ip="$(fcgexec traceroute -m 1 8.8.8.8 | sed -n '2{p;q}' | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)" | |
| if [ -z "$exit_ip" ]; then | |
| echo -e "\e[31mTest failed: Unable to determine source exit IP (found \"$exit_ip\").\e[0m" >&2 | |
| if [ "$skip" = true ]; then | |
| echo -e "\e[31mYou should remove --skip option to perform setup.\e[0m" >&2 | |
| fi | |
| return 0 | |
| fi | |
| fi | |
| if [ -z "$real_interface_gateway" ]; then | |
| echo -e "\e[31mTest failed: Unable to determine real interface gateway IP (found \"$real_interface_gateway\").\e[0m" >&2 | |
| return 0 | |
| fi | |
| if [ "$exit_ip" == "$real_interface_gateway" ]; then | |
| echo -e "\e[32mTest OK. Trafic exits with IP \"$exit_ip\".\e[0m" >&2 | |
| return 0 | |
| else | |
| echo -e "\e[31mTest failed: Trafic exits with \"$exit_ip\" instead of \"$real_interface_gateway\".\e[0m" >&2 | |
| return 1 | |
| fi | |
| } | |
| # Reconfigure routing | |
| reroute(){ | |
| if [ -z "$real_interface_gateway" ]; then | |
| echo -e "\e[31mCan't find default gateway of real interface \"${real_interface}\". Is it up?\e[0m" >&2 | |
| echo -e "\e[31mAborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| if [ "$skip" = false ]; then | |
| setup_config | |
| fi | |
| # MOVE ourself, as program caller, to cgroup | |
| echo $$ | sudo tee "$cgroup_base/${cgroup_name}/cgroup.procs" > /dev/null | |
| # TEST | |
| test_routing | |
| testresult=$? | |
| if [ "$skip" = false ]; then | |
| if [ "$testresult" = false ]; then | |
| if [ "$iptable_checked" = false ] && [ "$skip" = false ]; then | |
| echo -e "Trying to setup iptables and redo test..." >&2 | |
| check_sudo_conf=true | |
| setup_config | |
| test_routing | |
| testresult=$? | |
| fi | |
| fi | |
| fi | |
| if [ "$testresult" -ne 0 ]; then | |
| echo -e "\e[31mAborting.\e[0m" >&2 | |
| exit 1 | |
| fi | |
| } | |
| # List processes bypassing the VPN | |
| list_outside(){ | |
| return_status=1 | |
| echo -e "PID""\t""CMD" | |
| cat "$cgroup_base/${cgroup_name}/cgroup.procs" | \ | |
| while read task_pid | |
| do | |
| echo -e "${task_pid}""\t""`ps -p ${task_pid} -o comm=`"; | |
| return_status=0 | |
| done | |
| return $return_status | |
| } | |
| # Check/Install DEPENDENCIES | |
| if [ "$action" = "command" ] || [ "$action" = "outside" ]; then | |
| if [ "$skip" = false ]; then | |
| echo "Checking/Installing dependencies" >&2 | |
| install_dependencies | |
| fi | |
| fi | |
| # Find cgroup filesystem | |
| find_root | |
| # SETUP novpn routing | |
| if [ "$action" = "command" ] || [ "$action" = "outside" ]; then | |
| echo "Checking/Setting up system configuration" >&2 | |
| reroute | |
| fi | |
| # RUN command | |
| if [ "$action" = "command" ]; then | |
| if [ "$sudok" = true ]; then | |
| sudo -K | |
| fi | |
| if [ "$#" -eq 0 ]; then | |
| echo "Error: COMMAND not provided." >&2 | |
| exit 1 | |
| fi | |
| if [ "$background" = true ]; then | |
| #cgexec -g net_cls:"$cgroup_name" --sticky "$@" &>/dev/null & | |
| fcgexec "$@" &>/dev/null & | |
| exit 0 | |
| else | |
| #cgexec -g net_cls:"$cgroup_name" --sticky "$@" | |
| fcgexec "$@" | |
| exit $? | |
| fi | |
| # List process OUTSIDE tunnel | |
| # Exit code 0 (true) if at least 1 process is outside the tunnel | |
| elif [ "$action" = "list" ]; then | |
| echo "List of processes bypassing tunnel:" | |
| list_outside | |
| exit $? | |
| # Move process OUTSIDE tunnel | |
| elif [ "$action" = "outside" ]; then | |
| exit_code=1 | |
| for process in "$@" | |
| do | |
| if [ "$process" -eq "$process" ] 2>/dev/null; then | |
| # Is integer (PID) | |
| echo "$process" | sudo tee "$cgroup_base/${cgroup_name}/cgroup.procs" > /dev/null | |
| exit_code=0 | |
| else | |
| # Is process name | |
| pids=$(pidof "$process") | |
| for pid in $pids | |
| do | |
| echo "$pid" | sudo tee "$cgroup_base/${cgroup_name}/cgroup.procs" > /dev/null | |
| exit_code=0 | |
| done | |
| fi | |
| done | |
| echo -e "\e[93mWARNING: Moving running processes outside the VPN tunnel DOES NOT WORK.\e[0m" >&2 | |
| echo -e "\e[93mYou should start new processes and beware processes that have already opened windows: they may reuse existing PID.\e[0m" >&2 | |
| echo "List of processes bypassing tunnel:" | |
| list_outside | |
| reroute | |
| exit $exit_code | |
| # Move process INSIDE tunnel | |
| elif [ "$action" = "inside" ]; then | |
| for process in "$@" | |
| do | |
| if [ "$process" -eq "$process" ] 2>/dev/null; then | |
| # Is integer (PID) | |
| echo "$process" | sudo tee "$cgroup_base/cgroup.procs" > /dev/null | |
| else | |
| # Is process name | |
| pids=$(pidof "$process") | |
| for pid in $pids | |
| do | |
| echo "$pid" | sudo tee "$cgroup_base/cgroup.procs" > /dev/null | |
| done | |
| fi | |
| done | |
| echo "Remaining processes bypassing tunnel:" | |
| list_outside | |
| # INFO | |
| elif [ "$action" = "info" ]; then | |
| echo | |
| echo "Displaying information for cgroup v$cgroup_version" | |
| echo | |
| echo -e "\e[2mcat /etc/iproute2/rt_tables | grep --color \"^${ip_table_number}\s\|\\$\"\e[0m" | |
| cat /etc/iproute2/rt_tables | grep --color "^${ip_table_number}\s\|\$" | |
| echo | |
| echo -e "\e[2mip route show table all | grep -v 'table local' | grep --color 'table\|$'\e[0m" | |
| ip route show table all | grep -v 'table local' | grep --color 'table\|$' | |
| echo | |
| echo -e "\e[2mip rule list | grep --color 'fwmark\|$'\e[0m" | |
| ip rule list | grep --color 'fwmark\|$' | |
| echo | |
| echo -e "\e[2msudo iptables -t mangle -L -v --line-numbers | grep --color 'cgroup\|$'\e[0m" | |
| sudo iptables -t mangle -L -v --line-numbers | grep --color 'cgroup\|$' | |
| echo | |
| echo -e "\e[2msudo iptables -t nat -L -v --line-numbers | grep --color 'cgroup\|$'\e[0m" | |
| sudo iptables -t nat -L -v --line-numbers | grep --color 'cgroup\|$' | |
| echo | |
| echo -e "\e[2mls -l ${cgroup_base}/ | grep --color \"${cgroup_name}\|\\$\"\e[0m" | |
| ls -l ${cgroup_base}/ | grep --color "${cgroup_name}\|\$" | |
| echo | |
| echo -e "\e[2mls -l ${cgroup_base}/${cgroup_name}/ | grep --color \"${USER}\|\\$\"\e[0m" | |
| ls -l ${cgroup_base}/${cgroup_name}/ | grep --color "${USER}\|\$" | |
| echo | |
| echo -e "End of debug information." | |
| # CLEAN the mess | |
| elif [ "$action" = "clean" ]; then | |
| echo -e "Cleaning forced routing config generated by this script for cgroup version $cgroup_version." | |
| echo -e "Note: Cleaning partially cleans/breaks the custom configuration for the other cgroup version." | |
| echo -e " You should also clean the other cgroup version using the -2 (v2) or no (v1) flag." | |
| echo -e "Note: If you used a custom cgroup name through --group, you must use it with --clean." | |
| echo -e "Note: Use --info and --info -2 afterwards to check." | |
| echo -e "Don't bother with errors meaning there's nothing to remove." | |
| # Remove tasks | |
| if [ -f "$cgroup_base/${cgroup_name}/cgroup.procs" ]; then | |
| cat "$cgroup_base/${cgroup_name}/cgroup.procs" | \ | |
| while read task_pid | |
| do | |
| echo ${task_pid} | sudo tee "$cgroup_base/cgroup.procs" > /dev/null | |
| done | |
| fi | |
| # Delete cgroup | |
| if [ -d "$cgroup_base/${cgroup_name}" ]; then | |
| echo -n "Are you sure you want to delete cgroup $cgroup_base/${cgroup_name} ? [y/n] " | |
| old_stty_cfg=$(stty -g) | |
| stty raw -echo ; answer=$(head -c 1) ; stty $old_stty_cfg | |
| echo | |
| if echo "$answer" | grep -iq "^y" ;then | |
| sudo find "$cgroup_base/${cgroup_name}" -depth -type d -print -exec rmdir {} \; | |
| fi | |
| fi | |
| # This can cause issues if reverse path filtering is normally disabled on the system | |
| echo 1 | sudo tee "/proc/sys/net/ipv4/conf/all/rp_filter" > /dev/null | |
| echo 1 | sudo tee "/proc/sys/net/ipv4/conf/${real_interface}/rp_filter" > /dev/null | |
| sudo iptables -t mangle -D OUTPUT -m cgroup $iptables_arg -j MARK --set-mark "$ip_table_fwmark" | |
| sudo iptables -t nat -D POSTROUTING -m cgroup $iptables_arg -o "$real_interface" -j MASQUERADE | |
| sudo ip rule del fwmark "$ip_table_fwmark" table "$ip_table_name" | |
| sudo ip route del default table "$ip_table_name" | |
| sudo sed -i "/^${ip_table_number}\s/d" /etc/iproute2/rt_tables | |
| echo "Disabling IPv6 (still - too risky if not managed by VPN)" | |
| # sudo ip -6 route del blackhole default metric 1 | |
| echo 1 | sudo tee "/proc/sys/net/ipv6/conf/all/disable_ipv6" > /dev/null | |
| # Redundant | |
| #if [ -n "`lscgroup net_cls:$cgroup_name`" ]; then | |
| # sudo cgdelete net_cls:"$cgroup_name" | |
| #fi | |
| echo "All done." | |
| fi | |
| # BONUS: Useful commands: | |
| # ./novpn.sh traceroute www.google.com | |
| # Note: 1 firefox profile = 1 process only | |
| # killall firefox; ./novpn.sh --background firefox https://ipleak.net/ | |
| # ip=$(./novpn.sh curl 'https://wtfismyip.com/text' 2>/dev/null); echo "$ip"; whois "$ip" | grep -E "inetnum|route|netname|descr" |
As promised, here is my version so far. I've called it altnetworking https://gist.github.com/level323/54a921216f0baaa163127d960bfebbf0
It works on my system (Debian 8 w/iptables from unstable repo).
Thank you so much! This script works beautifully!
After hours of searching on the internet, finally found something which actually works. Thanks a lot!!
Can't find a valid cgroup v1 net_cls folder. Aborting.
On some linux kernel compilations, net_cls is not statically compiled with the kernel.
It can be determined through the kernel config file:
CONFIG_NET_CLS_CGROUP=m // meaning it was compiled as a separate kernel module we should load
(if =n, you will have to recompile the kernel with =(m|y))
So before using novpn.sh, it is recommended to run:
modprobe cls_cgroup
I just wanted to add a note for anyone having problems with missing net_cls folder on Ubuntu 20. I created the missing folder: /sys/fs/cgroup/net_cls then launched with novpn.sh --cgv2 to resolve the issue.
For Debian Bullseye :
- Copy this code in a document called "bypass.sh"
- Give it executable permissions by running
chmod +x bypass.shin a terminal - Inside bypass.sh :
Replace :
real_interface="enp0s3"
by :
real_interface="THE_INTERFACE_YOU_CHOOSE in sudo ifconfig"
Replace :
traceroute -n -m
by :
traceroute -m
Replace :
iptables_version=$(iptables --version
by :
iptables_version=$(sudo iptables --version - Install the deb package cgroup-lite_1.15_all.deb --> https://launchpad.net/ubuntu/jammy/amd64/cgroup-lite/1.15
- Turn off the VPN
- Run in your terminal :
sudo mkdir /sys/fs/cgroup/net_cls
sudo modprobe cls_cgroup
./bypass.sh PATH_TO_YOUR_APP - Turn on the VPN
- Run your app and enjoy :-)
Just another note if you are using Ubuntu. Launching a snap installed app (like Firefox) ignores the cgroup from this script and continues to use the VPN. This script only works if you install non snap apps.
I couldn't get this script working on its own, even with tweaks on Debian 11. I did however get it to work manually using the instructions from the answer to this question on serverfault by the author of this script. I use Nord VPN, with their custom interface thing, so I had to run nordvpn set firewall disable before it would work, but now nordvpn's port bypass setting doesn't seem to work. This is a problem, because it basically invalidates the whole reason I set this up in the first place. My intended setup is this: I have port 22 forwarded so I can connect to my desktop through the internet. I whitelisted port 22 in Nord VPN so that if I leave the VPN connected when I leave the house, I can still connect. I set up a cron job that retrieves the external IP address of my home network once an hour (using the novpn control group), and uploads that to a text file on a cloud storage service, in case I get a new dynamic IP. I can't seem to SSH in through the internet anymore while connected to a VPN after setting up this control group, even though the rest of my settings are the same. Could it be interfering with nordvpn's configuration somehow?
For Debian Bullseye :
- Copy this code in a document called "bypass.sh"
- Give it executable permissions by running
chmod +x bypass.shin a terminal- Inside bypass.sh :
Replace :
real_interface="enp0s3"
by :
real_interface="THE_INTERFACE_YOU_CHOOSE in sudo ifconfig"
Replace :
traceroute -n -m
by :
traceroute -m
Replace :
iptables_version=$(iptables --version
by :
iptables_version=$(sudo iptables --version- Install the deb package cgroup-lite_1.15_all.deb --> https://launchpad.net/ubuntu/jammy/amd64/cgroup-lite/1.15
- Turn off the VPN
- Run in your terminal :
sudo mkdir /sys/fs/cgroup/net_cls
sudo modprobe cls_cgroup
./bypass.sh PATH_TO_YOUR_APP- Turn on the VPN
- Run your app and enjoy :-)
For latest Debian Sid:
If you see error
cat: /sys/fs/cgroup/net_cls/novpn/net_cls.classid: No such file or directory
Applying net_cls class identifier 0x00110011 to cgroup novpn
tee: /sys/fs/cgroup/net_cls/novpn/net_cls.classid: Permission denied
then add to head of file after
sudo mkdir /sys/fs/cgroup/net_cls
sudo modprobe cls_cgroup
sudo mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls
@falshunov thanks, works for Ubuntu 22.04 as well.
Any ideas on how to make this work with Flatpak apps?
Doesn't work with Arch, it tries to use apt-get to install the dependencies
Stops working with Ubuntu 24.04 Version (connection stops working directly after the script runs)
Stops working with Ubuntu 24.04 Version (connection stops working directly after the script runs)
I'm running 24.04 with same script without a problem. Check my previous comments, it might be one of those.
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Excellent script. Thankyou for sharing it. I'm building something based on your fine work to scratch a more generic itch. I plan to post it when ready.
In the meantime, I noticed that $force (line #226) is an unbound variable in your script. Further to that, I'm not really sure what that whole block (lines 224-237) are actually achieving (it seems to assumes that the environment is setup except for the iptables rules - but how would that situation ever occur?).