Generate random virtual subnet, avoiding common subnets and those already used by the system

This commit is contained in:
Orazio 2021-12-25 14:40:37 +01:00
parent 478b8ecb6c
commit 85b3e82274

View file

@ -34,7 +34,7 @@ PKG_INSTALL="${PKG_MANAGER} --yes --no-install-recommends install"
PKG_COUNT="${PKG_MANAGER} -s -o Debug::NoLocking=true upgrade | grep -c ^Inst || true"
# Dependencies that are required by the script, regardless of the VPN protocol chosen
BASE_DEPS=(git tar curl grep dnsutils whiptail net-tools bsdmainutils bash-completion)
BASE_DEPS=(git tar curl grep dnsutils grepcidr whiptail net-tools bsdmainutils bash-completion)
# Dependencies that where actually installed by the script. For example if the script requires
# grep and dnsutils but dnsutils is already installed, we save grep here. This way when uninstalling
@ -1085,13 +1085,44 @@ setVPNDefaultVars(){
fi
}
generateRandomSubnet() {
# Source: https://community.openvpn.net/openvpn/wiki/AvoidRoutingConflicts
declare -a SUBNET_EXCLUDE_LIST=(10.0.0.0/24 10.0.1.0/24 10.1.1.0/24 10.1.10.0/24 10.2.0.0/24 10.8.0.0/24 10.10.1.0/24 10.90.90.0/24 10.100.1.0/24 10.255.255.0/24)
readarray -t CURRENTLY_USED_SUBNETS <<< "$(ip -o addr show | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\/[0-9]{1,2}')"
SUBNET_EXCLUDE_LIST=("${SUBNET_EXCLUDE_LIST[@]}" "${CURRENTLY_USED_SUBNETS[@]}")
local MATCHES
while true; do
MATCHES=0
pivpnNET="10.$((RANDOM%256)).$((RANDOM%256)).0"
for SUB in "${SUBNET_EXCLUDE_LIST[@]}"; do
if grepcidr "${SUB}" <<< "${pivpnNET}/$subnetClass" 2>&1 > /dev/null; then
((MATCHES++))
fi
done
if [ "${MATCHES}" -eq 0 ]; then
break
fi
done
echo "${pivpnNET}"
}
setOpenVPNDefaultVars(){
pivpnDEV="tun0"
# Allow custom NET via unattend setupVARs file. Use default if not provided.
if [ -z "$pivpnNET" ]; then
pivpnNET="10.8.0.0"
pivpnNET="$(generateRandomSubnet)"
fi
vpnGw="${pivpnNET/.0.0/.0.1}"
vpnGw="${pivpnNET/.0/.1}"
}
setWireguardDefaultVars(){
@ -1101,9 +1132,9 @@ setWireguardDefaultVars(){
pivpnDEV="wg0"
# Allow custom NET via unattend setupVARs file. Use default if not provided.
if [ -z "$pivpnNET" ]; then
pivpnNET="10.6.0.0"
pivpnNET="$(generateRandomSubnet)"
fi
vpnGw="${pivpnNET/.0.0/.0.1}"
vpnGw="${pivpnNET/.0/.1}"
# Allow custom allowed IPs via unattend setupVARs file. Use default if not provided.
if [ -z "$ALLOWED_IPS" ]; then
# Forward all traffic through PiVPN (i.e. full-tunnel), may be modified by
@ -1233,9 +1264,8 @@ installOpenVPN(){
updatePackageCache
fi
# grepcidr is used to redact IPs in the debug log whereas expect is used
# to feed easy-rsa with passwords
PIVPN_DEPS=(openvpn grepcidr expect)
# Expect is used to feed easy-rsa with passwords
PIVPN_DEPS=(openvpn expect)
installDependentPackages PIVPN_DEPS[@]
}