From 77c3d3f1a4b0c59b3aece4cbac0499fd10f80d4a Mon Sep 17 00:00:00 2001
From: Cyberes <cyberes@evulid.cc>
Date: Tue, 13 Jun 2023 10:33:04 -0600
Subject: [PATCH] add files

---
 bridge-install.sh | 220 ++++++++++++++++++++++++++++++++++++++++++++++
 config.sh.example |  15 ++++
 2 files changed, 235 insertions(+)
 create mode 100644 bridge-install.sh
 create mode 100644 config.sh.example

diff --git a/bridge-install.sh b/bridge-install.sh
new file mode 100644
index 0000000..13d256f
--- /dev/null
+++ b/bridge-install.sh
@@ -0,0 +1,220 @@
+#!/bin/bash
+# https://raspberrypi.stackexchange.com/questions/88954/workaround-for-a-wifi-bridge-on-a-raspberry-pi-with-proxy-arp
+# https://www.willhaley.com/blog/raspberry-pi-wifi-ethernet-bridge/
+
+# TODO: non-interactive install
+
+# ==============================================================================
+# Config
+
+SOURCE=${BASH_SOURCE[0]}
+while [ -L "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink
+  DIR=$( cd -P "$( dirname "$SOURCE" )" >/dev/null 2>&1 && pwd )
+  SOURCE=$(readlink "$SOURCE")
+  [[ $SOURCE != /* ]] && SOURCE=$DIR/$SOURCE # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located
+done
+DIR=$( cd -P "$( dirname "$SOURCE" )" >/dev/null 2>&1 && pwd )
+
+if [[ -f "$DIR/config.sh" ]]; then
+  source "$DIR/config.sh"
+else
+  echo "config.sh missing!"
+  exit 1
+fi
+
+# ==============================================================================
+# Setup
+
+# Must be run as root
+if [ "$(id -u)" -ne 0 ]; then
+        echo 'This script must be run as root.' >&2
+        exit 1
+fi
+
+# We only need to get the $WLAN_IFACE IP address and will copy it over to $ETH_IFACE later
+WLAN_IFACE_IP=$(ip -4 -br addr show $WLAN_IFACE | grep -Po "\\d+\\.\\d+\\.\\d+\\.\\d+")
+
+# ==============================================================================
+# Install stuff
+
+echo "# INSTALL THINGS #"
+
+THINGS_TO_INSTALL="parprouted dhcp-helper net-tools"
+
+if ! $NON_INTERACTIVE; then
+  echo "Going to install: $THINGS_TO_INSTALL"
+  read -p "Press ENTER to continue or CTRL+C to cancel..."
+fi
+
+echo -e "\n"
+
+apt-get install $THINGS_TO_INSTALL
+
+echo -e "\n\nSetting up services...\n"
+
+systemctl stop dhcp-helper
+systemctl enable dhcp-helper
+
+if ! $NON_INTERACTIVE; then
+  echo -e "\n\nGoing to replace networking with systemd-networkd."
+  read -p "Press ENTER to continue or CTRL+C to cancel..."
+fi
+
+echo -e "\n"
+apt-get --autoremove -y purge ifupdown dhcpcd5 isc-dhcp-client isc-dhcp-common
+
+echo -e "\n\nConnecting to WiFi..."
+
+WPA_SUPP_FILE="/etc/wpa_supplicant/wpa_supplicant-$WLAN_IFACE.conf"
+cat > "$WPA_SUPP_FILE" <<EOF
+ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
+update_config=1
+country=US
+network={
+ ssid="$WIFI_SSID"
+ scan_ssid=1
+ key_mgmt=WPA-EAP
+ eap=PEAP
+ identity="$WIFI_USERNAME"
+ password="$WIFI_PWD"
+ phase1="peaplabel=0"
+ phase2="auth=MSCHAPV2"
+}
+EOF
+chmod 600 "$WPA_SUPP_FILE"
+echo "Created wpa_supplicant: $WPA_SUPP_FILE"
+systemctl disable wpa_supplicant.service
+systemctl stop wpa_supplicant.service
+systemctl enable --now wpa_supplicant@$WLAN_IFACE.service
+systemctl status --no-pager wpa_supplicant@$WLAN_IFACE.service
+echo ""
+ifconfig $WLAN_IFACE
+
+
+echo -e "\n\n"https://raspberrypi.stackexchange.com/questions/88954/workaround-for-a-wifi-bridge-on-a-raspberry-pi-with-proxy-arp
+
+NET_CONF_FILE="/etc/systemd/network/08-$WLAN_IFACE.network"
+cat > "$NET_CONF_FILE" <<EOF
+[Match]
+Name=$WLAN_IFACE
+[Network]
+IPForward=yes
+DHCP=yes
+# for a static ip address, remove DHCP=yes and modify the following lines:
+#Address=192.168.50.2/24
+#Gateway=192.168.50.1
+#DNS=84.200.69.80 1.1.1.1
+EOF
+echo "Created network config: $WLAN_IFACE"
+echo -e "Finishing systemd-networkd install...\n\n"
+apt-get install -y libnss-resolve
+systemctl enable --now systemd-resolved.service
+ln -sf /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf
+systemctl enable --now systemd-networkd.service
+
+echo -e "\n\nInstall complete! Ignore any service errors for now..."
+
+# ==============================================================================
+# Create bridge interface
+
+echo -e "\n# BRIDGE $WLAN_IFACE TO $ETH_IFACE #"
+
+# brctl addbr br0
+# brctl addif br0 $WLAN_IFACE
+# brctl addif br0 $ETH_IFACE
+# ip addr flush dev $WLAN_IFACE
+# ip addr flush dev $ETH_IFACE
+# ip link set dev br0 up
+
+# IP="128.198.192.233"
+# MAC="f0:1f:af:6d:fd:54"
+# ebtables -F
+# ebtables -F -t nat
+# ebtables -t nat -A PREROUTING -i $WLAN_IFACE -j redirect --redirect-target ACCEPT
+# ebtables -t nat -A PREROUTING -i $ETH_IFACE -j redirect --redirect-target ACCEPT
+
+
+# This works but nat and is unreliable and breaks DHCP
+# IP_OTHR="128.198.192.233"
+# iptables -F
+# iptables -F -t nat
+# iptables -t nat -A PREROUTING  -d $IP_OTHR -i  $ETH_IFACE -j DNAT --to-destination $WLAN_IFACE_IP
+# iptables -t nat -A PREROUTING  -d $WLAN_IFACE_IP -i $WLAN_IFACE -j DNAT --to-destination $IP_OTHR
+# iptables -t nat -A POSTROUTING -s $WLAN_IFACE_IP          -j SNAT --to-source      $IP_OTHR
+# iptables -t nat -A POSTROUTING -s $IP_OTHR          -j SNAT --to-source      $WLAN_IFACE_IP
+
+# ==============================================================================
+# Set up configs
+
+echo -e "\n# SET UP CONFIG FILES #"
+
+sed -i'' 's/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=1/' /etc/sysctl.conf
+sudo sysctl -p /etc/sysctl.conf
+echo "Set net.ipv4.ip_forward=1 in /etc/sysctl.conf"
+
+DHCP_HELPER_CONF="/etc/default/dhcp-helper"
+for ip in $DHCP_SERVERS; do
+  DHCP_SERVERS_CONF+=" -s $ip"
+done
+cat > "$DHCP_HELPER_CONF" <<EOF
+# Relay DHCP requests as broadcast to $WLAN_IFACE
+DHCPHELPER_OPTS="$DHCP_SERVERS_CONF"
+EOF
+echo "Created dhcp-helper config: $DHCP_HELPER_CONF"
+
+# Enable IP forwarding for $WLAN_IFACE if it's not already enabled.
+# grep '^option ip-forwarding 1$' /etc/dhcpcd.conf || printf "option ip-forwarding 1\n" >> /etc/dhcpcd.conf
+
+# Disable dhcpcd control of $ETH_IFACE.
+# grep "^denyinterfaces ${ETH_IFACE}\$" /etc/dhcpcd.conf || printf "denyinterfaces $ETH_IFACE\n" >> /etc/dhcpcd.conf
+
+# Enable avahi reflector if it's not already enabled.
+sed -i'' 's/#enable-reflector=no/enable-reflector=yes/' /etc/avahi/avahi-daemon.conf
+grep '^enable-reflector=yes$' /etc/avahi/avahi-daemon.conf || {
+  printf "something went wrong...\n\n"
+  printf "Manually set 'enable-reflector=yes in /etc/avahi/avahi-daemon.conf'\n"
+}
+echo "Enabled avahi reflector."
+
+PARPROUTED_SERVICE="/etc/systemd/system/parprouted.service"
+cat > "$PARPROUTED_SERVICE" <<EOF
+[Unit]
+Description=proxy arp routing service
+Documentation=https://raspberrypi.stackexchange.com/q/88954/79866
+Requires=sys-subsystem-net-devices-$WLAN_IFACE.device
+# dhcpcd.service
+After=sys-subsystem-net-devices-$WLAN_IFACE.device
+# dhcpcd.service
+
+[Service]
+Type=forking
+# Restart until $WLAN_IFACE gained carrier
+Restart=on-failure
+RestartSec=5
+TimeoutStartSec=30
+# clone the dhcp-allocated IP to $ETH_IFACE so dhcp-helper will relay for the correct subnet
+ExecStartPre=/bin/bash -c '/sbin/ip addr add $WLAN_IFACE_IP/32 dev $ETH_IFACE'
+ExecStartPre=/sbin/ip link set dev $ETH_IFACE up
+ExecStartPre=/sbin/ip link set $WLAN_IFACE promisc on
+ExecStart=-/usr/sbin/parprouted $ETH_IFACE $WLAN_IFACE
+ExecStopPost=/sbin/ip link set $WLAN_IFACE promisc off
+ExecStopPost=/sbin/ip link set dev $ETH_IFACE down
+ExecStopPost=/bin/bash -c '/sbin/ip addr del $WLAN_IFACE_IP/32 dev $ETH_IFACE'
+
+[Install]
+WantedBy=wpa_supplicant.service
+EOF
+echo "Created systemd service: $PARPROUTED_SERVICE"
+
+systemctl daemon-reload
+systemctl enable --now parprouted dhcp-helper
+systemctl restart parprouted dhcp-helper
+echo -e "Enabled and started parprouted and dhcp-helper"
+
+echo -e "Waiting 5 seconds...\n"
+sleep 5
+
+systemctl status --no-pager parprouted
+systemctl status --no-pager dhcp-helper
+
+echo -e "\n\n\n==============\nDone!\nNow reboot!"
diff --git a/config.sh.example b/config.sh.example
new file mode 100644
index 0000000..dfc76c3
--- /dev/null
+++ b/config.sh.example
@@ -0,0 +1,15 @@
+# Interface names
+ETH_IFACE="enp0s31f6"
+WLAN_IFACE="wlxc8d7193710f4"
+
+# IP address(es) of your DHCP servers. If multiple, separate
+# them with a space.
+DHCP_SERVERS="192.168.1.1 192.168.1.2"
+
+# RADIUS login
+WIFI_SSID="Example-Network"
+WIFI_USERNAME="username"
+WIFI_PWD="password"
+
+# Don't prompt the user for confirmation
+NON_INTERACTIVE=false