commit 68b1ee8b3c72433eded63f103072dc307229b193
Author: Caleb Fontenot <foley2431@gmail.com>
Date:   Fri Sep 3 14:56:24 2021 -0500

    Init

diff --git a/pinephoneReverseTether.sh b/pinephoneReverseTether.sh
new file mode 100755
index 0000000..dae0beb
--- /dev/null
+++ b/pinephoneReverseTether.sh
@@ -0,0 +1,51 @@
+#/bin/bash
+# https://stackoverflow.com/a/32708121
+# A prompt confirm function.
+prompt_confirm() {
+  while true; do
+    read -r -n 1 -p "${1:-Continue?} [y/n]: " REPLY
+    case $REPLY in
+      [yY]) echo ; return 0 ;;
+      [nN]) echo ; return 1 ;;
+      *) printf " \033[31m %s \n\033[0m" "invalid input"
+    esac 
+  done  
+}
+# Get array of interfaces
+interfaces=()
+for iface in $(ifconfig | cut -d ' ' -f1| tr ':' '\n' | awk NF)
+do
+        #printf "$iface\n"
+        interfaces+=("$iface")
+done
+#echo ${interfaces[@]}
+echo "${#interfaces[@]} interfaces detected!"
+# This function prompts the user to select an interface.
+function determine_interface() {
+    local prompt=$1
+    #local $INTERFACE_RETURN
+    echo -e "\e[1m$prompt\e[0m" >&2
+    select INTERFACE_RETURN in ${interfaces[@]}; do
+        prompt_confirm "Select $INTERFACE_RETURN"?; break
+    done
+    printf "$INTERFACE_RETURN"
+}
+get_ip() {
+    printf "$(ip addr show $1| awk '/inet /{print substr($2,1)}' | awk '{print substr($1, 1, length($1)-3)}')"
+}
+
+INTERNET_FACING_INTERFACE=$(determine_interface "Select the interface that is exposed to the internet:")
+echo "$INTERNET_FACING_INTERFACE selected as internet facing interface"
+echo "IP address of $INTERNET_FACING_INTERFACE is $(get_ip $INTERNET_FACING_INTERFACE)"
+PINEPHONE_FACING_INTERFACE=$(determine_interface "Select the interface that is created by the PinePhone's tether script:")
+echo "$PINEPHONE_FACING_INTERFACE selected as PinePhone facing interface"
+echo "IP address of $PINEPHONE_FACING_INTERFACE is $(get_ip $PINEPHONE_FACING_INTERFACE)"
+
+echo "Setting IP Tables... (will prompt for password multiple times)"
+sudo iptables -t nat -A POSTROUTING -o $INTERNET_FACING_INTERFACE -j MASQUERADE
+sudo iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
+sudo iptables -A FORWARD -i $PINEPHONE_FACING_INTERFACE -o $INTERNET_FACING_INTERFACE -j ACCEPT
+echo "IP Tables set!"
+echo "Attempting to set default route on PinePhone..."
+echo "NOTE: Due to the fact we're running sudo in ssh without a shell, sudo is unable to hide your password! Make sure no one's looking at your screen before continuing!"
+ssh 10.15.19.82 sudo -S ip route add default via $(get_ip $PINEPHONE_FACING_INTERFACE) dev usb0; echo "Success!"