#!/bin/bash

################
##   CONFIG   ##
################

# Folder to save snaps in
SNAP_FOLDER=~/server_states

# Array with files to snapshot
declare -a CFGBKP=(
	"/etc/motd"
	"/etc/hosts"
)

# Bash color definitions
GREEN='\033[00;92m'
BLUE='\033[00;94m'
RST='\033[0m'

# print color message
function msg() {
        echo -e "$BLUE * $GREEN$1$RST"
}

# colorify diff output
function colorDiff {
	awk '/^>/ { print "\033[31m"$0"\033[0m"; } /^</ { print "\033[32m"$0"\033[0m"; } /^[^<>]/ { print $0; }'
}

# print horizontal line
function HL {
	echo -e "$BLUE============================================================================$RST"
}

# print and format unique processes names
function procList {
	ps aux | awk '{ print $11 }' | sort | uniq | egrep -v '^\['
}

# print and format opened TCP/UDP ports and process names
function portList {
	netstat -lpn | egrep "(tcp.*LISTEN|udp)" | sort | uniq | awk '{split($NF,arr,"/"); print $1 "   " $4 "   " arr[2]}'
}

# print firewall rules (standard + NAT table)
function firewallRules {
	(/sbin/iptables -L -n; echo -e "\n#NAT\n";  /sbin/iptables -L -nt nat)
}

# print routing table
function routingTable {
	/sbin/ip route
}

# make status snap
function makeSnap {
	FOLDER=$SNAP_FOLDER/state_$(date '+%Y%m%d_%H%M%S')
	mkdir -p $FOLDER
	procList > $FOLDER/ps.out
	portList > $FOLDER/netstat.out
	firewallRules > $FOLDER/iptables.out
	/sbin/iptables-save > $FOLDER/iptables-save.out
	mount > $FOLDER/mount.out
	routingTable > $FOLDER/routing.out
        for i in "${CFGBKP[@]}"
        do
		DIR=$(dirname "${i}")
		mkdir -p "$FOLDER/cfg$DIR"
		cp "$i" "$FOLDER/cfg$i"
        done
	msg "Written state snapshot to $FOLDER"
}

# comapring states to previous snap
function compare {
	FOLDER=$SNAP_FOLDER/$(ls ~/server_states/ | tail -n 1)
	msg "Comparing with snap $FOLDER"
	echo -e "$GREEN\nProcesses diff$RST"; HL; procList | diff - $FOLDER/ps.out | colorDiff
	echo -e "$GREEN\nOpened ports diff$RST"; HL; portList | diff - $FOLDER/netstat.out | colorDiff
	echo -e "$GREEN\nFirewall rules diff$RST"; HL; firewallRules | diff - $FOLDER/iptables.out | colorDiff
	echo -e "$GREEN\nMounts diff$RST"; HL; mount | diff - $FOLDER/mount.out | colorDiff
	echo -e "$GREEN\nRouting table diff$RST"; HL; routingTable | diff - $FOLDER/routing.out | colorDiff
        for i in "${CFGBKP[@]}"
        do
		echo -e "$GREEN\n$i config diff$RST"; HL; diff "$i" "$FOLDER/cfg$i" | colorDiff
        done
}

# Checking if root privileges
function nonRootExit {
	if [[ $EUID -ne 0 ]]; then
		msg "This command must be run as root"
		exit 1
	fi
}

# Printing help
function printHelp {
	echo -e "State Snap 0.3"; HL
	echo -e "Use: $0 [PARAMETRS]...\n"
	printf "   $GREEN%-6s$RST %s\n" "snap" "- Make server status snapshot"
	printf "   $GREEN%-6s$RST %s\n" "diff" "- Make a diff comparison against latest snapshot"
	printf "   $GREEN%-6s$RST %s\n\n" "clear" "- Delete all previous snapshots"
	exit 0;
}

# Print help if no arguments
if [ $# -lt 1 ]; then
	printHelp
fi

# Program starts here
case $1 in
	diff)
	nonRootExit
	compare
	;;
	snap)
	nonRootExit
	makeSnap
	;;
	clear)
	rm -r $SNAP_FOLDER/*
	;;
	*)
	msg "Unrecognised command. Run \"$0 help\" to view help."
	;;
esac