#!/bin/bash
# (c) 2015 Helge Jung <hej@c3pb.de>
#
# This script is controlled by environment variables,
# only the first being mandatory:
#
# CANDIDATE       = directory in which to find the to-be-checked firmware images
# REFERENCE       = directory of your build firmware, defaults to './src/images'
# MANIFEST        = if given, use files referenced in Gluon manifest file
#                   if left empty (unset), 'find' is used to examine all '.bin' files
# VERBOSE         = 0 (default) or 1, putting lots of debug output
#

MY_DIR=$(dirname $0)
MY_DIR=$(readlink -f "$MY_DIR")

pushd "$MY_DIR" > /dev/null
. functions.sh

# check for necessary tools
for tool in bbe binwalk find gawk unsquashfs; do
	[ -x "$(which $tool)" ] || abort "Missing necessary tool '$tool'."
done

# check that CANDIDATE dir is given and existing
[ "_$CANDIDATE" == "_" ] && abort "Please specify CANDIDATE environment variable point to the directory of to-be-checked firmware images."
[ ! -d "$CANDIDATE" ] && abort "The directory indicated by CANDIDATE was not found."
CANDIDATE=$(readlink -f $CANDIDATE)

# set defaults for environment variables
[ -n "${REFERENCE}" ] || REFERENCE="./src/images"
if [ "_$VERBOSE" == "_1" ]; then VERBOSE=1; else VERBOSE=0; fi

# assemble file list
declare -a FILELIST
if [ -n "$MANIFEST" ]; then
	progress "Assembling file list from manifest file ..."
	FILELIST=()
else
	[ ! -d "$REFERENCE" ] && abort "The REFERENCE directory was not found. Have you built the firmware?"
	REFERENCE=$(readlink -f $REFERENCE)

	progress "Assembling file list ..."
	FILELIST=($(find "$REFERENCE" -type f -name "*.bin"))
fi

COUNT=${#FILELIST[*]}
[ "$COUNT" = 0 ] && abort "No firmware files found. Please check that you built software in the REFERENCE dir."

info "Need to check $COUNT files."

# setup temp dir for checking
TEMPDIR=$(mktemp -d)
debug "Temporary dir = $TEMPDIR"

# check each file
IDX=0
declare -a ERRORS

filter_timestamp() {
	file=$1
	cp "$file" "$file.orig"
	egrep -ao '(Mon|Tue|Wed|Thu|Fri|Sat|Sun) (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) [0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2} UTC [0-9]{4}' "$file" | sort -u | while read ts; do
		debug "Normalizing timestamp: '$ts'"
		bbe -e "s/$ts/Abc Def 12 34:56:78 UTC 9010/" -o "${file}" "${file}.orig"
	done
}

for ref in ${FILELIST[*]}; do
        IDX=$(($IDX + 1))
        NAME=`basename "$ref"`
	[ $VERBOSE -eq 1 ] && progress "[${IDX}/${COUNT}] $NAME"

	if [ ! -r "$ref" ]; then
		ERRORS=( "${ERRORS[@]}" "$NAME: missing reference file ($ref)" )
		continue
	fi

        cand=$(readlink -f "${CANDIDATE}/${NAME}")
	if [ ! -r "$cand" ]; then
		ERRORS=( "${ERRORS[@]}" "$NAME: missing candidate file in $CANDIDATE" )
		continue
	fi

	pushd "$TEMPDIR" > /dev/null

	rm -Rf candidate ; mkdir candidate
	rm -Rf reference ; mkdir reference

	# TODO: check output of binwalk that there are only the two expected parts
	cd candidate
	binwalk -qe "$cand" 2>/dev/null
	cd ../reference
	binwalk -qe "$ref" 2>/dev/null
	cd ..

	# check ROM part
	debug "Filtering timestamps in ROM part (uboot+kernel) ..."
	filter_timestamp candidate/200
	filter_timestamp reference/200

	hash_rom_cand=$(sha512sum candidate/200)
	hash_rom_ref=$(sha512sum reference/200)
        if [ "$hash_rom_cand" != "$hash_rom_ref" ]; then
		ERRORS=( "${ERRORS[@]}" "$NAME: ROM part mismatch" )

		debug "Calling vbindiff for your visual pleasure."
		vbindiff reference/200 candidate/200
	fi

	# extract root filesystem
	for dir in candidate reference; do
		cd $dir
		unsquashfs -n -f *.squashfs > /dev/null
		cd ..
	done

	fsdiff=$(diff -ur reference/squashfs-root candidate/squashfs-root 2>&1)
	# TODO: intelligent diff statt 'diff -r', Verhalten abhängig vom Dateinamen
	#   squashfs-root/usr/lib/opkg/info/*.list: erst sortieren, dann diffen
	#   squashfs-root/usr/lib/opkg/info/*.control: Unterschied in "Installed Size" ignorieren (kommt vermutlich durch unterschiedliche Reihenfolge und Block-Alignments?)
        #   squashfs-root/usr/lib/opkg/status: Delta in "Installed-Time: " Zeilen ignorieren
	#   squashfs-root/usr/lib/lua/luci/version.lua: neoraider/openwrt hauen, die Änderung im luciversion-String kommt durch manuelles git patching
	#   else: binary file compare, sha512sum
	if [ "$?" -ne 0 ]; then
		ERRORS=( "${ERRORS[@]}" "$NAME: Filesystems do not match" )
		echo $fsdiff | less
	fi

	popd > /dev/null
done
rm -R "$TEMPDIR"

# check if everything was fine - if yes, exit clean+smooth
if [ ${#ERRORS[*]} -eq 0 ]; then
	success "Everything OK, what a nice and lovely built firmware \o/"
	exit 0
fi

# got some errors - output them
for errmsg in "${ERRORS[@]}"; do
    echo $errmsg
done

abort "Firmware check failed, see above :("