#!/bin/sh -x

set -e
set -u
set -x

UBNTBOX_PATCHED="/tmp/fwupdate.real"
MD5FILE="/tmp/patchmd5"

# 2.5.0:
# cat <<EOF > ${MD5FILE}
# c33235322da5baca5a7b237c09bc8df1  /sbin/fwupdate.real
# EOF

# 2.8.3:
cat <<EOF > ${MD5FILE}
f6b3a605704f3d8d8ed489f4a5f20584  /sbin/fwupdate.real
EOF

# check md5 of files that will be patched
if ! md5sum -c ${MD5FILE}
then
        echo "******** Error when checking files. Refuse to do anything. ********"
        exit 0
fi

# prepare some overlay functionality
LOWERDIR="/tmp/lower_root"
mkdir -p ${LOWERDIR}
mount -t squashfs -oro /dev/mtdblock3 ${LOWERDIR}
overlay_some_path()
{
        PATH_TO_OVERLAY=$1
        ALIAS=$2
        UPPERDIR="/tmp/over_${ALIAS}"
        WORKDIR="/tmp/over_${ALIAS}_work"

        mkdir -p ${UPPERDIR}
        mkdir -p ${WORKDIR}

        mount -t overlay -o lowerdir=${LOWERDIR}${PATH_TO_OVERLAY},upperdir=${UPPERDIR},workdir=${WORKDIR} overlay ${PATH_TO_OVERLAY}
}

# patch the ubntbox binary.
overlay_some_path "/sbin" "sbin"

# 2.5.0: Only one patch to disable signature check
# echo -en '\x10' | dd of=/sbin/fwupdate.real conv=notrunc bs=1 count=1 seek=24598

# 2.8.3: Two patches to disable signature and version check
echo -en '\x65\x00' | dd of=/sbin/fwupdate.real conv=notrunc bs=1 count=2 seek=26484
echo -en '\x10' | dd of=/sbin/fwupdate.real conv=notrunc bs=1 count=1 seek=25586

echo "******** Done ********"