#!/bin/sh
# checks boot options to see what to do when the system has a flash configuration corruption
STAG=checkflashcfg:
PENDINGCHK=/tmp/.boot_pending
# lock wait time max 15mn * 60 = 900 secs (sufficient time to check it)
LOCKWAIT=900
bname=checkflashcfg
_curr_dir=""
__USESYSLOG=1
VERBOSE=''
__EXITCODE=0
CONFIGMOUNT=/mnt/rom/user
CONFIGMOUNTTYPE=jffs2
DEVCONFIG=/dev/mtdblock9
tempdir=""
TMPMOUNT=/tmp/.mnt_config
__NOHANG=0
_RECOVERY=1

readonly LOCKFILE_DIR=/var/lock
readonly LOCK_FD=977

# Get boot options configuration file
if [ -f "/etc/bootoptions.conf" ]; then
    source "/etc/bootoptions.conf"
fi

lock() {
    local prefix=$1
    local fd=${2:-$LOCK_FD}
    local lock_file=$LOCKFILE_DIR/$prefix.lock

    # still allow to run unlocked if the lock dir does not exist
    if [ ! -d "${LOCKFILE_DIR}" ]; then
        return 0
    fi

    # create lock file
    eval "exec $fd>$lock_file"
    # still allow to run unlocked if the lock file cannot be created
    if [ $? -ne 0 ]; then
        return 0
    fi

    # acquier the lock
    flock -w ${LOCKWAIT} $fd \
        && return 0 \
        || return 1
}

unlock() {
    local prefix=$1
    local fd=${2:-$LOCK_FD}
    local lock_file=$LOCKFILE_DIR/$prefix.lock

    # release the lock
    flock -u $fd
    sync
}

function my_exit()
{
    trap - SIGINT
    trap - SIGQUIT
    trap - SIGTERM
    trap - SIGHUP
    sync
    if [ -d "${tempdir}" ]; then
        if mount | grep -q "${tempdir}"; then
            umount "$tempdir"
        fi
        rmdir "$tempdir"
    fi
    cd "$_curr_dir"
    unlock $bname
    exit $*
}

checkrecovery() {
    if mount | grep -q "on / type nfs" ; then
        return 0
    else
        return 1
    fi
}

function __sig_int {
    log_write " "
    log_write "$STAG WARNING: SIGINT caught"
    my_exit 110
}

function __sig_quit {
    log_write " "
    log_write "$STAG WARNING: SIGQUIT caught"
    my_exit 111
}

function __sig_term {
    log_write " "
    log_write "$STAG WARNING: SIGTERM caught"
    my_exit 112
}

function __sig_hup {
    log_write " "
    log_write "$STAG WARNING: SIGHUP caught"
    my_exit 113
}

checkflashconfig() {
    if ! grep -q "$* " /proc/mounts; then
        return 14
    fi
    return 0
}

function log_write()
{
	if [ ! -z ${VERBOSE} ] || [ ${__USESYSLOG} -eq 0 ]; then
		echo "$*"
	fi
	if [ ${__USESYSLOG} -ne 0 ] ; then
		logger -p local4.info  "$*"
	fi
}

function show_help {
    echo "checkflashcfg help information:"
    echo "Usage: checkflashcfg [ [ [-d] [-n] ] | [--help] ]"
    echo "Verify boot options and flash config state to learn what to do when corrupted"
    echo "WARNING: this script may intentionnaly hang if -n is not provided and flash is corrupted"
    echo "         if not hanging, it may attempt to recreate an unmountable corrupted flash"
    echo "          config partition"
    echo "          -d           # print debug verbose info"
    echo "          -n           # no hang even if boot option specifies blocking in corruption"
    echo "          --help       # displays this help information"
    echo "example: checkflashcfg;      # checks flash corruption and boot options silently"
    echo "example: checkflashcfg -d -n;# checks flash corruption and boot options verbose, no hang"
}

if [ -e "${PENDINGCHK}" ]; then
    echo "$STAG Pending reboot, could not run!"
    exit 97
fi

_curr_dir=`pwd`

# Lock to test a single instance is running, and exit if wait timeout
echo "$STAG Checking if allowed to run..."
lock $bname || ( echo "$STAG Checking if allowed to run... failed"; exit 100 )
echo "$STAG Checking if allowed to run... done"

# Set TRAPs to release lock if forced to exit
trap __sig_int SIGINT
trap __sig_quit SIGQUIT
trap __sig_term SIGTERM
trap __sig_hup SIGHUP

if [ -e "${PENDINGCHK}" ]; then
    echo "$STAG Pending reboot, could not run!"
    my_exit 97
fi

#keeps log file from getting big
rm /var/log/$LOG_FILE >/dev/null 2>&1

TOTALARG=$#
while getopts :dn- FLAG; do
    case $FLAG in
		d ) VERBOSE=1;;
		n ) __NOHANG=1;;
        '-')
        show_help
        my_exit 0;;
        \?)
        log_write "Invalid option: -$OPTARG" && my_exit 1;;
        \:)
        log_write "Required argument not found for option: -$OPTARG" && my_exit 2;;
  esac
done

# removes processed option(s) from the cmd line args
shift $((OPTIND-1))

log_write "$STAG checking..."

# checks if user flash is mounted correctly
if ! checkflashconfig "$CONFIGMOUNT" "$CONFIGMOUNTTYPE" ; then
    # verifies if in recovery mode
    checkrecovery
    _RECOVERY=$?
    # checks if the block boot option is active from bootoptions.conf
    if [ ${BLOCKOPTION} -eq 1 ]; then
        if [ ${__NOHANG} -ne 1 ]; then
            if [ $_RECOVERY -eq 0 ]; then
                log_write "$STAG script process is blocked as flash config is in recovery mode!"
            else
                log_write "$STAG script process is blocked as flash config needs to be repaired!"
            fi
            _MYCOUNTER=0
            # makes sure the watchdog is manually started as systemd booting seq would be stuck to our process
            /etc/init.d/watchdog.sh start
            #loops forever to make sure any dependant service won't start when booting
            while [ $_MYCOUNTER -eq 0 ]; do
                sleep 1s
            done
        else
            if [ $_RECOVERY -ne 0 ]; then
                log_write "$STAG flash config needs to be repaired!"
                __EXITCODE=3
            fi
        fi
    else
        if [ $_RECOVERY -ne 0 ]; then
            # checks if flash could be mounted correctly
            tempdir=`mktemp -d`
            if [ $? -ne 0 ]; then
                log_write "$STAG could not create tmp directory!"
                my_exit 4
            fi
            if ! mount -t ${CONFIGMOUNTTYPE} -o ro,noatime,sync ${DEVCONFIG} ${tempdir}; then
                # we need to recreate flash content cause the system could not self warns the problem
                # and the flash is not mountable
                log_write "$STAG recreating configuration flash partition..."
                _C_RES=$(flash_erase -j /dev/mtd9 0 0 2>&1)
                _C_RET=$?
                if [ $_C_RET -ne 0 ]; then
                    log_write "Warning: cannot recreate flash partition!"
                    __EXITCODE=5
                else
                    log_write "$STAG recreating configuration flash partition... Done"
                    # attempt to use mountuser tool to get flash access
                    _C_RES=$(/usr/bin/mountuser rw 2>&1)
                    _C_RET=$?
                    if [ $_C_RET -eq 0 ]; then
                        log_write "$STAG recreating config flash partition content..."
                        cp -rf $CONFIGMOUNT/* $TMPMOUNT
                        if [ $? -ne 0 ]; then
                            log_write "Warning: cannot copy current config to flash mount!"
                            __EXITCODE=6
                        else
                            echo "---------------------------" >> $TMPMOUNT/config/motd
                            echo "Attempted to recreate Flash" >> $TMPMOUNT/config/motd
                            echo "---------------------------" >> $TMPMOUNT/config/motd
                            _C_RES=$(/usr/bin/mountuser ro 2>&1)
                            _C_RET=$?
                            if [ $_C_RET -ne 0 ]; then
                                log_write "Warning: cannot remount flash mount to read only!"
                                __EXITCODE=7
                            else
                                log_write "$STAG recreating config flash partition content... Done"
                            fi
                        fi
                    else
                        log_write "$STAG cannot access flash for rw access!"
                        __EXITCODE=8
                    fi
                fi
            else
                log_write "$STAG flash is mountable, won't be automatically repaired!"
                __EXITCODE=9
            fi
        fi
    fi
fi

log_write "$STAG checking... Done"
my_exit $__EXITCODE