shark-files/usr/bin/UPDATE_FIRMWARE

#!/bin/bash

export LOG="logger -t Shark [*]"
export LOG_ERR="logger -t Shark -p 3 [!]"

upgrade_leds() {
    /usr/bin/LED OFF
    while true
    do
        echo 1 > /sys/class/leds/shark:red:system/brightness
        sleep 0.2
        echo 0 > /sys/class/leds/shark:red:system/brightness
        echo 1 > /sys/class/leds/shark:blue:system/brightness
        sleep 0.2
        echo 0 > /sys/class/leds/shark:blue:system/brightness
    done
}

# $1: Upgrade file
# $2: MD5 file
# $3: Upgrade file size in bytes
extract_md5() {
    dd if="${1}" of="${2}" skip="${3}" bs=1 count=33
}

# $1: Upgrade file
# $2: MD5 file
verify_md5() {
    expected=$(cat "${2}")
    checksum=$(md5sum "${1}" | awk '{print $1}')
    [ "${expected}" = "${checksum}" ] && {
        return 0
    }
    return 1
}

# $1: Upgrade file
# $2: Upgrade file size in bytes
truncate_upgrade() {
    dd if=/dev/null of="${1}" bs=1 seek="${2}"
}

execute_upgrade() {
    # Check for upgrade file in default location
    upgrade_file=$(find /tmp/upgrade-* -type f 2>/dev/null | tail -n1)

    if [ -f "${upgrade_file}" ]; then
        # Upgrade file found
        $LOG "Firmware upgrade found"

        $LOG "Verifying firmware upgrade"
        upgrade_file_size=$(( $(wc -c "${upgrade_file}" | awk '{print $1}') - 33 ))

        # Extract md5sum from upgrade file
        echo "extracting md5"
        extract_md5 "${upgrade_file}" /tmp/upgrade.md5 "${upgrade_file_size}"

        cp "${upgrade_file}" /tmp/upgrade.bin
        echo "truncating"
        truncate_upgrade /tmp/upgrade.bin "${upgrade_file_size}"

        # Verify upgrade file
        if ! verify_md5 /tmp/upgrade.bin /tmp/upgrade.md5; then
            # Upgrade file not verified; exit
            $LOG "Firmware upgrade not verified. File may be corrupt"
            LED FAIL &
            return 1
        fi
        $LOG "Firmware upgrade verified"
        LED OFF && LED G SUCCESS

        # Check battery state first
        $LOG "Checking device power state"
        battery_state=$(/usr/bin/BATTERY)
        if [ "${battery_state}" = "discharging" ] && [ ! -f "/etc/shark/cable" ]; then
            # Device is not plugged in
            $LOG "Device is not powered. Do not attempt firmware upgrade"
            return 1
        fi
        $LOG "Device is powered"

        # Remove upgrade file
        rm -rf "${upgrade_file}"
        sync

        # Upgrade file verified; run upgrade
        $LOG "Executing UPGRADE"
        sleep 2 && upgrade_leds &
        echo "sysupgrade -n /tmp/upgrade.bin" | at now

        exit
    else
        # Upgrade file not found; enter arming mode
        echo "Firmware update file is missing. Exiting."
        exit 1
    fi
}

check_for_internet() {
    if ! ping -q -c 1 -W 1 8.8.8.8 &>/dev/null 2>&1; then
        echo "You must have an internet connection to check for updates."
        exit 0
    fi
}

check_for_upgrade() {
    echo "Checking for updates"

    URL="https://downloads.hak5.org/api/devices/sharkjack/firmwares"
    if [ -f "/etc/shark/cable" ]; then
        URL="https://downloads.hak5.org/api/devices/sharkjack-cable/firmwares"
    fi

    wget $URL -qO /tmp/firmware_check
    remote_version=$(cat /tmp/firmware_check | jq -c '.[] | select( .latest_version == true ) | .version' | sed 's/-stable//' | sed 's/"//g')
    local_version=$(cat /root/VERSION)

    if [[ $remote_version != $local_version ]]; then
        echo "There is an update available!"
        echo "Press CTRL+C within the next 10 seconds to cancel."
        for i in {10..1}; do
            echo -n "$i..."
            sleep 1
        done
        echo ""
        echo ""
        echo "Please do not power off the device!"
        curl -sL https://downloads.hak5.org/api/devices/sharkjack/firmwares/$remote_version-stable -o "/tmp/upgrade-$remote_version.bin"
        execute_upgrade
    else
        echo "Your device is up-to-date."
        exit 0
    fi
}

main() {
    echo "Checking internet connection"
    check_for_internet

    check_for_upgrade
}

main