#!/bin/sh
#
# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# THIS FILE DEPENDS ON common.sh.

# ----------------------------------------------------------------------------
# ChromeOS Specific Utilities

# Retrieves MD5 hash of a given file.
cros_get_file_hash() {
  md5sum -b "$1" 2>/dev/null | sed 's/ .*//'
}

# Compares two files on Chrome OS (there may be no cmp/diff)
cros_compare_file() {
  local hash1="$(cros_get_file_hash "$1")"
  local hash2="$(cros_get_file_hash "$2")"
  debug_msg "cros_compare_file($1, $2): $hash1, $hash2"
  [ -n "$hash1" ] && [ "$hash1" = "$hash2" ]
}

# Compares two version string on Chrome OS
cros_compare_version() {
  local base="$1"
  local target="$2"

  # Return directly if exact match.
  if [ "$base" = "$target" ]; then
    echo "0"
    return
  fi

  # Now, compare each token by magic "sort -V" (--version-sort).
  local prior="$( (echo "$base"; echo "$target") | sort -V | head -n 1)"
  if [ "$prior" = "$base" ]; then
    echo "-1"
  else
    echo "1"
  fi
}

# Shortcut to compare version compatibility.
# Ex: cros_version_greater_than "$mp_fwid" "$RO_FWID" && die "Need update"
cros_version_greater_than() {
  [ "$(cros_compare_version "$1" "$2")" = "1" ]
}

# Gets file size.
cros_get_file_size() {
  [ -e "$1" ] || die "cros_get_file_size: invalid file: $1"
  stat -c "%s" "$1" 2>/dev/null
}

# Gets a Chrome OS system property (must exist).
cros_get_prop() {
  crossystem "$@" || die "cannot get crossystem property: $@"
}

# Sets a Chrome OS system property.
cros_set_prop() {
  if [ "${FLAGS_dry_run}" = "${FLAGS_TRUE}" ]; then
    alert "dry_run: cros_set_prop $@"
    return ${FLAGS_TRUE}
  fi
  crossystem "$@" || die "cannot SET crossystem property: $@"
}

# Queries a Chrome OS system property, return error if not available.
cros_query_prop() {
  crossystem "$@" 2>/dev/null || debug_msg "FAILURE: crossystem $@"
}

# Sets the "startup update tries" counter.
cros_set_startup_update_tries() {
  local startup_update_tries="$1"
  local fwupdate_tries=$(crossystem fwupdate_tries)
  if [ -n "$fwupdate_tries" ]; then
    cros_set_prop fwupdate_tries=$startup_update_tries
  fi
}

# Gets the "startup update tries" counter.
cros_get_startup_update_tries() {
  local fwupdate_tries=$(crossystem fwupdate_tries || echo 0)
  echo $fwupdate_tries
}

# Sets the "firmare B tries" counter
cros_set_fwb_tries() {
  cros_set_prop fwb_tries="$1"
}

cros_get_fwb_tries() {
  cros_query_prop fwb_tries
}

# Reboots the system immediately
cros_reboot() {
  verbose_msg "Rebooting system..."
  if [ "${FLAGS_dry_run}" = "${FLAGS_TRUE}" ]; then
    alert "dry_run: reboot"
    return ${FLAGS_TRUE}
  elif [ "${FLAGS_allow_reboot}" = "${FLAGS_FALSE}" ]; then
    alert "Rebooting from updater is disabled."
    return ${FLAGS_TRUE}
  fi
  sync
  # For systems with low speed disk storage, more few seconds for hardware to
  # complete I/O.
  sleep 1
  reboot
  # 'reboot' command terminates immediately, so we must block here to prevent
  # further execution.
  sleep 1d
}

# Returns if the hardware write-protection switch is enabled.
cros_is_hardware_write_protected() {
  local ret=""
  # In current design, hardware write protection is one single switch for all
  # targets (BIOS & EC). On some platforms, wpsw_cur is not availble and only
  # wpsw_boot can be trusted. NOTE: if wpsw_* all gives error, we should treat
  # wpsw as "protected", just to be safe.
  case "$(cros_query_prop wpsw_cur)" in
    "0" )
      ret=$FLAGS_FALSE
      ;;
    "1" )
      ret=$FLAGS_TRUE
      ;;
  esac
  [ "$ret" = "" ] && case "$(cros_query_prop wpsw_boot)" in
    "0" )
      alert "Warning: wpsw_cur is not availble, using wpsw_boot (0)"
      ret=$FLAGS_FALSE
      ;;
    "1" )
      alert "Warning: wpsw_cur is not availble, using wpsw_boot (1)"
      ret=$FLAGS_TRUE
      ;;
    * )
      # All wp* failed.
      alert "Warning: wpsw_boot/cur all failed. Assuming HW write protected."
      ret=$FLAGS_TRUE
      ;;
  esac
  return $ret
}

# Returns if the software write-protection register is enabled.
cros_is_software_write_protected() {
  local opt="$1"
  # Do not pipe flashrom stdout to grep to prevent SIGPIPE
  FLASHROM_OUT=$(flashrom $opt --wp-status 2>/dev/null)
  echo $FLASHROM_OUT | grep -q "write protect is enabled"
}

# Reports write protection status
cros_report_wp_status() {
  local test_main="$1" test_ec="$2"
  local wp_hw="off" wp_sw_main="off" wp_sw_ec="off"
  cros_is_hardware_write_protected && wp_hw="ON"
  local message="Hardware: $wp_hw, Software:"
  if [ "$test_main" = $FLAGS_TRUE ]; then
    cros_is_software_write_protected "$TARGET_OPT_MAIN" && wp_sw_main="ON"
    message="$message Main=$wp_sw_main"
  fi

  # On many 3rd party EC implementations, checking write protection
  # (--wp-status) may hang device for up to 2~3 seconds, so we want to prevent
  # querying WP status in modes that does not touch EC.
  case "$FLAGS_mode" in
    autoupdate | bootok | todev )
      test_ec=$FLAGS_FALSE
      ;;
  esac

  if [ "$test_ec" = $FLAGS_TRUE ]; then
    cros_is_software_write_protected "$TARGET_OPT_EC" && wp_sw_ec="ON"
    message="$message EC=$wp_sw_ec"
  fi
  echo "$message"
}

# Reports the information from given key file.
cros_report_key() {
  local key_file="$1"
  local key_hash="$(vbutil_key --unpack "$key_file" |
                    sed -nr 's/^Key sha1sum: *([^ ]*)$/\1/p')"
  local label=""
  case "$key_hash" in
    b11d74edd286c144e1135b49e7f0bc20cf041f10 )
      label="DEV-signed rootkey"
      ;;
    "" )
      label="Unknown (failed to unpack key)"
      ;;
    * )
      ;;
  esac
  echo "$key_hash $label"
}

# Checks if the root keys (from Google Binary Block) are the same.
cros_check_same_root_keys() {
  check_param "cros_check_same_root_keys(current, target)" "$@"
  local keyfile1="_gk1"
  local keyfile2="_gk2"
  local keyfile1_strip="${keyfile1}_strip"
  local keyfile2_strip="${keyfile2}_strip"
  local ret=${FLAGS_TRUE}

  # current(1) may not contain root key, but target(2) MUST have a root key
  if silent_invoke "gbb_utility -g --rootkey=$keyfile1 $1" 2>/dev/null; then
    silent_invoke "gbb_utility -g --rootkey=$keyfile2 $2" ||
      die "Cannot find ChromeOS GBB RootKey in $2."
    # to workaround key paddings...
    cat $keyfile1 | sed 's/\xff*$//g; s/\x00*$//g;' >$keyfile1_strip
    cat $keyfile2 | sed 's/\xff*$//g; s/\x00*$//g;' >$keyfile2_strip
    if ! cros_compare_file "$keyfile1_strip" "$keyfile2_strip"; then
      ret=$FLAGS_FALSE
      alert "Current key: $(cros_report_key "$keyfile1")"
      alert "Target  key: $(cros_report_key "$keyfile2")"
    fi
  else
    debug_msg "warning: cannot get rootkey from $1"
    ret=$FLAGS_ERROR
  fi
  return $ret
}

# Gets the vbutil_firmware information of a RW firmware image.
cros_get_rw_firmware_info() {
  check_param "cros_get_rw_firmware_info(vblock, fw_main, image)" "$@"
  local vblock="$1"
  local fw_main="$2"
  local image="$3"

  local rootkey="_rootkey"
  silent_invoke "gbb_utility -g --rootkey=$rootkey $image" 2>/dev/null ||
    return

  local fw_info
  fw_info="$(vbutil_firmware --verify "$vblock" \
                             --signpubkey "$rootkey" \
                             --fv "$fw_main" 2>/dev/null)" || fw_info=""
  echo "$fw_info"
}

# Checks if the firmare key and version are allowed by TPM.
cros_check_tpm_key_version() {
  check_param "cros_check_tpm_key_version(fw_info)" "$@"
  local fw_info="$1"

  local tpm_fwver="$(cros_query_prop tpm_fwver)"
  if [ -z "$tpm_fwver" ]; then
    die "Failed to retrieve TPM information."
  fi
  tpm_fwver="$((tpm_fwver))"
  debug_msg "tpm_fwver: $tpm_fwver"

  local data_key_version="$(
    echo "$fw_info" | sed -n '/^ *Data key version:/s/.*:[ \t]*//p')"
  debug_msg "data_key_version: $data_key_version"
  local firmware_version="$(
    echo "$fw_info" | sed -n '/^ *Firmware version:/s/.*:[ \t]*//p')"
  debug_msg "firmware_version: $firmware_version"
  if [ -z "$data_key_version" ] || [ -z "$firmware_version" ]; then
    die "Cannot verify firmware key version from target image."
  fi

  local fw_key_version="$((
    (data_key_version << 16) | (firmware_version & 0xFFFF) ))"
  debug_msg "fw_key_version: $fw_key_version"

  if [ "$tpm_fwver" -gt "$fw_key_version" ]; then
    fw_key_version="$(printf "0x%x" $fw_key_version)"
    tpm_fwver="$(printf "0x%x" $tpm_fwver)"
    alert "Firmware key ($fw_key_version) will be rejected by TPM ($tpm_fwver)."
    return $FLAGS_FALSE
  fi
  return $FLAGS_TRUE
}

# Gets the flag of firmware preamble data.
cros_get_firmware_preamble_flags() {
  check_param "cros_get_firmware_preamble_flags(fw_info)" "$@"
  local fw_info="$1"

  local preamble_flags="$(
    echo "$fw_info" | sed -n '/^ *Preamble flags:/s/.*:[ \t]*//p')"
  debug_msg "preamble_flags: $preamble_flags"
  echo "$preamble_flags"
}

# Returns if firmware was boot with VBSD_LF_USE_RO_NORMAL flag.
cros_is_ro_normal_boot() {
  local VBSD_LF_USE_RO_NORMAL=0x08
  local vdat_flags="$(cros_get_prop vdat_flags 2>/dev/null)"
  [ "$((vdat_flags & VBSD_LF_USE_RO_NORMAL))" -gt "0" ]
}

# Clears ChromeOS related NVData (usually stored on NVRAM/CMOS, storing firmware
# related settings and cookies).
cros_clear_nvdata() {
  mosys nvram clear >/dev/null 2>&1 ||
    debug_msg " - (NVData not cleared)."
}

# Adds path to PATH if given tool is available (and supports empty param).
cros_add_tool_path() {
  local path="$1"
  local tool="$2"
  if [ -x "$path/$tool" ] && "$path/$tool" >/dev/null 2>&1; then
    debug_msg "$path/$tool works fine."
    PATH="$path:$PATH"; export PATH
    return $FLAGS_TRUE
  fi
  return $FLAGS_FALSE
}

# Configures PATH by detecting if current architecture is compatible with
# bundled executable binaries, then "32b" (if exist) or system default ones.
cros_setup_path() {
  local base="$(readlink -f "$SCRIPT_BASE")"
  if cros_add_tool_path "$base" "crossystem"; then
    debug_msg "Using programs in $base."
    return
  fi

  if cros_add_tool_path "$base/32b" "crossystem"; then
    debug_msg "Using programs in $base/32b."
    return
  fi

  debug_msg "Using programs in system."

  # flashrom has changed its syntax (crosbug.com/p/16211). When we're upgrading
  # with programs in previous system, it is possible the old flashrom does not
  # support new syntax so we must check.
  if ! flashrom $TARGET_OPT_MAIN --version >/dev/null 2>&1; then
    alert "Using flashrom in current system rootfs with legacy target syntax."
    TARGET_OPT_MAIN="-p internal:bus=spi"
    TARGET_OPT_EC="-p internal:bus=lpc"
  fi
}

# Reset lock file variable.
LOCK_FILE=""

cros_acquire_lock() {
  LOCK_FILE="${1:-/tmp/chromeos-firmwareupdate-running}"
  debug_msg "cros_acquire_lock: Set lock file to $LOCK_FILE."
  # TODO(hungte) Use flock to help locking in better way.
  if [ -r "$LOCK_FILE" ]; then
    local pid="$(cat "$LOCK_FILE")"
    if [ -z "$pid" ]; then
      # For legacy updaters or corrupted systems, PID is empty.
      die "Firmware Updater already running ($LOCK_FILE) with unknown process."
    else
      ps "$pid" >/dev/null 2>&1 &&
        die "
          Firmware Updater already running ($LOCK_FILE).
          Please wait for process $pid to finish and retry later."
    fi
    alert "Warning: Removing expired session lock: $LOCK_FILE ($pid)"
  fi
  echo "$PPID" >"$LOCK_FILE"
  # Clean up on regular or error exits.
  trap cros_release_lock EXIT
}

cros_release_lock() {
  if [ -n "$LOCK_FILE" ]; then
    rm -f "$LOCK_FILE" || alert "Warning: failed to release $LOCK_FILE."
  fi
}

# Utility function to override RW firmware image by version.
# Example: cros_override_rw_firmware_by_version "$RO_FWID" "$TARGET_FWID"
cros_override_rw_firmware_by_version() {
  local current_id="$1"
  local min_ro_id="$2"
  local is_factory=""

  # RW update only happens in autoupdate and recovery (without WP) modes.
  case "$FLAGS_mode" in
    startup | bootok | todev | tonormal | factory_final | factory_install | \
      incompatible_update )
      return
      ;;
    recovery )
      # For recovery mode, if WP is not enabled, we will work in
      # factory/incompatible update mode.
      is_mainfw_write_protected || return
      ;;
    autoupdate )
      true
      ;;
    * )
      debug_msg "Warning: unknown mode for RW version test: $FLAGS_mode"
      return
  esac

  debug_msg "cros_override_rw_firmware_by_version($current_id, $min_ro_id)"
  if cros_version_greater_than "$min_ro_id" "$current_id"; then
    is_mainfw_write_protected || alert "
      You are updating a device with deprecated RO firmware $current_id.
      For safety concern, we don't push RO updates by default.
      If you are willing to take the RISK OF BRICKING DEVICE, you can manually
      invoke firmware updater (and make sure write protection is disabled) as:

       chromeos-firmwareupdate --mode=incompatible_update
      "
    [ -s "$IMAGE_MAIN_RW" ] && cp -f "$IMAGE_MAIN_RW" "$IMAGE_MAIN" &&
      preserve_hwid &&
      alert "Updating with RW firmware (slower boot time)." ||
      die "Failed to load RW firmware. Can't update."
  fi
}