#!/bin/sh

# Copyright (c) 2012 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.

UNDO_MOUNTS=
cleanup_mounts()
{
  # On failure unmount all saved mount points and repair stateful
  for mount_point in ${UNDO_MOUNTS}; do
    umount -n ${mount_point}
  done
  # Leave /mnt/stateful_partition mounted for clobber-state to handle.
  chromeos-boot-alert self_repair
  clobber-log -- \
    "Self-repair incoherent stateful partition: $*. History: ${UNDO_MOUNTS}"
  exec clobber-state "fast keepimg"
}
remember_mount()
{
    UNDO_MOUNTS="$1 ${UNDO_MOUNTS}"
}
mount_or_fail()
{
  local mount_point
  # -c: Never canonicalize: it is a hazard to resolve symlinks.
  # -n: Do not write to mtab: we don't use it.
  if mount -c -n "$@" ; then
    # Last parameter contains the mount point
    shift $(( $# - 1 ))
    # Push it on the undo stack if we fail later
    remember_mount "$1"
    return
  fi
  cleanup_mounts "failed to mount $*"
}

# Mount debugfs as bootstat depends on /sys/kernel/debug
mount -n -t debugfs -o nodev,noexec,nosuid,mode=0750,uid=0,gid=debugfs-access \
  debugfs /sys/kernel/debug

# bootstat writes timings to both tmpfs and debugfs.
bootstat pre-startup

# Some startup functions are split into a separate library which may be
# different for different targets (e.g., regular Chrome OS vs. embedded).
. /usr/share/cros/startup_utils.sh

# Factory related functions
. /usr/share/cros/factory_utils.sh

mkdir -p /dev/pts /dev/shm
mount -n -t tmpfs -o nodev,noexec,nosuid shmfs /dev/shm
mount -n -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts

# Initialize kernel sysctl settings early so that they take effect for boot
# processes.
sysctl -q -p /etc/sysctl.conf

# CROS_DEBUG equals one if we've booted in developer mode or we've
# booted a developer image.
crossystem "cros_debug?1"
CROS_DEBUG=$((! $?))

# Prepare to mount stateful partition
ROOT_DEV=$(rootdev -s)
ROOTDEV_RET_CODE=$?
# Example root dev types we need to handle: /dev/sda2 -> /dev/sda,
# /dev/mmcblk0p0 -> /dev/mmcblk0p, /dev/ubi2_1 -> /dev/ubi
ROOTDEV_TYPE=$(echo $ROOT_DEV | sed 's/[0-9_]*$//')
ROOTDEV_NAME=${ROOTDEV_TYPE##/dev/}
ROOTDEV_REMOVABLE=$(cat "/sys/block/${ROOTDEV_NAME}/removable")

# Load the GPT helper functions and the image settings.
. "/usr/sbin/write_gpt.sh"
if [ "${ROOTDEV_REMOVABLE}" = "1" ]; then
  load_partition_vars
else
  load_base_vars
fi

# Check if we are booted on physical media. rootdev will fail if we are in
# an initramfs or tmpfs rootfs (ex, factory installer images. Note recovery
# image also uses initramfs but it never reach here). When using initrd+tftpboot
# (some old netboot factory installer), ROOTDEV_TYPE will be /dev/ram.
if [ "$ROOTDEV_RET_CODE" = "0" -a "$ROOTDEV_TYPE" != "/dev/ram" ]; then
  # Find our stateful partition. It's always partition 1.
  # Unless we're on UBI, when it's ubi1_0.
  STATE_FLAGS="nodev,noexec,nosuid"
  if [ "${FORMAT_STATE}" = "ubi" ]; then
    STATE_DEV="/dev/ubi1_0"
  else
    STATE_DEV=${ROOTDEV_TYPE}1
    STATE_FLAGS="${STATE_FLAGS},commit=600"
  fi

  # Mount stateful partition from STATE_DEV.
  if ! mount -n -t ${FS_FORMAT_STATE} -o ${STATE_FLAGS} \
         "$STATE_DEV" /mnt/stateful_partition; then
    # Try to rebuild the stateful partition by clobber-state
    # (for security concern, we don't use fast mode)
    chromeos-boot-alert self_repair
    clobber-log --repair "$STATE_DEV" "Self-repair corrupted stateful partition"
    exec clobber-state "keepimg"
  fi

  # Mount the OEM partition.
  # mount_or_fail isn't used since this partition only has a filesystem
  # on some boards.
  OEM_FLAGS="ro,nodev,noexec,nosuid"
  if [ "${FORMAT_OEM}" = "ubi" ]; then
    OEM_DEV="/dev/ubi8_0"
  else
    OEM_DEV=${ROOTDEV_TYPE}8
  fi
  mount -n -t ${FS_FORMAT_OEM} -o ${OEM_FLAGS} ${OEM_DEV} /usr/share/oem
fi

# Sanity check the date (crosbug.com/13200)
if [ $(date +%Y) -lt 1970 ]; then
  date 010200001970.00
fi

# This file indicates a blocked developer mode transition attempt has occurred.
BLOCKED_DEV_MODE_FILE="/mnt/stateful_partition/.blocked_dev_mode"

# Check whether the device is allowed to boot in dev mode. If a debug
# build is already installed on the system, ignore block_devmode. It
# is pointless in this case, as the device is already in a state where
# the local user has full control.
#
# The up-front CROS_DEBUG check avoids forking a crossystem process in verified
# mode, thus keeping the check as lightweight as possible for normal boot.
if [ $CROS_DEBUG -eq 1 ]; then
  if crossystem "block_devmode?1" "debug_build?0" "devsw_boot?1"; then
    # Put a flag file into place that will trigger a stateful partition wipe
    # after reboot in verified mode.
    touch ${BLOCKED_DEV_MODE_FILE}
    chromeos-boot-alert block_devmode
  fi
fi

# 'firmware-boot-update' is provided by chromeos-firmware for legacy systems.
# On most new boards, it should be simply an empty file.
firmware-boot-update

# Now that stateful partition is mounted, we can check if we are in factory
# mode.
FACTORY_MODE=
if is_factory_mode; then
  FACTORY_MODE=factory
fi

# File used to trigger a stateful reset.  Contains arguments for
# the "clobber-state" call.  This file may exist at boot time, as
# some use cases operate by creating this file with the necessary
# arguments and then rebooting.
RESET_FILE="/mnt/stateful_partition/factory_install_reset"

# This file is created by clobber-state after the transition
# to dev mode.
DEV_MODE_FILE="/mnt/stateful_partition/.developer_mode"

FIRMWARE_TYPE=$(crossystem mainfw_type)

# Check for whether we need a stateful wipe, and alert the user as
# necessary.  We can wipe for several different reasons:
#  + Wipe for the factory build process.  This is signaled by
#    the existence of ${RESET_FILE} prior to reboot; the arguments
#    for clobber-state are set up before rebooting.
#  + User requested "power wash".  This is signaled in the same
#    way as the factory reset, but with different arguments in
#    ${RESET_FILE}.
#  + Switch from verified mode to dev mode.  We do this if we're in
#    dev mode, and ${DEV_MODE_FILE} doesn't exist.  clobber-state
#    in this case will create the file, to prevent re-wipe.
#  + Switch from dev mode to verified mode.  We do this if we're in
#    verified mode, and ${DEV_MODE_FILE} still exists.  (This check
#    isn't necessarily reliable.)
#
# Stateful wipe for dev mode switching is skipped if the build
# is a debug build or if we've booted in recovery mode (meaning
# from USB); this protects various development use cases, most
# especially booting Chromium OS on non-Chrome hardware.
#
if [ -O ${RESET_FILE} ]; then
  # Wipe requested on previous boot.  In the case of a factory wipe,
  # there can be a special message localized for the factory personnel.
  WIPE_MESSAGE_FILE=/mnt/stateful_partition/wipe_message.txt
  if [ -O "${WIPE_MESSAGE_FILE}" ]; then
    chromeos-boot-alert wipe "${WIPE_MESSAGE_FILE}"
  else
    chromeos-boot-alert power_wash
  fi
elif [ -z "$FACTORY_MODE" -a "$FIRMWARE_TYPE" != "recovery" ]; then
  if crossystem "devsw_boot?1" ; then
    # We've booted in dev mode.  For platforms using separated
    # normal/developer firmware, we need to display an extra boot
    # alert for the developer mode warning plus the 30-second delay.
    # Note that we want this message and the delay regardless of
    # whether we plan to wipe.
    if [ "$FIRMWARE_TYPE" != "developer" ]; then
      chromeos-boot-alert warn_dev
    fi

    if [ ! -O ${DEV_MODE_FILE} ] && crossystem "debug_build?0"; then
      # We're transitioning from verified boot to dev mode.
      # TODO(wad,wfrichar) Have user provide sudo/vt2 password here.
      chromeos-boot-alert enter_dev
      echo "keepimg" > ${RESET_FILE}
      clobber-log -- "Enter developer mode"
    fi

  elif [ -O ${DEV_MODE_FILE} -o -O ${BLOCKED_DEV_MODE_FILE} ] &&
      crossystem "debug_build?0"; then
    # We're transitioning from dev mode to verified boot.
    # When coming back from developer mode, we don't need to
    # clobber as aggressively.  Fast will do the trick.
    chromeos-boot-alert leave_dev
    echo "fast keepimg" > ${RESET_FILE}
    clobber-log -- "Leave developer mode"
  fi
fi

if [ -O ${RESET_FILE} ]; then
  ARGS="$(cat ${RESET_FILE})"
  exec clobber-state "$ARGS"
fi

# Check if we have an update to stateful pending.
STATEFUL_UPDATE="/mnt/stateful_partition/.update_available"
if [ $CROS_DEBUG -eq 1 -a -f "$STATEFUL_UPDATE" ] ; then
  # To remain compatible with the prior update_stateful tarballs, expect
  # the "var_new" unpack location, but move it into the new "var_overlay"
  # target location.
  VAR_TARGET="/mnt/stateful_partition/var"
  VAR_NEW="${VAR_TARGET}_new"
  VAR_OLD="${VAR_TARGET}_old"
  VAR_TARGET="${VAR_TARGET}_overlay"
  DEVELOPER_TARGET="/mnt/stateful_partition/dev_image"
  DEVELOPER_NEW="${DEVELOPER_TARGET}_new"
  DEVELOPER_OLD="${DEVELOPER_TARGET}_old"
  STATEFUL_UPDATE_ARGS=$(cat "$STATEFUL_UPDATE")

  # Only replace the developer and var_overlay directories if new replacements
  # are available.
  if [ -d "$DEVELOPER_NEW" -a -d "$VAR_NEW" ]; then
    clobber-log -- "Updating from $DEVELOPER_NEW && $VAR_NEW."
    rm -rf "$DEVELOPER_OLD" "$VAR_OLD"
    mv "$VAR_TARGET" "$VAR_OLD" || true
    mv "$DEVELOPER_TARGET" "$DEVELOPER_OLD" || true
    mv "$VAR_NEW" "$VAR_TARGET"
    mv "$DEVELOPER_NEW" "$DEVELOPER_TARGET"
  else
    clobber-log -- "Stateful update did not find $DEVELOPER_NEW && $VAR_NEW."
    clobber-log -- "Keeping old development tools."
  fi

  # Check for clobber.
  if [ "$STATEFUL_UPDATE_ARGS" = "clobber" ] ; then
    PRESERVE_DIR="/mnt/stateful_partition/unencrypted/preserve"

    # Find everything in stateful and delete it, except for protected paths, and
    # non-empty directories. The non-empty directories contain protected content
    # or they would already be empty from depth first traversal.

    find "/mnt/stateful_partition"  -depth -mindepth 1 \
        -not -path "/mnt/stateful_partition/.labmachine" \
        -not -path "${DEVELOPER_TARGET}/*" \
        -not -path "${VAR_TARGET}/*" \
        -not -path "${PRESERVE_DIR}/*" \
        -not -type d -print0 | xargs --null -r rm -f

    find "/mnt/stateful_partition"  -depth -mindepth 1 \
        -not -path "${DEVELOPER_TARGET}/*" \
        -not -path "${VAR_TARGET}/*" \
        -not -path "${PRESERVE_DIR}/*" \
        -type d -print0 | xargs --null -r rmdir --ignore-fail-on-non-empty

    # Let's really be done before coming back.
    sync
  fi

  # Backgrounded to take off boot path.
  rm -rf "$STATEFUL_UPDATE" "$DEVELOPER_OLD" "$VAR_OLD" &
fi

# Make sure unencrypted stateful partition has the needed common directories.
# Any non-common directories should be created in the device implementation of
# "mount_var_and_home_chronos".
for d in home home/chronos home/root home/user \
         unencrypted/cache unencrypted/preserve; do
  mkdir -p -m 0755 /mnt/stateful_partition/$d
done

# Mount /home.  This mount inherits nodev,noexec,nosuid from
# /mnt/stateful_partition above.
mount_or_fail --bind /mnt/stateful_partition/home /home

remember_mount /var
remember_mount /home/chronos
mount_var_and_home_chronos ${FACTORY_MODE} || cleanup_mounts "var and home"

# For dev/test images, if .gatherme presents, copy files listed in .gatherme to
# /mnt/stateful_partition/unencrypted/prior_logs.
LAB_PRESERVE_LOGS="/mnt/stateful_partition/.gatherme"
PRIOR_LOG_DIR="/mnt/stateful_partition/unencrypted/prior_logs"

if [ ${CROS_DEBUG} -eq 1 -a -f "${LAB_PRESERVE_LOGS}" ]; then
  for log_path in $(sed -e '/^#/ d' -e '/^$/ d' "${LAB_PRESERVE_LOGS}"); do
    if [ -d "${log_path}" ]; then
      cp -a -r --parents "${log_path}" "${PRIOR_LOG_DIR}" || true
    elif [ -f "${log_path}" ]; then
      cp -a "${log_path}" "${PRIOR_LOG_DIR}" || true
    fi
  done
  rm -rf /var/*
  rm -rf /home/chronos/*
  rm "${LAB_PRESERVE_LOGS}"
fi

# /run is now tmpfs used for runtime data. Make sure /var/run and /var/lock
# are sym links to /run and /run/lock respectively for backwards compatibility.
if [ ! -L /var/run ]; then
  rm -rf /var/run
  ln -s /run /var/run
fi
if [ ! -L /var/lock ]; then
  rm -rf /var/lock
  ln -s /run/lock /var/lock
fi

# Make sure required /var subdirectories exist.
mkdir -p -m 0755 /var/cache /var/db /var/empty /var/log/metrics \
                 /var/tmp

# /var/tmp must be world-writable and sticky
chmod 1777 /var/tmp
# /home/root must be group-writable and sticky
chmod 1771 /home/root
# Selected directories must belong to the chronos user.
chown chronos:chronos /home/chronos /var/log/metrics
# rsyslog needs to be able to create new logfiles, but not delete other logs
chgrp syslog /var/log
chmod 1775 /var/log

mount -n -t tmpfs -o nodev,noexec,nosuid media /media

# Mount stateful partition for dev packages.
if [ ${CROS_DEBUG} -eq 1 ]; then
  # Set up the logging dir that ASAN compiled programs will write to.  We want
  # any privileged account to be able to write here so unittests need not worry
  # about settings things up ahead of time.  See crbug.com/453579 for details.
  mkdir -p /var/log/asan
  chmod 1777 /var/log/asan

  # Capture a snapshot of "normal" mount state here, for auditability,
  # before we start applying devmode-specific changes.
  cat /proc/mounts > /var/log/mount_options.log
  # Create dev_image directory in base images in developer mode.
  if [ ! -d /mnt/stateful_partition/dev_image ]; then
    mkdir -p -m 0755 /mnt/stateful_partition/dev_image
  fi
  # Mount and then remount to enable exec/suid.
  mount_or_fail --bind /mnt/stateful_partition/dev_image /usr/local
  mount -n -o remount,exec,suid /usr/local

  # Set up /var elements needed by gmerge.
  # TODO(keescook) Use dev/test package installs instead of piling more
  # things here (crosbug.com/14091).
  BASE=/mnt/stateful_partition/var_overlay
  if [ -d ${BASE} ]; then
    # Keep this list in sync with the var_overlay elements in the DIRLIST
    # found in chromeos-install from chromeos-base/chromeos-installer.
    DIRLIST="
      db/pkg
      lib/portage
    "
    for DIR in ${DIRLIST}; do
      if [ ! -d ${BASE}/${DIR} ]; then
        continue
      fi
      DEST=/var/${DIR}
      if [ -e ${DEST} ]; then
        continue
      fi
      PARENT=$(dirname ${DEST})
      mkdir -p ${PARENT}
      ln -sf ${BASE}/${DIR} ${DEST}
    done
  fi
fi

bootstat post-startup

# Always return success to avoid killing init
exit 0