alcove.sh

#!/system/bin/sh

# MIT License
#
# Copyright (c) 2018-2019 urain39 & Kyono
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# Exit safely
trap ":" HUP INT QUIT TERM

# NOTE: Below exit codes also applied to sub-scripts,
#       such as ${NEWROOT}/init.sh ...

NO_ERROR=0
ENV_ERROR=1
PERM_ERROR=2
BOOT_ERROR=3
UNKNOWN_ERROR=255

# XXX: '$(id -u)' may not work on android.
if [ x"${UID}" = "x" ]; then
  UID="$(id)"
  UID="${UID#*=}"
  UID="${UID%% *}"
  UID="${UID%\(*}"
fi

BOOT_DIR=""
umask 022 # Fix default permissions.

#
# Prechecks
#

type chroot > /dev/null 2>&1 || {
  echo "Not found chroot!"
  echo "Please install chroot and try again!"
  exit "${ENV_ERROR}"
}

[ "${UID}" != "0" ] && {
  echo "Please run ${0##*/} as root!"
  exit "${PERM_ERROR}"
}

#
# Functions
#

show_help()
{
  # NOTE: "${0}" always is same in script,
  #       it is name of script.
  cat <<HELP
alcove - a script to run linux on termux.

Usage: ${0##*/} <init|boot> <bootdir>

See also:
  QQGroup: 494453985
  https://github.com/95e2/linux-on-termux
HELP
}

alcove_init()
{
  cat > "${BOOT_DIR}/init.sh" <<INIT_SCRIPT
#!/bin/sh

# Exit safely
trap ":" HUP INT QUIT TERM

unset PREFIX TMPDIR HOME SHELL
unset LD_LIBRARY_PATH HISTFILE
unset ANDROID_ROOT ANDROID_DATA
unset EXTERNAL_STORAGE PROOT_TMP_DIR

export TERM="xterm"
export HOME="/root"
export PATH="/bin:/sbin:/usr/bin:/usr/sbin"
export PATH="\${PATH}:/usr/local/bin:/opt/bin"

# Preload profile
. /etc/profile

# Show logo, even though it was crashed.
echo "    _    _                    "
echo "   / \\\\  | | ___ _____   _____ "
echo "  / _ \\\\ | |/ __/ _ \\\\ \\\\ / / _ \\\\"
echo " / ___ \\\\| | (_| (_) \\\\ V /  __/"
echo "/_/   \\\\_\\\\_|\\\\___\\\\___/ \\\\_/ \\\\___| v1.2.5"
echo "                              "
echo " A chroot scripts to run linux on termux."

if [ -f /tmp/.alcove/alcove.running ]; then
  echo "Do not run /init.sh on a same system twice or more!"
  # NOTE: Exit code has been formatted.
  exit "${UNKNOWN_ERROR}"
fi

echo "IS RUNNING" > /tmp/.alcove/alcove.running

#
# Event-Hooks
#

COLOR_RESET="\033[0m"
COLOR_CLEAR="\r\033[K"
COLOR_BOLD_RED="\033[1;31m"
COLOR_BOLD_GREEN="\033[1;32m"

clear_print() {
  printf "\${COLOR_CLEAR}\${@}"
}

print_msg() {
  printf "\${@}"
}

print_ok() {
  clear_print "[  \${COLOR_BOLD_GREEN}OK\${COLOR_RESET}  ] \${@}\n"
}

print_failed() {
  clear_print "[\${COLOR_BOLD_RED}FAILED\${COLOR_RESET}] \${@}\n"
}

if [ -d /alcove-hooks ]; then
  rm -rf /tmp/.alcove/alcove-hooks # Path-Safe
  cp -rp /alcove-hooks /tmp/.alcove/alcove-hooks

  print_msg "Starting...\n"
  for s in /tmp/.alcove/alcove-hooks/*; do
    if [ ! -f "\${s}" ] || [ ! -x "\${s}" ]; then
      continue
    fi

    print_msg "Starting \${s} ..."
    "\${s}" "start"

    if [ "\${?}" = 0 ]; then
      print_ok "\${s}"
    else
      print_failed "\${s}"
    fi
  done

  su - root; ret="\${?}"

  print_msg "Stopping...\n"
  ls /tmp/.alcove/alcove-hooks/* | sort -r | while read -r s; do
    if [ ! -f "\${s}" ] || [ ! -x "\${s}" ]; then
      continue
    fi

    print_msg "Stopping \${s} ..."
    "\${s}" "stop"

    if [ "\${?}" = 0 ]; then
      print_ok "\${s}"
    else
      print_failed "\${s}"
    fi
  done
else
  su - root; ret="\${?}"
fi

# Cleanup
rm /tmp/.alcove/alcove.running
exit "\${ret}"
INIT_SCRIPT

  chmod 755 "${BOOT_DIR}"
  chmod 750 "${BOOT_DIR}/init.sh"

  # alcove binds
  cat > "${BOOT_DIR}/alcove.binds" <<ALCOVE_BINDS
# Syntax:
#   source_dir  newroot_dir
#   Use '#' at begin of a line to comment it.

# Example:

# sdcard
#/sdcard  /mnt/intsd
ALCOVE_BINDS

  chmod 644 "${BOOT_DIR}/alcove.binds"

  # mount point
  mkdir -p "${BOOT_DIR}/mnt/intsd"
  mkdir -p "${BOOT_DIR}/mnt/extsd"

  chmod 755 "${BOOT_DIR}/mnt/intsd"
  chmod 755 "${BOOT_DIR}/mnt/extsd"

  # alcove hooks
  mkdir -p "${BOOT_DIR}/alcove-hooks"
  cat > "${BOOT_DIR}/alcove-hooks/00-alcover" <<00_ALCOVER
#!/bin/sh

# Do nothing, always exit 0
exit 0
00_ALCOVER

  chmod 755 "${BOOT_DIR}/alcove-hooks"
  chmod 755 "${BOOT_DIR}/alcove-hooks/00-alcover"
}

alcove_mount()
{
  if [ -f "${BOOT_DIR}/tmp/.alcove/alcove.mounted" ]; then
    return
  fi

  mount -o bind /dev "${BOOT_DIR}/dev"
  mount -o bind /dev/pts "${BOOT_DIR}/dev/pts"
  mount -o bind /proc "${BOOT_DIR}/proc"
  mount -o bind /sys "${BOOT_DIR}/sys"
  mount -t tmpfs tmpfs "${BOOT_DIR}/tmp"

  if [ ! -d "${BOOT_DIR}/tmp/.alcove" ]; then
    mkdir "${BOOT_DIR}/tmp/.alcove"
  fi

  if [ ! -d "${BOOT_DIR}/dev/shm" ]; then
    mkdir "${BOOT_DIR}/dev/shm" && mount -t tmpfs tmpfs "${BOOT_DIR}/dev/shm" \
                                && chmod 1777 "${BOOT_DIR}/dev/shm"
    echo "SHM LOCKED" > "${BOOT_DIR}/tmp/.alcove/alcove.shmlock"
  fi

  if [ -f "${BOOT_DIR}/alcove.binds" ]; then
    # Fix error when user edited /alcove.binds .
    sed -n '/^#/d;/^[ \t]*$/d;p' "${BOOT_DIR}/alcove.binds" > "${BOOT_DIR}/tmp/.alcove/alcove.binds"
    while read -r SRC_PNT DST_PNT; do
      mount -o bind "${SRC_PNT}" "${BOOT_DIR}/${DST_PNT}"
    done < "${BOOT_DIR}/tmp/.alcove/alcove.binds" 
  fi

  if [ -d /data ] && [ -d /sdcard ]; then
    mount -o suid,remount /data
  fi

  echo "IS MOUNTED" > "${BOOT_DIR}/tmp/.alcove/alcove.mounted"
}

alcove_umount()
{
  if [ ! -f "${BOOT_DIR}/tmp/.alcove/alcove.mounted" ]; then
    return
  fi

  if [ -f "${BOOT_DIR}/tmp/.alcove/alcove.shmlock" ]; then
    umount "${BOOT_DIR}/dev/shm" && rm -r "${BOOT_DIR}/dev/shm"
    rm "${BOOT_DIR}/tmp/.alcove/alcove.shmlock"
  fi

  umount "${BOOT_DIR}/dev/pts"
  umount "${BOOT_DIR}/dev"
  umount "${BOOT_DIR}/proc"
  umount "${BOOT_DIR}/sys"

  if [ -f "${BOOT_DIR}/tmp/.alcove/alcove.binds" ]; then
    while read -r SRC_PNT DST_PNT; do
      umount "${BOOT_DIR}/${DST_PNT}"
    done < "${BOOT_DIR}/tmp/.alcove/alcove.binds" 
  fi

  if [ -d /data ] && [ -d /sdcard ]; then
    mount -o nosuid,remount /data
  fi

  rm "${BOOT_DIR}/tmp/.alcove/alcove.mounted"
  # Why and who cares about others?
  rm -r "${BOOT_DIR}/tmp/.alcove"
  umount "${BOOT_DIR}/tmp"
}

alcove_boot()
{
  unset LD_PRELOAD
  if [ ! -f "${BOOT_DIR}/etc/.resolv.conf.ok" ]; then
    rm -f "${BOOT_DIR}/etc/resolv.conf"
    echo "nameserver 8.8.4.4" > "${BOOT_DIR}/etc/resolv.conf"
    echo "nameserver 8.8.8.8" >> "${BOOT_DIR}/etc/resolv.conf"
    chmod 644 "${BOOT_DIR}/etc/resolv.conf"
    echo "DNS IS OK" > "${BOOT_DIR}/etc/.resolv.conf.ok"
  fi

  [ ! -f "${BOOT_DIR}/init.sh" ] && {
    echo "Not found [${BOOT_DIR}/init.sh]"
    echo "Have you run ${0##*/} init?"
    exit "${BOOT_ERROR}"
  }


  [ -f "${BOOT_DIR}/tmp/.alcove/alcove.mounted" ] && {
    echo "Do not boot a same system twice or more!"
    exit "${BOOT_ERROR}"
  }

  alcove_mount
  chroot "${BOOT_DIR}" /init.sh
  alcove_umount
}

main()
{
  if [ "${#}" -lt 2 ]; then
    show_help
    exit "${NO_ERROR}"
  fi

  BOOT_DIR="${2}"

  if [ ! -d "${BOOT_DIR}" ]; then
    echo "Not found path [${BOOT_DIR}]!"
    exit "${ENV_ERROR}"
  fi

  [ "${BOOT_DIR}" = "/" ] && exit "${ENV_ERROR}"

  case "${1}" in
  "init")
    alcove_init
    ;;
  "boot")
    alcove_boot
    ;;
  *)
    show_help
    exit "${NO_ERROR}"
    ;;
  esac
}


main "${@}"