# Copyright 2016 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.

description    "Starts and stops the iSCSI initiator services and logs in to default targets"
author         "chromium-os-dev@chromium.org"

# TODO(printesoi): For now, booting from iSCSI will not work because
# InitiatorName file and idbm database must be writable and are located on the
# stateful partition.

start on started system-services
stop on stopping system-services
respawn

env CONFIG_FILE="/etc/iscsi/iscsid.conf"
env ISCSID_RUNTIME_DIR="/var/lib/iscsi"
env INITIATORNAME_FILE="/var/lib/iscsi/initiatorname.iscsi"

pre-start script
  log_msg() {
    logger -is -p daemon.info -t "$UPSTART_JOB" -- "$@"
  }

  log_error() {
    logger -is -p daemon.error -t "$UPSTART_JOB" -- "$@"
  }

  log_warning() {
    logger -is -p daemon.warning -t "$UPSTART_JOB" -- "$@"
  }

  check_runtime_dir() {
    local out ret=0
    if [ -d "${ISCSID_RUNTIME_DIR}" ]; then
      return 0
    fi
    out=$(mkdir -p "${ISCSID_RUNTIME_DIR}" 2>&1) || ret=$?
    if [ ${ret} -ne 0 ]; then
      log_error "Cannot create directory ${ISCSID_RUNTIME_DIR}: ${out}"
      log_error "The iSCSI driver cannot start."
      return 1
    fi
  }

  check_config() {
    if [ ! -e "${CONFIG_FILE}" ]; then
      log_error "Configuration file ${CONFIG_FILE} is missing!"
      log_error "The iSCSI driver has not been correctly installed and cannot start."
      return 1
    fi

    if [ ! -e "${INITIATORNAME_FILE}" ]; then
      log_error "InitiatorName file ${INITIATORNAME_FILE} is missing!"
      log_error "The iSCSI driver has not been correctly installed and cannot start."
      return 1
    fi

    if ! grep -q "^InitiatorName=[^[:space:]]" "${INITIATORNAME_FILE}"; then
      log_error "${INITIATORNAME_FILE} does not contain a valid InitiatorName"
      log_error "The iSCSI driver has not been correctly installed and cannot start."
      return 1
    fi
  }

  check_modules() {
    # Ensure that the kernel modules are loaded.
    modprobe -q iscsi_tcp 2>/dev/null || true
    modprobe -q ib_iser 2>/dev/null || true
  }

  if ! check_runtime_dir ; then
    stop
    exit 1
  fi
  if ! check_config ; then
    stop
    exit 2
  fi
  check_modules
end script

exec /sbin/minijail0 -I -l -v -r -p -- /usr/sbin/iscsid -c "${CONFIG_FILE}" \
       -i "${INITIATORNAME_FILE}"

post-start script
  log_msg() {
    logger -is -p daemon.info -t "$UPSTART_JOB" -- "$@"
  }

  log_warning() {
    logger -is -p daemon.warning -t "$UPSTART_JOB" -- "$@"
  }

  start_targets() {
    local ret=0
    log_msg "Setting up iSCSI targets"
    iscsiadm -m node --loginall=automatic 2>/dev/null || ret=$?
    if [ ${ret} -eq 21 ]; then
      ret=0
    fi
    return ${ret}
  }

  if ! start_targets ; then
    log_warning "Cannot start automatic target!"
    return 0
  fi
end script

pre-stop script
  log_msg() {
    logger -is -p daemon.info -t "$UPSTART_JOB" -- "$@"
  }

  log_warning() {
    logger -is -p daemon.warning -t "$UPSTART_JOB" -- "$@"
  }

  umount_path() {
    if [ $# -ne 1 ]; then
      return 1
    fi

    local ret=0 mount_point

    # Use printf because mount points may contain special characters like
    # spaces. Posix printf does not have '-v' so run a subshell.
    mount_point=$(printf "%b" "$1")
    out=$(sudo umount "${mount_point}" 2>&1)
    if [ $? -ne 0 ]; then
      log_warning "Could not unmount ${mount_point}"
      ret=1
    fi

    return ${ret}
  }

  block_is_iscsi() {
    if [ $# -ne 1 ]; then
      return 1
    fi

    local block_name="$1" platform_dev session_dir
    platform_dev="$(readlink -f "/sys/class/block/${block_name}")"
    session_dir="${platform_dev%%/target*/*:*}"

    if [ ! -d "${session_dir}/iscsi_session" ]; then
      return 1
    fi

    return 0
  }

  umount_iscsi() {
    local ret=0 block_dev mount_point tmp block_name platform_dev

    while IFS=' ' read -r block_dev mount_point tmp; do
      # Only check block devices.
      if [ "${block_dev#/dev/}" = "${block_dev}" ]; then
        continue;
      fi

      block_dev=$(readlink -f "${block_dev}")
      block_name="${block_dev##*/}"

      # TODO(printesoi): We must also unmount virtual block devices, such as
      # LVM2, software RAID or dm-crypt that contain iscsi slaves.
      if [ ! "${block_name#dm-}" = "${block_name}" ]; then
        continue
      fi

      if ! block_is_iscsi "${block_name}"; then
        continue
      fi
      if ! umount_path "${mount_point}"; then
        ret=1
      fi
    done </proc/mounts

    return ${ret}
  }

  stop_targets() {
    local ret=0

    log_msg "Disconnecting iSCSI targets"
    iscsiadm -m node --logoutall=all 2>/dev/null || ret=$?
    if [ ${ret} -eq 21 ]; then
      ret=0
    fi

    return ${ret}
  }

  if ! umount_iscsi ; then
    stop
    exit 1
  fi
  if ! stop_targets ; then
    stop
    exit 2
  fi
end script