#! /bin/sh
#
# smartd warning script
#
# Home page of code is: https://www.smartmontools.org
#
# Copyright (C) 2012-22 Christian Franke
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# $Id: smartd_warning.sh.in 5597 2024-01-24 10:30:14Z chrfranke $
#

set -e

# Set by config.status
export PATH="/usr/local/bin:/usr/bin:/bin"
# shellcheck disable=SC2034
PACKAGE="smartmontools"
VERSION="7.5"
prefix="/opt/local"
sysconfdir="${prefix}/etc"
smartdscriptdir="${sysconfdir}"

# Default mailer
os_mailer="mail"

# Plugin directory (disabled if empty)
plugindir="${smartdscriptdir}/smartd_warning.d"

# Detect accidental use of '-M exec /path/to/smartd_warning.sh'.
if [ -n "$SMARTD_SUBJECT" ]; then
  echo "$0: SMARTD_SUBJECT is already set - possible recursion" >&2
  exit 1
fi

# Parse options
dryrun=
case $1 in
  --dryrun) dryrun=t; shift ;;
esac

if [ $# != 0 ]; then
  cat <<EOF
smartd $VERSION warning message script

Usage:
  export SMARTD_MAILER='Path to external script, empty for "$os_mailer"'
  export SMARTD_ADDRESS='Space separated mail addresses, empty if none'
  export SMARTD_MESSAGE='Error Message'
  export SMARTD_FAILTYPE='Type of failure, "EMailTest" for tests'
  export SMARTD_TFIRST='Date of first message sent, empty if none'
  #export SMARTD_TFIRSTEPOCH='time_t format of above'
  export SMARTD_PREVCNT='Number of previous messages, 0 if none'
  export SMARTD_NEXTDAYS='Number of days until next message, empty if none'
  export SMARTD_DEVICEINFO='Device identify information'
  #export SMARTD_DEVICE='Device name'
  #export SMARTD_DEVICESTRING='Annotated device name'
  #export SMARTD_DEVICETYPE='Device type from -d directive, "auto" if none'
  $0 [--dryrun]
EOF
  exit 1
fi

if [ -z "${SMARTD_ADDRESS}${SMARTD_MAILER}" ]; then
  echo "$0: SMARTD_ADDRESS or SMARTD_MAILER must be set" >&2
  exit 1
fi

# Get host and domain names
# shellcheck disable=SC2041
for cmd in 'hostname' 'uname -n' 'echo "[Unknown]"'; do
  hostname=`eval $cmd 2>/dev/null` || continue
  test -n "$hostname" || continue
  break
done

dnsdomain=${hostname#*.}
if [ "$dnsdomain" != "$hostname" ]; then
  # hostname command printed FQDN
  hostname=${hostname%%.*}
else
  # shellcheck disable=SC2041
  for cmd in  'echo'; do
    dnsdomain=`eval $cmd 2>/dev/null` || continue
    break
  done
  test "$dnsdomain" != "(none)" || dnsdomain=
fi

# shellcheck disable=SC2041
for cmd in 'domainname' 'echo'; do
  nisdomain=`eval $cmd 2>/dev/null` || continue
  break
done
test "$nisdomain" != "(none)" || nisdomain=

# Format subject
export SMARTD_SUBJECT="SMART error (${SMARTD_FAILTYPE-[SMARTD_FAILTYPE]}) detected on host: $hostname"

# Format message
fullmessage=`
  echo "This message was generated by the smartd daemon running on:"
  echo
  echo "   host name:  $hostname"
  echo "   DNS domain: ${dnsdomain:-[Empty]}"
  test -z "$nisdomain" ||
    echo "   NIS domain: $nisdomain"
  #test -z "$USERDOMAIN" ||
  #  echo "   Win domain: $USERDOMAIN"
  echo
  echo "The following warning/error was logged by the smartd daemon:"
  echo
  echo "${SMARTD_MESSAGE-[SMARTD_MESSAGE]}"
  echo
  echo "Device info:"
  echo "${SMARTD_DEVICEINFO-[SMARTD_DEVICEINFO]}"
  echo
  echo "For details see host's SYSLOG."
  if [ "$SMARTD_FAILTYPE" != "EmailTest" ]; then
    echo
    echo "You can also use the smartctl utility for further investigation."
    test "$SMARTD_PREVCNT" = "0" ||
      echo "The original message about this issue was sent at ${SMARTD_TFIRST-[SMARTD_TFIRST]}"
    case $SMARTD_NEXTDAYS in
      '') echo "No additional messages about this problem will be sent." ;;
      0)  echo "Another message will be sent upon next check if the problem persists." ;;
      1)  echo "Another message will be sent in 24 hours if the problem persists." ;;
      *)  echo "Another message will be sent in $SMARTD_NEXTDAYS days if the problem persists." ;;
    esac
  fi
`

# Check whether a message line begins with the default 'mail' command escape char '~'.
# Heuristically detect dangerous command escapes for possible other escape characters.
esc=`echo "$fullmessage" | sed -n -e '/^~/p' -e '/^[^ 0-9A-Za-z][[:space:]]*[!:<r|][[:space:]]/p'`
if [ -n "$esc" ]; then
  echo "$0: Security: Message contains possible 'mail' command escape" >&2
  exit 1
fi

# Export message with trailing newline
export SMARTD_FULLMESSAGE="$fullmessage
"

# Run plugin scripts if requested
unset SMARTD_ADDRESS_ORIG
case " $SMARTD_ADDRESS" in
  *\ @*)
    # Collect and remove plugin names from SMARTD_ADDRESS
    export SMARTD_ADDRESS_ORIG=$SMARTD_ADDRESS
    SMARTD_ADDRESS=
    plugins=
    for ad in $SMARTD_ADDRESS_ORIG; do
      case $ad in
        @ALL)
          if [ -n "$plugindir" ]; then
            for cmd in "$plugindir"/*; do
              if [ -f "$cmd" ] && [ -x "$cmd" ]; then
                plugins="${plugins}${plugins:+ }${cmd##*/}"
              fi
            done
          fi
          ;;
        @?*)
          if [ -n "$plugindir" ]; then
            plugins="${plugins}${plugins:+ }${ad#@}"
          fi
          ;;
        *)
          SMARTD_ADDRESS="${SMARTD_ADDRESS}${SMARTD_ADDRESS:+ }$ad"
          ;;
      esac
    done

    # Run all scripts
    if [ -n "$plugins" ]; then
      if [ -n "$dryrun" ]; then
        echo "export SMARTD_ADDRESS='$SMARTD_ADDRESS'"
        echo "export SMARTD_ADDRESS_ORIG='$SMARTD_ADDRESS_ORIG'"
        echo "export SMARTD_SUBJECT='$SMARTD_SUBJECT'"
        echo "export SMARTD_FULLMESSAGE='$SMARTD_FULLMESSAGE'"
      fi
      for p in $plugins; do
        cmd="$plugindir/$p"
        if [ -f "$cmd" ]; then
          if [ -x "$cmd" ]; then
            if [ -n "$dryrun" ]; then
              echo "$cmd </dev/null"
            else
              rc=0
              "$cmd" </dev/null || rc=$?
              if [ $rc != 0 ]; then
                echo "$cmd: exit $rc" >&2
                exit $rc
              fi
            fi
          fi
        else
          echo "$cmd: not found" >&2
          exit 1
        fi
      done
    fi

    # Send email to remaining addresses
    test -n "$SMARTD_ADDRESS" || exit 0
    ;;
esac

# Send mail or run command
if [ -n "$SMARTD_ADDRESS" ]; then

  # Send mail, use platform mailer by default
  test -n "$SMARTD_MAILER" || SMARTD_MAILER=$os_mailer
  if [ -n "$dryrun" ]; then
    echo "exec '$SMARTD_MAILER' -s '$SMARTD_SUBJECT' $SMARTD_ADDRESS <<EOF
$fullmessage
EOF"
  else
    exec "$SMARTD_MAILER" -s "$SMARTD_SUBJECT" $SMARTD_ADDRESS <<EOF
$fullmessage
EOF
  fi

elif [ -n "$SMARTD_MAILER" ]; then

  # Run command
  if [ -n "$dryrun" ]; then
    echo "export SMARTD_SUBJECT='$SMARTD_SUBJECT'"
    echo "export SMARTD_FULLMESSAGE='$SMARTD_FULLMESSAGE'"
    echo "exec '$SMARTD_MAILER' </dev/null"
  else
    unset SMARTD_ADDRESS
    exec "$SMARTD_MAILER" </dev/null
  fi

fi
