#!/bin/sh
# This file contains functions that are used in multiple other scripts, i.e.
# shared functions. The purpose of centralising these, is to deduplicate code
# and increase maintainability
#
# By Dennis Groenen <tj.groenen@gmail.com>
# GPLv3 licensed
#

# Verbose-aware echo
ECHO_VERBOSE() {
  if test $VERBOSE == 1; then 
    echo -e "$1"; fi
}

# Detect the current environment
CHECK_ENV() {
    if test -d /scratchbox; then
      ENVIRONMENT="SDK"
    else
      if test -e /proc/component_version; then
        PROD=$($EXECPWR cat /proc/component_version | $EXECPWR grep product | $EXECPWR cut -d" " -f 6)
      else
        PROD=$(/usr/bin/sysinfoclient --get /component/product | $EXECPWR awk '{ print $3 }')
      fi

      case $PROD in
        RX-51)
          ENVIRONMENT="FREMANTLE"
          ;;
        RM-680|RM-696)
          ENVIRONMENT="HARMATTAN"
          ;;
        *)
          echo "busybox-power: unsupported environment: $PROD"
          exit 1
          ;;
      esac
    fi
}

# Check whether the user is root
CHECK_ROOT() {
    if test "`$EXECPWR id -u`" -ne 0; then
      echo "error: you're not running me as root"
      exit 1
    fi
}

# Get the version string of the package providing /bin/busybox
GETBBVERSION() {
    # XXX We assume the package "busybox" provides /bin/busybox
    /usr/bin/dpkg -s busybox | $EXECPWR awk '/^Version:/ {print $2}'
}

# Get the enforcement status of aegis' source origin check. Returns "1" when
# the check is active, otherwise "0"
GETORIGINCHECK_STATUS() {
    ENFORCE="/sys/kernel/security/validator/enforce"
    ENFORCE_HEX=`$EXECPWR cat $ENFORCE`
    SID_CHECK_BIT="2"

    if test "$ENFORCE_HEX" == ""; then exit 1; fi
    RETVAL="1"
    if test `echo $(($ENFORCE_HEX & $SID_CHECK_BIT))` -eq 0; then
      RETVAL="0"
    fi
    echo $RETVAL
}

# Set the enforcement status of aegis' source origin check. The check will be
# enabled when passed "1"; passing "0" will disable it.
# Works in both normal and open mode via aegisctl, and in patched open mode via
# via writing to sysfs entries directly
SETORIGINCHECK_STATUS() {
    ENABLE=$1

    ENFORCE="/sys/kernel/security/validator/enforce"
    ENFORCE_HEX=`$EXECPWR cat $ENFORCE`
    SID_CHECK_BIT="2"

    if test $ENABLE -gt 0; then
      if test `GETORIGINCHECK_STATUS` -eq 1; then return; fi # Already on
      ENFORCE_NEW_DEC=`echo $(($ENFORCE_HEX | $SID_CHECK_BIT))`
      ENFORCE_NEW_HEX=`printf "0x%02x" $ENFORCE_NEW_DEC`
      echo $ENFORCE_NEW_HEX > $ENFORCE 2> /dev/null
      if test $? -gt 0; then
        # Do not exit 1 on failure to re-enable the origincheck; not fatal for
        # (un)installation of busybox-power
        /usr/sbin/aegisctl +s > /dev/null
      fi
    else
      if test `GETORIGINCHECK_STATUS` -eq 0; then return; fi # Already off
      ENFORCE_NEW_DEC=`echo $(($ENFORCE_HEX ^ $SID_CHECK_BIT))`
      ENFORCE_NEW_HEX=`printf "0x%02x" $ENFORCE_NEW_DEC`
      echo $ENFORCE_NEW_HEX > $ENFORCE 2> /dev/null
      if test $? -gt 0; then
        /usr/sbin/aegisctl @s > /dev/null || exit 1
      fi
    fi

    ECHO_VERBOSE "new origincheck: $ENABLE ($ENFORCE_NEW_HEX)"
}