Ticket #3053: ifdown

#!/bin/bash 
########################################################################
# Begin /sbin/ifdown
#
# Description : Interface Down
#
# Authors     : Nathan Coulson - nathan@linuxfromscratch.org
#               Kevin P. Fleming - kpfleming@linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs@linuxfromscratch.org
#
# Version     : LFS 7.0
#
# Notes       : the ${file} variable is passed to the scripts found
#               in the /lib/services directory, to indicate what file the
#               service should source to get interface specifications.
#
########################################################################

RELEASE="7.0"

USAGE="Usage: $0 [ -hV ] [--help] [--version] interface"
VERSTR="LFS ifdown, version ${RELEASE}"

while [ $# -gt 0 ]; do
  case "$1" in
     --help | -h)     help="y"; break ;;

     --version | -V)  echo "${VERSTR}"; exit 0 ;;

     -*)              echo "ifup: ${1}: invalid option" >&2
                      echo "${USAGE}" >& 2
                      exit 2 ;;

     *)               break ;;
  esac
done

if [ -n "$help" ]; then
  echo "${VERSTR}"
  echo "${USAGE}"
  echo
  cat << HERE_EOF
ifdown is used to bring down a network interface.  The interface
parameter, e.g. eth0 or eth0:2, must match the trailing part of the
interface specifications file, e.g. /etc/sysconfig/ifconfig.eth0:2.

HERE_EOF
  exit 0
fi

file=/etc/sysconfig/ifconfig.${1}

# Skip backup files
[ "${file}" = "${file%""~""}" ] || exit 0

. /lib/lsb/init-functions 

if [ ! -r "${file}" ]; then
  log_warning_msg "${file} is missing or cannot be accessed."
  exit 1
fi

. ${file}

if [ -z "$PHYS" ]; then
  log_failure_msg "${file} does not define any physical interfaces [PHYS]."
  exit 1
fi

# Reverse the order
SERVICES=
for S in ${SERVICE}; do SERVICES="${SERVICES} ${S}"; done

# This will run the service scripts
EXISTING_INTERFACES=
for PHY in ${PHYS} ; do
  if ip link show ${PHY} > /dev/null 2>&1 ; then
    EXISTING_INTERFACES="${EXISTING_INTERFACES} ${PHY}"
  else
    log_warning_msg "Interface ${PHY} doesn't exist."
  fi
done

if [ -n "${EXISTING_INTERFACES}" ] ; then
  for S in ${SERVICES}; do

    if [ -n "${S}" -a -x "/lib/services/${S}" ]; then
      IFCONFIG=${file} /lib/services/${S} ${file} down
    else
      MSG="Unable to process ${file}.  Either"
      MSG="${MSG} the SERVICE variable was not set"
      MSG="${MSG} or the specified service cannot be executed."
      log_failure_msg "$MSG"
      exit 1
   fi
 done

  for PHY in "${EXISTING_INTERFACES}" ; do
    link_status=`ip link show ${PHY} 2>/dev/null`

    if [ -n "${link_status}" ]; then
      if [ "$(echo "${link_status}" | grep UP)" != "" ]; then
         #QRUX - Why does it matter if ${PHY} has an IP address?
         #QRUX - Seems like it should be taken it down regardless.
         if [ "$(ip addr show ${PHY} | grep 'inet ')" != ""  ]; then
            log_info_msg "Bringing down the ${PHY} interface..."
            ip link set ${PHY} down
            evaluate_retval
         fi
      fi
    fi
  done
else
  log_warning_msg "No interfaces among (${PHYS}) exist."
fi

# End /sbin/ifdown