source: bootscripts/lfs/sysconfig/network-devices/ifdown@ a45cfee

#!/bin/sh
########################################################################
# Begin $network_devices/ifdown
#
# Description : Interface Down
#
# Authors     : Nathan Coulson - nathan@linuxfromscratch.org
#               Kevin P. Fleming - kpfleming@linuxfromscratch.org
#
# Version     : 00.01
#
# Notes       : the IFCONFIG variable is passed to the scripts found
#               in the services directory, to indicate what file the
#               service should source to get environmental variables.
#
########################################################################

. /etc/sysconfig/rc 
. ${rc_functions} 

# Collect a list of configuration files for our interface
if [ -n "${2}" ]; then
        for file in ${@#$1}; do # All parameters except $1
                FILES="${FILES} ${network_devices}/ifconfig.${1}/${file}"
        done
elif [ -d "${network_devices}/ifconfig.${1}" ]; then
        FILES=`echo ${network_devices}/ifconfig.${1}/*`
else
        FILES="${network_devices}/ifconfig.${1}"
fi

# Reverse the order configuration files are processed in
for file in ${FILES}; do
        FILES2="${file} ${FILES2}"
done
FILES=${FILES2}

# Process each configuration file
for file in ${FILES}; do
        # skip backup files
        if [ "${file}" != "${file%""~""}" ]; then
                continue
        fi

        if [ ! -f "${file}" ]; then
                boot_mesg "${file} is not a network configuration file or directory." ${WARNING}
                echo_warning
                continue
        fi
        (
                . ${file}

                # Will not process this service if started by boot, and ONBOOT
                # is not set to yes
                if [ "${IN_BOOT}" = "1" -a "${ONBOOT}" != "yes" ]; then
                        continue
                fi

                # Will not process this service if started by hotplug, and 
                # ONHOTPLUG is not set to yes
                if [ "${IN_HOTPLUG}" = "1" -a "${ONHOTPLUG}" != "yes" ]; then
                        continue
                fi
        
                # This will run the service script, if SERVICE is set
                if [ -n "${SERVICE}" -a -x "${network_devices}/services/${SERVICE}" ]; then
                        if ip link show ${1} > /dev/null 2>&1
                        then
                                IFCONFIG=${file} ${network_devices}/services/${SERVICE} ${1} down
                        else
                                boot_mesg "Interface ${1} doesn't exist." ${WARNING}
                                echo_warning
                        fi
                else
                        boot_mesg -n "Unable to process ${file}.  Either" ${FAILURE}
                        boot_mesg -n " the SERVICE variable was not set,"
                        boot_mesg " or the specified service cannot be executed."
                        echo_failure
                        continue
                fi
        )
done

if [ -z "${2}" ]; then
        link_status=`ip link show $1 2> /dev/null`
        if [ -n "${link_status}" ]; then
                if echo "${link_status}" | grep -q UP; then
                        boot_mesg "Bringing down the ${1} interface..."
                        ip link set ${1} down
                        evaluate_retval
                fi
        fi
fi

# End $network_devices/ifdown