source: bootscripts/lfs/init.d/network

#!/bin/sh
########################################################################
# Begin network
#
# Description : Network Control Script
#
# Authors     : Gerard Beekmans - gerard@linuxfromscratch.org
#               Nathan Coulson - nathan@linuxfromscratch.org
#               Kevin P. Fleming - kpfleming@linuxfromscratch.org
#               DJ Lucas - dj@linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs@linuxfromscratch.org
#
# Version     : LFS 7.0
#
########################################################################

### BEGIN INIT INFO
# Provides:            $network
# Required-Start:      $local_fs localnet swap
# Should-Start:        $syslog firewalld iptables nftables
# Required-Stop:       $local_fs localnet swap
# Should-Stop:         $syslog firewalld iptables nftables
# Default-Start:       2 3 4 5
# Default-Stop:        0 1 6
# Short-Description:   Starts and configures network interfaces.
# Description:         Starts and configures network interfaces.
# X-LFS-Provided-By:   LFS
### END INIT INFO

case "${1}" in
   start)
      # if the default route exists, network is already configured
      if ip route | grep -q "^default"; then return 0; fi
      # Start all network interfaces
      for file in /etc/sysconfig/ifconfig.*
      do
         interface=${file##*/ifconfig.}

         # Skip if $file is * (because nothing was found)
         if [ "${interface}" = "*" ]; then continue; fi

         /sbin/ifup ${interface}
      done
      ;;

   stop)
      # Unmount any network mounted file systems
       umount --all --force --types nfs,cifs,nfs4

      # Reverse list
      net_files=""
      for file in  /etc/sysconfig/ifconfig.*
      do
         net_files="${file} ${net_files}"
      done

      # Stop all network interfaces
      for file in ${net_files}
      do
         interface=${file##*/ifconfig.}

         # Skip if $file is * (because nothing was found)
         if [ "${interface}" = "*" ]; then continue; fi

         # See if interface exists
         if [ ! -e /sys/class/net/$interface ]; then continue; fi

         # Is interface UP?
         ip link show $interface 2>/dev/null | grep -q "state UP"
         if [ $? -ne 0 ];  then continue; fi

         /sbin/ifdown ${interface}
      done
      ;;

   restart)
      ${0} stop
      sleep 1
      ${0} start
      ;;

   *)
      echo "Usage: ${0} {start|stop|restart}"
      exit 1
      ;;
esac

exit 0

# End network