lfs-book-zh_CN/bootscripts/lfs/lib/services/ipv4-static

#!/bin/sh
########################################################################
# Begin /lib/services/ipv4-static
#
# Description : IPV4 Static Boot Script
#
# Authors     : Nathan Coulson - nathan@linuxfromscratch.org
#               Kevin P. Fleming - kpfleming@linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs@linuxfromscratch.org
#
# Version     : LFS 7.0
#
########################################################################

. /lib/lsb/init-functions
. ${IFCONFIG}

if [ -z "${IP}" ]; then
   log_failure_msg "\nIP variable missing from ${IFCONFIG}, cannot continue."
   exit 1
fi

if [ -z "${PREFIX}" -a -z "${PEER}" ]; then
   log_warning_msg "\nPREFIX variable missing from ${IFCONFIG}, assuming 24."
   PREFIX=24
   args="${args} ${IP}/${PREFIX}"

elif [ -n "${PREFIX}" -a -n "${PEER}" ]; then
   log_failure_msg "\nPREFIX and PEER both specified in ${IFCONFIG}, cannot continue."
   exit 1

elif [ -n "${PREFIX}" ]; then
   args="${args} ${IP}/${PREFIX}"

elif [ -n "${PEER}" ]; then
   args="${args} ${IP} peer ${PEER}"
fi

if [ -n "${BROADCAST}" ]; then
   args="${args} broadcast ${BROADCAST}"
fi

case "${2}" in
   up)
      if [ "$(ip addr show ${1} | grep ${IP})" == "" ]; then
         log_info_msg2 "\n" # Terminate the previous message
         log_info_msg "Adding IPv4 address ${IP} to the ${1} interface..."
         ip addr add ${args} dev ${1}
         evaluate_retval

         if [ -n "${GATEWAY}" ]; then
            if ip route | grep -q default; then
               log_warning_msg "\nGateway already setup; skipping."
            else
               log_info_msg "Setting up default gateway..."
               ip route add default via ${GATEWAY} dev ${1}
               evaluate_retval
             fi
         fi
      else
         msg="Cannot add IPv4 address ${IP} to ${1}.  Already present."
         log_warning_msg "$msg"
      fi
   ;;

   down)
      if [ "$(ip addr show ${1} | grep ${IP})" != "" ]; then
         log_info_msg "Removing IPv4 address ${IP} from the ${1} interface..."
         ip addr del ${args} dev ${1}
         evaluate_retval
      fi

      if [ -n "${GATEWAY}" ]; then
         # Only remove the gateway if ther are no remaining ipv4 addresses
         if [ "$(ip addr show ${1} | grep 'inet ')" != "" ]; then
            log_info_msg "Removing default gateway..."
            ip route del default
            evaluate_retval
         fi
      fi
   ;;

   *)
      echo "Usage: ${0} [interface] {up|down}"
      exit 1
   ;;
esac

# End /lib/services/ipv4-static