#!/bin/bash
# /etc/rc.d/rc.inet1
# This script is used to bring up the various network interfaces.
#
# @(#)/etc/rc.d/rc.inet1 10.2  Sun Jul 24 12:45:56 PDT 2005  (pjv)

############################
# READ NETWORK CONFIG FILE #
############################

# Get the configuration information from /etc/rc.d/rc.inet1.conf:
. /etc/rc.d/rc.inet1.conf

###########
# LOGGING #
###########

# If possible, log events in /var/log/messages:
if [ -f /var/run/syslogd.pid ] && [ -x /usr/bin/logger ]; then
  LOGGER=/usr/bin/logger
else # output to stdout/stderr:
  LOGGER=/bin/cat
fi

# Handy wrapper for verbose logging
debug_log() {
  if [ "$DEBUG_ETH_UP" = "yes" ]; then
    echo "/etc/rc.d/rc.inet1:  $*" | $LOGGER
  fi
}

############################
# DETERMINE INTERFACE LIST #
############################

# Compose a list of interfaces from /etc/rc.d/rc.inet1.conf (with a maximum
# of 6 interfaces, but you can easily enlarge the interface limit
# - send me a picture of such a box :-).
# If a value for IFNAME[n] is not set, we assume it is an eth'n' interface.
# This way, the new script is compatible with older rc.inet1.conf files.
# The IFNAME array will be used to determine which interfaces to bring up/down.
MAXNICS=${MAXNICS:-6}
i=0
while [ $i -lt $MAXNICS ];
do
  IFNAME[$i]=${IFNAME[$i]:=eth${i}}
  i=$(($i+1))
done
debug_log "List of interfaces: '${IFNAME[*]}'"

####################
# PRE-LOAD MODULES #
####################

for i in "${IFNAME[@]}"; do
  # If the interface isn't in the kernel yet (but there's an alias for it in modules.conf),
  # then it should be loaded first:
  if [ ! -e /sys/class/net/${i%%:*} ]; then # no interface yet
    if /sbin/modprobe -c | grep -v "^#" | grep -w "alias ${i%%:*}" | grep -vw "alias ${i%%:*} off" >/dev/null; then
      echo "/etc/rc.d/rc.inet1:  /sbin/modprobe ${i%%:*}" | $LOGGER
      /sbin/modprobe ${i%%:*}
      _DID_MODPROBE=1
    fi
  fi
done
# Normally the ipv6 module would be automatically loaded when the first IP is assigned to an
# interface (assuming ipv6 has not been disabled entirely), but autoconf/accept_ra need to be
# set to 0 before that happens, so try to pre-load ipv6 here.
if [ ! -e /proc/sys/net/ipv6 ]; then
  /sbin/modprobe ipv6
  _DID_MODPROBE=1
fi
# If we did any module loading in the blocks above, sleep for a couple of
# seconds to give time for everything to "take"
[ -n "${_DID_MODPROBE}" ] && sleep 2
unset _DID_MODPROBE

######################
# LOOPBACK FUNCTIONS #
######################

# Function to bring up the loopback interface.  If loopback is
# already up, do nothing.
lo_up() {
  if [ -e /sys/class/net/lo ]; then
    if ! /sbin/ip link show dev lo | grep -wq -e "state UP" -e "state UNKNOWN" ; then
      echo "/etc/rc.d/rc.inet1:  /sbin/ip address add 127.0.0.1/8 dev lo" | $LOGGER
      /sbin/ip address add 127.0.0.1/8 dev lo
      /sbin/ip link set dev lo up
      echo "/etc/rc.d/rc.inet1:  /sbin/ip route add 127.0.0.0/8 dev lo" | $LOGGER
      /sbin/ip route add 127.0.0.0/8 dev lo
    fi
  fi
}

# Function to take down the loopback interface:
lo_down() {
  if [ -e /sys/class/net/lo ]; then
    echo "/etc/rc.d/rc.inet1:  /sbin/ip address flush dev lo" | $LOGGER
    /sbin/ip address flush dev lo
    echo "/etc/rc.d/rc.inet1:  /sbin/ip link set dev lo down" | $LOGGER
    /sbin/ip link set dev lo down
  fi
}

#######################
# INTERFACE FUNCTIONS #
#######################

# Function to create virtual interfaces
virtif_create() {
  # argument is 'i' - the position of this interface in the VIRTIFNAME array.
  # this loop goes from i=0 to i=number_of_configured_virtual_interfaces_minus_one
  # which means it doesn't do anything if there are none.
  for i in $(seq 0 $((${#VIRTIFNAME[@]} - 1))); do
    /sbin/ip tuntap add dev ${VIRTIFNAME[$i]} mode ${VIRTIFTYPE[$i]} user ${VIRTIFUSER[$i]} group ${VIRTIFGROUP[$i]}
  done
}

# Function to destory virtual interfaces
virtif_destroy() {
  # argument is 'i' - the position of this interface in the VIRTIFNAME array.
  for i in $(seq 0 $((${#VIRTIFNAME[@]} - 1))); do
    /sbin/ip tuntap del dev ${VIRTIFNAME[$i]} mode ${VIRTIFTYPE[$i]}
  done
}

# Function to assemble a bridge interface.
br_open() {
  # argument is 'i' - the position of this interface in the IFNAME array.
  /sbin/ip link add name ${IFNAME[$1]} type bridge
  for BRIF in ${BRNICS[$1]}; do
    /sbin/ip link set dev $BRIF down
    /sbin/ip address add 0.0.0.0 dev $BRIF
    /sbin/ip link set dev $BRIF master ${IFNAME[$1]}
    /sbin/ip link set dev $BRIF up
  done
  /sbin/ip link set dev ${IFNAME[$1]} up
}

# Function to disassemble a bridge interface.
br_close() {
  /sbin/ip link set dev ${IFNAME[$1]} down
  # argument is 'i' - the position of this interface in the IFNAME array.
  #for BRIF in ${BRNICS[$1]}; do
  for BRIF in $(ls --indicator-style=none /sys/class/net/${IFNAME[$1]}/brif/)
  do
    /sbin/ip link set dev $BRIF nomaster
  done
  /sbin/ip link set dev ${IFNAME[$1]} down
  /sbin/ip link del ${IFNAME[$1]}
}

# Function to bring up a network interface.  If the interface is
# already up or does not yet exist (perhaps because the kernel driver
# is not loaded yet), do nothing.
if_up() {
  # Determine position 'i' of this interface in the IFNAME array:
  i=0
  while [ $i -lt $MAXNICS ]; do
    [ "${IFNAME[$i]}" = "${1}" ] && break
    i=$(($i+1))
  done
  # If "i" is greater or equal to "MAXNICS" at this point, it means we didn't
  # find an entry in IFNAME array corresponding to "$1", which likely means
  # there are more interfaces configured than MAXNICS. Let's err on the
  # side of caution and do nothing instead of possibly doing the wrong thing.
  if [ $i -ge $MAXNICS ]; then
    echo "/etc/rc.d/rc.inet1:  skipping ${1}, you might need to increase MAXNICS" | $LOGGER
    return
  fi
  # If the interface is a bridge, then create it first:
  [ -n "${BRNICS[$i]}" ] && br_open $i
  # Skip unconfigured interfaces:
  if [ -z "${IPADDR[$i]}" ] && [ "${USE_DHCP[$i]}" != "yes" ] && [ -z "${IP6ADDR[$i]}" ] && \
      [ "${USE_DHCP6[$i]}" != "yes" ] && [ "${USE_SLAAC[$i]}" != "yes" ]; then
    debug_log "skipping ${1} early, interface is not configured in /etc/rc.d/rc.inet1.conf"
    return
  fi
  if [ -e /sys/class/net/${1%%:*} ]; then # interface exists
    if ! /sbin/ip address show scope global dev ${1} 2>/dev/null | grep -Ewq '(inet|inet6)' || \
        ! /sbin/ip link show dev ${1} | grep -wq "state UP"; then # interface not up or not configured
      # Set hardware address _before_ the interface goes up:
      if [ -n "${HWADDR[$i]}" ]; then
        echo "/etc/rc.d/rc.inet1:  /sbin/ip link set dev ${1} address ${HWADDR[$i]}" | $LOGGER
        /sbin/ip link set dev ${1} address ${HWADDR[$i]}
      fi
      # Initialize any wireless parameters:
      if [ -x /etc/rc.d/rc.wireless ]; then
        . /etc/rc.d/rc.wireless ${1} start
      fi
      if [ -e /proc/sys/net/ipv6 ]; then # ipv6 networking is available
        # Disable v6 IP auto configuration before trying to bring up the interface:
        echo "0" >/proc/sys/net/ipv6/conf/$1/autoconf
        if [ "${USE_RA[$i]}" = "yes" ]; then
          # Unconditionally accept router advertisements on this interface:
          echo "1" >/proc/sys/net/ipv6/conf/$1/accept_ra
        else
          # Disable router advertisments on this interface until SLAAC is enabled:
          echo "0" >/proc/sys/net/ipv6/conf/$1/accept_ra
        fi
      fi
      local IF_UP=0
      # Slackware historically favours dynamic configuration over fixed IP to configure interfaces, so keep that tradition:
      if [ "${USE_DHCP[$i]}" = "yes" ] || { [ -e /proc/sys/net/ipv6 ] && [ "${USE_DHCP6[$i]}" = "yes" ]; }; then # use dhcpcd
        # Declare DHCP_OPTIONS array before adding new options to it:
        declare -a DHCP_OPTIONS=()
        # Set DHCP_OPTIONS for this interface:
        if [ -e /proc/sys/net/ipv6 ]; then
          if [ "${USE_DHCP[$i]}" = "yes" ] && [ "${USE_DHCP6[$i]}" != "yes" ]; then # only try v4 dhcp
            DHCP_OPTIONS+=("-4")
          elif [ "${USE_DHCP[$i]}" != "yes" ] && [ "${USE_DHCP6[$i]}" = "yes" ]; then # only try v6 dhcp
            DHCP_OPTIONS+=("-6")
          fi
        else
          DHCP_OPTIONS+=("-4")
        fi
        [ -n "${DHCP_HOSTNAME[$i]}" ] && DHCP_OPTIONS+=("-h" "${DHCP_HOSTNAME[$i]}")
        [ "${DHCP_KEEPRESOLV[$i]}" = "yes" ] && DHCP_OPTIONS+=("-C" "resolv.conf")
        [ "${DHCP_KEEPNTP[$i]}" = "yes" ] && DHCP_OPTIONS+=("-C" "ntp.conf")
        [ "${DHCP_KEEPGW[$i]}" = "yes" ] && DHCP_OPTIONS+=("-G")
        [ "${DHCP_DEBUG[$i]}" = "yes" ] && DHCP_OPTIONS+=("-d")
        # The -L option used to be hard coded into the dhcpcd command line in -current.  Previous versions did not have
        # this hard coded.  The code here keeps the 14.2 behaviour, but can be altered to make the use of -L default as
        # in -current.  To change the behaviour, alter the test to be:  [ "${DHCP_NOIPV4LL[$i]}" != "no" ]
        [ "${DHCP_NOIPV4LL[$i]}" = "yes" ] && DHCP_OPTIONS+=("-L")
        [ -n "${DHCP_IPADDR[$i]}" ] && DHCP_OPTIONS+=("-r" "${DHCP_IPADDR[$i]}")
        echo "${1}: polling for DHCP server"
        # 15 seconds should be a reasonable default DHCP timeout.  30 was too much.
        echo "/etc/rc.d/rc.inet1:  /sbin/dhcpcd -t ${DHCP_TIMEOUT[$i]:-15} ${DHCP_OPTIONS[@]} ${1}" | $LOGGER
        if /sbin/dhcpcd -t "${DHCP_TIMEOUT[$i]:-15}" "${DHCP_OPTIONS[@]}" ${1}; then
          # Enable accepting of RA packets if explicitly told to:
          if [ -e /proc/sys/net/ipv6 ] && [ "${USE_RA[$i]}" = "yes" ]; then
            echo "1" >/proc/sys/net/ipv6/conf/$1/accept_ra
          fi
          IF_UP=1
        else
          echo "/etc/rc.d/rc.inet1:  failed to obtain DHCP lease for ${1}" | $LOGGER
          /sbin/ip address flush dev ${1}
          /sbin/ip link set dev ${1} down
        fi
      fi
      if [ -e /proc/sys/net/ipv6 ] && [ "${USE_DHCP6[$i]}" != "yes" ] && [ "${USE_SLAAC[$i]}" = "yes" ]; then # configure via SLAAC
        # Enable accepting of RA packets, unless explicitly configured not to:
        if [ "${USE_RA[$i]}" = "no" ]; then
          echo "0" >/proc/sys/net/ipv6/conf/$1/accept_ra
        else
          echo "/etc/rc.d/rc.inet1:  enabling RA for ${1}" | $LOGGER
          echo "1" >/proc/sys/net/ipv6/conf/$1/accept_ra
        fi
        # Enable auto configuration of interfaces:
        echo "/etc/rc.d/rc.inet1:  enabling SLAAC for ${1}" | $LOGGER
        echo "1" >/proc/sys/net/ipv6/conf/$1/autoconf
        # Bring the interface up:
        /sbin/ip link set dev ${1} up
        echo "${1}: waiting for router announcement"
        for ((j = ${SLAAC_TIMEOUT[$i]:=15} * 2; j--;)); do # by default, wait a max of 15 seconds for the interface to configure
          /sbin/ip -6 address show dynamic dev ${1} 2>/dev/null | grep -Ewq 'inet6' && { IF_UP=1; break; }
          sleep 0.5
        done
        if (($IF_UP != 1)); then
          echo "${1}: timed out"
          echo "/etc/rc.d/rc.inet1:  failed to auto configure ${1} after ${SLAAC_TIMEOUT[$i]} seconds" | $LOGGER
          /sbin/ip address flush dev ${1}
          /sbin/ip link set dev ${1} down
        fi
      fi
      if [ "${USE_DHCP[$i]}" != "yes" ] && [ -n "${IPADDR[$i]}" ]; then # add a fixed v4 IP to the interface
        if [ -z "${NETMASK[$i]}" ]; then
          echo "/etc/rc.d/rc.inet1:  no NETMASK set for ${1} - assuming 24 (aka, 255.255.255.0)" | $LOGGER
          NETMASK[$i]="24"
        fi
        echo "/etc/rc.d/rc.inet1:  /sbin/ip -4 address add ${IPADDR[$i]}/${NETMASK[$i]#/} broadcast + dev ${1}" | $LOGGER
        if /sbin/ip -4 address add ${IPADDR[$i]}/${NETMASK[$i]#/} broadcast + dev ${1} && \
            /sbin/ip link set dev ${1} up; then
          IF_UP=1
        else
          echo "/etc/rc.d/rc.inet1:  failed to set IP ${IPADDR[$i]} for ${1}" | $LOGGER
          /sbin/ip address flush dev ${1}
          /sbin/ip link set dev ${1} down
        fi
      fi
      if [ -e /proc/sys/net/ipv6 ] && [ "${USE_DHCP6[$i]}" != "yes" ] && [ "${USE_SLAAC[$i]}" != "yes" ] && \
          [ -n "${IP6ADDR[$i]}" ]; then # add a fixed v6 IP
        # IPv6's Duplicate Address Detection (DAD) causes a race condition when bringing up interfaces, as
        # described here:  https://www.agwa.name/blog/post/beware_the_ipv6_dad_race_condition
        # Disable DAD while bringing up the interface - but note that this means the loss of detection of a
        # duplicate address.  It's a trade off, unfortunately.
        echo "0" >/proc/sys/net/ipv6/conf/$1/accept_dad
        if [ -z "${PREFIXLEN[$i]}" ]; then
          echo "/etc/rc.d/rc.inet1:  no PREFIXLEN set for ${1} - assuming 64" | $LOGGER
          PREFIXLEN[$i]="64"
        fi
        echo "/etc/rc.d/rc.inet1:  /sbin/ip -6 address add ${IP6ADDR[$i]}/${PREFIXLEN[$i]#/} dev ${1}" | $LOGGER
        if /sbin/ip -6 address add ${IP6ADDR[$i]}/${PREFIXLEN[$i]#/} dev ${1} && \
            /sbin/ip link set dev ${1} up; then
          # Enable accepting of RA packets if explicitly told to.
          if [ "${USE_RA[$i]}" = "yes" ]; then
            echo "1" >/proc/sys/net/ipv6/conf/$1/accept_ra
          fi
          IF_UP=1
        else
          echo "/etc/rc.d/rc.inet1:  failed to set IP ${IP6ADDR[$i]} for ${1}" | $LOGGER
          if (($IF_UP != 1)); then # a v4 address was configured, don't flush it
            /sbin/ip address flush dev ${1}
            /sbin/ip link set dev ${1} down
          fi
        fi
      fi
      if (($IF_UP == 1)); then # only do further config if the interface came up
        # Add extra IPv4 and v6 addresses to the interface:
        if [ -n "${IPALIASES[$i]}" ]; then
          num=0
          for ipalias in ${IPALIASES[$i]}; do
            ip="${ipalias%/*}"
            nm="${ipalias#*/}"
            [ -z "$nm" ] || [ "$ip" == "$nm" ] && nm="24"
            echo "/etc/rc.d/rc.inet1:  /sbin/ip -4 address add ${ip}/${nm} dev ${1} label ${1}:${num}" | $LOGGER
            if /sbin/ip -4 address add ${ip}/${nm} dev ${1} label ${1}:${num}; then
              num=$(($num + 1))
            else
              echo "/etc/rc.d/rc.inet1:  failed to add IP ${ip} to ${1}" | $LOGGER
            fi
          done
        fi
        if [ -e /proc/sys/net/ipv6 ] && [ -n "${IP6ALIASES[$i]}" ]; then
          # IPv6's Duplicate Address Detection (DAD) causes a race condition when bringing up interfaces, as
          # described here:  https://www.agwa.name/blog/post/beware_the_ipv6_dad_race_condition
          # Disable DAD while bringing up the interface - but note that this means the loss of detection of a
          # duplicate address.  It's a trade off, unfortunately.
          echo "0" >/proc/sys/net/ipv6/conf/$1/accept_dad
          for ipalias in ${IP6ALIASES[$i]}; do
            ip="${ipalias%/*}"
            nm="${ipalias#*/}"
            [ -z "$nm" ] || [ "$ip" == "$nm" ] && nm="64"
            # Unlike IPv4, v6 addresses don't get a label:
            echo "/etc/rc.d/rc.inet1:  /sbin/ip -6 address add ${ip}/${nm} dev ${1}" | $LOGGER
            /sbin/ip -6 address add ${ip}/${nm} dev ${1} || \
                echo "/etc/rc.d/rc.inet1:  failed to add IP ${ip} to ${1}" | $LOGGER
          done
        fi
        # Force an MTU (possibly over-riding that set by DHCP or RA):
        if [ -n "${MTU[$i]}" ]; then
          echo "/etc/rc.d/rc.inet1:  /sbin/ip link set dev ${1} mtu ${MTU[$i]}" | $LOGGER
          /sbin/ip link set dev ${1} mtu ${MTU[$i]}
        fi
        # Set promiscuous mode on the interface:
        if [ "${PROMISCUOUS[$i]}" = "yes" ]; then
          echo "/etc/rc.d/rc.inet1:  /sbin/ip link set dev ${1} promisc on" | $LOGGER
          /sbin/ip link set dev ${1} promisc on
        fi
        # Reset accept_dad back to default now all the IPs are configured:
        if [ -e /proc/sys/net/ipv6 ]; then
          cat /proc/sys/net/ipv6/conf/default/accept_dad >/proc/sys/net/ipv6/conf/$1/accept_dad
        fi
      fi
    else
      debug_log "${1} is already up, skipping"
    fi
  else
    debug_log "${1} interface does not exist (yet)"
  fi
}

# Function to take down a network interface:
if_down() {
  # Determine position 'i' of this interface in the IFNAME array:
  i=0
  while [ $i -lt $MAXNICS ]; do
    [ "${IFNAME[$i]}" = "${1}" ] && break
    i=$(($i+1))
  done
  if [ $i -ge $MAXNICS ]; then
    echo "/etc/rc.d/rc.inet1:  skipping ${1}, you might need to increase MAXNICS" | $LOGGER
    return
  fi
  if [ -e /sys/class/net/${1%%:*} ]; then
    if [ "${USE_DHCP[$i]}" = "yes" ] || [ "${USE_DHCP6[$i]}" = "yes" ]; then # take down dhcpcd
      # When using -k, dhcpcd requires some command line options to match those used to invoke it:
      if [ "${USE_DHCP[$i]}" = "yes" ] && [ "${USE_DHCP6[$i]}" != "yes" ]; then # only v4 dhcp
        DHCP_OPTIONS="-4"
      elif [ "${USE_DHCP[$i]}" != "yes" ] && [ "${USE_DHCP6[$i]}" = "yes" ]; then # only v6 dhcp
        DHCP_OPTIONS="-6"
      fi
      echo "/etc/rc.d/rc.inet1:  /sbin/dhcpcd $DHCP_OPTIONS -k -d ${1}" | $LOGGER
      /sbin/dhcpcd $DHCP_OPTIONS -k -d ${1} 2>/dev/null || \
          echo "/etc/rc.d/rc.inet1:  failed to stop dhcpcd for interface ${1}" | $LOGGER
    fi
    # Disable v6 IP auto configuration and RA before trying to clear the IP from the interface:
    if [ -e /proc/sys/net/ipv6 ]; then
      echo "0" >/proc/sys/net/ipv6/conf/$1/autoconf
      echo "0" >/proc/sys/net/ipv6/conf/$1/accept_ra
    fi
    sleep 0.5 # allow time for dhcp/ra to unconfigure the interface
    # Flush any remaining IPs:
    echo "/etc/rc.d/rc.inet1:  /sbin/ip address flush dev ${1}" | $LOGGER
    /sbin/ip address flush dev ${1}
    # Bring the interface down:
    echo "/etc/rc.d/rc.inet1:  /sbin/ip link set dev ${1} down" | $LOGGER
    /sbin/ip link set dev ${1} down
    # Reset autoconf and accept_ra back to defaults:
    if [ -e /proc/sys/net/ipv6 ]; then
      cat /proc/sys/net/ipv6/conf/default/autoconf >/proc/sys/net/ipv6/conf/$1/autoconf
      cat /proc/sys/net/ipv6/conf/default/accept_ra >/proc/sys/net/ipv6/conf/$1/accept_ra
    fi
    # Kill wireless daemons if any:
    if [ -x /etc/rc.d/rc.wireless ]; then
      . /etc/rc.d/rc.wireless ${1} stop
    fi
    # If the interface is a bridge, then destroy it now:
    if [ -n "${BRNICS[$i]}" ]; then
      br_close $i
    fi
  fi
}

#####################
# GATEWAY FUNCTIONS #
#####################

# Function to bring up the gateway if there is not yet a default route:
gateway_up() {
  # Bring up the IPv4 gateway:
  if [ -n "$GATEWAY" ]; then
    if ! /sbin/ip -4 route show | grep -wq default; then
      echo "/etc/rc.d/rc.inet1:  /sbin/ip -4 route add default via ${GATEWAY}" | $LOGGER
      /sbin/ip -4 route add default via ${GATEWAY}
    fi
  fi
  # Bring up the IPv6 gateway:
  if [ -n "$GATEWAY6" ]; then
    if ! /sbin/ip -6 route show | grep -wq default; then
      echo "/etc/rc.d/rc.inet1:  /sbin/ip -6 route add default via ${GATEWAY6}" | $LOGGER
      /sbin/ip -6 route add default via ${GATEWAY6}
    fi
  fi
}

# Function to take down an existing default gateway:
gateway_down() {
  if /sbin/ip -4 route show | grep -wq default ; then
    echo "/etc/rc.d/rc.inet1:  /sbin/ip -4 route del default" | $LOGGER
    /sbin/ip -4 route del default
  fi
  if /sbin/ip -6 route show | grep -wq default ; then
    echo "/etc/rc.d/rc.inet1:  /sbin/ip -6 route del default" | $LOGGER
    /sbin/ip -6 route del default
  fi
}

# Function to start the network:
start() {
  lo_up
  virtif_create
  for i in "${IFNAME[@]}" ; do
    if_up $i
  done
  gateway_up
}

# Function to stop the network:
stop() {
  gateway_down
  for i in "${IFNAME[@]}" ; do
    if_down $i
  done
  virtif_destroy
  lo_down
}


############
### MAIN ###
############

case "$1" in
start|up) # "start" (or "up") brings up all configured interfaces:
  start
  ;;
stop|down) # "stop" (or "down") takes down all configured interfaces:
  stop
  ;;
restart) # "restart" restarts the network:
  stop
  start
  ;;
lo_start|lo_up) # Start the loopback interface:
  lo_up
  ;;
lo_stop|lo_down) # Stop the loopback interface:
  lo_down
  ;;
*_start|*_up) # Example: "eth1_start" (or "eth1_up") will start the specified interface 'eth1'
  INTERFACE=$(echo $1 | /bin/cut -d '_' -f 1)
  if_up $INTERFACE
  gateway_up
  ;;
*_stop|*_down) # Example: "eth0_stop" (or "eth0_down") will stop the specified interface 'eth0'
  INTERFACE=$(echo $1 | /bin/cut -d '_' -f 1)
  if_down $INTERFACE
  ;;
*_restart) # Example: "wlan0_restart" will take 'wlan0' down and up again
  INTERFACE=$(echo $1 | /bin/cut -d '_' -f 1)
  if_down $INTERFACE
  sleep 1
  if_up $INTERFACE
  gateway_up
  ;;
*) # The default is to bring up all configured interfaces:
  start
esac

# End of /etc/rc.d/rc.inet1