#!/bin/bash

# dhclient-script for Linux. Dan Halbert, March, 1997.
# Updated for Linux 2.[12] by Brian J. Murrell, January 1999.
# Modified for Debian.  Matt Zimmerman and Eloy Paris, December 2003
# Modified to remove useless tests for antiquated kernel versions that
# this doesn't even work with anyway, and introduces a dependency on /usr
# being mounted, which causes cosmetic errors on hosts that NFS mount /usr
# Andrew Pollock, February 2005
# Modified to work on point-to-point links. Andrew Pollock, June 2005

# The alias handling in here probably still sucks. -mdz

if [ -n "${dhc_dbus}" ]; then
   /usr/bin/dbus-send \
       --system \
       --dest=com.redhat.dhcp \
       --type=method_call \
       /com/redhat/dhcp/$interface \
       com.redhat.dhcp.set \
       'string:'"`env | /bin/egrep -v '^(PATH|SHLVL|_|PWD|dhc_dbus)\='`";
       if (( ( dhc_dbus & 31 ) == 31 )); then
           exit 0;
       fi;
fi;

make_resolv_conf() {
    if [ -n "$new_domain_name" -o -n "$new_domain_name_servers" ]; then
        local new_resolv_conf=/etc/resolv.conf.dhclient-new
        rm -f $new_resolv_conf

        if [ -n "$new_domain_name" ]; then
            echo search $new_domain_name >> $new_resolv_conf
        else # keep 'old' search/domain scope
            egrep -i '^ *[:space:]*(search|domain)' /etc/resolv.conf >> \
                  $new_resolv_conf
        fi
        
        if [ -n "$new_domain_name_servers" ]; then
            for nameserver in $new_domain_name_servers; do
                echo nameserver $nameserver >>$new_resolv_conf
            done
        else # keep 'old' nameservers
            egrep -i '^ *[:space:]*nameserver' /etc/resolv.conf >> \
                  $new_resolv_conf
        fi

        chown --reference=/etc/resolv.conf $new_resolv_conf
        chmod --reference=/etc/resolv.conf $new_resolv_conf
        mv $new_resolv_conf /etc/resolv.conf
    fi
}

run_hook() {
    local script="$1"
    local exit_status

    if [ -f $script ]; then
        . $script
    fi


    if [ -n "$exit_status" ] && [ "$exit_status" -ne 0 ]; then
        logger -p daemon.err "$script returned non-zero exit status $exit_status"
        save_exit_status=$exit_status
    fi

    return $exit_status
}

run_hookdir() {
    local dir="$1"
    local exit_status

    if [ -d "$dir" ]; then
        for script in $(run-parts --list $dir); do
            run_hook $script || true
            exit_status=$?
        done
    fi

    return $exit_status
}

# Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
exit_with_hooks() {
    exit_status=$1

    # Source the documented exit-hook script, if it exists
    if ! run_hook /etc/dhcp3/dhclient-exit-hooks; then
        exit_status=$?
    fi

    # Now run scripts in the Debian-specific directory.
    if ! run_hookdir /etc/dhcp3/dhclient-exit-hooks.d; then
        exit_status=$?
    fi

    exit $exit_status
}

set_hostname() {
    local current_hostname=$(hostname)
    if [ -z "$current_hostname" -o "$current_hostname" = "(none)" ]; then
        hostname "$new_host_name"
    fi
}

if [ -n "$new_broadcast_address" ]; then
    new_broadcast_arg="broadcast $new_broadcast_address"
fi
if [ -n "$old_broadcast_address" ]; then
    old_broadcast_arg="broadcast $old_broadcast_address"
fi
if [ -n "$new_subnet_mask" ]; then
    new_subnet_arg="netmask $new_subnet_mask"
fi
if [ -n "$old_subnet_mask" ]; then
    old_subnet_arg="netmask $old_subnet_mask"
fi
if [ -n "$alias_subnet_mask" ]; then
    alias_subnet_arg="netmask $alias_subnet_mask"
fi
if [ -n "$new_interface_mtu" ]; then
    mtu_arg="mtu $new_interface_mtu"
fi
if [ -n "$IF_METRIC" ]; then
    metric_arg="metric $IF_METRIC"	# interfaces(5), "metric" option
fi


# The action starts here

# Invoke the local dhcp client enter hooks, if they exist.
run_hook /etc/dhcp3/dhclient-enter-hooks
run_hookdir /etc/dhcp3/dhclient-enter-hooks.d

# Execute the operation
case "$reason" in
    MEDIUM|ARPCHECK|ARPSEND)
        # Do nothing
        ;;
    PREINIT)
        # The DHCP client is requesting that an interface be
        # configured as required in order to send packets prior to
        # receiving an actual address. - dhclient-script(8)

        if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
         if [ -n "$alias_ip_address" ]; then
            # Bring down alias interface. Its routes will disappear too.
            ifconfig $interface:0- inet 0
         fi
         ifconfig $interface 0 up
        fi
        ;;
    BOUND|RENEW|REBIND|REBOOT)

        set_hostname
        
        if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
         if [ -n "$old_ip_address" -a -n "$alias_ip_address" -a \
             "$alias_ip_address" != "$old_ip_address" ]; then
            # Possible new alias. Remove old alias.
            ifconfig $interface:0- inet 0
         fi

         if [ -n "$old_ip_address" -a \
             "$old_ip_address" != "$new_ip_address" ]; then
            # IP address changed. Bringing down the interface will delete all routes,
            # and clear the ARP cache.
            ifconfig $interface inet 0 down

         fi
        fi

        if [ -z "$old_ip_address" -o "$old_ip_address" != "$new_ip_address" -o \
            "$reason" = "BOUND" -o "$reason" = "REBOOT" ]; then
          if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
            ifconfig $interface inet $new_ip_address $new_subnet_arg \
                $new_broadcast_arg $mtu_arg
          fi
          
          if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 4 ) != 4 )); then
            for router in $new_routers; do
                route add default dev $interface gw $router $metric_arg
            done
          fi
        fi

        
       if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
        if [ "$new_ip_address" != "$alias_ip_address" -a -n "$alias_ip_address" ];
            then
            ifconfig $interface:0- inet 0
            ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
            route add -host $alias_ip_address $interface:0
         fi
        fi
        
       if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 1 ) != 1 )); then
        make_resolv_conf
       fi

        ;;

    EXPIRE|FAIL|RELEASE|STOP)
        if [ -n "$alias_ip_address" ]; then
            # Turn off alias interface.
            ifconfig $interface:0- inet 0
        fi

        if [ -n "$old_ip_address" ]; then
            # Shut down interface, which will delete routes and clear arp cache.
            ifconfig $interface inet 0 down
        fi

        if [ -n "$alias_ip_address" ]; then
            ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
            route add -host $alias_ip_address $interface:0
        fi

        ;;

    TIMEOUT)
       if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
        if [ -n "$alias_ip_address" ]; then
            ifconfig $interface:0- inet 0
        fi

        ifconfig $interface inet $new_ip_address $new_subnet_arg \
            $new_broadcast_arg $mtu_arg
       fi

        set -- $new_routers
        first_router="$1"

        if ping -q -c 1 $first_router; then
         if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
            if [ "$new_ip_address" != "$alias_ip_address" -a \
                -n "$alias_ip_address" ]; then
                ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
                route add -host $alias_ip_address dev $interface:0
            fi
         fi

         # point to point
         if [ "$new_subnet_mask" == "255.255.255.255" ]; then
             for router in $new_routers; do
                 route add -host $router dev $interface
             done
         fi

         if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 4 ) != 4 )); then
            for router in $new_routers; do
                route add default dev $interface gw $router $metric_arg
            done
         fi

         if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 1 ) != 1 )); then
            make_resolv_conf
         fi
        else
            # Changed from 'ifconfig $interface inet 0 down' - see Debian bug #144666
          if [ -z "${dhc_dbus}" ] || (( ( dhc_dbus & 2 ) != 2 )); then
            ifconfig $interface inet 0
          fi
            exit_with_hooks 2
        fi

        ;;
esac

exit_with_hooks 0
