#!/bin/sh
#----------------------------------------------------------------------------
# /etc/ppp/addr-down - called whenever a circuit loses a local IPv4 address
#
# Input:
#   $1 = network interface
#   $2 = circuit identifier
#   $3 = local IPv4 address
#   $4 = if non-empty, we are called from within ip-down
#
# Last Update:     $Id$
#----------------------------------------------------------------------------

. /etc/boot.d/forking.inc
. /etc/boot.d/lazy.inc
. /etc/boot.d/locking.inc
. /etc/boot.d/networking.inc

script_name="$(basename $0)"
script="$script_name[$$]"
facility=$circuit_logfacility
logmsgprio=$facility.notice
. /usr/share/logfunc.sh

export PATH=/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin

interface=$1
circ_id=$2
address=$3
ipdown=$4

{
fork_call_handlers
sync_lock_resource addrupdown-$circ_id "$script"

echo "$circ_id[$interface]: IPv4 address $address has disappeared"

is_default_route=no
circuit_read_field $circ_id circ_nets_ipv4_n
for i in $(seq 1 $circ_nets_ipv4_n)
do
    circuit_read_field $circ_id circ_nets_ipv4_$i net
    if [ "$net" = "0.0.0.0/0" ]
    then
        is_default_route=yes
        break
    fi
done

if [ "$is_default_route" = yes ]
then
    # a local address connected to a gateway is assumed to be externally
    # visible, so remove it from dynamic.ip
    regex=$(echo $address | sed 's/\./\\./g;s,/,\\/,g')
    sync_lock_resource dynamic.ip addr-down
    sed -i "/^$regex$/d" /var/run/dynamic.ip
    [ -s /var/run/dynamic.ip ] || rm -f /var/run/dynamic.ip
    sync_unlock_resource dynamic.ip addr-down
fi

circuit_deregister_local_address $circ_id ipv4 $address
setup-dynamic-iptables.sh

# Call all custom addr-downs
lazy_begin
for j in /etc/ppp/addr-down[0-9][0-9][0-9].*
do
    if [ -f $j ]
    then
        echo "executing $j"
        . $j
    fi
done
lazy_end

cur_addresses=$(circuit_get_local_addresses $circ_id ipv4)
if [ -z "$cur_addresses" -a -z "$ipdown" ]
then
    # call ip-down when the last address is about to disappear
    /etc/ppp/ip-down $interface /dev/null 0 $address "" $circ_id 1 &
fi

sync_unlock_resource addrupdown-$circ_id "$script"
} 2>&1 | logmsg "$script" $logmsgprio