f1bacaa501
/tmp may not be writeable yet when dhclient is first run via /etc/rc.d/netif so using it may not work. Also, writing to a predictable file in /tmp as root is a really bad idea since a malicious user may be able to win a race and insert a symlink which will allow them to cause any file to be overwritten. To solve these problems, create the tempory file in /var/run which will exist this early and is writable only by root. Security: Local risk if users can cause dhclient to run on demand (such as by unplugging and replugging the network cable).
296 lines
7.2 KiB
Bash
296 lines
7.2 KiB
Bash
#!/bin/sh
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#
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# $OpenBSD: dhclient-script,v 1.6 2004/05/06 18:22:41 claudio Exp $
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# $FreeBSD$
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#
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# Copyright (c) 2003 Kenneth R Westerback <krw@openbsd.org>
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#
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# Permission to use, copy, modify, and distribute this software for any
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# purpose with or without fee is hereby granted, provided that the above
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# copyright notice and this permission notice appear in all copies.
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#
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# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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#
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#
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ARP=/usr/sbin/arp
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AWK=/usr/bin/awk
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HOSTNAME=/bin/hostname
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NETSTAT=/usr/bin/netstat
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LOCALHOST=127.0.0.1
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if [ -x /usr/bin/logger ]; then
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LOGGER="/usr/bin/logger -s -p user.notice -t dhclient"
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else
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LOGGER=echo
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fi
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#
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# Helper functions that implement common actions.
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#
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check_hostname() {
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current_hostname=`$HOSTNAME`
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if [ -z "$current_hostname" ]; then
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$LOGGER "New Hostname ($interface): $new_host_name"
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$HOSTNAME $new_host_name
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elif [ "$current_hostname" = "$old_host_name" -a \
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"$new_host_name" != "$old_host_name" ]; then
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$LOGGER "New Hostname ($interface): $new_host_name"
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$HOSTNAME $new_host_name
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fi
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}
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arp_flush() {
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arp -an -i $interface | \
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sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \
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sh >/dev/null 2>&1
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}
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delete_old_address() {
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eval "ifconfig $interface inet -alias $old_ip_address $medium"
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}
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add_new_address() {
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eval "ifconfig $interface \
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inet $new_ip_address \
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netmask $new_subnet_mask \
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broadcast $new_broadcast_address \
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$medium"
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$LOGGER "New IP Address ($interface): $new_ip_address"
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$LOGGER "New Subnet Mask ($interface): $new_subnet_mask"
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$LOGGER "New Broadcast Address ($interface): $new_broadcast_address"
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$LOGGER "New Routers ($interface): $new_routers"
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}
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delete_old_alias() {
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if [ -n "$alias_ip_address" ]; then
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ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
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#route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1
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fi
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}
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add_new_alias() {
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if [ -n "$alias_ip_address" ]; then
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ifconfig $interface inet alias $alias_ip_address netmask \
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$alias_subnet_mask
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#route add $alias_ip_address $LOCALHOST
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fi
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}
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delete_old_routes() {
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#route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1
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for router in $old_routers; do
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if [ $if_defaultroute = x -o $if_defaultroute = $interface ]; then
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route delete default $route >/dev/null 2>&1
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fi
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done
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if [ -n "$old_static_routes" ]; then
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set $old_static_routes
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while [ $# -gt 1 ]; do
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route delete "$1" "$2"
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shift; shift
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done
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fi
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arp_flush
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}
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add_new_routes() {
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#route add $new_ip_address $LOCALHOST >/dev/null 2>&1
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for router in $new_routers; do
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if [ "$new_ip_address" = "$router" ]; then
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route add default -iface $router >/dev/null 2>&1
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else
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route add default $router >/dev/null 2>&1
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fi
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# 2nd and subsequent default routers error out, so explicitly
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# stop processing the list after the first one.
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break
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done
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if [ -n "$new_static_routes" ]; then
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$LOGGER "New Static Routes ($interface): $new_static_routes"
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set $new_static_routes
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while [ $# -gt 1 ]; do
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route add $1 $2
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shift; shift
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done
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fi
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}
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add_new_resolv_conf() {
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# XXX Old code did not create/update resolv.conf unless both
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# $new_domain_name and $new_domain_name_servers were provided. PR
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# #3135 reported some ISP's only provide $new_domain_name_servers and
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# thus broke the script. This code creates the resolv.conf if either
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# are provided.
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local tmpres=/var/run/resolv.conf.${interface}
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rm -f $tmpres
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if [ -n "$new_domain_name" ]; then
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echo "search $new_domain_name" >>$tmpres
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fi
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if [ -n "$new_domain_name_servers" ]; then
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for nameserver in $new_domain_name_servers; do
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echo "nameserver $nameserver" >>$tmpres
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done
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fi
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if [ -f $tmpres ]; then
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if [ -f /etc/resolv.conf.tail ]; then
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cat /etc/resolv.conf.tail >>$tmpres
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fi
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# When resolv.conf is not changed actually, we don't
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# need to update it.
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# If /usr is not mounted yet, we cannot use cmp, then
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# the following test fails. In such case, we simply
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# ignore an error and do update resolv.conf.
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if cmp -s $tmpres /etc/resolv.conf; then
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rm -f $tmpres
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return 0
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fi 2>/dev/null
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# In case (e.g. during OpenBSD installs) /etc/resolv.conf
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# is a symbolic link, take care to preserve the link and write
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# the new data in the correct location.
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if [ -f /etc/resolv.conf ]; then
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cat /etc/resolv.conf > /etc/resolv.conf.save
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fi
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cat $tmpres > /etc/resolv.conf
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rm -f $tmpres
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# Try to ensure correct ownership and permissions.
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chown -RL root:wheel /etc/resolv.conf
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chmod -RL 644 /etc/resolv.conf
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return 0
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fi
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return 1
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}
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# Must be used on exit. Invokes the local dhcp client exit hooks, if any.
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exit_with_hooks() {
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exit_status=$1
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if [ -f /etc/dhclient-exit-hooks ]; then
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. /etc/dhclient-exit-hooks
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fi
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# probably should do something with exit status of the local script
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exit $exit_status
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}
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#
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# Start of active code.
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#
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# Invoke the local dhcp client enter hooks, if they exist.
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if [ -f /etc/dhclient-enter-hooks ]; then
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exit_status=0
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. /etc/dhclient-enter-hooks
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# allow the local script to abort processing of this state
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# local script must set exit_status variable to nonzero.
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if [ $exit_status -ne 0 ]; then
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exit $exit_status
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fi
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fi
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if [ -x $NETSTAT ]; then
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if_defaultroute=`$NETSTAT -rnf inet | $AWK '{if ($1=="default") printf $6}'`
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else
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if_defaultroute="x"
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fi
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case $reason in
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MEDIUM)
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eval "ifconfig $interface $medium"
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eval "ifconfig $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1
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sleep 1
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;;
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PREINIT)
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delete_old_alias
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ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up
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;;
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ARPCHECK|ARPSEND)
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;;
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BOUND|RENEW|REBIND|REBOOT)
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check_hostname
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if [ -n "$old_ip_address" ]; then
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if [ "$old_ip_address" != "$alias_ip_address" ]; then
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delete_old_alias
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fi
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if [ "$old_ip_address" != "$new_ip_address" ]; then
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delete_old_address
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delete_old_routes
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fi
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fi
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if [ "$reason" = BOUND ] || \
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[ "$reason" = REBOOT ] || \
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[ -z "$old_ip_address" ] || \
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[ "$old_ip_address" != "$new_ip_address" ]; then
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add_new_address
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add_new_routes
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fi
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if [ "$new_ip_address" != "$alias_ip_address" ]; then
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add_new_alias
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fi
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add_new_resolv_conf
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;;
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EXPIRE|FAIL)
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delete_old_alias
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if [ -n "$old_ip_address" ]; then
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delete_old_address
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delete_old_routes
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fi
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if [ -x $ARP ]; then
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$ARP -d -a -i $interface
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fi
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# XXX Why add alias we just deleted above?
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add_new_alias
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if [ -f /etc/resolv.conf.save ]; then
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cat /etc/resolv.conf.save > /etc/resolv.conf
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fi
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;;
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TIMEOUT)
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delete_old_alias
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add_new_address
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sleep 1
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if [ -n "$new_routers" ]; then
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$LOGGER "New Routers ($interface): $new_routers"
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set "$new_routers"
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if ping -q -c 1 -t 1 "$1"; then
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if [ "$new_ip_address" != "$alias_ip_address" ]; then
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add_new_alias
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fi
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add_new_routes
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if add_new_resolv_conf; then
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exit_with_hooks 0
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fi
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fi
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fi
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eval "ifconfig $interface inet -alias $new_ip_address $medium"
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delete_old_routes
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exit_with_hooks 1
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;;
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esac
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exit_with_hooks 0
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