iproute2/examples/dhcp-client-script
2004-04-15 20:56:59 +00:00

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#!/bin/bash
#
# dhclient-script for Linux.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version
# 2 of the License, or (at your option) any later version.
#
# Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
#
# Probably, I did not understand, what this funny feature as "alias"
# means exactly. For now I suppose, that it is a static address, which
# we should install and preserve.
#
exec >> /tmp/DHS.log 2>&1
echo dhc-script $* reason=$reason
set | grep "^\(old_\|new_\|check_\)"
LOG () {
echo LOG $* ;
}
# convert 8bit mask to length
# arg: $1 = mask
#
Mask8ToLen() {
local l=0;
while [ $l -le 7 ]; do
if [ $[ ( 1 << $l ) + $1 ] -eq 256 ]; then
return $[ 8 - $l ]
fi
l=$[ $l + 1 ]
done
return 0;
}
# convert inet dotted quad mask to length
# arg: $1 = dotquad mask
#
MaskToLen() {
local masklen=0
local mask8=$1
case $1 in
0.0.0.0)
return 0;
;;
255.*.0.0)
masklen=8
mask8=${mask8#255.}
mask8=${mask8%.0.0}
;;
255.255.*.0)
masklen=16
mask8=${mask8#255.255.}
mask8=${mask8%.0}
;;
255.255.255.*)
masklen=24
mask8=${mask8#255.255.255.}
;;
*)
return 255
;;
esac
Mask8ToLen $mask8
return $[ $? + $masklen ]
}
# calculate ABC "natural" mask
# arg: $1 = dotquad address
#
ABCMask () {
local class;
class=${1%%.*}
if [ "$1" = "255.255.255.255" ]; then
echo $1
elif [ "$1" = "0.0.0.0" ]; then
echo $1
elif [ $class -ge 224 ]; then
echo 240.0.0.0
elif [ $class -ge 192 ]; then
echo 255.255.255.0
elif [ $class -ge 128 ]; then
echo 255.255.0.0
else
echo 255.0.0.0
fi
}
# calculate ABC "natural" mask length
# arg: $1 = dotquad address
#
ABCMaskLen () {
local class;
class=${1%%.*}
if [ "$1" = "255.255.255.255" ]; then
return 32
elif [ "$1" = "0.0.0.0" ]; then
return 0
elif [ $class -ge 224 ]; then
return 4;
elif [ $class -ge 192 ]; then
return 24;
elif [ $class -ge 128 ]; then
return 16;
else
return 8;
fi
}
# Delete IP address
# args: $1 = interface
# $2 = address
# $3 = mask
# $4 = broadcast
# $5 = label
#
DelINETAddr () {
local masklen=32
local addrid=$1
LOG DelINETAddr $*
if [ "$5" ]; then
addrid=$addrid:$5
fi
LOG ifconfig $addrid down
ifconfig $addrid down
}
# Add IP address
# args: $1 = interface
# $2 = address
# $3 = mask
# $4 = broadcast
# $5 = label
#
AddINETAddr () {
local mask_arg
local brd_arg
local addrid=$1
LOG AddINETAddr $*
if [ "$5" ]; then
addrid=$addrid:$5
fi
if [ "$3" ]; then
mask_arg="netmask $3"
fi
if [ "$4" ]; then
brd_arg="broadcast $4"
fi
LOG ifconfig $addrid $2 $mask_arg $brd_arg up
ifconfig $addrid $2 $mask_arg $brd_arg up
}
# Add default routes
# args: $1 = routers list
#
AddDefaultRoutes() {
local router
if [ "$1" ]; then
LOG AddDefaultRoutes $*
for router in $1; do
LOG route add default gw $router
route add default gw $router
done ;
fi
}
# Delete default routes
# args: $1 = routers list
#
DelDefaultRoutes() {
local router
if [ "$1" ]; then
LOG DelDefaultRoutes $*
for router in $1; do
LOG route del default gw $router
route del default gw $router
done
fi
}
# ping a host
# args: $1 = dotquad address of the host
#
PingNode() {
LOG PingNode $*
if ping -q -c 1 -w 2 $1 ; then
return 0;
fi
return 1;
}
# Check (and add route, if alive) default routers
# args: $1 = routers list
# returns: 0 if at least one router is alive.
#
CheckRouterList() {
local router
local succeed=1
LOG CheckRouterList $*
for router in $1; do
if PingNode $router ; then
succeed=0
route add default gw $router
fi
done
return $succeed
}
# Delete/create static routes.
# args: $1 = operation (del/add)
# $2 = routes list in format "dst1 nexthop1 dst2 ..."
#
# BEWARE: this feature of DHCP is obsolete, because does not
# support subnetting.
#
X-StaticRouteList() {
local op=$1
local lst="$2"
local masklen
LOG X-StaticRouteList $*
if [ "$lst" ]; then
set $lst
while [ $# -gt 1 ]; do
route $op -net $1 netmask `ABCMask "$1"` gw $2
shift; shift;
done
fi
}
# Create static routes.
# arg: $1 = routes list in format "dst1 nexthop1 dst2 ..."
#
AddStaticRouteList() {
LOG AddStaticRouteList $*
X-StaticRouteList add "$1"
}
# Delete static routes.
# arg: $1 = routes list in format "dst1 nexthop1 dst2 ..."
#
DelStaticRouteList() {
LOG DelStaticRouteList $*
X-StaticRouteList del "$1"
}
# Broadcast unsolicited ARP to update neighbours' caches.
# args: $1 = interface
# $2 = address
#
UnsolicitedARP() {
if [ -f /sbin/arping ]; then
/sbin/arping -A -c 1 -I "$1" "$2" &
(sleep 2 ; /sbin/arping -U -c 1 -I "$1" "$2" ) &
fi
}
# Duplicate address detection.
# args: $1 = interface
# $2 = test address
# returns: 0, if DAD succeeded.
DAD() {
if [ -f /sbin/arping ]; then
/sbin/arping -c 2 -w 3 -D -I "$1" "$2"
return $?
fi
return 0
}
# Setup resolver.
# args: NO
# domain and nameserver list are passed in global variables.
#
# NOTE: we try to be careful and not to break user supplied resolv.conf.
# The script mangles it, only if it has dhcp magic signature.
#
UpdateDNS() {
local nameserver
local idstring="#### Generated by DHCPCD"
LOG UpdateDNS $*
if [ "$new_domain_name" = "" -a "$new_domain_name_servers" = "" ]; then
return 0;
fi
echo $idstring > /etc/resolv.conf.dhcp
if [ "$new_domain_name" ]; then
echo search $new_domain_name >> /etc/resolv.conf.dhcp
fi
echo options ndots:1 >> /etc/resolv.conf.dhcp
if [ "$new_domain_name_servers" ]; then
for nameserver in $new_domain_name_servers; do
echo nameserver $nameserver >> /etc/resolv.conf.dhcp
done
else
echo nameserver 127.0.0.1 >> /etc/resolv.conf.dhcp
fi
if [ -f /etc/resolv.conf ]; then
if [ "`head -1 /etc/resolv.conf`" != "$idstring" ]; then
return 0
fi
if [ "$old_domain_name" = "$new_domain_name" -a
"$new_domain_name_servers" = "$old_domain_name_servers" ]; then
return 0
fi
fi
mv /etc/resolv.conf.dhcp /etc/resolv.conf
}
case $reason in
NBI)
exit 1
;;
MEDIUM)
exit 0
;;
PREINIT)
ifconfig $interface:dhcp down
ifconfig $interface:dhcp1 down
if [ -d /proc/sys/net/ipv4/conf/$interface ]; then
ifconfig $interface:dhcp 10.10.10.10 netmask 255.255.255.255
ifconfig $interface:dhcp down
if [ -d /proc/sys/net/ipv4/conf/$interface ]; then
LOG The interface $interface already configured.
fi
fi
ifconfig $interface:dhcp up
exit 0
;;
ARPSEND)
exit 0
;;
ARPCHECK)
if DAD "$interface" "$check_ip_address" ; then
exit 0
fi
exit 1
;;
BOUND|RENEW|REBIND|REBOOT)
if [ "$old_ip_address" -a "$alias_ip_address" -a \
"$alias_ip_address" != "$old_ip_address" ]; then
DelINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
if [ "$old_ip_address" -a "$old_ip_address" != "$new_ip_address" ]; then
DelINETAddr "$interface" "$old_ip_address" "$old_subnet_mask" "$old_broadcast_address" dhcp
DelDefaultRoutes "$old_routers"
DelStaticRouteList "$old_static_routes"
fi
if [ "$old_ip_address" = "" -o "$old_ip_address" != "$new_ip_address" -o \
"$reason" = "BOUND" -o "$reason" = "REBOOT" ]; then
AddINETAddr "$interface" "$new_ip_address" "$new_subnet_mask" "$new_broadcast_address" dhcp
AddStaticRouteList "$new_static_routes"
AddDefaultRoutes "$new_routers"
UnsolicitedARP "$interface" "$new_ip_address"
fi
if [ "$new_ip_address" != "$alias_ip_address" -a "$alias_ip_address" ]; then
AddINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
UpdateDNS
exit 0
;;
EXPIRE|FAIL)
if [ "$alias_ip_address" ]; then
DelINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
if [ "$old_ip_address" ]; then
DelINETAddr "$interface" "$old_ip_address" "$old_subnet_mask" "$old_broadcast_address" dhcp
DelDefaultRoutes "$old_routers"
DelStaticRouteList "$old_static_routes"
fi
if [ "$alias_ip_address" ]; then
AddINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
exit 0
;;
TIMEOUT)
if [ "$alias_ip_address" ]; then
DelINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
# Seems, <null address> means, that no more old leases found.
# Or does it mean bug in dhcpcd? 8) Fail for now.
if [ "$new_ip_address" = "<null address>" ]; then
if [ "$old_ip_address" ]; then
DelINETAddr "$interface" "$old_ip_address" "$old_subnet_mask" "$old_broadcast_address" dhcp
fi
if [ "$alias_ip_address" ]; then
AddINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
exit 1
fi
if DAD "$interface" "$new_ip_address" ; then
AddINETAddr "$interface" "$new_ip_address" "$new_subnet_mask" "$new_broadcast_address" dhcp
UnsolicitedARP "$interface" "$new_ip_address"
if [ "$alias_ip_address" -a "$alias_ip_address" != "$new_ip_address" ]; then
AddINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
UnsolicitedARP "$interface" "$alias_ip_address"
fi
if CheckRouterList "$new_routers" ; then
AddStaticRouteList "$new_static_routes"
UpdateDNS
exit 0
fi
fi
DelINETAddr "$interface" "$new_ip_address" "$new_subnet_mask" "$new_broadcast_address" dhcp
DelDefaultRoutes "$old_routers"
DelStaticRouteList "$old_static_routes"
if [ "$alias_ip_address" ]; then
AddINETAddr "$interface" "$alias_ip_address" "$alias_subnet_mask" "$alias_broadcast_address" dhcp1
fi
exit 1
;;
esac
exit 0