#!/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, # # 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 >> /var/log/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, means, that no more old leases found. # Or does it mean bug in dhcpcd? 8) Fail for now. if [ "$new_ip_address" = "" ]; then if [ "$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