#!/bin/bash # vim:set ft=sh sw=2 noet: # 20230809 PeterG printenv > /tmp/dhc RTO_MIN='5ms' if true then disp() { case "$1" in ?*) printf "$2\n" "$1";; esac; } : ' | text aligned to here' case "$reason" in 'PREINIT') disp "$reason" 'reason "%s"';; 'BOUND'|'RENEW'|'REBIND'|'REBOOT') disp "$reason" 'reason "%s"' disp "$interface" 'interface "%s"' disp "$new_interface_mtu" 'new_interface_mtu "%s"' disp "$new_ip_address" 'new_ip_address "%s"' disp "$new_network_number" 'new_network_number "%s"' disp "$new_subnet_mask" 'new_subnet_mask "%s"' disp "$new_broadcast_address" 'new_broadcast_address "%s"' disp "$alias_ip_address" 'alias_ip_address "%s"' disp "$alias_subnet_mask" 'alias_subnet_mask "%s"' disp "$old_ip_address" 'old_ip_address "%s"' disp "$old_network_number" 'old_network_number "%s"' disp "$old_broadcast_address" 'old_broadcast_address "%s"' disp "$old_subnet_mask" 'old_subnet_mask "%s"' disp "$old_routers" 'old_routers "%s"' disp "$old_domain_name" 'old_domain_name "%s"' disp "$old_domain_name_servers" 'old_domain_name_servers "%s"' disp "$METRIC" 'METRIC "%s"' disp "$GATEWAY" 'GATEWAY "%s"' disp "$GATEWAYDEV" 'GATEWAYDEV "%s"' disp "$DHCLIENT_IGNORE_GATEWAY" 'DHCLIENT_IGNORE_GATEWAY "%s"' disp "$new_routers" 'new_routers "%s"' disp "$new_static_routes" 'new_static_routes "%s"' disp "$new_host_name" 'new_host_name "%s"' disp "$new_domain_name" 'new_domain_name "%s"' disp "$new_domain_name_servers" 'new_domain_name_servers "%s"' disp "$PEERNIS" 'PEERNIS "%s"' disp "$new_nis_domain" 'new_nis_domain "%s"' disp "$new_nis_servers" 'new_nis_servers "%s"' disp "$PEERNTP" 'PEERNTP "%s"' disp "$new_ntp_servers" 'new_ntp_servers "%s"' disp "$new_time_offset" 'new_time_offset "%s"' disp "$DHCP_TIME_OFFSET_SETS_TIMEZONE" 'DHCP_TIME_OFFSET_SETS_TIMEZONE "%s"' disp "$DHCLIENT_DELAY" 'DHCLIENT_DELAY "%s"';; 'EXPIRE'|'FAIL'|'RELEASE'|'STOP') disp "$reason" 'reason "%s"' disp "$interface" 'interface "%s"' disp "$old_ip_address" 'old_ip_address "%s"' disp "$old_network_number" 'old_network_number "%s"' disp "$old_broadcast_address" 'old_broadcast_address "%s"' disp "$old_subnet_mask" 'old_subnet_mask "%s"' disp "$old_routers" 'old_routers "%s"' disp "$old_domain_name" 'old_domain_name "%s"' disp "$old_domain_name_servers" 'old_domain_name_servers "%s"';; esac fi : 'The things that this script sets are: * primary interface mtu, address, subnet, netmask, broadcast * secondary interface address, netmask * default route gateway, metric, device * /etc/localtime * /etc/ntp.conf * /etc/resolv.conf * /etc/yp.conf It also runs: * /etc/dhclient-${interface}-up-hooks or /etc/dhclient-up-hooks * /etc/dhclient-${interface}-down-hooks or /etc/dhclient-down-hooks ' : '/etc/localtime: $new_time_offset' : '/etc/ntp.conf: $new_ntp_servers' : '/etc/resolv.conf $new_domain_name, $new_domain_name_servers' : '/etc/yp.conf: $new_nis_name, $new_nis_servers' ip_dotted_decimal() { B3="`expr "$1" : '\([0-9]*\)\.[0-9]*\.[0-9]*\.[0-9]*'`" B2="`expr "$1" : '[0-9]*\.\([0-9]*\)\.[0-9]*\.[0-9]*'`" B1="`expr "$1" : '[0-9]*\.[0-9]*\.\([0-9]*\)\.[0-9]*'`" B0="`expr "$1" : '[0-9]*\.[0-9]*\.[0-9]*\.\([0-9]*\)'`" echo "`expr $B0 + $B1 \* 256 + $B2 \* 65536 + $B3 \* 16777216`" } previous_push() { F="$1" N=0 while S=`printf '_%03d' "$N"` test -e "$F$S" do N=`expr "$N" + 1` done if mv "$F" "$F$S" then cp "$F$S" "$F" echo "$F$S" fi } previous_pop() { F="$1" N=0 while S=`printf '_%03d' "$N"` test -e "$F$S" do N=`expr "$N" + 1` done case "$N" in '0') : ;; *) N=`expr "$N" - 1` S=`printf '_%03d' "$N"` mv "$F$S" "$F";; esac } if ! test -x /bin/ipcalc then old_subnet_prfx="$old_subnet_mask" new_subnet_prfx="$new_subnet_mask" else case "$old_ip_address;$old_subnet_mask" in ?*';'?*) old_subnet_prfx=`/bin/ipcalc -p "$old_ip_address" "$old_subnet_mask"` old_subnet_prfx=`expr "$old_subnet_prfx" : 'PREFIX=\([0-9]*\)'`;; esac case "$new_ip_address;$new_subnet_mask" in ?*';'?*) new_subnet_prfx=`/bin/ipcalc -p "$new_ip_address" "$new_subnet_mask"` new_subnet_prfx=`expr "$new_subnet_prfx" : 'PREFIX=\([0-9]*\)'`;; esac fi LOGF='local7' TSTAMP="`date -R`" k_release=$(uname -r) k_relmaj=$(echo $release | cut -f1 -d'.') k_relmin=$(echo $release | cut -f2 -d'.') case "$new_ip_address" in ?*) new_ip_address_d=`ip_dotted_decimal "$new_ip_address"` new_ip_address_x=`printf "%08x" "$new_ip_address_d"`;; esac case "$new_interface_mtu" in ?*) new_mtu="$new_interface_mtu";; '') case "$interface" in 'w'*) new_mtu='576';; *) new_mtu='1472';; esac;; esac case "$reason" in 'PREINIT') : 'DHCP start preparation' case "$DHCLIENT_DELAY" in ?*) sleep "$DHCLIENT_DELAY";; esac;; 'ARPCHECK'|'ARPSEND') : 'DHCP check ARP' case "$interface#$new_ip_address" in ?*'#'?*) arping -q -f -c 2 -w 3 -D -I ${interface} ${new_ip_address};; esac;; 'BOUND'|'RENEW'|'REBIND'|'REBOOT') case "$new_mtu" in ?*) ip link set mtu "$new_mtu" dev "$interface";; esac case "$old_routers" in "$new_routers") : 'No change';; ?*) for old_router in $old_routers do ip route delete 0/0 via "$old_router" done;; esac case "$old_network_number" in '') old_address_prfx='32';; ?*) old_address_prfx="$old_subnet_prfx";; esac case "$old_ip_address" in "$new_ip_address") : 'No change';; ?*) ip address delete "$old_ip_address"/"$old_address_prfx" \ dev "$interface";; esac case "$new_network_number" in '') new_address_prfx='32';; ?*) new_address_prfx="$new_subnet_prfx";; esac case "$new_ip_address" in ?*) ip address add "$new_ip_address"/"$new_address_prfx" \ dev "$interface";; esac case "$new_routers" in ?*) for new_router in $new_routers do case "$METRIC" in '') ip route add 0/0 via "$new_router" rto_min "$RTO_MIN";; ?*) ip route add 0/0 via "$new_router" rto_min "$RTO_MIN" metric "$METRIC";; esac done;; esac case "$new_host_name" in ?*) hostname "$new_host_name" if test -f '/etc/sysconfig/network' then PREVIOUS="`previous_push '/etc/sysconfig/network'`" echo "# dhclient-script $TSTAMP NETWORKING=yes HOSTNAME=$new_host_name" > '/etc/sysconfig/network' elif test -f '/etc/hostname' then PREVIOUS="`previous_push '/etc/hostname'`" echo "$new_host_name" > '/etc/hostname' fi;; esac case "$PEERDNS" in ''|[Yy]*) case "$reason;$new_domain_name;$new_domain_name_servers" in "RENEW;$old_domain_name;$old_domain_name_servers") : ;; *';'?*';'?*) PREVIOUS="`previous_push '/etc/resolv.conf'`" ( echo "; dhclient-script $TSTAMP" echo "options no-check-names attempts:3 timeout:4 ndots:1" echo "search $new_domain_name" for new_domain_name_server in $new_domain_name_servers do echo "nameserver $new_domain_name_server" done ) > '/etc/resolv.conf' chmod a+r '/etc/resolv.conf' : service nscd condrestart esac;; esac case "$PEERNTP" in ''|[Yy]*) case "reason;$new_ntp_servers" in "RENEW;$old_ntp_servers") : ;; *';'?*) PREVIOUS="`previous_push '/etc/ntp.conf'`" ( echo "# dhclient-script $TSTAMP" for new_ntp_server in $new_ntp_servers do echo "server $new_ntp_server" done if test -n "$PREVIOUS" -a -e "$PREVIOUS" then echo " # dhclient-script previous content follows " cat "$PREVIOUS" else echo " restrict default kod nomodify notrap nopeer noquery restrict -6 default kod nomodify notrap nopeer noquery restrict 127.0.0.1 restrict -6 ::1 driftfile /var/etc/ntp/ntp.drift statsdir /var/log/ntpstats/ statistics loopstats peerstats clockstats filegen loopstats file loopstats type day enable filegen peerstats file peerstats type day enable filegen clockstats file clockstats type day enable enable kernel monitor ntp stats disable auth bclient" fi ) > '/etc/ntp.conf' service ntpd condrestart esac;; esac case "$DHCP_TIME_OFFSET_SETS_TIMEZONE" in ''|[Yy]*) case "$reason;$new_time_offset" in "RENEW;$old_time_offset") : ;; *';'?*) PREVIOUS="`previous_push '/etc/localtime'`" ( new_hours_offset="`expr $new_time_offset / 3600`" case "$new_hours_offset" in [0-9]*) new_hours_offset="+$new_hours_offset";; esac cat "/usr/share/zoneinfo/Etc/GMT$new_hours_offset" ) > '/etc/localtime' chmod a+r '/etc/localtime' esac;; esac ;; 'TIMEOUT') : 'DHCP timeout';; 'EXPIRE'|'FAIL'|'RELEASE'|'STOP') if test -f '/etc/sysconfig/network' then previous_pop '/etc/sysconfig/network' . /etc/sysconfig/network elif test -f '/etc/hostname' then previous_pop '/etc/hostname' HOSTNAME="`cat '/etc/hostname'`" fi case "$HOSTNAME" in ?*) hostname "$HOSTNAME";; esac case "$PEERDNS" in ''|[Yy]*) previous_pop '/etc/resolv.conf';; esac case "$PEERNTP" in ''|[Yy]*) previous_pop '/etc/ntp.conf';; esac case "$DHCP_TIME_OFFSET_SETS_TIMEZONE" in ''|[Yy]*) previous_pop '/etc/localtime';; esac case "$old_routers" in ?*) for old_router in $old_routers do ip route delete 0/0 via "$old_router" done;; esac case "$old_network_number" in '') old_address_prfx='32';; ?*) old_address_prfx="$old_subnet_prfx";; esac case "$old_ip_address" in ?*) ip address delete "$old_ip_address"/"$old_address_prfx" \ dev "$interface";; esac;; esac exit $?