Merge lp:~harmw/cirros/udhcpc-wrapper into lp:cirros

[Harm Weites]

Add a wrapper for handling dhcp.

This way there is no need to rebuild busybox for having it ask for more options if we'd want that in the future (hostname?), plus we gain flexibility in having one central script that handles dhcp aspects.

The cirros-dhcpc scripts is called by ifup, it in turn calls udhcpc which uses cirros-dhcpc yet again (instead of default.script found in /usr/share) to apply the configuration.

Besides asking for additional routes, udhcpc will also ask for an mtu to configure.

[lp:~harmw/cirros/udhcpc-wrapper]

320. By Harm Weites on 2014-08-01

change: Remove DISABLED since this is better done through etc/networks.

321. By Harm Weites on 2014-08-01

fix: Have busybox call cirros-dhcpc with the interface to use as
argument, since that will be passed on from ifup/ifdown.

322. By Harm Weites on 2014-08-01

fix: Explicitly create the pid file, as is done in ifupdown.c in bb.

323. By Harm Weites on 2014-08-01

fix: Send the hostname as a proper option to the dhcp server, just like
in ifupdown.c. The clientid (-c) was being sent as well, though that
isn't a supported option (-x) anymore.

324. By Harm Weites on 2014-08-01

fix: Oops, udhcpc will not supply $2 to --script, so don't exit if $2
is missing in every case. Only if it's missing from up or down.

325. By Harm Weites on 2014-08-01

change: Renamed $INTERFACE to $IFACE to make it easier to distinguish
from $interface (which is lowercase, but still).

326. By Harm Weites on 2014-08-01

change: Since $2 is assigned to $IFACE at this stage, just use that.

327. By Harm Weites on 2014-08-01

merge: Pull in some changes from smoser. Most notably we now use the
shlib to take care of some common stuff and the actions in cirros-dhcpc
are moved to separate functions.

=== modified file 'conf/busybox.config'
--- conf/busybox.config	2013-11-25 20:17:08 +0000
+++ conf/busybox.config	2014-08-01 19:42:44 +0000
@@ -781,7 +781,7 @@
 CONFIG_FEATURE_IFUPDOWN_IPV4=y
 CONFIG_FEATURE_IFUPDOWN_IPV6=y
 CONFIG_FEATURE_IFUPDOWN_MAPPING=y
-# CONFIG_FEATURE_IFUPDOWN_EXTERNAL_DHCP is not set
+CONFIG_FEATURE_IFUPDOWN_EXTERNAL_DHCP=y
 CONFIG_INETD=y
 CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO=y
 CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD=y

=== added file 'patches-buildroot/ifupdown-cirros.patch'
--- patches-buildroot/ifupdown-cirros.patch	1970-01-01 00:00:00 +0000
+++ patches-buildroot/ifupdown-cirros.patch	2014-08-01 19:42:44 +0000
@@ -0,0 +1,21 @@
+--- a/package/busybox/1.20.1/busybox-ifupdown-cirros.patch	1970-01-01 01:00:00.000000000 +0100
++++ b/package/busybox/1.20.1/busybox-ifupdown-cirros.patch	2014-07-30 11:49:02.213528074 +0200
+@@ -0,0 +1,17 @@
++Busybox tries several dhcpclients in a specific order, if one is found as
++executable it gets the honor of asking for an address. By adding cirros as the
++first option we make sure the /sbin/ifupdown script is used.
++This depends heavily on CONFIG_FEATURE_IFUPDOWN_EXTERNAL_DHCP=y.
++
++--- a/networking/ifupdown.c	2014-07-30 11:38:03.708210386 +0200
+++++ b/networking/ifupdown.c	2014-07-30 11:38:24.106941433 +0200
++@@ -521,6 +521,10 @@
++ };
++ 
++ static const struct dhcp_client_t ext_dhcp_clients[] = {
+++	{ "cirros-dhcpc",
+++		"cirros-dhcpc up %iface%",
+++		"cirros-dhcpc down %iface%",
+++	},
++ 	{ "dhcpcd",
++ 		"dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
++ 		"dhcpcd -k %iface%",

=== modified file 'patches-buildroot/series'
--- patches-buildroot/series	2012-06-08 02:31:13 +0000
+++ patches-buildroot/series	2014-08-01 19:42:44 +0000
@@ -1,1 +1,2 @@
 sudo-install-sudoers-so.patch
+ifupdown-cirros.patch

=== added file 'src/etc/default/udhcpc'
--- src/etc/default/udhcpc	1970-01-01 00:00:00 +0000
+++ src/etc/default/udhcpc	2014-08-01 19:42:44 +0000
@@ -0,0 +1,3 @@
+OPTIONS="staticroutes mtu"
+TIMEOUT="60"
+MTU="1500"

=== added file 'src/sbin/cirros-dhcpc'
--- src/sbin/cirros-dhcpc	1970-01-01 00:00:00 +0000
+++ src/sbin/cirros-dhcpc	2014-08-01 19:42:44 +0000
@@ -0,0 +1,146 @@
+#!/bin/sh
+# A simple wrapper around udhcpc so that we are able to dynamically specify
+# which options it should ask for.
+
+. ${CIRROS_SHLIB:=/lib/cirros/shlib} ||
+	{ echo "failed to read ${CIRROS_SHLIB}" 1>&2; exit 1; }
+
+set -f
+
+OPTS_FILE="/etc/default/udhcpc"
+RESOLV_CONF="/etc/resolv.conf"
+
+apply_static_routes() {
+	# routes are pairs of network and gateway
+	# 169.254.169.254/32 10.65.0.128
+	local net="" router="" err=0
+	while [ $# -ne 0 ]; do
+		net="$1"
+		router="$2"
+		[ -n "$net" ] || continue
+		debug 1 "adding net $net with router $router"
+		route add -net "$net" gw "$router" || {
+			error "WARN: failed: route add -net \"$net\" gw \"$router\""
+			err=$(($err+1));
+		}
+		shift 2 || {
+			error "apply_static_routes: failed shift 2. odd number of args?"
+			return 1;
+		}
+	done
+	return $err
+}
+
+
+readconfig() {
+	[ ! -f "$OPTS_FILE" ] || . "$OPTS_FILE" ||
+		{ error "failed to read $OPTS_FILE"; return 1; }
+	# these are expected to be set.
+	OPTIONS=${OPTIONS:-staticroutes mtu}
+	TIMEOUT=${TIMEOUT:-60}
+	MTU=${MTU:-1500}
+}
+
+up() {
+	[ $# -ge 1 ] || { error "$0 up: must provide interface"; return 1; }
+	local iface="$1" opts="" hostname=""
+
+	readconfig || return
+	hostname=$(hostname 2>/dev/null)
+
+	# Gather all options and start udhcpc.
+	for opt in $OPTIONS; do
+		opts="-O $opt $opts"
+	done
+
+	debug 1 "Starting udhcpc on $iface, asking for options {$OPTIONS}"
+	/sbin/udhcpc -p "/var/run/udhcpc.${iface}.pid" -R -n \
+		${TIMEOUT:+"-T ${TIMEOUT}"} -i "$iface" -s "$0" \
+		$opts ${hostname:+-x "hostname:${hostname}"}
+}
+
+down() {
+	local iface="$1" pidfile="" pid=""
+	[ $# -ge 1 ] || { error "$0 down: must provide interface"; return 1; }
+	pidfile="/var/run/udchpc.$iface.pid"
+	[ -f "$pidfile" ] ||
+		{ error "$iface: no pidfile"; return 1; }
+	read pid < "$pidfile" ||
+		{ error "failed to read pid from '$pidfile' for '$iface'"; return 1; }
+	kill $pid >/dev/null
+	return
+}
+
+renew_bound() {
+	local flags="" mode="$1" i=""
+	shift;
+	[ -n "$interface" ] ||
+		{ error "$0 $mode: 'interface' not provided"; return 1; }
+
+	readconfig || return
+
+	[ -n "$broadcast" ] && flags="$flags broadcast $broadcast"
+	[ -n "$subnet" ] && flags="$flags netmask $subnet"
+	flags="$flags mtu ${mtu:-${MTU}}"
+
+	debug 1 "/sbin/ifconfig $interface $flags"
+	/sbin/ifconfig $interface $flags
+
+	if [ -n "$router" ] ; then
+		local out="" ret=""
+		debug 1 "deleting routers"
+		# cirros: this loop is cirros modification to remove a message
+		# like the following going to the console:
+		#   route: SIOCDELRT: No such process		 
+		while :; do					   
+			out=$(route del default gw 0.0.0.0 dev $interface 2>&1)
+			ret=$?
+			[ $ret -eq 0 ] && break
+			case "$out" in
+				*SIOCDELRT*[Nn]o\ such\ process*) break;;
+			esac
+			error "deleting routes failed: $out" 1>&2
+		done
+		# end cirros modification 
+
+		for i in $router; do
+			route add default gw $i dev $interface
+		done
+	fi
+
+	local msg="configuring $RESOLV_CONF for $interface. domain=$domain"
+	msg="$msg nameservers: $dns"
+	debug 1 "$msg"
+	{
+		[ -n "$domain" ] && echo "search $domain"
+		for i in $dns ; do
+			echo nameserver $i
+		done
+	} > "$RESOLV_CONF"
+
+	apply_static_routes $staticroutes
+}
+
+case "$1" in
+	up)
+		shift
+		up "$@"
+		;;
+	down)
+		shift;
+		down "$@"
+		;;
+	deconfig)
+		/sbin/ifconfig $interface 0.0.0.0
+		;;
+	renew|bound)
+		renew_bound "$@";
+		;;
+	*)
+		error "Usage: $0 <up|down>"
+		exit 1
+		;;
+esac
+
+exit
+# vi: ts=4 noexpandtab syntax=sh

=== removed file 'src/usr/share/udhcpc/default.script'
--- src/usr/share/udhcpc/default.script	2013-11-26 01:40:36 +0000
+++ src/usr/share/udhcpc/default.script	1970-01-01 00:00:00 +0000
@@ -1,74 +0,0 @@
-#!/bin/sh
-
-# udhcpc script edited by Tim Riker <[e-mail]>
-
-set -f
-
-[ -z "$1" ] && echo "Error: should be called from udhcpc" && exit 1
-
-RESOLV_CONF="/etc/resolv.conf"
-[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
-[ -n "$subnet" ] && NETMASK="netmask $subnet"
-
-apply_static_routes() {
-	# routes are pairs of network and gateway
-	# 169.254.169.254/32 10.65.0.128
-	local net="" router="" err=0
-	while [ $# -ne 0 ]; do
-		net="$1"
-		router="$2"
-		[ -n "$net" ] || continue
-		echo "adding net $net with router $router" 1>&2
-		route add -net "$net" gw "$router" || {
-			echo "WARN: failed: route add -net \"$net\" gw \"$router\"" 1>&2;
-			err=$(($err+1));
-		}
-		shift 2 || {
-			echo "apply_static_routes: failed shift 2. odd number of args?" 1>&2;
-			return 1;
-		}
-	done
-	return $err
-}
-
-case "$1" in
-	deconfig)
-		/sbin/ifconfig $interface 0.0.0.0
-		;;
-
-	renew|bound)
-		/sbin/ifconfig $interface $ip $BROADCAST $NETMASK
-
-		if [ -n "$router" ] ; then
-			echo "deleting routers"
-			# cirros: this loop is cirros modification to remove a message
-			# like the following going to the console:
-			#   route: SIOCDELRT: No such process		 
-			while :; do					   
-				out=$(route del default gw 0.0.0.0 dev $interface 2>&1)
-				ret=$?
-				[ $ret -eq 0 ] && break
-				case "$out" in
-					*SIOCDELRT*[Nn]o\ such\ process*) break;;
-				esac
-				echo "deleting routes failed: $out" 1>&2
-			done
-			# end cirros modification 
-
-			for i in $router ; do
-				route add default gw $i dev $interface
-			done
-		fi
-
-		echo -n > $RESOLV_CONF
-		[ -n "$domain" ] && echo search $domain >> $RESOLV_CONF
-		for i in $dns ; do
-			echo adding dns $i
-			echo nameserver $i >> $RESOLV_CONF
-		done
-
-		apply_static_routes $staticroutes
-		;;
-esac
-
-exit 0