dnsmasq: make bind-dynamic 'non-wildcard' interfaces default

'non-wildcard' interfaces enables dnsmasq's '--bind-dynamic' mode.  This
binds to interfaces rather than wildcard addresses *and* keeps track of
interface comings/goings via a unique Linux api.

Quoting dnsmasq's author "bind-dynamic (bind individual addresses, keep
up with changes in interface config) ... On linux, there's actually no
sane reason not to use --bind-dynamic, and it's only not the default for
historical reasons."

Let's change history, well on LEDE at least, and change the default!

Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>

package/network/services/dnsmasq/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dnsmasq
 PKG_VERSION:=2.77
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=http://thekelleys.org.uk/dnsmasq/

package/network/services/dnsmasq/files/dhcp.conf

@@ -15,7 +15,7 @@ config dnsmasq
 	option leasefile	'/tmp/dhcp.leases'
 	option resolvfile	'/tmp/resolv.conf.auto'
 	#list server		'/mycompany.local/1.2.3.4'
-	#option nonwildcard	1
+	option nonwildcard	1 # bind to & keep track of interfaces
 	#list interface		br-lan
 	#list notinterface	lo
 	#list bogusnxdomain     '64.94.110.11'

package/network/services/dnsmasq/files/dnsmasq.init

@@ -103,8 +103,10 @@ append_bool() {
 	local section="$1"
 	local option="$2"
 	local value="$3"
+	local default="$4"
 	local _loctmp
-	config_get_bool _loctmp "$section" "$option" 0
+	[ -z "$default" ] && default="0"
+	config_get_bool _loctmp "$section" "$option" "$default"
 	[ $_loctmp -gt 0 ] && xappend "$value"
 }
 
@@ -791,7 +793,7 @@ dnsmasq_start()
 	config_get tftp_root "$cfg" "tftp_root"
 	[ -n "$tftp_root" ] && mkdir -p "$tftp_root" && append_bool "$cfg" enable_tftp "--enable-tftp"
 	append_bool "$cfg" tftp_no_fail "--tftp-no-fail"
-	append_bool "$cfg" nonwildcard "--bind-dynamic"
+	append_bool "$cfg" nonwildcard "--bind-dynamic" 1
 	append_bool "$cfg" fqdn "--dhcp-fqdn"
 	append_bool "$cfg" proxydnssec "--proxy-dnssec"
 	append_bool "$cfg" localservice "--local-service"