dnsmasq: rework init procedure

	- cache udhcp check results to speed up subsequent reloads
	- enable procd file tracking for /var/etc/dnsmasq.conf to only reload service if needed
	- implement reload action to only restart dnsmasq if /var/etc/dnsmasq.conf actually changed
	- launch dnsmasq from interface hotplug to avoid race conditions with network bringup

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39152 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/package/network/services/dnsmasq/Makefile b/package/network/services/dnsmasq/Makefile
index 02712bd..0673465 100644 (file)
--- a/package/network/services/dnsmasq/Makefile
+++ b/package/network/services/dnsmasq/Makefile
@@ -83,6 +83,8 @@ define Package/dnsmasq/install
        $(INSTALL_DATA) ./files/dnsmasq.conf $(1)/etc/dnsmasq.conf
        $(INSTALL_DIR) $(1)/etc/init.d
        $(INSTALL_BIN) ./files/dnsmasq.init $(1)/etc/init.d/dnsmasq
+       $(INSTALL_DIR) $(1)/etc/hotplug.d/iface
+       $(INSTALL_DATA) ./files/dnsmasq.hotplug $(1)/etc/hotplug.d/iface/25-dnsmasq
 endef
 
 Package/dnsmasq-dhcpv6/install = $(Package/dnsmasq/install)

diff --git a/package/network/services/dnsmasq/files/dnsmasq.hotplug b/package/network/services/dnsmasq/files/dnsmasq.hotplug
new file mode 100644 (file)
index 0000000..ca5d10c
--- /dev/null
+++ b/package/network/services/dnsmasq/files/dnsmasq.hotplug
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+[ "$ACTION" = ifup ] || exit 0
+
+/etc/init.d/dnsmasq enabled && /etc/init.d/dnsmasq start

diff --git a/package/network/services/dnsmasq/files/dnsmasq.init b/package/network/services/dnsmasq/files/dnsmasq.init
index 045fc7e..0ff987f 100644 (file)
--- a/package/network/services/dnsmasq/files/dnsmasq.init
+++ b/package/network/services/dnsmasq/files/dnsmasq.init
@@ -33,6 +33,29 @@ dhcp_calc() {
        echo "$res"
 }
 
+dhcp_check() {
+       local ifname="$1"
+       local stamp="/var/run/dnsmasq.$ifname.dhcp"
+       local rv=0
+
+       [ -s "$stamp" ] && return $(cat "$stamp")
+
+       udhcpc -n -q -s /bin/true -t 1 -i "$ifname" >&- && rv=1 || rv=0
+
+       [ $rv -eq 1 ] && \
+               logger -t dnsmasq \
+                       "found already running DHCP-server on interface '$ifname'" \
+                       "refusing to start, use 'option force 1' to override"
+
+       echo $rv > "$stamp"
+       return $rv
+}
+
+log_once() {
+       pidof dnsmasq >/dev/null || \
+               logger -t dnsmasq "$@"
+}
+
 append_bool() {
        local section="$1"
        local option="$2"
@@ -141,7 +164,7 @@ dnsmasq() {
        local rebind
        config_get_bool rebind "$cfg" rebind_protection 1
        [ $rebind -gt 0 ] && {
-               logger -t dnsmasq \
+               log_once \
                        "DNS rebinding protection is active," \
                        "will discard upstream RFC1918 responses!"
                xappend "--stop-dns-rebind"
@@ -149,12 +172,12 @@ dnsmasq() {
                local rebind_localhost
                config_get_bool rebind_localhost "$cfg" rebind_localhost 0
                [ $rebind_localhost -gt 0 ] && {
-                       logger -t dnsmasq "Allowing 127.0.0.0/8 responses"
+                       log_once "Allowing 127.0.0.0/8 responses"
                        xappend "--rebind-localhost-ok"
                }
 
                append_rebind_domain() {
-                       logger -t dnsmasq "Allowing RFC1918 responses for domain $1"
+                       log_once "Allowing RFC1918 responses for domain $1"
                        xappend "--rebind-domain-ok=$1"
                }
 
@@ -356,14 +379,7 @@ dhcp_add() {
 
        #check for an already active dhcp server on the interface, unless 'force' is set
        config_get_bool force "$cfg" force 0
-       [ $force -gt 0 ] || {
-               udhcpc -n -q -s /bin/true -t 1 -i $ifname >&- && {
-                       logger -t dnsmasq \
-                               "found already running DHCP-server on interface '$ifname'" \
-                               "refusing to start, use 'option force 1' to override"
-                       return 0
-               }
-       }
+       [ $force -gt 0 ] || dhcp_check "$ifname" || return 0
 
        config_get start "$cfg" start
        config_get limit "$cfg" limit
@@ -492,6 +508,11 @@ service_triggers()
        procd_add_reload_trigger "dhcp"
 }
 
+boot() {
+       # Will be launched through hotplug
+       return 0
+}
+
 start_service() {
        include /lib/functions
 
@@ -499,6 +520,7 @@ start_service() {
 
        procd_open_instance
        procd_set_param command $PROG -C $CONFIGFILE -k
+       procd_set_param file $CONFIGFILE
        procd_close_instance
 
        # before we can call xappend
@@ -552,9 +574,15 @@ start_service() {
        done
 }
 
+reload_service() {
+       rc_procd start_service "$@"
+       return 0
+}
+
 stop_service() {
        [ -f /tmp/resolv.conf ] && {
                rm -f /tmp/resolv.conf
                ln -s /tmp/resolv.conf.auto /tmp/resolv.conf
        }
+       rm -f /var/run/dnsmasq.*.dhcp
 }