sqm-scripts: backport from trunk "Teach SQM hotplug tricks"

Backport from trunk the commit that adds support for hotplug action.
5b61cfba07

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

net/sqm-scripts/Makefile

@@ -8,8 +8,8 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=sqm-scripts
-PKG_VERSION:=7
-PKG_RELEASE:=3
+PKG_VERSION:=8
+PKG_RELEASE:=1
 PKG_LICENSE:=GPLv2
 
 PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
@@ -46,6 +46,8 @@ endef
 define Package/sqm-scripts/install
 	$(INSTALL_DIR) $(1)/etc/init.d
 	$(INSTALL_BIN) ./files/etc/init.d/sqm $(1)/etc/init.d/sqm
+	$(INSTALL_DIR) $(1)/etc/hotplug.d/iface
+	$(INSTALL_BIN) ./files/etc/hotplug.d/iface/11-sqm $(1)/etc/hotplug.d/iface/11-sqm
 	$(INSTALL_DIR) $(1)/etc/config
 	$(INSTALL_DATA) ./files/etc/config/sqm $(1)/etc/config/sqm
 	$(INSTALL_DIR) $(1)/usr/lib/sqm

net/sqm-scripts/files/etc/hotplug.d/iface/11-sqm

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+# teach SQM to re-enable itself when an interface re-appears
+logger -t SQM -s "hotplug on interface: ${DEVICE} action: ${ACTION}"
+
+[ "$ACTION" = ifup ] && /usr/lib/sqm/run.sh interface ${DEVICE}
+

net/sqm-scripts/files/usr/lib/sqm/run.sh

@@ -9,16 +9,37 @@
 
 . /lib/functions.sh
 
-STOP=$1
+STOP=
 ACTIVE_STATE_PREFIX="SQM_active_on_"
 ACTIVE_STATE_FILE_DIR="/var/run/SQM"
 mkdir -p ${ACTIVE_STATE_FILE_DIR}
+PROTO_STATE_FILE_LIST=$( ls ${ACTIVE_STATE_FILE_DIR}/${ACTIVE_STATE_PREFIX}* 2> /dev/null )
+
+
+case ${1} in
+    stop)
+        logger -t SQM -s "run.sh stop"
+	STOP=$1
+        ;;
+    interface)
+	START_ON_IF=$2	# only process this interface
+	logger -t SQM -s "Re/starting sqm on interface ${START_ON_IF}"
+	# TODO if $2 is empty just bail...
+	if [ -z ${START_ON_IF} ] ;
+	then
+	    logger -t SQM -s "Interface name missing, nothing to do, bailing out"
+	    return 0
+	fi
+	# only try to restart the just hotplugged interface, so reduce the list of interfaces to stop to the specified one
+	PROTO_STATE_FILE_LIST=${ACTIVE_STATE_FILE_DIR}/${ACTIVE_STATE_PREFIX}${START_ON_IF}
+	;;
+esac
+
 
 # the current uci config file does not necessarily contain sections for all interfaces with active
 # SQM instances, so use the ACTIVE_STATE_FILES to detect the interfaces on which to stop SQM.
 # Currently the .qos scripts start with stopping any existing traffic shaping so this should not
 # effectively change anything...
-PROTO_STATE_FILE_LIST=$( ls ${ACTIVE_STATE_FILE_DIR}/${ACTIVE_STATE_PREFIX}* 2> /dev/null )
 for STATE_FILE in ${PROTO_STATE_FILE_LIST} ; do
     if [ -f ${STATE_FILE} ] ;
     then
@@ -35,6 +56,11 @@ config_load sqm
 run_simple_qos() {
 	local section="$1"
 	export IFACE=$(config_get "$section" interface)
+
+	# If called explicitly for one interface only , so ignore anything else
+	[ -n "${START_ON_IF}" -a "$START_ON_IF" != "$IFACE" ] && return
+	#logger -t SQM -s "marching on..."
+
 	ACTIVE_STATE_FILE_FQN="${ACTIVE_STATE_FILE_DIR}/${ACTIVE_STATE_PREFIX}${IFACE}"	# this marks interfaces as active with SQM
 	[ -f "${ACTIVE_STATE_FILE_FQN}" ] && logger -t SQM -s "Uh, oh, ${ACTIVE_STATE_FILE_FQN} should already be stopped."	# Not supposed to happen
 

net/sqm-scripts/files/usr/lib/sqm/simple.qos

@@ -37,6 +37,9 @@ ipt -t mangle -A QOS_MARK_${IFACE} -m tos  --tos Minimize-Delay -j MARK --set-ma
 
 # Turn it on. Preserve classification if already performed
 
+#sm: is it correct to do this in $IFACE? Should ingress not be on $DEV? since HTB acts on $DEV?
+#	SQUASH also does not work on $DEV (that is the IFB will still see the incoming ToS bits whether we squash or not)
+#	SQUASH is still useful to protect internal machines...
 if [ "$SQUASH_DSCP" = "1" ]
 then
 sqm_logger "Squashing differentiated services code points (DSCP) from ingress."