From 39f58789e603fd31b763887282fc6b042a4d9d54 Mon Sep 17 00:00:00 2001
From: Aaron Goodman <aaronjg@stanford.edu>
Date: Sat, 25 Jul 2020 11:35:09 -0400
Subject: [PATCH] mwan3: use ip monitor route to detect routing changes

use only committed uci changes for updating routing table

use functions.sh functions rather than uci command line tool
to find interfaces for routing table.

consolidate rtmon_ipv4 and rtmon_ipv6 functions into a single function

Signed-off-by: Aaron Goodman <aaronjg@stanford.edu>
---
 net/mwan3/files/etc/config/mwan3             |   1 -
 net/mwan3/files/etc/hotplug.d/iface/15-mwan3 |   1 +
 net/mwan3/files/etc/hotplug.d/iface/16-mwan3 |  27 --
 net/mwan3/files/lib/mwan3/mwan3.sh           | 294 +++++++++++--------
 net/mwan3/files/usr/sbin/mwan3               |  19 +-
 net/mwan3/files/usr/sbin/mwan3rtmon          | 117 ++++++--
 6 files changed, 272 insertions(+), 187 deletions(-)
 delete mode 100644 net/mwan3/files/etc/hotplug.d/iface/16-mwan3

diff --git a/net/mwan3/files/etc/config/mwan3 b/net/mwan3/files/etc/config/mwan3
index 750d6c4ae..926719a3c 100644
--- a/net/mwan3/files/etc/config/mwan3
+++ b/net/mwan3/files/etc/config/mwan3
@@ -1,7 +1,6 @@
 
 config globals 'globals'
 	option mmx_mask '0x3F00'
-	option rtmon_interval '5'
 
 config interface 'wan'
 	option enabled '1'
diff --git a/net/mwan3/files/etc/hotplug.d/iface/15-mwan3 b/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
index 645cdd3e4..6898df819 100644
--- a/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
+++ b/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
@@ -17,6 +17,7 @@ config_load mwan3
 config_get_bool enabled globals 'enabled' '0'
 [ "${enabled}" -gt 0 ] || {
 	mwan3_unlock "$ACTION" "$INTERFACE"
+	mwan3_flush_conntrack "$INTERFACE" "$ACTION"
 	exit 0
 }
 
diff --git a/net/mwan3/files/etc/hotplug.d/iface/16-mwan3 b/net/mwan3/files/etc/hotplug.d/iface/16-mwan3
deleted file mode 100644
index dd09358eb..000000000
--- a/net/mwan3/files/etc/hotplug.d/iface/16-mwan3
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/sh
-
-. /lib/functions.sh
-. /lib/functions/network.sh
-. /lib/mwan3/mwan3.sh
-
-mwan3_lock "$ACTION" "mwan3rtmon"
-
-config_load mwan3
-config_get_bool enabled globals 'enabled' '0'
-[ "${enabled}" -gt 0 ] || {
-	mwan3_unlock "$ACTION" "mwan3rtmon"
-	exit 0
-}
-
-if [ "$ACTION" = "ifup" ]; then
-	mwan3_rtmon
-fi
-
-config_get_bool enabled "$INTERFACE" 'enabled' '0'
-[ "${enabled}" -eq 0 ] || {
-	mwan3_flush_conntrack "$INTERFACE" "$ACTION"
-}
-
-mwan3_unlock "$ACTION" "mwan3rtmon"
-
-exit 0
diff --git a/net/mwan3/files/lib/mwan3/mwan3.sh b/net/mwan3/files/lib/mwan3/mwan3.sh
index 3c7422dc0..ad41030ad 100644
--- a/net/mwan3/files/lib/mwan3/mwan3.sh
+++ b/net/mwan3/files/lib/mwan3/mwan3.sh
@@ -1,5 +1,4 @@
 #!/bin/sh
-
 . /usr/share/libubox/jshn.sh
 
 IP4="ip -4"
@@ -37,89 +36,82 @@ MM_UNREACHABLE=""
 command -v ip6tables > /dev/null
 NO_IPV6=$?
 
-# return true(=0) if has any mwan3 interface enabled
-# otherwise return false
-mwan3_rtmon_ipv4()
+mwan3_push_update()
 {
-	local idx=0
-	local ret=1
-	local tbl=""
-
-	local tid family enabled
-
-	mkdir -p /tmp/mwan3rtmon
-	($IP4 route list table main  | grep -v "^default\|linkdown" | sort -n; echo empty fixup) >/tmp/mwan3rtmon/ipv4.main
-	while uci get mwan3.@interface[$idx] >/dev/null 2>&1 ; do
-		tid=$((idx+1))
-
-		family="$(uci -q get mwan3.@interface[$idx].family)"
-		[ -z "$family" ] && family="ipv4"
-
-		enabled="$(uci -q get mwan3.@interface[$idx].enabled)"
-		[ -z "$enabled" ] && enabled="0"
-
-		[ "$family" = "ipv4" ] && {
-			tbl=$($IP4 route list table $tid 2>/dev/null)
-			if echo "$tbl" | grep -q ^default; then
-				(echo "$tbl"  | grep -v "^default\|linkdown" | sort -n; echo empty fixup) >/tmp/mwan3rtmon/ipv4.$tid
-				cat /tmp/mwan3rtmon/ipv4.$tid | grep -v -x -F -f /tmp/mwan3rtmon/ipv4.main | while read line; do
-					$IP4 route del table $tid $line
-				done
-				cat /tmp/mwan3rtmon/ipv4.main | grep -v -x -F -f /tmp/mwan3rtmon/ipv4.$tid | while read line; do
-					$IP4 route add table $tid $line
-				done
-			fi
-		}
-		if [ "$enabled" = "1" ]; then
-			ret=0
-		fi
-		idx=$((idx+1))
-	done
-	rm -f /tmp/mwan3rtmon/ipv4.*
-	return $ret
+	# helper function to build an update string to pass on to
+	# IPTR or IPS RESTORE. Modifies the 'update' variable in
+	# the local scope.
+	update="$update
+$*";
 }
 
-# return true(=0) if has any mwan3 interface enabled
-# otherwise return false
-mwan3_rtmon_ipv6()
+mwan3_update_dev_to_table()
 {
-	local idx=0
-	local ret=1
-	local tbl=""
+	local _tid
+	mwan3_dev_tbl_ipv4=" "
+	mwan3_dev_tbl_ipv6=" "
 
-	local tid family enabled
+	update_table()
+	{
+		local family curr_table device enabled
+		let _tid++
+		config_get family "$1" family ipv4
+		network_get_device device "$1"
+		[ -z "$device" ] && return
+		config_get enabled "$1" enabled
+		[ "$enabled" -eq 0 ] && return
+		curr_table=$(eval "echo	 \"\$mwan3_dev_tbl_${family}\"")
+		export "mwan3_dev_tbl_$family=${curr_table}${device}=$_tid "
+	}
+	network_flush_cache
+	config_foreach update_table interface
+}
 
-	mkdir -p /tmp/mwan3rtmon
-	($IP6 route list table main  | grep -v "^default\|^::/0\|^fe80::/64\|^unreachable" | sort -n; echo empty fixup) >/tmp/mwan3rtmon/ipv6.main
-	while uci get mwan3.@interface[$idx] >/dev/null 2>&1 ; do
-		tid=$((idx+1))
+mwan3_update_iface_to_table()
+{
+	local _tid section family cfgtype curr_table _mwan3_iface_tbl
+	mwan3_iface_tbl=" "
+	update_table()
+	{
+		let _tid++
+		export mwan3_iface_tbl="${mwan3_iface_tbl}${1}=$_tid "
+	}
+	config_foreach update_table interface
+}
 
-		family="$(uci -q get mwan3.@interface[$idx].family)"
-		# Set default family to ipv4 that is no mistake
-		[ -z "$family" ] && family="ipv4"
+mwan3_get_true_iface()
+{
+	local family V
+	_true_iface=$2
+	config_get family "$iface" family ipv4
+	if [ "$family" = "ipv4" ]; then
+		V=4
+	elif [ "$family" = "ipv6" ]; then
+		V=6
+	fi
+	ubus call "network.interface.${iface}_${V}" status &>/dev/null && _true_iface="${iface}_${V}"
+	export "$1=$_true_iface"
+}
 
-		enabled="$(uci -q get mwan3.@interface[$idx].enabled)"
-		[ -z "$enabled" ] && enabled="0"
+mwan3_route_line_dev()
+{
+	# must have mwan3 config already loaded
+	# arg 1 is route device
+	local  _tid route_line route_device route_family entry curr_table
+	route_line=$2
+	route_family=$3
+	route_device=$(echo "$route_line" | sed -ne "s/.*dev \([^ ]*\).*/\1/p")
+	unset "$1"
+	[ -z "$route_device" ] && return
 
-		[ "$family" = "ipv6" ] && {
-			tbl=$($IP6 route list table $tid 2>/dev/null)
-			if echo "$tbl" | grep -q "^default\|^::/0"; then
-				(echo "$tbl"  | grep -v "^default\|^::/0\|^unreachable" | sort -n; echo empty fixup) >/tmp/mwan3rtmon/ipv6.$tid
-				cat /tmp/mwan3rtmon/ipv6.$tid | grep -v -x -F -f /tmp/mwan3rtmon/ipv6.main | while read line; do
-					$IP6 route del table $tid $line
-				done
-				cat /tmp/mwan3rtmon/ipv6.main | grep -v -x -F -f /tmp/mwan3rtmon/ipv6.$tid | while read line; do
-					$IP6 route add table $tid $line
-				done
-			fi
-		}
-		if [ "$enabled" = "1" ]; then
-			ret=0
+	curr_table=$(eval "echo	 \"\$mwan3_dev_tbl_${route_family}\"")
+	for entry in $curr_table; do
+		if [ "${entry%%=*}" = "$route_device" ]; then
+			_tid=${entry##*=}
+			export "$1=$_tid"
+			return
 		fi
-		idx=$((idx+1))
 	done
-	rm -f /tmp/mwan3rtmon/ipv6.*
-	return $ret
 }
 
 # counts how many bits are set to 1
@@ -205,16 +197,10 @@ mwan3_unlock() {
 
 mwan3_get_iface_id()
 {
-	local _tmp _iface _iface_count
-
-	_iface="$2"
-
-	mwan3_get_id()
-	{
-		let _iface_count++
-		[ "$1" = "$_iface" ] && _tmp=$_iface_count
-	}
-	config_foreach mwan3_get_id interface
+	local _tmp
+	[ -z "$mwan3_iface_tbl" ] && mwan3_update_iface_to_table
+	_tmp="${mwan3_iface_tbl##* ${2}=}"
+	_tmp=${_tmp%% *}
 	export "$1=$_tmp"
 }
 
@@ -312,7 +298,7 @@ mwan3_set_connected_iptables()
 
 		$IPS -! create mwan3_source_v6 hash:net family inet6
 		$IPS create mwan3_source_v6_temp hash:net family inet6
-		for source_network_v6 in $($IP6 addr ls  | sed -ne 's/ *inet6 \([^ \/]*\).* scope global.*/\1/p'); do
+		for source_network_v6 in $($IP6 addr ls | sed -ne 's/ *inet6 \([^ \/]*\).* scope global.*/\1/p'); do
 			$IPS -! add mwan3_source_v6_temp "$source_network_v6"
 		done
 		$IPS swap mwan3_source_v6_temp mwan3_source_v6
@@ -506,44 +492,109 @@ mwan3_delete_iface_iptables()
 
 mwan3_create_iface_route()
 {
-	local id via metric V V_ IP
+	local id via metric V V_ IP family
+	local iface device cmd true_iface
 
+	iface=$1
+	device=$2
+	config_get family "$iface" family ipv4
+	mwan3_get_iface_id id "$iface"
+
+	[ -n "$id" ] || return 0
+
+	mwan3_get_true_iface true_iface $iface
+	if [ "$family" = "ipv4" ]; then
+		V_=""
+		IP="$IP4"
+	elif [ "$family" = "ipv6" ]; then
+		V_=6
+		IP="$IP6"
+	fi
+
+	network_get_gateway${V_} via "$true_iface"
+
+	{ [ -z "$via" ] || [ "$via" = "0.0.0.0" ] || [ "$via" = "::" ] ; } && unset via
+
+	network_get_metric metric "$true_iface"
+
+	$IP route flush table "$id"
+	cmd="$IP route add table $id default \
+	     ${via:+via} $via \
+	     ${metric:+metric} $metric \
+	     dev $2"
+	$cmd || LOG warn "ip cmd failed $cmd"
+
+}
+
+mwan3_add_non_default_iface_route()
+{
+	local tid route_line family IP id
 	config_get family "$1" family ipv4
 	mwan3_get_iface_id id "$1"
 
 	[ -n "$id" ] || return 0
 
 	if [ "$family" = "ipv4" ]; then
-		V=4
-		V_=""
 		IP="$IP4"
 	elif [ "$family" = "ipv6" ]; then
-		V=6
-		V_=6
 		IP="$IP6"
-	else
-		return
 	fi
 
-	if ubus call network.interface.${1}_${V} status &>/dev/null; then
-		network_get_gateway${V_} via "${1}_${V}"
-	else
-		network_get_gateway${V_} via "$1"
-	fi
-
-	( [ -z "$via" ] || [ "$via" = "0.0.0.0" ] || [ "$via" = "::" ] ) && unset via
-
-	network_get_metric metric "$1"
-
-	$IP route flush table "$id"
-	$IP route add table "$id" default \
-	     ${via:+via} $via \
-	     ${metric:+metric} $metric \
-	     dev "$2"
-	mwan3_rtmon_ipv${V}
+	mwan3_update_dev_to_table
+	$IP route list table main  | grep -v "^default\|linkdown\|^::/0\|^fe80::/64\|^unreachable" | while read route_line; do
+		mwan3_route_line_dev "tid" "$route_line" "$family"
+		if [ -z "$tid" ] || [ "$tid" = "$id" ]; then
+			$IP route add table $id $route_line ||
+				LOG warn "failed to add $route_line to table $id"
+		fi
 
+	done
 }
 
+mwan3_add_all_nondefault_routes()
+{
+	local tid IP route_line ipv family active_tbls tid
+
+	add_active_tbls()
+	{
+		let tid++
+		config_get family "$1" family ipv4
+		[ "$family" != "$ipv" ] && return
+		$IP route list table $tid 2>/dev/null | grep -q "^default\|^::/0" && {
+			active_tbls="$active_tbls${tid} "
+		}
+	}
+
+	add_route()
+	{
+		let tid++
+		config_get family "$section" family ipv4
+		[ -n "${active_tbls##* $tid *}" ] && return
+		$IP route add table $tid $route_line ||
+			LOG warn "failed to add $route_line to table $tid"
+	}
+
+	mwan3_update_dev_to_table
+	for ipv in ipv4 ipv6; do
+		[ "$ipv" = "ipv6" ] && [ $NO_IPV6 -ne 0 ] && continue
+		if [ "$ipv" = "ipv4" ]; then
+			IP="$IP4"
+		elif [ "$ipv" = "ipv6" ]; then
+			IP="$IP6"
+		fi
+		tid=0
+		active_tbls=" "
+		config_foreach add_active_tbls interface
+		$IP route list table main  | grep -v "^default\|linkdown\|^::/0\|^fe80::/64\|^unreachable" | while read route_line; do
+			mwan3_route_line_dev "tid" "$route_line" "$ipv"
+			if [ -n "$tid" ]; then
+				$IP route add table $tid $route_line
+			else
+				config_foreach add_route interface
+			fi
+		done
+	done
+}
 mwan3_delete_iface_route()
 {
 	local id
@@ -649,12 +700,14 @@ mwan3_delete_iface_ipset_entries()
 
 mwan3_rtmon()
 {
-	pid="$(pgrep -f mwan3rtmon)"
-	if [ "${pid}" != "" ]; then
-		kill -USR1 "${pid}"
-	else
-		[ -x /usr/sbin/mwan3rtmon ] && /usr/sbin/mwan3rtmon &
-	fi
+	local protocol
+	for protocol in "ipv4" "ipv6"; do
+		pid="$(pgrep -f "mwan3rtmon $protocol")"
+		[ "$protocol" = "ipv6" ] && [ $NO_IPV6 -ne 0 ] && continue
+		if [ "${pid}" = "" ]; then
+			[ -x /usr/sbin/mwan3rtmon ] && /usr/sbin/mwan3rtmon $protocol &
+		fi
+	done
 }
 
 mwan3_track()
@@ -667,13 +720,10 @@ mwan3_track()
 	}
 	config_list_foreach "$1" track_ip mwan3_list_track_ips
 
-	for pid in $(pgrep -f "mwan3track $1 $2"); do
-		kill -TERM "$pid" > /dev/null 2>&1
-	done
+	kill -TERM $(pgrep -f "mwan3track $1 $2") > /dev/null 2>&1
 	sleep 1
-	for pid in $(pgrep -f "mwan3track $1 $2"); do
-		kill -KILL "$pid" > /dev/null 2>&1
-	done
+	kill -KILL $(pgrep -f "mwan3track $1 $2") > /dev/null 2>&1
+
 	if [ -n "$track_ips" ]; then
 		[ -x /usr/sbin/mwan3track ] && /usr/sbin/mwan3track "$1" "$2" "$3" "$4" $track_ips &
 	fi
@@ -723,7 +773,7 @@ mwan3_set_policy()
 			total_weight_v4=$weight
 			lowest_metric_v4=$metric
 		elif [ "$metric" -eq "$lowest_metric_v4" ]; then
-		       	total_weight_v4=$(($total_weight_v4+$weight))
+			total_weight_v4=$(($total_weight_v4+$weight))
 			total_weight=$total_weight_v4
 		else
 			return
@@ -757,7 +807,7 @@ mwan3_set_policy()
 		else
 			probability="1"
 		fi
-		
+
 		$IPT -I "mwan3_policy_$policy" \
 			-m mark --mark 0x0/$MMX_MASK \
 			-m statistic \
@@ -885,7 +935,7 @@ mwan3_set_user_iptables_rule()
 	[ -z "$ipset" ] && unset ipset
 	[ -z "$src_port" ]  && unset src_port
 	[ -z "$dest_port" ]  && unset dest_port
-	[ "$proto"  != 'tcp' ]  && [ "$proto" != 'udp' ] && {
+	[ "$proto"  != 'tcp' ]	&& [ "$proto" != 'udp' ] && {
 		[ -n "$src_port" ] && {
 			$LOG warn "src_port set to '$src_port' but proto set to '$proto' not tcp or udp. src_port will be ignored"
 		}
diff --git a/net/mwan3/files/usr/sbin/mwan3 b/net/mwan3/files/usr/sbin/mwan3
index 79a0eba25..392d7f500 100755
--- a/net/mwan3/files/usr/sbin/mwan3
+++ b/net/mwan3/files/usr/sbin/mwan3
@@ -145,6 +145,7 @@ start()
 
 	config_load mwan3
 	config_foreach ifup interface
+	mwan3_rtmon
 }
 
 stop()
@@ -154,23 +155,13 @@ stop()
 	mwan3_lock "command" "mwan3"
 	uci_toggle_state mwan3 globals enabled "0"
 
-	for pid in $(pgrep -f "mwan3rtmon"); do
-		kill -TERM "$pid" > /dev/null 2>&1
-	done
-
-	for pid in $(pgrep -f "mwan3track"); do
-		kill -TERM "$pid" > /dev/null 2>&1
-	done
+	kill -TERM $(pgrep -f "mwan3rtmon") > /dev/null 2>&1
+	kill -TERM $(pgrep -f "mwan3track") > /dev/null 2>&1
 
 	sleep 1
 
-	for pid in $(pgrep -f "mwan3rtmon"); do
-		kill -KILL "$pid" > /dev/null 2>&1
-	done
-
-	for pid in $(pgrep -f "mwan3track"); do
-		kill -KILL "$pid" > /dev/null 2>&1
-	done
+	kill -KILL $(pgrep -f "mwan3rtmon") > /dev/null 2>&1
+	kill -KILL $(pgrep -f "mwan3track") > /dev/null 2>&1
 
 	config_load mwan3
 	config_foreach mwan3_track_clean interface
diff --git a/net/mwan3/files/usr/sbin/mwan3rtmon b/net/mwan3/files/usr/sbin/mwan3rtmon
index 9165de554..1075041bf 100755
--- a/net/mwan3/files/usr/sbin/mwan3rtmon
+++ b/net/mwan3/files/usr/sbin/mwan3rtmon
@@ -1,38 +1,109 @@
 #!/bin/sh
-
 . /lib/functions.sh
+. /lib/functions/network.sh
 . /lib/mwan3/mwan3.sh
 
-LOG="logger -t $(basename "$0")[$$] -p"
 
-clean_up() {
-	$LOG notice "Stopping mwan3rtmon..."
-	exit 0
+mwan3_rtmon_route_handle()
+{
+	config_load mwan3
+	local section action route_line family tbl device metric tos dst line
+	local route_device tid
+	route_line=${1##"Deleted "}
+	route_family=$2
+
+	if [ "$route_family" = "ipv4" ]; then
+		IP="$IP4"
+	elif [ "$route_family" = "ipv6" ] && [ $NO_IPV6 -eq 0 ]; then
+		IP="$IP6"
+	else
+		return
+	fi
+
+	if [ "$route_line" == "$1" ]; then
+		action="add"
+	else
+		action="del"
+	fi
+
+	# never add default route lines, since this is handled elsewhere
+	[ -z "${route_line##default*}" ] && return
+	[ -z "${route_line##::/0*}" ] && return
+	route_line=${route_line%% linkdown*}
+	route_line=${route_line%% unreachable*}
+	mwan3_update_dev_to_table
+	mwan3_route_line_dev "tid" "$route_line" "$route_family"
+	handle_route() {
+		tbl=$($IP route list table $tid)
+		if [ $action = "add" ]; then
+			echo "$tbl" | grep -q "^default\|^::/0" || return
+		else
+			[ -z "$tbl" ] && return
+		fi
+		# check that action needs to be performed. May not need to take action if:
+		# Got a route update on ipv6 where route is already in the table
+		# Got a delete event, but table was already flushed
+
+		[ $action = "add" ] && [ -z "${tbl##*$route_line*}" ] && return
+		[ $action = "del" ] && [ -n "${tbl##*$route_line*}" ] && return
+		network_get_device device "$section"
+		LOG debug "adjusting route $device: $IP route "$action" table $tid $route_line"
+		$IP route "$action" table $tid $route_line ||
+			LOG warn "failed: $IP route $action table $tid $route_line"
+	}
+	handle_route_cb(){
+		let tid++
+		config_get family "$section" family ipv4
+		[ "$family" != "$route_family" ] && return
+		handle_route
+	}
+
+	if [ $action = "add" ]; then
+		## handle old routes from 'change' or 'replace'
+		metric=${route_line##*metric }
+		[ "$metric" = "$route_line" ] && unset metric || metric=${metric%% *}
+
+		tos=${route_line##*tos }
+		[ "$tos" = "$route_line" ] && unset tos || tos=${tos%% *}
+
+		dst=${route_line%% *}
+		grep_line="$dst ${tos:+tos $tos}.*table [0-9].*${metric:+metric $metric}"
+		$IP route list table all | grep "$grep_line" | while read line; do
+			tbl=${line##*table }
+			tbl=${tbl%% *}
+			[ $tbl -gt $MWAN3_INTERFACE_MAX ] && continue
+			LOG debug "removing route on ip route change/replace: $line"
+			$IP route del $line
+		done
+	fi
+
+	if [ -n "$tid" ]; then
+		handle_route
+	else
+		config_foreach handle_route_cb interface
+	fi
 }
 
-rtchange() {
-	$LOG info "Detect rtchange event."
-}
-
-main() {
-	local rtmon_interval
-	trap clean_up TERM
-	trap rtchange USR1
+main()
+{
+	local IP family
 
 	config_load mwan3
-	config_get rtmon_interval globals rtmon_interval '5'
+	family=$1
+	[ -z $family ] && family=ipv4
+	if [ "$family" = ipv6 ]; then
+		IP="$IP6"
+	else
+		IP="$IP4"
+	fi
+	mwan3_init
 
-	sleep 3
-	while true; do
+	$IP monitor route | while read line; do
+		[ -z "${line##*table*}" ] && continue
+		LOG debug "handling route update $family $line"
 		mwan3_lock "service" "mwan3rtmon"
-		mwan3_rtmon_ipv4 || mwan3_rtmon_ipv6
-		ret=$?
+		mwan3_rtmon_route_handle "$line" "$family"
 		mwan3_unlock "service" "mwan3rtmon"
-		[ "$ret" = "0" ] || break
-		[ "$rtmon_interval" = "0" ] && break
-		sleep "$rtmon_interval" &
-		wait
 	done
 }
-
 main "$@"