mwan3: report an error code on status failure

Signed-off-by: Aaron Goodman <aaronjg@stanford.edu>

net/mwan3/files/lib/mwan3/mwan3.sh

@@ -1017,7 +1017,7 @@ mwan3_get_iface_hotplug_state() {
 
 mwan3_report_iface_status()
 {
-	local device result tracking IP IPT
+	local device result tracking IP IPT error
 
 	mwan3_get_iface_id id "$1"
 	network_get_device device "$1"
@@ -1036,11 +1036,23 @@ mwan3_report_iface_status()
 
 	if [ -z "$id" ] || [ -z "$device" ]; then
 		result="offline"
-	elif [ -n "$($IP rule | awk '$1 == "'$((id+1000)):'"')" ] && \
-		     [ -n "$($IP rule | awk '$1 == "'$((id+2000)):'"')" ] && \
-		     [ -n "$($IP rule | awk '$1 == "'$((id+3000)):'"')" ] && \
-		     [ -n "$($IPT -S mwan3_iface_in_$1 2> /dev/null)" ] && \
-		     [ -n "$($IP route list table $id default dev $device 2> /dev/null)" ]; then
+	else
+		error=0
+		[ -n "$($IP rule | awk '$1 == "'$((id+1000)):'"')" ] ||
+			error=$((error+1))
+		[ -n "$($IP rule | awk '$1 == "'$((id+2000)):'"')" ] ||
+			error=$((error+2))
+		[ -n "$($IP rule | awk '$1 == "'$((id+3000)):'"')" ] ||
+			error=$((error+4))
+		[ -n "$($IPT -S mwan3_iface_in_$1 2> /dev/null)" ] ||
+			error=$((error+8))
+		[ -n "$($IP route list table $id default dev $device 2> /dev/null)" ] ||
+			error=$((error+16))
+	fi
+
+	if [ "$result" = "offline" ]; then
+		:
+	elif [ $error -eq 0 ]; then
 		json_init
 		json_add_string section interfaces
 		json_add_string interface "$1"
@@ -1053,12 +1065,8 @@ mwan3_report_iface_status()
 		online="$(printf '%02dh:%02dm:%02ds\n' $((online/3600)) $((online%3600/60)) $((online%60)))"
 		uptime="$(printf '%02dh:%02dm:%02ds\n' $((uptime/3600)) $((uptime%3600/60)) $((uptime%60)))"
 		result="$(mwan3_get_iface_hotplug_state $1) $online, uptime $uptime"
-	elif [ -n "$($IP rule | awk '$1 == "'$((id+1000)):'"')" ] || \
-		     [ -n "$($IP rule | awk '$1 == "'$((id+2000)):'"')" ] || \
-		     [ -n "$($IP rule | awk '$1 == "'$((id+3000)):'"')" ] || \
-		     [ -n "$($IPT -S mwan3_iface_in_$1 2> /dev/null)" ] || \
-		     [ -n "$($IP route list table $id default dev $device 2> /dev/null)" ]; then
-		result="error"
+	elif [ $error -gt 0 ] && [ $error -ne 31 ]; then
+		result="error (${error})"
 	elif [ "$enabled" = "1" ]; then
 		result="offline"
 	else