mwan3: Improve logs when member metric is too big

If metric of member interface is bigger then 256, it is not
appended to policy, now at least warn message is printed into
syslog

Signed-off-by: Jakub Janco <kubco2@gmail.com>

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

@@ -10,6 +10,7 @@ CONNTRACK_FILE="/proc/net/nf_conntrack"
 
 MWAN3_STATUS_DIR="/var/run/mwan3"
 MWAN3TRACK_STATUS_DIR="/var/run/mwan3track"
+DEFAULT_LOWEST_METRIC=256
 
 [ -d $MWAN3_STATUS_DIR ] || mkdir -p $MWAN3_STATUS_DIR/iface_state
 # mwan3's MARKing mask (at least 3 bits should be set)
@@ -480,6 +481,7 @@ mwan3_set_policy()
 	config_get weight $1 weight 1
 
 	[ -n "$iface" ] || return 0
+	[ "$metric" -gt $DEFAULT_LOWEST_METRIC ] && $LOG warn "Member interface $iface has >$DEFAULT_LOWEST_METRIC metric. Not appending to policy" && return 0
 
 	mwan3_get_iface_id id $iface
 
@@ -587,10 +589,10 @@ mwan3_create_policies_iptables()
 		esac
 	done
 
-	lowest_metric_v4=256
+	lowest_metric_v4=$DEFAULT_LOWEST_METRIC
 	total_weight_v4=0
 
-	lowest_metric_v6=256
+	lowest_metric_v6=$DEFAULT_LOWEST_METRIC
 	total_weight_v6=0
 
 	config_list_foreach $1 use_member mwan3_set_policy