selftests: net: push jq workaround into separate helper

Push the jq return value workaround code into a separate helper so it
could be used by the rest of the code.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/forwarding/lib.sh

@@ -250,6 +250,25 @@ setup_wait()
 	sleep $WAIT_TIME
 }
 
+cmd_jq()
+{
+	local cmd=$1
+	local jq_exp=$2
+	local ret
+	local output
+
+	output="$($cmd)"
+	# it the command fails, return error right away
+	ret=$?
+	if [[ $ret -ne 0 ]]; then
+		return $ret
+	fi
+	output=$(echo $output | jq -r "$jq_exp")
+	echo $output
+	# return success only in case of non-empty output
+	[ ! -z "$output" ]
+}
+
 lldpad_app_wait_set()
 {
 	local dev=$1; shift

tools/testing/selftests/net/forwarding/tc_common.sh

@@ -8,18 +8,9 @@ tc_check_packets()
 	local id=$1
 	local handle=$2
 	local count=$3
-	local ret
 
-	output="$(tc -j -s filter show $id)"
-	# workaround the jq bug which causes jq to return 0 in case input is ""
-	ret=$?
-	if [[ $ret -ne 0 ]]; then
-		return $ret
-	fi
-	echo $output | \
-		jq -e ".[] \
-		| select(.options.handle == $handle) \
-		| select(.options.actions[0].stats.packets == $count)" \
-		&> /dev/null
-	return $?
+	cmd_jq "tc -j -s filter show $id" \
+	       ".[] | select(.options.handle == $handle) | \
+	              select(.options.actions[0].stats.packets == $count)" \
+	       &> /dev/null
 }