Petr Machata [off-list ref] writes:


[...]

+static int parse_qos_mapping(__u32 key, char *value, void *data)
+{
+	struct nlmsghdr *n = data;
+	struct ifla_vlan_qos_mapping m = {
+		.from = key,
+	};
+
+	if (get_u32(&m.to, value, 0))
+		return 1;
+
+	addattr_l(n, 1024, IFLA_VLAN_QOS_MAPPING, &m, sizeof(m));
+	return 0;
+}

addatr_l() may fail if netlink buffer size is not sufficient, may be:

return addattr_l(...);

would be better.