net/sched: mqprio: refactor nlattr parsing to a separate function

mqprio_init() is quite large and unwieldy to add more code to.
Split the netlink attribute parsing to a dedicated function.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_mqprio.c

@@ -130,6 +130,67 @@ static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
 	return 0;
 }
 
+static int mqprio_parse_nlattr(struct Qdisc *sch, struct tc_mqprio_qopt *qopt,
+			       struct nlattr *opt)
+{
+	struct mqprio_sched *priv = qdisc_priv(sch);
+	struct nlattr *tb[TCA_MQPRIO_MAX + 1];
+	struct nlattr *attr;
+	int i, rem, err;
+
+	err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
+			 sizeof(*qopt));
+	if (err < 0)
+		return err;
+
+	if (!qopt->hw)
+		return -EINVAL;
+
+	if (tb[TCA_MQPRIO_MODE]) {
+		priv->flags |= TC_MQPRIO_F_MODE;
+		priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
+	}
+
+	if (tb[TCA_MQPRIO_SHAPER]) {
+		priv->flags |= TC_MQPRIO_F_SHAPER;
+		priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
+	}
+
+	if (tb[TCA_MQPRIO_MIN_RATE64]) {
+		if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
+			return -EINVAL;
+		i = 0;
+		nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
+				    rem) {
+			if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64)
+				return -EINVAL;
+			if (i >= qopt->num_tc)
+				break;
+			priv->min_rate[i] = *(u64 *)nla_data(attr);
+			i++;
+		}
+		priv->flags |= TC_MQPRIO_F_MIN_RATE;
+	}
+
+	if (tb[TCA_MQPRIO_MAX_RATE64]) {
+		if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
+			return -EINVAL;
+		i = 0;
+		nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
+				    rem) {
+			if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64)
+				return -EINVAL;
+			if (i >= qopt->num_tc)
+				break;
+			priv->max_rate[i] = *(u64 *)nla_data(attr);
+			i++;
+		}
+		priv->flags |= TC_MQPRIO_F_MAX_RATE;
+	}
+
+	return 0;
+}
+
 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 		       struct netlink_ext_ack *extack)
 {
@@ -139,9 +200,6 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 	struct Qdisc *qdisc;
 	int i, err = -EOPNOTSUPP;
 	struct tc_mqprio_qopt *qopt = NULL;
-	struct nlattr *tb[TCA_MQPRIO_MAX + 1];
-	struct nlattr *attr;
-	int rem;
 	int len;
 
 	BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
@@ -166,55 +224,9 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 
 	len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 	if (len > 0) {
-		err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
-				 sizeof(*qopt));
-		if (err < 0)
+		err = mqprio_parse_nlattr(sch, qopt, opt);
+		if (err)
 			return err;
-
-		if (!qopt->hw)
-			return -EINVAL;
-
-		if (tb[TCA_MQPRIO_MODE]) {
-			priv->flags |= TC_MQPRIO_F_MODE;
-			priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
-		}
-
-		if (tb[TCA_MQPRIO_SHAPER]) {
-			priv->flags |= TC_MQPRIO_F_SHAPER;
-			priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
-		}
-
-		if (tb[TCA_MQPRIO_MIN_RATE64]) {
-			if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
-				return -EINVAL;
-			i = 0;
-			nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
-					    rem) {
-				if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64)
-					return -EINVAL;
-				if (i >= qopt->num_tc)
-					break;
-				priv->min_rate[i] = *(u64 *)nla_data(attr);
-				i++;
-			}
-			priv->flags |= TC_MQPRIO_F_MIN_RATE;
-		}
-
-		if (tb[TCA_MQPRIO_MAX_RATE64]) {
-			if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
-				return -EINVAL;
-			i = 0;
-			nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
-					    rem) {
-				if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64)
-					return -EINVAL;
-				if (i >= qopt->num_tc)
-					break;
-				priv->max_rate[i] = *(u64 *)nla_data(attr);
-				i++;
-			}
-			priv->flags |= TC_MQPRIO_F_MAX_RATE;
-		}
 	}
 
 	/* pre-allocate qdisc, attachment can't fail */