[PATCH net-next v2 3/5] net/sched: netem: replace pr_info with netlink extack error messages

[Stephen Hemminger <stephen@networkplumber.org>]

Use netlink extack to report errors instead of sending them
to the kernel log with pr_info(). The error message can them be seen
with tc commands; and avoids log spam.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 net/sched/sch_netem.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 2b0b5c032e70..53961d1e70d7 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -921,7 +921,8 @@ static void get_rate(struct netem_sched_data *q, const struct nlattr *attr)
 		q->cell_size_reciprocal = (struct reciprocal_value) { 0 };
 }
 
-static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr)
+static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr,
+			struct netlink_ext_ack *extack)
 {
 	const struct nlattr *la;
 	int rem;
@@ -934,7 +935,8 @@ static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr)
 			const struct tc_netem_gimodel *gi = nla_data(la);
 
 			if (nla_len(la) < sizeof(struct tc_netem_gimodel)) {
-				pr_info("netem: incorrect gi model size\n");
+				NL_SET_ERR_MSG_ATTR(extack, la,
+						    "netem: incorrect gi model size");
 				return -EINVAL;
 			}
 
@@ -953,7 +955,8 @@ static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr)
 			const struct tc_netem_gemodel *ge = nla_data(la);
 
 			if (nla_len(la) < sizeof(struct tc_netem_gemodel)) {
-				pr_info("netem: incorrect ge model size\n");
+				NL_SET_ERR_MSG_ATTR(extack, la,
+						    "netem: incorrect ge model size");
 				return -EINVAL;
 			}
 
@@ -967,7 +970,8 @@ static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr)
 		}
 
 		default:
-			pr_info("netem: unknown loss type %u\n", type);
+			NL_SET_ERR_MSG_ATTR_FMT(extack, la,
+						"netem: unknown loss type %u", type);
 			return -EINVAL;
 		}
 	}
@@ -990,19 +994,21 @@ static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = {
 };
 
 static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
-		      const struct nla_policy *policy, int len)
+		      const struct nla_policy *policy, int len,
+		      struct netlink_ext_ack *extack)
 {
 	int nested_len = nla_len(nla) - NLA_ALIGN(len);
 
 	if (nested_len < 0) {
-		pr_info("netem: invalid attributes len %d\n", nested_len);
+		NL_SET_ERR_MSG_FMT(extack, "netem: invalid attributes len %u < %d",
+				   nla_len(nla), NLA_ALIGN(len));
 		return -EINVAL;
 	}
 
 	if (nested_len >= nla_attr_size(0))
 		return nla_parse_deprecated(tb, maxtype,
 					    nla_data(nla) + NLA_ALIGN(len),
-					    nested_len, policy, NULL);
+					    nested_len, policy, extack);
 
 	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
 	return 0;
@@ -1044,8 +1050,7 @@ static int check_netem_in_tree(struct Qdisc *sch, bool duplicates,
 }
 
 /* Parse netlink message to set options */
-static int netem_change(struct Qdisc *sch, struct nlattr *opt,
-			struct netlink_ext_ack *extack)
+static int netem_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack)
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
 	struct nlattr *tb[TCA_NETEM_MAX + 1];
@@ -1057,7 +1062,7 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt,
 	int ret;
 
 	qopt = nla_data(opt);
-	ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt));
+	ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt), extack);
 	if (ret < 0)
 		return ret;
 
@@ -1097,7 +1102,7 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt,
 	old_loss_model = q->loss_model;
 
 	if (tb[TCA_NETEM_LOSS]) {
-		ret = get_loss_clg(q, tb[TCA_NETEM_LOSS]);
+		ret = get_loss_clg(q, tb[TCA_NETEM_LOSS], extack);
 		if (ret) {
 			q->loss_model = old_loss_model;
 			q->clg = old_clg;
@@ -1193,8 +1198,6 @@ static int netem_init(struct Qdisc *sch, struct nlattr *opt,
 	prandom_seed_state(&q->prng.prng_state, q->prng.seed);
 
 	ret = netem_change(sch, opt, extack);
-	if (ret)
-		pr_info("netem: change failed\n");
 	return ret;
 }
 
-- 
2.53.0