1 files changed, 61 insertions, 8 deletions

diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 1695421333e3..c7de47c942e3 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -35,7 +35,11 @@
 
 struct red_sched_data {
 	u32			limit;		/* HARD maximal queue length */
+
 	unsigned char		flags;
+	/* Non-flags in tc_red_qopt.flags. */
+	unsigned char		userbits;
+
 	struct timer_list	adapt_timer;
 	struct Qdisc		*sch;
 	struct red_parms	parms;
@@ -44,6 +48,8 @@ struct red_sched_data {
 	struct Qdisc		*qdisc;
 };
 
+static const u32 red_supported_flags = TC_RED_HISTORIC_FLAGS | TC_RED_NODROP;
+
 static inline int red_use_ecn(struct red_sched_data *q)
 {
 	return q->flags & TC_RED_ECN;
@@ -54,6 +60,11 @@ static inline int red_use_harddrop(struct red_sched_data *q)
 	return q->flags & TC_RED_HARDDROP;
 }
 
+static int red_use_nodrop(struct red_sched_data *q)
+{
+	return q->flags & TC_RED_NODROP;
+}
+
 static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
@@ -74,23 +85,36 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 
 	case RED_PROB_MARK:
 		qdisc_qstats_overlimit(sch);
-		if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) {
+		if (!red_use_ecn(q)) {
 			q->stats.prob_drop++;
 			goto congestion_drop;
 		}
 
-		q->stats.prob_mark++;
+		if (INET_ECN_set_ce(skb)) {
+			q->stats.prob_mark++;
+		} else if (!red_use_nodrop(q)) {
+			q->stats.prob_drop++;
+			goto congestion_drop;
+		}
+
+		/* Non-ECT packet in ECN nodrop mode: queue it. */
 		break;
 
 	case RED_HARD_MARK:
 		qdisc_qstats_overlimit(sch);
-		if (red_use_harddrop(q) || !red_use_ecn(q) ||
-		    !INET_ECN_set_ce(skb)) {
+		if (red_use_harddrop(q) || !red_use_ecn(q)) {
+			q->stats.forced_drop++;
+			goto congestion_drop;
+		}
+
+		if (INET_ECN_set_ce(skb)) {
+			q->stats.forced_mark++;
+		} else if (!red_use_nodrop(q)) {
 			q->stats.forced_drop++;
 			goto congestion_drop;
 		}
 
-		q->stats.forced_mark++;
+		/* Non-ECT packet in ECN nodrop mode: queue it. */
 		break;
 	}
 
@@ -165,6 +189,7 @@ static int red_offload(struct Qdisc *sch, bool enable)
 		opt.set.limit = q->limit;
 		opt.set.is_ecn = red_use_ecn(q);
 		opt.set.is_harddrop = red_use_harddrop(q);
+		opt.set.is_nodrop = red_use_nodrop(q);
 		opt.set.qstats = &sch->qstats;
 	} else {
 		opt.command = TC_RED_DESTROY;
@@ -183,9 +208,12 @@ static void red_destroy(struct Qdisc *sch)
 }
 
 static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
+	[TCA_RED_UNSPEC] = { .strict_start_type = TCA_RED_FLAGS },
 	[TCA_RED_PARMS]	= { .len = sizeof(struct tc_red_qopt) },
 	[TCA_RED_STAB]	= { .len = RED_STAB_SIZE },
 	[TCA_RED_MAX_P] = { .type = NLA_U32 },
+	[TCA_RED_FLAGS] = { .type = NLA_BITFIELD32,
+			    .validation_data = &red_supported_flags },
 };
 
 static int red_change(struct Qdisc *sch, struct nlattr *opt,
@@ -194,7 +222,10 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
 	struct Qdisc *old_child = NULL, *child = NULL;
 	struct red_sched_data *q = qdisc_priv(sch);
 	struct nlattr *tb[TCA_RED_MAX + 1];
+	struct nla_bitfield32 flags_bf;
 	struct tc_red_qopt *ctl;
+	unsigned char userbits;
+	unsigned char flags;
 	int err;
 	u32 max_P;
 
@@ -216,6 +247,12 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
 	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
 		return -EINVAL;
 
+	err = red_get_flags(ctl->flags, TC_RED_HISTORIC_FLAGS,
+			    tb[TCA_RED_FLAGS], red_supported_flags,
+			    &flags_bf, &userbits, extack);
+	if (err)
+		return err;
+
 	if (ctl->limit > 0) {
 		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
 					 extack);
@@ -227,7 +264,14 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
 	}
 
 	sch_tree_lock(sch);
-	q->flags = ctl->flags;
+
+	flags = (q->flags & ~flags_bf.selector) | flags_bf.value;
+	err = red_validate_flags(flags, extack);
+	if (err)
+		goto unlock_out;
+
+	q->flags = flags;
+	q->userbits = userbits;
 	q->limit = ctl->limit;
 	if (child) {
 		qdisc_tree_flush_backlog(q->qdisc);
@@ -256,6 +300,12 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
 	if (old_child)
 		qdisc_put(old_child);
 	return 0;
+
+unlock_out:
+	sch_tree_unlock(sch);
+	if (child)
+		qdisc_put(child);
+	return err;
 }
 
 static inline void red_adaptative_timer(struct timer_list *t)
@@ -302,7 +352,8 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
 	struct nlattr *opts = NULL;
 	struct tc_red_qopt opt = {
 		.limit		= q->limit,
-		.flags		= q->flags,
+		.flags		= (q->flags & TC_RED_HISTORIC_FLAGS) |
+				  q->userbits,
 		.qth_min	= q->parms.qth_min >> q->parms.Wlog,
 		.qth_max	= q->parms.qth_max >> q->parms.Wlog,
 		.Wlog		= q->parms.Wlog,
@@ -319,7 +370,9 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
 	if (opts == NULL)
 		goto nla_put_failure;
 	if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
-	    nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
+	    nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P) ||
+	    nla_put_bitfield32(skb, TCA_RED_FLAGS,
+			       q->flags, red_supported_flags))
 		goto nla_put_failure;
 	return nla_nest_end(skb, opts);