Commit e4ae004b authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

netem: add ECN capability 



Add ECN (Explicit Congestion Notification) marking capability to netem

tc qdisc add dev eth0 root netem drop 0.5 ecn

Instead of dropping packets, try to ECN mark them.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: default avatarHagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 18d07000

include/linux/pkt_sched.h

+1 −0
Original line number Diff line number Diff line
@@ -509,6 +509,7 @@ enum { 
	TCA_NETEM_CORRUPT,

	TCA_NETEM_LOSS,

	TCA_NETEM_RATE,

	TCA_NETEM_ECN,

	__TCA_NETEM_MAX,

};

net/sched/sch_netem.c

+15 −3
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 


#include <net/netlink.h>

#include <net/pkt_sched.h>

#include <net/inet_ecn.h>



#define VERSION "1.3"
@@ -78,6 +79,7 @@ struct netem_sched_data { 
	psched_tdiff_t jitter;



	u32 loss;

	u32 ecn;

	u32 limit;

	u32 counter;

	u32 gap;
@@ -374,9 +376,12 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) 
		++count;



	/* Drop packet? */

	if (loss_event(q))

	if (loss_event(q)) {

		if (q->ecn && INET_ECN_set_ce(skb))

			sch->qstats.drops++; /* mark packet */

		else

			--count;



	}

	if (count == 0) {

		sch->qstats.drops++;

		kfree_skb(skb);
@@ -706,6 +711,7 @@ static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = { 
	[TCA_NETEM_CORRUPT]	= { .len = sizeof(struct tc_netem_corrupt) },

	[TCA_NETEM_RATE]	= { .len = sizeof(struct tc_netem_rate) },

	[TCA_NETEM_LOSS]	= { .type = NLA_NESTED },

	[TCA_NETEM_ECN]		= { .type = NLA_U32 },

};



static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
@@ -776,6 +782,9 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) 
	if (tb[TCA_NETEM_RATE])

		get_rate(sch, tb[TCA_NETEM_RATE]);



	if (tb[TCA_NETEM_ECN])

		q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]);



	q->loss_model = CLG_RANDOM;

	if (tb[TCA_NETEM_LOSS])

		ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]);
@@ -902,6 +911,9 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) 
	if (nla_put(skb, TCA_NETEM_RATE, sizeof(rate), &rate))

		goto nla_put_failure;



	if (q->ecn && nla_put_u32(skb, TCA_NETEM_ECN, q->ecn))

		goto nla_put_failure;



	if (dump_loss_model(q, skb) != 0)

		goto nla_put_failure;

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