[PATCH net-next] netem: add ECN capability
From: Eric Dumazet <hidden>
Date: 2012-05-01 09:11:10
Subsystem:
netem network emulator, networking [general], tc subsystem, the rest · Maintainers:
Stephen Hemminger, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> 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: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <redacted> Cc: Hagen Paul Pfeifer <redacted> Cc: Stephen Hemminger <redacted> --- include/linux/pkt_sched.h | 1 + net/sched/sch_netem.c | 18 +++++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 410b33d..ffe975c 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h@@ -509,6 +509,7 @@ enum { TCA_NETEM_CORRUPT, TCA_NETEM_LOSS, TCA_NETEM_RATE, + TCA_NETEM_ECN, __TCA_NETEM_MAX, };
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 1109731..231cd11 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c@@ -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)) - --count; - + 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;