Bloat » Cerowrt

---------- Forwarded message ----------
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, May 1, 2012 at 2:11 AM
Subject: [PATCH net-next] netem: add ECN capability
To: David Miller <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>, Tom Herbert
<therbert@google.com>, Neal Cardwell <ncardwell@google.com>, Hagen
Paul Pfeifer <hagen@jauu.net>, Stephen Hemminger
<shemminger@vyatta.com>

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 <therbert@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
---
 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;