2 files changed, 50 insertions, 13 deletions

diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 73d84c071cb1..1d9da36eb9db 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -427,6 +427,7 @@ enum
         TCA_NETEM_UNSPEC,
         TCA_NETEM_CORR,
         TCA_NETEM_DELAY_DIST,
+        TCA_NETEM_REORDER,
         __TCA_NETEM_MAX,
 };
 
@@ -437,7 +438,7 @@ struct tc_netem_qopt
         __u32   latency;        /* added delay (us) */
         __u32   limit;          /* fifo limit (packets) */
         __u32   loss;           /* random packet loss (0=none ~0=100%) */
-        __u32   gap;            /* re-ordering gap (0 for delay all) */
+        __u32   gap;            /* re-ordering gap (0 for none) */
         __u32   duplicate;      /* random packet dup  (0=none ~0=100%) */
         __u32   jitter;         /* random jitter in latency (us) */
 };
@@ -449,6 +450,12 @@ struct tc_netem_corr
         __u32   dup_corr;       /* duplicate correlation  */
 };
 
+struct tc_netem_reorder
+{
+        __u32   probability;
+        __u32   correlation;
+};
+
 #define NETEM_DIST_SCALE        8192
 
 #endif
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 48360f7eec5d..bb9bf8d5003c 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -62,11 +62,12 @@ struct netem_sched_data {
         u32 gap;
         u32 jitter;
         u32 duplicate;
+        u32 reorder;
 
         struct crndstate {
                 unsigned long last;
                 unsigned long rho;
-        } delay_cor, loss_cor, dup_cor;
+        } delay_cor, loss_cor, dup_cor, reorder_cor;
 
         struct disttable {
                 u32  size;
@@ -180,23 +181,23 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                 q->duplicate = dupsave;
         }
 
-        /* 
-         * Do re-ordering by putting one out of N packets at the front
-         * of the queue.
-         * gap == 0 is special case for no-reordering.
-         */
-        if (q->gap == 0 || q->counter != q->gap) {
+        if (q->gap == 0                 /* not doing reordering */
+            || q->counter < q->gap      /* inside last reordering gap */
+            || q->reorder < get_crandom(&q->reorder_cor)) {
                 psched_time_t now;
                 PSCHED_GET_TIME(now);
-                PSCHED_TADD2(now, 
-                             tabledist(q->latency, q->jitter, &q->delay_cor, q->delay_dist),
+                PSCHED_TADD2(now, tabledist(q->latency, q->jitter, 
+                                            &q->delay_cor, q->delay_dist),
                              cb->time_to_send);
-                
                 ++q->counter;
                 ret = q->qdisc->enqueue(skb, q->qdisc);
         } else {
-                q->counter = 0;
+                /* 
+                 * Do re-ordering by putting one out of N packets at the front
+                 * of the queue.
+                 */
                 PSCHED_GET_TIME(cb->time_to_send);
+                q->counter = 0;
                 ret = q->qdisc->ops->requeue(skb, q->qdisc);
         }
 
@@ -351,6 +352,19 @@ static int get_correlation(struct Qdisc *sch, const struct rtattr *attr)
         return 0;
 }
 
+static int get_reorder(struct Qdisc *sch, const struct rtattr *attr)
+{
+        struct netem_sched_data *q = qdisc_priv(sch);
+        const struct tc_netem_reorder *r = RTA_DATA(attr);
+
+        if (RTA_PAYLOAD(attr) != sizeof(*r))
+                return -EINVAL;
+
+        q->reorder = r->probability;
+        init_crandom(&q->reorder_cor, r->correlation);
+        return 0;
+}
+
 static int netem_change(struct Qdisc *sch, struct rtattr *opt)
 {
         struct netem_sched_data *q = qdisc_priv(sch);
@@ -371,9 +385,15 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt)
         q->jitter = qopt->jitter;
         q->limit = qopt->limit;
         q->gap = qopt->gap;
+        q->counter = 0;
         q->loss = qopt->loss;
         q->duplicate = qopt->duplicate;
 
+        /* for compatiablity with earlier versions.
+         * if gap is set, need to assume 100% probablity
+         */
+        q->reorder = ~0;
+
         /* Handle nested options after initial queue options.
          * Should have put all options in nested format but too late now.
          */ 
@@ -395,6 +415,11 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt)
                         if (ret)
                                 return ret;
                 }
+                if (tb[TCA_NETEM_REORDER-1]) {
+                        ret = get_reorder(sch, tb[TCA_NETEM_REORDER-1]);
+                        if (ret)
+                                return ret;
+                }
         }
 
 
@@ -412,7 +437,6 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt)
         init_timer(&q->timer);
         q->timer.function = netem_watchdog;
         q->timer.data = (unsigned long) sch;
-        q->counter = 0;
 
         q->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
         if (!q->qdisc) {
@@ -444,6 +468,7 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
         struct rtattr *rta = (struct rtattr *) b;
         struct tc_netem_qopt qopt;
         struct tc_netem_corr cor;
+        struct tc_netem_reorder reorder;
 
         qopt.latency = q->latency;
         qopt.jitter = q->jitter;
@@ -457,6 +482,11 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
         cor.loss_corr = q->loss_cor.rho;
         cor.dup_corr = q->dup_cor.rho;
         RTA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor);
+
+        reorder.probability = q->reorder;
+        reorder.correlation = q->reorder_cor.rho;
+        RTA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder);
+
         rta->rta_len = skb->tail - b;
 
         return skb->len;