diff options
| -rw-r--r-- | net/sched/sch_netem.c | 53 |
1 files changed, 29 insertions, 24 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index e0c9fbe..5c0f0c2 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -203,42 +203,47 @@ static int netem_run(struct Qdisc *sch) return 0; } +/* + * Insert one skb into qdisc. + * Note: parent depends on return value to account for queue length. + * NET_XMIT_DROP: queue length didn't change. + * NET_XMIT_SUCCESS: one skb was queued. + */ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) { struct netem_sched_data *q = qdisc_priv(sch); + struct sk_buff *skb2; int ret; + int count = 1; pr_debug("netem_enqueue skb=%p\n", skb); + /* Random duplication */ + if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) + ++count; + /* Random packet drop 0 => none, ~0 => all */ - if (q->loss && q->loss >= get_crandom(&q->loss_cor)) { - pr_debug("netem_enqueue: random loss\n"); + if (q->loss && q->loss >= get_crandom(&q->loss_cor)) + --count; + + if (count == 0) { sch->qstats.drops++; kfree_skb(skb); - return 0; /* lie about loss so TCP doesn't know */ + return NET_XMIT_DROP; } - /* Random duplication */ - if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) { - struct sk_buff *skb2; - - skb2 = skb_clone(skb, GFP_ATOMIC); - if (skb2 && netem_delay(sch, skb2) == NET_XMIT_SUCCESS) { - struct Qdisc *qp; - - /* Since one packet can generate two packets in the - * queue, the parent's qlen accounting gets confused, - * so fix it. - */ - qp = qdisc_lookup(sch->dev, TC_H_MAJ(sch->parent)); - if (qp) - qp->q.qlen++; - - sch->q.qlen++; - sch->bstats.bytes += skb2->len; - sch->bstats.packets++; - } else - sch->qstats.drops++; + /* + * If we need to duplicate packet, then re-insert at top of the + * qdisc tree, since parent queuer expects that only one + * skb will be queued. + */ + if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { + struct Qdisc *rootq = sch->dev->qdisc; + u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ + q->duplicate = 0; + + rootq->enqueue(skb2, rootq); + q->duplicate = dupsave; } /* If doing simple delay then gap == 0 so all packets |
