diff options
| -rw-r--r-- | net/sched/sch_netem.c | 61 |
1 files changed, 59 insertions, 2 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 9640bb39a5d2..4befe97a9034 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -395,6 +395,25 @@ static void tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) sch->q.qlen++; } +/* netem can't properly corrupt a megapacket (like we get from GSO), so instead + * when we statistically choose to corrupt one, we instead segment it, returning + * the first packet to be corrupted, and re-enqueue the remaining frames + */ +static struct sk_buff *netem_segment(struct sk_buff *skb, struct Qdisc *sch) +{ + struct sk_buff *segs; + netdev_features_t features = netif_skb_features(skb); + + segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); + + if (IS_ERR_OR_NULL(segs)) { + qdisc_reshape_fail(skb, sch); + return NULL; + } + consume_skb(skb); + return segs; +} + /* * Insert one skb into qdisc. * Note: parent depends on return value to account for queue length. @@ -407,7 +426,11 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) /* We don't fill cb now as skb_unshare() may invalidate it */ struct netem_skb_cb *cb; struct sk_buff *skb2; + struct sk_buff *segs = NULL; + unsigned int len = 0, last_len, prev_len = qdisc_pkt_len(skb); + int nb = 0; int count = 1; + int rc = NET_XMIT_SUCCESS; /* Random duplication */ if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) @@ -453,10 +476,23 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) * do it now in software before we mangle it. */ if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) { + if (skb_is_gso(skb)) { + segs = netem_segment(skb, sch); + if (!segs) + return NET_XMIT_DROP; + } else { + segs = skb; + } + + skb = segs; + segs = segs->next; + if (!(skb = skb_unshare(skb, GFP_ATOMIC)) || (skb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_help(skb))) - return qdisc_drop(skb, sch); + skb_checksum_help(skb))) { + rc = qdisc_drop(skb, sch); + goto finish_segs; + } skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); @@ -516,6 +552,27 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) sch->qstats.requeues++; } +finish_segs: + if (segs) { + while (segs) { + skb2 = segs->next; + segs->next = NULL; + qdisc_skb_cb(segs)->pkt_len = segs->len; + last_len = segs->len; + rc = qdisc_enqueue(segs, sch); + if (rc != NET_XMIT_SUCCESS) { + if (net_xmit_drop_count(rc)) + qdisc_qstats_drop(sch); + } else { + nb++; + len += last_len; + } + segs = skb2; + } + sch->q.qlen += nb; + if (nb > 1) + qdisc_tree_reduce_backlog(sch, 1 - nb, prev_len - len); + } return NET_XMIT_SUCCESS; } |