* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
+ * 2 of the License.
*
* Many of the algorithms and ideas for this came from
* NIST Net which is not copyrighted.
* Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
*/
-#include <linux/config.h>
#include <linux/module.h>
-#include <asm/bitops.h>
+#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <net/pkt_sched.h>
+#define VERSION "1.2"
+
/* Network Emulation Queuing algorithm.
====================================
struct netem_sched_data {
struct Qdisc *qdisc;
- struct sk_buff_head delayed;
struct timer_list timer;
u32 latency;
u32 gap;
u32 jitter;
u32 duplicate;
+ u32 reorder;
+ u32 corrupt;
struct crndstate {
unsigned long last;
unsigned long rho;
- } delay_cor, loss_cor, dup_cor;
+ } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;
struct disttable {
u32 size;
return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
}
-/* Put skb in the private delayed queue. */
-static int delay_skb(struct Qdisc *sch, struct sk_buff *skb)
-{
- struct netem_sched_data *q = qdisc_priv(sch);
- struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
- psched_time_t now;
-
- PSCHED_GET_TIME(now);
- PSCHED_TADD2(now, tabledist(q->latency, q->jitter,
- &q->delay_cor, q->delay_dist),
- cb->time_to_send);
-
- /* Always queue at tail to keep packets in order */
- if (likely(q->delayed.qlen < q->limit)) {
- __skb_queue_tail(&q->delayed, skb);
- sch->q.qlen++;
- sch->stats.bytes += skb->len;
- sch->stats.packets++;
- return NET_XMIT_SUCCESS;
- }
-
- sch->stats.drops++;
- kfree_skb(skb);
- return NET_XMIT_DROP;
-}
-
+/*
+ * 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);
+ /* We don't fill cb now as skb_unshare() may invalidate it */
+ struct netem_skb_cb *cb;
+ struct sk_buff *skb2;
+ int ret;
+ int count = 1;
- pr_debug("netem_enqueue skb=%p @%lu\n", skb, jiffies);
+ 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");
- sch->stats.drops++;
- return 0; /* lie about loss so TCP doesn't know */
+ if (q->loss && q->loss >= get_crandom(&q->loss_cor))
+ --count;
+
+ if (count == 0) {
+ sch->qstats.drops++;
+ kfree_skb(skb);
+ return NET_XMIT_BYPASS;
}
- /* Random duplication */
- if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) {
- struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+ skb_orphan(skb);
- pr_debug("netem_enqueue: dup %p\n", skb2);
- if (skb2)
- delay_skb(sch, skb2);
+ /*
+ * 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
- * go into the delayed holding queue
- * otherwise if doing out of order only "1 out of gap"
- * packets will be delayed.
+ /*
+ * Randomized packet corruption.
+ * Make copy if needed since we are modifying
+ * If packet is going to be hardware checksummed, then
+ * do it now in software before we mangle it.
*/
- if (q->counter < q->gap) {
- int ret;
+ if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
+ if (!(skb = skb_unshare(skb, GFP_ATOMIC))
+ || (skb->ip_summed == CHECKSUM_PARTIAL
+ && skb_checksum_help(skb))) {
+ sch->qstats.drops++;
+ return NET_XMIT_DROP;
+ }
+ skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8);
+ }
+
+ cb = (struct netem_skb_cb *)skb->cb;
+ 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_tdiff_t delay;
+
+ delay = tabledist(q->latency, q->jitter,
+ &q->delay_cor, q->delay_dist);
+
+ PSCHED_GET_TIME(now);
+ PSCHED_TADD2(now, delay, cb->time_to_send);
++q->counter;
ret = q->qdisc->enqueue(skb, q->qdisc);
- if (ret)
- sch->stats.drops++;
- return ret;
+ } else {
+ /*
+ * 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);
}
-
- q->counter = 0;
- return delay_skb(sch, skb);
+ if (likely(ret == NET_XMIT_SUCCESS)) {
+ sch->q.qlen++;
+ sch->bstats.bytes += skb->len;
+ sch->bstats.packets++;
+ } else
+ sch->qstats.drops++;
+
+ pr_debug("netem: enqueue ret %d\n", ret);
+ return ret;
}
/* Requeue packets but don't change time stamp */
struct netem_sched_data *q = qdisc_priv(sch);
int ret;
- if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0)
+ if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0) {
sch->q.qlen++;
+ sch->qstats.requeues++;
+ }
return ret;
}
static unsigned int netem_drop(struct Qdisc* sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
- unsigned int len;
+ unsigned int len = 0;
- if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
+ if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
sch->q.qlen--;
- sch->stats.drops++;
+ sch->qstats.drops++;
}
return len;
}
-/* Dequeue packet.
- * Move all packets that are ready to send from the delay holding
- * list to the underlying qdisc, then just call dequeue
- */
static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
- psched_time_t now;
- PSCHED_GET_TIME(now);
- while ((skb = skb_peek(&q->delayed)) != NULL) {
+ skb = q->qdisc->dequeue(q->qdisc);
+ if (skb) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
- long delay
- = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
- pr_debug("netem_dequeue: delay queue %p@%lu %ld\n",
- skb, jiffies, delay);
+ psched_time_t now;
/* if more time remaining? */
- if (delay > 0) {
- mod_timer(&q->timer, jiffies + delay);
- break;
- }
- __skb_unlink(skb, &q->delayed);
+ PSCHED_GET_TIME(now);
+
+ if (PSCHED_TLESS(cb->time_to_send, now)) {
+ pr_debug("netem_dequeue: return skb=%p\n", skb);
+ sch->q.qlen--;
+ sch->flags &= ~TCQ_F_THROTTLED;
+ return skb;
+ } else {
+ psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now);
+
+ if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
+ qdisc_tree_decrease_qlen(q->qdisc, 1);
+ sch->qstats.drops++;
+ printk(KERN_ERR "netem: queue discpline %s could not requeue\n",
+ q->qdisc->ops->id);
+ }
- if (q->qdisc->enqueue(skb, q->qdisc))
- sch->stats.drops++;
+ mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay));
+ sch->flags |= TCQ_F_THROTTLED;
+ }
}
- skb = q->qdisc->dequeue(q->qdisc);
- if (skb)
- sch->q.qlen--;
- return skb;
+ return NULL;
}
static void netem_watchdog(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
- pr_debug("netem_watchdog: fired @%lu\n", jiffies);
+ pr_debug("netem_watchdog qlen=%d\n", sch->q.qlen);
+ sch->flags &= ~TCQ_F_THROTTLED;
netif_schedule(sch->dev);
}
struct netem_sched_data *q = qdisc_priv(sch);
qdisc_reset(q->qdisc);
- skb_queue_purge(&q->delayed);
-
sch->q.qlen = 0;
+ sch->flags &= ~TCQ_F_THROTTLED;
del_timer_sync(&q->timer);
}
+/* Pass size change message down to embedded FIFO */
static int set_fifo_limit(struct Qdisc *q, int limit)
{
struct rtattr *rta;
int ret = -ENOMEM;
+ /* Hack to avoid sending change message to non-FIFO */
+ if (strncmp(q->ops->id + 1, "fifo", 4) != 0)
+ return 0;
+
rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
if (rta) {
rta->rta_type = RTM_NEWQDISC;
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 get_corrupt(struct Qdisc *sch, const struct rtattr *attr)
+{
+ struct netem_sched_data *q = qdisc_priv(sch);
+ const struct tc_netem_corrupt *r = RTA_DATA(attr);
+
+ if (RTA_PAYLOAD(attr) != sizeof(*r))
+ return -EINVAL;
+
+ q->corrupt = r->probability;
+ init_crandom(&q->corrupt_cor, r->correlation);
+ return 0;
+}
+
+/* Parse netlink message to set options */
static int netem_change(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
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.
*/
if (ret)
return ret;
}
+
+ if (tb[TCA_NETEM_REORDER-1]) {
+ ret = get_reorder(sch, tb[TCA_NETEM_REORDER-1]);
+ if (ret)
+ return ret;
+ }
+
+ if (tb[TCA_NETEM_CORRUPT-1]) {
+ ret = get_corrupt(sch, tb[TCA_NETEM_CORRUPT-1]);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Special case version of FIFO queue for use by netem.
+ * It queues in order based on timestamps in skb's
+ */
+struct fifo_sched_data {
+ u32 limit;
+};
+
+static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
+{
+ struct fifo_sched_data *q = qdisc_priv(sch);
+ struct sk_buff_head *list = &sch->q;
+ const struct netem_skb_cb *ncb
+ = (const struct netem_skb_cb *)nskb->cb;
+ struct sk_buff *skb;
+
+ if (likely(skb_queue_len(list) < q->limit)) {
+ skb_queue_reverse_walk(list, skb) {
+ const struct netem_skb_cb *cb
+ = (const struct netem_skb_cb *)skb->cb;
+
+ if (!PSCHED_TLESS(ncb->time_to_send, cb->time_to_send))
+ break;
+ }
+
+ __skb_queue_after(list, skb, nskb);
+
+ sch->qstats.backlog += nskb->len;
+ sch->bstats.bytes += nskb->len;
+ sch->bstats.packets++;
+
+ return NET_XMIT_SUCCESS;
}
+ return qdisc_drop(nskb, sch);
+}
+
+static int tfifo_init(struct Qdisc *sch, struct rtattr *opt)
+{
+ struct fifo_sched_data *q = qdisc_priv(sch);
+
+ if (opt) {
+ struct tc_fifo_qopt *ctl = RTA_DATA(opt);
+ if (RTA_PAYLOAD(opt) < sizeof(*ctl))
+ return -EINVAL;
+
+ q->limit = ctl->limit;
+ } else
+ q->limit = max_t(u32, sch->dev->tx_queue_len, 1);
return 0;
}
+static int tfifo_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct fifo_sched_data *q = qdisc_priv(sch);
+ struct tc_fifo_qopt opt = { .limit = q->limit };
+
+ RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+ return skb->len;
+
+rtattr_failure:
+ return -1;
+}
+
+static struct Qdisc_ops tfifo_qdisc_ops = {
+ .id = "tfifo",
+ .priv_size = sizeof(struct fifo_sched_data),
+ .enqueue = tfifo_enqueue,
+ .dequeue = qdisc_dequeue_head,
+ .requeue = qdisc_requeue,
+ .drop = qdisc_queue_drop,
+ .init = tfifo_init,
+ .reset = qdisc_reset_queue,
+ .change = tfifo_init,
+ .dump = tfifo_dump,
+};
+
static int netem_init(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
if (!opt)
return -EINVAL;
- skb_queue_head_init(&q->delayed);
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);
+ q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops,
+ TC_H_MAKE(sch->handle, 1));
if (!q->qdisc) {
pr_debug("netem: qdisc create failed\n");
return -ENOMEM;
struct rtattr *rta = (struct rtattr *) b;
struct tc_netem_qopt qopt;
struct tc_netem_corr cor;
+ struct tc_netem_reorder reorder;
+ struct tc_netem_corrupt corrupt;
qopt.latency = q->latency;
qopt.jitter = q->jitter;
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);
+
+ corrupt.probability = q->corrupt;
+ corrupt.correlation = q->corrupt_cor.rho;
+ RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
+
rta->rta_len = skb->tail - b;
return skb->len;
sch_tree_lock(sch);
*old = xchg(&q->qdisc, new);
+ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
- sch->q.qlen = 0;
sch_tree_unlock(sch);
return 0;
static int __init netem_module_init(void)
{
+ pr_info("netem: version " VERSION "\n");
return register_qdisc(&netem_qdisc_ops);
}
static void __exit netem_module_exit(void)
git://git.onelab.eu / linux-2.6.git / blobdiff