2 * net/sched/sch_netem.c Network emulator
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
9 * Many of the algorithms and ideas for this came from
10 * NIST Net which is not copyrighted.
12 * Authors: Stephen Hemminger <shemminger@osdl.org>
13 * Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/skbuff.h>
23 #include <linux/vmalloc.h>
24 #include <linux/rtnetlink.h>
25 #include <linux/reciprocal_div.h>
27 #include <net/netlink.h>
28 #include <net/pkt_sched.h>
29 #include <net/inet_ecn.h>
33 /* Network Emulation Queuing algorithm.
34 ====================================
36 Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based
37 Network Emulation Tool
38 [2] Luigi Rizzo, DummyNet for FreeBSD
40 ----------------------------------------------------------------
42 This started out as a simple way to delay outgoing packets to
43 test TCP but has grown to include most of the functionality
44 of a full blown network emulator like NISTnet. It can delay
45 packets and add random jitter (and correlation). The random
46 distribution can be loaded from a table as well to provide
47 normal, Pareto, or experimental curves. Packet loss,
48 duplication, and reordering can also be emulated.
50 This qdisc does not do classification that can be handled in
51 layering other disciplines. It does not need to do bandwidth
52 control either since that can be handled by using token
53 bucket or other rate control.
55 Correlated Loss Generator models
57 Added generation of correlated loss according to the
58 "Gilbert-Elliot" model, a 4-state markov model.
61 [1] NetemCLG Home http://netgroup.uniroma2.it/NetemCLG
62 [2] S. Salsano, F. Ludovici, A. Ordine, "Definition of a general
63 and intuitive loss model for packet networks and its implementation
64 in the Netem module in the Linux kernel", available in [1]
66 Authors: Stefano Salsano <stefano.salsano at uniroma2.it
67 Fabio Ludovici <fabio.ludovici at yahoo.it>
70 struct netem_sched_data
{
71 /* internal t(ime)fifo qdisc uses sch->q and sch->limit */
73 /* optional qdisc for classful handling (NULL at netem init) */
76 struct qdisc_watchdog watchdog
;
78 psched_tdiff_t latency
;
79 psched_tdiff_t jitter
;
92 u32 cell_size_reciprocal
;
98 } delay_cor
, loss_cor
, dup_cor
, reorder_cor
, corrupt_cor
;
111 /* Correlated Loss Generation models */
113 /* state of the Markov chain */
116 /* 4-states and Gilbert-Elliot models */
117 u32 a1
; /* p13 for 4-states or p for GE */
118 u32 a2
; /* p31 for 4-states or r for GE */
119 u32 a3
; /* p32 for 4-states or h for GE */
120 u32 a4
; /* p14 for 4-states or 1-k for GE */
121 u32 a5
; /* p23 used only in 4-states */
126 /* Time stamp put into socket buffer control block
127 * Only valid when skbs are in our internal t(ime)fifo queue.
129 struct netem_skb_cb
{
130 psched_time_t time_to_send
;
133 static inline struct netem_skb_cb
*netem_skb_cb(struct sk_buff
*skb
)
135 qdisc_cb_private_validate(skb
, sizeof(struct netem_skb_cb
));
136 return (struct netem_skb_cb
*)qdisc_skb_cb(skb
)->data
;
139 /* init_crandom - initialize correlated random number generator
140 * Use entropy source for initial seed.
142 static void init_crandom(struct crndstate
*state
, unsigned long rho
)
145 state
->last
= net_random();
148 /* get_crandom - correlated random number generator
149 * Next number depends on last value.
150 * rho is scaled to avoid floating point.
152 static u32
get_crandom(struct crndstate
*state
)
155 unsigned long answer
;
157 if (state
->rho
== 0) /* no correlation */
160 value
= net_random();
161 rho
= (u64
)state
->rho
+ 1;
162 answer
= (value
* ((1ull<<32) - rho
) + state
->last
* rho
) >> 32;
163 state
->last
= answer
;
167 /* loss_4state - 4-state model loss generator
168 * Generates losses according to the 4-state Markov chain adopted in
169 * the GI (General and Intuitive) loss model.
171 static bool loss_4state(struct netem_sched_data
*q
)
173 struct clgstate
*clg
= &q
->clg
;
174 u32 rnd
= net_random();
177 * Makes a comparison between rnd and the transition
178 * probabilities outgoing from the current state, then decides the
179 * next state and if the next packet has to be transmitted or lost.
180 * The four states correspond to:
181 * 1 => successfully transmitted packets within a gap period
182 * 4 => isolated losses within a gap period
183 * 3 => lost packets within a burst period
184 * 2 => successfully transmitted packets within a burst period
186 switch (clg
->state
) {
191 } else if (clg
->a4
< rnd
&& rnd
< clg
->a1
) {
194 } else if (clg
->a1
< rnd
)
209 else if (clg
->a3
< rnd
&& rnd
< clg
->a2
+ clg
->a3
) {
212 } else if (clg
->a2
+ clg
->a3
< rnd
) {
225 /* loss_gilb_ell - Gilbert-Elliot model loss generator
226 * Generates losses according to the Gilbert-Elliot loss model or
227 * its special cases (Gilbert or Simple Gilbert)
229 * Makes a comparison between random number and the transition
230 * probabilities outgoing from the current state, then decides the
231 * next state. A second random number is extracted and the comparison
232 * with the loss probability of the current state decides if the next
233 * packet will be transmitted or lost.
235 static bool loss_gilb_ell(struct netem_sched_data
*q
)
237 struct clgstate
*clg
= &q
->clg
;
239 switch (clg
->state
) {
241 if (net_random() < clg
->a1
)
243 if (net_random() < clg
->a4
)
246 if (net_random() < clg
->a2
)
248 if (clg
->a3
> net_random())
255 static bool loss_event(struct netem_sched_data
*q
)
257 switch (q
->loss_model
) {
259 /* Random packet drop 0 => none, ~0 => all */
260 return q
->loss
&& q
->loss
>= get_crandom(&q
->loss_cor
);
263 /* 4state loss model algorithm (used also for GI model)
264 * Extracts a value from the markov 4 state loss generator,
265 * if it is 1 drops a packet and if needed writes the event in
268 return loss_4state(q
);
271 /* Gilbert-Elliot loss model algorithm
272 * Extracts a value from the Gilbert-Elliot loss generator,
273 * if it is 1 drops a packet and if needed writes the event in
276 return loss_gilb_ell(q
);
279 return false; /* not reached */
283 /* tabledist - return a pseudo-randomly distributed value with mean mu and
284 * std deviation sigma. Uses table lookup to approximate the desired
285 * distribution, and a uniformly-distributed pseudo-random source.
287 static psched_tdiff_t
tabledist(psched_tdiff_t mu
, psched_tdiff_t sigma
,
288 struct crndstate
*state
,
289 const struct disttable
*dist
)
298 rnd
= get_crandom(state
);
300 /* default uniform distribution */
302 return (rnd
% (2*sigma
)) - sigma
+ mu
;
304 t
= dist
->table
[rnd
% dist
->size
];
305 x
= (sigma
% NETEM_DIST_SCALE
) * t
;
307 x
+= NETEM_DIST_SCALE
/2;
309 x
-= NETEM_DIST_SCALE
/2;
311 return x
/ NETEM_DIST_SCALE
+ (sigma
/ NETEM_DIST_SCALE
) * t
+ mu
;
314 static psched_time_t
packet_len_2_sched_time(unsigned int len
, struct netem_sched_data
*q
)
318 len
+= q
->packet_overhead
;
321 u32 cells
= reciprocal_divide(len
, q
->cell_size_reciprocal
);
323 if (len
> cells
* q
->cell_size
) /* extra cell needed for remainder */
325 len
= cells
* (q
->cell_size
+ q
->cell_overhead
);
328 ticks
= (u64
)len
* NSEC_PER_SEC
;
330 do_div(ticks
, q
->rate
);
331 return PSCHED_NS2TICKS(ticks
);
334 static void tfifo_enqueue(struct sk_buff
*nskb
, struct Qdisc
*sch
)
336 struct sk_buff_head
*list
= &sch
->q
;
337 psched_time_t tnext
= netem_skb_cb(nskb
)->time_to_send
;
338 struct sk_buff
*skb
= skb_peek_tail(list
);
340 /* Optimize for add at tail */
341 if (likely(!skb
|| tnext
>= netem_skb_cb(skb
)->time_to_send
))
342 return __skb_queue_tail(list
, nskb
);
344 skb_queue_reverse_walk(list
, skb
) {
345 if (tnext
>= netem_skb_cb(skb
)->time_to_send
)
349 __skb_queue_after(list
, skb
, nskb
);
353 * Insert one skb into qdisc.
354 * Note: parent depends on return value to account for queue length.
355 * NET_XMIT_DROP: queue length didn't change.
356 * NET_XMIT_SUCCESS: one skb was queued.
358 static int netem_enqueue(struct sk_buff
*skb
, struct Qdisc
*sch
)
360 struct netem_sched_data
*q
= qdisc_priv(sch
);
361 /* We don't fill cb now as skb_unshare() may invalidate it */
362 struct netem_skb_cb
*cb
;
363 struct sk_buff
*skb2
;
366 /* Random duplication */
367 if (q
->duplicate
&& q
->duplicate
>= get_crandom(&q
->dup_cor
))
372 if (q
->ecn
&& INET_ECN_set_ce(skb
))
373 sch
->qstats
.drops
++; /* mark packet */
380 return NET_XMIT_SUCCESS
| __NET_XMIT_BYPASS
;
386 * If we need to duplicate packet, then re-insert at top of the
387 * qdisc tree, since parent queuer expects that only one
388 * skb will be queued.
390 if (count
> 1 && (skb2
= skb_clone(skb
, GFP_ATOMIC
)) != NULL
) {
391 struct Qdisc
*rootq
= qdisc_root(sch
);
392 u32 dupsave
= q
->duplicate
; /* prevent duplicating a dup... */
395 qdisc_enqueue_root(skb2
, rootq
);
396 q
->duplicate
= dupsave
;
400 * Randomized packet corruption.
401 * Make copy if needed since we are modifying
402 * If packet is going to be hardware checksummed, then
403 * do it now in software before we mangle it.
405 if (q
->corrupt
&& q
->corrupt
>= get_crandom(&q
->corrupt_cor
)) {
406 if (!(skb
= skb_unshare(skb
, GFP_ATOMIC
)) ||
407 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
408 skb_checksum_help(skb
)))
409 return qdisc_drop(skb
, sch
);
411 skb
->data
[net_random() % skb_headlen(skb
)] ^= 1<<(net_random() % 8);
414 if (unlikely(skb_queue_len(&sch
->q
) >= sch
->limit
))
415 return qdisc_reshape_fail(skb
, sch
);
417 sch
->qstats
.backlog
+= qdisc_pkt_len(skb
);
419 cb
= netem_skb_cb(skb
);
420 if (q
->gap
== 0 || /* not doing reordering */
421 q
->counter
< q
->gap
- 1 || /* inside last reordering gap */
422 q
->reorder
< get_crandom(&q
->reorder_cor
)) {
424 psched_tdiff_t delay
;
426 delay
= tabledist(q
->latency
, q
->jitter
,
427 &q
->delay_cor
, q
->delay_dist
);
429 now
= psched_get_time();
432 struct sk_buff_head
*list
= &sch
->q
;
434 delay
+= packet_len_2_sched_time(skb
->len
, q
);
436 if (!skb_queue_empty(list
)) {
438 * Last packet in queue is reference point (now).
439 * First packet in queue is already in flight,
440 * calculate this time bonus and substract
443 delay
-= now
- netem_skb_cb(skb_peek(list
))->time_to_send
;
444 now
= netem_skb_cb(skb_peek_tail(list
))->time_to_send
;
448 cb
->time_to_send
= now
+ delay
;
450 tfifo_enqueue(skb
, sch
);
453 * Do re-ordering by putting one out of N packets at the front
456 cb
->time_to_send
= psched_get_time();
459 __skb_queue_head(&sch
->q
, skb
);
460 sch
->qstats
.requeues
++;
463 return NET_XMIT_SUCCESS
;
466 static unsigned int netem_drop(struct Qdisc
*sch
)
468 struct netem_sched_data
*q
= qdisc_priv(sch
);
471 len
= qdisc_queue_drop(sch
);
472 if (!len
&& q
->qdisc
&& q
->qdisc
->ops
->drop
)
473 len
= q
->qdisc
->ops
->drop(q
->qdisc
);
480 static struct sk_buff
*netem_dequeue(struct Qdisc
*sch
)
482 struct netem_sched_data
*q
= qdisc_priv(sch
);
485 if (qdisc_is_throttled(sch
))
489 skb
= qdisc_peek_head(sch
);
491 const struct netem_skb_cb
*cb
= netem_skb_cb(skb
);
493 /* if more time remaining? */
494 if (cb
->time_to_send
<= psched_get_time()) {
495 __skb_unlink(skb
, &sch
->q
);
496 sch
->qstats
.backlog
-= qdisc_pkt_len(skb
);
498 #ifdef CONFIG_NET_CLS_ACT
500 * If it's at ingress let's pretend the delay is
501 * from the network (tstamp will be updated).
503 if (G_TC_FROM(skb
->tc_verd
) & AT_INGRESS
)
504 skb
->tstamp
.tv64
= 0;
508 int err
= qdisc_enqueue(skb
, q
->qdisc
);
510 if (unlikely(err
!= NET_XMIT_SUCCESS
)) {
511 if (net_xmit_drop_count(err
)) {
513 qdisc_tree_decrease_qlen(sch
, 1);
519 qdisc_unthrottled(sch
);
520 qdisc_bstats_update(sch
, skb
);
525 skb
= q
->qdisc
->ops
->dequeue(q
->qdisc
);
529 qdisc_watchdog_schedule(&q
->watchdog
, cb
->time_to_send
);
533 skb
= q
->qdisc
->ops
->dequeue(q
->qdisc
);
540 static void netem_reset(struct Qdisc
*sch
)
542 struct netem_sched_data
*q
= qdisc_priv(sch
);
544 qdisc_reset_queue(sch
);
546 qdisc_reset(q
->qdisc
);
547 qdisc_watchdog_cancel(&q
->watchdog
);
550 static void dist_free(struct disttable
*d
)
553 if (is_vmalloc_addr(d
))
561 * Distribution data is a variable size payload containing
562 * signed 16 bit values.
564 static int get_dist_table(struct Qdisc
*sch
, const struct nlattr
*attr
)
566 struct netem_sched_data
*q
= qdisc_priv(sch
);
567 size_t n
= nla_len(attr
)/sizeof(__s16
);
568 const __s16
*data
= nla_data(attr
);
569 spinlock_t
*root_lock
;
574 if (n
> NETEM_DIST_MAX
)
577 s
= sizeof(struct disttable
) + n
* sizeof(s16
);
578 d
= kmalloc(s
, GFP_KERNEL
| __GFP_NOWARN
);
585 for (i
= 0; i
< n
; i
++)
586 d
->table
[i
] = data
[i
];
588 root_lock
= qdisc_root_sleeping_lock(sch
);
590 spin_lock_bh(root_lock
);
591 swap(q
->delay_dist
, d
);
592 spin_unlock_bh(root_lock
);
598 static void get_correlation(struct Qdisc
*sch
, const struct nlattr
*attr
)
600 struct netem_sched_data
*q
= qdisc_priv(sch
);
601 const struct tc_netem_corr
*c
= nla_data(attr
);
603 init_crandom(&q
->delay_cor
, c
->delay_corr
);
604 init_crandom(&q
->loss_cor
, c
->loss_corr
);
605 init_crandom(&q
->dup_cor
, c
->dup_corr
);
608 static void get_reorder(struct Qdisc
*sch
, const struct nlattr
*attr
)
610 struct netem_sched_data
*q
= qdisc_priv(sch
);
611 const struct tc_netem_reorder
*r
= nla_data(attr
);
613 q
->reorder
= r
->probability
;
614 init_crandom(&q
->reorder_cor
, r
->correlation
);
617 static void get_corrupt(struct Qdisc
*sch
, const struct nlattr
*attr
)
619 struct netem_sched_data
*q
= qdisc_priv(sch
);
620 const struct tc_netem_corrupt
*r
= nla_data(attr
);
622 q
->corrupt
= r
->probability
;
623 init_crandom(&q
->corrupt_cor
, r
->correlation
);
626 static void get_rate(struct Qdisc
*sch
, const struct nlattr
*attr
)
628 struct netem_sched_data
*q
= qdisc_priv(sch
);
629 const struct tc_netem_rate
*r
= nla_data(attr
);
632 q
->packet_overhead
= r
->packet_overhead
;
633 q
->cell_size
= r
->cell_size
;
635 q
->cell_size_reciprocal
= reciprocal_value(q
->cell_size
);
636 q
->cell_overhead
= r
->cell_overhead
;
639 static int get_loss_clg(struct Qdisc
*sch
, const struct nlattr
*attr
)
641 struct netem_sched_data
*q
= qdisc_priv(sch
);
642 const struct nlattr
*la
;
645 nla_for_each_nested(la
, attr
, rem
) {
646 u16 type
= nla_type(la
);
649 case NETEM_LOSS_GI
: {
650 const struct tc_netem_gimodel
*gi
= nla_data(la
);
652 if (nla_len(la
) < sizeof(struct tc_netem_gimodel
)) {
653 pr_info("netem: incorrect gi model size\n");
657 q
->loss_model
= CLG_4_STATES
;
668 case NETEM_LOSS_GE
: {
669 const struct tc_netem_gemodel
*ge
= nla_data(la
);
671 if (nla_len(la
) < sizeof(struct tc_netem_gemodel
)) {
672 pr_info("netem: incorrect ge model size\n");
676 q
->loss_model
= CLG_GILB_ELL
;
686 pr_info("netem: unknown loss type %u\n", type
);
694 static const struct nla_policy netem_policy
[TCA_NETEM_MAX
+ 1] = {
695 [TCA_NETEM_CORR
] = { .len
= sizeof(struct tc_netem_corr
) },
696 [TCA_NETEM_REORDER
] = { .len
= sizeof(struct tc_netem_reorder
) },
697 [TCA_NETEM_CORRUPT
] = { .len
= sizeof(struct tc_netem_corrupt
) },
698 [TCA_NETEM_RATE
] = { .len
= sizeof(struct tc_netem_rate
) },
699 [TCA_NETEM_LOSS
] = { .type
= NLA_NESTED
},
700 [TCA_NETEM_ECN
] = { .type
= NLA_U32
},
703 static int parse_attr(struct nlattr
*tb
[], int maxtype
, struct nlattr
*nla
,
704 const struct nla_policy
*policy
, int len
)
706 int nested_len
= nla_len(nla
) - NLA_ALIGN(len
);
708 if (nested_len
< 0) {
709 pr_info("netem: invalid attributes len %d\n", nested_len
);
713 if (nested_len
>= nla_attr_size(0))
714 return nla_parse(tb
, maxtype
, nla_data(nla
) + NLA_ALIGN(len
),
717 memset(tb
, 0, sizeof(struct nlattr
*) * (maxtype
+ 1));
721 /* Parse netlink message to set options */
722 static int netem_change(struct Qdisc
*sch
, struct nlattr
*opt
)
724 struct netem_sched_data
*q
= qdisc_priv(sch
);
725 struct nlattr
*tb
[TCA_NETEM_MAX
+ 1];
726 struct tc_netem_qopt
*qopt
;
732 qopt
= nla_data(opt
);
733 ret
= parse_attr(tb
, TCA_NETEM_MAX
, opt
, netem_policy
, sizeof(*qopt
));
737 sch
->limit
= qopt
->limit
;
739 q
->latency
= qopt
->latency
;
740 q
->jitter
= qopt
->jitter
;
741 q
->limit
= qopt
->limit
;
744 q
->loss
= qopt
->loss
;
745 q
->duplicate
= qopt
->duplicate
;
747 /* for compatibility with earlier versions.
748 * if gap is set, need to assume 100% probability
753 if (tb
[TCA_NETEM_CORR
])
754 get_correlation(sch
, tb
[TCA_NETEM_CORR
]);
756 if (tb
[TCA_NETEM_DELAY_DIST
]) {
757 ret
= get_dist_table(sch
, tb
[TCA_NETEM_DELAY_DIST
]);
762 if (tb
[TCA_NETEM_REORDER
])
763 get_reorder(sch
, tb
[TCA_NETEM_REORDER
]);
765 if (tb
[TCA_NETEM_CORRUPT
])
766 get_corrupt(sch
, tb
[TCA_NETEM_CORRUPT
]);
768 if (tb
[TCA_NETEM_RATE
])
769 get_rate(sch
, tb
[TCA_NETEM_RATE
]);
771 if (tb
[TCA_NETEM_ECN
])
772 q
->ecn
= nla_get_u32(tb
[TCA_NETEM_ECN
]);
774 q
->loss_model
= CLG_RANDOM
;
775 if (tb
[TCA_NETEM_LOSS
])
776 ret
= get_loss_clg(sch
, tb
[TCA_NETEM_LOSS
]);
781 static int netem_init(struct Qdisc
*sch
, struct nlattr
*opt
)
783 struct netem_sched_data
*q
= qdisc_priv(sch
);
789 qdisc_watchdog_init(&q
->watchdog
, sch
);
791 q
->loss_model
= CLG_RANDOM
;
792 ret
= netem_change(sch
, opt
);
794 pr_info("netem: change failed\n");
798 static void netem_destroy(struct Qdisc
*sch
)
800 struct netem_sched_data
*q
= qdisc_priv(sch
);
802 qdisc_watchdog_cancel(&q
->watchdog
);
804 qdisc_destroy(q
->qdisc
);
805 dist_free(q
->delay_dist
);
808 static int dump_loss_model(const struct netem_sched_data
*q
,
813 nest
= nla_nest_start(skb
, TCA_NETEM_LOSS
);
815 goto nla_put_failure
;
817 switch (q
->loss_model
) {
819 /* legacy loss model */
820 nla_nest_cancel(skb
, nest
);
821 return 0; /* no data */
824 struct tc_netem_gimodel gi
= {
832 if (nla_put(skb
, NETEM_LOSS_GI
, sizeof(gi
), &gi
))
833 goto nla_put_failure
;
837 struct tc_netem_gemodel ge
= {
844 if (nla_put(skb
, NETEM_LOSS_GE
, sizeof(ge
), &ge
))
845 goto nla_put_failure
;
850 nla_nest_end(skb
, nest
);
854 nla_nest_cancel(skb
, nest
);
858 static int netem_dump(struct Qdisc
*sch
, struct sk_buff
*skb
)
860 const struct netem_sched_data
*q
= qdisc_priv(sch
);
861 struct nlattr
*nla
= (struct nlattr
*) skb_tail_pointer(skb
);
862 struct tc_netem_qopt qopt
;
863 struct tc_netem_corr cor
;
864 struct tc_netem_reorder reorder
;
865 struct tc_netem_corrupt corrupt
;
866 struct tc_netem_rate rate
;
868 qopt
.latency
= q
->latency
;
869 qopt
.jitter
= q
->jitter
;
870 qopt
.limit
= q
->limit
;
873 qopt
.duplicate
= q
->duplicate
;
874 if (nla_put(skb
, TCA_OPTIONS
, sizeof(qopt
), &qopt
))
875 goto nla_put_failure
;
877 cor
.delay_corr
= q
->delay_cor
.rho
;
878 cor
.loss_corr
= q
->loss_cor
.rho
;
879 cor
.dup_corr
= q
->dup_cor
.rho
;
880 if (nla_put(skb
, TCA_NETEM_CORR
, sizeof(cor
), &cor
))
881 goto nla_put_failure
;
883 reorder
.probability
= q
->reorder
;
884 reorder
.correlation
= q
->reorder_cor
.rho
;
885 if (nla_put(skb
, TCA_NETEM_REORDER
, sizeof(reorder
), &reorder
))
886 goto nla_put_failure
;
888 corrupt
.probability
= q
->corrupt
;
889 corrupt
.correlation
= q
->corrupt_cor
.rho
;
890 if (nla_put(skb
, TCA_NETEM_CORRUPT
, sizeof(corrupt
), &corrupt
))
891 goto nla_put_failure
;
894 rate
.packet_overhead
= q
->packet_overhead
;
895 rate
.cell_size
= q
->cell_size
;
896 rate
.cell_overhead
= q
->cell_overhead
;
897 if (nla_put(skb
, TCA_NETEM_RATE
, sizeof(rate
), &rate
))
898 goto nla_put_failure
;
900 if (q
->ecn
&& nla_put_u32(skb
, TCA_NETEM_ECN
, q
->ecn
))
901 goto nla_put_failure
;
903 if (dump_loss_model(q
, skb
) != 0)
904 goto nla_put_failure
;
906 return nla_nest_end(skb
, nla
);
909 nlmsg_trim(skb
, nla
);
913 static int netem_dump_class(struct Qdisc
*sch
, unsigned long cl
,
914 struct sk_buff
*skb
, struct tcmsg
*tcm
)
916 struct netem_sched_data
*q
= qdisc_priv(sch
);
918 if (cl
!= 1 || !q
->qdisc
) /* only one class */
921 tcm
->tcm_handle
|= TC_H_MIN(1);
922 tcm
->tcm_info
= q
->qdisc
->handle
;
927 static int netem_graft(struct Qdisc
*sch
, unsigned long arg
, struct Qdisc
*new,
930 struct netem_sched_data
*q
= qdisc_priv(sch
);
936 qdisc_tree_decrease_qlen(*old
, (*old
)->q
.qlen
);
939 sch_tree_unlock(sch
);
944 static struct Qdisc
*netem_leaf(struct Qdisc
*sch
, unsigned long arg
)
946 struct netem_sched_data
*q
= qdisc_priv(sch
);
950 static unsigned long netem_get(struct Qdisc
*sch
, u32 classid
)
955 static void netem_put(struct Qdisc
*sch
, unsigned long arg
)
959 static void netem_walk(struct Qdisc
*sch
, struct qdisc_walker
*walker
)
962 if (walker
->count
>= walker
->skip
)
963 if (walker
->fn(sch
, 1, walker
) < 0) {
971 static const struct Qdisc_class_ops netem_class_ops
= {
972 .graft
= netem_graft
,
977 .dump
= netem_dump_class
,
980 static struct Qdisc_ops netem_qdisc_ops __read_mostly
= {
982 .cl_ops
= &netem_class_ops
,
983 .priv_size
= sizeof(struct netem_sched_data
),
984 .enqueue
= netem_enqueue
,
985 .dequeue
= netem_dequeue
,
986 .peek
= qdisc_peek_dequeued
,
989 .reset
= netem_reset
,
990 .destroy
= netem_destroy
,
991 .change
= netem_change
,
993 .owner
= THIS_MODULE
,
997 static int __init
netem_module_init(void)
999 pr_info("netem: version " VERSION
"\n");
1000 return register_qdisc(&netem_qdisc_ops
);
1002 static void __exit
netem_module_exit(void)
1004 unregister_qdisc(&netem_qdisc_ops
);
1006 module_init(netem_module_init
)
1007 module_exit(netem_module_exit
)
1008 MODULE_LICENSE("GPL");