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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * net/sched/sch_netem.c Network emulator | |
3 | * | |
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 | |
798b6b19 | 7 | * 2 of the License. |
1da177e4 LT |
8 | * |
9 | * Many of the algorithms and ideas for this came from | |
10297b99 | 10 | * NIST Net which is not copyrighted. |
1da177e4 LT |
11 | * |
12 | * Authors: Stephen Hemminger <shemminger@osdl.org> | |
13 | * Catalin(ux aka Dino) BOIE <catab at umbrella dot ro> | |
14 | */ | |
15 | ||
b7f080cf | 16 | #include <linux/mm.h> |
1da177e4 | 17 | #include <linux/module.h> |
5a0e3ad6 | 18 | #include <linux/slab.h> |
1da177e4 LT |
19 | #include <linux/types.h> |
20 | #include <linux/kernel.h> | |
21 | #include <linux/errno.h> | |
1da177e4 | 22 | #include <linux/skbuff.h> |
78776d3f | 23 | #include <linux/vmalloc.h> |
1da177e4 | 24 | #include <linux/rtnetlink.h> |
90b41a1c | 25 | #include <linux/reciprocal_div.h> |
1da177e4 | 26 | |
dc5fc579 | 27 | #include <net/netlink.h> |
1da177e4 LT |
28 | #include <net/pkt_sched.h> |
29 | ||
250a65f7 | 30 | #define VERSION "1.3" |
eb229c4c | 31 | |
1da177e4 LT |
32 | /* Network Emulation Queuing algorithm. |
33 | ==================================== | |
34 | ||
35 | Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based | |
36 | Network Emulation Tool | |
37 | [2] Luigi Rizzo, DummyNet for FreeBSD | |
38 | ||
39 | ---------------------------------------------------------------- | |
40 | ||
41 | This started out as a simple way to delay outgoing packets to | |
42 | test TCP but has grown to include most of the functionality | |
43 | of a full blown network emulator like NISTnet. It can delay | |
44 | packets and add random jitter (and correlation). The random | |
45 | distribution can be loaded from a table as well to provide | |
46 | normal, Pareto, or experimental curves. Packet loss, | |
47 | duplication, and reordering can also be emulated. | |
48 | ||
49 | This qdisc does not do classification that can be handled in | |
50 | layering other disciplines. It does not need to do bandwidth | |
51 | control either since that can be handled by using token | |
52 | bucket or other rate control. | |
661b7972 | 53 | |
54 | Correlated Loss Generator models | |
55 | ||
56 | Added generation of correlated loss according to the | |
57 | "Gilbert-Elliot" model, a 4-state markov model. | |
58 | ||
59 | References: | |
60 | [1] NetemCLG Home http://netgroup.uniroma2.it/NetemCLG | |
61 | [2] S. Salsano, F. Ludovici, A. Ordine, "Definition of a general | |
62 | and intuitive loss model for packet networks and its implementation | |
63 | in the Netem module in the Linux kernel", available in [1] | |
64 | ||
65 | Authors: Stefano Salsano <stefano.salsano at uniroma2.it | |
66 | Fabio Ludovici <fabio.ludovici at yahoo.it> | |
1da177e4 LT |
67 | */ |
68 | ||
69 | struct netem_sched_data { | |
50612537 ED |
70 | /* internal t(ime)fifo qdisc uses sch->q and sch->limit */ |
71 | ||
72 | /* optional qdisc for classful handling (NULL at netem init) */ | |
1da177e4 | 73 | struct Qdisc *qdisc; |
50612537 | 74 | |
59cb5c67 | 75 | struct qdisc_watchdog watchdog; |
1da177e4 | 76 | |
b407621c SH |
77 | psched_tdiff_t latency; |
78 | psched_tdiff_t jitter; | |
79 | ||
1da177e4 LT |
80 | u32 loss; |
81 | u32 limit; | |
82 | u32 counter; | |
83 | u32 gap; | |
1da177e4 | 84 | u32 duplicate; |
0dca51d3 | 85 | u32 reorder; |
c865e5d9 | 86 | u32 corrupt; |
7bc0f28c | 87 | u32 rate; |
90b41a1c HPP |
88 | s32 packet_overhead; |
89 | u32 cell_size; | |
90 | u32 cell_size_reciprocal; | |
91 | s32 cell_overhead; | |
1da177e4 LT |
92 | |
93 | struct crndstate { | |
b407621c SH |
94 | u32 last; |
95 | u32 rho; | |
c865e5d9 | 96 | } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor; |
1da177e4 LT |
97 | |
98 | struct disttable { | |
99 | u32 size; | |
100 | s16 table[0]; | |
101 | } *delay_dist; | |
661b7972 | 102 | |
103 | enum { | |
104 | CLG_RANDOM, | |
105 | CLG_4_STATES, | |
106 | CLG_GILB_ELL, | |
107 | } loss_model; | |
108 | ||
109 | /* Correlated Loss Generation models */ | |
110 | struct clgstate { | |
111 | /* state of the Markov chain */ | |
112 | u8 state; | |
113 | ||
114 | /* 4-states and Gilbert-Elliot models */ | |
115 | u32 a1; /* p13 for 4-states or p for GE */ | |
116 | u32 a2; /* p31 for 4-states or r for GE */ | |
117 | u32 a3; /* p32 for 4-states or h for GE */ | |
118 | u32 a4; /* p14 for 4-states or 1-k for GE */ | |
119 | u32 a5; /* p23 used only in 4-states */ | |
120 | } clg; | |
121 | ||
1da177e4 LT |
122 | }; |
123 | ||
50612537 ED |
124 | /* Time stamp put into socket buffer control block |
125 | * Only valid when skbs are in our internal t(ime)fifo queue. | |
126 | */ | |
1da177e4 LT |
127 | struct netem_skb_cb { |
128 | psched_time_t time_to_send; | |
129 | }; | |
130 | ||
5f86173b JK |
131 | static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb) |
132 | { | |
175f9c1b JK |
133 | BUILD_BUG_ON(sizeof(skb->cb) < |
134 | sizeof(struct qdisc_skb_cb) + sizeof(struct netem_skb_cb)); | |
135 | return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; | |
5f86173b JK |
136 | } |
137 | ||
1da177e4 LT |
138 | /* init_crandom - initialize correlated random number generator |
139 | * Use entropy source for initial seed. | |
140 | */ | |
141 | static void init_crandom(struct crndstate *state, unsigned long rho) | |
142 | { | |
143 | state->rho = rho; | |
144 | state->last = net_random(); | |
145 | } | |
146 | ||
147 | /* get_crandom - correlated random number generator | |
148 | * Next number depends on last value. | |
149 | * rho is scaled to avoid floating point. | |
150 | */ | |
b407621c | 151 | static u32 get_crandom(struct crndstate *state) |
1da177e4 LT |
152 | { |
153 | u64 value, rho; | |
154 | unsigned long answer; | |
155 | ||
bb2f8cc0 | 156 | if (state->rho == 0) /* no correlation */ |
1da177e4 LT |
157 | return net_random(); |
158 | ||
159 | value = net_random(); | |
160 | rho = (u64)state->rho + 1; | |
161 | answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32; | |
162 | state->last = answer; | |
163 | return answer; | |
164 | } | |
165 | ||
661b7972 | 166 | /* loss_4state - 4-state model loss generator |
167 | * Generates losses according to the 4-state Markov chain adopted in | |
168 | * the GI (General and Intuitive) loss model. | |
169 | */ | |
170 | static bool loss_4state(struct netem_sched_data *q) | |
171 | { | |
172 | struct clgstate *clg = &q->clg; | |
173 | u32 rnd = net_random(); | |
174 | ||
175 | /* | |
25985edc | 176 | * Makes a comparison between rnd and the transition |
661b7972 | 177 | * probabilities outgoing from the current state, then decides the |
178 | * next state and if the next packet has to be transmitted or lost. | |
179 | * The four states correspond to: | |
180 | * 1 => successfully transmitted packets within a gap period | |
181 | * 4 => isolated losses within a gap period | |
182 | * 3 => lost packets within a burst period | |
183 | * 2 => successfully transmitted packets within a burst period | |
184 | */ | |
185 | switch (clg->state) { | |
186 | case 1: | |
187 | if (rnd < clg->a4) { | |
188 | clg->state = 4; | |
189 | return true; | |
190 | } else if (clg->a4 < rnd && rnd < clg->a1) { | |
191 | clg->state = 3; | |
192 | return true; | |
193 | } else if (clg->a1 < rnd) | |
194 | clg->state = 1; | |
195 | ||
196 | break; | |
197 | case 2: | |
198 | if (rnd < clg->a5) { | |
199 | clg->state = 3; | |
200 | return true; | |
201 | } else | |
202 | clg->state = 2; | |
203 | ||
204 | break; | |
205 | case 3: | |
206 | if (rnd < clg->a3) | |
207 | clg->state = 2; | |
208 | else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) { | |
209 | clg->state = 1; | |
210 | return true; | |
211 | } else if (clg->a2 + clg->a3 < rnd) { | |
212 | clg->state = 3; | |
213 | return true; | |
214 | } | |
215 | break; | |
216 | case 4: | |
217 | clg->state = 1; | |
218 | break; | |
219 | } | |
220 | ||
221 | return false; | |
222 | } | |
223 | ||
224 | /* loss_gilb_ell - Gilbert-Elliot model loss generator | |
225 | * Generates losses according to the Gilbert-Elliot loss model or | |
226 | * its special cases (Gilbert or Simple Gilbert) | |
227 | * | |
25985edc | 228 | * Makes a comparison between random number and the transition |
661b7972 | 229 | * probabilities outgoing from the current state, then decides the |
25985edc | 230 | * next state. A second random number is extracted and the comparison |
661b7972 | 231 | * with the loss probability of the current state decides if the next |
232 | * packet will be transmitted or lost. | |
233 | */ | |
234 | static bool loss_gilb_ell(struct netem_sched_data *q) | |
235 | { | |
236 | struct clgstate *clg = &q->clg; | |
237 | ||
238 | switch (clg->state) { | |
239 | case 1: | |
240 | if (net_random() < clg->a1) | |
241 | clg->state = 2; | |
242 | if (net_random() < clg->a4) | |
243 | return true; | |
244 | case 2: | |
245 | if (net_random() < clg->a2) | |
246 | clg->state = 1; | |
247 | if (clg->a3 > net_random()) | |
248 | return true; | |
249 | } | |
250 | ||
251 | return false; | |
252 | } | |
253 | ||
254 | static bool loss_event(struct netem_sched_data *q) | |
255 | { | |
256 | switch (q->loss_model) { | |
257 | case CLG_RANDOM: | |
258 | /* Random packet drop 0 => none, ~0 => all */ | |
259 | return q->loss && q->loss >= get_crandom(&q->loss_cor); | |
260 | ||
261 | case CLG_4_STATES: | |
262 | /* 4state loss model algorithm (used also for GI model) | |
263 | * Extracts a value from the markov 4 state loss generator, | |
264 | * if it is 1 drops a packet and if needed writes the event in | |
265 | * the kernel logs | |
266 | */ | |
267 | return loss_4state(q); | |
268 | ||
269 | case CLG_GILB_ELL: | |
270 | /* Gilbert-Elliot loss model algorithm | |
271 | * Extracts a value from the Gilbert-Elliot loss generator, | |
272 | * if it is 1 drops a packet and if needed writes the event in | |
273 | * the kernel logs | |
274 | */ | |
275 | return loss_gilb_ell(q); | |
276 | } | |
277 | ||
278 | return false; /* not reached */ | |
279 | } | |
280 | ||
281 | ||
1da177e4 LT |
282 | /* tabledist - return a pseudo-randomly distributed value with mean mu and |
283 | * std deviation sigma. Uses table lookup to approximate the desired | |
284 | * distribution, and a uniformly-distributed pseudo-random source. | |
285 | */ | |
b407621c SH |
286 | static psched_tdiff_t tabledist(psched_tdiff_t mu, psched_tdiff_t sigma, |
287 | struct crndstate *state, | |
288 | const struct disttable *dist) | |
1da177e4 | 289 | { |
b407621c SH |
290 | psched_tdiff_t x; |
291 | long t; | |
292 | u32 rnd; | |
1da177e4 LT |
293 | |
294 | if (sigma == 0) | |
295 | return mu; | |
296 | ||
297 | rnd = get_crandom(state); | |
298 | ||
299 | /* default uniform distribution */ | |
10297b99 | 300 | if (dist == NULL) |
1da177e4 LT |
301 | return (rnd % (2*sigma)) - sigma + mu; |
302 | ||
303 | t = dist->table[rnd % dist->size]; | |
304 | x = (sigma % NETEM_DIST_SCALE) * t; | |
305 | if (x >= 0) | |
306 | x += NETEM_DIST_SCALE/2; | |
307 | else | |
308 | x -= NETEM_DIST_SCALE/2; | |
309 | ||
310 | return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu; | |
311 | } | |
312 | ||
90b41a1c | 313 | static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sched_data *q) |
7bc0f28c | 314 | { |
90b41a1c | 315 | u64 ticks; |
fc33cc72 | 316 | |
90b41a1c HPP |
317 | len += q->packet_overhead; |
318 | ||
319 | if (q->cell_size) { | |
320 | u32 cells = reciprocal_divide(len, q->cell_size_reciprocal); | |
321 | ||
322 | if (len > cells * q->cell_size) /* extra cell needed for remainder */ | |
323 | cells++; | |
324 | len = cells * (q->cell_size + q->cell_overhead); | |
325 | } | |
326 | ||
327 | ticks = (u64)len * NSEC_PER_SEC; | |
328 | ||
329 | do_div(ticks, q->rate); | |
fc33cc72 | 330 | return PSCHED_NS2TICKS(ticks); |
7bc0f28c HPP |
331 | } |
332 | ||
50612537 ED |
333 | static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) |
334 | { | |
335 | struct sk_buff_head *list = &sch->q; | |
336 | psched_time_t tnext = netem_skb_cb(nskb)->time_to_send; | |
337 | struct sk_buff *skb; | |
338 | ||
339 | if (likely(skb_queue_len(list) < sch->limit)) { | |
340 | skb = skb_peek_tail(list); | |
341 | /* Optimize for add at tail */ | |
342 | if (likely(!skb || tnext >= netem_skb_cb(skb)->time_to_send)) | |
343 | return qdisc_enqueue_tail(nskb, sch); | |
344 | ||
345 | skb_queue_reverse_walk(list, skb) { | |
346 | if (tnext >= netem_skb_cb(skb)->time_to_send) | |
347 | break; | |
348 | } | |
349 | ||
350 | __skb_queue_after(list, skb, nskb); | |
351 | sch->qstats.backlog += qdisc_pkt_len(nskb); | |
352 | return NET_XMIT_SUCCESS; | |
353 | } | |
354 | ||
355 | return qdisc_reshape_fail(nskb, sch); | |
356 | } | |
357 | ||
0afb51e7 SH |
358 | /* |
359 | * Insert one skb into qdisc. | |
360 | * Note: parent depends on return value to account for queue length. | |
361 | * NET_XMIT_DROP: queue length didn't change. | |
362 | * NET_XMIT_SUCCESS: one skb was queued. | |
363 | */ | |
1da177e4 LT |
364 | static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
365 | { | |
366 | struct netem_sched_data *q = qdisc_priv(sch); | |
89e1df74 GC |
367 | /* We don't fill cb now as skb_unshare() may invalidate it */ |
368 | struct netem_skb_cb *cb; | |
0afb51e7 | 369 | struct sk_buff *skb2; |
1da177e4 | 370 | int ret; |
0afb51e7 | 371 | int count = 1; |
1da177e4 | 372 | |
0afb51e7 SH |
373 | /* Random duplication */ |
374 | if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) | |
375 | ++count; | |
376 | ||
661b7972 | 377 | /* Drop packet? */ |
378 | if (loss_event(q)) | |
0afb51e7 SH |
379 | --count; |
380 | ||
381 | if (count == 0) { | |
1da177e4 LT |
382 | sch->qstats.drops++; |
383 | kfree_skb(skb); | |
c27f339a | 384 | return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
1da177e4 LT |
385 | } |
386 | ||
4e8a5201 DM |
387 | skb_orphan(skb); |
388 | ||
0afb51e7 SH |
389 | /* |
390 | * If we need to duplicate packet, then re-insert at top of the | |
391 | * qdisc tree, since parent queuer expects that only one | |
392 | * skb will be queued. | |
393 | */ | |
394 | if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { | |
7698b4fc | 395 | struct Qdisc *rootq = qdisc_root(sch); |
0afb51e7 SH |
396 | u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ |
397 | q->duplicate = 0; | |
398 | ||
5f86173b | 399 | qdisc_enqueue_root(skb2, rootq); |
0afb51e7 | 400 | q->duplicate = dupsave; |
1da177e4 LT |
401 | } |
402 | ||
c865e5d9 SH |
403 | /* |
404 | * Randomized packet corruption. | |
405 | * Make copy if needed since we are modifying | |
406 | * If packet is going to be hardware checksummed, then | |
407 | * do it now in software before we mangle it. | |
408 | */ | |
409 | if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) { | |
f64f9e71 JP |
410 | if (!(skb = skb_unshare(skb, GFP_ATOMIC)) || |
411 | (skb->ip_summed == CHECKSUM_PARTIAL && | |
412 | skb_checksum_help(skb))) { | |
c865e5d9 SH |
413 | sch->qstats.drops++; |
414 | return NET_XMIT_DROP; | |
415 | } | |
416 | ||
417 | skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8); | |
418 | } | |
419 | ||
5f86173b | 420 | cb = netem_skb_cb(skb); |
cc7ec456 ED |
421 | if (q->gap == 0 || /* not doing reordering */ |
422 | q->counter < q->gap || /* inside last reordering gap */ | |
f64f9e71 | 423 | q->reorder < get_crandom(&q->reorder_cor)) { |
0f9f32ac | 424 | psched_time_t now; |
07aaa115 SH |
425 | psched_tdiff_t delay; |
426 | ||
427 | delay = tabledist(q->latency, q->jitter, | |
428 | &q->delay_cor, q->delay_dist); | |
429 | ||
3bebcda2 | 430 | now = psched_get_time(); |
7bc0f28c HPP |
431 | |
432 | if (q->rate) { | |
50612537 | 433 | struct sk_buff_head *list = &sch->q; |
7bc0f28c | 434 | |
90b41a1c | 435 | delay += packet_len_2_sched_time(skb->len, q); |
7bc0f28c HPP |
436 | |
437 | if (!skb_queue_empty(list)) { | |
438 | /* | |
439 | * Last packet in queue is reference point (now). | |
440 | * First packet in queue is already in flight, | |
441 | * calculate this time bonus and substract | |
442 | * from delay. | |
443 | */ | |
444 | delay -= now - netem_skb_cb(skb_peek(list))->time_to_send; | |
445 | now = netem_skb_cb(skb_peek_tail(list))->time_to_send; | |
446 | } | |
447 | } | |
448 | ||
7c59e25f | 449 | cb->time_to_send = now + delay; |
1da177e4 | 450 | ++q->counter; |
50612537 | 451 | ret = tfifo_enqueue(skb, sch); |
1da177e4 | 452 | } else { |
10297b99 | 453 | /* |
0dca51d3 SH |
454 | * Do re-ordering by putting one out of N packets at the front |
455 | * of the queue. | |
456 | */ | |
3bebcda2 | 457 | cb->time_to_send = psched_get_time(); |
0dca51d3 | 458 | q->counter = 0; |
8ba25dad | 459 | |
50612537 | 460 | __skb_queue_head(&sch->q, skb); |
8ba25dad JP |
461 | q->qdisc->qstats.backlog += qdisc_pkt_len(skb); |
462 | q->qdisc->qstats.requeues++; | |
463 | ret = NET_XMIT_SUCCESS; | |
1da177e4 LT |
464 | } |
465 | ||
10f6dfcf | 466 | if (ret != NET_XMIT_SUCCESS) { |
467 | if (net_xmit_drop_count(ret)) { | |
468 | sch->qstats.drops++; | |
469 | return ret; | |
470 | } | |
378a2f09 | 471 | } |
1da177e4 | 472 | |
10f6dfcf | 473 | return NET_XMIT_SUCCESS; |
1da177e4 LT |
474 | } |
475 | ||
cc7ec456 | 476 | static unsigned int netem_drop(struct Qdisc *sch) |
1da177e4 LT |
477 | { |
478 | struct netem_sched_data *q = qdisc_priv(sch); | |
50612537 | 479 | unsigned int len; |
1da177e4 | 480 | |
50612537 ED |
481 | len = qdisc_queue_drop(sch); |
482 | if (!len && q->qdisc && q->qdisc->ops->drop) | |
483 | len = q->qdisc->ops->drop(q->qdisc); | |
484 | if (len) | |
1da177e4 | 485 | sch->qstats.drops++; |
50612537 | 486 | |
1da177e4 LT |
487 | return len; |
488 | } | |
489 | ||
1da177e4 LT |
490 | static struct sk_buff *netem_dequeue(struct Qdisc *sch) |
491 | { | |
492 | struct netem_sched_data *q = qdisc_priv(sch); | |
493 | struct sk_buff *skb; | |
494 | ||
fd245a4a | 495 | if (qdisc_is_throttled(sch)) |
11274e5a SH |
496 | return NULL; |
497 | ||
50612537 ED |
498 | tfifo_dequeue: |
499 | skb = qdisc_peek_head(sch); | |
771018e7 | 500 | if (skb) { |
5f86173b | 501 | const struct netem_skb_cb *cb = netem_skb_cb(skb); |
0f9f32ac SH |
502 | |
503 | /* if more time remaining? */ | |
50612537 ED |
504 | if (cb->time_to_send <= psched_get_time()) { |
505 | skb = qdisc_dequeue_tail(sch); | |
77be155c | 506 | if (unlikely(!skb)) |
50612537 | 507 | goto qdisc_dequeue; |
03c05f0d | 508 | |
8caf1539 JP |
509 | #ifdef CONFIG_NET_CLS_ACT |
510 | /* | |
511 | * If it's at ingress let's pretend the delay is | |
512 | * from the network (tstamp will be updated). | |
513 | */ | |
514 | if (G_TC_FROM(skb->tc_verd) & AT_INGRESS) | |
515 | skb->tstamp.tv64 = 0; | |
516 | #endif | |
10f6dfcf | 517 | |
50612537 ED |
518 | if (q->qdisc) { |
519 | int err = qdisc_enqueue(skb, q->qdisc); | |
520 | ||
521 | if (unlikely(err != NET_XMIT_SUCCESS)) { | |
522 | if (net_xmit_drop_count(err)) { | |
523 | sch->qstats.drops++; | |
524 | qdisc_tree_decrease_qlen(sch, 1); | |
525 | } | |
526 | } | |
527 | goto tfifo_dequeue; | |
528 | } | |
529 | deliver: | |
10f6dfcf | 530 | qdisc_unthrottled(sch); |
531 | qdisc_bstats_update(sch, skb); | |
0f9f32ac | 532 | return skb; |
07aaa115 | 533 | } |
11274e5a | 534 | |
50612537 ED |
535 | if (q->qdisc) { |
536 | skb = q->qdisc->ops->dequeue(q->qdisc); | |
537 | if (skb) | |
538 | goto deliver; | |
539 | } | |
11274e5a | 540 | qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); |
0f9f32ac SH |
541 | } |
542 | ||
50612537 ED |
543 | qdisc_dequeue: |
544 | if (q->qdisc) { | |
545 | skb = q->qdisc->ops->dequeue(q->qdisc); | |
546 | if (skb) | |
547 | goto deliver; | |
548 | } | |
0f9f32ac | 549 | return NULL; |
1da177e4 LT |
550 | } |
551 | ||
1da177e4 LT |
552 | static void netem_reset(struct Qdisc *sch) |
553 | { | |
554 | struct netem_sched_data *q = qdisc_priv(sch); | |
555 | ||
50612537 ED |
556 | qdisc_reset_queue(sch); |
557 | if (q->qdisc) | |
558 | qdisc_reset(q->qdisc); | |
59cb5c67 | 559 | qdisc_watchdog_cancel(&q->watchdog); |
1da177e4 LT |
560 | } |
561 | ||
6373a9a2 | 562 | static void dist_free(struct disttable *d) |
563 | { | |
564 | if (d) { | |
565 | if (is_vmalloc_addr(d)) | |
566 | vfree(d); | |
567 | else | |
568 | kfree(d); | |
569 | } | |
570 | } | |
571 | ||
1da177e4 LT |
572 | /* |
573 | * Distribution data is a variable size payload containing | |
574 | * signed 16 bit values. | |
575 | */ | |
1e90474c | 576 | static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) |
1da177e4 LT |
577 | { |
578 | struct netem_sched_data *q = qdisc_priv(sch); | |
6373a9a2 | 579 | size_t n = nla_len(attr)/sizeof(__s16); |
1e90474c | 580 | const __s16 *data = nla_data(attr); |
7698b4fc | 581 | spinlock_t *root_lock; |
1da177e4 LT |
582 | struct disttable *d; |
583 | int i; | |
6373a9a2 | 584 | size_t s; |
1da177e4 | 585 | |
df173bda | 586 | if (n > NETEM_DIST_MAX) |
1da177e4 LT |
587 | return -EINVAL; |
588 | ||
6373a9a2 | 589 | s = sizeof(struct disttable) + n * sizeof(s16); |
bb52c7ac | 590 | d = kmalloc(s, GFP_KERNEL | __GFP_NOWARN); |
6373a9a2 | 591 | if (!d) |
592 | d = vmalloc(s); | |
1da177e4 LT |
593 | if (!d) |
594 | return -ENOMEM; | |
595 | ||
596 | d->size = n; | |
597 | for (i = 0; i < n; i++) | |
598 | d->table[i] = data[i]; | |
10297b99 | 599 | |
102396ae | 600 | root_lock = qdisc_root_sleeping_lock(sch); |
7698b4fc DM |
601 | |
602 | spin_lock_bh(root_lock); | |
bb52c7ac | 603 | swap(q->delay_dist, d); |
7698b4fc | 604 | spin_unlock_bh(root_lock); |
bb52c7ac ED |
605 | |
606 | dist_free(d); | |
1da177e4 LT |
607 | return 0; |
608 | } | |
609 | ||
265eb67f | 610 | static void get_correlation(struct Qdisc *sch, const struct nlattr *attr) |
1da177e4 LT |
611 | { |
612 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 613 | const struct tc_netem_corr *c = nla_data(attr); |
1da177e4 | 614 | |
1da177e4 LT |
615 | init_crandom(&q->delay_cor, c->delay_corr); |
616 | init_crandom(&q->loss_cor, c->loss_corr); | |
617 | init_crandom(&q->dup_cor, c->dup_corr); | |
1da177e4 LT |
618 | } |
619 | ||
265eb67f | 620 | static void get_reorder(struct Qdisc *sch, const struct nlattr *attr) |
0dca51d3 SH |
621 | { |
622 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 623 | const struct tc_netem_reorder *r = nla_data(attr); |
0dca51d3 | 624 | |
0dca51d3 SH |
625 | q->reorder = r->probability; |
626 | init_crandom(&q->reorder_cor, r->correlation); | |
0dca51d3 SH |
627 | } |
628 | ||
265eb67f | 629 | static void get_corrupt(struct Qdisc *sch, const struct nlattr *attr) |
c865e5d9 SH |
630 | { |
631 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 632 | const struct tc_netem_corrupt *r = nla_data(attr); |
c865e5d9 | 633 | |
c865e5d9 SH |
634 | q->corrupt = r->probability; |
635 | init_crandom(&q->corrupt_cor, r->correlation); | |
c865e5d9 SH |
636 | } |
637 | ||
7bc0f28c HPP |
638 | static void get_rate(struct Qdisc *sch, const struct nlattr *attr) |
639 | { | |
640 | struct netem_sched_data *q = qdisc_priv(sch); | |
641 | const struct tc_netem_rate *r = nla_data(attr); | |
642 | ||
643 | q->rate = r->rate; | |
90b41a1c HPP |
644 | q->packet_overhead = r->packet_overhead; |
645 | q->cell_size = r->cell_size; | |
646 | if (q->cell_size) | |
647 | q->cell_size_reciprocal = reciprocal_value(q->cell_size); | |
648 | q->cell_overhead = r->cell_overhead; | |
7bc0f28c HPP |
649 | } |
650 | ||
661b7972 | 651 | static int get_loss_clg(struct Qdisc *sch, const struct nlattr *attr) |
652 | { | |
653 | struct netem_sched_data *q = qdisc_priv(sch); | |
654 | const struct nlattr *la; | |
655 | int rem; | |
656 | ||
657 | nla_for_each_nested(la, attr, rem) { | |
658 | u16 type = nla_type(la); | |
659 | ||
660 | switch(type) { | |
661 | case NETEM_LOSS_GI: { | |
662 | const struct tc_netem_gimodel *gi = nla_data(la); | |
663 | ||
2494654d | 664 | if (nla_len(la) < sizeof(struct tc_netem_gimodel)) { |
661b7972 | 665 | pr_info("netem: incorrect gi model size\n"); |
666 | return -EINVAL; | |
667 | } | |
668 | ||
669 | q->loss_model = CLG_4_STATES; | |
670 | ||
671 | q->clg.state = 1; | |
672 | q->clg.a1 = gi->p13; | |
673 | q->clg.a2 = gi->p31; | |
674 | q->clg.a3 = gi->p32; | |
675 | q->clg.a4 = gi->p14; | |
676 | q->clg.a5 = gi->p23; | |
677 | break; | |
678 | } | |
679 | ||
680 | case NETEM_LOSS_GE: { | |
681 | const struct tc_netem_gemodel *ge = nla_data(la); | |
682 | ||
2494654d | 683 | if (nla_len(la) < sizeof(struct tc_netem_gemodel)) { |
684 | pr_info("netem: incorrect ge model size\n"); | |
661b7972 | 685 | return -EINVAL; |
686 | } | |
687 | ||
688 | q->loss_model = CLG_GILB_ELL; | |
689 | q->clg.state = 1; | |
690 | q->clg.a1 = ge->p; | |
691 | q->clg.a2 = ge->r; | |
692 | q->clg.a3 = ge->h; | |
693 | q->clg.a4 = ge->k1; | |
694 | break; | |
695 | } | |
696 | ||
697 | default: | |
698 | pr_info("netem: unknown loss type %u\n", type); | |
699 | return -EINVAL; | |
700 | } | |
701 | } | |
702 | ||
703 | return 0; | |
704 | } | |
705 | ||
27a3421e PM |
706 | static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = { |
707 | [TCA_NETEM_CORR] = { .len = sizeof(struct tc_netem_corr) }, | |
708 | [TCA_NETEM_REORDER] = { .len = sizeof(struct tc_netem_reorder) }, | |
709 | [TCA_NETEM_CORRUPT] = { .len = sizeof(struct tc_netem_corrupt) }, | |
7bc0f28c | 710 | [TCA_NETEM_RATE] = { .len = sizeof(struct tc_netem_rate) }, |
661b7972 | 711 | [TCA_NETEM_LOSS] = { .type = NLA_NESTED }, |
27a3421e PM |
712 | }; |
713 | ||
2c10b32b TG |
714 | static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla, |
715 | const struct nla_policy *policy, int len) | |
716 | { | |
717 | int nested_len = nla_len(nla) - NLA_ALIGN(len); | |
718 | ||
661b7972 | 719 | if (nested_len < 0) { |
720 | pr_info("netem: invalid attributes len %d\n", nested_len); | |
2c10b32b | 721 | return -EINVAL; |
661b7972 | 722 | } |
723 | ||
2c10b32b TG |
724 | if (nested_len >= nla_attr_size(0)) |
725 | return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len), | |
726 | nested_len, policy); | |
661b7972 | 727 | |
2c10b32b TG |
728 | memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); |
729 | return 0; | |
730 | } | |
731 | ||
c865e5d9 | 732 | /* Parse netlink message to set options */ |
1e90474c | 733 | static int netem_change(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
734 | { |
735 | struct netem_sched_data *q = qdisc_priv(sch); | |
b03f4672 | 736 | struct nlattr *tb[TCA_NETEM_MAX + 1]; |
1da177e4 LT |
737 | struct tc_netem_qopt *qopt; |
738 | int ret; | |
10297b99 | 739 | |
b03f4672 | 740 | if (opt == NULL) |
1da177e4 LT |
741 | return -EINVAL; |
742 | ||
2c10b32b TG |
743 | qopt = nla_data(opt); |
744 | ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt)); | |
b03f4672 PM |
745 | if (ret < 0) |
746 | return ret; | |
747 | ||
50612537 | 748 | sch->limit = qopt->limit; |
10297b99 | 749 | |
1da177e4 LT |
750 | q->latency = qopt->latency; |
751 | q->jitter = qopt->jitter; | |
752 | q->limit = qopt->limit; | |
753 | q->gap = qopt->gap; | |
0dca51d3 | 754 | q->counter = 0; |
1da177e4 LT |
755 | q->loss = qopt->loss; |
756 | q->duplicate = qopt->duplicate; | |
757 | ||
bb2f8cc0 SH |
758 | /* for compatibility with earlier versions. |
759 | * if gap is set, need to assume 100% probability | |
0dca51d3 | 760 | */ |
a362e0a7 SH |
761 | if (q->gap) |
762 | q->reorder = ~0; | |
0dca51d3 | 763 | |
265eb67f SH |
764 | if (tb[TCA_NETEM_CORR]) |
765 | get_correlation(sch, tb[TCA_NETEM_CORR]); | |
1da177e4 | 766 | |
b03f4672 PM |
767 | if (tb[TCA_NETEM_DELAY_DIST]) { |
768 | ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]); | |
769 | if (ret) | |
770 | return ret; | |
771 | } | |
c865e5d9 | 772 | |
265eb67f SH |
773 | if (tb[TCA_NETEM_REORDER]) |
774 | get_reorder(sch, tb[TCA_NETEM_REORDER]); | |
1da177e4 | 775 | |
265eb67f SH |
776 | if (tb[TCA_NETEM_CORRUPT]) |
777 | get_corrupt(sch, tb[TCA_NETEM_CORRUPT]); | |
1da177e4 | 778 | |
7bc0f28c HPP |
779 | if (tb[TCA_NETEM_RATE]) |
780 | get_rate(sch, tb[TCA_NETEM_RATE]); | |
781 | ||
661b7972 | 782 | q->loss_model = CLG_RANDOM; |
783 | if (tb[TCA_NETEM_LOSS]) | |
784 | ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]); | |
785 | ||
786 | return ret; | |
1da177e4 LT |
787 | } |
788 | ||
1e90474c | 789 | static int netem_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
790 | { |
791 | struct netem_sched_data *q = qdisc_priv(sch); | |
792 | int ret; | |
793 | ||
794 | if (!opt) | |
795 | return -EINVAL; | |
796 | ||
59cb5c67 | 797 | qdisc_watchdog_init(&q->watchdog, sch); |
1da177e4 | 798 | |
661b7972 | 799 | q->loss_model = CLG_RANDOM; |
1da177e4 | 800 | ret = netem_change(sch, opt); |
50612537 | 801 | if (ret) |
250a65f7 | 802 | pr_info("netem: change failed\n"); |
1da177e4 LT |
803 | return ret; |
804 | } | |
805 | ||
806 | static void netem_destroy(struct Qdisc *sch) | |
807 | { | |
808 | struct netem_sched_data *q = qdisc_priv(sch); | |
809 | ||
59cb5c67 | 810 | qdisc_watchdog_cancel(&q->watchdog); |
50612537 ED |
811 | if (q->qdisc) |
812 | qdisc_destroy(q->qdisc); | |
6373a9a2 | 813 | dist_free(q->delay_dist); |
1da177e4 LT |
814 | } |
815 | ||
661b7972 | 816 | static int dump_loss_model(const struct netem_sched_data *q, |
817 | struct sk_buff *skb) | |
818 | { | |
819 | struct nlattr *nest; | |
820 | ||
821 | nest = nla_nest_start(skb, TCA_NETEM_LOSS); | |
822 | if (nest == NULL) | |
823 | goto nla_put_failure; | |
824 | ||
825 | switch (q->loss_model) { | |
826 | case CLG_RANDOM: | |
827 | /* legacy loss model */ | |
828 | nla_nest_cancel(skb, nest); | |
829 | return 0; /* no data */ | |
830 | ||
831 | case CLG_4_STATES: { | |
832 | struct tc_netem_gimodel gi = { | |
833 | .p13 = q->clg.a1, | |
834 | .p31 = q->clg.a2, | |
835 | .p32 = q->clg.a3, | |
836 | .p14 = q->clg.a4, | |
837 | .p23 = q->clg.a5, | |
838 | }; | |
839 | ||
840 | NLA_PUT(skb, NETEM_LOSS_GI, sizeof(gi), &gi); | |
841 | break; | |
842 | } | |
843 | case CLG_GILB_ELL: { | |
844 | struct tc_netem_gemodel ge = { | |
845 | .p = q->clg.a1, | |
846 | .r = q->clg.a2, | |
847 | .h = q->clg.a3, | |
848 | .k1 = q->clg.a4, | |
849 | }; | |
850 | ||
851 | NLA_PUT(skb, NETEM_LOSS_GE, sizeof(ge), &ge); | |
852 | break; | |
853 | } | |
854 | } | |
855 | ||
856 | nla_nest_end(skb, nest); | |
857 | return 0; | |
858 | ||
859 | nla_put_failure: | |
860 | nla_nest_cancel(skb, nest); | |
861 | return -1; | |
862 | } | |
863 | ||
1da177e4 LT |
864 | static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) |
865 | { | |
866 | const struct netem_sched_data *q = qdisc_priv(sch); | |
861d7f74 | 867 | struct nlattr *nla = (struct nlattr *) skb_tail_pointer(skb); |
1da177e4 LT |
868 | struct tc_netem_qopt qopt; |
869 | struct tc_netem_corr cor; | |
0dca51d3 | 870 | struct tc_netem_reorder reorder; |
c865e5d9 | 871 | struct tc_netem_corrupt corrupt; |
7bc0f28c | 872 | struct tc_netem_rate rate; |
1da177e4 LT |
873 | |
874 | qopt.latency = q->latency; | |
875 | qopt.jitter = q->jitter; | |
876 | qopt.limit = q->limit; | |
877 | qopt.loss = q->loss; | |
878 | qopt.gap = q->gap; | |
879 | qopt.duplicate = q->duplicate; | |
1e90474c | 880 | NLA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt); |
1da177e4 LT |
881 | |
882 | cor.delay_corr = q->delay_cor.rho; | |
883 | cor.loss_corr = q->loss_cor.rho; | |
884 | cor.dup_corr = q->dup_cor.rho; | |
1e90474c | 885 | NLA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor); |
0dca51d3 SH |
886 | |
887 | reorder.probability = q->reorder; | |
888 | reorder.correlation = q->reorder_cor.rho; | |
1e90474c | 889 | NLA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder); |
0dca51d3 | 890 | |
c865e5d9 SH |
891 | corrupt.probability = q->corrupt; |
892 | corrupt.correlation = q->corrupt_cor.rho; | |
1e90474c | 893 | NLA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt); |
c865e5d9 | 894 | |
7bc0f28c | 895 | rate.rate = q->rate; |
90b41a1c HPP |
896 | rate.packet_overhead = q->packet_overhead; |
897 | rate.cell_size = q->cell_size; | |
898 | rate.cell_overhead = q->cell_overhead; | |
7bc0f28c HPP |
899 | NLA_PUT(skb, TCA_NETEM_RATE, sizeof(rate), &rate); |
900 | ||
661b7972 | 901 | if (dump_loss_model(q, skb) != 0) |
902 | goto nla_put_failure; | |
903 | ||
861d7f74 | 904 | return nla_nest_end(skb, nla); |
1da177e4 | 905 | |
1e90474c | 906 | nla_put_failure: |
861d7f74 | 907 | nlmsg_trim(skb, nla); |
1da177e4 LT |
908 | return -1; |
909 | } | |
910 | ||
10f6dfcf | 911 | static int netem_dump_class(struct Qdisc *sch, unsigned long cl, |
912 | struct sk_buff *skb, struct tcmsg *tcm) | |
913 | { | |
914 | struct netem_sched_data *q = qdisc_priv(sch); | |
915 | ||
50612537 | 916 | if (cl != 1 || !q->qdisc) /* only one class */ |
10f6dfcf | 917 | return -ENOENT; |
918 | ||
919 | tcm->tcm_handle |= TC_H_MIN(1); | |
920 | tcm->tcm_info = q->qdisc->handle; | |
921 | ||
922 | return 0; | |
923 | } | |
924 | ||
925 | static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
926 | struct Qdisc **old) | |
927 | { | |
928 | struct netem_sched_data *q = qdisc_priv(sch); | |
929 | ||
10f6dfcf | 930 | sch_tree_lock(sch); |
931 | *old = q->qdisc; | |
932 | q->qdisc = new; | |
50612537 ED |
933 | if (*old) { |
934 | qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); | |
935 | qdisc_reset(*old); | |
936 | } | |
10f6dfcf | 937 | sch_tree_unlock(sch); |
938 | ||
939 | return 0; | |
940 | } | |
941 | ||
942 | static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg) | |
943 | { | |
944 | struct netem_sched_data *q = qdisc_priv(sch); | |
945 | return q->qdisc; | |
946 | } | |
947 | ||
948 | static unsigned long netem_get(struct Qdisc *sch, u32 classid) | |
949 | { | |
950 | return 1; | |
951 | } | |
952 | ||
953 | static void netem_put(struct Qdisc *sch, unsigned long arg) | |
954 | { | |
955 | } | |
956 | ||
957 | static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker) | |
958 | { | |
959 | if (!walker->stop) { | |
960 | if (walker->count >= walker->skip) | |
961 | if (walker->fn(sch, 1, walker) < 0) { | |
962 | walker->stop = 1; | |
963 | return; | |
964 | } | |
965 | walker->count++; | |
966 | } | |
967 | } | |
968 | ||
969 | static const struct Qdisc_class_ops netem_class_ops = { | |
970 | .graft = netem_graft, | |
971 | .leaf = netem_leaf, | |
972 | .get = netem_get, | |
973 | .put = netem_put, | |
974 | .walk = netem_walk, | |
975 | .dump = netem_dump_class, | |
976 | }; | |
977 | ||
20fea08b | 978 | static struct Qdisc_ops netem_qdisc_ops __read_mostly = { |
1da177e4 | 979 | .id = "netem", |
10f6dfcf | 980 | .cl_ops = &netem_class_ops, |
1da177e4 LT |
981 | .priv_size = sizeof(struct netem_sched_data), |
982 | .enqueue = netem_enqueue, | |
983 | .dequeue = netem_dequeue, | |
77be155c | 984 | .peek = qdisc_peek_dequeued, |
1da177e4 LT |
985 | .drop = netem_drop, |
986 | .init = netem_init, | |
987 | .reset = netem_reset, | |
988 | .destroy = netem_destroy, | |
989 | .change = netem_change, | |
990 | .dump = netem_dump, | |
991 | .owner = THIS_MODULE, | |
992 | }; | |
993 | ||
994 | ||
995 | static int __init netem_module_init(void) | |
996 | { | |
eb229c4c | 997 | pr_info("netem: version " VERSION "\n"); |
1da177e4 LT |
998 | return register_qdisc(&netem_qdisc_ops); |
999 | } | |
1000 | static void __exit netem_module_exit(void) | |
1001 | { | |
1002 | unregister_qdisc(&netem_qdisc_ops); | |
1003 | } | |
1004 | module_init(netem_module_init) | |
1005 | module_exit(netem_module_exit) | |
1006 | MODULE_LICENSE("GPL"); |