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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 { | |
70 | struct Qdisc *qdisc; | |
59cb5c67 | 71 | struct qdisc_watchdog watchdog; |
1da177e4 | 72 | |
b407621c SH |
73 | psched_tdiff_t latency; |
74 | psched_tdiff_t jitter; | |
75 | ||
1da177e4 LT |
76 | u32 loss; |
77 | u32 limit; | |
78 | u32 counter; | |
79 | u32 gap; | |
1da177e4 | 80 | u32 duplicate; |
0dca51d3 | 81 | u32 reorder; |
c865e5d9 | 82 | u32 corrupt; |
7bc0f28c | 83 | u32 rate; |
90b41a1c HPP |
84 | s32 packet_overhead; |
85 | u32 cell_size; | |
86 | u32 cell_size_reciprocal; | |
87 | s32 cell_overhead; | |
1da177e4 LT |
88 | |
89 | struct crndstate { | |
b407621c SH |
90 | u32 last; |
91 | u32 rho; | |
c865e5d9 | 92 | } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor; |
1da177e4 LT |
93 | |
94 | struct disttable { | |
95 | u32 size; | |
96 | s16 table[0]; | |
97 | } *delay_dist; | |
661b7972 | 98 | |
99 | enum { | |
100 | CLG_RANDOM, | |
101 | CLG_4_STATES, | |
102 | CLG_GILB_ELL, | |
103 | } loss_model; | |
104 | ||
105 | /* Correlated Loss Generation models */ | |
106 | struct clgstate { | |
107 | /* state of the Markov chain */ | |
108 | u8 state; | |
109 | ||
110 | /* 4-states and Gilbert-Elliot models */ | |
111 | u32 a1; /* p13 for 4-states or p for GE */ | |
112 | u32 a2; /* p31 for 4-states or r for GE */ | |
113 | u32 a3; /* p32 for 4-states or h for GE */ | |
114 | u32 a4; /* p14 for 4-states or 1-k for GE */ | |
115 | u32 a5; /* p23 used only in 4-states */ | |
116 | } clg; | |
117 | ||
1da177e4 LT |
118 | }; |
119 | ||
120 | /* Time stamp put into socket buffer control block */ | |
121 | struct netem_skb_cb { | |
122 | psched_time_t time_to_send; | |
123 | }; | |
124 | ||
5f86173b JK |
125 | static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb) |
126 | { | |
175f9c1b JK |
127 | BUILD_BUG_ON(sizeof(skb->cb) < |
128 | sizeof(struct qdisc_skb_cb) + sizeof(struct netem_skb_cb)); | |
129 | return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; | |
5f86173b JK |
130 | } |
131 | ||
1da177e4 LT |
132 | /* init_crandom - initialize correlated random number generator |
133 | * Use entropy source for initial seed. | |
134 | */ | |
135 | static void init_crandom(struct crndstate *state, unsigned long rho) | |
136 | { | |
137 | state->rho = rho; | |
138 | state->last = net_random(); | |
139 | } | |
140 | ||
141 | /* get_crandom - correlated random number generator | |
142 | * Next number depends on last value. | |
143 | * rho is scaled to avoid floating point. | |
144 | */ | |
b407621c | 145 | static u32 get_crandom(struct crndstate *state) |
1da177e4 LT |
146 | { |
147 | u64 value, rho; | |
148 | unsigned long answer; | |
149 | ||
bb2f8cc0 | 150 | if (state->rho == 0) /* no correlation */ |
1da177e4 LT |
151 | return net_random(); |
152 | ||
153 | value = net_random(); | |
154 | rho = (u64)state->rho + 1; | |
155 | answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32; | |
156 | state->last = answer; | |
157 | return answer; | |
158 | } | |
159 | ||
661b7972 | 160 | /* loss_4state - 4-state model loss generator |
161 | * Generates losses according to the 4-state Markov chain adopted in | |
162 | * the GI (General and Intuitive) loss model. | |
163 | */ | |
164 | static bool loss_4state(struct netem_sched_data *q) | |
165 | { | |
166 | struct clgstate *clg = &q->clg; | |
167 | u32 rnd = net_random(); | |
168 | ||
169 | /* | |
25985edc | 170 | * Makes a comparison between rnd and the transition |
661b7972 | 171 | * probabilities outgoing from the current state, then decides the |
172 | * next state and if the next packet has to be transmitted or lost. | |
173 | * The four states correspond to: | |
174 | * 1 => successfully transmitted packets within a gap period | |
175 | * 4 => isolated losses within a gap period | |
176 | * 3 => lost packets within a burst period | |
177 | * 2 => successfully transmitted packets within a burst period | |
178 | */ | |
179 | switch (clg->state) { | |
180 | case 1: | |
181 | if (rnd < clg->a4) { | |
182 | clg->state = 4; | |
183 | return true; | |
184 | } else if (clg->a4 < rnd && rnd < clg->a1) { | |
185 | clg->state = 3; | |
186 | return true; | |
187 | } else if (clg->a1 < rnd) | |
188 | clg->state = 1; | |
189 | ||
190 | break; | |
191 | case 2: | |
192 | if (rnd < clg->a5) { | |
193 | clg->state = 3; | |
194 | return true; | |
195 | } else | |
196 | clg->state = 2; | |
197 | ||
198 | break; | |
199 | case 3: | |
200 | if (rnd < clg->a3) | |
201 | clg->state = 2; | |
202 | else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) { | |
203 | clg->state = 1; | |
204 | return true; | |
205 | } else if (clg->a2 + clg->a3 < rnd) { | |
206 | clg->state = 3; | |
207 | return true; | |
208 | } | |
209 | break; | |
210 | case 4: | |
211 | clg->state = 1; | |
212 | break; | |
213 | } | |
214 | ||
215 | return false; | |
216 | } | |
217 | ||
218 | /* loss_gilb_ell - Gilbert-Elliot model loss generator | |
219 | * Generates losses according to the Gilbert-Elliot loss model or | |
220 | * its special cases (Gilbert or Simple Gilbert) | |
221 | * | |
25985edc | 222 | * Makes a comparison between random number and the transition |
661b7972 | 223 | * probabilities outgoing from the current state, then decides the |
25985edc | 224 | * next state. A second random number is extracted and the comparison |
661b7972 | 225 | * with the loss probability of the current state decides if the next |
226 | * packet will be transmitted or lost. | |
227 | */ | |
228 | static bool loss_gilb_ell(struct netem_sched_data *q) | |
229 | { | |
230 | struct clgstate *clg = &q->clg; | |
231 | ||
232 | switch (clg->state) { | |
233 | case 1: | |
234 | if (net_random() < clg->a1) | |
235 | clg->state = 2; | |
236 | if (net_random() < clg->a4) | |
237 | return true; | |
238 | case 2: | |
239 | if (net_random() < clg->a2) | |
240 | clg->state = 1; | |
241 | if (clg->a3 > net_random()) | |
242 | return true; | |
243 | } | |
244 | ||
245 | return false; | |
246 | } | |
247 | ||
248 | static bool loss_event(struct netem_sched_data *q) | |
249 | { | |
250 | switch (q->loss_model) { | |
251 | case CLG_RANDOM: | |
252 | /* Random packet drop 0 => none, ~0 => all */ | |
253 | return q->loss && q->loss >= get_crandom(&q->loss_cor); | |
254 | ||
255 | case CLG_4_STATES: | |
256 | /* 4state loss model algorithm (used also for GI model) | |
257 | * Extracts a value from the markov 4 state loss generator, | |
258 | * if it is 1 drops a packet and if needed writes the event in | |
259 | * the kernel logs | |
260 | */ | |
261 | return loss_4state(q); | |
262 | ||
263 | case CLG_GILB_ELL: | |
264 | /* Gilbert-Elliot loss model algorithm | |
265 | * Extracts a value from the Gilbert-Elliot loss generator, | |
266 | * if it is 1 drops a packet and if needed writes the event in | |
267 | * the kernel logs | |
268 | */ | |
269 | return loss_gilb_ell(q); | |
270 | } | |
271 | ||
272 | return false; /* not reached */ | |
273 | } | |
274 | ||
275 | ||
1da177e4 LT |
276 | /* tabledist - return a pseudo-randomly distributed value with mean mu and |
277 | * std deviation sigma. Uses table lookup to approximate the desired | |
278 | * distribution, and a uniformly-distributed pseudo-random source. | |
279 | */ | |
b407621c SH |
280 | static psched_tdiff_t tabledist(psched_tdiff_t mu, psched_tdiff_t sigma, |
281 | struct crndstate *state, | |
282 | const struct disttable *dist) | |
1da177e4 | 283 | { |
b407621c SH |
284 | psched_tdiff_t x; |
285 | long t; | |
286 | u32 rnd; | |
1da177e4 LT |
287 | |
288 | if (sigma == 0) | |
289 | return mu; | |
290 | ||
291 | rnd = get_crandom(state); | |
292 | ||
293 | /* default uniform distribution */ | |
10297b99 | 294 | if (dist == NULL) |
1da177e4 LT |
295 | return (rnd % (2*sigma)) - sigma + mu; |
296 | ||
297 | t = dist->table[rnd % dist->size]; | |
298 | x = (sigma % NETEM_DIST_SCALE) * t; | |
299 | if (x >= 0) | |
300 | x += NETEM_DIST_SCALE/2; | |
301 | else | |
302 | x -= NETEM_DIST_SCALE/2; | |
303 | ||
304 | return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu; | |
305 | } | |
306 | ||
90b41a1c | 307 | static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sched_data *q) |
7bc0f28c | 308 | { |
90b41a1c | 309 | u64 ticks; |
fc33cc72 | 310 | |
90b41a1c HPP |
311 | len += q->packet_overhead; |
312 | ||
313 | if (q->cell_size) { | |
314 | u32 cells = reciprocal_divide(len, q->cell_size_reciprocal); | |
315 | ||
316 | if (len > cells * q->cell_size) /* extra cell needed for remainder */ | |
317 | cells++; | |
318 | len = cells * (q->cell_size + q->cell_overhead); | |
319 | } | |
320 | ||
321 | ticks = (u64)len * NSEC_PER_SEC; | |
322 | ||
323 | do_div(ticks, q->rate); | |
fc33cc72 | 324 | return PSCHED_NS2TICKS(ticks); |
7bc0f28c HPP |
325 | } |
326 | ||
0afb51e7 SH |
327 | /* |
328 | * Insert one skb into qdisc. | |
329 | * Note: parent depends on return value to account for queue length. | |
330 | * NET_XMIT_DROP: queue length didn't change. | |
331 | * NET_XMIT_SUCCESS: one skb was queued. | |
332 | */ | |
1da177e4 LT |
333 | static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
334 | { | |
335 | struct netem_sched_data *q = qdisc_priv(sch); | |
89e1df74 GC |
336 | /* We don't fill cb now as skb_unshare() may invalidate it */ |
337 | struct netem_skb_cb *cb; | |
0afb51e7 | 338 | struct sk_buff *skb2; |
1da177e4 | 339 | int ret; |
0afb51e7 | 340 | int count = 1; |
1da177e4 | 341 | |
0afb51e7 SH |
342 | /* Random duplication */ |
343 | if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) | |
344 | ++count; | |
345 | ||
661b7972 | 346 | /* Drop packet? */ |
347 | if (loss_event(q)) | |
0afb51e7 SH |
348 | --count; |
349 | ||
350 | if (count == 0) { | |
1da177e4 LT |
351 | sch->qstats.drops++; |
352 | kfree_skb(skb); | |
c27f339a | 353 | return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
1da177e4 LT |
354 | } |
355 | ||
4e8a5201 DM |
356 | skb_orphan(skb); |
357 | ||
0afb51e7 SH |
358 | /* |
359 | * If we need to duplicate packet, then re-insert at top of the | |
360 | * qdisc tree, since parent queuer expects that only one | |
361 | * skb will be queued. | |
362 | */ | |
363 | if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { | |
7698b4fc | 364 | struct Qdisc *rootq = qdisc_root(sch); |
0afb51e7 SH |
365 | u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ |
366 | q->duplicate = 0; | |
367 | ||
5f86173b | 368 | qdisc_enqueue_root(skb2, rootq); |
0afb51e7 | 369 | q->duplicate = dupsave; |
1da177e4 LT |
370 | } |
371 | ||
c865e5d9 SH |
372 | /* |
373 | * Randomized packet corruption. | |
374 | * Make copy if needed since we are modifying | |
375 | * If packet is going to be hardware checksummed, then | |
376 | * do it now in software before we mangle it. | |
377 | */ | |
378 | if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) { | |
f64f9e71 JP |
379 | if (!(skb = skb_unshare(skb, GFP_ATOMIC)) || |
380 | (skb->ip_summed == CHECKSUM_PARTIAL && | |
381 | skb_checksum_help(skb))) { | |
c865e5d9 SH |
382 | sch->qstats.drops++; |
383 | return NET_XMIT_DROP; | |
384 | } | |
385 | ||
386 | skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8); | |
387 | } | |
388 | ||
5f86173b | 389 | cb = netem_skb_cb(skb); |
cc7ec456 ED |
390 | if (q->gap == 0 || /* not doing reordering */ |
391 | q->counter < q->gap || /* inside last reordering gap */ | |
f64f9e71 | 392 | q->reorder < get_crandom(&q->reorder_cor)) { |
0f9f32ac | 393 | psched_time_t now; |
07aaa115 SH |
394 | psched_tdiff_t delay; |
395 | ||
396 | delay = tabledist(q->latency, q->jitter, | |
397 | &q->delay_cor, q->delay_dist); | |
398 | ||
3bebcda2 | 399 | now = psched_get_time(); |
7bc0f28c HPP |
400 | |
401 | if (q->rate) { | |
402 | struct sk_buff_head *list = &q->qdisc->q; | |
403 | ||
90b41a1c | 404 | delay += packet_len_2_sched_time(skb->len, q); |
7bc0f28c HPP |
405 | |
406 | if (!skb_queue_empty(list)) { | |
407 | /* | |
408 | * Last packet in queue is reference point (now). | |
409 | * First packet in queue is already in flight, | |
410 | * calculate this time bonus and substract | |
411 | * from delay. | |
412 | */ | |
413 | delay -= now - netem_skb_cb(skb_peek(list))->time_to_send; | |
414 | now = netem_skb_cb(skb_peek_tail(list))->time_to_send; | |
415 | } | |
416 | } | |
417 | ||
7c59e25f | 418 | cb->time_to_send = now + delay; |
1da177e4 | 419 | ++q->counter; |
5f86173b | 420 | ret = qdisc_enqueue(skb, q->qdisc); |
1da177e4 | 421 | } else { |
10297b99 | 422 | /* |
0dca51d3 SH |
423 | * Do re-ordering by putting one out of N packets at the front |
424 | * of the queue. | |
425 | */ | |
3bebcda2 | 426 | cb->time_to_send = psched_get_time(); |
0dca51d3 | 427 | q->counter = 0; |
8ba25dad JP |
428 | |
429 | __skb_queue_head(&q->qdisc->q, skb); | |
430 | q->qdisc->qstats.backlog += qdisc_pkt_len(skb); | |
431 | q->qdisc->qstats.requeues++; | |
432 | ret = NET_XMIT_SUCCESS; | |
1da177e4 LT |
433 | } |
434 | ||
10f6dfcf | 435 | if (ret != NET_XMIT_SUCCESS) { |
436 | if (net_xmit_drop_count(ret)) { | |
437 | sch->qstats.drops++; | |
438 | return ret; | |
439 | } | |
378a2f09 | 440 | } |
1da177e4 | 441 | |
10f6dfcf | 442 | sch->q.qlen++; |
443 | return NET_XMIT_SUCCESS; | |
1da177e4 LT |
444 | } |
445 | ||
cc7ec456 | 446 | static unsigned int netem_drop(struct Qdisc *sch) |
1da177e4 LT |
447 | { |
448 | struct netem_sched_data *q = qdisc_priv(sch); | |
6d037a26 | 449 | unsigned int len = 0; |
1da177e4 | 450 | |
6d037a26 | 451 | if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) { |
1da177e4 LT |
452 | sch->q.qlen--; |
453 | sch->qstats.drops++; | |
454 | } | |
455 | return len; | |
456 | } | |
457 | ||
1da177e4 LT |
458 | static struct sk_buff *netem_dequeue(struct Qdisc *sch) |
459 | { | |
460 | struct netem_sched_data *q = qdisc_priv(sch); | |
461 | struct sk_buff *skb; | |
462 | ||
fd245a4a | 463 | if (qdisc_is_throttled(sch)) |
11274e5a SH |
464 | return NULL; |
465 | ||
03c05f0d | 466 | skb = q->qdisc->ops->peek(q->qdisc); |
771018e7 | 467 | if (skb) { |
5f86173b | 468 | const struct netem_skb_cb *cb = netem_skb_cb(skb); |
3bebcda2 | 469 | psched_time_t now = psched_get_time(); |
0f9f32ac SH |
470 | |
471 | /* if more time remaining? */ | |
104e0878 | 472 | if (cb->time_to_send <= now) { |
77be155c JP |
473 | skb = qdisc_dequeue_peeked(q->qdisc); |
474 | if (unlikely(!skb)) | |
03c05f0d JP |
475 | return NULL; |
476 | ||
8caf1539 JP |
477 | #ifdef CONFIG_NET_CLS_ACT |
478 | /* | |
479 | * If it's at ingress let's pretend the delay is | |
480 | * from the network (tstamp will be updated). | |
481 | */ | |
482 | if (G_TC_FROM(skb->tc_verd) & AT_INGRESS) | |
483 | skb->tstamp.tv64 = 0; | |
484 | #endif | |
10f6dfcf | 485 | |
0f9f32ac | 486 | sch->q.qlen--; |
10f6dfcf | 487 | qdisc_unthrottled(sch); |
488 | qdisc_bstats_update(sch, skb); | |
0f9f32ac | 489 | return skb; |
07aaa115 | 490 | } |
11274e5a | 491 | |
11274e5a | 492 | qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); |
0f9f32ac SH |
493 | } |
494 | ||
495 | return NULL; | |
1da177e4 LT |
496 | } |
497 | ||
1da177e4 LT |
498 | static void netem_reset(struct Qdisc *sch) |
499 | { | |
500 | struct netem_sched_data *q = qdisc_priv(sch); | |
501 | ||
502 | qdisc_reset(q->qdisc); | |
1da177e4 | 503 | sch->q.qlen = 0; |
59cb5c67 | 504 | qdisc_watchdog_cancel(&q->watchdog); |
1da177e4 LT |
505 | } |
506 | ||
6373a9a2 | 507 | static void dist_free(struct disttable *d) |
508 | { | |
509 | if (d) { | |
510 | if (is_vmalloc_addr(d)) | |
511 | vfree(d); | |
512 | else | |
513 | kfree(d); | |
514 | } | |
515 | } | |
516 | ||
1da177e4 LT |
517 | /* |
518 | * Distribution data is a variable size payload containing | |
519 | * signed 16 bit values. | |
520 | */ | |
1e90474c | 521 | static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) |
1da177e4 LT |
522 | { |
523 | struct netem_sched_data *q = qdisc_priv(sch); | |
6373a9a2 | 524 | size_t n = nla_len(attr)/sizeof(__s16); |
1e90474c | 525 | const __s16 *data = nla_data(attr); |
7698b4fc | 526 | spinlock_t *root_lock; |
1da177e4 LT |
527 | struct disttable *d; |
528 | int i; | |
6373a9a2 | 529 | size_t s; |
1da177e4 | 530 | |
df173bda | 531 | if (n > NETEM_DIST_MAX) |
1da177e4 LT |
532 | return -EINVAL; |
533 | ||
6373a9a2 | 534 | s = sizeof(struct disttable) + n * sizeof(s16); |
535 | d = kmalloc(s, GFP_KERNEL); | |
536 | if (!d) | |
537 | d = vmalloc(s); | |
1da177e4 LT |
538 | if (!d) |
539 | return -ENOMEM; | |
540 | ||
541 | d->size = n; | |
542 | for (i = 0; i < n; i++) | |
543 | d->table[i] = data[i]; | |
10297b99 | 544 | |
102396ae | 545 | root_lock = qdisc_root_sleeping_lock(sch); |
7698b4fc DM |
546 | |
547 | spin_lock_bh(root_lock); | |
6373a9a2 | 548 | dist_free(q->delay_dist); |
b94c8afc | 549 | q->delay_dist = d; |
7698b4fc | 550 | spin_unlock_bh(root_lock); |
1da177e4 LT |
551 | return 0; |
552 | } | |
553 | ||
265eb67f | 554 | static void get_correlation(struct Qdisc *sch, const struct nlattr *attr) |
1da177e4 LT |
555 | { |
556 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 557 | const struct tc_netem_corr *c = nla_data(attr); |
1da177e4 | 558 | |
1da177e4 LT |
559 | init_crandom(&q->delay_cor, c->delay_corr); |
560 | init_crandom(&q->loss_cor, c->loss_corr); | |
561 | init_crandom(&q->dup_cor, c->dup_corr); | |
1da177e4 LT |
562 | } |
563 | ||
265eb67f | 564 | static void get_reorder(struct Qdisc *sch, const struct nlattr *attr) |
0dca51d3 SH |
565 | { |
566 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 567 | const struct tc_netem_reorder *r = nla_data(attr); |
0dca51d3 | 568 | |
0dca51d3 SH |
569 | q->reorder = r->probability; |
570 | init_crandom(&q->reorder_cor, r->correlation); | |
0dca51d3 SH |
571 | } |
572 | ||
265eb67f | 573 | static void get_corrupt(struct Qdisc *sch, const struct nlattr *attr) |
c865e5d9 SH |
574 | { |
575 | struct netem_sched_data *q = qdisc_priv(sch); | |
1e90474c | 576 | const struct tc_netem_corrupt *r = nla_data(attr); |
c865e5d9 | 577 | |
c865e5d9 SH |
578 | q->corrupt = r->probability; |
579 | init_crandom(&q->corrupt_cor, r->correlation); | |
c865e5d9 SH |
580 | } |
581 | ||
7bc0f28c HPP |
582 | static void get_rate(struct Qdisc *sch, const struct nlattr *attr) |
583 | { | |
584 | struct netem_sched_data *q = qdisc_priv(sch); | |
585 | const struct tc_netem_rate *r = nla_data(attr); | |
586 | ||
587 | q->rate = r->rate; | |
90b41a1c HPP |
588 | q->packet_overhead = r->packet_overhead; |
589 | q->cell_size = r->cell_size; | |
590 | if (q->cell_size) | |
591 | q->cell_size_reciprocal = reciprocal_value(q->cell_size); | |
592 | q->cell_overhead = r->cell_overhead; | |
7bc0f28c HPP |
593 | } |
594 | ||
661b7972 | 595 | static int get_loss_clg(struct Qdisc *sch, const struct nlattr *attr) |
596 | { | |
597 | struct netem_sched_data *q = qdisc_priv(sch); | |
598 | const struct nlattr *la; | |
599 | int rem; | |
600 | ||
601 | nla_for_each_nested(la, attr, rem) { | |
602 | u16 type = nla_type(la); | |
603 | ||
604 | switch(type) { | |
605 | case NETEM_LOSS_GI: { | |
606 | const struct tc_netem_gimodel *gi = nla_data(la); | |
607 | ||
608 | if (nla_len(la) != sizeof(struct tc_netem_gimodel)) { | |
609 | pr_info("netem: incorrect gi model size\n"); | |
610 | return -EINVAL; | |
611 | } | |
612 | ||
613 | q->loss_model = CLG_4_STATES; | |
614 | ||
615 | q->clg.state = 1; | |
616 | q->clg.a1 = gi->p13; | |
617 | q->clg.a2 = gi->p31; | |
618 | q->clg.a3 = gi->p32; | |
619 | q->clg.a4 = gi->p14; | |
620 | q->clg.a5 = gi->p23; | |
621 | break; | |
622 | } | |
623 | ||
624 | case NETEM_LOSS_GE: { | |
625 | const struct tc_netem_gemodel *ge = nla_data(la); | |
626 | ||
627 | if (nla_len(la) != sizeof(struct tc_netem_gemodel)) { | |
628 | pr_info("netem: incorrect gi model size\n"); | |
629 | return -EINVAL; | |
630 | } | |
631 | ||
632 | q->loss_model = CLG_GILB_ELL; | |
633 | q->clg.state = 1; | |
634 | q->clg.a1 = ge->p; | |
635 | q->clg.a2 = ge->r; | |
636 | q->clg.a3 = ge->h; | |
637 | q->clg.a4 = ge->k1; | |
638 | break; | |
639 | } | |
640 | ||
641 | default: | |
642 | pr_info("netem: unknown loss type %u\n", type); | |
643 | return -EINVAL; | |
644 | } | |
645 | } | |
646 | ||
647 | return 0; | |
648 | } | |
649 | ||
27a3421e PM |
650 | static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = { |
651 | [TCA_NETEM_CORR] = { .len = sizeof(struct tc_netem_corr) }, | |
652 | [TCA_NETEM_REORDER] = { .len = sizeof(struct tc_netem_reorder) }, | |
653 | [TCA_NETEM_CORRUPT] = { .len = sizeof(struct tc_netem_corrupt) }, | |
7bc0f28c | 654 | [TCA_NETEM_RATE] = { .len = sizeof(struct tc_netem_rate) }, |
661b7972 | 655 | [TCA_NETEM_LOSS] = { .type = NLA_NESTED }, |
27a3421e PM |
656 | }; |
657 | ||
2c10b32b TG |
658 | static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla, |
659 | const struct nla_policy *policy, int len) | |
660 | { | |
661 | int nested_len = nla_len(nla) - NLA_ALIGN(len); | |
662 | ||
661b7972 | 663 | if (nested_len < 0) { |
664 | pr_info("netem: invalid attributes len %d\n", nested_len); | |
2c10b32b | 665 | return -EINVAL; |
661b7972 | 666 | } |
667 | ||
2c10b32b TG |
668 | if (nested_len >= nla_attr_size(0)) |
669 | return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len), | |
670 | nested_len, policy); | |
661b7972 | 671 | |
2c10b32b TG |
672 | memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); |
673 | return 0; | |
674 | } | |
675 | ||
c865e5d9 | 676 | /* Parse netlink message to set options */ |
1e90474c | 677 | static int netem_change(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
678 | { |
679 | struct netem_sched_data *q = qdisc_priv(sch); | |
b03f4672 | 680 | struct nlattr *tb[TCA_NETEM_MAX + 1]; |
1da177e4 LT |
681 | struct tc_netem_qopt *qopt; |
682 | int ret; | |
10297b99 | 683 | |
b03f4672 | 684 | if (opt == NULL) |
1da177e4 LT |
685 | return -EINVAL; |
686 | ||
2c10b32b TG |
687 | qopt = nla_data(opt); |
688 | ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt)); | |
b03f4672 PM |
689 | if (ret < 0) |
690 | return ret; | |
691 | ||
fb0305ce | 692 | ret = fifo_set_limit(q->qdisc, qopt->limit); |
1da177e4 | 693 | if (ret) { |
250a65f7 | 694 | pr_info("netem: can't set fifo limit\n"); |
1da177e4 LT |
695 | return ret; |
696 | } | |
10297b99 | 697 | |
1da177e4 LT |
698 | q->latency = qopt->latency; |
699 | q->jitter = qopt->jitter; | |
700 | q->limit = qopt->limit; | |
701 | q->gap = qopt->gap; | |
0dca51d3 | 702 | q->counter = 0; |
1da177e4 LT |
703 | q->loss = qopt->loss; |
704 | q->duplicate = qopt->duplicate; | |
705 | ||
bb2f8cc0 SH |
706 | /* for compatibility with earlier versions. |
707 | * if gap is set, need to assume 100% probability | |
0dca51d3 | 708 | */ |
a362e0a7 SH |
709 | if (q->gap) |
710 | q->reorder = ~0; | |
0dca51d3 | 711 | |
265eb67f SH |
712 | if (tb[TCA_NETEM_CORR]) |
713 | get_correlation(sch, tb[TCA_NETEM_CORR]); | |
1da177e4 | 714 | |
b03f4672 PM |
715 | if (tb[TCA_NETEM_DELAY_DIST]) { |
716 | ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]); | |
717 | if (ret) | |
718 | return ret; | |
719 | } | |
c865e5d9 | 720 | |
265eb67f SH |
721 | if (tb[TCA_NETEM_REORDER]) |
722 | get_reorder(sch, tb[TCA_NETEM_REORDER]); | |
1da177e4 | 723 | |
265eb67f SH |
724 | if (tb[TCA_NETEM_CORRUPT]) |
725 | get_corrupt(sch, tb[TCA_NETEM_CORRUPT]); | |
1da177e4 | 726 | |
7bc0f28c HPP |
727 | if (tb[TCA_NETEM_RATE]) |
728 | get_rate(sch, tb[TCA_NETEM_RATE]); | |
729 | ||
661b7972 | 730 | q->loss_model = CLG_RANDOM; |
731 | if (tb[TCA_NETEM_LOSS]) | |
732 | ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]); | |
733 | ||
734 | return ret; | |
1da177e4 LT |
735 | } |
736 | ||
300ce174 SH |
737 | /* |
738 | * Special case version of FIFO queue for use by netem. | |
739 | * It queues in order based on timestamps in skb's | |
740 | */ | |
741 | struct fifo_sched_data { | |
742 | u32 limit; | |
075aa573 | 743 | psched_time_t oldest; |
300ce174 SH |
744 | }; |
745 | ||
746 | static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) | |
747 | { | |
748 | struct fifo_sched_data *q = qdisc_priv(sch); | |
749 | struct sk_buff_head *list = &sch->q; | |
5f86173b | 750 | psched_time_t tnext = netem_skb_cb(nskb)->time_to_send; |
300ce174 SH |
751 | struct sk_buff *skb; |
752 | ||
753 | if (likely(skb_queue_len(list) < q->limit)) { | |
075aa573 | 754 | /* Optimize for add at tail */ |
104e0878 | 755 | if (likely(skb_queue_empty(list) || tnext >= q->oldest)) { |
075aa573 SH |
756 | q->oldest = tnext; |
757 | return qdisc_enqueue_tail(nskb, sch); | |
758 | } | |
759 | ||
300ce174 | 760 | skb_queue_reverse_walk(list, skb) { |
5f86173b | 761 | const struct netem_skb_cb *cb = netem_skb_cb(skb); |
300ce174 | 762 | |
104e0878 | 763 | if (tnext >= cb->time_to_send) |
300ce174 SH |
764 | break; |
765 | } | |
766 | ||
767 | __skb_queue_after(list, skb, nskb); | |
768 | ||
0abf77e5 | 769 | sch->qstats.backlog += qdisc_pkt_len(nskb); |
300ce174 SH |
770 | |
771 | return NET_XMIT_SUCCESS; | |
772 | } | |
773 | ||
075aa573 | 774 | return qdisc_reshape_fail(nskb, sch); |
300ce174 SH |
775 | } |
776 | ||
1e90474c | 777 | static int tfifo_init(struct Qdisc *sch, struct nlattr *opt) |
300ce174 SH |
778 | { |
779 | struct fifo_sched_data *q = qdisc_priv(sch); | |
780 | ||
781 | if (opt) { | |
1e90474c PM |
782 | struct tc_fifo_qopt *ctl = nla_data(opt); |
783 | if (nla_len(opt) < sizeof(*ctl)) | |
300ce174 SH |
784 | return -EINVAL; |
785 | ||
786 | q->limit = ctl->limit; | |
787 | } else | |
5ce2d488 | 788 | q->limit = max_t(u32, qdisc_dev(sch)->tx_queue_len, 1); |
300ce174 | 789 | |
a084980d | 790 | q->oldest = PSCHED_PASTPERFECT; |
300ce174 SH |
791 | return 0; |
792 | } | |
793 | ||
794 | static int tfifo_dump(struct Qdisc *sch, struct sk_buff *skb) | |
795 | { | |
796 | struct fifo_sched_data *q = qdisc_priv(sch); | |
797 | struct tc_fifo_qopt opt = { .limit = q->limit }; | |
798 | ||
1e90474c | 799 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
300ce174 SH |
800 | return skb->len; |
801 | ||
1e90474c | 802 | nla_put_failure: |
300ce174 SH |
803 | return -1; |
804 | } | |
805 | ||
20fea08b | 806 | static struct Qdisc_ops tfifo_qdisc_ops __read_mostly = { |
300ce174 SH |
807 | .id = "tfifo", |
808 | .priv_size = sizeof(struct fifo_sched_data), | |
809 | .enqueue = tfifo_enqueue, | |
810 | .dequeue = qdisc_dequeue_head, | |
8e3af978 | 811 | .peek = qdisc_peek_head, |
300ce174 SH |
812 | .drop = qdisc_queue_drop, |
813 | .init = tfifo_init, | |
814 | .reset = qdisc_reset_queue, | |
815 | .change = tfifo_init, | |
816 | .dump = tfifo_dump, | |
817 | }; | |
818 | ||
1e90474c | 819 | static int netem_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
820 | { |
821 | struct netem_sched_data *q = qdisc_priv(sch); | |
822 | int ret; | |
823 | ||
824 | if (!opt) | |
825 | return -EINVAL; | |
826 | ||
59cb5c67 | 827 | qdisc_watchdog_init(&q->watchdog, sch); |
1da177e4 | 828 | |
661b7972 | 829 | q->loss_model = CLG_RANDOM; |
3511c913 | 830 | q->qdisc = qdisc_create_dflt(sch->dev_queue, &tfifo_qdisc_ops, |
9f9afec4 | 831 | TC_H_MAKE(sch->handle, 1)); |
1da177e4 | 832 | if (!q->qdisc) { |
250a65f7 | 833 | pr_notice("netem: qdisc create tfifo qdisc failed\n"); |
1da177e4 LT |
834 | return -ENOMEM; |
835 | } | |
836 | ||
837 | ret = netem_change(sch, opt); | |
838 | if (ret) { | |
250a65f7 | 839 | pr_info("netem: change failed\n"); |
1da177e4 LT |
840 | qdisc_destroy(q->qdisc); |
841 | } | |
842 | return ret; | |
843 | } | |
844 | ||
845 | static void netem_destroy(struct Qdisc *sch) | |
846 | { | |
847 | struct netem_sched_data *q = qdisc_priv(sch); | |
848 | ||
59cb5c67 | 849 | qdisc_watchdog_cancel(&q->watchdog); |
1da177e4 | 850 | qdisc_destroy(q->qdisc); |
6373a9a2 | 851 | dist_free(q->delay_dist); |
1da177e4 LT |
852 | } |
853 | ||
661b7972 | 854 | static int dump_loss_model(const struct netem_sched_data *q, |
855 | struct sk_buff *skb) | |
856 | { | |
857 | struct nlattr *nest; | |
858 | ||
859 | nest = nla_nest_start(skb, TCA_NETEM_LOSS); | |
860 | if (nest == NULL) | |
861 | goto nla_put_failure; | |
862 | ||
863 | switch (q->loss_model) { | |
864 | case CLG_RANDOM: | |
865 | /* legacy loss model */ | |
866 | nla_nest_cancel(skb, nest); | |
867 | return 0; /* no data */ | |
868 | ||
869 | case CLG_4_STATES: { | |
870 | struct tc_netem_gimodel gi = { | |
871 | .p13 = q->clg.a1, | |
872 | .p31 = q->clg.a2, | |
873 | .p32 = q->clg.a3, | |
874 | .p14 = q->clg.a4, | |
875 | .p23 = q->clg.a5, | |
876 | }; | |
877 | ||
878 | NLA_PUT(skb, NETEM_LOSS_GI, sizeof(gi), &gi); | |
879 | break; | |
880 | } | |
881 | case CLG_GILB_ELL: { | |
882 | struct tc_netem_gemodel ge = { | |
883 | .p = q->clg.a1, | |
884 | .r = q->clg.a2, | |
885 | .h = q->clg.a3, | |
886 | .k1 = q->clg.a4, | |
887 | }; | |
888 | ||
889 | NLA_PUT(skb, NETEM_LOSS_GE, sizeof(ge), &ge); | |
890 | break; | |
891 | } | |
892 | } | |
893 | ||
894 | nla_nest_end(skb, nest); | |
895 | return 0; | |
896 | ||
897 | nla_put_failure: | |
898 | nla_nest_cancel(skb, nest); | |
899 | return -1; | |
900 | } | |
901 | ||
1da177e4 LT |
902 | static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) |
903 | { | |
904 | const struct netem_sched_data *q = qdisc_priv(sch); | |
861d7f74 | 905 | struct nlattr *nla = (struct nlattr *) skb_tail_pointer(skb); |
1da177e4 LT |
906 | struct tc_netem_qopt qopt; |
907 | struct tc_netem_corr cor; | |
0dca51d3 | 908 | struct tc_netem_reorder reorder; |
c865e5d9 | 909 | struct tc_netem_corrupt corrupt; |
7bc0f28c | 910 | struct tc_netem_rate rate; |
1da177e4 LT |
911 | |
912 | qopt.latency = q->latency; | |
913 | qopt.jitter = q->jitter; | |
914 | qopt.limit = q->limit; | |
915 | qopt.loss = q->loss; | |
916 | qopt.gap = q->gap; | |
917 | qopt.duplicate = q->duplicate; | |
1e90474c | 918 | NLA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt); |
1da177e4 LT |
919 | |
920 | cor.delay_corr = q->delay_cor.rho; | |
921 | cor.loss_corr = q->loss_cor.rho; | |
922 | cor.dup_corr = q->dup_cor.rho; | |
1e90474c | 923 | NLA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor); |
0dca51d3 SH |
924 | |
925 | reorder.probability = q->reorder; | |
926 | reorder.correlation = q->reorder_cor.rho; | |
1e90474c | 927 | NLA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder); |
0dca51d3 | 928 | |
c865e5d9 SH |
929 | corrupt.probability = q->corrupt; |
930 | corrupt.correlation = q->corrupt_cor.rho; | |
1e90474c | 931 | NLA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt); |
c865e5d9 | 932 | |
7bc0f28c | 933 | rate.rate = q->rate; |
90b41a1c HPP |
934 | rate.packet_overhead = q->packet_overhead; |
935 | rate.cell_size = q->cell_size; | |
936 | rate.cell_overhead = q->cell_overhead; | |
7bc0f28c HPP |
937 | NLA_PUT(skb, TCA_NETEM_RATE, sizeof(rate), &rate); |
938 | ||
661b7972 | 939 | if (dump_loss_model(q, skb) != 0) |
940 | goto nla_put_failure; | |
941 | ||
861d7f74 | 942 | return nla_nest_end(skb, nla); |
1da177e4 | 943 | |
1e90474c | 944 | nla_put_failure: |
861d7f74 | 945 | nlmsg_trim(skb, nla); |
1da177e4 LT |
946 | return -1; |
947 | } | |
948 | ||
10f6dfcf | 949 | static int netem_dump_class(struct Qdisc *sch, unsigned long cl, |
950 | struct sk_buff *skb, struct tcmsg *tcm) | |
951 | { | |
952 | struct netem_sched_data *q = qdisc_priv(sch); | |
953 | ||
954 | if (cl != 1) /* only one class */ | |
955 | return -ENOENT; | |
956 | ||
957 | tcm->tcm_handle |= TC_H_MIN(1); | |
958 | tcm->tcm_info = q->qdisc->handle; | |
959 | ||
960 | return 0; | |
961 | } | |
962 | ||
963 | static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
964 | struct Qdisc **old) | |
965 | { | |
966 | struct netem_sched_data *q = qdisc_priv(sch); | |
967 | ||
968 | if (new == NULL) | |
969 | new = &noop_qdisc; | |
970 | ||
971 | sch_tree_lock(sch); | |
972 | *old = q->qdisc; | |
973 | q->qdisc = new; | |
974 | qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); | |
975 | qdisc_reset(*old); | |
976 | sch_tree_unlock(sch); | |
977 | ||
978 | return 0; | |
979 | } | |
980 | ||
981 | static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg) | |
982 | { | |
983 | struct netem_sched_data *q = qdisc_priv(sch); | |
984 | return q->qdisc; | |
985 | } | |
986 | ||
987 | static unsigned long netem_get(struct Qdisc *sch, u32 classid) | |
988 | { | |
989 | return 1; | |
990 | } | |
991 | ||
992 | static void netem_put(struct Qdisc *sch, unsigned long arg) | |
993 | { | |
994 | } | |
995 | ||
996 | static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker) | |
997 | { | |
998 | if (!walker->stop) { | |
999 | if (walker->count >= walker->skip) | |
1000 | if (walker->fn(sch, 1, walker) < 0) { | |
1001 | walker->stop = 1; | |
1002 | return; | |
1003 | } | |
1004 | walker->count++; | |
1005 | } | |
1006 | } | |
1007 | ||
1008 | static const struct Qdisc_class_ops netem_class_ops = { | |
1009 | .graft = netem_graft, | |
1010 | .leaf = netem_leaf, | |
1011 | .get = netem_get, | |
1012 | .put = netem_put, | |
1013 | .walk = netem_walk, | |
1014 | .dump = netem_dump_class, | |
1015 | }; | |
1016 | ||
20fea08b | 1017 | static struct Qdisc_ops netem_qdisc_ops __read_mostly = { |
1da177e4 | 1018 | .id = "netem", |
10f6dfcf | 1019 | .cl_ops = &netem_class_ops, |
1da177e4 LT |
1020 | .priv_size = sizeof(struct netem_sched_data), |
1021 | .enqueue = netem_enqueue, | |
1022 | .dequeue = netem_dequeue, | |
77be155c | 1023 | .peek = qdisc_peek_dequeued, |
1da177e4 LT |
1024 | .drop = netem_drop, |
1025 | .init = netem_init, | |
1026 | .reset = netem_reset, | |
1027 | .destroy = netem_destroy, | |
1028 | .change = netem_change, | |
1029 | .dump = netem_dump, | |
1030 | .owner = THIS_MODULE, | |
1031 | }; | |
1032 | ||
1033 | ||
1034 | static int __init netem_module_init(void) | |
1035 | { | |
eb229c4c | 1036 | pr_info("netem: version " VERSION "\n"); |
1da177e4 LT |
1037 | return register_qdisc(&netem_qdisc_ops); |
1038 | } | |
1039 | static void __exit netem_module_exit(void) | |
1040 | { | |
1041 | unregister_qdisc(&netem_qdisc_ops); | |
1042 | } | |
1043 | module_init(netem_module_init) | |
1044 | module_exit(netem_module_exit) | |
1045 | MODULE_LICENSE("GPL"); |