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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 | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Many of the algorithms and ideas for this came from | |
10 | * NIST Net which is not copyrighted. | |
11 | * | |
12 | * Authors: Stephen Hemminger <shemminger@osdl.org> | |
13 | * Catalin(ux aka Dino) BOIE <catab at umbrella dot ro> | |
14 | */ | |
15 | ||
1da177e4 LT |
16 | #include <linux/module.h> |
17 | #include <linux/bitops.h> | |
18 | #include <linux/types.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/errno.h> | |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/skbuff.h> | |
23 | #include <linux/rtnetlink.h> | |
24 | ||
25 | #include <net/pkt_sched.h> | |
26 | ||
c865e5d9 | 27 | #define VERSION "1.2" |
eb229c4c | 28 | |
1da177e4 LT |
29 | /* Network Emulation Queuing algorithm. |
30 | ==================================== | |
31 | ||
32 | Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based | |
33 | Network Emulation Tool | |
34 | [2] Luigi Rizzo, DummyNet for FreeBSD | |
35 | ||
36 | ---------------------------------------------------------------- | |
37 | ||
38 | This started out as a simple way to delay outgoing packets to | |
39 | test TCP but has grown to include most of the functionality | |
40 | of a full blown network emulator like NISTnet. It can delay | |
41 | packets and add random jitter (and correlation). The random | |
42 | distribution can be loaded from a table as well to provide | |
43 | normal, Pareto, or experimental curves. Packet loss, | |
44 | duplication, and reordering can also be emulated. | |
45 | ||
46 | This qdisc does not do classification that can be handled in | |
47 | layering other disciplines. It does not need to do bandwidth | |
48 | control either since that can be handled by using token | |
49 | bucket or other rate control. | |
50 | ||
51 | The simulator is limited by the Linux timer resolution | |
52 | and will create packet bursts on the HZ boundary (1ms). | |
53 | */ | |
54 | ||
55 | struct netem_sched_data { | |
56 | struct Qdisc *qdisc; | |
1da177e4 LT |
57 | struct timer_list timer; |
58 | ||
59 | u32 latency; | |
60 | u32 loss; | |
61 | u32 limit; | |
62 | u32 counter; | |
63 | u32 gap; | |
64 | u32 jitter; | |
65 | u32 duplicate; | |
0dca51d3 | 66 | u32 reorder; |
c865e5d9 | 67 | u32 corrupt; |
1da177e4 LT |
68 | |
69 | struct crndstate { | |
70 | unsigned long last; | |
71 | unsigned long rho; | |
c865e5d9 | 72 | } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor; |
1da177e4 LT |
73 | |
74 | struct disttable { | |
75 | u32 size; | |
76 | s16 table[0]; | |
77 | } *delay_dist; | |
78 | }; | |
79 | ||
80 | /* Time stamp put into socket buffer control block */ | |
81 | struct netem_skb_cb { | |
82 | psched_time_t time_to_send; | |
83 | }; | |
84 | ||
85 | /* init_crandom - initialize correlated random number generator | |
86 | * Use entropy source for initial seed. | |
87 | */ | |
88 | static void init_crandom(struct crndstate *state, unsigned long rho) | |
89 | { | |
90 | state->rho = rho; | |
91 | state->last = net_random(); | |
92 | } | |
93 | ||
94 | /* get_crandom - correlated random number generator | |
95 | * Next number depends on last value. | |
96 | * rho is scaled to avoid floating point. | |
97 | */ | |
98 | static unsigned long get_crandom(struct crndstate *state) | |
99 | { | |
100 | u64 value, rho; | |
101 | unsigned long answer; | |
102 | ||
103 | if (state->rho == 0) /* no correllation */ | |
104 | return net_random(); | |
105 | ||
106 | value = net_random(); | |
107 | rho = (u64)state->rho + 1; | |
108 | answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32; | |
109 | state->last = answer; | |
110 | return answer; | |
111 | } | |
112 | ||
113 | /* tabledist - return a pseudo-randomly distributed value with mean mu and | |
114 | * std deviation sigma. Uses table lookup to approximate the desired | |
115 | * distribution, and a uniformly-distributed pseudo-random source. | |
116 | */ | |
117 | static long tabledist(unsigned long mu, long sigma, | |
118 | struct crndstate *state, const struct disttable *dist) | |
119 | { | |
120 | long t, x; | |
121 | unsigned long rnd; | |
122 | ||
123 | if (sigma == 0) | |
124 | return mu; | |
125 | ||
126 | rnd = get_crandom(state); | |
127 | ||
128 | /* default uniform distribution */ | |
129 | if (dist == NULL) | |
130 | return (rnd % (2*sigma)) - sigma + mu; | |
131 | ||
132 | t = dist->table[rnd % dist->size]; | |
133 | x = (sigma % NETEM_DIST_SCALE) * t; | |
134 | if (x >= 0) | |
135 | x += NETEM_DIST_SCALE/2; | |
136 | else | |
137 | x -= NETEM_DIST_SCALE/2; | |
138 | ||
139 | return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu; | |
140 | } | |
141 | ||
0afb51e7 SH |
142 | /* |
143 | * Insert one skb into qdisc. | |
144 | * Note: parent depends on return value to account for queue length. | |
145 | * NET_XMIT_DROP: queue length didn't change. | |
146 | * NET_XMIT_SUCCESS: one skb was queued. | |
147 | */ | |
1da177e4 LT |
148 | static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
149 | { | |
150 | struct netem_sched_data *q = qdisc_priv(sch); | |
0f9f32ac | 151 | struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb; |
0afb51e7 | 152 | struct sk_buff *skb2; |
1da177e4 | 153 | int ret; |
0afb51e7 | 154 | int count = 1; |
1da177e4 | 155 | |
771018e7 | 156 | pr_debug("netem_enqueue skb=%p\n", skb); |
1da177e4 | 157 | |
0afb51e7 SH |
158 | /* Random duplication */ |
159 | if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) | |
160 | ++count; | |
161 | ||
1da177e4 | 162 | /* Random packet drop 0 => none, ~0 => all */ |
0afb51e7 SH |
163 | if (q->loss && q->loss >= get_crandom(&q->loss_cor)) |
164 | --count; | |
165 | ||
166 | if (count == 0) { | |
1da177e4 LT |
167 | sch->qstats.drops++; |
168 | kfree_skb(skb); | |
89bbb0a3 | 169 | return NET_XMIT_BYPASS; |
1da177e4 LT |
170 | } |
171 | ||
0afb51e7 SH |
172 | /* |
173 | * If we need to duplicate packet, then re-insert at top of the | |
174 | * qdisc tree, since parent queuer expects that only one | |
175 | * skb will be queued. | |
176 | */ | |
177 | if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { | |
178 | struct Qdisc *rootq = sch->dev->qdisc; | |
179 | u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ | |
180 | q->duplicate = 0; | |
181 | ||
182 | rootq->enqueue(skb2, rootq); | |
183 | q->duplicate = dupsave; | |
1da177e4 LT |
184 | } |
185 | ||
c865e5d9 SH |
186 | /* |
187 | * Randomized packet corruption. | |
188 | * Make copy if needed since we are modifying | |
189 | * If packet is going to be hardware checksummed, then | |
190 | * do it now in software before we mangle it. | |
191 | */ | |
192 | if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) { | |
193 | if (!(skb = skb_unshare(skb, GFP_ATOMIC)) | |
194 | || (skb->ip_summed == CHECKSUM_HW | |
195 | && skb_checksum_help(skb, 0))) { | |
196 | sch->qstats.drops++; | |
197 | return NET_XMIT_DROP; | |
198 | } | |
199 | ||
200 | skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8); | |
201 | } | |
202 | ||
0dca51d3 SH |
203 | if (q->gap == 0 /* not doing reordering */ |
204 | || q->counter < q->gap /* inside last reordering gap */ | |
205 | || q->reorder < get_crandom(&q->reorder_cor)) { | |
0f9f32ac | 206 | psched_time_t now; |
07aaa115 SH |
207 | psched_tdiff_t delay; |
208 | ||
209 | delay = tabledist(q->latency, q->jitter, | |
210 | &q->delay_cor, q->delay_dist); | |
211 | ||
0f9f32ac | 212 | PSCHED_GET_TIME(now); |
07aaa115 | 213 | PSCHED_TADD2(now, delay, cb->time_to_send); |
1da177e4 LT |
214 | ++q->counter; |
215 | ret = q->qdisc->enqueue(skb, q->qdisc); | |
216 | } else { | |
0dca51d3 SH |
217 | /* |
218 | * Do re-ordering by putting one out of N packets at the front | |
219 | * of the queue. | |
220 | */ | |
0f9f32ac | 221 | PSCHED_GET_TIME(cb->time_to_send); |
0dca51d3 | 222 | q->counter = 0; |
0f9f32ac | 223 | ret = q->qdisc->ops->requeue(skb, q->qdisc); |
1da177e4 LT |
224 | } |
225 | ||
226 | if (likely(ret == NET_XMIT_SUCCESS)) { | |
227 | sch->q.qlen++; | |
228 | sch->bstats.bytes += skb->len; | |
229 | sch->bstats.packets++; | |
230 | } else | |
231 | sch->qstats.drops++; | |
232 | ||
d5d75cd6 | 233 | pr_debug("netem: enqueue ret %d\n", ret); |
1da177e4 LT |
234 | return ret; |
235 | } | |
236 | ||
237 | /* Requeue packets but don't change time stamp */ | |
238 | static int netem_requeue(struct sk_buff *skb, struct Qdisc *sch) | |
239 | { | |
240 | struct netem_sched_data *q = qdisc_priv(sch); | |
241 | int ret; | |
242 | ||
243 | if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0) { | |
244 | sch->q.qlen++; | |
245 | sch->qstats.requeues++; | |
246 | } | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | static unsigned int netem_drop(struct Qdisc* sch) | |
252 | { | |
253 | struct netem_sched_data *q = qdisc_priv(sch); | |
6d037a26 | 254 | unsigned int len = 0; |
1da177e4 | 255 | |
6d037a26 | 256 | if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) { |
1da177e4 LT |
257 | sch->q.qlen--; |
258 | sch->qstats.drops++; | |
259 | } | |
260 | return len; | |
261 | } | |
262 | ||
1da177e4 LT |
263 | static struct sk_buff *netem_dequeue(struct Qdisc *sch) |
264 | { | |
265 | struct netem_sched_data *q = qdisc_priv(sch); | |
266 | struct sk_buff *skb; | |
267 | ||
268 | skb = q->qdisc->dequeue(q->qdisc); | |
771018e7 | 269 | if (skb) { |
0f9f32ac SH |
270 | const struct netem_skb_cb *cb |
271 | = (const struct netem_skb_cb *)skb->cb; | |
272 | psched_time_t now; | |
0f9f32ac SH |
273 | |
274 | /* if more time remaining? */ | |
275 | PSCHED_GET_TIME(now); | |
07aaa115 SH |
276 | |
277 | if (PSCHED_TLESS(cb->time_to_send, now)) { | |
0f9f32ac SH |
278 | pr_debug("netem_dequeue: return skb=%p\n", skb); |
279 | sch->q.qlen--; | |
280 | sch->flags &= ~TCQ_F_THROTTLED; | |
281 | return skb; | |
07aaa115 SH |
282 | } else { |
283 | psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now); | |
0f9f32ac | 284 | |
07aaa115 SH |
285 | if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) { |
286 | sch->qstats.drops++; | |
771018e7 | 287 | |
07aaa115 SH |
288 | /* After this qlen is confused */ |
289 | printk(KERN_ERR "netem: queue discpline %s could not requeue\n", | |
290 | q->qdisc->ops->id); | |
291 | ||
292 | sch->q.qlen--; | |
293 | } | |
294 | ||
295 | mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay)); | |
296 | sch->flags |= TCQ_F_THROTTLED; | |
297 | } | |
0f9f32ac SH |
298 | } |
299 | ||
300 | return NULL; | |
1da177e4 LT |
301 | } |
302 | ||
303 | static void netem_watchdog(unsigned long arg) | |
304 | { | |
305 | struct Qdisc *sch = (struct Qdisc *)arg; | |
1da177e4 | 306 | |
771018e7 SH |
307 | pr_debug("netem_watchdog qlen=%d\n", sch->q.qlen); |
308 | sch->flags &= ~TCQ_F_THROTTLED; | |
309 | netif_schedule(sch->dev); | |
1da177e4 LT |
310 | } |
311 | ||
312 | static void netem_reset(struct Qdisc *sch) | |
313 | { | |
314 | struct netem_sched_data *q = qdisc_priv(sch); | |
315 | ||
316 | qdisc_reset(q->qdisc); | |
1da177e4 | 317 | sch->q.qlen = 0; |
771018e7 | 318 | sch->flags &= ~TCQ_F_THROTTLED; |
1da177e4 LT |
319 | del_timer_sync(&q->timer); |
320 | } | |
321 | ||
300ce174 | 322 | /* Pass size change message down to embedded FIFO */ |
1da177e4 LT |
323 | static int set_fifo_limit(struct Qdisc *q, int limit) |
324 | { | |
325 | struct rtattr *rta; | |
326 | int ret = -ENOMEM; | |
327 | ||
300ce174 SH |
328 | /* Hack to avoid sending change message to non-FIFO */ |
329 | if (strncmp(q->ops->id + 1, "fifo", 4) != 0) | |
330 | return 0; | |
331 | ||
1da177e4 LT |
332 | rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL); |
333 | if (rta) { | |
334 | rta->rta_type = RTM_NEWQDISC; | |
335 | rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt)); | |
336 | ((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit; | |
337 | ||
338 | ret = q->ops->change(q, rta); | |
339 | kfree(rta); | |
340 | } | |
341 | return ret; | |
342 | } | |
343 | ||
344 | /* | |
345 | * Distribution data is a variable size payload containing | |
346 | * signed 16 bit values. | |
347 | */ | |
348 | static int get_dist_table(struct Qdisc *sch, const struct rtattr *attr) | |
349 | { | |
350 | struct netem_sched_data *q = qdisc_priv(sch); | |
351 | unsigned long n = RTA_PAYLOAD(attr)/sizeof(__s16); | |
352 | const __s16 *data = RTA_DATA(attr); | |
353 | struct disttable *d; | |
354 | int i; | |
355 | ||
356 | if (n > 65536) | |
357 | return -EINVAL; | |
358 | ||
359 | d = kmalloc(sizeof(*d) + n*sizeof(d->table[0]), GFP_KERNEL); | |
360 | if (!d) | |
361 | return -ENOMEM; | |
362 | ||
363 | d->size = n; | |
364 | for (i = 0; i < n; i++) | |
365 | d->table[i] = data[i]; | |
366 | ||
367 | spin_lock_bh(&sch->dev->queue_lock); | |
368 | d = xchg(&q->delay_dist, d); | |
369 | spin_unlock_bh(&sch->dev->queue_lock); | |
370 | ||
371 | kfree(d); | |
372 | return 0; | |
373 | } | |
374 | ||
375 | static int get_correlation(struct Qdisc *sch, const struct rtattr *attr) | |
376 | { | |
377 | struct netem_sched_data *q = qdisc_priv(sch); | |
378 | const struct tc_netem_corr *c = RTA_DATA(attr); | |
379 | ||
380 | if (RTA_PAYLOAD(attr) != sizeof(*c)) | |
381 | return -EINVAL; | |
382 | ||
383 | init_crandom(&q->delay_cor, c->delay_corr); | |
384 | init_crandom(&q->loss_cor, c->loss_corr); | |
385 | init_crandom(&q->dup_cor, c->dup_corr); | |
386 | return 0; | |
387 | } | |
388 | ||
0dca51d3 SH |
389 | static int get_reorder(struct Qdisc *sch, const struct rtattr *attr) |
390 | { | |
391 | struct netem_sched_data *q = qdisc_priv(sch); | |
392 | const struct tc_netem_reorder *r = RTA_DATA(attr); | |
393 | ||
394 | if (RTA_PAYLOAD(attr) != sizeof(*r)) | |
395 | return -EINVAL; | |
396 | ||
397 | q->reorder = r->probability; | |
398 | init_crandom(&q->reorder_cor, r->correlation); | |
399 | return 0; | |
400 | } | |
401 | ||
c865e5d9 SH |
402 | static int get_corrupt(struct Qdisc *sch, const struct rtattr *attr) |
403 | { | |
404 | struct netem_sched_data *q = qdisc_priv(sch); | |
405 | const struct tc_netem_corrupt *r = RTA_DATA(attr); | |
406 | ||
407 | if (RTA_PAYLOAD(attr) != sizeof(*r)) | |
408 | return -EINVAL; | |
409 | ||
410 | q->corrupt = r->probability; | |
411 | init_crandom(&q->corrupt_cor, r->correlation); | |
412 | return 0; | |
413 | } | |
414 | ||
415 | /* Parse netlink message to set options */ | |
1da177e4 LT |
416 | static int netem_change(struct Qdisc *sch, struct rtattr *opt) |
417 | { | |
418 | struct netem_sched_data *q = qdisc_priv(sch); | |
419 | struct tc_netem_qopt *qopt; | |
420 | int ret; | |
421 | ||
422 | if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt)) | |
423 | return -EINVAL; | |
424 | ||
425 | qopt = RTA_DATA(opt); | |
426 | ret = set_fifo_limit(q->qdisc, qopt->limit); | |
427 | if (ret) { | |
428 | pr_debug("netem: can't set fifo limit\n"); | |
429 | return ret; | |
430 | } | |
431 | ||
432 | q->latency = qopt->latency; | |
433 | q->jitter = qopt->jitter; | |
434 | q->limit = qopt->limit; | |
435 | q->gap = qopt->gap; | |
0dca51d3 | 436 | q->counter = 0; |
1da177e4 LT |
437 | q->loss = qopt->loss; |
438 | q->duplicate = qopt->duplicate; | |
439 | ||
0dca51d3 SH |
440 | /* for compatiablity with earlier versions. |
441 | * if gap is set, need to assume 100% probablity | |
442 | */ | |
443 | q->reorder = ~0; | |
444 | ||
1da177e4 LT |
445 | /* Handle nested options after initial queue options. |
446 | * Should have put all options in nested format but too late now. | |
447 | */ | |
448 | if (RTA_PAYLOAD(opt) > sizeof(*qopt)) { | |
449 | struct rtattr *tb[TCA_NETEM_MAX]; | |
450 | if (rtattr_parse(tb, TCA_NETEM_MAX, | |
451 | RTA_DATA(opt) + sizeof(*qopt), | |
452 | RTA_PAYLOAD(opt) - sizeof(*qopt))) | |
453 | return -EINVAL; | |
454 | ||
455 | if (tb[TCA_NETEM_CORR-1]) { | |
456 | ret = get_correlation(sch, tb[TCA_NETEM_CORR-1]); | |
457 | if (ret) | |
458 | return ret; | |
459 | } | |
460 | ||
461 | if (tb[TCA_NETEM_DELAY_DIST-1]) { | |
462 | ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST-1]); | |
463 | if (ret) | |
464 | return ret; | |
465 | } | |
c865e5d9 | 466 | |
0dca51d3 SH |
467 | if (tb[TCA_NETEM_REORDER-1]) { |
468 | ret = get_reorder(sch, tb[TCA_NETEM_REORDER-1]); | |
469 | if (ret) | |
470 | return ret; | |
471 | } | |
1da177e4 | 472 | |
c865e5d9 SH |
473 | if (tb[TCA_NETEM_CORRUPT-1]) { |
474 | ret = get_corrupt(sch, tb[TCA_NETEM_CORRUPT-1]); | |
475 | if (ret) | |
476 | return ret; | |
477 | } | |
478 | } | |
1da177e4 LT |
479 | |
480 | return 0; | |
481 | } | |
482 | ||
300ce174 SH |
483 | /* |
484 | * Special case version of FIFO queue for use by netem. | |
485 | * It queues in order based on timestamps in skb's | |
486 | */ | |
487 | struct fifo_sched_data { | |
488 | u32 limit; | |
489 | }; | |
490 | ||
491 | static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) | |
492 | { | |
493 | struct fifo_sched_data *q = qdisc_priv(sch); | |
494 | struct sk_buff_head *list = &sch->q; | |
495 | const struct netem_skb_cb *ncb | |
496 | = (const struct netem_skb_cb *)nskb->cb; | |
497 | struct sk_buff *skb; | |
498 | ||
499 | if (likely(skb_queue_len(list) < q->limit)) { | |
500 | skb_queue_reverse_walk(list, skb) { | |
501 | const struct netem_skb_cb *cb | |
502 | = (const struct netem_skb_cb *)skb->cb; | |
503 | ||
aa875166 | 504 | if (!PSCHED_TLESS(ncb->time_to_send, cb->time_to_send)) |
300ce174 SH |
505 | break; |
506 | } | |
507 | ||
508 | __skb_queue_after(list, skb, nskb); | |
509 | ||
510 | sch->qstats.backlog += nskb->len; | |
511 | sch->bstats.bytes += nskb->len; | |
512 | sch->bstats.packets++; | |
513 | ||
514 | return NET_XMIT_SUCCESS; | |
515 | } | |
516 | ||
517 | return qdisc_drop(nskb, sch); | |
518 | } | |
519 | ||
520 | static int tfifo_init(struct Qdisc *sch, struct rtattr *opt) | |
521 | { | |
522 | struct fifo_sched_data *q = qdisc_priv(sch); | |
523 | ||
524 | if (opt) { | |
525 | struct tc_fifo_qopt *ctl = RTA_DATA(opt); | |
526 | if (RTA_PAYLOAD(opt) < sizeof(*ctl)) | |
527 | return -EINVAL; | |
528 | ||
529 | q->limit = ctl->limit; | |
530 | } else | |
531 | q->limit = max_t(u32, sch->dev->tx_queue_len, 1); | |
532 | ||
533 | return 0; | |
534 | } | |
535 | ||
536 | static int tfifo_dump(struct Qdisc *sch, struct sk_buff *skb) | |
537 | { | |
538 | struct fifo_sched_data *q = qdisc_priv(sch); | |
539 | struct tc_fifo_qopt opt = { .limit = q->limit }; | |
540 | ||
541 | RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); | |
542 | return skb->len; | |
543 | ||
544 | rtattr_failure: | |
545 | return -1; | |
546 | } | |
547 | ||
548 | static struct Qdisc_ops tfifo_qdisc_ops = { | |
549 | .id = "tfifo", | |
550 | .priv_size = sizeof(struct fifo_sched_data), | |
551 | .enqueue = tfifo_enqueue, | |
552 | .dequeue = qdisc_dequeue_head, | |
553 | .requeue = qdisc_requeue, | |
554 | .drop = qdisc_queue_drop, | |
555 | .init = tfifo_init, | |
556 | .reset = qdisc_reset_queue, | |
557 | .change = tfifo_init, | |
558 | .dump = tfifo_dump, | |
559 | }; | |
560 | ||
1da177e4 LT |
561 | static int netem_init(struct Qdisc *sch, struct rtattr *opt) |
562 | { | |
563 | struct netem_sched_data *q = qdisc_priv(sch); | |
564 | int ret; | |
565 | ||
566 | if (!opt) | |
567 | return -EINVAL; | |
568 | ||
1da177e4 LT |
569 | init_timer(&q->timer); |
570 | q->timer.function = netem_watchdog; | |
571 | q->timer.data = (unsigned long) sch; | |
1da177e4 | 572 | |
300ce174 | 573 | q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops); |
1da177e4 LT |
574 | if (!q->qdisc) { |
575 | pr_debug("netem: qdisc create failed\n"); | |
576 | return -ENOMEM; | |
577 | } | |
578 | ||
579 | ret = netem_change(sch, opt); | |
580 | if (ret) { | |
581 | pr_debug("netem: change failed\n"); | |
582 | qdisc_destroy(q->qdisc); | |
583 | } | |
584 | return ret; | |
585 | } | |
586 | ||
587 | static void netem_destroy(struct Qdisc *sch) | |
588 | { | |
589 | struct netem_sched_data *q = qdisc_priv(sch); | |
590 | ||
591 | del_timer_sync(&q->timer); | |
592 | qdisc_destroy(q->qdisc); | |
593 | kfree(q->delay_dist); | |
594 | } | |
595 | ||
596 | static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) | |
597 | { | |
598 | const struct netem_sched_data *q = qdisc_priv(sch); | |
599 | unsigned char *b = skb->tail; | |
600 | struct rtattr *rta = (struct rtattr *) b; | |
601 | struct tc_netem_qopt qopt; | |
602 | struct tc_netem_corr cor; | |
0dca51d3 | 603 | struct tc_netem_reorder reorder; |
c865e5d9 | 604 | struct tc_netem_corrupt corrupt; |
1da177e4 LT |
605 | |
606 | qopt.latency = q->latency; | |
607 | qopt.jitter = q->jitter; | |
608 | qopt.limit = q->limit; | |
609 | qopt.loss = q->loss; | |
610 | qopt.gap = q->gap; | |
611 | qopt.duplicate = q->duplicate; | |
612 | RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt); | |
613 | ||
614 | cor.delay_corr = q->delay_cor.rho; | |
615 | cor.loss_corr = q->loss_cor.rho; | |
616 | cor.dup_corr = q->dup_cor.rho; | |
617 | RTA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor); | |
0dca51d3 SH |
618 | |
619 | reorder.probability = q->reorder; | |
620 | reorder.correlation = q->reorder_cor.rho; | |
621 | RTA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder); | |
622 | ||
c865e5d9 SH |
623 | corrupt.probability = q->corrupt; |
624 | corrupt.correlation = q->corrupt_cor.rho; | |
625 | RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt); | |
626 | ||
1da177e4 LT |
627 | rta->rta_len = skb->tail - b; |
628 | ||
629 | return skb->len; | |
630 | ||
631 | rtattr_failure: | |
632 | skb_trim(skb, b - skb->data); | |
633 | return -1; | |
634 | } | |
635 | ||
636 | static int netem_dump_class(struct Qdisc *sch, unsigned long cl, | |
637 | struct sk_buff *skb, struct tcmsg *tcm) | |
638 | { | |
639 | struct netem_sched_data *q = qdisc_priv(sch); | |
640 | ||
641 | if (cl != 1) /* only one class */ | |
642 | return -ENOENT; | |
643 | ||
644 | tcm->tcm_handle |= TC_H_MIN(1); | |
645 | tcm->tcm_info = q->qdisc->handle; | |
646 | ||
647 | return 0; | |
648 | } | |
649 | ||
650 | static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
651 | struct Qdisc **old) | |
652 | { | |
653 | struct netem_sched_data *q = qdisc_priv(sch); | |
654 | ||
655 | if (new == NULL) | |
656 | new = &noop_qdisc; | |
657 | ||
658 | sch_tree_lock(sch); | |
659 | *old = xchg(&q->qdisc, new); | |
660 | qdisc_reset(*old); | |
661 | sch->q.qlen = 0; | |
662 | sch_tree_unlock(sch); | |
663 | ||
664 | return 0; | |
665 | } | |
666 | ||
667 | static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg) | |
668 | { | |
669 | struct netem_sched_data *q = qdisc_priv(sch); | |
670 | return q->qdisc; | |
671 | } | |
672 | ||
673 | static unsigned long netem_get(struct Qdisc *sch, u32 classid) | |
674 | { | |
675 | return 1; | |
676 | } | |
677 | ||
678 | static void netem_put(struct Qdisc *sch, unsigned long arg) | |
679 | { | |
680 | } | |
681 | ||
682 | static int netem_change_class(struct Qdisc *sch, u32 classid, u32 parentid, | |
683 | struct rtattr **tca, unsigned long *arg) | |
684 | { | |
685 | return -ENOSYS; | |
686 | } | |
687 | ||
688 | static int netem_delete(struct Qdisc *sch, unsigned long arg) | |
689 | { | |
690 | return -ENOSYS; | |
691 | } | |
692 | ||
693 | static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker) | |
694 | { | |
695 | if (!walker->stop) { | |
696 | if (walker->count >= walker->skip) | |
697 | if (walker->fn(sch, 1, walker) < 0) { | |
698 | walker->stop = 1; | |
699 | return; | |
700 | } | |
701 | walker->count++; | |
702 | } | |
703 | } | |
704 | ||
705 | static struct tcf_proto **netem_find_tcf(struct Qdisc *sch, unsigned long cl) | |
706 | { | |
707 | return NULL; | |
708 | } | |
709 | ||
710 | static struct Qdisc_class_ops netem_class_ops = { | |
711 | .graft = netem_graft, | |
712 | .leaf = netem_leaf, | |
713 | .get = netem_get, | |
714 | .put = netem_put, | |
715 | .change = netem_change_class, | |
716 | .delete = netem_delete, | |
717 | .walk = netem_walk, | |
718 | .tcf_chain = netem_find_tcf, | |
719 | .dump = netem_dump_class, | |
720 | }; | |
721 | ||
722 | static struct Qdisc_ops netem_qdisc_ops = { | |
723 | .id = "netem", | |
724 | .cl_ops = &netem_class_ops, | |
725 | .priv_size = sizeof(struct netem_sched_data), | |
726 | .enqueue = netem_enqueue, | |
727 | .dequeue = netem_dequeue, | |
728 | .requeue = netem_requeue, | |
729 | .drop = netem_drop, | |
730 | .init = netem_init, | |
731 | .reset = netem_reset, | |
732 | .destroy = netem_destroy, | |
733 | .change = netem_change, | |
734 | .dump = netem_dump, | |
735 | .owner = THIS_MODULE, | |
736 | }; | |
737 | ||
738 | ||
739 | static int __init netem_module_init(void) | |
740 | { | |
eb229c4c | 741 | pr_info("netem: version " VERSION "\n"); |
1da177e4 LT |
742 | return register_qdisc(&netem_qdisc_ops); |
743 | } | |
744 | static void __exit netem_module_exit(void) | |
745 | { | |
746 | unregister_qdisc(&netem_qdisc_ops); | |
747 | } | |
748 | module_init(netem_module_init) | |
749 | module_exit(netem_module_exit) | |
750 | MODULE_LICENSE("GPL"); |