xref: /freebsd/sys/netpfil/ipfw/dn_sched_fq_pie.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*
2  * FQ_PIE - The FlowQueue-PIE scheduler/AQM
3  *
4  * Copyright (C) 2016 Centre for Advanced Internet Architectures,
5  *  Swinburne University of Technology, Melbourne, Australia.
6  * Portions of this code were made possible in part by a gift from
7  *  The Comcast Innovation Fund.
8  * Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au>
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /* Important note:
33  * As there is no an office document for FQ-PIE specification, we used
34  * FQ-CoDel algorithm with some modifications to implement FQ-PIE.
35  * This FQ-PIE implementation is a beta version and have not been tested
36  * extensively. Our FQ-PIE uses stand-alone PIE AQM per sub-queue. By
37  * default, timestamp is used to calculate queue delay instead of departure
38  * rate estimation method. Although departure rate estimation is available
39  * as testing option, the results could be incorrect. Moreover, turning PIE on
40  * and off option is available but it does not work properly in this version.
41  */
42 
43 #ifdef _KERNEL
44 #include <sys/malloc.h>
45 #include <sys/socket.h>
46 #include <sys/kernel.h>
47 #include <sys/mbuf.h>
48 #include <sys/lock.h>
49 #include <sys/module.h>
50 #include <sys/mutex.h>
51 #include <net/if.h>	/* IFNAMSIZ */
52 #include <netinet/in.h>
53 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
54 #include <netinet/ip_fw.h>	/* flow_id */
55 #include <netinet/ip_dummynet.h>
56 
57 #include <sys/proc.h>
58 #include <sys/rwlock.h>
59 
60 #include <netpfil/ipfw/ip_fw_private.h>
61 #include <sys/sysctl.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip6.h>
64 #include <netinet/ip_icmp.h>
65 #include <netinet/tcp.h>
66 #include <netinet/udp.h>
67 #include <sys/queue.h>
68 #include <sys/hash.h>
69 
70 #include <netpfil/ipfw/dn_heap.h>
71 #include <netpfil/ipfw/ip_dn_private.h>
72 
73 #include <netpfil/ipfw/dn_aqm.h>
74 #include <netpfil/ipfw/dn_aqm_pie.h>
75 #include <netpfil/ipfw/dn_sched.h>
76 
77 #else
78 #include <dn_test.h>
79 #endif
80 
81 #define DN_SCHED_FQ_PIE 7
82 
83 /* list of queues */
84 STAILQ_HEAD(fq_pie_list, fq_pie_flow);
85 
86 /* FQ_PIE parameters including PIE */
87 struct dn_sch_fq_pie_parms {
88 	struct dn_aqm_pie_parms	pcfg;	/* PIE configuration Parameters */
89 	/* FQ_PIE Parameters */
90 	uint32_t flows_cnt;	/* number of flows */
91 	uint32_t limit;	/* hard limit of FQ_PIE queue size*/
92 	uint32_t quantum;
93 };
94 
95 /* flow (sub-queue) stats */
96 struct flow_stats {
97 	uint64_t tot_pkts;	/* statistics counters  */
98 	uint64_t tot_bytes;
99 	uint32_t length;		/* Queue length, in packets */
100 	uint32_t len_bytes;	/* Queue length, in bytes */
101 	uint32_t drops;
102 };
103 
104 /* A flow of packets (sub-queue)*/
105 struct fq_pie_flow {
106 	struct mq	mq;	/* list of packets */
107 	struct flow_stats stats;	/* statistics */
108 	int deficit;
109 	int active;		/* 1: flow is active (in a list) */
110 	struct pie_status pst;	/* pie status variables */
111 	struct fq_pie_si_extra *psi_extra;
112 	STAILQ_ENTRY(fq_pie_flow) flowchain;
113 };
114 
115 /* extra fq_pie scheduler configurations */
116 struct fq_pie_schk {
117 	struct dn_sch_fq_pie_parms cfg;
118 };
119 
120 /* fq_pie scheduler instance extra state vars.
121  * The purpose of separation this structure is to preserve number of active
122  * sub-queues and the flows array pointer even after the scheduler instance
123  * is destroyed.
124  * Preserving these varaiables allows freeing the allocated memory by
125  * fqpie_callout_cleanup() independently from fq_pie_free_sched().
126  */
127 struct fq_pie_si_extra {
128 	uint32_t nr_active_q;	/* number of active queues */
129 	struct fq_pie_flow *flows;	/* array of flows (queues) */
130 	};
131 
132 /* fq_pie scheduler instance */
133 struct fq_pie_si {
134 	struct dn_sch_inst _si;	/* standard scheduler instance. SHOULD BE FIRST */
135 	struct dn_queue main_q; /* main queue is after si directly */
136 	uint32_t perturbation; 	/* random value */
137 	struct fq_pie_list newflows;	/* list of new queues */
138 	struct fq_pie_list oldflows;	/* list of old queues */
139 	struct fq_pie_si_extra *si_extra; /* extra state vars*/
140 };
141 
142 static struct dn_alg fq_pie_desc;
143 
144 /*  Default FQ-PIE parameters including PIE */
145 /*  PIE defaults
146  * target=15ms, max_burst=150ms, max_ecnth=0.1,
147  * alpha=0.125, beta=1.25, tupdate=15ms
148  * FQ-
149  * flows=1024, limit=10240, quantum =1514
150  */
151 struct dn_sch_fq_pie_parms
152  fq_pie_sysctl = {{15000 * AQM_TIME_1US, 15000 * AQM_TIME_1US,
153 	150000 * AQM_TIME_1US, PIE_SCALE * 0.1, PIE_SCALE * 0.125,
154 	PIE_SCALE * 1.25,	PIE_CAPDROP_ENABLED | PIE_DERAND_ENABLED},
155 	1024, 10240, 1514};
156 
157 static int
158 fqpie_sysctl_alpha_beta_handler(SYSCTL_HANDLER_ARGS)
159 {
160 	int error;
161 	long  value;
162 
163 	if (!strcmp(oidp->oid_name,"alpha"))
164 		value = fq_pie_sysctl.pcfg.alpha;
165 	else
166 		value = fq_pie_sysctl.pcfg.beta;
167 
168 	value = value * 1000 / PIE_SCALE;
169 	error = sysctl_handle_long(oidp, &value, 0, req);
170 	if (error != 0 || req->newptr == NULL)
171 		return (error);
172 	if (value < 1 || value > 7 * PIE_SCALE)
173 		return (EINVAL);
174 	value = (value * PIE_SCALE) / 1000;
175 	if (!strcmp(oidp->oid_name,"alpha"))
176 			fq_pie_sysctl.pcfg.alpha = value;
177 	else
178 		fq_pie_sysctl.pcfg.beta = value;
179 	return (0);
180 }
181 
182 static int
183 fqpie_sysctl_target_tupdate_maxb_handler(SYSCTL_HANDLER_ARGS)
184 {
185 	int error;
186 	long  value;
187 
188 	if (!strcmp(oidp->oid_name,"target"))
189 		value = fq_pie_sysctl.pcfg.qdelay_ref;
190 	else if (!strcmp(oidp->oid_name,"tupdate"))
191 		value = fq_pie_sysctl.pcfg.tupdate;
192 	else
193 		value = fq_pie_sysctl.pcfg.max_burst;
194 
195 	value = value / AQM_TIME_1US;
196 	error = sysctl_handle_long(oidp, &value, 0, req);
197 	if (error != 0 || req->newptr == NULL)
198 		return (error);
199 	if (value < 1 || value > 10 * AQM_TIME_1S)
200 		return (EINVAL);
201 	value = value * AQM_TIME_1US;
202 
203 	if (!strcmp(oidp->oid_name,"target"))
204 		fq_pie_sysctl.pcfg.qdelay_ref  = value;
205 	else if (!strcmp(oidp->oid_name,"tupdate"))
206 		fq_pie_sysctl.pcfg.tupdate  = value;
207 	else
208 		fq_pie_sysctl.pcfg.max_burst = value;
209 	return (0);
210 }
211 
212 static int
213 fqpie_sysctl_max_ecnth_handler(SYSCTL_HANDLER_ARGS)
214 {
215 	int error;
216 	long  value;
217 
218 	value = fq_pie_sysctl.pcfg.max_ecnth;
219 	value = value * 1000 / PIE_SCALE;
220 	error = sysctl_handle_long(oidp, &value, 0, req);
221 	if (error != 0 || req->newptr == NULL)
222 		return (error);
223 	if (value < 1 || value > PIE_SCALE)
224 		return (EINVAL);
225 	value = (value * PIE_SCALE) / 1000;
226 	fq_pie_sysctl.pcfg.max_ecnth = value;
227 	return (0);
228 }
229 
230 /* define FQ- PIE sysctl variables */
231 SYSBEGIN(f4)
232 SYSCTL_DECL(_net_inet);
233 SYSCTL_DECL(_net_inet_ip);
234 SYSCTL_DECL(_net_inet_ip_dummynet);
235 static SYSCTL_NODE(_net_inet_ip_dummynet, OID_AUTO, fqpie,
236     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
237     "FQ_PIE");
238 
239 #ifdef SYSCTL_NODE
240 
241 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, target,
242     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
243     fqpie_sysctl_target_tupdate_maxb_handler, "L",
244     "queue target in microsecond");
245 
246 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, tupdate,
247     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
248     fqpie_sysctl_target_tupdate_maxb_handler, "L",
249     "the frequency of drop probability calculation in microsecond");
250 
251 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, max_burst,
252     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
253     fqpie_sysctl_target_tupdate_maxb_handler, "L",
254     "Burst allowance interval in microsecond");
255 
256 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, max_ecnth,
257     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
258     fqpie_sysctl_max_ecnth_handler, "L",
259     "ECN safeguard threshold scaled by 1000");
260 
261 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, alpha,
262     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
263     fqpie_sysctl_alpha_beta_handler, "L",
264     "PIE alpha scaled by 1000");
265 
266 SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, beta,
267     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
268     fqpie_sysctl_alpha_beta_handler, "L",
269     "beta scaled by 1000");
270 
271 SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, quantum,
272 	CTLFLAG_RW, &fq_pie_sysctl.quantum, 1514, "quantum for FQ_PIE");
273 SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, flows,
274 	CTLFLAG_RW, &fq_pie_sysctl.flows_cnt, 1024, "Number of queues for FQ_PIE");
275 SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, limit,
276 	CTLFLAG_RW, &fq_pie_sysctl.limit, 10240, "limit for FQ_PIE");
277 #endif
278 
279 /* Helper function to update queue&main-queue and scheduler statistics.
280  * negative len & drop -> drop
281  * negative len -> dequeue
282  * positive len -> enqueue
283  * positive len + drop -> drop during enqueue
284  */
285 __inline static void
286 fq_update_stats(struct fq_pie_flow *q, struct fq_pie_si *si, int len,
287 	int drop)
288 {
289 	int inc = 0;
290 
291 	if (len < 0)
292 		inc = -1;
293 	else if (len > 0)
294 		inc = 1;
295 
296 	if (drop) {
297 		si->main_q.ni.drops ++;
298 		q->stats.drops ++;
299 		si->_si.ni.drops ++;
300 		V_dn_cfg.io_pkt_drop ++;
301 	}
302 
303 	if (!drop || (drop && len < 0)) {
304 		/* Update stats for the main queue */
305 		si->main_q.ni.length += inc;
306 		si->main_q.ni.len_bytes += len;
307 
308 		/*update sub-queue stats */
309 		q->stats.length += inc;
310 		q->stats.len_bytes += len;
311 
312 		/*update scheduler instance stats */
313 		si->_si.ni.length += inc;
314 		si->_si.ni.len_bytes += len;
315 	}
316 
317 	if (inc > 0) {
318 		si->main_q.ni.tot_bytes += len;
319 		si->main_q.ni.tot_pkts ++;
320 
321 		q->stats.tot_bytes +=len;
322 		q->stats.tot_pkts++;
323 
324 		si->_si.ni.tot_bytes +=len;
325 		si->_si.ni.tot_pkts ++;
326 	}
327 
328 }
329 
330 /*
331  * Extract a packet from the head of sub-queue 'q'
332  * Return a packet or NULL if the queue is empty.
333  * If getts is set, also extract packet's timestamp from mtag.
334  */
335 __inline static struct mbuf *
336 fq_pie_extract_head(struct fq_pie_flow *q, aqm_time_t *pkt_ts,
337 	struct fq_pie_si *si, int getts)
338 {
339 	struct mbuf *m;
340 
341 next:	m = q->mq.head;
342 	if (m == NULL)
343 		return m;
344 	q->mq.head = m->m_nextpkt;
345 
346 	fq_update_stats(q, si, -m->m_pkthdr.len, 0);
347 
348 	if (si->main_q.ni.length == 0) /* queue is now idle */
349 			si->main_q.q_time = V_dn_cfg.curr_time;
350 
351 	if (getts) {
352 		/* extract packet timestamp*/
353 		struct m_tag *mtag;
354 		mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
355 		if (mtag == NULL){
356 			D("PIE timestamp mtag not found!");
357 			*pkt_ts = 0;
358 		} else {
359 			*pkt_ts = *(aqm_time_t *)(mtag + 1);
360 			m_tag_delete(m,mtag);
361 		}
362 	}
363 	if (m->m_pkthdr.rcvif != NULL &&
364 	    __predict_false(m_rcvif_restore(m) == NULL)) {
365 		m_freem(m);
366 		goto next;
367 	}
368 	return m;
369 }
370 
371 /*
372  * Callout function for drop probability calculation
373  * This function is called over tupdate ms and takes pointer of FQ-PIE
374  * flow as an argument
375   */
376 static void
377 fq_calculate_drop_prob(void *x)
378 {
379 	struct fq_pie_flow *q = (struct fq_pie_flow *) x;
380 	struct pie_status *pst = &q->pst;
381 	struct dn_aqm_pie_parms *pprms;
382 	int64_t p, prob, oldprob;
383 	int p_isneg;
384 
385 	pprms = pst->parms;
386 	prob = pst->drop_prob;
387 
388 	/* calculate current qdelay using DRE method.
389 	 * If TS is used and no data in the queue, reset current_qdelay
390 	 * as it stays at last value during dequeue process.
391 	*/
392 	if (pprms->flags & PIE_DEPRATEEST_ENABLED)
393 		pst->current_qdelay = ((uint64_t)q->stats.len_bytes  * pst->avg_dq_time)
394 			>> PIE_DQ_THRESHOLD_BITS;
395 	else
396 		if (!q->stats.len_bytes)
397 			pst->current_qdelay = 0;
398 
399 	/* calculate drop probability */
400 	p = (int64_t)pprms->alpha *
401 		((int64_t)pst->current_qdelay - (int64_t)pprms->qdelay_ref);
402 	p +=(int64_t) pprms->beta *
403 		((int64_t)pst->current_qdelay - (int64_t)pst->qdelay_old);
404 
405 	/* take absolute value so right shift result is well defined */
406 	p_isneg = p < 0;
407 	if (p_isneg) {
408 		p = -p;
409 	}
410 
411 	/* We PIE_MAX_PROB shift by 12-bits to increase the division precision  */
412 	p *= (PIE_MAX_PROB << 12) / AQM_TIME_1S;
413 
414 	/* auto-tune drop probability */
415 	if (prob < (PIE_MAX_PROB / 1000000)) /* 0.000001 */
416 		p >>= 11 + PIE_FIX_POINT_BITS + 12;
417 	else if (prob < (PIE_MAX_PROB / 100000)) /* 0.00001 */
418 		p >>= 9 + PIE_FIX_POINT_BITS + 12;
419 	else if (prob < (PIE_MAX_PROB / 10000)) /* 0.0001 */
420 		p >>= 7 + PIE_FIX_POINT_BITS + 12;
421 	else if (prob < (PIE_MAX_PROB / 1000)) /* 0.001 */
422 		p >>= 5 + PIE_FIX_POINT_BITS + 12;
423 	else if (prob < (PIE_MAX_PROB / 100)) /* 0.01 */
424 		p >>= 3 + PIE_FIX_POINT_BITS + 12;
425 	else if (prob < (PIE_MAX_PROB / 10)) /* 0.1 */
426 		p >>= 1 + PIE_FIX_POINT_BITS + 12;
427 	else
428 		p >>= PIE_FIX_POINT_BITS + 12;
429 
430 	oldprob = prob;
431 
432 	if (p_isneg) {
433 		prob = prob - p;
434 
435 		/* check for multiplication underflow */
436 		if (prob > oldprob) {
437 			prob= 0;
438 			D("underflow");
439 		}
440 	} else {
441 		/* Cap Drop adjustment */
442 		if ((pprms->flags & PIE_CAPDROP_ENABLED) &&
443 		    prob >= PIE_MAX_PROB / 10 &&
444 		    p > PIE_MAX_PROB / 50 ) {
445 			p = PIE_MAX_PROB / 50;
446 		}
447 
448 		prob = prob + p;
449 
450 		/* check for multiplication overflow */
451 		if (prob<oldprob) {
452 			D("overflow");
453 			prob= PIE_MAX_PROB;
454 		}
455 	}
456 
457 	/*
458 	 * decay the drop probability exponentially
459 	 * and restrict it to range 0 to PIE_MAX_PROB
460 	 */
461 	if (prob < 0) {
462 		prob = 0;
463 	} else {
464 		if (pst->current_qdelay == 0 && pst->qdelay_old == 0) {
465 			/* 0.98 ~= 1- 1/64 */
466 			prob = prob - (prob >> 6);
467 		}
468 
469 		if (prob > PIE_MAX_PROB) {
470 			prob = PIE_MAX_PROB;
471 		}
472 	}
473 
474 	pst->drop_prob = prob;
475 
476 	/* store current delay value */
477 	pst->qdelay_old = pst->current_qdelay;
478 
479 	/* update burst allowance */
480 	if ((pst->sflags & PIE_ACTIVE) && pst->burst_allowance) {
481 		if (pst->burst_allowance > pprms->tupdate)
482 			pst->burst_allowance -= pprms->tupdate;
483 		else
484 			pst->burst_allowance = 0;
485 	}
486 
487 	if (pst->sflags & PIE_ACTIVE)
488 	callout_reset_sbt(&pst->aqm_pie_callout,
489 		(uint64_t)pprms->tupdate * SBT_1US,
490 		0, fq_calculate_drop_prob, q, 0);
491 
492 	mtx_unlock(&pst->lock_mtx);
493 }
494 
495 /*
496  * Reset PIE variables & activate the queue
497  */
498 __inline static void
499 fq_activate_pie(struct fq_pie_flow *q)
500 {
501 	struct pie_status *pst = &q->pst;
502 	struct dn_aqm_pie_parms *pprms;
503 
504 	mtx_lock(&pst->lock_mtx);
505 	pprms = pst->parms;
506 
507 	pprms = pst->parms;
508 	pst->drop_prob = 0;
509 	pst->qdelay_old = 0;
510 	pst->burst_allowance = pprms->max_burst;
511 	pst->accu_prob = 0;
512 	pst->dq_count = 0;
513 	pst->avg_dq_time = 0;
514 	pst->sflags = PIE_INMEASUREMENT | PIE_ACTIVE;
515 	pst->measurement_start = AQM_UNOW;
516 
517 	callout_reset_sbt(&pst->aqm_pie_callout,
518 		(uint64_t)pprms->tupdate * SBT_1US,
519 		0, fq_calculate_drop_prob, q, 0);
520 
521 	mtx_unlock(&pst->lock_mtx);
522 }
523 
524  /*
525   * Deactivate PIE and stop probe update callout
526   */
527 __inline static void
528 fq_deactivate_pie(struct pie_status *pst)
529 {
530 	mtx_lock(&pst->lock_mtx);
531 	pst->sflags &= ~(PIE_ACTIVE | PIE_INMEASUREMENT);
532 	callout_stop(&pst->aqm_pie_callout);
533 	//D("PIE Deactivated");
534 	mtx_unlock(&pst->lock_mtx);
535 }
536 
537  /*
538   * Initialize PIE for sub-queue 'q'
539   */
540 static int
541 pie_init(struct fq_pie_flow *q, struct fq_pie_schk *fqpie_schk)
542 {
543 	struct pie_status *pst=&q->pst;
544 	struct dn_aqm_pie_parms *pprms = pst->parms;
545 
546 	int err = 0;
547 	if (!pprms){
548 		D("AQM_PIE is not configured");
549 		err = EINVAL;
550 	} else {
551 		q->psi_extra->nr_active_q++;
552 
553 		/* For speed optimization, we caculate 1/3 queue size once here */
554 		// XXX limit divided by number of queues divided by 3 ???
555 		pst->one_third_q_size = (fqpie_schk->cfg.limit /
556 			fqpie_schk->cfg.flows_cnt) / 3;
557 
558 		mtx_init(&pst->lock_mtx, "mtx_pie", NULL, MTX_DEF);
559 		callout_init_mtx(&pst->aqm_pie_callout, &pst->lock_mtx,
560 			CALLOUT_RETURNUNLOCKED);
561 	}
562 
563 	return err;
564 }
565 
566 /*
567  * callout function to destroy PIE lock, and free fq_pie flows and fq_pie si
568  * extra memory when number of active sub-queues reaches zero.
569  * 'x' is a fq_pie_flow to be destroyed
570  */
571 static void
572 fqpie_callout_cleanup(void *x)
573 {
574 	struct fq_pie_flow *q = x;
575 	struct pie_status *pst = &q->pst;
576 	struct fq_pie_si_extra *psi_extra;
577 
578 	mtx_unlock(&pst->lock_mtx);
579 	mtx_destroy(&pst->lock_mtx);
580 	psi_extra = q->psi_extra;
581 
582 	dummynet_sched_lock();
583 	psi_extra->nr_active_q--;
584 
585 	/* when all sub-queues are destroyed, free flows fq_pie extra vars memory */
586 	if (!psi_extra->nr_active_q) {
587 		free(psi_extra->flows, M_DUMMYNET);
588 		free(psi_extra, M_DUMMYNET);
589 		fq_pie_desc.ref_count--;
590 	}
591 	dummynet_sched_unlock();
592 }
593 
594 /*
595  * Clean up PIE status for sub-queue 'q'
596  * Stop callout timer and destroy mtx using fqpie_callout_cleanup() callout.
597  */
598 static int
599 pie_cleanup(struct fq_pie_flow *q)
600 {
601 	struct pie_status *pst  = &q->pst;
602 
603 	mtx_lock(&pst->lock_mtx);
604 	callout_reset_sbt(&pst->aqm_pie_callout,
605 		SBT_1US, 0, fqpie_callout_cleanup, q, 0);
606 	mtx_unlock(&pst->lock_mtx);
607 	return 0;
608 }
609 
610 /*
611  * Dequeue and return a pcaket from sub-queue 'q' or NULL if 'q' is empty.
612  * Also, caculate depature time or queue delay using timestamp
613  */
614  static struct mbuf *
615 pie_dequeue(struct fq_pie_flow *q, struct fq_pie_si *si)
616 {
617 	struct mbuf *m;
618 	struct dn_aqm_pie_parms *pprms;
619 	struct pie_status *pst;
620 	aqm_time_t now;
621 	aqm_time_t pkt_ts, dq_time;
622 	int32_t w;
623 
624 	pst  = &q->pst;
625 	pprms = q->pst.parms;
626 
627 	/*we extarct packet ts only when Departure Rate Estimation dis not used*/
628 	m = fq_pie_extract_head(q, &pkt_ts, si,
629 		!(pprms->flags & PIE_DEPRATEEST_ENABLED));
630 
631 	if (!m || !(pst->sflags & PIE_ACTIVE))
632 		return m;
633 
634 	now = AQM_UNOW;
635 	if (pprms->flags & PIE_DEPRATEEST_ENABLED) {
636 		/* calculate average depature time */
637 		if(pst->sflags & PIE_INMEASUREMENT) {
638 			pst->dq_count += m->m_pkthdr.len;
639 
640 			if (pst->dq_count >= PIE_DQ_THRESHOLD) {
641 				dq_time = now - pst->measurement_start;
642 
643 				/*
644 				 * if we don't have old avg dq_time i.e PIE is (re)initialized,
645 				 * don't use weight to calculate new avg_dq_time
646 				 */
647 				if(pst->avg_dq_time == 0)
648 					pst->avg_dq_time = dq_time;
649 				else {
650 					/*
651 					 * weight = PIE_DQ_THRESHOLD/2^6, but we scaled
652 					 * weight by 2^8. Thus, scaled
653 					 * weight = PIE_DQ_THRESHOLD /2^8
654 					 * */
655 					w = PIE_DQ_THRESHOLD >> 8;
656 					pst->avg_dq_time = (dq_time* w
657 						+ (pst->avg_dq_time * ((1L << 8) - w))) >> 8;
658 					pst->sflags &= ~PIE_INMEASUREMENT;
659 				}
660 			}
661 		}
662 
663 		/*
664 		 * Start new measurement cycle when the queue has
665 		 * PIE_DQ_THRESHOLD worth of bytes.
666 		 */
667 		if(!(pst->sflags & PIE_INMEASUREMENT) &&
668 			q->stats.len_bytes >= PIE_DQ_THRESHOLD) {
669 			pst->sflags |= PIE_INMEASUREMENT;
670 			pst->measurement_start = now;
671 			pst->dq_count = 0;
672 		}
673 	}
674 	/* Optionally, use packet timestamp to estimate queue delay */
675 	else
676 		pst->current_qdelay = now - pkt_ts;
677 
678 	return m;
679 }
680 
681  /*
682  * Enqueue a packet in q, subject to space and FQ-PIE queue management policy
683  * (whose parameters are in q->fs).
684  * Update stats for the queue and the scheduler.
685  * Return 0 on success, 1 on drop. The packet is consumed anyways.
686  */
687 static int
688 pie_enqueue(struct fq_pie_flow *q, struct mbuf* m, struct fq_pie_si *si)
689 {
690 	uint64_t len;
691 	struct pie_status *pst;
692 	struct dn_aqm_pie_parms *pprms;
693 	int t;
694 
695 	len = m->m_pkthdr.len;
696 	pst  = &q->pst;
697 	pprms = pst->parms;
698 	t = ENQUE;
699 
700 	/* drop/mark the packet when PIE is active and burst time elapsed */
701 	if (pst->sflags & PIE_ACTIVE && pst->burst_allowance == 0
702 		&& drop_early(pst, q->stats.len_bytes) == DROP) {
703 			/*
704 			 * if drop_prob over ECN threshold, drop the packet
705 			 * otherwise mark and enqueue it.
706 			 */
707 			if (pprms->flags & PIE_ECN_ENABLED && pst->drop_prob <
708 				(pprms->max_ecnth << (PIE_PROB_BITS - PIE_FIX_POINT_BITS))
709 				&& ecn_mark(m))
710 				t = ENQUE;
711 			else
712 				t = DROP;
713 		}
714 
715 	/* Turn PIE on when 1/3 of the queue is full */
716 	if (!(pst->sflags & PIE_ACTIVE) && q->stats.len_bytes >=
717 		pst->one_third_q_size) {
718 		fq_activate_pie(q);
719 	}
720 
721 	/*  reset burst tolerance and optinally turn PIE off*/
722 	if (pst->drop_prob == 0 && pst->current_qdelay < (pprms->qdelay_ref >> 1)
723 		&& pst->qdelay_old < (pprms->qdelay_ref >> 1)) {
724 
725 			pst->burst_allowance = pprms->max_burst;
726 		if (pprms->flags & PIE_ON_OFF_MODE_ENABLED && q->stats.len_bytes<=0)
727 			fq_deactivate_pie(pst);
728 	}
729 
730 	/* Use timestamp if Departure Rate Estimation mode is disabled */
731 	if (t != DROP && !(pprms->flags & PIE_DEPRATEEST_ENABLED)) {
732 		/* Add TS to mbuf as a TAG */
733 		struct m_tag *mtag;
734 		mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
735 		if (mtag == NULL)
736 			mtag = m_tag_alloc(MTAG_ABI_COMPAT, DN_AQM_MTAG_TS,
737 				sizeof(aqm_time_t), M_NOWAIT);
738 		if (mtag == NULL) {
739 			t = DROP;
740 		} else {
741 			*(aqm_time_t *)(mtag + 1) = AQM_UNOW;
742 			m_tag_prepend(m, mtag);
743 		}
744 	}
745 
746 	if (t != DROP) {
747 		mq_append(&q->mq, m);
748 		fq_update_stats(q, si, len, 0);
749 		return 0;
750 	} else {
751 		fq_update_stats(q, si, len, 1);
752 		pst->accu_prob = 0;
753 		FREE_PKT(m);
754 		return 1;
755 	}
756 
757 	return 0;
758 }
759 
760 /* Drop a packet form the head of FQ-PIE sub-queue */
761 static void
762 pie_drop_head(struct fq_pie_flow *q, struct fq_pie_si *si)
763 {
764 	struct mbuf *m = q->mq.head;
765 
766 	if (m == NULL)
767 		return;
768 	q->mq.head = m->m_nextpkt;
769 
770 	fq_update_stats(q, si, -m->m_pkthdr.len, 1);
771 
772 	if (si->main_q.ni.length == 0) /* queue is now idle */
773 			si->main_q.q_time = V_dn_cfg.curr_time;
774 	/* reset accu_prob after packet drop */
775 	q->pst.accu_prob = 0;
776 
777 	FREE_PKT(m);
778 }
779 
780 /*
781  * Classify a packet to queue number using Jenkins hash function.
782  * Return: queue number
783  * the input of the hash are protocol no, perturbation, src IP, dst IP,
784  * src port, dst port,
785  */
786 static inline int
787 fq_pie_classify_flow(struct mbuf *m, uint16_t fcount, struct fq_pie_si *si)
788 {
789 	struct ip *ip;
790 	struct tcphdr *th;
791 	struct udphdr *uh;
792 	uint8_t tuple[41];
793 	uint16_t hash=0;
794 
795 	ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off);
796 //#ifdef INET6
797 	struct ip6_hdr *ip6;
798 	int isip6;
799 	isip6 = (ip->ip_v == 6);
800 
801 	if(isip6) {
802 		ip6 = (struct ip6_hdr *)ip;
803 		*((uint8_t *) &tuple[0]) = ip6->ip6_nxt;
804 		*((uint32_t *) &tuple[1]) = si->perturbation;
805 		memcpy(&tuple[5], ip6->ip6_src.s6_addr, 16);
806 		memcpy(&tuple[21], ip6->ip6_dst.s6_addr, 16);
807 
808 		switch (ip6->ip6_nxt) {
809 		case IPPROTO_TCP:
810 			th = (struct tcphdr *)(ip6 + 1);
811 			*((uint16_t *) &tuple[37]) = th->th_dport;
812 			*((uint16_t *) &tuple[39]) = th->th_sport;
813 			break;
814 
815 		case IPPROTO_UDP:
816 			uh = (struct udphdr *)(ip6 + 1);
817 			*((uint16_t *) &tuple[37]) = uh->uh_dport;
818 			*((uint16_t *) &tuple[39]) = uh->uh_sport;
819 			break;
820 		default:
821 			memset(&tuple[37], 0, 4);
822 		}
823 
824 		hash = jenkins_hash(tuple, 41, HASHINIT) %  fcount;
825 		return hash;
826 	}
827 //#endif
828 
829 	/* IPv4 */
830 	*((uint8_t *) &tuple[0]) = ip->ip_p;
831 	*((uint32_t *) &tuple[1]) = si->perturbation;
832 	*((uint32_t *) &tuple[5]) = ip->ip_src.s_addr;
833 	*((uint32_t *) &tuple[9]) = ip->ip_dst.s_addr;
834 
835 	switch (ip->ip_p) {
836 		case IPPROTO_TCP:
837 			th = (struct tcphdr *)(ip + 1);
838 			*((uint16_t *) &tuple[13]) = th->th_dport;
839 			*((uint16_t *) &tuple[15]) = th->th_sport;
840 			break;
841 
842 		case IPPROTO_UDP:
843 			uh = (struct udphdr *)(ip + 1);
844 			*((uint16_t *) &tuple[13]) = uh->uh_dport;
845 			*((uint16_t *) &tuple[15]) = uh->uh_sport;
846 			break;
847 		default:
848 			memset(&tuple[13], 0, 4);
849 	}
850 	hash = jenkins_hash(tuple, 17, HASHINIT) % fcount;
851 
852 	return hash;
853 }
854 
855 /*
856  * Enqueue a packet into an appropriate queue according to
857  * FQ-CoDe; algorithm.
858  */
859 static int
860 fq_pie_enqueue(struct dn_sch_inst *_si, struct dn_queue *_q,
861 	struct mbuf *m)
862 {
863 	struct fq_pie_si *si;
864 	struct fq_pie_schk *schk;
865 	struct dn_sch_fq_pie_parms *param;
866 	struct dn_queue *mainq;
867 	struct fq_pie_flow *flows;
868 	int idx, drop, i, maxidx;
869 
870 	mainq = (struct dn_queue *)(_si + 1);
871 	si = (struct fq_pie_si *)_si;
872 	flows = si->si_extra->flows;
873 	schk = (struct fq_pie_schk *)(si->_si.sched+1);
874 	param = &schk->cfg;
875 
876 	 /* classify a packet to queue number*/
877 	idx = fq_pie_classify_flow(m, param->flows_cnt, si);
878 
879 	/* enqueue packet into appropriate queue using PIE AQM.
880 	 * Note: 'pie_enqueue' function returns 1 only when it unable to
881 	 * add timestamp to packet (no limit check)*/
882 	drop = pie_enqueue(&flows[idx], m, si);
883 
884 	/* pie unable to timestamp a packet */
885 	if (drop)
886 		return 1;
887 
888 	/* If the flow (sub-queue) is not active ,then add it to tail of
889 	 * new flows list, initialize and activate it.
890 	 */
891 	if (!flows[idx].active) {
892 		STAILQ_INSERT_TAIL(&si->newflows, &flows[idx], flowchain);
893 		flows[idx].deficit = param->quantum;
894 		fq_activate_pie(&flows[idx]);
895 		flows[idx].active = 1;
896 	}
897 
898 	/* check the limit for all queues and remove a packet from the
899 	 * largest one
900 	 */
901 	if (mainq->ni.length > schk->cfg.limit) {
902 		/* find first active flow */
903 		for (maxidx = 0; maxidx < schk->cfg.flows_cnt; maxidx++)
904 			if (flows[maxidx].active)
905 				break;
906 		if (maxidx < schk->cfg.flows_cnt) {
907 			/* find the largest sub- queue */
908 			for (i = maxidx + 1; i < schk->cfg.flows_cnt; i++)
909 				if (flows[i].active && flows[i].stats.length >
910 					flows[maxidx].stats.length)
911 					maxidx = i;
912 			pie_drop_head(&flows[maxidx], si);
913 			drop = 1;
914 		}
915 	}
916 
917 	return drop;
918 }
919 
920 /*
921  * Dequeue a packet from an appropriate queue according to
922  * FQ-CoDel algorithm.
923  */
924 static struct mbuf *
925 fq_pie_dequeue(struct dn_sch_inst *_si)
926 {
927 	struct fq_pie_si *si;
928 	struct fq_pie_schk *schk;
929 	struct dn_sch_fq_pie_parms *param;
930 	struct fq_pie_flow *f;
931 	struct mbuf *mbuf;
932 	struct fq_pie_list *fq_pie_flowlist;
933 
934 	si = (struct fq_pie_si *)_si;
935 	schk = (struct fq_pie_schk *)(si->_si.sched+1);
936 	param = &schk->cfg;
937 
938 	do {
939 		/* select a list to start with */
940 		if (STAILQ_EMPTY(&si->newflows))
941 			fq_pie_flowlist = &si->oldflows;
942 		else
943 			fq_pie_flowlist = &si->newflows;
944 
945 		/* Both new and old queue lists are empty, return NULL */
946 		if (STAILQ_EMPTY(fq_pie_flowlist))
947 			return NULL;
948 
949 		f = STAILQ_FIRST(fq_pie_flowlist);
950 		while (f != NULL)	{
951 			/* if there is no flow(sub-queue) deficit, increase deficit
952 			 * by quantum, move the flow to the tail of old flows list
953 			 * and try another flow.
954 			 * Otherwise, the flow will be used for dequeue.
955 			 */
956 			if (f->deficit < 0) {
957 				 f->deficit += param->quantum;
958 				 STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain);
959 				 STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain);
960 			 } else
961 				 break;
962 
963 			f = STAILQ_FIRST(fq_pie_flowlist);
964 		}
965 
966 		/* the new flows list is empty, try old flows list */
967 		if (STAILQ_EMPTY(fq_pie_flowlist))
968 			continue;
969 
970 		/* Dequeue a packet from the selected flow */
971 		mbuf = pie_dequeue(f, si);
972 
973 		/* pie did not return a packet */
974 		if (!mbuf) {
975 			/* If the selected flow belongs to new flows list, then move
976 			 * it to the tail of old flows list. Otherwise, deactivate it and
977 			 * remove it from the old list and
978 			 */
979 			if (fq_pie_flowlist == &si->newflows) {
980 				STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain);
981 				STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain);
982 			}	else {
983 				f->active = 0;
984 				fq_deactivate_pie(&f->pst);
985 				STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain);
986 			}
987 			/* start again */
988 			continue;
989 		}
990 
991 		/* we have a packet to return,
992 		 * update flow deficit and return the packet*/
993 		f->deficit -= mbuf->m_pkthdr.len;
994 		return mbuf;
995 
996 	} while (1);
997 
998 	/* unreachable point */
999 	return NULL;
1000 }
1001 
1002 /*
1003  * Initialize fq_pie scheduler instance.
1004  * also, allocate memory for flows array.
1005  */
1006 static int
1007 fq_pie_new_sched(struct dn_sch_inst *_si)
1008 {
1009 	struct fq_pie_si *si;
1010 	struct dn_queue *q;
1011 	struct fq_pie_schk *schk;
1012 	struct fq_pie_flow *flows;
1013 	int i;
1014 
1015 	si = (struct fq_pie_si *)_si;
1016 	schk = (struct fq_pie_schk *)(_si->sched+1);
1017 
1018 	if(si->si_extra) {
1019 		D("si already configured!");
1020 		return 0;
1021 	}
1022 
1023 	/* init the main queue */
1024 	q = &si->main_q;
1025 	set_oid(&q->ni.oid, DN_QUEUE, sizeof(*q));
1026 	q->_si = _si;
1027 	q->fs = _si->sched->fs;
1028 
1029 	/* allocate memory for scheduler instance extra vars */
1030 	si->si_extra = malloc(sizeof(struct fq_pie_si_extra),
1031 		 M_DUMMYNET, M_NOWAIT | M_ZERO);
1032 	if (si->si_extra == NULL) {
1033 		D("cannot allocate memory for fq_pie si extra vars");
1034 		return ENOMEM ;
1035 	}
1036 	/* allocate memory for flows array */
1037 	si->si_extra->flows = mallocarray(schk->cfg.flows_cnt,
1038 	    sizeof(struct fq_pie_flow), M_DUMMYNET, M_NOWAIT | M_ZERO);
1039 	flows = si->si_extra->flows;
1040 	if (flows == NULL) {
1041 		free(si->si_extra, M_DUMMYNET);
1042 		si->si_extra = NULL;
1043 		D("cannot allocate memory for fq_pie flows");
1044 		return ENOMEM ;
1045 	}
1046 
1047 	/* init perturbation for this si */
1048 	si->perturbation = random();
1049 	si->si_extra->nr_active_q = 0;
1050 
1051 	/* init the old and new flows lists */
1052 	STAILQ_INIT(&si->newflows);
1053 	STAILQ_INIT(&si->oldflows);
1054 
1055 	/* init the flows (sub-queues) */
1056 	for (i = 0; i < schk->cfg.flows_cnt; i++) {
1057 		flows[i].pst.parms = &schk->cfg.pcfg;
1058 		flows[i].psi_extra = si->si_extra;
1059 		pie_init(&flows[i], schk);
1060 	}
1061 
1062 	dummynet_sched_lock();
1063 	fq_pie_desc.ref_count++;
1064 	dummynet_sched_unlock();
1065 
1066 	return 0;
1067 }
1068 
1069 /*
1070  * Free fq_pie scheduler instance.
1071  */
1072 static int
1073 fq_pie_free_sched(struct dn_sch_inst *_si)
1074 {
1075 	struct fq_pie_si *si;
1076 	struct fq_pie_schk *schk;
1077 	struct fq_pie_flow *flows;
1078 	int i;
1079 
1080 	si = (struct fq_pie_si *)_si;
1081 	schk = (struct fq_pie_schk *)(_si->sched+1);
1082 	flows = si->si_extra->flows;
1083 	for (i = 0; i < schk->cfg.flows_cnt; i++) {
1084 		pie_cleanup(&flows[i]);
1085 	}
1086 	si->si_extra = NULL;
1087 	return 0;
1088 }
1089 
1090 /*
1091  * Configure FQ-PIE scheduler.
1092  * the configurations for the scheduler is passed fromipfw  userland.
1093  */
1094 static int
1095 fq_pie_config(struct dn_schk *_schk)
1096 {
1097 	struct fq_pie_schk *schk;
1098 	struct dn_extra_parms *ep;
1099 	struct dn_sch_fq_pie_parms *fqp_cfg;
1100 
1101 	schk = (struct fq_pie_schk *)(_schk+1);
1102 	ep = (struct dn_extra_parms *) _schk->cfg;
1103 
1104 	/* par array contains fq_pie configuration as follow
1105 	 * PIE: 0- qdelay_ref,1- tupdate, 2- max_burst
1106 	 * 3- max_ecnth, 4- alpha, 5- beta, 6- flags
1107 	 * FQ_PIE: 7- quantum, 8- limit, 9- flows
1108 	 */
1109 	if (ep && ep->oid.len ==sizeof(*ep) &&
1110 		ep->oid.subtype == DN_SCH_PARAMS) {
1111 		fqp_cfg = &schk->cfg;
1112 		if (ep->par[0] < 0)
1113 			fqp_cfg->pcfg.qdelay_ref = fq_pie_sysctl.pcfg.qdelay_ref;
1114 		else
1115 			fqp_cfg->pcfg.qdelay_ref = ep->par[0];
1116 		if (ep->par[1] < 0)
1117 			fqp_cfg->pcfg.tupdate = fq_pie_sysctl.pcfg.tupdate;
1118 		else
1119 			fqp_cfg->pcfg.tupdate = ep->par[1];
1120 		if (ep->par[2] < 0)
1121 			fqp_cfg->pcfg.max_burst = fq_pie_sysctl.pcfg.max_burst;
1122 		else
1123 			fqp_cfg->pcfg.max_burst = ep->par[2];
1124 		if (ep->par[3] < 0)
1125 			fqp_cfg->pcfg.max_ecnth = fq_pie_sysctl.pcfg.max_ecnth;
1126 		else
1127 			fqp_cfg->pcfg.max_ecnth = ep->par[3];
1128 		if (ep->par[4] < 0)
1129 			fqp_cfg->pcfg.alpha = fq_pie_sysctl.pcfg.alpha;
1130 		else
1131 			fqp_cfg->pcfg.alpha = ep->par[4];
1132 		if (ep->par[5] < 0)
1133 			fqp_cfg->pcfg.beta = fq_pie_sysctl.pcfg.beta;
1134 		else
1135 			fqp_cfg->pcfg.beta = ep->par[5];
1136 		if (ep->par[6] < 0)
1137 			fqp_cfg->pcfg.flags = 0;
1138 		else
1139 			fqp_cfg->pcfg.flags = ep->par[6];
1140 
1141 		/* FQ configurations */
1142 		if (ep->par[7] < 0)
1143 			fqp_cfg->quantum = fq_pie_sysctl.quantum;
1144 		else
1145 			fqp_cfg->quantum = ep->par[7];
1146 		if (ep->par[8] < 0)
1147 			fqp_cfg->limit = fq_pie_sysctl.limit;
1148 		else
1149 			fqp_cfg->limit = ep->par[8];
1150 		if (ep->par[9] < 0)
1151 			fqp_cfg->flows_cnt = fq_pie_sysctl.flows_cnt;
1152 		else
1153 			fqp_cfg->flows_cnt = ep->par[9];
1154 
1155 		/* Bound the configurations */
1156 		fqp_cfg->pcfg.qdelay_ref = BOUND_VAR(fqp_cfg->pcfg.qdelay_ref,
1157 			1, 5 * AQM_TIME_1S);
1158 		fqp_cfg->pcfg.tupdate = BOUND_VAR(fqp_cfg->pcfg.tupdate,
1159 			1, 5 * AQM_TIME_1S);
1160 		fqp_cfg->pcfg.max_burst = BOUND_VAR(fqp_cfg->pcfg.max_burst,
1161 			0, 5 * AQM_TIME_1S);
1162 		fqp_cfg->pcfg.max_ecnth = BOUND_VAR(fqp_cfg->pcfg.max_ecnth,
1163 			0, PIE_SCALE);
1164 		fqp_cfg->pcfg.alpha = BOUND_VAR(fqp_cfg->pcfg.alpha, 0, 7 * PIE_SCALE);
1165 		fqp_cfg->pcfg.beta = BOUND_VAR(fqp_cfg->pcfg.beta, 0, 7 * PIE_SCALE);
1166 
1167 		fqp_cfg->quantum = BOUND_VAR(fqp_cfg->quantum,1,9000);
1168 		fqp_cfg->limit= BOUND_VAR(fqp_cfg->limit,1,20480);
1169 		fqp_cfg->flows_cnt= BOUND_VAR(fqp_cfg->flows_cnt,1,65536);
1170 	}
1171 	else {
1172 		D("Wrong parameters for fq_pie scheduler");
1173 		return 1;
1174 	}
1175 
1176 	return 0;
1177 }
1178 
1179 /*
1180  * Return FQ-PIE scheduler configurations
1181  * the configurations for the scheduler is passed to userland.
1182  */
1183 static int
1184 fq_pie_getconfig (struct dn_schk *_schk, struct dn_extra_parms *ep) {
1185 	struct fq_pie_schk *schk = (struct fq_pie_schk *)(_schk+1);
1186 	struct dn_sch_fq_pie_parms *fqp_cfg;
1187 
1188 	fqp_cfg = &schk->cfg;
1189 
1190 	strcpy(ep->name, fq_pie_desc.name);
1191 	ep->par[0] = fqp_cfg->pcfg.qdelay_ref;
1192 	ep->par[1] = fqp_cfg->pcfg.tupdate;
1193 	ep->par[2] = fqp_cfg->pcfg.max_burst;
1194 	ep->par[3] = fqp_cfg->pcfg.max_ecnth;
1195 	ep->par[4] = fqp_cfg->pcfg.alpha;
1196 	ep->par[5] = fqp_cfg->pcfg.beta;
1197 	ep->par[6] = fqp_cfg->pcfg.flags;
1198 
1199 	ep->par[7] = fqp_cfg->quantum;
1200 	ep->par[8] = fqp_cfg->limit;
1201 	ep->par[9] = fqp_cfg->flows_cnt;
1202 
1203 	return 0;
1204 }
1205 
1206 /*
1207  *  FQ-PIE scheduler descriptor
1208  * contains the type of the scheduler, the name, the size of extra
1209  * data structures, and function pointers.
1210  */
1211 static struct dn_alg fq_pie_desc = {
1212 	_SI( .type = )  DN_SCHED_FQ_PIE,
1213 	_SI( .name = ) "FQ_PIE",
1214 	_SI( .flags = ) 0,
1215 
1216 	_SI( .schk_datalen = ) sizeof(struct fq_pie_schk),
1217 	_SI( .si_datalen = ) sizeof(struct fq_pie_si) - sizeof(struct dn_sch_inst),
1218 	_SI( .q_datalen = ) 0,
1219 
1220 	_SI( .enqueue = ) fq_pie_enqueue,
1221 	_SI( .dequeue = ) fq_pie_dequeue,
1222 	_SI( .config = ) fq_pie_config, /* new sched i.e. sched X config ...*/
1223 	_SI( .destroy = ) NULL,  /*sched x delete */
1224 	_SI( .new_sched = ) fq_pie_new_sched, /* new schd instance */
1225 	_SI( .free_sched = ) fq_pie_free_sched,	/* delete schd instance */
1226 	_SI( .new_fsk = ) NULL,
1227 	_SI( .free_fsk = ) NULL,
1228 	_SI( .new_queue = ) NULL,
1229 	_SI( .free_queue = ) NULL,
1230 	_SI( .getconfig = )  fq_pie_getconfig,
1231 	_SI( .ref_count = ) 0
1232 };
1233 
1234 DECLARE_DNSCHED_MODULE(dn_fq_pie, &fq_pie_desc);
1235