xref: /freebsd/sys/netpfil/ipfw/dn_sched_fq_codel.c (revision 942815c54820783d3d4f7f6faa71ab7919b5f0e5)
1 /*
2  * FQ_Codel - The FlowQueue-Codel scheduler/AQM
3  *
4  * $FreeBSD$
5  *
6  * Copyright (C) 2016 Centre for Advanced Internet Architectures,
7  *  Swinburne University of Technology, Melbourne, Australia.
8  * Portions of this code were made possible in part by a gift from
9  *  The Comcast Innovation Fund.
10  * Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au>
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifdef _KERNEL
35 #include <sys/malloc.h>
36 #include <sys/socket.h>
37 //#include <sys/socketvar.h>
38 #include <sys/kernel.h>
39 #include <sys/mbuf.h>
40 #include <sys/module.h>
41 #include <net/if.h>	/* IFNAMSIZ */
42 #include <netinet/in.h>
43 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
44 #include <netinet/ip_fw.h>	/* flow_id */
45 #include <netinet/ip_dummynet.h>
46 
47 #include <sys/lock.h>
48 #include <sys/proc.h>
49 #include <sys/rwlock.h>
50 
51 #include <netpfil/ipfw/ip_fw_private.h>
52 #include <sys/sysctl.h>
53 #include <netinet/ip.h>
54 #include <netinet/ip6.h>
55 #include <netinet/ip_icmp.h>
56 #include <netinet/tcp.h>
57 #include <netinet/udp.h>
58 #include <sys/queue.h>
59 #include <sys/hash.h>
60 
61 #include <netpfil/ipfw/dn_heap.h>
62 #include <netpfil/ipfw/ip_dn_private.h>
63 
64 #include <netpfil/ipfw/dn_aqm.h>
65 #include <netpfil/ipfw/dn_aqm_codel.h>
66 #include <netpfil/ipfw/dn_sched.h>
67 #include <netpfil/ipfw/dn_sched_fq_codel.h>
68 #include <netpfil/ipfw/dn_sched_fq_codel_helper.h>
69 
70 #else
71 #include <dn_test.h>
72 #endif
73 
74 /* NOTE: In fq_codel module, we reimplements CoDel AQM functions
75  * because fq_codel use different flows (sub-queues) structure and
76  * dn_queue includes many variables not needed by a flow (sub-queue
77  * )i.e. avoid extra overhead (88 bytes vs 208 bytes).
78  * Also, CoDel functions manages stats of sub-queues as well as the main queue.
79  */
80 
81 #define DN_SCHED_FQ_CODEL 6
82 
83 static struct dn_alg fq_codel_desc;
84 
85 /* fq_codel default parameters including codel */
86 struct dn_sch_fq_codel_parms
87 fq_codel_sysctl = {{5000 * AQM_TIME_1US, 100000 * AQM_TIME_1US,
88 	CODEL_ECN_ENABLED}, 1024, 10240, 1514};
89 
90 static int
91 fqcodel_sysctl_interval_handler(SYSCTL_HANDLER_ARGS)
92 {
93 	int error;
94 	long  value;
95 
96 	value = fq_codel_sysctl.ccfg.interval;
97 	value /= AQM_TIME_1US;
98 	error = sysctl_handle_long(oidp, &value, 0, req);
99 	if (error != 0 || req->newptr == NULL)
100 		return (error);
101 	if (value < 1 || value > 100 * AQM_TIME_1S)
102 		return (EINVAL);
103 	fq_codel_sysctl.ccfg.interval = value * AQM_TIME_1US ;
104 
105 	return (0);
106 }
107 
108 static int
109 fqcodel_sysctl_target_handler(SYSCTL_HANDLER_ARGS)
110 {
111 	int error;
112 	long  value;
113 
114 	value = fq_codel_sysctl.ccfg.target;
115 	value /= AQM_TIME_1US;
116 	error = sysctl_handle_long(oidp, &value, 0, req);
117 	if (error != 0 || req->newptr == NULL)
118 		return (error);
119 	if (value < 1 || value > 5 * AQM_TIME_1S)
120 		return (EINVAL);
121 	fq_codel_sysctl.ccfg.target = value * AQM_TIME_1US ;
122 
123 	return (0);
124 }
125 
126 SYSBEGIN(f4)
127 
128 SYSCTL_DECL(_net_inet);
129 SYSCTL_DECL(_net_inet_ip);
130 SYSCTL_DECL(_net_inet_ip_dummynet);
131 static SYSCTL_NODE(_net_inet_ip_dummynet, OID_AUTO, fqcodel,
132     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
133     "FQ_CODEL");
134 
135 #ifdef SYSCTL_NODE
136 
137 SYSCTL_PROC(_net_inet_ip_dummynet_fqcodel, OID_AUTO, target,
138     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
139     NULL, 0, fqcodel_sysctl_target_handler, "L",
140     "FQ_CoDel target in microsecond");
141 SYSCTL_PROC(_net_inet_ip_dummynet_fqcodel, OID_AUTO, interval,
142     CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
143     NULL, 0, fqcodel_sysctl_interval_handler, "L",
144     "FQ_CoDel interval in microsecond");
145 
146 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, quantum,
147 	CTLFLAG_RW, &fq_codel_sysctl.quantum, 1514, "FQ_CoDel quantum");
148 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, flows,
149 	CTLFLAG_RW, &fq_codel_sysctl.flows_cnt, 1024,
150 	"Number of queues for FQ_CoDel");
151 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, limit,
152 	CTLFLAG_RW, &fq_codel_sysctl.limit, 10240, "FQ_CoDel queues size limit");
153 #endif
154 
155 /* Drop a packet form the head of codel queue */
156 static void
157 codel_drop_head(struct fq_codel_flow *q, struct fq_codel_si *si)
158 {
159 	struct mbuf *m = q->mq.head;
160 
161 	if (m == NULL)
162 		return;
163 	q->mq.head = m->m_nextpkt;
164 
165 	fq_update_stats(q, si, -m->m_pkthdr.len, 1);
166 
167 	if (si->main_q.ni.length == 0) /* queue is now idle */
168 			si->main_q.q_time = V_dn_cfg.curr_time;
169 
170 	FREE_PKT(m);
171 }
172 
173 /* Enqueue a packet 'm' to a queue 'q' and add timestamp to that packet.
174  * Return 1 when unable to add timestamp, otherwise return 0
175  */
176 static int
177 codel_enqueue(struct fq_codel_flow *q, struct mbuf *m, struct fq_codel_si *si)
178 {
179 	uint64_t len;
180 
181 	len = m->m_pkthdr.len;
182 	/* finding maximum packet size */
183 	if (len > q->cst.maxpkt_size)
184 		q->cst.maxpkt_size = len;
185 
186 	/* Add timestamp to mbuf as MTAG */
187 	struct m_tag *mtag;
188 	mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
189 	if (mtag == NULL)
190 		mtag = m_tag_alloc(MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, sizeof(aqm_time_t),
191 			M_NOWAIT);
192 	if (mtag == NULL)
193 		goto drop;
194 	*(aqm_time_t *)(mtag + 1) = AQM_UNOW;
195 	m_tag_prepend(m, mtag);
196 
197 	if (m->m_pkthdr.rcvif != NULL)
198 		m_rcvif_serialize(m);
199 
200 	mq_append(&q->mq, m);
201 	fq_update_stats(q, si, len, 0);
202 	return 0;
203 
204 drop:
205 	fq_update_stats(q, si, len, 1);
206 	m_freem(m);
207 	return 1;
208 }
209 
210 /*
211  * Classify a packet to queue number using Jenkins hash function.
212  * Return: queue number
213  * the input of the hash are protocol no, perturbation, src IP, dst IP,
214  * src port, dst port,
215  */
216 static inline int
217 fq_codel_classify_flow(struct mbuf *m, uint16_t fcount, struct fq_codel_si *si)
218 {
219 	struct ip *ip;
220 	struct tcphdr *th;
221 	struct udphdr *uh;
222 	uint8_t tuple[41];
223 	uint16_t hash=0;
224 
225 	ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off);
226 //#ifdef INET6
227 	struct ip6_hdr *ip6;
228 	int isip6;
229 	isip6 = (ip->ip_v == 6);
230 
231 	if(isip6) {
232 		ip6 = (struct ip6_hdr *)ip;
233 		*((uint8_t *) &tuple[0]) = ip6->ip6_nxt;
234 		*((uint32_t *) &tuple[1]) = si->perturbation;
235 		memcpy(&tuple[5], ip6->ip6_src.s6_addr, 16);
236 		memcpy(&tuple[21], ip6->ip6_dst.s6_addr, 16);
237 
238 		switch (ip6->ip6_nxt) {
239 		case IPPROTO_TCP:
240 			th = (struct tcphdr *)(ip6 + 1);
241 			*((uint16_t *) &tuple[37]) = th->th_dport;
242 			*((uint16_t *) &tuple[39]) = th->th_sport;
243 			break;
244 
245 		case IPPROTO_UDP:
246 			uh = (struct udphdr *)(ip6 + 1);
247 			*((uint16_t *) &tuple[37]) = uh->uh_dport;
248 			*((uint16_t *) &tuple[39]) = uh->uh_sport;
249 			break;
250 		default:
251 			memset(&tuple[37], 0, 4);
252 		}
253 
254 		hash = jenkins_hash(tuple, 41, HASHINIT) %  fcount;
255 		return hash;
256 	}
257 //#endif
258 
259 	/* IPv4 */
260 	*((uint8_t *) &tuple[0]) = ip->ip_p;
261 	*((uint32_t *) &tuple[1]) = si->perturbation;
262 	*((uint32_t *) &tuple[5]) = ip->ip_src.s_addr;
263 	*((uint32_t *) &tuple[9]) = ip->ip_dst.s_addr;
264 
265 	switch (ip->ip_p) {
266 		case IPPROTO_TCP:
267 			th = (struct tcphdr *)(ip + 1);
268 			*((uint16_t *) &tuple[13]) = th->th_dport;
269 			*((uint16_t *) &tuple[15]) = th->th_sport;
270 			break;
271 
272 		case IPPROTO_UDP:
273 			uh = (struct udphdr *)(ip + 1);
274 			*((uint16_t *) &tuple[13]) = uh->uh_dport;
275 			*((uint16_t *) &tuple[15]) = uh->uh_sport;
276 			break;
277 		default:
278 			memset(&tuple[13], 0, 4);
279 	}
280 	hash = jenkins_hash(tuple, 17, HASHINIT) %  fcount;
281 
282 	return hash;
283 }
284 
285 /*
286  * Enqueue a packet into an appropriate queue according to
287  * FQ_CODEL algorithm.
288  */
289 static int
290 fq_codel_enqueue(struct dn_sch_inst *_si, struct dn_queue *_q,
291 	struct mbuf *m)
292 {
293 	struct fq_codel_si *si;
294 	struct fq_codel_schk *schk;
295 	struct dn_sch_fq_codel_parms *param;
296 	struct dn_queue *mainq;
297 	int idx, drop, i, maxidx;
298 
299 	mainq = (struct dn_queue *)(_si + 1);
300 	si = (struct fq_codel_si *)_si;
301 	schk = (struct fq_codel_schk *)(si->_si.sched+1);
302 	param = &schk->cfg;
303 
304 	 /* classify a packet to queue number*/
305 	idx = fq_codel_classify_flow(m, param->flows_cnt, si);
306 	/* enqueue packet into appropriate queue using CoDel AQM.
307 	 * Note: 'codel_enqueue' function returns 1 only when it unable to
308 	 * add timestamp to packet (no limit check)*/
309 	drop = codel_enqueue(&si->flows[idx], m, si);
310 
311 	/* codel unable to timestamp a packet */
312 	if (drop)
313 		return 1;
314 
315 	/* If the flow (sub-queue) is not active ,then add it to the tail of
316 	 * new flows list, initialize and activate it.
317 	 */
318 	if (!si->flows[idx].active ) {
319 		STAILQ_INSERT_TAIL(&si->newflows, &si->flows[idx], flowchain);
320 		si->flows[idx].deficit = param->quantum;
321 		si->flows[idx].cst.dropping = false;
322 		si->flows[idx].cst.first_above_time = 0;
323 		si->flows[idx].active = 1;
324 		//D("activate %d",idx);
325 	}
326 
327 	/* check the limit for all queues and remove a packet from the
328 	 * largest one
329 	 */
330 	if (mainq->ni.length > schk->cfg.limit) { D("over limit");
331 		/* find first active flow */
332 		for (maxidx = 0; maxidx < schk->cfg.flows_cnt; maxidx++)
333 			if (si->flows[maxidx].active)
334 				break;
335 		if (maxidx < schk->cfg.flows_cnt) {
336 			/* find the largest sub- queue */
337 			for (i = maxidx + 1; i < schk->cfg.flows_cnt; i++)
338 				if (si->flows[i].active && si->flows[i].stats.length >
339 					si->flows[maxidx].stats.length)
340 					maxidx = i;
341 			codel_drop_head(&si->flows[maxidx], si);
342 			D("maxidx = %d",maxidx);
343 			drop = 1;
344 		}
345 	}
346 
347 	return drop;
348 }
349 
350 /*
351  * Dequeue a packet from an appropriate queue according to
352  * FQ_CODEL algorithm.
353  */
354 static struct mbuf *
355 fq_codel_dequeue(struct dn_sch_inst *_si)
356 {
357 	struct fq_codel_si *si;
358 	struct fq_codel_schk *schk;
359 	struct dn_sch_fq_codel_parms *param;
360 	struct fq_codel_flow *f;
361 	struct mbuf *mbuf;
362 	struct fq_codel_list *fq_codel_flowlist;
363 
364 	si = (struct fq_codel_si *)_si;
365 	schk = (struct fq_codel_schk *)(si->_si.sched+1);
366 	param = &schk->cfg;
367 
368 	do {
369 		/* select a list to start with */
370 		if (STAILQ_EMPTY(&si->newflows))
371 			fq_codel_flowlist = &si->oldflows;
372 		else
373 			fq_codel_flowlist = &si->newflows;
374 
375 		/* Both new and old queue lists are empty, return NULL */
376 		if (STAILQ_EMPTY(fq_codel_flowlist))
377 			return NULL;
378 
379 		f = STAILQ_FIRST(fq_codel_flowlist);
380 		while (f != NULL)	{
381 			/* if there is no flow(sub-queue) deficit, increase deficit
382 			 * by quantum, move the flow to the tail of old flows list
383 			 * and try another flow.
384 			 * Otherwise, the flow will be used for dequeue.
385 			 */
386 			if (f->deficit < 0) {
387 				 f->deficit += param->quantum;
388 				 STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain);
389 				 STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain);
390 			 } else
391 				 break;
392 
393 			f = STAILQ_FIRST(fq_codel_flowlist);
394 		}
395 
396 		/* the new flows list is empty, try old flows list */
397 		if (STAILQ_EMPTY(fq_codel_flowlist))
398 			continue;
399 
400 		/* Dequeue a packet from the selected flow */
401 		mbuf = fqc_codel_dequeue(f, si);
402 
403 		/* Codel did not return a packet */
404 		if (!mbuf) {
405 			/* If the selected flow belongs to new flows list, then move
406 			 * it to the tail of old flows list. Otherwise, deactivate it and
407 			 * remove it from the old list and
408 			 */
409 			if (fq_codel_flowlist == &si->newflows) {
410 				STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain);
411 				STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain);
412 			}	else {
413 				f->active = 0;
414 				STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain);
415 			}
416 			/* start again */
417 			continue;
418 		}
419 
420 		/* we have a packet to return,
421 		 * update flow deficit and return the packet*/
422 		f->deficit -= mbuf->m_pkthdr.len;
423 		return mbuf;
424 
425 	} while (1);
426 
427 	/* unreachable point */
428 	return NULL;
429 }
430 
431 /*
432  * Initialize fq_codel scheduler instance.
433  * also, allocate memory for flows array.
434  */
435 static int
436 fq_codel_new_sched(struct dn_sch_inst *_si)
437 {
438 	struct fq_codel_si *si;
439 	struct dn_queue *q;
440 	struct fq_codel_schk *schk;
441 	int i;
442 
443 	si = (struct fq_codel_si *)_si;
444 	schk = (struct fq_codel_schk *)(_si->sched+1);
445 
446 	if(si->flows) {
447 		D("si already configured!");
448 		return 0;
449 	}
450 
451 	/* init the main queue */
452 	q = &si->main_q;
453 	set_oid(&q->ni.oid, DN_QUEUE, sizeof(*q));
454 	q->_si = _si;
455 	q->fs = _si->sched->fs;
456 
457 	/* allocate memory for flows array */
458 	si->flows = mallocarray(schk->cfg.flows_cnt,
459 	    sizeof(struct fq_codel_flow), M_DUMMYNET, M_NOWAIT | M_ZERO);
460 	if (si->flows == NULL) {
461 		D("cannot allocate memory for fq_codel configuration parameters");
462 		return ENOMEM ;
463 	}
464 
465 	/* init perturbation for this si */
466 	si->perturbation = random();
467 
468 	/* init the old and new flows lists */
469 	STAILQ_INIT(&si->newflows);
470 	STAILQ_INIT(&si->oldflows);
471 
472 	/* init the flows (sub-queues) */
473 	for (i = 0; i < schk->cfg.flows_cnt; i++) {
474 		/* init codel */
475 		si->flows[i].cst.maxpkt_size = 500;
476 	}
477 
478 	fq_codel_desc.ref_count++;
479 	return 0;
480 }
481 
482 /*
483  * Free fq_codel scheduler instance.
484  */
485 static int
486 fq_codel_free_sched(struct dn_sch_inst *_si)
487 {
488 	struct fq_codel_si *si = (struct fq_codel_si *)_si ;
489 
490 	/* free the flows array */
491 	free(si->flows , M_DUMMYNET);
492 	si->flows = NULL;
493 	fq_codel_desc.ref_count--;
494 
495 	return 0;
496 }
497 
498 /*
499  * Configure fq_codel scheduler.
500  * the configurations for the scheduler is passed from userland.
501  */
502 static int
503 fq_codel_config(struct dn_schk *_schk)
504 {
505 	struct fq_codel_schk *schk;
506 	struct dn_extra_parms *ep;
507 	struct dn_sch_fq_codel_parms *fqc_cfg;
508 
509 	schk = (struct fq_codel_schk *)(_schk+1);
510 	ep = (struct dn_extra_parms *) _schk->cfg;
511 
512 	/* par array contains fq_codel configuration as follow
513 	 * Codel: 0- target,1- interval, 2- flags
514 	 * FQ_CODEL: 3- quantum, 4- limit, 5- flows
515 	 */
516 	if (ep && ep->oid.len ==sizeof(*ep) &&
517 		ep->oid.subtype == DN_SCH_PARAMS) {
518 		fqc_cfg = &schk->cfg;
519 		if (ep->par[0] < 0)
520 			fqc_cfg->ccfg.target = fq_codel_sysctl.ccfg.target;
521 		else
522 			fqc_cfg->ccfg.target = ep->par[0] * AQM_TIME_1US;
523 
524 		if (ep->par[1] < 0)
525 			fqc_cfg->ccfg.interval = fq_codel_sysctl.ccfg.interval;
526 		else
527 			fqc_cfg->ccfg.interval = ep->par[1] * AQM_TIME_1US;
528 
529 		if (ep->par[2] < 0)
530 			fqc_cfg->ccfg.flags = 0;
531 		else
532 			fqc_cfg->ccfg.flags = ep->par[2];
533 
534 		/* FQ configurations */
535 		if (ep->par[3] < 0)
536 			fqc_cfg->quantum = fq_codel_sysctl.quantum;
537 		else
538 			fqc_cfg->quantum = ep->par[3];
539 
540 		if (ep->par[4] < 0)
541 			fqc_cfg->limit = fq_codel_sysctl.limit;
542 		else
543 			fqc_cfg->limit = ep->par[4];
544 
545 		if (ep->par[5] < 0)
546 			fqc_cfg->flows_cnt = fq_codel_sysctl.flows_cnt;
547 		else
548 			fqc_cfg->flows_cnt = ep->par[5];
549 
550 		/* Bound the configurations */
551 		fqc_cfg->ccfg.target = BOUND_VAR(fqc_cfg->ccfg.target, 1 ,
552 			5 * AQM_TIME_1S); ;
553 		fqc_cfg->ccfg.interval = BOUND_VAR(fqc_cfg->ccfg.interval, 1,
554 			100 * AQM_TIME_1S);
555 
556 		fqc_cfg->quantum = BOUND_VAR(fqc_cfg->quantum,1, 9000);
557 		fqc_cfg->limit= BOUND_VAR(fqc_cfg->limit,1,20480);
558 		fqc_cfg->flows_cnt= BOUND_VAR(fqc_cfg->flows_cnt,1,65536);
559 	}
560 	else
561 		return 1;
562 
563 	return 0;
564 }
565 
566 /*
567  * Return fq_codel scheduler configurations
568  * the configurations for the scheduler is passed to userland.
569  */
570 static int
571 fq_codel_getconfig (struct dn_schk *_schk, struct dn_extra_parms *ep) {
572 	struct fq_codel_schk *schk = (struct fq_codel_schk *)(_schk+1);
573 	struct dn_sch_fq_codel_parms *fqc_cfg;
574 
575 	fqc_cfg = &schk->cfg;
576 
577 	strcpy(ep->name, fq_codel_desc.name);
578 	ep->par[0] = fqc_cfg->ccfg.target / AQM_TIME_1US;
579 	ep->par[1] = fqc_cfg->ccfg.interval / AQM_TIME_1US;
580 	ep->par[2] = fqc_cfg->ccfg.flags;
581 
582 	ep->par[3] = fqc_cfg->quantum;
583 	ep->par[4] = fqc_cfg->limit;
584 	ep->par[5] = fqc_cfg->flows_cnt;
585 
586 	return 0;
587 }
588 
589 /*
590  * fq_codel scheduler descriptor
591  * contains the type of the scheduler, the name, the size of extra
592  * data structures, and function pointers.
593  */
594 static struct dn_alg fq_codel_desc = {
595 	_SI( .type = )  DN_SCHED_FQ_CODEL,
596 	_SI( .name = ) "FQ_CODEL",
597 	_SI( .flags = ) 0,
598 
599 	_SI( .schk_datalen = ) sizeof(struct fq_codel_schk),
600 	_SI( .si_datalen = ) sizeof(struct fq_codel_si) - sizeof(struct dn_sch_inst),
601 	_SI( .q_datalen = ) 0,
602 
603 	_SI( .enqueue = ) fq_codel_enqueue,
604 	_SI( .dequeue = ) fq_codel_dequeue,
605 	_SI( .config = ) fq_codel_config, /* new sched i.e. sched X config ...*/
606 	_SI( .destroy = ) NULL,  /*sched x delete */
607 	_SI( .new_sched = ) fq_codel_new_sched, /* new schd instance */
608 	_SI( .free_sched = ) fq_codel_free_sched,	/* delete schd instance */
609 	_SI( .new_fsk = ) NULL,
610 	_SI( .free_fsk = ) NULL,
611 	_SI( .new_queue = ) NULL,
612 	_SI( .free_queue = ) NULL,
613 	_SI( .getconfig = )  fq_codel_getconfig,
614 	_SI( .ref_count = ) 0
615 };
616 
617 DECLARE_DNSCHED_MODULE(dn_fq_codel, &fq_codel_desc);
618