altq_rio.c revision 1.10 1 /* $NetBSD: altq_rio.c,v 1.10 2006/05/14 21:24:49 elad Exp $ */
2 /* $KAME: altq_rio.c,v 1.8 2000/12/14 08:12:46 thorpej Exp $ */
3
4 /*
5 * Copyright (C) 1998-2000
6 * Sony Computer Science Laboratories Inc. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29 /*
30 * Copyright (c) 1990-1994 Regents of the University of California.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 * must display the following acknowledgement:
43 * This product includes software developed by the Computer Systems
44 * Engineering Group at Lawrence Berkeley Laboratory.
45 * 4. Neither the name of the University nor of the Laboratory may be used
46 * to endorse or promote products derived from this software without
47 * specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 */
61
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: altq_rio.c,v 1.10 2006/05/14 21:24:49 elad Exp $");
64
65 #if defined(__FreeBSD__) || defined(__NetBSD__)
66 #include "opt_altq.h"
67 #if (__FreeBSD__ != 2)
68 #include "opt_inet.h"
69 #ifdef __FreeBSD__
70 #include "opt_inet6.h"
71 #endif
72 #endif
73 #endif /* __FreeBSD__ || __NetBSD__ */
74 #ifdef ALTQ_RIO /* rio is enabled by ALTQ_RIO option in opt_altq.h */
75
76 #include <sys/param.h>
77 #include <sys/malloc.h>
78 #include <sys/mbuf.h>
79 #include <sys/socket.h>
80 #include <sys/sockio.h>
81 #include <sys/systm.h>
82 #include <sys/proc.h>
83 #include <sys/errno.h>
84 #include <sys/kernel.h>
85
86 #include <net/if.h>
87 #include <net/if_types.h>
88
89 #include <netinet/in.h>
90 #include <netinet/in_systm.h>
91 #include <netinet/ip.h>
92 #ifdef INET6
93 #include <netinet/ip6.h>
94 #endif
95
96 #include <altq/altq.h>
97 #include <altq/altq_conf.h>
98 #include <altq/altq_cdnr.h>
99 #include <altq/altq_red.h>
100 #include <altq/altq_rio.h>
101
102 /*
103 * RIO: RED with IN/OUT bit
104 * described in
105 * "Explicit Allocation of Best Effort Packet Delivery Service"
106 * David D. Clark and Wenjia Fang, MIT Lab for Computer Science
107 * http://diffserv.lcs.mit.edu/Papers/exp-alloc-ddc-wf.{ps,pdf}
108 *
109 * this implementation is extended to support more than 2 drop precedence
110 * values as described in RFC2597 (Assured Forwarding PHB Group).
111 *
112 */
113 /*
114 * AF DS (differentiated service) codepoints.
115 * (classes can be mapped to CBQ or H-FSC classes.)
116 *
117 * 0 1 2 3 4 5 6 7
118 * +---+---+---+---+---+---+---+---+
119 * | CLASS |DropPre| 0 | CU |
120 * +---+---+---+---+---+---+---+---+
121 *
122 * class 1: 001
123 * class 2: 010
124 * class 3: 011
125 * class 4: 100
126 *
127 * low drop prec: 01
128 * medium drop prec: 10
129 * high drop prec: 01
130 */
131
132 /* normal red parameters */
133 #define W_WEIGHT 512 /* inverse of weight of EWMA (511/512) */
134 /* q_weight = 0.00195 */
135
136 /* red parameters for a slow link */
137 #define W_WEIGHT_1 128 /* inverse of weight of EWMA (127/128) */
138 /* q_weight = 0.0078125 */
139
140 /* red parameters for a very slow link (e.g., dialup) */
141 #define W_WEIGHT_2 64 /* inverse of weight of EWMA (63/64) */
142 /* q_weight = 0.015625 */
143
144 /* fixed-point uses 12-bit decimal places */
145 #define FP_SHIFT 12 /* fixed-point shift */
146
147 /* red parameters for drop probability */
148 #define INV_P_MAX 10 /* inverse of max drop probability */
149 #define TH_MIN 5 /* min threshold */
150 #define TH_MAX 15 /* max threshold */
151
152 #define RIO_LIMIT 60 /* default max queue length */
153
154 #define TV_DELTA(a, b, delta) { \
155 register int xxs; \
156 \
157 delta = (a)->tv_usec - (b)->tv_usec; \
158 if ((xxs = (a)->tv_sec - (b)->tv_sec) != 0) { \
159 if (xxs < 0) { \
160 printf("rm_class: bogus time values"); \
161 delta = 60000000; \
162 } else if (xxs > 4) { \
163 if (xxs > 60) \
164 delta = 60000000; \
165 else \
166 delta += xxs * 1000000; \
167 } else while (xxs > 0) { \
168 delta += 1000000; \
169 xxs--; \
170 } \
171 } \
172 }
173
174 /* rio_list keeps all rio_queue_t's allocated. */
175 static rio_queue_t *rio_list = NULL;
176 /* default rio parameter values */
177 static struct redparams default_rio_params[RIO_NDROPPREC] = {
178 /* th_min, th_max, inv_pmax */
179 { TH_MAX * 2 + TH_MIN, TH_MAX * 3, INV_P_MAX }, /* low drop precedence */
180 { TH_MAX + TH_MIN, TH_MAX * 2, INV_P_MAX }, /* medium drop precedence */
181 { TH_MIN, TH_MAX, INV_P_MAX } /* high drop precedence */
182 };
183
184 /* internal function prototypes */
185 static int rio_enqueue __P((struct ifaltq *, struct mbuf *,
186 struct altq_pktattr *));
187 static struct mbuf *rio_dequeue __P((struct ifaltq *, int));
188 static int rio_request __P((struct ifaltq *, int, void *));
189 static int rio_detach __P((rio_queue_t *));
190 static int dscp2index __P((u_int8_t));
191
192 /*
193 * rio device interface
194 */
195 altqdev_decl(rio);
196
197 int
198 rioopen(dev, flag, fmt, l)
199 dev_t dev;
200 int flag, fmt;
201 struct lwp *l;
202 {
203 /* everything will be done when the queueing scheme is attached. */
204 return 0;
205 }
206
207 int
208 rioclose(dev, flag, fmt, l)
209 dev_t dev;
210 int flag, fmt;
211 struct lwp *l;
212 {
213 rio_queue_t *rqp;
214 int err, error = 0;
215
216 while ((rqp = rio_list) != NULL) {
217 /* destroy all */
218 err = rio_detach(rqp);
219 if (err != 0 && error == 0)
220 error = err;
221 }
222
223 return error;
224 }
225
226 int
227 rioioctl(dev, cmd, addr, flag, l)
228 dev_t dev;
229 ioctlcmd_t cmd;
230 caddr_t addr;
231 int flag;
232 struct lwp *l;
233 {
234 rio_queue_t *rqp;
235 struct rio_interface *ifacep;
236 struct ifnet *ifp;
237 struct proc *p = l->l_proc;
238 int error = 0;
239
240 /* check super-user privilege */
241 switch (cmd) {
242 case RIO_GETSTATS:
243 break;
244 default:
245 #if (__FreeBSD_version > 400000)
246 if ((error = suser(p)) != 0)
247 return (error);
248 #else
249 if ((error = kauth_authorize_generic(p->p_cred,
250 KAUTH_GENERIC_ISSUSER,
251 &p->p_acflag)) != 0)
252 return (error);
253 #endif
254 break;
255 }
256
257 switch (cmd) {
258
259 case RIO_ENABLE:
260 ifacep = (struct rio_interface *)addr;
261 if ((rqp = altq_lookup(ifacep->rio_ifname, ALTQT_RIO)) == NULL) {
262 error = EBADF;
263 break;
264 }
265 error = altq_enable(rqp->rq_ifq);
266 break;
267
268 case RIO_DISABLE:
269 ifacep = (struct rio_interface *)addr;
270 if ((rqp = altq_lookup(ifacep->rio_ifname, ALTQT_RIO)) == NULL) {
271 error = EBADF;
272 break;
273 }
274 error = altq_disable(rqp->rq_ifq);
275 break;
276
277 case RIO_IF_ATTACH:
278 ifp = ifunit(((struct rio_interface *)addr)->rio_ifname);
279 if (ifp == NULL) {
280 error = ENXIO;
281 break;
282 }
283
284 /* allocate and initialize rio_queue_t */
285 rqp = malloc(sizeof(rio_queue_t), M_DEVBUF, M_WAITOK|M_ZERO);
286 if (rqp == NULL) {
287 error = ENOMEM;
288 break;
289 }
290
291 rqp->rq_q = malloc(sizeof(class_queue_t), M_DEVBUF,
292 M_WAITOK|M_ZERO);
293 if (rqp->rq_q == NULL) {
294 free(rqp, M_DEVBUF);
295 error = ENOMEM;
296 break;
297 }
298
299 rqp->rq_rio = rio_alloc(0, NULL, 0, 0);
300 if (rqp->rq_rio == NULL) {
301 free(rqp->rq_q, M_DEVBUF);
302 free(rqp, M_DEVBUF);
303 error = ENOMEM;
304 break;
305 }
306
307 rqp->rq_ifq = &ifp->if_snd;
308 qtail(rqp->rq_q) = NULL;
309 qlen(rqp->rq_q) = 0;
310 qlimit(rqp->rq_q) = RIO_LIMIT;
311 qtype(rqp->rq_q) = Q_RIO;
312
313 /*
314 * set RIO to this ifnet structure.
315 */
316 error = altq_attach(rqp->rq_ifq, ALTQT_RIO, rqp,
317 rio_enqueue, rio_dequeue, rio_request,
318 NULL, NULL);
319 if (error) {
320 rio_destroy(rqp->rq_rio);
321 free(rqp->rq_q, M_DEVBUF);
322 free(rqp, M_DEVBUF);
323 break;
324 }
325
326 /* add this state to the rio list */
327 rqp->rq_next = rio_list;
328 rio_list = rqp;
329 break;
330
331 case RIO_IF_DETACH:
332 ifacep = (struct rio_interface *)addr;
333 if ((rqp = altq_lookup(ifacep->rio_ifname, ALTQT_RIO)) == NULL) {
334 error = EBADF;
335 break;
336 }
337 error = rio_detach(rqp);
338 break;
339
340 case RIO_GETSTATS:
341 do {
342 struct rio_stats *q_stats;
343 rio_t *rp;
344 int i;
345
346 q_stats = (struct rio_stats *)addr;
347 if ((rqp = altq_lookup(q_stats->iface.rio_ifname,
348 ALTQT_RIO)) == NULL) {
349 error = EBADF;
350 break;
351 }
352
353 rp = rqp->rq_rio;
354
355 q_stats->q_limit = qlimit(rqp->rq_q);
356 q_stats->weight = rp->rio_weight;
357 q_stats->flags = rp->rio_flags;
358
359 for (i = 0; i < RIO_NDROPPREC; i++) {
360 q_stats->q_len[i] = rp->rio_precstate[i].qlen;
361 (void)memcpy(&q_stats->q_stats[i],
362 &rp->q_stats[i], sizeof(struct redstats));
363 q_stats->q_stats[i].q_avg =
364 rp->rio_precstate[i].avg >> rp->rio_wshift;
365
366 q_stats->q_params[i].inv_pmax
367 = rp->rio_precstate[i].inv_pmax;
368 q_stats->q_params[i].th_min
369 = rp->rio_precstate[i].th_min;
370 q_stats->q_params[i].th_max
371 = rp->rio_precstate[i].th_max;
372 }
373 } while (0);
374 break;
375
376 case RIO_CONFIG:
377 do {
378 struct rio_conf *fc;
379 rio_t *new;
380 int s, limit, i;
381
382 fc = (struct rio_conf *)addr;
383 if ((rqp = altq_lookup(fc->iface.rio_ifname,
384 ALTQT_RIO)) == NULL) {
385 error = EBADF;
386 break;
387 }
388
389 new = rio_alloc(fc->rio_weight, &fc->q_params[0],
390 fc->rio_flags, fc->rio_pkttime);
391 if (new == NULL) {
392 error = ENOMEM;
393 break;
394 }
395
396 s = splnet();
397 _flushq(rqp->rq_q);
398 limit = fc->rio_limit;
399 if (limit < fc->q_params[RIO_NDROPPREC-1].th_max)
400 limit = fc->q_params[RIO_NDROPPREC-1].th_max;
401 qlimit(rqp->rq_q) = limit;
402
403 rio_destroy(rqp->rq_rio);
404 rqp->rq_rio = new;
405
406 splx(s);
407
408 /* write back new values */
409 fc->rio_limit = limit;
410 for (i = 0; i < RIO_NDROPPREC; i++) {
411 fc->q_params[i].inv_pmax =
412 rqp->rq_rio->rio_precstate[i].inv_pmax;
413 fc->q_params[i].th_min =
414 rqp->rq_rio->rio_precstate[i].th_min;
415 fc->q_params[i].th_max =
416 rqp->rq_rio->rio_precstate[i].th_max;
417 }
418 } while (0);
419 break;
420
421 case RIO_SETDEFAULTS:
422 do {
423 struct redparams *rp;
424 int i;
425
426 rp = (struct redparams *)addr;
427 for (i = 0; i < RIO_NDROPPREC; i++)
428 default_rio_params[i] = rp[i];
429 } while (0);
430 break;
431
432 default:
433 error = EINVAL;
434 break;
435 }
436
437 return error;
438 }
439
440 static int
441 rio_detach(rqp)
442 rio_queue_t *rqp;
443 {
444 rio_queue_t *tmp;
445 int error = 0;
446
447 if (ALTQ_IS_ENABLED(rqp->rq_ifq))
448 altq_disable(rqp->rq_ifq);
449
450 if ((error = altq_detach(rqp->rq_ifq)))
451 return (error);
452
453 if (rio_list == rqp)
454 rio_list = rqp->rq_next;
455 else {
456 for (tmp = rio_list; tmp != NULL; tmp = tmp->rq_next)
457 if (tmp->rq_next == rqp) {
458 tmp->rq_next = rqp->rq_next;
459 break;
460 }
461 if (tmp == NULL)
462 printf("rio_detach: no state found in rio_list!\n");
463 }
464
465 rio_destroy(rqp->rq_rio);
466 free(rqp->rq_q, M_DEVBUF);
467 free(rqp, M_DEVBUF);
468 return (error);
469 }
470
471 /*
472 * rio support routines
473 */
474 static int
475 rio_request(ifq, req, arg)
476 struct ifaltq *ifq;
477 int req;
478 void *arg;
479 {
480 rio_queue_t *rqp = (rio_queue_t *)ifq->altq_disc;
481
482 switch (req) {
483 case ALTRQ_PURGE:
484 _flushq(rqp->rq_q);
485 if (ALTQ_IS_ENABLED(ifq))
486 ifq->ifq_len = 0;
487 break;
488 }
489 return (0);
490 }
491
492
493 rio_t *
494 rio_alloc(weight, params, flags, pkttime)
495 int weight;
496 struct redparams *params;
497 int flags, pkttime;
498 {
499 rio_t *rp;
500 int w, i;
501 int npkts_per_sec;
502
503 rp = malloc(sizeof(rio_t), M_DEVBUF, M_WAITOK|M_ZERO);
504 if (rp == NULL)
505 return (NULL);
506
507 rp->rio_flags = flags;
508 if (pkttime == 0)
509 /* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */
510 rp->rio_pkttime = 800;
511 else
512 rp->rio_pkttime = pkttime;
513
514 if (weight != 0)
515 rp->rio_weight = weight;
516 else {
517 /* use derfault */
518 rp->rio_weight = W_WEIGHT;
519
520 /* when the link is very slow, adjust red parameters */
521 npkts_per_sec = 1000000 / rp->rio_pkttime;
522 if (npkts_per_sec < 50) {
523 /* up to about 400Kbps */
524 rp->rio_weight = W_WEIGHT_2;
525 } else if (npkts_per_sec < 300) {
526 /* up to about 2.4Mbps */
527 rp->rio_weight = W_WEIGHT_1;
528 }
529 }
530
531 /* calculate wshift. weight must be power of 2 */
532 w = rp->rio_weight;
533 for (i = 0; w > 1; i++)
534 w = w >> 1;
535 rp->rio_wshift = i;
536 w = 1 << rp->rio_wshift;
537 if (w != rp->rio_weight) {
538 printf("invalid weight value %d for red! use %d\n",
539 rp->rio_weight, w);
540 rp->rio_weight = w;
541 }
542
543 /* allocate weight table */
544 rp->rio_wtab = wtab_alloc(rp->rio_weight);
545
546 for (i = 0; i < RIO_NDROPPREC; i++) {
547 struct dropprec_state *prec = &rp->rio_precstate[i];
548
549 prec->avg = 0;
550 prec->idle = 1;
551
552 if (params == NULL || params[i].inv_pmax == 0)
553 prec->inv_pmax = default_rio_params[i].inv_pmax;
554 else
555 prec->inv_pmax = params[i].inv_pmax;
556 if (params == NULL || params[i].th_min == 0)
557 prec->th_min = default_rio_params[i].th_min;
558 else
559 prec->th_min = params[i].th_min;
560 if (params == NULL || params[i].th_max == 0)
561 prec->th_max = default_rio_params[i].th_max;
562 else
563 prec->th_max = params[i].th_max;
564
565 /*
566 * th_min_s and th_max_s are scaled versions of th_min
567 * and th_max to be compared with avg.
568 */
569 prec->th_min_s = prec->th_min << (rp->rio_wshift + FP_SHIFT);
570 prec->th_max_s = prec->th_max << (rp->rio_wshift + FP_SHIFT);
571
572 /*
573 * precompute probability denominator
574 * probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point
575 */
576 prec->probd = (2 * (prec->th_max - prec->th_min)
577 * prec->inv_pmax) << FP_SHIFT;
578
579 microtime(&prec->last);
580 }
581
582 return (rp);
583 }
584
585 void
586 rio_destroy(rp)
587 rio_t *rp;
588 {
589 wtab_destroy(rp->rio_wtab);
590 free(rp, M_DEVBUF);
591 }
592
593 void
594 rio_getstats(rp, sp)
595 rio_t *rp;
596 struct redstats *sp;
597 {
598 int i;
599
600 for (i = 0; i < RIO_NDROPPREC; i++) {
601 (void)memcpy(sp, &rp->q_stats[i], sizeof(struct redstats));
602 sp->q_avg = rp->rio_precstate[i].avg >> rp->rio_wshift;
603 sp++;
604 }
605 }
606
607 /*
608 * enqueue routine:
609 *
610 * returns: 0 when successfully queued.
611 * ENOBUFS when drop occurs.
612 */
613 static int
614 rio_enqueue(ifq, m, pktattr)
615 struct ifaltq *ifq;
616 struct mbuf *m;
617 struct altq_pktattr *pktattr;
618 {
619 rio_queue_t *rqp = (rio_queue_t *)ifq->altq_disc;
620 int error = 0;
621
622 if (rio_addq(rqp->rq_rio, rqp->rq_q, m, pktattr) == 0)
623 ifq->ifq_len++;
624 else
625 error = ENOBUFS;
626 return error;
627 }
628
629 #if (RIO_NDROPPREC == 3)
630 /*
631 * internally, a drop precedence value is converted to an index
632 * starting from 0.
633 */
634 static int
635 dscp2index(u_int8_t dscp)
636 {
637 int dpindex = dscp & AF_DROPPRECMASK;
638
639 if (dpindex == 0)
640 return (0);
641 return ((dpindex >> 3) - 1);
642 }
643 #endif
644
645 #if 1
646 /*
647 * kludge: when a packet is dequeued, we need to know its drop precedence
648 * in order to keep the queue length of each drop precedence.
649 * use m_pkthdr.rcvif to pass this info.
650 */
651 #define RIOM_SET_PRECINDEX(m, idx) \
652 do { (m)->m_pkthdr.rcvif = (struct ifnet *)((long)(idx)); } while (0)
653 #define RIOM_GET_PRECINDEX(m) \
654 ({ long idx; idx = (long)((m)->m_pkthdr.rcvif); \
655 (m)->m_pkthdr.rcvif = NULL; idx; })
656 #endif
657
658 int
659 rio_addq(rp, q, m, pktattr)
660 rio_t *rp;
661 class_queue_t *q;
662 struct mbuf *m;
663 struct altq_pktattr *pktattr;
664 {
665 int avg, droptype;
666 u_int8_t dsfield, odsfield;
667 int dpindex, i, n, t;
668 struct timeval now;
669 struct dropprec_state *prec;
670
671 dsfield = odsfield = read_dsfield(m, pktattr);
672 dpindex = dscp2index(dsfield);
673
674 /*
675 * update avg of the precedence states whose drop precedence
676 * is larger than or equal to the drop precedence of the packet
677 */
678 now.tv_sec = 0;
679 for (i = dpindex; i < RIO_NDROPPREC; i++) {
680 prec = &rp->rio_precstate[i];
681 avg = prec->avg;
682 if (prec->idle) {
683 prec->idle = 0;
684 if (now.tv_sec == 0)
685 microtime(&now);
686 t = (now.tv_sec - prec->last.tv_sec);
687 if (t > 60)
688 avg = 0;
689 else {
690 t = t * 1000000 +
691 (now.tv_usec - prec->last.tv_usec);
692 n = t / rp->rio_pkttime;
693 /* calculate (avg = (1 - Wq)^n * avg) */
694 if (n > 0)
695 avg = (avg >> FP_SHIFT) *
696 pow_w(rp->rio_wtab, n);
697 }
698 }
699
700 /* run estimator. (avg is scaled by WEIGHT in fixed-point) */
701 avg += (prec->qlen << FP_SHIFT) - (avg >> rp->rio_wshift);
702 prec->avg = avg; /* save the new value */
703 /*
704 * count keeps a tally of arriving traffic that has not
705 * been dropped.
706 */
707 prec->count++;
708 }
709
710 prec = &rp->rio_precstate[dpindex];
711 avg = prec->avg;
712
713 /* see if we drop early */
714 droptype = DTYPE_NODROP;
715 if (avg >= prec->th_min_s && prec->qlen > 1) {
716 if (avg >= prec->th_max_s) {
717 /* avg >= th_max: forced drop */
718 droptype = DTYPE_FORCED;
719 } else if (prec->old == 0) {
720 /* first exceeds th_min */
721 prec->count = 1;
722 prec->old = 1;
723 } else if (drop_early((avg - prec->th_min_s) >> rp->rio_wshift,
724 prec->probd, prec->count)) {
725 /* unforced drop by red */
726 droptype = DTYPE_EARLY;
727 }
728 } else {
729 /* avg < th_min */
730 prec->old = 0;
731 }
732
733 /*
734 * if the queue length hits the hard limit, it's a forced drop.
735 */
736 if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q))
737 droptype = DTYPE_FORCED;
738
739 if (droptype != DTYPE_NODROP) {
740 /* always drop incoming packet (as opposed to randomdrop) */
741 for (i = dpindex; i < RIO_NDROPPREC; i++)
742 rp->rio_precstate[i].count = 0;
743 #ifdef RIO_STATS
744 if (droptype == DTYPE_EARLY)
745 rp->q_stats[dpindex].drop_unforced++;
746 else
747 rp->q_stats[dpindex].drop_forced++;
748 PKTCNTR_ADD(&rp->q_stats[dpindex].drop_cnt, m_pktlen(m));
749 #endif
750 m_freem(m);
751 return (-1);
752 }
753
754 for (i = dpindex; i < RIO_NDROPPREC; i++)
755 rp->rio_precstate[i].qlen++;
756
757 /* save drop precedence index in mbuf hdr */
758 RIOM_SET_PRECINDEX(m, dpindex);
759
760 if (rp->rio_flags & RIOF_CLEARDSCP)
761 dsfield &= ~DSCP_MASK;
762
763 if (dsfield != odsfield)
764 write_dsfield(m, pktattr, dsfield);
765
766 _addq(q, m);
767
768 #ifdef RIO_STATS
769 PKTCNTR_ADD(&rp->q_stats[dpindex].xmit_cnt, m_pktlen(m));
770 #endif
771 return (0);
772 }
773
774 /*
775 * dequeue routine:
776 * must be called in splnet.
777 *
778 * returns: mbuf dequeued.
779 * NULL when no packet is available in the queue.
780 */
781
782 static struct mbuf *
783 rio_dequeue(ifq, op)
784 struct ifaltq *ifq;
785 int op;
786 {
787 rio_queue_t *rqp = (rio_queue_t *)ifq->altq_disc;
788 struct mbuf *m = NULL;
789
790 if (op == ALTDQ_POLL)
791 return qhead(rqp->rq_q);
792
793 m = rio_getq(rqp->rq_rio, rqp->rq_q);
794 if (m != NULL)
795 ifq->ifq_len--;
796 return m;
797 }
798
799 struct mbuf *
800 rio_getq(rp, q)
801 rio_t *rp;
802 class_queue_t *q;
803 {
804 struct mbuf *m;
805 int dpindex, i;
806
807 if ((m = _getq(q)) == NULL)
808 return NULL;
809
810 dpindex = RIOM_GET_PRECINDEX(m);
811 for (i = dpindex; i < RIO_NDROPPREC; i++) {
812 if (--rp->rio_precstate[i].qlen == 0) {
813 if (rp->rio_precstate[i].idle == 0) {
814 rp->rio_precstate[i].idle = 1;
815 microtime(&rp->rio_precstate[i].last);
816 }
817 }
818 }
819 return (m);
820 }
821
822 #ifdef KLD_MODULE
823
824 static struct altqsw rio_sw =
825 {"rio", rioopen, rioclose, rioioctl};
826
827 ALTQ_MODULE(altq_rio, ALTQT_RIO, &rio_sw);
828
829 #endif /* KLD_MODULE */
830
831 #endif /* ALTQ_RIO */
832