xref: /freebsd/sys/netgraph/ng_car.c (revision 662c13053f4bf2d6245ba7e2b66c10d1cd5c1fb9)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005 Nuno Antunes <nuno.antunes@gmail.com>
5  * Copyright (c) 2007 Alexander Motin <mav@freebsd.org>
6  * 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 AUTHOR 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 AUTHOR 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  * $FreeBSD$
30  */
31 
32 /*
33  * ng_car - An implementation of committed access rate for netgraph
34  *
35  * TODO:
36  *	- Sanitize input config values (impose some limits)
37  *	- Implement internal packet painting (possibly using mbuf tags)
38  *	- Implement color-aware mode
39  *	- Implement DSCP marking for IPv4
40  */
41 
42 #include <sys/param.h>
43 #include <sys/errno.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 
48 #include <netgraph/ng_message.h>
49 #include <netgraph/ng_parse.h>
50 #include <netgraph/netgraph.h>
51 #include <netgraph/ng_car.h>
52 
53 #define NG_CAR_QUEUE_SIZE	100	/* Maximum queue size for SHAPE mode */
54 #define NG_CAR_QUEUE_MIN_TH	8	/* Minimum RED threshold for SHAPE mode */
55 
56 /* Hook private info */
57 struct hookinfo {
58 	hook_p		hook;		/* this (source) hook */
59 	hook_p		dest;		/* destination hook */
60 
61 	int64_t 	tc;		/* committed token bucket counter */
62 	int64_t 	te;		/* exceeded/peak token bucket counter */
63 	struct bintime	lastRefill;	/* last token refill time */
64 
65 	struct ng_car_hookconf conf;	/* hook configuration */
66 	struct ng_car_hookstats stats;	/* hook stats */
67 
68 	struct mbuf	*q[NG_CAR_QUEUE_SIZE];	/* circular packet queue */
69 	u_int		q_first;	/* first queue element */
70 	u_int		q_last;		/* last queue element */
71 	struct callout	q_callout;	/* periodic queue processing routine */
72 	struct mtx	q_mtx;		/* queue mutex */
73 };
74 
75 /* Private information for each node instance */
76 struct privdata {
77 	node_p node;				/* the node itself */
78 	struct hookinfo upper;			/* hook to upper layers */
79 	struct hookinfo lower;			/* hook to lower layers */
80 };
81 typedef struct privdata *priv_p;
82 
83 static ng_constructor_t	ng_car_constructor;
84 static ng_rcvmsg_t	ng_car_rcvmsg;
85 static ng_shutdown_t	ng_car_shutdown;
86 static ng_newhook_t	ng_car_newhook;
87 static ng_rcvdata_t	ng_car_rcvdata;
88 static ng_disconnect_t	ng_car_disconnect;
89 
90 static void	ng_car_refillhook(struct hookinfo *h);
91 static void	ng_car_schedule(struct hookinfo *h);
92 void		ng_car_q_event(node_p node, hook_p hook, void *arg, int arg2);
93 static void	ng_car_enqueue(struct hookinfo *h, item_p item);
94 
95 /* Parse type for struct ng_car_hookstats */
96 static const struct ng_parse_struct_field ng_car_hookstats_type_fields[]
97 	= NG_CAR_HOOKSTATS;
98 static const struct ng_parse_type ng_car_hookstats_type = {
99 	&ng_parse_struct_type,
100 	&ng_car_hookstats_type_fields
101 };
102 
103 /* Parse type for struct ng_car_bulkstats */
104 static const struct ng_parse_struct_field ng_car_bulkstats_type_fields[]
105 	= NG_CAR_BULKSTATS(&ng_car_hookstats_type);
106 static const struct ng_parse_type ng_car_bulkstats_type = {
107 	&ng_parse_struct_type,
108 	&ng_car_bulkstats_type_fields
109 };
110 
111 /* Parse type for struct ng_car_hookconf */
112 static const struct ng_parse_struct_field ng_car_hookconf_type_fields[]
113 	= NG_CAR_HOOKCONF;
114 static const struct ng_parse_type ng_car_hookconf_type = {
115 	&ng_parse_struct_type,
116 	&ng_car_hookconf_type_fields
117 };
118 
119 /* Parse type for struct ng_car_bulkconf */
120 static const struct ng_parse_struct_field ng_car_bulkconf_type_fields[]
121 	= NG_CAR_BULKCONF(&ng_car_hookconf_type);
122 static const struct ng_parse_type ng_car_bulkconf_type = {
123 	&ng_parse_struct_type,
124 	&ng_car_bulkconf_type_fields
125 };
126 
127 /* Command list */
128 static struct ng_cmdlist ng_car_cmdlist[] = {
129 	{
130 	  NGM_CAR_COOKIE,
131 	  NGM_CAR_GET_STATS,
132 	  "getstats",
133 	  NULL,
134 	  &ng_car_bulkstats_type,
135 	},
136 	{
137 	  NGM_CAR_COOKIE,
138 	  NGM_CAR_CLR_STATS,
139 	  "clrstats",
140 	  NULL,
141 	  NULL,
142 	},
143 	{
144 	  NGM_CAR_COOKIE,
145 	  NGM_CAR_GETCLR_STATS,
146 	  "getclrstats",
147 	  NULL,
148 	  &ng_car_bulkstats_type,
149 	},
150 
151 	{
152 	  NGM_CAR_COOKIE,
153 	  NGM_CAR_GET_CONF,
154 	  "getconf",
155 	  NULL,
156 	  &ng_car_bulkconf_type,
157 	},
158 	{
159 	  NGM_CAR_COOKIE,
160 	  NGM_CAR_SET_CONF,
161 	  "setconf",
162 	  &ng_car_bulkconf_type,
163 	  NULL,
164 	},
165 	{ 0 }
166 };
167 
168 /* Netgraph node type descriptor */
169 static struct ng_type ng_car_typestruct = {
170 	.version =	NG_ABI_VERSION,
171 	.name =		NG_CAR_NODE_TYPE,
172 	.constructor =	ng_car_constructor,
173 	.rcvmsg =	ng_car_rcvmsg,
174 	.shutdown =	ng_car_shutdown,
175 	.newhook =	ng_car_newhook,
176 	.rcvdata =	ng_car_rcvdata,
177 	.disconnect =	ng_car_disconnect,
178 	.cmdlist =	ng_car_cmdlist,
179 };
180 NETGRAPH_INIT(car, &ng_car_typestruct);
181 
182 /*
183  * Node constructor
184  */
185 static int
186 ng_car_constructor(node_p node)
187 {
188 	priv_p priv;
189 
190 	/* Initialize private descriptor. */
191 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
192 
193 	NG_NODE_SET_PRIVATE(node, priv);
194 	priv->node = node;
195 
196 	/*
197 	 * Arbitrary default values
198 	 */
199 
200 	priv->upper.hook = NULL;
201 	priv->upper.dest = NULL;
202 	priv->upper.tc = priv->upper.conf.cbs = NG_CAR_CBS_MIN;
203 	priv->upper.te = priv->upper.conf.ebs = NG_CAR_EBS_MIN;
204 	priv->upper.conf.cir = NG_CAR_CIR_DFLT;
205 	priv->upper.conf.green_action = NG_CAR_ACTION_FORWARD;
206 	priv->upper.conf.yellow_action = NG_CAR_ACTION_FORWARD;
207 	priv->upper.conf.red_action = NG_CAR_ACTION_DROP;
208 	priv->upper.conf.mode = 0;
209 	getbinuptime(&priv->upper.lastRefill);
210 	priv->upper.q_first = 0;
211 	priv->upper.q_last = 0;
212 	ng_callout_init(&priv->upper.q_callout);
213 	mtx_init(&priv->upper.q_mtx, "ng_car_u", NULL, MTX_DEF);
214 
215 	priv->lower.hook = NULL;
216 	priv->lower.dest = NULL;
217 	priv->lower.tc = priv->lower.conf.cbs = NG_CAR_CBS_MIN;
218 	priv->lower.te = priv->lower.conf.ebs = NG_CAR_EBS_MIN;
219 	priv->lower.conf.cir = NG_CAR_CIR_DFLT;
220 	priv->lower.conf.green_action = NG_CAR_ACTION_FORWARD;
221 	priv->lower.conf.yellow_action = NG_CAR_ACTION_FORWARD;
222 	priv->lower.conf.red_action = NG_CAR_ACTION_DROP;
223 	priv->lower.conf.mode = 0;
224 	priv->lower.lastRefill = priv->upper.lastRefill;
225 	priv->lower.q_first = 0;
226 	priv->lower.q_last = 0;
227 	ng_callout_init(&priv->lower.q_callout);
228 	mtx_init(&priv->lower.q_mtx, "ng_car_l", NULL, MTX_DEF);
229 
230 	return (0);
231 }
232 
233 /*
234  * Add a hook.
235  */
236 static int
237 ng_car_newhook(node_p node, hook_p hook, const char *name)
238 {
239 	const priv_p priv = NG_NODE_PRIVATE(node);
240 
241 	if (strcmp(name, NG_CAR_HOOK_LOWER) == 0) {
242 		priv->lower.hook = hook;
243 		priv->upper.dest = hook;
244 		bzero(&priv->lower.stats, sizeof(priv->lower.stats));
245 		NG_HOOK_SET_PRIVATE(hook, &priv->lower);
246 	} else if (strcmp(name, NG_CAR_HOOK_UPPER) == 0) {
247 		priv->upper.hook = hook;
248 		priv->lower.dest = hook;
249 		bzero(&priv->upper.stats, sizeof(priv->upper.stats));
250 		NG_HOOK_SET_PRIVATE(hook, &priv->upper);
251 	} else
252 		return (EINVAL);
253 	return(0);
254 }
255 
256 /*
257  * Data has arrived.
258  */
259 static int
260 ng_car_rcvdata(hook_p hook, item_p item )
261 {
262 	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
263 	struct mbuf *m;
264 	int error = 0;
265 	u_int len;
266 
267 	/* If queue is not empty now then enqueue packet. */
268 	if (hinfo->q_first != hinfo->q_last) {
269 		ng_car_enqueue(hinfo, item);
270 		return (0);
271 	}
272 
273 	m = NGI_M(item);
274 
275 #define NG_CAR_PERFORM_MATCH_ACTION(a)			\
276 	do {						\
277 		switch (a) {				\
278 		case NG_CAR_ACTION_FORWARD:		\
279 			/* Do nothing. */		\
280 			break;				\
281 		case NG_CAR_ACTION_MARK:		\
282 			/* XXX find a way to mark packets (mbuf tag?) */ \
283 			++hinfo->stats.errors;		\
284 			break;				\
285 		case NG_CAR_ACTION_DROP:		\
286 		default:				\
287 			/* Drop packet and return. */	\
288 			NG_FREE_ITEM(item);		\
289 			++hinfo->stats.dropped_pkts;	\
290 			return (0);			\
291 		}					\
292 	} while (0)
293 
294 	/* Packet is counted as 128 tokens for better resolution */
295 	if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
296 		len = 128;
297 	} else {
298 		len = m->m_pkthdr.len;
299 	}
300 
301 	/* Check committed token bucket. */
302 	if (hinfo->tc - len >= 0) {
303 		/* This packet is green. */
304 		++hinfo->stats.green_pkts;
305 		hinfo->tc -= len;
306 		NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.green_action);
307 	} else {
308 		/* Refill only if not green without it. */
309 		ng_car_refillhook(hinfo);
310 
311 		 /* Check committed token bucket again after refill. */
312 		if (hinfo->tc - len >= 0) {
313 			/* This packet is green */
314 			++hinfo->stats.green_pkts;
315 			hinfo->tc -= len;
316 			NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.green_action);
317 
318 		/* If not green and mode is SHAPE, enqueue packet. */
319 		} else if (hinfo->conf.mode == NG_CAR_SHAPE) {
320 			ng_car_enqueue(hinfo, item);
321 			return (0);
322 
323 		/* If not green and mode is RED, calculate probability. */
324 		} else if (hinfo->conf.mode == NG_CAR_RED) {
325 			/* Is packet is bigger then extended burst? */
326 			if (len - (hinfo->tc - len) > hinfo->conf.ebs) {
327 				/* This packet is definitely red. */
328 				++hinfo->stats.red_pkts;
329 				hinfo->te = 0;
330 				NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
331 
332 			/* Use token bucket to simulate RED-like drop
333 			   probability. */
334 			} else if (hinfo->te + (len - hinfo->tc) <
335 			    hinfo->conf.ebs) {
336 				/* This packet is yellow */
337 				++hinfo->stats.yellow_pkts;
338 				hinfo->te += len - hinfo->tc;
339 				/* Go to negative tokens. */
340 				hinfo->tc -= len;
341 				NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.yellow_action);
342 			} else {
343 				/* This packet is probably red. */
344 				++hinfo->stats.red_pkts;
345 				hinfo->te = 0;
346 				NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
347 			}
348 		/* If not green and mode is SINGLE/DOUBLE RATE. */
349 		} else {
350 			/* Check extended token bucket. */
351 			if (hinfo->te - len >= 0) {
352 				/* This packet is yellow */
353 				++hinfo->stats.yellow_pkts;
354 				hinfo->te -= len;
355 				NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.yellow_action);
356 			} else {
357 				/* This packet is red */
358 				++hinfo->stats.red_pkts;
359 				NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
360 			}
361 		}
362 	}
363 
364 #undef NG_CAR_PERFORM_MATCH_ACTION
365 
366 	NG_FWD_ITEM_HOOK(error, item, hinfo->dest);
367 	if (error != 0)
368 		++hinfo->stats.errors;
369 	++hinfo->stats.passed_pkts;
370 
371 	return (error);
372 }
373 
374 /*
375  * Receive a control message.
376  */
377 static int
378 ng_car_rcvmsg(node_p node, item_p item, hook_p lasthook)
379 {
380 	const priv_p priv = NG_NODE_PRIVATE(node);
381 	struct ng_mesg *resp = NULL;
382 	int error = 0;
383 	struct ng_mesg *msg;
384 
385 	NGI_GET_MSG(item, msg);
386 	switch (msg->header.typecookie) {
387 	case NGM_CAR_COOKIE:
388 		switch (msg->header.cmd) {
389 		case NGM_CAR_GET_STATS:
390 		case NGM_CAR_GETCLR_STATS:
391 			{
392 				struct ng_car_bulkstats *bstats;
393 
394 				NG_MKRESPONSE(resp, msg,
395 					sizeof(*bstats), M_NOWAIT);
396 				if (resp == NULL) {
397 					error = ENOMEM;
398 					break;
399 				}
400 				bstats = (struct ng_car_bulkstats *)resp->data;
401 
402 				bcopy(&priv->upper.stats, &bstats->downstream,
403 				    sizeof(bstats->downstream));
404 				bcopy(&priv->lower.stats, &bstats->upstream,
405 				    sizeof(bstats->upstream));
406 			}
407 			if (msg->header.cmd == NGM_CAR_GET_STATS)
408 				break;
409 		case NGM_CAR_CLR_STATS:
410 			bzero(&priv->upper.stats,
411 				sizeof(priv->upper.stats));
412 			bzero(&priv->lower.stats,
413 				sizeof(priv->lower.stats));
414 			break;
415 		case NGM_CAR_GET_CONF:
416 			{
417 				struct ng_car_bulkconf *bconf;
418 
419 				NG_MKRESPONSE(resp, msg,
420 					sizeof(*bconf), M_NOWAIT);
421 				if (resp == NULL) {
422 					error = ENOMEM;
423 					break;
424 				}
425 				bconf = (struct ng_car_bulkconf *)resp->data;
426 
427 				bcopy(&priv->upper.conf, &bconf->downstream,
428 				    sizeof(bconf->downstream));
429 				bcopy(&priv->lower.conf, &bconf->upstream,
430 				    sizeof(bconf->upstream));
431 				/* Convert internal 1/(8*128) of pps into pps */
432 				if (bconf->downstream.opt & NG_CAR_COUNT_PACKETS) {
433 				    bconf->downstream.cir /= 1024;
434 				    bconf->downstream.pir /= 1024;
435 				    bconf->downstream.cbs /= 128;
436 				    bconf->downstream.ebs /= 128;
437 				}
438 				if (bconf->upstream.opt & NG_CAR_COUNT_PACKETS) {
439 				    bconf->upstream.cir /= 1024;
440 				    bconf->upstream.pir /= 1024;
441 				    bconf->upstream.cbs /= 128;
442 				    bconf->upstream.ebs /= 128;
443 				}
444 			}
445 			break;
446 		case NGM_CAR_SET_CONF:
447 			{
448 				struct ng_car_bulkconf *const bconf =
449 				(struct ng_car_bulkconf *)msg->data;
450 
451 				/* Check for invalid or illegal config. */
452 				if (msg->header.arglen != sizeof(*bconf)) {
453 					error = EINVAL;
454 					break;
455 				}
456 				/* Convert pps into internal 1/(8*128) of pps */
457 				if (bconf->downstream.opt & NG_CAR_COUNT_PACKETS) {
458 				    bconf->downstream.cir *= 1024;
459 				    bconf->downstream.pir *= 1024;
460 				    bconf->downstream.cbs *= 125;
461 				    bconf->downstream.ebs *= 125;
462 				}
463 				if (bconf->upstream.opt & NG_CAR_COUNT_PACKETS) {
464 				    bconf->upstream.cir *= 1024;
465 				    bconf->upstream.pir *= 1024;
466 				    bconf->upstream.cbs *= 125;
467 				    bconf->upstream.ebs *= 125;
468 				}
469 				if ((bconf->downstream.cir > 1000000000) ||
470 				    (bconf->downstream.pir > 1000000000) ||
471 				    (bconf->upstream.cir > 1000000000) ||
472 				    (bconf->upstream.pir > 1000000000) ||
473 				    (bconf->downstream.cbs == 0 &&
474 					bconf->downstream.ebs == 0) ||
475 				    (bconf->upstream.cbs == 0 &&
476 					bconf->upstream.ebs == 0))
477 				{
478 					error = EINVAL;
479 					break;
480 				}
481 				if ((bconf->upstream.mode == NG_CAR_SHAPE) &&
482 				    (bconf->upstream.cir == 0)) {
483 					error = EINVAL;
484 					break;
485 				}
486 				if ((bconf->downstream.mode == NG_CAR_SHAPE) &&
487 				    (bconf->downstream.cir == 0)) {
488 					error = EINVAL;
489 					break;
490 				}
491 
492 				/* Copy downstream config. */
493 				bcopy(&bconf->downstream, &priv->upper.conf,
494 				    sizeof(priv->upper.conf));
495     				priv->upper.tc = priv->upper.conf.cbs;
496 				if (priv->upper.conf.mode == NG_CAR_RED ||
497 				    priv->upper.conf.mode == NG_CAR_SHAPE) {
498 					priv->upper.te = 0;
499 				} else {
500 					priv->upper.te = priv->upper.conf.ebs;
501 				}
502 
503 				/* Copy upstream config. */
504 				bcopy(&bconf->upstream, &priv->lower.conf,
505 				    sizeof(priv->lower.conf));
506     				priv->lower.tc = priv->lower.conf.cbs;
507 				if (priv->lower.conf.mode == NG_CAR_RED ||
508 				    priv->lower.conf.mode == NG_CAR_SHAPE) {
509 					priv->lower.te = 0;
510 				} else {
511 					priv->lower.te = priv->lower.conf.ebs;
512 				}
513 			}
514 			break;
515 		default:
516 			error = EINVAL;
517 			break;
518 		}
519 		break;
520 	default:
521 		error = EINVAL;
522 		break;
523 	}
524 	NG_RESPOND_MSG(error, node, item, resp);
525 	NG_FREE_MSG(msg);
526 	return (error);
527 }
528 
529 /*
530  * Do local shutdown processing.
531  */
532 static int
533 ng_car_shutdown(node_p node)
534 {
535 	const priv_p priv = NG_NODE_PRIVATE(node);
536 
537 	ng_uncallout(&priv->upper.q_callout, node);
538 	ng_uncallout(&priv->lower.q_callout, node);
539 	mtx_destroy(&priv->upper.q_mtx);
540 	mtx_destroy(&priv->lower.q_mtx);
541 	NG_NODE_UNREF(priv->node);
542 	free(priv, M_NETGRAPH);
543 	return (0);
544 }
545 
546 /*
547  * Hook disconnection.
548  *
549  * For this type, removal of the last link destroys the node.
550  */
551 static int
552 ng_car_disconnect(hook_p hook)
553 {
554 	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
555 	const node_p node = NG_HOOK_NODE(hook);
556 	const priv_p priv = NG_NODE_PRIVATE(node);
557 
558 	if (hinfo) {
559 		/* Purge queue if not empty. */
560 		while (hinfo->q_first != hinfo->q_last) {
561 			NG_FREE_M(hinfo->q[hinfo->q_first]);
562 			hinfo->q_first++;
563 			if (hinfo->q_first >= NG_CAR_QUEUE_SIZE)
564 		    		hinfo->q_first = 0;
565 		}
566 		/* Remove hook refs. */
567 		if (hinfo->hook == priv->upper.hook)
568 			priv->lower.dest = NULL;
569 		else
570 			priv->upper.dest = NULL;
571 		hinfo->hook = NULL;
572 	}
573 	/* Already shutting down? */
574 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
575 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
576 		ng_rmnode_self(NG_HOOK_NODE(hook));
577 	return (0);
578 }
579 
580 /*
581  * Hook's token buckets refillment.
582  */
583 static void
584 ng_car_refillhook(struct hookinfo *h)
585 {
586 	struct bintime newt, deltat;
587 	unsigned int deltat_us;
588 
589 	/* Get current time. */
590 	getbinuptime(&newt);
591 
592 	/* Get time delta since last refill. */
593 	deltat = newt;
594 	bintime_sub(&deltat, &h->lastRefill);
595 
596 	/* Time must go forward. */
597 	if (deltat.sec < 0) {
598 	    h->lastRefill = newt;
599 	    return;
600 	}
601 
602 	/* But not too far forward. */
603 	if (deltat.sec >= 1000) {
604 	    deltat_us = (1000 << 20);
605 	} else {
606 	    /* convert bintime to the 1/(2^20) of sec */
607 	    deltat_us = (deltat.sec << 20) + (deltat.frac >> 44);
608 	}
609 
610 	if (h->conf.mode == NG_CAR_SINGLE_RATE) {
611 		int64_t	delta;
612 		/* Refill committed token bucket. */
613 		h->tc += (h->conf.cir * deltat_us) >> 23;
614 		delta = h->tc - h->conf.cbs;
615 		if (delta > 0) {
616 			h->tc = h->conf.cbs;
617 
618 			/* Refill exceeded token bucket. */
619 			h->te += delta;
620 			if (h->te > ((int64_t)h->conf.ebs))
621 				h->te = h->conf.ebs;
622 		}
623 
624 	} else if (h->conf.mode == NG_CAR_DOUBLE_RATE) {
625 		/* Refill committed token bucket. */
626 		h->tc += (h->conf.cir * deltat_us) >> 23;
627 		if (h->tc > ((int64_t)h->conf.cbs))
628 			h->tc = h->conf.cbs;
629 
630 		/* Refill peak token bucket. */
631 		h->te += (h->conf.pir * deltat_us) >> 23;
632 		if (h->te > ((int64_t)h->conf.ebs))
633 			h->te = h->conf.ebs;
634 
635 	} else { /* RED or SHAPE mode. */
636 		/* Refill committed token bucket. */
637 		h->tc += (h->conf.cir * deltat_us) >> 23;
638 		if (h->tc > ((int64_t)h->conf.cbs))
639 			h->tc = h->conf.cbs;
640 	}
641 
642 	/* Remember this moment. */
643 	h->lastRefill = newt;
644 }
645 
646 /*
647  * Schedule callout when we will have required tokens.
648  */
649 static void
650 ng_car_schedule(struct hookinfo *hinfo)
651 {
652 	int 	delay;
653 
654 	delay = (-(hinfo->tc)) * hz * 8 / hinfo->conf.cir + 1;
655 
656 	ng_callout(&hinfo->q_callout, NG_HOOK_NODE(hinfo->hook), hinfo->hook,
657 	    delay, &ng_car_q_event, NULL, 0);
658 }
659 
660 /*
661  * Queue processing callout handler.
662  */
663 void
664 ng_car_q_event(node_p node, hook_p hook, void *arg, int arg2)
665 {
666 	struct hookinfo	*hinfo = NG_HOOK_PRIVATE(hook);
667 	struct mbuf 	*m;
668 	int		error;
669 
670 	/* Refill tokens for time we have slept. */
671 	ng_car_refillhook(hinfo);
672 
673 	/* If we have some tokens */
674 	while (hinfo->tc >= 0) {
675 		/* Send packet. */
676 		m = hinfo->q[hinfo->q_first];
677 		NG_SEND_DATA_ONLY(error, hinfo->dest, m);
678 		if (error != 0)
679 			++hinfo->stats.errors;
680 		++hinfo->stats.passed_pkts;
681 
682 		/* Get next one. */
683 		hinfo->q_first++;
684 		if (hinfo->q_first >= NG_CAR_QUEUE_SIZE)
685 			hinfo->q_first = 0;
686 
687 		/* Stop if none left. */
688 		if (hinfo->q_first == hinfo->q_last)
689 			break;
690 
691 		/* If we have more packet, try it. */
692 		m = hinfo->q[hinfo->q_first];
693 		if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
694 			hinfo->tc -= 128;
695 		} else {
696 			hinfo->tc -= m->m_pkthdr.len;
697 		}
698 	}
699 
700 	/* If something left */
701 	if (hinfo->q_first != hinfo->q_last)
702 		/* Schedule queue processing. */
703 		ng_car_schedule(hinfo);
704 }
705 
706 /*
707  * Enqueue packet.
708  */
709 static void
710 ng_car_enqueue(struct hookinfo *hinfo, item_p item)
711 {
712 	struct mbuf 	*m;
713 	int		len;
714 
715 	NGI_GET_M(item, m);
716 	NG_FREE_ITEM(item);
717 
718 	/* Lock queue mutex. */
719 	mtx_lock(&hinfo->q_mtx);
720 
721 	/* Calculate used queue length. */
722 	len = hinfo->q_last - hinfo->q_first;
723 	if (len < 0)
724 		len += NG_CAR_QUEUE_SIZE;
725 
726 	/* If queue is overflowed or we have no RED tokens. */
727 	if ((len >= (NG_CAR_QUEUE_SIZE - 1)) ||
728 	    (hinfo->te + len >= NG_CAR_QUEUE_SIZE)) {
729 		/* Drop packet. */
730 		++hinfo->stats.red_pkts;
731 		++hinfo->stats.dropped_pkts;
732 		NG_FREE_M(m);
733 
734 		hinfo->te = 0;
735 	} else {
736 		/* This packet is yellow. */
737 		++hinfo->stats.yellow_pkts;
738 
739 		/* Enqueue packet. */
740 		hinfo->q[hinfo->q_last] = m;
741 		hinfo->q_last++;
742 		if (hinfo->q_last >= NG_CAR_QUEUE_SIZE)
743 			hinfo->q_last = 0;
744 
745 		/* Use RED tokens. */
746 		if (len > NG_CAR_QUEUE_MIN_TH)
747 			hinfo->te += len - NG_CAR_QUEUE_MIN_TH;
748 
749 		/* If this is a first packet in the queue. */
750 		if (len == 0) {
751 			if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
752 				hinfo->tc -= 128;
753 			} else {
754 				hinfo->tc -= m->m_pkthdr.len;
755 			}
756 
757 			/* Schedule queue processing. */
758 			ng_car_schedule(hinfo);
759 		}
760 	}
761 
762 	/* Unlock queue mutex. */
763 	mtx_unlock(&hinfo->q_mtx);
764 }
765