1/*-
2 * Copyright (C) 1998-2003
3 *	Sony Computer Science Laboratories Inc.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26/*-
27 * Copyright (c) 1990-1994 Regents of the University of California.
28 * All rights reserved.
29 *
30 * Redistribution and use in source and binary forms, with or without
31 * modification, are permitted provided that the following conditions
32 * are met:
33 * 1. Redistributions of source code must retain the above copyright
34 *    notice, this list of conditions and the following disclaimer.
35 * 2. Redistributions in binary form must reproduce the above copyright
36 *    notice, this list of conditions and the following disclaimer in the
37 *    documentation and/or other materials provided with the distribution.
38 * 3. All advertising materials mentioning features or use of this software
39 *    must display the following acknowledgement:
40 *	This product includes software developed by the Computer Systems
41 *	Engineering Group at Lawrence Berkeley Laboratory.
42 * 4. Neither the name of the University nor of the Laboratory may be used
43 *    to endorse or promote products derived from this software without
44 *    specific prior written permission.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56 * SUCH DAMAGE.
57 *
58 * $KAME: altq_rio.c,v 1.17 2003/07/10 12:07:49 kjc Exp $
59 * $FreeBSD$
60 */
61
62#include "opt_altq.h"
63#include "opt_inet.h"
64#include "opt_inet6.h"
65#ifdef ALTQ_RIO	/* rio is enabled by ALTQ_RIO option in opt_altq.h */
66
67#include <sys/param.h>
68#include <sys/malloc.h>
69#include <sys/mbuf.h>
70#include <sys/socket.h>
71#include <sys/systm.h>
72#include <sys/errno.h>
73#if 1 /* ALTQ3_COMPAT */
74#include <sys/proc.h>
75#include <sys/sockio.h>
76#include <sys/kernel.h>
77#endif
78
79#include <net/if.h>
80#include <net/if_var.h>
81
82#include <netinet/in.h>
83#include <netinet/in_systm.h>
84#include <netinet/ip.h>
85#ifdef INET6
86#include <netinet/ip6.h>
87#endif
88
89#include <netpfil/pf/pf.h>
90#include <netpfil/pf/pf_altq.h>
91#include <net/altq/altq.h>
92#include <net/altq/altq_cdnr.h>
93#include <net/altq/altq_red.h>
94#include <net/altq/altq_rio.h>
95
96/*
97 * RIO: RED with IN/OUT bit
98 *   described in
99 *	"Explicit Allocation of Best Effort Packet Delivery Service"
100 *	David D. Clark and Wenjia Fang, MIT Lab for Computer Science
101 *	http://diffserv.lcs.mit.edu/Papers/exp-alloc-ddc-wf.{ps,pdf}
102 *
103 * this implementation is extended to support more than 2 drop precedence
104 * values as described in RFC2597 (Assured Forwarding PHB Group).
105 *
106 */
107/*
108 * AF DS (differentiated service) codepoints.
109 * (classes can be mapped to CBQ or H-FSC classes.)
110 *
111 *      0   1   2   3   4   5   6   7
112 *    +---+---+---+---+---+---+---+---+
113 *    |   CLASS   |DropPre| 0 |  CU   |
114 *    +---+---+---+---+---+---+---+---+
115 *
116 *    class 1: 001
117 *    class 2: 010
118 *    class 3: 011
119 *    class 4: 100
120 *
121 *    low drop prec:    01
122 *    medium drop prec: 10
123 *    high drop prec:   01
124 */
125
126/* normal red parameters */
127#define	W_WEIGHT	512	/* inverse of weight of EWMA (511/512) */
128				/* q_weight = 0.00195 */
129
130/* red parameters for a slow link */
131#define	W_WEIGHT_1	128	/* inverse of weight of EWMA (127/128) */
132				/* q_weight = 0.0078125 */
133
134/* red parameters for a very slow link (e.g., dialup) */
135#define	W_WEIGHT_2	64	/* inverse of weight of EWMA (63/64) */
136				/* q_weight = 0.015625 */
137
138/* fixed-point uses 12-bit decimal places */
139#define	FP_SHIFT	12	/* fixed-point shift */
140
141/* red parameters for drop probability */
142#define	INV_P_MAX	10	/* inverse of max drop probability */
143#define	TH_MIN		 5	/* min threshold */
144#define	TH_MAX		15	/* max threshold */
145
146#define	RIO_LIMIT	60	/* default max queue length */
147#define	RIO_STATS		/* collect statistics */
148
149#define	TV_DELTA(a, b, delta) {					\
150	int	xxs;						\
151								\
152	delta = (a)->tv_usec - (b)->tv_usec; 			\
153	if ((xxs = (a)->tv_sec - (b)->tv_sec) != 0) { 		\
154		if (xxs < 0) { 					\
155			delta = 60000000;			\
156		} else if (xxs > 4)  {				\
157			if (xxs > 60)				\
158				delta = 60000000;		\
159			else					\
160				delta += xxs * 1000000;		\
161		} else while (xxs > 0) {			\
162			delta += 1000000;			\
163			xxs--;					\
164		}						\
165	}							\
166}
167
168/* default rio parameter values */
169static struct redparams default_rio_params[RIO_NDROPPREC] = {
170  /* th_min,		 th_max,     inv_pmax */
171  { TH_MAX * 2 + TH_MIN, TH_MAX * 3, INV_P_MAX }, /* low drop precedence */
172  { TH_MAX + TH_MIN,	 TH_MAX * 2, INV_P_MAX }, /* medium drop precedence */
173  { TH_MIN,		 TH_MAX,     INV_P_MAX }  /* high drop precedence */
174};
175
176/* internal function prototypes */
177static int dscp2index(u_int8_t);
178
179rio_t *
180rio_alloc(int weight, struct redparams *params, int flags, int pkttime)
181{
182	rio_t	*rp;
183	int	 w, i;
184	int	 npkts_per_sec;
185
186	rp = malloc(sizeof(rio_t), M_DEVBUF, M_NOWAIT | M_ZERO);
187	if (rp == NULL)
188		return (NULL);
189
190	rp->rio_flags = flags;
191	if (pkttime == 0)
192		/* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */
193		rp->rio_pkttime = 800;
194	else
195		rp->rio_pkttime = pkttime;
196
197	if (weight != 0)
198		rp->rio_weight = weight;
199	else {
200		/* use default */
201		rp->rio_weight = W_WEIGHT;
202
203		/* when the link is very slow, adjust red parameters */
204		npkts_per_sec = 1000000 / rp->rio_pkttime;
205		if (npkts_per_sec < 50) {
206			/* up to about 400Kbps */
207			rp->rio_weight = W_WEIGHT_2;
208		} else if (npkts_per_sec < 300) {
209			/* up to about 2.4Mbps */
210			rp->rio_weight = W_WEIGHT_1;
211		}
212	}
213
214	/* calculate wshift.  weight must be power of 2 */
215	w = rp->rio_weight;
216	for (i = 0; w > 1; i++)
217		w = w >> 1;
218	rp->rio_wshift = i;
219	w = 1 << rp->rio_wshift;
220	if (w != rp->rio_weight) {
221		printf("invalid weight value %d for red! use %d\n",
222		       rp->rio_weight, w);
223		rp->rio_weight = w;
224	}
225
226	/* allocate weight table */
227	rp->rio_wtab = wtab_alloc(rp->rio_weight);
228
229	for (i = 0; i < RIO_NDROPPREC; i++) {
230		struct dropprec_state *prec = &rp->rio_precstate[i];
231
232		prec->avg = 0;
233		prec->idle = 1;
234
235		if (params == NULL || params[i].inv_pmax == 0)
236			prec->inv_pmax = default_rio_params[i].inv_pmax;
237		else
238			prec->inv_pmax = params[i].inv_pmax;
239		if (params == NULL || params[i].th_min == 0)
240			prec->th_min = default_rio_params[i].th_min;
241		else
242			prec->th_min = params[i].th_min;
243		if (params == NULL || params[i].th_max == 0)
244			prec->th_max = default_rio_params[i].th_max;
245		else
246			prec->th_max = params[i].th_max;
247
248		/*
249		 * th_min_s and th_max_s are scaled versions of th_min
250		 * and th_max to be compared with avg.
251		 */
252		prec->th_min_s = prec->th_min << (rp->rio_wshift + FP_SHIFT);
253		prec->th_max_s = prec->th_max << (rp->rio_wshift + FP_SHIFT);
254
255		/*
256		 * precompute probability denominator
257		 *  probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point
258		 */
259		prec->probd = (2 * (prec->th_max - prec->th_min)
260			       * prec->inv_pmax) << FP_SHIFT;
261
262		microtime(&prec->last);
263	}
264
265	return (rp);
266}
267
268void
269rio_destroy(rio_t *rp)
270{
271	wtab_destroy(rp->rio_wtab);
272	free(rp, M_DEVBUF);
273}
274
275void
276rio_getstats(rio_t *rp, struct redstats *sp)
277{
278	int	i;
279
280	for (i = 0; i < RIO_NDROPPREC; i++) {
281		bcopy(&rp->q_stats[i], sp, sizeof(struct redstats));
282		sp->q_avg = rp->rio_precstate[i].avg >> rp->rio_wshift;
283		sp++;
284	}
285}
286
287#if (RIO_NDROPPREC == 3)
288/*
289 * internally, a drop precedence value is converted to an index
290 * starting from 0.
291 */
292static int
293dscp2index(u_int8_t dscp)
294{
295	int	dpindex = dscp & AF_DROPPRECMASK;
296
297	if (dpindex == 0)
298		return (0);
299	return ((dpindex >> 3) - 1);
300}
301#endif
302
303#if 1
304/*
305 * kludge: when a packet is dequeued, we need to know its drop precedence
306 * in order to keep the queue length of each drop precedence.
307 * use m_pkthdr.rcvif to pass this info.
308 */
309#define	RIOM_SET_PRECINDEX(m, idx)	\
310	do { (m)->m_pkthdr.rcvif = (void *)((long)(idx)); } while (0)
311#define	RIOM_GET_PRECINDEX(m)	\
312	({ long idx; idx = (long)((m)->m_pkthdr.rcvif); \
313	(m)->m_pkthdr.rcvif = NULL; idx; })
314#endif
315
316int
317rio_addq(rio_t *rp, class_queue_t *q, struct mbuf *m,
318    struct altq_pktattr *pktattr)
319{
320	int			 avg, droptype;
321	u_int8_t		 dsfield, odsfield;
322	int			 dpindex, i, n, t;
323	struct timeval		 now;
324	struct dropprec_state	*prec;
325
326	dsfield = odsfield = read_dsfield(m, pktattr);
327	dpindex = dscp2index(dsfield);
328
329	/*
330	 * update avg of the precedence states whose drop precedence
331	 * is larger than or equal to the drop precedence of the packet
332	 */
333	now.tv_sec = 0;
334	for (i = dpindex; i < RIO_NDROPPREC; i++) {
335		prec = &rp->rio_precstate[i];
336		avg = prec->avg;
337		if (prec->idle) {
338			prec->idle = 0;
339			if (now.tv_sec == 0)
340				microtime(&now);
341			t = (now.tv_sec - prec->last.tv_sec);
342			if (t > 60)
343				avg = 0;
344			else {
345				t = t * 1000000 +
346					(now.tv_usec - prec->last.tv_usec);
347				n = t / rp->rio_pkttime;
348				/* calculate (avg = (1 - Wq)^n * avg) */
349				if (n > 0)
350					avg = (avg >> FP_SHIFT) *
351						pow_w(rp->rio_wtab, n);
352			}
353		}
354
355		/* run estimator. (avg is scaled by WEIGHT in fixed-point) */
356		avg += (prec->qlen << FP_SHIFT) - (avg >> rp->rio_wshift);
357		prec->avg = avg;		/* save the new value */
358		/*
359		 * count keeps a tally of arriving traffic that has not
360		 * been dropped.
361		 */
362		prec->count++;
363	}
364
365	prec = &rp->rio_precstate[dpindex];
366	avg = prec->avg;
367
368	/* see if we drop early */
369	droptype = DTYPE_NODROP;
370	if (avg >= prec->th_min_s && prec->qlen > 1) {
371		if (avg >= prec->th_max_s) {
372			/* avg >= th_max: forced drop */
373			droptype = DTYPE_FORCED;
374		} else if (prec->old == 0) {
375			/* first exceeds th_min */
376			prec->count = 1;
377			prec->old = 1;
378		} else if (drop_early((avg - prec->th_min_s) >> rp->rio_wshift,
379				      prec->probd, prec->count)) {
380			/* unforced drop by red */
381			droptype = DTYPE_EARLY;
382		}
383	} else {
384		/* avg < th_min */
385		prec->old = 0;
386	}
387
388	/*
389	 * if the queue length hits the hard limit, it's a forced drop.
390	 */
391	if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q))
392		droptype = DTYPE_FORCED;
393
394	if (droptype != DTYPE_NODROP) {
395		/* always drop incoming packet (as opposed to randomdrop) */
396		for (i = dpindex; i < RIO_NDROPPREC; i++)
397			rp->rio_precstate[i].count = 0;
398#ifdef RIO_STATS
399		if (droptype == DTYPE_EARLY)
400			rp->q_stats[dpindex].drop_unforced++;
401		else
402			rp->q_stats[dpindex].drop_forced++;
403		PKTCNTR_ADD(&rp->q_stats[dpindex].drop_cnt, m_pktlen(m));
404#endif
405		m_freem(m);
406		return (-1);
407	}
408
409	for (i = dpindex; i < RIO_NDROPPREC; i++)
410		rp->rio_precstate[i].qlen++;
411
412	/* save drop precedence index in mbuf hdr */
413	RIOM_SET_PRECINDEX(m, dpindex);
414
415	if (rp->rio_flags & RIOF_CLEARDSCP)
416		dsfield &= ~DSCP_MASK;
417
418	if (dsfield != odsfield)
419		write_dsfield(m, pktattr, dsfield);
420
421	_addq(q, m);
422
423#ifdef RIO_STATS
424	PKTCNTR_ADD(&rp->q_stats[dpindex].xmit_cnt, m_pktlen(m));
425#endif
426	return (0);
427}
428
429struct mbuf *
430rio_getq(rio_t *rp, class_queue_t *q)
431{
432	struct mbuf	*m;
433	int		 dpindex, i;
434
435	if ((m = _getq(q)) == NULL)
436		return NULL;
437
438	dpindex = RIOM_GET_PRECINDEX(m);
439	for (i = dpindex; i < RIO_NDROPPREC; i++) {
440		if (--rp->rio_precstate[i].qlen == 0) {
441			if (rp->rio_precstate[i].idle == 0) {
442				rp->rio_precstate[i].idle = 1;
443				microtime(&rp->rio_precstate[i].last);
444			}
445		}
446	}
447	return (m);
448}
449
450
451#endif /* ALTQ_RIO */
452