/*-
* Copyright (C) 1998-2003
* Sony Computer Science Laboratories Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*-
* Copyright (c) 1990-1994 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $KAME: altq_rio.c,v 1.17 2003/07/10 12:07:49 kjc Exp $
* $FreeBSD$
*/
#include "opt_altq.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#ifdef ALTQ_RIO /* rio is enabled by ALTQ_RIO option in opt_altq.h */
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/errno.h>
#if 1 /* ALTQ3_COMPAT */
#include <sys/proc.h>
#include <sys/sockio.h>
#include <sys/kernel.h>
#endif
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <netpfil/pf/pf.h>
#include <netpfil/pf/pf_altq.h>
#include <net/altq/altq.h>
#include <net/altq/altq_cdnr.h>
#include <net/altq/altq_red.h>
#include <net/altq/altq_rio.h>
/*
* RIO: RED with IN/OUT bit
* described in
* "Explicit Allocation of Best Effort Packet Delivery Service"
* David D. Clark and Wenjia Fang, MIT Lab for Computer Science
* http://diffserv.lcs.mit.edu/Papers/exp-alloc-ddc-wf.{ps,pdf}
*
* this implementation is extended to support more than 2 drop precedence
* values as described in RFC2597 (Assured Forwarding PHB Group).
*
*/
/*
* AF DS (differentiated service) codepoints.
* (classes can be mapped to CBQ or H-FSC classes.)
*
* 0 1 2 3 4 5 6 7
* +---+---+---+---+---+---+---+---+
* | CLASS |DropPre| 0 | CU |
* +---+---+---+---+---+---+---+---+
*
* class 1: 001
* class 2: 010
* class 3: 011
* class 4: 100
*
* low drop prec: 01
* medium drop prec: 10
* high drop prec: 01
*/
/* normal red parameters */
#define W_WEIGHT 512 /* inverse of weight of EWMA (511/512) */
/* q_weight = 0.00195 */
/* red parameters for a slow link */
#define W_WEIGHT_1 128 /* inverse of weight of EWMA (127/128) */
/* q_weight = 0.0078125 */
/* red parameters for a very slow link (e.g., dialup) */
#define W_WEIGHT_2 64 /* inverse of weight of EWMA (63/64) */
/* q_weight = 0.015625 */
/* fixed-point uses 12-bit decimal places */
#define FP_SHIFT 12 /* fixed-point shift */
/* red parameters for drop probability */
#define INV_P_MAX 10 /* inverse of max drop probability */
#define TH_MIN 5 /* min threshold */
#define TH_MAX 15 /* max threshold */
#define RIO_LIMIT 60 /* default max queue length */
#define RIO_STATS /* collect statistics */
#define TV_DELTA(a, b, delta) { \
int xxs; \
\
delta = (a)->tv_usec - (b)->tv_usec; \
if ((xxs = (a)->tv_sec - (b)->tv_sec) != 0) { \
if (xxs < 0) { \
delta = 60000000; \
} else if (xxs > 4) { \
if (xxs > 60) \
delta = 60000000; \
else \
delta += xxs * 1000000; \
} else while (xxs > 0) { \
delta += 1000000; \
xxs--; \
} \
} \
}
/* default rio parameter values */
static struct redparams default_rio_params[RIO_NDROPPREC] = {
/* th_min, th_max, inv_pmax */
{ TH_MAX * 2 + TH_MIN, TH_MAX * 3, INV_P_MAX }, /* low drop precedence */
{ TH_MAX + TH_MIN, TH_MAX * 2, INV_P_MAX }, /* medium drop precedence */
{ TH_MIN, TH_MAX, INV_P_MAX } /* high drop precedence */
};
/* internal function prototypes */
static int dscp2index(u_int8_t);
rio_t *
rio_alloc(int weight, struct redparams *params, int flags, int pkttime)
{
rio_t *rp;
int w, i;
int npkts_per_sec;
rp = malloc(sizeof(rio_t), M_DEVBUF, M_NOWAIT | M_ZERO);
if (rp == NULL)
return (NULL);
rp->rio_flags = flags;
if (pkttime == 0)
/* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */
rp->rio_pkttime = 800;
else
rp->rio_pkttime = pkttime;
if (weight != 0)
rp->rio_weight = weight;
else {
/* use default */
rp->rio_weight = W_WEIGHT;
/* when the link is very slow, adjust red parameters */
npkts_per_sec = 1000000 / rp->rio_pkttime;
if (npkts_per_sec < 50) {
/* up to about 400Kbps */
rp->rio_weight = W_WEIGHT_2;
} else if (npkts_per_sec < 300) {
/* up to about 2.4Mbps */
rp->rio_weight = W_WEIGHT_1;
}
}
/* calculate wshift. weight must be power of 2 */
w = rp->rio_weight;
for (i = 0; w > 1; i++)
w = w >> 1;
rp->rio_wshift = i;
w = 1 << rp->rio_wshift;
if (w != rp->rio_weight) {
printf("invalid weight value %d for red! use %d\n",
rp->rio_weight, w);
rp->rio_weight = w;
}
/* allocate weight table */
rp->rio_wtab = wtab_alloc(rp->rio_weight);
for (i = 0; i < RIO_NDROPPREC; i++) {
struct dropprec_state *prec = &rp->rio_precstate[i];
prec->avg = 0;
prec->idle = 1;
if (params == NULL || params[i].inv_pmax == 0)
prec->inv_pmax = default_rio_params[i].inv_pmax;
else
prec->inv_pmax = params[i].inv_pmax;
if (params == NULL || params[i].th_min == 0)
prec->th_min = default_rio_params[i].th_min;
else
prec->th_min = params[i].th_min;
if (params == NULL || params[i].th_max == 0)
prec->th_max = default_rio_params[i].th_max;
else
prec->th_max = params[i].th_max;
/*
* th_min_s and th_max_s are scaled versions of th_min
* and th_max to be compared with avg.
*/
prec->th_min_s = prec->th_min << (rp->rio_wshift + FP_SHIFT);
prec->th_max_s = prec->th_max << (rp->rio_wshift + FP_SHIFT);
/*
* precompute probability denominator
* probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point
*/
prec->probd = (2 * (prec->th_max - prec->th_min)
* prec->inv_pmax) << FP_SHIFT;
microtime(&prec->last);
}
return (rp);
}
void
rio_destroy(rio_t *rp)
{
wtab_destroy(rp->rio_wtab);
free(rp, M_DEVBUF);
}
void
rio_getstats(rio_t *rp, struct redstats *sp)
{
int i;
for (i = 0; i < RIO_NDROPPREC; i++) {
bcopy(&rp->q_stats[i], sp, sizeof(struct redstats));
sp->q_avg = rp->rio_precstate[i].avg >> rp->rio_wshift;
sp++;
}
}
#if (RIO_NDROPPREC == 3)
/*
* internally, a drop precedence value is converted to an index
* starting from 0.
*/
static int
dscp2index(u_int8_t dscp)
{
int dpindex = dscp & AF_DROPPRECMASK;
if (dpindex == 0)
return (0);
return ((dpindex >> 3) - 1);
}
#endif
#if 1
/*
* kludge: when a packet is dequeued, we need to know its drop precedence
* in order to keep the queue length of each drop precedence.
* use m_pkthdr.rcvif to pass this info.
*/
#define RIOM_SET_PRECINDEX(m, idx) \
do { (m)->m_pkthdr.rcvif = (void *)((long)(idx)); } while (0)
#define RIOM_GET_PRECINDEX(m) \
({ long idx; idx = (long)((m)->m_pkthdr.rcvif); \
(m)->m_pkthdr.rcvif = NULL; idx; })
#endif
int
rio_addq(rio_t *rp, class_queue_t *q, struct mbuf *m,
struct altq_pktattr *pktattr)
{
int avg, droptype;
u_int8_t dsfield, odsfield;
int dpindex, i, n, t;
struct timeval now;
struct dropprec_state *prec;
dsfield = odsfield = read_dsfield(m, pktattr);
dpindex = dscp2index(dsfield);
/*
* update avg of the precedence states whose drop precedence
* is larger than or equal to the drop precedence of the packet
*/
now.tv_sec = 0;
for (i = dpindex; i < RIO_NDROPPREC; i++) {
prec = &rp->rio_precstate[i];
avg = prec->avg;
if (prec->idle) {
prec->idle = 0;
if (now.tv_sec == 0)
microtime(&now);
t = (now.tv_sec - prec->last.tv_sec);
if (t > 60)
avg = 0;
else {
t = t * 1000000 +
(now.tv_usec - prec->last.tv_usec);
n = t / rp->rio_pkttime;
/* calculate (avg = (1 - Wq)^n * avg) */
if (n > 0)
avg = (avg >> FP_SHIFT) *
pow_w(rp->rio_wtab, n);
}
}
/* run estimator. (avg is scaled by WEIGHT in fixed-point) */
avg += (prec->qlen << FP_SHIFT) - (avg >> rp->rio_wshift);
prec->avg = avg; /* save the new value */
/*
* count keeps a tally of arriving traffic that has not
* been dropped.
*/
prec->count++;
}
prec = &rp->rio_precstate[dpindex];
avg = prec->avg;
/* see if we drop early */
droptype = DTYPE_NODROP;
if (avg >= prec->th_min_s && prec->qlen > 1) {
if (avg >= prec->th_max_s) {
/* avg >= th_max: forced drop */
droptype = DTYPE_FORCED;
} else if (prec->old == 0) {
/* first exceeds th_min */
prec->count = 1;
prec->old = 1;
} else if (drop_early((avg - prec->th_min_s) >> rp->rio_wshift,
prec->probd, prec->count)) {
/* unforced drop by red */
droptype = DTYPE_EARLY;
}
} else {
/* avg < th_min */
prec->old = 0;
}
/*
* if the queue length hits the hard limit, it's a forced drop.
*/
if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q))
droptype = DTYPE_FORCED;
if (droptype != DTYPE_NODROP) {
/* always drop incoming packet (as opposed to randomdrop) */
for (i = dpindex; i < RIO_NDROPPREC; i++)
rp->rio_precstate[i].count = 0;
#ifdef RIO_STATS
if (droptype == DTYPE_EARLY)
rp->q_stats[dpindex].drop_unforced++;
else
rp->q_stats[dpindex].drop_forced++;
PKTCNTR_ADD(&rp->q_stats[dpindex].drop_cnt, m_pktlen(m));
#endif
m_freem(m);
return (-1);
}
for (i = dpindex; i < RIO_NDROPPREC; i++)
rp->rio_precstate[i].qlen++;
/* save drop precedence index in mbuf hdr */
RIOM_SET_PRECINDEX(m, dpindex);
if (rp->rio_flags & RIOF_CLEARDSCP)
dsfield &= ~DSCP_MASK;
if (dsfield != odsfield)
write_dsfield(m, pktattr, dsfield);
_addq(q, m);
#ifdef RIO_STATS
PKTCNTR_ADD(&rp->q_stats[dpindex].xmit_cnt, m_pktlen(m));
#endif
return (0);
}
struct mbuf *
rio_getq(rio_t *rp, class_queue_t *q)
{
struct mbuf *m;
int dpindex, i;
if ((m = _getq(q)) == NULL)
return NULL;
dpindex = RIOM_GET_PRECINDEX(m);
for (i = dpindex; i < RIO_NDROPPREC; i++) {
if (--rp->rio_precstate[i].qlen == 0) {
if (rp->rio_precstate[i].idle == 0) {
rp->rio_precstate[i].idle = 1;
microtime(&rp->rio_precstate[i].last);
}
}
}
return (m);
}
#endif /* ALTQ_RIO */