#include <machine/rtems-bsd-kernel-space.h>
/* $FreeBSD$ */
/* $NetBSD: ieee80211_rssadapt.c,v 1.9 2005/02/26 22:45:09 perry Exp $ */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
* Copyright (c) 2003, 2004 David Young. 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. The name of David Young may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY David Young ``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 David
* Young 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.
*/
#include <rtems/bsd/local/opt_wlan.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_rssadapt.h>
#include <net80211/ieee80211_ratectl.h>
struct rssadapt_expavgctl {
/* RSS threshold decay. */
u_int rc_decay_denom;
u_int rc_decay_old;
/* RSS threshold update. */
u_int rc_thresh_denom;
u_int rc_thresh_old;
/* RSS average update. */
u_int rc_avgrssi_denom;
u_int rc_avgrssi_old;
};
static struct rssadapt_expavgctl master_expavgctl = {
.rc_decay_denom = 16,
.rc_decay_old = 15,
.rc_thresh_denom = 8,
.rc_thresh_old = 4,
.rc_avgrssi_denom = 8,
.rc_avgrssi_old = 4
};
#ifdef interpolate
#undef interpolate
#endif
#define interpolate(parm, old, new) ((parm##_old * (old) + \
(parm##_denom - parm##_old) * (new)) / \
parm##_denom)
static void rssadapt_setinterval(const struct ieee80211vap *, int);
static void rssadapt_init(struct ieee80211vap *);
static void rssadapt_deinit(struct ieee80211vap *);
static void rssadapt_updatestats(struct ieee80211_rssadapt_node *);
static void rssadapt_node_init(struct ieee80211_node *);
static void rssadapt_node_deinit(struct ieee80211_node *);
static int rssadapt_rate(struct ieee80211_node *, void *, uint32_t);
static void rssadapt_lower_rate(struct ieee80211_rssadapt_node *, int, int);
static void rssadapt_raise_rate(struct ieee80211_rssadapt_node *,
int, int);
static void rssadapt_tx_complete(const struct ieee80211_node *,
const struct ieee80211_ratectl_tx_status *);
static void rssadapt_sysctlattach(struct ieee80211vap *,
struct sysctl_ctx_list *, struct sysctl_oid *);
/* number of references from net80211 layer */
static int nrefs = 0;
static const struct ieee80211_ratectl rssadapt = {
.ir_name = "rssadapt",
.ir_attach = NULL,
.ir_detach = NULL,
.ir_init = rssadapt_init,
.ir_deinit = rssadapt_deinit,
.ir_node_init = rssadapt_node_init,
.ir_node_deinit = rssadapt_node_deinit,
.ir_rate = rssadapt_rate,
.ir_tx_complete = rssadapt_tx_complete,
.ir_tx_update = NULL,
.ir_setinterval = rssadapt_setinterval,
};
IEEE80211_RATECTL_MODULE(rssadapt, 1);
IEEE80211_RATECTL_ALG(rssadapt, IEEE80211_RATECTL_RSSADAPT, rssadapt);
static void
rssadapt_setinterval(const struct ieee80211vap *vap, int msecs)
{
struct ieee80211_rssadapt *rs = vap->iv_rs;
int t;
if (msecs < 100)
msecs = 100;
t = msecs_to_ticks(msecs);
rs->interval = (t < 1) ? 1 : t;
}
static void
rssadapt_init(struct ieee80211vap *vap)
{
struct ieee80211_rssadapt *rs;
KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized",
__func__));
nrefs++; /* XXX locking */
vap->iv_rs = rs = IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt),
M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
if (rs == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
return;
}
rs->vap = vap;
rssadapt_setinterval(vap, 500 /* msecs */);
rssadapt_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
}
static void
rssadapt_deinit(struct ieee80211vap *vap)
{
IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL);
KASSERT(nrefs > 0, ("imbalanced attach/detach"));
nrefs--; /* XXX locking */
}
static void
rssadapt_updatestats(struct ieee80211_rssadapt_node *ra)
{
long interval;
ra->ra_pktrate = (ra->ra_pktrate + 10*(ra->ra_nfail + ra->ra_nok))/2;
ra->ra_nfail = ra->ra_nok = 0;
/*
* A node is eligible for its rate to be raised every 1/10 to 10
* seconds, more eligible in proportion to recent packet rates.
*/
interval = MAX(10*1000, 10*1000 / MAX(1, 10 * ra->ra_pktrate));
ra->ra_raise_interval = msecs_to_ticks(interval);
}
static void
rssadapt_node_init(struct ieee80211_node *ni)
{
struct ieee80211_rssadapt_node *ra;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211_rssadapt *rsa = vap->iv_rs;
const struct ieee80211_rateset *rs = &ni->ni_rates;
if (ni->ni_rctls == NULL) {
ni->ni_rctls = ra =
IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt_node),
M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
if (ra == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
"structure\n");
return;
}
} else
ra = ni->ni_rctls;
ra->ra_rs = rsa;
ra->ra_rates = *rs;
rssadapt_updatestats(ra);
/* pick initial rate */
for (ra->ra_rix = rs->rs_nrates - 1;
ra->ra_rix > 0 && (rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL) > 72;
ra->ra_rix--)
;
ni->ni_txrate = rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL;
ra->ra_ticks = ticks;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"RSSADAPT initial rate %d", ni->ni_txrate);
}
static void
rssadapt_node_deinit(struct ieee80211_node *ni)
{
IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL);
}
static __inline int
bucket(int pktlen)
{
int i, top, thridx;
for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
i < IEEE80211_RSSADAPT_BKTS;
i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
thridx = i;
if (pktlen <= top)
break;
}
return thridx;
}
static int
rssadapt_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg)
{
struct ieee80211_rssadapt_node *ra = ni->ni_rctls;
u_int pktlen = iarg;
const struct ieee80211_rateset *rs = &ra->ra_rates;
uint16_t (*thrs)[IEEE80211_RATE_SIZE];
int rix, rssi;
if ((ticks - ra->ra_ticks) > ra->ra_rs->interval) {
rssadapt_updatestats(ra);
ra->ra_ticks = ticks;
}
thrs = &ra->ra_rate_thresh[bucket(pktlen)];
/* XXX this is average rssi, should be using last value */
rssi = ni->ni_ic->ic_node_getrssi(ni);
for (rix = rs->rs_nrates-1; rix >= 0; rix--)
if ((*thrs)[rix] < (rssi << 8))
break;
if (rix != ra->ra_rix) {
/* update public rate */
ni->ni_txrate = ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL;
ra->ra_rix = rix;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"RSSADAPT new rate %d (pktlen %d rssi %d)",
ni->ni_txrate, pktlen, rssi);
}
return rix;
}
/*
* Adapt the data rate to suit the conditions. When a transmitted
* packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions,
* raise the RSS threshold for transmitting packets of similar length at
* the same data rate.
*/
static void
rssadapt_lower_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi)
{
uint16_t last_thr;
uint16_t (*thrs)[IEEE80211_RATE_SIZE];
u_int rix;
thrs = &ra->ra_rate_thresh[bucket(pktlen)];
rix = ra->ra_rix;
last_thr = (*thrs)[rix];
(*thrs)[rix] = interpolate(master_expavgctl.rc_thresh,
last_thr, (rssi << 8));
IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL,
"RSSADAPT lower threshold for rate %d (last_thr %d new thr %d rssi %d)\n",
ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL,
last_thr, (*thrs)[rix], rssi);
}
static void
rssadapt_raise_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi)
{
uint16_t (*thrs)[IEEE80211_RATE_SIZE];
uint16_t newthr, oldthr;
int rix;
thrs = &ra->ra_rate_thresh[bucket(pktlen)];
rix = ra->ra_rix;
if ((*thrs)[rix + 1] > (*thrs)[rix]) {
oldthr = (*thrs)[rix + 1];
if ((*thrs)[rix] == 0)
newthr = (rssi << 8);
else
newthr = (*thrs)[rix];
(*thrs)[rix + 1] = interpolate(master_expavgctl.rc_decay,
oldthr, newthr);
IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL,
"RSSADAPT raise threshold for rate %d (oldthr %d newthr %d rssi %d)\n",
ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL,
oldthr, newthr, rssi);
ra->ra_last_raise = ticks;
}
}
static void
rssadapt_tx_complete(const struct ieee80211_node *ni,
const struct ieee80211_ratectl_tx_status *status)
{
struct ieee80211_rssadapt_node *ra = ni->ni_rctls;
int pktlen, rssi;
if ((status->flags &
(IEEE80211_RATECTL_STATUS_PKTLEN|IEEE80211_RATECTL_STATUS_RSSI)) !=
(IEEE80211_RATECTL_STATUS_PKTLEN|IEEE80211_RATECTL_STATUS_RSSI))
return;
pktlen = status->pktlen;
rssi = status->rssi;
if (status->status == IEEE80211_RATECTL_TX_SUCCESS) {
ra->ra_nok++;
if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates &&
(ticks - ra->ra_last_raise) >= ra->ra_raise_interval)
rssadapt_raise_rate(ra, pktlen, rssi);
} else {
ra->ra_nfail++;
rssadapt_lower_rate(ra, pktlen, rssi);
}
}
static int
rssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS)
{
struct ieee80211vap *vap = arg1;
struct ieee80211_rssadapt *rs = vap->iv_rs;
int msecs = ticks_to_msecs(rs->interval);
int error;
error = sysctl_handle_int(oidp, &msecs, 0, req);
if (error || !req->newptr)
return error;
rssadapt_setinterval(vap, msecs);
return 0;
}
static void
rssadapt_sysctlattach(struct ieee80211vap *vap,
struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
{
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"rssadapt_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)");
}
