NetBSD-5.0.2/sys/net80211/ieee80211_rssadapt.c
/* $NetBSD: ieee80211_rssadapt.c,v 1.15 2008/06/24 10:33:46 gmcgarry Exp $ */
/*-
* 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 <sys/cdefs.h>
#ifdef __NetBSD__
__KERNEL_RCSID(0, "$NetBSD: ieee80211_rssadapt.c,v 1.15 2008/06/24 10:33:46 gmcgarry Exp $");
#endif
#include <sys/param.h>
#include <sys/types.h>
#include <sys/kernel.h> /* for hz */
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_ether.h>
#include <net80211/ieee80211_netbsd.h>
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211.h>
#include <net80211/ieee80211_rssadapt.h>
#ifdef interpolate
#undef interpolate
#endif
#define interpolate(parm, old, new) ((parm##_old * (old) + \
(parm##_denom - parm##_old) * (new)) / \
parm##_denom)
#ifdef IEEE80211_DEBUG
static struct timeval lastrateadapt; /* time of last rate adaptation msg */
static int currssadaptps = 0; /* rate-adaptation msgs this second */
static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */
#define RSSADAPT_DO_PRINT() \
((ieee80211_rssadapt_debug > 0) && \
ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate))
#define RSSADAPT_PRINTF(X) \
if (RSSADAPT_DO_PRINT()) \
printf X
int ieee80211_rssadapt_debug = 0;
#else
#define RSSADAPT_DO_PRINT() (0)
#define RSSADAPT_PRINTF(X)
#endif
static struct ieee80211_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 __NetBSD__
#ifdef IEEE80211_DEBUG
/* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
static int
sysctl_ieee80211_rssadapt_debug(SYSCTLFN_ARGS)
{
int error, t;
struct sysctlnode node;
node = *rnode;
t = *(int*)rnode->sysctl_data;
node.sysctl_data = &t;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
if (t < 0 || t > 2)
return (EINVAL);
*(int*)rnode->sysctl_data = t;
return (0);
}
#endif /* IEEE80211_DEBUG */
/* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
static int
sysctl_ieee80211_rssadapt_expavgctl(SYSCTLFN_ARGS)
{
struct ieee80211_rssadapt_expavgctl rc;
int error;
struct sysctlnode node;
node = *rnode;
rc = *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data;
node.sysctl_data = &rc;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
if (/* rc.rc_decay_old < 0 || */
rc.rc_decay_denom < rc.rc_decay_old)
return (EINVAL);
if (/* rc.rc_thresh_old < 0 || */
rc.rc_thresh_denom < rc.rc_thresh_old)
return (EINVAL);
if (/* rc.rc_avgrssi_old < 0 || */
rc.rc_avgrssi_denom < rc.rc_avgrssi_old)
return (EINVAL);
*(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data = rc;
return (0);
}
/*
* Setup sysctl(3) MIB, net.ieee80211.*
*
* TBD condition CTLFLAG_PERMANENT on being an LKM or not
*/
SYSCTL_SETUP(sysctl_ieee80211_rssadapt,
"sysctl ieee80211 rssadapt subtree setup")
{
int rc;
const struct sysctlnode *node;
if ((rc = sysctl_createv(clog, 0, NULL, &node,
CTLFLAG_PERMANENT, CTLTYPE_NODE, "net", NULL,
NULL, 0, NULL, 0, CTL_NET, CTL_EOL)) != 0)
goto err;
if ((rc = sysctl_createv(clog, 0, &node, &node,
CTLFLAG_PERMANENT, CTLTYPE_NODE, "link", NULL,
NULL, 0, NULL, 0, PF_LINK, CTL_EOL)) != 0)
goto err;
if ((rc = sysctl_createv(clog, 0, &node, &node,
CTLFLAG_PERMANENT, CTLTYPE_NODE, "ieee80211", NULL,
NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
goto err;
if ((rc = sysctl_createv(clog, 0, &node, &node,
CTLFLAG_PERMANENT, CTLTYPE_NODE, "rssadapt",
SYSCTL_DESCR("Received Signal Strength adaptation controls"),
NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
goto err;
#ifdef IEEE80211_DEBUG
/* control debugging printfs */
if ((rc = sysctl_createv(clog, 0, &node, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
SYSCTL_DESCR("Enable RSS adaptation debugging output"),
sysctl_ieee80211_rssadapt_debug, 0, &ieee80211_rssadapt_debug, 0,
CTL_CREATE, CTL_EOL)) != 0)
goto err;
#endif /* IEEE80211_DEBUG */
/* control rate of decay for exponential averages */
if ((rc = sysctl_createv(clog, 0, &node, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_STRUCT,
"expavgctl", SYSCTL_DESCR("RSS exponential averaging control"),
sysctl_ieee80211_rssadapt_expavgctl, 0,
&master_expavgctl, sizeof(master_expavgctl), CTL_CREATE,
CTL_EOL)) != 0)
goto err;
return;
err:
printf("%s: sysctl_createv failed (rc = %d)\n", __func__, rc);
}
#endif /* __NetBSD__ */
int
ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra,
struct ieee80211_rateset *rs, struct ieee80211_frame *wh, u_int len,
int fixed_rate, const char *dvname, int do_not_adapt)
{
u_int16_t (*thrs)[IEEE80211_RATE_SIZE];
int flags = 0, i, rateidx = 0, thridx, top;
if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
flags |= IEEE80211_RATE_BASIC;
for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
i < IEEE80211_RSSADAPT_BKTS;
i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
thridx = i;
if (len <= top)
break;
}
thrs = &ra->ra_rate_thresh[thridx];
if (fixed_rate != -1) {
if ((rs->rs_rates[fixed_rate] & flags) == flags) {
rateidx = fixed_rate;
goto out;
}
flags |= IEEE80211_RATE_BASIC;
i = fixed_rate;
} else
i = rs->rs_nrates;
while (--i >= 0) {
rateidx = i;
if ((rs->rs_rates[i] & flags) != flags)
continue;
if (do_not_adapt)
break;
if ((*thrs)[i] < ra->ra_avg_rssi)
break;
}
out:
#ifdef IEEE80211_DEBUG
if (ieee80211_rssadapt_debug && dvname != NULL) {
printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n",
dvname, ether_sprintf(wh->i_addr1), len,
(rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2,
(rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
(*thrs)[rateidx], ra->ra_avg_rssi);
}
#endif /* IEEE80211_DEBUG */
return rateidx;
}
void
ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *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(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
}
void
ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni,
struct ieee80211_rssadapt *ra, int rssi)
{
#ifdef IEEE80211_DEBUG
int last_avg_rssi = ra->ra_avg_rssi;
#endif
ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
ra->ra_avg_rssi, (rssi << 8));
RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n",
ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr),
rssi, last_avg_rssi, ra->ra_avg_rssi));
}
/*
* Adapt the data rate to suit the conditions. When a transmitted
* packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions,
* raise the RSS threshold for transmitting packets of similar length at
* the same data rate.
*/
void
ieee80211_rssadapt_lower_rate(struct ieee80211com *ic,
struct ieee80211_node *ni, struct ieee80211_rssadapt *ra,
struct ieee80211_rssdesc *id)
{
struct ieee80211_rateset *rs = &ni->ni_rates;
u_int16_t last_thr;
u_int i, thridx, top;
ra->ra_nfail++;
if (id->id_rateidx >= rs->rs_nrates) {
RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: "
"%s rate #%d > #%d out of bounds\n",
ether_sprintf(ni->ni_macaddr), id->id_rateidx,
rs->rs_nrates - 1));
return;
}
for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
i < IEEE80211_RSSADAPT_BKTS;
i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
thridx = i;
if (id->id_len <= top)
break;
}
last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
ra->ra_rate_thresh[thridx][id->id_rateidx] =
interpolate(master_expavgctl.rc_thresh, last_thr,
(id->id_rssi << 8));
RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n",
ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr),
id->id_rssi, id->id_len,
(rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2,
(rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx]));
}
void
ieee80211_rssadapt_raise_rate(struct ieee80211com *ic,
struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id)
{
u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
struct ieee80211_node *ni = id->id_node;
struct ieee80211_rateset *rs = &ni->ni_rates;
int i, rate, top;
#ifdef IEEE80211_DEBUG
int j;
#endif
ra->ra_nok++;
if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval))
return;
for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
i < IEEE80211_RSSADAPT_BKTS;
i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
thrs = &ra->ra_rate_thresh[i];
if (id->id_len <= top)
break;
}
if (id->id_rateidx + 1 < rs->rs_nrates &&
(*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL);
RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ",
ic->ic_ifp->if_xname,
IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i),
rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1]));
oldthr = (*thrs)[id->id_rateidx + 1];
if ((*thrs)[id->id_rateidx] == 0)
newthr = ra->ra_avg_rssi;
else
newthr = (*thrs)[id->id_rateidx];
(*thrs)[id->id_rateidx + 1] =
interpolate(master_expavgctl.rc_decay, oldthr, newthr);
RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1]));
}
#ifdef IEEE80211_DEBUG
if (RSSADAPT_DO_PRINT()) {
printf("%s: dst %s thresholds\n", ic->ic_ifp->if_xname,
ether_sprintf(ni->ni_macaddr));
for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) {
printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i));
for (j = 0; j < rs->rs_nrates; j++) {
rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL);
printf(", T[%d.%d] = %d", rate / 2,
rate * 5 % 10, ra->ra_rate_thresh[i][j]);
}
printf("\n");
}
}
#endif /* IEEE80211_DEBUG */
}