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/* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */
/*-
* Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
* Copyright (c) 2006
* Damien Bergamini <damien.bergamini@free.fr>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*-
* Naive implementation of the Adaptive Multi Rate Retry algorithm:
*
* "IEEE 802.11 Rate Adaptation: A Practical Approach"
* Mathieu Lacage, Hossein Manshaei, Thierry Turletti
* INRIA Sophia - Projet Planete
* http://www-sop.inria.fr/rapports/sophia/RR-5208.html
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/kernel.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>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_ht.h>
#include <net80211/ieee80211_amrr.h>
#include <net80211/ieee80211_ratectl.h>
#define is_success(amn) \
((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
#define is_failure(amn) \
((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
#define is_enough(amn) \
((amn)->amn_txcnt > 10)
static void amrr_setinterval(const struct ieee80211vap *, int);
static void amrr_init(struct ieee80211vap *);
static void amrr_deinit(struct ieee80211vap *);
static void amrr_node_init(struct ieee80211_node *);
static void amrr_node_deinit(struct ieee80211_node *);
static int amrr_update(struct ieee80211_amrr *,
struct ieee80211_amrr_node *, struct ieee80211_node *);
static int amrr_rate(struct ieee80211_node *, void *, uint32_t);
static void amrr_tx_complete(const struct ieee80211vap *,
const struct ieee80211_node *, int,
void *, void *);
static void amrr_tx_update(const struct ieee80211vap *vap,
const struct ieee80211_node *, void *, void *, void *);
static void amrr_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 amrr = {
.ir_name = "amrr",
.ir_attach = NULL,
.ir_detach = NULL,
.ir_init = amrr_init,
.ir_deinit = amrr_deinit,
.ir_node_init = amrr_node_init,
.ir_node_deinit = amrr_node_deinit,
.ir_rate = amrr_rate,
.ir_tx_complete = amrr_tx_complete,
.ir_tx_update = amrr_tx_update,
.ir_setinterval = amrr_setinterval,
};
IEEE80211_RATECTL_MODULE(amrr, 1);
IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr);
static void
amrr_setinterval(const struct ieee80211vap *vap, int msecs)
{
struct ieee80211_amrr *amrr = vap->iv_rs;
int t;
if (msecs < 100)
msecs = 100;
t = msecs_to_ticks(msecs);
amrr->amrr_interval = (t < 1) ? 1 : t;
}
static void
amrr_init(struct ieee80211vap *vap)
{
struct ieee80211_amrr *amrr;
KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
amrr = vap->iv_rs = malloc(sizeof(struct ieee80211_amrr),
M_80211_RATECTL, M_NOWAIT|M_ZERO);
if (amrr == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
return;
}
amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD;
amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD;
amrr_setinterval(vap, 500 /* ms */);
amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
}
static void
amrr_deinit(struct ieee80211vap *vap)
{
free(vap->iv_rs, M_80211_RATECTL);
}
static int
amrr_node_is_11n(struct ieee80211_node *ni)
{
if (ni->ni_chan == NULL)
return (0);
if (ni->ni_chan == IEEE80211_CHAN_ANYC)
return (0);
return (IEEE80211_IS_CHAN_HT(ni->ni_chan));
}
static void
amrr_node_init(struct ieee80211_node *ni)
{
const struct ieee80211_rateset *rs = NULL;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211_amrr *amrr = vap->iv_rs;
struct ieee80211_amrr_node *amn;
uint8_t rate;
if (ni->ni_rctls == NULL) {
ni->ni_rctls = amn = malloc(sizeof(struct ieee80211_amrr_node),
M_80211_RATECTL, M_NOWAIT|M_ZERO);
if (amn == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
"structure\n");
return;
}
} else
amn = ni->ni_rctls;
amn->amn_amrr = amrr;
amn->amn_success = 0;
amn->amn_recovery = 0;
amn->amn_txcnt = amn->amn_retrycnt = 0;
amn->amn_success_threshold = amrr->amrr_min_success_threshold;
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"%s: 11n node", __func__);
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"%s: non-11n node", __func__);
rs = &ni->ni_rates;
}
/* Initial rate - lowest */
rate = rs->rs_rates[0];
/* XXX clear the basic rate flag if it's not 11n */
if (! amrr_node_is_11n(ni))
rate &= IEEE80211_RATE_VAL;
/* pick initial rate from the rateset - HT or otherwise */
for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
amn->amn_rix--) {
/* legacy - anything < 36mbit, stop searching */
/* 11n - stop at MCS4 / MCS12 / MCS28 */
if (amrr_node_is_11n(ni) &&
(rs->rs_rates[amn->amn_rix] & 0x7) < 4)
break;
else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
break;
rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
}
/* if the rate is an 11n rate, ensure the MCS bit is set */
if (amrr_node_is_11n(ni))
rate |= IEEE80211_RATE_MCS;
/* Assign initial rate from the rateset */
ni->ni_txrate = rate;
amn->amn_ticks = ticks;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR: nrates=%d, initial rate %d",
rs->rs_nrates,
rate);
}
static void
amrr_node_deinit(struct ieee80211_node *ni)
{
free(ni->ni_rctls, M_80211_RATECTL);
}
static int
amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
struct ieee80211_node *ni)
{
int rix = amn->amn_rix;
const struct ieee80211_rateset *rs = NULL;
KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
rs = &ni->ni_rates;
}
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR: current rate %d, txcnt=%d, retrycnt=%d",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt,
amn->amn_retrycnt);
/*
* XXX This is totally bogus for 11n, as although high MCS
* rates for each stream may be failing, the next stream
* should be checked.
*
* Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
* MCS23, we should skip 6/7 and try 8 onwards.
*/
if (is_success(amn)) {
amn->amn_success++;
if (amn->amn_success >= amn->amn_success_threshold &&
rix + 1 < rs->rs_nrates) {
amn->amn_recovery = 1;
amn->amn_success = 0;
rix++;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
} else {
amn->amn_recovery = 0;
}
} else if (is_failure(amn)) {
amn->amn_success = 0;
if (rix > 0) {
if (amn->amn_recovery) {
amn->amn_success_threshold *= 2;
if (amn->amn_success_threshold >
amrr->amrr_max_success_threshold)
amn->amn_success_threshold =
amrr->amrr_max_success_threshold;
} else {
amn->amn_success_threshold =
amrr->amrr_min_success_threshold;
}
rix--;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
}
amn->amn_recovery = 0;
}
/* reset counters */
amn->amn_txcnt = 0;
amn->amn_retrycnt = 0;
return rix;
}
/*
* Return the rate index to use in sending a data frame.
* Update our internal state if it's been long enough.
* If the rate changes we also update ni_txrate to match.
*/
static int
amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
struct ieee80211_amrr *amrr = amn->amn_amrr;
const struct ieee80211_rateset *rs = NULL;
int rix;
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
rs = &ni->ni_rates;
}
if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
rix = amrr_update(amrr, amn, ni);
if (rix != amn->amn_rix) {
/* update public rate */
ni->ni_txrate = rs->rs_rates[rix];
/* XXX strip basic rate flag from txrate, if non-11n */
if (amrr_node_is_11n(ni))
ni->ni_txrate |= IEEE80211_RATE_MCS;
else
ni->ni_txrate &= IEEE80211_RATE_VAL;
amn->amn_rix = rix;
}
amn->amn_ticks = ticks;
} else
rix = amn->amn_rix;
return rix;
}
/*
* Update statistics with tx complete status. Ok is non-zero
* if the packet is known to be ACK'd. Retries has the number
* retransmissions (i.e. xmit attempts - 1).
*/
static void
amrr_tx_complete(const struct ieee80211vap *vap,
const struct ieee80211_node *ni, int ok,
void *arg1, void *arg2 __unused)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
int retries = *(int *)arg1;
amn->amn_txcnt++;
if (ok)
amn->amn_success++;
amn->amn_retrycnt += retries;
}
/*
* Set tx count/retry statistics explicitly. Intended for
* drivers that poll the device for statistics maintained
* in the device.
*/
static void
amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni,
void *arg1, void *arg2, void *arg3)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3;
amn->amn_txcnt = txcnt;
amn->amn_success = success;
amn->amn_retrycnt = retrycnt;
}
static int
amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
{
struct ieee80211vap *vap = arg1;
struct ieee80211_amrr *amrr = vap->iv_rs;
int msecs = ticks_to_msecs(amrr->amrr_interval);
int error;
error = sysctl_handle_int(oidp, &msecs, 0, req);
if (error || !req->newptr)
return error;
amrr_setinterval(vap, msecs);
return 0;
}
static void
amrr_sysctlattach(struct ieee80211vap *vap,
struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
{
struct ieee80211_amrr *amrr = vap->iv_rs;
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
/* XXX bounds check values */
SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_max_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_max_success_threshold, 0, "");
SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_min_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_min_success_threshold, 0, "");
}
|