freebsd-dev/sys/net80211/ieee80211_amrr.c

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/* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */
/*-
* 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_media.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_amrr.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_sysctlattach(struct ieee80211_amrr *amrr,
struct sysctl_ctx_list *ctx, struct sysctl_oid *tree);
/* number of references from net80211 layer */
static int nrefs = 0;
void
ieee80211_amrr_setinterval(struct ieee80211_amrr *amrr, int msecs)
{
int t;
if (msecs < 100)
msecs = 100;
t = msecs_to_ticks(msecs);
amrr->amrr_interval = (t < 1) ? 1 : t;
}
void
ieee80211_amrr_init(struct ieee80211_amrr *amrr,
struct ieee80211vap *vap, int amin, int amax, int interval)
{
/* XXX bounds check? */
Update 802.11 wireless support: o major overhaul of the way channels are handled: channels are now fully enumerated and uniquely identify the operating characteristics; these changes are visible to user applications which require changes o make scanning support independent of the state machine to enable background scanning and roaming o move scanning support into loadable modules based on the operating mode to enable different policies and reduce the memory footprint on systems w/ constrained resources o add background scanning in station mode (no support for adhoc/ibss mode yet) o significantly speedup sta mode scanning with a variety of techniques o add roaming support when background scanning is supported; for now we use a simple algorithm to trigger a roam: we threshold the rssi and tx rate, if either drops too low we try to roam to a new ap o add tx fragmentation support o add first cut at 802.11n support: this code works with forthcoming drivers but is incomplete; it's included now to establish a baseline for other drivers to be developed and for user applications o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates prepending mbufs for traffic generated locally o add support for Atheros protocol extensions; mainly the fast frames encapsulation (note this can be used with any card that can tx+rx large frames correctly) o add sta support for ap's that beacon both WPA1+2 support o change all data types from bsd-style to posix-style o propagate noise floor data from drivers to net80211 and on to user apps o correct various issues in the sta mode state machine related to handling authentication and association failures o enable the addition of sta mode power save support for drivers that need net80211 support (not in this commit) o remove old WI compatibility ioctls (wicontrol is officially dead) o change the data structures returned for get sta info and get scan results so future additions will not break user apps o fixed tx rate is now maintained internally as an ieee rate and not an index into the rate set; this needs to be extended to deal with multi-mode operation o add extended channel specifications to radiotap to enable 11n sniffing Drivers: o ath: add support for bg scanning, tx fragmentation, fast frames, dynamic turbo (lightly tested), 11n (sniffing only and needs new hal) o awi: compile tested only o ndis: lightly tested o ipw: lightly tested o iwi: add support for bg scanning (well tested but may have some rough edges) o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data o wi: lightly tested This work is based on contributions by Atheros, kmacy, sephe, thompsa, mlaier, kevlo, and others. Much of the scanning work was supported by Atheros. The 11n work was supported by Marvell.
2007-06-11 03:36:55 +00:00
amrr->amrr_min_success_threshold = amin;
amrr->amrr_max_success_threshold = amax;
ieee80211_amrr_setinterval(amrr, interval);
amrr_sysctlattach(amrr, vap->iv_sysctl, vap->iv_oid);
}
void
ieee80211_amrr_cleanup(struct ieee80211_amrr *amrr)
{
}
void
ieee80211_amrr_node_init(struct ieee80211_amrr *amrr,
struct ieee80211_amrr_node *amn, struct ieee80211_node *ni)
{
const struct ieee80211_rateset *rs = &ni->ni_rates;
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;
/* pick initial rate */
for (amn->amn_rix = rs->rs_nrates - 1;
amn->amn_rix > 0 && (rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) > 72;
amn->amn_rix--)
;
ni->ni_txrate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
amn->amn_ticks = ticks;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR initial rate %d", ni->ni_txrate);
}
static int
amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
struct ieee80211_node *ni)
{
int rix = amn->amn_rix;
KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
if (is_success(amn)) {
amn->amn_success++;
if (amn->amn_success >= amn->amn_success_threshold &&
rix + 1 < ni->ni_rates.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)",
ni->ni_rates.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)",
ni->ni_rates.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.
*/
int
ieee80211_amrr_choose(struct ieee80211_node *ni,
struct ieee80211_amrr_node *amn)
{
struct ieee80211_amrr *amrr = amn->amn_amrr;
int rix;
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 =
ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL;
amn->amn_rix = rix;
}
amn->amn_ticks = ticks;
} else
rix = amn->amn_rix;
return rix;
}
static int
amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
{
struct ieee80211_amrr *amrr = arg1;
int msecs = ticks_to_msecs(amrr->amrr_interval);
int error;
error = sysctl_handle_int(oidp, &msecs, 0, req);
if (error || !req->newptr)
return error;
ieee80211_amrr_setinterval(amrr, msecs);
return 0;
}
static void
amrr_sysctlattach(struct ieee80211_amrr *amrr,
struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
{
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, amrr,
0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
/* XXX bounds check values */
SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_max_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_max_success_threshold, 0, "");
SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_min_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_min_success_threshold, 0, "");
}
/*
* Module glue.
*/
IEEE80211_RATE_MODULE(amrr, 1);