freebsd-dev/sys/net80211/ieee80211_amrr.c
Sam Leffler 68e8e04e93 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

165 lines
4.4 KiB
C

/* $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 <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)
#define is_min_rate(ni) \
((ni)->ni_txrate == 0)
#define is_max_rate(ni) \
((ni)->ni_txrate == (ni)->ni_rates.rs_nrates - 1)
#define increase_rate(ni) \
((ni)->ni_txrate++)
#define decrease_rate(ni) \
((ni)->ni_txrate--)
#define reset_cnt(amn) \
do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0)
void
ieee80211_amrr_init(struct ieee80211_amrr *amrr,
struct ieee80211com *ic, int amin, int amax)
{
/* XXX bounds check? */
amrr->amrr_min_success_threshold = amin;
amrr->amrr_max_success_threshold = amax;
amrr->amrr_ic = ic;
}
void
ieee80211_amrr_node_init(struct ieee80211_amrr *amrr,
struct ieee80211_amrr_node *amn)
{
amn->amn_success = 0;
amn->amn_recovery = 0;
amn->amn_txcnt = amn->amn_retrycnt = 0;
amn->amn_success_threshold = amrr->amrr_min_success_threshold;
}
/*
* Update ni->ni_txrate.
*/
void
ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni,
struct ieee80211_amrr_node *amn)
{
int need_change = 0;
if (is_success(amn) && is_enough(amn)) {
amn->amn_success++;
if (amn->amn_success >= amn->amn_success_threshold &&
!is_max_rate(ni)) {
amn->amn_recovery = 1;
amn->amn_success = 0;
increase_rate(ni);
IEEE80211_DPRINTF(amrr->amrr_ic, IEEE80211_MSG_RATECTL,
"AMRR increasing rate %d (txcnt=%d "
"retrycnt=%d)\n",
ni->ni_rates.rs_rates[ni->ni_txrate] &
IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
need_change = 1;
} else {
amn->amn_recovery = 0;
}
} else if (is_failure(amn)) {
amn->amn_success = 0;
if (!is_min_rate(ni)) {
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;
}
decrease_rate(ni);
IEEE80211_DPRINTF(amrr->amrr_ic, IEEE80211_MSG_RATECTL,
"AMRR decreasing rate %d (txcnt=%d "
"retrycnt=%d)\n",
ni->ni_rates.rs_rates[ni->ni_txrate] &
IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
need_change = 1;
}
amn->amn_recovery = 0;
}
if (is_enough(amn) || need_change)
reset_cnt(amn);
}
/*
* Module glue.
*/
static int
amrr_modevent(module_t mod, int type, void *unused)
{
switch (type) {
case MOD_LOAD:
if (bootverbose)
printf("wlan_amrr: <AMRR Transmit Rate Control Algorithm>\n");
return 0;
case MOD_UNLOAD:
return 0;
}
return EINVAL;
}
static moduledata_t amrr_mod = {
"wlan_amrr",
amrr_modevent,
0
};
DECLARE_MODULE(wlan_amrr, amrr_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
MODULE_VERSION(wlan_amrr, 1);
MODULE_DEPEND(wlan_amrr, wlan, 1, 1, 1);