diff options
Diffstat (limited to 'sys/net80211/ieee80211_rssadapt.c')
| -rw-r--r-- | sys/net80211/ieee80211_rssadapt.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/sys/net80211/ieee80211_rssadapt.c b/sys/net80211/ieee80211_rssadapt.c new file mode 100644 index 0000000..f1fc409 --- /dev/null +++ b/sys/net80211/ieee80211_rssadapt.c @@ -0,0 +1,273 @@ +/* $FreeBSD$ */ +/* $NetBSD: ieee80211_rssadapt.c,v 1.9 2005/02/26 22:45:09 perry 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 "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> + +#include <net80211/ieee80211_var.h> +#include <net80211/ieee80211_rssadapt.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_sysctlattach(struct ieee80211_rssadapt *rs, + struct sysctl_ctx_list *ctx, struct sysctl_oid *tree); + +/* number of references from net80211 layer */ +static int nrefs = 0; + +void +ieee80211_rssadapt_setinterval(struct ieee80211_rssadapt *rs, int msecs) +{ + int t; + + if (msecs < 100) + msecs = 100; + t = msecs_to_ticks(msecs); + rs->interval = (t < 1) ? 1 : t; +} + +void +ieee80211_rssadapt_init(struct ieee80211_rssadapt *rs, struct ieee80211vap *vap, int interval) +{ + rs->vap = vap; + ieee80211_rssadapt_setinterval(rs, interval); + + rssadapt_sysctlattach(rs, vap->iv_sysctl, vap->iv_oid); +} + +void +ieee80211_rssadapt_cleanup(struct ieee80211_rssadapt *rs) +{ +} + +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); +} + +void +ieee80211_rssadapt_node_init(struct ieee80211_rssadapt *rsa, + struct ieee80211_rssadapt_node *ra, struct ieee80211_node *ni) +{ + const struct ieee80211_rateset *rs = &ni->ni_rates; + + 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 __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; +} + +int +ieee80211_rssadapt_choose(struct ieee80211_node *ni, + struct ieee80211_rssadapt_node *ra, u_int pktlen) +{ + 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. + */ +void +ieee80211_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); +} + +void +ieee80211_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 int +rssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS) +{ + struct ieee80211_rssadapt *rs = arg1; + int msecs = ticks_to_msecs(rs->interval); + int error; + + error = sysctl_handle_int(oidp, &msecs, 0, req); + if (error || !req->newptr) + return error; + ieee80211_rssadapt_setinterval(rs, msecs); + return 0; +} + +static void +rssadapt_sysctlattach(struct ieee80211_rssadapt *rs, + 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, rs, + 0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)"); +} + +/* + * Module glue. + */ +IEEE80211_RATE_MODULE(rssadapt, 1); |
