ieee80211_rssadapt.c revision 206419
1178354Ssam/* $FreeBSD: head/sys/net80211/ieee80211_rssadapt.c 206419 2010-04-09 12:06:19Z rpaulo $ */ 2178354Ssam/* $NetBSD: ieee80211_rssadapt.c,v 1.9 2005/02/26 22:45:09 perry Exp $ */ 3178354Ssam/*- 4206358Srpaulo * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org> 5178354Ssam * Copyright (c) 2003, 2004 David Young. All rights reserved. 6178354Ssam * 7178354Ssam * Redistribution and use in source and binary forms, with or 8178354Ssam * without modification, are permitted provided that the following 9178354Ssam * conditions are met: 10178354Ssam * 1. Redistributions of source code must retain the above copyright 11178354Ssam * notice, this list of conditions and the following disclaimer. 12178354Ssam * 2. Redistributions in binary form must reproduce the above 13178354Ssam * copyright notice, this list of conditions and the following 14178354Ssam * disclaimer in the documentation and/or other materials provided 15178354Ssam * with the distribution. 16178354Ssam * 3. The name of David Young may not be used to endorse or promote 17178354Ssam * products derived from this software without specific prior 18178354Ssam * written permission. 19178354Ssam * 20178354Ssam * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY 21178354Ssam * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 22178354Ssam * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 23178354Ssam * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David 24178354Ssam * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25178354Ssam * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 26178354Ssam * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27178354Ssam * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 28178354Ssam * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29178354Ssam * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30178354Ssam * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 31178354Ssam * OF SUCH DAMAGE. 32178354Ssam */ 33178354Ssam#include "opt_wlan.h" 34178354Ssam 35178354Ssam#include <sys/param.h> 36178354Ssam#include <sys/kernel.h> 37178354Ssam#include <sys/module.h> 38178354Ssam#include <sys/socket.h> 39178354Ssam#include <sys/sysctl.h> 40178354Ssam 41178354Ssam#include <net/if.h> 42178354Ssam#include <net/if_media.h> 43178354Ssam 44178354Ssam#include <net80211/ieee80211_var.h> 45178354Ssam#include <net80211/ieee80211_rssadapt.h> 46206358Srpaulo#include <net80211/ieee80211_ratectl.h> 47178354Ssam 48178354Ssamstruct rssadapt_expavgctl { 49178354Ssam /* RSS threshold decay. */ 50178354Ssam u_int rc_decay_denom; 51178354Ssam u_int rc_decay_old; 52178354Ssam /* RSS threshold update. */ 53178354Ssam u_int rc_thresh_denom; 54178354Ssam u_int rc_thresh_old; 55178354Ssam /* RSS average update. */ 56178354Ssam u_int rc_avgrssi_denom; 57178354Ssam u_int rc_avgrssi_old; 58178354Ssam}; 59178354Ssam 60178354Ssamstatic struct rssadapt_expavgctl master_expavgctl = { 61178354Ssam rc_decay_denom : 16, 62178354Ssam rc_decay_old : 15, 63178354Ssam rc_thresh_denom : 8, 64178354Ssam rc_thresh_old : 4, 65178354Ssam rc_avgrssi_denom : 8, 66178354Ssam rc_avgrssi_old : 4 67178354Ssam}; 68178354Ssam 69178354Ssam#ifdef interpolate 70178354Ssam#undef interpolate 71178354Ssam#endif 72178354Ssam#define interpolate(parm, old, new) ((parm##_old * (old) + \ 73178354Ssam (parm##_denom - parm##_old) * (new)) / \ 74178354Ssam parm##_denom) 75178354Ssam 76206358Srpaulostatic void rssadapt_setinterval(const struct ieee80211vap *, int); 77206358Srpaulostatic void rssadapt_init(struct ieee80211vap *); 78206358Srpaulostatic void rssadapt_deinit(struct ieee80211vap *); 79206358Srpaulostatic void rssadapt_updatestats(struct ieee80211_rssadapt_node *); 80206358Srpaulostatic void rssadapt_node_init(struct ieee80211_node *); 81206358Srpaulostatic void rssadapt_node_deinit(struct ieee80211_node *); 82206358Srpaulostatic int rssadapt_rate(struct ieee80211_node *, void *, uint32_t); 83206358Srpaulostatic void rssadapt_lower_rate(struct ieee80211_rssadapt_node *, int, int); 84206358Srpaulostatic void rssadapt_raise_rate(struct ieee80211_rssadapt_node *, 85206358Srpaulo int, int); 86206358Srpaulostatic void rssadapt_tx_complete(const struct ieee80211vap *, 87206358Srpaulo const struct ieee80211_node *, int, 88206358Srpaulo void *, void *); 89206358Srpaulostatic void rssadapt_sysctlattach(struct ieee80211vap *, 90206358Srpaulo struct sysctl_ctx_list *, struct sysctl_oid *); 91178354Ssam 92178354Ssam/* number of references from net80211 layer */ 93178354Ssamstatic int nrefs = 0; 94178354Ssam 95206358Srpaulostatic const struct ieee80211_ratectl rssadapt = { 96206358Srpaulo .ir_name = "rssadapt", 97206358Srpaulo .ir_attach = NULL, 98206358Srpaulo .ir_detach = NULL, 99206358Srpaulo .ir_init = rssadapt_init, 100206358Srpaulo .ir_deinit = rssadapt_deinit, 101206358Srpaulo .ir_node_init = rssadapt_node_init, 102206358Srpaulo .ir_node_deinit = rssadapt_node_deinit, 103206358Srpaulo .ir_rate = rssadapt_rate, 104206358Srpaulo .ir_tx_complete = rssadapt_tx_complete, 105206358Srpaulo .ir_tx_update = NULL, 106206358Srpaulo .ir_setinterval = rssadapt_setinterval, 107206358Srpaulo}; 108206358SrpauloIEEE80211_RATECTL_MODULE(rssadapt, 1); 109206358SrpauloIEEE80211_RATECTL_ALG(rssadapt, IEEE80211_RATECTL_RSSADAPT, rssadapt); 110206358Srpaulo 111206358Srpaulostatic void 112206358Srpaulorssadapt_setinterval(const struct ieee80211vap *vap, int msecs) 113178354Ssam{ 114206358Srpaulo struct ieee80211_rssadapt *rs = vap->iv_rs; 115178354Ssam int t; 116178354Ssam 117178354Ssam if (msecs < 100) 118178354Ssam msecs = 100; 119178354Ssam t = msecs_to_ticks(msecs); 120178354Ssam rs->interval = (t < 1) ? 1 : t; 121178354Ssam} 122178354Ssam 123206358Srpaulostatic void 124206358Srpaulorssadapt_init(struct ieee80211vap *vap) 125178354Ssam{ 126206358Srpaulo struct ieee80211_rssadapt *rs; 127206358Srpaulo 128206358Srpaulo KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized", 129206358Srpaulo __func__)); 130206358Srpaulo 131206419Srpaulo vap->iv_rs = rs = malloc(sizeof(struct ieee80211_rssadapt), 132206419Srpaulo M_80211_RATECTL, M_NOWAIT|M_ZERO); 133206419Srpaulo if (rs == NULL) { 134206419Srpaulo if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 135206419Srpaulo return; 136206419Srpaulo } 137178354Ssam rs->vap = vap; 138206358Srpaulo rssadapt_setinterval(vap, 500 /* msecs */); 139206358Srpaulo rssadapt_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 140178354Ssam} 141178354Ssam 142206358Srpaulostatic void 143206358Srpaulorssadapt_deinit(struct ieee80211vap *vap) 144178354Ssam{ 145206358Srpaulo free(vap->iv_rs, M_80211_RATECTL); 146178354Ssam} 147178354Ssam 148178354Ssamstatic void 149178354Ssamrssadapt_updatestats(struct ieee80211_rssadapt_node *ra) 150178354Ssam{ 151178354Ssam long interval; 152178354Ssam 153178354Ssam ra->ra_pktrate = (ra->ra_pktrate + 10*(ra->ra_nfail + ra->ra_nok))/2; 154178354Ssam ra->ra_nfail = ra->ra_nok = 0; 155178354Ssam 156178354Ssam /* 157178354Ssam * A node is eligible for its rate to be raised every 1/10 to 10 158178354Ssam * seconds, more eligible in proportion to recent packet rates. 159178354Ssam */ 160178354Ssam interval = MAX(10*1000, 10*1000 / MAX(1, 10 * ra->ra_pktrate)); 161178354Ssam ra->ra_raise_interval = msecs_to_ticks(interval); 162178354Ssam} 163178354Ssam 164206358Srpaulostatic void 165206358Srpaulorssadapt_node_init(struct ieee80211_node *ni) 166178354Ssam{ 167206358Srpaulo struct ieee80211_rssadapt_node *ra; 168206419Srpaulo struct ieee80211vap *vap = ni->ni_vap; 169206419Srpaulo struct ieee80211_rssadapt *rsa = vap->iv_rs; 170178354Ssam const struct ieee80211_rateset *rs = &ni->ni_rates; 171178354Ssam 172206419Srpaulo ni->ni_rctls = ra = malloc(sizeof(struct ieee80211_rssadapt_node), 173206419Srpaulo M_80211_RATECTL, M_NOWAIT|M_ZERO); 174206419Srpaulo if (ra == NULL) { 175206419Srpaulo if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 176206419Srpaulo "structure\n"); 177206419Srpaulo return; 178206419Srpaulo } 179178354Ssam ra->ra_rs = rsa; 180178354Ssam ra->ra_rates = *rs; 181178354Ssam rssadapt_updatestats(ra); 182178354Ssam 183178354Ssam /* pick initial rate */ 184178354Ssam for (ra->ra_rix = rs->rs_nrates - 1; 185178354Ssam ra->ra_rix > 0 && (rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL) > 72; 186178354Ssam ra->ra_rix--) 187178354Ssam ; 188178354Ssam ni->ni_txrate = rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL; 189178354Ssam ra->ra_ticks = ticks; 190178354Ssam 191178354Ssam IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 192178354Ssam "RSSADAPT initial rate %d", ni->ni_txrate); 193178354Ssam} 194178354Ssam 195206358Srpaulostatic void 196206358Srpaulorssadapt_node_deinit(struct ieee80211_node *ni) 197206358Srpaulo{ 198206358Srpaulo 199206358Srpaulo free(ni->ni_rctls, M_80211_RATECTL); 200206358Srpaulo} 201206358Srpaulo 202178354Ssamstatic __inline int 203178354Ssambucket(int pktlen) 204178354Ssam{ 205178354Ssam int i, top, thridx; 206178354Ssam 207178354Ssam for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 208178354Ssam i < IEEE80211_RSSADAPT_BKTS; 209178354Ssam i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 210178354Ssam thridx = i; 211178354Ssam if (pktlen <= top) 212178354Ssam break; 213178354Ssam } 214178354Ssam return thridx; 215178354Ssam} 216178354Ssam 217206358Srpaulostatic int 218206358Srpaulorssadapt_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg) 219178354Ssam{ 220206358Srpaulo struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 221206358Srpaulo u_int pktlen = iarg; 222178354Ssam const struct ieee80211_rateset *rs = &ra->ra_rates; 223178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 224178354Ssam int rix, rssi; 225178354Ssam 226178354Ssam if ((ticks - ra->ra_ticks) > ra->ra_rs->interval) { 227178354Ssam rssadapt_updatestats(ra); 228178354Ssam ra->ra_ticks = ticks; 229178354Ssam } 230178354Ssam 231178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 232178354Ssam 233178354Ssam /* XXX this is average rssi, should be using last value */ 234178354Ssam rssi = ni->ni_ic->ic_node_getrssi(ni); 235178354Ssam for (rix = rs->rs_nrates-1; rix >= 0; rix--) 236178354Ssam if ((*thrs)[rix] < (rssi << 8)) 237178354Ssam break; 238178354Ssam if (rix != ra->ra_rix) { 239178354Ssam /* update public rate */ 240178354Ssam ni->ni_txrate = ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL; 241178354Ssam ra->ra_rix = rix; 242178354Ssam 243178354Ssam IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 244178354Ssam "RSSADAPT new rate %d (pktlen %d rssi %d)", 245178354Ssam ni->ni_txrate, pktlen, rssi); 246178354Ssam } 247178354Ssam return rix; 248178354Ssam} 249178354Ssam 250178354Ssam/* 251178354Ssam * Adapt the data rate to suit the conditions. When a transmitted 252178354Ssam * packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions, 253178354Ssam * raise the RSS threshold for transmitting packets of similar length at 254178354Ssam * the same data rate. 255178354Ssam */ 256206358Srpaulostatic void 257206358Srpaulorssadapt_lower_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 258178354Ssam{ 259178354Ssam uint16_t last_thr; 260178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 261178354Ssam u_int rix; 262178354Ssam 263178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 264178354Ssam 265178354Ssam rix = ra->ra_rix; 266178354Ssam last_thr = (*thrs)[rix]; 267178354Ssam (*thrs)[rix] = interpolate(master_expavgctl.rc_thresh, 268178354Ssam last_thr, (rssi << 8)); 269178354Ssam 270178354Ssam IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 271178354Ssam "RSSADAPT lower threshold for rate %d (last_thr %d new thr %d rssi %d)\n", 272178354Ssam ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 273178354Ssam last_thr, (*thrs)[rix], rssi); 274178354Ssam} 275178354Ssam 276206358Srpaulostatic void 277206358Srpaulorssadapt_raise_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 278178354Ssam{ 279178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 280178354Ssam uint16_t newthr, oldthr; 281178354Ssam int rix; 282178354Ssam 283178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 284178354Ssam 285178354Ssam rix = ra->ra_rix; 286178354Ssam if ((*thrs)[rix + 1] > (*thrs)[rix]) { 287178354Ssam oldthr = (*thrs)[rix + 1]; 288178354Ssam if ((*thrs)[rix] == 0) 289178354Ssam newthr = (rssi << 8); 290178354Ssam else 291178354Ssam newthr = (*thrs)[rix]; 292178354Ssam (*thrs)[rix + 1] = interpolate(master_expavgctl.rc_decay, 293178354Ssam oldthr, newthr); 294178354Ssam 295178354Ssam IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 296178354Ssam "RSSADAPT raise threshold for rate %d (oldthr %d newthr %d rssi %d)\n", 297178354Ssam ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 298178354Ssam oldthr, newthr, rssi); 299178354Ssam 300178354Ssam ra->ra_last_raise = ticks; 301178354Ssam } 302178354Ssam} 303178354Ssam 304206358Srpaulostatic void 305206358Srpaulorssadapt_tx_complete(const struct ieee80211vap *vap, 306206358Srpaulo const struct ieee80211_node *ni, int success, void *arg1, void *arg2) 307206358Srpaulo{ 308206358Srpaulo struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 309206358Srpaulo int pktlen = *(int *)arg1, rssi = *(int *)arg2; 310206358Srpaulo 311206358Srpaulo if (success) { 312206358Srpaulo ra->ra_nok++; 313206358Srpaulo if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates && 314206358Srpaulo (ticks - ra->ra_last_raise) >= ra->ra_raise_interval) 315206358Srpaulo rssadapt_raise_rate(ra, pktlen, rssi); 316206358Srpaulo } else { 317206358Srpaulo ra->ra_nfail++; 318206358Srpaulo rssadapt_lower_rate(ra, pktlen, rssi); 319206358Srpaulo } 320206358Srpaulo} 321206358Srpaulo 322178354Ssamstatic int 323178354Ssamrssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS) 324178354Ssam{ 325206358Srpaulo struct ieee80211vap *vap = arg1; 326206358Srpaulo struct ieee80211_rssadapt *rs = vap->iv_rs; 327178354Ssam int msecs = ticks_to_msecs(rs->interval); 328178354Ssam int error; 329178354Ssam 330178354Ssam error = sysctl_handle_int(oidp, &msecs, 0, req); 331178354Ssam if (error || !req->newptr) 332178354Ssam return error; 333206358Srpaulo rssadapt_setinterval(vap, msecs); 334178354Ssam return 0; 335178354Ssam} 336178354Ssam 337178354Ssamstatic void 338206358Srpaulorssadapt_sysctlattach(struct ieee80211vap *vap, 339178354Ssam struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 340178354Ssam{ 341178354Ssam 342178354Ssam SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 343206358Srpaulo "rssadapt_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 344178354Ssam 0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)"); 345178354Ssam} 346