1178354Ssam/* $FreeBSD: releng/11.0/sys/net80211/ieee80211_rssadapt.c 283538 2015-05-25 19:18:16Z adrian $ */ 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> 36257241Sglebius#include <sys/systm.h> 37178354Ssam#include <sys/kernel.h> 38257241Sglebius#include <sys/malloc.h> 39178354Ssam#include <sys/module.h> 40178354Ssam#include <sys/socket.h> 41178354Ssam#include <sys/sysctl.h> 42178354Ssam 43178354Ssam#include <net/if.h> 44257241Sglebius#include <net/if_var.h> 45178354Ssam#include <net/if_media.h> 46257241Sglebius#include <net/ethernet.h> 47178354Ssam 48178354Ssam#include <net80211/ieee80211_var.h> 49178354Ssam#include <net80211/ieee80211_rssadapt.h> 50206358Srpaulo#include <net80211/ieee80211_ratectl.h> 51178354Ssam 52178354Ssamstruct rssadapt_expavgctl { 53178354Ssam /* RSS threshold decay. */ 54178354Ssam u_int rc_decay_denom; 55178354Ssam u_int rc_decay_old; 56178354Ssam /* RSS threshold update. */ 57178354Ssam u_int rc_thresh_denom; 58178354Ssam u_int rc_thresh_old; 59178354Ssam /* RSS average update. */ 60178354Ssam u_int rc_avgrssi_denom; 61178354Ssam u_int rc_avgrssi_old; 62178354Ssam}; 63178354Ssam 64178354Ssamstatic struct rssadapt_expavgctl master_expavgctl = { 65209092Sed .rc_decay_denom = 16, 66209092Sed .rc_decay_old = 15, 67209092Sed .rc_thresh_denom = 8, 68209092Sed .rc_thresh_old = 4, 69209092Sed .rc_avgrssi_denom = 8, 70209092Sed .rc_avgrssi_old = 4 71178354Ssam}; 72178354Ssam 73178354Ssam#ifdef interpolate 74178354Ssam#undef interpolate 75178354Ssam#endif 76178354Ssam#define interpolate(parm, old, new) ((parm##_old * (old) + \ 77178354Ssam (parm##_denom - parm##_old) * (new)) / \ 78178354Ssam parm##_denom) 79178354Ssam 80206358Srpaulostatic void rssadapt_setinterval(const struct ieee80211vap *, int); 81206358Srpaulostatic void rssadapt_init(struct ieee80211vap *); 82206358Srpaulostatic void rssadapt_deinit(struct ieee80211vap *); 83206358Srpaulostatic void rssadapt_updatestats(struct ieee80211_rssadapt_node *); 84206358Srpaulostatic void rssadapt_node_init(struct ieee80211_node *); 85206358Srpaulostatic void rssadapt_node_deinit(struct ieee80211_node *); 86206358Srpaulostatic int rssadapt_rate(struct ieee80211_node *, void *, uint32_t); 87206358Srpaulostatic void rssadapt_lower_rate(struct ieee80211_rssadapt_node *, int, int); 88206358Srpaulostatic void rssadapt_raise_rate(struct ieee80211_rssadapt_node *, 89206358Srpaulo int, int); 90206358Srpaulostatic void rssadapt_tx_complete(const struct ieee80211vap *, 91206358Srpaulo const struct ieee80211_node *, int, 92206358Srpaulo void *, void *); 93206358Srpaulostatic void rssadapt_sysctlattach(struct ieee80211vap *, 94206358Srpaulo struct sysctl_ctx_list *, struct sysctl_oid *); 95178354Ssam 96178354Ssam/* number of references from net80211 layer */ 97178354Ssamstatic int nrefs = 0; 98178354Ssam 99206358Srpaulostatic const struct ieee80211_ratectl rssadapt = { 100206358Srpaulo .ir_name = "rssadapt", 101206358Srpaulo .ir_attach = NULL, 102206358Srpaulo .ir_detach = NULL, 103206358Srpaulo .ir_init = rssadapt_init, 104206358Srpaulo .ir_deinit = rssadapt_deinit, 105206358Srpaulo .ir_node_init = rssadapt_node_init, 106206358Srpaulo .ir_node_deinit = rssadapt_node_deinit, 107206358Srpaulo .ir_rate = rssadapt_rate, 108206358Srpaulo .ir_tx_complete = rssadapt_tx_complete, 109206358Srpaulo .ir_tx_update = NULL, 110206358Srpaulo .ir_setinterval = rssadapt_setinterval, 111206358Srpaulo}; 112206358SrpauloIEEE80211_RATECTL_MODULE(rssadapt, 1); 113206358SrpauloIEEE80211_RATECTL_ALG(rssadapt, IEEE80211_RATECTL_RSSADAPT, rssadapt); 114206358Srpaulo 115206358Srpaulostatic void 116206358Srpaulorssadapt_setinterval(const struct ieee80211vap *vap, int msecs) 117178354Ssam{ 118206358Srpaulo struct ieee80211_rssadapt *rs = vap->iv_rs; 119178354Ssam int t; 120178354Ssam 121178354Ssam if (msecs < 100) 122178354Ssam msecs = 100; 123178354Ssam t = msecs_to_ticks(msecs); 124178354Ssam rs->interval = (t < 1) ? 1 : t; 125178354Ssam} 126178354Ssam 127206358Srpaulostatic void 128206358Srpaulorssadapt_init(struct ieee80211vap *vap) 129178354Ssam{ 130206358Srpaulo struct ieee80211_rssadapt *rs; 131206358Srpaulo 132206358Srpaulo KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized", 133206358Srpaulo __func__)); 134206358Srpaulo 135283538Sadrian vap->iv_rs = rs = IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt), 136283538Sadrian M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 137206419Srpaulo if (rs == NULL) { 138206419Srpaulo if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 139206419Srpaulo return; 140206419Srpaulo } 141178354Ssam rs->vap = vap; 142206358Srpaulo rssadapt_setinterval(vap, 500 /* msecs */); 143206358Srpaulo rssadapt_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 144178354Ssam} 145178354Ssam 146206358Srpaulostatic void 147206358Srpaulorssadapt_deinit(struct ieee80211vap *vap) 148178354Ssam{ 149283538Sadrian IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 150178354Ssam} 151178354Ssam 152178354Ssamstatic void 153178354Ssamrssadapt_updatestats(struct ieee80211_rssadapt_node *ra) 154178354Ssam{ 155178354Ssam long interval; 156178354Ssam 157178354Ssam ra->ra_pktrate = (ra->ra_pktrate + 10*(ra->ra_nfail + ra->ra_nok))/2; 158178354Ssam ra->ra_nfail = ra->ra_nok = 0; 159178354Ssam 160178354Ssam /* 161178354Ssam * A node is eligible for its rate to be raised every 1/10 to 10 162178354Ssam * seconds, more eligible in proportion to recent packet rates. 163178354Ssam */ 164178354Ssam interval = MAX(10*1000, 10*1000 / MAX(1, 10 * ra->ra_pktrate)); 165178354Ssam ra->ra_raise_interval = msecs_to_ticks(interval); 166178354Ssam} 167178354Ssam 168206358Srpaulostatic void 169206358Srpaulorssadapt_node_init(struct ieee80211_node *ni) 170178354Ssam{ 171206358Srpaulo struct ieee80211_rssadapt_node *ra; 172206419Srpaulo struct ieee80211vap *vap = ni->ni_vap; 173206419Srpaulo struct ieee80211_rssadapt *rsa = vap->iv_rs; 174178354Ssam const struct ieee80211_rateset *rs = &ni->ni_rates; 175178354Ssam 176207323Srpaulo if (ni->ni_rctls == NULL) { 177207323Srpaulo ni->ni_rctls = ra = 178283538Sadrian IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt_node), 179283538Sadrian M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 180207323Srpaulo if (ra == NULL) { 181207323Srpaulo if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 182207323Srpaulo "structure\n"); 183207323Srpaulo return; 184207323Srpaulo } 185207323Srpaulo } else 186207323Srpaulo ra = ni->ni_rctls; 187178354Ssam ra->ra_rs = rsa; 188178354Ssam ra->ra_rates = *rs; 189178354Ssam rssadapt_updatestats(ra); 190178354Ssam 191178354Ssam /* pick initial rate */ 192178354Ssam for (ra->ra_rix = rs->rs_nrates - 1; 193178354Ssam ra->ra_rix > 0 && (rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL) > 72; 194178354Ssam ra->ra_rix--) 195178354Ssam ; 196178354Ssam ni->ni_txrate = rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL; 197178354Ssam ra->ra_ticks = ticks; 198178354Ssam 199178354Ssam IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 200178354Ssam "RSSADAPT initial rate %d", ni->ni_txrate); 201178354Ssam} 202178354Ssam 203206358Srpaulostatic void 204206358Srpaulorssadapt_node_deinit(struct ieee80211_node *ni) 205206358Srpaulo{ 206206358Srpaulo 207283538Sadrian IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 208206358Srpaulo} 209206358Srpaulo 210178354Ssamstatic __inline int 211178354Ssambucket(int pktlen) 212178354Ssam{ 213178354Ssam int i, top, thridx; 214178354Ssam 215178354Ssam for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 216178354Ssam i < IEEE80211_RSSADAPT_BKTS; 217178354Ssam i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 218178354Ssam thridx = i; 219178354Ssam if (pktlen <= top) 220178354Ssam break; 221178354Ssam } 222178354Ssam return thridx; 223178354Ssam} 224178354Ssam 225206358Srpaulostatic int 226206358Srpaulorssadapt_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg) 227178354Ssam{ 228206358Srpaulo struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 229206358Srpaulo u_int pktlen = iarg; 230178354Ssam const struct ieee80211_rateset *rs = &ra->ra_rates; 231178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 232178354Ssam int rix, rssi; 233178354Ssam 234178354Ssam if ((ticks - ra->ra_ticks) > ra->ra_rs->interval) { 235178354Ssam rssadapt_updatestats(ra); 236178354Ssam ra->ra_ticks = ticks; 237178354Ssam } 238178354Ssam 239178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 240178354Ssam 241178354Ssam /* XXX this is average rssi, should be using last value */ 242178354Ssam rssi = ni->ni_ic->ic_node_getrssi(ni); 243178354Ssam for (rix = rs->rs_nrates-1; rix >= 0; rix--) 244178354Ssam if ((*thrs)[rix] < (rssi << 8)) 245178354Ssam break; 246178354Ssam if (rix != ra->ra_rix) { 247178354Ssam /* update public rate */ 248178354Ssam ni->ni_txrate = ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL; 249178354Ssam ra->ra_rix = rix; 250178354Ssam 251178354Ssam IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 252178354Ssam "RSSADAPT new rate %d (pktlen %d rssi %d)", 253178354Ssam ni->ni_txrate, pktlen, rssi); 254178354Ssam } 255178354Ssam return rix; 256178354Ssam} 257178354Ssam 258178354Ssam/* 259178354Ssam * Adapt the data rate to suit the conditions. When a transmitted 260178354Ssam * packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions, 261178354Ssam * raise the RSS threshold for transmitting packets of similar length at 262178354Ssam * the same data rate. 263178354Ssam */ 264206358Srpaulostatic void 265206358Srpaulorssadapt_lower_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 266178354Ssam{ 267178354Ssam uint16_t last_thr; 268178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 269178354Ssam u_int rix; 270178354Ssam 271178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 272178354Ssam 273178354Ssam rix = ra->ra_rix; 274178354Ssam last_thr = (*thrs)[rix]; 275178354Ssam (*thrs)[rix] = interpolate(master_expavgctl.rc_thresh, 276178354Ssam last_thr, (rssi << 8)); 277178354Ssam 278178354Ssam IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 279178354Ssam "RSSADAPT lower threshold for rate %d (last_thr %d new thr %d rssi %d)\n", 280178354Ssam ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 281178354Ssam last_thr, (*thrs)[rix], rssi); 282178354Ssam} 283178354Ssam 284206358Srpaulostatic void 285206358Srpaulorssadapt_raise_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 286178354Ssam{ 287178354Ssam uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 288178354Ssam uint16_t newthr, oldthr; 289178354Ssam int rix; 290178354Ssam 291178354Ssam thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 292178354Ssam 293178354Ssam rix = ra->ra_rix; 294178354Ssam if ((*thrs)[rix + 1] > (*thrs)[rix]) { 295178354Ssam oldthr = (*thrs)[rix + 1]; 296178354Ssam if ((*thrs)[rix] == 0) 297178354Ssam newthr = (rssi << 8); 298178354Ssam else 299178354Ssam newthr = (*thrs)[rix]; 300178354Ssam (*thrs)[rix + 1] = interpolate(master_expavgctl.rc_decay, 301178354Ssam oldthr, newthr); 302178354Ssam 303178354Ssam IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 304178354Ssam "RSSADAPT raise threshold for rate %d (oldthr %d newthr %d rssi %d)\n", 305178354Ssam ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 306178354Ssam oldthr, newthr, rssi); 307178354Ssam 308178354Ssam ra->ra_last_raise = ticks; 309178354Ssam } 310178354Ssam} 311178354Ssam 312206358Srpaulostatic void 313206358Srpaulorssadapt_tx_complete(const struct ieee80211vap *vap, 314206358Srpaulo const struct ieee80211_node *ni, int success, void *arg1, void *arg2) 315206358Srpaulo{ 316206358Srpaulo struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 317206358Srpaulo int pktlen = *(int *)arg1, rssi = *(int *)arg2; 318206358Srpaulo 319206358Srpaulo if (success) { 320206358Srpaulo ra->ra_nok++; 321206358Srpaulo if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates && 322206358Srpaulo (ticks - ra->ra_last_raise) >= ra->ra_raise_interval) 323206358Srpaulo rssadapt_raise_rate(ra, pktlen, rssi); 324206358Srpaulo } else { 325206358Srpaulo ra->ra_nfail++; 326206358Srpaulo rssadapt_lower_rate(ra, pktlen, rssi); 327206358Srpaulo } 328206358Srpaulo} 329206358Srpaulo 330178354Ssamstatic int 331178354Ssamrssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS) 332178354Ssam{ 333206358Srpaulo struct ieee80211vap *vap = arg1; 334206358Srpaulo struct ieee80211_rssadapt *rs = vap->iv_rs; 335178354Ssam int msecs = ticks_to_msecs(rs->interval); 336178354Ssam int error; 337178354Ssam 338178354Ssam error = sysctl_handle_int(oidp, &msecs, 0, req); 339178354Ssam if (error || !req->newptr) 340178354Ssam return error; 341206358Srpaulo rssadapt_setinterval(vap, msecs); 342178354Ssam return 0; 343178354Ssam} 344178354Ssam 345178354Ssamstatic void 346206358Srpaulorssadapt_sysctlattach(struct ieee80211vap *vap, 347178354Ssam struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 348178354Ssam{ 349178354Ssam 350178354Ssam SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 351206358Srpaulo "rssadapt_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 352178354Ssam 0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)"); 353178354Ssam} 354