1 /* $FreeBSD$ */ 2 /* $NetBSD: ieee80211_rssadapt.c,v 1.9 2005/02/26 22:45:09 perry Exp $ */ 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org> 7 * Copyright (c) 2003, 2004 David Young. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or 10 * without modification, are permitted provided that the following 11 * conditions are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer in the documentation and/or other materials provided 17 * with the distribution. 18 * 3. The name of David Young may not be used to endorse or promote 19 * products derived from this software without specific prior 20 * written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY 23 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 25 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David 26 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 28 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 33 * OF SUCH DAMAGE. 34 */ 35 #include "opt_wlan.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/module.h> 42 #include <sys/socket.h> 43 #include <sys/sysctl.h> 44 45 #include <net/if.h> 46 #include <net/if_var.h> 47 #include <net/if_media.h> 48 #include <net/ethernet.h> 49 50 #include <net80211/ieee80211_var.h> 51 #include <net80211/ieee80211_rssadapt.h> 52 #include <net80211/ieee80211_ratectl.h> 53 54 struct rssadapt_expavgctl { 55 /* RSS threshold decay. */ 56 u_int rc_decay_denom; 57 u_int rc_decay_old; 58 /* RSS threshold update. */ 59 u_int rc_thresh_denom; 60 u_int rc_thresh_old; 61 /* RSS average update. */ 62 u_int rc_avgrssi_denom; 63 u_int rc_avgrssi_old; 64 }; 65 66 static struct rssadapt_expavgctl master_expavgctl = { 67 .rc_decay_denom = 16, 68 .rc_decay_old = 15, 69 .rc_thresh_denom = 8, 70 .rc_thresh_old = 4, 71 .rc_avgrssi_denom = 8, 72 .rc_avgrssi_old = 4 73 }; 74 75 #ifdef interpolate 76 #undef interpolate 77 #endif 78 #define interpolate(parm, old, new) ((parm##_old * (old) + \ 79 (parm##_denom - parm##_old) * (new)) / \ 80 parm##_denom) 81 82 static void rssadapt_setinterval(const struct ieee80211vap *, int); 83 static void rssadapt_init(struct ieee80211vap *); 84 static void rssadapt_deinit(struct ieee80211vap *); 85 static void rssadapt_updatestats(struct ieee80211_rssadapt_node *); 86 static void rssadapt_node_init(struct ieee80211_node *); 87 static void rssadapt_node_deinit(struct ieee80211_node *); 88 static int rssadapt_rate(struct ieee80211_node *, void *, uint32_t); 89 static void rssadapt_lower_rate(struct ieee80211_rssadapt_node *, int, int); 90 static void rssadapt_raise_rate(struct ieee80211_rssadapt_node *, 91 int, int); 92 static void rssadapt_tx_complete(const struct ieee80211_node *, 93 const struct ieee80211_ratectl_tx_status *); 94 static void rssadapt_sysctlattach(struct ieee80211vap *, 95 struct sysctl_ctx_list *, struct sysctl_oid *); 96 97 /* number of references from net80211 layer */ 98 static int nrefs = 0; 99 100 static const struct ieee80211_ratectl rssadapt = { 101 .ir_name = "rssadapt", 102 .ir_attach = NULL, 103 .ir_detach = NULL, 104 .ir_init = rssadapt_init, 105 .ir_deinit = rssadapt_deinit, 106 .ir_node_init = rssadapt_node_init, 107 .ir_node_deinit = rssadapt_node_deinit, 108 .ir_rate = rssadapt_rate, 109 .ir_tx_complete = rssadapt_tx_complete, 110 .ir_tx_update = NULL, 111 .ir_setinterval = rssadapt_setinterval, 112 }; 113 IEEE80211_RATECTL_MODULE(rssadapt, 1); 114 IEEE80211_RATECTL_ALG(rssadapt, IEEE80211_RATECTL_RSSADAPT, rssadapt); 115 116 static void 117 rssadapt_setinterval(const struct ieee80211vap *vap, int msecs) 118 { 119 struct ieee80211_rssadapt *rs = vap->iv_rs; 120 121 if (!rs) 122 return; 123 124 if (msecs < 100) 125 msecs = 100; 126 rs->interval = msecs_to_ticks(msecs); 127 } 128 129 static void 130 rssadapt_init(struct ieee80211vap *vap) 131 { 132 struct ieee80211_rssadapt *rs; 133 134 KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized", 135 __func__)); 136 137 nrefs++; /* XXX locking */ 138 vap->iv_rs = rs = IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt), 139 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 140 if (rs == NULL) { 141 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 142 return; 143 } 144 rs->vap = vap; 145 rssadapt_setinterval(vap, 500 /* msecs */); 146 rssadapt_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 147 } 148 149 static void 150 rssadapt_deinit(struct ieee80211vap *vap) 151 { 152 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 153 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 154 nrefs--; /* XXX locking */ 155 } 156 157 static void 158 rssadapt_updatestats(struct ieee80211_rssadapt_node *ra) 159 { 160 long interval; 161 162 ra->ra_pktrate = (ra->ra_pktrate + 10*(ra->ra_nfail + ra->ra_nok))/2; 163 ra->ra_nfail = ra->ra_nok = 0; 164 165 /* 166 * A node is eligible for its rate to be raised every 1/10 to 10 167 * seconds, more eligible in proportion to recent packet rates. 168 */ 169 interval = MAX(10*1000, 10*1000 / MAX(1, 10 * ra->ra_pktrate)); 170 ra->ra_raise_interval = msecs_to_ticks(interval); 171 } 172 173 static void 174 rssadapt_node_init(struct ieee80211_node *ni) 175 { 176 struct ieee80211_rssadapt_node *ra; 177 struct ieee80211vap *vap = ni->ni_vap; 178 struct ieee80211_rssadapt *rsa = vap->iv_rs; 179 const struct ieee80211_rateset *rs = &ni->ni_rates; 180 181 if (!rsa) { 182 if_printf(vap->iv_ifp, "ratectl structure was not allocated, " 183 "per-node structure allocation skipped\n"); 184 return; 185 } 186 187 if (ni->ni_rctls == NULL) { 188 ni->ni_rctls = ra = 189 IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt_node), 190 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 191 if (ra == NULL) { 192 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 193 "structure\n"); 194 return; 195 } 196 } else 197 ra = ni->ni_rctls; 198 ra->ra_rs = rsa; 199 ra->ra_rates = *rs; 200 rssadapt_updatestats(ra); 201 202 /* pick initial rate */ 203 for (ra->ra_rix = rs->rs_nrates - 1; 204 ra->ra_rix > 0 && (rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL) > 72; 205 ra->ra_rix--) 206 ; 207 ni->ni_txrate = rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL; 208 ra->ra_ticks = ticks; 209 210 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 211 "RSSADAPT initial rate %d", ni->ni_txrate); 212 } 213 214 static void 215 rssadapt_node_deinit(struct ieee80211_node *ni) 216 { 217 218 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 219 } 220 221 static __inline int 222 bucket(int pktlen) 223 { 224 int i, top, thridx; 225 226 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 227 i < IEEE80211_RSSADAPT_BKTS; 228 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 229 thridx = i; 230 if (pktlen <= top) 231 break; 232 } 233 return thridx; 234 } 235 236 static int 237 rssadapt_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg) 238 { 239 struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 240 u_int pktlen = iarg; 241 const struct ieee80211_rateset *rs; 242 uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 243 int rix, rssi; 244 245 /* XXX should return -1 here, but drivers may not expect this... */ 246 if (!ra) 247 { 248 ni->ni_txrate = ni->ni_rates.rs_rates[0]; 249 return 0; 250 } 251 252 rs = &ra->ra_rates; 253 if ((ticks - ra->ra_ticks) > ra->ra_rs->interval) { 254 rssadapt_updatestats(ra); 255 ra->ra_ticks = ticks; 256 } 257 258 thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 259 260 /* XXX this is average rssi, should be using last value */ 261 rssi = ni->ni_ic->ic_node_getrssi(ni); 262 for (rix = rs->rs_nrates-1; rix >= 0; rix--) 263 if ((*thrs)[rix] < (rssi << 8)) 264 break; 265 if (rix != ra->ra_rix) { 266 /* update public rate */ 267 ni->ni_txrate = ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL; 268 ra->ra_rix = rix; 269 270 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 271 "RSSADAPT new rate %d (pktlen %d rssi %d)", 272 ni->ni_txrate, pktlen, rssi); 273 } 274 return rix; 275 } 276 277 /* 278 * Adapt the data rate to suit the conditions. When a transmitted 279 * packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions, 280 * raise the RSS threshold for transmitting packets of similar length at 281 * the same data rate. 282 */ 283 static void 284 rssadapt_lower_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 285 { 286 uint16_t last_thr; 287 uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 288 u_int rix; 289 290 thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 291 292 rix = ra->ra_rix; 293 last_thr = (*thrs)[rix]; 294 (*thrs)[rix] = interpolate(master_expavgctl.rc_thresh, 295 last_thr, (rssi << 8)); 296 297 IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 298 "RSSADAPT lower threshold for rate %d (last_thr %d new thr %d rssi %d)\n", 299 ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 300 last_thr, (*thrs)[rix], rssi); 301 } 302 303 static void 304 rssadapt_raise_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi) 305 { 306 uint16_t (*thrs)[IEEE80211_RATE_SIZE]; 307 uint16_t newthr, oldthr; 308 int rix; 309 310 thrs = &ra->ra_rate_thresh[bucket(pktlen)]; 311 312 rix = ra->ra_rix; 313 if ((*thrs)[rix + 1] > (*thrs)[rix]) { 314 oldthr = (*thrs)[rix + 1]; 315 if ((*thrs)[rix] == 0) 316 newthr = (rssi << 8); 317 else 318 newthr = (*thrs)[rix]; 319 (*thrs)[rix + 1] = interpolate(master_expavgctl.rc_decay, 320 oldthr, newthr); 321 322 IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL, 323 "RSSADAPT raise threshold for rate %d (oldthr %d newthr %d rssi %d)\n", 324 ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL, 325 oldthr, newthr, rssi); 326 327 ra->ra_last_raise = ticks; 328 } 329 } 330 331 static void 332 rssadapt_tx_complete(const struct ieee80211_node *ni, 333 const struct ieee80211_ratectl_tx_status *status) 334 { 335 struct ieee80211_rssadapt_node *ra = ni->ni_rctls; 336 int pktlen, rssi; 337 338 if (!ra) 339 return; 340 341 if ((status->flags & 342 (IEEE80211_RATECTL_STATUS_PKTLEN|IEEE80211_RATECTL_STATUS_RSSI)) != 343 (IEEE80211_RATECTL_STATUS_PKTLEN|IEEE80211_RATECTL_STATUS_RSSI)) 344 return; 345 346 pktlen = status->pktlen; 347 rssi = status->rssi; 348 349 if (status->status == IEEE80211_RATECTL_TX_SUCCESS) { 350 ra->ra_nok++; 351 if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates && 352 (ticks - ra->ra_last_raise) >= ra->ra_raise_interval) 353 rssadapt_raise_rate(ra, pktlen, rssi); 354 } else { 355 ra->ra_nfail++; 356 rssadapt_lower_rate(ra, pktlen, rssi); 357 } 358 } 359 360 static int 361 rssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS) 362 { 363 struct ieee80211vap *vap = arg1; 364 struct ieee80211_rssadapt *rs = vap->iv_rs; 365 int msecs, error; 366 367 if (!rs) 368 return ENOMEM; 369 370 msecs = ticks_to_msecs(rs->interval); 371 error = sysctl_handle_int(oidp, &msecs, 0, req); 372 if (error || !req->newptr) 373 return error; 374 rssadapt_setinterval(vap, msecs); 375 return 0; 376 } 377 378 static void 379 rssadapt_sysctlattach(struct ieee80211vap *vap, 380 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 381 { 382 383 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 384 "rssadapt_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 385 0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)"); 386 } 387