1/* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */ 2 3/*- 4 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org> 5 * Copyright (c) 2006 6 * Damien Bergamini <damien.bergamini@free.fr> 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 21#include <sys/cdefs.h> 22__FBSDID("$FreeBSD: stable/10/sys/net80211/ieee80211_amrr.c 343036 2019-01-15 02:26:03Z avos $"); 23 24/*- 25 * Naive implementation of the Adaptive Multi Rate Retry algorithm: 26 * 27 * "IEEE 802.11 Rate Adaptation: A Practical Approach" 28 * Mathieu Lacage, Hossein Manshaei, Thierry Turletti 29 * INRIA Sophia - Projet Planete 30 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html 31 */ 32#include "opt_wlan.h" 33 34#include <sys/param.h> 35#include <sys/kernel.h> 36#include <sys/module.h> 37#include <sys/socket.h> 38#include <sys/sysctl.h> 39 40#include <net/if.h> 41#include <net/if_media.h> 42 43#ifdef INET 44#include <netinet/in.h> 45#include <netinet/if_ether.h> 46#endif 47 48#include <net80211/ieee80211_var.h> 49#include <net80211/ieee80211_ht.h> 50#include <net80211/ieee80211_amrr.h> 51#include <net80211/ieee80211_ratectl.h> 52 53#define is_success(amn) \ 54 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 55#define is_failure(amn) \ 56 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 57#define is_enough(amn) \ 58 ((amn)->amn_txcnt > 10) 59 60static void amrr_setinterval(const struct ieee80211vap *, int); 61static void amrr_init(struct ieee80211vap *); 62static void amrr_deinit(struct ieee80211vap *); 63static void amrr_node_init(struct ieee80211_node *); 64static void amrr_node_deinit(struct ieee80211_node *); 65static int amrr_update(struct ieee80211_amrr *, 66 struct ieee80211_amrr_node *, struct ieee80211_node *); 67static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 68static void amrr_tx_complete(const struct ieee80211vap *, 69 const struct ieee80211_node *, int, 70 void *, void *); 71static void amrr_tx_update(const struct ieee80211vap *vap, 72 const struct ieee80211_node *, void *, void *, void *); 73static void amrr_sysctlattach(struct ieee80211vap *, 74 struct sysctl_ctx_list *, struct sysctl_oid *); 75 76/* number of references from net80211 layer */ 77static int nrefs = 0; 78 79static const struct ieee80211_ratectl amrr = { 80 .ir_name = "amrr", 81 .ir_attach = NULL, 82 .ir_detach = NULL, 83 .ir_init = amrr_init, 84 .ir_deinit = amrr_deinit, 85 .ir_node_init = amrr_node_init, 86 .ir_node_deinit = amrr_node_deinit, 87 .ir_rate = amrr_rate, 88 .ir_tx_complete = amrr_tx_complete, 89 .ir_tx_update = amrr_tx_update, 90 .ir_setinterval = amrr_setinterval, 91}; 92IEEE80211_RATECTL_MODULE(amrr, 1); 93IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 94 95static void 96amrr_setinterval(const struct ieee80211vap *vap, int msecs) 97{ 98 struct ieee80211_amrr *amrr = vap->iv_rs; 99 int t; 100 101 if (!amrr) 102 return; 103 104 if (msecs < 100) 105 msecs = 100; 106 t = msecs_to_ticks(msecs); 107 amrr->amrr_interval = (t < 1) ? 1 : t; 108} 109 110static void 111amrr_init(struct ieee80211vap *vap) 112{ 113 struct ieee80211_amrr *amrr; 114 115 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 116 117 nrefs++; /* XXX locking */ 118 amrr = vap->iv_rs = malloc(sizeof(struct ieee80211_amrr), 119 M_80211_RATECTL, M_NOWAIT|M_ZERO); 120 if (amrr == NULL) { 121 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 122 return; 123 } 124 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 125 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 126 amrr_setinterval(vap, 500 /* ms */); 127 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 128} 129 130static void 131amrr_deinit(struct ieee80211vap *vap) 132{ 133 free(vap->iv_rs, M_80211_RATECTL); 134 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 135 nrefs--; /* XXX locking */ 136} 137 138static int 139amrr_node_is_11n(struct ieee80211_node *ni) 140{ 141 142 if (ni->ni_chan == NULL) 143 return (0); 144 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 145 return (0); 146 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 147} 148 149static void 150amrr_node_init(struct ieee80211_node *ni) 151{ 152 const struct ieee80211_rateset *rs = NULL; 153 struct ieee80211vap *vap = ni->ni_vap; 154 struct ieee80211_amrr *amrr = vap->iv_rs; 155 struct ieee80211_amrr_node *amn; 156 uint8_t rate; 157 158 if (!amrr) { 159 if_printf(vap->iv_ifp, "ratectl structure was not allocated, " 160 "per-node structure allocation skipped\n"); 161 return; 162 } 163 164 if (ni->ni_rctls == NULL) { 165 ni->ni_rctls = amn = malloc(sizeof(struct ieee80211_amrr_node), 166 M_80211_RATECTL, M_NOWAIT|M_ZERO); 167 if (amn == NULL) { 168 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 169 "structure\n"); 170 return; 171 } 172 } else 173 amn = ni->ni_rctls; 174 amn->amn_amrr = amrr; 175 amn->amn_success = 0; 176 amn->amn_recovery = 0; 177 amn->amn_txcnt = amn->amn_retrycnt = 0; 178 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 179 180 /* 11n or not? Pick the right rateset */ 181 if (amrr_node_is_11n(ni)) { 182 /* XXX ew */ 183 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 184 "%s: 11n node", __func__); 185 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 186 } else { 187 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 188 "%s: non-11n node", __func__); 189 rs = &ni->ni_rates; 190 } 191 192 /* Initial rate - lowest */ 193 rate = rs->rs_rates[0]; 194 195 /* XXX clear the basic rate flag if it's not 11n */ 196 if (! amrr_node_is_11n(ni)) 197 rate &= IEEE80211_RATE_VAL; 198 199 /* pick initial rate from the rateset - HT or otherwise */ 200 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 201 amn->amn_rix--) { 202 /* legacy - anything < 36mbit, stop searching */ 203 /* 11n - stop at MCS4 / MCS12 / MCS28 */ 204 if (amrr_node_is_11n(ni) && 205 (rs->rs_rates[amn->amn_rix] & 0x7) < 4) 206 break; 207 else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 208 break; 209 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 210 } 211 212 /* if the rate is an 11n rate, ensure the MCS bit is set */ 213 if (amrr_node_is_11n(ni)) 214 rate |= IEEE80211_RATE_MCS; 215 216 /* Assign initial rate from the rateset */ 217 ni->ni_txrate = rate; 218 amn->amn_ticks = ticks; 219 220 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 221 "AMRR: nrates=%d, initial rate %d", 222 rs->rs_nrates, 223 rate); 224} 225 226static void 227amrr_node_deinit(struct ieee80211_node *ni) 228{ 229 free(ni->ni_rctls, M_80211_RATECTL); 230} 231 232static int 233amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 234 struct ieee80211_node *ni) 235{ 236 int rix = amn->amn_rix; 237 const struct ieee80211_rateset *rs = NULL; 238 239 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 240 241 /* 11n or not? Pick the right rateset */ 242 if (amrr_node_is_11n(ni)) { 243 /* XXX ew */ 244 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 245 } else { 246 rs = &ni->ni_rates; 247 } 248 249 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 250 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 251 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 252 amn->amn_txcnt, 253 amn->amn_retrycnt); 254 255 /* 256 * XXX This is totally bogus for 11n, as although high MCS 257 * rates for each stream may be failing, the next stream 258 * should be checked. 259 * 260 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 261 * MCS23, we should skip 6/7 and try 8 onwards. 262 */ 263 if (is_success(amn)) { 264 amn->amn_success++; 265 if (amn->amn_success >= amn->amn_success_threshold && 266 rix + 1 < rs->rs_nrates) { 267 amn->amn_recovery = 1; 268 amn->amn_success = 0; 269 rix++; 270 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 271 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 272 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 273 amn->amn_txcnt, amn->amn_retrycnt); 274 } else { 275 amn->amn_recovery = 0; 276 } 277 } else if (is_failure(amn)) { 278 amn->amn_success = 0; 279 if (rix > 0) { 280 if (amn->amn_recovery) { 281 amn->amn_success_threshold *= 2; 282 if (amn->amn_success_threshold > 283 amrr->amrr_max_success_threshold) 284 amn->amn_success_threshold = 285 amrr->amrr_max_success_threshold; 286 } else { 287 amn->amn_success_threshold = 288 amrr->amrr_min_success_threshold; 289 } 290 rix--; 291 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 292 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 293 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 294 amn->amn_txcnt, amn->amn_retrycnt); 295 } 296 amn->amn_recovery = 0; 297 } 298 299 /* reset counters */ 300 amn->amn_txcnt = 0; 301 amn->amn_retrycnt = 0; 302 303 return rix; 304} 305 306/* 307 * Return the rate index to use in sending a data frame. 308 * Update our internal state if it's been long enough. 309 * If the rate changes we also update ni_txrate to match. 310 */ 311static int 312amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 313{ 314 struct ieee80211_amrr_node *amn = ni->ni_rctls; 315 struct ieee80211_amrr *amrr; 316 const struct ieee80211_rateset *rs = NULL; 317 int rix; 318 319 /* XXX should return -1 here, but drivers may not expect this... */ 320 if (!amn) 321 { 322 ni->ni_txrate = ni->ni_rates.rs_rates[0]; 323 return 0; 324 } 325 326 amrr = amn->amn_amrr; 327 328 /* 11n or not? Pick the right rateset */ 329 if (amrr_node_is_11n(ni)) { 330 /* XXX ew */ 331 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 332 } else { 333 rs = &ni->ni_rates; 334 } 335 336 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 337 rix = amrr_update(amrr, amn, ni); 338 if (rix != amn->amn_rix) { 339 /* update public rate */ 340 ni->ni_txrate = rs->rs_rates[rix]; 341 /* XXX strip basic rate flag from txrate, if non-11n */ 342 if (amrr_node_is_11n(ni)) 343 ni->ni_txrate |= IEEE80211_RATE_MCS; 344 else 345 ni->ni_txrate &= IEEE80211_RATE_VAL; 346 amn->amn_rix = rix; 347 } 348 amn->amn_ticks = ticks; 349 } else 350 rix = amn->amn_rix; 351 return rix; 352} 353 354/* 355 * Update statistics with tx complete status. Ok is non-zero 356 * if the packet is known to be ACK'd. Retries has the number 357 * retransmissions (i.e. xmit attempts - 1). 358 */ 359static void 360amrr_tx_complete(const struct ieee80211vap *vap, 361 const struct ieee80211_node *ni, int ok, 362 void *arg1, void *arg2 __unused) 363{ 364 struct ieee80211_amrr_node *amn = ni->ni_rctls; 365 int retries = *(int *)arg1; 366 367 if (!amn) 368 return; 369 370 amn->amn_txcnt++; 371 if (ok) 372 amn->amn_success++; 373 amn->amn_retrycnt += retries; 374} 375 376/* 377 * Set tx count/retry statistics explicitly. Intended for 378 * drivers that poll the device for statistics maintained 379 * in the device. 380 */ 381static void 382amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 383 void *arg1, void *arg2, void *arg3) 384{ 385 struct ieee80211_amrr_node *amn = ni->ni_rctls; 386 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 387 388 amn->amn_txcnt = txcnt; 389 amn->amn_success = success; 390 amn->amn_retrycnt = retrycnt; 391} 392 393static int 394amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 395{ 396 struct ieee80211vap *vap = arg1; 397 struct ieee80211_amrr *amrr = vap->iv_rs; 398 int msecs, error; 399 400 if (!amrr) 401 return ENOMEM; 402 403 msecs = ticks_to_msecs(amrr->amrr_interval); 404 error = sysctl_handle_int(oidp, &msecs, 0, req); 405 if (error || !req->newptr) 406 return error; 407 amrr_setinterval(vap, msecs); 408 return 0; 409} 410 411static void 412amrr_sysctlattach(struct ieee80211vap *vap, 413 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 414{ 415 struct ieee80211_amrr *amrr = vap->iv_rs; 416 417 if (!amrr) 418 return; 419 420 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 421 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 422 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 423 /* XXX bounds check values */ 424 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 425 "amrr_max_sucess_threshold", CTLFLAG_RW, 426 &amrr->amrr_max_success_threshold, 0, ""); 427 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 428 "amrr_min_sucess_threshold", CTLFLAG_RW, 429 &amrr->amrr_min_success_threshold, 0, ""); 430} 431