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: releng/12.0/sys/net80211/ieee80211_amrr.c 321401 2017-07-23 22:38:00Z 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/malloc.h> 37#include <sys/module.h> 38#include <sys/sbuf.h> 39#include <sys/socket.h> 40#include <sys/sysctl.h> 41 42#include <net/if.h> 43#include <net/if_var.h> 44#include <net/if_media.h> 45#include <net/ethernet.h> 46 47#ifdef INET 48#include <netinet/in.h> 49#include <netinet/if_ether.h> 50#endif 51 52#include <net80211/ieee80211_var.h> 53#include <net80211/ieee80211_ht.h> 54#include <net80211/ieee80211_amrr.h> 55#include <net80211/ieee80211_ratectl.h> 56 57#define is_success(amn) \ 58 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 59#define is_failure(amn) \ 60 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 61#define is_enough(amn) \ 62 ((amn)->amn_txcnt > 10) 63 64static void amrr_setinterval(const struct ieee80211vap *, int); 65static void amrr_init(struct ieee80211vap *); 66static void amrr_deinit(struct ieee80211vap *); 67static void amrr_node_init(struct ieee80211_node *); 68static void amrr_node_deinit(struct ieee80211_node *); 69static int amrr_update(struct ieee80211_amrr *, 70 struct ieee80211_amrr_node *, struct ieee80211_node *); 71static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 72static void amrr_tx_complete(const struct ieee80211_node *, 73 const struct ieee80211_ratectl_tx_status *); 74static void amrr_tx_update_cb(void *, struct ieee80211_node *); 75static void amrr_tx_update(struct ieee80211vap *vap, 76 struct ieee80211_ratectl_tx_stats *); 77static void amrr_sysctlattach(struct ieee80211vap *, 78 struct sysctl_ctx_list *, struct sysctl_oid *); 79static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s); 80 81/* number of references from net80211 layer */ 82static int nrefs = 0; 83 84static const struct ieee80211_ratectl amrr = { 85 .ir_name = "amrr", 86 .ir_attach = NULL, 87 .ir_detach = NULL, 88 .ir_init = amrr_init, 89 .ir_deinit = amrr_deinit, 90 .ir_node_init = amrr_node_init, 91 .ir_node_deinit = amrr_node_deinit, 92 .ir_rate = amrr_rate, 93 .ir_tx_complete = amrr_tx_complete, 94 .ir_tx_update = amrr_tx_update, 95 .ir_setinterval = amrr_setinterval, 96 .ir_node_stats = amrr_node_stats, 97}; 98IEEE80211_RATECTL_MODULE(amrr, 1); 99IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 100 101static void 102amrr_setinterval(const struct ieee80211vap *vap, int msecs) 103{ 104 struct ieee80211_amrr *amrr = vap->iv_rs; 105 106 if (!amrr) 107 return; 108 109 if (msecs < 100) 110 msecs = 100; 111 amrr->amrr_interval = msecs_to_ticks(msecs); 112} 113 114static void 115amrr_init(struct ieee80211vap *vap) 116{ 117 struct ieee80211_amrr *amrr; 118 119 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 120 121 nrefs++; /* XXX locking */ 122 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 123 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 124 if (amrr == NULL) { 125 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 126 return; 127 } 128 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 129 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 130 amrr_setinterval(vap, 500 /* ms */); 131 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 132} 133 134static void 135amrr_deinit(struct ieee80211vap *vap) 136{ 137 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 138 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 139 nrefs--; /* XXX locking */ 140} 141 142/* 143 * Return whether 11n rates are possible. 144 * 145 * Some 11n devices may return HT information but no HT rates. 146 * Thus, we shouldn't treat them as an 11n node. 147 */ 148static int 149amrr_node_is_11n(struct ieee80211_node *ni) 150{ 151 152 if (ni->ni_chan == NULL) 153 return (0); 154 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 155 return (0); 156 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 157 return (0); 158 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 159} 160 161static void 162amrr_node_init(struct ieee80211_node *ni) 163{ 164 const struct ieee80211_rateset *rs = NULL; 165 struct ieee80211vap *vap = ni->ni_vap; 166 struct ieee80211_amrr *amrr = vap->iv_rs; 167 struct ieee80211_amrr_node *amn; 168 uint8_t rate; 169 170 if (!amrr) { 171 if_printf(vap->iv_ifp, "ratectl structure was not allocated, " 172 "per-node structure allocation skipped\n"); 173 return; 174 } 175 176 if (ni->ni_rctls == NULL) { 177 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 178 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 179 if (amn == NULL) { 180 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 181 "structure\n"); 182 return; 183 } 184 } else 185 amn = ni->ni_rctls; 186 amn->amn_amrr = amrr; 187 amn->amn_success = 0; 188 amn->amn_recovery = 0; 189 amn->amn_txcnt = amn->amn_retrycnt = 0; 190 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 191 192 /* 11n or not? Pick the right rateset */ 193 if (amrr_node_is_11n(ni)) { 194 /* XXX ew */ 195 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 196 "%s: 11n node", __func__); 197 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 198 } else { 199 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 200 "%s: non-11n node", __func__); 201 rs = &ni->ni_rates; 202 } 203 204 /* Initial rate - lowest */ 205 rate = rs->rs_rates[0]; 206 207 /* XXX clear the basic rate flag if it's not 11n */ 208 if (! amrr_node_is_11n(ni)) 209 rate &= IEEE80211_RATE_VAL; 210 211 /* pick initial rate from the rateset - HT or otherwise */ 212 /* Pick something low that's likely to succeed */ 213 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 214 amn->amn_rix--) { 215 /* legacy - anything < 36mbit, stop searching */ 216 /* 11n - stop at MCS4 */ 217 if (amrr_node_is_11n(ni)) { 218 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 219 break; 220 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 221 break; 222 } 223 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 224 225 /* if the rate is an 11n rate, ensure the MCS bit is set */ 226 if (amrr_node_is_11n(ni)) 227 rate |= IEEE80211_RATE_MCS; 228 229 /* Assign initial rate from the rateset */ 230 ni->ni_txrate = rate; 231 amn->amn_ticks = ticks; 232 233 /* XXX TODO: we really need a rate-to-string method */ 234 /* XXX TODO: non-11n rate should be divided by two.. */ 235 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 236 "AMRR: nrates=%d, initial rate %s%d", 237 rs->rs_nrates, 238 amrr_node_is_11n(ni) ? "MCS " : "", 239 rate & IEEE80211_RATE_VAL); 240} 241 242static void 243amrr_node_deinit(struct ieee80211_node *ni) 244{ 245 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 246} 247 248static int 249amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 250 struct ieee80211_node *ni) 251{ 252 int rix = amn->amn_rix; 253 const struct ieee80211_rateset *rs = NULL; 254 255 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 256 257 /* 11n or not? Pick the right rateset */ 258 if (amrr_node_is_11n(ni)) { 259 /* XXX ew */ 260 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 261 } else { 262 rs = &ni->ni_rates; 263 } 264 265 /* XXX TODO: we really need a rate-to-string method */ 266 /* XXX TODO: non-11n rate should be divided by two.. */ 267 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 268 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 269 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 270 amn->amn_txcnt, 271 amn->amn_retrycnt); 272 273 /* 274 * XXX This is totally bogus for 11n, as although high MCS 275 * rates for each stream may be failing, the next stream 276 * should be checked. 277 * 278 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 279 * MCS23, we should skip 6/7 and try 8 onwards. 280 */ 281 if (is_success(amn)) { 282 amn->amn_success++; 283 if (amn->amn_success >= amn->amn_success_threshold && 284 rix + 1 < rs->rs_nrates) { 285 amn->amn_recovery = 1; 286 amn->amn_success = 0; 287 rix++; 288 /* XXX TODO: we really need a rate-to-string method */ 289 /* XXX TODO: non-11n rate should be divided by two.. */ 290 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 291 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 292 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 293 amn->amn_txcnt, amn->amn_retrycnt); 294 } else { 295 amn->amn_recovery = 0; 296 } 297 } else if (is_failure(amn)) { 298 amn->amn_success = 0; 299 if (rix > 0) { 300 if (amn->amn_recovery) { 301 amn->amn_success_threshold *= 2; 302 if (amn->amn_success_threshold > 303 amrr->amrr_max_success_threshold) 304 amn->amn_success_threshold = 305 amrr->amrr_max_success_threshold; 306 } else { 307 amn->amn_success_threshold = 308 amrr->amrr_min_success_threshold; 309 } 310 rix--; 311 /* XXX TODO: we really need a rate-to-string method */ 312 /* XXX TODO: non-11n rate should be divided by two.. */ 313 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 314 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 315 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 316 amn->amn_txcnt, amn->amn_retrycnt); 317 } 318 amn->amn_recovery = 0; 319 } 320 321 /* reset counters */ 322 amn->amn_txcnt = 0; 323 amn->amn_retrycnt = 0; 324 325 return rix; 326} 327 328/* 329 * Return the rate index to use in sending a data frame. 330 * Update our internal state if it's been long enough. 331 * If the rate changes we also update ni_txrate to match. 332 */ 333static int 334amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 335{ 336 struct ieee80211_amrr_node *amn = ni->ni_rctls; 337 struct ieee80211_amrr *amrr; 338 const struct ieee80211_rateset *rs = NULL; 339 int rix; 340 341 /* XXX should return -1 here, but drivers may not expect this... */ 342 if (!amn) 343 { 344 ni->ni_txrate = ni->ni_rates.rs_rates[0]; 345 return 0; 346 } 347 348 amrr = amn->amn_amrr; 349 350 /* 11n or not? Pick the right rateset */ 351 if (amrr_node_is_11n(ni)) { 352 /* XXX ew */ 353 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 354 } else { 355 rs = &ni->ni_rates; 356 } 357 358 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 359 rix = amrr_update(amrr, amn, ni); 360 if (rix != amn->amn_rix) { 361 /* update public rate */ 362 ni->ni_txrate = rs->rs_rates[rix]; 363 /* XXX strip basic rate flag from txrate, if non-11n */ 364 if (amrr_node_is_11n(ni)) 365 ni->ni_txrate |= IEEE80211_RATE_MCS; 366 else 367 ni->ni_txrate &= IEEE80211_RATE_VAL; 368 amn->amn_rix = rix; 369 } 370 amn->amn_ticks = ticks; 371 } else 372 rix = amn->amn_rix; 373 return rix; 374} 375 376/* 377 * Update statistics with tx complete status. Ok is non-zero 378 * if the packet is known to be ACK'd. Retries has the number 379 * retransmissions (i.e. xmit attempts - 1). 380 */ 381static void 382amrr_tx_complete(const struct ieee80211_node *ni, 383 const struct ieee80211_ratectl_tx_status *status) 384{ 385 struct ieee80211_amrr_node *amn = ni->ni_rctls; 386 int retries; 387 388 if (!amn) 389 return; 390 391 retries = 0; 392 if (status->flags & IEEE80211_RATECTL_STATUS_LONG_RETRY) 393 retries = status->long_retries; 394 395 amn->amn_txcnt++; 396 if (status->status == IEEE80211_RATECTL_TX_SUCCESS) 397 amn->amn_success++; 398 amn->amn_retrycnt += retries; 399} 400 401static void 402amrr_tx_update_cb(void *arg, struct ieee80211_node *ni) 403{ 404 struct ieee80211_ratectl_tx_stats *stats = arg; 405 struct ieee80211_amrr_node *amn = ni->ni_rctls; 406 int txcnt, success, retrycnt; 407 408 if (!amn) 409 return; 410 411 txcnt = stats->nframes; 412 success = stats->nsuccess; 413 retrycnt = 0; 414 if (stats->flags & IEEE80211_RATECTL_TX_STATS_RETRIES) 415 retrycnt = stats->nretries; 416 417 amn->amn_txcnt += txcnt; 418 amn->amn_success += success; 419 amn->amn_retrycnt += retrycnt; 420} 421 422/* 423 * Set tx count/retry statistics explicitly. Intended for 424 * drivers that poll the device for statistics maintained 425 * in the device. 426 */ 427static void 428amrr_tx_update(struct ieee80211vap *vap, 429 struct ieee80211_ratectl_tx_stats *stats) 430{ 431 432 if (stats->flags & IEEE80211_RATECTL_TX_STATS_NODE) 433 amrr_tx_update_cb(stats, stats->ni); 434 else { 435 ieee80211_iterate_nodes_vap(&vap->iv_ic->ic_sta, vap, 436 amrr_tx_update_cb, stats); 437 } 438} 439 440static int 441amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 442{ 443 struct ieee80211vap *vap = arg1; 444 struct ieee80211_amrr *amrr = vap->iv_rs; 445 int msecs, error; 446 447 if (!amrr) 448 return ENOMEM; 449 450 msecs = ticks_to_msecs(amrr->amrr_interval); 451 error = sysctl_handle_int(oidp, &msecs, 0, req); 452 if (error || !req->newptr) 453 return error; 454 amrr_setinterval(vap, msecs); 455 return 0; 456} 457 458static void 459amrr_sysctlattach(struct ieee80211vap *vap, 460 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 461{ 462 struct ieee80211_amrr *amrr = vap->iv_rs; 463 464 if (!amrr) 465 return; 466 467 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 468 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 469 vap, 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 470 /* XXX bounds check values */ 471 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 472 "amrr_max_sucess_threshold", CTLFLAG_RW, 473 &amrr->amrr_max_success_threshold, 0, ""); 474 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 475 "amrr_min_sucess_threshold", CTLFLAG_RW, 476 &amrr->amrr_min_success_threshold, 0, ""); 477} 478 479static void 480amrr_print_node_rate(struct ieee80211_amrr_node *amn, 481 struct ieee80211_node *ni, struct sbuf *s) 482{ 483 int rate; 484 struct ieee80211_rateset *rs; 485 486 if (amrr_node_is_11n(ni)) { 487 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 488 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 489 sbuf_printf(s, "rate: MCS %d\n", rate); 490 } else { 491 rs = &ni->ni_rates; 492 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 493 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 494 } 495} 496 497static void 498amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 499{ 500 struct ieee80211_amrr_node *amn = ni->ni_rctls; 501 502 /* XXX TODO: check locking? */ 503 504 if (!amn) 505 return; 506 507 amrr_print_node_rate(amn, ni, s); 508 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 509 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 510 sbuf_printf(s, "success: %u\n", amn->amn_success); 511 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 512 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 513 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 514} 515