ieee80211_amrr.c revision 296925
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: head/sys/net80211/ieee80211_amrr.c 296925 2016-03-16 02:07:04Z adrian $"); 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 ieee80211vap *, 73 const struct ieee80211_node *, int, 74 void *, void *); 75static void amrr_tx_update(const struct ieee80211vap *vap, 76 const struct ieee80211_node *, void *, void *, void *); 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 int t; 106 107 if (msecs < 100) 108 msecs = 100; 109 t = msecs_to_ticks(msecs); 110 amrr->amrr_interval = (t < 1) ? 1 : t; 111} 112 113static void 114amrr_init(struct ieee80211vap *vap) 115{ 116 struct ieee80211_amrr *amrr; 117 118 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 119 120 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 121 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 122 if (amrr == NULL) { 123 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 124 return; 125 } 126 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 127 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 128 amrr_setinterval(vap, 500 /* ms */); 129 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 130} 131 132static void 133amrr_deinit(struct ieee80211vap *vap) 134{ 135 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 136} 137 138/* 139 * Return whether 11n rates are possible. 140 * 141 * Some 11n devices may return HT information but no HT rates. 142 * Thus, we shouldn't treat them as an 11n node. 143 */ 144static int 145amrr_node_is_11n(struct ieee80211_node *ni) 146{ 147 148 if (ni->ni_chan == NULL) 149 return (0); 150 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 151 return (0); 152 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 153 return (0); 154 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 155} 156 157static void 158amrr_node_init(struct ieee80211_node *ni) 159{ 160 const struct ieee80211_rateset *rs = NULL; 161 struct ieee80211vap *vap = ni->ni_vap; 162 struct ieee80211_amrr *amrr = vap->iv_rs; 163 struct ieee80211_amrr_node *amn; 164 uint8_t rate; 165 166 if (ni->ni_rctls == NULL) { 167 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 168 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 169 if (amn == NULL) { 170 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 171 "structure\n"); 172 return; 173 } 174 } else 175 amn = ni->ni_rctls; 176 amn->amn_amrr = amrr; 177 amn->amn_success = 0; 178 amn->amn_recovery = 0; 179 amn->amn_txcnt = amn->amn_retrycnt = 0; 180 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 181 182 /* 11n or not? Pick the right rateset */ 183 if (amrr_node_is_11n(ni)) { 184 /* XXX ew */ 185 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 186 "%s: 11n node", __func__); 187 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 188 } else { 189 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 190 "%s: non-11n node", __func__); 191 rs = &ni->ni_rates; 192 } 193 194 /* Initial rate - lowest */ 195 rate = rs->rs_rates[0]; 196 197 /* XXX clear the basic rate flag if it's not 11n */ 198 if (! amrr_node_is_11n(ni)) 199 rate &= IEEE80211_RATE_VAL; 200 201 /* pick initial rate from the rateset - HT or otherwise */ 202 /* Pick something low that's likely to succeed */ 203 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 204 amn->amn_rix--) { 205 /* legacy - anything < 36mbit, stop searching */ 206 /* 11n - stop at MCS4 */ 207 if (amrr_node_is_11n(ni)) { 208 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 209 break; 210 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 211 break; 212 } 213 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 214 215 /* if the rate is an 11n rate, ensure the MCS bit is set */ 216 if (amrr_node_is_11n(ni)) 217 rate |= IEEE80211_RATE_MCS; 218 219 /* Assign initial rate from the rateset */ 220 ni->ni_txrate = rate; 221 amn->amn_ticks = ticks; 222 223 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 224 "AMRR: nrates=%d, initial rate %d", 225 rs->rs_nrates, 226 rate); 227} 228 229static void 230amrr_node_deinit(struct ieee80211_node *ni) 231{ 232 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 233} 234 235static int 236amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 237 struct ieee80211_node *ni) 238{ 239 int rix = amn->amn_rix; 240 const struct ieee80211_rateset *rs = NULL; 241 242 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 243 244 /* 11n or not? Pick the right rateset */ 245 if (amrr_node_is_11n(ni)) { 246 /* XXX ew */ 247 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 248 } else { 249 rs = &ni->ni_rates; 250 } 251 252 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 253 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 254 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 255 amn->amn_txcnt, 256 amn->amn_retrycnt); 257 258 /* 259 * XXX This is totally bogus for 11n, as although high MCS 260 * rates for each stream may be failing, the next stream 261 * should be checked. 262 * 263 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 264 * MCS23, we should skip 6/7 and try 8 onwards. 265 */ 266 if (is_success(amn)) { 267 amn->amn_success++; 268 if (amn->amn_success >= amn->amn_success_threshold && 269 rix + 1 < rs->rs_nrates) { 270 amn->amn_recovery = 1; 271 amn->amn_success = 0; 272 rix++; 273 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 274 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 275 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 276 amn->amn_txcnt, amn->amn_retrycnt); 277 } else { 278 amn->amn_recovery = 0; 279 } 280 } else if (is_failure(amn)) { 281 amn->amn_success = 0; 282 if (rix > 0) { 283 if (amn->amn_recovery) { 284 amn->amn_success_threshold *= 2; 285 if (amn->amn_success_threshold > 286 amrr->amrr_max_success_threshold) 287 amn->amn_success_threshold = 288 amrr->amrr_max_success_threshold; 289 } else { 290 amn->amn_success_threshold = 291 amrr->amrr_min_success_threshold; 292 } 293 rix--; 294 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 295 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 296 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 297 amn->amn_txcnt, amn->amn_retrycnt); 298 } 299 amn->amn_recovery = 0; 300 } 301 302 /* reset counters */ 303 amn->amn_txcnt = 0; 304 amn->amn_retrycnt = 0; 305 306 return rix; 307} 308 309/* 310 * Return the rate index to use in sending a data frame. 311 * Update our internal state if it's been long enough. 312 * If the rate changes we also update ni_txrate to match. 313 */ 314static int 315amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 316{ 317 struct ieee80211_amrr_node *amn = ni->ni_rctls; 318 struct ieee80211_amrr *amrr = amn->amn_amrr; 319 const struct ieee80211_rateset *rs = NULL; 320 int rix; 321 322 /* 11n or not? Pick the right rateset */ 323 if (amrr_node_is_11n(ni)) { 324 /* XXX ew */ 325 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 326 } else { 327 rs = &ni->ni_rates; 328 } 329 330 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 331 rix = amrr_update(amrr, amn, ni); 332 if (rix != amn->amn_rix) { 333 /* update public rate */ 334 ni->ni_txrate = rs->rs_rates[rix]; 335 /* XXX strip basic rate flag from txrate, if non-11n */ 336 if (amrr_node_is_11n(ni)) 337 ni->ni_txrate |= IEEE80211_RATE_MCS; 338 else 339 ni->ni_txrate &= IEEE80211_RATE_VAL; 340 amn->amn_rix = rix; 341 } 342 amn->amn_ticks = ticks; 343 } else 344 rix = amn->amn_rix; 345 return rix; 346} 347 348/* 349 * Update statistics with tx complete status. Ok is non-zero 350 * if the packet is known to be ACK'd. Retries has the number 351 * retransmissions (i.e. xmit attempts - 1). 352 */ 353static void 354amrr_tx_complete(const struct ieee80211vap *vap, 355 const struct ieee80211_node *ni, int ok, 356 void *arg1, void *arg2 __unused) 357{ 358 struct ieee80211_amrr_node *amn = ni->ni_rctls; 359 int retries = *(int *)arg1; 360 361 amn->amn_txcnt++; 362 if (ok) 363 amn->amn_success++; 364 amn->amn_retrycnt += retries; 365} 366 367/* 368 * Set tx count/retry statistics explicitly. Intended for 369 * drivers that poll the device for statistics maintained 370 * in the device. 371 */ 372static void 373amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 374 void *arg1, void *arg2, void *arg3) 375{ 376 struct ieee80211_amrr_node *amn = ni->ni_rctls; 377 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 378 379 amn->amn_txcnt = txcnt; 380 amn->amn_success = success; 381 amn->amn_retrycnt = retrycnt; 382} 383 384static int 385amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 386{ 387 struct ieee80211vap *vap = arg1; 388 struct ieee80211_amrr *amrr = vap->iv_rs; 389 int msecs = ticks_to_msecs(amrr->amrr_interval); 390 int error; 391 392 error = sysctl_handle_int(oidp, &msecs, 0, req); 393 if (error || !req->newptr) 394 return error; 395 amrr_setinterval(vap, msecs); 396 return 0; 397} 398 399static void 400amrr_sysctlattach(struct ieee80211vap *vap, 401 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 402{ 403 struct ieee80211_amrr *amrr = vap->iv_rs; 404 405 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 406 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 407 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 408 /* XXX bounds check values */ 409 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 410 "amrr_max_sucess_threshold", CTLFLAG_RW, 411 &amrr->amrr_max_success_threshold, 0, ""); 412 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 413 "amrr_min_sucess_threshold", CTLFLAG_RW, 414 &amrr->amrr_min_success_threshold, 0, ""); 415} 416 417static void 418amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 419{ 420 int rate; 421 struct ieee80211_amrr_node *amn = ni->ni_rctls; 422 struct ieee80211_rateset *rs; 423 424 /* XXX TODO: check locking? */ 425 426 /* XXX TODO: this should be a method */ 427 if (amrr_node_is_11n(ni)) { 428 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 429 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 430 sbuf_printf(s, "rate: MCS %d\n", rate); 431 } else { 432 rs = &ni->ni_rates; 433 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 434 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 435 } 436 437 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 438 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 439 sbuf_printf(s, "success: %u\n", amn->amn_success); 440 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 441 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 442 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 443} 444