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