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 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 } 131 132 static void 133 amrr_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 */ 144 static int 145 amrr_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 } 156 157 static void 158 amrr_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 /* XXX TODO: we really need a rate-to-string method */ 224 /* XXX TODO: non-11n rate should be divided by two.. */ 225 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 226 "AMRR: nrates=%d, initial rate %s%d", 227 rs->rs_nrates, 228 amrr_node_is_11n(ni) ? "MCS " : "", 229 rate & IEEE80211_RATE_VAL); 230 } 231 232 static void 233 amrr_node_deinit(struct ieee80211_node *ni) 234 { 235 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 236 } 237 238 static int 239 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 240 struct ieee80211_node *ni) 241 { 242 int rix = amn->amn_rix; 243 const struct ieee80211_rateset *rs = NULL; 244 245 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 246 247 /* 11n or not? Pick the right rateset */ 248 if (amrr_node_is_11n(ni)) { 249 /* XXX ew */ 250 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 251 } else { 252 rs = &ni->ni_rates; 253 } 254 255 /* XXX TODO: we really need a rate-to-string method */ 256 /* XXX TODO: non-11n rate should be divided by two.. */ 257 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 258 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 259 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 260 amn->amn_txcnt, 261 amn->amn_retrycnt); 262 263 /* 264 * XXX This is totally bogus for 11n, as although high MCS 265 * rates for each stream may be failing, the next stream 266 * should be checked. 267 * 268 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 269 * MCS23, we should skip 6/7 and try 8 onwards. 270 */ 271 if (is_success(amn)) { 272 amn->amn_success++; 273 if (amn->amn_success >= amn->amn_success_threshold && 274 rix + 1 < rs->rs_nrates) { 275 amn->amn_recovery = 1; 276 amn->amn_success = 0; 277 rix++; 278 /* XXX TODO: we really need a rate-to-string method */ 279 /* XXX TODO: non-11n rate should be divided by two.. */ 280 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 281 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 282 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 283 amn->amn_txcnt, amn->amn_retrycnt); 284 } else { 285 amn->amn_recovery = 0; 286 } 287 } else if (is_failure(amn)) { 288 amn->amn_success = 0; 289 if (rix > 0) { 290 if (amn->amn_recovery) { 291 amn->amn_success_threshold *= 2; 292 if (amn->amn_success_threshold > 293 amrr->amrr_max_success_threshold) 294 amn->amn_success_threshold = 295 amrr->amrr_max_success_threshold; 296 } else { 297 amn->amn_success_threshold = 298 amrr->amrr_min_success_threshold; 299 } 300 rix--; 301 /* XXX TODO: we really need a rate-to-string method */ 302 /* XXX TODO: non-11n rate should be divided by two.. */ 303 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 304 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 305 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 306 amn->amn_txcnt, amn->amn_retrycnt); 307 } 308 amn->amn_recovery = 0; 309 } 310 311 /* reset counters */ 312 amn->amn_txcnt = 0; 313 amn->amn_retrycnt = 0; 314 315 return rix; 316 } 317 318 /* 319 * Return the rate index to use in sending a data frame. 320 * Update our internal state if it's been long enough. 321 * If the rate changes we also update ni_txrate to match. 322 */ 323 static int 324 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 325 { 326 struct ieee80211_amrr_node *amn = ni->ni_rctls; 327 struct ieee80211_amrr *amrr = amn->amn_amrr; 328 const struct ieee80211_rateset *rs = NULL; 329 int rix; 330 331 /* 11n or not? Pick the right rateset */ 332 if (amrr_node_is_11n(ni)) { 333 /* XXX ew */ 334 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 335 } else { 336 rs = &ni->ni_rates; 337 } 338 339 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 340 rix = amrr_update(amrr, amn, ni); 341 if (rix != amn->amn_rix) { 342 /* update public rate */ 343 ni->ni_txrate = rs->rs_rates[rix]; 344 /* XXX strip basic rate flag from txrate, if non-11n */ 345 if (amrr_node_is_11n(ni)) 346 ni->ni_txrate |= IEEE80211_RATE_MCS; 347 else 348 ni->ni_txrate &= IEEE80211_RATE_VAL; 349 amn->amn_rix = rix; 350 } 351 amn->amn_ticks = ticks; 352 } else 353 rix = amn->amn_rix; 354 return rix; 355 } 356 357 /* 358 * Update statistics with tx complete status. Ok is non-zero 359 * if the packet is known to be ACK'd. Retries has the number 360 * retransmissions (i.e. xmit attempts - 1). 361 */ 362 static void 363 amrr_tx_complete(const struct ieee80211_node *ni, 364 const struct ieee80211_ratectl_tx_status *status) 365 { 366 struct ieee80211_amrr_node *amn = ni->ni_rctls; 367 int retries; 368 369 retries = 0; 370 if (status->flags & IEEE80211_RATECTL_STATUS_LONG_RETRY) 371 retries = status->long_retries; 372 373 amn->amn_txcnt++; 374 if (status->status == IEEE80211_RATECTL_TX_SUCCESS) 375 amn->amn_success++; 376 amn->amn_retrycnt += retries; 377 } 378 379 static void 380 amrr_tx_update_cb(void *arg, struct ieee80211_node *ni) 381 { 382 struct ieee80211_ratectl_tx_stats *stats = arg; 383 struct ieee80211_amrr_node *amn = ni->ni_rctls; 384 int txcnt, success, retrycnt; 385 386 txcnt = stats->nframes; 387 success = stats->nsuccess; 388 retrycnt = 0; 389 if (stats->flags & IEEE80211_RATECTL_TX_STATS_RETRIES) 390 retrycnt = stats->nretries; 391 392 amn->amn_txcnt += txcnt; 393 amn->amn_success += success; 394 amn->amn_retrycnt += retrycnt; 395 } 396 397 /* 398 * Set tx count/retry statistics explicitly. Intended for 399 * drivers that poll the device for statistics maintained 400 * in the device. 401 */ 402 static void 403 amrr_tx_update(struct ieee80211vap *vap, 404 struct ieee80211_ratectl_tx_stats *stats) 405 { 406 407 if (stats->flags & IEEE80211_RATECTL_TX_STATS_NODE) 408 amrr_tx_update_cb(stats, stats->ni); 409 else { 410 ieee80211_iterate_nodes_vap(&vap->iv_ic->ic_sta, vap, 411 amrr_tx_update_cb, stats); 412 } 413 } 414 415 static int 416 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 417 { 418 struct ieee80211vap *vap = arg1; 419 struct ieee80211_amrr *amrr = vap->iv_rs; 420 int msecs = ticks_to_msecs(amrr->amrr_interval); 421 int error; 422 423 error = sysctl_handle_int(oidp, &msecs, 0, req); 424 if (error || !req->newptr) 425 return error; 426 amrr_setinterval(vap, msecs); 427 return 0; 428 } 429 430 static void 431 amrr_sysctlattach(struct ieee80211vap *vap, 432 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 433 { 434 struct ieee80211_amrr *amrr = vap->iv_rs; 435 436 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 437 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 438 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 439 /* XXX bounds check values */ 440 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 441 "amrr_max_sucess_threshold", CTLFLAG_RW, 442 &amrr->amrr_max_success_threshold, 0, ""); 443 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 444 "amrr_min_sucess_threshold", CTLFLAG_RW, 445 &amrr->amrr_min_success_threshold, 0, ""); 446 } 447 448 static void 449 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 450 { 451 int rate; 452 struct ieee80211_amrr_node *amn = ni->ni_rctls; 453 struct ieee80211_rateset *rs; 454 455 /* XXX TODO: check locking? */ 456 457 /* XXX TODO: this should be a method */ 458 if (amrr_node_is_11n(ni)) { 459 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 460 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 461 sbuf_printf(s, "rate: MCS %d\n", rate); 462 } else { 463 rs = &ni->ni_rates; 464 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 465 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 466 } 467 468 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 469 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 470 sbuf_printf(s, "success: %u\n", amn->amn_success); 471 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 472 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 473 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 474 } 475