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 /*- 23 * Naive implementation of the Adaptive Multi Rate Retry algorithm: 24 * 25 * "IEEE 802.11 Rate Adaptation: A Practical Approach" 26 * Mathieu Lacage, Hossein Manshaei, Thierry Turletti 27 * INRIA Sophia - Projet Planete 28 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html 29 */ 30 #include "opt_wlan.h" 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/malloc.h> 35 #include <sys/module.h> 36 #include <sys/sbuf.h> 37 #include <sys/socket.h> 38 #include <sys/sysctl.h> 39 40 #include <net/if.h> 41 #include <net/if_var.h> 42 #include <net/if_media.h> 43 #include <net/ethernet.h> 44 45 #ifdef INET 46 #include <netinet/in.h> 47 #include <netinet/if_ether.h> 48 #endif 49 50 #include <net80211/ieee80211_var.h> 51 #include <net80211/ieee80211_ht.h> 52 #include <net80211/ieee80211_amrr.h> 53 #include <net80211/ieee80211_ratectl.h> 54 55 #define is_success(amn) \ 56 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 57 #define is_failure(amn) \ 58 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 59 #define is_enough(amn) \ 60 ((amn)->amn_txcnt > 10) 61 62 static void amrr_setinterval(const struct ieee80211vap *, int); 63 static void amrr_init(struct ieee80211vap *); 64 static void amrr_deinit(struct ieee80211vap *); 65 static void amrr_node_init(struct ieee80211_node *); 66 static void amrr_node_deinit(struct ieee80211_node *); 67 static int amrr_update(struct ieee80211_amrr *, 68 struct ieee80211_amrr_node *, struct ieee80211_node *); 69 static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 70 static void amrr_tx_complete(const struct ieee80211_node *, 71 const struct ieee80211_ratectl_tx_status *); 72 static void amrr_tx_update_cb(void *, struct ieee80211_node *); 73 static void amrr_tx_update(struct ieee80211vap *vap, 74 struct ieee80211_ratectl_tx_stats *); 75 static void amrr_sysctlattach(struct ieee80211vap *, 76 struct sysctl_ctx_list *, struct sysctl_oid *); 77 static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s); 78 79 /* number of references from net80211 layer */ 80 static int nrefs = 0; 81 82 static const struct ieee80211_ratectl amrr = { 83 .ir_name = "amrr", 84 .ir_attach = NULL, 85 .ir_detach = NULL, 86 .ir_init = amrr_init, 87 .ir_deinit = amrr_deinit, 88 .ir_node_init = amrr_node_init, 89 .ir_node_deinit = amrr_node_deinit, 90 .ir_rate = amrr_rate, 91 .ir_tx_complete = amrr_tx_complete, 92 .ir_tx_update = amrr_tx_update, 93 .ir_setinterval = amrr_setinterval, 94 .ir_node_stats = amrr_node_stats, 95 }; 96 IEEE80211_RATECTL_MODULE(amrr, 1); 97 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 98 99 static void 100 amrr_setinterval(const struct ieee80211vap *vap, int msecs) 101 { 102 struct ieee80211_amrr *amrr = vap->iv_rs; 103 104 if (!amrr) 105 return; 106 107 if (msecs < 100) 108 msecs = 100; 109 amrr->amrr_interval = msecs_to_ticks(msecs); 110 } 111 112 static void 113 amrr_init(struct ieee80211vap *vap) 114 { 115 struct ieee80211_amrr *amrr; 116 117 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 118 119 nrefs++; /* XXX locking */ 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 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 137 nrefs--; /* XXX locking */ 138 } 139 140 /* 141 * Return whether 11n rates are possible. 142 * 143 * Some 11n devices may return HT information but no HT rates. 144 * Thus, we shouldn't treat them as an 11n node. 145 */ 146 static int 147 amrr_node_is_11n(struct ieee80211_node *ni) 148 { 149 150 if (ni->ni_chan == NULL) 151 return (0); 152 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 153 return (0); 154 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 155 return (0); 156 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 157 } 158 159 static void 160 amrr_node_init(struct ieee80211_node *ni) 161 { 162 const struct ieee80211_rateset *rs = NULL; 163 struct ieee80211vap *vap = ni->ni_vap; 164 struct ieee80211_amrr *amrr = vap->iv_rs; 165 struct ieee80211_amrr_node *amn; 166 uint8_t rate; 167 168 if (!amrr) { 169 if_printf(vap->iv_ifp, "ratectl structure was not allocated, " 170 "per-node structure allocation skipped\n"); 171 return; 172 } 173 174 if (ni->ni_rctls == NULL) { 175 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 176 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 177 if (amn == NULL) { 178 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 179 "structure\n"); 180 return; 181 } 182 } else 183 amn = ni->ni_rctls; 184 amn->amn_amrr = amrr; 185 amn->amn_success = 0; 186 amn->amn_recovery = 0; 187 amn->amn_txcnt = amn->amn_retrycnt = 0; 188 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 189 190 /* 11n or not? Pick the right rateset */ 191 if (amrr_node_is_11n(ni)) { 192 /* XXX ew */ 193 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 194 "%s: 11n node", __func__); 195 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 196 } else { 197 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 198 "%s: non-11n node", __func__); 199 rs = &ni->ni_rates; 200 } 201 202 /* Initial rate - lowest */ 203 rate = rs->rs_rates[0]; 204 205 /* XXX clear the basic rate flag if it's not 11n */ 206 if (! amrr_node_is_11n(ni)) 207 rate &= IEEE80211_RATE_VAL; 208 209 /* pick initial rate from the rateset - HT or otherwise */ 210 /* Pick something low that's likely to succeed */ 211 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 212 amn->amn_rix--) { 213 /* legacy - anything < 36mbit, stop searching */ 214 /* 11n - stop at MCS4 */ 215 if (amrr_node_is_11n(ni)) { 216 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 217 break; 218 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 219 break; 220 } 221 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 222 223 /* if the rate is an 11n rate, ensure the MCS bit is set */ 224 if (amrr_node_is_11n(ni)) 225 rate |= IEEE80211_RATE_MCS; 226 227 /* Assign initial rate from the rateset */ 228 ni->ni_txrate = rate; 229 amn->amn_ticks = ticks; 230 231 /* XXX TODO: we really need a rate-to-string method */ 232 /* XXX TODO: non-11n rate should be divided by two.. */ 233 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 234 "AMRR: nrates=%d, initial rate %s%d", 235 rs->rs_nrates, 236 amrr_node_is_11n(ni) ? "MCS " : "", 237 rate & IEEE80211_RATE_VAL); 238 } 239 240 static void 241 amrr_node_deinit(struct ieee80211_node *ni) 242 { 243 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 244 } 245 246 static int 247 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 248 struct ieee80211_node *ni) 249 { 250 int rix = amn->amn_rix; 251 const struct ieee80211_rateset *rs = NULL; 252 253 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 254 255 /* 11n or not? Pick the right rateset */ 256 if (amrr_node_is_11n(ni)) { 257 /* XXX ew */ 258 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 259 } else { 260 rs = &ni->ni_rates; 261 } 262 263 /* XXX TODO: we really need a rate-to-string method */ 264 /* XXX TODO: non-11n rate should be divided by two.. */ 265 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 266 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 267 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 268 amn->amn_txcnt, 269 amn->amn_retrycnt); 270 271 /* 272 * XXX This is totally bogus for 11n, as although high MCS 273 * rates for each stream may be failing, the next stream 274 * should be checked. 275 * 276 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 277 * MCS23, we should skip 6/7 and try 8 onwards. 278 */ 279 if (is_success(amn)) { 280 amn->amn_success++; 281 if (amn->amn_success >= amn->amn_success_threshold && 282 rix + 1 < rs->rs_nrates) { 283 amn->amn_recovery = 1; 284 amn->amn_success = 0; 285 rix++; 286 /* XXX TODO: we really need a rate-to-string method */ 287 /* XXX TODO: non-11n rate should be divided by two.. */ 288 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 289 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 290 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 291 amn->amn_txcnt, amn->amn_retrycnt); 292 } else { 293 amn->amn_recovery = 0; 294 } 295 } else if (is_failure(amn)) { 296 amn->amn_success = 0; 297 if (rix > 0) { 298 if (amn->amn_recovery) { 299 amn->amn_success_threshold *= 2; 300 if (amn->amn_success_threshold > 301 amrr->amrr_max_success_threshold) 302 amn->amn_success_threshold = 303 amrr->amrr_max_success_threshold; 304 } else { 305 amn->amn_success_threshold = 306 amrr->amrr_min_success_threshold; 307 } 308 rix--; 309 /* XXX TODO: we really need a rate-to-string method */ 310 /* XXX TODO: non-11n rate should be divided by two.. */ 311 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 312 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 313 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 314 amn->amn_txcnt, amn->amn_retrycnt); 315 } 316 amn->amn_recovery = 0; 317 } 318 319 /* reset counters */ 320 amn->amn_txcnt = 0; 321 amn->amn_retrycnt = 0; 322 323 return rix; 324 } 325 326 /* 327 * Return the rate index to use in sending a data frame. 328 * Update our internal state if it's been long enough. 329 * If the rate changes we also update ni_txrate to match. 330 */ 331 static int 332 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 333 { 334 struct ieee80211_amrr_node *amn = ni->ni_rctls; 335 struct ieee80211_amrr *amrr; 336 const struct ieee80211_rateset *rs = NULL; 337 int rix; 338 339 /* XXX should return -1 here, but drivers may not expect this... */ 340 if (!amn) 341 { 342 ni->ni_txrate = ni->ni_rates.rs_rates[0]; 343 return 0; 344 } 345 346 amrr = amn->amn_amrr; 347 348 /* 11n or not? Pick the right rateset */ 349 if (amrr_node_is_11n(ni)) { 350 /* XXX ew */ 351 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 352 } else { 353 rs = &ni->ni_rates; 354 } 355 356 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 357 rix = amrr_update(amrr, amn, ni); 358 if (rix != amn->amn_rix) { 359 /* update public rate */ 360 ni->ni_txrate = rs->rs_rates[rix]; 361 /* XXX strip basic rate flag from txrate, if non-11n */ 362 if (amrr_node_is_11n(ni)) 363 ni->ni_txrate |= IEEE80211_RATE_MCS; 364 else 365 ni->ni_txrate &= IEEE80211_RATE_VAL; 366 amn->amn_rix = rix; 367 } 368 amn->amn_ticks = ticks; 369 } else 370 rix = amn->amn_rix; 371 return rix; 372 } 373 374 /* 375 * Update statistics with tx complete status. Ok is non-zero 376 * if the packet is known to be ACK'd. Retries has the number 377 * retransmissions (i.e. xmit attempts - 1). 378 */ 379 static void 380 amrr_tx_complete(const struct ieee80211_node *ni, 381 const struct ieee80211_ratectl_tx_status *status) 382 { 383 struct ieee80211_amrr_node *amn = ni->ni_rctls; 384 int retries; 385 386 if (!amn) 387 return; 388 389 retries = 0; 390 if (status->flags & IEEE80211_RATECTL_STATUS_LONG_RETRY) 391 retries = status->long_retries; 392 393 amn->amn_txcnt++; 394 if (status->status == IEEE80211_RATECTL_TX_SUCCESS) 395 amn->amn_success++; 396 amn->amn_retrycnt += retries; 397 } 398 399 static void 400 amrr_tx_update_cb(void *arg, struct ieee80211_node *ni) 401 { 402 struct ieee80211_ratectl_tx_stats *stats = arg; 403 struct ieee80211_amrr_node *amn = ni->ni_rctls; 404 int txcnt, success, retrycnt; 405 406 if (!amn) 407 return; 408 409 txcnt = stats->nframes; 410 success = stats->nsuccess; 411 retrycnt = 0; 412 if (stats->flags & IEEE80211_RATECTL_TX_STATS_RETRIES) 413 retrycnt = stats->nretries; 414 415 amn->amn_txcnt += txcnt; 416 amn->amn_success += success; 417 amn->amn_retrycnt += retrycnt; 418 } 419 420 /* 421 * Set tx count/retry statistics explicitly. Intended for 422 * drivers that poll the device for statistics maintained 423 * in the device. 424 */ 425 static void 426 amrr_tx_update(struct ieee80211vap *vap, 427 struct ieee80211_ratectl_tx_stats *stats) 428 { 429 430 if (stats->flags & IEEE80211_RATECTL_TX_STATS_NODE) 431 amrr_tx_update_cb(stats, stats->ni); 432 else { 433 ieee80211_iterate_nodes_vap(&vap->iv_ic->ic_sta, vap, 434 amrr_tx_update_cb, stats); 435 } 436 } 437 438 static int 439 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 440 { 441 struct ieee80211vap *vap = arg1; 442 struct ieee80211_amrr *amrr = vap->iv_rs; 443 int msecs, error; 444 445 if (!amrr) 446 return ENOMEM; 447 448 msecs = ticks_to_msecs(amrr->amrr_interval); 449 error = sysctl_handle_int(oidp, &msecs, 0, req); 450 if (error || !req->newptr) 451 return error; 452 amrr_setinterval(vap, msecs); 453 return 0; 454 } 455 456 static void 457 amrr_sysctlattach(struct ieee80211vap *vap, 458 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 459 { 460 struct ieee80211_amrr *amrr = vap->iv_rs; 461 462 if (!amrr) 463 return; 464 465 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 466 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 467 vap, 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 468 /* XXX bounds check values */ 469 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 470 "amrr_max_sucess_threshold", CTLFLAG_RW, 471 &amrr->amrr_max_success_threshold, 0, ""); 472 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 473 "amrr_min_sucess_threshold", CTLFLAG_RW, 474 &amrr->amrr_min_success_threshold, 0, ""); 475 } 476 477 static void 478 amrr_print_node_rate(struct ieee80211_amrr_node *amn, 479 struct ieee80211_node *ni, struct sbuf *s) 480 { 481 int rate; 482 struct ieee80211_rateset *rs; 483 484 if (amrr_node_is_11n(ni)) { 485 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 486 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 487 sbuf_printf(s, "rate: MCS %d\n", rate); 488 } else { 489 rs = &ni->ni_rates; 490 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 491 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 492 } 493 } 494 495 static void 496 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 497 { 498 struct ieee80211_amrr_node *amn = ni->ni_rctls; 499 500 /* XXX TODO: check locking? */ 501 502 if (!amn) 503 return; 504 505 amrr_print_node_rate(amn, ni, s); 506 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 507 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 508 sbuf_printf(s, "success: %u\n", amn->amn_success); 509 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 510 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 511 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 512 } 513