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 #include <netproto/802_11/ieee80211_var.h> 48 #include <netproto/802_11/ieee80211_ht.h> 49 #include <netproto/802_11/ieee80211_amrr.h> 50 #include <netproto/802_11/ieee80211_ratectl.h> 51 52 #define is_success(amn) \ 53 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 54 #define is_failure(amn) \ 55 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 56 #define is_enough(amn) \ 57 ((amn)->amn_txcnt > 10) 58 59 static void amrr_setinterval(const struct ieee80211vap *, int); 60 static void amrr_init(struct ieee80211vap *); 61 static void amrr_deinit(struct ieee80211vap *); 62 static void amrr_node_init(struct ieee80211_node *); 63 static void amrr_node_deinit(struct ieee80211_node *); 64 static int amrr_update(struct ieee80211_amrr *, 65 struct ieee80211_amrr_node *, struct ieee80211_node *); 66 static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 67 static void amrr_tx_complete(const struct ieee80211vap *, 68 const struct ieee80211_node *, int, 69 void *, void *); 70 static void amrr_tx_update(const struct ieee80211vap *vap, 71 const struct ieee80211_node *, void *, void *, void *); 72 static void amrr_sysctlattach(struct ieee80211vap *, 73 struct sysctl_ctx_list *, struct sysctl_oid *); 74 static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s); 75 76 /* number of references from net80211 layer */ 77 static int nrefs = 0; 78 79 static const struct ieee80211_ratectl amrr = { 80 .ir_name = "amrr", 81 .ir_attach = NULL, 82 .ir_detach = NULL, 83 .ir_init = amrr_init, 84 .ir_deinit = amrr_deinit, 85 .ir_node_init = amrr_node_init, 86 .ir_node_deinit = amrr_node_deinit, 87 .ir_rate = amrr_rate, 88 .ir_tx_complete = amrr_tx_complete, 89 .ir_tx_update = amrr_tx_update, 90 .ir_setinterval = amrr_setinterval, 91 .ir_node_stats = amrr_node_stats, 92 }; 93 IEEE80211_RATECTL_MODULE(amrr, 1); 94 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 95 96 static void 97 amrr_setinterval(const struct ieee80211vap *vap, int msecs) 98 { 99 struct ieee80211_amrr *amrr = vap->iv_rs; 100 int t; 101 102 if (msecs < 100) 103 msecs = 100; 104 t = msecs_to_ticks(msecs); 105 amrr->amrr_interval = (t < 1) ? 1 : t; 106 } 107 108 static void 109 amrr_init(struct ieee80211vap *vap) 110 { 111 struct ieee80211_amrr *amrr; 112 113 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 114 115 #if defined(__DragonFly__) 116 amrr = vap->iv_rs = kmalloc(sizeof(struct ieee80211_amrr), 117 M_80211_RATECTL, M_INTWAIT|M_ZERO); 118 #else 119 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 120 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 121 #endif 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 #if defined(__DragonFly__) 168 ni->ni_rctls = amn = kmalloc(sizeof(struct ieee80211_amrr_node), 169 M_80211_RATECTL, M_INTWAIT|M_ZERO); 170 #else 171 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 172 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 173 #endif 174 if (amn == NULL) { 175 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 176 "structure\n"); 177 return; 178 } 179 } else 180 amn = ni->ni_rctls; 181 amn->amn_amrr = amrr; 182 amn->amn_success = 0; 183 amn->amn_recovery = 0; 184 amn->amn_txcnt = amn->amn_retrycnt = 0; 185 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 186 187 /* 11n or not? Pick the right rateset */ 188 if (amrr_node_is_11n(ni)) { 189 /* XXX ew */ 190 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 191 "%s: 11n node", __func__); 192 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 193 } else { 194 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 195 "%s: non-11n node", __func__); 196 rs = &ni->ni_rates; 197 } 198 199 /* Initial rate - lowest */ 200 rate = rs->rs_rates[0]; 201 202 /* XXX clear the basic rate flag if it's not 11n */ 203 if (! amrr_node_is_11n(ni)) 204 rate &= IEEE80211_RATE_VAL; 205 206 /* pick initial rate from the rateset - HT or otherwise */ 207 /* Pick something low that's likely to succeed */ 208 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 209 amn->amn_rix--) { 210 /* legacy - anything < 36mbit, stop searching */ 211 /* 11n - stop at MCS4 */ 212 if (amrr_node_is_11n(ni)) { 213 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 214 break; 215 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 216 break; 217 } 218 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 219 220 /* if the rate is an 11n rate, ensure the MCS bit is set */ 221 if (amrr_node_is_11n(ni)) 222 rate |= IEEE80211_RATE_MCS; 223 224 /* Assign initial rate from the rateset */ 225 ni->ni_txrate = rate; 226 amn->amn_ticks = ticks; 227 228 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 229 "AMRR: nrates=%d, initial rate %d", 230 rs->rs_nrates, 231 rate); 232 } 233 234 static void 235 amrr_node_deinit(struct ieee80211_node *ni) 236 { 237 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 238 } 239 240 static int 241 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 242 struct ieee80211_node *ni) 243 { 244 int rix = amn->amn_rix; 245 const struct ieee80211_rateset *rs = NULL; 246 247 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 248 249 /* 11n or not? Pick the right rateset */ 250 if (amrr_node_is_11n(ni)) { 251 /* XXX ew */ 252 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 253 } else { 254 rs = &ni->ni_rates; 255 } 256 257 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 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 279 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 280 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 281 amn->amn_txcnt, amn->amn_retrycnt); 282 } else { 283 amn->amn_recovery = 0; 284 } 285 } else if (is_failure(amn)) { 286 amn->amn_success = 0; 287 if (rix > 0) { 288 if (amn->amn_recovery) { 289 amn->amn_success_threshold *= 2; 290 if (amn->amn_success_threshold > 291 amrr->amrr_max_success_threshold) 292 amn->amn_success_threshold = 293 amrr->amrr_max_success_threshold; 294 } else { 295 amn->amn_success_threshold = 296 amrr->amrr_min_success_threshold; 297 } 298 rix--; 299 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 300 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 301 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 302 amn->amn_txcnt, amn->amn_retrycnt); 303 } 304 amn->amn_recovery = 0; 305 } 306 307 /* reset counters */ 308 amn->amn_txcnt = 0; 309 amn->amn_retrycnt = 0; 310 311 return rix; 312 } 313 314 /* 315 * Return the rate index to use in sending a data frame. 316 * Update our internal state if it's been long enough. 317 * If the rate changes we also update ni_txrate to match. 318 */ 319 static int 320 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 321 { 322 struct ieee80211_amrr_node *amn = ni->ni_rctls; 323 struct ieee80211_amrr *amrr = amn->amn_amrr; 324 const struct ieee80211_rateset *rs = NULL; 325 int rix; 326 327 /* 11n or not? Pick the right rateset */ 328 if (amrr_node_is_11n(ni)) { 329 /* XXX ew */ 330 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 331 } else { 332 rs = &ni->ni_rates; 333 } 334 335 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 336 rix = amrr_update(amrr, amn, ni); 337 if (rix != amn->amn_rix) { 338 /* update public rate */ 339 ni->ni_txrate = rs->rs_rates[rix]; 340 /* XXX strip basic rate flag from txrate, if non-11n */ 341 if (amrr_node_is_11n(ni)) 342 ni->ni_txrate |= IEEE80211_RATE_MCS; 343 else 344 ni->ni_txrate &= IEEE80211_RATE_VAL; 345 amn->amn_rix = rix; 346 } 347 amn->amn_ticks = ticks; 348 } else 349 rix = amn->amn_rix; 350 return rix; 351 } 352 353 /* 354 * Update statistics with tx complete status. Ok is non-zero 355 * if the packet is known to be ACK'd. Retries has the number 356 * retransmissions (i.e. xmit attempts - 1). 357 */ 358 static void 359 amrr_tx_complete(const struct ieee80211vap *vap, 360 const struct ieee80211_node *ni, int ok, 361 void *arg1, void *arg2 __unused) 362 { 363 struct ieee80211_amrr_node *amn = ni->ni_rctls; 364 int retries = *(int *)arg1; 365 366 amn->amn_txcnt++; 367 if (ok) 368 amn->amn_success++; 369 amn->amn_retrycnt += retries; 370 } 371 372 /* 373 * Set tx count/retry statistics explicitly. Intended for 374 * drivers that poll the device for statistics maintained 375 * in the device. 376 */ 377 static void 378 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 379 void *arg1, void *arg2, void *arg3) 380 { 381 struct ieee80211_amrr_node *amn = ni->ni_rctls; 382 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 383 384 amn->amn_txcnt = txcnt; 385 amn->amn_success = success; 386 amn->amn_retrycnt = retrycnt; 387 } 388 389 static int 390 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 391 { 392 struct ieee80211vap *vap = arg1; 393 struct ieee80211_amrr *amrr = vap->iv_rs; 394 int msecs = ticks_to_msecs(amrr->amrr_interval); 395 int error; 396 397 error = sysctl_handle_int(oidp, &msecs, 0, req); 398 if (error || !req->newptr) 399 return error; 400 amrr_setinterval(vap, msecs); 401 return 0; 402 } 403 404 static void 405 amrr_sysctlattach(struct ieee80211vap *vap, 406 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 407 { 408 struct ieee80211_amrr *amrr = vap->iv_rs; 409 410 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 411 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 412 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 413 /* XXX bounds check values */ 414 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 415 "amrr_max_sucess_threshold", CTLFLAG_RW, 416 &amrr->amrr_max_success_threshold, 0, ""); 417 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 418 "amrr_min_sucess_threshold", CTLFLAG_RW, 419 &amrr->amrr_min_success_threshold, 0, ""); 420 } 421 422 static void 423 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 424 { 425 int rate; 426 struct ieee80211_amrr_node *amn = ni->ni_rctls; 427 struct ieee80211_rateset *rs; 428 429 /* XXX TODO: check locking? */ 430 431 /* XXX TODO: this should be a method */ 432 if (amrr_node_is_11n(ni)) { 433 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 434 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 435 sbuf_printf(s, "rate: MCS %d\n", rate); 436 } else { 437 rs = &ni->ni_rates; 438 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 439 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 440 } 441 442 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 443 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 444 sbuf_printf(s, "success: %u\n", amn->amn_success); 445 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 446 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 447 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 448 } 449