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 <netproto/802_11/ieee80211_var.h> 53 #include <netproto/802_11/ieee80211_ht.h> 54 #include <netproto/802_11/ieee80211_amrr.h> 55 #include <netproto/802_11/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 ieee80211vap *, 73 const struct ieee80211_node *, int, 74 void *, void *); 75 static void amrr_tx_update(const struct ieee80211vap *vap, 76 const struct ieee80211_node *, void *, void *, void *); 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 #if defined(__DragonFly__) 121 amrr = vap->iv_rs = kmalloc(sizeof(struct ieee80211_amrr), 122 M_80211_RATECTL, M_INTWAIT|M_ZERO); 123 #else 124 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 125 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 126 #endif 127 if (amrr == NULL) { 128 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 129 return; 130 } 131 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 132 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 133 amrr_setinterval(vap, 500 /* ms */); 134 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 135 } 136 137 static void 138 amrr_deinit(struct ieee80211vap *vap) 139 { 140 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 141 } 142 143 /* 144 * Return whether 11n rates are possible. 145 * 146 * Some 11n devices may return HT information but no HT rates. 147 * Thus, we shouldn't treat them as an 11n node. 148 */ 149 static int 150 amrr_node_is_11n(struct ieee80211_node *ni) 151 { 152 153 if (ni->ni_chan == NULL) 154 return (0); 155 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 156 return (0); 157 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 158 return (0); 159 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 160 } 161 162 static void 163 amrr_node_init(struct ieee80211_node *ni) 164 { 165 const struct ieee80211_rateset *rs = NULL; 166 struct ieee80211vap *vap = ni->ni_vap; 167 struct ieee80211_amrr *amrr = vap->iv_rs; 168 struct ieee80211_amrr_node *amn; 169 uint8_t rate; 170 171 if (ni->ni_rctls == NULL) { 172 #if defined(__DragonFly__) 173 ni->ni_rctls = amn = kmalloc(sizeof(struct ieee80211_amrr_node), 174 M_80211_RATECTL, M_INTWAIT|M_ZERO); 175 #else 176 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 177 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 178 #endif 179 if (amn == NULL) { 180 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 181 "structure\n"); 182 return; 183 } 184 } else 185 amn = ni->ni_rctls; 186 amn->amn_amrr = amrr; 187 amn->amn_success = 0; 188 amn->amn_recovery = 0; 189 amn->amn_txcnt = amn->amn_retrycnt = 0; 190 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 191 192 /* 11n or not? Pick the right rateset */ 193 if (amrr_node_is_11n(ni)) { 194 /* XXX ew */ 195 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 196 "%s: 11n node", __func__); 197 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 198 } else { 199 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 200 "%s: non-11n node", __func__); 201 rs = &ni->ni_rates; 202 } 203 204 /* Initial rate - lowest */ 205 rate = rs->rs_rates[0]; 206 207 /* XXX clear the basic rate flag if it's not 11n */ 208 if (! amrr_node_is_11n(ni)) 209 rate &= IEEE80211_RATE_VAL; 210 211 /* pick initial rate from the rateset - HT or otherwise */ 212 /* Pick something low that's likely to succeed */ 213 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 214 amn->amn_rix--) { 215 /* legacy - anything < 36mbit, stop searching */ 216 /* 11n - stop at MCS4 */ 217 if (amrr_node_is_11n(ni)) { 218 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 219 break; 220 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 221 break; 222 } 223 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 224 225 /* if the rate is an 11n rate, ensure the MCS bit is set */ 226 if (amrr_node_is_11n(ni)) 227 rate |= IEEE80211_RATE_MCS; 228 229 /* Assign initial rate from the rateset */ 230 ni->ni_txrate = rate; 231 amn->amn_ticks = ticks; 232 233 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 234 "AMRR: nrates=%d, initial rate %d", 235 rs->rs_nrates, 236 rate); 237 } 238 239 static void 240 amrr_node_deinit(struct ieee80211_node *ni) 241 { 242 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 243 } 244 245 static int 246 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 247 struct ieee80211_node *ni) 248 { 249 int rix = amn->amn_rix; 250 const struct ieee80211_rateset *rs = NULL; 251 252 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 253 254 /* 11n or not? Pick the right rateset */ 255 if (amrr_node_is_11n(ni)) { 256 /* XXX ew */ 257 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 258 } else { 259 rs = &ni->ni_rates; 260 } 261 262 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 263 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 264 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 265 amn->amn_txcnt, 266 amn->amn_retrycnt); 267 268 /* 269 * XXX This is totally bogus for 11n, as although high MCS 270 * rates for each stream may be failing, the next stream 271 * should be checked. 272 * 273 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 274 * MCS23, we should skip 6/7 and try 8 onwards. 275 */ 276 if (is_success(amn)) { 277 amn->amn_success++; 278 if (amn->amn_success >= amn->amn_success_threshold && 279 rix + 1 < rs->rs_nrates) { 280 amn->amn_recovery = 1; 281 amn->amn_success = 0; 282 rix++; 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 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 305 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 306 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 307 amn->amn_txcnt, amn->amn_retrycnt); 308 } 309 amn->amn_recovery = 0; 310 } 311 312 /* reset counters */ 313 amn->amn_txcnt = 0; 314 amn->amn_retrycnt = 0; 315 316 return rix; 317 } 318 319 /* 320 * Return the rate index to use in sending a data frame. 321 * Update our internal state if it's been long enough. 322 * If the rate changes we also update ni_txrate to match. 323 */ 324 static int 325 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 326 { 327 struct ieee80211_amrr_node *amn = ni->ni_rctls; 328 struct ieee80211_amrr *amrr = amn->amn_amrr; 329 const struct ieee80211_rateset *rs = NULL; 330 int rix; 331 332 /* 11n or not? Pick the right rateset */ 333 if (amrr_node_is_11n(ni)) { 334 /* XXX ew */ 335 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 336 } else { 337 rs = &ni->ni_rates; 338 } 339 340 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 341 rix = amrr_update(amrr, amn, ni); 342 if (rix != amn->amn_rix) { 343 /* update public rate */ 344 ni->ni_txrate = rs->rs_rates[rix]; 345 /* XXX strip basic rate flag from txrate, if non-11n */ 346 if (amrr_node_is_11n(ni)) 347 ni->ni_txrate |= IEEE80211_RATE_MCS; 348 else 349 ni->ni_txrate &= IEEE80211_RATE_VAL; 350 amn->amn_rix = rix; 351 } 352 amn->amn_ticks = ticks; 353 } else 354 rix = amn->amn_rix; 355 return rix; 356 } 357 358 /* 359 * Update statistics with tx complete status. Ok is non-zero 360 * if the packet is known to be ACK'd. Retries has the number 361 * retransmissions (i.e. xmit attempts - 1). 362 */ 363 static void 364 amrr_tx_complete(const struct ieee80211vap *vap, 365 const struct ieee80211_node *ni, int ok, 366 void *arg1, void *arg2 __unused) 367 { 368 struct ieee80211_amrr_node *amn = ni->ni_rctls; 369 int retries = *(int *)arg1; 370 371 amn->amn_txcnt++; 372 if (ok) 373 amn->amn_success++; 374 amn->amn_retrycnt += retries; 375 } 376 377 /* 378 * Set tx count/retry statistics explicitly. Intended for 379 * drivers that poll the device for statistics maintained 380 * in the device. 381 */ 382 static void 383 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 384 void *arg1, void *arg2, void *arg3) 385 { 386 struct ieee80211_amrr_node *amn = ni->ni_rctls; 387 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 388 389 amn->amn_txcnt = txcnt; 390 amn->amn_success = success; 391 amn->amn_retrycnt = retrycnt; 392 } 393 394 static int 395 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 396 { 397 struct ieee80211vap *vap = arg1; 398 struct ieee80211_amrr *amrr = vap->iv_rs; 399 int msecs = ticks_to_msecs(amrr->amrr_interval); 400 int error; 401 402 error = sysctl_handle_int(oidp, &msecs, 0, req); 403 if (error || !req->newptr) 404 return error; 405 amrr_setinterval(vap, msecs); 406 return 0; 407 } 408 409 static void 410 amrr_sysctlattach(struct ieee80211vap *vap, 411 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 412 { 413 struct ieee80211_amrr *amrr = vap->iv_rs; 414 415 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 416 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 417 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 418 /* XXX bounds check values */ 419 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 420 "amrr_max_sucess_threshold", CTLFLAG_RW, 421 &amrr->amrr_max_success_threshold, 0, ""); 422 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 423 "amrr_min_sucess_threshold", CTLFLAG_RW, 424 &amrr->amrr_min_success_threshold, 0, ""); 425 } 426 427 static void 428 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) 429 { 430 int rate; 431 struct ieee80211_amrr_node *amn = ni->ni_rctls; 432 struct ieee80211_rateset *rs; 433 434 /* XXX TODO: check locking? */ 435 436 /* XXX TODO: this should be a method */ 437 if (amrr_node_is_11n(ni)) { 438 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 439 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 440 sbuf_printf(s, "rate: MCS %d\n", rate); 441 } else { 442 rs = &ni->ni_rates; 443 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 444 sbuf_printf(s, "rate: %d Mbit\n", rate / 2); 445 } 446 447 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); 448 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); 449 sbuf_printf(s, "success: %u\n", amn->amn_success); 450 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); 451 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); 452 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); 453 } 454