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/socket.h> 39 #include <sys/sysctl.h> 40 41 #include <net/if.h> 42 #include <net/if_var.h> 43 #include <net/if_media.h> 44 #include <net/ethernet.h> 45 46 #ifdef INET 47 #include <netinet/in.h> 48 #include <netinet/if_ether.h> 49 #endif 50 51 #include <net80211/ieee80211_var.h> 52 #include <net80211/ieee80211_ht.h> 53 #include <net80211/ieee80211_amrr.h> 54 #include <net80211/ieee80211_ratectl.h> 55 56 #define is_success(amn) \ 57 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 58 #define is_failure(amn) \ 59 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 60 #define is_enough(amn) \ 61 ((amn)->amn_txcnt > 10) 62 63 static void amrr_setinterval(const struct ieee80211vap *, int); 64 static void amrr_init(struct ieee80211vap *); 65 static void amrr_deinit(struct ieee80211vap *); 66 static void amrr_node_init(struct ieee80211_node *); 67 static void amrr_node_deinit(struct ieee80211_node *); 68 static int amrr_update(struct ieee80211_amrr *, 69 struct ieee80211_amrr_node *, struct ieee80211_node *); 70 static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 71 static void amrr_tx_complete(const struct ieee80211vap *, 72 const struct ieee80211_node *, int, 73 void *, void *); 74 static void amrr_tx_update(const struct ieee80211vap *vap, 75 const struct ieee80211_node *, void *, void *, void *); 76 static void amrr_sysctlattach(struct ieee80211vap *, 77 struct sysctl_ctx_list *, struct sysctl_oid *); 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 }; 95 IEEE80211_RATECTL_MODULE(amrr, 1); 96 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 97 98 static void 99 amrr_setinterval(const struct ieee80211vap *vap, int msecs) 100 { 101 struct ieee80211_amrr *amrr = vap->iv_rs; 102 int t; 103 104 if (msecs < 100) 105 msecs = 100; 106 t = msecs_to_ticks(msecs); 107 amrr->amrr_interval = (t < 1) ? 1 : t; 108 } 109 110 static void 111 amrr_init(struct ieee80211vap *vap) 112 { 113 struct ieee80211_amrr *amrr; 114 115 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 116 117 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 118 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 119 if (amrr == NULL) { 120 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 121 return; 122 } 123 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 124 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 125 amrr_setinterval(vap, 500 /* ms */); 126 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 127 } 128 129 static void 130 amrr_deinit(struct ieee80211vap *vap) 131 { 132 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 133 } 134 135 /* 136 * Return whether 11n rates are possible. 137 * 138 * Some 11n devices may return HT information but no HT rates. 139 * Thus, we shouldn't treat them as an 11n node. 140 */ 141 static int 142 amrr_node_is_11n(struct ieee80211_node *ni) 143 { 144 145 if (ni->ni_chan == NULL) 146 return (0); 147 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 148 return (0); 149 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 150 return (0); 151 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 152 } 153 154 static void 155 amrr_node_init(struct ieee80211_node *ni) 156 { 157 const struct ieee80211_rateset *rs = NULL; 158 struct ieee80211vap *vap = ni->ni_vap; 159 struct ieee80211_amrr *amrr = vap->iv_rs; 160 struct ieee80211_amrr_node *amn; 161 uint8_t rate; 162 163 if (ni->ni_rctls == NULL) { 164 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 165 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 166 if (amn == NULL) { 167 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 168 "structure\n"); 169 return; 170 } 171 } else 172 amn = ni->ni_rctls; 173 amn->amn_amrr = amrr; 174 amn->amn_success = 0; 175 amn->amn_recovery = 0; 176 amn->amn_txcnt = amn->amn_retrycnt = 0; 177 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 178 179 /* 11n or not? Pick the right rateset */ 180 if (amrr_node_is_11n(ni)) { 181 /* XXX ew */ 182 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 183 "%s: 11n node", __func__); 184 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 185 } else { 186 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 187 "%s: non-11n node", __func__); 188 rs = &ni->ni_rates; 189 } 190 191 /* Initial rate - lowest */ 192 rate = rs->rs_rates[0]; 193 194 /* XXX clear the basic rate flag if it's not 11n */ 195 if (! amrr_node_is_11n(ni)) 196 rate &= IEEE80211_RATE_VAL; 197 198 /* pick initial rate from the rateset - HT or otherwise */ 199 /* Pick something low that's likely to succeed */ 200 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 201 amn->amn_rix--) { 202 /* legacy - anything < 36mbit, stop searching */ 203 /* 11n - stop at MCS4 */ 204 if (amrr_node_is_11n(ni)) { 205 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 206 break; 207 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 208 break; 209 } 210 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 211 212 /* if the rate is an 11n rate, ensure the MCS bit is set */ 213 if (amrr_node_is_11n(ni)) 214 rate |= IEEE80211_RATE_MCS; 215 216 /* Assign initial rate from the rateset */ 217 ni->ni_txrate = rate; 218 amn->amn_ticks = ticks; 219 220 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 221 "AMRR: nrates=%d, initial rate %d", 222 rs->rs_nrates, 223 rate); 224 } 225 226 static void 227 amrr_node_deinit(struct ieee80211_node *ni) 228 { 229 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 230 } 231 232 static int 233 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 234 struct ieee80211_node *ni) 235 { 236 int rix = amn->amn_rix; 237 const struct ieee80211_rateset *rs = NULL; 238 239 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 240 241 /* 11n or not? Pick the right rateset */ 242 if (amrr_node_is_11n(ni)) { 243 /* XXX ew */ 244 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 245 } else { 246 rs = &ni->ni_rates; 247 } 248 249 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 250 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 251 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 252 amn->amn_txcnt, 253 amn->amn_retrycnt); 254 255 /* 256 * XXX This is totally bogus for 11n, as although high MCS 257 * rates for each stream may be failing, the next stream 258 * should be checked. 259 * 260 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 261 * MCS23, we should skip 6/7 and try 8 onwards. 262 */ 263 if (is_success(amn)) { 264 amn->amn_success++; 265 if (amn->amn_success >= amn->amn_success_threshold && 266 rix + 1 < rs->rs_nrates) { 267 amn->amn_recovery = 1; 268 amn->amn_success = 0; 269 rix++; 270 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 271 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 272 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 273 amn->amn_txcnt, amn->amn_retrycnt); 274 } else { 275 amn->amn_recovery = 0; 276 } 277 } else if (is_failure(amn)) { 278 amn->amn_success = 0; 279 if (rix > 0) { 280 if (amn->amn_recovery) { 281 amn->amn_success_threshold *= 2; 282 if (amn->amn_success_threshold > 283 amrr->amrr_max_success_threshold) 284 amn->amn_success_threshold = 285 amrr->amrr_max_success_threshold; 286 } else { 287 amn->amn_success_threshold = 288 amrr->amrr_min_success_threshold; 289 } 290 rix--; 291 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 292 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 293 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 294 amn->amn_txcnt, amn->amn_retrycnt); 295 } 296 amn->amn_recovery = 0; 297 } 298 299 /* reset counters */ 300 amn->amn_txcnt = 0; 301 amn->amn_retrycnt = 0; 302 303 return rix; 304 } 305 306 /* 307 * Return the rate index to use in sending a data frame. 308 * Update our internal state if it's been long enough. 309 * If the rate changes we also update ni_txrate to match. 310 */ 311 static int 312 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 313 { 314 struct ieee80211_amrr_node *amn = ni->ni_rctls; 315 struct ieee80211_amrr *amrr = amn->amn_amrr; 316 const struct ieee80211_rateset *rs = NULL; 317 int rix; 318 319 /* 11n or not? Pick the right rateset */ 320 if (amrr_node_is_11n(ni)) { 321 /* XXX ew */ 322 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 323 } else { 324 rs = &ni->ni_rates; 325 } 326 327 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 328 rix = amrr_update(amrr, amn, ni); 329 if (rix != amn->amn_rix) { 330 /* update public rate */ 331 ni->ni_txrate = rs->rs_rates[rix]; 332 /* XXX strip basic rate flag from txrate, if non-11n */ 333 if (amrr_node_is_11n(ni)) 334 ni->ni_txrate |= IEEE80211_RATE_MCS; 335 else 336 ni->ni_txrate &= IEEE80211_RATE_VAL; 337 amn->amn_rix = rix; 338 } 339 amn->amn_ticks = ticks; 340 } else 341 rix = amn->amn_rix; 342 return rix; 343 } 344 345 /* 346 * Update statistics with tx complete status. Ok is non-zero 347 * if the packet is known to be ACK'd. Retries has the number 348 * retransmissions (i.e. xmit attempts - 1). 349 */ 350 static void 351 amrr_tx_complete(const struct ieee80211vap *vap, 352 const struct ieee80211_node *ni, int ok, 353 void *arg1, void *arg2 __unused) 354 { 355 struct ieee80211_amrr_node *amn = ni->ni_rctls; 356 int retries = *(int *)arg1; 357 358 amn->amn_txcnt++; 359 if (ok) 360 amn->amn_success++; 361 amn->amn_retrycnt += retries; 362 } 363 364 /* 365 * Set tx count/retry statistics explicitly. Intended for 366 * drivers that poll the device for statistics maintained 367 * in the device. 368 */ 369 static void 370 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 371 void *arg1, void *arg2, void *arg3) 372 { 373 struct ieee80211_amrr_node *amn = ni->ni_rctls; 374 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 375 376 amn->amn_txcnt = txcnt; 377 amn->amn_success = success; 378 amn->amn_retrycnt = retrycnt; 379 } 380 381 static int 382 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 383 { 384 struct ieee80211vap *vap = arg1; 385 struct ieee80211_amrr *amrr = vap->iv_rs; 386 int msecs = ticks_to_msecs(amrr->amrr_interval); 387 int error; 388 389 error = sysctl_handle_int(oidp, &msecs, 0, req); 390 if (error || !req->newptr) 391 return error; 392 amrr_setinterval(vap, msecs); 393 return 0; 394 } 395 396 static void 397 amrr_sysctlattach(struct ieee80211vap *vap, 398 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 399 { 400 struct ieee80211_amrr *amrr = vap->iv_rs; 401 402 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 403 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 404 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 405 /* XXX bounds check values */ 406 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 407 "amrr_max_sucess_threshold", CTLFLAG_RW, 408 &amrr->amrr_max_success_threshold, 0, ""); 409 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 410 "amrr_min_sucess_threshold", CTLFLAG_RW, 411 &amrr->amrr_min_success_threshold, 0, ""); 412 } 413