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/module.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 ieee80211vap *, 71 const struct ieee80211_node *, int, 72 void *, void *); 73 static void amrr_tx_update(const struct ieee80211vap *vap, 74 const struct ieee80211_node *, void *, void *, void *); 75 static void amrr_sysctlattach(struct ieee80211vap *, 76 struct sysctl_ctx_list *, struct sysctl_oid *); 77 78 /* number of references from net80211 layer */ 79 static int nrefs = 0; 80 81 static const struct ieee80211_ratectl amrr = { 82 .ir_name = "amrr", 83 .ir_attach = NULL, 84 .ir_detach = NULL, 85 .ir_init = amrr_init, 86 .ir_deinit = amrr_deinit, 87 .ir_node_init = amrr_node_init, 88 .ir_node_deinit = amrr_node_deinit, 89 .ir_rate = amrr_rate, 90 .ir_tx_complete = amrr_tx_complete, 91 .ir_tx_update = amrr_tx_update, 92 .ir_setinterval = amrr_setinterval, 93 }; 94 IEEE80211_RATECTL_MODULE(amrr, 1); 95 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 96 97 static void 98 amrr_setinterval(const struct ieee80211vap *vap, int msecs) 99 { 100 struct ieee80211_amrr *amrr = vap->iv_rs; 101 int t; 102 103 if (msecs < 100) 104 msecs = 100; 105 t = msecs_to_ticks(msecs); 106 amrr->amrr_interval = (t < 1) ? 1 : t; 107 } 108 109 static void 110 amrr_init(struct ieee80211vap *vap) 111 { 112 struct ieee80211_amrr *amrr; 113 114 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 115 116 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), 117 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 118 if (amrr == NULL) { 119 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 120 return; 121 } 122 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 123 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 124 amrr_setinterval(vap, 500 /* ms */); 125 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 126 } 127 128 static void 129 amrr_deinit(struct ieee80211vap *vap) 130 { 131 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); 132 } 133 134 /* 135 * Return whether 11n rates are possible. 136 * 137 * Some 11n devices may return HT information but no HT rates. 138 * Thus, we shouldn't treat them as an 11n node. 139 */ 140 static int 141 amrr_node_is_11n(struct ieee80211_node *ni) 142 { 143 144 if (ni->ni_chan == NULL) 145 return (0); 146 if (ni->ni_chan == IEEE80211_CHAN_ANYC) 147 return (0); 148 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) 149 return (0); 150 return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); 151 } 152 153 static void 154 amrr_node_init(struct ieee80211_node *ni) 155 { 156 const struct ieee80211_rateset *rs = NULL; 157 struct ieee80211vap *vap = ni->ni_vap; 158 struct ieee80211_amrr *amrr = vap->iv_rs; 159 struct ieee80211_amrr_node *amn; 160 uint8_t rate; 161 162 if (ni->ni_rctls == NULL) { 163 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), 164 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 165 if (amn == NULL) { 166 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 167 "structure\n"); 168 return; 169 } 170 } else 171 amn = ni->ni_rctls; 172 amn->amn_amrr = amrr; 173 amn->amn_success = 0; 174 amn->amn_recovery = 0; 175 amn->amn_txcnt = amn->amn_retrycnt = 0; 176 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 177 178 /* 11n or not? Pick the right rateset */ 179 if (amrr_node_is_11n(ni)) { 180 /* XXX ew */ 181 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 182 "%s: 11n node", __func__); 183 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 184 } else { 185 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 186 "%s: non-11n node", __func__); 187 rs = &ni->ni_rates; 188 } 189 190 /* Initial rate - lowest */ 191 rate = rs->rs_rates[0]; 192 193 /* XXX clear the basic rate flag if it's not 11n */ 194 if (! amrr_node_is_11n(ni)) 195 rate &= IEEE80211_RATE_VAL; 196 197 /* pick initial rate from the rateset - HT or otherwise */ 198 /* Pick something low that's likely to succeed */ 199 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; 200 amn->amn_rix--) { 201 /* legacy - anything < 36mbit, stop searching */ 202 /* 11n - stop at MCS4 */ 203 if (amrr_node_is_11n(ni)) { 204 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) 205 break; 206 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) 207 break; 208 } 209 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 210 211 /* if the rate is an 11n rate, ensure the MCS bit is set */ 212 if (amrr_node_is_11n(ni)) 213 rate |= IEEE80211_RATE_MCS; 214 215 /* Assign initial rate from the rateset */ 216 ni->ni_txrate = rate; 217 amn->amn_ticks = ticks; 218 219 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 220 "AMRR: nrates=%d, initial rate %d", 221 rs->rs_nrates, 222 rate); 223 } 224 225 static void 226 amrr_node_deinit(struct ieee80211_node *ni) 227 { 228 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); 229 } 230 231 static int 232 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 233 struct ieee80211_node *ni) 234 { 235 int rix = amn->amn_rix; 236 const struct ieee80211_rateset *rs = NULL; 237 238 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 239 240 /* 11n or not? Pick the right rateset */ 241 if (amrr_node_is_11n(ni)) { 242 /* XXX ew */ 243 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 244 } else { 245 rs = &ni->ni_rates; 246 } 247 248 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 249 "AMRR: current rate %d, txcnt=%d, retrycnt=%d", 250 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 251 amn->amn_txcnt, 252 amn->amn_retrycnt); 253 254 /* 255 * XXX This is totally bogus for 11n, as although high MCS 256 * rates for each stream may be failing, the next stream 257 * should be checked. 258 * 259 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to 260 * MCS23, we should skip 6/7 and try 8 onwards. 261 */ 262 if (is_success(amn)) { 263 amn->amn_success++; 264 if (amn->amn_success >= amn->amn_success_threshold && 265 rix + 1 < rs->rs_nrates) { 266 amn->amn_recovery = 1; 267 amn->amn_success = 0; 268 rix++; 269 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 270 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 271 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 272 amn->amn_txcnt, amn->amn_retrycnt); 273 } else { 274 amn->amn_recovery = 0; 275 } 276 } else if (is_failure(amn)) { 277 amn->amn_success = 0; 278 if (rix > 0) { 279 if (amn->amn_recovery) { 280 amn->amn_success_threshold *= 2; 281 if (amn->amn_success_threshold > 282 amrr->amrr_max_success_threshold) 283 amn->amn_success_threshold = 284 amrr->amrr_max_success_threshold; 285 } else { 286 amn->amn_success_threshold = 287 amrr->amrr_min_success_threshold; 288 } 289 rix--; 290 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 291 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 292 rs->rs_rates[rix] & IEEE80211_RATE_VAL, 293 amn->amn_txcnt, amn->amn_retrycnt); 294 } 295 amn->amn_recovery = 0; 296 } 297 298 /* reset counters */ 299 amn->amn_txcnt = 0; 300 amn->amn_retrycnt = 0; 301 302 return rix; 303 } 304 305 /* 306 * Return the rate index to use in sending a data frame. 307 * Update our internal state if it's been long enough. 308 * If the rate changes we also update ni_txrate to match. 309 */ 310 static int 311 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 312 { 313 struct ieee80211_amrr_node *amn = ni->ni_rctls; 314 struct ieee80211_amrr *amrr = amn->amn_amrr; 315 const struct ieee80211_rateset *rs = NULL; 316 int rix; 317 318 /* 11n or not? Pick the right rateset */ 319 if (amrr_node_is_11n(ni)) { 320 /* XXX ew */ 321 rs = (struct ieee80211_rateset *) &ni->ni_htrates; 322 } else { 323 rs = &ni->ni_rates; 324 } 325 326 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 327 rix = amrr_update(amrr, amn, ni); 328 if (rix != amn->amn_rix) { 329 /* update public rate */ 330 ni->ni_txrate = rs->rs_rates[rix]; 331 /* XXX strip basic rate flag from txrate, if non-11n */ 332 if (amrr_node_is_11n(ni)) 333 ni->ni_txrate |= IEEE80211_RATE_MCS; 334 else 335 ni->ni_txrate &= IEEE80211_RATE_VAL; 336 amn->amn_rix = rix; 337 } 338 amn->amn_ticks = ticks; 339 } else 340 rix = amn->amn_rix; 341 return rix; 342 } 343 344 /* 345 * Update statistics with tx complete status. Ok is non-zero 346 * if the packet is known to be ACK'd. Retries has the number 347 * retransmissions (i.e. xmit attempts - 1). 348 */ 349 static void 350 amrr_tx_complete(const struct ieee80211vap *vap, 351 const struct ieee80211_node *ni, int ok, 352 void *arg1, void *arg2 __unused) 353 { 354 struct ieee80211_amrr_node *amn = ni->ni_rctls; 355 int retries = *(int *)arg1; 356 357 amn->amn_txcnt++; 358 if (ok) 359 amn->amn_success++; 360 amn->amn_retrycnt += retries; 361 } 362 363 /* 364 * Set tx count/retry statistics explicitly. Intended for 365 * drivers that poll the device for statistics maintained 366 * in the device. 367 */ 368 static void 369 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 370 void *arg1, void *arg2, void *arg3) 371 { 372 struct ieee80211_amrr_node *amn = ni->ni_rctls; 373 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 374 375 amn->amn_txcnt = txcnt; 376 amn->amn_success = success; 377 amn->amn_retrycnt = retrycnt; 378 } 379 380 static int 381 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 382 { 383 struct ieee80211vap *vap = arg1; 384 struct ieee80211_amrr *amrr = vap->iv_rs; 385 int msecs = ticks_to_msecs(amrr->amrr_interval); 386 int error; 387 388 error = sysctl_handle_int(oidp, &msecs, 0, req); 389 if (error || !req->newptr) 390 return error; 391 amrr_setinterval(vap, msecs); 392 return 0; 393 } 394 395 static void 396 amrr_sysctlattach(struct ieee80211vap *vap, 397 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 398 { 399 struct ieee80211_amrr *amrr = vap->iv_rs; 400 401 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 402 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 403 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 404 /* XXX bounds check values */ 405 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 406 "amrr_max_sucess_threshold", CTLFLAG_RW, 407 &amrr->amrr_max_success_threshold, 0, ""); 408 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 409 "amrr_min_sucess_threshold", CTLFLAG_RW, 410 &amrr->amrr_min_success_threshold, 0, ""); 411 } 412