ieee80211_amrr.c revision 207323
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: head/sys/net80211/ieee80211_amrr.c 207323 2010-04-28 13:25:53Z rpaulo $"); 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_media.h> 42 43#ifdef INET 44#include <netinet/in.h> 45#include <netinet/if_ether.h> 46#endif 47 48#include <net80211/ieee80211_var.h> 49#include <net80211/ieee80211_amrr.h> 50#include <net80211/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 59static void amrr_setinterval(const struct ieee80211vap *, int); 60static void amrr_init(struct ieee80211vap *); 61static void amrr_deinit(struct ieee80211vap *); 62static void amrr_node_init(struct ieee80211_node *); 63static void amrr_node_deinit(struct ieee80211_node *); 64static int amrr_update(struct ieee80211_amrr *, 65 struct ieee80211_amrr_node *, struct ieee80211_node *); 66static int amrr_rate(struct ieee80211_node *, void *, uint32_t); 67static void amrr_tx_complete(const struct ieee80211vap *, 68 const struct ieee80211_node *, int, 69 void *, void *); 70static void amrr_tx_update(const struct ieee80211vap *vap, 71 const struct ieee80211_node *, void *, void *, void *); 72static void amrr_sysctlattach(struct ieee80211vap *, 73 struct sysctl_ctx_list *, struct sysctl_oid *); 74 75/* number of references from net80211 layer */ 76static int nrefs = 0; 77 78static const struct ieee80211_ratectl amrr = { 79 .ir_name = "amrr", 80 .ir_attach = NULL, 81 .ir_detach = NULL, 82 .ir_init = amrr_init, 83 .ir_deinit = amrr_deinit, 84 .ir_node_init = amrr_node_init, 85 .ir_node_deinit = amrr_node_deinit, 86 .ir_rate = amrr_rate, 87 .ir_tx_complete = amrr_tx_complete, 88 .ir_tx_update = amrr_tx_update, 89 .ir_setinterval = amrr_setinterval, 90}; 91IEEE80211_RATECTL_MODULE(amrr, 1); 92IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 93 94static void 95amrr_setinterval(const struct ieee80211vap *vap, int msecs) 96{ 97 struct ieee80211_amrr *amrr = vap->iv_rs; 98 int t; 99 100 if (msecs < 100) 101 msecs = 100; 102 t = msecs_to_ticks(msecs); 103 amrr->amrr_interval = (t < 1) ? 1 : t; 104} 105 106static void 107amrr_init(struct ieee80211vap *vap) 108{ 109 struct ieee80211_amrr *amrr; 110 111 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); 112 113 amrr = vap->iv_rs = malloc(sizeof(struct ieee80211_amrr), 114 M_80211_RATECTL, M_NOWAIT|M_ZERO); 115 if (amrr == NULL) { 116 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); 117 return; 118 } 119 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; 120 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; 121 amrr_setinterval(vap, 500 /* ms */); 122 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); 123} 124 125static void 126amrr_deinit(struct ieee80211vap *vap) 127{ 128 free(vap->iv_rs, M_80211_RATECTL); 129} 130 131static void 132amrr_node_init(struct ieee80211_node *ni) 133{ 134 const struct ieee80211_rateset *rs = &ni->ni_rates; 135 struct ieee80211vap *vap = ni->ni_vap; 136 struct ieee80211_amrr *amrr = vap->iv_rs; 137 struct ieee80211_amrr_node *amn; 138 139 if (ni->ni_rctls == NULL) { 140 ni->ni_rctls = amn = malloc(sizeof(struct ieee80211_amrr_node), 141 M_80211_RATECTL, M_NOWAIT|M_ZERO); 142 if (amn == NULL) { 143 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " 144 "structure\n"); 145 return; 146 } 147 } else 148 amn = ni->ni_rctls; 149 amn->amn_amrr = amrr; 150 amn->amn_success = 0; 151 amn->amn_recovery = 0; 152 amn->amn_txcnt = amn->amn_retrycnt = 0; 153 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 154 155 /* pick initial rate */ 156 for (amn->amn_rix = rs->rs_nrates - 1; 157 amn->amn_rix > 0 && (rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) > 72; 158 amn->amn_rix--) 159 ; 160 ni->ni_txrate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; 161 amn->amn_ticks = ticks; 162 163 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 164 "AMRR initial rate %d", ni->ni_txrate); 165} 166 167static void 168amrr_node_deinit(struct ieee80211_node *ni) 169{ 170 free(ni->ni_rctls, M_80211_RATECTL); 171} 172 173static int 174amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, 175 struct ieee80211_node *ni) 176{ 177 int rix = amn->amn_rix; 178 179 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); 180 181 if (is_success(amn)) { 182 amn->amn_success++; 183 if (amn->amn_success >= amn->amn_success_threshold && 184 rix + 1 < ni->ni_rates.rs_nrates) { 185 amn->amn_recovery = 1; 186 amn->amn_success = 0; 187 rix++; 188 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 189 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", 190 ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL, 191 amn->amn_txcnt, amn->amn_retrycnt); 192 } else { 193 amn->amn_recovery = 0; 194 } 195 } else if (is_failure(amn)) { 196 amn->amn_success = 0; 197 if (rix > 0) { 198 if (amn->amn_recovery) { 199 amn->amn_success_threshold *= 2; 200 if (amn->amn_success_threshold > 201 amrr->amrr_max_success_threshold) 202 amn->amn_success_threshold = 203 amrr->amrr_max_success_threshold; 204 } else { 205 amn->amn_success_threshold = 206 amrr->amrr_min_success_threshold; 207 } 208 rix--; 209 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 210 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", 211 ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL, 212 amn->amn_txcnt, amn->amn_retrycnt); 213 } 214 amn->amn_recovery = 0; 215 } 216 217 /* reset counters */ 218 amn->amn_txcnt = 0; 219 amn->amn_retrycnt = 0; 220 221 return rix; 222} 223 224/* 225 * Return the rate index to use in sending a data frame. 226 * Update our internal state if it's been long enough. 227 * If the rate changes we also update ni_txrate to match. 228 */ 229static int 230amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) 231{ 232 struct ieee80211_amrr_node *amn = ni->ni_rctls; 233 struct ieee80211_amrr *amrr = amn->amn_amrr; 234 int rix; 235 236 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { 237 rix = amrr_update(amrr, amn, ni); 238 if (rix != amn->amn_rix) { 239 /* update public rate */ 240 ni->ni_txrate = 241 ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL; 242 amn->amn_rix = rix; 243 } 244 amn->amn_ticks = ticks; 245 } else 246 rix = amn->amn_rix; 247 return rix; 248} 249 250/* 251 * Update statistics with tx complete status. Ok is non-zero 252 * if the packet is known to be ACK'd. Retries has the number 253 * retransmissions (i.e. xmit attempts - 1). 254 */ 255static void 256amrr_tx_complete(const struct ieee80211vap *vap, 257 const struct ieee80211_node *ni, int ok, 258 void *arg1, void *arg2 __unused) 259{ 260 struct ieee80211_amrr_node *amn = ni->ni_rctls; 261 int retries = *(int *)arg1; 262 263 amn->amn_txcnt++; 264 if (ok) 265 amn->amn_success++; 266 amn->amn_retrycnt += retries; 267} 268 269/* 270 * Set tx count/retry statistics explicitly. Intended for 271 * drivers that poll the device for statistics maintained 272 * in the device. 273 */ 274static void 275amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, 276 void *arg1, void *arg2, void *arg3) 277{ 278 struct ieee80211_amrr_node *amn = ni->ni_rctls; 279 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; 280 281 amn->amn_txcnt = txcnt; 282 amn->amn_success = success; 283 amn->amn_retrycnt = retrycnt; 284} 285 286static int 287amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) 288{ 289 struct ieee80211vap *vap = arg1; 290 struct ieee80211_amrr *amrr = vap->iv_rs; 291 int msecs = ticks_to_msecs(amrr->amrr_interval); 292 int error; 293 294 error = sysctl_handle_int(oidp, &msecs, 0, req); 295 if (error || !req->newptr) 296 return error; 297 amrr_setinterval(vap, msecs); 298 return 0; 299} 300 301static void 302amrr_sysctlattach(struct ieee80211vap *vap, 303 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) 304{ 305 struct ieee80211_amrr *amrr = vap->iv_rs; 306 307 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 308 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 309 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); 310 /* XXX bounds check values */ 311 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 312 "amrr_max_sucess_threshold", CTLFLAG_RW, 313 &amrr->amrr_max_success_threshold, 0, ""); 314 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 315 "amrr_min_sucess_threshold", CTLFLAG_RW, 316 &amrr->amrr_min_success_threshold, 0, ""); 317} 318