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_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 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 75 /* number of references from net80211 layer */ 76 static int nrefs = 0; 77 78 static 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 }; 91 IEEE80211_RATECTL_MODULE(amrr, 1); 92 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); 93 94 static void 95 amrr_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 } 105 106 static void 107 amrr_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 } 124 125 static void 126 amrr_deinit(struct ieee80211vap *vap) 127 { 128 free(vap->iv_rs, M_80211_RATECTL); 129 } 130 131 static void 132 amrr_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 } 166 167 static void 168 amrr_node_deinit(struct ieee80211_node *ni) 169 { 170 free(ni->ni_rctls, M_80211_RATECTL); 171 } 172 173 static int 174 amrr_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 */ 229 static int 230 amrr_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 */ 255 static void 256 amrr_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 */ 274 static void 275 amrr_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 } 285 286 static int 287 amrr_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 } 300 301 static void 302 amrr_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_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 312 "amrr_max_sucess_threshold", CTLFLAG_RW, 313 &amrr->amrr_max_success_threshold, 0, ""); 314 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 315 "amrr_min_sucess_threshold", CTLFLAG_RW, 316 &amrr->amrr_min_success_threshold, 0, ""); 317 } 318