1 /* $NetBSD: ieee80211_rssadapt.c,v 1.17 2009/10/19 23:19:39 rmind Exp $ */ 2 /*- 3 * Copyright (c) 2003, 2004 David Young. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or 6 * without modification, are permitted provided that the following 7 * conditions are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following 12 * disclaimer in the documentation and/or other materials provided 13 * with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 18 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David 19 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 21 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 26 * OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #ifdef __NetBSD__ 31 __KERNEL_RCSID(0, "$NetBSD: ieee80211_rssadapt.c,v 1.17 2009/10/19 23:19:39 rmind Exp $"); 32 #endif 33 34 #include <sys/param.h> 35 #include <sys/types.h> 36 #include <sys/kernel.h> /* for hz */ 37 #include <sys/sysctl.h> 38 39 #include <net/if.h> 40 #include <net/if_media.h> 41 #include <net/if_ether.h> 42 43 #include <net80211/ieee80211_netbsd.h> 44 #include <net80211/ieee80211_var.h> 45 #include <net80211/ieee80211.h> 46 #include <net80211/ieee80211_rssadapt.h> 47 48 #ifdef interpolate 49 #undef interpolate 50 #endif 51 #define interpolate(parm, old, new) ((parm##_old * (old) + \ 52 (parm##_denom - parm##_old) * (new)) / \ 53 parm##_denom) 54 55 #ifdef IEEE80211_DEBUG 56 static struct timeval lastrateadapt; /* time of last rate adaptation msg */ 57 static int currssadaptps = 0; /* rate-adaptation msgs this second */ 58 static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */ 59 60 #define RSSADAPT_DO_PRINT() \ 61 ((ieee80211_rssadapt_debug > 0) && \ 62 ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate)) 63 #define RSSADAPT_PRINTF(X) \ 64 if (RSSADAPT_DO_PRINT()) \ 65 printf X 66 67 int ieee80211_rssadapt_debug = 0; 68 69 #else 70 #define RSSADAPT_DO_PRINT() (0) 71 #define RSSADAPT_PRINTF(X) 72 #endif 73 74 static struct ieee80211_rssadapt_expavgctl master_expavgctl = { 75 .rc_decay_denom = 16, 76 .rc_decay_old = 15, 77 .rc_thresh_denom = 8, 78 .rc_thresh_old = 4, 79 .rc_avgrssi_denom = 8, 80 .rc_avgrssi_old = 4 81 }; 82 83 #ifdef __NetBSD__ 84 #ifdef IEEE80211_DEBUG 85 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */ 86 static int 87 sysctl_ieee80211_rssadapt_debug(SYSCTLFN_ARGS) 88 { 89 int error, t; 90 struct sysctlnode node; 91 92 node = *rnode; 93 t = *(int*)rnode->sysctl_data; 94 node.sysctl_data = &t; 95 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 96 if (error || newp == NULL) 97 return (error); 98 99 if (t < 0 || t > 2) 100 return (EINVAL); 101 *(int*)rnode->sysctl_data = t; 102 103 return (0); 104 } 105 #endif /* IEEE80211_DEBUG */ 106 107 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */ 108 static int 109 sysctl_ieee80211_rssadapt_expavgctl(SYSCTLFN_ARGS) 110 { 111 struct ieee80211_rssadapt_expavgctl rc; 112 int error; 113 struct sysctlnode node; 114 115 node = *rnode; 116 rc = *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data; 117 node.sysctl_data = &rc; 118 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 119 if (error || newp == NULL) 120 return (error); 121 122 if (/* rc.rc_decay_old < 0 || */ 123 rc.rc_decay_denom < rc.rc_decay_old) 124 return (EINVAL); 125 126 if (/* rc.rc_thresh_old < 0 || */ 127 rc.rc_thresh_denom < rc.rc_thresh_old) 128 return (EINVAL); 129 130 if (/* rc.rc_avgrssi_old < 0 || */ 131 rc.rc_avgrssi_denom < rc.rc_avgrssi_old) 132 return (EINVAL); 133 134 *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data = rc; 135 136 return (0); 137 } 138 139 /* 140 * Setup sysctl(3) MIB, net.ieee80211.* 141 * 142 * TBD condition CTLFLAG_PERMANENT on being a module or not 143 */ 144 SYSCTL_SETUP(sysctl_ieee80211_rssadapt, 145 "sysctl ieee80211 rssadapt subtree setup") 146 { 147 int rc; 148 const struct sysctlnode *node; 149 150 if ((rc = sysctl_createv(clog, 0, NULL, &node, 151 CTLFLAG_PERMANENT, CTLTYPE_NODE, "net", NULL, 152 NULL, 0, NULL, 0, CTL_NET, CTL_EOL)) != 0) 153 goto err; 154 155 if ((rc = sysctl_createv(clog, 0, &node, &node, 156 CTLFLAG_PERMANENT, CTLTYPE_NODE, "link", NULL, 157 NULL, 0, NULL, 0, PF_LINK, CTL_EOL)) != 0) 158 goto err; 159 160 if ((rc = sysctl_createv(clog, 0, &node, &node, 161 CTLFLAG_PERMANENT, CTLTYPE_NODE, "ieee80211", NULL, 162 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0) 163 goto err; 164 165 if ((rc = sysctl_createv(clog, 0, &node, &node, 166 CTLFLAG_PERMANENT, CTLTYPE_NODE, "rssadapt", 167 SYSCTL_DESCR("Received Signal Strength adaptation controls"), 168 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0) 169 goto err; 170 171 #ifdef IEEE80211_DEBUG 172 /* control debugging printfs */ 173 if ((rc = sysctl_createv(clog, 0, &node, NULL, 174 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "debug", 175 SYSCTL_DESCR("Enable RSS adaptation debugging output"), 176 sysctl_ieee80211_rssadapt_debug, 0, &ieee80211_rssadapt_debug, 0, 177 CTL_CREATE, CTL_EOL)) != 0) 178 goto err; 179 #endif /* IEEE80211_DEBUG */ 180 181 /* control rate of decay for exponential averages */ 182 if ((rc = sysctl_createv(clog, 0, &node, NULL, 183 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_STRUCT, 184 "expavgctl", SYSCTL_DESCR("RSS exponential averaging control"), 185 sysctl_ieee80211_rssadapt_expavgctl, 0, 186 &master_expavgctl, sizeof(master_expavgctl), CTL_CREATE, 187 CTL_EOL)) != 0) 188 goto err; 189 190 return; 191 err: 192 printf("%s: sysctl_createv failed (rc = %d)\n", __func__, rc); 193 } 194 #endif /* __NetBSD__ */ 195 196 int 197 ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra, 198 struct ieee80211_rateset *rs, struct ieee80211_frame *wh, u_int len, 199 int fixed_rate, const char *dvname, int do_not_adapt) 200 { 201 u_int16_t (*thrs)[IEEE80211_RATE_SIZE]; 202 int flags = 0, i, rateidx = 0, thridx, top; 203 204 if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL) 205 flags |= IEEE80211_RATE_BASIC; 206 207 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 208 i < IEEE80211_RSSADAPT_BKTS; 209 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 210 thridx = i; 211 if (len <= top) 212 break; 213 } 214 215 thrs = &ra->ra_rate_thresh[thridx]; 216 217 if (fixed_rate != -1) { 218 if ((rs->rs_rates[fixed_rate] & flags) == flags) { 219 rateidx = fixed_rate; 220 goto out; 221 } 222 flags |= IEEE80211_RATE_BASIC; 223 i = fixed_rate; 224 } else 225 i = rs->rs_nrates; 226 227 while (--i >= 0) { 228 rateidx = i; 229 if ((rs->rs_rates[i] & flags) != flags) 230 continue; 231 if (do_not_adapt) 232 break; 233 if ((*thrs)[i] < ra->ra_avg_rssi) 234 break; 235 } 236 237 out: 238 #ifdef IEEE80211_DEBUG 239 if (ieee80211_rssadapt_debug && dvname != NULL) { 240 printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n", 241 dvname, ether_sprintf(wh->i_addr1), len, 242 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2, 243 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10, 244 (*thrs)[rateidx], ra->ra_avg_rssi); 245 } 246 #endif /* IEEE80211_DEBUG */ 247 return rateidx; 248 } 249 250 void 251 ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra) 252 { 253 long interval; 254 255 ra->ra_pktrate = 256 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2; 257 ra->ra_nfail = ra->ra_nok = 0; 258 259 /* a node is eligible for its rate to be raised every 1/10 to 10 260 * seconds, more eligible in proportion to recent packet rates. 261 */ 262 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate)); 263 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000); 264 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000); 265 } 266 267 void 268 ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni, 269 struct ieee80211_rssadapt *ra, int rssi) 270 { 271 #ifdef IEEE80211_DEBUG 272 int last_avg_rssi = ra->ra_avg_rssi; 273 #endif 274 275 ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi, 276 ra->ra_avg_rssi, (rssi << 8)); 277 278 RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n", 279 ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr), 280 rssi, last_avg_rssi, ra->ra_avg_rssi)); 281 } 282 283 /* 284 * Adapt the data rate to suit the conditions. When a transmitted 285 * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions, 286 * raise the RSS threshold for transmitting packets of similar length at 287 * the same data rate. 288 */ 289 void 290 ieee80211_rssadapt_lower_rate(struct ieee80211com *ic, 291 struct ieee80211_node *ni, struct ieee80211_rssadapt *ra, 292 struct ieee80211_rssdesc *id) 293 { 294 struct ieee80211_rateset *rs = &ni->ni_rates; 295 u_int16_t last_thr; 296 u_int i, thridx, top; 297 298 ra->ra_nfail++; 299 300 if (id->id_rateidx >= rs->rs_nrates) { 301 RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: " 302 "%s rate #%d > #%d out of bounds\n", 303 ether_sprintf(ni->ni_macaddr), id->id_rateidx, 304 rs->rs_nrates - 1)); 305 return; 306 } 307 308 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 309 i < IEEE80211_RSSADAPT_BKTS; 310 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 311 thridx = i; 312 if (id->id_len <= top) 313 break; 314 } 315 316 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx]; 317 ra->ra_rate_thresh[thridx][id->id_rateidx] = 318 interpolate(master_expavgctl.rc_thresh, last_thr, 319 (id->id_rssi << 8)); 320 321 RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n", 322 ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr), 323 id->id_rssi, id->id_len, 324 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2, 325 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10, 326 last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx])); 327 } 328 329 void 330 ieee80211_rssadapt_raise_rate(struct ieee80211com *ic, 331 struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id) 332 { 333 u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr; 334 struct ieee80211_node *ni = id->id_node; 335 struct ieee80211_rateset *rs = &ni->ni_rates; 336 int i, rate, top; 337 #ifdef IEEE80211_DEBUG 338 int j; 339 #endif 340 341 ra->ra_nok++; 342 343 if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval)) 344 return; 345 346 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 347 i < IEEE80211_RSSADAPT_BKTS; 348 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 349 thrs = &ra->ra_rate_thresh[i]; 350 if (id->id_len <= top) 351 break; 352 } 353 354 if (id->id_rateidx + 1 < rs->rs_nrates && 355 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) { 356 rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL); 357 358 RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ", 359 ic->ic_ifp->if_xname, 360 IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i), 361 rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1])); 362 oldthr = (*thrs)[id->id_rateidx + 1]; 363 if ((*thrs)[id->id_rateidx] == 0) 364 newthr = ra->ra_avg_rssi; 365 else 366 newthr = (*thrs)[id->id_rateidx]; 367 (*thrs)[id->id_rateidx + 1] = 368 interpolate(master_expavgctl.rc_decay, oldthr, newthr); 369 370 RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1])); 371 } 372 373 #ifdef IEEE80211_DEBUG 374 if (RSSADAPT_DO_PRINT()) { 375 printf("%s: dst %s thresholds\n", ic->ic_ifp->if_xname, 376 ether_sprintf(ni->ni_macaddr)); 377 for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) { 378 printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i)); 379 for (j = 0; j < rs->rs_nrates; j++) { 380 rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL); 381 printf(", T[%d.%d] = %d", rate / 2, 382 rate * 5 % 10, ra->ra_rate_thresh[i][j]); 383 } 384 printf("\n"); 385 } 386 } 387 #endif /* IEEE80211_DEBUG */ 388 } 389