1 /* 2 * ACS - Automatic Channel Selection module 3 * Copyright (c) 2011, Atheros Communications 4 * Copyright (c) 2013, Qualcomm Atheros, Inc. 5 * 6 * This software may be distributed under the terms of the BSD license. 7 * See README for more details. 8 */ 9 10 #include "utils/includes.h" 11 #include <math.h> 12 13 #include "utils/common.h" 14 #include "utils/list.h" 15 #include "utils/eloop.h" 16 #include "common/ieee802_11_defs.h" 17 #include "common/hw_features_common.h" 18 #include "common/wpa_ctrl.h" 19 #include "drivers/driver.h" 20 #include "hostapd.h" 21 #include "ap_drv_ops.h" 22 #include "ap_config.h" 23 #include "hw_features.h" 24 #include "acs.h" 25 26 /* 27 * Automatic Channel Selection 28 * =========================== 29 * 30 * More info at 31 * ------------ 32 * http://wireless.kernel.org/en/users/Documentation/acs 33 * 34 * How to use 35 * ---------- 36 * - make sure you have CONFIG_ACS=y in hostapd's .config 37 * - use channel=0 or channel=acs to enable ACS 38 * 39 * How does it work 40 * ---------------- 41 * 1. passive scans are used to collect survey data 42 * (it is assumed that scan trigger collection of survey data in driver) 43 * 2. interference factor is calculated for each channel 44 * 3. ideal channel is picked depending on channel width by using adjacent 45 * channel interference factors 46 * 47 * Known limitations 48 * ----------------- 49 * - Current implementation depends heavily on the amount of time willing to 50 * spend gathering survey data during hostapd startup. Short traffic bursts 51 * may be missed and a suboptimal channel may be picked. 52 * - Ideal channel may end up overlapping a channel with 40 MHz intolerant BSS 53 * 54 * Todo / Ideas 55 * ------------ 56 * - implement other interference computation methods 57 * - BSS/RSSI based 58 * - spectral scan based 59 * (should be possibly to hook this up with current ACS scans) 60 * - add wpa_supplicant support (for P2P) 61 * - collect a histogram of interference over time allowing more educated 62 * guess about an ideal channel (perhaps CSA could be used to migrate AP to a 63 * new "better" channel while running) 64 * - include neighboring BSS scan to avoid conflicts with 40 MHz intolerant BSSs 65 * when choosing the ideal channel 66 * 67 * Survey interference factor implementation details 68 * ------------------------------------------------- 69 * Generic interference_factor in struct hostapd_channel_data is used. 70 * 71 * The survey interference factor is defined as the ratio of the 72 * observed busy time over the time we spent on the channel, 73 * this value is then amplified by the observed noise floor on 74 * the channel in comparison to the lowest noise floor observed 75 * on the entire band. 76 * 77 * This corresponds to: 78 * --- 79 * (busy time - tx time) / (active time - tx time) * 2^(chan_nf - band_min_nf) 80 * --- 81 * 82 * The coefficient of 2 reflects the way power in "far-field" 83 * radiation decreases as the square of distance from the antenna [1]. 84 * What this does is it decreases the observed busy time ratio if the 85 * noise observed was low but increases it if the noise was high, 86 * proportionally to the way "far field" radiation changes over 87 * distance. 88 * 89 * If channel busy time is not available the fallback is to use channel RX time. 90 * 91 * Since noise floor is in dBm it is necessary to convert it into Watts so that 92 * combined channel interference (e.g., HT40, which uses two channels) can be 93 * calculated easily. 94 * --- 95 * (busy time - tx time) / (active time - tx time) * 96 * 2^(10^(chan_nf/10) - 10^(band_min_nf/10)) 97 * --- 98 * 99 * However to account for cases where busy/rx time is 0 (channel load is then 100 * 0%) channel noise floor signal power is combined into the equation so a 101 * channel with lower noise floor is preferred. The equation becomes: 102 * --- 103 * 10^(chan_nf/5) + (busy time - tx time) / (active time - tx time) * 104 * 2^(10^(chan_nf/10) - 10^(band_min_nf/10)) 105 * --- 106 * 107 * All this "interference factor" is purely subjective and only time 108 * will tell how usable this is. By using the minimum noise floor we 109 * remove any possible issues due to card calibration. The computation 110 * of the interference factor then is dependent on what the card itself 111 * picks up as the minimum noise, not an actual real possible card 112 * noise value. 113 * 114 * Total interference computation details 115 * -------------------------------------- 116 * The above channel interference factor is calculated with no respect to 117 * target operational bandwidth. 118 * 119 * To find an ideal channel the above data is combined by taking into account 120 * the target operational bandwidth and selected band. E.g., on 2.4 GHz channels 121 * overlap with 20 MHz bandwidth, but there is no overlap for 20 MHz bandwidth 122 * on 5 GHz. 123 * 124 * Each valid and possible channel spec (i.e., channel + width) is taken and its 125 * interference factor is computed by summing up interferences of each channel 126 * it overlaps. The one with least total interference is picked up. 127 * 128 * Note: This implies base channel interference factor must be non-negative 129 * allowing easy summing up. 130 * 131 * Example ACS analysis printout 132 * ----------------------------- 133 * 134 * ACS: Trying survey-based ACS 135 * ACS: Survey analysis for channel 1 (2412 MHz) 136 * ACS: 1: min_nf=-113 interference_factor=0.0802469 nf=-113 time=162 busy=0 rx=13 137 * ACS: 2: min_nf=-113 interference_factor=0.0745342 nf=-113 time=161 busy=0 rx=12 138 * ACS: 3: min_nf=-113 interference_factor=0.0679012 nf=-113 time=162 busy=0 rx=11 139 * ACS: 4: min_nf=-113 interference_factor=0.0310559 nf=-113 time=161 busy=0 rx=5 140 * ACS: 5: min_nf=-113 interference_factor=0.0248447 nf=-113 time=161 busy=0 rx=4 141 * ACS: * interference factor average: 0.0557166 142 * ACS: Survey analysis for channel 2 (2417 MHz) 143 * ACS: 1: min_nf=-113 interference_factor=0.0185185 nf=-113 time=162 busy=0 rx=3 144 * ACS: 2: min_nf=-113 interference_factor=0.0246914 nf=-113 time=162 busy=0 rx=4 145 * ACS: 3: min_nf=-113 interference_factor=0.037037 nf=-113 time=162 busy=0 rx=6 146 * ACS: 4: min_nf=-113 interference_factor=0.149068 nf=-113 time=161 busy=0 rx=24 147 * ACS: 5: min_nf=-113 interference_factor=0.0248447 nf=-113 time=161 busy=0 rx=4 148 * ACS: * interference factor average: 0.050832 149 * ACS: Survey analysis for channel 3 (2422 MHz) 150 * ACS: 1: min_nf=-113 interference_factor=2.51189e-23 nf=-113 time=162 busy=0 rx=0 151 * ACS: 2: min_nf=-113 interference_factor=0.0185185 nf=-113 time=162 busy=0 rx=3 152 * ACS: 3: min_nf=-113 interference_factor=0.0186335 nf=-113 time=161 busy=0 rx=3 153 * ACS: 4: min_nf=-113 interference_factor=0.0186335 nf=-113 time=161 busy=0 rx=3 154 * ACS: 5: min_nf=-113 interference_factor=0.0186335 nf=-113 time=161 busy=0 rx=3 155 * ACS: * interference factor average: 0.0148838 156 * ACS: Survey analysis for channel 4 (2427 MHz) 157 * ACS: 1: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 158 * ACS: 2: min_nf=-114 interference_factor=0.0555556 nf=-114 time=162 busy=0 rx=9 159 * ACS: 3: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=161 busy=0 rx=0 160 * ACS: 4: min_nf=-114 interference_factor=0.0186335 nf=-114 time=161 busy=0 rx=3 161 * ACS: 5: min_nf=-114 interference_factor=0.00621118 nf=-114 time=161 busy=0 rx=1 162 * ACS: * interference factor average: 0.0160801 163 * ACS: Survey analysis for channel 5 (2432 MHz) 164 * ACS: 1: min_nf=-114 interference_factor=0.409938 nf=-113 time=161 busy=0 rx=66 165 * ACS: 2: min_nf=-114 interference_factor=0.0432099 nf=-113 time=162 busy=0 rx=7 166 * ACS: 3: min_nf=-114 interference_factor=0.0124224 nf=-113 time=161 busy=0 rx=2 167 * ACS: 4: min_nf=-114 interference_factor=0.677019 nf=-113 time=161 busy=0 rx=109 168 * ACS: 5: min_nf=-114 interference_factor=0.0186335 nf=-114 time=161 busy=0 rx=3 169 * ACS: * interference factor average: 0.232244 170 * ACS: Survey analysis for channel 6 (2437 MHz) 171 * ACS: 1: min_nf=-113 interference_factor=0.552795 nf=-113 time=161 busy=0 rx=89 172 * ACS: 2: min_nf=-113 interference_factor=0.0807453 nf=-112 time=161 busy=0 rx=13 173 * ACS: 3: min_nf=-113 interference_factor=0.0310559 nf=-113 time=161 busy=0 rx=5 174 * ACS: 4: min_nf=-113 interference_factor=0.434783 nf=-112 time=161 busy=0 rx=70 175 * ACS: 5: min_nf=-113 interference_factor=0.0621118 nf=-113 time=161 busy=0 rx=10 176 * ACS: * interference factor average: 0.232298 177 * ACS: Survey analysis for channel 7 (2442 MHz) 178 * ACS: 1: min_nf=-113 interference_factor=0.440994 nf=-112 time=161 busy=0 rx=71 179 * ACS: 2: min_nf=-113 interference_factor=0.385093 nf=-113 time=161 busy=0 rx=62 180 * ACS: 3: min_nf=-113 interference_factor=0.0372671 nf=-113 time=161 busy=0 rx=6 181 * ACS: 4: min_nf=-113 interference_factor=0.0372671 nf=-113 time=161 busy=0 rx=6 182 * ACS: 5: min_nf=-113 interference_factor=0.0745342 nf=-113 time=161 busy=0 rx=12 183 * ACS: * interference factor average: 0.195031 184 * ACS: Survey analysis for channel 8 (2447 MHz) 185 * ACS: 1: min_nf=-114 interference_factor=0.0496894 nf=-112 time=161 busy=0 rx=8 186 * ACS: 2: min_nf=-114 interference_factor=0.0496894 nf=-114 time=161 busy=0 rx=8 187 * ACS: 3: min_nf=-114 interference_factor=0.0372671 nf=-113 time=161 busy=0 rx=6 188 * ACS: 4: min_nf=-114 interference_factor=0.12963 nf=-113 time=162 busy=0 rx=21 189 * ACS: 5: min_nf=-114 interference_factor=0.166667 nf=-114 time=162 busy=0 rx=27 190 * ACS: * interference factor average: 0.0865885 191 * ACS: Survey analysis for channel 9 (2452 MHz) 192 * ACS: 1: min_nf=-114 interference_factor=0.0124224 nf=-114 time=161 busy=0 rx=2 193 * ACS: 2: min_nf=-114 interference_factor=0.0310559 nf=-114 time=161 busy=0 rx=5 194 * ACS: 3: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=161 busy=0 rx=0 195 * ACS: 4: min_nf=-114 interference_factor=0.00617284 nf=-114 time=162 busy=0 rx=1 196 * ACS: 5: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 197 * ACS: * interference factor average: 0.00993022 198 * ACS: Survey analysis for channel 10 (2457 MHz) 199 * ACS: 1: min_nf=-114 interference_factor=0.00621118 nf=-114 time=161 busy=0 rx=1 200 * ACS: 2: min_nf=-114 interference_factor=0.00621118 nf=-114 time=161 busy=0 rx=1 201 * ACS: 3: min_nf=-114 interference_factor=0.00621118 nf=-114 time=161 busy=0 rx=1 202 * ACS: 4: min_nf=-114 interference_factor=0.0493827 nf=-114 time=162 busy=0 rx=8 203 * ACS: 5: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 204 * ACS: * interference factor average: 0.0136033 205 * ACS: Survey analysis for channel 11 (2462 MHz) 206 * ACS: 1: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=161 busy=0 rx=0 207 * ACS: 2: min_nf=-114 interference_factor=2.51189e-23 nf=-113 time=161 busy=0 rx=0 208 * ACS: 3: min_nf=-114 interference_factor=2.51189e-23 nf=-113 time=161 busy=0 rx=0 209 * ACS: 4: min_nf=-114 interference_factor=0.0432099 nf=-114 time=162 busy=0 rx=7 210 * ACS: 5: min_nf=-114 interference_factor=0.0925926 nf=-114 time=162 busy=0 rx=15 211 * ACS: * interference factor average: 0.0271605 212 * ACS: Survey analysis for channel 12 (2467 MHz) 213 * ACS: 1: min_nf=-114 interference_factor=0.0621118 nf=-113 time=161 busy=0 rx=10 214 * ACS: 2: min_nf=-114 interference_factor=0.00621118 nf=-114 time=161 busy=0 rx=1 215 * ACS: 3: min_nf=-114 interference_factor=2.51189e-23 nf=-113 time=162 busy=0 rx=0 216 * ACS: 4: min_nf=-114 interference_factor=2.51189e-23 nf=-113 time=162 busy=0 rx=0 217 * ACS: 5: min_nf=-114 interference_factor=0.00617284 nf=-113 time=162 busy=0 rx=1 218 * ACS: * interference factor average: 0.0148992 219 * ACS: Survey analysis for channel 13 (2472 MHz) 220 * ACS: 1: min_nf=-114 interference_factor=0.0745342 nf=-114 time=161 busy=0 rx=12 221 * ACS: 2: min_nf=-114 interference_factor=0.0555556 nf=-114 time=162 busy=0 rx=9 222 * ACS: 3: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 223 * ACS: 4: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 224 * ACS: 5: min_nf=-114 interference_factor=1.58489e-23 nf=-114 time=162 busy=0 rx=0 225 * ACS: * interference factor average: 0.0260179 226 * ACS: Survey analysis for selected bandwidth 20MHz 227 * ACS: * channel 1: total interference = 0.121432 228 * ACS: * channel 2: total interference = 0.137512 229 * ACS: * channel 3: total interference = 0.369757 230 * ACS: * channel 4: total interference = 0.546338 231 * ACS: * channel 5: total interference = 0.690538 232 * ACS: * channel 6: total interference = 0.762242 233 * ACS: * channel 7: total interference = 0.756092 234 * ACS: * channel 8: total interference = 0.537451 235 * ACS: * channel 9: total interference = 0.332313 236 * ACS: * channel 10: total interference = 0.152182 237 * ACS: * channel 11: total interference = 0.0916111 238 * ACS: * channel 12: total interference = 0.0816809 239 * ACS: * channel 13: total interference = 0.0680776 240 * ACS: Ideal channel is 13 (2472 MHz) with total interference factor of 0.0680776 241 * 242 * [1] http://en.wikipedia.org/wiki/Near_and_far_field 243 */ 244 245 enum bw_type { 246 ACS_BW40, 247 ACS_BW80, 248 ACS_BW160, 249 ACS_BW320_1, 250 ACS_BW320_2, 251 }; 252 253 struct bw_item { 254 int first; 255 int last; 256 int center_chan; 257 }; 258 259 static const struct bw_item bw_40[] = { 260 { 5180, 5200, 38 }, { 5220, 5240, 46 }, { 5260, 5280, 54 }, 261 { 5300, 5320, 62 }, { 5500, 5520, 102 }, { 5540, 5560, 110 }, 262 { 5580, 5600, 118 }, { 5620, 5640, 126 }, { 5660, 5680, 134 }, 263 { 5700, 5720, 142 }, { 5745, 5765, 151 }, { 5785, 5805, 159 }, 264 { 5825, 5845, 167 }, { 5865, 5885, 175 }, 265 { 5955, 5975, 3 }, { 5995, 6015, 11 }, { 6035, 6055, 19 }, 266 { 6075, 6095, 27 }, { 6115, 6135, 35 }, { 6155, 6175, 43 }, 267 { 6195, 6215, 51 }, { 6235, 6255, 59 }, { 6275, 6295, 67 }, 268 { 6315, 6335, 75 }, { 6355, 6375, 83 }, { 6395, 6415, 91 }, 269 { 6435, 6455, 99 }, { 6475, 6495, 107 }, { 6515, 6535, 115 }, 270 { 6555, 6575, 123 }, { 6595, 6615, 131 }, { 6635, 6655, 139 }, 271 { 6675, 6695, 147 }, { 6715, 6735, 155 }, { 6755, 6775, 163 }, 272 { 6795, 6815, 171 }, { 6835, 6855, 179 }, { 6875, 6895, 187 }, 273 { 6915, 6935, 195 }, { 6955, 6975, 203 }, { 6995, 7015, 211 }, 274 { 7035, 7055, 219 }, { 7075, 7095, 227}, { -1, -1, -1 } 275 }; 276 static const struct bw_item bw_80[] = { 277 { 5180, 5240, 42 }, { 5260, 5320, 58 }, { 5500, 5560, 106 }, 278 { 5580, 5640, 122 }, { 5660, 5720, 138 }, { 5745, 5805, 155 }, 279 { 5825, 5885, 171}, 280 { 5955, 6015, 7 }, { 6035, 6095, 23 }, { 6115, 6175, 39 }, 281 { 6195, 6255, 55 }, { 6275, 6335, 71 }, { 6355, 6415, 87 }, 282 { 6435, 6495, 103 }, { 6515, 6575, 119 }, { 6595, 6655, 135 }, 283 { 6675, 6735, 151 }, { 6755, 6815, 167 }, { 6835, 6895, 183 }, 284 { 6915, 6975, 199 }, { 6995, 7055, 215 }, { -1, -1, -1 } 285 }; 286 static const struct bw_item bw_160[] = { 287 { 5180, 5320, 50 }, { 5500, 5640, 114 }, { 5745, 5885, 163 }, 288 { 5955, 6095, 15 }, { 6115, 6255, 47 }, { 6275, 6415, 79 }, 289 { 6435, 6575, 111 }, { 6595, 6735, 143 }, 290 { 6755, 6895, 175 }, { 6915, 7055, 207 }, { -1, -1, -1 } 291 }; 292 static const struct bw_item bw_320_1[] = { 293 { 5955, 6255, 31 }, { 6275, 6575, 95 }, { 6595, 6895, 159 }, 294 { -1, -1, -1 } 295 }; 296 static const struct bw_item bw_320_2[] = { 297 { 6115, 6415, 63 }, { 6435, 6735, 127 }, { 6755, 7055, 191 }, 298 { -1, -1, -1 } 299 }; 300 static const struct bw_item *bw_desc[] = { 301 [ACS_BW40] = bw_40, 302 [ACS_BW80] = bw_80, 303 [ACS_BW160] = bw_160, 304 [ACS_BW320_1] = bw_320_1, 305 [ACS_BW320_2] = bw_320_2, 306 }; 307 308 309 static int acs_request_scan(struct hostapd_iface *iface); 310 static int acs_survey_is_sufficient(struct freq_survey *survey); 311 static void acs_scan_retry(void *eloop_data, void *user_data); 312 313 314 static void acs_clean_chan_surveys(struct hostapd_channel_data *chan) 315 { 316 struct freq_survey *survey, *tmp; 317 318 if (dl_list_empty(&chan->survey_list)) 319 return; 320 321 dl_list_for_each_safe(survey, tmp, &chan->survey_list, 322 struct freq_survey, list) { 323 dl_list_del(&survey->list); 324 os_free(survey); 325 } 326 } 327 328 329 static void acs_cleanup_mode(struct hostapd_hw_modes *mode) 330 { 331 int i; 332 struct hostapd_channel_data *chan; 333 334 for (i = 0; i < mode->num_channels; i++) { 335 chan = &mode->channels[i]; 336 337 if (chan->flag & HOSTAPD_CHAN_SURVEY_LIST_INITIALIZED) 338 acs_clean_chan_surveys(chan); 339 340 dl_list_init(&chan->survey_list); 341 chan->flag |= HOSTAPD_CHAN_SURVEY_LIST_INITIALIZED; 342 chan->min_nf = 0; 343 chan->punct_bitmap = 0; 344 } 345 } 346 347 348 void acs_cleanup(struct hostapd_iface *iface) 349 { 350 int i; 351 352 for (i = 0; i < iface->num_hw_features; i++) 353 acs_cleanup_mode(&iface->hw_features[i]); 354 355 iface->chans_surveyed = 0; 356 iface->acs_num_completed_scans = 0; 357 iface->acs_num_retries = 0; 358 eloop_cancel_timeout(acs_scan_retry, iface, NULL); 359 } 360 361 362 static void acs_fail(struct hostapd_iface *iface) 363 { 364 wpa_printf(MSG_ERROR, "ACS: Failed to start"); 365 acs_cleanup(iface); 366 hostapd_disable_iface(iface); 367 } 368 369 370 static long double 371 acs_survey_interference_factor(struct freq_survey *survey, s8 min_nf) 372 { 373 long double factor, busy, total; 374 375 if (survey->filled & SURVEY_HAS_CHAN_TIME_BUSY) 376 busy = survey->channel_time_busy; 377 else if (survey->filled & SURVEY_HAS_CHAN_TIME_RX) 378 busy = survey->channel_time_rx; 379 else { 380 wpa_printf(MSG_ERROR, "ACS: Survey data missing"); 381 return 0; 382 } 383 384 total = survey->channel_time; 385 386 if (survey->filled & SURVEY_HAS_CHAN_TIME_TX) { 387 busy -= survey->channel_time_tx; 388 total -= survey->channel_time_tx; 389 } 390 391 /* TODO: figure out the best multiplier for noise floor base */ 392 factor = pow(10, survey->nf / 5.0L) + 393 (total ? (busy / total) : 0) * 394 pow(2, pow(10, (long double) survey->nf / 10.0L) - 395 pow(10, (long double) min_nf / 10.0L)); 396 397 return factor; 398 } 399 400 401 static void 402 acs_survey_chan_interference_factor(struct hostapd_iface *iface, 403 struct hostapd_channel_data *chan) 404 { 405 struct freq_survey *survey; 406 unsigned int i = 0; 407 long double int_factor = 0; 408 unsigned count = 0; 409 410 if (dl_list_empty(&chan->survey_list) || 411 (chan->flag & HOSTAPD_CHAN_DISABLED)) 412 return; 413 414 chan->interference_factor = 0; 415 416 dl_list_for_each(survey, &chan->survey_list, struct freq_survey, list) 417 { 418 i++; 419 420 if (!acs_survey_is_sufficient(survey)) { 421 wpa_printf(MSG_DEBUG, "ACS: %d: insufficient data", i); 422 continue; 423 } 424 425 count++; 426 int_factor = acs_survey_interference_factor(survey, 427 iface->lowest_nf); 428 chan->interference_factor += int_factor; 429 wpa_printf(MSG_DEBUG, "ACS: %d: min_nf=%d interference_factor=%Lg nf=%d time=%lu busy=%lu rx=%lu", 430 i, chan->min_nf, int_factor, 431 survey->nf, (unsigned long) survey->channel_time, 432 (unsigned long) survey->channel_time_busy, 433 (unsigned long) survey->channel_time_rx); 434 } 435 436 if (count) 437 chan->interference_factor /= count; 438 } 439 440 441 static bool acs_usable_bw_chan(const struct hostapd_channel_data *chan, 442 enum bw_type bw) 443 { 444 unsigned int i = 0; 445 446 while (bw_desc[bw][i].first != -1) { 447 if (chan->freq == bw_desc[bw][i].first) 448 return true; 449 i++; 450 } 451 452 return false; 453 } 454 455 456 static int acs_get_bw_center_chan(int freq, enum bw_type bw) 457 { 458 unsigned int i = 0; 459 460 while (bw_desc[bw][i].first != -1) { 461 if (freq >= bw_desc[bw][i].first && 462 freq <= bw_desc[bw][i].last) 463 return bw_desc[bw][i].center_chan; 464 i++; 465 } 466 467 return 0; 468 } 469 470 471 static int acs_survey_is_sufficient(struct freq_survey *survey) 472 { 473 if (!(survey->filled & SURVEY_HAS_NF)) { 474 wpa_printf(MSG_INFO, 475 "ACS: Survey for freq %d is missing noise floor", 476 survey->freq); 477 return 0; 478 } 479 480 if (!(survey->filled & SURVEY_HAS_CHAN_TIME)) { 481 wpa_printf(MSG_INFO, 482 "ACS: Survey for freq %d is missing channel time", 483 survey->freq); 484 return 0; 485 } 486 487 if (!(survey->filled & SURVEY_HAS_CHAN_TIME_BUSY) && 488 !(survey->filled & SURVEY_HAS_CHAN_TIME_RX)) { 489 wpa_printf(MSG_INFO, 490 "ACS: Survey for freq %d is missing RX and busy time (at least one is required)", 491 survey->freq); 492 return 0; 493 } 494 495 return 1; 496 } 497 498 499 static int acs_survey_list_is_sufficient(struct hostapd_channel_data *chan) 500 { 501 struct freq_survey *survey; 502 int ret = -1; 503 504 dl_list_for_each(survey, &chan->survey_list, struct freq_survey, list) 505 { 506 if (acs_survey_is_sufficient(survey)) { 507 ret = 1; 508 break; 509 } 510 ret = 0; 511 } 512 513 if (ret == -1) 514 ret = 0; /* no survey list entries */ 515 516 if (!ret) { 517 wpa_printf(MSG_INFO, 518 "ACS: Channel %d has insufficient survey data", 519 chan->chan); 520 } 521 522 return ret; 523 } 524 525 526 static int acs_surveys_are_sufficient_mode(struct hostapd_hw_modes *mode) 527 { 528 int i; 529 struct hostapd_channel_data *chan; 530 531 for (i = 0; i < mode->num_channels; i++) { 532 chan = &mode->channels[i]; 533 if (!(chan->flag & HOSTAPD_CHAN_DISABLED) && 534 acs_survey_list_is_sufficient(chan)) 535 return 1; 536 } 537 538 return 0; 539 } 540 541 542 static int acs_surveys_are_sufficient(struct hostapd_iface *iface) 543 { 544 int i; 545 struct hostapd_hw_modes *mode; 546 547 for (i = 0; i < iface->num_hw_features; i++) { 548 mode = &iface->hw_features[i]; 549 if (!hostapd_hw_skip_mode(iface, mode) && 550 acs_surveys_are_sufficient_mode(mode)) 551 return 1; 552 } 553 554 return 0; 555 } 556 557 558 static int acs_usable_chan(struct hostapd_channel_data *chan) 559 { 560 return !dl_list_empty(&chan->survey_list) && 561 !(chan->flag & HOSTAPD_CHAN_DISABLED) && 562 acs_survey_list_is_sufficient(chan); 563 } 564 565 566 static int is_in_chanlist(struct hostapd_iface *iface, 567 struct hostapd_channel_data *chan) 568 { 569 if (!iface->conf->acs_ch_list.num) 570 return 1; 571 572 return freq_range_list_includes(&iface->conf->acs_ch_list, chan->chan); 573 } 574 575 576 static int is_in_freqlist(struct hostapd_iface *iface, 577 struct hostapd_channel_data *chan) 578 { 579 if (!iface->conf->acs_freq_list.num) 580 return 1; 581 582 return freq_range_list_includes(&iface->conf->acs_freq_list, 583 chan->freq); 584 } 585 586 587 static void acs_survey_mode_interference_factor( 588 struct hostapd_iface *iface, struct hostapd_hw_modes *mode) 589 { 590 int i; 591 struct hostapd_channel_data *chan; 592 593 for (i = 0; i < mode->num_channels; i++) { 594 chan = &mode->channels[i]; 595 596 if (!acs_usable_chan(chan)) 597 continue; 598 599 if ((chan->flag & HOSTAPD_CHAN_RADAR) && 600 iface->conf->acs_exclude_dfs) 601 continue; 602 603 if (!is_in_chanlist(iface, chan)) 604 continue; 605 606 if (!is_in_freqlist(iface, chan)) 607 continue; 608 609 if (chan->max_tx_power < iface->conf->min_tx_power) 610 continue; 611 612 if ((chan->flag & HOSTAPD_CHAN_INDOOR_ONLY) && 613 iface->conf->country[2] == 0x4f) 614 continue; 615 616 wpa_printf(MSG_DEBUG, "ACS: Survey analysis for channel %d (%d MHz)", 617 chan->chan, chan->freq); 618 619 acs_survey_chan_interference_factor(iface, chan); 620 621 wpa_printf(MSG_DEBUG, "ACS: * interference factor average: %Lg", 622 chan->interference_factor); 623 } 624 } 625 626 627 static void acs_survey_all_chans_interference_factor( 628 struct hostapd_iface *iface) 629 { 630 int i; 631 struct hostapd_hw_modes *mode; 632 633 for (i = 0; i < iface->num_hw_features; i++) { 634 mode = &iface->hw_features[i]; 635 if (!hostapd_hw_skip_mode(iface, mode)) 636 acs_survey_mode_interference_factor(iface, mode); 637 } 638 } 639 640 641 static struct hostapd_channel_data * 642 acs_find_chan_mode(struct hostapd_hw_modes *mode, int freq) 643 { 644 struct hostapd_channel_data *chan; 645 int i; 646 647 for (i = 0; i < mode->num_channels; i++) { 648 chan = &mode->channels[i]; 649 650 if (chan->flag & HOSTAPD_CHAN_DISABLED) 651 continue; 652 653 if (chan->freq == freq) 654 return chan; 655 } 656 657 return NULL; 658 } 659 660 661 static enum hostapd_hw_mode 662 acs_find_mode(struct hostapd_iface *iface, int freq) 663 { 664 int i; 665 struct hostapd_hw_modes *mode; 666 struct hostapd_channel_data *chan; 667 668 for (i = 0; i < iface->num_hw_features; i++) { 669 mode = &iface->hw_features[i]; 670 if (!hostapd_hw_skip_mode(iface, mode)) { 671 chan = acs_find_chan_mode(mode, freq); 672 if (chan) 673 return mode->mode; 674 } 675 } 676 677 return HOSTAPD_MODE_IEEE80211ANY; 678 } 679 680 681 static struct hostapd_channel_data * 682 acs_find_chan(struct hostapd_iface *iface, int freq) 683 { 684 int i; 685 struct hostapd_hw_modes *mode; 686 struct hostapd_channel_data *chan; 687 688 for (i = 0; i < iface->num_hw_features; i++) { 689 mode = &iface->hw_features[i]; 690 if (!hostapd_hw_skip_mode(iface, mode)) { 691 chan = acs_find_chan_mode(mode, freq); 692 if (chan) 693 return chan; 694 } 695 } 696 697 return NULL; 698 } 699 700 701 static int is_24ghz_mode(enum hostapd_hw_mode mode) 702 { 703 return mode == HOSTAPD_MODE_IEEE80211B || 704 mode == HOSTAPD_MODE_IEEE80211G; 705 } 706 707 708 static int is_common_24ghz_chan(int chan) 709 { 710 return chan == 1 || chan == 6 || chan == 11; 711 } 712 713 714 #ifndef ACS_ADJ_WEIGHT 715 #define ACS_ADJ_WEIGHT 0.85 716 #endif /* ACS_ADJ_WEIGHT */ 717 718 #ifndef ACS_NEXT_ADJ_WEIGHT 719 #define ACS_NEXT_ADJ_WEIGHT 0.55 720 #endif /* ACS_NEXT_ADJ_WEIGHT */ 721 722 #ifndef ACS_24GHZ_PREFER_1_6_11 723 /* 724 * Select commonly used channels 1, 6, 11 by default even if a neighboring 725 * channel has a smaller interference factor as long as it is not better by more 726 * than this multiplier. 727 */ 728 #define ACS_24GHZ_PREFER_1_6_11 0.8 729 #endif /* ACS_24GHZ_PREFER_1_6_11 */ 730 731 732 #ifdef CONFIG_IEEE80211BE 733 static void acs_update_puncturing_bitmap(struct hostapd_iface *iface, 734 struct hostapd_hw_modes *mode, u32 bw, 735 int n_chans, 736 struct hostapd_channel_data *chan, 737 long double factor, 738 int index_primary) 739 { 740 struct hostapd_config *conf = iface->conf; 741 struct hostapd_channel_data *adj_chan = NULL, *first_chan = chan; 742 int i; 743 long double threshold; 744 745 /* 746 * If threshold is 0 or user configured puncturing pattern is 747 * available then don't add additional puncturing. 748 */ 749 if (!conf->punct_acs_threshold || conf->punct_bitmap) 750 return; 751 752 if (is_24ghz_mode(mode->mode) || bw < 80) 753 return; 754 755 threshold = factor * conf->punct_acs_threshold / 100; 756 for (i = 0; i < n_chans; i++) { 757 int adj_freq; 758 759 if (i == index_primary) 760 continue; /* Cannot puncture primary channel */ 761 762 if (i > index_primary) 763 adj_freq = chan->freq + (i - index_primary) * 20; 764 else 765 adj_freq = chan->freq - (index_primary - i) * 20; 766 767 adj_chan = acs_find_chan(iface, adj_freq); 768 if (!adj_chan) { 769 chan->punct_bitmap = 0; 770 return; 771 } 772 773 if (i == 0) 774 first_chan = adj_chan; 775 776 if (adj_chan->interference_factor > threshold) 777 chan->punct_bitmap |= BIT(i); 778 } 779 780 if (!is_punct_bitmap_valid(bw, (chan->freq - first_chan->freq) / 20, 781 chan->punct_bitmap)) 782 chan->punct_bitmap = 0; 783 } 784 #endif /* CONFIG_IEEE80211BE */ 785 786 787 static bool 788 acs_usable_bw320_chan(struct hostapd_iface *iface, 789 struct hostapd_channel_data *chan, int *bw320_offset) 790 { 791 const char *bw320_str[] = { "320 MHz", "320 MHz-1", "320 MHz-2" }; 792 int conf_bw320_offset = hostapd_get_bw320_offset(iface->conf); 793 794 *bw320_offset = 0; 795 switch (conf_bw320_offset) { 796 case 1: 797 if (acs_usable_bw_chan(chan, ACS_BW320_1)) 798 *bw320_offset = 1; 799 break; 800 case 2: 801 if (acs_usable_bw_chan(chan, ACS_BW320_2)) 802 *bw320_offset = 2; 803 break; 804 case 0: 805 default: 806 conf_bw320_offset = 0; 807 if (acs_usable_bw_chan(chan, ACS_BW320_1)) 808 *bw320_offset = 1; 809 else if (acs_usable_bw_chan(chan, ACS_BW320_2)) 810 *bw320_offset = 2; 811 break; 812 } 813 814 if (!*bw320_offset) 815 wpa_printf(MSG_DEBUG, 816 "ACS: Channel %d: not allowed as primary channel for %s bandwidth", 817 chan->chan, bw320_str[conf_bw320_offset]); 818 819 return *bw320_offset != 0; 820 } 821 822 823 static void 824 acs_find_ideal_chan_mode(struct hostapd_iface *iface, 825 struct hostapd_hw_modes *mode, 826 int n_chans, u32 bw, 827 struct hostapd_channel_data **rand_chan, 828 struct hostapd_channel_data **ideal_chan, 829 long double *ideal_factor) 830 { 831 struct hostapd_channel_data *chan, *adj_chan = NULL, *best; 832 long double factor; 833 int i, j; 834 int bw320_offset = 0, ideal_bw320_offset = 0; 835 unsigned int k; 836 int secondary_channel = 1, freq_offset; 837 #ifdef CONFIG_IEEE80211BE 838 int index_primary = 0; 839 #endif /* CONFIG_IEEE80211BE */ 840 841 if (is_24ghz_mode(mode->mode)) 842 secondary_channel = iface->conf->secondary_channel; 843 844 for (i = 0; i < mode->num_channels; i++) { 845 double total_weight = 0; 846 struct acs_bias *bias, tmp_bias; 847 848 chan = &mode->channels[i]; 849 850 /* Since in the current ACS implementation the first channel is 851 * always a primary channel, skip channels not available as 852 * primary until more sophisticated channel selection is 853 * implemented. 854 * 855 * If this implementation is changed to allow any channel in 856 * the bandwidth to be the primary one, the last parameter to 857 * acs_update_puncturing_bitmap() should be changed to the index 858 * of the primary channel 859 */ 860 if (!chan_pri_allowed(chan)) 861 continue; 862 863 if ((chan->flag & HOSTAPD_CHAN_RADAR) && 864 iface->conf->acs_exclude_dfs) 865 continue; 866 867 if (!is_in_chanlist(iface, chan)) 868 continue; 869 870 if (!is_in_freqlist(iface, chan)) 871 continue; 872 873 if (chan->max_tx_power < iface->conf->min_tx_power) 874 continue; 875 876 if ((chan->flag & HOSTAPD_CHAN_INDOOR_ONLY) && 877 iface->conf->country[2] == 0x4f) 878 continue; 879 880 if (!chan_bw_allowed(chan, bw, secondary_channel != -1, 1)) { 881 wpa_printf(MSG_DEBUG, 882 "ACS: Channel %d: BW %u is not supported", 883 chan->chan, bw); 884 continue; 885 } 886 887 /* HT40 on 5 GHz has a limited set of primary channels as per 888 * 11n Annex J */ 889 if (mode->mode == HOSTAPD_MODE_IEEE80211A && 890 ((iface->conf->ieee80211n && 891 iface->conf->secondary_channel) || 892 is_6ghz_freq(chan->freq)) && 893 !acs_usable_bw_chan(chan, ACS_BW40)) { 894 wpa_printf(MSG_DEBUG, 895 "ACS: Channel %d: not allowed as primary channel for 40 MHz bandwidth", 896 chan->chan); 897 continue; 898 } 899 900 if (mode->mode == HOSTAPD_MODE_IEEE80211A && 901 (iface->conf->ieee80211ac || iface->conf->ieee80211ax || 902 iface->conf->ieee80211be)) { 903 if (hostapd_get_oper_chwidth(iface->conf) == 904 CONF_OPER_CHWIDTH_80MHZ && 905 !acs_usable_bw_chan(chan, ACS_BW80)) { 906 wpa_printf(MSG_DEBUG, 907 "ACS: Channel %d: not allowed as primary channel for 80 MHz bandwidth", 908 chan->chan); 909 continue; 910 } 911 912 if (hostapd_get_oper_chwidth(iface->conf) == 913 CONF_OPER_CHWIDTH_160MHZ && 914 !acs_usable_bw_chan(chan, ACS_BW160)) { 915 wpa_printf(MSG_DEBUG, 916 "ACS: Channel %d: not allowed as primary channel for 160 MHz bandwidth", 917 chan->chan); 918 continue; 919 } 920 } 921 922 if (mode->mode == HOSTAPD_MODE_IEEE80211A && 923 iface->conf->ieee80211be) { 924 if (hostapd_get_oper_chwidth(iface->conf) == 925 CONF_OPER_CHWIDTH_320MHZ && 926 !acs_usable_bw320_chan(iface, chan, &bw320_offset)) 927 continue; 928 } 929 930 factor = 0; 931 best = NULL; 932 if (acs_usable_chan(chan)) { 933 factor = chan->interference_factor; 934 total_weight = 1; 935 best = chan; 936 } 937 938 for (j = 1; j < n_chans; j++) { 939 adj_chan = acs_find_chan(iface, chan->freq + 940 j * secondary_channel * 20); 941 if (!adj_chan) 942 break; 943 944 if (!chan_bw_allowed(adj_chan, bw, 1, 0)) { 945 wpa_printf(MSG_DEBUG, 946 "ACS: PRI Channel %d: secondary channel %d BW %u is not supported", 947 chan->chan, adj_chan->chan, bw); 948 break; 949 } 950 951 if (!acs_usable_chan(adj_chan)) 952 continue; 953 954 factor += adj_chan->interference_factor; 955 total_weight += 1; 956 957 /* find the best channel in this segment */ 958 if (!best || adj_chan->interference_factor < 959 best->interference_factor) 960 best = adj_chan; 961 } 962 963 if (j != n_chans) { 964 wpa_printf(MSG_DEBUG, "ACS: Channel %d: not enough bandwidth", 965 chan->chan); 966 continue; 967 } 968 969 /* If the AP is in the 5 GHz or 6 GHz band, lets prefer a less 970 * crowded primary channel if one was found in the segment */ 971 if (iface->current_mode && 972 iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A && 973 best && chan != best) { 974 wpa_printf(MSG_DEBUG, 975 "ACS: promoting channel %d over %d (less interference %Lg/%Lg)", 976 best->chan, chan->chan, 977 chan->interference_factor, 978 best->interference_factor); 979 #ifdef CONFIG_IEEE80211BE 980 index_primary = (chan->freq - best->freq) / 20; 981 #endif /* CONFIG_IEEE80211BE */ 982 chan = best; 983 } 984 985 /* 2.4 GHz has overlapping 20 MHz channels. Include adjacent 986 * channel interference factor. */ 987 if (is_24ghz_mode(mode->mode)) { 988 for (j = 0; j < n_chans; j++) { 989 freq_offset = j * 20 * secondary_channel; 990 adj_chan = acs_find_chan(iface, chan->freq + 991 freq_offset - 5); 992 if (adj_chan && acs_usable_chan(adj_chan)) { 993 factor += ACS_ADJ_WEIGHT * 994 adj_chan->interference_factor; 995 total_weight += ACS_ADJ_WEIGHT; 996 } 997 998 adj_chan = acs_find_chan(iface, chan->freq + 999 freq_offset - 10); 1000 if (adj_chan && acs_usable_chan(adj_chan)) { 1001 factor += ACS_NEXT_ADJ_WEIGHT * 1002 adj_chan->interference_factor; 1003 total_weight += ACS_NEXT_ADJ_WEIGHT; 1004 } 1005 1006 adj_chan = acs_find_chan(iface, chan->freq + 1007 freq_offset + 5); 1008 if (adj_chan && acs_usable_chan(adj_chan)) { 1009 factor += ACS_ADJ_WEIGHT * 1010 adj_chan->interference_factor; 1011 total_weight += ACS_ADJ_WEIGHT; 1012 } 1013 1014 adj_chan = acs_find_chan(iface, chan->freq + 1015 freq_offset + 10); 1016 if (adj_chan && acs_usable_chan(adj_chan)) { 1017 factor += ACS_NEXT_ADJ_WEIGHT * 1018 adj_chan->interference_factor; 1019 total_weight += ACS_NEXT_ADJ_WEIGHT; 1020 } 1021 } 1022 } 1023 1024 if (total_weight == 0) 1025 continue; 1026 1027 factor /= total_weight; 1028 1029 bias = NULL; 1030 if (iface->conf->acs_chan_bias) { 1031 for (k = 0; k < iface->conf->num_acs_chan_bias; k++) { 1032 bias = &iface->conf->acs_chan_bias[k]; 1033 if (bias->channel == chan->chan) 1034 break; 1035 bias = NULL; 1036 } 1037 } else if (is_24ghz_mode(mode->mode) && 1038 is_common_24ghz_chan(chan->chan)) { 1039 tmp_bias.channel = chan->chan; 1040 tmp_bias.bias = ACS_24GHZ_PREFER_1_6_11; 1041 bias = &tmp_bias; 1042 } 1043 1044 if (bias) { 1045 factor *= bias->bias; 1046 wpa_printf(MSG_DEBUG, 1047 "ACS: * channel %d: total interference = %Lg (%f bias)", 1048 chan->chan, factor, bias->bias); 1049 } else { 1050 wpa_printf(MSG_DEBUG, 1051 "ACS: * channel %d: total interference = %Lg", 1052 chan->chan, factor); 1053 } 1054 1055 if (acs_usable_chan(chan) && 1056 (!*ideal_chan || factor < *ideal_factor)) { 1057 /* Reset puncturing bitmap for the previous ideal 1058 * channel */ 1059 if (*ideal_chan) 1060 (*ideal_chan)->punct_bitmap = 0; 1061 1062 *ideal_factor = factor; 1063 *ideal_chan = chan; 1064 ideal_bw320_offset = bw320_offset; 1065 1066 #ifdef CONFIG_IEEE80211BE 1067 if (iface->conf->ieee80211be) 1068 acs_update_puncturing_bitmap(iface, mode, bw, 1069 n_chans, chan, 1070 factor, 1071 index_primary); 1072 #endif /* CONFIG_IEEE80211BE */ 1073 } 1074 1075 /* This channel would at least be usable */ 1076 if (!(*rand_chan)) { 1077 *rand_chan = chan; 1078 ideal_bw320_offset = bw320_offset; 1079 } 1080 } 1081 1082 hostapd_set_and_check_bw320_offset(iface->conf, ideal_bw320_offset); 1083 } 1084 1085 1086 /* 1087 * At this point it's assumed chan->interference_factor has been computed. 1088 * This function should be reusable regardless of interference computation 1089 * option (survey, BSS, spectral, ...). chan->interference factor must be 1090 * summable (i.e., must be always greater than zero). 1091 */ 1092 static struct hostapd_channel_data * 1093 acs_find_ideal_chan(struct hostapd_iface *iface) 1094 { 1095 struct hostapd_channel_data *ideal_chan = NULL, 1096 *rand_chan = NULL; 1097 long double ideal_factor = 0; 1098 int i; 1099 int n_chans = 1; 1100 u32 bw; 1101 struct hostapd_hw_modes *mode; 1102 1103 if (is_6ghz_op_class(iface->conf->op_class)) { 1104 bw = op_class_to_bandwidth(iface->conf->op_class); 1105 n_chans = bw / 20; 1106 goto bw_selected; 1107 } 1108 1109 if (iface->conf->ieee80211n && 1110 iface->conf->secondary_channel) 1111 n_chans = 2; 1112 1113 if (iface->conf->ieee80211ac || iface->conf->ieee80211ax || 1114 iface->conf->ieee80211be) { 1115 switch (hostapd_get_oper_chwidth(iface->conf)) { 1116 case CONF_OPER_CHWIDTH_80MHZ: 1117 n_chans = 4; 1118 break; 1119 case CONF_OPER_CHWIDTH_160MHZ: 1120 n_chans = 8; 1121 break; 1122 case CONF_OPER_CHWIDTH_320MHZ: 1123 n_chans = 16; 1124 break; 1125 default: 1126 break; 1127 } 1128 } 1129 1130 bw = num_chan_to_bw(n_chans); 1131 1132 bw_selected: 1133 /* TODO: VHT/HE80+80. Update acs_adjust_center_freq() too. */ 1134 1135 wpa_printf(MSG_DEBUG, 1136 "ACS: Survey analysis for selected bandwidth %d MHz", bw); 1137 1138 for (i = 0; i < iface->num_hw_features; i++) { 1139 mode = &iface->hw_features[i]; 1140 if (!hostapd_hw_skip_mode(iface, mode)) 1141 acs_find_ideal_chan_mode(iface, mode, n_chans, bw, 1142 &rand_chan, &ideal_chan, 1143 &ideal_factor); 1144 } 1145 1146 if (ideal_chan) { 1147 wpa_printf(MSG_DEBUG, "ACS: Ideal channel is %d (%d MHz) with total interference factor of %Lg", 1148 ideal_chan->chan, ideal_chan->freq, ideal_factor); 1149 1150 #ifdef CONFIG_IEEE80211BE 1151 if (iface->conf->punct_acs_threshold) 1152 wpa_printf(MSG_DEBUG, "ACS: RU puncturing bitmap 0x%x", 1153 ideal_chan->punct_bitmap); 1154 #endif /* CONFIG_IEEE80211BE */ 1155 1156 return ideal_chan; 1157 } 1158 1159 return rand_chan; 1160 } 1161 1162 1163 static void acs_adjust_secondary(struct hostapd_iface *iface) 1164 { 1165 unsigned int i; 1166 1167 /* When working with bandwidth over 20 MHz on the 5 GHz or 6 GHz band, 1168 * ACS can return a secondary channel which is not the first channel of 1169 * the segment and we need to adjust. */ 1170 if (!iface->conf->secondary_channel || 1171 acs_find_mode(iface, iface->freq) != HOSTAPD_MODE_IEEE80211A) 1172 return; 1173 1174 wpa_printf(MSG_DEBUG, 1175 "ACS: Adjusting HT/VHT/HE/EHT secondary frequency"); 1176 1177 for (i = 0; bw_desc[ACS_BW40][i].first != -1; i++) { 1178 if (iface->freq == bw_desc[ACS_BW40][i].first) 1179 iface->conf->secondary_channel = 1; 1180 else if (iface->freq == bw_desc[ACS_BW40][i].last) 1181 iface->conf->secondary_channel = -1; 1182 } 1183 } 1184 1185 1186 static void acs_adjust_center_freq(struct hostapd_iface *iface) 1187 { 1188 int center; 1189 1190 wpa_printf(MSG_DEBUG, "ACS: Adjusting center frequency"); 1191 1192 switch (hostapd_get_oper_chwidth(iface->conf)) { 1193 case CONF_OPER_CHWIDTH_USE_HT: 1194 if (iface->conf->secondary_channel && 1195 iface->freq >= 2400 && iface->freq < 2500) 1196 center = iface->conf->channel + 1197 2 * iface->conf->secondary_channel; 1198 else if (iface->conf->secondary_channel) 1199 center = acs_get_bw_center_chan(iface->freq, ACS_BW40); 1200 else 1201 center = iface->conf->channel; 1202 break; 1203 case CONF_OPER_CHWIDTH_80MHZ: 1204 center = acs_get_bw_center_chan(iface->freq, ACS_BW80); 1205 break; 1206 case CONF_OPER_CHWIDTH_160MHZ: 1207 center = acs_get_bw_center_chan(iface->freq, ACS_BW160); 1208 break; 1209 case CONF_OPER_CHWIDTH_320MHZ: 1210 switch (hostapd_get_bw320_offset(iface->conf)) { 1211 case 1: 1212 center = acs_get_bw_center_chan(iface->freq, 1213 ACS_BW320_1); 1214 break; 1215 case 2: 1216 center = acs_get_bw_center_chan(iface->freq, 1217 ACS_BW320_2); 1218 break; 1219 default: 1220 wpa_printf(MSG_INFO, 1221 "ACS: BW320 offset is not selected"); 1222 return; 1223 } 1224 1225 break; 1226 default: 1227 /* TODO: How can this be calculated? Adjust 1228 * acs_find_ideal_chan() */ 1229 wpa_printf(MSG_INFO, 1230 "ACS: Only VHT20/40/80/160/320 is supported now"); 1231 return; 1232 } 1233 1234 hostapd_set_oper_centr_freq_seg0_idx(iface->conf, center); 1235 } 1236 1237 1238 static int acs_study_survey_based(struct hostapd_iface *iface) 1239 { 1240 wpa_printf(MSG_DEBUG, "ACS: Trying survey-based ACS"); 1241 1242 if (!iface->chans_surveyed) { 1243 wpa_printf(MSG_ERROR, "ACS: Unable to collect survey data"); 1244 return -1; 1245 } 1246 1247 if (!acs_surveys_are_sufficient(iface)) { 1248 wpa_printf(MSG_ERROR, "ACS: Surveys have insufficient data"); 1249 return -1; 1250 } 1251 1252 acs_survey_all_chans_interference_factor(iface); 1253 return 0; 1254 } 1255 1256 1257 static int acs_study_options(struct hostapd_iface *iface) 1258 { 1259 if (acs_study_survey_based(iface) == 0) 1260 return 0; 1261 1262 /* TODO: If no surveys are available/sufficient this is a good 1263 * place to fallback to BSS-based ACS */ 1264 1265 return -1; 1266 } 1267 1268 1269 static void acs_study(struct hostapd_iface *iface) 1270 { 1271 struct hostapd_channel_data *ideal_chan; 1272 int err; 1273 1274 err = acs_study_options(iface); 1275 if (err < 0) { 1276 wpa_printf(MSG_ERROR, "ACS: All study options have failed"); 1277 goto fail; 1278 } 1279 1280 ideal_chan = acs_find_ideal_chan(iface); 1281 if (!ideal_chan) { 1282 wpa_printf(MSG_ERROR, "ACS: Failed to compute ideal channel"); 1283 err = -1; 1284 goto fail; 1285 } 1286 1287 iface->conf->channel = ideal_chan->chan; 1288 iface->freq = ideal_chan->freq; 1289 #ifdef CONFIG_IEEE80211BE 1290 iface->conf->punct_bitmap = ideal_chan->punct_bitmap; 1291 #endif /* CONFIG_IEEE80211BE */ 1292 1293 if (iface->conf->ieee80211ac || iface->conf->ieee80211ax || 1294 iface->conf->ieee80211be) { 1295 acs_adjust_secondary(iface); 1296 acs_adjust_center_freq(iface); 1297 } 1298 1299 err = hostapd_select_hw_mode(iface); 1300 if (err) { 1301 wpa_printf(MSG_ERROR, 1302 "ACS: Could not (err: %d) select hw_mode for freq=%d channel=%d", 1303 err, iface->freq, iface->conf->channel); 1304 err = -1; 1305 goto fail; 1306 } 1307 1308 err = 0; 1309 fail: 1310 /* 1311 * hostapd_setup_interface_complete() will return -1 on failure, 1312 * 0 on success and 0 is HOSTAPD_CHAN_VALID :) 1313 */ 1314 if (hostapd_acs_completed(iface, err) == HOSTAPD_CHAN_VALID) { 1315 acs_cleanup(iface); 1316 return; 1317 } 1318 1319 /* This can possibly happen if channel parameters (secondary 1320 * channel, center frequencies) are misconfigured */ 1321 wpa_printf(MSG_ERROR, "ACS: Possibly channel configuration is invalid, please report this along with your config file."); 1322 acs_fail(iface); 1323 } 1324 1325 1326 static void acs_scan_complete(struct hostapd_iface *iface) 1327 { 1328 int err; 1329 1330 iface->scan_cb = NULL; 1331 iface->acs_num_retries = 0; 1332 1333 wpa_printf(MSG_DEBUG, "ACS: Using survey based algorithm (acs_num_scans=%d)", 1334 iface->conf->acs_num_scans); 1335 1336 err = hostapd_drv_get_survey(iface->bss[0], 0); 1337 if (err) { 1338 wpa_printf(MSG_ERROR, "ACS: Failed to get survey data"); 1339 goto fail; 1340 } 1341 1342 if (++iface->acs_num_completed_scans < iface->conf->acs_num_scans) { 1343 err = acs_request_scan(iface); 1344 if (err && err != -EBUSY) { 1345 wpa_printf(MSG_ERROR, "ACS: Failed to request scan"); 1346 goto fail; 1347 } 1348 1349 return; 1350 } 1351 1352 acs_study(iface); 1353 return; 1354 fail: 1355 hostapd_acs_completed(iface, 1); 1356 acs_fail(iface); 1357 } 1358 1359 1360 static int * acs_request_scan_add_freqs(struct hostapd_iface *iface, 1361 struct hostapd_hw_modes *mode, 1362 int *freq) 1363 { 1364 struct hostapd_channel_data *chan; 1365 int i; 1366 1367 for (i = 0; i < mode->num_channels; i++) { 1368 chan = &mode->channels[i]; 1369 if ((chan->flag & HOSTAPD_CHAN_DISABLED) || 1370 ((chan->flag & HOSTAPD_CHAN_RADAR) && 1371 iface->conf->acs_exclude_dfs)) 1372 continue; 1373 1374 if (!is_in_chanlist(iface, chan)) 1375 continue; 1376 1377 if (!is_in_freqlist(iface, chan)) 1378 continue; 1379 1380 if (chan->max_tx_power < iface->conf->min_tx_power) 1381 continue; 1382 1383 if ((chan->flag & HOSTAPD_CHAN_INDOOR_ONLY) && 1384 iface->conf->country[2] == 0x4f) 1385 continue; 1386 1387 *freq++ = chan->freq; 1388 } 1389 1390 return freq; 1391 } 1392 1393 1394 static int acs_request_scan(struct hostapd_iface *iface) 1395 { 1396 struct wpa_driver_scan_params params; 1397 int i, *freq, ret; 1398 int num_channels; 1399 struct hostapd_hw_modes *mode; 1400 1401 os_memset(¶ms, 0, sizeof(params)); 1402 1403 num_channels = 0; 1404 for (i = 0; i < iface->num_hw_features; i++) { 1405 mode = &iface->hw_features[i]; 1406 if (!hostapd_hw_skip_mode(iface, mode)) 1407 num_channels += mode->num_channels; 1408 } 1409 1410 params.freqs = os_calloc(num_channels + 1, sizeof(params.freqs[0])); 1411 if (params.freqs == NULL) 1412 return -1; 1413 1414 freq = params.freqs; 1415 1416 for (i = 0; i < iface->num_hw_features; i++) { 1417 mode = &iface->hw_features[i]; 1418 if (!hostapd_hw_skip_mode(iface, mode)) 1419 freq = acs_request_scan_add_freqs(iface, mode, freq); 1420 } 1421 1422 *freq = 0; 1423 1424 if (params.freqs == freq) { 1425 wpa_printf(MSG_ERROR, "ACS: No available channels found"); 1426 os_free(params.freqs); 1427 return -1; 1428 } 1429 1430 if (!iface->acs_num_retries) 1431 wpa_printf(MSG_DEBUG, "ACS: Scanning %d / %d", 1432 iface->acs_num_completed_scans + 1, 1433 iface->conf->acs_num_scans); 1434 else 1435 wpa_printf(MSG_DEBUG, 1436 "ACS: Re-try scanning attempt %d (%d / %d)", 1437 iface->acs_num_retries, 1438 iface->acs_num_completed_scans + 1, 1439 iface->conf->acs_num_scans); 1440 1441 ret = hostapd_driver_scan(iface->bss[0], ¶ms); 1442 os_free(params.freqs); 1443 1444 if (ret == -EBUSY) { 1445 iface->acs_num_retries++; 1446 if (iface->acs_num_retries >= ACS_SCAN_RETRY_MAX_COUNT) { 1447 wpa_printf(MSG_ERROR, 1448 "ACS: Failed to request initial scan (all re-attempts failed)"); 1449 acs_fail(iface); 1450 return -1; 1451 } 1452 1453 wpa_printf(MSG_INFO, 1454 "Failed to request acs scan ret=%d (%s) - try to scan after %d seconds", 1455 ret, strerror(-ret), ACS_SCAN_RETRY_INTERVAL); 1456 eloop_cancel_timeout(acs_scan_retry, iface, NULL); 1457 eloop_register_timeout(ACS_SCAN_RETRY_INTERVAL, 0, 1458 acs_scan_retry, iface, NULL); 1459 return 0; 1460 } 1461 1462 if (ret < 0) { 1463 wpa_printf(MSG_ERROR, "ACS: Failed to request initial scan"); 1464 acs_cleanup(iface); 1465 return -1; 1466 } 1467 1468 iface->scan_cb = acs_scan_complete; 1469 1470 return 0; 1471 } 1472 1473 1474 static void acs_scan_retry(void *eloop_data, void *user_data) 1475 { 1476 struct hostapd_iface *iface = eloop_data; 1477 1478 if (acs_request_scan(iface)) { 1479 wpa_printf(MSG_ERROR, 1480 "ACS: Failed to request re-try of initial scan"); 1481 acs_fail(iface); 1482 } 1483 } 1484 1485 1486 enum hostapd_chan_status acs_init(struct hostapd_iface *iface) 1487 { 1488 int err; 1489 1490 wpa_printf(MSG_INFO, "ACS: Automatic channel selection started, this may take a bit"); 1491 1492 if (iface->drv_flags & WPA_DRIVER_FLAGS_ACS_OFFLOAD) { 1493 wpa_printf(MSG_INFO, "ACS: Offloading to driver"); 1494 1495 err = hostapd_drv_do_acs(iface->bss[0]); 1496 if (err) { 1497 if (err == 1) 1498 return HOSTAPD_CHAN_INVALID_NO_IR; 1499 return HOSTAPD_CHAN_INVALID; 1500 } 1501 1502 return HOSTAPD_CHAN_ACS; 1503 } 1504 1505 if (!iface->current_mode && 1506 iface->conf->hw_mode != HOSTAPD_MODE_IEEE80211ANY) 1507 return HOSTAPD_CHAN_INVALID; 1508 1509 acs_cleanup(iface); 1510 1511 if (acs_request_scan(iface) < 0) 1512 return HOSTAPD_CHAN_INVALID; 1513 1514 hostapd_set_state(iface, HAPD_IFACE_ACS); 1515 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, ACS_EVENT_STARTED); 1516 1517 return HOSTAPD_CHAN_ACS; 1518 } 1519
Indexes created Tue Feb 24 01:34:59 UTC 2026