1 /* 2 * Copyright (c) 2012 Neratec Solutions AG 3 * 4 * Permission to use, copy, modify, and/or distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #include <linux/slab.h> 18 #include <linux/export.h> 19 20 #include "dfs_pattern_detector.h" 21 #include "dfs_pri_detector.h" 22 #include "ath.h" 23 24 /** 25 * struct radar_types - contains array of patterns defined for one DFS domain 26 * @region: regulatory DFS region 27 * @num_radar_types: number of radar types to follow 28 * @radar_types: radar types array 29 */ 30 struct radar_types { 31 enum nl80211_dfs_regions region; 32 u32 num_radar_types; 33 const struct radar_detector_specs *radar_types; 34 }; 35 36 /* percentage on ppb threshold to trigger detection */ 37 #define MIN_PPB_THRESH 50 38 #define PPB_THRESH_RATE(PPB, RATE) ((PPB * RATE + 100 - RATE) / 100) 39 #define PPB_THRESH(PPB) PPB_THRESH_RATE(PPB, MIN_PPB_THRESH) 40 #define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF) 41 /* percentage of pulse width tolerance */ 42 #define WIDTH_TOLERANCE 5 43 #define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100) 44 #define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100) 45 46 #define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \ 47 { \ 48 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 49 (PRF2PRI(PMAX) - PRI_TOLERANCE), \ 50 (PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \ 51 PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \ 52 } 53 54 /* radar types as defined by ETSI EN-301-893 v1.5.1 */ 55 static const struct radar_detector_specs etsi_radar_ref_types_v15[] = { 56 ETSI_PATTERN(0, 0, 1, 700, 700, 1, 18, false), 57 ETSI_PATTERN(1, 0, 5, 200, 1000, 1, 10, false), 58 ETSI_PATTERN(2, 0, 15, 200, 1600, 1, 15, false), 59 ETSI_PATTERN(3, 0, 15, 2300, 4000, 1, 25, false), 60 ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20, false), 61 ETSI_PATTERN(5, 0, 2, 300, 400, 3, 10, false), 62 ETSI_PATTERN(6, 0, 2, 400, 1200, 3, 15, false), 63 }; 64 65 static const struct radar_types etsi_radar_types_v15 = { 66 .region = NL80211_DFS_ETSI, 67 .num_radar_types = ARRAY_SIZE(etsi_radar_ref_types_v15), 68 .radar_types = etsi_radar_ref_types_v15, 69 }; 70 71 #define FCC_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \ 72 { \ 73 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 74 PMIN - PRI_TOLERANCE, \ 75 PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \ 76 PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \ 77 } 78 79 /* radar types released on August 14, 2014 80 * type 1 PRI values randomly selected within the range of 518 and 3066. 81 * divide it to 3 groups is good enough for both of radar detection and 82 * avoiding false detection based on practical test results 83 * collected for more than a year. 84 */ 85 static const struct radar_detector_specs fcc_radar_ref_types[] = { 86 FCC_PATTERN(0, 0, 1, 1428, 1428, 1, 18, false), 87 FCC_PATTERN(101, 0, 1, 518, 938, 1, 57, false), 88 FCC_PATTERN(102, 0, 1, 938, 2000, 1, 27, false), 89 FCC_PATTERN(103, 0, 1, 2000, 3066, 1, 18, false), 90 FCC_PATTERN(2, 0, 5, 150, 230, 1, 23, false), 91 FCC_PATTERN(3, 6, 10, 200, 500, 1, 16, false), 92 FCC_PATTERN(4, 11, 20, 200, 500, 1, 12, false), 93 FCC_PATTERN(5, 50, 100, 1000, 2000, 1, 1, true), 94 FCC_PATTERN(6, 0, 1, 333, 333, 1, 9, false), 95 }; 96 97 static const struct radar_types fcc_radar_types = { 98 .region = NL80211_DFS_FCC, 99 .num_radar_types = ARRAY_SIZE(fcc_radar_ref_types), 100 .radar_types = fcc_radar_ref_types, 101 }; 102 103 #define JP_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, RATE, CHIRP) \ 104 { \ 105 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 106 PMIN - PRI_TOLERANCE, \ 107 PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \ 108 PPB_THRESH_RATE(PPB, RATE), PRI_TOLERANCE, CHIRP \ 109 } 110 static const struct radar_detector_specs jp_radar_ref_types[] = { 111 JP_PATTERN(0, 0, 1, 1428, 1428, 1, 18, 29, false), 112 JP_PATTERN(1, 2, 3, 3846, 3846, 1, 18, 29, false), 113 JP_PATTERN(2, 0, 1, 1388, 1388, 1, 18, 50, false), 114 JP_PATTERN(3, 0, 4, 4000, 4000, 1, 18, 50, false), 115 JP_PATTERN(4, 0, 5, 150, 230, 1, 23, 50, false), 116 JP_PATTERN(5, 6, 10, 200, 500, 1, 16, 50, false), 117 JP_PATTERN(6, 11, 20, 200, 500, 1, 12, 50, false), 118 JP_PATTERN(7, 50, 100, 1000, 2000, 1, 3, 50, true), 119 JP_PATTERN(5, 0, 1, 333, 333, 1, 9, 50, false), 120 }; 121 122 static const struct radar_types jp_radar_types = { 123 .region = NL80211_DFS_JP, 124 .num_radar_types = ARRAY_SIZE(jp_radar_ref_types), 125 .radar_types = jp_radar_ref_types, 126 }; 127 128 static const struct radar_types *dfs_domains[] = { 129 &etsi_radar_types_v15, 130 &fcc_radar_types, 131 &jp_radar_types, 132 }; 133 134 /** 135 * get_dfs_domain_radar_types() - get radar types for a given DFS domain 136 * @region: regulatory DFS region 137 * 138 * Return value: radar_types ptr on success, NULL if DFS domain is not supported 139 */ 140 static const struct radar_types * 141 get_dfs_domain_radar_types(enum nl80211_dfs_regions region) 142 { 143 u32 i; 144 for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) { 145 if (dfs_domains[i]->region == region) 146 return dfs_domains[i]; 147 } 148 return NULL; 149 } 150 151 /** 152 * struct channel_detector - detector elements for a DFS channel 153 * @head: list_head 154 * @freq: frequency for this channel detector in MHz 155 * @detectors: array of dynamically created detector elements for this freq 156 * 157 * Channel detectors are required to provide multi-channel DFS detection, e.g. 158 * to support off-channel scanning. A pattern detector has a list of channels 159 * radar pulses have been reported for in the past. 160 */ 161 struct channel_detector { 162 struct list_head head; 163 u16 freq; 164 struct pri_detector *detectors[]; 165 }; 166 167 /* channel_detector_reset() - reset detector lines for a given channel */ 168 static void channel_detector_reset(struct dfs_pattern_detector *dpd, 169 struct channel_detector *cd) 170 { 171 u32 i; 172 if (cd == NULL) 173 return; 174 for (i = 0; i < dpd->num_radar_types; i++) 175 cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts); 176 } 177 178 /* channel_detector_exit() - destructor */ 179 static void channel_detector_exit(struct dfs_pattern_detector *dpd, 180 struct channel_detector *cd) 181 { 182 u32 i; 183 if (cd == NULL) 184 return; 185 list_del(&cd->head); 186 187 for (i = 0; i < dpd->num_radar_types; i++) { 188 struct pri_detector *de = cd->detectors[i]; 189 if (de != NULL) 190 de->exit(de); 191 } 192 193 kfree(cd); 194 } 195 196 static struct channel_detector * 197 channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq) 198 { 199 u32 i; 200 struct channel_detector *cd; 201 202 cd = kzalloc(struct_size(cd, detectors, dpd->num_radar_types), GFP_ATOMIC); 203 if (cd == NULL) 204 goto fail; 205 206 INIT_LIST_HEAD(&cd->head); 207 cd->freq = freq; 208 209 for (i = 0; i < dpd->num_radar_types; i++) { 210 const struct radar_detector_specs *rs = &dpd->radar_spec[i]; 211 struct pri_detector *de = pri_detector_init(rs); 212 if (de == NULL) 213 goto fail; 214 cd->detectors[i] = de; 215 } 216 list_add(&cd->head, &dpd->channel_detectors); 217 return cd; 218 219 fail: 220 ath_dbg(dpd->common, DFS, 221 "failed to allocate channel_detector for freq=%d\n", freq); 222 channel_detector_exit(dpd, cd); 223 return NULL; 224 } 225 226 /** 227 * channel_detector_get() - get channel detector for given frequency 228 * @dpd: DPD instance pointer 229 * @freq: freq frequency in MHz 230 * 231 * Return value: pointer to channel detector on success, NULL otherwise 232 * 233 * Return existing channel detector for the given frequency or return a 234 * newly create one. 235 */ 236 static struct channel_detector * 237 channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq) 238 { 239 struct channel_detector *cd; 240 list_for_each_entry(cd, &dpd->channel_detectors, head) { 241 if (cd->freq == freq) 242 return cd; 243 } 244 return channel_detector_create(dpd, freq); 245 } 246 247 /* 248 * DFS Pattern Detector 249 */ 250 251 /* dpd_reset(): reset all channel detectors */ 252 static void dpd_reset(struct dfs_pattern_detector *dpd) 253 { 254 struct channel_detector *cd; 255 list_for_each_entry(cd, &dpd->channel_detectors, head) 256 channel_detector_reset(dpd, cd); 257 258 } 259 static void dpd_exit(struct dfs_pattern_detector *dpd) 260 { 261 struct channel_detector *cd, *cd0; 262 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 263 channel_detector_exit(dpd, cd); 264 kfree(dpd); 265 } 266 267 static bool 268 dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event, 269 struct radar_detector_specs *rs) 270 { 271 u32 i; 272 struct channel_detector *cd; 273 274 /* 275 * pulses received for a non-supported or un-initialized 276 * domain are treated as detected radars for fail-safety 277 */ 278 if (dpd->region == NL80211_DFS_UNSET) 279 return true; 280 281 cd = channel_detector_get(dpd, event->freq); 282 if (cd == NULL) 283 return false; 284 285 /* reset detector on time stamp wraparound, caused by TSF reset */ 286 if (event->ts < dpd->last_pulse_ts) 287 dpd_reset(dpd); 288 dpd->last_pulse_ts = event->ts; 289 290 /* do type individual pattern matching */ 291 for (i = 0; i < dpd->num_radar_types; i++) { 292 struct pri_detector *pd = cd->detectors[i]; 293 struct pri_sequence *ps = pd->add_pulse(pd, event); 294 if (ps != NULL) { 295 if (rs != NULL) 296 memcpy(rs, pd->rs, sizeof(*rs)); 297 ath_dbg(dpd->common, DFS, 298 "DFS: radar found on freq=%d: id=%d, pri=%d, " 299 "count=%d, count_false=%d\n", 300 event->freq, pd->rs->type_id, 301 ps->pri, ps->count, ps->count_falses); 302 pd->reset(pd, dpd->last_pulse_ts); 303 return true; 304 } 305 } 306 return false; 307 } 308 309 static struct ath_dfs_pool_stats 310 dpd_get_stats(struct dfs_pattern_detector *dpd) 311 { 312 return global_dfs_pool_stats; 313 } 314 315 static bool dpd_set_domain(struct dfs_pattern_detector *dpd, 316 enum nl80211_dfs_regions region) 317 { 318 const struct radar_types *rt; 319 struct channel_detector *cd, *cd0; 320 321 if (dpd->region == region) 322 return true; 323 324 dpd->region = NL80211_DFS_UNSET; 325 326 rt = get_dfs_domain_radar_types(region); 327 if (rt == NULL) 328 return false; 329 330 /* delete all channel detectors for previous DFS domain */ 331 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 332 channel_detector_exit(dpd, cd); 333 dpd->radar_spec = rt->radar_types; 334 dpd->num_radar_types = rt->num_radar_types; 335 336 dpd->region = region; 337 return true; 338 } 339 340 static const struct dfs_pattern_detector default_dpd = { 341 .exit = dpd_exit, 342 .set_dfs_domain = dpd_set_domain, 343 .add_pulse = dpd_add_pulse, 344 .get_stats = dpd_get_stats, 345 .region = NL80211_DFS_UNSET, 346 }; 347 348 struct dfs_pattern_detector * 349 dfs_pattern_detector_init(struct ath_common *common, 350 enum nl80211_dfs_regions region) 351 { 352 struct dfs_pattern_detector *dpd; 353 354 if (!IS_ENABLED(CONFIG_CFG80211_CERTIFICATION_ONUS)) 355 return NULL; 356 357 dpd = kmalloc(sizeof(*dpd), GFP_KERNEL); 358 if (dpd == NULL) 359 return NULL; 360 361 *dpd = default_dpd; 362 INIT_LIST_HEAD(&dpd->channel_detectors); 363 364 dpd->common = common; 365 if (dpd->set_dfs_domain(dpd, region)) 366 return dpd; 367 368 ath_dbg(common, DFS,"Could not set DFS domain to %d", region); 369 kfree(dpd); 370 return NULL; 371 } 372 EXPORT_SYMBOL(dfs_pattern_detector_init); 373