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 for (i = 0; i < dpd->num_radar_types; i++) { 187 struct pri_detector *de = cd->detectors[i]; 188 if (de != NULL) 189 de->exit(de); 190 } 191 kfree(cd->detectors); 192 kfree(cd); 193 } 194 195 static struct channel_detector * 196 channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq) 197 { 198 u32 sz, i; 199 struct channel_detector *cd; 200 201 cd = kmalloc(sizeof(*cd), GFP_ATOMIC); 202 if (cd == NULL) 203 goto fail; 204 205 INIT_LIST_HEAD(&cd->head); 206 cd->freq = freq; 207 sz = sizeof(cd->detectors) * dpd->num_radar_types; 208 cd->detectors = kzalloc(sz, GFP_ATOMIC); 209 if (cd->detectors == NULL) 210 goto fail; 211 212 for (i = 0; i < dpd->num_radar_types; i++) { 213 const struct radar_detector_specs *rs = &dpd->radar_spec[i]; 214 struct pri_detector *de = pri_detector_init(rs); 215 if (de == NULL) 216 goto fail; 217 cd->detectors[i] = de; 218 } 219 list_add(&cd->head, &dpd->channel_detectors); 220 return cd; 221 222 fail: 223 ath_dbg(dpd->common, DFS, 224 "failed to allocate channel_detector for freq=%d\n", freq); 225 channel_detector_exit(dpd, cd); 226 return NULL; 227 } 228 229 /** 230 * channel_detector_get() - get channel detector for given frequency 231 * @dpd: DPD instance pointer 232 * @freq: freq frequency in MHz 233 * 234 * Return value: pointer to channel detector on success, NULL otherwise 235 * 236 * Return existing channel detector for the given frequency or return a 237 * newly create one. 238 */ 239 static struct channel_detector * 240 channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq) 241 { 242 struct channel_detector *cd; 243 list_for_each_entry(cd, &dpd->channel_detectors, head) { 244 if (cd->freq == freq) 245 return cd; 246 } 247 return channel_detector_create(dpd, freq); 248 } 249 250 /* 251 * DFS Pattern Detector 252 */ 253 254 /* dpd_reset(): reset all channel detectors */ 255 static void dpd_reset(struct dfs_pattern_detector *dpd) 256 { 257 struct channel_detector *cd; 258 list_for_each_entry(cd, &dpd->channel_detectors, head) 259 channel_detector_reset(dpd, cd); 260 261 } 262 static void dpd_exit(struct dfs_pattern_detector *dpd) 263 { 264 struct channel_detector *cd, *cd0; 265 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 266 channel_detector_exit(dpd, cd); 267 kfree(dpd); 268 } 269 270 static bool 271 dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event, 272 struct radar_detector_specs *rs) 273 { 274 u32 i; 275 struct channel_detector *cd; 276 277 /* 278 * pulses received for a non-supported or un-initialized 279 * domain are treated as detected radars for fail-safety 280 */ 281 if (dpd->region == NL80211_DFS_UNSET) 282 return true; 283 284 cd = channel_detector_get(dpd, event->freq); 285 if (cd == NULL) 286 return false; 287 288 /* reset detector on time stamp wraparound, caused by TSF reset */ 289 if (event->ts < dpd->last_pulse_ts) 290 dpd_reset(dpd); 291 dpd->last_pulse_ts = event->ts; 292 293 /* do type individual pattern matching */ 294 for (i = 0; i < dpd->num_radar_types; i++) { 295 struct pri_detector *pd = cd->detectors[i]; 296 struct pri_sequence *ps = pd->add_pulse(pd, event); 297 if (ps != NULL) { 298 if (rs != NULL) 299 memcpy(rs, pd->rs, sizeof(*rs)); 300 ath_dbg(dpd->common, DFS, 301 "DFS: radar found on freq=%d: id=%d, pri=%d, " 302 "count=%d, count_false=%d\n", 303 event->freq, pd->rs->type_id, 304 ps->pri, ps->count, ps->count_falses); 305 pd->reset(pd, dpd->last_pulse_ts); 306 return true; 307 } 308 } 309 return false; 310 } 311 312 static struct ath_dfs_pool_stats 313 dpd_get_stats(struct dfs_pattern_detector *dpd) 314 { 315 return global_dfs_pool_stats; 316 } 317 318 static bool dpd_set_domain(struct dfs_pattern_detector *dpd, 319 enum nl80211_dfs_regions region) 320 { 321 const struct radar_types *rt; 322 struct channel_detector *cd, *cd0; 323 324 if (dpd->region == region) 325 return true; 326 327 dpd->region = NL80211_DFS_UNSET; 328 329 rt = get_dfs_domain_radar_types(region); 330 if (rt == NULL) 331 return false; 332 333 /* delete all channel detectors for previous DFS domain */ 334 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 335 channel_detector_exit(dpd, cd); 336 dpd->radar_spec = rt->radar_types; 337 dpd->num_radar_types = rt->num_radar_types; 338 339 dpd->region = region; 340 return true; 341 } 342 343 static const struct dfs_pattern_detector default_dpd = { 344 .exit = dpd_exit, 345 .set_dfs_domain = dpd_set_domain, 346 .add_pulse = dpd_add_pulse, 347 .get_stats = dpd_get_stats, 348 .region = NL80211_DFS_UNSET, 349 }; 350 351 struct dfs_pattern_detector * 352 dfs_pattern_detector_init(struct ath_common *common, 353 enum nl80211_dfs_regions region) 354 { 355 struct dfs_pattern_detector *dpd; 356 357 if (!IS_ENABLED(CONFIG_CFG80211_CERTIFICATION_ONUS)) 358 return NULL; 359 360 dpd = kmalloc(sizeof(*dpd), GFP_KERNEL); 361 if (dpd == NULL) 362 return NULL; 363 364 *dpd = default_dpd; 365 INIT_LIST_HEAD(&dpd->channel_detectors); 366 367 dpd->common = common; 368 if (dpd->set_dfs_domain(dpd, region)) 369 return dpd; 370 371 ath_dbg(common, DFS,"Could not set DFS domain to %d", region); 372 kfree(dpd); 373 return NULL; 374 } 375 EXPORT_SYMBOL(dfs_pattern_detector_init); 376