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(entry: &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(objp: 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(list: &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(new: &cd->head, 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(objp: 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, freq: 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(size: sizeof(*dpd), GFP_KERNEL); |
358 | if (dpd == NULL) |
359 | return NULL; |
360 | |
361 | *dpd = default_dpd; |
362 | INIT_LIST_HEAD(list: &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(objp: dpd); |
370 | return NULL; |
371 | } |
372 | EXPORT_SYMBOL(dfs_pattern_detector_init); |
373 | |