/*
* Copyright (c) 2012 Neratec Solutions AG
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/slab.h>
#include <linux/export.h>
#include "dfs_pattern_detector.h"
#include "dfs_pri_detector.h"
#include "ath.h"
/**
* struct radar_types - contains array of patterns defined for one DFS domain
* @domain: DFS regulatory domain
* @num_radar_types: number of radar types to follow
* @radar_types: radar types array
*/
struct radar_types {
enum nl80211_dfs_regions region;
u32 num_radar_types;
const struct radar_detector_specs *radar_types;
};
/* percentage on ppb threshold to trigger detection */
#define MIN_PPB_THRESH 50
#define PPB_THRESH_RATE(PPB, RATE) ((PPB * RATE + 100 - RATE) / 100)
#define PPB_THRESH(PPB) PPB_THRESH_RATE(PPB, MIN_PPB_THRESH)
#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
/* percentage of pulse width tolerance */
#define WIDTH_TOLERANCE 5
#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)
#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \
{ \
ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
(PRF2PRI(PMAX) - PRI_TOLERANCE), \
(PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \
PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \
}
/* radar types as defined by ETSI EN-301-893 v1.5.1 */
static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
ETSI_PATTERN(0, 0, 1, 700, 700, 1, 18, false),
ETSI_PATTERN(1, 0, 5, 200, 1000, 1, 10, false),
ETSI_PATTERN(2, 0, 15, 200, 1600, 1, 15, false),
ETSI_PATTERN(3, 0, 15, 2300, 4000, 1, 25, false),
ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20, false),
ETSI_PATTERN(5, 0, 2, 300, 400, 3, 10, false),
ETSI_PATTERN(6, 0, 2, 400, 1200, 3, 15, false),
};
static const struct radar_types etsi_radar_types_v15 = {
.region = NL80211_DFS_ETSI,
.num_radar_types = ARRAY_SIZE(etsi_radar_ref_types_v15),
.radar_types = etsi_radar_ref_types_v15,
};
#define FCC_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \
{ \
ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
PMIN - PRI_TOLERANCE, \
PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \
PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \
}
/* radar types released on August 14, 2014
* type 1 PRI values randomly selected within the range of 518 and 3066.
* divide it to 3 groups is good enough for both of radar detection and
* avoiding false detection based on practical test results
* collected for more than a year.
*/
static const struct radar_detector_specs fcc_radar_ref_types[] = {
FCC_PATTERN(0, 0, 1, 1428, 1428, 1, 18, false),
FCC_PATTERN(101, 0, 1, 518, 938, 1, 57, false),
FCC_PATTERN(102, 0, 1, 938, 2000, 1, 27, false),
FCC_PATTERN(103, 0, 1, 2000, 3066, 1, 18, false),
FCC_PATTERN(2, 0, 5, 150, 230, 1, 23, false),
FCC_PATTERN(3, 6, 10, 200, 500, 1, 16, false),
FCC_PATTERN(4, 11, 20, 200, 500, 1, 12, false),
FCC_PATTERN(5, 50, 100, 1000, 2000, 1, 1, true),
FCC_PATTERN(6, 0, 1, 333, 333, 1, 9, false),
};
static const struct radar_types fcc_radar_types = {
.region = NL80211_DFS_FCC,
.num_radar_types = ARRAY_SIZE(fcc_radar_ref_types),
.radar_types = fcc_radar_ref_types,
};
#define JP_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, RATE, CHIRP) \
{ \
ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
PMIN - PRI_TOLERANCE, \
PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \
PPB_THRESH_RATE(PPB, RATE), PRI_TOLERANCE, CHIRP \
}
static const struct radar_detector_specs jp_radar_ref_types[] = {
JP_PATTERN(0, 0, 1, 1428, 1428, 1, 18, 29, false),
JP_PATTERN(1, 2, 3, 3846, 3846, 1, 18, 29, false),
JP_PATTERN(2, 0, 1, 1388, 1388, 1, 18, 50, false),
JP_PATTERN(3, 1, 2, 4000, 4000, 1, 18, 50, false),
JP_PATTERN(4, 0, 5, 150, 230, 1, 23, 50, false),
JP_PATTERN(5, 6, 10, 200, 500, 1, 16, 50, false),
JP_PATTERN(6, 11, 20, 200, 500, 1, 12, 50, false),
JP_PATTERN(7, 50, 100, 1000, 2000, 1, 3, 50, false),
JP_PATTERN(5, 0, 1, 333, 333, 1, 9, 50, false),
};
static const struct radar_types jp_radar_types = {
.region = NL80211_DFS_JP,
.num_radar_types = ARRAY_SIZE(jp_radar_ref_types),
.radar_types = jp_radar_ref_types,
};
static const struct radar_types *dfs_domains[] = {
&etsi_radar_types_v15,
&fcc_radar_types,
&jp_radar_types,
};
/**
* get_dfs_domain_radar_types() - get radar types for a given DFS domain
* @param domain DFS domain
* @return radar_types ptr on success, NULL if DFS domain is not supported
*/
static const struct radar_types *
get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
{
u32 i;
for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
if (dfs_domains[i]->region == region)
return dfs_domains[i];
}
return NULL;
}
/**
* struct channel_detector - detector elements for a DFS channel
* @head: list_head
* @freq: frequency for this channel detector in MHz
* @detectors: array of dynamically created detector elements for this freq
*
* Channel detectors are required to provide multi-channel DFS detection, e.g.
* to support off-channel scanning. A pattern detector has a list of channels
* radar pulses have been reported for in the past.
*/
struct channel_detector {
struct list_head head;
u16 freq;
struct pri_detector **detectors;
};
/* channel_detector_reset() - reset detector lines for a given channel */
static void channel_detector_reset(struct dfs_pattern_detector *dpd,
struct channel_detector *cd)
{
u32 i;
if (cd == NULL)
return;
for (i = 0; i < dpd->num_radar_types; i++)
cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
}
/* channel_detector_exit() - destructor */
static void channel_detector_exit(struct dfs_pattern_detector *dpd,
struct channel_detector *cd)
{
u32 i;
if (cd == NULL)
return;
list_del(&cd->head);
for (i = 0; i < dpd->num_radar_types; i++) {
struct pri_detector *de = cd->detectors[i];
if (de != NULL)
de->exit(de);
}
kfree(cd->detectors);
kfree(cd);
}
static struct channel_detector *
channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
{
u32 sz, i;
struct channel_detector *cd;
cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
if (cd == NULL)
goto fail;
INIT_LIST_HEAD(&cd->head);
cd->freq = freq;
sz = sizeof(cd->detectors) * dpd->num_radar_types;
cd->detectors = kzalloc(sz, GFP_ATOMIC);
if (cd->detectors == NULL)
goto fail;
for (i = 0; i < dpd->num_radar_types; i++) {
const struct radar_detector_specs *rs = &dpd->radar_spec[i];
struct pri_detector *de = pri_detector_init(rs);
if (de == NULL)
goto fail;
cd->detectors[i] = de;
}
list_add(&cd->head, &dpd->channel_detectors);
return cd;
fail:
ath_dbg(dpd->common, DFS,
"failed to allocate channel_detector for freq=%d\n", freq);
channel_detector_exit(dpd, cd);
return NULL;
}
/**
* channel_detector_get() - get channel detector for given frequency
* @param dpd instance pointer
* @param freq frequency in MHz
* @return pointer to channel detector on success, NULL otherwise
*
* Return existing channel detector for the given frequency or return a
* newly create one.
*/
static struct channel_detector *
channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
{
struct channel_detector *cd;
list_for_each_entry(cd, &dpd->channel_detectors, head) {
if (cd->freq == freq)
return cd;
}
return channel_detector_create(dpd, freq);
}
/*
* DFS Pattern Detector
*/
/* dpd_reset(): reset all channel detectors */
static void dpd_reset(struct dfs_pattern_detector *dpd)
{
struct channel_detector *cd;
if (!list_empty(&dpd->channel_detectors))
list_for_each_entry(cd, &dpd->channel_detectors, head)
channel_detector_reset(dpd, cd);
}
static void dpd_exit(struct dfs_pattern_detector *dpd)
{
struct channel_detector *cd, *cd0;
if (!list_empty(&dpd->channel_detectors))
list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
channel_detector_exit(dpd, cd);
kfree(dpd);
}
static bool
dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
{
u32 i;
struct channel_detector *cd;
/*
* pulses received for a non-supported or un-initialized
* domain are treated as detected radars for fail-safety
*/
if (dpd->region == NL80211_DFS_UNSET)
return true;
cd = channel_detector_get(dpd, event->freq);
if (cd == NULL)
return false;
/* reset detector on time stamp wraparound, caused by TSF reset */
if (event->ts < dpd->last_pulse_ts)
dpd_reset(dpd);
dpd->last_pulse_ts = event->ts;
/* do type individual pattern matching */
for (i = 0; i < dpd->num_radar_types; i++) {
struct pri_detector *pd = cd->detectors[i];
struct pri_sequence *ps = pd->add_pulse(pd, event);
if (ps != NULL) {
ath_dbg(dpd->common, DFS,
"DFS: radar found on freq=%d: id=%d, pri=%d, "
"count=%d, count_false=%d\n",
event->freq, pd->rs->type_id,
ps->pri, ps->count, ps->count_falses);
pd->reset(pd, dpd->last_pulse_ts);
return true;
}
}
return false;
}
static struct ath_dfs_pool_stats
dpd_get_stats(struct dfs_pattern_detector *dpd)
{
return global_dfs_pool_stats;
}
static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
enum nl80211_dfs_regions region)
{
const struct radar_types *rt;
struct channel_detector *cd, *cd0;
if (dpd->region == region)
return true;
dpd->region = NL80211_DFS_UNSET;
rt = get_dfs_domain_radar_types(region);
if (rt == NULL)
return false;
/* delete all channel detectors for previous DFS domain */
if (!list_empty(&dpd->channel_detectors))
list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
channel_detector_exit(dpd, cd);
dpd->radar_spec = rt->radar_types;
dpd->num_radar_types = rt->num_radar_types;
dpd->region = region;
return true;
}
static const struct dfs_pattern_detector default_dpd = {
.exit = dpd_exit,
.set_dfs_domain = dpd_set_domain,
.add_pulse = dpd_add_pulse,
.get_stats = dpd_get_stats,
.region = NL80211_DFS_UNSET,
};
struct dfs_pattern_detector *
dfs_pattern_detector_init(struct ath_common *common,
enum nl80211_dfs_regions region)
{
struct dfs_pattern_detector *dpd;
if (!IS_ENABLED([31mCONFIG_CFG80211_CERTIFICATION_ONUS[0m))
return NULL;
dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
if (dpd == NULL)
return NULL;
*dpd = default_dpd;
INIT_LIST_HEAD(&dpd->channel_detectors);
dpd->common = common;
if (dpd->set_dfs_domain(dpd, region))
return dpd;
ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
kfree(dpd);
return NULL;
}
EXPORT_SYMBOL(dfs_pattern_detector_init);