esp-ena/components/ena/ena-exposure.c
2020-12-06 12:46:36 +01:00

400 lines
11 KiB
C

// Copyright 2020 Lukas Haubaum
//
// Licensed under the GNU Affero General Public License, Version 3;
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// https://www.gnu.org/licenses/agpl-3.0.html
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include <time.h>
#include <limits.h>
#include "esp_err.h"
#include "esp_log.h"
#include "ena-crypto.h"
#include "ena-storage.h"
#include "ena-beacons.h"
#include "ena-exposure.h"
static ena_exposure_summary_t *current_summary;
static ena_exposure_config_t DEFAULT_ENA_EXPOSURE_CONFIG = {
// transmission_risk_values
{
MINIMAL, // UNKNOWN
LOW, // CONFIRMED_TEST_LOW
MEDIUM, // CONFIRMED_TEST_STANDARD
HIGH, // CONFIRMED_TEST_HIGH
VERY_HIGH, // CONFIRMED_CLINICAL_DIAGNOSIS
VERY_LOW, // SELF_REPORT
ZERO, // NEGATIVE
MINIMAL // RECURSIVE
},
// duration_risk_values
{
MINIMAL, // D = 0 min
MINIMAL, // D <= 5 min
MEDIUM, // D <= 10 min
VERY_HIGH, // D <= 15 min
VERY_HIGH, // D <= 20 min
MAXIMUM, // D <= 25 min
MAXIMUM, // D <= 30 min
MAXIMUM // D > 30 min
},
// days_risk_values
{
MINIMAL, // >= 14 days
VERY_LOW, // 12-13 days
VERY_LOW, // 10-11 days
MEDIUM, // 8-9 days
HIGH, // 6-7 days
MAXIMUM, // 4-5 days
MAXIMUM, // 2-3 days
MAXIMUM // 0-1 days
},
// attenuation_risk_values
{
MINIMAL, // A > 73 dB
MINIMAL, // 73 >= A > 63
MINIMAL, // 63 >= A > 61
MAXIMUM, // 51 >= A > 33
MAXIMUM, // 33 >= A > 27
MAXIMUM, // 27 >= A > 15
MAXIMUM, // 15 >= A > 10
MAXIMUM // A <= 10
},
};
int ena_exposure_transmission_risk_score(ena_exposure_config_t *config, ena_exposure_parameter_t params)
{
return config->transmission_risk_values[params.report_type];
}
int ena_exposure_duration_risk_score(ena_exposure_config_t *config, ena_exposure_parameter_t params)
{
// calc duration level
int duration_level = MINUTES_0;
if (params.duration > 0)
{
if (params.duration <= 5)
{
duration_level = MINUTES_5;
}
else if (params.duration <= 10)
{
duration_level = MINUTES_10;
}
if (params.duration <= 15)
{
duration_level = MINUTES_15;
}
if (params.duration <= 20)
{
duration_level = MINUTES_20;
}
if (params.duration <= 25)
{
duration_level = MINUTES_25;
}
if (params.duration <= 30)
{
duration_level = MINUTES_30;
}
else
{
duration_level = MINUTES_LONGER;
}
}
return config->duration_risk_values[duration_level];
}
int ena_exposure_days_risk_score(ena_exposure_config_t *config, ena_exposure_parameter_t params)
{
// calc days level
int days_level = DAYS_14;
if (params.days < 2)
{
days_level = DAYS_0;
}
else if (params.days < 4)
{
days_level = DAYS_3;
}
else if (params.days < 6)
{
days_level = DAYS_5;
}
else if (params.days < 8)
{
days_level = DAYS_7;
}
else if (params.days < 10)
{
days_level = DAYS_9;
}
else if (params.days < 12)
{
days_level = DAYS_11;
}
else if (params.days < 14)
{
days_level = DAYS_13;
}
return config->days_risk_values[days_level];
}
int ena_exposure_attenuation_risk_score(ena_exposure_config_t *config, ena_exposure_parameter_t params)
{
// calc attenuation level
int attenuation_level = ATTENUATION_73;
if (params.attenuation <= 10)
{
attenuation_level = ATTENUATION_LOWER;
}
else if (params.attenuation <= 15)
{
attenuation_level = ATTENUATION_10;
}
else if (params.attenuation <= 27)
{
attenuation_level = ATTENUATION_15;
}
else if (params.attenuation <= 33)
{
attenuation_level = ATTENUATION_27;
}
else if (params.attenuation <= 51)
{
attenuation_level = ATTENUATION_33;
}
else if (params.attenuation <= 63)
{
attenuation_level = ATTENUATION_51;
}
else if (params.attenuation <= 73)
{
attenuation_level = ATTENUATION_63;
}
return config->attenuation_risk_values[attenuation_level];
}
int ena_exposure_risk_score(ena_exposure_config_t *config, ena_exposure_parameter_t params)
{
int score = 1;
score *= ena_exposure_transmission_risk_score(config, params);
score *= ena_exposure_duration_risk_score(config, params);
score *= ena_exposure_days_risk_score(config, params);
score *= ena_exposure_attenuation_risk_score(config, params);
if (score > 255)
{
score = 255;
}
return score;
}
void ena_exposure_summary(ena_exposure_config_t *config)
{
uint32_t count = ena_storage_exposure_information_count();
uint32_t current_time = (uint32_t)time(NULL);
if (current_summary == NULL)
{
current_summary = malloc(sizeof(ena_exposure_summary_t));
}
current_summary->last_update = ena_storage_read_last_exposure_date();
current_summary->days_since_last_exposure = INT_MAX;
current_summary->max_risk_score = 0;
current_summary->risk_score_sum = 0;
current_summary->num_exposures = count;
if (count == 0)
{
current_summary->days_since_last_exposure = -1;
}
ena_exposure_information_t exposure_info;
ena_exposure_parameter_t params;
for (int i = 0; i < count; i++)
{
ena_storage_get_exposure_information(i, &exposure_info);
params.days = (current_time - exposure_info.day) / (60 * 60 * 24); // difference in days
if (params.days < current_summary->days_since_last_exposure)
{
current_summary->days_since_last_exposure = params.days;
}
params.duration = exposure_info.duration_minutes;
params.attenuation = exposure_info.typical_attenuation;
params.report_type = exposure_info.report_type;
int score = ena_exposure_risk_score(config, params);
if (score > current_summary->max_risk_score)
{
current_summary->max_risk_score = score;
}
current_summary->risk_score_sum += score;
}
}
ena_exposure_summary_t *ena_exposure_current_summary(void)
{
if (current_summary == NULL)
{
ena_exposure_summary(ena_exposure_default_config());
}
return current_summary;
}
ena_exposure_config_t *ena_exposure_default_config(void)
{
return &DEFAULT_ENA_EXPOSURE_CONFIG;
}
void ena_exposure_check(ena_beacon_t beacon, ena_temporary_exposure_key_t temporary_exposure_key)
{
uint32_t timestamp_day_start = temporary_exposure_key.rolling_start_interval_number * ENA_TIME_WINDOW;
uint32_t timestamp_day_end = (temporary_exposure_key.rolling_start_interval_number + temporary_exposure_key.rolling_period) * ENA_TIME_WINDOW;
if (beacon.timestamp_first > timestamp_day_start && beacon.timestamp_last < timestamp_day_end)
{
bool match = false;
ena_exposure_information_t exposure_info;
exposure_info.day = timestamp_day_start;
exposure_info.duration_minutes = 0;
exposure_info.min_attenuation = INT_MAX;
exposure_info.typical_attenuation = 0;
exposure_info.report_type = temporary_exposure_key.report_type;
uint8_t rpi[ENA_KEY_LENGTH];
uint8_t rpik[ENA_KEY_LENGTH];
ena_crypto_rpik(rpik, temporary_exposure_key.key_data);
for (int i = 0; i < temporary_exposure_key.rolling_period; i++)
{
ena_crypto_rpi(rpi, rpik, temporary_exposure_key.rolling_start_interval_number + i);
if (memcmp(beacon.rpi, rpi, sizeof(ENA_KEY_LENGTH)) == 0)
{
match = true;
exposure_info.duration_minutes += ((beacon.timestamp_last - beacon.timestamp_first) / 60);
exposure_info.typical_attenuation = (exposure_info.typical_attenuation + beacon.rssi) / 2;
if (beacon.rssi < exposure_info.min_attenuation)
{
exposure_info.min_attenuation = beacon.rssi;
}
}
}
if (match)
{
ena_storage_add_exposure_information(&exposure_info);
}
}
}
int ena_expore_check_find_min_rec(int min, int max, uint32_t timestamp)
{
if (min < 0)
{
return -1;
}
if (min >= max - 1)
{
return min;
}
ena_beacon_t beacon;
int mid = min + (max - min) / 2;
ena_storage_get_beacon(min, &beacon);
if (beacon.timestamp_first < timestamp)
{
return ena_expore_check_find_min_rec(mid, max, timestamp);
}
else if (beacon.timestamp_first > timestamp)
{
return ena_expore_check_find_min_rec(min - ((max - min) / 2), mid, timestamp);
}
else
{
return min;
}
}
int ena_expore_check_find_min(uint32_t timestamp)
{
return ena_expore_check_find_min_rec(0, (ena_storage_beacons_count() - 1), timestamp);
}
int ena_expore_check_find_max_rec(int min, int max, int max_max, uint32_t timestamp)
{
if (max > max_max)
{
return -1;
}
if (max <= (min + 1))
{
return max;
}
ena_beacon_t beacon;
int mid = min + (max - min) / 2;
ena_storage_get_beacon(max, &beacon);
if (beacon.timestamp_first > timestamp)
{
return ena_expore_check_find_max_rec(min, mid, max_max, timestamp);
}
else if (beacon.timestamp_first < timestamp)
{
return ena_expore_check_find_max_rec(mid, max + ((max - min) / 2), max_max, timestamp);
}
else
{
return max;
}
}
int ena_expore_check_find_max(uint32_t timestamp)
{
return ena_expore_check_find_max_rec(0, (ena_storage_beacons_count() - 1), (ena_storage_beacons_count() - 1), timestamp);
}
void ena_exposure_check_temporary_exposure_key(ena_temporary_exposure_key_t temporary_exposure_key)
{
uint32_t timestamp_start = temporary_exposure_key.rolling_start_interval_number * ENA_TIME_WINDOW;
uint32_t timestamp_end = (temporary_exposure_key.rolling_start_interval_number + temporary_exposure_key.rolling_period) * ENA_TIME_WINDOW;
int min = ena_expore_check_find_min(timestamp_start);
int max = ena_expore_check_find_max(timestamp_end);
if (min == -1 || max == -1)
{
return;
}
ena_beacon_t beacon;
for (int y = min; y <= max; y++)
{
ena_storage_get_beacon(y, &beacon);
ena_exposure_check(beacon, temporary_exposure_key);
}
}