CovidBracelet/src/contacts.c

329 lines
11 KiB
C

/*
* Copyright (c) 2020 Olaf Landsiedel
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stddef.h>
#include <string.h>
#include <sys/printk.h>
#include <sys/util.h>
#include <timing/timing.h>
#include <zephyr.h>
#include <zephyr/types.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>
#include "bloom.h"
#include "contacts.h"
#include "covid.h"
#include "covid_types.h"
#include "ens/records.h"
#include "ens/storage.h"
#include "exposure-notification.h"
// #define CONFIG_INTERVAL_SPREAD 100
void print_key(_ENBaseKey* key) {
for (int i = 0; i < sizeof(key->b); i++) {
printk("%02x", key->b[i]);
}
}
void print_rpi(rolling_proximity_identifier_t* rpi) {
for (int i = 0; i < sizeof(rolling_proximity_identifier_t); i++) {
printk("%02x", rpi->b[i]);
}
}
void print_aem(associated_encrypted_metadata_t* aem) {
for (int i = 0; i < sizeof(associated_encrypted_metadata_t); i++) {
printk("%02x", aem->data[i]);
}
}
int register_record(record_t* record) {
return add_record(record);
}
/**
* Simple implementation, where an iterator is created for every element in the passed arrray.
*/
int get_number_of_infected_for_multiple_intervals_simple(infected_for_interval_ident_ctx_t* ctx, int count) {
record_iterator_t iterator;
for (int i = 0; i < count; i++) {
if (!ctx[i].met) {
continue;
}
ctx[i].met = 0;
int rc = ens_records_iterator_init_timerange(&iterator, &ctx[i].search_start, &ctx[i].search_end);
if (rc) {
// on error, skip this rpi
continue;
}
record_t* current;
while ((current = ens_records_iterator_next(&iterator))) {
if (memcmp(&(current->rolling_proximity_identifier), &ctx[i].interval_identifier,
sizeof(rolling_proximity_identifier_t)) == 0) {
ctx[i].met++;
}
}
}
return 0;
}
/**
* Fill the bloom filter with all stored records.
*/
void fill_bloom_with_stored_records(bloom_filter_t* bloom) {
// init iterator for filling bloom filter
record_iterator_t iterator;
int rc = ens_records_iterator_init_timerange(&iterator, NULL, NULL);
if (rc) {
printk("init iterator failed0 (err %d)\n", rc);
return;
}
// fill bloom filter with records
record_t* current;
while ((current = ens_records_iterator_next(&iterator))) {
bloom_add_record(bloom, &(current->rolling_proximity_identifier));
}
}
/**
* Fill the bloom filter with flash records and test passed RPIs against it.
*/
int64_t bloom_filter(infected_for_interval_ident_ctx_t* ctx, int count) {
bloom_filter_t* bloom = bloom_init(get_num_records() * 2);
if (!bloom) {
printk("bloom init failed\n");
return -1;
}
fill_bloom_with_stored_records(bloom);
// test bloom performance
for (int i = 0; i < count; i++) {
if (bloom_probably_has_record(bloom, &ctx[i].interval_identifier)) {
ctx[i].met++;
}
}
bloom_destroy(bloom);
return get_number_of_infected_for_multiple_intervals_simple(ctx, count);
}
////////////////////
// FILL TEST DATA //
////////////////////
static ENPeriodKey infectedPeriodKey = {
.b = {0x75, 0xc7, 0x34, 0xc6, 0xdd, 0x1a, 0x78, 0x2d, 0xe7, 0xa9, 0x65, 0xda, 0x5e, 0xb9, 0x31, 0x25}};
static ENPeriodKey dummyPeriodKey = {
.b = {0x89, 0xa7, 0x34, 0xc6, 0xdd, 0x1a, 0x14, 0xda, 0xe7, 0x00, 0x65, 0xda, 0x6a, 0x9b, 0x13, 0x52}};
static ENPeriodKey testKey = {
.b = {0x89, 0xa7, 0x72, 0xc6, 0xdd, 0x10, 0x14, 0xda, 0xe7, 0x00, 0x65, 0xda, 0x8a, 0x9b, 0x13, 0x52}};
static ENPeriodIdentifierKey infectedPik;
static ENPeriodIdentifierKey dummyPik;
static ENPeriodIdentifierKey testPik;
void fill_test_rki_data(infected_for_interval_ident_ctx_t* infectedIntervals, int count) {
int totalTime = EN_TEK_ROLLING_PERIOD * EN_INTERVAL_LENGTH;
int stepSize = totalTime / count;
for (int i = 0; i < count; i++) {
int intervalNumber = (i * stepSize) / EN_INTERVAL_LENGTH;
en_derive_interval_identifier(&infectedIntervals[i].interval_identifier, &infectedPik, intervalNumber);
infectedIntervals[i].met = 0;
infectedIntervals[i].search_start = i < 3 ? 0 : (i - 2) * stepSize;
infectedIntervals[i].search_end = (i + 2) * stepSize;
}
}
////////////////////
// MEASURING FUNC //
////////////////////
void measure_perf(infected_for_interval_ident_ctx_t testIntervals[], int count) {
const char* label = "bloom filter";
printk("---------------------------\n'%s': starting measurement\n", label);
// fill_test_rki_data(infectedIntervals, count);
// setup our ordered array with met RPIs
printk("Starting measurements with %d RPIs to seach and an infection rate of %d\n", count,
CONFIG_TEST_INFECTED_RATE);
timing_t start_time, end_time;
uint64_t total_cycles;
uint64_t total_ns;
timing_init();
timing_start();
start_time = timing_counter_get();
check_possible_contacts_for_intervals(testIntervals, count);
end_time = timing_counter_get();
total_cycles = timing_cycles_get(&start_time, &end_time);
total_ns = timing_cycles_to_ns(total_cycles);
timing_stop();
printk("\n'%s' took %lld ms\n---------------------------\n", label, total_ns / 1000000);
}
void check_results(infected_for_interval_ident_ctx_t testIntervals[], int count) {
int counter = 0;
for (int i = 0; i < count / 2; i++) {
counter += CONFIG_TEST_RECORDS_PER_INTERVAL * CONFIG_TEST_INFECTED_RATE;
int met = counter / 100;
counter %= 100;
if (testIntervals[i].met != met) {
printk("interval %d should have been met %d times (met %d)\n", i, met, testIntervals[i].met);
return;
}
}
for (int j = count / 2; j < count; j++) {
if (testIntervals[j].met) {
printk("infected interval should not have been met (interval %d)\n", j);
return;
}
}
printk("all results are as expected!\n");
}
int reverse_bloom_filter(infected_for_interval_ident_ctx_t* ctx, int count) {
bloom_filter_t* bloom = bloom_init(count * 2);
if (!bloom) {
printk("bloom init failed\n");
return -1;
}
// init bloom filter with passed records
for (int i = 0; i < count; i++) {
bloom_add_record(bloom, &ctx[i].interval_identifier);
}
int rc = 0;
// init iterator over the entire storage
record_iterator_t iterator;
rc = ens_records_iterator_init_timerange(&iterator, NULL, NULL);
if (rc) {
printk("init iterator failed (err %d)\n", rc);
goto cleanup;
}
record_t* current;
while ((current = ens_records_iterator_next(&iterator))) {
if (bloom_probably_has_record(bloom, &(current->rolling_proximity_identifier))) {
for (int i = 0; i < count; i++) {
if (memcmp(&(current->rolling_proximity_identifier), &ctx[i].interval_identifier,
sizeof(current->rolling_proximity_identifier)) == 0) {
ctx[i].met++;
}
}
}
}
cleanup:
// destroy bloom filter after things are finished
bloom_destroy(bloom);
return rc;
}
////////////////////
// SETUP DATA //
////////////////////
void setup_test_data(infected_for_interval_ident_ctx_t testIntervals[], int count) {
en_derive_period_identifier_key(&infectedPik, &infectedPeriodKey);
en_derive_period_identifier_key(&dummyPik, &dummyPeriodKey);
en_derive_period_identifier_key(&testPik, &testKey);
int counter = 0;
for (int i = 0; i < EN_TEK_ROLLING_PERIOD; i++) {
record_t infectedRecord;
record_t dummyRecord;
en_derive_interval_identifier((ENIntervalIdentifier*)&infectedRecord.rolling_proximity_identifier, &infectedPik,
i);
en_derive_interval_identifier((ENIntervalIdentifier*)&dummyRecord.rolling_proximity_identifier, &dummyPik, i);
for (int j = 0; j < CONFIG_TEST_RECORDS_PER_INTERVAL; j++) {
counter += CONFIG_TEST_INFECTED_RATE;
record_t* curRecord;
if (counter >= 100) {
counter -= 100;
curRecord = &infectedRecord;
} else {
curRecord = &dummyRecord;
}
curRecord->timestamp = i * EN_INTERVAL_LENGTH + j * (EN_INTERVAL_LENGTH / CONFIG_TEST_RECORDS_PER_INTERVAL);
int rc = add_record(curRecord);
if (rc) {
printk("err %d\n", rc);
}
}
}
for (int i = 0; i < count / 2; i++) {
en_derive_interval_identifier(&testIntervals[i].interval_identifier, &infectedPik, i);
testIntervals[i].met = 0;
testIntervals[i].search_start = MAX(0, (i * EN_INTERVAL_LENGTH - 2 * 60 * 60));
testIntervals[i].search_end = i * EN_INTERVAL_LENGTH + 2 * 60 * 60;
int j = i + count / 2;
en_derive_interval_identifier(&testIntervals[j].interval_identifier, &testPik, i);
testIntervals[j].met = 0;
testIntervals[j].search_start = MAX(0, (i * EN_INTERVAL_LENGTH - 2 * 60 * 60));
testIntervals[j].search_end = i * EN_INTERVAL_LENGTH + 2 * 60 * 60;
}
}
int init_contacts() {
#if CONFIG_CONTACTS_PERFORM_RISC_CHECK_TEST
static infected_for_interval_ident_ctx_t testIntervals[EN_TEK_ROLLING_PERIOD * 2];
reset_record_storage();
setup_test_data(testIntervals, EN_TEK_ROLLING_PERIOD * 2);
measure_perf(testIntervals, EN_TEK_ROLLING_PERIOD * 2);
check_results(testIntervals, EN_TEK_ROLLING_PERIOD * 2);
#endif
return 0;
}
int check_possible_contacts_for_intervals(infected_for_interval_ident_ctx_t* ctx, int count) {
#if CONFIG_CONTACTS_BLOOM_REVERSE
return reverse_bloom_filter(ctx, count);
#else
return bloom_filter(ctx, count);
#endif
}
int check_possible_contacts_for_periods(period_key_information_t periodKeyInformation[], int count) {
for (int i = 0; i < count; i++) {
static infected_for_interval_ident_ctx_t intervalIdents[EN_TEK_ROLLING_PERIOD];
int periodStart = en_get_interval_number(periodKeyInformation[i].start);
for (int interval = 0; interval < EN_TEK_ROLLING_PERIOD; interval++) {
en_derive_interval_identifier(&intervalIdents[interval].interval_identifier,
&periodKeyInformation[i].periodKey, periodStart + interval);
}
int rc = check_possible_contacts_for_intervals(intervalIdents, 0);
if (rc < 0) {
return rc;
}
periodKeyInformation[i].met = rc;
}
return 0;
}