src/match.c

   1 /** \ingroup contrac
   2  * @file
   3  * @author      David Llewellyn-Jones
   4  * @version     $(VERSION)
   5  *
   6  * @section LICENSE
   7  *
   8  *
   9  *
  10  * @brief
  11  * @section DESCRIPTION
  12  *
  13  *
  14  *
  15  */
  16
  17 // Includes
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <stddef.h>
  22 #include <stdint.h>
  23
  24 #include <openssl/crypto.h>
  25 #include <openssl/hmac.h>
  26 #include <openssl/err.h>
  27
  28 #include "contrac/contrac.h"
  29 #include "contrac/utils.h"
  30 #include "contrac/log.h"
  31 #include "contrac/rpi_list.h"
  32 #include "contrac/dtk_list.h"
  33
  34 #include "contrac/match.h"
  35
  36 // Defines
  37
  38 // Structures
  39
  40 struct _MatchListItem {
  41         uint32_t day_number;
  42         uint8_t time_interval_number;
  43
  44         MatchListItem * next;
  45 };
  46
  47 struct _MatchList {
  48         size_t count;
  49         MatchListItem * first;
  50         MatchListItem * last;
  51 };
  52
  53 // Function prototypes
  54
  55 MatchListItem * match_list_item_new();
  56 void match_list_item_delete(MatchListItem * data);
  57 void match_list_append(MatchList * data, MatchListItem * item);
  58
  59 // Function definitions
  60
  61 MatchList * match_list_new() {
  62         MatchList * data;
  63
  64         data = calloc(sizeof(MatchList), 1);
  65
  66         return data;
  67 }
  68
  69 void match_list_delete(MatchList * data) {
  70         if (data) {
  71                 match_list_clear(data);
  72
  73                 free(data);
  74         }
  75 }
  76
  77 MatchListItem * match_list_item_new() {
  78         MatchListItem * data;
  79
  80         data = calloc(sizeof(MatchListItem), 1);
  81
  82         return data;
  83 }
  84
  85 void match_list_item_delete(MatchListItem * data) {
  86         if (data) {
  87                 free(data);
  88         }
  89 }
  90
  91 void match_list_clear(MatchList * data) {
  92         MatchListItem * item;
  93         MatchListItem * next;
  94
  95         item = data->first;
  96         while (item) {
  97                 next = item->next;
  98                 match_list_item_delete(item);
  99                 item = next;
 100         }
 101
 102         data->first = NULL;
 103         data->last = NULL;
 104         data->count = 0;
 105 }
 106
 107 size_t match_list_count(MatchList * data) {
 108         return data->count;
 109 }
 110
 111 MatchListItem const * match_list_first(MatchList const * data) {
 112         return data->first;
 113 }
 114
 115 MatchListItem const * match_list_next(MatchListItem const * data) {
 116         return data->next;
 117 }
 118
 119
 120 uint32_t match_list_get_day_number(MatchListItem const * data) {
 121         return data->day_number;
 122 }
 123
 124 uint8_t match_list_get_time_interval_number(MatchListItem const * data) {
 125         return data->time_interval_number;
 126 }
 127
 128 void match_list_append(MatchList * data, MatchListItem * item) {
 129         if (data->last == NULL) {
 130                 data->first = item;
 131                 data->last = item;
 132         }
 133         else {
 134                 data->last->next = item;
 135                 data->last = item;
 136         }
 137         data->count++;
 138 }
 139
 140 void match_list_find_matches(MatchList * data, RpiList * beacons, DtkList * diagnosis_keys) {
 141         // For each diagnosis key, generate the RPIs and compare them against the captured RPI beacons
 142         DtkListItem const * dtk_item;
 143         RpiListItem const * rpi_item;
 144         uint8_t interval;
 145         bool result;
 146         Rpi * generated;
 147         MatchListItem * match;
 148         Dtk const * diagnosis_key;
 149         Rpi const * rpi;
 150
 151         dtk_item = dtk_list_first(diagnosis_keys);
 152         generated = rpi_new();
 153
 154         while (dtk_item != NULL) {
 155                 diagnosis_key = dtk_list_get_dtk(dtk_item);
 156                 // Generate all possible RPIs for this dtk and compare agsinst the beacons
 157                 for (interval = 0; interval < RPI_INTERVAL_MAX; ++interval) {
 158                         result = rpi_generate_proximity_id(generated, diagnosis_key, interval);
 159                         if (result) {
 160                                 // Check against all beacons
 161                                 rpi_item = rpi_list_first(beacons);
 162                                 while (rpi_item != NULL) {
 163                                         rpi = rpi_list_get_rpi(rpi_item);
 164                                         result = rpi_compare(rpi, generated);
 165
 166                                         if (result) {
 167                                                 if (interval != rpi_get_time_interval_number(rpi)) {
 168                                                         result = false;
 169                                                         LOG(LOG_DEBUG, "Matched beacons don't match intervals\n");
 170                                                 }
 171                                         }
 172
 173                                         if (result) {
 174                                                 match = match_list_item_new();
 175                                                 match->day_number = dtk_get_day_number(diagnosis_key);
 176                                                 match->time_interval_number = interval;
 177                                                 match_list_append(data, match);
 178                                         }
 179
 180                                         rpi_item = rpi_list_next(rpi_item);
 181                                 }
 182                         }
 183                 }
 184
 185                 dtk_item = dtk_list_next(dtk_item);
 186         }
 187
 188         rpi_delete(generated);
 189 }
 190
 191