Line data    Source code

       1              : #include "testitall.h"
       2              : #include <stdio.h>
       3              : #include <stdlib.h>
       4              : #include <stdint.h>
       5              : 
       6              : /**
       7              :  * @brief Generates a random number within the specified [start..end] range (inclusive).
       8              :  *
       9              :  * Reads 8 bytes from /dev/urandom to obtain a 64-bit unsigned random value.
      10              :  * The value is then mapped to the given range and stored in the variable pointed to by random_number.
      11              :  *
      12              :  * @param random_number Pointer to an unsigned 64-bit integer where the result will be stored
      13              :  * @param start Beginning of the range (inclusive)
      14              :  * @param end End of the range (inclusive)
      15              :  */
      16       755989 : Return random_number_generator(
      17              :         uint64_t *random_number,
      18              :         uint64_t start,
      19              :         uint64_t end)
      20              : {
      21       755989 :         Return status = SUCCESS;
      22              : 
      23       755989 :         FILE *fp = fopen("/dev/urandom","rb");
      24              : 
      25       755989 :         if(fp == NULL)
      26              :         {
      27            0 :                 echo(STDERR,"Can't open /dev/urandom\n");
      28            0 :                 provide(FAILURE);
      29              :         }
      30              : 
      31              :         uint64_t random_value;
      32              : 
      33       755989 :         if(SUCCESS == status)
      34              :         {
      35       755989 :                 if(fread(&random_value,sizeof(random_value),1,fp)!=1)
      36              :                 {
      37            0 :                         echo(STDERR,"Failed to read from /dev/urandom\n");
      38            0 :                         status = FAILURE;
      39              :                 }
      40              :         }
      41              : 
      42       755989 :         if(fp != NULL)
      43              :         {
      44       755989 :                 fclose(fp);
      45              :         }
      46              : 
      47       755989 :         if(SUCCESS == status)
      48              :         {
      49       755989 :                 if(end<start)
      50              :                 {
      51            0 :                         echo(STDERR,"Invalid range: end < start\n");
      52            0 :                         status = FAILURE;
      53              :                 }
      54              : 
      55       755989 :                 uint64_t range = (end-start)+1;
      56       755989 :                 *random_number = (random_value%range)+start;
      57              :         }
      58              : 
      59              :         #if 0
      60              :         printf("random:%zu\n",*random_number);
      61              :         #endif
      62              : 
      63       755989 :         provide(status);
      64              : }