lib/checksum_test.c

   1 /*
   2  *      BIRD Library -- IP One-Complement Checksum Tests
   3  *
   4  *      (c) 2015 CZ.NIC z.s.p.o.
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #include <stdio.h>
  10
  11 #include "test/birdtest.h"
  12
  13 #include "lib/checksum.h"
  14
  15 #define MAX_NUM 10000
  16
  17 static u16
  18 ipsum_calculate_expected(u32 *a)
  19 {
  20   int i;
  21   u32 sum = 0;
  22
  23   for(i = 0; i < MAX_NUM; i++)
  24   {
  25     sum += a[i] & 0xffff;
  26     bt_debug("low) \t0x%08X \n", sum);
  27
  28     sum += a[i] >> 16;
  29     bt_debug("high) \t0x%08X \n", sum);
  30
  31     u16 carry = sum >> 16;
  32     sum = (sum & 0xffff) + carry;
  33     bt_debug("carry) \t0x%08X \n\n", sum);
  34   }
  35   bt_debug("sum) \t0x%08X \n", sum);
  36
  37   sum = sum ^ 0xffff;
  38   bt_debug("~sum) \t0x%08X \n", sum);
  39
  40   return sum;
  41 }
  42
  43 static int
  44 t_calculate(void)
  45 {
  46   u32 a[MAX_NUM];
  47   int i;
  48
  49   for (i = 0; i < MAX_NUM; i++)
  50     a[i] = bt_random();
  51
  52   u16 sum_calculated   = ipsum_calculate(a, sizeof(a), NULL);
  53   u16 sum_calculated_2 = ipsum_calculate(&a[0], sizeof(u32)*(MAX_NUM/2), &a[MAX_NUM/2], sizeof(u32)*(MAX_NUM - MAX_NUM/2), NULL);
  54   bt_assert(sum_calculated == sum_calculated_2);
  55
  56   u16 sum_expected = ipsum_calculate_expected(a);
  57
  58   bt_debug("sum_calculated: %08X \n", sum_calculated);
  59   bt_debug("sum_expected:   %08X \n", sum_expected);
  60
  61   bt_assert(sum_calculated == sum_expected);
  62
  63   return 1;
  64 }
  65
  66 static int
  67 t_verify(void)
  68 {
  69   u32 a[MAX_NUM+1];
  70   int i;
  71
  72   for (i = 0; i < MAX_NUM; i++)
  73     a[i] = bt_random();
  74
  75   u16 sum = ipsum_calculate_expected(a);
  76
  77   a[MAX_NUM] = sum;
  78
  79   bt_assert(ipsum_verify(a, sizeof(a), NULL));
  80
  81   return 1;
  82 }
  83
  84
  85 int
  86 main(int argc, char *argv[])
  87 {
  88   bt_init(argc, argv);
  89
  90   bt_test_suite(t_calculate, "Checksum of pseudo-random data");
  91   bt_test_suite(t_verify, "Verification of pseudo-random data.");
  92
  93   return bt_exit_value();
  94 }