Birdtest: Add Fletcher-16 Checksum Tests

/*

 *	BIRD Library -- Fletcher-16 checksum Tests

 *

 *	(c) 2015 Ondrej Zajicek <santiago@crfreenet.org>

 *	(c) 2015 CZ.NIC z.s.p.o.

 *

 *	Can be freely distributed and used under the terms of the GNU GPL.

 */

#include "test/birdtest.h"

#include "test/birdtest_support.h"	/* REMOVE ME */

#include "lib/fletcher16.h"

struct in {

  u8 *data;

  int count;

};

static u16

straightforward_fletcher16_compute(const char *data)

{

  int count = strlen(data);

  u16 sum1 = 0;

  u16 sum2 = 0;

  int index;

  for(index = 0; index < count; ++index)

  {

    sum1 = (sum1 + data[index]) % 255;

    sum2 = (sum2 + sum1) % 255;

  }

  return (sum2 << 8) | sum1;

}

static u16

straightforward_fletcher16_checksum(const char *data)

{

  u16 csum;

  u8 c0,c1,f0,f1;

  csum = straightforward_fletcher16_compute(data);

  f0 = csum & 0xff;

  f1 = (csum >> 8) & 0xff;

  c0 = 0xff - ((f0 + f1) % 0xff);

  c1 = 0xff - ((f0 + c0) % 0xff);

  return (c1 << 8) | c0;

}

static u16

get_fletcher16_compute(const char *str)

{

  struct fletcher16_context ctxt;

  fletcher16_init(&ctxt);

  fletcher16_update(&ctxt, str, strlen(str));

  u16 f;

  put_u16(&f, fletcher16_compute(&ctxt));

  return f;

}

static u16

get_fletcher16_checksum(const char *str)

{

  struct fletcher16_context ctxt;

  int len = strlen(str);

  fletcher16_init(&ctxt);

  fletcher16_update(&ctxt, str, len);

  u16 f;

  put_u16(&f, fletcher16_final(&ctxt, len, len));

  return f;

}

static int

t_fletcher16_compute(void)

{

  struct in_out {

    char *in;

    u16 out;

  } in_out[] = {

      {

	  .in  = "\001\002",

	  .out = 0x0403,

      },

      {

	  .in  = "",

	  .out = straightforward_fletcher16_compute(""),

      },

      {

	  .in  = "a",

	  .out = straightforward_fletcher16_compute("a"),

      },

      {

	  .in  = "abcd",

	  .out = straightforward_fletcher16_compute("abcd"),

      },

      {

	  .in  = "message digest",

	  .out = straightforward_fletcher16_compute("message digest"),

      },

      {

	  .in  = "abcdefghijklmnopqrstuvwxyz",

	  .out = straightforward_fletcher16_compute("abcdefghijklmnopqrstuvwxyz"),

      },

      {

	  .in  = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",

	  .out = straightforward_fletcher16_compute("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"),

      },

      {

	  .in  = "12345678901234567890123456789012345678901234567890123456789012345678901234567890",

	  .out = straightforward_fletcher16_compute("12345678901234567890123456789012345678901234567890123456789012345678901234567890"),

      },

  };

  bt_assert_out_fn_in(get_fletcher16_compute, in_out, "'%s'", "0x%04X");

  return BT_SUCCESS;

}

static int

t_fletcher16_checksum(void)

{

  struct in_out {

    char *in;

    u16 out;

  } in_out[] = {

      {

	  .in  = "\001\002",

	  .out = straightforward_fletcher16_checksum("\001\002"),

      },

      {

	  .in  = "",

	  .out = straightforward_fletcher16_checksum(""),

      },

      {

	  .in  = "a",

	  .out = straightforward_fletcher16_checksum("a"),

      },

      {

	  .in  = "abcd",

	  .out = straightforward_fletcher16_checksum("abcd"),

      },

      {

	  .in  = "message digest",

	  .out = straightforward_fletcher16_checksum("message digest"),

      },

      {

	  .in  = "abcdefghijklmnopqrstuvwxyz",

	  .out = straightforward_fletcher16_checksum("abcdefghijklmnopqrstuvwxyz"),

      },

      {

	  .in  = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",

	  .out = straightforward_fletcher16_checksum("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"),

      },

      {

	  .in  = "12345678901234567890123456789012345678901234567890123456789012345678901234567890",

	  .out = straightforward_fletcher16_checksum("12345678901234567890123456789012345678901234567890123456789012345678901234567890"),

      },

  };

  bt_assert_out_fn_in(get_fletcher16_checksum, in_out, "'%s'", "0x%04X");

  return BT_SUCCESS;

}

int

main(int argc, char *argv[])

{

  bt_init(argc, argv);

  bt_test_suite(t_fletcher16_compute, "Fletcher-16 Compute Tests");

  bt_test_suite(t_fletcher16_checksum, "Fletcher-16 Checksum Tests");

  return bt_end();

}