rand7 w/ rand5 in C

int rand7 ()
{
  int r = 0;

  while (r == 0)
    {
      int bits[3] = {0, 0, 0};
      int v = 3;

      for (int i = 0; i < 3; i ++)
        {
          while (v == 3)
            v = rand5 ();

          if (v < 3)
            bits[i] = 1;

          v = 3;
        }

      r = (bits[2] << 2) | (bits[1] << 1) | (bits[0]);
    }

  return r;
}