/* This is a lot like try_load_world but much more thorough, and doesn't
* pass data through or leave a file open. This needs to be done before
* any data is ever loaded, so that Megazeux can cleanly abort if there
* is an issue.
*/
enum val_result validate_world_file(const char *filename,
int savegame, int *end_of_global_offset, int decrypt_attempted)
{
enum val_result result = VAL_SUCCESS;
FILE *f;
char magic[15];
int num_boards;
int board_name_offset;
int v, i;
/* TEST 1: Make sure it's a readable file */
if(!(f = val_fopen(filename)))
{
val_error(FILE_DOES_NOT_EXIST, 0);
result = VAL_MISSING;
goto err_out;
}
/* TEST 2: Is it a save file? */
if(savegame)
{
int screen_mode, num_counters, num_strings, len;
if(fread(magic, 5, 1, f) != 1)
goto err_invalid;
v = save_magic(magic);
if(!v)
goto err_invalid;
else if (v > WORLD_VERSION)
{
val_error(SAVE_VERSION_TOO_RECENT, v);
result = VAL_VERSION;
goto err_close;
}
else if (v < WORLD_VERSION)
{
val_error(SAVE_VERSION_OLD, v);
result = VAL_VERSION;
goto err_close;
}
/* TEST 3: Check for truncation, savegame style, hope this
* doesn't explode :erm:
*/
if(
fseek(f, 8, SEEK_SET) ||
fseek(f, WORLD_BLOCK_1_SIZE, SEEK_CUR) ||
fseek(f, 71, SEEK_CUR) ||
fseek(f, (len = fgetw(f)), SEEK_CUR) ||
(len < 0) ||
fseek(f, WORLD_BLOCK_2_SIZE, SEEK_CUR) ||
fseek(f, 24, SEEK_CUR))
{
debug("pre-counters\n");
goto err_invalid;
}
//do counters - vvvvnnnn(name)
num_counters = fgetd(f);
if(num_counters < 0)
{
debug("counter num\n");
goto err_invalid;
}
for(i = 0; i < num_counters; i++)
{
if(
fseek(f, 4, SEEK_CUR) || //value
fseek(f, (len = fgetd(f)), SEEK_CUR) ||
(len < 0))
{
debug("counters\n");
goto err_invalid;
}
}
//do strings- nnnnllll(name)(value)
num_strings = fgetd(f);
if(num_strings < 0)
{
debug("string num\n");
goto err_invalid;
}
for(i = 0; i < num_strings; i++)
{
int name_length = fgetd(f);
int value_length = fgetd(f);
if(
(name_length < 0) ||
(value_length < 0) ||
fseek(f, name_length, SEEK_CUR) ||
fseek(f, value_length, SEEK_CUR))
{
debug("strings\n");
goto err_invalid;
}
}
if(
fseek(f, 4612, SEEK_CUR) || //sprites
fseek(f, 12, SEEK_CUR) || //misc
fseek(f, fgetw(f), SEEK_CUR) || //fread_open
fseek(f, 4, SEEK_CUR) || //fread_pos
fseek(f, fgetw(f), SEEK_CUR) || //fwrite_open
fseek(f, 4, SEEK_CUR)) //fwrite_pos
{
debug("post strings\n");
goto err_invalid;
}
screen_mode = fgetw(f);
if((screen_mode > 3) || (screen_mode > 1 &&
fseek(f, 768, SEEK_CUR))) //smzx palette
{
debug("smzx palette\n");
goto err_invalid;
}
if(
fseek(f, 4, SEEK_CUR) || //commands
((len = fgetd(f)) < 0) || //vlayer size
fseek(f, 4, SEEK_CUR) || // width & height
fseek(f, len, SEEK_CUR) || //chars
fseek(f, len, SEEK_CUR)) //colors
{
debug("vlayer\n");
goto err_invalid;
}
/* now we should be at the global robot pointer! */
}
else /* !savegame */
{
int protection_method;
/* TEST 3: Check for truncation */
if(fseek(f, WORLD_GLOBAL_OFFSET_OFFSET, SEEK_SET))
goto err_invalid;
fseek(f, BOARD_NAME_SIZE, SEEK_SET);
/* TEST 4: If we think it's locked, try to decrypt it. */
protection_method = fgetc(f);
if(protection_method > 0)
{
if(protection_method > 3)
goto err_invalid;
if(decrypt_attempted) // In the unlikely event that this will happen again
goto err_invalid;
val_error(WORLD_PASSWORD_PROTECTED, 0);
if(!confirm(NULL, "Would you like to decrypt it?"))
{
result = VAL_NEED_UNLOCK;
goto err_close;
}
else
{
val_error(WORLD_LOCKED, 0);
result = VAL_ABORTED;
goto err_close;
}
}
/* TEST 5: Make sure the magic is awwrightttt~ */
fread(magic, 1, 3, f);
v = world_magic(magic);
if(v == 0)
goto err_invalid;
else if (v < 0x0205)
{
val_error(WORLD_FILE_VERSION_OLD, v);
result = VAL_VERSION;
goto err_close;
}
else if (v > WORLD_VERSION)
{
val_error(WORLD_FILE_VERSION_TOO_RECENT, v);
result = VAL_VERSION;
goto err_close;
}
/* TEST 6: Attempt to eliminate invalid files by
* testing the palette for impossible values.
*/
fseek(f, WORLD_GLOBAL_OFFSET_OFFSET - 48, SEEK_SET);
for(i = 0; i<48; i++)
{
int val = fgetc(f);
if((val < 0) || (val > 63))
goto err_invalid;
}
/* now we should be at the global robot pointer! */
}
/* TEST 7: Either branch should be at the global robot pointer now.
* Test for valid SFX structure, if applicable, and board information.
*/
fseek(f, 4, SEEK_CUR);
// Do the sfx
num_boards = fgetc(f);
if(num_boards == 0)
{
int sfx_size = fgetw(f);
int sfx_off = ftell(f);
for (i = 0; i < NUM_SFX; i++)
{
if(fseek(f, fgetc(f), SEEK_CUR))
break;
}
if((i != NUM_SFX) || ((ftell(f) - sfx_off) != sfx_size))
goto err_invalid;
num_boards = fgetc(f);
}
if(num_boards == 0)
goto err_invalid;
board_name_offset = ftell(f);
//Make sure board name and pointer data exists
if(
fseek(f, num_boards * BOARD_NAME_SIZE, SEEK_CUR) ||
fseek(f, num_boards * 8, SEEK_CUR) ||
((ftell(f) - board_name_offset) != num_boards * (BOARD_NAME_SIZE + 8)))
goto err_invalid;
/* If any of the pointers are less than this pos we probably
* aren't dealing with a valid world, but it's not our job
* to figure that out right now, so we'll pass it back.
*/
if(end_of_global_offset)
*end_of_global_offset = ftell(f);
//todo: maybe have a complete fail when N number of pointers fail?
goto err_close;
err_invalid:
result = VAL_INVALID;
if(savegame)
val_error(SAVE_FILE_INVALID, 0);
else
val_error(WORLD_FILE_INVALID, 0);
err_close:
fclose(f);
err_out:
return result;
}
int save_world(struct world *mzx_world, const char *file, int savegame)
{
int i, num_boards;
int gl_rob_position, gl_rob_save_position;
int board_offsets_position, board_begin_position, board_end_position;
int board_size;
unsigned int *size_offset_list;
unsigned char *charset_mem;
unsigned char r, g, b;
struct board *cur_board;
FILE *fp;
int meter_target = 2 + mzx_world->num_boards, meter_curr = 0;
#ifdef CONFIG_DEBYTECODE
if(!savegame)
{
fp = fopen(file, "rb");
if(fp)
{
if(!fseek(fp, 0x1A, SEEK_SET))
{
char tmp[3];
if(fread(tmp, 1, 3, fp) == 3)
{
// If it's not a 2.90 world, abort the save
if(world_magic(tmp) < 0x025A)
{
error("Save would overwrite older world. Aborted.", 0, 1, 1337);
goto exit_close;
}
}
}
fclose(fp);
}
}
#endif
fp = fopen(file, "wb");
if(!fp)
{
error("Error saving world", 1, 8, 0x0D01);
return -1;
}
meter_initial_draw(meter_curr, meter_target, "Saving...");
if(savegame)
{
// Write this MZX's version string
fputs("MZS", fp);
fputc((WORLD_VERSION >> 8) & 0xff, fp);
fputc(WORLD_VERSION & 0xff, fp);
// Write the version of the loaded world for this SAV
fputw(mzx_world->version, fp);
fputc(mzx_world->current_board_id, fp);
}
else
{
