int
T64Archive::getNumberOfItems()
{
int noOfItems;
// Get number of files from the file header...
noOfItems = LO_HI(data[0x24], data[0x25]);
if (noOfItems == 0) {
// Note: Some archives don't store this value properly.
// In this case, we can determine the number of files
// by iterating through the directory area...
while (directoryItemIsPresent(noOfItems))
noOfItems++;
}
return noOfItems;
}
bool
T64File::repair()
{
unsigned i, n;
uint16_t noOfItems = numberOfItems();
//
// 1. Repair number of items, if this value is zero
//
if (noOfItems == 0) {
while (directoryItemIsPresent(noOfItems))
noOfItems++;
uint16_t noOfItemsStatedInHeader = numberOfItems();
if (noOfItems != noOfItemsStatedInHeader) {
debug(1, "Repairing corrupted T64 archive: Changing number of items from %d to %d.\n",
noOfItemsStatedInHeader, noOfItems);
data[0x24] = LO_BYTE(noOfItems);
data[0x25] = HI_BYTE(noOfItems);
}
assert(noOfItems == numberOfItems());
}
for (i = 0; i < noOfItems; i++) {
//
// 2. Check relative offset information for each item
//
// Compute start address in file
n = 0x48 + (i * 0x20);
uint16_t startAddrInContainer = LO_LO_HI_HI(data[n], data[n+1], data[n+2], data[n+3]);
if (startAddrInContainer >= size) {
warn("T64 archive is corrupt (offset mismatch). Sorry, can't repair.\n");
return false;
}
//
// 3. Check for file end address mismatches (as created by CONVC64)
//
// Compute start address in memory
n = 0x42 + (i * 0x20);
uint16_t startAddrInMemory = LO_HI(data[n], data[n+1]);
// Compute end address in memory
n = 0x44 + (i * 0x20);
uint16_t endAddrInMemory = LO_HI(data[n], data[n+1]);
if (endAddrInMemory == 0xC3C6) {
// Let's assume that the rest of the file data belongs to this file ...
uint16_t fixedEndAddrInMemory = startAddrInMemory + (size - startAddrInContainer);
debug(1, "Repairing corrupted T64 archive: Changing end address of item %d from %04X to %04X.\n",
i, endAddrInMemory, fixedEndAddrInMemory);
data[n] = LO_BYTE(fixedEndAddrInMemory);
data[n+1] = HI_BYTE(fixedEndAddrInMemory);
}
}
return 1; // Archive repaired successfully
}