Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Calculates true parent's relative path in Differencing VHD locator #5153

Merged
merged 4 commits into from
Aug 9, 2024
Merged

Calculates true parent's relative path in Differencing VHD locator #5153

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
4c1555b
fill W2ru relative locator with a true relative path
maxpat78 Aug 4, 2024
1e8bb63
Merge branch 'master' of https://github.com/maxpat78/dosbox-x
maxpat78 Aug 4, 2024
c9599a4
Update .gitignore
maxpat78 Aug 4, 2024
31a0d99
Update bios_vhd.cpp
maxpat78 Aug 5, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions .gitignore
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -140,3 +140,7 @@ contrib/macos/dosbox-x.plist
/dosbox-x.conf
/src/dosbox-x.conf

src/dos/dos_programs.7z
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Do we need to ignore these files?
There are no such file in the current code tree.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No, you don't. In fact those files came by mistake from another code tree of mine, but they hadn't to.

src/lnkvhd.cpp
src/mkvhd.cpp
src/mkvhd.exe
95 changes: 77 additions & 18 deletions src/ints/bios_vhd.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,51 @@
*
*/

// returns the path of "base" in a form relative to "child", where both exist
char* calc_relative_path(const char* base, const char* child) {
#ifndef WIN32
char abs_base[PATH_MAX];
char abs_child[PATH_MAX];
#else
char abs_base[MAX_PATH];
char abs_child[MAX_PATH];
#endif
char* p = abs_base, * q = abs_child, * x, * y, * z;
uint32_t n = 0;

if(!base || !child) return 0;

// retrieves the corresponding absolute paths
#ifndef WIN32
realpath(base, abs_base);
realpath(child, abs_child);
#else
_fullpath(abs_base, base, MAX_PATH);
_fullpath(abs_child, child, MAX_PATH);
#endif
if(!*abs_base || !*abs_child) return 0;

// strips common subpath, if any
while(*p++ == *q++);
p--, q--;
x = q;
// count slashes
while(*x) {
if(*x == '/' || *x == '\\') n++;
x++;
}
// allocates space for the resulting string
y = (char*)malloc(strlen(q) + n * 3); // n * strlen("..\\")
z = y;
while(n--) {
strcpy(z, "..\\");
z += 3;
}
strcpy(z, p);
LOG_MSG("%s is base %s relative to child %s", y, base, child);
return y;
}

imageDiskVHD::ErrorCodes imageDiskVHD::Open(const char* fileName, const bool readOnly, imageDisk** disk) {
return Open(fileName, readOnly, disk, nullptr);
}
Expand Down Expand Up @@ -273,6 +318,7 @@ imageDiskVHD::ErrorCodes imageDiskVHD::TryOpenParent(const char* childFileName,

switch (entry.platformCode) {
case 0x57327275:
LOG_MSG("TryOpenParent (W2ru) %s", childFileName);
//Unicode relative pathname (UTF-16) on Windows

#if defined (WIN32) || defined(OS2)
Expand All @@ -295,14 +341,14 @@ imageDiskVHD::ErrorCodes imageDiskVHD::TryOpenParent(const char* childFileName,
return imageDiskVHD::Open(str.c_str(), true, disk, uniqueId);

case 0x57326B75:
LOG_MSG("TryOpenParent (W2ku) %s", childFileName);
//Unicode absolute pathname (UTF-16) on Windows

#if defined (WIN32) || defined(OS2)
/* nothing */
#else
// Linux
// Todo: convert absolute pathname to something applicable for Linux
break;
#endif

//convert byte order, and UTF-16 to ASCII, and change backslashes to slashes if on Linux
Expand Down Expand Up @@ -644,6 +690,7 @@ void imageDiskVHD::SizeToCHS(uint64_t size, uint16_t* c, uint8_t* h, uint8_t* s)

//creates a Dynamic VHD image
uint32_t imageDiskVHD::CreateDynamic(const char* filename, uint64_t size) {
LOG_MSG("CreateDynamic filename=\"%s\"", filename);
uint32_t STATUS = OPEN_SUCCESS;
if(filename == NULL) return ERROR_OPENING;
if(size < 3145728 || size > 2190433320960) // 2040GB is the Windows 11 mounter limit
Expand Down Expand Up @@ -695,6 +742,7 @@ uint32_t imageDiskVHD::CreateDynamic(const char* filename, uint64_t size) {

//creates a Differencing VHD image
uint32_t imageDiskVHD::CreateDifferencing(const char* filename, const char* basename) {
LOG_MSG("CreateDifferencing filename=\"%s\" basename=\"%s\"", filename, basename);
if(filename == NULL || basename == NULL) return ERROR_OPENING;
imageDiskVHD* base_vhd;
if(Open(basename, true, (imageDisk**)&base_vhd) != OPEN_SUCCESS) return ERROR_OPENING_PARENT;
Expand Down Expand Up @@ -732,25 +780,29 @@ uint32_t imageDiskVHD::CreateDifferencing(const char* filename, const char* base
uint32_t table_size = (4 * header.maxTableEntries + 511) / 512 * 512;

//Locators - Windows 11 wants at least the relative W2ru locator, or won't mount!
// we store the absolute pathname to prevent complex depth calculations
#if defined (WIN32)
char absBasePathName[MAX_PATH];
_fullpath(absBasePathName, basename, MAX_PATH);
#else
char absBasePathName[PATH_MAX];
realpath(basename, absBasePathName);
#endif
uint32_t l_basename = strlen(absBasePathName);
uint32_t platsize = (2 * l_basename + 511) / 512 * 512;
header.parentLocatorEntry[0].platformCode = 0x57326B75; //W2ku
header.parentLocatorEntry[0].platformDataLength = 2 * l_basename;
header.parentLocatorEntry[0].platformDataSpace = platsize;
uint32_t len1 = strlen(absBasePathName);
uint32_t plat1 = (2 * len1 + 511) / 512 * 512;
header.parentLocatorEntry[0].platformCode = 0x57326B75; //W2ku (absolute)
header.parentLocatorEntry[0].platformDataLength = 2 * len1;
header.parentLocatorEntry[0].platformDataSpace = plat1;
header.parentLocatorEntry[0].platformDataOffset = 1536 + table_size;

header.parentLocatorEntry[1].platformCode = 0x57327275; // W2ru
header.parentLocatorEntry[1].platformDataLength = 2 * l_basename;
header.parentLocatorEntry[1].platformDataSpace = platsize;
header.parentLocatorEntry[1].platformDataOffset = 2048 + table_size;
// path of parent relative to child
char* relpath = calc_relative_path(basename, filename);

uint32_t len2 = strlen(relpath);
uint32_t plat2 = (2 * len2 + 511) / 512 * 512;
header.parentLocatorEntry[1].platformCode = 0x57327275; // W2ru (relative)
header.parentLocatorEntry[1].platformDataLength = 2 * len2;
header.parentLocatorEntry[1].platformDataSpace = plat2;
header.parentLocatorEntry[1].platformDataOffset = header.parentLocatorEntry[0].platformDataOffset + plat1;

//write dynamic Header
header.checksum = header.CalculateChecksum();
Expand All @@ -768,20 +820,27 @@ uint32_t imageDiskVHD::CreateDifferencing(const char* filename, const char* base
table_size -= 512;
}
//write Parent Locator sectors
uint16_t* w_basename = (uint16_t*)malloc(platsize);
memset(w_basename, 0, platsize);
for(uint32_t i = 0; i < l_basename; i++)
uint16_t* w_basename = (uint16_t*)malloc(plat1);
memset(w_basename, 0, plat1);
for(uint32_t i = 0; i < len1; i++)
//dirty hack to quickly convert ASCII -> UTF-16 *LE* and fix slashes
w_basename[i] = SDL_SwapLE16(absBasePathName[i]=='/'? (uint16_t)'\\' : (uint16_t)absBasePathName[i]);
if (fwrite(w_basename, 1, platsize, vhd) != platsize) STATUS = ERROR_WRITING;
if (fwrite(w_basename, 1, platsize, vhd) != platsize) STATUS = ERROR_WRITING;
w_basename[i] = SDL_SwapLE16(absBasePathName[i] == '/' ? (uint16_t)'\\' : (uint16_t)absBasePathName[i]);
if(fwrite(w_basename, 1, plat1, vhd) != plat1) STATUS = ERROR_WRITING;

w_basename = (uint16_t*)realloc(w_basename, plat2);
memset(w_basename, 0, plat2);
for(uint32_t i = 0; i < len2; i++)
//dirty hack to quickly convert ASCII -> UTF-16 *LE* and fix slashes
w_basename[i] = SDL_SwapLE16(relpath[i] == '/' ? (uint16_t)'\\' : (uint16_t)relpath[i]);
if(fwrite(w_basename, 1, plat2, vhd) != plat2) STATUS = ERROR_WRITING;

//write footer copy
if(fwrite(&footer, 1, 512, vhd) != 512) STATUS = ERROR_WRITING;

delete base_vhd;
free(w_basename);
fclose(vhd);
free(w_basename);
free(relpath);
return STATUS;
}

Expand Down
Loading