/*
- * win32_common.c - Windows code common to applying and capturing images, as
- * well as replacements for various functions not available on Windows, such as
- * fsync().
+ * win32_common.c - Windows code common to applying and capturing images.
*/
/*
- * Copyright (C) 2013 Eric Biggers
+ * Copyright (C) 2013, 2014 Eric Biggers
*
* This file is part of wimlib, a library for working with WIM files.
*
#ifdef __WIN32__
-#include <shlwapi.h> /* for PathMatchSpecW() */
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
#include <errno.h>
-#include "win32_common.h"
+#include "wimlib/win32_common.h"
+#include "wimlib/error.h"
+#include "wimlib/util.h"
-#ifdef ENABLE_ERROR_MESSAGES
-void
-win32_error(DWORD err_code)
-{
- wchar_t *buffer;
- DWORD nchars;
- nchars = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
- FORMAT_MESSAGE_ALLOCATE_BUFFER,
- NULL, err_code, 0,
- (wchar_t*)&buffer, 0, NULL);
- if (nchars == 0) {
- ERROR("Error printing error message! "
- "Computer will self-destruct in 3 seconds.");
- } else {
- ERROR("Win32 error: %ls", buffer);
- LocalFree(buffer);
- }
-}
-#endif /* ENABLE_ERROR_MESSAGES */
-
-int
+static int
win32_error_to_errno(DWORD err_code)
{
/* This mapping is that used in Cygwin.
}
void
-set_errno_from_GetLastError()
+set_errno_from_win32_error(DWORD err)
{
- errno = win32_error_to_errno(GetLastError());
+ errno = win32_error_to_errno(err);
}
-/* Replacement for POSIX fsync() */
-int
-fsync(int fd)
+void
+set_errno_from_GetLastError(void)
{
- HANDLE h;
-
- h = (HANDLE)_get_osfhandle(fd);
- if (h == INVALID_HANDLE_VALUE)
- goto err;
- if (!FlushFileBuffers(h))
- goto err_set_errno;
- return 0;
-err_set_errno:
- set_errno_from_GetLastError();
-err:
- return -1;
+ set_errno_from_win32_error(GetLastError());
}
-/* Use the Win32 API to get the number of processors */
-unsigned
-win32_get_number_of_processors()
+void
+set_errno_from_nt_status(NTSTATUS status)
{
- SYSTEM_INFO sysinfo;
- GetSystemInfo(&sysinfo);
- return sysinfo.dwNumberOfProcessors;
+ set_errno_from_win32_error((*func_RtlNtStatusToDosError)(status));
}
-/* Replacement for POSIX-2008 realpath(). Warning: partial functionality only
- * (resolved_path must be NULL). Also I highly doubt that GetFullPathName
- * really does the right thing under all circumstances. */
-wchar_t *
-realpath(const wchar_t *path, wchar_t *resolved_path)
+static bool
+win32_modify_privilege(const wchar_t *privilege, bool enable)
{
- DWORD ret;
- DWORD err;
- wimlib_assert(resolved_path == NULL);
-
- ret = GetFullPathNameW(path, 0, NULL, NULL);
- if (!ret) {
- err = GetLastError();
- goto fail_win32;
- }
-
- resolved_path = TMALLOC(ret);
- if (!resolved_path)
+ HANDLE hToken;
+ LUID luid;
+ TOKEN_PRIVILEGES newState;
+ bool ret = FALSE;
+
+ if (!OpenProcessToken(GetCurrentProcess(),
+ TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
+ &hToken))
goto out;
- ret = GetFullPathNameW(path, ret, resolved_path, NULL);
- if (!ret) {
- err = GetLastError();
- free(resolved_path);
- resolved_path = NULL;
- goto fail_win32;
- }
- goto out;
-fail_win32:
- errno = win32_error_to_errno(err);
+
+ if (!LookupPrivilegeValue(NULL, privilege, &luid))
+ goto out_close_handle;
+
+ newState.PrivilegeCount = 1;
+ newState.Privileges[0].Luid = luid;
+ newState.Privileges[0].Attributes = (enable ? SE_PRIVILEGE_ENABLED : 0);
+ SetLastError(ERROR_SUCCESS);
+ ret = AdjustTokenPrivileges(hToken, FALSE, &newState, 0, NULL, NULL);
+ if (ret && GetLastError() == ERROR_NOT_ALL_ASSIGNED)
+ ret = FALSE;
+out_close_handle:
+ CloseHandle(hToken);
out:
- return resolved_path;
+ return ret;
}
-/* rename() on Windows fails if the destination file exists. And we need to
- * make it work on wide characters. Fix it. */
-int
-win32_rename_replacement(const wchar_t *oldpath, const wchar_t *newpath)
+static bool
+win32_modify_capture_privileges(bool enable)
{
- if (MoveFileExW(oldpath, newpath, MOVEFILE_REPLACE_EXISTING)) {
- return 0;
- } else {
- set_errno_from_GetLastError();
- return -1;
- }
+ return win32_modify_privilege(SE_BACKUP_NAME, enable)
+ && win32_modify_privilege(SE_SECURITY_NAME, enable);
}
-/* Replacement for POSIX fnmatch() (partial functionality only) */
-int
-fnmatch(const wchar_t *pattern, const wchar_t *string, int flags)
+static bool
+win32_modify_apply_privileges(bool enable)
{
- if (PathMatchSpecW(string, pattern))
- return 0;
- else
- return FNM_NOMATCH;
+ return win32_modify_privilege(SE_RESTORE_NAME, enable)
+ && win32_modify_privilege(SE_SECURITY_NAME, enable)
+ && win32_modify_privilege(SE_TAKE_OWNERSHIP_NAME, enable);
}
-/* truncate() replacement */
-int
-win32_truncate_replacement(const wchar_t *path, off_t size)
+static void
+win32_release_capture_and_apply_privileges(void)
{
- DWORD err = NO_ERROR;
- LARGE_INTEGER liOffset;
-
- HANDLE h = win32_open_existing_file(path, GENERIC_WRITE);
- if (h == INVALID_HANDLE_VALUE)
- goto fail;
-
- liOffset.QuadPart = size;
- if (!SetFilePointerEx(h, liOffset, NULL, FILE_BEGIN))
- goto fail_close_handle;
-
- if (!SetEndOfFile(h))
- goto fail_close_handle;
- CloseHandle(h);
- return 0;
-
-fail_close_handle:
- err = GetLastError();
- CloseHandle(h);
-fail:
- if (err == NO_ERROR)
- err = GetLastError();
- errno = win32_error_to_errno(err);
- return -1;
+ win32_modify_capture_privileges(false);
+ win32_modify_apply_privileges(false);
}
-
-/* This really could be replaced with _wcserror_s, but this doesn't seem to
- * actually be available in MSVCRT.DLL on Windows XP (perhaps it's statically
- * linked in by Visual Studio...?). */
-extern int
-win32_strerror_r_replacement(int errnum, wchar_t *buf, size_t buflen)
+/* Pointers to dynamically loaded functions */
+
+/* ntdll.dll */
+
+NTSTATUS (WINAPI *func_NtCreateFile)(PHANDLE FileHandle,
+ ACCESS_MASK DesiredAccess,
+ POBJECT_ATTRIBUTES ObjectAttributes,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PLARGE_INTEGER AllocationSize,
+ ULONG FileAttributes,
+ ULONG ShareAccess,
+ ULONG CreateDisposition,
+ ULONG CreateOptions,
+ PVOID EaBuffer,
+ ULONG EaLength);
+
+NTSTATUS (WINAPI *func_NtOpenFile) (PHANDLE FileHandle,
+ ACCESS_MASK DesiredAccess,
+ POBJECT_ATTRIBUTES ObjectAttributes,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ ULONG ShareAccess,
+ ULONG OpenOptions);
+
+NTSTATUS (WINAPI *func_NtReadFile) (HANDLE FileHandle,
+ HANDLE Event,
+ PIO_APC_ROUTINE ApcRoutine,
+ PVOID ApcContext,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID Buffer,
+ ULONG Length,
+ PLARGE_INTEGER ByteOffset,
+ PULONG Key);
+
+NTSTATUS (WINAPI *func_NtWriteFile) (HANDLE FileHandle,
+ HANDLE Event,
+ PIO_APC_ROUTINE ApcRoutine,
+ PVOID ApcContext,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID Buffer,
+ ULONG Length,
+ PLARGE_INTEGER ByteOffset,
+ PULONG Key);
+
+NTSTATUS (WINAPI *func_NtQueryInformationFile)(HANDLE FileHandle,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID FileInformation,
+ ULONG Length,
+ FILE_INFORMATION_CLASS FileInformationClass);
+
+NTSTATUS (WINAPI *func_NtQuerySecurityObject)(HANDLE handle,
+ SECURITY_INFORMATION SecurityInformation,
+ PSECURITY_DESCRIPTOR SecurityDescriptor,
+ ULONG Length,
+ PULONG LengthNeeded);
+
+NTSTATUS (WINAPI *func_NtQueryDirectoryFile) (HANDLE FileHandle,
+ HANDLE Event,
+ PIO_APC_ROUTINE ApcRoutine,
+ PVOID ApcContext,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID FileInformation,
+ ULONG Length,
+ FILE_INFORMATION_CLASS FileInformationClass,
+ BOOLEAN ReturnSingleEntry,
+ PUNICODE_STRING FileName,
+ BOOLEAN RestartScan);
+
+NTSTATUS (WINAPI *func_NtQueryVolumeInformationFile) (HANDLE FileHandle,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID FsInformation,
+ ULONG Length,
+ FS_INFORMATION_CLASS FsInformationClass);
+
+NTSTATUS (WINAPI *func_NtSetInformationFile)(HANDLE FileHandle,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ PVOID FileInformation,
+ ULONG Length,
+ FILE_INFORMATION_CLASS FileInformationClass);
+
+NTSTATUS (WINAPI *func_NtSetSecurityObject)(HANDLE Handle,
+ SECURITY_INFORMATION SecurityInformation,
+ PSECURITY_DESCRIPTOR SecurityDescriptor);
+
+NTSTATUS (WINAPI *func_NtFsControlFile) (HANDLE FileHandle,
+ HANDLE Event,
+ PIO_APC_ROUTINE ApcRoutine,
+ PVOID ApcContext,
+ PIO_STATUS_BLOCK IoStatusBlock,
+ ULONG FsControlCode,
+ PVOID InputBuffer,
+ ULONG InputBufferLength,
+ PVOID OutputBuffer,
+ ULONG OutputBufferLength);
+
+NTSTATUS (WINAPI *func_NtClose) (HANDLE Handle);
+
+DWORD (WINAPI *func_RtlNtStatusToDosError)(NTSTATUS status);
+
+BOOLEAN (WINAPI *func_RtlDosPathNameToNtPathName_U)
+ (IN PCWSTR DosName,
+ OUT PUNICODE_STRING NtName,
+ OUT PCWSTR *PartName,
+ OUT PRTL_RELATIVE_NAME_U RelativeName);
+
+NTSTATUS (WINAPI *func_RtlDosPathNameToNtPathName_U_WithStatus)
+ (IN PCWSTR DosName,
+ OUT PUNICODE_STRING NtName,
+ OUT PCWSTR *PartName,
+ OUT PRTL_RELATIVE_NAME_U RelativeName);
+
+NTSTATUS (WINAPI *func_RtlCreateSystemVolumeInformationFolder)
+ (PCUNICODE_STRING VolumeRootPath);
+
+static OSVERSIONINFO windows_version_info = {
+ .dwOSVersionInfoSize = sizeof(OSVERSIONINFO),
+};
+
+static bool acquired_privileges = false;
+
+bool
+windows_version_is_at_least(unsigned major, unsigned minor)
{
- static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;
-
- pthread_mutex_lock(&strerror_lock);
- mbstowcs(buf, strerror(errnum), buflen);
- buf[buflen - 1] = '\0';
- pthread_mutex_unlock(&strerror_lock);
- return 0;
+ return windows_version_info.dwMajorVersion > major ||
+ (windows_version_info.dwMajorVersion == major &&
+ windows_version_info.dwMinorVersion >= minor);
}
-static int
-do_pread_or_pwrite(int fd, void *buf, size_t count, off_t offset,
- bool is_pwrite)
-{
- HANDLE h;
- LARGE_INTEGER orig_offset;
- DWORD bytes_read_or_written;
- LARGE_INTEGER relative_offset;
- OVERLAPPED overlapped;
- BOOL bret;
-
- wimlib_assert(count <= 0xffffffff);
-
- h = (HANDLE)_get_osfhandle(fd);
- if (h == INVALID_HANDLE_VALUE)
- goto err;
-
- /* Get original position */
- relative_offset.QuadPart = 0;
- if (!SetFilePointerEx(h, relative_offset, &orig_offset, FILE_CURRENT))
- goto err_set_errno;
-
- memset(&overlapped, 0, sizeof(overlapped));
- overlapped.Offset = offset;
- overlapped.OffsetHigh = offset >> 32;
-
- /* Do the read or write at the specified offset */
- if (is_pwrite)
- bret = WriteFile(h, buf, count, &bytes_read_or_written, &overlapped);
- else
- bret = ReadFile(h, buf, count, &bytes_read_or_written, &overlapped);
- if (!bret)
- goto err_set_errno;
-
- /* Restore the original position */
- if (!SetFilePointerEx(h, orig_offset, NULL, FILE_BEGIN))
- goto err_set_errno;
-
- return bytes_read_or_written;
-err_set_errno:
- set_errno_from_GetLastError();
-err:
- return -1;
-}
+struct dll_sym {
+ void **func_ptr;
+ const char *name;
+ bool required;
+};
+
+#define DLL_SYM(name, required) { (void **)&func_##name, #name, required }
+
+#define for_each_sym(sym, spec) \
+ for ((sym) = (spec)->syms; (sym)->name; (sym)++)
+
+struct dll_spec {
+ const wchar_t *name;
+ HMODULE handle;
+ const struct dll_sym syms[];
+};
+
+struct dll_spec ntdll_spec = {
+ .name = L"ntdll.dll",
+ .syms = {
+ DLL_SYM(NtCreateFile, true),
+ DLL_SYM(NtOpenFile, true),
+ DLL_SYM(NtReadFile, true),
+ DLL_SYM(NtWriteFile, true),
+ DLL_SYM(NtQueryInformationFile, true),
+ DLL_SYM(NtQuerySecurityObject, true),
+ DLL_SYM(NtQueryDirectoryFile, true),
+ DLL_SYM(NtQueryVolumeInformationFile, true),
+ DLL_SYM(NtSetInformationFile, true),
+ DLL_SYM(NtSetSecurityObject, true),
+ DLL_SYM(NtFsControlFile, true),
+ DLL_SYM(NtClose, true),
+ DLL_SYM(RtlNtStatusToDosError, true),
+ DLL_SYM(RtlCreateSystemVolumeInformationFolder, false),
+ DLL_SYM(RtlDosPathNameToNtPathName_U, true),
+ DLL_SYM(RtlDosPathNameToNtPathName_U_WithStatus, false), /* Not present on XP */
+ {NULL, NULL},
+ },
+};
-/* Dumb Windows implementation of pread(). It temporarily changes the file
- * offset, so it is not safe to use with readers/writers on the same file
- * descriptor. */
-extern ssize_t
-win32_pread(int fd, void *buf, size_t count, off_t offset)
-{
- return do_pread_or_pwrite(fd, buf, count, offset, false);
-}
-
-/* Dumb Windows implementation of pwrite(). It temporarily changes the file
- * offset, so it is not safe to use with readers/writers on the same file
- * descriptor. */
-extern ssize_t
-win32_pwrite(int fd, const void *buf, size_t count, off_t offset)
-{
- return do_pread_or_pwrite(fd, (void*)buf, count, offset, true);
-}
-
-/* Dumb Windows implementation of writev(). It writes the vectors one at a
- * time. */
-extern ssize_t
-win32_writev(int fd, const struct iovec *iov, int iovcnt)
+static int
+init_dll(struct dll_spec *spec)
{
- ssize_t total_bytes_written = 0;
-
- if (iovcnt <= 0) {
- errno = EINVAL;
- return -1;
+ const struct dll_sym *sym;
+ void *addr;
+
+ if (!spec->handle)
+ spec->handle = LoadLibrary(spec->name);
+ if (!spec->handle) {
+ for_each_sym(sym, spec) {
+ if (sym->required) {
+ ERROR("%ls could not be loaded!", spec->name);
+ return WIMLIB_ERR_UNSUPPORTED;
+ }
+ }
+ return 0;
}
- for (int i = 0; i < iovcnt; i++) {
- ssize_t bytes_written;
-
- bytes_written = write(fd, iov[i].iov_base, iov[i].iov_len);
- if (bytes_written >= 0)
- total_bytes_written += bytes_written;
- if (bytes_written != iov[i].iov_len) {
- if (total_bytes_written == 0)
- total_bytes_written = -1;
- break;
+ for_each_sym(sym, spec) {
+ addr = (void *)GetProcAddress(spec->handle, sym->name);
+ if (addr) {
+ *(sym->func_ptr) = addr;
+ } else if (sym->required) {
+ ERROR("Can't find %s in %ls", sym->name, spec->name);
+ return WIMLIB_ERR_UNSUPPORTED;
}
}
- return total_bytes_written;
+ return 0;
}
-/* Given a path, which may not yet exist, get a set of flags that describe the
- * features of the volume the path is on. */
-int
-win32_get_vol_flags(const wchar_t *path, unsigned *vol_flags_ret)
+static void
+cleanup_dll(struct dll_spec *spec)
{
- wchar_t *volume;
- BOOL bret;
- DWORD vol_flags;
-
- if (path[0] != L'\0' && path[0] != L'\\' &&
- path[0] != L'/' && path[1] == L':')
- {
- /* Path starts with a drive letter; use it. */
- volume = alloca(4 * sizeof(wchar_t));
- volume[0] = path[0];
- volume[1] = path[1];
- volume[2] = L'\\';
- volume[3] = L'\0';
- } else {
- /* Path does not start with a drive letter; use the volume of
- * the current working directory. */
- volume = NULL;
- }
- bret = GetVolumeInformationW(volume, /* lpRootPathName */
- NULL, /* lpVolumeNameBuffer */
- 0, /* nVolumeNameSize */
- NULL, /* lpVolumeSerialNumber */
- NULL, /* lpMaximumComponentLength */
- &vol_flags, /* lpFileSystemFlags */
- NULL, /* lpFileSystemNameBuffer */
- 0); /* nFileSystemNameSize */
- if (!bret) {
- DWORD err = GetLastError();
- WARNING("Failed to get volume information for path \"%ls\"", path);
- win32_error(err);
- vol_flags = 0xffffffff;
- }
+ const struct dll_sym *sym;
- DEBUG("using vol_flags = %x", vol_flags);
- *vol_flags_ret = vol_flags;
- return 0;
-}
+ if (spec->handle) {
+ FreeLibrary(spec->handle);
+ spec->handle = NULL;
-HANDLE
-win32_open_existing_file(const wchar_t *path, DWORD dwDesiredAccess)
-{
- return CreateFileW(path,
- dwDesiredAccess,
- FILE_SHARE_READ,
- NULL, /* lpSecurityAttributes */
- OPEN_EXISTING,
- FILE_FLAG_BACKUP_SEMANTICS |
- FILE_FLAG_OPEN_REPARSE_POINT,
- NULL /* hTemplateFile */);
+ for_each_sym(sym, spec)
+ *(sym->func_ptr) = NULL;
+ }
}
-HANDLE
-win32_open_file_data_only(const wchar_t *path)
+/* One-time initialization for Windows capture/apply code. */
+int
+win32_global_init(int init_flags)
{
- return win32_open_existing_file(path, FILE_READ_DATA);
-}
+ int ret;
+
+ /* Try to acquire useful privileges. */
+ if (!(init_flags & WIMLIB_INIT_FLAG_DONT_ACQUIRE_PRIVILEGES)) {
+ ret = WIMLIB_ERR_INSUFFICIENT_PRIVILEGES;
+ if (!win32_modify_capture_privileges(true))
+ if (init_flags & WIMLIB_INIT_FLAG_STRICT_CAPTURE_PRIVILEGES)
+ goto out_drop_privs;
+ if (!win32_modify_apply_privileges(true))
+ if (init_flags & WIMLIB_INIT_FLAG_STRICT_APPLY_PRIVILEGES)
+ goto out_drop_privs;
+ acquired_privileges = true;
+ }
-/* Pointers to functions that are not available on all targetted versions of
- * Windows (XP and later). NOTE: The WINAPI annotations seem to be important; I
- * assume it specifies a certain calling convention. */
+ /* Get Windows version information. */
+ GetVersionEx(&windows_version_info);
-/* Vista and later */
-HANDLE (WINAPI *win32func_FindFirstStreamW)(LPCWSTR lpFileName,
- STREAM_INFO_LEVELS InfoLevel,
- LPVOID lpFindStreamData,
- DWORD dwFlags) = NULL;
+ ret = init_dll(&ntdll_spec);
+ if (ret)
+ goto out_drop_privs;
-/* Vista and later */
-BOOL (WINAPI *win32func_FindNextStreamW)(HANDLE hFindStream,
- LPVOID lpFindStreamData) = NULL;
+ return 0;
-static HMODULE hKernel32 = NULL;
+out_drop_privs:
+ win32_release_capture_and_apply_privileges();
+ return ret;
+}
-/* Try to dynamically load some functions */
void
-win32_global_init()
+win32_global_cleanup(void)
{
- DWORD err;
-
- if (hKernel32 == NULL) {
- DEBUG("Loading Kernel32.dll");
- hKernel32 = LoadLibraryW(L"Kernel32.dll");
- if (hKernel32 == NULL) {
- err = GetLastError();
- WARNING("Can't load Kernel32.dll");
- win32_error(err);
- return;
- }
- }
+ if (acquired_privileges)
+ win32_release_capture_and_apply_privileges();
- win32func_FindFirstStreamW = (void*)GetProcAddress(hKernel32,
- "FindFirstStreamW");
- if (win32func_FindFirstStreamW) {
- win32func_FindNextStreamW = (void*)GetProcAddress(hKernel32,
- "FindNextStreamW");
- if (!win32func_FindNextStreamW)
- win32func_FindFirstStreamW = NULL;
- }
+ cleanup_dll(&ntdll_spec);
}
-void
-win32_global_cleanup()
+/*
+ * Translates a Win32-namespace path into an NT-namespace path.
+ *
+ * On success, returns 0. The NT-namespace path will be stored in the
+ * UNICODE_STRING structure pointed to by nt_path. nt_path->Buffer will be set
+ * to a new buffer that must later be freed with HeapFree(). (Really
+ * RtlHeapFree(), but HeapFree() seems to be the same thing.)
+ *
+ * On failure, returns WIMLIB_ERR_NOMEM or WIMLIB_ERR_INVALID_PARAM.
+ */
+int
+win32_path_to_nt_path(const wchar_t *win32_path, UNICODE_STRING *nt_path)
{
- if (hKernel32 != NULL) {
- DEBUG("Closing Kernel32.dll");
- FreeLibrary(hKernel32);
- hKernel32 = NULL;
+ NTSTATUS status;
+
+ if (func_RtlDosPathNameToNtPathName_U_WithStatus) {
+ status = (*func_RtlDosPathNameToNtPathName_U_WithStatus)(win32_path,
+ nt_path,
+ NULL, NULL);
+ } else {
+ if ((*func_RtlDosPathNameToNtPathName_U)(win32_path, nt_path,
+ NULL, NULL))
+ status = STATUS_SUCCESS;
+ else
+ status = STATUS_NO_MEMORY;
}
+
+ if (likely(NT_SUCCESS(status)))
+ return 0;
+
+ if (status == STATUS_NO_MEMORY)
+ return WIMLIB_ERR_NOMEM;
+
+ ERROR("\"%ls\": invalid path name (status=0x%08"PRIx32")",
+ win32_path, (u32)status);
+ return WIMLIB_ERR_INVALID_PARAM;
}
#endif /* __WIN32__ */
git://wimlib.net / wimlib / blobdiff