return ret;
}
-/* Reparse point fixup status code */
+/* Reparse point fixup status code */
enum rp_status {
- /* Reparse point corresponded to an absolute symbolic link or junction
- * point that pointed outside the directory tree being captured, and
- * therefore was excluded. */
- RP_EXCLUDED = 0x0,
-
- /* Reparse point was not fixed as it was either a relative symbolic
- * link, a mount point, or something else we could not understand. */
- RP_NOT_FIXED = 0x1,
-
- /* Reparse point corresponded to an absolute symbolic link or junction
- * point that pointed inside the directory tree being captured, where
- * the target was specified by a "full" \??\ prefixed path, and
- * therefore was fixed to be relative to the root of the directory tree
- * being captured. */
- RP_FIXED_FULLPATH = 0x2,
-
- /* Same as RP_FIXED_FULLPATH, except the absolute link target did not
- * have the \??\ prefix. It may have begun with a drive letter though.
- * */
- RP_FIXED_ABSPATH = 0x4,
-
- /* Either RP_FIXED_FULLPATH or RP_FIXED_ABSPATH. */
- RP_FIXED = RP_FIXED_FULLPATH | RP_FIXED_ABSPATH,
+ /* Reparse point should be excluded from capture */
+ RP_EXCLUDED = -0,
+
+ /* Reparse point will be captured literally (no fixup) */
+ RP_NOT_FIXED = -1,
+
+ /* Reparse point will be captured with fixup */
+ RP_FIXED = -2,
};
-/* Given the "substitute name" target of a Windows reparse point, try doing a
- * fixup where we change it to be absolute relative to the root of the directory
- * tree being captured.
+static bool
+file_has_ino_and_dev(HANDLE h, u64 ino, u64 dev)
+{
+ NTSTATUS status;
+ IO_STATUS_BLOCK iosb;
+ FILE_INTERNAL_INFORMATION int_info;
+ FILE_FS_VOLUME_INFORMATION vol_info;
+
+ status = (*func_NtQueryInformationFile)(h, &iosb,
+ &int_info, sizeof(int_info),
+ FileInternalInformation);
+ if (!NT_SUCCESS(status))
+ return false;
+
+ if (int_info.IndexNumber.QuadPart != ino)
+ return false;
+
+ status = (*func_NtQueryVolumeInformationFile)(h, &iosb,
+ &vol_info, sizeof(vol_info),
+ FileFsVolumeInformation);
+ if (!(NT_SUCCESS(status) || status == STATUS_BUFFER_OVERFLOW))
+ return false;
+
+ if (iosb.Information <
+ offsetof(FILE_FS_VOLUME_INFORMATION, VolumeSerialNumber) +
+ sizeof(vol_info.VolumeSerialNumber))
+ return false;
+
+ return (vol_info.VolumeSerialNumber == dev);
+}
+
+/*
+ * Given an (expected) NT namespace symbolic link or junction target @target of
+ * length @target_nbytes, determine if a prefix of the target points to a file
+ * identified by @capture_root_ino and @capture_root_dev.
+ *
+ * If yes, return a pointer to the portion of the link following this prefix.
*
- * Note that this is only executed when WIMLIB_ADD_FLAG_RPFIX has been
- * set.
+ * If no, return NULL.
*
- * @capture_root_ino and @capture_root_dev indicate the inode number and device
- * of the root of the directory tree being captured. They are meant to identify
- * this directory (as an alternative to its actual path, which could potentially
- * be reached via multiple destinations due to other symbolic links). This may
- * not work properly on FAT, which doesn't seem to supply proper inode numbers
- * or file IDs. However, FAT doesn't support reparse points so this function
- * wouldn't even be called anyway.
+ * If the link target does not appear to be a valid NT namespace path, return
+ * @target itself.
*/
-static enum rp_status
-winnt_capture_maybe_rpfix_target(wchar_t *target, u16 *target_nbytes_p,
- u64 capture_root_ino, u64 capture_root_dev,
- u32 rptag)
+static const wchar_t *
+winnt_get_root_relative_target(const wchar_t *target, size_t target_nbytes,
+ u64 capture_root_ino, u64 capture_root_dev)
{
- u16 target_nchars = *target_nbytes_p / 2;
- size_t stripped_chars;
- wchar_t *orig_target;
- int ret;
+ UNICODE_STRING name;
+ OBJECT_ATTRIBUTES attr;
+ IO_STATUS_BLOCK iosb;
+ NTSTATUS status;
+ const wchar_t *target_end;
+ const wchar_t *p;
- ret = parse_substitute_name(target, *target_nbytes_p, rptag);
- if (ret < 0)
- return RP_NOT_FIXED;
- stripped_chars = ret;
- if (stripped_chars)
- stripped_chars -= 2;
- target[target_nchars] = L'\0';
- orig_target = target;
- target = capture_fixup_absolute_symlink(target + stripped_chars,
- capture_root_ino, capture_root_dev);
- if (!target)
- return RP_EXCLUDED;
- target_nchars = wcslen(target);
- wmemmove(orig_target + stripped_chars, target, target_nchars + 1);
- *target_nbytes_p = (target_nchars + stripped_chars) * sizeof(wchar_t);
- if (stripped_chars)
- return RP_FIXED_FULLPATH;
- else
- return RP_FIXED_ABSPATH;
+ target_end = target + (target_nbytes / sizeof(wchar_t));
+
+ /* Empty path??? */
+ if (target_end == target)
+ return target;
+
+ /* No leading slash??? */
+ if (target[0] != L'\\')
+ return target;
+
+ /* UNC path??? */
+ if ((target_end - target) >= 2 &&
+ target[0] == L'\\' && target[1] == L'\\')
+ return target;
+
+ attr.Length = sizeof(attr);
+ attr.RootDirectory = NULL;
+ attr.ObjectName = &name;
+ attr.Attributes = 0;
+ attr.SecurityDescriptor = NULL;
+ attr.SecurityQualityOfService = NULL;
+
+ name.Buffer = (wchar_t *)target;
+ name.Length = 0;
+ p = target;
+ do {
+ HANDLE h;
+ const wchar_t *orig_p = p;
+
+ /* Skip non-backslashes */
+ while (p != target_end && *p != L'\\')
+ p++;
+
+ /* Skip backslashes */
+ while (p != target_end && *p == L'\\')
+ p++;
+
+ /* Append path component */
+ name.Length += (p - orig_p) * sizeof(wchar_t);
+ name.MaximumLength = name.Length;
+
+ /* Try opening the file */
+ status = (*func_NtOpenFile) (&h,
+ FILE_READ_ATTRIBUTES | FILE_TRAVERSE,
+ &attr,
+ &iosb,
+ FILE_SHARE_VALID_FLAGS,
+ FILE_OPEN_FOR_BACKUP_INTENT);
+
+ if (NT_SUCCESS(status)) {
+ /* Reset root directory */
+ if (attr.RootDirectory)
+ (*func_NtClose)(attr.RootDirectory);
+ attr.RootDirectory = h;
+ name.Buffer = (wchar_t *)p;
+ name.Length = 0;
+
+ if (file_has_ino_and_dev(h, capture_root_ino,
+ capture_root_dev))
+ goto out_close_root_dir;
+ }
+ } while (p != target_end);
+
+ p = NULL;
+
+out_close_root_dir:
+ if (attr.RootDirectory)
+ (*func_NtClose)(attr.RootDirectory);
+ return p;
}
-/* Returns: `enum rp_status' value on success; negative WIMLIB_ERR_* value on
- * failure. */
-static int
-winnt_capture_try_rpfix(u8 *rpbuf, u16 *rpbuflen_p,
- u64 capture_root_ino, u64 capture_root_dev,
- const wchar_t *path, struct add_image_params *params)
+static enum rp_status
+winnt_try_rpfix(u8 *rpbuf, u16 *rpbuflen_p,
+ u64 capture_root_ino, u64 capture_root_dev,
+ const wchar_t *path, struct add_image_params *params)
{
struct reparse_data rpdata;
- int ret;
- enum rp_status rp_status;
+ const wchar_t *rel_target;
- ret = parse_reparse_data(rpbuf, *rpbuflen_p, &rpdata);
- if (ret)
- return -ret;
-
- rp_status = winnt_capture_maybe_rpfix_target(rpdata.substitute_name,
- &rpdata.substitute_name_nbytes,
- capture_root_ino,
- capture_root_dev,
- le32_to_cpu(*(le32*)rpbuf));
- if (rp_status & RP_FIXED) {
- wimlib_assert(rpdata.substitute_name_nbytes % 2 == 0);
- utf16lechar substitute_name_copy[rpdata.substitute_name_nbytes / 2];
- wmemcpy(substitute_name_copy, rpdata.substitute_name,
- rpdata.substitute_name_nbytes / 2);
- rpdata.substitute_name = substitute_name_copy;
- rpdata.print_name = substitute_name_copy;
- rpdata.print_name_nbytes = rpdata.substitute_name_nbytes;
- if (rp_status == RP_FIXED_FULLPATH) {
- /* "full path", meaning \??\ prefixed. We should not
- * include this prefix in the print name, as it is
- * apparently meant for the filesystem driver only. */
- rpdata.print_name += 4;
- rpdata.print_name_nbytes -= 8;
- }
- ret = make_reparse_buffer(&rpdata, rpbuf, rpbuflen_p);
- if (ret == 0)
- ret = rp_status;
- else
- ret = -ret;
- } else {
- if (rp_status == RP_EXCLUDED) {
- /* Ignoring absolute symbolic link or junction point
- * that points out of the tree to be captured. */
- size_t print_name_nchars = rpdata.print_name_nbytes / 2;
- wchar_t print_name0[print_name_nchars + 1];
- print_name0[print_name_nchars] = L'\0';
- wmemcpy(print_name0, rpdata.print_name, print_name_nchars);
-
- params->progress.scan.cur_path = printable_path(path);
- params->progress.scan.symlink_target = print_name0;
- do_capture_progress(params,
- WIMLIB_SCAN_DENTRY_EXCLUDED_SYMLINK,
- NULL);
- }
- ret = rp_status;
+ if (parse_reparse_data(rpbuf, *rpbuflen_p, &rpdata)) {
+ /* Couldn't even understand the reparse data. Don't try the
+ * fixup. */
+ return RP_NOT_FIXED;
}
- return ret;
+
+ /*
+ * Don't do reparse point fixups on relative symbolic links.
+ *
+ * On Windows, a relative symbolic link is supposed to be identifiable
+ * by having reparse tag WIM_IO_REPARSE_TAG_SYMLINK and flags
+ * SYMBOLIC_LINK_RELATIVE. We will use this information, although this
+ * may not always do what the user expects, since drive-relative
+ * symbolic links such as "\Users\Public" have SYMBOLIC_LINK_RELATIVE
+ * set, in addition to truely relative symbolic links such as "Users" or
+ * "Users\Public". However, WIMGAPI (as of Windows 8.1) has this same
+ * behavior.
+ *
+ * Otherwise, as far as I can tell, the targets of symbolic links that
+ * are NOT relative, as well as junctions (note: a mountpoint is the
+ * sames thing as a junction), must be NT namespace paths, for example:
+ *
+ * - \??\e:\Users\Public
+ * - \DosDevices\e:\Users\Public
+ * - \Device\HardDiskVolume4\Users\Public
+ * - \??\Volume{c47cb07c-946e-4155-b8f7-052e9cec7628}\Users\Public
+ * - \DosDevices\Volume{c47cb07c-946e-4155-b8f7-052e9cec7628}\Users\Public
+ */
+ if (rpdata.rptag == WIM_IO_REPARSE_TAG_SYMLINK &&
+ (rpdata.rpflags & SYMBOLIC_LINK_RELATIVE))
+ return RP_NOT_FIXED;
+
+ rel_target = winnt_get_root_relative_target(rpdata.substitute_name,
+ rpdata.substitute_name_nbytes,
+ capture_root_ino,
+ capture_root_dev);
+ if (!rel_target) {
+ /* Target points outside of the tree being captured. Exclude
+ * this reparse point from the capture (but inform the library
+ * user). */
+ size_t print_name_nchars = rpdata.print_name_nbytes / sizeof(wchar_t);
+ wchar_t print_name0[print_name_nchars + 1];
+ print_name0[print_name_nchars] = L'\0';
+ wmemcpy(print_name0, rpdata.print_name, print_name_nchars);
+
+ params->progress.scan.cur_path = printable_path(path);
+ params->progress.scan.symlink_target = print_name0;
+ do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED_SYMLINK, NULL);
+ return RP_EXCLUDED;
+ }
+
+ if (rel_target == rpdata.substitute_name) {
+ /* Weird target --- keep the reparse point and don't mess with
+ * it. */
+ return RP_NOT_FIXED;
+ }
+
+ /* We have an absolute target pointing within the directory being
+ * captured, @rel_target is the suffix of the link target that is the
+ * part relative to the directory being captured.
+ *
+ * We will cut off the prefix before this part (which is the path to the
+ * directory being captured) and add a dummy prefix. Since the process
+ * will need to be reversed when applying the image, it shouldn't matter
+ * what exactly the prefix is, as long as it looks like an absolute
+ * path.
+ */
+
+ {
+ size_t rel_target_nbytes =
+ rpdata.substitute_name_nbytes - ((const u8 *)rel_target -
+ (const u8 *)rpdata.substitute_name);
+ size_t rel_target_nchars = rel_target_nbytes / sizeof(wchar_t);
+
+ wchar_t tmp[rel_target_nchars + 7];
+
+ wmemcpy(tmp, L"\\??\\X:\\", 7);
+ wmemcpy(tmp + 7, rel_target, rel_target_nchars);
+
+ rpdata.substitute_name = tmp;
+ rpdata.substitute_name_nbytes = rel_target_nbytes + (7 * sizeof(wchar_t));
+ rpdata.print_name = tmp + 4;
+ rpdata.print_name_nbytes = rel_target_nbytes + (3 * sizeof(wchar_t));
+
+ if (make_reparse_buffer(&rpdata, rpbuf, rpbuflen_p))
+ return RP_NOT_FIXED;
+ }
+ return RP_FIXED;
}
/*
* fixing the targets of absolute symbolic links and junction points to be
* relative to the root of capture.
*
- * @h: Open handle to the reparse point.
- * @path: Path to the reparse point file.
- * @params: Additional parameters, including whether to do reparse point fixups
- * or not.
- * @rpbuf: Buffer of length at least REPARSE_POINT_MAX_SIZE bytes into which
- * the reparse point buffer will be loaded.
- * @rpbuflen_ret: On success, the length of the reparse point buffer in bytes
- * is written to this location.
- *
- * Returns:
- * On success, returns an `enum rp_status' value that indicates if and/or
- * how the reparse point fixup was done.
+ * @h:
+ * Open handle to the reparse point file.
+ * @path:
+ * Path to the reparse point file.
+ * @params:
+ * Capture parameters. add_flags, capture_root_ino, capture_root_dev,
+ * progress_func, and progress are used.
+ * @rpbuf:
+ * Buffer of length at least REPARSE_POINT_MAX_SIZE bytes into which the
+ * reparse point buffer will be loaded.
+ * @rpbuflen_ret:
+ * On success, the length of the reparse point buffer in bytes is written
+ * to this location.
*
- * On failure, returns a negative value that is a negated WIMLIB_ERR_*
- * code.
+ * On success, returns a nonpositive `enum rp_status' value.
+ * On failure, returns a positive error code.
*/
static int
winnt_get_reparse_data(HANDLE h, const wchar_t *path,
struct add_image_params *params,
u8 *rpbuf, u16 *rpbuflen_ret)
{
- DWORD bytesReturned;
+ DWORD bytes_returned;
u32 reparse_tag;
int ret;
u16 rpbuflen;
if (!DeviceIoControl(h, FSCTL_GET_REPARSE_POINT,
- NULL, /* "Not used with this operation; set to NULL" */
- 0, /* "Not used with this operation; set to 0" */
- rpbuf, /* "A pointer to a buffer that
- receives the reparse point data */
- REPARSE_POINT_MAX_SIZE, /* "The size of the output
- buffer, in bytes */
- &bytesReturned,
- NULL))
+ NULL, 0, rpbuf, REPARSE_POINT_MAX_SIZE,
+ &bytes_returned, NULL))
{
set_errno_from_GetLastError();
- return -WIMLIB_ERR_READ;
+ return WIMLIB_ERR_READ;
}
- if (bytesReturned < 8 || bytesReturned > REPARSE_POINT_MAX_SIZE) {
+ if (unlikely(bytes_returned < 8)) {
errno = EINVAL;
- return -WIMLIB_ERR_INVALID_REPARSE_DATA;
+ return WIMLIB_ERR_INVALID_REPARSE_DATA;
}
- rpbuflen = bytesReturned;
+ rpbuflen = bytes_returned;
reparse_tag = le32_to_cpu(*(le32*)rpbuf);
+ ret = RP_NOT_FIXED;
if (params->add_flags & WIMLIB_ADD_FLAG_RPFIX &&
(reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT))
{
- /* Try doing reparse point fixup */
- ret = winnt_capture_try_rpfix(rpbuf,
- &rpbuflen,
- params->capture_root_ino,
- params->capture_root_dev,
- path,
- params);
- } else {
- ret = RP_NOT_FIXED;
+ ret = winnt_try_rpfix(rpbuf, &rpbuflen,
+ params->capture_root_ino,
+ params->capture_root_dev,
+ path, params);
}
*rpbuflen_ret = rpbuflen;
return ret;
rpbuf = alloca(REPARSE_POINT_MAX_SIZE);
ret = winnt_get_reparse_data(h, full_path, params,
rpbuf, &rpbuflen);
- if (ret < 0) {
- /* WIMLIB_ERR_* (inverted) */
- ret = -ret;
- ERROR_WITH_ERRNO("\"%ls\": Can't get reparse data",
- printable_path(full_path));
- goto out;
- } else if (ret & RP_FIXED) {
- not_rpfixed = 0;
- } else if (ret == RP_EXCLUDED) {
+ switch (ret) {
+ case RP_EXCLUDED:
ret = 0;
goto out;
- } else {
+ case RP_FIXED:
+ not_rpfixed = 0;
+ break;
+ case RP_NOT_FIXED:
not_rpfixed = 1;
+ break;
+ default:
+ ERROR_WITH_ERRNO("\"%ls\": Can't get reparse data",
+ printable_path(full_path));
+ goto out;
}
}
git://wimlib.net / wimlib / commitdiff