]> wimlib.net Git - wimlib/blobdiff - src/dentry.c
Remove some unused variables
[wimlib] / src / dentry.c
index 86a82eb6ffe771581ef358d77137a9856df61cb4..02db923af710b33cb192e55176027715f797239b 100644 (file)
@@ -38,6 +38,7 @@
 #include "wimlib/lookup_table.h"
 #include "wimlib/metadata.h"
 #include "wimlib/resource.h"
+#include "wimlib/security.h"
 #include "wimlib/sha1.h"
 #include "wimlib/timestamp.h"
 
@@ -72,18 +73,107 @@ struct wim_ads_entry_on_disk {
 
 #define WIM_ADS_ENTRY_DISK_SIZE 38
 
-/* WIM directory entry (on-disk format) */
+/* On-disk format of a WIM dentry (directory entry), located in the metadata
+ * resource for a WIM image.  */
 struct wim_dentry_on_disk {
+
+       /* Length of this directory entry in bytes, not including any alternate
+        * data stream entries.  Should be a multiple of 8 so that the following
+        * dentry or alternate data stream entry is aligned on an 8-byte
+        * boundary.  (If not, wimlib will round it up.)  It must be at least as
+        * long as the fixed-length fields of the dentry (WIM_DENTRY_DISK_SIZE),
+        * plus the lengths of the file name and/or short name if present.
+        *
+        * It is also possible for this field to be 0.  This situation, which is
+        * undocumented, indicates the end of a list of sibling nodes in a
+        * directory.  It also means the real length is 8, because the dentry
+        * included only the length field, but that takes up 8 bytes.  */
        le64 length;
+
+       /* Attributes of the file or directory.  This is a bitwise OR of the
+        * FILE_ATTRIBUTE_* constants and should correspond to the value
+        * retrieved by GetFileAttributes() on Windows. */
        le32 attributes;
+
+       /* A value that specifies the security descriptor for this file or
+        * directory.  If -1, the file or directory has no security descriptor.
+        * Otherwise, it is a 0-based index into the WIM image's table of
+        * security descriptors (see: `struct wim_security_data') */
        sle32 security_id;
+
+       /* Offset, in bytes, from the start of the uncompressed metadata
+        * resource of this directory's child directory entries, or 0 if this
+        * directory entry does not correspond to a directory or otherwise does
+        * not have any children. */
        le64 subdir_offset;
+
+       /* Reserved fields */
        le64 unused_1;
        le64 unused_2;
+
+
+       /* Creation time, last access time, and last write time, in
+        * 100-nanosecond intervals since 12:00 a.m UTC January 1, 1601.  They
+        * should correspond to the times gotten by calling GetFileTime() on
+        * Windows. */
        le64 creation_time;
        le64 last_access_time;
        le64 last_write_time;
+
+       /* Vaguely, the SHA-1 message digest ("hash") of the file's contents.
+        * More specifically, this is for the "unnamed data stream" rather than
+        * any "alternate data streams".  This hash value is used to look up the
+        * corresponding entry in the WIM's stream lookup table to actually find
+        * the file contents within the WIM.
+        *
+        * If the file has no unnamed data stream (e.g. is a directory), then
+        * this field will be all zeroes.  If the unnamed data stream is empty
+        * (i.e. an "empty file"), then this field is also expected to be all
+        * zeroes.  (It will be if wimlib created the WIM image, at least;
+        * otherwise it can't be ruled out that the SHA-1 message digest of 0
+        * bytes of data is given explicitly.)
+        *
+        * If the file has reparse data, then this field will instead specify
+        * the SHA-1 message digest of the reparse data.  If it is somehow
+        * possible for a file to have both an unnamed data stream and reparse
+        * data, then this is not handled by wimlib.
+        *
+        * As a further special case, if this field is all zeroes but there is
+        * an alternate data stream entry with no name and a nonzero SHA-1
+        * message digest field, then that hash must be used instead of this
+        * one.  (wimlib does not use this quirk on WIM images it creates.)
+        */
        u8 unnamed_stream_hash[SHA1_HASH_SIZE];
+
+       /* The format of the following data is not yet completely known and they
+        * do not correspond to Microsoft's documentation.
+        *
+        * If this directory entry is for a reparse point (has
+        * FILE_ATTRIBUTE_REPARSE_POINT set in the attributes field), then the
+        * version of the following fields containing the reparse tag is valid.
+        * Furthermore, the field notated as not_rpfixed, as far as I can tell,
+        * is supposed to be set to 1 if reparse point fixups (a.k.a. fixing the
+        * targets of absolute symbolic links) were *not* done, and otherwise 0.
+        *
+        * If this directory entry is not for a reparse point, then the version
+        * of the following fields containing the hard_link_group_id is valid.
+        * All MS says about this field is that "If this file is part of a hard
+        * link set, all the directory entries in the set will share the same
+        * value in this field.".  However, more specifically I have observed
+        * the following:
+        *    - If the file is part of a hard link set of size 1, then the
+        *    hard_link_group_id should be set to either 0, which is treated
+        *    specially as indicating "not hardlinked", or any unique value.
+        *    - The specific nonzero values used to identity hard link sets do
+        *    not matter, as long as they are unique.
+        *    - However, due to bugs in Microsoft's software, it is actually NOT
+        *    guaranteed that directory entries that share the same hard link
+        *    group ID are actually hard linked to each either.  We have to
+        *    handle this by using special code to use distinguishing features
+        *    (which is possible because some information about the underlying
+        *    inode is repeated in each dentry) to split up these fake hard link
+        *    groups into what they actually are supposed to be.
+        */
        union {
                struct {
                        le32 rp_unknown_1;
@@ -96,14 +186,28 @@ struct wim_dentry_on_disk {
                        le64 hard_link_group_id;
                } _packed_attribute nonreparse;
        };
+
+       /* Number of alternate data stream entries that directly follow this
+        * dentry on-disk. */
        le16 num_alternate_data_streams;
+
+       /* Length of this file's UTF-16LE encoded short name (8.3 DOS-compatible
+        * name), if present, in bytes, excluding the null terminator.  If this
+        * file has no short name, then this field should be 0.  */
        le16 short_name_nbytes;
+
+       /* Length of this file's UTF-16LE encoded "long" name, excluding the
+        * null terminator.  If this file has no short name, then this field
+        * should be 0.  It's expected that only the root dentry has this field
+        * set to 0.  */
        le16 file_name_nbytes;
 
-       /* Follewed by variable length file name, if file_name_nbytes != 0 */
-       utf16lechar file_name[];
+       /* Followed by variable length file name, in UTF16-LE, if
+        * file_name_nbytes != 0.  Includes null terminator. */
+       /*utf16lechar file_name[];*/
 
-       /* Followed by variable length short name, if short_name_nbytes != 0 */
+       /* Followed by variable length short name, in UTF16-LE, if
+        * short_name_nbytes != 0.  Includes null terminator. */
        /*utf16lechar short_name[];*/
 } _packed_attribute;
 
@@ -880,13 +984,6 @@ new_timeless_inode(void)
                inode->i_next_stream_id = 1;
                inode->i_not_rpfixed = 1;
                INIT_LIST_HEAD(&inode->i_list);
-       #ifdef WITH_FUSE
-               if (pthread_mutex_init(&inode->i_mutex, NULL) != 0) {
-                       ERROR_WITH_ERRNO("Error initializing mutex");
-                       FREE(inode);
-                       return NULL;
-               }
-       #endif
                INIT_LIST_HEAD(&inode->i_dentry);
        }
        return inode;
@@ -1025,16 +1122,10 @@ free_inode(struct wim_inode *inode)
                                destroy_ads_entry(&inode->i_ads_entries[i]);
                        FREE(inode->i_ads_entries);
                }
-       #ifdef WITH_FUSE
-               wimlib_assert(inode->i_num_opened_fds == 0);
-               FREE(inode->i_fds);
-               pthread_mutex_destroy(&inode->i_mutex);
-       #endif
                /* HACK: This may instead delete the inode from i_list, but the
                 * hlist_del() behaves the same as list_del(). */
                if (!hlist_unhashed(&inode->i_hlist))
                        hlist_del(&inode->i_hlist);
-               FREE(inode->i_extracted_file);
                FREE(inode);
        }
 }
@@ -1900,8 +1991,9 @@ dentry_get_file_type_string(const struct wim_dentry *dentry)
  * Returns zero on success; nonzero on failure.
  */
 int
-read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
-                struct wim_dentry *dentry)
+read_dentry_tree(const u8 * restrict metadata_resource,
+                u64 metadata_resource_len,
+                struct wim_dentry * restrict dentry)
 {
        u64 cur_offset = dentry->subdir_offset;
        struct wim_dentry *child;
@@ -1960,6 +2052,14 @@ read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
                 * entries. */
                cur_offset += dentry_total_length(child);
 
+               if (unlikely(!dentry_has_long_name(child))) {
+                       WARNING("Ignoring unnamed dentry in "
+                               "directory \"%"TS"\"",
+                               dentry_full_path(dentry));
+                       free_dentry(child);
+                       continue;
+               }
+
                duplicate = dentry_add_child(dentry, child);
                if (unlikely(duplicate)) {
                        const tchar *child_type, *duplicate_type;
@@ -1971,23 +2071,23 @@ read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
                                child_type, dentry_full_path(duplicate),
                                duplicate_type);
                        free_dentry(child);
-               } else {
-                       inode_add_dentry(child, child->d_inode);
-                       /* If there are children of this child, call this
-                        * procedure recursively. */
-                       if (child->subdir_offset != 0) {
-                               if (likely(dentry_is_directory(child))) {
-                                       ret = read_dentry_tree(metadata_resource,
-                                                              metadata_resource_len,
-                                                              child);
-                                       if (ret)
-                                               break;
-                               } else {
-                                       WARNING("Ignoring children of non-directory \"%"TS"\"",
-                                               dentry_full_path(child));
-                               }
-                       }
+                       continue;
+               }
 
+               inode_add_dentry(child, child->d_inode);
+               /* If there are children of this child, call this
+                * procedure recursively. */
+               if (child->subdir_offset != 0) {
+                       if (likely(dentry_is_directory(child))) {
+                               ret = read_dentry_tree(metadata_resource,
+                                                      metadata_resource_len,
+                                                      child);
+                               if (ret)
+                                       break;
+                       } else {
+                               WARNING("Ignoring children of non-directory \"%"TS"\"",
+                                       dentry_full_path(child));
+                       }
                }
        }
        return ret;
@@ -2041,6 +2141,8 @@ write_dentry(const struct wim_dentry * restrict dentry, u8 * restrict p)
        disk_dentry->file_name_nbytes = cpu_to_le16(dentry->file_name_nbytes);
        p += sizeof(struct wim_dentry_on_disk);
 
+       wimlib_assert(dentry_is_root(dentry) != dentry_has_long_name(dentry));
+
        if (dentry_has_long_name(dentry))
                p = mempcpy(p, dentry->file_name, dentry->file_name_nbytes + 2);
 
@@ -2137,7 +2239,7 @@ write_dentry_tree_recursive(const struct wim_dentry *parent, u8 *p)
  * Returns pointer to the byte after the last byte we wrote.
  */
 u8 *
-write_dentry_tree(const struct wim_dentry *root, u8 *p)
+write_dentry_tree(const struct wim_dentry * restrict root, u8 * restrict p)
 {
        DEBUG("Writing dentry tree.");
        wimlib_assert(dentry_is_root(root));
@@ -2154,3 +2256,198 @@ write_dentry_tree(const struct wim_dentry *root, u8 *p)
        /* Recursively write the rest of the dentry tree. */
        return write_dentry_tree_recursive(root, p);
 }
+
+
+static int
+init_wimlib_dentry(struct wimlib_dir_entry *wdentry,
+                  struct wim_dentry *dentry,
+                  const WIMStruct *wim)
+{
+       int ret;
+       size_t dummy;
+       const struct wim_inode *inode = dentry->d_inode;
+       struct wim_lookup_table_entry *lte;
+
+#if TCHAR_IS_UTF16LE
+       wdentry->filename = dentry->file_name;
+       wdentry->dos_name = dentry->short_name;
+#else
+       if (dentry_has_long_name(dentry)) {
+               ret = utf16le_to_tstr(dentry->file_name,
+                                     dentry->file_name_nbytes,
+                                     (tchar**)&wdentry->filename,
+                                     &dummy);
+               if (ret)
+                       return ret;
+       }
+       if (dentry_has_short_name(dentry)) {
+               ret = utf16le_to_tstr(dentry->short_name,
+                                     dentry->short_name_nbytes,
+                                     (tchar**)&wdentry->dos_name,
+                                     &dummy);
+               if (ret)
+                       return ret;
+       }
+#endif
+       ret = calculate_dentry_full_path(dentry);
+       if (ret)
+               return ret;
+       wdentry->full_path = dentry->_full_path;
+
+       for (struct wim_dentry *d = dentry; !dentry_is_root(d); d = d->parent)
+               wdentry->depth++;
+
+       if (inode->i_security_id >= 0) {
+               const struct wim_security_data *sd = wim_const_security_data(wim);
+               wdentry->security_descriptor = sd->descriptors[inode->i_security_id];
+               wdentry->security_descriptor_size = sd->sizes[inode->i_security_id];
+       }
+       wdentry->reparse_tag = inode->i_reparse_tag;
+       wdentry->num_links = inode->i_nlink;
+       wdentry->attributes = inode->i_attributes;
+       wdentry->hard_link_group_id = inode->i_ino;
+       wdentry->creation_time = wim_timestamp_to_timespec(inode->i_creation_time);
+       wdentry->last_write_time = wim_timestamp_to_timespec(inode->i_last_write_time);
+       wdentry->last_access_time = wim_timestamp_to_timespec(inode->i_last_access_time);
+
+       lte = inode_unnamed_lte(inode, wim->lookup_table);
+       if (lte)
+               lte_to_wimlib_resource_entry(lte, &wdentry->streams[0].resource);
+
+       for (unsigned i = 0; i < inode->i_num_ads; i++) {
+               if (inode->i_ads_entries[i].stream_name == NULL)
+                       continue;
+               lte = inode_stream_lte(inode, i + 1, wim->lookup_table);
+               wdentry->num_named_streams++;
+               if (lte) {
+                       lte_to_wimlib_resource_entry(lte, &wdentry->streams[
+                                                               wdentry->num_named_streams].resource);
+               }
+       #if TCHAR_IS_UTF16LE
+               wdentry->streams[wdentry->num_named_streams].stream_name =
+                               inode->i_ads_entries[i].stream_name;
+       #else
+               size_t dummy;
+
+               ret = utf16le_to_tstr(inode->i_ads_entries[i].stream_name,
+                                     inode->i_ads_entries[i].stream_name_nbytes,
+                                     (tchar**)&wdentry->streams[
+                                               wdentry->num_named_streams].stream_name,
+                                     &dummy);
+               if (ret)
+                       return ret;
+       #endif
+       }
+       return 0;
+}
+
+static void
+free_wimlib_dentry(struct wimlib_dir_entry *wdentry)
+{
+#if !TCHAR_IS_UTF16LE
+       FREE((tchar*)wdentry->filename);
+       FREE((tchar*)wdentry->dos_name);
+       for (unsigned i = 1; i <= wdentry->num_named_streams; i++)
+               FREE((tchar*)wdentry->streams[i].stream_name);
+#endif
+       FREE(wdentry);
+}
+
+struct iterate_dir_tree_ctx {
+       WIMStruct *wim;
+       int flags;
+       wimlib_iterate_dir_tree_callback_t cb;
+       void *user_ctx;
+};
+
+static int
+do_iterate_dir_tree(WIMStruct *wim,
+                   struct wim_dentry *dentry, int flags,
+                   wimlib_iterate_dir_tree_callback_t cb,
+                   void *user_ctx);
+
+static int
+call_do_iterate_dir_tree(struct wim_dentry *dentry, void *_ctx)
+{
+       struct iterate_dir_tree_ctx *ctx = _ctx;
+       return do_iterate_dir_tree(ctx->wim, dentry, ctx->flags,
+                                  ctx->cb, ctx->user_ctx);
+}
+
+static int
+do_iterate_dir_tree(WIMStruct *wim,
+                   struct wim_dentry *dentry, int flags,
+                   wimlib_iterate_dir_tree_callback_t cb,
+                   void *user_ctx)
+{
+       struct wimlib_dir_entry *wdentry;
+       int ret = WIMLIB_ERR_NOMEM;
+
+
+       wdentry = CALLOC(1, sizeof(struct wimlib_dir_entry) +
+                                 (1 + dentry->d_inode->i_num_ads) *
+                                       sizeof(struct wimlib_stream_entry));
+       if (!wdentry)
+               goto out;
+
+       ret = init_wimlib_dentry(wdentry, dentry, wim);
+       if (ret)
+               goto out_free_wimlib_dentry;
+
+       if (!(flags & WIMLIB_ITERATE_DIR_TREE_FLAG_CHILDREN)) {
+               ret = (*cb)(wdentry, user_ctx);
+               if (ret)
+                       goto out_free_wimlib_dentry;
+       }
+
+       if (flags & (WIMLIB_ITERATE_DIR_TREE_FLAG_RECURSIVE |
+                    WIMLIB_ITERATE_DIR_TREE_FLAG_CHILDREN))
+       {
+               struct iterate_dir_tree_ctx ctx = {
+                       .wim      = wim,
+                       .flags    = flags &= ~WIMLIB_ITERATE_DIR_TREE_FLAG_CHILDREN,
+                       .cb       = cb,
+                       .user_ctx = user_ctx,
+               };
+               ret = for_dentry_child(dentry, call_do_iterate_dir_tree, &ctx);
+       }
+out_free_wimlib_dentry:
+       free_wimlib_dentry(wdentry);
+out:
+       return ret;
+}
+
+struct image_iterate_dir_tree_ctx {
+       const tchar *path;
+       int flags;
+       wimlib_iterate_dir_tree_callback_t cb;
+       void *user_ctx;
+};
+
+
+static int
+image_do_iterate_dir_tree(WIMStruct *wim)
+{
+       struct image_iterate_dir_tree_ctx *ctx = wim->private;
+       struct wim_dentry *dentry;
+
+       dentry = get_dentry(wim, ctx->path);
+       if (!dentry)
+               return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
+       return do_iterate_dir_tree(wim, dentry, ctx->flags, ctx->cb, ctx->user_ctx);
+}
+
+WIMLIBAPI int
+wimlib_iterate_dir_tree(WIMStruct *wim, int image, const tchar *path,
+                       int flags,
+                       wimlib_iterate_dir_tree_callback_t cb, void *user_ctx)
+{
+       struct image_iterate_dir_tree_ctx ctx = {
+               .path = path,
+               .flags = flags,
+               .cb = cb,
+               .user_ctx = user_ctx,
+       };
+       wim->private = &ctx;
+       return for_image(wim, image, image_do_iterate_dir_tree);
+}