[wimlib] / include / wimlib / dentry.h

#ifndef _WIMLIB_DENTRY_H
#define _WIMLIB_DENTRY_H

#include "wimlib/compiler.h"
#include "wimlib/list.h"
#include "wimlib/rbtree.h"
#include "wimlib/sha1.h"
#include "wimlib/types.h"

#include <string.h>
#include <sys/types.h> /* uid_t, gid_t */

struct wim_lookup_table;
struct wim_lookup_table_entry;
struct wimfs_fd;
struct wim_inode;
struct wim_security_data;

/* Size of the struct wim_dentry up to and including the file_name_len. */
#define WIM_DENTRY_DISK_SIZE    102

/*
 * Reparse tags documented at
 * http://msdn.microsoft.com/en-us/library/dd541667(v=prot.10).aspx
 */
#define WIM_IO_REPARSE_TAG_RESERVED_ZERO        0x00000000
#define WIM_IO_REPARSE_TAG_RESERVED_ONE         0x00000001
#define WIM_IO_REPARSE_TAG_MOUNT_POINT          0xA0000003
#define WIM_IO_REPARSE_TAG_HSM                  0xC0000004
#define WIM_IO_REPARSE_TAG_HSM2                 0x80000006
#define WIM_IO_REPARSE_TAG_DRIVER_EXTENDER      0x80000005
#define WIM_IO_REPARSE_TAG_SIS                  0x80000007
#define WIM_IO_REPARSE_TAG_DFS                  0x8000000A
#define WIM_IO_REPARSE_TAG_DFSR                 0x80000012
#define WIM_IO_REPARSE_TAG_FILTER_MANAGER       0x8000000B
#define WIM_IO_REPARSE_TAG_SYMLINK              0xA000000C

#define FILE_ATTRIBUTE_READONLY            0x00000001
#define FILE_ATTRIBUTE_HIDDEN              0x00000002
#define FILE_ATTRIBUTE_SYSTEM              0x00000004
#define FILE_ATTRIBUTE_DIRECTORY           0x00000010
#define FILE_ATTRIBUTE_ARCHIVE             0x00000020
#define FILE_ATTRIBUTE_DEVICE              0x00000040
#define FILE_ATTRIBUTE_NORMAL              0x00000080
#define FILE_ATTRIBUTE_TEMPORARY           0x00000100
#define FILE_ATTRIBUTE_SPARSE_FILE         0x00000200
#define FILE_ATTRIBUTE_REPARSE_POINT       0x00000400
#define FILE_ATTRIBUTE_COMPRESSED          0x00000800
#define FILE_ATTRIBUTE_OFFLINE             0x00001000
#define FILE_ATTRIBUTE_NOT_CONTENT_INDEXED 0x00002000
#define FILE_ATTRIBUTE_ENCRYPTED           0x00004000
#define FILE_ATTRIBUTE_VIRTUAL             0x00010000


/* Alternate data stream entry.
 *
 * We read this from disk in the read_ads_entries() function; see that function
 * for more explanation. */
struct wim_ads_entry {
        union {
                /* SHA-1 message digest of stream contents */
                u8 hash[SHA1_HASH_SIZE];

                /* The corresponding lookup table entry (only for resolved
                 * streams) */
                struct wim_lookup_table_entry *lte;
        };

        /* Length of UTF16-encoded stream name, in bytes, not including the
         * terminating null character; or 0 if the stream is unnamed. */
        u16 stream_name_nbytes;

        /* Number to identify an alternate data stream even after it's possibly
         * been moved or renamed. */
        u32 stream_id;

        /* Stream name (UTF-16LE), null-terminated, or NULL if the stream is
         * unnamed.  */
        utf16lechar *stream_name;

        /* Reserved field.  We read it into memory so we can write it out
         * unchanged. */
        u64 reserved;
};


static inline bool
ads_entries_have_same_name(const struct wim_ads_entry *entry_1,
                           const struct wim_ads_entry *entry_2)
{
        return entry_1->stream_name_nbytes == entry_2->stream_name_nbytes &&
               memcmp(entry_1->stream_name, entry_2->stream_name,
                      entry_1->stream_name_nbytes) == 0;
}

/*
 * In-memory structure for a WIM directory entry (dentry).  There is a directory
 * tree for each image in the WIM.
 *
 * Note that this is a directory entry and not an inode.  Since NTFS allows hard
 * links, it's possible for a NTFS inode to correspond to multiple WIM dentries.
 * The hard link group ID field of the on-disk WIM dentry tells us the number of
 * the NTFS inode that the dentry corresponds to (and this gets placed in
 * d_inode->i_ino).
 *
 * Unfortunately, WIM files do not have an analogue to an inode; instead certain
 * information, such as file attributes, the security descriptor, and file
 * streams is replicated in each hard-linked dentry, even though this
 * information really is associated with an inode.  In-memory, we fix up this
 * flaw by allocating a `struct wim_inode' for each dentry that contains some of
 * this duplicated information, then combining the inodes for each hard link
 * group together.
 *
 * Confusingly, it's possible for stream information to be missing from a dentry
 * in a hard link set, in which case the stream information needs to be gotten
 * from one of the other dentries in the hard link set.  In addition, it is
 * possible for dentries to have inconsistent security IDs, file attributes, or
 * file streams when they share the same hard link ID (don't even ask.  I hope
 * that Microsoft may have fixed this problem, since I've only noticed it in the
 * 'install.wim' for Windows 7).  For those dentries, we have to use the
 * conflicting fields to split up the hard link groups.  (See
 * dentry_tree_fix_inodes() in hardlink.c).
 */
struct wim_dentry {
        /* Pointer to the inode for this dentry.  This will contain some
         * information that was factored out of the on-disk WIM dentry as common
         * to all dentries in a hard link group.  */
        struct wim_inode *d_inode;

        /* Node for the parent's red-black tree of child dentries, sorted by
         * case sensitive long name. */
        struct rb_node rb_node;

#ifdef __WIN32__
        /* Node for the parent's red-black tree of child dentries, sorted by
         * case insensitive long name. */
        struct rb_node rb_node_case_insensitive;

        /* List of dentries in a directory that have different case sensitive
         * long names but share the same case insensitive long name */
        struct list_head case_insensitive_conflict_list;
#endif

        /* Length of UTF-16LE encoded short filename, in bytes, not including
         * the terminating zero wide-character. */
        u16 short_name_nbytes;

        /* Length of UTF-16LE encoded "long" file name, in bytes, not including
         * the terminating null character. */
        u16 file_name_nbytes;

        /* Length of full path name encoded using "tchars", in bytes, not
         * including the terminating null character. */
        u32 full_path_nbytes;

        /* For extraction operations, a subtree of dentries will have this flag
         * set so we can keep track of which dentries still need to be
         * extracted.  Otherwise this will always be 0.  */
        u8 needs_extraction : 1;

        /* For extraction operations, this flag will be set when a dentry in the
         * tree being extracted is not being extracted for some reason (file
         * type not supported by target filesystem or contains invalid
         * characters).  Otherwise this will always be 0. */
        u8 not_extracted : 1;

        /* When capturing from a NTFS volume using NTFS-3g, this flag is set on
         * dentries that were created from a filename in the WIN32 or WIN32+DOS
         * namespaces rather than the POSIX namespace.  Otherwise this will
         * always be 0.  */
        u8 is_win32_name : 1;

        /* When verifying the dentry tree after reading it into memory, this
         * flag will be set on all dentries in a hard link group that have a
         * nonempty DOS name except one.  This is because it is supposed to be
         * illegal (on NTFS, at least) for a single inode to have multiple DOS
         * names.  */
        u8 dos_name_invalid : 1;

        /* Temporary list field used to make lists of dentries in a few places.
         * */
        struct list_head tmp_list;

        /* Linked list node that places this dentry in the list of aliases for
         * its inode (d_inode) */
        struct list_head d_alias;

        /* The parent of this directory entry. */
        struct wim_dentry *parent;

        /* 'length' and 'subdir_offset' are only used while reading and writing
         * this dentry; see the corresponding field in
         * `struct wim_dentry_on_disk' for explanation.  */
        u64 length;
        u64 subdir_offset;

        /* These correspond to the two unused fields in the on-disk WIM dentry;
         * we read them into memory so we can write them unchanged.  These
         * fields are set to 0 on new dentries.  */
        u64 d_unused_1;
        u64 d_unused_2;

        /* Pointer to the UTF-16LE short filename (malloc()ed buffer), or NULL
         * if this dentry has no short name.  */
        utf16lechar *short_name;

        /* Pointer to the UTF-16LE filename (malloc()ed buffer), or NULL if this
         * dentry has no filename.  */
        utf16lechar *file_name;

        /* Full path to this dentry in the WIM, in platform-dependent tchars
         * that can be printed without conversion.  By default this field will
         * be NULL and will only be calculated on-demand by the
         * calculate_dentry_full_path() or dentry_full_path() functions.  */
        tchar *_full_path;

        /* (Extraction only) Actual name to extract this dentry as, along with
         * its length in tchars excluding the NULL terminator.  This usually
         * will be the same as file_name, with the character encoding converted
         * if needed.  But if file_name contains characters not accepted on the
         * current platform, then this may be set slightly differently from
         * file_name.  This will be either NULL or a malloc()ed buffer that may
         * alias file_name.  */
        tchar *extraction_name;
        size_t extraction_name_nchars;

        /* (Extraction only) List head for building a list of dentries that
         * contain a certain stream. */
        struct list_head extraction_stream_list;
};

#define rbnode_dentry(node) container_of(node, struct wim_dentry, rb_node)

/*
 * WIM inode.
 *
 * As mentioned in the comment above `struct wim_dentry', in the WIM file that
 * is no on-disk analogue of a real inode, as most of these fields are
 * duplicated in the dentries.  Instead, a `struct wim_inode' is something we
 * create ourselves to simplify the handling of hard links.
 */
struct wim_inode {
        /* If i_resolved == 0:
         *      SHA1 message digest of the contents of the unnamed-data stream
         *      of this inode.
         *
         * If i_resolved == 1:
         *      Pointer to the lookup table entry for the unnamed data stream
         *      of this inode, or NULL.
         *
         * i_hash corresponds to the 'unnamed_stream_hash' field of the `struct
         * wim_dentry_on_disk' and the additional caveats documented about that
         * field apply here (for example, the quirks regarding all-zero hashes).
         */
        union {
                u8 i_hash[SHA1_HASH_SIZE];
                struct wim_lookup_table_entry *i_lte;
        };

        /* Corresponds to the 'attributes' field of `struct wim_dentry_on_disk';
         * bitwise OR of the FILE_ATTRIBUTE_* flags that give the attributes of
         * this inode. */
        u32 i_attributes;

        /* Root of a red-black tree storing the child dentries of this inode, if
         * any.  Keyed by wim_dentry->file_name, case sensitively. */
        struct rb_root i_children;

#ifdef __WIN32__
        /* Root of a red-black tree storing the children of this inode, if any.
         * Keyed by wim_dentry->file_name, case insensitively. */
        struct rb_root i_children_case_insensitive;
#endif

        /* List of dentries that are aliases for this inode.  There will be
         * i_nlink dentries in this list.  */
        struct list_head i_dentry;

        /* Field to place this inode into a list. */
        union {
                /* Hash list node- used in hardlink.c when the inodes are placed
                 * into a hash table keyed by inode number and optionally device
                 * number, in order to detect dentries that are aliases for the
                 * same inode. */
                struct hlist_node i_hlist;

                /* Normal list node- used to connect all the inodes of a WIM image
                 * into a single linked list referenced from the
                 * `struct wim_image_metadata' for that image. */
                struct list_head i_list;
        };

        /* Number of dentries that are aliases for this inode.  */
        u32 i_nlink;

        /* Number of alternate data streams associated with this inode */
        u16 i_num_ads;

        /* Flag that indicates whether this inode's streams have been
         * "resolved".  By default, the inode starts as "unresolved", meaning
         * that the i_hash field, along with the hash field of any associated
         * wim_ads_entry's, are valid and should be used as keys in the WIM
         * lookup table to find the associated `struct wim_lookup_table_entry'.
         * But if the inode has been resolved, then each of these fields is
         * replaced with a pointer directly to the appropriate `struct
         * wim_lookup_table_entry', or NULL if the stream is empty.  */
        u8 i_resolved : 1;

        /* Flag used to mark this inode as visited; this is used when visiting
         * all the inodes in a dentry tree exactly once.  It will be 0 by
         * default and must be cleared following the tree traversal, even in
         * error paths.  */
        u8 i_visited : 1;

        /* For NTFS-3g extraction:  Set after the DOS name for this inode has
         * been extracted.  */
        u8 i_dos_name_extracted : 1;

        /* Pointer to a malloc()ed array of i_num_ads alternate data stream
         * entries for this inode.  */
        struct wim_ads_entry *i_ads_entries;

        /* Creation time, last access time, and last write time for this inode, 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. */
        u64 i_creation_time;
        u64 i_last_access_time;
        u64 i_last_write_time;

        /* Corresponds to 'security_id' in `struct wim_dentry_on_disk':  The
         * index of this inode's security descriptor in the WIM image's table of
         * security descriptors, or -1.  Note: in verify_inode(), called
         * whenever a WIM image is loaded, out-of-bounds indices are set to -1,
         * so the extraction code does not need to do bounds checks.  */
        int32_t i_security_id;

        /* Identity of a reparse point.  See
         * http://msdn.microsoft.com/en-us/library/windows/desktop/aa365503(v=vs.85).aspx
         * for what a reparse point is. */
        u32 i_reparse_tag;

        /* Unused/unknown fields that we just read into memory so we can
         * re-write them unchanged.  */
        u32 i_rp_unknown_1;
        u16 i_rp_unknown_2;

        /* Corresponds to not_rpfixed in `struct wim_dentry_on_disk':  Set to 0
         * if reparse point fixups have been done.  Otherwise set to 1.  Note:
         * this actually may reflect the SYMBOLIC_LINK_RELATIVE flag.
         */
        u16 i_not_rpfixed;

        /* Inode number; corresponds to hard_link_group_id in the `struct
         * wim_dentry_on_disk'.  */
        u64 i_ino;

        union {
                /* Device number, used only during image capture, so we can
                 * identify hard linked files by the combination of inode number
                 * and device number (rather than just inode number, which could
                 * be ambigious if the captured tree spans a mountpoint).  Set
                 * to 0 otherwise.  */
                u64 i_devno;

                /* Used only during image extraction: pointer to the first path
                 * (malloc()ed buffer) at which this inode has been extracted.
                 * Freed and set to NULL after the extraction is done (either
                 * success or failure).  */
                tchar *i_extracted_file;
        };

        /* Next alternate data stream ID to be assigned */
        u32 i_next_stream_id;

#ifdef WITH_FUSE
        /* wimfs file descriptors table for the inode */
        u16 i_num_opened_fds;
        u16 i_num_allocated_fds;
        struct wimfs_fd **i_fds;
#endif
};

#define inode_for_each_dentry(dentry, inode) \
                list_for_each_entry((dentry), &(inode)->i_dentry, d_alias)

#define inode_add_dentry(dentry, inode) \
                list_add_tail(&(dentry)->d_alias, &(inode)->i_dentry)

#define inode_first_dentry(inode) \
                container_of(inode->i_dentry.next, struct wim_dentry, d_alias)

#define inode_first_full_path(inode) \
                dentry_full_path(inode_first_dentry(inode))

static inline bool
dentry_is_first_in_inode(const struct wim_dentry *dentry)
{
        return inode_first_dentry(dentry->d_inode) == dentry;
}

extern u64
dentry_correct_total_length(const struct wim_dentry *dentry);

extern int
for_dentry_in_tree(struct wim_dentry *root,
                   int (*visitor)(struct wim_dentry*, void*),
                   void *args);

extern int
for_dentry_in_rbtree(struct rb_node *node,
                     int (*visitor)(struct wim_dentry *, void *),
                     void *arg);

static inline int
for_dentry_child(const struct wim_dentry *dentry,
                 int (*visitor)(struct wim_dentry *, void *),
                 void *arg)
{
        return for_dentry_in_rbtree(dentry->d_inode->i_children.rb_node,
                                    visitor,
                                    arg);
}

extern int
for_dentry_in_tree_depth(struct wim_dentry *root,
                         int (*visitor)(struct wim_dentry*, void*),
                         void *args);

extern void
calculate_subdir_offsets(struct wim_dentry *dentry, u64 *subdir_offset_p);

extern int
set_dentry_name(struct wim_dentry *dentry, const tchar *new_name);

extern struct wim_dentry *
get_dentry(struct WIMStruct *w, const tchar *path);

extern struct wim_inode *
wim_pathname_to_inode(struct WIMStruct *w, const tchar *path);

extern struct wim_dentry *
get_dentry_child_with_name(const struct wim_dentry *dentry,
                           const tchar *name);

extern struct wim_dentry *
get_dentry_child_with_utf16le_name(const struct wim_dentry *dentry,
                                   const utf16lechar *name,
                                   size_t name_nbytes);

extern struct wim_dentry *
get_parent_dentry(struct WIMStruct *w, const tchar *path);

extern int
print_dentry(struct wim_dentry *dentry, void *lookup_table);

extern int
print_dentry_full_path(struct wim_dentry *entry, void *ignore);

extern int
calculate_dentry_full_path(struct wim_dentry *dentry);

extern int
calculate_dentry_tree_full_paths(struct wim_dentry *root);

extern tchar *
dentry_full_path(struct wim_dentry *dentry);

extern struct wim_inode *
new_timeless_inode(void) _malloc_attribute;

extern int
new_dentry(const tchar *name, struct wim_dentry **dentry_ret);

extern int
new_dentry_with_inode(const tchar *name, struct wim_dentry **dentry_ret);

extern int
new_dentry_with_timeless_inode(const tchar *name, struct wim_dentry **dentry_ret);

extern int
new_filler_directory(const tchar *name, struct wim_dentry **dentry_ret);

extern void
free_inode(struct wim_inode *inode);

extern void
free_dentry(struct wim_dentry *dentry);

extern void
put_dentry(struct wim_dentry *dentry);

extern void
free_dentry_tree(struct wim_dentry *root,
                 struct wim_lookup_table *lookup_table);

extern void
unlink_dentry(struct wim_dentry *dentry);

extern struct wim_dentry *
dentry_add_child(struct wim_dentry * restrict parent,
                 struct wim_dentry * restrict child);

extern struct wim_ads_entry *
inode_get_ads_entry(struct wim_inode *inode, const tchar *stream_name,
                    u16 *idx_ret);

extern struct wim_ads_entry *
inode_add_ads_utf16le(struct wim_inode *inode,
                      const utf16lechar *stream_name,
                      size_t stream_name_nbytes);

extern struct wim_ads_entry *
inode_add_ads(struct wim_inode *dentry, const tchar *stream_name);

extern int
inode_add_ads_with_data(struct wim_inode *inode, const tchar *name,
                        const void *value, size_t size,
                        struct wim_lookup_table *lookup_table);

extern int
inode_set_unnamed_stream(struct wim_inode *inode, const void *data, size_t len,
                         struct wim_lookup_table *lookup_table);

extern void
inode_remove_ads(struct wim_inode *inode, u16 idx,
                 struct wim_lookup_table *lookup_table);


#define WIMLIB_UNIX_DATA_TAG "$$__wimlib_UNIX_data"
#define WIMLIB_UNIX_DATA_TAG_NBYTES (sizeof(WIMLIB_UNIX_DATA_TAG) - 1)

#define WIMLIB_UNIX_DATA_TAG_UTF16LE "$\0$\0_\0_\0w\0i\0m\0l\0i\0b\0_\0U\0N\0I\0X\0_\0d\0a\0t\0a\0"
#define WIMLIB_UNIX_DATA_TAG_UTF16LE_NBYTES (sizeof(WIMLIB_UNIX_DATA_TAG_UTF16LE) - 1)

/* Format for special alternate data stream entries to store UNIX data for files
 * and directories (see: WIMLIB_ADD_FLAG_UNIX_DATA) */
struct wimlib_unix_data {
        u16 version; /* Must be 0 */
        u16 uid;
        u16 gid;
        u16 mode;
} _packed_attribute;

#ifndef __WIN32__

#define NO_UNIX_DATA (-1)
#define BAD_UNIX_DATA (-2)
extern int
inode_get_unix_data(const struct wim_inode *inode,
                    struct wimlib_unix_data *unix_data,
                    u16 *stream_idx_ret);

#define UNIX_DATA_UID    0x1
#define UNIX_DATA_GID    0x2
#define UNIX_DATA_MODE   0x4
#define UNIX_DATA_ALL    (UNIX_DATA_UID | UNIX_DATA_GID | UNIX_DATA_MODE)
#define UNIX_DATA_CREATE 0x8
extern int
inode_set_unix_data(struct wim_inode *inode, uid_t uid, gid_t gid, mode_t mode,
                    struct wim_lookup_table *lookup_table, int which);
#endif

extern int
read_dentry(const u8 *metadata_resource, u64 metadata_resource_len,
            u64 offset, struct wim_dentry *dentry);

extern int
read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
                 struct wim_dentry *dentry);

extern u8 *
write_dentry_tree(const struct wim_dentry *tree, u8 *p);

static inline bool
dentry_is_root(const struct wim_dentry *dentry)
{
        return dentry->parent == dentry;
}

static inline bool
inode_is_directory(const struct wim_inode *inode)
{
        return (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
                && !(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT);
}

static inline bool
dentry_is_directory(const struct wim_dentry *dentry)
{
        return inode_is_directory(dentry->d_inode);
}

/* For our purposes, we consider "real" symlinks and "junction points" to both
 * be symlinks. */
static inline bool
inode_is_symlink(const struct wim_inode *inode)
{
        return (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT)
                && (inode->i_reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
                    inode->i_reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT);
}

static inline bool
inode_is_regular_file(const struct wim_inode *inode)
{
        return !inode_is_directory(inode) && !inode_is_symlink(inode);
}

static inline bool
dentry_is_regular_file(const struct wim_dentry *dentry)
{
        return inode_is_regular_file(dentry->d_inode);
}

static inline bool
inode_has_children(const struct wim_inode *inode)
{
        return inode->i_children.rb_node != NULL;
}

static inline bool
dentry_has_children(const struct wim_dentry *dentry)
{
        return inode_has_children(dentry->d_inode);
}

static inline bool
dentry_has_short_name(const struct wim_dentry *dentry)
{
        return dentry->short_name_nbytes != 0;
}

static inline bool
dentry_has_long_name(const struct wim_dentry *dentry)
{
        return dentry->file_name_nbytes != 0;
}

extern void
inode_ref_streams(struct wim_inode *inode);

extern int
dentry_tree_fix_inodes(struct wim_dentry *root, struct list_head *inode_list);

int
verify_inode(struct wim_inode *inode, const struct wim_security_data *sd);

#endif