[wimlib] / include / wimlib / inode.h

#ifndef _WIMLIB_INODE_H
#define _WIMLIB_INODE_H

#include "wimlib/assert.h"
#include "wimlib/list.h"
#include "wimlib/sha1.h"
#include "wimlib/types.h"

struct avl_tree_node;
struct blob_descriptor;
struct blob_table;
struct wim_dentry;
struct wim_security_data;
struct wimfs_fd;

/* Valid values for the 'stream_type' field of a 'struct wim_inode_stream'  */
enum wim_inode_stream_type {

        /* Data stream, may be unnamed (usual case) or named  */
        STREAM_TYPE_DATA,

        /* Reparse point stream.  This is the same as the data of the on-disk
         * reparse point attribute, except that the first 8 bytes of the on-disk
         * attribute are omitted.  The omitted bytes contain the reparse tag
         * (which is instead stored in the on-disk WIM dentry), the reparse data
         * size (which is redundant with the stream size), and a reserved field
         * that is always zero.  */
        STREAM_TYPE_REPARSE_POINT,

        /* Encrypted data in the "EFSRPC raw data format" specified by [MS-EFSR]
         * section 2.2.3.  This contains metadata for the Encrypting File System
         * as well as the encrypted data of all the file's data streams.  */
        STREAM_TYPE_EFSRPC_RAW_DATA,

        /* Stream type could not be determined  */
        STREAM_TYPE_UNKNOWN,
};

extern const utf16lechar NO_STREAM_NAME[1];

/*
 * 'struct wim_inode_stream' describes a "stream", which associates a blob of
 * data with an inode.  Each stream has a type and optionally a name.
 *
 * The most frequently seen kind of stream is the "unnamed data stream"
 * (stream_type == STREAM_TYPE_DATA && stream_name == NO_STREAM_NAME), which is
 * the "default file contents".  Many inodes just have an unnamed data stream
 * and no other streams.  However, files on NTFS filesystems may have
 * additional, "named" data streams, and this is supported by the WIM format.
 *
 * A "reparse point" is an inode with reparse data set.  The reparse data is
 * stored in a stream of type STREAM_TYPE_REPARSE_POINT.  There should be only
 * one such stream, and it should be unnamed.  However, it is possible for an
 * inode to have both a reparse point stream and an unnamed data stream, and
 * even named data streams as well.
 */
struct wim_inode_stream {

        /* The name of the stream or NO_STREAM_NAME.  */
        utf16lechar *stream_name;

        /*
         * If 'stream_resolved' = 0, then 'stream_hash' is the SHA-1 message
         * digest of the uncompressed data of this stream, or all zeroes if this
         * stream is empty.
         *
         * If 'stream_resolved' = 1, then 'stream_blob' is a pointer directly to
         * a descriptor for this stream's blob, or NULL if this stream is empty.
         */
        union {
                u8 _stream_hash[SHA1_HASH_SIZE];
                struct blob_descriptor *_stream_blob;
        } _packed_attribute; /* union is SHA1_HASH_SIZE bytes */

        /* 'stream_resolved' determines whether 'stream_hash' or 'stream_blob'
         * is valid as described above.  */
        u32 stream_resolved : 1;

        /* A unique identifier for this stream within the context of its inode.
         * This stays constant even if the streams array is reallocated.  */
        u32 stream_id : 28;

        /* The type of this stream as one of the STREAM_TYPE_* values  */
        u32 stream_type : 3;
};

/*
 * WIM inode - a "file" in an image which may be accessible via multiple paths
 *
 * Note: in WIM files there is no true on-disk analogue of an inode; there are
 * only directory entries, and some fields are duplicated among all links to a
 * file.  However, wimlib uses inode structures internally to simplify handling
 * of hard links.
 */
struct wim_inode {

        /*
         * The collection of streams for this inode.  'i_streams' points to
         * either 'i_embedded_streams' or an allocated array.
         */
        struct wim_inode_stream *i_streams;
        struct wim_inode_stream i_embedded_streams[1];
        unsigned i_num_streams;

        /* Windows file attribute flags (FILE_ATTRIBUTE_*).  */
        u32 i_attributes;

        /* Root of a balanced binary search tree storing the child directory
         * entries of this inode, if any.  Keyed by wim_dentry->file_name, case
         * sensitively.  If this inode is not a directory or if it has no
         * children then this will be an empty tree (NULL).  */
        struct avl_tree_node *i_children;

        /* Root of a balanced binary search tree storing the child directory
         * entries of this inode, if any.  Keyed by wim_dentry->file_name, case
         * insensitively.  If this inode is not a directory or if it has no
         * children then this will be an empty tree (NULL).  */
        struct avl_tree_node *i_children_ci;

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

        /* Field to place this inode into a list.  While reading a WIM image or
         * adding files to a WIM image this is owned by the inode table;
         * otherwise this links the inodes for the WIM image.  */
        struct hlist_node i_hlist;

        /* Number of dentries that are aliases for this inode.  */
        u32 i_nlink : 30;

        /* 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.  */
        u32 i_visited : 1;

        /* Cached value  */
        u32 i_can_externally_back : 1;

        /* If not NULL, a pointer to the extra data that was read from the
         * dentry.  This should be a series of tagged items, each of which
         * represents a bit of extra metadata, such as the file's object ID.
         * See tagged_items.c for more information.  */
        void *i_extra;

        /* Size of @i_extra buffer in bytes.  If 0, there is no extra data.  */
        size_t i_extra_size;

        /* 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 if this inode does not have a security
         * descriptor.  */
        s32 i_security_id;

        /* Unknown field that we only read into memory so we can re-write it
         * unchanged.  Probably it's actually just padding...  */
        u32 i_unknown_0x54;

        /* The following fields correspond to 'reparse_tag', 'rp_reserved', and
         * 'rp_flags' in `struct wim_dentry_on_disk'.  They are only meaningful
         * for reparse point files.  */
        u32 i_reparse_tag;
        u16 i_rp_reserved;
        u16 i_rp_flags;

        /* 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;

                /* Fields used only during extraction  */
                struct {
                        /* A singly linked list of aliases of this dentry that
                         * are being extracted in the current extraction
                         * operation.  This list may be shorter than the inode's
                         * full alias list.  This list will be constructed
                         * regardless of whether the extraction backend supports
                         * hard links or not.  */
                        struct wim_dentry *i_first_extraction_alias;

                #ifdef WITH_NTFS_3G
                        /* In NTFS-3g extraction mode, this is set to the Master
                         * File Table (MFT) number of the NTFS file that was
                         * created for this inode.  */
                        u64 i_mft_no;
                #endif
                };

                /* Used during WIM writing with
                 * WIMLIB_WRITE_FLAG_SEND_DONE_WITH_FILE_MESSAGES:  the number
                 * of streams this inode has that have not yet been fully read.
                 * */
                u32 i_num_remaining_streams;

#ifdef WITH_FUSE
                struct {
                        /* Used only during image mount:  Table of file
                         * descriptors that have been opened to this inode.
                         * This table is freed when the last file descriptor is
                         * closed.  */
                        struct wimfs_fd **i_fds;

                        /* Lower bound on the index of the next available entry
                         * in 'i_fds'.  */
                        u16 i_next_fd;
                };
#endif
        };

#ifdef WITH_FUSE
        u16 i_num_opened_fds;
        u16 i_num_allocated_fds;
#endif

        /* Next stream ID to be assigned  */
        u32 i_next_stream_id;
};

/*
 * The available reparse tags are documented at
 * http://msdn.microsoft.com/en-us/library/dd541667(v=prot.10).aspx.
 * Here we only define the ones of interest to us.
 */
#define WIM_IO_REPARSE_TAG_MOUNT_POINT          0xA0000003
#define WIM_IO_REPARSE_TAG_SYMLINK              0xA000000C
#define WIM_IO_REPARSE_TAG_WOF                  0x80000017

/* Flags for the rp_flags field.  Currently the only known flag is NOT_FIXED,
 * which indicates that the target of the absolute symbolic link or junction was
 * not changed when it was stored.  */
#define WIM_RP_FLAG_NOT_FIXED              0x0001

/* Windows file attribute flags  */
#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

extern struct wim_inode *
new_inode(struct wim_dentry *dentry, bool set_timestamps);

/* Iterate through each alias of the specified inode.  */
#define inode_for_each_dentry(dentry, inode) \
        hlist_for_each_entry((dentry), &(inode)->i_dentry, d_alias)

/* Return an alias of the specified inode.  */
#define inode_first_dentry(inode) \
        hlist_entry(inode->i_dentry.first, struct wim_dentry, d_alias)

/* Return the full path of an alias of the specified inode, or NULL if a full
 * path could not be determined.  */
#define inode_first_full_path(inode) \
        dentry_full_path(inode_first_dentry(inode))

extern void
d_associate(struct wim_dentry *dentry, struct wim_inode *inode);

extern void
d_disassociate(struct wim_dentry *dentry);

#ifdef WITH_FUSE
extern void
inode_dec_num_opened_fds(struct wim_inode *inode);
#endif

/* Is the inode a directory?
 * This doesn't count directories with reparse data.
 * wimlib only allows inodes of this type to have children.
 */
static inline bool
inode_is_directory(const struct wim_inode *inode)
{
        return (inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
                                       FILE_ATTRIBUTE_REPARSE_POINT))
                        == FILE_ATTRIBUTE_DIRECTORY;
}

/* Is the inode a symbolic link?
 * This returns true iff the inode is a reparse point that is either a "real"
 * symbolic link or a junction point.  */
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);
}

/* Does the inode have children?  Currently (based on read_dentry_tree() as well
 * as the various build-dentry-tree implementations), this can only return true
 * for inodes for which inode_is_directory() returns true.  */
static inline bool
inode_has_children(const struct wim_inode *inode)
{
        return inode->i_children != NULL;
}

/* Does the inode have a security descriptor?  */
static inline bool
inode_has_security_descriptor(const struct wim_inode *inode)
{
        return inode->i_security_id >= 0;
}

extern struct wim_inode_stream *
inode_get_stream(const struct wim_inode *inode, int stream_type,
                 const utf16lechar *stream_name);

extern struct wim_inode_stream *
inode_get_unnamed_stream(const struct wim_inode *inode, int stream_type);

static inline struct wim_inode_stream *
inode_get_unnamed_data_stream(const struct wim_inode *inode)
{
        return inode_get_unnamed_stream(inode, STREAM_TYPE_DATA);
}

extern struct wim_inode_stream *
inode_add_stream(struct wim_inode *inode, int stream_type,
                 const utf16lechar *stream_name, struct blob_descriptor *blob);

extern void
inode_replace_stream_blob(struct wim_inode *inode,
                          struct wim_inode_stream *strm,
                          struct blob_descriptor *new_blob,
                          struct blob_table *blob_table);

extern bool
inode_replace_stream_data(struct wim_inode *inode,
                          struct wim_inode_stream *strm,
                          const void *data, size_t size,
                          struct blob_table *blob_table);

extern bool
inode_add_stream_with_data(struct wim_inode *inode, int stream_type,
                           const utf16lechar *stream_name,
                           const void *data, size_t size,
                           struct blob_table *blob_table);

extern void
inode_remove_stream(struct wim_inode *inode, struct wim_inode_stream *strm,
                    struct blob_table *blob_table);

static inline struct blob_descriptor *
stream_blob_resolved(const struct wim_inode_stream *strm)
{
        wimlib_assert(strm->stream_resolved);
        return strm->_stream_blob;
}

static inline bool
stream_is_named(const struct wim_inode_stream *strm)
{
        return strm->stream_name != NO_STREAM_NAME;
}

static inline bool
stream_is_unnamed_data_stream(const struct wim_inode_stream *strm)
{
        return strm->stream_type == STREAM_TYPE_DATA && !stream_is_named(strm);
}

static inline bool
stream_is_named_data_stream(const struct wim_inode_stream *strm)
{
        return strm->stream_type == STREAM_TYPE_DATA && stream_is_named(strm);
}

extern bool
inode_has_named_data_stream(const struct wim_inode *inode);

extern int
inode_resolve_streams(struct wim_inode *inode,
                      struct blob_table *table, bool force);

extern int
blob_not_found_error(const struct wim_inode *inode, const u8 *hash);

extern struct blob_descriptor *
stream_blob(const struct wim_inode_stream *strm, const struct blob_table *table);

extern struct blob_descriptor *
inode_get_blob_for_unnamed_data_stream(const struct wim_inode *inode,
                                       const struct blob_table *blob_table);

extern struct blob_descriptor *
inode_get_blob_for_unnamed_data_stream_resolved(const struct wim_inode *inode);

extern const u8 *
stream_hash(const struct wim_inode_stream *strm);

extern const u8 *
inode_get_hash_of_unnamed_data_stream(const struct wim_inode *inode);

extern void
inode_ref_blobs(struct wim_inode *inode);

extern void
inode_unref_blobs(struct wim_inode *inode, struct blob_table *blob_table);

/* inode_fixup.c  */
extern int
dentry_tree_fix_inodes(struct wim_dentry *root, struct hlist_head *inode_list);

#endif /* _WIMLIB_INODE_H  */