[wimlib] / src / ntfs-apply.c

/*
 * ntfs-apply.c
 *
 * Apply a WIM image to a NTFS volume.  Restore as much information as possible,
 * including security data, file attributes, DOS names, and alternate data
 * streams.
 */

/*
 * Copyright (C) 2012, 2013 Eric Biggers
 *
 * This file is part of wimlib, a library for working with WIM files.
 *
 * wimlib is free software; you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option)
 * any later version.
 *
 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with wimlib; if not, see http://www.gnu.org/licenses/.
 */


#include "config.h"

#include <ntfs-3g/endians.h>
#include <ntfs-3g/types.h>

#include "wimlib_internal.h"
#include "buffer_io.h"
#include "dentry.h"
#include "lookup_table.h"

#include <ntfs-3g/attrib.h>
#include <ntfs-3g/security.h> /* security.h before xattrs.h */
#include <ntfs-3g/reparse.h>
#include <ntfs-3g/xattrs.h>
#include <string.h>
#include <locale.h>

struct ntfs_attr_extract_ctx {
        u64 offset;
        ntfs_attr *na;
};

static int
extract_wim_chunk_to_ntfs_attr(const void *buf, size_t len, void *_ctx)
{
        struct ntfs_attr_extract_ctx *ctx = _ctx;
        if (ntfs_attr_pwrite(ctx->na, ctx->offset, len, buf) == len) {
                ctx->offset += len;
                return 0;
        } else {
                ERROR_WITH_ERRNO("Error extracting WIM resource to NTFS attribute");
                return WIMLIB_ERR_WRITE;
        }
}

/*
 * Extracts a WIM resource to a NTFS attribute.
 */
static int
extract_wim_resource_to_ntfs_attr(const struct wim_lookup_table_entry *lte,
                                  ntfs_attr *na)
{
        struct ntfs_attr_extract_ctx ctx;
        ctx.na = na;
        ctx.offset = 0;
        return extract_wim_resource(lte, wim_resource_size(lte),
                                    extract_wim_chunk_to_ntfs_attr, &ctx);
}

/* Writes the data streams of a WIM inode to the data attributes of a NTFS
 * inode.
 *
 * @ni:      The NTFS inode to which the streams are to be extracted.
 *
 * @dentry:  The WIM dentry being extracted.  The @d_inode member points to the
 *           corresponding WIM inode that contains the streams being extracted.
 *           The WIM dentry itself is only needed to provide a file path for
 *           better error messages.
 *
 * @progress_info:  Progress information for the image application.  The number
 *                  of extracted bytes will be incremented by the uncompressed
 *                  size of each stream extracted.
 *
 * Returns 0 on success, nonzero on failure.
 */
static int
write_ntfs_data_streams(ntfs_inode *ni, struct wim_dentry *dentry,
                        union wimlib_progress_info *progress_info)
{
        int ret = 0;
        unsigned stream_idx = 0;
        ntfschar *stream_name = AT_UNNAMED;
        u32 stream_name_nbytes = 0;
        const struct wim_inode *inode = dentry->d_inode;
        struct wim_lookup_table_entry *lte;

        DEBUG("Writing %u NTFS data stream%s for `%s'",
              inode->i_num_ads + 1,
              (inode->i_num_ads == 0 ? "" : "s"),
              dentry->_full_path);

        lte = inode->i_lte;
        while (1) {
                if (stream_name_nbytes) {
                        /* Skip special UNIX data entries (see documentation for
                         * WIMLIB_ADD_IMAGE_FLAG_UNIX_DATA) */
                        if (stream_name_nbytes == WIMLIB_UNIX_DATA_TAG_UTF16LE_NBYTES
                            && !memcmp(stream_name,
                                       WIMLIB_UNIX_DATA_TAG_UTF16LE,
                                       WIMLIB_UNIX_DATA_TAG_UTF16LE_NBYTES))
                                goto cont;

                        /* Create an empty named stream. */
                        ret = ntfs_attr_add(ni, AT_DATA, stream_name,
                                            stream_name_nbytes / 2, NULL, 0);
                        if (ret != 0) {
                                ERROR_WITH_ERRNO("Failed to create named data "
                                                 "stream for extracted file "
                                                 "`%s'",
                                                 dentry->_full_path);
                                ret = WIMLIB_ERR_NTFS_3G;
                                break;

                        }
                }

                /* If there's no lookup table entry, it's an empty stream.
                 * Otherwise, open the attribute and extract the data. */
                if (lte) {
                        ntfs_attr *na;

                        na = ntfs_attr_open(ni, AT_DATA, stream_name,
                                            stream_name_nbytes / 2);
                        if (!na) {
                                ERROR_WITH_ERRNO("Failed to open a data stream of "
                                                 "extracted file `%s'",
                                                 dentry->_full_path);
                                ret = WIMLIB_ERR_NTFS_3G;
                                break;
                        }

                        /* The WIM lookup table entry provides the stream
                         * length, so the NTFS attribute should be resized to
                         * this length before starting to extract the data. */
                        ret = ntfs_attr_truncate_solid(na, wim_resource_size(lte));
                        if (ret != 0) {
                                ntfs_attr_close(na);
                                break;
                        }

                        /* Actually extract the stream */
                        ret = extract_wim_resource_to_ntfs_attr(lte, na);

                        /* Close the attribute */
                        ntfs_attr_close(na);
                        if (ret != 0)
                                break;

                        /* Record the number of bytes of uncompressed data that
                         * have been extracted. */
                        progress_info->extract.completed_bytes += wim_resource_size(lte);
                }
        cont:
                if (stream_idx == inode->i_num_ads) /* Has the last stream been extracted? */
                        break;

                /* Get the name and lookup table entry for the next stream. */
                stream_name = inode->i_ads_entries[stream_idx].stream_name;
                stream_name_nbytes = inode->i_ads_entries[stream_idx].stream_name_nbytes;
                lte = inode->i_ads_entries[stream_idx].lte;
                stream_idx++;
        }
        return ret;
}

/* Open the NTFS inode that corresponds to the parent of a WIM dentry.  Returns
 * the opened inode, or NULL on failure. */
static ntfs_inode *
dentry_open_parent_ni(struct wim_dentry *dentry, ntfs_volume *vol)
{
        char *p;
        const char *dir_name;
        ntfs_inode *dir_ni;
        char orig;

        p = dentry->_full_path + dentry->full_path_nbytes;
        do {
                p--;
        } while (*p != '/');

        orig = *p;
        *p = '\0';
        dir_name = dentry->_full_path;
        dir_ni = ntfs_pathname_to_inode(vol, NULL, dir_name);
        if (!dir_ni) {
                ERROR_WITH_ERRNO("Could not find NTFS inode for `%s'",
                                 dir_name);
        }
        *p = orig;
        return dir_ni;
}

/*
 * Makes a NTFS hard link.
 *
 * The hard link is named @from_dentry->file_name and is located under the
 * directory specified by @dir_ni, and it is made to point to the previously
 * extracted file located at @inode->i_extracted_file.
 *
 * Or, in other words, this adds a new name @from_dentry->full_path to an
 * existing NTFS inode which already has a name @inode->i_extracted_file.
 *
 * The new name is made in the POSIX namespace (this is the behavior of
 * ntfs_link()).
 *
 * Return 0 on success, nonzero on failure.  dir_ni is closed either way.
 */
static int
apply_ntfs_hardlink(struct wim_dentry *from_dentry,
                    const struct wim_inode *inode,
                    ntfs_inode *dir_ni)
{
        int ret;
        ntfs_inode *to_ni;
        ntfs_volume *vol;

        vol = dir_ni->vol;
        ret = ntfs_inode_close(dir_ni);
        if (ret != 0) {
                ERROR_WITH_ERRNO("Error closing directory");
                return WIMLIB_ERR_NTFS_3G;
        }

        DEBUG("Extracting NTFS hard link `%s' => `%s'",
              from_dentry->_full_path, inode->i_extracted_file);

        to_ni = ntfs_pathname_to_inode(vol, NULL, inode->i_extracted_file);
        if (!to_ni) {
                ERROR_WITH_ERRNO("Could not find NTFS inode for `%s'",
                                 inode->i_extracted_file);
                return WIMLIB_ERR_NTFS_3G;
        }

        dir_ni = dentry_open_parent_ni(from_dentry, vol);
        if (!dir_ni) {
                ntfs_inode_close(to_ni);
                return WIMLIB_ERR_NTFS_3G;
        }

        ret = ntfs_link(to_ni, dir_ni,
                        from_dentry->file_name,
                        from_dentry->file_name_nbytes / 2);
        ret |= ntfs_inode_close(dir_ni);
        ret |= ntfs_inode_close(to_ni);
        if (ret) {
                ERROR_WITH_ERRNO("Could not create hard link `%s' => `%s'",
                                 from_dentry->_full_path,
                                 inode->i_extracted_file);
                ret = WIMLIB_ERR_NTFS_3G;
        }
        return ret;
}

/* Transfers file attributes and possibly a security descriptor from a WIM inode
 * to a NTFS inode.
 *
 * @ni:      The NTFS inode to apply the metadata to.
 * @dir_ni:  The NTFS inode for a directory containing @ni.
 * @dentry:  The WIM dentry whose inode contains the metadata to apply.
 * @w:       The WIMStruct for the WIM, through which the table of security
 *              descriptors can be accessed.
 *
 * Returns 0 on success, nonzero on failure.
 */
static int
apply_file_attributes_and_security_data(ntfs_inode *ni,
                                        ntfs_inode *dir_ni,
                                        struct wim_dentry *dentry,
                                        const WIMStruct *w,
                                        int extract_flags)
{
        int ret;
        struct SECURITY_CONTEXT ctx;
        u32 attributes_le32;
        const struct wim_inode *inode;

        inode = dentry->d_inode;

        DEBUG("Setting NTFS file attributes on `%s' to %#"PRIx32,
              dentry->_full_path, inode->i_attributes);

        attributes_le32 = cpu_to_le32(inode->i_attributes);
        memset(&ctx, 0, sizeof(ctx));
        ctx.vol = ni->vol;
        ret = ntfs_xattr_system_setxattr(&ctx, XATTR_NTFS_ATTRIB,
                                         ni, dir_ni,
                                         (const char*)&attributes_le32,
                                         sizeof(u32), 0);
        if (ret != 0) {
                ERROR("Failed to set NTFS file attributes on `%s'",
                      dentry->_full_path);
                return WIMLIB_ERR_NTFS_3G;
        }
        if (inode->i_security_id != -1 &&
            !(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS))
        {
                const char *desc;
                const struct wim_security_data *sd;

                sd = wim_const_security_data(w);
                wimlib_assert(inode->i_security_id < sd->num_entries);
                desc = (const char *)sd->descriptors[inode->i_security_id];
                DEBUG("Applying security descriptor %d to `%s'",
                      inode->i_security_id, dentry->_full_path);

                ret = ntfs_xattr_system_setxattr(&ctx, XATTR_NTFS_ACL,
                                                 ni, dir_ni, desc,
                                                 sd->sizes[inode->i_security_id], 0);

                if (ret != 0) {
                        ERROR_WITH_ERRNO("Failed to set security data on `%s'",
                                        dentry->_full_path);
                        return WIMLIB_ERR_NTFS_3G;
                }
        }
        return 0;
}

/*
 * Transfers the reparse data from a WIM inode (which must represent a reparse
 * point) to a NTFS inode.
 */
static int
apply_reparse_data(ntfs_inode *ni, struct wim_dentry *dentry,
                   union wimlib_progress_info *progress_info)
{
        struct wim_lookup_table_entry *lte;
        int ret = 0;

        lte = inode_unnamed_lte_resolved(dentry->d_inode);

        DEBUG("Applying reparse data to `%s'", dentry->_full_path);

        if (!lte) {
                ERROR("Could not find reparse data for `%s'",
                      dentry->_full_path);
                return WIMLIB_ERR_INVALID_DENTRY;
        }

        if (wim_resource_size(lte) >= 0xffff) {
                ERROR("Reparse data of `%s' is too long (%"PRIu64" bytes)",
                      dentry->_full_path, wim_resource_size(lte));
                return WIMLIB_ERR_INVALID_DENTRY;
        }

        u8 reparse_data_buf[8 + wim_resource_size(lte)];
        u8 *p = reparse_data_buf;
        p = put_u32(p, dentry->d_inode->i_reparse_tag); /* ReparseTag */
        DEBUG("ReparseTag = %#x", dentry->d_inode->i_reparse_tag);
        p = put_u16(p, wim_resource_size(lte)); /* ReparseDataLength */
        p = put_u16(p, 0); /* Reserved */

        ret = read_full_resource_into_buf(lte, p, false);
        if (ret)
                return ret;

        ret = ntfs_set_ntfs_reparse_data(ni, (char*)reparse_data_buf,
                                         wim_resource_size(lte) + 8, 0);
        if (ret) {
                ERROR_WITH_ERRNO("Failed to set NTFS reparse data on `%s'",
                                 dentry->_full_path);
                return WIMLIB_ERR_NTFS_3G;
        }
        progress_info->extract.completed_bytes += wim_resource_size(lte);
        return 0;
}

/*
 * Applies a WIM dentry to a NTFS filesystem.
 *
 * @dentry:  The WIM dentry to apply
 * @dir_ni:  The NTFS inode for the parent directory
 *
 * @return:  0 on success; nonzero on failure.
 */
static int
do_apply_dentry_ntfs(struct wim_dentry *dentry, ntfs_inode *dir_ni,
                     struct apply_args *args)
{
        int ret = 0;
        mode_t type;
        ntfs_inode *ni = NULL;
        struct wim_inode *inode = dentry->d_inode;
        dentry->is_extracted = 1;

        if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
                type = S_IFDIR;
        } else {
                type = S_IFREG;
                if (inode->i_nlink > 1) {
                        /* Inode has multiple dentries referencing it. */
                        if (inode->i_extracted_file) {
                                /* Already extracted another dentry in the hard
                                 * link group.  Make a hard link instead of
                                 * extracting the file data. */
                                ret = apply_ntfs_hardlink(dentry, inode, dir_ni);
                                /* dir_ni was closed */
                                goto out;
                        } else {
                                /* None of the dentries of this inode have been
                                 * extracted yet, so go ahead and extract the
                                 * first one. */
                                FREE(inode->i_extracted_file);
                                const tchar *full_path = dentry->_full_path;

                                if (!full_path ||
                                    !(inode->i_extracted_file = STRDUP(full_path)))
                                {
                                        ret = WIMLIB_ERR_NOMEM;
                                        goto out_close_dir_ni;
                                }
                        }
                }
        }

        /* Create a NTFS directory or file.
         *
         * Note: For symbolic links that are not directory junctions, S_IFREG is
         * passed here, since the reparse data and file attributes are set
         * later. */
        ni = ntfs_create(dir_ni, 0, dentry->file_name,
                         dentry->file_name_nbytes / 2, type);

        if (!ni) {
                ERROR_WITH_ERRNO("Could not create NTFS inode for `%s'",
                                 dentry->_full_path);
                ret = WIMLIB_ERR_NTFS_3G;
                goto out_close_dir_ni;
        }

        /* Write the data streams, unless this is a directory or reparse point
         * */
        if (!(inode->i_attributes & (FILE_ATTRIBUTE_REPARSE_POINT |
                                   FILE_ATTRIBUTE_DIRECTORY))) {
                ret = write_ntfs_data_streams(ni, dentry, &args->progress);
                if (ret != 0)
                        goto out_close_dir_ni;
        }

        ret = apply_file_attributes_and_security_data(ni, dir_ni, dentry,
                                                      args->w,
                                                      args->extract_flags);
        if (ret != 0)
                goto out_close_dir_ni;

        if (inode->i_attributes & FILE_ATTR_REPARSE_POINT) {
                ret = apply_reparse_data(ni, dentry, &args->progress);
                if (ret != 0)
                        goto out_close_dir_ni;
        }

        /* Set DOS (short) name if given */
        if (dentry_has_short_name(dentry)) {
                char *short_name_mbs;
                size_t short_name_mbs_nbytes;
                ret = utf16le_to_tstr(dentry->short_name,
                                      dentry->short_name_nbytes,
                                      &short_name_mbs,
                                      &short_name_mbs_nbytes);
                if (ret != 0)
                        goto out_close_dir_ni;

                DEBUG("Setting short (DOS) name of `%s' to %s",
                      dentry->_full_path, short_name_mbs);

                ret = ntfs_set_ntfs_dos_name(ni, dir_ni, short_name_mbs,
                                             short_name_mbs_nbytes, 0);
                FREE(short_name_mbs);
                if (ret != 0) {
                        ERROR_WITH_ERRNO("Could not set DOS (short) name for `%s'",
                                         dentry->_full_path);
                        ret = WIMLIB_ERR_NTFS_3G;
                }
                /* inodes have been closed by ntfs_set_ntfs_dos_name(). */
                goto out;
        }
out_close_dir_ni:
        if (dir_ni) {
                if (ni) {
                        if (ntfs_inode_close_in_dir(ni, dir_ni)) {
                                if (ret == 0)
                                        ret = WIMLIB_ERR_NTFS_3G;
                                ERROR_WITH_ERRNO("Failed to close inode for `%s'",
                                                 dentry->_full_path);
                        }
                }
                if (ntfs_inode_close(dir_ni)) {
                        if (ret == 0)
                                ret = WIMLIB_ERR_NTFS_3G;
                        ERROR_WITH_ERRNO("Failed to close inode of directory "
                                         "containing `%s'",
                                         dentry->_full_path);
                }
        }
out:
        return ret;
}

static int
apply_root_dentry_ntfs(struct wim_dentry *dentry,
                       ntfs_volume *vol, const WIMStruct *w,
                       int extract_flags)
{
        ntfs_inode *ni;
        int ret = 0;

        ni = ntfs_pathname_to_inode(vol, NULL, "/");
        if (!ni) {
                ERROR_WITH_ERRNO("Could not find root NTFS inode");
                return WIMLIB_ERR_NTFS_3G;
        }
        ret = apply_file_attributes_and_security_data(ni, ni, dentry, w,
                                                      extract_flags);
        if (ntfs_inode_close(ni) != 0) {
                ERROR_WITH_ERRNO("Failed to close NTFS inode for root "
                                 "directory");
                ret = WIMLIB_ERR_NTFS_3G;
        }
        return ret;
}

/* Applies a WIM dentry to the NTFS volume */
int
apply_dentry_ntfs(struct wim_dentry *dentry, void *arg)
{
        struct apply_args *args = arg;
        ntfs_volume *vol = args->vol;
        WIMStruct *w = args->w;
        struct wim_dentry *orig_dentry;
        struct wim_dentry *other;
        int ret;

        /* Treat the root dentry specially. */
        if (dentry_is_root(dentry))
                return apply_root_dentry_ntfs(dentry, vol, w,
                                              args->extract_flags);

        /* NTFS filename namespaces need careful consideration.  A name for a
         * NTFS file may be in either the POSIX, Win32, DOS, or Win32+DOS
         * namespaces.  A NTFS file (a.k.a. inode) may have multiple names in
         * multiple directories (i.e. hard links); however, a NTFS file can have
         * at most 1 DOS name total.  Furthermore, a Win32 name is always
         * associated with a DOS name (either as a Win32+DOS name, or a Win32
         * name and a DOS name separately), which implies that a NTFS file can
         * have at most 1 Win32 name.
         *
         * A WIM dentry just contains a "long name", which wimlib makes sure is
         * non-empty, and a "short name", which may be empty.  So, wimlib must
         * map these to the correct NTFS names.  wimlib collects all WIM
         * dentries that map to the same NTFS inode and factors out the common
         * information into a 'struct wim_inode', so this should make the
         * mapping a little more obvious.  As a NTFS file can have at most 1 DOS
         * name, a WIM inode cannot have more than 1 dentry with a non-empty
         * short name, and this is checked in the verify_inode() function in
         * verify.c.  Furthermore, a WIM dentry, if any, that has a DOS name
         * must have a long name that corresponds to a Win32 name or Win32+DOS
         * name.
         *
         * WIM dentries that have a long name but no associated short name are
         * assumed to be in the POSIX namespace.
         *
         * So, given a WIM inode that is to map to a NTFS inode, we must apply
         * the Win32 and DOS or Win32+DOS names, if they exist, then any
         * additional (POSIX) names.  A caveat when actually doing this:  as
         * confirmed by the libntfs-3g authors, ntfs_set_ntfs_dos_name() is only
         * guaranteed to associate a DOS name with the appropriate long name if
         * it's called when that long name is the only one in existence for that
         * file.  So, this implies that the correct ordering of function calls
         * to extract a NTFS file are:
         *
         *      if (file has a DOS name) {
         *              - Call ntfs_create() to create long name associated with
         *              the DOS name (this initially creates a POSIX name)
         *              - Call ntfs_set_ntfs_dos_name() to associate a DOS name
         *              with the long name just created.  This either changes
         *              the POSIX name to Win32+DOS, or changes the POSIX name
         *              to Win32 and creates a separate DOS name.
         *      } else {
         *              - Call ntfs_create() to create the first link to the
         *              file in the POSIX namespace
         *      }
         *      - Call ntfs_link() to create the other names of the file, in the
         *      POSIX namespace.
         */
again:
        orig_dentry = NULL;
        if (!dentry->d_inode->i_dos_name_extracted &&
            !dentry_has_short_name(dentry))
        {
                inode_for_each_dentry(other, dentry->d_inode) {
                        if (dentry_has_short_name(other)) {
                                orig_dentry = dentry;
                                dentry = other;
                                break;
                        }
                }
        }
        dentry->d_inode->i_dos_name_extracted = 1;
        ntfs_inode *dir_ni = dentry_open_parent_ni(dentry, vol);
        if (dir_ni) {
                ret = do_apply_dentry_ntfs(dentry, dir_ni, arg);
                if (ret == 0 && orig_dentry != NULL) {
                        dentry = orig_dentry;
                        goto again;
                }
        } else {
                ret = WIMLIB_ERR_NTFS_3G;
        }
        return ret;
}

/* Transfers the 100-nanosecond precision timestamps from a WIM dentry to a NTFS
 * inode */
int
apply_dentry_timestamps_ntfs(struct wim_dentry *dentry, void *arg)
{
        struct apply_args *args = arg;
        ntfs_volume *vol = args->vol;
        u8 *p;
        u8 buf[24];
        ntfs_inode *ni;
        int ret;

        DEBUG("Setting timestamps on `%s'", dentry->_full_path);

        ni = ntfs_pathname_to_inode(vol, NULL, dentry->_full_path);
        if (!ni) {
                ERROR_WITH_ERRNO("Could not find NTFS inode for `%s'",
                                 dentry->_full_path);
                return WIMLIB_ERR_NTFS_3G;
        }

        p = buf;
        p = put_u64(p, dentry->d_inode->i_creation_time);
        p = put_u64(p, dentry->d_inode->i_last_write_time);
        p = put_u64(p, dentry->d_inode->i_last_access_time);
        ret = ntfs_inode_set_times(ni, (const char*)buf, 3 * sizeof(u64), 0);
        if (ret != 0) {
                ERROR_WITH_ERRNO("Failed to set NTFS timestamps on `%s'",
                                 dentry->_full_path);
                ret = WIMLIB_ERR_NTFS_3G;
        }

        if (ntfs_inode_close(ni) != 0) {
                if (ret == 0)
                        ret = WIMLIB_ERR_NTFS_3G;
                ERROR_WITH_ERRNO("Failed to close NTFS inode for `%s'",
                                 dentry->_full_path);
        }
        return ret;
}

void
libntfs3g_global_init()
{
        ntfs_set_char_encoding(setlocale(LC_ALL, ""));
}