ntfs-3g/libntfs/attrlist.c

/*
 * attrlist.c - Attribute list attribute handling code.  Part of the Linux-NTFS
 *		project.
 *
 * Copyright (c) 2004 Anton Altaparmakov
 * Copyright (c) 2004 Yura Pakhuchiy
 *
 * This program/include file 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file 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 this program (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#include <stdlib.h>
#include <errno.h>

#include "types.h"
#include "layout.h"
#include "attrib.h"
#include "attrlist.h"
#include "debug.h"
#include "unistr.h"

/**
 * ntfs_attrlist_entry_add - add an attribute list attribute entry
 * @ni:		opened ntfs inode, to which attribute list add entry
 * @mref:	mft reference of record where new attribute placed
 * @attr:	attribute record to add to attribute list
 *
 * @mref should be in little endian, use MK_LE_MREF to build it.
 * 
 * Return 0 on success and -1 on error with errno set to the error code. The
 * following error codes are defined:
 *	EINVAL
 *	ENOMEM
 *	ENOTSUP
 *	EIO
 */
int ntfs_attrlist_entry_add(ntfs_inode *ni, MFT_REF mref, ATTR_RECORD *attr)
{
	ATTR_LIST_ENTRY *ale;
	ntfs_attr *na = NULL;
	u8 *new_al;
	int new_al_len;
	runlist *rl;
	int rl_size;
	int err;

	Dprintf("%s(): Entering for inode 0x%llx, mref 0x%llx, attr 0x%x.\n",
			 __FUNCTION__, ni->mft_no, mref, attr->type);

	if (!ni || !attr) {
		errno = EINVAL;
		return -1;
	}

	if (ni->nr_extents == -1)
		ni = ni->base_ni;

	new_al_len = (ni->attr_list_size + sizeof(ATTR_LIST_ENTRY) +
			sizeof(ntfschar) * attr->name_length + 7) & ~7;
	new_al = malloc(new_al_len);
	if (!new_al) {
		Dprintf("%s(): Not enough memory.\n", __FUNCTION__);
		err = ENOMEM;
		return -1;
	}

	/* Find offset at which insert new entry. */
	ale = (ATTR_LIST_ENTRY *) ni->attr_list;
	for(; (u8 *)ale < ni->attr_list + ni->attr_list_size;
				ale = (ATTR_LIST_ENTRY *)((u8 *) ale +
				le16_to_cpu(ale->length))) {
		if (le32_to_cpu(ale->type) < le32_to_cpu(attr->type))
			continue;
		if (le32_to_cpu(ale->type) > le32_to_cpu(attr->type))
			break;
		err = ntfs_names_collate(ale->name, ale->name_length,
			(ntfschar *)((u8 *)attr + attr->name_length),
			attr->name_length, -2, CASE_SENSITIVE, 0, 0);
		if (err == -2) {
			err = EIO;
			Dprintf("%s(): Corrupt attribute name. Run chkdsk.\n",
						__FUNCTION__);
			goto err_out;
		}
		if (err < 0)
			continue;
		if (err > 0)
			break;
		if (sle16_to_cpu(ale->lowest_vcn) <
				sle16_to_cpu(attr->lowest_vcn))
			continue;
		if (sle16_to_cpu(ale->lowest_vcn) ==
				sle16_to_cpu(attr->lowest_vcn)) {
			err = EINVAL;
			Dprintf("%s(): Attribute with same type, name and "
				"lowest vcn already present in attribute "
				"list.\n", __FUNCTION__);
			goto err_out;
		}
		break;
	}

	/* Copy entries from old attribute list to new. */
	memcpy(new_al, ni->attr_list, (u8 *)ale - ni->attr_list);
	memcpy(new_al + new_al_len - ni->attr_list_size + ((u8 *)ale -
			ni->attr_list), ale, ni->attr_list_size -
			((u8 *)ale - ni->attr_list));

	/* Set pointer to new entry. */
	ale = (ATTR_LIST_ENTRY *)(new_al + ((u8 *)ale - ni->attr_list));

	/* Fill new entry with values. */
	ale->type = attr->type;
	ale->length = cpu_to_le16(new_al_len - ni->attr_list_size);
	ale->name_length = attr->name_length;
	ale->name_offset = (u8 *)ale->name - (u8 *)ale;
	ale->lowest_vcn = attr->lowest_vcn;
	ale->mft_reference = mref;
	ale->instance = attr->instance;
	memcpy(ale->name, (u8 *)attr + attr->name_length, attr->name_length);

	/* Resize $ATTRIBUTE_LIST attribute. */
	na = ntfs_attr_open(ni, AT_ATTRIBUTE_LIST, 0, 0);
	if (!na) {
		err = errno;
		Dprintf("%s(): Coudn't open $ATTRIBUTE_LIST.\n", __FUNCTION__);
		goto err_out;
	}
	if (ntfs_attr_truncate(na, new_al_len)) {
		if (errno == ENOSPC) {
			// FIXME: Free space in mft record and try again.
			err = ENOTSUP;
			goto err_out;
		} else {
			err = errno;
			Dprintf("%s(): $ATTRIBUTE_LIST resize failed.\n",
						__FUNCTION__);
			goto err_out;
		}
	}

	/* Update ntfs inode. */
	if (NAttrNonResident(na)) {
		/* Get new runlist. */
		for (rl = na->rl, rl_size = 1; rl->length; rl++)
			rl_size++;
		rl_size = (rl_size * sizeof(runlist_element) + 0xfff) & ~0xfff;	
		rl = malloc(rl_size);
		if (!rl) {
			Dprintf("%s(): Not enough memory.\n", __FUNCTION__);
			if (ntfs_attr_truncate(na, ni->attr_list_size))
				Dprintf("%s(): Rollback failed. Leaving "
					"inconsist metadata.\n", __FUNCTION__);
			err = ENOMEM;
			goto err_out;
		}
		memcpy(rl, na->rl, rl_size);
		free(ni->attr_list_rl);	
		ni->attr_list_rl = rl;
		NInoSetAttrListNonResident(ni);
	} else
		NInoClearAttrListNonResident(ni);

	free(ni->attr_list);
	ni->attr_list = new_al;
	ni->attr_list_size = new_al_len;
	NInoAttrListSetDirty(ni);
	return 0;

err_out:
	free(new_al);
	if (na)
		ntfs_attr_close(na);
	errno = err;
	return -1;
}

/**
 * ntfs_attrlist_entry_rm - remove an attribute list attribute entry
 * @ctx:	attribute search context describing the attrubute list entry
 *
 * Remove the attribute list entry @ctx->al_entry from the attribute list
 * attribute of the base mft record to which the attribute @ctx->attr belongs.
 *
 * Return 0 on success and -1 on error with errno set to the error code.
 */
int ntfs_attrlist_entry_rm(ntfs_attr_search_ctx *ctx __attribute__((unused)))
{
	errno = ENOTSUP;
	return -1;
}