freebsd-skq/sys/fs/ext2fs/ext2_extattr.h
Pedro F. Giffuni 34f4388801 ext2fs: add read-write support for Extended Attributes.
Extended attributes and their particular implementation in linux are
different from FreeBSD so in this case we have started diverging from
the  UFS EA implementation, which would be the natural reference.

Depending on future progress implementing ACLs this approach may change
but for now bring to the tree an implementation that is consistent and
can be tested.

Submitted by:	Fedor Uporov

Differential Revision:	https://reviews.freebsd.org/D10460
2017-05-03 22:35:41 +00:00

126 lines
4.6 KiB
C

/*-
* Copyright (c) 2017, Fedor Uporov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _FS_EXT2FS_EXT2_EXTARTTR_H_
#define _FS_EXT2FS_EXT2_EXTARTTR_H_
/* Linux xattr name indexes */
#define EXT4_XATTR_INDEX_USER 1
#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EXT4_XATTR_INDEX_TRUSTED 4
#define EXT4_XATTR_INDEX_LUSTRE 5
#define EXT4_XATTR_INDEX_SECURITY 6
#define EXT4_XATTR_INDEX_SYSTEM 7
#define EXT4_XATTR_INDEX_RICHACL 8
#define EXT4_XATTR_INDEX_ENCRYPTION 9
/* Magic value in attribute blocks */
#define EXTATTR_MAGIC 0xEA020000
/* Max EA name length */
#define EXT2_EXTATTR_NAMELEN_MAX 255
/* EA hash constants */
#define EXT2_EXTATTR_NAME_HASH_SHIFT 5
#define EXT2_EXTATTR_VALUE_HASH_SHIFT 16
#define EXT2_EXTATTR_BLOCK_HASH_SHIFT 16
struct ext2fs_extattr_header {
int32_t h_magic; /* magic number for identification */
int32_t h_refcount; /* reference count */
int32_t h_blocks; /* number of disk blocks used */
int32_t h_hash; /* hash value of all attributes */
uint32_t h_reserved[4]; /* zero right now */
};
struct ext2fs_extattr_dinode_header {
int32_t h_magic; /* magic number for identification */
};
struct ext2fs_extattr_entry {
uint8_t e_name_len; /* length of name */
uint8_t e_name_index; /* attribute name index */
uint16_t e_value_offs; /* offset in disk block of value */
uint32_t e_value_block; /* disk block attribute is stored on (n/i) */
uint32_t e_value_size; /* size of attribute value */
uint32_t e_hash; /* hash value of name and value */
char e_name[0]; /* attribute name */
};
#define EXT2_IFIRST(hdr) ((struct ext2fs_extattr_entry *)((hdr)+1))
#define EXT2_HDR(bh) ((struct ext2fs_extattr_header *)((bh)->b_data))
#define EXT2_ENTRY(ptr) ((struct ext2fs_extattr_entry *)(ptr))
#define EXT2_FIRST_ENTRY(bh) EXT2_ENTRY(EXT2_HDR(bh)+1)
#define EXT2_IS_LAST_ENTRY(entry) (*(uint32_t *)(entry) == 0)
#define EXT2_EXTATTR_PAD_BITS 2
#define EXT2_EXTATTR_PAD (1<<EXT2_EXTATTR_PAD_BITS)
#define EXT2_EXTATTR_ROUND (EXT2_EXTATTR_PAD-1)
#define EXT2_EXTATTR_LEN(name_len) \
(((name_len) + EXT2_EXTATTR_ROUND + \
sizeof(struct ext2fs_extattr_entry)) & ~EXT2_EXTATTR_ROUND)
#define EXT2_EXTATTR_SIZE(size) \
(((size) + EXT2_EXTATTR_ROUND) & ~EXT2_EXTATTR_ROUND)
#define EXT2_EXTATTR_NEXT(entry) \
( (struct ext2fs_extattr_entry *)( \
(char *)(entry) + EXT2_EXTATTR_LEN((entry)->e_name_len)) )
int ext2_extattr_inode_delete(struct inode *ip, int attrnamespace,
const char *name);
int ext2_extattr_block_delete(struct inode *ip, int attrnamespace,
const char *name);
int ext2_extattr_free(struct inode *ip);
int ext2_extattr_inode_list(struct inode *ip, int attrnamespace,
struct uio *uio, size_t *size);
int ext2_extattr_block_list(struct inode *ip, int attrnamespace,
struct uio *uio, size_t *size);
int ext2_extattr_inode_get(struct inode *ip, int attrnamespace,
const char *name, struct uio *uio, size_t *size);
int ext2_extattr_block_get(struct inode *ip, int attrnamespace,
const char *name, struct uio *uio, size_t *size);
int ext2_extattr_inode_set(struct inode *ip, int attrnamespace,
const char *name, struct uio *uio);
int ext2_extattr_block_set(struct inode *ip, int attrnamespace,
const char *name, struct uio *uio);
int ext2_extattr_valid_attrname(int attrnamespace, const char *attrname);
#endif /* !_FS_EXT2FS_EXT2_EXTARTTR_H_ */