1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 *   Copyright (C) 2021 Samsung Electronics Co., Ltd.
4 */
5
6#ifndef __XATTR_H__
7#define __XATTR_H__
8
9/*
10 * These are on-disk structures to store additional metadata into xattr to
11 * reproduce windows filesystem semantics. And they are encoded with NDR to
12 * compatible with samba's xattr meta format. The compatibility with samba
13 * is important because it can lose the information(file attribute,
14 * creation time, acls) about the existing files when switching between
15 * ksmbd and samba.
16 */
17
18/*
19 * Dos attribute flags used for what variable is valid.
20 */
21enum {
22	XATTR_DOSINFO_ATTRIB		= 0x00000001,
23	XATTR_DOSINFO_EA_SIZE		= 0x00000002,
24	XATTR_DOSINFO_SIZE		= 0x00000004,
25	XATTR_DOSINFO_ALLOC_SIZE	= 0x00000008,
26	XATTR_DOSINFO_CREATE_TIME	= 0x00000010,
27	XATTR_DOSINFO_CHANGE_TIME	= 0x00000020,
28	XATTR_DOSINFO_ITIME		= 0x00000040
29};
30
31/*
32 * Dos attribute structure which is compatible with samba's one.
33 * Storing it into the xattr named "DOSATTRIB" separately from inode
34 * allows ksmbd to faithfully reproduce windows filesystem semantics
35 * on top of a POSIX filesystem.
36 */
37struct xattr_dos_attrib {
38	__u16	version;	/* version 3 or version 4 */
39	__u32	flags;		/* valid flags */
40	__u32	attr;		/* Dos attribute */
41	__u32	ea_size;	/* EA size */
42	__u64	size;
43	__u64	alloc_size;
44	__u64	create_time;	/* File creation time */
45	__u64	change_time;	/* File change time */
46	__u64	itime;		/* Invented/Initial time */
47};
48
49/*
50 * Enumeration is used for computing posix acl hash.
51 */
52enum {
53	SMB_ACL_TAG_INVALID = 0,
54	SMB_ACL_USER,
55	SMB_ACL_USER_OBJ,
56	SMB_ACL_GROUP,
57	SMB_ACL_GROUP_OBJ,
58	SMB_ACL_OTHER,
59	SMB_ACL_MASK
60};
61
62#define SMB_ACL_READ			4
63#define SMB_ACL_WRITE			2
64#define SMB_ACL_EXECUTE			1
65
66struct xattr_acl_entry {
67	int type;
68	uid_t uid;
69	gid_t gid;
70	mode_t perm;
71};
72
73/*
74 * xattr_smb_acl structure is used for computing posix acl hash.
75 */
76struct xattr_smb_acl {
77	int count;
78	int next;
79	struct xattr_acl_entry entries[];
80};
81
82/* 64bytes hash in xattr_ntacl is computed with sha256 */
83#define XATTR_SD_HASH_TYPE_SHA256	0x1
84#define XATTR_SD_HASH_SIZE		64
85
86/*
87 * xattr_ntacl is used for storing ntacl and hashes.
88 * Hash is used for checking valid posix acl and ntacl in xattr.
89 */
90struct xattr_ntacl {
91	__u16	version; /* version 4*/
92	void	*sd_buf;
93	__u32	sd_size;
94	__u16	hash_type; /* hash type */
95	__u8	desc[10]; /* posix_acl description */
96	__u16	desc_len;
97	__u64	current_time;
98	__u8	hash[XATTR_SD_HASH_SIZE]; /* 64bytes hash for ntacl */
99	__u8	posix_acl_hash[XATTR_SD_HASH_SIZE]; /* 64bytes hash for posix acl */
100};
101
102/* DOS ATTRIBUITE XATTR PREFIX */
103#define DOS_ATTRIBUTE_PREFIX		"DOSATTRIB"
104#define DOS_ATTRIBUTE_PREFIX_LEN	(sizeof(DOS_ATTRIBUTE_PREFIX) - 1)
105#define XATTR_NAME_DOS_ATTRIBUTE	(XATTR_USER_PREFIX DOS_ATTRIBUTE_PREFIX)
106#define XATTR_NAME_DOS_ATTRIBUTE_LEN	\
107		(sizeof(XATTR_USER_PREFIX DOS_ATTRIBUTE_PREFIX) - 1)
108
109/* STREAM XATTR PREFIX */
110#define STREAM_PREFIX			"DosStream."
111#define STREAM_PREFIX_LEN		(sizeof(STREAM_PREFIX) - 1)
112#define XATTR_NAME_STREAM		(XATTR_USER_PREFIX STREAM_PREFIX)
113#define XATTR_NAME_STREAM_LEN		(sizeof(XATTR_NAME_STREAM) - 1)
114
115/* SECURITY DESCRIPTOR(NTACL) XATTR PREFIX */
116#define SD_PREFIX			"NTACL"
117#define SD_PREFIX_LEN	(sizeof(SD_PREFIX) - 1)
118#define XATTR_NAME_SD	(XATTR_SECURITY_PREFIX SD_PREFIX)
119#define XATTR_NAME_SD_LEN	\
120		(sizeof(XATTR_SECURITY_PREFIX SD_PREFIX) - 1)
121
122#endif /* __XATTR_H__ */
123