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__ */