ksmbd: reorder and document on-disk and netlink structures in headers

Reorder and document on-disk and netlink structures in headers.

This is a userspace ABI to communicate data between ksmbd and user IPC
daemon using netlink. This is added to track and cache user account DB
and share configuration info from userspace.

 - KSMBD_EVENT_HEARTBEAT_REQUEST(ksmbd_heartbeat)
   This event is to check whether user IPC daemon is alive. If user IPC
   daemon is dead, ksmbd keep existing connection till disconnecting and
   new connection will be denied.

 - KSMBD_EVENT_STARTING_UP(ksmbd_startup_request)
   This event is to receive the information that initializes the ksmbd
   server from the user IPC daemon and to start the server. The global
   section parameters are given from smb.conf as initialization
   information.

 - KSMBD_EVENT_SHUTTING_DOWN(ksmbd_shutdown_request)
   This event is to shutdown ksmbd server.

 - KSMBD_EVENT_LOGIN_REQUEST/RESPONSE(ksmbd_login_request/response)
   This event is to get user account info to user IPC daemon.

 - KSMBD_EVENT_SHARE_CONFIG_REQUEST/RESPONSE
   (ksmbd_share_config_request/response)
   This event is to get net share configuration info.

 - KSMBD_EVENT_TREE_CONNECT_REQUEST/RESPONSE
   (ksmbd_tree_connect_request/response)
   This event is to get session and tree connect info.

 - KSMBD_EVENT_TREE_DISCONNECT_REQUEST(ksmbd_tree_disconnect_request)
   This event is to send tree disconnect info to user IPC daemon.

 - KSMBD_EVENT_LOGOUT_REQUEST(ksmbd_logout_request)
   This event is to send logout request to user IPC daemon.

 - KSMBD_EVENT_RPC_REQUEST/RESPONSE(ksmbd_rpc_command)
   This event is to make DCE/RPC request like srvsvc, wkssvc, lsarpc,
   samr to be processed in userspace.

 - KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST/RESPONSE
   (ksmbd_spnego_authen_request/response)
   This event is to make kerberos authentication to be processed in
   userspace.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/fs/ksmbd/xattr.h b/fs/ksmbd/xattr.h
new file mode 100644
index 000000000000..8857c01093d9
--- /dev/null
+++ b/fs/ksmbd/xattr.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2021 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __XATTR_H__
+#define __XATTR_H__
+
+/*
+ * These are on-disk structures to store additional metadata into xattr to
+ * reproduce windows filesystem semantics. And they are encoded with NDR to
+ * compatible with samba's xattr meta format. The compatibility with samba
+ * is important because it can lose the information(file attribute,
+ * creation time, acls) about the existing files when switching between
+ * ksmbd and samba.
+ */
+
+/*
+ * Dos attribute flags used for what variable is valid.
+ */
+enum {
+	XATTR_DOSINFO_ATTRIB		= 0x00000001,
+	XATTR_DOSINFO_EA_SIZE		= 0x00000002,
+	XATTR_DOSINFO_SIZE		= 0x00000004,
+	XATTR_DOSINFO_ALLOC_SIZE	= 0x00000008,
+	XATTR_DOSINFO_CREATE_TIME	= 0x00000010,
+	XATTR_DOSINFO_CHANGE_TIME	= 0x00000020,
+	XATTR_DOSINFO_ITIME		= 0x00000040
+};
+
+/*
+ * Dos attribute structure which is compatible with samba's one.
+ * Storing it into the xattr named "DOSATTRIB" separately from inode
+ * allows ksmbd to faithfully reproduce windows filesystem semantics
+ * on top of a POSIX filesystem.
+ */
+struct xattr_dos_attrib {
+	__u16	version;	/* version 3 or version 4 */
+	__u32	flags;		/* valid flags */
+	__u32	attr;		/* Dos attribute */
+	__u32	ea_size;	/* EA size */
+	__u64	size;
+	__u64	alloc_size;
+	__u64	create_time;	/* File creation time */
+	__u64	change_time;	/* File change time */
+	__u64	itime;		/* Invented/Initial time */
+};
+
+/*
+ * Enumeration is used for computing posix acl hash.
+ */
+enum {
+	SMB_ACL_TAG_INVALID = 0,
+	SMB_ACL_USER,
+	SMB_ACL_USER_OBJ,
+	SMB_ACL_GROUP,
+	SMB_ACL_GROUP_OBJ,
+	SMB_ACL_OTHER,
+	SMB_ACL_MASK
+};
+
+#define SMB_ACL_READ			4
+#define SMB_ACL_WRITE			2
+#define SMB_ACL_EXECUTE			1
+
+struct xattr_acl_entry {
+	int type;
+	uid_t uid;
+	gid_t gid;
+	mode_t perm;
+};
+
+/*
+ * xattr_smb_acl structure is used for computing posix acl hash.
+ */
+struct xattr_smb_acl {
+	int count;
+	int next;
+	struct xattr_acl_entry entries[0];
+};
+
+/* 64bytes hash in xattr_ntacl is computed with sha256 */
+#define XATTR_SD_HASH_TYPE_SHA256	0x1
+#define XATTR_SD_HASH_SIZE		64
+
+/*
+ * xattr_ntacl is used for storing ntacl and hashes.
+ * Hash is used for checking valid posix acl and ntacl in xattr.
+ */
+struct xattr_ntacl {
+	__u16	version; /* version 4*/
+	void	*sd_buf;
+	__u32	sd_size;
+	__u16	hash_type; /* hash type */
+	__u8	desc[10]; /* posix_acl description */
+	__u16	desc_len;
+	__u64	current_time;
+	__u8	hash[XATTR_SD_HASH_SIZE]; /* 64bytes hash for ntacl */
+	__u8	posix_acl_hash[XATTR_SD_HASH_SIZE]; /* 64bytes hash for posix acl */
+};
+
+/* DOS ATTRIBUITE XATTR PREFIX */
+#define DOS_ATTRIBUTE_PREFIX		"DOSATTRIB"
+#define DOS_ATTRIBUTE_PREFIX_LEN	(sizeof(DOS_ATTRIBUTE_PREFIX) - 1)
+#define XATTR_NAME_DOS_ATTRIBUTE	(XATTR_USER_PREFIX DOS_ATTRIBUTE_PREFIX)
+#define XATTR_NAME_DOS_ATTRIBUTE_LEN	\
+		(sizeof(XATTR_USER_PREFIX DOS_ATTRIBUTE_PREFIX) - 1)
+
+/* STREAM XATTR PREFIX */
+#define STREAM_PREFIX			"DosStream."
+#define STREAM_PREFIX_LEN		(sizeof(STREAM_PREFIX) - 1)
+#define XATTR_NAME_STREAM		(XATTR_USER_PREFIX STREAM_PREFIX)
+#define XATTR_NAME_STREAM_LEN		(sizeof(XATTR_NAME_STREAM) - 1)
+
+/* SECURITY DESCRIPTOR(NTACL) XATTR PREFIX */
+#define SD_PREFIX			"NTACL"
+#define SD_PREFIX_LEN	(sizeof(SD_PREFIX) - 1)
+#define XATTR_NAME_SD	(XATTR_SECURITY_PREFIX SD_PREFIX)
+#define XATTR_NAME_SD_LEN	\
+		(sizeof(XATTR_SECURITY_PREFIX SD_PREFIX) - 1)
+
+#endif /* __XATTR_H__ */