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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

fs/ksmbd/ksmbd_server.h → fs/ksmbd/ksmbd_netlink.h

@@ -10,6 +10,49 @@
 
 #include <linux/types.h>
 
+/*
+ * 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.
+ */
+
 #define KSMBD_GENL_NAME		"SMBD_GENL"
 #define KSMBD_GENL_VERSION		0x01
 
@@ -17,6 +60,9 @@
 #define KSMBD_REQ_MAX_HASH_SZ		18
 #define KSMBD_REQ_MAX_SHARE_NAME	64
 
+/*
+ * IPC heartbeat frame to check whether user IPC daemon is alive.
+ */
 struct ksmbd_heartbeat {
 	__u32	handle;
 };
@@ -29,53 +75,79 @@ struct ksmbd_heartbeat {
 #define KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION	BIT(1)
 #define KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL	BIT(2)
 
+/*
+ * IPC request for ksmbd server startup
+ */
 struct ksmbd_startup_request {
-	__u32	flags;
-	__s32	signing;
-	__s8	min_prot[16];
-	__s8	max_prot[16];
+	__u32	flags;			/* Flags for global config */
+	__s32	signing;		/* Signing enabled */
+	__s8	min_prot[16];		/* The minimum SMB protocol version */
+	__s8	max_prot[16];		/* The maximum SMB protocol version */
 	__s8	netbios_name[16];
-	__s8	work_group[64];
-	__s8	server_string[64];
-	__u16	tcp_port;
-	__u16	ipc_timeout;
-	__u32	deadtime;
-	__u32	file_max;
-	__u32	smb2_max_write;
-	__u32	smb2_max_read;
-	__u32	smb2_max_trans;
-	__u32	share_fake_fscaps;
-	__u32	sub_auth[3];
-	__u32	ifc_list_sz;
+	__s8	work_group[64];		/* Workgroup */
+	__s8	server_string[64];	/* Server string */
+	__u16	tcp_port;		/* tcp port */
+	__u16	ipc_timeout;		/*
+					 * specifies the number of seconds
+					 * server will wait for the userspace to
+					 * reply to heartbeat frames.
+					 */
+	__u32	deadtime;		/* Number of minutes of inactivity */
+	__u32	file_max;		/* Limits the maximum number of open files */
+	__u32	smb2_max_write;		/* MAX write size */
+	__u32	smb2_max_read;		/* MAX read size */
+	__u32	smb2_max_trans;		/* MAX trans size */
+	__u32	share_fake_fscaps;	/*
+					 * Support some special application that
+					 * makes QFSINFO calls to check whether
+					 * we set the SPARSE_FILES bit (0x40).
+					 */
+	__u32	sub_auth[3];		/* Subauth value for Security ID */
+	__u32	ifc_list_sz;		/* interfaces list size */
 	__s8	____payload[];
 };
 
 #define KSMBD_STARTUP_CONFIG_INTERFACES(s)	((s)->____payload)
 
+/*
+ * IPC request to shutdown ksmbd server.
+ */
 struct ksmbd_shutdown_request {
 	__s32	reserved;
 };
 
+/*
+ * IPC user login request.
+ */
 struct ksmbd_login_request {
 	__u32	handle;
-	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */
 };
 
+/*
+ * IPC user login response.
+ */
 struct ksmbd_login_response {
 	__u32	handle;
-	__u32	gid;
-	__u32	uid;
-	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+	__u32	gid;					/* group id */
+	__u32	uid;					/* user id */
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */
 	__u16	status;
-	__u16	hash_sz;
-	__s8	hash[KSMBD_REQ_MAX_HASH_SZ];
+	__u16	hash_sz;			/* hash size */
+	__s8	hash[KSMBD_REQ_MAX_HASH_SZ];	/* password hash */
 };
 
+/*
+ * IPC request to fetch net share config.
+ */
 struct ksmbd_share_config_request {
 	__u32	handle;
-	__s8	share_name[KSMBD_REQ_MAX_SHARE_NAME];
+	__s8	share_name[KSMBD_REQ_MAX_SHARE_NAME]; /* share name */
 };
 
+/*
+ * IPC response to the net share config request.
+ */
 struct ksmbd_share_config_response {
 	__u32	handle;
 	__u32	flags;
@@ -102,6 +174,10 @@ ksmbd_share_config_path(struct ksmbd_share_config_response *sc)
 	return p;
 }
 
+/*
+ * IPC request for tree connection. This request include session and tree
+ * connect info from client.
+ */
 struct ksmbd_tree_connect_request {
 	__u32	handle;
 	__u16	account_flags;
@@ -113,21 +189,34 @@ struct ksmbd_tree_connect_request {
 	__s8	peer_addr[64];
 };
 
+/*
+ * IPC Response structure for tree connection.
+ */
 struct ksmbd_tree_connect_response {
 	__u32	handle;
 	__u16	status;
 	__u16	connection_flags;
 };
 
+/*
+ * IPC Request struture to disconnect tree connection.
+ */
 struct ksmbd_tree_disconnect_request {
-	__u64	session_id;
-	__u64	connect_id;
+	__u64	session_id;	/* session id */
+	__u64	connect_id;	/* tree connection id */
 };
 
+/*
+ * IPC Response structure to logout user account.
+ */
 struct ksmbd_logout_request {
-	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */
 };
 
+/*
+ * RPC command structure to send rpc request like srvsvc or wkssvc to
+ * IPC user daemon.
+ */
 struct ksmbd_rpc_command {
 	__u32	handle;
 	__u32	flags;
@@ -135,18 +224,36 @@ struct ksmbd_rpc_command {
 	__u8	payload[];
 };
 
+/*
+ * IPC Request Kerberos authentication
+ */
 struct ksmbd_spnego_authen_request {
 	__u32	handle;
-	__u16	spnego_blob_len;
-	__u8	spnego_blob[0];
+	__u16	spnego_blob_len;	/* the length of spnego_blob */
+	__u8	spnego_blob[0];		/*
+					 * the GSS token from SecurityBuffer of
+					 * SMB2 SESSION SETUP request
+					 */
 };
 
+/*
+ * Response data which includes the GSS token and the session key generated by
+ * user daemon.
+ */
 struct ksmbd_spnego_authen_response {
 	__u32	handle;
-	struct ksmbd_login_response	login_response;
-	__u16	session_key_len;
-	__u16	spnego_blob_len;
-	__u8	payload[];		/* session key + AP_REP */
+	struct ksmbd_login_response login_response; /*
+						     * the login response with
+						     * a user identified by the
+						     * GSS token from a client
+						     */
+	__u16	session_key_len; /* the length of the session key */
+	__u16	spnego_blob_len; /*
+				  * the length of  the GSS token which will be
+				  * stored in SecurityBuffer of SMB2 SESSION
+				  * SETUP response
+				  */
+	__u8	payload[]; /* session key + AP_REP */
 };
 
 /*
@@ -185,6 +292,9 @@ enum ksmbd_event {
 	KSMBD_EVENT_MAX
 };
 
+/*
+ * Enumeration for IPC tree connect status.
+ */
 enum KSMBD_TREE_CONN_STATUS {
 	KSMBD_TREE_CONN_STATUS_OK		= 0,
 	KSMBD_TREE_CONN_STATUS_NOMEM,
@@ -262,6 +372,9 @@ enum KSMBD_TREE_CONN_STATUS {
 #define KSMBD_RPC_LSARPC_METHOD_INVOKE	BIT(11)
 #define KSMBD_RPC_LSARPC_METHOD_RETURN	(KSMBD_RPC_LSARPC_METHOD_INVOKE | KSMBD_RPC_METHOD_RETURN)
 
+/*
+ * RPC status definitions.
+ */
 #define KSMBD_RPC_OK			0
 #define KSMBD_RPC_EBAD_FUNC		0x00000001
 #define KSMBD_RPC_EACCESS_DENIED	0x00000005

fs/ksmbd/ksmbd_work.c

@@ -12,7 +12,6 @@
 #include "connection.h"
 #include "ksmbd_work.h"
 #include "mgmt/ksmbd_ida.h"
-#include "ksmbd_server.h"
 
 static struct kmem_cache *work_cache;
 static struct workqueue_struct *ksmbd_wq;

fs/ksmbd/mgmt/tree_connect.h

@@ -8,7 +8,7 @@
 
 #include <linux/hashtable.h>
 
-#include "../ksmbd_server.h"
+#include "../ksmbd_netlink.h"
 
 struct ksmbd_share_config;
 struct ksmbd_user;

fs/ksmbd/smb2ops.c

@@ -12,7 +12,6 @@
 #include "connection.h"
 #include "smb_common.h"
 #include "server.h"
-#include "ksmbd_server.h"
 
 static struct smb_version_values smb21_server_values = {
 	.version_string = SMB21_VERSION_STRING,

fs/ksmbd/smbacl.c

@@ -14,7 +14,6 @@
 #include "smb_common.h"
 #include "server.h"
 #include "misc.h"
-#include "ksmbd_server.h"
 #include "mgmt/share_config.h"
 
 static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5},

fs/ksmbd/vfs.h

@@ -14,92 +14,7 @@
 #include <linux/posix_acl.h>
 
 #include "smbacl.h"
-
-/* 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)
-
-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
-};
-
-struct xattr_dos_attrib {
-	__u16	version;
-	__u32	flags;
-	__u32	attr;
-	__u32	ea_size;
-	__u64	size;
-	__u64	alloc_size;
-	__u64	create_time;
-	__u64	change_time;
-	__u64	itime;
-};
-
-/* 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)
-
-#define XATTR_SD_HASH_TYPE_SHA256	0x1
-#define XATTR_SD_HASH_SIZE		64
-
-#define SMB_ACL_READ			4
-#define SMB_ACL_WRITE			2
-#define SMB_ACL_EXECUTE			1
-
-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
-};
-
-struct xattr_acl_entry {
-	int type;
-	uid_t uid;
-	gid_t gid;
-	mode_t perm;
-};
-
-struct xattr_smb_acl {
-	int count;
-	int next;
-	struct xattr_acl_entry entries[0];
-};
-
-struct xattr_ntacl {
-	__u16	version;
-	void	*sd_buf;
-	__u32	sd_size;
-	__u16	hash_type;
-	__u8	desc[10];
-	__u16	desc_len;
-	__u64	current_time;
-	__u8	hash[XATTR_SD_HASH_SIZE];
-	__u8	posix_acl_hash[XATTR_SD_HASH_SIZE];
-};
-
-/* SECURITY DESCRIPTOR 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)
+#include "xattr.h"
 
 /*
  * Enumeration for stream type.

fs/ksmbd/xattr.h

+/* 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__ */