/* 
   Unix SMB/CIFS implementation.
   NTVFS structures and defines
   Copyright (C) Andrew Tridgell			2003
   Copyright (C) Stefan Metzmacher			2004
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/* modules can use the following to determine if the interface has changed */
/* version 1 -> 0 - make module stacking easier -- metze */
#define NTVFS_INTERFACE_VERSION 0

struct ntvfs_module_context;

/* each backend has to be one one of the following 3 basic types. In
 * earlier versions of Samba backends needed to handle all types, now
 * we implement them separately. */
enum ntvfs_type {NTVFS_DISK, NTVFS_PRINT, NTVFS_IPC};

/* the ntvfs operations structure - contains function pointers to 
   the backend implementations of each operation */
struct ntvfs_ops {
	const char *name;
	enum ntvfs_type type;
	
	/* initial setup */
	NTSTATUS (*connect)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, const char *sharename);
	NTSTATUS (*disconnect)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_tcon *tcon);

	/* path operations */
	NTSTATUS (*unlink)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_unlink *unl);
	NTSTATUS (*chkpath)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_chkpath *cp);
	NTSTATUS (*qpathinfo)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_fileinfo *st);
	NTSTATUS (*setpathinfo)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_setfileinfo *st);
	NTSTATUS (*openfile)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_open *oi);
	NTSTATUS (*mkdir)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_mkdir *md);
	NTSTATUS (*rmdir)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_rmdir *rd);
	NTSTATUS (*rename)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_rename *ren);
	NTSTATUS (*copy)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_copy *cp);

	/* directory search */
	NTSTATUS (*search_first)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_search_first *io, void *private,
				 BOOL (*callback)(void *private, union smb_search_data *file));
	NTSTATUS (*search_next)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_search_next *io, void *private,
				 BOOL (*callback)(void *private, union smb_search_data *file));
	NTSTATUS (*search_close)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_search_close *io);

	/* operations on open files */
	NTSTATUS (*ioctl)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_ioctl *io);
	NTSTATUS (*read)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_read *io);
	NTSTATUS (*write)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_write *io);
	NTSTATUS (*seek)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_seek *io);
	NTSTATUS (*flush)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_flush *flush);
	NTSTATUS (*close)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_close *io);
	NTSTATUS (*exit)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req);
	NTSTATUS (*lock)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_lock *lck);
	NTSTATUS (*setfileinfo)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_setfileinfo *info);
	NTSTATUS (*qfileinfo)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_fileinfo *info);

	/* filesystem operations */
	NTSTATUS (*fsinfo)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_fsinfo *fs);

	/* printing specific operations */
	NTSTATUS (*lpq)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, union smb_lpq *lpq);

	/* trans2 interface - only used by CIFS backend to prover complete passthru for testing */
	NTSTATUS (*trans2)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_trans2 *trans2);

	/* trans interface - used by IPC backend for pipes and RAP calls */
	NTSTATUS (*trans)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, struct smb_trans2 *trans);

	/* logoff - called when a vuid is closed */
	NTSTATUS (*logoff)(struct ntvfs_module_context *ntvfs, 
			   struct smbsrv_request *req);

	/* async_setup - called when a backend is processing a async request */
	NTSTATUS (*async_setup)(struct ntvfs_module_context *ntvfs, 
				struct smbsrv_request *req, void *private);

	/* cancel - cancels any pending async request */
	NTSTATUS (*cancel)(struct ntvfs_module_context *ntvfs, 
			   struct smbsrv_request *req);
};

struct ntvfs_module_context {
	struct ntvfs_module_context *prev, *next;
	void *private_data;
	const struct ntvfs_ops *ops;
	int depth;
};

struct ntvfs_context {
	enum ntvfs_type type;
	/* 
	 * linked list of module contexts
	 */
	struct ntvfs_module_context *modules;
};


/* a set of flags to control handling of request structures */
#define NTVFS_ASYNC_STATE_ASYNC     (1<<1) /* the backend will answer this one later */
#define NTVFS_ASYNC_STATE_MAY_ASYNC (1<<2) /* the backend is allowed to answer async */

/* the ntvfs_async_state structure allows backend functions to 
   delay replying to requests. To use this, the front end must
   set send_fn to a function to be called by the backend
   when the reply is finally ready to be sent. The backend
   must set status to the status it wants in the
   reply. The backend must set the NTVFS_ASYNC_STATE_ASYNC
   control_flag on the request to indicate that it wishes to
   delay the reply

   If NTVFS_ASYNC_STATE_MAY_ASYNC is not set then the backend cannot
   ask for a delayed reply for this request

   note that the private_data pointer is private to the layer which alloced this struct
*/
struct ntvfs_async_state {
	struct ntvfs_async_state *prev, *next;
	/* the async handling infos */
	uint_t state;
	void *private_data;
	void (*send_fn)(struct smbsrv_request *);
	NTSTATUS status;

	/* the passthru module's per session private data */
	struct ntvfs_module_context *ntvfs;
};

/* this structure is used by backends to determine the size of some critical types */
struct ntvfs_critical_sizes {
	int interface_version;
	int sizeof_ntvfs_critical_sizes;
	int sizeof_ntvfs_context;
	int sizeof_ntvfs_module_context;
	int sizeof_ntvfs_ops;
	int sizeof_ntvfs_async_state;
	int sizeof_smbsrv_tcon;
	int sizeof_smbsrv_request;
};