/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * vim:noexpandtab:shiftwidth=8:tabstop=8:
 *
 *   Copyright (C) International Business Machines  Corp., 2010
 *   Author(s): Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library 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 Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/**
 * @file FSAL/FSAL_VFS/vfs_methods.h
 * @brief System calls for the FreeBSD handle calls
 */

/* VFS methods for handles
 */

#ifndef VFS_METHODS_H
#define VFS_METHODS_H

#include "fsal_handle_syscalls.h"
#include "fsal_api.h"
#include "FSAL/fsal_commonlib.h"
#include "FSAL/fsal_localfs.h"
#include "FSAL/access_check.h"

struct vfs_fsal_obj_handle;
struct vfs_fsal_export;

/*
 * VFS internal module
 */
struct vfs_fsal_module {
	struct fsal_module module;
	struct fsal_obj_ops handle_ops;
	bool only_one_user;
};

/*
 * VFS internal export
 */
struct vfs_fsal_export {
	struct fsal_export export;
	int fsid_type;
	bool async_hsm_restore;
};

#define EXPORT_VFS_FROM_FSAL(fsal) \
	container_of((fsal), struct vfs_fsal_export, export)

/* private helpers from export
 */

void vfs_handle_ops_init(struct fsal_obj_ops *ops);

static inline int root_fd(struct fsal_filesystem *fs)
{
	int fd = (long)fs->private_data;

	return fd;
}

static inline int vfs_get_root_fd(struct fsal_export *exp_hdl)
{
	return root_fd(exp_hdl->root_fs);
}

/* Internal VFS method linkage to export object
 */

int vfs_claim_filesystem(struct fsal_filesystem *fs, struct fsal_export *exp,
			 void **private_data);

void vfs_unclaim_filesystem(struct fsal_filesystem *fs);

fsal_status_t vfs_create_export(struct fsal_module *fsal_hdl, void *parse_node,
				struct config_error_type *err_type,
				const struct fsal_up_vector *up_ops);

fsal_status_t vfs_update_export(struct fsal_module *fsal_hdl, void *parse_node,
				struct config_error_type *err_type,
				struct fsal_export *original,
				struct fsal_module *updated_super);

/* method proto linkage to handle.c for export
 */

fsal_status_t vfs_lookup_path(struct fsal_export *exp_hdl, const char *path,
			      struct fsal_obj_handle **handle,
			      struct fsal_attrlist *attrs_out);

fsal_status_t vfs_create_handle(struct fsal_export *exp_hdl,
				struct gsh_buffdesc *hdl_desc,
				struct fsal_obj_handle **handle,
				struct fsal_attrlist *attrs_out);

struct vfs_subfsal_obj_ops {
	/**
 * @brief Gte sub-fsal attributes from an object
 *
 * @param[in] vfs_hdl    The VFS object to modify
 * @param[in] fd		 Open filehandle on object
 *
 * @return FSAL status.
 */
	fsal_status_t (*getattrs)(struct vfs_fsal_obj_handle *vfs_hdl, int fd,
				  attrmask_t request_mask,
				  struct fsal_attrlist *attrs);
	/**
 * @brief Set sub-fsal attributes on an object
 *
 * @param[in] vfs_hdl    The VFS object to modify
 * @param[in] fd		 Open filehandle on object
 * @param[in] attrib_set Attributes to set
 *
 * @return FSAL status.
 */
	fsal_status_t (*setattrs)(struct vfs_fsal_obj_handle *vfs_hdl, int fd,
				  attrmask_t request_mask,
				  struct fsal_attrlist *attrib_set);
};

struct vfs_fd {
	/** open and share mode plus fd management */
	struct fsal_fd fsal_fd;
	/** The kernel file descriptor. */
	int fd;
};

struct vfs_state_fd {
	/** state MUST be first to use default free_state */
	struct state_t state;
	struct vfs_fd vfs_fd;
};

/**
 * @brief VFS internal object handle
 *
 * The handle is a pointer because
 *  a) the last element of file_handle is a char[] meaning variable len...
 *  b) we cannot depend on it *always* being last or being the only
 *     variable sized struct here...  a pointer is safer.
 * wrt locks, should this be a lock counter??
 * AF_UNIX sockets are strange ducks.  I personally cannot see why they
 * are here except for the ability of a client to see such an animal with
 * an 'ls' or get rid of one with an 'rm'.  You can't open them in the
 * usual file way so open_by_handle_at leads to a deadend.  To work around
 * this, we save the args that were used to mknod or lookup the socket.
 */

struct vfs_fsal_obj_handle {
	struct fsal_obj_handle obj_handle;
	fsal_dev_t dev;
	vfs_file_handle_t *handle;
#ifdef ENABLE_VFS_DEBUG_ACL
	uint32_t mode; /*< POSIX access mode */
#endif
	struct vfs_subfsal_obj_ops *sub_ops; /*< Optional subfsal ops */
	const struct fsal_up_vector *up_ops; /*< Upcall operations */
	union {
		struct {
			struct fsal_share share;
			struct vfs_fd fd;
		} file;
		struct {
			unsigned char *link_content;
			int link_size;
		} symlink;
		struct {
			vfs_file_handle_t *dir;
			char *name;
		} unopenable;
	} u;
};

#define OBJ_VFS_FROM_FSAL(fsal) \
	container_of((fsal), struct vfs_fsal_obj_handle, obj_handle)

/* default vex ops */
int vfs_fd_to_handle(int fd, struct fsal_filesystem *fs, vfs_file_handle_t *fh);

int vfs_name_to_handle(int atfd, struct fsal_filesystem *fs, const char *name,
		       vfs_file_handle_t *fh);

int vfs_open_by_handle(struct fsal_filesystem *fs, vfs_file_handle_t *fh,
		       int openflags, fsal_errors_t *fsal_error);

int vfs_encode_dummy_handle(vfs_file_handle_t *fh, struct fsal_filesystem *fs);

bool vfs_is_dummy_handle(vfs_file_handle_t *fh);

fsal_status_t vfs_check_handle(struct fsal_export *exp_hdl,
			       struct gsh_buffdesc *hdl_desc,
			       struct fsal_filesystem **fs,
			       vfs_file_handle_t *fh, bool *dummy);

bool vfs_valid_handle(struct gsh_buffdesc *desc);

int vfs_readlink(struct vfs_fsal_obj_handle *myself, fsal_errors_t *fsal_error);

int vfs_extract_fsid(vfs_file_handle_t *fh, enum fsid_type *fsid_type,
		     struct fsal_fsid__ *fsid);

int vfs_get_root_handle(struct fsal_filesystem *fs, struct vfs_fsal_export *exp,
			int *root_fd);

int vfs_re_index(struct fsal_filesystem *fs, struct vfs_fsal_export *exp);

/*
 * VFS structure to tell subfunctions whether they should close the
 * returned fd or not
 */
struct closefd {
	int fd;
	int close_fd;
};

int vfs_fsal_open(struct vfs_fsal_obj_handle *hdl, int openflags,
		  fsal_errors_t *fsal_error);

fsal_status_t vfs_close_func(struct fsal_obj_handle *obj_hdl,
			     struct fsal_fd *fd);

fsal_status_t vfs_reopen_func(struct fsal_obj_handle *obj_hdl,
			      fsal_openflags_t openflags,
			      struct fsal_fd *fsal_fd);

struct vfs_fsal_obj_handle *alloc_handle(int dirfd, vfs_file_handle_t *fh,
					 struct fsal_filesystem *fs,
					 struct stat *stat,
					 vfs_file_handle_t *dir_fh,
					 const char *path,
					 struct fsal_export *exp_hdl);

void free_vfs_fsal_obj_handle(struct vfs_fsal_obj_handle **hdl);

static inline bool vfs_unopenable_type(object_file_type_t type)
{
	if ((type == SOCKET_FILE) || (type == CHARACTER_FILE) ||
	    (type == BLOCK_FILE)) {
		return true;
	} else {
		return false;
	}
}

/* State storage */
void vfs_state_init(void);
void vfs_state_release(struct gsh_buffdesc *key);
struct state_hdl *vfs_state_locate(struct fsal_obj_handle *obj);

/* I/O management */
fsal_status_t vfs_close_my_fd(struct vfs_fd *my_fd);

fsal_status_t vfs_close(struct fsal_obj_handle *obj_hdl);

/* Multiple file descriptor methods */
struct state_t *vfs_alloc_state(struct fsal_export *exp_hdl,
				enum state_type state_type,
				struct state_t *related_state);

fsal_status_t vfs_merge(struct fsal_obj_handle *orig_hdl,
			struct fsal_obj_handle *dupe_hdl);

fsal_status_t vfs_open2(struct fsal_obj_handle *obj_hdl, struct state_t *state,
			fsal_openflags_t openflags,
			enum fsal_create_mode createmode, const char *name,
			struct fsal_attrlist *attrib_set,
			fsal_verifier_t verifier,
			struct fsal_obj_handle **new_obj,
			struct fsal_attrlist *attrs_out,
			bool *caller_perm_check,
			struct fsal_attrlist *parent_pre_attrs_out,
			struct fsal_attrlist *parent_post_attrs_out);

fsal_openflags_t vfs_status2(struct fsal_obj_handle *obj_hdl,
			     struct state_t *state);

fsal_status_t vfs_reopen2(struct fsal_obj_handle *obj_hdl,
			  struct state_t *state, fsal_openflags_t openflags);

void vfs_read2(struct fsal_obj_handle *obj_hdl, bool bypass,
	       fsal_async_cb done_cb, struct fsal_io_arg *read_arg,
	       void *caller_arg);

void vfs_write2(struct fsal_obj_handle *obj_hdl, bool bypass,
		fsal_async_cb done_cb, struct fsal_io_arg *write_arg,
		void *caller_arg);

#ifdef __USE_GNU
fsal_status_t vfs_seek2(struct fsal_obj_handle *obj_hdl, struct state_t *state,
			struct io_info *info);
#endif

#ifdef FALLOC_FL_PUNCH_HOLE
fsal_status_t vfs_fallocate(struct fsal_obj_handle *obj_hdl,
			    struct state_t *state, uint64_t offset,
			    uint64_t length, bool allocate);
#endif

fsal_status_t vfs_commit2(struct fsal_obj_handle *obj_hdl, off_t offset,
			  size_t len);

fsal_status_t vfs_lock_op2(struct fsal_obj_handle *obj_hdl,
			   struct state_t *state, void *owner,
			   fsal_lock_op_t lock_op,
			   fsal_lock_param_t *request_lock,
			   fsal_lock_param_t *conflicting_lock);

fsal_status_t getattr2(struct fsal_obj_handle *obj_hdl);

fsal_status_t vfs_getattr2(struct fsal_obj_handle *obj_hdl,
			   struct fsal_attrlist *attrs);

fsal_status_t vfs_setattr2(struct fsal_obj_handle *obj_hdl, bool bypass,
			   struct state_t *state,
			   struct fsal_attrlist *attrib_set);

fsal_status_t vfs_close2(struct fsal_obj_handle *obj_hdl,
			 struct state_t *state);

/* extended attributes management */
fsal_status_t vfs_list_ext_attrs(struct fsal_obj_handle *obj_hdl,
				 unsigned int cookie,
				 fsal_xattrent_t *xattrs_tab,
				 unsigned int xattrs_tabsize,
				 unsigned int *p_nb_returned, int *end_of_list);
fsal_status_t vfs_getextattr_id_by_name(struct fsal_obj_handle *obj_hdl,
					const char *xattr_name,
					unsigned int *pxattr_id);
fsal_status_t vfs_getextattr_value(struct vfs_fsal_obj_handle *vfs_hdl, int fd,
				   const char *xattr_name, void *buffer_addr,
				   size_t buffer_size, size_t *p_output_size);
fsal_status_t vfs_getextattr_value_by_name(struct fsal_obj_handle *obj_hdl,
					   const char *xattr_name,
					   void *buffer_addr,
					   size_t buffer_size,
					   size_t *p_output_size);
fsal_status_t vfs_getextattr_value_by_id(struct fsal_obj_handle *obj_hdl,
					 unsigned int xattr_id,
					 void *buffer_addr, size_t buffer_size,
					 size_t *p_output_size);
fsal_status_t vfs_setextattr_value(struct fsal_obj_handle *obj_hdl,
				   const char *xattr_name, void *buffer_addr,
				   size_t buffer_size, int create);
fsal_status_t vfs_setextattr_value_by_id(struct fsal_obj_handle *obj_hdl,
					 unsigned int xattr_id,
					 void *buffer_addr, size_t buffer_size);
fsal_status_t vfs_remove_extattr_by_id(struct fsal_obj_handle *obj_hdl,
				       unsigned int xattr_id);
fsal_status_t vfs_remove_extattr_by_name(struct fsal_obj_handle *obj_hdl,
					 const char *xattr_name);

fsal_status_t check_hsm_by_fd(int fd);

fsal_status_t vfs_get_fs_locations(struct vfs_fsal_obj_handle *hdl, int fd,
				   struct fsal_attrlist *attrs_out);

static inline bool vfs_set_credentials(const struct user_cred *creds,
				       const struct fsal_module *fsal_module)
{
	bool only_one_user =
		container_of(fsal_module, struct vfs_fsal_module, module)
			->only_one_user;

	if (only_one_user)
		return fsal_set_credentials_only_one_user(creds);
	else {
		fsal_set_credentials(creds);
		return true;
	}
}

static inline void
vfs_restore_ganesha_credentials(const struct fsal_module *fsal_module)
{
	bool only_one_user =
		container_of(fsal_module, struct vfs_fsal_module, module)
			->only_one_user;

	if (!only_one_user)
		fsal_restore_ganesha_credentials();
}

fsal_status_t find_fd(struct fsal_fd **out_fd, struct fsal_obj_handle *obj_hdl,
		      struct fsal_fd *tmp_fd, struct state_t *state,
		      fsal_openflags_t openflags, bool bypass);

#endif /* VFS_METHODS_H */
