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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
/* This file defines the library interface of FUSE */
#include <sys/types.h>
#include <sys/stat.h>
#include <utime.h>
/** Handle for a FUSE filesystem */
struct fuse;
/** Handle for a getdir() operation */
typedef struct fuse_dirhandle *fuse_dirh_t;
/** Function to add an entry in a getdir() operation */
typedef int (*fuse_dirfil_t) (fuse_dirh_t, const char *, int type);
/** Credentials for an operation, these are determined by the fsuid
and fsgid of the calling process */
struct fuse_cred {
uid_t uid;
gid_t gid;
/* FIXME: supplementary groups should also be included */
/* (And capabilities???) */
};
/**
* The file system operations:
*
* Most of these should work very similarly to the well known UNIX
* file system operations. Exceptions are:
*
* - All operations get a fuse_cred structure by which the filesystem
* implementation can check, whether the operation is permitted or
* not.
*
* - All operations should return the negated error value (-errno) on
* error.
*
* - readlink() should fill the buffer with a null terminated string.
* The buffer size argument includes the space for the terminating
* null character. If the linkname is too long to fit in the buffer,
* it should be truncated. The return value should be 0 for success.
*
* - getdir() is the opendir(), readdir(), ..., closedir() sequence
* in one call. For each directory entry the filldir parameter should
* be called.
*
* - There is no create() operation, mknod() will be called for
* creation of all non directory, non symlink nodes.
*
* - open() should not return a filehandle, but 0 on success. No
* creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be
* passed to open(). Open should only check if the operation is
* permitted for the given flags.
*
* - read(), write() are not passed a filehandle, but rather a
* pathname. The offset of the read and write is passed as the last
* argument, like the pread() and pwrite() system calls. */
struct fuse_operations {
int (*getattr) (struct fuse_cred *, const char *, struct stat *);
int (*readlink) (struct fuse_cred *, const char *, char *, size_t);
int (*getdir) (struct fuse_cred *, const char *, fuse_dirh_t, fuse_dirfil_t);
int (*mknod) (struct fuse_cred *, const char *, mode_t, dev_t);
int (*mkdir) (struct fuse_cred *, const char *, mode_t);
int (*unlink) (struct fuse_cred *, const char *);
int (*rmdir) (struct fuse_cred *, const char *);
int (*symlink) (struct fuse_cred *, const char *, const char *);
int (*rename) (struct fuse_cred *, const char *, const char *);
int (*link) (struct fuse_cred *, const char *, const char *);
int (*chmod) (struct fuse_cred *, const char *, mode_t);
int (*chown) (struct fuse_cred *, const char *, uid_t, gid_t);
int (*truncate) (struct fuse_cred *, const char *, off_t);
int (*utime) (struct fuse_cred *, const char *, struct utimbuf *);
int (*open) (struct fuse_cred *, const char *, int);
int (*read) (struct fuse_cred *, const char *, char *, size_t, off_t);
int (*write) (struct fuse_cred *, const char *, const char *, size_t, off_t);
};
/* FUSE flags: */
/** Process requests in multiple threads */
#define FUSE_MULTITHREAD (1 << 0)
/** Enable debuging output */
#define FUSE_DEBUG (1 << 1)
/**
* Create a new FUSE filesystem. The filesystem is not yet mounted
*
* @param flags any combination of the FUSE flags defined above, or 0
* @param root the file type of the root node. 0 is the default (directory).
* @return the created FUSE handle
*/
struct fuse *fuse_new(int flags, mode_t root);
/**
* Connect to the kernel and mount the filesystem.
*
* @param f the FUSE handle
* @param mnt the mount point
* @return 0 on success -1 on failure
*/
int fuse_mount(struct fuse *f, const char *mnt);
/**
* Set the filesystem operations.
*
* Operations which are initialised to NULL will return ENOSYS to the
* calling process. This function can be called anytime after
* fuse_new() and before fuse_loop().
*
* @param f the FUSE handle
* @param op the operations
*/
void fuse_set_operations(struct fuse *f, const struct fuse_operations *op);
/**
* FUSE event loop.
*
* Requests from the kernel are processed, and the apropriate
* operations are called.
*
* @param f the FUSE handle
*/
void fuse_loop(struct fuse *f);
/**
* Disconnect from the kernel and unmount the filesystem
*
* @param f the FUSE handle
*/
int fuse_unmount(struct fuse *f);
/**
* Destroy the filesystem.
*
* The filesystem is not unmounted (call fuse_unmount() for that).
* After a fork() system call it is possible to call fuse_destroy() in
* one process, and leave the other process to service the filesystem
* requests.
*
* @param f the FUSE handle
*/
void fuse_destroy(struct fuse *f);
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