use std::ffi::{OsStr, CString};
use std::fs::File;
+use std::io::BufReader;
use std::os::unix::ffi::OsStrExt;
use std::path::Path;
+use std::sync::Mutex;
use libc;
use libc::{c_int, c_void, c_char, size_t};
use failure::*;
+use super::decoder::Decoder;
+
+/// Node ID of the root inode
+/// This is the only one whose ID is not equal to the offset in the file.
+/// This is ok since offset 1 is part of the entry header and will therefore
+/// not occur again, but remapping to the correct offset of 0 is required.
+const FUSE_ROOT_ID: u64 = 1;
+
+fn decoder_callback(path: &Path) -> Result<(), Error> {
+ println!("{:#?}", path);
+ Ok(())
+}
+
+/// FFI types for easier readability
+type Request = *mut c_void;
+type MutPtr = *mut c_void;
+type ConstPtr = *const c_void;
+type StrPtr = *const c_char;
+
#[link(name = "fuse3")]
extern "C" {
- fn fuse_session_new(args: *const FuseArgs, oprs: *const Operations, size: size_t, op: *const c_void) -> *mut c_void;
- fn fuse_set_signal_handlers(session: *const c_void) -> c_int;
- fn fuse_remove_signal_handlers(session: *const c_void);
+ fn fuse_session_new(args: *const FuseArgs, oprs: *const Operations, size: size_t, op: ConstPtr) -> MutPtr;
+ fn fuse_set_signal_handlers(session: ConstPtr) -> c_int;
+ fn fuse_remove_signal_handlers(session: ConstPtr);
fn fuse_daemonize(foreground: c_int) -> c_int;
- fn fuse_session_mount(session: *const c_void, mountpoint: *const c_char) -> c_int;
- fn fuse_session_unmount(session: *const c_void);
- fn fuse_session_loop(session: *const c_void) -> c_int;
- fn fuse_session_destroy(session: *const c_void);
+ fn fuse_session_mount(session: ConstPtr, mountpoint: StrPtr) -> c_int;
+ fn fuse_session_unmount(session: ConstPtr);
+ fn fuse_session_loop(session: ConstPtr) -> c_int;
+ fn fuse_session_destroy(session: ConstPtr);
+ fn fuse_reply_attr(req: Request, attr: *const libc::stat, timeout: f64) -> c_int;
+ fn fuse_reply_err(req: Request, errno: c_int) -> c_int;
+ fn fuse_req_userdata(req: Request) -> MutPtr;
}
/// Command line arguments passed to fuse.
#[derive(Debug)]
struct FuseArgs {
argc: c_int,
- argv: *const *const c_char,
+ argv: *const StrPtr,
allocated: c_int,
}
/// `Session` stores a pointer to the session context and is used to mount the
/// archive to the given mountpoint.
-#[derive(Debug)]
pub struct Session {
- ptr: *mut c_void,
- archive: File,
+ ptr: MutPtr,
verbose: bool,
}
/// `Operations` defines the callback function table of supported operations.
#[repr(C)]
+#[derive(Default)]
struct Operations {
- init: extern fn(userdata: *mut c_void) -> *mut c_void,
- destroy: extern fn(userdata: *mut c_void) -> *mut c_void,
+ // The order in which the functions are listed matters, as the offset in the
+ // struct defines what function the fuse driver uses.
+ // It should therefore not be altered!
+ init: Option<extern fn(userdata: MutPtr)>,
+ destroy: Option<extern fn(userdata: MutPtr)>,
+ lookup: Option<extern fn(req: Request, parent: u64, name: StrPtr)>,
+ forget: Option<extern fn(req: Request, inode: u64, nlookup: u64)>,
+ getattr: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr)>,
+ setattr: Option<extern fn(req: Request, inode: u64, attr: MutPtr, to_set: c_int, fileinfo: MutPtr)>,
+ readlink: Option<extern fn(req: Request, inode: u64)>,
+ mknod: Option<extern fn(req: Request, parent: u64, name: StrPtr, mode: c_int, rdev: c_int)>,
+ mkdir: Option<extern fn(req: Request, parent: u64, name: StrPtr, mode: c_int)>,
+ unlink: Option<extern fn(req: Request, parent: u64, name: StrPtr)>,
+ rmdir: Option<extern fn(req: Request, parent: u64, name: StrPtr)>,
+ symlink: Option<extern fn(req: Request, link: StrPtr, parent: u64, name: StrPtr)>,
+ rename: Option<extern fn(req: Request, parent: u64, name: StrPtr, newparent: u64, newname: StrPtr, flags: c_int)>,
+ link: Option<extern fn(req: Request, inode: u64, newparent: u64, newname: StrPtr)>,
+ open: Option<extern fn(req: Request, indoe: u64, fileinfo: MutPtr)>,
+ read: Option<extern fn(req: Request, inode: u64, size: size_t, offset: c_int, fileinfo: MutPtr)>,
+ write: Option<extern fn(req: Request, inode: u64, buffer: StrPtr, size: size_t, offset: c_void, fileinfo: MutPtr)>,
+ flush: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr)>,
+ release: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr)>,
+ fsync: Option<extern fn(req: Request, inode: u64, datasync: c_int, fileinfo: MutPtr)>,
+ opendir: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr)>,
+ readdir: Option<extern fn(req: Request, inode: u64, size: size_t, offset: c_int, fileinfo: MutPtr)>,
+ releasedir: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr)>,
+ fsyncdir: Option<extern fn(req: Request, inode: u64, datasync: c_int, fileinfo: MutPtr)>,
+ statfs: Option<extern fn(req: Request, inode: u64)>,
+ setxattr: Option<extern fn(req: Request, inode: u64, name: StrPtr, value: StrPtr, size: size_t, flags: c_int)>,
+ getxattr: Option<extern fn(req: Request, inode: u64, name: StrPtr, size: size_t)>,
+ listxattr: Option<extern fn(req: Request, inode: u64, size: size_t)>,
+ removexattr: Option<extern fn(req: Request, inode: u64, name: StrPtr)>,
+ access: Option<extern fn(req: Request, inode: u64, mask: i32)>,
+ create: Option<extern fn(req: Request, parent: u64, name: StrPtr, mode: c_int, fileinfo: MutPtr)>,
+ getlk: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr, lock: MutPtr)>,
+ setlk: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr, lock: MutPtr, sleep: c_int)>,
+ bmap: Option<extern fn(req: Request, inode: u64, blocksize: size_t, idx: u64)>,
+ ioctl: Option<extern fn(req: Request, inode: u64, cmd: c_int, arg: MutPtr, fileinfo: MutPtr, flags: c_int, in_buf: ConstPtr, in_bufsz: size_t, out_bufsz: size_t)>,
+ poll: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr, pollhandle: MutPtr)>,
+ write_buf: Option<extern fn(req: Request, inode: u64, bufv: MutPtr, offset: c_int, fileinfo: MutPtr)>,
+ retrieve_reply: Option<extern fn(req: Request, cookie: ConstPtr, inode: u64, offset: c_int, bufv: MutPtr)>,
+ forget_multi: Option<extern fn(req: Request, count: size_t, forgets: MutPtr)>,
+ flock: Option<extern fn(req: Request, inode: u64, fileinfo: MutPtr, op: c_int)>,
+ fallocate: Option<extern fn(req: Request, inode: u64, mode: c_int, offset: c_int, length: c_int, fileinfo: MutPtr)>,
+ readdirplus: Option<extern fn(req: Request, inode: u64, size: size_t, offset: c_int, fileinfo: MutPtr)>,
+ copy_file_range: Option<extern fn(req: Request, ino_in: u64, off_in: c_int, fi_in: MutPtr, ino_out: u64, off_out: c_int, fi_out: MutPtr, len: size_t, flags: c_int)>,
}
impl Session {
};
// Register the callback funcitons for the session
- let oprs = Operations {
- init: init,
- destroy: destroy,
- };
+ let mut oprs = Operations::default();
+ oprs.init = Some(init);
+ oprs.destroy = Some(destroy);
+ oprs.lookup = Some(lookup);
+ oprs.getattr = Some(getattr);
+ oprs.open = Some(open);
+ oprs.read = Some(read);
+ oprs.opendir = Some(opendir);
+ oprs.readdir = Some(readdir);
+ // By storing the decoder as userdata of the session, each request may
+ // access it.
+ let reader = BufReader::new(file);
+ let decoder = Decoder::new(reader, decoder_callback as fn(&Path) -> Result<(), Error>)?;
+ let session_decoder = Box::new(Mutex::new(decoder));
let session_ptr = unsafe { fuse_session_new(
&args as *const FuseArgs,
&oprs as *const Operations,
std::mem::size_of::<Operations>(),
- std::ptr::null()
+ // Ownership of session_decoder is passed to the session here.
+ // It has to be reclaimed before dropping the session to free
+ // the decoder and close the underlying file. This is done inside
+ // the destroy callback function.
+ Box::into_raw(session_decoder) as ConstPtr
)};
if session_ptr.is_null() {
Ok(Self {
ptr: session_ptr,
- archive: file,
verbose: verbose,
})
}
}
}
+/// Creates a context providing an exclusive mutable reference to the decoder.
+///
+/// Each callback function needing access to the decoder can easily get an
+/// exclusive handle by running the code inside this context.
+/// Responses with error code can easily be generated by returning with the
+/// error code.
+fn run_in_context<F: FnOnce(&mut Decoder<BufReader<File>, fn(&Path) -> Result<(), Error>>) -> Result<(), i32>>(req: Request, code: F) {
+ let ptr = unsafe { fuse_req_userdata(req) as *mut Mutex<Decoder<BufReader<File>, fn(&Path) -> Result<(), Error>>> };
+ let boxed_decoder = unsafe { Box::from_raw(ptr) };
+ let result = boxed_decoder.lock()
+ .map(|mut decoder| code(&mut decoder))
+ .unwrap_or(Err(libc::ENOENT));
+
+ if let Err(err) = result {
+ unsafe { let _res = fuse_reply_err(req, err); }
+ }
+
+ // Release ownership of boxed decoder, do not drop it.
+ let _ = Box::into_raw(boxed_decoder);
+}
+
+
/// Callback functions for fuse kernel driver.
-extern "C" fn init(_userdata: *mut c_void) -> *mut c_void {
- println!("Init callback");
- return std::ptr::null_mut();
+extern "C" fn init(_decoder: MutPtr) {
+ // Notting to do here for now
+}
+
+/// Cleanup the userdata created while creating the session, which is the decoder
+extern "C" fn destroy(decoder: MutPtr) {
+ // Get ownership of the decoder and drop it when Box goes out of scope.
+ unsafe { Box::from_raw(decoder); }
+}
+
+extern "C" fn lookup(req: Request, _parent: u64, _name: StrPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
+}
+
+extern "C" fn getattr(req: Request, _inode: u64, _fileinfo: MutPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
+}
+
+extern "C" fn open(req: Request, _inode: u64, _fileinfo: MutPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
}
-extern "C" fn destroy(_userdata: *mut c_void) -> *mut c_void {
- println!("Destroy callback");
- return std::ptr::null_mut();
+extern "C" fn read(req: Request, _inode: u64, _size: size_t, _offset: c_int, _fileinfo: MutPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
+}
+
+extern "C" fn opendir(req: Request, _inode: u64, _fileinfo: MutPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
}
+
+extern "C" fn readdir(req: Request, _inode: u64, _size: size_t, _offset: c_int, _fileinfo: MutPtr) {
+ run_in_context(req, |decoder| {
+ // code goes here
+
+ Err(libc::ENOENT)
+ });
+}
+
projects / proxmox-backup.git / commitdiff