itd/internal/fusefs/fuse.go
yannickulrich 9ecd45dadd Added FUSE support (#55)
This exposes the watches' file system over FUSE. This way, we can access files on the watch without having to go through `itctl` or developing 3rd party tools.

**Features**

- [x] read/write access to the file system
- [x] read access to momentary sensor data
- [x] live access to sensor data (i.e. WatchMotion rather than Motion)
- [x] configuration of mount point

Co-authored-by: Yannick Ulrich <yannick.ulrich@durham.ac.uk>
Reviewed-on: https://gitea.arsenm.dev/Arsen6331/itd/pulls/55
Co-authored-by: yannickulrich <yannick.ulrich@protonmail.com>
Co-committed-by: yannickulrich <yannick.ulrich@protonmail.com>
2023-03-25 22:23:51 +00:00

573 lines
14 KiB
Go

package fusefs
import (
"go.arsenm.dev/infinitime"
"go.arsenm.dev/infinitime/blefs"
"go.arsenm.dev/logger/log"
"context"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
"io"
"bytes"
"strconv"
)
type ITProperty struct {
name string
Ino uint64
gen func() ([]byte, error)
}
type DirEntry struct {
isDir bool
modtime uint64
size uint32
path string
}
type ITNode struct {
fs.Inode
kind int
Ino uint64
lst []DirEntry
self DirEntry
path string
}
var myfs *blefs.FS = nil
var inodemap map[string]uint64 = nil
func BuildRootNode(dev *infinitime.Device) (*ITNode, error) {
var err error
inodemap = make(map[string]uint64)
myfs, err = dev.FS()
if err != nil {
log.Error("FUSE Failed to get filesystem").Err(err).Send()
return nil, err
}
return &ITNode{kind: 0}, nil
}
var properties = make([]ITProperty, 6)
func BuildProperties(dev *infinitime.Device) {
properties[0] = ITProperty{"heartrate", 2,
func() ([]byte, error) {
ans, err := dev.HeartRate()
return []byte(strconv.Itoa(int(ans)) + "\n"), err
}}
properties[1] = ITProperty{"battery", 3,
func() ([]byte, error) {
ans, err := dev.BatteryLevel()
return []byte(strconv.Itoa(int(ans)) + "\n"), err
}}
properties[2] = ITProperty{"motion", 4,
func() ([]byte, error) {
ans, err := dev.Motion()
return []byte(strconv.Itoa(int(ans.X)) + " " + strconv.Itoa(int(ans.Y)) + " " + strconv.Itoa(int(ans.Z)) + "\n"), err
}}
properties[3] = ITProperty{"stepcount", 6,
func() ([]byte, error) {
ans, err := dev.StepCount()
return []byte(strconv.Itoa(int(ans)) + "\n"), err
}}
properties[4] = ITProperty{"version", 7,
func() ([]byte, error) {
ans, err := dev.Version()
return []byte(ans + "\n"), err
}}
properties[5] = ITProperty{"address", 8,
func() ([]byte, error) {
ans := dev.Address()
return []byte(ans + "\n"), nil
}}
}
var _ fs.NodeReaddirer = (*ITNode)(nil)
// Readdir is part of the NodeReaddirer interface
func (n *ITNode) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
switch n.kind {
case 0:
// root folder
r := make([]fuse.DirEntry, 2)
r[0] = fuse.DirEntry{
Name: "info",
Ino: 0,
Mode: fuse.S_IFDIR,
}
r[1] = fuse.DirEntry{
Name: "fs",
Ino: 1,
Mode: fuse.S_IFDIR,
}
return fs.NewListDirStream(r), 0
case 1:
// info folder
r := make([]fuse.DirEntry, 6)
for ind, value := range properties {
r[ind] = fuse.DirEntry{
Name: value.name,
Ino: value.Ino,
Mode: fuse.S_IFREG,
}
}
return fs.NewListDirStream(r), 0
case 2:
// on info
files, err := myfs.ReadDir(n.path)
if err != nil {
log.Error("FUSE ReadDir failed").Str("path", n.path).Err(err).Send()
return nil, syscallErr(err)
}
log.Debug("FUSE ReadDir succeeded").Str("path", n.path).Int("objects", len(files)).Send()
r := make([]fuse.DirEntry, len(files))
n.lst = make([]DirEntry, len(files))
for ind, entry := range files {
info, err := entry.Info()
if err != nil {
log.Error("FUSE Info failed").Str("path", n.path).Err(err).Send()
return nil, syscallErr(err)
}
name := info.Name()
file := DirEntry{
path: n.path + "/" + name,
size: uint32(info.Size()),
modtime: uint64(info.ModTime().Unix()),
isDir: info.IsDir(),
}
n.lst[ind] = file
ino := inodemap[file.path]
if ino == 0 {
ino = uint64(len(inodemap)) + 1
inodemap[file.path] = ino
}
if file.isDir {
r[ind] = fuse.DirEntry{
Name: name,
Mode: fuse.S_IFDIR,
Ino : ino + 10,
}
} else {
r[ind] = fuse.DirEntry{
Name: name,
Mode: fuse.S_IFREG,
Ino : ino + 10,
}
}
}
return fs.NewListDirStream(r), 0
}
r := make([]fuse.DirEntry, 0)
return fs.NewListDirStream(r), 0
}
var _ fs.NodeLookuper = (*ITNode)(nil)
func (n *ITNode) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
switch n.kind {
case 0:
// root folder
if name == "info" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(0),
}
operations := &ITNode{kind: 1, Ino: 0}
child := n.NewInode(ctx, operations, stable)
return child, 0
} else if name == "fs" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(1),
}
operations := &ITNode{kind: 2, Ino: 1, path : ""}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
case 1:
// info folder
for _, value := range properties {
if value.name == name {
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: uint64(value.Ino),
}
operations := &ITNode{kind: 3, Ino: value.Ino}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
}
case 2:
// FS object
if len(n.lst) == 0 {
n.Readdir(ctx)
}
for _, file := range n.lst {
if file.path != n.path + "/" + name {
continue
}
log.Debug("FUSE Lookup successful").Str("path", file.path).Send()
if file.isDir {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: inodemap[file.path],
}
operations := &ITNode{kind: 2, path: file.path}
child := n.NewInode(ctx, operations, stable)
return child, 0
} else {
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: inodemap[file.path],
}
operations := &ITNode{
kind: 2, path: file.path,
self: file,
}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
break
}
log.Warn("FUSE Lookup failed").Str("path", n.path + "/" + name).Send()
}
return nil, syscall.ENOENT
}
type bytesFileReadHandle struct {
content []byte
}
var _ fs.FileReader = (*bytesFileReadHandle)(nil)
func (fh *bytesFileReadHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
log.Debug("FUSE Executing Read").Int("size", len(fh.content)).Send()
end := off + int64(len(dest))
if end > int64(len(fh.content)) {
end = int64(len(fh.content))
}
return fuse.ReadResultData(fh.content[off:end]), 0
}
type sensorFileReadHandle struct {
content []byte
}
var _ fs.FileReader = (*sensorFileReadHandle)(nil)
func (fh *sensorFileReadHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
log.Info("Executing Read").Int("size", len(fh.content)).Send()
end := off + int64(len(dest))
if end > int64(len(fh.content)) {
end = int64(len(fh.content))
}
return fuse.ReadResultData(fh.content[off:end]), 0
}
var _ fs.FileFlusher = (*sensorFileReadHandle)(nil)
func (fh *sensorFileReadHandle) Flush(ctx context.Context) (errno syscall.Errno) {
return 0
}
type bytesFileWriteHandle struct {
content []byte
path string
}
var _ fs.FileWriter = (*bytesFileWriteHandle)(nil)
func (fh *bytesFileWriteHandle) Write(ctx context.Context, data []byte, off int64) (written uint32, errno syscall.Errno) {
log.Info("Executing Write").Str("path", fh.path).Int("prev_size", len(fh.content)).Int("next_size", len(data)).Send()
if off != int64(len(fh.content)) {
log.Error("FUSE Write file size changed unexpectedly").Int("expect", int(off)).Int("received", len(fh.content)).Send()
return 0, syscall.ENXIO
}
fh.content = append(fh.content[:], data[:]...)
return uint32(len(data)), 0
}
var _ fs.FileFlusher = (*bytesFileWriteHandle)(nil)
func (fh *bytesFileWriteHandle) Flush(ctx context.Context) (errno syscall.Errno) {
log.Debug("FUSE Attempting flush").Str("path", fh.path).Send()
fp, err := myfs.Create(fh.path, uint32(len(fh.content)))
if err != nil {
log.Error("FUSE Flush failed: create").Str("path", fh.path).Err(err).Send()
return syscallErr(err)
}
if len(fh.content) == 0 {
log.Debug("FUSE Flush no data to write").Str("path", fh.path).Send()
err = fp.Close()
if err != nil {
log.Error("FUSE Flush failed during close").Str("path", fh.path).Err(err).Send()
return syscallErr(err)
}
return 0
}
go func() {
// For every progress event
for sent := range fp.Progress() {
log.Debug("FUSE Flush progress").Int("bytes", int(sent)).Int("total", len(fh.content)).Send()
}
}()
r := bytes.NewReader(fh.content)
nread, err := io.Copy(fp, r)
if err != nil {
log.Error("FUSE Flush failed during write").Str("path", fh.path).Err(err).Send()
fp.Close()
return syscallErr(err)
}
if int(nread) != len(fh.content) {
log.Error("FUSE Flush failed during write").Str("path", fh.path).Int("expect", len(fh.content)).Int("got", int(nread)).Send()
fp.Close()
return syscall.EIO
}
err = fp.Close()
if err != nil {
log.Error("FUSE Flush failed during close").Str("path", fh.path).Err(err).Send()
return syscallErr(err)
}
log.Debug("FUSE Flush done").Str("path", fh.path).Int("size", len(fh.content)).Send()
return 0
}
var _ fs.FileFsyncer = (*bytesFileWriteHandle)(nil)
func (fh *bytesFileWriteHandle) Fsync(ctx context.Context, flags uint32) (errno syscall.Errno) {
return fh.Flush(ctx)
}
var _ fs.NodeGetattrer = (*ITNode)(nil)
func (bn *ITNode) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
log.Debug("FUSE getattr").Str("path", bn.path).Send()
out.Ino = bn.Ino
out.Mtime = bn.self.modtime
out.Ctime = bn.self.modtime
out.Atime = bn.self.modtime
out.Size = uint64(bn.self.size)
return 0
}
var _ fs.NodeSetattrer = (*ITNode)(nil)
func (bn *ITNode) Setattr(ctx context.Context, fh fs.FileHandle, in *fuse.SetAttrIn, out *fuse.AttrOut) syscall.Errno {
log.Debug("FUSE setattr").Str("path", bn.path).Send()
out.Size = 0
out.Mtime = 0
return 0
}
var _ fs.NodeOpener = (*ITNode)(nil)
func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
switch f.kind {
case 2:
// FS file
if openFlags&syscall.O_RDWR != 0 {
log.Error("FUSE Open failed: RDWR").Str("path", f.path).Send()
return nil, 0, syscall.EROFS
}
if openFlags & syscall.O_WRONLY != 0 {
log.Debug("FUSE Opening for write").Str("path", f.path).Send()
fh = &bytesFileWriteHandle{
path : f.path,
content : make([]byte, 0),
}
return fh, fuse.FOPEN_DIRECT_IO, 0
} else {
log.Debug("FUSE Opening for read").Str("path", f.path).Send()
fp, err := myfs.Open(f.path)
if err != nil {
log.Error("FUSE: Opening failed").Str("path", f.path).Err(err).Send()
return nil, 0, syscallErr(err)
}
defer fp.Close()
b := &bytes.Buffer{}
go func() {
// For every progress event
for sent := range fp.Progress() {
log.Debug("FUSE Read progress").Int("bytes", int(sent)).Int("total", int(f.self.size)).Send()
}
}()
_, err = io.Copy(b, fp)
if err != nil {
log.Error("FUSE Read failed").Str("path", f.path).Err(err).Send()
fp.Close()
return nil, 0, syscallErr(err)
}
fh = &bytesFileReadHandle{
content: b.Bytes(),
}
return fh, fuse.FOPEN_DIRECT_IO, 0
}
case 3:
// Device file
// disallow writes
if openFlags&(syscall.O_RDWR|syscall.O_WRONLY) != 0 {
return nil, 0, syscall.EROFS
}
for _, value := range properties {
if value.Ino == f.Ino {
ans, err := value.gen()
if err != nil {
return nil, 0, syscallErr(err)
}
fh = &sensorFileReadHandle{
content : ans,
}
return fh, fuse.FOPEN_DIRECT_IO, 0
}
}
}
return nil, 0, syscall.EINVAL
}
var _ fs.NodeCreater = (*ITNode)(nil)
func (f *ITNode) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (node *fs.Inode, fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
if f.kind != 2 {
return nil, nil, 0, syscall.EROFS
}
path := f.path + "/" + name
ino := uint64(len(inodemap)) + 11
inodemap[path] = ino
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: ino,
}
operations := &ITNode{
kind: 2, Ino: ino,
path : path,
}
node = f.NewInode(ctx, operations, stable)
fh = &bytesFileWriteHandle{
path : path,
content : make([]byte, 0),
}
log.Debug("FUSE Creating file").Str("path", path).Send()
errno = 0
return node, fh, fuseFlags, 0
}
var _ fs.NodeMkdirer = (*ITNode)(nil)
func (f *ITNode) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
if f.kind != 2 {
return nil, syscall.EROFS
}
path := f.path + "/" + name
err := myfs.Mkdir(path)
if err != nil {
log.Error("FUSE Mkdir failed").
Str("path", path).
Err(err).
Send()
return nil, syscallErr(err)
}
ino := uint64(len(inodemap)) + 11
inodemap[path] = ino
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: ino,
}
operations := &ITNode{
kind: 2, Ino: ino,
path : path,
}
node := f.NewInode(ctx, operations, stable)
log.Debug("FUSE Mkdir success").
Str("path", path).
Int("ino", int(ino)).
Send()
return node, 0
}
var _ fs.NodeRenamer = (*ITNode)(nil)
func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbedder, newName string, flags uint32) syscall.Errno {
if f.kind != 2 {
return syscall.EROFS
}
p1 := f.path + "/" + name
p2 := newParent.EmbeddedInode().Path(nil)[2:] + "/" + newName
err := myfs.Rename(p1, p2)
if err != nil {
log.Error("FUSE Rename failed").
Str("src", p1).
Str("dest", p2).
Err(err).
Send()
return syscallErr(err)
}
log.Debug("FUSE Rename sucess").
Str("src", p1).
Str("dest", p2).
Send()
ino := inodemap[p1]
delete(inodemap, p1)
inodemap[p2] = ino
return 0
}
var _ fs.NodeUnlinker = (*ITNode)(nil)
func (f *ITNode) Unlink(ctx context.Context, name string) syscall.Errno {
if f.kind != 2 {
return syscall.EROFS
}
delete(inodemap, f.path + "/" + name)
err := myfs.Remove(f.path + "/" + name)
if err != nil {
log.Error("FUSE Unlink failed").
Str("file", f.path + "/" + name).
Err(err).
Send()
return syscallErr(err)
}
log.Debug("FUSE Unlink success").
Str("file", f.path + "/" + name).
Send()
return 0
}
var _ fs.NodeRmdirer = (*ITNode)(nil)
func (f *ITNode) Rmdir(ctx context.Context, name string) syscall.Errno {
return f.Unlink(ctx, name)
}