ipns_unix.go
// +build !nofuse
// package fuse/ipns implements a fuse filesystem that interfaces
// with ipns, the naming system for ipfs.
package ipns
import (
"errors"
"fmt"
"os"
fuse "github.com/ipfs/go-ipfs/Godeps/_workspace/src/bazil.org/fuse"
fs "github.com/ipfs/go-ipfs/Godeps/_workspace/src/bazil.org/fuse/fs"
"gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
logging "gx/ipfs/Qmazh5oNUVsDZTs2g59rq8aYQqwpss8tcUWQzor5sCCEuH/go-log"
key "github.com/ipfs/go-ipfs/blocks/key"
core "github.com/ipfs/go-ipfs/core"
dag "github.com/ipfs/go-ipfs/merkledag"
mfs "github.com/ipfs/go-ipfs/mfs"
path "github.com/ipfs/go-ipfs/path"
ft "github.com/ipfs/go-ipfs/unixfs"
ci "gx/ipfs/QmNefBbWHR9JEiP3KDVqZsBLQVRmH3GBG2D2Ke24SsFqfW/go-libp2p/p2p/crypto"
)
func init() {
if os.Getenv("IPFS_FUSE_DEBUG") != "" {
fuse.Debug = func(msg interface{}) {
fmt.Println(msg)
}
}
}
var log = logging.Logger("fuse/ipns")
// FileSystem is the readwrite IPNS Fuse Filesystem.
type FileSystem struct {
Ipfs *core.IpfsNode
RootNode *Root
}
// NewFileSystem constructs new fs using given core.IpfsNode instance.
func NewFileSystem(ipfs *core.IpfsNode, sk ci.PrivKey, ipfspath, ipnspath string) (*FileSystem, error) {
kmap := map[string]ci.PrivKey{
"local": sk,
}
root, err := CreateRoot(ipfs, kmap, ipfspath, ipnspath)
if err != nil {
return nil, err
}
return &FileSystem{Ipfs: ipfs, RootNode: root}, nil
}
// Root constructs the Root of the filesystem, a Root object.
func (f *FileSystem) Root() (fs.Node, error) {
log.Debug("Filesystem, get root")
return f.RootNode, nil
}
func (f *FileSystem) Destroy() {
err := f.RootNode.Close()
if err != nil {
log.Errorf("Error Shutting Down Filesystem: %s\n", err)
}
}
// Root is the root object of the filesystem tree.
type Root struct {
Ipfs *core.IpfsNode
Keys map[string]ci.PrivKey
// Used for symlinking into ipfs
IpfsRoot string
IpnsRoot string
LocalDirs map[string]fs.Node
Roots map[string]*keyRoot
LocalLinks map[string]*Link
}
func ipnsPubFunc(ipfs *core.IpfsNode, k ci.PrivKey) mfs.PubFunc {
return func(ctx context.Context, key key.Key) error {
return ipfs.Namesys.Publish(ctx, k, path.FromKey(key))
}
}
func loadRoot(ctx context.Context, rt *keyRoot, ipfs *core.IpfsNode, name string) (fs.Node, error) {
p, err := path.ParsePath("/ipns/" + name)
if err != nil {
log.Errorf("mkpath %s: %s", name, err)
return nil, err
}
node, err := core.Resolve(ctx, ipfs, p)
if err != nil {
log.Errorf("looking up %s: %s", p, err)
return nil, err
}
root, err := mfs.NewRoot(ctx, ipfs.DAG, node, ipnsPubFunc(ipfs, rt.k))
if err != nil {
return nil, err
}
rt.root = root
switch val := root.GetValue().(type) {
case *mfs.Directory:
return &Directory{dir: val}, nil
case *mfs.File:
return &FileNode{fi: val}, nil
default:
return nil, errors.New("unrecognized type")
}
panic("not reached")
}
type keyRoot struct {
k ci.PrivKey
alias string
root *mfs.Root
}
func CreateRoot(ipfs *core.IpfsNode, keys map[string]ci.PrivKey, ipfspath, ipnspath string) (*Root, error) {
ldirs := make(map[string]fs.Node)
roots := make(map[string]*keyRoot)
links := make(map[string]*Link)
for alias, k := range keys {
pkh, err := k.GetPublic().Hash()
if err != nil {
return nil, err
}
name := key.Key(pkh).B58String()
kr := &keyRoot{k: k, alias: alias}
fsn, err := loadRoot(ipfs.Context(), kr, ipfs, name)
if err != nil {
return nil, err
}
roots[name] = kr
ldirs[name] = fsn
// set up alias symlink
links[alias] = &Link{
Target: name,
}
}
return &Root{
Ipfs: ipfs,
IpfsRoot: ipfspath,
IpnsRoot: ipnspath,
Keys: keys,
LocalDirs: ldirs,
LocalLinks: links,
Roots: roots,
}, nil
}
// Attr returns file attributes.
func (*Root) Attr(ctx context.Context, a *fuse.Attr) error {
log.Debug("Root Attr")
a.Mode = os.ModeDir | 0111 // -rw+x
return nil
}
// Lookup performs a lookup under this node.
func (s *Root) Lookup(ctx context.Context, name string) (fs.Node, error) {
switch name {
case "mach_kernel", ".hidden", "._.":
// Just quiet some log noise on OS X.
return nil, fuse.ENOENT
}
if lnk, ok := s.LocalLinks[name]; ok {
return lnk, nil
}
nd, ok := s.LocalDirs[name]
if ok {
switch nd := nd.(type) {
case *Directory:
return nd, nil
case *FileNode:
return nd, nil
default:
return nil, fuse.EIO
}
}
// other links go through ipns resolution and are symlinked into the ipfs mountpoint
resolved, err := s.Ipfs.Namesys.Resolve(s.Ipfs.Context(), name)
if err != nil {
log.Warningf("ipns: namesys resolve error: %s", err)
return nil, fuse.ENOENT
}
segments := resolved.Segments()
if segments[0] == "ipfs" {
p := path.Join(resolved.Segments()[1:])
return &Link{s.IpfsRoot + "/" + p}, nil
}
log.Error("Invalid path.Path: ", resolved)
return nil, errors.New("invalid path from ipns record")
}
func (r *Root) Close() error {
for _, mr := range r.Roots {
err := mr.root.Close()
if err != nil {
return err
}
}
return nil
}
// Forget is called when the filesystem is unmounted. probably.
// see comments here: http://godoc.org/bazil.org/fuse/fs#FSDestroyer
func (r *Root) Forget() {
err := r.Close()
if err != nil {
log.Error(err)
}
}
// ReadDirAll reads a particular directory. Will show locally available keys
// as well as a symlink to the peerID key
func (r *Root) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
log.Debug("Root ReadDirAll")
var listing []fuse.Dirent
for alias, k := range r.Keys {
pub := k.GetPublic()
hash, err := pub.Hash()
if err != nil {
continue
}
ent := fuse.Dirent{
Name: key.Key(hash).Pretty(),
Type: fuse.DT_Dir,
}
link := fuse.Dirent{
Name: alias,
Type: fuse.DT_Link,
}
listing = append(listing, ent, link)
}
return listing, nil
}
// Directory is wrapper over an mfs directory to satisfy the fuse fs interface
type Directory struct {
dir *mfs.Directory
}
type FileNode struct {
fi *mfs.File
}
// File is wrapper over an mfs file to satisfy the fuse fs interface
type File struct {
fi mfs.FileDescriptor
}
// Attr returns the attributes of a given node.
func (d *Directory) Attr(ctx context.Context, a *fuse.Attr) error {
log.Debug("Directory Attr")
a.Mode = os.ModeDir | 0555
a.Uid = uint32(os.Getuid())
a.Gid = uint32(os.Getgid())
return nil
}
// Attr returns the attributes of a given node.
func (fi *FileNode) Attr(ctx context.Context, a *fuse.Attr) error {
log.Debug("File Attr")
size, err := fi.fi.Size()
if err != nil {
// In this case, the dag node in question may not be unixfs
return fmt.Errorf("fuse/ipns: failed to get file.Size(): %s", err)
}
a.Mode = os.FileMode(0666)
a.Size = uint64(size)
a.Uid = uint32(os.Getuid())
a.Gid = uint32(os.Getgid())
return nil
}
// Lookup performs a lookup under this node.
func (s *Directory) Lookup(ctx context.Context, name string) (fs.Node, error) {
child, err := s.dir.Child(name)
if err != nil {
// todo: make this error more versatile.
return nil, fuse.ENOENT
}
switch child := child.(type) {
case *mfs.Directory:
return &Directory{dir: child}, nil
case *mfs.File:
return &FileNode{fi: child}, nil
default:
// NB: if this happens, we do not want to continue, unpredictable behaviour
// may occur.
panic("invalid type found under directory. programmer error.")
}
}
// ReadDirAll reads the link structure as directory entries
func (dir *Directory) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
var entries []fuse.Dirent
listing, err := dir.dir.List()
if err != nil {
return nil, err
}
for _, entry := range listing {
dirent := fuse.Dirent{Name: entry.Name}
switch mfs.NodeType(entry.Type) {
case mfs.TDir:
dirent.Type = fuse.DT_Dir
case mfs.TFile:
dirent.Type = fuse.DT_File
}
entries = append(entries, dirent)
}
if len(entries) > 0 {
return entries, nil
}
return nil, fuse.ENOENT
}
func (fi *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
_, err := fi.fi.Seek(req.Offset, os.SEEK_SET)
if err != nil {
return err
}
fisize, err := fi.fi.Size()
if err != nil {
return err
}
select {
case <-ctx.Done():
return ctx.Err()
default:
}
readsize := min(req.Size, int(fisize-req.Offset))
n, err := fi.fi.CtxReadFull(ctx, resp.Data[:readsize])
resp.Data = resp.Data[:n]
return err
}
func (fi *File) Write(ctx context.Context, req *fuse.WriteRequest, resp *fuse.WriteResponse) error {
// TODO: at some point, ensure that WriteAt here respects the context
wrote, err := fi.fi.WriteAt(req.Data, req.Offset)
if err != nil {
return err
}
resp.Size = wrote
return nil
}
func (fi *File) Flush(ctx context.Context, req *fuse.FlushRequest) error {
errs := make(chan error, 1)
go func() {
errs <- fi.fi.Flush()
}()
select {
case err := <-errs:
return err
case <-ctx.Done():
return ctx.Err()
}
}
func (fi *File) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *fuse.SetattrResponse) error {
if req.Valid.Size() {
cursize, err := fi.fi.Size()
if err != nil {
return err
}
if cursize != int64(req.Size) {
err := fi.fi.Truncate(int64(req.Size))
if err != nil {
return err
}
}
}
return nil
}
// Fsync flushes the content in the file to disk, but does not
// update the dag tree internally
func (fi *FileNode) Fsync(ctx context.Context, req *fuse.FsyncRequest) error {
errs := make(chan error, 1)
go func() {
errs <- fi.fi.Sync()
}()
select {
case err := <-errs:
return err
case <-ctx.Done():
return ctx.Err()
}
}
func (fi *File) Forget() {
err := fi.fi.Sync()
if err != nil {
log.Debug("Forget file error: ", err)
}
}
func (dir *Directory) Mkdir(ctx context.Context, req *fuse.MkdirRequest) (fs.Node, error) {
child, err := dir.dir.Mkdir(req.Name)
if err != nil {
return nil, err
}
return &Directory{dir: child}, nil
}
func (fi *FileNode) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fs.Handle, error) {
var mfsflag int
switch {
case req.Flags.IsReadOnly():
mfsflag = mfs.OpenReadOnly
case req.Flags.IsWriteOnly():
mfsflag = mfs.OpenWriteOnly
case req.Flags.IsReadWrite():
mfsflag = mfs.OpenReadWrite
default:
return nil, errors.New("unsupported flag type")
}
fd, err := fi.fi.Open(mfsflag, true)
if err != nil {
return nil, err
}
if req.Flags&fuse.OpenTruncate != 0 {
if req.Flags.IsReadOnly() {
log.Error("tried to open a readonly file with truncate")
return nil, fuse.ENOTSUP
}
log.Info("Need to truncate file!")
err := fd.Truncate(0)
if err != nil {
return nil, err
}
} else if req.Flags&fuse.OpenAppend != 0 {
log.Info("Need to append to file!")
if req.Flags.IsReadOnly() {
log.Error("tried to open a readonly file with append")
return nil, fuse.ENOTSUP
}
_, err := fd.Seek(0, os.SEEK_END)
if err != nil {
log.Error("seek reset failed: ", err)
return nil, err
}
}
return &File{fi: fd}, nil
}
func (fi *File) Release(ctx context.Context, req *fuse.ReleaseRequest) error {
return fi.fi.Close()
}
func (dir *Directory) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (fs.Node, fs.Handle, error) {
// New 'empty' file
nd := &dag.Node{Data: ft.FilePBData(nil, 0)}
err := dir.dir.AddChild(req.Name, nd)
if err != nil {
return nil, nil, err
}
child, err := dir.dir.Child(req.Name)
if err != nil {
return nil, nil, err
}
fi, ok := child.(*mfs.File)
if !ok {
return nil, nil, errors.New("child creation failed")
}
nodechild := &FileNode{fi: fi}
var openflag int
switch {
case req.Flags.IsReadOnly():
openflag = mfs.OpenReadOnly
case req.Flags.IsWriteOnly():
openflag = mfs.OpenWriteOnly
case req.Flags.IsReadWrite():
openflag = mfs.OpenReadWrite
default:
return nil, nil, errors.New("unsupported open mode")
}
fd, err := fi.Open(openflag, true)
if err != nil {
return nil, nil, err
}
return nodechild, &File{fi: fd}, nil
}
func (dir *Directory) Remove(ctx context.Context, req *fuse.RemoveRequest) error {
err := dir.dir.Unlink(req.Name)
if err != nil {
return fuse.ENOENT
}
return nil
}
// Rename implements NodeRenamer
func (dir *Directory) Rename(ctx context.Context, req *fuse.RenameRequest, newDir fs.Node) error {
cur, err := dir.dir.Child(req.OldName)
if err != nil {
return err
}
err = dir.dir.Unlink(req.OldName)
if err != nil {
return err
}
switch newDir := newDir.(type) {
case *Directory:
nd, err := cur.GetNode()
if err != nil {
return err
}
err = newDir.dir.AddChild(req.NewName, nd)
if err != nil {
return err
}
case *FileNode:
log.Error("Cannot move node into a file!")
return fuse.EPERM
default:
log.Error("Unknown node type for rename target dir!")
return errors.New("Unknown fs node type!")
}
return nil
}
func min(a, b int) int {
if a < b {
return a
}
return b
}
// to check that out Node implements all the interfaces we want
type ipnsRoot interface {
fs.Node
fs.HandleReadDirAller
fs.NodeStringLookuper
}
var _ ipnsRoot = (*Root)(nil)
type ipnsDirectory interface {
fs.HandleReadDirAller
fs.Node
fs.NodeCreater
fs.NodeMkdirer
fs.NodeRemover
fs.NodeRenamer
fs.NodeStringLookuper
}
var _ ipnsDirectory = (*Directory)(nil)
type ipnsFile interface {
fs.HandleFlusher
fs.HandleReader
fs.HandleWriter
fs.HandleReleaser
}
type ipnsFileNode interface {
fs.Node
fs.NodeFsyncer
fs.NodeOpener
}
var _ ipnsFileNode = (*FileNode)(nil)
var _ ipnsFile = (*File)(nil)