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authorJakob Unterwurzacher2015-09-07 21:10:42 +0200
committerJakob Unterwurzacher2015-09-07 21:10:42 +0200
commitaf0ae03db23f845dbcf8a6738057222ce7986bd8 (patch)
tree90aa7fc12b9b12b28c486b9bdc3e62ab40eb0fe6 /cluefs_frontend
parentcd9512801525a63530c1f74ac184fb1d73bff67b (diff)
Rename frontend to "cluefs_frontend"
Enables adding another frontend later
Diffstat (limited to 'cluefs_frontend')
-rw-r--r--cluefs_frontend/fe_checks.go31
-rw-r--r--cluefs_frontend/fe_dir.go180
-rw-r--r--cluefs_frontend/fe_file.go152
-rw-r--r--cluefs_frontend/fe_fs.go46
4 files changed, 409 insertions, 0 deletions
diff --git a/cluefs_frontend/fe_checks.go b/cluefs_frontend/fe_checks.go
new file mode 100644
index 0000000..c555436
--- /dev/null
+++ b/cluefs_frontend/fe_checks.go
@@ -0,0 +1,31 @@
+package cluefs_frontend
+
+import (
+ "bazil.org/fuse/fs"
+)
+
+// Compile-time interface checks.
+var _ fs.FS = (*FS)(nil)
+var _ fs.FSStatfser = (*FS)(nil)
+
+var _ fs.Node = (*Dir)(nil)
+var _ fs.NodeCreater = (*Dir)(nil)
+var _ fs.NodeMkdirer = (*Dir)(nil)
+var _ fs.NodeRemover = (*Dir)(nil)
+var _ fs.NodeRenamer = (*Dir)(nil)
+var _ fs.HandleReadDirAller = (*Dir)(nil)
+
+var _ fs.HandleReader = (*File)(nil)
+var _ fs.HandleWriter = (*File)(nil)
+var _ fs.Node = (*File)(nil)
+var _ fs.NodeOpener = (*File)(nil)
+var _ fs.NodeSetattrer = (*File)(nil)
+
+func foo(h fs.HandleReadDirAller) {
+
+}
+
+func init() {
+ var d Dir
+ foo(&d)
+}
diff --git a/cluefs_frontend/fe_dir.go b/cluefs_frontend/fe_dir.go
new file mode 100644
index 0000000..65d92f1
--- /dev/null
+++ b/cluefs_frontend/fe_dir.go
@@ -0,0 +1,180 @@
+package cluefs_frontend
+
+// frontend sits between FUSE and ClueFS
+// and uses cryptfs for all crypto operations
+//
+// cryptfs
+// ^
+// |
+// v
+// FUSE <-> frontend <-> ClueFS
+//
+// This file handles directories
+
+import (
+ "fmt"
+ "github.com/rfjakob/gocryptfs/cryptfs"
+ "github.com/rfjakob/cluefs/lib/cluefs"
+ "bazil.org/fuse"
+ fusefs "bazil.org/fuse/fs"
+ "golang.org/x/net/context"
+)
+
+type Dir struct {
+ *cluefs.Dir
+ crfs *cryptfs.CryptFS
+}
+
+func NewDir(parent string, name string, fs *FS) *Dir {
+ cryptfs.Debug.Printf("NewDir parent=%s name=%s\n", parent, name)
+ return &Dir {
+ Dir: cluefs.NewDir(parent, name, fs.ClueFS),
+ crfs: fs.CryptFS,
+ }
+}
+
+func (d *Dir) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) {
+ cryptfs.Debug.Printf("Open\n")
+ h, err := d.Dir.Open(ctx, req, resp)
+ if err != nil {
+ return nil, err
+ }
+ clueDir := h.(*cluefs.Dir)
+
+ return &Dir {
+ Dir: clueDir,
+ crfs: d.crfs,
+ }, nil
+}
+
+func (d *Dir) Lookup(ctx context.Context, req *fuse.LookupRequest, resp *fuse.LookupResponse) (fusefs.Node, error) {
+ cryptfs.Debug.Printf("Lookup %s\n", req.Name)
+ req.Name = d.crfs.EncryptPath(req.Name)
+ node, err := d.Dir.Lookup(ctx, req, resp)
+ if err != nil {
+ return nil, err
+ }
+ clueDir, ok := node.(*cluefs.Dir)
+ if ok {
+ return &Dir {
+ Dir: clueDir,
+ crfs: d.crfs,
+ }, nil
+ } else {
+ resp.Attr.Size = d.crfs.PlainSize(resp.Attr.Size)
+ clueFile := node.(*cluefs.File)
+ return &File {
+ File: clueFile,
+ crfs: d.crfs,
+ }, nil
+ }
+}
+
+func (d *Dir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
+ cryptfs.Debug.Printf("ReadDirAll\n")
+ entries, err := d.Dir.ReadDirAll(ctx)
+ if err != nil {
+ return nil, err
+ }
+ var decrypted []fuse.Dirent
+ for _, e := range entries {
+ if e.Name == "." || e.Name == ".." {
+ decrypted = append(decrypted, e)
+ continue
+ }
+ newName, err := d.crfs.DecryptPath(e.Name)
+ if err != nil {
+ fmt.Printf("ReadDirAll: Error decoding \"%s\": %s\n", e.Name, err.Error())
+ continue
+ }
+ e.Name = newName
+ decrypted = append(decrypted, e)
+ }
+ return decrypted, nil
+}
+
+func (d *Dir) Mkdir(ctx context.Context, req *fuse.MkdirRequest) (fusefs.Node, error) {
+ cryptfs.Debug.Printf("Mkdir %s\n", req.Name)
+ req.Name = d.crfs.EncryptPath(req.Name)
+ n, err := d.Dir.Mkdir(ctx, req)
+ if err != nil {
+ return nil, err
+ }
+ clueDir := n.(*cluefs.Dir)
+ return &Dir {
+ Dir: clueDir,
+ crfs: d.crfs,
+ }, nil
+}
+
+func (d *Dir) Remove(ctx context.Context, req *fuse.RemoveRequest) error {
+ cryptfs.Debug.Printf("Remove\n")
+ req.Name = d.crfs.EncryptPath(req.Name)
+ return d.Dir.Remove(ctx, req)
+}
+
+func (d *Dir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (fusefs.Node, fusefs.Handle, error) {
+ cryptfs.Debug.Printf("Create\n")
+ req.Flags, _ = fixFlags(req.Flags)
+ req.Name = d.crfs.EncryptPath(req.Name)
+ n, _, err := d.Dir.Create(ctx, req, resp)
+ if err != nil {
+ return nil, nil, err
+ }
+ clueFile := n.(*cluefs.File)
+ cryptFile := &File {
+ File: clueFile,
+ crfs: d.crfs,
+ }
+ return cryptFile, cryptFile, nil
+}
+func (d *Dir) Symlink(ctx context.Context, req *fuse.SymlinkRequest) (fusefs.Node, error) {
+ req.Target = d.crfs.EncryptPath(req.Target)
+ req.NewName = d.crfs.EncryptPath(req.NewName)
+ node, err := d.Dir.Symlink(ctx, req)
+ if err != nil {
+ return nil, err
+ }
+
+ clueDir, ok := node.(*cluefs.Dir)
+ if ok {
+ return &Dir {
+ Dir: clueDir,
+ crfs: d.crfs,
+ }, nil
+ } else {
+ clueFile := node.(*cluefs.File)
+ return &File {
+ File: clueFile,
+ crfs: d.crfs,
+ }, nil
+ }
+}
+// We need to overwrite Readlink for both Dir and File. Do both right here to keep them in sync.
+func (d *Dir) Readlink(ctx context.Context, req *fuse.ReadlinkRequest) (string, error) {
+ dest, err := d.Dir.Readlink(ctx, req)
+ if err != nil {
+ return "", err
+ }
+ return d.crfs.DecryptPath(dest)
+}
+func (d *File) Readlink(ctx context.Context, req *fuse.ReadlinkRequest) (string, error) {
+ dest, err := d.File.Readlink(ctx, req)
+ if err != nil {
+ return "", err
+ }
+ return d.crfs.DecryptPath(dest)
+}
+// We need to overwrite Rename for both Dir and File. Do both right here to keep them in sync.
+func (d *Dir) Rename(ctx context.Context, req *fuse.RenameRequest, newDir fusefs.Node) error {
+ req.OldName = d.crfs.EncryptPath(req.OldName)
+ req.NewName = d.crfs.EncryptPath(req.NewName)
+ destDir := newDir.(*Dir)
+ return d.Dir.Rename(ctx, req, destDir.Dir)
+}
+func (d *File) Rename(ctx context.Context, req *fuse.RenameRequest, newDir fusefs.Node) error {
+ req.OldName = d.crfs.EncryptPath(req.OldName)
+ req.NewName = d.crfs.EncryptPath(req.NewName)
+ destDir := newDir.(*Dir)
+ return d.File.Rename(ctx, req, destDir.Dir)
+}
diff --git a/cluefs_frontend/fe_file.go b/cluefs_frontend/fe_file.go
new file mode 100644
index 0000000..4c4e38a
--- /dev/null
+++ b/cluefs_frontend/fe_file.go
@@ -0,0 +1,152 @@
+package cluefs_frontend
+
+// frontend sits between FUSE and ClueFS
+// and uses cryptfs for all crypto operations
+//
+// cryptfs
+// ^
+// |
+// v
+// FUSE <-> frontend <-> ClueFS
+//
+// This file handles files access
+
+import (
+ "fmt"
+ "github.com/rfjakob/gocryptfs/cryptfs"
+ "github.com/rfjakob/cluefs/lib/cluefs"
+
+ "bazil.org/fuse"
+ fusefs "bazil.org/fuse/fs"
+ "golang.org/x/net/context"
+)
+
+func fixFlags(flags fuse.OpenFlags) (fuse.OpenFlags, bool) {
+ cryptfs.Debug.Printf("fixFlags: Before: %s\n", flags.String())
+ var writeOnly bool
+ // We always need read access to do read-modify-write cycles
+ if flags & fuse.OpenWriteOnly > 0 {
+ flags = flags &^ fuse.OpenWriteOnly
+ flags = flags | fuse.OpenReadWrite
+ writeOnly = true
+ }
+ // We also cannot open the file in append mode, we need to seek back for RMW
+ flags = flags &^ fuse.OpenAppend
+ cryptfs.Debug.Printf("fixFlags: After: %s\n", flags.String())
+ return flags, writeOnly
+}
+
+func max(x int, y int) int {
+ if x > y {
+ return x
+ }
+ return y
+}
+
+type File struct {
+ *cluefs.File
+ crfs *cryptfs.CryptFS
+ // Remember if the file is supposed to be write-only
+ writeOnly bool
+}
+
+func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) {
+ cryptfs.Debug.Printf("File.Open\n")
+
+ req.Flags, f.writeOnly = fixFlags(req.Flags)
+
+ h, err := f.File.Open(ctx, req, resp)
+ if err != nil {
+ return nil, err
+ }
+ clueFile := h.(*cluefs.File)
+ return &File {
+ File: clueFile,
+ crfs: f.crfs,
+ }, nil
+}
+
+func (f *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
+
+ cryptfs.Debug.Printf("Read: o=%d l=%d\n", req.Offset, req.Size)
+
+ // Read the backing ciphertext in one go
+ iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(req.Size))
+ var cipherReq fuse.ReadRequest
+ var cipherResp fuse.ReadResponse
+ o, l := f.crfs.JoinCiphertextRange(iblocks)
+ cipherResp.Data = make([]byte, int(l))
+ cipherReq.Offset = int64(o)
+ cipherReq.Size = int(l)
+ cryptfs.Debug.Printf("Read: cipherReq o=%d l=%d\n", o, l)
+ err := f.File.Read(ctx, &cipherReq, &cipherResp)
+ if err != nil {
+ return err
+ }
+
+ // Decrypt it
+ plaintext, err := f.crfs.DecryptBlocks(cipherResp.Data)
+ if err != nil {
+ resp.Data = plaintext
+ return err
+ }
+ // Crop down to relevant part
+ resp.Data = f.crfs.CropPlaintext(plaintext, iblocks)
+
+ return nil
+}
+
+func (f *File) Write(ctx context.Context, req *fuse.WriteRequest, resp *fuse.WriteResponse) error {
+ cryptfs.Debug.Printf("File.Write\n")
+ resp.Size = 0
+ iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(len(req.Data)))
+ var blockData []byte
+ for _, ib := range iblocks {
+ if ib.IsPartial() {
+ // RMW
+ cryptfs.Debug.Printf("RMW\n")
+ blockData = make([]byte, f.crfs.PlainBS())
+ var readReq fuse.ReadRequest
+ var readResp fuse.ReadResponse
+ o, l := ib.PlaintextRange()
+ readReq.Offset = int64(o)
+ readReq.Size = int(l)
+ err := f.Read(ctx, &readReq, &readResp)
+ if err != nil {
+ return err
+ }
+ copy(blockData, readResp.Data)
+ copy(blockData[ib.Offset:ib.Offset+ib.Length], req.Data)
+ blockLen := max(len(readResp.Data), int(ib.Offset+ib.Length))
+ blockData = blockData[0:blockLen]
+ } else {
+ blockData = req.Data[0:f.crfs.PlainBS()]
+ }
+ ciphertext := f.crfs.EncryptBlock(blockData)
+ var partReq fuse.WriteRequest
+ var partResp fuse.WriteResponse
+ o, _ := ib.CiphertextRange()
+ partReq.Data = ciphertext
+ partReq.Offset = int64(o)
+ err := f.File.Write(ctx, &partReq, &partResp)
+ if err != nil {
+ fmt.Printf("Write failure: %s\n", err.Error())
+ return err
+ }
+ // Remove written data from the front of the request
+ cryptfs.Debug.Printf("req.Data[%d:%d]\n", int(ib.Length), len(req.Data))
+ req.Data = req.Data[int(ib.Length):len(req.Data)]
+ resp.Size += int(ib.Length)
+ }
+ return nil
+}
+
+func (f *File) Attr(ctx context.Context, attr *fuse.Attr) error {
+ cryptfs.Debug.Printf("Attr\n")
+ err := f.File.Node.Attr(ctx, attr)
+ if err != nil {
+ return err
+ }
+ attr.Size = f.crfs.PlainSize(attr.Size)
+ return nil
+}
diff --git a/cluefs_frontend/fe_fs.go b/cluefs_frontend/fe_fs.go
new file mode 100644
index 0000000..2b12da6
--- /dev/null
+++ b/cluefs_frontend/fe_fs.go
@@ -0,0 +1,46 @@
+package cluefs_frontend
+
+// frontend sits between FUSE and ClueFS
+// and uses cryptfs for all crypto operations
+//
+// cryptfs
+// ^
+// |
+// v
+// FUSE <-> frontend <-> ClueFS
+//
+// This file handles just the root directory
+
+import (
+ "github.com/rfjakob/gocryptfs/cryptfs"
+ "github.com/rfjakob/cluefs/lib/cluefs"
+ fusefs "bazil.org/fuse/fs"
+)
+
+type FS struct {
+ *cryptfs.CryptFS
+ *cluefs.ClueFS
+ backing string
+}
+
+type nullTracer struct {}
+
+func (nullTracer) Trace(op cluefs.FsOperTracer) {}
+
+func NewFS(key [16]byte, backing string, useOpenssl bool) (*FS, error) {
+ var tracer nullTracer
+ clfs, err := cluefs.NewClueFS(backing, tracer)
+ if err != nil {
+ return nil, err
+ }
+ return &FS {
+ CryptFS: cryptfs.NewCryptFS(key, useOpenssl),
+ ClueFS: clfs,
+ backing: backing,
+ }, nil
+}
+
+func (fs *FS) Root() (fusefs.Node, error) {
+ cryptfs.Debug.Printf("Root\n")
+ return NewDir("", fs.backing, fs), nil
+}