diff options
| -rw-r--r-- | internal/fusefrontend/node.go | 93 |
1 files changed, 51 insertions, 42 deletions
diff --git a/internal/fusefrontend/node.go b/internal/fusefrontend/node.go index bce4ea8..1fa6137 100644 --- a/internal/fusefrontend/node.go +++ b/internal/fusefrontend/node.go @@ -27,29 +27,50 @@ func (n *Node) path() string { return n.Path(n.Root()) } +// rootNode returns the Root Node of the filesystem. func (n *Node) rootNode() *RootNode { return n.Root().Operations().(*RootNode) } -// Lookup - FUSE call for discovering a file. -func (n *Node) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) { +// prepareAtSyscall returns a (dirfd, cName) pair that can be used +// with the "___at" family of system calls (openat, fstatat, unlinkat...) to +// access the backing encrypted directory. +// +// If you pass a `child` file name, the (dirfd, cName) pair will refer to +// a child of this node. +// If `child` is empty, the (dirfd, cName) pair refers to this node itself. +func (n *Node) prepareAtSyscall(child string) (dirfd int, cName string, errno syscall.Errno) { + p := n.path() + if child != "" { + p = filepath.Join(p, child) + } rn := n.rootNode() - p := filepath.Join(n.path(), name) if rn.isFiltered(p) { - return nil, syscall.EPERM + errno = syscall.EPERM + return } dirfd, cName, err := rn.openBackingDir(p) if err != nil { - return nil, fs.ToErrno(err) + errno = fs.ToErrno(err) + } + return +} + +// Lookup - FUSE call for discovering a file. +func (n *Node) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (ch *fs.Inode, errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall(name) + if errno != 0 { + return } defer syscall.Close(dirfd) + // Get device number and inode number into `st` st, err := syscallcompat.Fstatat2(dirfd, cName, unix.AT_SYMLINK_NOFOLLOW) if err != nil { return nil, fs.ToErrno(err) } // Get unique inode number - rn.inoMap.TranslateStat(st) + n.rootNode().inoMap.TranslateStat(st) out.Attr.FromStat(st) // Create child node id := fs.StableAttr{ @@ -58,18 +79,17 @@ func (n *Node) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fs Ino: st.Ino, } node := &Node{} - ch := n.NewInode(ctx, node, id) + ch = n.NewInode(ctx, node, id) return ch, 0 } // GetAttr - FUSE call for stat()ing a file. // // GetAttr is symlink-safe through use of openBackingDir() and Fstatat(). -func (n *Node) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno { - rn := n.rootNode() - dirfd, cName, err := rn.openBackingDir(n.path()) - if err != nil { - return fs.ToErrno(err) +func (n *Node) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) (errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall("") + if errno != 0 { + return } defer syscall.Close(dirfd) @@ -77,7 +97,7 @@ func (n *Node) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) if err != nil { return fs.ToErrno(err) } - rn.inoMap.TranslateStat(st) + n.rootNode().inoMap.TranslateStat(st) out.Attr.FromStat(st) return 0 } @@ -86,19 +106,16 @@ func (n *Node) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) // // Symlink-safe through the use of Openat(). func (n *Node) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (inode *fs.Inode, fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) { - rn := n.rootNode() - path := filepath.Join(n.path(), name) - if rn.isFiltered(path) { - return nil, nil, 0, syscall.EPERM - } - dirfd, cName, err := rn.openBackingDir(path) - if err != nil { - return nil, nil, 0, fs.ToErrno(err) + dirfd, cName, errno := n.prepareAtSyscall(name) + if errno != 0 { + return } defer syscall.Close(dirfd) + var err error fd := -1 // Make sure context is nil if we don't want to preserve the owner + rn := n.rootNode() if !rn.args.PreserveOwner { ctx = nil } @@ -106,7 +123,7 @@ func (n *Node) Create(ctx context.Context, name string, flags uint32, mode uint3 // Handle long file name if !rn.args.PlaintextNames && nametransform.IsLongContent(cName) { // Create ".name" - err = rn.nameTransform.WriteLongNameAt(dirfd, cName, path) + err = rn.nameTransform.WriteLongNameAt(dirfd, cName, name) if err != nil { return nil, nil, 0, fs.ToErrno(err) } @@ -153,24 +170,20 @@ func (n *Node) Create(ctx context.Context, name string, flags uint32, mode uint3 // Unlink - FUSE call. Delete a file. // // Symlink-safe through use of Unlinkat(). -func (n *Node) Unlink(ctx context.Context, name string) syscall.Errno { - rn := n.rootNode() - p := filepath.Join(n.path(), name) - if rn.isFiltered(p) { - return syscall.EPERM - } - dirfd, cName, err := rn.openBackingDir(p) - if err != nil { - return fs.ToErrno(err) +func (n *Node) Unlink(ctx context.Context, name string) (errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall(name) + if errno != 0 { + return } defer syscall.Close(dirfd) + // Delete content - err = syscallcompat.Unlinkat(dirfd, cName, 0) + err := syscallcompat.Unlinkat(dirfd, cName, 0) if err != nil { return fs.ToErrno(err) } // Delete ".name" file - if !rn.args.PlaintextNames && nametransform.IsLongContent(cName) { + if !n.rootNode().args.PlaintextNames && nametransform.IsLongContent(cName) { err = nametransform.DeleteLongNameAt(dirfd, cName) if err != nil { tlog.Warn.Printf("Unlink: could not delete .name file: %v", err) @@ -182,15 +195,10 @@ func (n *Node) Unlink(ctx context.Context, name string) syscall.Errno { // Readlink - FUSE call. // // Symlink-safe through openBackingDir() + Readlinkat(). -func (n *Node) Readlink(ctx context.Context) ([]byte, syscall.Errno) { - rn := n.rootNode() - p := n.path() - if rn.isFiltered(p) { - return nil, syscall.EPERM - } - dirfd, cName, err := rn.openBackingDir(p) - if err != nil { - return nil, fs.ToErrno(err) +func (n *Node) Readlink(ctx context.Context) (out []byte, errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall("") + if errno != 0 { + return } defer syscall.Close(dirfd) @@ -198,6 +206,7 @@ func (n *Node) Readlink(ctx context.Context) ([]byte, syscall.Errno) { if err != nil { return nil, fs.ToErrno(err) } + rn := n.rootNode() if rn.args.PlaintextNames { return []byte(cTarget), 0 } |