libgocryptfs/internal/fusefrontend_reverse/node_helpers.go
2020-08-01 22:28:25 +02:00

74 lines
1.9 KiB
Go

package fusefrontend_reverse
import (
"context"
"path/filepath"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
)
// translateSize translates the ciphertext size in `out` into plaintext size.
func (n *Node) translateSize(dirfd int, cName string, out *fuse.Attr) {
if out.IsRegular() {
rn := n.rootNode()
out.Size = rn.contentEnc.PlainSizeToCipherSize(out.Size)
} else if out.IsSymlink() {
panic("todo: call readlink once it is implemented")
}
}
// Path returns the relative plaintext path of this node
func (n *Node) Path() string {
return n.Inode.Path(n.Root())
}
// rootNode returns the Root Node of the filesystem.
func (n *Node) rootNode() *RootNode {
return n.Root().Operations().(*RootNode)
}
// 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()
dirfd, cName, err := rn.openBackingDir(p)
if err != nil {
errno = fs.ToErrno(err)
}
return
}
// newChild attaches a new child inode to n.
// The passed-in `st` will be modified to get a unique inode number.
func (n *Node) newChild(ctx context.Context, st *syscall.Stat_t, out *fuse.EntryOut) *fs.Inode {
// Get unique inode number
rn := n.rootNode()
rn.inoMap.TranslateStat(st)
out.Attr.FromStat(st)
// Create child node
id := fs.StableAttr{
Mode: uint32(st.Mode),
Gen: 1,
Ino: st.Ino,
}
node := &Node{}
return n.NewInode(ctx, node, id)
}
// isRoot returns true if this node is the root node
func (n *Node) isRoot() bool {
rn := n.rootNode()
return &rn.Node == n
}