libgocryptfs/internal/fusefrontend_reverse/node.go
2020-08-01 21:14:33 +02:00

78 lines
1.8 KiB
Go

package fusefrontend_reverse
import (
"context"
"syscall"
"golang.org/x/sys/unix"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
)
// Node is a file or directory in the filesystem tree
// in a `gocryptfs -reverse` mount.
type Node struct {
fs.Inode
}
// Lookup - FUSE call for discovering a file.
// TODO handle virtual files
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)
}
// Create new inode and fill `out`
ch = n.newChild(ctx, st, out)
// Translate ciphertext size in `out.Attr.Size` to plaintext size
n.translateSize(dirfd, cName, &out.Attr)
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) (errno syscall.Errno) {
// If the kernel gives us a file handle, use it.
if f != nil {
return f.(fs.FileGetattrer).Getattr(ctx, out)
}
dirfd, cName, errno := n.prepareAtSyscall("")
if errno != 0 {
return
}
defer syscall.Close(dirfd)
st, err := syscallcompat.Fstatat2(dirfd, cName, unix.AT_SYMLINK_NOFOLLOW)
if err != nil {
return fs.ToErrno(err)
}
// Fix inode number
rn := n.rootNode()
rn.inoMap.TranslateStat(st)
out.Attr.FromStat(st)
// Translate ciphertext size in `out.Attr.Size` to plaintext size
n.translateSize(dirfd, cName, &out.Attr)
if rn.args.ForceOwner != nil {
out.Owner = *rn.args.ForceOwner
}
return 0
}