v2api/reverse: implement Lookup & Getattr

1 files changed, 66 insertions, 0 deletions

diff --git a/internal/fusefrontend_reverse/node.go b/internal/fusefrontend_reverse/node.go
index 6a1294a..a102a66 100644
--- a/internal/fusefrontend_reverse/node.go
+++ b/internal/fusefrontend_reverse/node.go
@@ -1,7 +1,15 @@
 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
@@ -9,3 +17,61 @@ import (
 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
+}