v2api: fix missing size translation in Lookup

1 files changed, 34 insertions, 0 deletions

diff --git a/internal/fusefrontend/node_helpers.go b/internal/fusefrontend/node_helpers.go
index a7a32af..a31a41d 100644
--- a/internal/fusefrontend/node_helpers.go
+++ b/internal/fusefrontend/node_helpers.go
@@ -2,10 +2,14 @@ package fusefrontend
 
 import (
 	"context"
+	"syscall"
 
 	"github.com/hanwen/go-fuse/v2/fs"
 
 	"github.com/hanwen/go-fuse/v2/fuse"
+
+	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
+	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
 // toFuseCtx tries to extract a fuse.Context from a generic context.Context.
@@ -29,3 +33,33 @@ func toNode(op fs.InodeEmbedder) *Node {
 	}
 	return op.(*Node)
 }
+
+// readlink reads and decrypts a symlink. Used by Readlink, Getattr, Lookup.
+func (n *Node) readlink(dirfd int, cName string) (out []byte, errno syscall.Errno) {
+	cTarget, err := syscallcompat.Readlinkat(dirfd, cName)
+	if err != nil {
+		return nil, fs.ToErrno(err)
+	}
+	rn := n.rootNode()
+	if rn.args.PlaintextNames {
+		return []byte(cTarget), 0
+	}
+	// Symlinks are encrypted like file contents (GCM) and base64-encoded
+	target, err := rn.decryptSymlinkTarget(cTarget)
+	if err != nil {
+		tlog.Warn.Printf("Readlink %q: decrypting target failed: %v", cName, err)
+		return nil, syscall.EIO
+	}
+	return []byte(target), 0
+}
+
+// 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.CipherSizeToPlainSize(out.Size)
+	} else if out.IsSymlink() {
+		target, _ := n.readlink(dirfd, cName)
+		out.Size = uint64(len(target))
+	}
+}