small refactor*

server/pkg/go-nfs/nfs_onlookup.go

@@ -0,0 +1,86 @@
+package nfs
+
+import (
+	"bytes"
+	"context"
+	"os"
+
+	"github.com/willscott/go-nfs-client/nfs/xdr"
+)
+
+func lookupSuccessResponse(ctx context.Context, handle []byte, entPath, dirPath []string, fs Filesystem) ([]byte, error) {
+	writer := bytes.NewBuffer([]byte{})
+	if err := xdr.Write(writer, uint32(NFSStatusOk)); err != nil {
+		return nil, err
+	}
+	if err := xdr.Write(writer, handle); err != nil {
+		return nil, err
+	}
+	if err := WritePostOpAttrs(writer, tryStat(ctx, fs, entPath)); err != nil {
+		return nil, err
+	}
+	if err := WritePostOpAttrs(writer, tryStat(ctx, fs, dirPath)); err != nil {
+		return nil, err
+	}
+	return writer.Bytes(), nil
+}
+
+func onLookup(ctx context.Context, w *response, userHandle Handler) error {
+	w.errorFmt = opAttrErrorFormatter
+	obj := DirOpArg{}
+	err := xdr.Read(w.req.Body, &obj)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+
+	fs, p, err := userHandle.FromHandle(ctx, obj.Handle)
+	if err != nil {
+		return &NFSStatusError{NFSStatusStale, err}
+	}
+	dirInfo, err := fs.Lstat(ctx, fs.Join(p...))
+	if err != nil || !dirInfo.IsDir() {
+		return &NFSStatusError{NFSStatusNotDir, err}
+	}
+
+	// Special cases for "." and ".."
+	if bytes.Equal(obj.Filename, []byte(".")) {
+		resp, err := lookupSuccessResponse(ctx, obj.Handle, p, p, fs)
+		if err != nil {
+			return &NFSStatusError{NFSStatusServerFault, err}
+		}
+		if err := w.Write(resp); err != nil {
+			return &NFSStatusError{NFSStatusServerFault, err}
+		}
+		return nil
+	}
+	if bytes.Equal(obj.Filename, []byte("..")) {
+		if len(p) == 0 {
+			return &NFSStatusError{NFSStatusAccess, os.ErrPermission}
+		}
+		pPath := p[0 : len(p)-1]
+		pHandle := userHandle.ToHandle(ctx, fs, pPath)
+		resp, err := lookupSuccessResponse(ctx, pHandle, pPath, p, fs)
+		if err != nil {
+			return &NFSStatusError{NFSStatusServerFault, err}
+		}
+		if err := w.Write(resp); err != nil {
+			return &NFSStatusError{NFSStatusServerFault, err}
+		}
+		return nil
+	}
+
+	reqPath := append(p, string(obj.Filename))
+	if _, err = fs.Lstat(ctx, fs.Join(reqPath...)); err != nil {
+		return &NFSStatusError{NFSStatusNoEnt, os.ErrNotExist}
+	}
+
+	newHandle := userHandle.ToHandle(ctx, fs, reqPath)
+	resp, err := lookupSuccessResponse(ctx, newHandle, reqPath, p, fs)
+	if err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := w.Write(resp); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	return nil
+}