small refactor*

server/pkg/go-nfs/nfs_onlink.go

@@ -0,0 +1,94 @@
+package nfs
+
+import (
+	"bytes"
+	"context"
+	"os"
+
+	"github.com/go-git/go-billy/v5"
+	"github.com/willscott/go-nfs-client/nfs/xdr"
+)
+
+// Backing billy.FS doesn't support hard links
+func onLink(ctx context.Context, w *response, userHandle Handler) error {
+	w.errorFmt = wccDataErrorFormatter
+	obj := DirOpArg{}
+	err := xdr.Read(w.req.Body, &obj)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+	attrs, err := ReadSetFileAttributes(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+
+	target, err := xdr.ReadOpaque(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+
+	fs, path, err := userHandle.FromHandle(ctx, obj.Handle)
+	if err != nil {
+		return &NFSStatusError{NFSStatusStale, err}
+	}
+	if !CapabilityCheck(fs, billy.WriteCapability) {
+		return &NFSStatusError{NFSStatusROFS, os.ErrPermission}
+	}
+
+	if len(string(obj.Filename)) > PathNameMax {
+		return &NFSStatusError{NFSStatusNameTooLong, os.ErrInvalid}
+	}
+
+	newFilePath := fs.Join(append(path, string(obj.Filename))...)
+	if _, err := fs.Stat(ctx, newFilePath); err == nil {
+		return &NFSStatusError{NFSStatusExist, os.ErrExist}
+	}
+	if s, err := fs.Stat(ctx, fs.Join(path...)); err != nil {
+		return &NFSStatusError{NFSStatusAccess, err}
+	} else if !s.IsDir() {
+		return &NFSStatusError{NFSStatusNotDir, nil}
+	}
+
+	fp := userHandle.ToHandle(ctx, fs, append(path, string(obj.Filename)))
+	changer := userHandle.Change(fs)
+	if changer == nil {
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+	cos, ok := changer.(UnixChange)
+	if !ok {
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+
+	err = cos.Link(ctx, string(target), newFilePath)
+	if err != nil {
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+	if err := attrs.Apply(ctx, changer, fs, newFilePath); err != nil {
+		return &NFSStatusError{NFSStatusIO, err}
+	}
+
+	writer := bytes.NewBuffer([]byte{})
+	if err := xdr.Write(writer, uint32(NFSStatusOk)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	// "handle follows"
+	if err := xdr.Write(writer, uint32(1)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := xdr.Write(writer, fp); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := WritePostOpAttrs(writer, tryStat(ctx, fs, append(path, string(obj.Filename)))); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	if err := WriteWcc(writer, nil, tryStat(ctx, fs, path)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	if err := w.Write(writer.Bytes()); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	return nil
+}