small refactor*

server/pkg/go-nfs/nfs_onsetattr.go

@@ -0,0 +1,80 @@
+package nfs
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+
+	"github.com/go-git/go-billy/v5"
+	"github.com/willscott/go-nfs-client/nfs/xdr"
+)
+
+func onSetAttr(ctx context.Context, w *response, userHandle Handler) error {
+	w.errorFmt = wccDataErrorFormatter
+	handle, err := xdr.ReadOpaque(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+
+	fs, path, err := userHandle.FromHandle(ctx, handle)
+	if err != nil {
+		return &NFSStatusError{NFSStatusStale, err}
+	}
+	attrs, err := ReadSetFileAttributes(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+
+	fullPath := fs.Join(path...)
+	info, err := fs.Lstat(ctx, fullPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return &NFSStatusError{NFSStatusNoEnt, err}
+		}
+		if errors.Is(err, context.DeadlineExceeded) {
+			return &NFSStatusError{timeoutStatus, err}
+		}
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+
+	// see if there's a "guard"
+	if guard, err := xdr.ReadUint32(w.req.Body); err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	} else if guard != 0 {
+		// read the ctime.
+		t := FileTime{}
+		if err := xdr.Read(w.req.Body, &t); err != nil {
+			return &NFSStatusError{NFSStatusInval, err}
+		}
+		attr := ToFileAttribute(info, fullPath)
+		if t != attr.Ctime {
+			return &NFSStatusError{NFSStatusNotSync, nil}
+		}
+	}
+
+	if !CapabilityCheck(fs, billy.WriteCapability) {
+		return &NFSStatusError{NFSStatusROFS, os.ErrPermission}
+	}
+
+	changer := userHandle.Change(fs)
+	if err := attrs.Apply(ctx, changer, fs, fs.Join(path...)); err != nil {
+		// Already an nfsstatuserror
+		return err
+	}
+
+	preAttr := ToFileAttribute(info, fullPath).AsCache()
+
+	writer := bytes.NewBuffer([]byte{})
+	if err := xdr.Write(writer, uint32(NFSStatusOk)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := WriteWcc(writer, preAttr, tryStat(ctx, fs, path)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	if err := w.Write(writer.Bytes()); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	return nil
+}