small refactor*

server/pkg/go-nfs/nfs_oncreate.go

@@ -0,0 +1,125 @@
+package nfs
+
+import (
+	"bytes"
+	"context"
+	"os"
+
+	billy "github.com/go-git/go-billy/v5"
+	"github.com/willscott/go-nfs-client/nfs/xdr"
+)
+
+const (
+	createModeUnchecked = 0
+	createModeGuarded   = 1
+	createModeExclusive = 2
+)
+
+func onCreate(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}
+	}
+	how, err := xdr.ReadUint32(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+	var attrs *SetFileAttributes
+	if how == createModeUnchecked || how == createModeGuarded {
+		sattr, err := ReadSetFileAttributes(w.req.Body)
+		if err != nil {
+			return &NFSStatusError{NFSStatusInval, err}
+		}
+		attrs = sattr
+	} else if how == createModeExclusive {
+		// read createverf3
+		var verf [8]byte
+		if err := xdr.Read(w.req.Body, &verf); err != nil {
+			return &NFSStatusError{NFSStatusInval, err}
+		}
+		Log.Errorf("failing create to indicate lack of support for 'exclusive' mode.")
+		// TODO: support 'exclusive' mode.
+		return &NFSStatusError{NFSStatusNotSupp, os.ErrPermission}
+	} else {
+		// invalid
+		return &NFSStatusError{NFSStatusNotSupp, os.ErrInvalid}
+	}
+
+	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, nil}
+	}
+
+	newFile := append(path, string(obj.Filename))
+	newFilePath := fs.Join(newFile...)
+	if s, err := fs.Stat(ctx, newFilePath); err == nil {
+		if s.IsDir() {
+			return &NFSStatusError{NFSStatusExist, nil}
+		}
+		if how == createModeGuarded {
+			return &NFSStatusError{NFSStatusExist, os.ErrPermission}
+		}
+	} else {
+		if s, err := fs.Stat(ctx, fs.Join(path...)); err != nil {
+			return &NFSStatusError{NFSStatusAccess, err}
+		} else if !s.IsDir() {
+			return &NFSStatusError{NFSStatusNotDir, nil}
+		}
+	}
+
+	file, err := fs.Create(ctx, newFilePath)
+	if err != nil {
+		Log.Errorf("Error Creating: %v", err)
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+	if err := file.Close(ctx); err != nil {
+		Log.Errorf("Error Creating: %v", err)
+		return &NFSStatusError{NFSStatusAccess, err}
+	}
+
+	fp := userHandle.ToHandle(ctx, fs, newFile)
+	changer := userHandle.Change(fs)
+	if err := attrs.Apply(ctx, changer, fs, newFilePath); err != nil {
+		Log.Errorf("Error applying attributes: %v\n", err)
+		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, []string{file.Name()})); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	// dir_wcc (we don't include pre_op_attr)
+	if err := xdr.Write(writer, uint32(0)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := WritePostOpAttrs(writer, tryStat(ctx, fs, path)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	if err := w.Write(writer.Bytes()); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	return nil
+}