small refactor*

server/pkg/go-nfs/nfs_onfsinfo.go

@@ -0,0 +1,89 @@
+package nfs
+
+import (
+	"bytes"
+	"context"
+
+	"github.com/go-git/go-billy/v5"
+	"github.com/willscott/go-nfs-client/nfs/xdr"
+)
+
+const (
+	// FSInfoPropertyLink does the FS support hard links?
+	FSInfoPropertyLink = 0x0001
+	// FSInfoPropertySymlink does the FS support soft links?
+	FSInfoPropertySymlink = 0x0002
+	// FSInfoPropertyHomogeneous does the FS need PATHCONF calls for each file
+	FSInfoPropertyHomogeneous = 0x0008
+	// FSInfoPropertyCanSetTime can the FS support setting access/mod times?
+	FSInfoPropertyCanSetTime = 0x0010
+)
+
+func onFSInfo(ctx context.Context, w *response, userHandle Handler) error {
+	roothandle, err := xdr.ReadOpaque(w.req.Body)
+	if err != nil {
+		return &NFSStatusError{NFSStatusInval, err}
+	}
+	fs, path, err := userHandle.FromHandle(ctx, roothandle)
+	if err != nil {
+		return &NFSStatusError{NFSStatusStale, err}
+	}
+
+	writer := bytes.NewBuffer([]byte{})
+	if err := xdr.Write(writer, uint32(NFSStatusOk)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := WritePostOpAttrs(writer, tryStat(ctx, fs, path)); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+
+	type fsinfores struct {
+		Rtmax       uint32
+		Rtpref      uint32
+		Rtmult      uint32
+		Wtmax       uint32
+		Wtpref      uint32
+		Wtmult      uint32
+		Dtpref      uint32
+		Maxfilesize uint64
+		TimeDelta   uint64
+		Properties  uint32
+	}
+
+	res := fsinfores{
+		Rtmax:       1 << 30,
+		Rtpref:      1 << 30,
+		Rtmult:      4096,
+		Wtmax:       1 << 30,
+		Wtpref:      1 << 30,
+		Wtmult:      4096,
+		Dtpref:      8192,
+		Maxfilesize: 1 << 62, // wild guess. this seems big.
+		TimeDelta:   1,       // nanosecond precision.
+		Properties:  0,
+	}
+
+	// TODO: these aren't great indications of support, really.
+	// if _, ok := fs.(billy.Symlink); ok {
+	// 	res.Properties |= FSInfoPropertyLink
+	// 	res.Properties |= FSInfoPropertySymlink
+	// }
+	// TODO: if the nfs share spans multiple virtual mounts, may need
+	// to support granular PATHINFO responses.
+	res.Properties |= FSInfoPropertyHomogeneous
+	// TODO: not a perfect indicator
+
+	if CapabilityCheck(fs, billy.WriteCapability) {
+		res.Properties |= FSInfoPropertyCanSetTime
+	}
+
+	// TODO: this whole struct should be specifiable by the userhandler.
+
+	if err := xdr.Write(writer, res); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	if err := w.Write(writer.Bytes()); err != nil {
+		return &NFSStatusError{NFSStatusServerFault, err}
+	}
+	return nil
+}