Add Owner to MountOptions to override returned uid/gid.

fuse/api.go

@@ -90,6 +90,10 @@ type FileSystemOptions struct {
 	EntryTimeout    float64
 	AttrTimeout     float64
 	NegativeTimeout float64
+
+	// If set, replace all uids with given UID.  NewFileSystemOptions() will set
+	// this to the daemon's uid/gid.
+	*Owner
 }
 
 type MountOptions struct {
@@ -102,7 +106,7 @@ type DefaultFileSystem struct{}
 // DefaultFile returns ENOSYS for every operation.
 type DefaultFile struct{}
 
-// RawFileSystem is an interface closer to the FUSE wire protocol. 
+// RawFileSystem is an interface closer to the FUSE wire protocol.
 //
 // Unless you really know what you are doing, you should not implement
 // this, but rather the FileSystem interface; the details of getting

fuse/owner_test.go

+package fuse
+
+import (
+	"os"
+	"testing"
+)
+
+
+type ownerFs struct {
+	DefaultFileSystem
+}
+
+const _RANDOM_OWNER = 31415265
+
+func (me *ownerFs) GetAttr(name string) (*os.FileInfo, Status) {
+	if name == "" {
+		return &os.FileInfo{
+			Mode: S_IFDIR | 0755,
+		}, OK
+	}
+	return &os.FileInfo{
+		Mode: S_IFREG | 0644,
+		Uid: _RANDOM_OWNER,
+		Gid: _RANDOM_OWNER,
+	}, OK
+}
+
+func setupOwnerTest(opts *FileSystemOptions) (workdir string, cleanup func()) {
+	wd := MakeTempDir()
+
+	fs := &ownerFs{}
+	state, _, err := MountFileSystem(wd, fs, opts)
+	CheckSuccess(err)
+	go state.Loop(false)
+	return wd, func() {
+		state.Unmount()
+		os.RemoveAll(wd)
+	}
+}
+
+func TestOwnerDefault(t *testing.T) {
+	wd, cleanup := setupOwnerTest(NewFileSystemOptions())
+	defer cleanup()
+	fi, err := os.Lstat(wd + "/foo")
+	CheckSuccess(err)
+
+	if fi.Uid != os.Getuid() || fi.Gid != os.Getgid() {
+		t.Fatal("Should use current uid for mount", fi.Uid, fi.Gid)
+	}
+}
+
+func TestOwnerRoot(t *testing.T) {
+	wd, cleanup := setupOwnerTest(&FileSystemOptions{})
+	defer cleanup()
+	fi, err := os.Lstat(wd + "/foo")
+	CheckSuccess(err)
+
+	if fi.Uid != _RANDOM_OWNER || fi.Gid != _RANDOM_OWNER {
+		t.Fatal("Should use FS owner uid", fi.Uid, fi.Gid)
+	}
+}
+
+func TestOwnerOverride(t *testing.T) {
+	wd, cleanup := setupOwnerTest(&FileSystemOptions{Owner: &Owner{42, 43}})
+	defer cleanup()
+	fi, err := os.Lstat(wd + "/foo")
+	CheckSuccess(err)
+
+	if fi.Uid != 42 || fi.Gid != 43 {
+		t.Fatal("Should use current uid for mount", fi.Uid, fi.Gid)
+	}
+}
+

fuse/pathdebug.go

@@ -44,7 +44,6 @@ func (me *FileSystemDebug) Add(name string, callback getter) {
 }
 
 func (me *FileSystemDebug) Open(path string, flags uint32) (fuseFile File, status Status) {
-
 	content := me.getContent(path)
 	if content != nil {
 		return NewReadOnlyFile(content), OK

fuse/pathfilesystem.go

@@ -21,6 +21,7 @@ package fuse
 import (
 	"fmt"
 	"log"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -53,6 +54,13 @@ func newMount(fs FileSystem) *mountData {
 	return &mountData{fs: fs}
 }
 
+func (me *mountData) setOwner(attr *Attr) {
+	if me.options.Owner != nil {
+		attr.Owner = *me.options.Owner
+	}
+}
+
+
 // Tests should set to true.
 var paranoia = false
 
@@ -165,11 +173,19 @@ func (me *inode) setParent(newParent *inode) {
 	}
 }
 
+func CurrentOwner() *Owner {
+	return &Owner{
+	Uid: uint32(os.Getuid()),
+	Gid: uint32(os.Getgid()),
+	}
+}
+
 func NewFileSystemOptions() *FileSystemOptions {
 	return &FileSystemOptions{
 		NegativeTimeout: 0.0,
 		AttrTimeout:     1.0,
 		EntryTimeout:    1.0,
+		Owner: CurrentOwner(),
 	}
 }
 

fuse/pathops.go

@@ -72,9 +72,11 @@ func (me *FileSystemConnector) internalLookupWithNode(parent *inode, name string
 	SplitNs(mount.options.AttrTimeout, &out.AttrValid, &out.AttrValidNsec)
 	CopyFileInfo(fi, &out.Attr)
 	out.Attr.Ino = data.NodeId
+	mount.setOwner(&out.Attr)
 	return out, OK, data
 }
 
+
 func (me *FileSystemConnector) Forget(h *InHeader, input *ForgetIn) {
 	me.forgetUpdate(h.NodeId, int(input.Nlookup))
 }
@@ -110,8 +112,8 @@ func (me *FileSystemConnector) GetAttr(header *InHeader, input *GetAttrIn) (out
 	out = &AttrOut{}
 	CopyFileInfo(fi, &out.Attr)
 	out.Attr.Ino = header.NodeId
+	mount.setOwner(&out.Attr)
 	SplitNs(mount.options.AttrTimeout, &out.AttrValid, &out.AttrValidNsec)
-
 	return out, OK
 }