add grants to list-spaces (#2498)

When listing storage spaces we also want to have the spaces grants to be
able to show who has access to the space.

Co-authored-by: kobergj <jkoberg@owncloud.com>

changelog/unreleased/spaces-grants.md

@@ -0,0 +1,5 @@
+Enhancement: Include grants in list storage spaces response
+
+Added the grants to the response of list storage spaces. This allows service clients to show who has access to a space.
+
+https://github.com/cs3org/reva/pull/2498

pkg/storage/utils/decomposedfs/node/node.go

@@ -903,7 +903,7 @@ func (n *Node) ReadUserPermissions(ctx context.Context, u *userpb.User) (ap prov
 func (n *Node) ListGrantees(ctx context.Context) (grantees []string, err error) {
 	var attrs []string
 	if attrs, err = xattr.List(n.InternalPath()); err != nil {
-		appctx.GetLogger(ctx).Error().Err(err).Interface("node", n).Msg("error listing attributes")
+		appctx.GetLogger(ctx).Error().Err(err).Str("node", n.ID).Msg("error listing attributes")
 		return nil, err
 	}
 	for i := range attrs {
@@ -927,6 +927,30 @@ func (n *Node) ReadGrant(ctx context.Context, grantee string) (g *provider.Grant
 	return e.Grant(), nil
 }
 
+// ListGrants lists all grants of the current node.
+func (n *Node) ListGrants(ctx context.Context) ([]*provider.Grant, error) {
+	grantees, err := n.ListGrantees(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	grants := make([]*provider.Grant, 0, len(grantees))
+	for _, g := range grantees {
+		grant, err := n.ReadGrant(ctx, g)
+		if err != nil {
+			appctx.GetLogger(ctx).
+				Error().
+				Err(err).
+				Str("node", n.ID).
+				Str("grantee", g).
+				Msg("error reading grant")
+			continue
+		}
+		grants = append(grants, grant)
+	}
+	return grants, nil
+}
+
 // ReadBlobSizeAttr reads the blobsize from the xattrs
 func ReadBlobSizeAttr(path string) (int64, error) {
 	attrBytes, err := xattr.Get(path, xattrs.BlobsizeAttr)

pkg/storage/utils/decomposedfs/spaces.go

@@ -20,6 +20,7 @@ package decomposedfs
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"math"
 	"os"
@@ -478,6 +479,19 @@ func (fs *Decomposedfs) createStorageSpace(ctx context.Context, spaceType, space
 }
 
 func (fs *Decomposedfs) storageSpaceFromNode(ctx context.Context, n *node.Node, spaceType, nodePath string, canListAllSpaces bool) (*provider.StorageSpace, error) {
+	user := ctxpkg.ContextMustGetUser(ctx)
+	if !canListAllSpaces {
+		ok, err := node.NewPermissions(fs.lu).HasPermission(ctx, n, func(p *provider.ResourcePermissions) bool {
+			return p.Stat
+		})
+		if err != nil || !ok {
+			return nil, errtypes.PermissionDenied(fmt.Sprintf("user %s is not allowed to Stat the space %s", user.Username, n.SpaceRoot.ID))
+		}
+		if n.SpaceRoot != nil && strings.Contains(n.SpaceRoot.ID, node.TrashIDDelimiter) {
+			return nil, errtypes.PermissionDenied(fmt.Sprintf("user %s is not allowed to list deleted spaces %s", user.Username, n.SpaceRoot.ID))
+		}
+	}
+
 	owner, err := n.Owner()
 	if err != nil {
 		return nil, err
@@ -506,7 +520,39 @@ func (fs *Decomposedfs) storageSpaceFromNode(ctx context.Context, n *node.Node,
 
 	spaceType = filepath.Base(filepath.Dir(matches[0]))
 
+	grants, err := n.ListGrants(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	m := make(map[string]*provider.ResourcePermissions, len(grants))
+	for _, g := range grants {
+		var id string
+		switch g.Grantee.Type {
+		case provider.GranteeType_GRANTEE_TYPE_GROUP:
+			id = g.Grantee.GetGroupId().OpaqueId
+		case provider.GranteeType_GRANTEE_TYPE_USER:
+			id = g.Grantee.GetUserId().OpaqueId
+		default:
+			continue
+		}
+
+		m[id] = g.Permissions
+	}
+	marshalled, err := json.Marshal(m)
+	if err != nil {
+		return nil, err
+	}
+
 	space := &provider.StorageSpace{
+		Opaque: &types.Opaque{
+			Map: map[string]*types.OpaqueEntry{
+				"grants": {
+					Decoder: "json",
+					Value:   marshalled,
+				},
+			},
+		},
 		Id: &provider.StorageSpaceId{OpaqueId: n.SpaceRoot.ID},
 		Root: &provider.ResourceId{
 			StorageId: n.SpaceRoot.ID,
@@ -517,19 +563,6 @@ func (fs *Decomposedfs) storageSpaceFromNode(ctx context.Context, n *node.Node,
 		// Mtime is set either as node.tmtime or as fi.mtime below
 	}
 
-	user := ctxpkg.ContextMustGetUser(ctx)
-	if !canListAllSpaces {
-		ok, err := node.NewPermissions(fs.lu).HasPermission(ctx, n, func(p *provider.ResourcePermissions) bool {
-			return p.Stat
-		})
-		if err != nil || !ok {
-			return nil, errtypes.PermissionDenied(fmt.Sprintf("user %s is not allowed to Stat the space %+v", user.Username, space))
-		}
-		if strings.Contains(space.Root.OpaqueId, node.TrashIDDelimiter) {
-			return nil, errtypes.PermissionDenied(fmt.Sprintf("user %s is not allowed to list deleted spaces %+v", user.Username, space))
-		}
-	}
-
 	space.Owner = &userv1beta1.User{ // FIXME only return a UserID, not a full blown user object
 		Id: owner,
 	}