Add read-only interceptor to use on storage providers

changelog/unreleased/read-only-storageprovider-interceptor.md

@@ -0,0 +1,5 @@
+Enhancement: Add readonly interceptor
+
+The readonly interceptor could be used to configure a storageprovider in readonly mode. This could be handy in some migration scenarios.
+
+https://github.com/cs3org/reva/pull/1849

internal/grpc/interceptors/loader/loader.go

@@ -18,4 +18,8 @@
 
 package loader
 
-// Add your own.
+import (
+	// Load core GRPC services
+	_ "github.com/cs3org/reva/internal/grpc/interceptors/readonly"
+	// Add your own service here
+)

internal/grpc/interceptors/readonly/readonly.go

@@ -0,0 +1,146 @@
+// Copyright 2018-2021 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package readonly
+
+import (
+	"context"
+
+	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
+	registry "github.com/cs3org/go-cs3apis/cs3/storage/registry/v1beta1"
+	"github.com/cs3org/reva/pkg/appctx"
+	"github.com/cs3org/reva/pkg/rgrpc"
+	rstatus "github.com/cs3org/reva/pkg/rgrpc/status"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+const (
+	defaultPriority = 200
+)
+
+func init() {
+	rgrpc.RegisterUnaryInterceptor("readonly", NewUnary)
+}
+
+// NewUnary returns a new unary interceptor
+// that checks grpc calls and blocks write requests.
+func NewUnary(map[string]interface{}) (grpc.UnaryServerInterceptor, int, error) {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		log := appctx.GetLogger(ctx)
+
+		switch req.(type) {
+		// handle known non-write request types
+		case *provider.GetHomeRequest,
+			*provider.GetPathRequest,
+			*provider.GetQuotaRequest,
+			*registry.GetStorageProvidersRequest,
+			*provider.InitiateFileDownloadRequest,
+			*provider.ListFileVersionsRequest,
+			*provider.ListGrantsRequest,
+			*provider.ListRecycleRequest:
+			return handler(ctx, req)
+		case *provider.ListContainerRequest:
+			resp, err := handler(ctx, req)
+			if listResp, ok := resp.(*provider.ListContainerResponse); ok && listResp.Infos != nil {
+				for _, info := range listResp.Infos {
+					// use the existing PermissionsSet and change the writes to false
+					if info.PermissionSet != nil {
+						info.PermissionSet.AddGrant = false
+						info.PermissionSet.CreateContainer = false
+						info.PermissionSet.Delete = false
+						info.PermissionSet.InitiateFileUpload = false
+						info.PermissionSet.Move = false
+						info.PermissionSet.RemoveGrant = false
+						info.PermissionSet.PurgeRecycle = false
+						info.PermissionSet.RestoreFileVersion = false
+						info.PermissionSet.RestoreRecycleItem = false
+						info.PermissionSet.UpdateGrant = false
+					}
+				}
+			}
+			return resp, err
+		case *provider.StatRequest:
+			resp, err := handler(ctx, req)
+			if statResp, ok := resp.(*provider.StatResponse); ok && statResp.Info != nil && statResp.Info.PermissionSet != nil {
+				// use the existing PermissionsSet and change the writes to false
+				statResp.Info.PermissionSet.AddGrant = false
+				statResp.Info.PermissionSet.CreateContainer = false
+				statResp.Info.PermissionSet.Delete = false
+				statResp.Info.PermissionSet.InitiateFileUpload = false
+				statResp.Info.PermissionSet.Move = false
+				statResp.Info.PermissionSet.RemoveGrant = false
+				statResp.Info.PermissionSet.PurgeRecycle = false
+				statResp.Info.PermissionSet.RestoreFileVersion = false
+				statResp.Info.PermissionSet.RestoreRecycleItem = false
+				statResp.Info.PermissionSet.UpdateGrant = false
+			}
+			return resp, err
+		// Don't allow the following requests types
+		case *provider.AddGrantRequest:
+			return &provider.AddGrantResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to add grant on readonly storage"),
+			}, nil
+		case *provider.CreateContainerRequest:
+			return &provider.CreateContainerResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to create resoure on readonly storage"),
+			}, nil
+		case *provider.CreateHomeRequest:
+			return &provider.CreateHomeResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to create home on readonly storage"),
+			}, nil
+		case *provider.DeleteRequest:
+			return &provider.DeleteResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to delete resource on readonly storage"),
+			}, nil
+		case *provider.InitiateFileUploadRequest:
+			return &provider.InitiateFileUploadResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to upload resource on readonly storage"),
+			}, nil
+		case *provider.MoveRequest:
+			return &provider.MoveResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to move resource on readonly storage"),
+			}, nil
+		case *provider.PurgeRecycleRequest:
+			return &provider.PurgeRecycleResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to purge recycle on readonly storage"),
+			}, nil
+		case *provider.RemoveGrantRequest:
+			return &provider.RemoveGrantResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to remove grant on readonly storage"),
+			}, nil
+		case *provider.RestoreRecycleItemRequest:
+			return &provider.RestoreRecycleItemResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to restore recycle item on readonly storage"),
+			}, nil
+		case *provider.SetArbitraryMetadataRequest:
+			return &provider.SetArbitraryMetadataResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to set arbitrary metadata on readonly storage"),
+			}, nil
+		case *provider.UnsetArbitraryMetadataRequest:
+			return &provider.UnsetArbitraryMetadataResponse{
+				Status: rstatus.NewPermissionDenied(ctx, nil, "permission denied: tried to unset arbitrary metadata on readonly storage"),
+			}, nil
+		// block unknown request types and return error
+		default:
+			log.Debug().Msg("storage is readonly")
+			return nil, status.Errorf(codes.PermissionDenied, "permission denied: tried to execute an unknown operation: %T!", req)
+		}
+	}, defaultPriority, nil
+}

internal/http/services/owncloud/ocdav/copy.go

@@ -65,11 +65,23 @@ func (s *svc) handleCopy(w http.ResponseWriter, r *http.Request, ns string) {
 
 	if overwrite != "T" && overwrite != "F" {
 		w.WriteHeader(http.StatusBadRequest)
+		m := fmt.Sprintf("Overwrite header is set to incorrect value %v", overwrite)
+		b, err := Marshal(exception{
+			code:    SabredavBadRequest,
+			message: m,
+		})
+		HandleWebdavError(&sublog, w, b, err)
 		return
 	}
 
 	if depth != "infinity" && depth != "0" {
 		w.WriteHeader(http.StatusBadRequest)
+		m := fmt.Sprintf("Depth header is set to incorrect value %v", depth)
+		b, err := Marshal(exception{
+			code:    SabredavBadRequest,
+			message: m,
+		})
+		HandleWebdavError(&sublog, w, b, err)
 		return
 	}
 
@@ -91,6 +103,15 @@ func (s *svc) handleCopy(w http.ResponseWriter, r *http.Request, ns string) {
 	}
 
 	if srcStatRes.Status.Code != rpc.Code_CODE_OK {
+		if srcStatRes.Status.Code == rpc.Code_CODE_NOT_FOUND {
+			w.WriteHeader(http.StatusNotFound)
+			m := fmt.Sprintf("Resource %v not found", srcStatReq.Ref.Path)
+			b, err := Marshal(exception{
+				code:    SabredavNotFound,
+				message: m,
+			})
+			HandleWebdavError(&sublog, w, b, err)
+		}
 		HandleErrorStatus(&sublog, w, srcStatRes.Status)
 		return
 	}
@@ -115,7 +136,13 @@ func (s *svc) handleCopy(w http.ResponseWriter, r *http.Request, ns string) {
 
 		if overwrite == "F" {
 			sublog.Warn().Str("overwrite", overwrite).Msg("dst already exists")
-			w.WriteHeader(http.StatusPreconditionFailed) // 412, see https://tools.ietf.org/html/rfc4918#section-9.8.5
+			w.WriteHeader(http.StatusPreconditionFailed)
+			m := fmt.Sprintf("Could not overwrite Resource %v", dst)
+			b, err := Marshal(exception{
+				code:    SabredavPreconditionFailed,
+				message: m,
+			})
+			HandleWebdavError(&sublog, w, b, err) // 412, see https://tools.ietf.org/html/rfc4918#section-9.8.5
 			return
 		}
 
@@ -143,7 +170,7 @@ func (s *svc) handleCopy(w http.ResponseWriter, r *http.Request, ns string) {
 		// TODO what if intermediate is a file?
 	}
 
-	err = s.descend(ctx, client, srcStatRes.Info, dst, depth == "infinity")
+	err = s.descend(ctx, w, client, srcStatRes.Info, dst, depth == "infinity")
 	if err != nil {
 		sublog.Error().Err(err).Str("depth", depth).Msg("error descending directory")
 		w.WriteHeader(http.StatusInternalServerError)
@@ -152,7 +179,7 @@ func (s *svc) handleCopy(w http.ResponseWriter, r *http.Request, ns string) {
 	w.WriteHeader(successCode)
 }
 
-func (s *svc) descend(ctx context.Context, client gateway.GatewayAPIClient, src *provider.ResourceInfo, dst string, recurse bool) error {
+func (s *svc) descend(ctx context.Context, w http.ResponseWriter, client gateway.GatewayAPIClient, src *provider.ResourceInfo, dst string, recurse bool) error {
 	log := appctx.GetLogger(ctx)
 	log.Debug().Str("src", src.Path).Str("dst", dst).Msg("descending")
 	if src.Type == provider.ResourceType_RESOURCE_TYPE_CONTAINER {
@@ -161,10 +188,25 @@ func (s *svc) descend(ctx context.Context, client gateway.GatewayAPIClient, src
 			Ref: &provider.Reference{Path: dst},
 		}
 		createRes, err := client.CreateContainer(ctx, createReq)
-		if err != nil || createRes.Status.Code != rpc.Code_CODE_OK {
+		if err != nil {
+			log.Error().Err(err).Msg("error performing create container grpc request")
+			w.WriteHeader(http.StatusInternalServerError)
 			return err
 		}
 
+		if createRes.Status.Code != rpc.Code_CODE_OK {
+			if createRes.Status.Code == rpc.Code_CODE_PERMISSION_DENIED {
+				w.WriteHeader(http.StatusForbidden)
+				m := fmt.Sprintf("Permission denied to create %v", createReq.Ref.Path)
+				b, err := Marshal(exception{
+					code:    SabredavPermissionDenied,
+					message: m,
+				})
+				HandleWebdavError(log, w, b, err)
+			}
+			return nil
+		}
+
 		// TODO: also copy properties: https://tools.ietf.org/html/rfc4918#section-9.8.2
 
 		if !recurse {
@@ -185,7 +227,7 @@ func (s *svc) descend(ctx context.Context, client gateway.GatewayAPIClient, src
 
 		for i := range res.Infos {
 			childDst := path.Join(dst, path.Base(res.Infos[i].Path))
-			err := s.descend(ctx, client, res.Infos[i], childDst, recurse)
+			err := s.descend(ctx, w, client, res.Infos[i], childDst, recurse)
 			if err != nil {
 				return err
 			}
@@ -237,7 +279,17 @@ func (s *svc) descend(ctx context.Context, client gateway.GatewayAPIClient, src
 		}
 
 		if uRes.Status.Code != rpc.Code_CODE_OK {
-			return fmt.Errorf("status code %d", uRes.Status.Code)
+			if uRes.Status.Code == rpc.Code_CODE_PERMISSION_DENIED {
+				w.WriteHeader(http.StatusForbidden)
+				m := fmt.Sprintf("Permission denied to create %v", uReq.Ref.Path)
+				b, err := Marshal(exception{
+					code:    SabredavPermissionDenied,
+					message: m,
+				})
+				HandleWebdavError(log, w, b, err)
+			}
+			HandleErrorStatus(log, w, uRes.Status)
+			return nil
 		}
 
 		var uploadEP, uploadToken string

internal/http/services/owncloud/ocdav/delete.go

@@ -19,6 +19,7 @@
 package ocdav
 
 import (
+	"fmt"
 	"net/http"
 	"path"
 
@@ -54,6 +55,32 @@ func (s *svc) handleDelete(w http.ResponseWriter, r *http.Request, ns string) {
 	}
 
 	if res.Status.Code != rpc.Code_CODE_OK {
+		if res.Status.Code == rpc.Code_CODE_NOT_FOUND {
+			w.WriteHeader(http.StatusNotFound)
+			m := fmt.Sprintf("Resource %v not found", fn)
+			b, err := Marshal(exception{
+				code:    SabredavNotFound,
+				message: m,
+			})
+			HandleWebdavError(&sublog, w, b, err)
+		}
+		if res.Status.Code == rpc.Code_CODE_PERMISSION_DENIED {
+			w.WriteHeader(http.StatusForbidden)
+			m := fmt.Sprintf("Permission denied to delete %v", fn)
+			b, err := Marshal(exception{
+				code:    SabredavPermissionDenied,
+				message: m,
+			})
+			HandleWebdavError(&sublog, w, b, err)
+		}
+		if res.Status.Code == rpc.Code_CODE_INTERNAL && res.Status.Message == "can't delete mount path" {
+			w.WriteHeader(http.StatusForbidden)
+			b, err := Marshal(exception{
+				code:    SabredavPermissionDenied,
+				message: res.Status.Message,
+			})
+			HandleWebdavError(&sublog, w, b, err)
+		}
 		HandleErrorStatus(&sublog, w, res.Status)
 		return
 	}

internal/http/services/owncloud/ocdav/error.go

@@ -39,6 +39,10 @@ const (
 	SabredavNotAuthenticated
 	// SabredavPreconditionFailed maps to HTTP 412
 	SabredavPreconditionFailed
+	// SabredavPermissionDenied maps to HTTP 403
+	SabredavPermissionDenied
+	// SabredavNotFound maps to HTTP 404
+	SabredavNotFound
 )
 
 var (
@@ -47,6 +51,8 @@ var (
 		"Sabre\\DAV\\Exception\\MethodNotAllowed",
 		"Sabre\\DAV\\Exception\\NotAuthenticated",
 		"Sabre\\DAV\\Exception\\PreconditionFailed",
+		"Sabre\\DAV\\Exception\\PermissionDenied",
+		"Sabre\\DAV\\Exception\\NotFound",
 	}
 )
 
@@ -79,7 +85,8 @@ type errorXML struct {
 	Exception string   `xml:"s:exception"`
 	Message   string   `xml:"s:message"`
 	InnerXML  []byte   `xml:",innerxml"`
-	Header    string   `xml:"s:header"`
+	// Header is used to indicate the conflicting request header
+	Header string `xml:"s:header,omitempty"`
 }
 
 var errInvalidPropfind = errors.New("webdav: invalid propfind")
@@ -111,3 +118,17 @@ func HandleErrorStatus(log *zerolog.Logger, w http.ResponseWriter, s *rpc.Status
 		w.WriteHeader(http.StatusInternalServerError)
 	}
 }
+
+// HandleWebdavError checks the status code, logs an error and creates a webdav response body
+// if needed
+func HandleWebdavError(log *zerolog.Logger, w http.ResponseWriter, b []byte, err error) {
+	if err != nil {
+		log.Error().Msgf("error marshaling xml response: %s", b)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	_, err = w.Write(b)
+	if err != nil {
+		log.Err(err).Msg("error writing response")
+	}
+}