etcdserver: add cluster id check for hashKVHandler

backport https://github.com/etcd-io/etcd/pull/15924 to 3.4

Signed-off-by: Benjamin Wang <benjamin.ahrtr@gmail.com>

etcdserver/api/rafthttp/http.go

@@ -51,7 +51,7 @@ var (
 	RaftSnapshotPrefix = path.Join(RaftPrefix, "snapshot")
 
 	errIncompatibleVersion = errors.New("incompatible version")
-	errClusterIDMismatch   = errors.New("cluster ID mismatch")
+	ErrClusterIDMismatch   = errors.New("cluster ID mismatch")
 )
 
 type peerGetter interface {
@@ -558,7 +558,7 @@ func checkClusterCompatibilityFromHeader(lg *zap.Logger, localID types.ID, heade
 		} else {
 			plog.Errorf("request cluster ID mismatch (got %s want %s)", gcid, cid)
 		}
-		return errClusterIDMismatch
+		return ErrClusterIDMismatch
 	}
 	return nil
 }

etcdserver/api/rafthttp/stream.go

@@ -677,7 +677,7 @@ func (cr *streamReader) dial(t streamType) (io.ReadCloser, error) {
 			}
 			return nil, errIncompatibleVersion
 
-		case errClusterIDMismatch.Error():
+		case ErrClusterIDMismatch.Error():
 			if cr.lg != nil {
 				cr.lg.Warn(
 					"request sent was ignored by remote peer due to cluster ID mismatch",
@@ -685,13 +685,13 @@ func (cr *streamReader) dial(t streamType) (io.ReadCloser, error) {
 					zap.String("remote-peer-cluster-id", resp.Header.Get("X-Etcd-Cluster-ID")),
 					zap.String("local-member-id", cr.tr.ID.String()),
 					zap.String("local-member-cluster-id", cr.tr.ClusterID.String()),
-					zap.Error(errClusterIDMismatch),
+					zap.Error(ErrClusterIDMismatch),
 				)
 			} else {
 				plog.Errorf("request sent was ignored (cluster ID mismatch: peer[%s]=%s, local=%s)",
 					cr.peerID, resp.Header.Get("X-Etcd-Cluster-ID"), cr.tr.ClusterID)
 			}
-			return nil, errClusterIDMismatch
+			return nil, ErrClusterIDMismatch
 
 		default:
 			return nil, fmt.Errorf("unhandled error %q when precondition failed", string(b))

etcdserver/api/rafthttp/util.go

@@ -86,10 +86,10 @@ func checkPostResponse(resp *http.Response, body []byte, req *http.Request, to t
 		case errIncompatibleVersion.Error():
 			plog.Errorf("request sent was ignored by peer %s (server version incompatible)", to)
 			return errIncompatibleVersion
-		case errClusterIDMismatch.Error():
+		case ErrClusterIDMismatch.Error():
 			plog.Errorf("request sent was ignored (cluster ID mismatch: remote[%s]=%s, local=%s)",
 				to, resp.Header.Get("X-Etcd-Cluster-ID"), req.Header.Get("X-Etcd-Cluster-ID"))
-			return errClusterIDMismatch
+			return ErrClusterIDMismatch
 		default:
 			return fmt.Errorf("unhandled error %q when precondition failed", string(body))
 		}

etcdserver/api/v3rpc/rpctypes/error.go

@@ -45,6 +45,7 @@ var (
 	ErrGRPCMemberNotLearner       = status.New(codes.FailedPrecondition, "etcdserver: can only promote a learner member").Err()
 	ErrGRPCLearnerNotReady        = status.New(codes.FailedPrecondition, "etcdserver: can only promote a learner member which is in sync with leader").Err()
 	ErrGRPCTooManyLearners        = status.New(codes.FailedPrecondition, "etcdserver: too many learner members in cluster").Err()
+	ErrGRPCClusterIdMismatch      = status.New(codes.FailedPrecondition, "etcdserver: cluster ID mismatch").Err()
 
 	ErrGRPCRequestTooLarge        = status.New(codes.InvalidArgument, "etcdserver: request is too large").Err()
 	ErrGRPCRequestTooManyRequests = status.New(codes.ResourceExhausted, "etcdserver: too many requests").Err()
@@ -105,6 +106,7 @@ var (
 		ErrorDesc(ErrGRPCMemberNotLearner):       ErrGRPCMemberNotLearner,
 		ErrorDesc(ErrGRPCLearnerNotReady):        ErrGRPCLearnerNotReady,
 		ErrorDesc(ErrGRPCTooManyLearners):        ErrGRPCTooManyLearners,
+		ErrorDesc(ErrGRPCClusterIdMismatch):      ErrGRPCClusterIdMismatch,
 
 		ErrorDesc(ErrGRPCRequestTooLarge):        ErrGRPCRequestTooLarge,
 		ErrorDesc(ErrGRPCRequestTooManyRequests): ErrGRPCRequestTooManyRequests,
@@ -186,6 +188,7 @@ var (
 	ErrInvalidAuthToken     = Error(ErrGRPCInvalidAuthToken)
 	ErrAuthOldRevision      = Error(ErrGRPCAuthOldRevision)
 	ErrInvalidAuthMgmt      = Error(ErrGRPCInvalidAuthMgmt)
+	ErrClusterIdMismatch    = Error(ErrGRPCClusterIdMismatch)
 
 	ErrNoLeader                   = Error(ErrGRPCNoLeader)
 	ErrNotLeader                  = Error(ErrGRPCNotLeader)

etcdserver/corrupt.go

@@ -24,6 +24,7 @@ import (
 	"strings"
 	"time"
 
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 	"go.etcd.io/etcd/mvcc"
@@ -126,6 +127,19 @@ func (s *EtcdServer) CheckInitialHashKV() error {
 				} else {
 					plog.Warningf("%s cannot check the hash of peer(%q) at revision %d: local node is lagging behind(%q)", s.ID(), p.eps, rev, p.err.Error())
 				}
+			case rpctypes.ErrClusterIdMismatch:
+				if lg != nil {
+					lg.Warn(
+						"cluster ID mismatch",
+						zap.String("local-member-id", s.ID().String()),
+						zap.Int64("local-member-revision", rev),
+						zap.Int64("local-member-compact-revision", crev),
+						zap.Uint32("local-member-hash", h),
+						zap.String("remote-peer-id", p.id.String()),
+						zap.Strings("remote-peer-endpoints", p.eps),
+						zap.Error(err),
+					)
+				}
 			}
 		}
 	}
@@ -353,7 +367,7 @@ func (s *EtcdServer) getPeerHashKVs(rev int64) []*peerHashKVResp {
 			ctx, cancel := context.WithTimeout(context.Background(), s.Cfg.ReqTimeout())
 
 			var resp *pb.HashKVResponse
-			resp, lastErr = s.getPeerHashKVHTTP(ctx, ep, rev)
+			resp, lastErr = s.getPeerHashKVHTTP(ctx, s.cluster.ID(), ep, rev)
 			cancel()
 			if lastErr == nil {
 				resps = append(resps, &peerHashKVResp{peerInfo: p, resp: resp, err: nil})
@@ -440,6 +454,10 @@ func (h *hashKVHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "bad path", http.StatusBadRequest)
 		return
 	}
+	if gcid := r.Header.Get("X-Etcd-Cluster-ID"); gcid != "" && gcid != h.server.cluster.ID().String() {
+		http.Error(w, rafthttp.ErrClusterIDMismatch.Error(), http.StatusPreconditionFailed)
+		return
+	}
 
 	defer r.Body.Close()
 	b, err := ioutil.ReadAll(r.Body)
@@ -478,7 +496,7 @@ func (h *hashKVHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 // getPeerHashKVHTTP fetch hash of kv store at the given rev via http call to the given url
-func (s *EtcdServer) getPeerHashKVHTTP(ctx context.Context, url string, rev int64) (*pb.HashKVResponse, error) {
+func (s *EtcdServer) getPeerHashKVHTTP(ctx context.Context, cid types.ID, url string, rev int64) (*pb.HashKVResponse, error) {
 	cc := &http.Client{Transport: s.peerRt}
 	hashReq := &pb.HashKVRequest{Revision: rev}
 	hashReqBytes, err := json.Marshal(hashReq)
@@ -492,6 +510,7 @@ func (s *EtcdServer) getPeerHashKVHTTP(ctx context.Context, url string, rev int6
 	}
 	req = req.WithContext(ctx)
 	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Etcd-Cluster-ID", cid.String())
 	req.Cancel = ctx.Done()
 
 	resp, err := cc.Do(req)
@@ -511,6 +530,10 @@ func (s *EtcdServer) getPeerHashKVHTTP(ctx context.Context, url string, rev int6
 		if strings.Contains(string(b), mvcc.ErrFutureRev.Error()) {
 			return nil, rpctypes.ErrFutureRev
 		}
+	} else if resp.StatusCode == http.StatusPreconditionFailed {
+		if strings.Contains(string(b), rafthttp.ErrClusterIDMismatch.Error()) {
+			return nil, rpctypes.ErrClusterIdMismatch
+		}
 	}
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("unknown error: %s", string(b))

etcdserver/corrupt_test.go

@@ -0,0 +1,122 @@
+// Copyright 2023 The etcd Authors
+//
+// 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.
+
+package etcdserver
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+	betesting "go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/types"
+)
+
+func TestHashKVHandler(t *testing.T) {
+	var remoteClusterID = 111195
+	var localClusterID = 111196
+	var revision = 1
+
+	etcdSrv := &EtcdServer{}
+	etcdSrv.cluster = newTestCluster(nil)
+	etcdSrv.cluster.SetID(types.ID(localClusterID), types.ID(localClusterID))
+	be, _ := betesting.NewDefaultTmpBackend()
+	defer func() {
+		assert.NoError(t, be.Close())
+	}()
+	etcdSrv.kv = mvcc.New(zap.NewNop(), be, &lease.FakeLessor{}, nil, nil, mvcc.StoreConfig{})
+	ph := &hashKVHandler{
+		lg:     zap.NewNop(),
+		server: etcdSrv,
+	}
+	srv := httptest.NewServer(ph)
+	defer srv.Close()
+
+	tests := []struct {
+		name            string
+		remoteClusterID int
+		wcode           int
+		wKeyWords       string
+	}{
+		{
+			name:            "HashKV returns 200 if cluster hash matches",
+			remoteClusterID: localClusterID,
+			wcode:           http.StatusOK,
+			wKeyWords:       "",
+		},
+		{
+			name:            "HashKV returns 400 if cluster hash doesn't matche",
+			remoteClusterID: remoteClusterID,
+			wcode:           http.StatusPreconditionFailed,
+			wKeyWords:       "cluster ID mismatch",
+		},
+	}
+	for i, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			hashReq := &pb.HashKVRequest{Revision: int64(revision)}
+			hashReqBytes, err := json.Marshal(hashReq)
+			if err != nil {
+				t.Fatalf("failed to marshal request: %v", err)
+			}
+			req, err := http.NewRequest(http.MethodGet, srv.URL+PeerHashKVPath, bytes.NewReader(hashReqBytes))
+			if err != nil {
+				t.Fatalf("failed to create request: %v", err)
+			}
+			req.Header.Set("X-Etcd-Cluster-ID", strconv.FormatUint(uint64(tt.remoteClusterID), 16))
+
+			resp, err := http.DefaultClient.Do(req)
+			if err != nil {
+				t.Fatalf("failed to get http response: %v", err)
+			}
+			body, err := io.ReadAll(resp.Body)
+			resp.Body.Close()
+			if err != nil {
+				t.Fatalf("unexpected io.ReadAll error: %v", err)
+			}
+			if resp.StatusCode != tt.wcode {
+				t.Fatalf("#%d: code = %d, want %d", i, resp.StatusCode, tt.wcode)
+			}
+			if resp.StatusCode != http.StatusOK {
+				if !strings.Contains(string(body), tt.wKeyWords) {
+					t.Errorf("#%d: body: %s, want body to contain keywords: %s", i, string(body), tt.wKeyWords)
+				}
+				return
+			}
+
+			hashKVResponse := pb.HashKVResponse{}
+			err = json.Unmarshal(body, &hashKVResponse)
+			if err != nil {
+				t.Fatalf("unmarshal response error: %v", err)
+			}
+			hashValue, _, _, err := etcdSrv.KV().HashByRev(int64(revision))
+			if err != nil {
+				t.Fatalf("etcd server hash failed: %v", err)
+			}
+			if hashKVResponse.Hash != hashValue {
+				t.Fatalf("hash value inconsistent: %d != %d", hashKVResponse.Hash, hashValue)
+			}
+		})
+	}
+}