feat(backend): support federation-based remote node diagnosis

Route diagnosis for shared remote nodes through federation runtime APIs so tunnel and forward diagnostics work across panels, and add contract coverage for single-panel and dual-panel scenarios.

go-backend/internal/http/client/federation.go

@@ -69,6 +69,13 @@ type RuntimeReleaseRoleRequest struct {
 	ResourceKey   string `json:"resourceKey"`
 }
 
+type RuntimeDiagnoseRequest struct {
+	IP      string `json:"ip"`
+	Port    int    `json:"port"`
+	Count   int    `json:"count"`
+	Timeout int    `json:"timeout"`
+}
+
 func NewFederationClient() *FederationClient {
 	return &FederationClient{
 		client: &http.Client{
@@ -274,3 +281,46 @@ func (c *FederationClient) ReleaseRole(url, token, localDomain string, reqData R
 
 	return nil
 }
+
+func (c *FederationClient) Diagnose(url, token, localDomain string, reqData RuntimeDiagnoseRequest) (map[string]interface{}, error) {
+	url = strings.TrimSuffix(url, "/")
+	bodyBytes, _ := json.Marshal(reqData)
+	req, err := http.NewRequest("POST", url+"/api/v1/federation/runtime/diagnose", strings.NewReader(string(bodyBytes)))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	if localDomain != "" {
+		req.Header.Set("X-Panel-Domain", localDomain)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("remote error %d: %s", resp.StatusCode, string(body))
+	}
+
+	var res struct {
+		Code int                    `json:"code"`
+		Msg  string                 `json:"msg"`
+		Data map[string]interface{} `json:"data"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return nil, err
+	}
+	if res.Code != 0 {
+		return nil, fmt.Errorf("remote api error: %s", res.Msg)
+	}
+
+	if res.Data == nil {
+		return nil, fmt.Errorf("remote api error: empty diagnosis payload")
+	}
+
+	return res.Data, nil
+}

go-backend/internal/http/handler/control_plane.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"go-backend/internal/http/client"
 	"go-backend/internal/ws"
 )
 
@@ -791,7 +792,15 @@ func (h *Handler) appendPathDiagnosis(results *[]map[string]interface{}, nodeCac
 	}
 	item["nodeName"] = fromNode.Name
 
-	pingData, pingErr := h.tcpPingViaNode(fromNodeID, targetIP, targetPort)
+	var (
+		pingData map[string]interface{}
+		pingErr  error
+	)
+	if fromNode.IsRemote == 1 {
+		pingData, pingErr = h.tcpPingViaRemoteNode(fromNode, targetIP, targetPort)
+	} else {
+		pingData, pingErr = h.tcpPingViaNode(fromNodeID, targetIP, targetPort)
+	}
 	if pingErr != nil {
 		item["success"] = false
 		item["message"] = pingErr.Error()
@@ -931,6 +940,25 @@ func (h *Handler) tcpPingViaNode(nodeID int64, ip string, port int) (map[string]
 	return res.Data, nil
 }
 
+func (h *Handler) tcpPingViaRemoteNode(node *nodeRecord, ip string, port int) (map[string]interface{}, error) {
+	if node == nil {
+		return nil, errors.New("节点不存在")
+	}
+	remoteURL := strings.TrimSpace(node.RemoteURL)
+	remoteToken := strings.TrimSpace(node.RemoteToken)
+	if remoteURL == "" || remoteToken == "" {
+		return nil, errors.New("远程节点缺少共享配置")
+	}
+
+	fc := client.NewFederationClient()
+	return fc.Diagnose(remoteURL, remoteToken, h.federationLocalDomain(), client.RuntimeDiagnoseRequest{
+		IP:      strings.TrimSpace(ip),
+		Port:    port,
+		Count:   4,
+		Timeout: 5000,
+	})
+}
+
 func splitRemoteTargets(remoteAddr string) []string {
 	parts := strings.Split(remoteAddr, ",")
 	out := make([]string, 0, len(parts))

go-backend/internal/http/handler/federation.go

@@ -65,6 +65,13 @@ type federationRuntimeReleaseRoleRequest struct {
 	ResourceKey   string `json:"resourceKey"`
 }
 
+type federationRuntimeDiagnoseRequest struct {
+	IP      string `json:"ip"`
+	Port    int    `json:"port"`
+	Count   int    `json:"count"`
+	Timeout int    `json:"timeout"`
+}
+
 func (h *Handler) federationShareList(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
 		response.WriteJSON(w, response.ErrDefault("Invalid method"))
@@ -731,6 +738,55 @@ func (h *Handler) federationRuntimeReleaseRole(w http.ResponseWriter, r *http.Re
 	response.WriteJSON(w, response.OKEmpty())
 }
 
+func (h *Handler) federationRuntimeDiagnose(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		response.WriteJSON(w, response.ErrDefault("Invalid method"))
+		return
+	}
+
+	token := extractBearerToken(r)
+	share, err := h.repo.GetPeerShareByToken(token)
+	if err != nil || share == nil {
+		response.WriteJSON(w, response.Err(401, "Unauthorized"))
+		return
+	}
+
+	var req federationRuntimeDiagnoseRequest
+	if err := decodeJSON(r.Body, &req); err != nil {
+		response.WriteJSON(w, response.ErrDefault("Invalid JSON"))
+		return
+	}
+
+	req.IP = strings.TrimSpace(req.IP)
+	if req.IP == "" || req.Port <= 0 || req.Port > 65535 {
+		response.WriteJSON(w, response.ErrDefault("Invalid target"))
+		return
+	}
+	if req.Count <= 0 {
+		req.Count = 4
+	}
+	if req.Timeout <= 0 {
+		req.Timeout = 5000
+	}
+
+	res, err := h.sendNodeCommand(share.NodeID, "TcpPing", map[string]interface{}{
+		"ip":      req.IP,
+		"port":    req.Port,
+		"count":   req.Count,
+		"timeout": req.Timeout,
+	}, false, false)
+	if err != nil {
+		response.WriteJSON(w, response.ErrDefault(err.Error()))
+		return
+	}
+	if res.Data == nil {
+		response.WriteJSON(w, response.ErrDefault("Node did not return diagnosis data"))
+		return
+	}
+
+	response.WriteJSON(w, response.OK(res.Data))
+}
+
 func (h *Handler) pickPeerSharePort(share *sqlite.PeerShare, requestedPort int) (int, error) {
 	if share == nil {
 		return 0, fmt.Errorf("share not found")

go-backend/internal/http/handler/handler.go

@@ -161,6 +161,7 @@ func (h *Handler) Register(mux *http.ServeMux) {
 	mux.HandleFunc("/api/v1/federation/runtime/reserve-port", h.authPeer(h.federationRuntimeReservePort))
 	mux.HandleFunc("/api/v1/federation/runtime/apply-role", h.authPeer(h.federationRuntimeApplyRole))
 	mux.HandleFunc("/api/v1/federation/runtime/release-role", h.authPeer(h.federationRuntimeReleaseRole))
+	mux.HandleFunc("/api/v1/federation/runtime/diagnose", h.authPeer(h.federationRuntimeDiagnose))
 	mux.HandleFunc("/api/v1/federation/node/import", h.nodeImport)
 
 	mux.HandleFunc("/flow/test", h.flowTest)

go-backend/internal/http/middleware/auth.go

@@ -91,6 +91,8 @@ func shouldSkip(path string) bool {
 		return true
 	case path == "/api/v1/federation/runtime/release-role":
 		return true
+	case path == "/api/v1/federation/runtime/diagnose":
+		return true
 	default:
 		return false
 	}

go-backend/tests/contract/diagnosis_contract_test.go

@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -205,6 +206,173 @@ func TestDiagnosisChainCoverageContracts(t *testing.T) {
 	})
 }
 
+func TestDiagnosisUsesFederationRuntimeForRemoteNodes(t *testing.T) {
+	secret := "contract-jwt-secret"
+	router, repo := setupDiagnosisContractRouter(t, secret)
+	now := time.Now().UnixMilli()
+
+	remoteToken := "remote-diagnose-token"
+	var remoteDiagnoseCalls int32
+	remoteServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/federation/runtime/diagnose" {
+			http.NotFound(w, r)
+			return
+		}
+		if got := strings.TrimSpace(r.Header.Get("Authorization")); got != "Bearer "+remoteToken {
+			w.WriteHeader(http.StatusUnauthorized)
+			_ = json.NewEncoder(w).Encode(map[string]interface{}{"code": -1, "msg": "unauthorized"})
+			return
+		}
+
+		var req map[string]interface{}
+		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			_ = json.NewEncoder(w).Encode(map[string]interface{}{"code": -1, "msg": "bad request"})
+			return
+		}
+		if strings.TrimSpace(valueAsString(req["ip"])) != "10.50.0.30" {
+			w.WriteHeader(http.StatusBadRequest)
+			_ = json.NewEncoder(w).Encode(map[string]interface{}{"code": -1, "msg": "unexpected target ip"})
+			return
+		}
+		if valueAsInt(req["port"]) != 30003 {
+			w.WriteHeader(http.StatusBadRequest)
+			_ = json.NewEncoder(w).Encode(map[string]interface{}{"code": -1, "msg": "unexpected target port"})
+			return
+		}
+
+		atomic.AddInt32(&remoteDiagnoseCalls, 1)
+		_ = json.NewEncoder(w).Encode(map[string]interface{}{
+			"code": 0,
+			"msg":  "success",
+			"data": map[string]interface{}{
+				"success":     true,
+				"averageTime": 12.5,
+				"packetLoss":  0,
+				"message":     "remote tcp ok",
+			},
+		})
+	}))
+	defer remoteServer.Close()
+
+	insertLocalNode := func(name, ip string) int64 {
+		res, err := repo.DB().Exec(`
+			INSERT INTO node(name, secret, server_ip, server_ip_v4, server_ip_v6, port, interface_name, version, http, tls, socks, created_time, updated_time, status, tcp_listen_addr, udp_listen_addr, inx)
+			VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		`, name, name+"-secret", ip, ip, "", "30000-30010", "", "v1", 1, 1, 1, now, now, 1, "[::]", "[::]", 0)
+		if err != nil {
+			t.Fatalf("insert local node %s: %v", name, err)
+		}
+		id, err := res.LastInsertId()
+		if err != nil {
+			t.Fatalf("get local node id %s: %v", name, err)
+		}
+		return id
+	}
+
+	insertRemoteNode := func(name, ip string) int64 {
+		res, err := repo.DB().Exec(`
+			INSERT INTO node(name, secret, server_ip, server_ip_v4, server_ip_v6, port, interface_name, version, http, tls, socks, created_time, updated_time, status, tcp_listen_addr, udp_listen_addr, inx, is_remote, remote_url, remote_token, remote_config)
+			VALUES(?, ?, ?, ?, ?, ?, ?, ?, 0, 0, 0, ?, ?, 1, ?, ?, ?, 1, ?, ?, ?)
+		`, name, name+"-secret", ip, "", "", "31000-31010", "", "", now, now, "[::]", "[::]", 1, remoteServer.URL, remoteToken, `{"shareId": 123}`)
+		if err != nil {
+			t.Fatalf("insert remote node %s: %v", name, err)
+		}
+		id, err := res.LastInsertId()
+		if err != nil {
+			t.Fatalf("get remote node id %s: %v", name, err)
+		}
+		return id
+	}
+
+	entryNodeID := insertLocalNode("entry-local", "10.50.0.10")
+	remoteChainNodeID := insertRemoteNode("middle-remote", "10.50.0.20")
+	exitNodeID := insertLocalNode("exit-local", "10.50.0.30")
+
+	tunnelRes, err := repo.DB().Exec(`
+		INSERT INTO tunnel(name, traffic_ratio, type, protocol, flow, created_time, updated_time, status, in_ip, inx)
+		VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+	`, "diagnose-remote-tunnel", 1.0, 2, "tls", 99999, now, now, 1, nil, 0)
+	if err != nil {
+		t.Fatalf("insert tunnel: %v", err)
+	}
+	tunnelID, err := tunnelRes.LastInsertId()
+	if err != nil {
+		t.Fatalf("get tunnel id: %v", err)
+	}
+
+	if _, err := repo.DB().Exec(`
+		INSERT INTO chain_tunnel(tunnel_id, chain_type, node_id, port, strategy, inx, protocol)
+		VALUES(?, 1, ?, 30001, 'round', 1, 'tls')
+	`, tunnelID, entryNodeID); err != nil {
+		t.Fatalf("insert entry chain: %v", err)
+	}
+	if _, err := repo.DB().Exec(`
+		INSERT INTO chain_tunnel(tunnel_id, chain_type, node_id, port, strategy, inx, protocol)
+		VALUES(?, 2, ?, 30002, 'round', 1, 'tls')
+	`, tunnelID, remoteChainNodeID); err != nil {
+		t.Fatalf("insert middle chain: %v", err)
+	}
+	if _, err := repo.DB().Exec(`
+		INSERT INTO chain_tunnel(tunnel_id, chain_type, node_id, port, strategy, inx, protocol)
+		VALUES(?, 3, ?, 30003, 'round', 1, 'tls')
+	`, tunnelID, exitNodeID); err != nil {
+		t.Fatalf("insert exit chain: %v", err)
+	}
+
+	adminToken, err := auth.GenerateToken(1, "admin_user", 0, secret)
+	if err != nil {
+		t.Fatalf("generate admin token: %v", err)
+	}
+
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/tunnel/diagnose", bytes.NewBufferString(`{"tunnelId":`+strconv.FormatInt(tunnelID, 10)+`}`))
+	req.Header.Set("Authorization", adminToken)
+	res := httptest.NewRecorder()
+
+	router.ServeHTTP(res, req)
+
+	var out response.R
+	if err := json.NewDecoder(res.Body).Decode(&out); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if out.Code != 0 {
+		t.Fatalf("expected code 0, got %d (%s)", out.Code, out.Msg)
+	}
+
+	payload, ok := out.Data.(map[string]interface{})
+	if !ok {
+		t.Fatalf("expected object payload, got %T", out.Data)
+	}
+	results, ok := payload["results"].([]interface{})
+	if !ok || len(results) == 0 {
+		t.Fatalf("expected non-empty results, got %v", payload["results"])
+	}
+
+	remoteStepFound := false
+	for _, raw := range results {
+		item, ok := raw.(map[string]interface{})
+		if !ok {
+			continue
+		}
+		if valueAsInt(item["fromChainType"]) == 2 && valueAsInt(item["toChainType"]) == 3 {
+			remoteStepFound = true
+			if !valueAsBool(item["success"]) {
+				t.Fatalf("expected remote chain->exit diagnosis success, got item=%v", item)
+			}
+			if strings.TrimSpace(valueAsString(item["message"])) != "remote tcp ok" {
+				t.Fatalf("expected remote diagnosis message, got %q", valueAsString(item["message"]))
+			}
+		}
+	}
+
+	if !remoteStepFound {
+		t.Fatalf("expected chain->exit diagnosis item for remote node")
+	}
+	if atomic.LoadInt32(&remoteDiagnoseCalls) == 0 {
+		t.Fatalf("expected federation runtime diagnose endpoint to be called")
+	}
+}
+
 func valueAsInt(v interface{}) int {
 	switch n := v.(type) {
 	case float64:
@@ -223,6 +391,24 @@ func valueAsString(v interface{}) string {
 	return s
 }
 
+func valueAsBool(v interface{}) bool {
+	switch b := v.(type) {
+	case bool:
+		return b
+	case float64:
+		return b != 0
+	case int:
+		return b != 0
+	case int64:
+		return b != 0
+	case string:
+		s := strings.TrimSpace(strings.ToLower(b))
+		return s == "1" || s == "t" || s == "true" || s == "yes" || s == "y"
+	default:
+		return false
+	}
+}
+
 func setupDiagnosisContractRouter(t *testing.T, jwtSecret string) (http.Handler, *sqlite.Repository) {
 	t.Helper()
 	dbPath := filepath.Join(t.TempDir(), "diagnosis-contract.db")

go-backend/tests/contract/federation_dual_panel_contract_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/gorilla/websocket"
 
 	"go-backend/internal/auth"
+	"go-backend/internal/http/response"
 	"go-backend/internal/security"
 	"go-backend/internal/store/sqlite"
 )
@@ -152,6 +153,150 @@ func TestFederationDualPanelMiddleExitAutoPortContract(t *testing.T) {
 	assertCount(t, providerRepo, `SELECT COUNT(1) FROM peer_share_runtime WHERE share_id = ?`, entryShareID, 0)
 }
 
+func TestFederationDualPanelRemoteDiagnosisContract(t *testing.T) {
+	providerSecret := "provider-contract-jwt"
+	providerRouter, providerRepo := setupContractRouter(t, providerSecret)
+	providerServer := httptest.NewServer(providerRouter)
+	defer providerServer.Close()
+
+	consumerSecret := "consumer-contract-jwt"
+	consumerRouter, consumerRepo := setupContractRouter(t, consumerSecret)
+
+	consumerAdminToken, err := auth.GenerateToken(1, "consumer-admin", 0, consumerSecret)
+	if err != nil {
+		t.Fatalf("generate consumer admin token: %v", err)
+	}
+
+	now := time.Now().UnixMilli()
+	providerEntryNodeID := insertContractNode(t, providerRepo, "provider-entry-dx", "203.0.113.11", "53000-53010", "provider-entry-dx-secret", 1)
+	providerMiddleNodeID := insertContractNode(t, providerRepo, "provider-middle-dx", "203.0.113.12", "54000-54010", "provider-middle-dx-secret", 1)
+	providerExitNodeID := insertContractNode(t, providerRepo, "provider-exit-dx", "203.0.113.13", "55000-55010", "provider-exit-dx-secret", 1)
+
+	entryShareID := insertPeerShare(t, providerRepo, &sqlite.PeerShare{
+		Name:           "entry-share-dx",
+		NodeID:         providerEntryNodeID,
+		Token:          "share-entry-dx-token",
+		PortRangeStart: 53000,
+		PortRangeEnd:   53010,
+		IsActive:       1,
+		CreatedTime:    now,
+		UpdatedTime:    now,
+	})
+	middleShareID := insertPeerShare(t, providerRepo, &sqlite.PeerShare{
+		Name:           "middle-share-dx",
+		NodeID:         providerMiddleNodeID,
+		Token:          "share-middle-dx-token",
+		PortRangeStart: 54000,
+		PortRangeEnd:   54010,
+		IsActive:       1,
+		CreatedTime:    now,
+		UpdatedTime:    now,
+	})
+	exitShareID := insertPeerShare(t, providerRepo, &sqlite.PeerShare{
+		Name:           "exit-share-dx",
+		NodeID:         providerExitNodeID,
+		Token:          "share-exit-dx-token",
+		PortRangeStart: 55000,
+		PortRangeEnd:   55010,
+		IsActive:       1,
+		CreatedTime:    now,
+		UpdatedTime:    now,
+	})
+
+	importRemoteNodeForContract(t, consumerRouter, consumerAdminToken, providerServer.URL, "share-entry-dx-token")
+	importRemoteNodeForContract(t, consumerRouter, consumerAdminToken, providerServer.URL, "share-middle-dx-token")
+	importRemoteNodeForContract(t, consumerRouter, consumerAdminToken, providerServer.URL, "share-exit-dx-token")
+
+	entryRemoteNodeID := queryRemoteNodeIDByToken(t, consumerRepo, "share-entry-dx-token")
+	middleRemoteNodeID := queryRemoteNodeIDByToken(t, consumerRepo, "share-middle-dx-token")
+	exitRemoteNodeID := queryRemoteNodeIDByToken(t, consumerRepo, "share-exit-dx-token")
+
+	stopMiddle := startMockNodeSession(t, providerServer.URL, "provider-middle-dx-secret")
+	defer stopMiddle()
+	stopExit := startMockNodeSession(t, providerServer.URL, "provider-exit-dx-secret")
+	defer stopExit()
+
+	createPayload := map[string]interface{}{
+		"name":   "dual-panel-diagnose-remote",
+		"type":   2,
+		"flow":   99999,
+		"status": 1,
+		"inNodeId": []map[string]interface{}{
+			{"nodeId": entryRemoteNodeID, "protocol": "tls", "strategy": "round"},
+		},
+		"chainNodes": [][]map[string]interface{}{
+			{{"nodeId": middleRemoteNodeID, "protocol": "tls", "strategy": "round"}},
+		},
+		"outNodeId": []map[string]interface{}{
+			{"nodeId": exitRemoteNodeID, "protocol": "tls", "strategy": "round"},
+		},
+	}
+	body, err := json.Marshal(createPayload)
+	if err != nil {
+		t.Fatalf("marshal create payload: %v", err)
+	}
+	createReq := httptest.NewRequest(http.MethodPost, "/api/v1/tunnel/create", bytes.NewReader(body))
+	createReq.Header.Set("Authorization", consumerAdminToken)
+	createReq.Header.Set("Content-Type", "application/json")
+	createRes := httptest.NewRecorder()
+	consumerRouter.ServeHTTP(createRes, createReq)
+	assertCode(t, createRes, 0)
+
+	var tunnelID int64
+	if err := consumerRepo.DB().QueryRow(`SELECT id FROM tunnel WHERE name = ? ORDER BY id DESC LIMIT 1`, "dual-panel-diagnose-remote").Scan(&tunnelID); err != nil {
+		t.Fatalf("query tunnel id: %v", err)
+	}
+	if tunnelID <= 0 {
+		t.Fatalf("invalid tunnel id")
+	}
+
+	assertCount(t, providerRepo, `SELECT COUNT(1) FROM peer_share_runtime WHERE share_id = ? AND status = 1 AND applied = 1`, middleShareID, 1)
+	assertCount(t, providerRepo, `SELECT COUNT(1) FROM peer_share_runtime WHERE share_id = ? AND status = 1 AND applied = 1`, exitShareID, 1)
+	assertCount(t, providerRepo, `SELECT COUNT(1) FROM peer_share_runtime WHERE share_id = ?`, entryShareID, 0)
+
+	diagnoseReq := httptest.NewRequest(http.MethodPost, "/api/v1/tunnel/diagnose", bytes.NewBufferString(fmt.Sprintf(`{"tunnelId":%d}`, tunnelID)))
+	diagnoseReq.Header.Set("Authorization", consumerAdminToken)
+	diagnoseRes := httptest.NewRecorder()
+	consumerRouter.ServeHTTP(diagnoseRes, diagnoseReq)
+
+	var out response.R
+	if err := json.NewDecoder(diagnoseRes.Body).Decode(&out); err != nil {
+		t.Fatalf("decode diagnose response: %v", err)
+	}
+	if out.Code != 0 {
+		t.Fatalf("expected diagnose code 0, got %d (%s)", out.Code, out.Msg)
+	}
+
+	payload, ok := out.Data.(map[string]interface{})
+	if !ok {
+		t.Fatalf("expected map payload, got %T", out.Data)
+	}
+	results, ok := payload["results"].([]interface{})
+	if !ok || len(results) == 0 {
+		t.Fatalf("expected non-empty results, got %v", payload["results"])
+	}
+
+	chainToExitFound := false
+	for _, raw := range results {
+		item, ok := raw.(map[string]interface{})
+		if !ok {
+			continue
+		}
+		if valueAsInt(item["fromChainType"]) == 2 && valueAsInt(item["toChainType"]) == 3 {
+			chainToExitFound = true
+			if !valueAsBool(item["success"]) {
+				t.Fatalf("expected chain->exit diagnosis success, got item=%v", item)
+			}
+			if msg := strings.TrimSpace(valueAsString(item["message"])); msg != "mock tcp ok" {
+				t.Fatalf("expected remote diagnosis message 'mock tcp ok', got %q", msg)
+			}
+		}
+	}
+	if !chainToExitFound {
+		t.Fatalf("expected chain->exit diagnosis item in results")
+	}
+}
+
 func insertContractNode(t *testing.T, repo *sqlite.Repository, name, ip, portRange, secret string, status int) int64 {
 	t.Helper()
 	now := time.Now().UnixMilli()
@@ -306,12 +451,21 @@ func startMockNodeSession(t *testing.T, baseURL string, nodeSecret string) func(
 			}
 
 			respType := fmt.Sprintf("%sResponse", cmd.Type)
-			respBytes, err := json.Marshal(map[string]interface{}{
+			respPayload := map[string]interface{}{
 				"type":      respType,
 				"success":   true,
 				"message":   "OK",
 				"requestId": cmd.RequestID,
-			})
+			}
+			if strings.EqualFold(strings.TrimSpace(cmd.Type), "TcpPing") {
+				respPayload["data"] = map[string]interface{}{
+					"success":     true,
+					"averageTime": 8.5,
+					"packetLoss":  0,
+					"message":     "mock tcp ok",
+				}
+			}
+			respBytes, err := json.Marshal(respPayload)
 			if err != nil {
 				continue
 			}
@@ -324,3 +478,39 @@ func startMockNodeSession(t *testing.T, baseURL string, nodeSecret string) func(
 		wg.Wait()
 	}
 }
+
+func valueAsInt(v interface{}) int {
+	switch n := v.(type) {
+	case float64:
+		return int(n)
+	case int:
+		return n
+	case int64:
+		return int(n)
+	default:
+		return 0
+	}
+}
+
+func valueAsString(v interface{}) string {
+	s, _ := v.(string)
+	return s
+}
+
+func valueAsBool(v interface{}) bool {
+	switch b := v.(type) {
+	case bool:
+		return b
+	case float64:
+		return b != 0
+	case int:
+		return b != 0
+	case int64:
+		return b != 0
+	case string:
+		s := strings.TrimSpace(strings.ToLower(b))
+		return s == "1" || s == "t" || s == "true" || s == "yes" || s == "y"
+	default:
+		return false
+	}
+}