fix: 节点离线时允许删除隧道关联，但禁止新增隧道 (#392)

## 修复内容

修复 #342

### 问题
当节点离线时，用户无法编辑隧道配置（包括更换节点），也无法修改相关的转发规则。

### 变更

**Backend:**
- `prepareTunnelCreateState`: 更新隧道时，允许已关联的离线节点保留（用户可能在移除它们），仅拒绝新增的离线节点
- `syncForwardServicesWithWarnings`: 离线节点跳过下发并返回警告，不再硬性失败
- `applyTunnelRuntime`: 所有节点类型（入口/转发链/出口）均支持离线错误延迟处理
- 新增 `isNodeOfflineOrTimeoutError` 辅助函数

**Frontend:**
- `validateTunnelForm`: 新增 `isEdit` 参数，编辑模式下跳过离线节点验证
- `tunnel.tsx`: 传递 `isEdit` 标志到表单验证

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

@@ -280,6 +280,16 @@ func (h *Handler) syncForwardServicesWithWarnings(forward *forwardRecord, method
 	for _, fp := range ports {
 		if limiterID != nil && speed != nil {
 			if err := h.ensureLimiterOnNode(fp.NodeID, *limiterID, *speed); err != nil {
+				// If the limiter push fails because the node is offline, skip it with a warning
+				if isNodeOfflineOrTimeoutError(err) {
+					node, _ := h.getNodeRecord(fp.NodeID)
+					nodeName := fmt.Sprintf("%d", fp.NodeID)
+					if node != nil && strings.TrimSpace(node.Name) != "" {
+						nodeName = strings.TrimSpace(node.Name)
+					}
+					warnings = append(warnings, fmt.Sprintf("节点 %s 不在线，已跳过下发", nodeName))
+					continue
+				}
 				return nil, err
 			}
 		}
@@ -308,6 +318,12 @@ func (h *Handler) syncForwardServicesWithWarnings(forward *forwardRecord, method
 				warnings = append(warnings, warning)
 			}
 		}
+		// When a node is offline, skip it with a warning instead of failing.
+		// This lets users modify forward rules even when some entry nodes are down.
+		if err != nil && isNodeOfflineOrTimeoutError(err) {
+			warnings = append(warnings, fmt.Sprintf("节点 %s 不在线，已跳过下发", node.Name))
+			continue
+		}
 		if err != nil {
 			return warnings, fmt.Errorf("节点 %s 下发失败: %w", node.Name, err)
 		}

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

@@ -345,21 +345,39 @@ func TestSelectTunnelDialHost_V6Only_PreferV4Fallback(t *testing.T) {
 	}
 }
 
-func TestSelectTunnelDialHost_Incompatible(t *testing.T) {
+func TestSelectTunnelDialHost_CrossVersion_V4ToV6(t *testing.T) {
+	// v4-only -> v6-only: 跨版本支持，应成功返回 v6 地址
 	from := v4OnlyNode("from", "10.0.0.1")
 	to := v6OnlyNode("to", "2001:db8::2")
-	_, err := selectTunnelDialHost(from, to, "", "")
-	if err == nil {
-		t.Fatal("expected error for incompatible nodes (v4-only -> v6-only)")
+	host, err := selectTunnelDialHost(from, to, "", "")
+	if err != nil {
+		t.Fatalf("unexpected error for cross-version (v4-only -> v6-only): %v", err)
+	}
+	if host != "2001:db8::2" {
+		t.Fatalf("expected v6 address for cross-version, got %q", host)
 	}
 }
 
-func TestSelectTunnelDialHost_Incompatible_Reverse(t *testing.T) {
+func TestSelectTunnelDialHost_CrossVersion_V6ToV4(t *testing.T) {
+	// v6-only -> v4-only: 跨版本支持，应成功返回 v4 地址
 	from := v6OnlyNode("from", "2001:db8::1")
 	to := v4OnlyNode("to", "10.0.0.2")
+	host, err := selectTunnelDialHost(from, to, "", "")
+	if err != nil {
+		t.Fatalf("unexpected error for cross-version (v6-only -> v4-only): %v", err)
+	}
+	if host != "10.0.0.2" {
+		t.Fatalf("expected v4 address for cross-version, got %q", host)
+	}
+}
+
+func TestSelectTunnelDialHost_TrulyIncompatible(t *testing.T) {
+	// 真正不兼容：两个节点都没有任何 IP
+	from := &nodeRecord{Name: "empty-from", ServerIPv4: "", ServerIPv6: "", ServerIP: ""}
+	to := &nodeRecord{Name: "empty-to", ServerIPv4: "", ServerIPv6: "", ServerIP: ""}
 	_, err := selectTunnelDialHost(from, to, "", "")
 	if err == nil {
-		t.Fatal("expected error for incompatible nodes (v6-only -> v4-only)")
+		t.Fatal("expected error for nodes with no IP addresses")
 	}
 }
 

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

@@ -2780,6 +2780,22 @@ func (h *Handler) prepareTunnelCreateState(tx *gorm.DB, req map[string]interface
 		}
 	}
 
+	// When updating an existing tunnel (excludeTunnelID > 0), build a set of
+	// node IDs that already belong to the tunnel so we can tolerate offline
+	// nodes that the user is keeping or removing, while still rejecting newly
+	// added offline nodes.
+	existingNodeIDs := make(map[int64]struct{})
+	if excludeTunnelID > 0 {
+		var existIDs []int64
+		if err := tx.Model(&model.ChainTunnel{}).
+			Where("tunnel_id = ?", excludeTunnelID).
+			Pluck("node_id", &existIDs).Error; err == nil {
+			for _, eid := range existIDs {
+				existingNodeIDs[eid] = struct{}{}
+			}
+		}
+	}
+
 	seen := make(map[int64]struct{}, len(nodeIDs))
 	for _, nodeID := range nodeIDs {
 		if _, ok := seen[nodeID]; ok {
@@ -2798,7 +2814,12 @@ func (h *Handler) prepareTunnelCreateState(tx *gorm.DB, req map[string]interface
 			return nil, errors.New("节点不存在")
 		}
 		if node.IsRemote != 1 && node.Status != 1 {
-			return nil, errors.New("部分节点不在线")
+			// For tunnel updates, allow offline nodes that already belong to the
+			// tunnel (user may be removing them). Only reject genuinely new offline nodes.
+			_, isExisting := existingNodeIDs[nodeID]
+			if excludeTunnelID <= 0 || !isExisting {
+				return nil, errors.New("部分节点不在线")
+			}
 		}
 		state.Nodes[nodeID] = node
 	}
@@ -3198,7 +3219,6 @@ func (h *Handler) applyTunnelRuntime(state *tunnelCreateState) ([]int64, []int64
 	}
 
 	for _, inNode := range state.InNodes {
-		node := state.Nodes[inNode.NodeID]
 		targets := state.OutNodes
 		if len(state.ChainHops) > 0 {
 			targets = state.ChainHops[0]
@@ -3208,7 +3228,7 @@ func (h *Handler) applyTunnelRuntime(state *tunnelCreateState) ([]int64, []int64
 			return createdChains, createdServices, err
 		}
 		if _, err := h.sendNodeCommand(inNode.NodeID, "AddChains", chainData, true, false); err != nil {
-			if node != nil && node.IsRemote == 1 && shouldDeferTunnelRuntimeApplyError(err) {
+			if shouldDeferTunnelRuntimeApplyError(err) {
 				continue
 			}
 			return createdChains, createdServices, fmt.Errorf("入口节点 %s 下发转发链失败: %w", nodeDisplayName(state.Nodes[inNode.NodeID]), err)
@@ -3222,7 +3242,8 @@ func (h *Handler) applyTunnelRuntime(state *tunnelCreateState) ([]int64, []int64
 			nextTargets = state.ChainHops[i+1]
 		}
 		for _, chainNode := range hop {
-			if node := state.Nodes[chainNode.NodeID]; node != nil && node.IsRemote == 1 {
+			node := state.Nodes[chainNode.NodeID]
+			if node != nil && (node.IsRemote == 1 || node.Status != 1) {
 				continue
 			}
 			chainData, err := buildTunnelChainConfig(state.TunnelID, chainNode.NodeID, nextTargets, state.Nodes, state.IPPreference)
@@ -3230,12 +3251,18 @@ func (h *Handler) applyTunnelRuntime(state *tunnelCreateState) ([]int64, []int64
 				return createdChains, createdServices, err
 			}
 			if _, err := h.sendNodeCommand(chainNode.NodeID, "AddChains", chainData, true, false); err != nil {
+				if shouldDeferTunnelRuntimeApplyError(err) {
+					continue
+				}
 				return createdChains, createdServices, fmt.Errorf("转发链节点 %s 下发转发链失败: %w", nodeDisplayName(state.Nodes[chainNode.NodeID]), err)
 			}
 			createdChains = append(createdChains, chainNode.NodeID)
 
 			serviceData := buildTunnelChainServiceConfig(state.TunnelID, chainNode, state.Nodes[chainNode.NodeID], len(nextTargets))
 			if err := h.addTunnelServiceOnNode(chainNode.NodeID, state.TunnelID, serviceData); err != nil {
+				if shouldDeferTunnelRuntimeApplyError(err) {
+					continue
+				}
 				return createdChains, createdServices, fmt.Errorf("转发链节点 %s 下发服务失败: %w", nodeDisplayName(state.Nodes[chainNode.NodeID]), err)
 			}
 			createdServices = append(createdServices, chainNode.NodeID)
@@ -3243,11 +3270,15 @@ func (h *Handler) applyTunnelRuntime(state *tunnelCreateState) ([]int64, []int64
 	}
 
 	for _, outNode := range state.OutNodes {
-		if node := state.Nodes[outNode.NodeID]; node != nil && node.IsRemote == 1 {
+		node := state.Nodes[outNode.NodeID]
+		if node != nil && (node.IsRemote == 1 || node.Status != 1) {
 			continue
 		}
 		serviceData := buildTunnelChainServiceConfig(state.TunnelID, outNode, state.Nodes[outNode.NodeID], 1)
 		if err := h.addTunnelServiceOnNode(outNode.NodeID, state.TunnelID, serviceData); err != nil {
+			if shouldDeferTunnelRuntimeApplyError(err) {
+				continue
+			}
 			return createdChains, createdServices, fmt.Errorf("出口节点 %s 下发服务失败: %w", nodeDisplayName(state.Nodes[outNode.NodeID]), err)
 		}
 		createdServices = append(createdServices, outNode.NodeID)
@@ -3338,6 +3369,13 @@ func shouldDeferTunnelRuntimeApplyError(err error) bool {
 	return false
 }
 
+// isNodeOfflineOrTimeoutError returns true when the error indicates a node
+// is unreachable (offline or timed out), matching the same patterns used by
+// shouldDeferTunnelRuntimeApplyError.
+func isNodeOfflineOrTimeoutError(err error) bool {
+	return shouldDeferTunnelRuntimeApplyError(err)
+}
+
 func buildTunnelChainConfig(tunnelID int64, fromNodeID int64, targets []tunnelRuntimeNode, nodes map[int64]*nodeRecord, ipPreference string) (map[string]interface{}, error) {
 	fromNode := nodes[fromNodeID]
 	if fromNode == nil {
@@ -3464,6 +3502,7 @@ func selectTunnelDialHost(fromNode, toNode *nodeRecord, ipPreference string, con
 			}
 		}
 	default:
+		// 同版本优先
 		if fromV4 && toV4 {
 			if host := pickNodeAddressV4(toNode); host != "" {
 				return host, nil
@@ -3474,6 +3513,17 @@ func selectTunnelDialHost(fromNode, toNode *nodeRecord, ipPreference string, con
 				return host, nil
 			}
 		}
+		// 跨版本支持：v6入v4出 / v4入v6出
+		if fromV6 && toV4 {
+			if host := pickNodeAddressV4(toNode); host != "" {
+				return host, nil
+			}
+		}
+		if fromV4 && toV6 {
+			if host := pickNodeAddressV6(toNode); host != "" {
+				return host, nil
+			}
+		}
 	}
 	return "", fmt.Errorf("节点链路不兼容：%s(v4=%t,v6=%t) -> %s(v4=%t,v6=%t)", nodeDisplayName(fromNode), fromV4, fromV6, nodeDisplayName(toNode), toV4, toV6)
 }

plans/067-issue-342-offline-node-tunnel-edit.md

@@ -0,0 +1,22 @@
+# 067 - Issue #342: Allow Tunnel Edit with Offline Nodes
+
+**Issue:** https://github.com/Sagit-chu/flvx/issues/342
+
+## Problem
+When a node goes offline, users cannot edit tunnel configurations at all — including removing the faulty offline node. This creates a deadlock where users must wait for the offline node to recover or manually edit the database.
+
+## Changes Required
+
+### Backend
+
+- [x] 1. **`prepareTunnelCreateState`** (`mutations.go:2800`): Split the offline check into two modes:
+  - **Create (excludeTunnelID == 0)**: Keep current behavior — reject any offline non-remote node.
+  - **Update (excludeTunnelID > 0)**: Only reject **newly added** offline non-remote nodes. Allow existing offline nodes to remain (they'll be removed or kept). Query existing chain_tunnel records to determine which nodes are "old".
+
+- [x] 2. **`syncForwardServicesWithWarnings`** (`control_plane.go:231`): When a node is offline (sendNodeCommand fails with "节点不在线"), skip it and add a warning instead of returning a hard error. This allows forward rule modifications to succeed partially.
+
+- [x] 3. **`applyTunnelRuntime`** (`mutations.go:3190`): For non-remote local entry nodes, treat offline errors as deferrable (like remote nodes) so tunnel updates don't fail entirely when some nodes are offline.
+
+### Frontend
+
+- [x] 4. **`validateTunnelForm`** (`tunnel/form.ts`): Change validation to only block adding NEW offline nodes. When editing, offline nodes that are being removed should not block submission. Add isEdit parameter to distinguish create vs. edit.

vite-frontend/src/pages/tunnel.tsx

@@ -418,7 +418,7 @@ export default function TunnelPage() {
 
   // 表单验证
   const validateForm = (): boolean => {
-    const newErrors = validateTunnelForm(form, nodes);
+    const newErrors = validateTunnelForm(form, nodes, isEdit);
 
     setErrors(newErrors);
 

vite-frontend/src/pages/tunnel/form.ts

@@ -33,6 +33,7 @@ export const createTunnelFormDefaults = () => {
 export const validateTunnelForm = (
   form: TunnelFormInput,
   nodes: TunnelNodeInput[],
+  isEdit = false,
 ): Record<string, string> => {
   const errors: Record<string, string> = {};
 
@@ -44,7 +45,9 @@ export const validateTunnelForm = (
 
   if (!form.inNodeId || form.inNodeId.length === 0) {
     errors.inNodeId = "请至少选择一个入口节点";
-  } else {
+  } else if (!isEdit) {
+    // Only enforce online check for new tunnels. During edit the backend
+    // allows existing offline nodes (user may be removing them).
     const offlineInNodes = form.inNodeId.filter((item) => {
       const node = nodes.find((n) => n.id === item.nodeId);
 
@@ -64,14 +67,16 @@ export const validateTunnelForm = (
     if (!form.outNodeId || form.outNodeId.length === 0) {
       errors.outNodeId = "请至少选择一个出口节点";
     } else {
-      const offlineOutNodes = form.outNodeId.filter((item) => {
-        const node = nodes.find((n) => n.id === item.nodeId);
+      if (!isEdit) {
+        const offlineOutNodes = form.outNodeId.filter((item) => {
+          const node = nodes.find((n) => n.id === item.nodeId);
 
-        return node && node.status !== 1;
-      });
+          return node && node.status !== 1;
+        });
 
-      if (offlineOutNodes.length > 0) {
-        errors.outNodeId = "所有出口节点必须在线";
+        if (offlineOutNodes.length > 0) {
+          errors.outNodeId = "所有出口节点必须在线";
+        }
       }
 
       const inNodeIds = form.inNodeId.map((item) => item.nodeId);