fix: nil guards, safe type assertions, panic prevention, and rate limiter plugin (#3757)

Signed-off-by: Srikanth Patchava <spatchava@meta.com>
Signed-off-by: Srikanth Patchava <srpatcha@users.noreply.github.com>
Co-authored-by: Srikanth Patchava <srpatcha@users.noreply.github.com>

README.md

@@ -7,7 +7,7 @@
 <h4 align="center"> AI Native API Gateway </h4>
 
 <div align="center">
-    
+
 [![Build Status](https://github.com/alibaba/higress/actions/workflows/build-and-test.yaml/badge.svg?branch=main)](https://github.com/alibaba/higress/actions)
 [![license](https://img.shields.io/github/license/alibaba/higress.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
 [![discord](https://img.shields.io/discord/1364956090566971515?color=5865F2&label=discord&labelColor=black&logo=discord&logoColor=white&style=flat-square)](https://discord.gg/tSbww9VDaM)
@@ -34,7 +34,7 @@ Higress is a cloud-native API gateway based on Istio and Envoy, which can be ext
 
 ### Core Use Cases
 
-Higress's AI gateway capabilities support all [mainstream model providers](https://github.com/alibaba/higress/tree/main/plugins/wasm-go/extensions/ai-proxy/provider) both domestic and international. It also supports hosting MCP (Model Context Protocol) Servers through its plugin mechanism, enabling AI Agents to easily call various tools and services. With the [openapi-to-mcp tool](https://github.com/higress-group/openapi-to-mcpserver), you can quickly convert OpenAPI specifications into remote MCP servers for hosting. Higress provides unified management for both LLM API and MCP API. 
+Higress's AI gateway capabilities support all [mainstream model providers](https://github.com/alibaba/higress/tree/main/plugins/wasm-go/extensions/ai-proxy/provider) both domestic and international. It also supports hosting MCP (Model Context Protocol) Servers through its plugin mechanism, enabling AI Agents to easily call various tools and services. With the [openapi-to-mcp tool](https://github.com/higress-group/openapi-to-mcpserver), you can quickly convert OpenAPI specifications into remote MCP servers for hosting. Higress provides unified management for both LLM API and MCP API.
 
 **🌟 Try it now at [https://mcp.higress.ai/](https://mcp.higress.ai/)** to experience Higress-hosted Remote MCP Servers firsthand:
 
@@ -51,7 +51,7 @@ You can click the button below to install the enterprise version of Higress:
 
 ## Summary
 
-- [**Quick Start**](#quick-start)    
+- [**Quick Start**](#quick-start)
 - [**Feature Showcase**](#feature-showcase)
 - [**Use Cases**](#use-cases)
 - [**Core Advantages**](#core-advantages)
@@ -78,20 +78,20 @@ Port descriptions:
 
 > All Higress Docker images use Higress's own image repository and are not affected by Docker Hub rate limits.
 > In addition, the submission and updates of the images are protected by a security scanning mechanism (powered by Alibaba Cloud ACR), making them very secure for use in production environments.
-> 
+>
 > If you experience a timeout when pulling image from `higress-registry.cn-hangzhou.cr.aliyuncs.com`, you can try replacing it with the following docker registry mirror source:
-> 
+>
 > **North America**: `higress-registry.us-west-1.cr.aliyuncs.com`
-> 
+>
 > **Southeast Asia**: `higress-registry.ap-southeast-7.cr.aliyuncs.com`
 
 > **For Kubernetes deployments**, you can configure the `global.hub` parameter in Helm values to use a mirror registry closer to your region. This applies to both Higress component images and built-in Wasm plugin images:
-> 
+>
 > ```bash
 > # Example: Using North America mirror
 > helm install higress -n higress-system higress.io/higress --set global.hub=higress-registry.us-west-1.cr.aliyuncs.com --create-namespace
 > ```
-> 
+>
 > Available mirror registries:
 > - **China (Hangzhou)**: `higress-registry.cn-hangzhou.cr.aliyuncs.com` (default)
 > - **North America**: `higress-registry.us-west-1.cr.aliyuncs.com`
@@ -129,7 +129,7 @@ If you are deploying on the cloud, it is recommended to use the [Enterprise Edit
 - **Kubernetes ingress controller**:
 
   Higress can function as a feature-rich ingress controller, which is compatible with many annotations of K8s' nginx ingress controller.
-  
+
   [Gateway API](https://gateway-api.sigs.k8s.io/) is already supported, and it supports a smooth migration from Ingress API to Gateway API.
 
   Compared to ingress-nginx, the resource overhead has significantly decreased, and the speed at which route changes take effect has improved by ten times.
@@ -140,13 +140,13 @@ If you are deploying on the cloud, it is recommended to use the [Enterprise Edit
 
    ![](https://img.alicdn.com/imgextra/i1/O1CN01bhEtb229eeMNBWmdP_!!6000000008093-2-tps-750-547.png)
 
-  
+
 - **Microservice gateway**:
 
   Higress can function as a microservice gateway, which can discovery microservices from various service registries, such as Nacos, ZooKeeper, Consul, Eureka, etc.
-  
+
   It deeply integrates with [Dubbo](https://github.com/apache/dubbo), [Nacos](https://github.com/alibaba/nacos), [Sentinel](https://github.com/alibaba/Sentinel) and other microservice technology stacks.
-  
+
 - **Security gateway**:
 
   Higress can be used as a security gateway, supporting WAF and various authentication strategies, such as key-auth, hmac-auth, jwt-auth, basic-auth, oidc, etc.
@@ -165,15 +165,15 @@ If you are deploying on the cloud, it is recommended to use the [Enterprise Edit
   Supports true complete streaming processing of request/response bodies, Wasm plugins can easily customize the handling of streaming protocols such as SSE (Server-Sent Events).
 
   In high-bandwidth scenarios such as AI businesses, it can significantly reduce memory overhead.
-    
+
 - **Easy to Extend**
-  
+
   Provides a rich official plugin library covering AI, traffic management, security protection and other common functions, meeting more than 90% of business scenario requirements.
 
   Focuses on Wasm plugin extensions, ensuring memory safety through sandbox isolation, supporting multiple programming languages, allowing plugin versions to be upgraded independently, and achieving traffic-lossless hot updates of gateway logic.
 
 - **Secure and Easy to Use**
-  
+
   Based on Ingress API and Gateway API standards, provides out-of-the-box UI console, WAF protection plugin, IP/Cookie CC protection plugin ready to use.
 
   Supports connecting to Let's Encrypt for automatic issuance and renewal of free certificates, and can be deployed outside of K8s, started with a single Docker command, convenient for individual developers to use.

plugins/golang-filter/mcp-server/servers/gorm/db.go

@@ -164,14 +164,14 @@ func (c *DBClient) DescribeTable(table string) ([]map[string]interface{}, error)
 	switch c.dbType {
 	case MYSQL:
 		sql = `
-			select 
+			select
 			    column_name,
 				column_type,
 				is_nullable,
 				column_key,
 				column_default,
 				extra,
-				column_comment 
+				column_comment
 			from information_schema.columns
 			where table_schema = database() and table_name = ?
 		`
@@ -179,17 +179,17 @@ func (c *DBClient) DescribeTable(table string) ([]map[string]interface{}, error)
 
 	case POSTGRES:
 		sql = `
-			select 
+			select
 			    column_name,
 				data_type as column_type,
 				is_nullable,
-				case 
+				case
 				    when column_default like 'nextval%' then 'auto_increment'
 				    when column_default is not null then 'default'
 				    else ''
 				end as column_key,
 				column_default,
-				case 
+				case
 				    when column_default like 'nextval%' then 'auto_increment'
 				    else ''
 				end as extra,
@@ -202,7 +202,7 @@ func (c *DBClient) DescribeTable(table string) ([]map[string]interface{}, error)
 
 	case CLICKHOUSE:
 		sql = `
-			select 
+			select
 			    name as column_name,
 				type as column_type,
 				if(is_nullable, 'YES', 'NO') as is_nullable,
@@ -217,7 +217,7 @@ func (c *DBClient) DescribeTable(table string) ([]map[string]interface{}, error)
 
 	case SQLITE:
 		sql = `
-			select 
+			select
 			    name as column_name,
 				type as column_type,
 				not (notnull = 1) as is_nullable,
@@ -236,6 +236,10 @@ func (c *DBClient) DescribeTable(table string) ([]map[string]interface{}, error)
 
 // ListTables List all tables in the connected database.
 func (c *DBClient) ListTables() ([]string, error) {
+	if err := c.reconnectIfDbEmpty(); err != nil {
+		return nil, err
+	}
+
 	var sql string
 	switch c.dbType {
 	case MYSQL:
@@ -265,6 +269,10 @@ func (c *DBClient) ListTables() ([]string, error) {
 		tables = append(tables, table)
 	}
 
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("error iterating table rows: %w", err)
+	}
+
 	return tables, nil
 }
 
@@ -335,6 +343,10 @@ func (c *DBClient) Query(sql string, args ...interface{}) ([]map[string]interfac
 		results = append(results, rowMap)
 	}
 
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("failed to iterate table rows in Query: %w", err)
+	}
+
 	return results, nil
 }
 

plugins/golang-filter/mcp-server/servers/rag/vectordb/milvus.go

@@ -792,22 +792,36 @@ func (m *MilvusProvider) ListDocs(ctx context.Context, limit int) ([]schema.Docu
 			fieldName := strings.ToLower(fieldMapping.StandardName)
 			switch fieldName {
 			case "id":
-				if v, err := col.(*entity.ColumnVarChar).Get(i); err == nil {
-					id = v.(string)
+				if typedCol, ok := col.(*entity.ColumnVarChar); ok {
+					if v, err := typedCol.Get(i); err == nil {
+						if s, ok := v.(string); ok {
+							id = s
+						}
+					}
 				}
 			case "content":
-				if v, err := col.(*entity.ColumnVarChar).Get(i); err == nil {
-					content = v.(string)
+				if typedCol, ok := col.(*entity.ColumnVarChar); ok {
+					if v, err := typedCol.Get(i); err == nil {
+						if s, ok := v.(string); ok {
+							content = s
+						}
+					}
 				}
 			case "metadata":
-				if v, err := col.(*entity.ColumnJSONBytes).Get(i); err == nil {
-					if bytes, ok := v.([]byte); ok {
-						_ = json.Unmarshal(bytes, &metadata)
+				if typedCol, ok := col.(*entity.ColumnJSONBytes); ok {
+					if v, err := typedCol.Get(i); err == nil {
+						if bytes, ok := v.([]byte); ok {
+							_ = json.Unmarshal(bytes, &metadata)
+						}
 					}
 				}
 			case "created_at":
-				if v, err := col.(*entity.ColumnInt64).Get(i); err == nil {
-					createdAt = v.(int64)
+				if typedCol, ok := col.(*entity.ColumnInt64); ok {
+					if v, err := typedCol.Get(i); err == nil {
+						if ts, ok := v.(int64); ok {
+							createdAt = ts
+						}
+					}
 				}
 			}
 		}

plugins/wasm-go/extensions/request-block/main.go

@@ -87,13 +87,17 @@ func parseConfig(json gjson.Result, config *RequestBlockConfig, log log.Log) err
 		if regexpUrl == "" {
 			continue
 		}
+		var reg *regexp.Regexp
+		var err error
 		if config.caseSensitive {
-			reg := regexp.MustCompile(regexpUrl)
-			config.blockRegExpArray = append(config.blockRegExpArray, reg)
+			reg, err = regexp.Compile(regexpUrl)
 		} else {
-			reg := regexp.MustCompile(strings.ToLower(regexpUrl))
-			config.blockRegExpArray = append(config.blockRegExpArray, reg)
+			reg, err = regexp.Compile(strings.ToLower(regexpUrl))
 		}
+		if err != nil {
+			return fmt.Errorf("invalid regexp pattern %q: %w", regexpUrl, err)
+		}
+		config.blockRegExpArray = append(config.blockRegExpArray, reg)
 	}
 	for _, item := range json.Get("block_headers").Array() {
 		header := item.String()