passthrouth: fix passthrouth ttl

when `./Configure --api=1.0.0`, we should not use CRYPTO_set_id_callback().

.github/workflows/c-cpp.yml

@@ -0,0 +1,17 @@
+name: C/C++ CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: make
+      run: make

.gitignore

@@ -1,4 +1,4 @@
 .vscode
-.o
+*.o
 .DS_Store
-.swp.
+*.swp.

ReadMe.md

@@ -3,27 +3,34 @@
 **[English](ReadMe_en.md)**
 
 ![SmartDNS](doc/smartdns-banner.png)
-SmartDNS是一个运行在本地的DNS服务器，SmartDNS接受本地客户端的DNS查询请求，从多个上游DNS服务器获取DNS查询结果，并将访问速度最快的结果返回给客户端，提高网络访问速度。
+SmartDNS 是一个运行在本地的 DNS 服务器，它接受来自本地客户端的 DNS 查询请求，然后从多个上游 DNS 服务器获取 DNS 查询结果，并将访问速度最快的结果返回给客户端，以此提高网络访问速度。
-同时支持指定特定域名IP地址，并高性匹配，达到过滤广告的效果。  
+SmartDNS 同时支持指定特定域名 IP 地址，并高性匹配，可达到过滤广告的效果。  
-与dnsmasq的all-servers不同，smartdns返回的是访问速度最快的解析结果。 (详细差异请看[FAQ](#faq))  
+与 DNSmasq 的 all-servers 不同，SmartDNS 返回的是访问速度最快的解析结果。详细差异请看[常见问题](#常见问题)。
 
-支持树莓派，openwrt，华硕路由器，windows等设备。  
+支持树莓派、OpenWrt、华硕路由器原生固件和 Windows 系统等。  
 
 ## 目录
 
-1. [软件效果展示](#软件效果展示)
+- [SmartDNS](#smartdns)
-1. [特性](#特性)
+  - [目录](#目录)
-1. [架构](#架构)
+  - [软件效果展示](#软件效果展示)
-1. [使用](#使用)  
+  - [特性](#特性)
-    1. [下载配套安装包](#下载配套安装包)
+  - [架构](#架构)
-    1. [标准Linux系统安装](#标准linux系统安装树莓派x86_64系统)
+  - [下载](#下载)
-    1. [openwrt/LEDE](#openwrtlede)
+  - [安装和使用](#安装和使用)
-    1. [华硕路由器原生固件/梅林固件](#华硕路由器原生固件梅林固件)
+    - [标准 Linux 系统 / 树莓派](#标准-linux-系统--树莓派)
-    1. [optware/entware](#optwareentware)
+    - [OpenWrt](#openwrt)
-    1. [Windows 10 WSL安装/WSL ubuntu](#windows-10-wsl安装wsl-ubuntu)
+    - [华硕路由器原生固件 / 梅林固件](#华硕路由器原生固件--梅林固件)
-1. [配置参数](#配置参数)
+    - [Optware / Entware](#optware--entware)
-1. [捐助](#donate)
+    - [WSL](#wsl)
-1. [FAQ](#faq)
+  - [配置文件说明](#配置文件说明)
+  - [常见问题](#常见问题)
+  - [编译](#编译)
+  - [捐赠](#捐赠)
+    - [PayPal 贝宝](#paypal-贝宝)
+    - [AliPay 支付宝](#alipay-支付宝)
+    - [WeChat Pay 微信支付](#wechat-pay-微信支付)
+  - [开源声明](#开源声明)
 
 ## 软件效果展示
 
@@ -31,7 +38,7 @@ SmartDNS是一个运行在本地的DNS服务器，SmartDNS接受本地客户端
 使用阿里 DNS 查询百度IP，并检测结果。  
 
 ```shell
-pi@raspberrypi:~/code/smartdns_build $ nslookup www.baidu.com 223.5.5.5
+$ nslookup www.baidu.com 223.5.5.5
 Server:         223.5.5.5
 Address:        223.5.5.5#53
 
@@ -42,7 +49,7 @@ Address: 180.97.33.108
 Name:   www.a.shifen.com
 Address: 180.97.33.107
 
-pi@raspberrypi:~/code/smartdns_build $ ping 180.97.33.107 -c 2
+$ ping 180.97.33.107 -c 2
 PING 180.97.33.107 (180.97.33.107) 56(84) bytes of data.
 64 bytes from 180.97.33.107: icmp_seq=1 ttl=55 time=24.3 ms
 64 bytes from 180.97.33.107: icmp_seq=2 ttl=55 time=24.2 ms
@@ -60,11 +67,11 @@ PING 180.97.33.108 (180.97.33.108) 56(84) bytes of data.
 rtt min/avg/max/mdev = 31.014/31.094/31.175/0.193 ms
 ```
 
-**smartdns**  
+**SmartDNS**  
 使用 SmartDNS 查询百度 IP，并检测结果。
 
 ```shell
-pi@raspberrypi:~/code/smartdns_build $ nslookup www.baidu.com
+$ nslookup www.baidu.com
 Server:         192.168.1.1
 Address:        192.168.1.1#53
 
@@ -73,7 +80,7 @@ www.baidu.com   canonical name = www.a.shifen.com.
 Name:   www.a.shifen.com
 Address: 14.215.177.39
 
-pi@raspberrypi:~/code/smartdns_build $ ping 14.215.177.39 -c 2
+$ ping 14.215.177.39 -c 2
 PING 14.215.177.39 (14.215.177.39) 56(84) bytes of data.
 64 bytes from 14.215.177.39: icmp_seq=1 ttl=56 time=6.31 ms
 64 bytes from 14.215.177.39: icmp_seq=2 ttl=56 time=5.95 ms
@@ -81,138 +88,146 @@ PING 14.215.177.39 (14.215.177.39) 56(84) bytes of data.
 --- 14.215.177.39 ping statistics ---
 2 packets transmitted, 2 received, 0% packet loss, time 1001ms
 rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
-
 ```
 
-从对比看出，smartdns找到访问www.baidu.com最快的IP地址，这样访问百度比阿里DNS速度快5倍。
+从对比看出，SmartDNS 找到了访问 www.baidu.com 最快的 IP 地址，比阿里 DNS 速度快了 5 倍。
 
 ## 特性
 
 1. **多 DNS 上游服务器**  
    支持配置多个上游 DNS 服务器，并同时进行查询，即使其中有 DNS 服务器异常，也不会影响查询。  
 
-1. **返回最快IP地址**  
+2. **返回最快 IP 地址**  
    支持从域名所属 IP 地址列表中查找到访问速度最快的 IP 地址，并返回给客户端，提高网络访问速度。
 
-1. **支持多种查询协议**  
+3. **支持多种查询协议**  
-   支持UDP，TCP，TLS, HTTPS查询，以及非53端口查询。
+   支持 UDP、TCP、TLS 和 HTTPS 查询，以及非 53 端口查询。
 
-1. **特定域名IP地址指定**  
+4. **特定域名 IP 地址指定**  
-   支持指定域名的IP地址，达到广告过滤效果，避免恶意网站的效果。
+   支持指定域名的 IP 地址，达到广告过滤效果、避免恶意网站的效果。
 
-1. **域名高性能后缀匹配**  
+5. **域名高性能后缀匹配**  
-   支持域名后缀匹配模式，简化过滤配置，过滤20万条记录时间<1ms
+   支持域名后缀匹配模式，简化过滤配置，过滤 20 万条记录时间 < 1ms。
 
-1. **域名分流**  
+6. **域名分流**  
-   支持域名分流，不同类型的域名到不同的DNS服务器查询。
+   支持域名分流，不同类型的域名向不同的 DNS 服务器查询。
 
-1. **Linux/Windows多平台支持**  
+7. **Windows / Linux 多平台支持**  
-   支持标准Linux系统（树莓派），openwrt系统各种固件，华硕路由器原生固件。以及支持Windows 10 WSL (Windows Subsystem for Linux)。
+   支持标准 Linux 系统（树莓派）、OpenWrt 系统各种固件和华硕路由器原生固件。同时还支持 WSL（Windows Subsystem for Linux，适用于 Linux 的 Windows 子系统）。
 
-1. **支持IPV4, IPV6双栈**  
+8. **支持 IPv4、IPv6 双栈**  
-   支持IPV4，IPV6网络，支持查询A, AAAA记录，支持双栈IP速度优化，并支持完全禁用IPV6 AAAA解析。
+   支持 IPv4 和 IPV 6网络，支持查询 A 和 AAAA 记录，支持双栈 IP 速度优化，并支持完全禁用 IPv6 AAAA 解析。
 
-1. **高性能，占用资源少**  
+9. **高性能、占用资源少**  
    多线程异步 IO 模式，cache 缓存查询结果。
 
 ## 架构
 
-![Architecture](doc/architecture.png)
+![Architecture](https://github.com/pymumu/test/releases/download/blob/architecture.png)
 
-1. SmartDNS接收本地网络设备的DNS查询请求，如PC，手机的查询请求。  
+1. SmartDNS 接收本地网络设备的DNS 查询请求，如 PC、手机的查询请求；
-2. SmartDNS将查询请求发送到多个上游DNS服务器，可采用标准UDP查询，非标准端口UDP查询，及TCP查询。  
+2. 然后将查询请求发送到多个上游 DNS 服务器，可支持 UDP 标准端口或非标准端口查询，以及 TCP 查询；
-3. 上游DNS服务器返回域名对应的Server IP地址列表。SmartDNS检测与本地网络访问速度最快的Server IP。  
+3. 上游 DNS 服务器返回域名对应的服务器 IP 地址列表，SmartDNS 则会检测从本地网络访问速度最快的服务器 IP；
-4. 将访问速度最快的Server IP返回给本地客户端。  
+4. 最后将访问速度最快的服务器 IP 返回给本地客户端。
 
-## 使用
+## 下载
-
-### 下载配套安装包  
 
 --------------
 
-下载配套版本的SmartDNS安装包，对应安装包配套关系如下。
+下载对应系统或固件版本的 SmartDNS 安装包，对应关系如下。
 
-|系统 |安装包|说明
+| 支持系统（架构） | 安装包 | 支持说明 |
-|-----|-----|-----
+| :--- | :--- | :--- |
-|标准Linux系统(树莓派)| smartdns.xxxxxxxx.arm-debian-all.deb|支持树莓派Raspbian stretch，Debian 9系统。
+| 标准 Linux 系统（ARM） | smartdns.1.yyyy.MM.dd-REL.arm-debian-all.deb | ARM 的树莓派 Raspbian Stretch 和 Debian 9 系统 |
-|标准Linux系统(Armbian arm64)| smartdns.xxxxxxxx.aarch64-debian-all.deb|支持ARM64的Debian stretch，Debian 9系统。
+| 标准 Linux 系统（ARM64） | smartdns.1.yyyy.MM.dd-REL.aarch64-debian-all.deb | ARM64 的 Debian Stretch 和 Debian 9 系统 |
-|标准Linux系统(x86_64)| smartdns.xxxxxxxx.x86_64-linux-all.tar.gz|支持x86_64 Linux 系统。
+| 标准 Linux 系统（x86_64） | smartdns.1.yyyy.MM.dd-REL.x86_64-linux-all.tar.gz | 64 位 Linux 系统 |
-|Windows 10 WSL (ubuntu)| smartdns.xxxxxxxx.x86_64-linux-all.tar.gz|支持Windows 10 WSL ubuntu系统。
+| 标准 Linux 系统（x86） | smartdns.1.yyyy.MM.dd-REL.x86-linux-all.tar.gz | 32 位 Linux 系统 |
-|标准Linux系统(x86)| smartdns.xxxxxxxx.x86-linux-all.tar.gz|支持x86系统。
+| WSL | smartdns.1.yyyy.MM.dd-REL.x86_64-linux-all.tar.gz | WSL |
-|optware|smartdns.xxxxxxxx.mips-optware-all.ipk|支持MIPS大端架构的optware系统。
+| Optware | smartdns.1.yyyy.MM.dd-REL.mips-optware-all.ipk | MIPS 大端架构的 Optware 系统 |
-|optware|smartdns.xxxxxxxx.mipsel-optware-all.ipk|支持MIPS小端架构的optware系统。
+| Optware（MIPS Little Endian） | smartdns.1.yyyy.MM.dd-REL.mipsel-optware-all.ipk | MIPS 小端架构的 Optware 系统 |
-|optware|smartdns.xxxxxxxx.arm-optware-all.ipk|支持arm小端架构的optware系统。
+| Optware（ARM） | smartdns.1.yyyy.MM.dd-REL.arm-optware-all.ipk | ARM 小端架构的 Optware 系统 |
-|openwrt|smartdns.xxxxxxxx.mips-openwrt-all.ipk|支持MIPS大端架构的openwrt系统。
+| OpenWrt（MIPS） | smartdns.1.yyyy.MM.dd-REL.mips-openwrt-all.ipk | MIPS 大端架构的 OpenWrt 系统 |
-|openwrt|smartdns.xxxxxxxx.mipsel-openwrt-all.ipk|支持MIPS小端架构的openwrt系统。
+| OpenWrt（MIPS Little Endian） | smartdns.1.yyyy.MM.dd-REL.mipsel-openwrt-all.ipk | MIPS 小端架构的 OpenWrt 系统 |
-|openwrt|smartdns.xxxxxxxx.arm-openwrt-all.ipk|支持arm小端架构的openwrt系统。
+| OpenWrt（ARM） | smartdns.1.yyyy.MM.dd-REL.arm-openwrt-all.ipk | ARM 小端架构的 OpenWrt 系统 |
-|openwrt LUCI|luci-app-smartdns.xxxxxxxxx.all.ipk|openwrt管理界面。
+| OpenWrt LuCI | luci-app-smartdns.1.yyyy.MM.dd-REL.all.ipk | OpenWrt 管理界面 |
-|openwrt LUCI|luci-app-smartdns.xxxxxxxxx.all-luci-compat-all|兼容版本openwrt管理界面, openwrt 18.xx及之前版本安装。
+| OpenWrt LuCI | luci-app-smartdns.1.yyyy.MM.dd-REL.all-luci-compat-all.ipk | OpenWrt 管理界面、OpenWrt 18.xx 及之前版本 |
 
-* 单独release的软件包为静态编译软件包，无外部依赖，但体积大。若需要小体积软件包，请自行编译或从openwrt/entware仓库获取。
+**[前往 Release 页面下载](https://github.com/pymumu/smartdns/releases)。**
-* 因静态编译，软件包未强制判断CPU架构，安装不正确的软件包将会导致服务无法启动，请获取正确的软件包。
 
-* **请在Release页面下载：[点击此处下载](https://github.com/pymumu/smartdns/releases)**
+**请注意：**
 
-```shell
+* Release 释出的软件包采取静态编译，无外部依赖，但体积大。若需要小体积软件包，请自行编译或从 OpenWrt / Entware 仓库获取。
-https://github.com/pymumu/smartdns/releases
-```
 
-* 各种设备的安装步骤，请参考后面的章节。
+* 静态编译的软件包未强制判断 CPU 架构，安装不正确的软件包将会导致服务无法启动，请确保正确安装对应的版本。
 
-### 标准Linux系统安装/树莓派/X86_64系统
+## 安装和使用
+
+### 标准 Linux 系统 / 树莓派
 
 --------------
 
 1. 安装
    
-    下载配套安装包`smartdns.xxxxxxxx.arm-debian-all.deb`，并上传到Linux系统中。 执行如下命令安装
+   下载配套安装包，并上传到 Linux 系统中。 
+   
+   标准 Linux 系统（X86 / X86_64）请执行如下命令安装：
    
    ```shell
-    dpkg -i smartdns.xxxxxxxx.arm-debian-all.deb
+   $ tar zxf smartdns.1.yyyy.MM.dd-REL.x86_64-linux-all.tar.gz
+   $ cd smartdns
+   $ chmod +x ./install
+   $ ./install -i
    ```
    
-    x86系统下载配套安装包`smartdns.xxxxxxxx.x86_64-linux-all.tar.gz`, 并上传到Linux系统中。 执行如下命令安装
+   树莓派或其他 Debian 系系统（ARM / ARM64）请执行如下命令安装：
    
    ```shell
-    tar zxf smartdns.xxxxxxxx.x86_64-linux-all.tar.gz
+   # dpkg -i smartdns.1.yyyy.MM.dd-REL.arm-debian-all.deb
-    cd smartdns
-    chmod +x ./install
-    ./install -i
    ```
 
-1. 修改配置
+2. 修改配置
    
-    安装完成后，可配置smartdns的上游服务器信息。具体配置参数参考`配置参数`说明。  
+    安装完成后，可配置 SmartDNS 的上游服务器信息。
-    一般情况下，只需要增加`server [IP]:port`, `server-tcp [IP]:port`配置项，
+   
-    尽可能配置多个上游DNS服务器，包括国内外的服务器。配置参数请查看`配置参数`章节。
+    一般情况下，只需要增加 `server `[`IP`]`:port` 和 `server-tcp `[`IP`]`:port` 配置项。
+   
+    请尽可能配置多个上游 DNS 服务器，包括国内外的服务器。
+   
+    具体配置参数请参考[配置文件说明](#配置文件说明)。  
    
    ```shell
-    vi /etc/smartdns/smartdns.conf
+   # vi /etc/smartdns/smartdns.conf
    ```
 
-1. 启动服务
+3. 启动服务
    
    ```shell
-    systemctl enable smartdns
+   # systemctl enable smartdns
-    systemctl start smartdns
+   # systemctl start smartdns
    ```
 
-1. 将DNS请求转发的SmartDNS解析。
+4. 将 DNS 请求转发到 SmartDNS 解析
    
     修改本地路由器的 DNS 服务器，将 DNS 服务器配置为 SmartDNS。
-    * 登录到本地网络的路由器中，配置树莓派分配静态IP地址。
+   
+   * 登录到本地网络的路由器中，配置树莓派，分配其静态 IP 地址。
    * 修改 WAN 口或者 DHCP DNS 为树莓派 IP 地址。
-    注意：  
+     **注意：**
-    I. 每款路由器配置方法不尽相同，请百度搜索相关的配置方法。  
+      I. 每款路由器配置方法不尽相同，请在网络上搜索对应配置方法。
-    II.华为等路由器可能不支持配置DNS为本地IP，请修改PC端，手机端DNS服务器为树莓派IP。
+      II. 华为等路由器可能不支持配置 DNS 为本地 IP，可修改电脑端或手机端的 DNS 服务器为树莓派 IP。
 
-1. 检测服务是否配置成功。
+5. 检测服务是否配置成功
    
-    使用`nslookup -querytype=ptr smartdns`查询域名  
+    执行
-    看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
    
    ```shell
-    pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+   $ nslookup -querytype=ptr smartdns
+   ```
+   
+    查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+   
+   ```shell
+   $ nslookup -querytype=ptr smartdns
    Server:         192.168.1.1
    Address:        192.168.1.1#53
    
@@ -220,45 +235,51 @@ https://github.com/pymumu/smartdns/releases
    smartdns        name = smartdns.
    ```
 
-### openwrt
+### OpenWrt
 
 --------------
 
 1. 安装
    
-    将软件使用winscp上传到路由器的/root目录，执行如下命令安装  
+    将软件包（使用 WinSCP 等）上传到路由器的 `/root` 目录，执行如下命令安装
    
    ```shell
-    opkg install smartdns.xxxxxxxx.xxxx.ipk
+   # opkg install smartdns.1.yyyy.MM.dd-REL.xxxx.ipk
-    opkg install luci-app-smartdns.xxxxxxxx.xxxx.all.ipk
+   # opkg install luci-app-smartdns.1.yyyy.MM.dd-REL.all.ipk
    ```
    
-    * 注意： 19.07之前的版本，请安装`luci-app-smartdns.xxxxxxxxx.all-luci-compat-all`界面。
+   * **注意：** 19.07 之前的版本，请务必安装 `luci-app-smartdns.1.yyyy.MM.dd-REL.all-luci-compat-all.ipk`。
 
-1. 修改配置
+2. 修改配置
+   
+    登录 OpenWrt 管理页面，打开 `Services` -> `SmartDNS` 进行配置。
    
-    登录openwrt管理页面，打开`Services`->`SmartDNS`进行配置。
    * 在 `Upstream Servers` 增加上游 DNS 服务器配置，建议配置多个国内外 DNS 服务器。
    * 在 `Domain Address` 指定特定域名的 IP 地址，可用于广告屏蔽。
 
-1. 启用服务
+3. 启用服务
    
-   SmartDNS服务生效方法有两种，`一种是直接作为主DNS服务`；`另一种是作为dnsmasq的上游`。  
+   SmartDNS 服务生效方法有两种，一种是**直接作为主 DNS 服务**，另一种是**作为 DNSmasq 的上游**。
    默认情况下，SmartDNS 采用第一种方式。如下两种方式根据需求选择即可。
    
-1. 启用方法一：作为主DNS(默认方案)
+   - **方法一：作为主 DNS 服务（默认方案）**
      
-    * **启用smartdns的53端口重定向**
+     * 启用 SmartDNS 的 53 端口重定向
        
-        登录路由器，点击`Services`->`SmartDNS`->`redirect`，选择`重定向53端口到SmartDNS`启用53端口转发。
+       登录 OpenWrt 管理界面，点击 `Services` -> `SmartDNS` -> `redirect`，选择 `重定向 53 端口到 SmartDNS `启用 53 端口转发。
      
-    * **检测转发服务是否配置成功**
+     * 检测转发服务是否配置成功
        
-        使用`nslookup -querytype=ptr smartdns`查询域名  
+       执行
-        看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
        
        ```shell
-        pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+       $ nslookup -querytype=ptr smartdns
+       ```
+       
+       查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+       
+       ```shell
+       $ nslookup -querytype=ptr smartdns
        Server:         192.168.1.1
        Address:        192.168.1.1#53
        
@@ -266,32 +287,42 @@ https://github.com/pymumu/smartdns/releases
        smartdns        name = smartdns.
        ```
      
-    * **界面提示重定向失败**
+     * 界面提示重定向失败
        
-        * 检查iptable，ip6table命令是否正确安装。
+       * 检查 `iptables` 和/或 `ip6tables` 命令是否正确安装。
-        * openwrt 15.01系统不支持IPV6重定向，如网络需要支持IPV6，请将DNSMASQ上游改为smartdns，或者将smartdns的端口改为53，并停用dnsmasq。
+       
-        * LEDE之后系统，请安装IPV6的nat转发驱动。点击`system`->`Software`，点击`update lists`更新软件列表后，安装`ip6tables-mod-nat`
+       * OpenWrt 15.01 系统不支持 IPv6 重定向，如网络需要支持 IPv6，请将 DNSmasq 上游改为 SmartDNS，或者将 SmartDNS 的端口改为53，并停用 DNSmasq。
-        * 使用如下命令检查路由规则是否生效。  
+       
+       * LEDE 系统请安装 IPv6 的 NAT 转发驱动。点击 `System` -> `Software`，点击 `Update lists` 更新软件列表后，安装 `ip6tables-mod-nat`。
+       
+       * 使用如下命令检查路由规则是否生效
          
          ```shell
          iptables -t nat -L PREROUTING | grep REDIRECT
          ```
        
-        * 如转发功能不正常，请使用方法二：作为DNSMASQ的上游。
+       * 如转发功能不正常，请使用**方法二：作为 DNSmasq 的上游**。
    
-1. 方法二：作为DNSMASQ的上游
+   - **方法二：作为 DNSmasq 的上游**
      
-    * **将dnsmasq的请求发送到smartdns**
+     * **将 DNSmasq 的请求发送到 SmartDNS**
        
-        登录路由器，点击`Services`->`SmartDNS`->`redirect`，选择`作为dnsmasq的上游服务器`设置dnsmasq的上游服务器为smartdns。
+       登录 OpenWrt 管理界面，点击 `Services` -> `SmartDNS` -> `Redirect`，选择`作为 DNSmasq 的上游服务器`，设置 DNSmasq 的上游服务器为 SmartDNS。
      
      * **检测上游服务是否配置成功**
        
-        * 方法一：使用`nslookup -querytype=ptr smartdns`查询域名  
+       * 方法一
-        看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
+         
+         执行
          
          ```shell
-        pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+         $ nslookup -querytype=ptr smartdns
+         ```
+         
+         查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+         
+         ```shell
+         $ nslookup -querytype=ptr smartdns
          Server:         192.168.1.1
          Address:        192.168.1.1#53
          
@@ -299,10 +330,12 @@ https://github.com/pymumu/smartdns/releases
          smartdns        name = smartdns.
          ```
        
-        * 方法二：使用`nslookup`查询`www.baidu.com`域名，查看结果中百度的IP地址是否`只有一个`，如有多个IP地址返回，则表示未生效，请多尝试几个域名检查。
+       * 方法二
+         
+         使用 `nslookup` 查询域名（例如 `www.baidu.com`），查看结果中 IP 地址是否**只有一个**，如有多个 IP 地址返回，则表示未生效，请多尝试几个域名检查。
          
          ```shell
-        pi@raspberrypi:~ $ nslookup www.baidu.com 192.168.1.1
+         $ nslookup www.baidu.com 192.168.1.1
          Server:         192.168.1.1
          Address:        192.168.1.1#53
          
@@ -312,50 +345,55 @@ https://github.com/pymumu/smartdns/releases
          Address: 14.215.177.38
          ```
 
-1. 启动服务
+4. 启动服务
    
-    勾选配置页面中的`Enable(启用)`来启动SmartDNS
+    勾选配置页面中的 `Enable（启用）`来启动 SmartDNS。
 
-1. 注意：
+5. **注意：**
    
-    * 如已经安装chinaDNS，建议将chinaDNS的上游配置为SmartDNS。
+   * 如已经安装 ChinaDNS，建议将 ChinaDNS 的上游配置为 SmartDNS。
-    * SmartDNS默认情况，将53端口的请求转发到SmartDNS的本地端口，由`Redirect`配置选项控制。
+   * SmartDNS 默认情况下将 53 端口的请求转发到 SmartDNS的 本地端口，此行为由 `Redirect` 配置选项控制。
 
 ### 华硕路由器原生固件 / 梅林固件
 
 --------------
 
-说明：梅林固件派生自华硕固件，理论上可以直接使用华硕配套的安装包使用。但目前未经验证，如有问题，请提交issue。
+**说明：** 梅林固件派生自华硕固件，理论上可以直接使用华硕配套的安装包使用。但目前未经验证，如有问题，请提交 Issue。
 
 1. 准备
    
     在使用此软件时，需要确认路由器是否支持 U 盘，并准备好 U 盘一个。
 
-1. 启用SSH登录
+2. 启用 SSH 登录
    
-    登录管理界面，点击`系统管理`->点击`系统设置`，配置`Enable SSH`为`Lan Only`。  
+    登录管理界面，点击 `系统管理` -> `系统设置`，配置 `Enable SSH` 为 `Lan Only`。  
     SSH 登录用户名密码与管理界面相同。
 
-1. 下载`Download Master`
+3. 下载 `Download Master`
    
-    在管理界面点击`USB相关应用`->点击`Download Master`下载。  
+    在管理界面点击 `USB 相关应用` -> `Download Master` 下载。  
-    下载完成后，启用`Download Master`，如果不需要下载功能，此处可以卸载`Download Master`，但要保证卸载前Download Master是启用的。  
+    下载完成后，启用 `Download Master`，如果不需要下载功能，此时可以卸载 `Download Master`，但要保证卸载前 `Download Master` 是启用的。  
 
-1. 安装SmartDNS
+4. 安装 SmartDNS
    
-    将软件使用winscp上传到路由器的`/tmp/mnt/sda1`目录。（或网上邻居复制到sda1共享目录）
+    将软件包（使用 WinSCP 等）上传到路由器的 `/tmp/mnt/sda1` 目录（或网上邻居复制到 sda1 共享目录），执行如下命令安装
    
    ```shell
-    ipkg install smartdns.xxxxxxx.mipsbig.ipk
+   # ipkg install smartdns.1.yyyy.MM.dd-REL.mipsbig.ipk
    ```
 
-1. 重启路由器生效服务
+5. 重启路由器使服务生效
    
-    待路由器启动后，使用`nslookup -querytype=ptr smartdns`查询域名  
+    待路由器启动后， 执行
-    看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
    
    ```shell
-    pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+   $ nslookup -querytype=ptr smartdns
+   ```
+   
+    查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+   
+   ```shell
+   $ nslookup -querytype=ptr smartdns
    Server:         192.168.1.1
    Address:        192.168.1.1#53
    
@@ -363,10 +401,10 @@ https://github.com/pymumu/smartdns/releases
    smartdns        name = smartdns.
    ```
 
-1. 额外说明
+6. **额外说明**
    
-    上述过程，smartdns将安装到U盘根目录，采用optware的模式运行。
+    上述过程，SmartDNS 将安装到 U 盘根目录，采用 Optware 的模式运行。
-    其目录结构如下： （此处仅列出smartdns相关文件）  
+    其目录结构如下（此处仅列出 SmartDNS 相关文件）： 
    
    ```shell
    U 盘
@@ -385,10 +423,10 @@ https://github.com/pymumu/smartdns/releases
            ....
    ```
    
-    如要修改配置，可以ssh登录路由器，使用vi命令修改  
+    如要修改配置，可以 SSH 登录路由器，使用 vi 命令修改
    
    ```shell
-    vi /opt/etc/smartdns/smartdns.conf
+   # vi /opt/etc/smartdns/smartdns.conf
    ```
    
    也可以通过网上邻居修改，网上邻居共享目录 `sda1` 看不到 `asusware.mipsbig` 目录，但可以直接在`文件管理器`中输入 `asusware.mipsbig\etc\init.d` 访问
@@ -397,7 +435,7 @@ https://github.com/pymumu/smartdns/releases
    \\192.168.1.1\sda1\asusware.mipsbig\etc\init.d
    ```
 
-### optware/entware
+### Optware / Entware
 
 --------------
 
@@ -405,33 +443,38 @@ https://github.com/pymumu/smartdns/releases
    
     在使用此软件时，需要确认路由器是否支持 U 盘，并准备好 U 盘一个。
 
-1. 安装SmartDNS
+2. 安装 SmartDNS
    
-    将软件使用winscp上传到路由器的`/tmp`目录。
+    将软件（使用 WinSCP 等）上传到路由器的 `/tmp` 目录，执行如下命令安装
    
    ```shell
-    ipkg install smartdns.xxxxxxx.mipsbig.ipk
+   # ipkg install smartdns.1.yyyy.MM.dd-REL.mipsbig.ipk
    ```
 
-1. 修改smartdns配置
+3. 修改 SmartDNS 配置
    
    ```shell
-    vi /opt/etc/smartdns/smartdns.conf
+   # vi /opt/etc/smartdns/smartdns.conf
    ```
    
-    另外，如需支持IPV6，可设置工作模式为`2`，将dnsmasq的DNS服务禁用，smartdns为主用DNS服务器。将文件`/opt/etc/smartdns/smartdns-opt.conf`，中的`SMARTDNS_WORKMODE`修改为2.
+    另外，如需支持 IPv6，可设置工作模式为 `2`，将 DNSmasq 的 DNS 服务禁用，设置 SmartDNS 为主用 DNS 服务器。将文件 `/opt/etc/smartdns/smartdns-opt.conf` 中的 `SMARTDNS_WORKMODE` 的值修改为 `2`
    
    ```shell
    SMARTDNS_WORKMODE="2"
    ```
 
-1. 重启路由器生效服务
+4. 重启路由器使服务生效
    
-    待路由器启动后，使用`nslookup -querytype=ptr smartdns`查询域名  
+    待路由器启动后， 执行
-    看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
    
    ```shell
-    pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+   $ nslookup -querytype=ptr smartdns
+   ```
+   
+    查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+   
+   ```shell
+   $ nslookup -querytype=ptr smartdns
    Server:         192.168.1.1
    Address:        192.168.1.1#53
    
@@ -439,19 +482,19 @@ https://github.com/pymumu/smartdns/releases
    smartdns        name = smartdns.
    ```
    
-    注意：若服务没有自动启动，则需要设置optwre/entware自动启动，具体方法参考optware/entware的文档。
+    **注意：** 若服务没有自动启动，则需要设置 Optware / Entware 自动启动，具体方法请参考 Optware/Entware 的文档。
 
-### Windows 10 WSL安装/WSL ubuntu
+### WSL
 
 --------------
 
-1. 安装Windows 10 WSL ubuntu系统
+1. 安装 WSL
    
-    安装Windows 10 WSL运行环境，发行版本选择ubuntu系统。安装步骤请参考[WSL安装说明](https://docs.microsoft.com/en-us/windows/wsl/install-win10)
+    安装 WSL 运行环境，发行版本选择 Ubuntu 系统为例。安装步骤请参考 [WSL 安装说明](https://docs.microsoft.com/zh-CN/windows/wsl/install)
 
-1. 安装smartdns
+2. 安装 SmartDNS
    
-    下载安装包`smartdns.xxxxxxxx.x86-linux-all.tar.gz`，并解压到D盘根目录。解压后目录如下：
+    下载适用于 WSL 的安装包，并解压到如 D 盘根目录。解压后目录如下：
    
    ```shell
    D:\SMARTDNS
@@ -463,32 +506,39 @@ https://github.com/pymumu/smartdns/releases
    │  └─windows
    ├─src
    └─systemd
-
    ```
    
      双击 `D:\smartdns\package\windows` 目录下的 `install.bat` 进行安装。要求输入密码时，请输入 `WLS ubuntu` 的密码。
 
-1. 修改配置
+3. 修改配置
    
-    记事本打开`D:\smartdns\etc\smartdns`目录中的`smartdns.conf`配置文件配置smartdns。具体配置参数参考`配置参数`说明。  
+    用记事本等打开 `D:\smartdns\etc\smartdns` 目录中的 `smartdns.conf` 配置文件配置 SmartDNS。
-    一般情况下，只需要增加`server [IP]:port`, `server-tcp [IP]:port`配置项，
-    尽可能配置多个上游DNS服务器，包括国内外的服务器。配置参数请查看`配置参数`章节。
    
-1. 重新加载配置
+    一般情况下，只需要增加 `server [IP]:port` 和 `server-tcp [IP]:port` 配置项，
+    尽可能配置多个上游DNS服务器，包括国内外的服务器。
    
-    双击`D:\smartdns\package\windows`目录下的`reload.bat`进行安装。要求输入密码时，请输入`WLS ubuntu`的密码。
+    具体配置请参考[配置文件说明](#配置文件说明)。
 
-1. 将DNS请求转发的SmartDNS解析。
+4. 重新加载配置
    
-    将Windows的默认DNS服务器修改为`127.0.0.1`，具体步骤参考[IP配置](https://support.microsoft.com/zh-cn/help/15089/windows-change-tcp-ip-settings)
+    双击 `D:\smartdns\package\windows` 目录下的 `reload.bat` 进行重新加载。要求输入密码时，请输入 `WLS ubuntu` 的密码。
 
-1. 检测服务是否配置成功。
+5. 将 DNS 请求转发到 SmartDNS 解析
    
-    使用`nslookup -querytype=ptr smartdns`查询域名  
+    将 Windows 的默认 DNS 服务器修改为 `127.0.0.1`，具体步骤参考 Windows [更改 TCP/IP 设置](https://support.microsoft.com/zh-cn/help/15089/windows-change-tcp-ip-settings)。
-    看命令结果中的`name`项目是否显示为`smartdns`或`主机名`，如`smartdns`则表示生效  
+
+6. 检测服务是否配置成功
+   
+    执行
    
    ```shell
-    pi@raspberrypi:~/code/smartdns_build $ nslookup -querytype=ptr smartdns
+   $ nslookup -querytype=ptr smartdns
+   ```
+   
+    查看命令结果中的 `name` 是否为 `smartdns` 或你的主机名，如果是则表示生效
+   
+   ```shell
+   $ nslookup -querytype=ptr smartdns
    Server:         192.168.1.1
    Address:        192.168.1.1#53
    
@@ -496,107 +546,119 @@ https://github.com/pymumu/smartdns/releases
    smartdns        name = smartdns.
    ```
 
-## 配置参数
+## 配置文件说明
 
-|参数|  功能  |默认值|配置值|例子|
+| 键名 | 功能说明 | 默认值 | 可用值/要求 | 举例 |
-|--|--|--|--|--|
+| :--- | :--- | :--- | :--- | :--- |
-|server-name|DNS服务器名称|操作系统主机名/smartdns|符合主机名规格的字符串|server-name smartdns
+| `server-name` | DNS 服务器名称 | 操作系统主机名 / `smartdns` | 符合主机名规格的字符串 | `server-name smartdns` |
-|bind|DNS监听端口号|[::]:53|可绑定多个端口<br>`IP:PORT`: 服务器IP，端口号。<br>`[-group]`: 请求时使用的DNS服务器组。<br>`[-no-rule-addr]`：跳过address规则。<br>`[-no-rule-nameserver]`：跳过Nameserver规则。<br>`[-no-rule-ipset]`：跳过Ipset规则。<br>`[no-rule-soa]`：跳过SOA(#)规则.<br>`[no-dualstack-selection]`：停用双栈测速。<br>`[-no-speed-check]`：停用测速。<br>`[-no-cache]`：停止缓存|bind :53
+| `bind` | DNS 监听端口号  | `[::]:53` | 可绑定多个端口。<br>`IP:PORT`: 服务器 IP:端口号<br>[`-group`]: 请求时使用的 DNS 服务器组<br>[`-no-rule-addr`]：跳过 address 规则<br>[`-no-rule-nameserver`]：跳过 Nameserver 规则<br>[`-no-rule-ipset`]：跳过 ipset 规则<br>[`-no-rule-soa`]：跳过 SOA(#) 规则<br>[`-no-dualstack-selection`]：停用双栈测速<br>[`-no-speed-check`]：停用测速<br>[`-no-cache`]：停止缓存 | `bind :53` |
-|bind-tcp|TCP DNS监听端口号|[::]:53|可绑定多个端口<br>`IP:PORT`: 服务器IP，端口号。<br>`[-group]`: 请求时使用的DNS服务器组。<br>`[-no-rule-addr]`：跳过address规则。<br>`[-no-rule-nameserver]`：跳过Nameserver规则。<br>`[-no-rule-ipset]`：跳过Ipset规则。<br>`[no-rule-soa]`：跳过SOA(#)规则.<br>`[no-dualstack-selection]`：停用双栈测速。<br>`[-no-speed-check]`：停用测速。<br>`[-no-cache]`：停止缓存|bind-tcp :53
+| `bind-tcp` | DNS TCP 监听端口号 | `[::]:53` | 可绑定多个端口。<br>`IP:PORT`: 服务器 IP:端口号<br>[`-group`]: 请求时使用的 DNS 服务器组<br>[`-no-rule-addr`]：跳过 address 规则<br>[`-no-rule-nameserver`]：跳过 `nameserver` 规则<br>[`-no-rule-ipset`]：跳过 `ipset` 规则。<br>[`-no-rule-soa`]：跳过 SOA(#) 规则<br>[`-no-dualstack-selection`]：停用双栈测速<br>[`-no-speed-check`]：停用测速<br>[`-no-cache`]：停止缓存 | `bind-tcp :53` |
-|cache-size|域名结果缓存个数|512|数字|cache-size 512
+| `cache-size` | 域名结果缓存个数 | `512` | 大于等于 `0` 的数字 | `cache-size 512` |
-|tcp-idle-time|TCP链接空闲超时时间|120|数字|tcp-idle-time 120
+| `cache-persist` | 是否持久化缓存 | 自动。<br>当 `cache-file` 所在的位置有超过 128 MB 的可用空间时启用，否则禁用。 | [`yes`\|`no`] | `cache-persist yes` |
-|rr-ttl|域名结果TTL|远程查询结果|大于0的数字|rr-ttl 600
+| `cache-file` | 缓存持久化文件路径 | `/tmp/smartdns.cache` | 合法路径字符串 | `cache-file /tmp/smartdns.cache` |
-|rr-ttl-min|允许的最小TTL值|远程查询结果|大于0的数字|rr-ttl-min 60
+| `tcp-idle-time` | TCP 链接空闲超时时间 | `120` | 大于等于 `0` 的数字 | `tcp-idle-time 120` |
-|rr-ttl-max|允许的最大TTL值|远程查询结果|大于0的数字|rr-ttl-max 600
+| `rr-ttl` | 域名结果 TTL | 远程查询结果 | 大于 `0` 的数字 | `rr-ttl 600` |
-|log-level|设置日志级别|error|fatal,error,warn,notice,info,debug|log-level error
+| `rr-ttl-min` | 允许的最小 TTL 值 | 远程查询结果 | 大于 `0` 的数字 | `rr-ttl-min 60` |
-|log-file|日志文件路径|/var/log/smartdns.log|路径|log-file /var/log/smartdns.log
+| `rr-ttl-max` | 允许的最大 TTL 值 | 远程查询结果 | 大于 `0` 的数字 | `rr-ttl-max 600` |
-|log-size|日志大小|128K|数字+K,M,G|log-size 128K
+| `rr-ttl-reply-max` | 允许返回给客户端的最大 TTL 值 | 远程查询结果 | 大于 `0` 的数字 | `rr-ttl-reply-max 60` |
-|log-num|日志归档个数|2|数字|log-num 2
+| `log-level` | 设置日志级别 | `error` | `fatal`、`error`、`warn`、`notice`、`info` 或 `debug` | `log-level error` |
-|audit-enable|设置审计启用|no|[yes\|no]|audit-enable yes
+| `log-file` | 日志文件路径 | `/var/log/smartdns.log` | 合法路径字符串 | `log-file /var/log/smartdns.log` |
-|audit-file|审计文件路径|/var/log/smartdns-audit.log|路径|audit-file /var/log/smartdns-audit.log
+| `log-size` | 日志大小 | `128K` | 数字 + `K`、`M` 或 `G` | `log-size 128K` |
-|audit-size|审计大小|128K|数字+K,M,G|audit-size 128K
+| `log-num` | 日志归档个数 | `2` | 大于等于 `0` 的数字 | `log-num 2` |
-|audit-num|审计归档个数|2|数字|audit-num 2
+| `audit-enable` | 设置审计启用 | `no` | [`yes`\|`no`] | `audit-enable yes` |
-|conf-file|附加配置文件|无|文件路径|conf-file /etc/smartdns/smartdns.more.conf
+| `audit-file` | 审计文件路径 | `/var/log/smartdns-audit.log` | 合法路径字符串 | `audit-file /var/log/smartdns-audit.log` |
-|server|上游UDP DNS|无|可重复<br>`[ip][:port]`：服务器IP，端口可选。<br>`[-blacklist-ip]`：blacklist-ip参数指定使用blacklist-ip配置IP过滤结果。<br>`[-whitelist-ip]`：whitelist-ip参数指定仅接受whitelist-ip中配置IP范围。<br>`[-group [group] ...]`：DNS服务器所属组，比如office, foreign，和nameserver配套使用。<br>`[-exclude-default-group]`：将DNS服务器从默认组中排除| server 8.8.8.8:53 -blacklist-ip -group g1
+| `audit-size` | 审计大小 | `128K` | 数字 + `K`、`M` 或 `G` | `audit-size 128K` |
-|server-tcp|上游TCP DNS|无|可重复<br>`[ip][:port]`：服务器IP，端口可选。<br>`[-blacklist-ip]`：blacklist-ip参数指定使用blacklist-ip配置IP过滤结果。<br>`[-whitelist-ip]`：whitelist-ip参数指定仅接受whitelist-ip中配置IP范围。<br>`[-group [group] ...]`：DNS服务器所属组，比如office, foreign，和nameserver配套使用。<br>`[-exclude-default-group]`：将DNS服务器从默认组中排除| server-tcp 8.8.8.8:53
+| `audit-num` | 审计归档个数 | `2` | 大于等于 `0` 的数字 | `audit-num 2` |
-|server-tls|上游TLS DNS|无|可重复<br>`[ip][:port]`：服务器IP，端口可选。<br>`[-spki-pin [sha256-pin]]`: TLS合法性校验SPKI值，base64编码的sha256 SPKI pin值<br>`[-host-name]`：TLS SNI名称。<br>`[-tls-host-verify]`: TLS证书主机名校验。<br> `-no-check-certificate:`：跳过证书校验。<br>`[-blacklist-ip]`：blacklist-ip参数指定使用blacklist-ip配置IP过滤结果。<br>`[-whitelist-ip]`：whitelist-ip参数指定仅接受whitelist-ip中配置IP范围。<br>`[-group [group] ...]`：DNS服务器所属组，比如office, foreign，和nameserver配套使用。<br>`[-exclude-default-group]`：将DNS服务器从默认组中排除| server-tls 8.8.8.8:853
+| `conf-file` | 附加配置文件 | 无 | 合法路径字符串 | `conf-file /etc/smartdns/smartdns.more.conf` |
-|server-https|上游HTTPS DNS|无|可重复<br>`https://[host][:port]/path`：服务器IP，端口可选。<br>`[-spki-pin [sha256-pin]]`: TLS合法性校验SPKI值，base64编码的sha256 SPKI pin值<br>`[-host-name]`：TLS SNI名称<br>`[-http-host]`：http协议头主机名。<br>`[-tls-host-verify]`: TLS证书主机名校验。<br> `-no-check-certificate:`：跳过证书校验。<br>`[-blacklist-ip]`：blacklist-ip参数指定使用blacklist-ip配置IP过滤结果。<br>`[-whitelist-ip]`：whitelist-ip参数指定仅接受whitelist-ip中配置IP范围。<br>`[-group [group] ...]`：DNS服务器所属组，比如office, foreign，和nameserver配套使用。<br>`[-exclude-default-group]`：将DNS服务器从默认组中排除| server-https https://cloudflare-dns.com/dns-query
+| `server` | 上游 UDP DNS | 无 | 可重复。<br>[`ip`][`:port`]：服务器 IP:端口（可选）<br>[`-blacklist-ip`]：配置 IP 过滤结果。<br>[`-whitelist-ip`]：指定仅接受参数中配置的 IP 范围<br>[`-group` [`group`] ...]：DNS 服务器所属组，比如 `office` 和 `foreign`，和 `nameserver` 配套使用<br>[`-exclude-default-group`]：将 DNS 服务器从默认组中排除 | `server 8.8.8.8:53 -blacklist-ip -group g1` |
-|speed-check-mode|测速模式选择|无|[ping\|tcp:[80]\|none]|speed-check-mode ping,tcp:80
+| `server-tcp` | 上游 TCP DNS | 无 | 可重复。<br>[`ip`][`:port`]：服务器 IP:端口（可选）<br>[`-blacklist-ip`]：配置 IP 过滤结果<br>[`-whitelist-ip`]：指定仅接受参数中配置的 IP 范围。<br>[`-group` [`group`] ...]：DNS 服务器所属组，比如 `office` 和 `foreign`，和 `nameserver` 配套使用<br>[`-exclude-default-group`]：将 DNS 服务器从默认组中排除  | `server-tcp 8.8.8.8:53` |
-|address|指定域名IP地址|无|address /domain/[ip\|-\|-4\|-6\|#\|#4\|#6] <br>`-`表示忽略 <br>`#`表示返回SOA <br>`4`表示IPV4 <br>`6`表示IPV6| address /www.example.com/1.2.3.4
+| `server-tls` | 上游 TLS DNS | 无 | 可重复。<br>[`ip`][`:port`]：服务器 IP:端口（可选)<br>[`-spki-pin` [`sha256-pin`]]：TLS 合法性校验 SPKI 值，base64 编码的 sha256 SPKI pin 值<br>[`-host-name`]：TLS SNI 名称<br>[`-tls-host-verify`]：TLS 证书主机名校验<br> [`-no-check-certificate`]：跳过证书校验<br>[`-blacklist-ip`]：配置 IP 过滤结果<br>[`-whitelist-ip`]：仅接受参数中配置的 IP 范围<br>[`-group` [`group`] ...]：DNS 服务器所属组，比如 `office` 和 `foreign`，和 `nameserver` 配套使用<br>[`-exclude-default-group`]：将 DNS 服务器从默认组中排除 | `server-tls 8.8.8.8:853` |
-|nameserver|指定域名使用server组解析|无|nameserver /domain/[group\|-], `group`为组名，`-`表示忽略此规则，配套server中的`-group`参数使用| nameserver /www.example.com/office
+| `server-https` | 上游 HTTPS DNS | 无 | 可重复。<br>`https://`[`host`][`:port`]`/path`：服务器 IP:端口（可选）<br>[`-spki-pin` [`sha256-pin`]]：TLS 合法性校验 SPKI 值，base64 编码的 sha256 SPKI pin 值<br>[`-host-name`]：TLS SNI 名称<br>[`-http-host`]：http 协议头主机名<br>[`-tls-host-verify`]：TLS 证书主机名校验<br> [`-no-check-certificate`]：跳过证书校验<br>[`-blacklist-ip`]：配置 IP 过滤结果<br>[`-whitelist-ip`]：仅接受参数中配置的 IP 范围。<br>[`-group` [`group`] ...]：DNS 服务器所属组，比如 office 和 foreign，和 nameserver 配套使用<br>[`-exclude-default-group`]：将 DNS 服务器从默认组中排除 | `server-https https://cloudflare-dns.com/dns-query` |
-|ipset|域名IPSET|None|ipset /domain/[ipset\|-], `-`表示忽略|ipset /www.example.com/pass
+| `speed-check-mode` | 测速模式选择 | 无 | [`ping`\|`tcp:`[`80`]\|`none`] | `speed-check-mode ping,tcp:80` |
-|ipset-timeout|设置IPSET超时功能启用|auto|[yes]|ipset-timeout yes
+| `address` | 指定域名 IP 地址 | 无 | `address /domain/`[`ip`\|`-`\|`-4`\|`-6`\|`#`\|`#4`\|`#6`] <br>`-` 表示忽略 <br>`#` 表示返回 SOA <br>`4` 表示 IPv4 <br>`6` 表示 IPv6 | `address /www.example.com/1.2.3.4` |
-|domain-rules|设置域名规则|无|domain-rules /domain/ [-rules...]<br>`[-speed-check-mode]`: 测速模式，参考`speed-check-mode`配置<br>`[-address]`: 参考`address`配置<br>`[-nameserver]`: 参考`nameserver`配置<br>`[-ipset]`:参考`ipset`配置|domain-rules /www.example.com/ -speed-check-mode none
+| `nameserver` | 指定域名使用 `server` 组解析 | 无 | `nameserver /domain/`[`group`\|`-`], `group` 为组名，`-` 表示忽略此规则，配套 `server` 中的 `-group` 参数使用 | `nameserver /www.example.com/office` |
-|bogus-nxdomain|假冒IP地址过滤|无|[ip/subnet]，可重复| bogus-nxdomain 1.2.3.4/16
+| `ipset` | 域名 ipset | 无 | `ipset /domain/`[`ipset`\|`-`\|`#`[`4`\|`6`]:[`ipset`\|`-`][`,#`[`4`\|`6`]`:`[`ipset`\|`-`]]]，`-`表示忽略 | `ipset /www.example.com/#4:dns4,#6:-` |
-|ignore-ip|忽略IP地址|无|[ip/subnet]，可重复| ignore-ip 1.2.3.4/16
+| `ipset-timeout` | 设置 `ipset` 超时功能启用  | 自动 | [`yes`] | `ipset-timeout yes` |
-|whitelist-ip|白名单IP地址|无|[ip/subnet]，可重复| whitelist-ip 1.2.3.4/16
+| `domain-rules` | 设置域名规则 | 无 | `domain-rules /domain/` [`-rules`...]<br>[`-c`\|`-speed-check-mode`]：测速模式，参考 `speed-check-mode` 配置<br>[`-a`\|`-address`]：参考 `address` 配置<br>[`-n`\|`-nameserver`]：参考 `nameserver` 配置<br>[`-p`\|`-ipset`]：参考`ipset`配置<br>[`-d`\|`-dualstack-ip-selection`]：参考 `dualstack-ip-selection`  | `domain-rules /www.example.com/ -speed-check-mode none` |
-|blacklist-ip|黑名单IP地址|无|[ip/subnet]，可重复| blacklist-ip 1.2.3.4/16
+| `bogus-nxdomain` | 假冒 IP 地址过滤 | 无 | [`ip/subnet`]，可重复 | `bogus-nxdomain 1.2.3.4/16` |
-|force-AAAA-SOA|强制AAAA地址返回SOA|no|[yes\|no]|force-AAAA-SOA yes
+| `ignore-ip` | 忽略 IP 地址 | 无 | [`ip/subnet`]，可重复 | `ignore-ip 1.2.3.4/16` |
-|prefetch-domain|域名预先获取功能|no|[yes\|no]|prefetch-domain yes
+| `whitelist-ip` | 白名单 IP 地址 | 无 | [`ip/subnet`]，可重复 | `whitelist-ip 1.2.3.4/16` |
-|serve-expired|过期缓存服务功能|no|[yes\|no]，开启此功能后，如果有请求时尝试回应TTL为0的过期记录，并并发查询记录，以避免查询等待|serve-expired yes
+| `blacklist-ip` | 黑名单 IP 地址 | 无 | [`ip/subnet`]，可重复 | `blacklist-ip 1.2.3.4/16` |
-|serve-expired-ttl|过期缓存服务最长超时时间|0|秒，0：表示停用超时，> 0表示指定的超时的秒数|serve-expired-ttl 0
+| `force-AAAA-SOA` | 强制 AAAA 地址返回 SOA | `no` | [`yes`\|`no`] | `force-AAAA-SOA yes` |
-|dualstack-ip-selection|双栈IP优选|no|[yes\|no]|dualstack-ip-selection yes
+| `force-qtype-SOA` | 强制指定 qtype 返回 SOA | qtype id | [`<qtypeid>` \| ...] | `force-qtype-SOA 65 28`
-|dualstack-ip-selection-threshold|双栈IP优选阈值|30ms|毫秒|dualstack-ip-selection-threshold [0-1000]
+| `prefetch-domain` | 域名预先获取功能 | `no` | [`yes`\|`no`] | `prefetch-domain yes` |
-|ca-file|证书文件|/etc/ssl/certs/ca-certificates.crt|路径|ca-file /etc/ssl/certs/ca-certificates.crt
+| `serve-expired` | 过期缓存服务功能 | `yes` | [`yes`\|`no`]，开启此功能后，如果有请求时尝试回应 TTL 为 0 的过期记录，并发查询记录，以避免查询等待 |
-|ca-path|证书文件路径|/etc/ssl/certs|路径|ca-path /etc/ssl/certs
+| `serve-expired-ttl` | 过期缓存服务最长超时时间 | `0` | 秒，`0` 表示停用超时，大于 `0` 表示指定的超时的秒数 | `serve-expired-ttl 0` |
+| `serve-expired-reply-ttl` | 回应的过期缓存 TTL | `5` | 秒，`0` 表示停用超时，大于 `0` 表示指定的超时的秒数 | `serve-expired-reply-ttl 30` |
+| `dualstack-ip-selection` | 双栈 IP 优选 | `yes` | [`yes`\|`no`] | `dualstack-ip-selection yes` |
+| `dualstack-ip-selection-threshold` | 双栈 IP 优选阈值 | `15ms` | 单位为毫秒（`ms`） | `dualstack-ip-selection-threshold [0-1000]` |
+| `ca-file` | 证书文件 | `/etc/ssl/certs/ca-certificates.crt` | 合法路径字符串 | `ca-file /etc/ssl/certs/ca-certificates.crt` |
+| `ca-path` | 证书文件路径 | `/etc/ssl/certs` | 合法路径字符串 | `ca-path /etc/ssl/certs` |
 
-## FAQ
+## 常见问题
+
+1. SmartDNS 和 DNSmasq 有什么区别？
+   
+    SmartDNS 在设计上并不是 DNSmasq 的替代品，它的主要功能集中在 DNS 解析增强上，增强部分有：
    
-1. SmartDNS和DNSMASQ有什么区别  
-    SMARTDNS在设计上并不是替换DNSMASQ的，SMARTDNS主要功能集中在DNS解析增强上，增强部分有：
    * 多上游服务器并发请求，对结果进行测速后，返回最佳结果；
-    * address，ipset域名匹配采用高效算法，查询匹配更加快速高效，路由器设备依然高效。
+   * address、ipset 域名匹配采用高效算法，查询匹配更加快速，即使是路由器设备也依然高效；
-    * 域名匹配支持忽略特定域名，可单独匹配IPv4， IPV6，支持多样化定制。
+   * 域名匹配支持忽略特定域名，可单独匹配 IPv4 和 IPv6，支持多样化定制；
    * 针对广告屏蔽功能做增强，返回 SOA，屏蔽广告效果更佳；
-    * IPV4，IPV6双栈IP优选机制，在双网情况下，选择最快的网络通讯。
+   * IPv4、IPv6 双栈 IP 优选机制，在双网情况下，选择最快的网络通讯；
-    * 支持最新的TLS, HTTPS协议，提供安全的DNS查询能力。
+   * 支持最新的 TLS 和 HTTPS 协议，提供安全的 DNS 查询能力；
-    * ECS支持，是查询结果更佳准确。
+   * ECS 支持，使查询结果更佳准确；
-    * IP黑名单，忽略IP机制，使域名查询更佳准确。
+   * IP 黑名单和忽略 IP 机制，使域名查询更佳准确；
-    * 域名预查询，访问常用网站更加快速。
+   * 域名预查询，访问常用网站更加快速；
-    * 域名TTL可指定，使访问更快速。
+   * 域名 TTL 可指定，使访问更快速；
-    * 高速缓存机制，使访问更快速。
+   * 高速缓存机制，使访问更快速；
-    * 异步日志，审计机制，在记录信息的同时不影响DNS查询性能。
+   * 异步日志，审计机制，在记录信息的同时不影响 DNS 查询性能；
-    * 域名组（group）机制，特定域名使用特定上游服务器组查询，避免隐私泄漏。
+   * 域名组（group）机制，特定域名使用特定上游服务器组查询，避免隐私泄漏；
    * 第二 DNS 支持自定义更多行为。
 
-1. 如何配置上游服务器最佳。  
+2. 如何配置上游服务器最佳？
-    smartdns有测速机制，在配置上游服务器时，建议配置多个上游DNS服务器，包含多个不同区域的服务器，但总数建议在10个左右。推荐配置  
+   
+    SmartDNS 有测速机制，在配置上游服务器时，建议配置多个上游 DNS 服务器，包含多个不同区域的服务器，但总数建议在 10 个左右。推荐搭配
+   
    * 运营商 DNS。
    * 国内公共 DNS，如 `119.29.29.29`, `223.5.5.5`。
    * 国外公共 DNS，如 `8.8.8.8`, `8.8.4.4`。
 
-1. 如何启用审计日志  
+3. 如何启用审计日志？
-    审计日志记录客户端请求的域名，记录信息包括，请求时间，请求IP，请求域名，请求类型，如果要启用审计日志，在配置界面配置`audit-enable yes`启用，`audit-size`, `audit-file`, `audit-num`分别配置审计日志文件大小，审计日志文件路径，和审计日志文件个数。审计日志文件将会压缩存储以节省空间。
+   
+    审计日志记录客户端请求的域名，记录信息包括，请求时间，请求 IP，请求域名，请求类型，如果要启用审计日志，在配置界面配置 `audit-enable yes` 启用，`audit-size`、 `audit-file`、`audit-num` 分别配置审计日志文件大小，审计日志文件路径，和审计日志文件个数。审计日志文件将会压缩存储以节省空间。
+
+4. 如何避免隐私泄漏？
+   
+    默认情况下，SmartDNS 会将请求发送到所有配置的DNS服务器，若上游 DNS 服务器使用DNS，或记录日志，将会导致隐私泄漏。为避免隐私泄漏，请尽量：  
    
-1. 如何避免隐私泄漏  
-    smartdns默认情况下，会将请求发送到所有配置的DNS服务器，若上游DNS服务器使用DNS，或记录日志，将会导致隐私泄漏。为避免隐私泄漏，请尽量：  
    * 配置使用可信的DNS服务器。
    * 优先使用 TLS 查询。
    * 设置上游 DNS 服务器组。
 
-1. 如何屏蔽广告  
+5. 如何屏蔽广告？
-    smartdns具备高性能域名匹配算法，通过域名方式过滤广告非常高效，如要屏蔽广告，只需要配置类似如下记录即可，如，屏蔽`*.ad.com`，则配置：
+   
+    SmartDNS 具备高性能域名匹配算法，通过域名方式过滤广告非常高效，如要屏蔽广告，只需要配置类似如下记录即可，如，屏蔽 `*.ad.com`，则配置：
    
    ```sh
    address /ad.com/#
    ```
    
-    域名的使后缀模式，过滤*.ad.com，`#`表示返回SOA，使屏蔽广告更加高效，如果要单独屏蔽IPV4， 或IPV6， 在`#`后面增加数字，如`#4`表示对IPV4生效。若想忽略特定子域名的屏蔽，可配置如下，如忽略`pass.ad.com`，可配置如下：
+    域名的使后缀模式，过滤 `*.ad.com`，`#` 表示返回 SOA，使屏蔽广告更加高效，如果要单独屏蔽 IPv4 或 IPv6， 在 `#` 后面增加数字，如 `#4` 表示对 IPv4 生效。若想忽略特定子域名的屏蔽，如忽略 `pass.ad.com`，可配置如下：
    
    ```sh
    address /pass.ad.com/-
    ```
 
-1. 如何使用DNS查询分流  
+6. 如何使用 DNS 查询分流？
-    某些情况下，需要将有些域名使用特定的DNS服务器来查询来做到DNS分流。比如。
+   
+    某些情况下，需要将有些域名使用特定的 DNS 服务器来查询来做到 DNS 分流。比如
    
    ```sh
-    .home -> 192.168.1.1
+   .home -> 192.168.1.1 # .home 结尾的域名发送到 192.168.1.1 解析
-    .office -> 10.0.0.1
+   .office -> 10.0.0.1  # .office 结尾的域名发送到 10.0.0.1 解析
    ```
    
-    .home 结尾的域名发送到192.168.1.1解析  
-    .office 结尾的域名发送到10.0.0.1解析
     其他域名采用默认的模式解析。
     这种情况的分流配置如下：
    
@@ -611,62 +673,81 @@ https://github.com/pymumu/smartdns/releases
    nameserver /.office/office
    ```
    
-    通过上述配置即可实现DNS解析分流，如果需要实现按请求端端口分流，可以配置第二DNS服务器，bind配置增加--group参数指定分流名称。
+    通过上述配置即可实现 DNS 解析分流，如果需要实现按请求端端口分流，可以配置第二 DNS 服务器，`bind` 配置增加 `--group` 参数指定分流名称。
    
    ```sh
    bind :7053 -group office
    bind :8053 -group home
    ```
 
-1. IPV4, IPV6双栈IP优选功能如何使用  
+7. IPv4、IPv6 双栈 IP 优选功能如何使用？
-    目前IPV6已经开始普及，但IPV6网络在速度上，某些情况下还不如IPV4，为在双栈网络下获得较好的体验，smartdns提供来双栈IP优选机制，同一个域名，若IPV4的速度远快与IPV6，那么smartdns就会阻止IPV6的解析，让PC使用IPV4访问，具体配置文件通过`dualstack-ip-selection yes`启用此功能，通过`dualstack-ip-selection-threshold [time]`来修改阈值。如果要完全禁止IPV6 AAAA记录解析，可设置`force-AAAA-SOA yes`。
+   
+    目前 IPv6 已经开始普及，但 IPv6 网络在速度上，某些情况下还不如 IPv4。为在双栈网络下获得较好的体验，SmartDNS 提供来双栈IP优选机制，同一个域名，若 IPv4 的速度远快与 IPv6，那么 SmartDNS 就会阻止IPv6的解析、使用 IPv4 访问。可在配置文件中通过设置 `dualstack-ip-selection yes` 启用此功能，通过 `dualstack-ip-selection-threshold [time]` 来修改阈值。如果要完全禁止 IPv6 AAAA记录解析，可设置 `force-AAAA-SOA yes`。
+
+8. 如何提高缓存效率，加快访问速度？
+   
+    SmartDNS 提供了域名缓存机制，对查询的域名，进行缓存，缓存时间符合 DNS TTL 规范。为提高缓存命中率，可采用如下措施：  
+   
+   * 适当增大缓存的记录数
      
-1. 如何提高cache效率，加快访问速度  
-    smartdns提供了域名缓存机制，对查询的域名，进行缓存，缓存时间符合DNS TTL规范。为提高缓存命中率，可采用如下措施：  
-    * 适当增大cache的记录数  
      通过 `cache-size` 来设置缓存记录数。  
+     
      查询压力大的环境下，并且有内存大的机器的情况下，可适当调大。  
    
    * 适当设置最小 TTL 值
+     
      通过 `rr-ttl-min` 将最低 DNS TTL 时间设置为一个合理值，延长缓存时间。
+     
      建议是超时时间设置在 10～30 分钟，避免服务器域名变化时，查询到失效域名。
    
    * 开启域名预获取功能
+     
      通过 `prefetch-domain yes` 来启用域名预先获取功能，提高查询命中率。
-    配合上述ttl超时时间，smartdns将在域名ttl即将超时使，再次发送查询请求，并缓存查询结果供后续使用。频繁访问的域名将会持续缓存。此功能将在空闲时消耗更多的CPU。
+     
+     配合上述 TTL 超时时间，SmartDNS 将在域名 TTL 即将超时时，再次发送查询请求，并缓存查询结果供后续使用。频繁访问的域名将会持续缓存。此功能将在空闲时消耗更多的 CPU。
    
    * 过期缓存服务功能  
+     
      通过 `serve-expired` 来启用过期缓存服务功能，可提高缓存命中率的同时，降低CPU占用。
+     
      此功能会在TTL超时后，将返回 TTL=0 给客户端，并且同时再次发送查询请求，并缓存新的结果给后续使用。
 
-1. 第二DNS如何自定义更多行为  
+9. 第二 DNS 如何自定义更多行为？
+   
    第二 DNS 可以作为其他 DNS 服务器的上游，提供更多的查询行为，通过 bind 配置支持可以绑定多个端口，不同端口可设置不同的标志，实现不同的功能，如
    
    ```sh
-    # 绑定 6053端口，6053端口的请求将采用配置office组的上游查询，且不对结果进行测速，忽略address的配置地址。
+   # 绑定 6053 端口，6053 端口的请求将采用配置 office 组的上游查询，且不对结果进行测速，忽略 address 的配置地址
    bind [::]:6053 -no-speed-check -group office -no-rule-addr
    ```
 
+10. DoT 的 SPKI 如何获取？
+    SPKI 可以通过 DNS 服务商发布的页面获取，如果没有发布，可以通过如下命令获取，其中将对应IP地址更换为要获取 SPKI 的 IP 地址。
+
+    ```sh
+    $ echo | openssl s_client -connect '1.0.0.1:853' 2>/dev/null | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64
+    ```
+
 ## 编译
 
-smartdns包含了编译软件包的脚本，支持编译luci，debian，openwrt，optare安装包，可执行`package/build-pkg.sh`编译。
+  SmartDNS 提供了编译软件包的脚本（`package/build-pkg.sh`），支持编译 LuCI、Debian、OpenWrt 和 Optware 安装包。
 
-## Donate
+## 捐赠
 
-如果你觉得此项目对你有帮助，请捐助我们，以使项目能持续发展，更加完善。
+如果你觉得此项目对你有帮助，请捐助我们，使项目能持续发展和更加完善。
 
-### PayPal
+### PayPal 贝宝
 
 [![Support via PayPal](https://cdn.rawgit.com/twolfson/paypal-github-button/1.0.0/dist/button.svg)](https://paypal.me/PengNick/)
 
-### Alipay 支付宝
+### AliPay 支付宝
 
 ![alipay](doc/alipay_donate.jpg)
 
-### Wechat 微信
+### WeChat Pay 微信支付
 
 ![wechat](doc/wechat_donate.jpg)
 
 ## 开源声明
 
-Smartdns 基于GPL V3协议开源。
+SmartDNS 基于 GPL V3 协议开源。

ReadMe_en.md

@@ -498,9 +498,12 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |bind|DNS listening port number|[::]:53|Support binding multiple ports<br>`IP:PORT`: server IP, port number. <br>`[-group]`: The DNS server group used when requesting. <br>`[-no-rule-addr]`: Skip the address rule. <br>`[-no-rule-nameserver]`: Skip the Nameserver rule. <br>`[-no-rule-ipset]`: Skip the Ipset rule. <br>`[-no-rule-soa]`: Skip address SOA(#) rules.<br>`[-no-dualstack-selection]`: Disable dualstack ip selection.<br>`[-no-speed-check]`: Disable speed measurement. <br>`[-no-cache]`: stop caching |bind :53
 |bind-tcp|TCP mode DNS listening port number|[::]:53|Support binding multiple ports<br>`IP:PORT`: server IP, port number. <br>`[-group]`: The DNS server group used when requesting. <br>`[-no-rule-addr]`: Skip the address rule. <br>`[-no-rule-nameserver]`: Skip the Nameserver rule. <br>`[-no-rule-ipset]`: Skip the Ipset rule. <br>`[-no-rule-soa]`: Skip address SOA(#) rules.<br>`[-no-dualstack-selection]`: Disable dualstack ip selection.<br>`[-no-speed-check]`: Disable speed measurement. <br>`[-no-cache]`: stop caching |bind-tcp :53
 |cache-size|Domain name result cache number|512|integer|cache-size 512
+|cache-persist|enable persist cache|Auto: Enabled if the location of `cache-file` has more than 128MB of free space.|[yes\|no]|cache-persist yes
+|cache-file|cache persist file|/tmp/smartdns.cache|路径|cache-file /tmp/smartdns.cache
 |tcp-idle-time|TCP connection idle timeout|120|integer|tcp-idle-time 120
 |rr-ttl|Domain name TTL|Remote query result|number greater than 0|rr-ttl 600
 |rr-ttl-min|Domain name Minimum TTL|Remote query result|number greater than 0|rr-ttl-min 60
+|rr-ttl-reply-max|Domain name Minimum Reply TTL|Remote query result|number greater than 0|rr-ttl-reply-max 60
 |rr-ttl-max|Domain name Maximum TTL|Remote query result|number greater than 0|rr-ttl-max 600
 |log-level|log level|error|fatal,error,warn,notice,info,debug|log-level error
 |log-file|log path|/var/log/smartdns.log|File Pah|log-file /var/log/smartdns.log
@@ -518,19 +521,21 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |speed-check-mode|Speed ​​mode|None|[ping\|tcp:[80]\|none]|speed-check-mode ping,tcp:443
 |address|Domain IP address|None|address /domain/[ip\|-\|-4\|-6\|#\|#4\|#6], `-` for ignore, `#` for return SOA, `4` for IPV4, `6` for IPV6| address /www.example.com/1.2.3.4
 |nameserver|To query domain with specific server group|None|nameserver /domain/[group\|-], `group` is the group name, `-` means ignore this rule, use the `-group` parameter in the related server|nameserver /www.example.com/office
-|ipset|Domain IPSet|None|ipset /domain/[ipset\|-], `-` for ignore|ipset /www.example.com/pass
+|ipset|Domain IPSet|None|ipset /domain/[ipset\|-\|#[4\|6]:[ipset\|-][,#[4\|6]:[ipset\|-]]], `-` for ignore|ipset /www.example.com/#4:dns4,#6:-
 |ipset-timeout|ipset timeout enable|auto|[yes]|ipset-timeout yes
-|domain-rules|set domain rules|None|domain-rules /domain/ [-rules...]<br>`[-speed-check-mode]`: set speed check mode，same as parameter `speed-check-mode`<br>`[-address]`: same as  parameter `address` <br>`[-nameserver]`: same as parameter `nameserver`<br>`[-ipset]`: same as parameter `ipset`|domain-rules /www.example.com/ -speed-check-mode none
+|domain-rules|set domain rules|None|domain-rules /domain/ [-rules...]<br>`[-c\|-speed-check-mode]`: set speed check mode，same as parameter `speed-check-mode`<br>`[-a\|-address]`: same as  parameter `address` <br>`[-n\|-nameserver]`: same as parameter `nameserver`<br>`[-p\|-ipset]`: same as parameter `ipset`<br>`[-d\|-dualstack-ip-selection]`: same as parameter `dualstack-ip-selection`|domain-rules /www.example.com/ -speed-check-mode none
 |bogus-nxdomain|bogus IP address|None|[IP/subnet], Repeatable| bogus-nxdomain 1.2.3.4/16
 |ignore-ip|ignore ip address|None|[ip/subnet], Repeatable| ignore-ip 1.2.3.4/16
 |whitelist-ip|ip whitelist|None|[ip/subnet], Repeatable，When the filtering server responds IPs in the IP whitelist, only result in whitelist will be accepted| whitelist-ip 1.2.3.4/16
 |blacklist-ip|ip blacklist|None|[ip/subnet], Repeatable，When the filtering server responds IPs in the IP blacklist, The result will be discarded directly| blacklist-ip 1.2.3.4/16
 |force-AAAA-SOA|force AAAA query return SOA|no|[yes\|no]|force-AAAA-SOA yes
+|force-qtype-SOA|force specific qtype return SOA|qtype id|[qtypeid | ...]|force-qtype-SOA 65 28
 |prefetch-domain|domain prefetch feature|no|[yes\|no]|prefetch-domain yes
-|serve-expired|Cache serve expired feature|no|[yes\|no], Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish.|serve-expired yes
+|serve-expired|Cache serve expired feature|yes|[yes\|no], Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish.|serve-expired yes
 |serve-expired-ttl|Cache serve expired limite TTL|0|second，0：disable，> 0  seconds after expiration|serve-expired-ttl 0
-|dualstack-ip-selection|Dualstack ip selection|no|[yes\|no]|dualstack-ip-selection yes
+|serve-expired-reply-ttl|TTL value to use when replying with expired data|5|second，0：disable，> 0  seconds after expiration|serve-expired-reply-ttl 30
-|dualstack-ip-selection-threshold|Dualstack ip select threadhold|30ms|millisecond|dualstack-ip-selection-threshold [0-1000]
+|dualstack-ip-selection|Dualstack ip selection|yes|[yes\|no]|dualstack-ip-selection yes
+|dualstack-ip-selection-threshold|Dualstack ip select threadhold|15ms|millisecond|dualstack-ip-selection-threshold [0-1000]
 |ca-file|certificate file|/etc/ssl/certs/ca-certificates.crt|path|ca-file /etc/ssl/certs/ca-certificates.crt
 |ca-path|certificates path|/etc/ssl/certs|path|ca-path /etc/ssl/certs
 
@@ -643,6 +648,13 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
     bind [::]:6053 -no-speed-check -group office -no-rule-addr
     ```
 
+1. How to get SPKI of DOT  
+    The SPKI can be obtained from the page published by the DNS service provider. If it is not published, it can be obtained by the following command, replace IP with your own IP.
+
+    ````sh
+    echo | openssl s_client -connect '1.0.0.1:853' 2>/dev/null | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64
+    ````
+
 ## Compile
 
 smartdns contains scripts for compiling packages, supports compiling luci, debian, openwrt, opare installation packages, and can execute `package/build-pkg.sh` compilation.

etc/init.d/smartdns

@@ -68,11 +68,23 @@ case $1 in
 			echo "Stop smartdns server failed."
 			exit 1;
 		fi
-		rm -f "$PIDFILE"
+		LOOP=1
+		while true; do
+			if [ ! -d "/proc/$PID" ]; then
+				break;
+			fi
+
+			if [ $LOOP -gt 12 ]; then
+				kill -9 "$PID"
+				break;
+			fi
+			LOOP=$((LOOP+1))
+			sleep .5
+		done
 		echo "Stop smartdns server success."
 		;;
 	restart)
-		"$0" stop && sleep 1 && "$0" start
+		"$0" stop && "$0" start
 		;;
 	status)
 		PID="$(cat "$PIDFILE" 2>/dev/null)"

etc/smartdns/smartdns.conf

@@ -38,7 +38,13 @@ bind [::]:53
 # dns cache size
 # cache-size [number]
 #   0: for no cache
-cache-size 512
+cache-size 4096
+
+# enable persist cache when restart
+# cache-persist yes
+
+# cache persist file
+# cache-file /tmp/smartdns.cache
 
 # prefetch domain
 # prefetch-domain [yes|no]
@@ -52,6 +58,10 @@ cache-size 512
 # serve-expired-ttl [num]
 # serve-expired-ttl 0
 
+# reply TTL value to use when replying with expired data
+# serve-expired-reply-ttl [num]
+# serve-expired-reply-ttl 30
+
 # List of hosts that supply bogus NX domain results 
 # bogus-nxdomain [ip/subnet]
 
@@ -74,6 +84,10 @@ cache-size 512
 # force AAAA query return SOA
 # force-AAAA-SOA [yes|no]
 
+# force specific qtype return soa
+# force-qtype-SOA [qtypeid |...]
+# force-qtype-SOA 65 28
+
 # Enable IPV4, IPV6 dual stack IP optimization selection strategy
 # dualstack-ip-selection-threshold [num] (0~1000)
 # dualstack-ip-selection [yes|no]
@@ -88,10 +102,12 @@ cache-size 512
 # rr-ttl: ttl for all record
 # rr-ttl-min: minimum ttl for resource record
 # rr-ttl-max: maximum ttl for resource record
+# tr-ttl-reply-max: maximum reply ttl for resource record
 # example:
 # rr-ttl 300
 # rr-ttl-min 60
 # rr-ttl-max 86400
+# rr-ttl-reply-max 60
 
 # set log level
 # log-level: [level], level=fatal, error, warn, notice, info, debug
@@ -179,8 +195,9 @@ log-level info
 # set domain rules
 # domain-rules /domain/ [-speed-check-mode [...]]
 # rules:
-#   -speed-check-mode [mode]: speed check mode
+#   [-c] -speed-check-mode [mode]: speed check mode
 #                             speed-check-mode [ping|tcp:port|none|,]
-#   -address [address|-]: same as address option
+#   [-a] -address [address|-]: same as address option
-#   -nameserver [group|-]: same as nameserver option
+#   [-n] -nameserver [group|-]: same as nameserver option
-#   -ipset [ipset|-]: same as ipset option
+#   [-p] -ipset [ipset|-]: same as ipset option
+#   [-d] -dualstack-ip-selection [yes|no]: same as dualstack-ip-selection option

package/luci-compat/files/luci/i18n/smartdns.zh-cn.po

@@ -104,13 +104,13 @@ msgid "Cache Size"
 msgstr "缓存大小"
 
 msgid "DNS domain result cache size"
-msgstr "缓存DNS的结果，缓存大小，配置零则不缓存"
+msgstr "缓存DNS的结果，缓存大小，配置零则不缓存（单位：条）"
 
 msgid "Domain TTL"
 msgstr "域名TTL"
 
 msgid "TTL for all domain result."
-msgstr "设置所有域名的TTL值"
+msgstr "设置所有域名的TTL值（单位：秒，下同）"
 
 msgid "Domain TTL Min"
 msgstr "域名TTL最小值"
@@ -124,6 +124,9 @@ msgstr "域名TTL最大值"
 msgid "Maximum TTL for all domain result."
 msgstr "设置所有域名的TTL最大值"
 
+msgid "Maximum Reply TTL for all domain result."
+msgstr "设置返回给客户端的TTL最大值"
+
 msgid "smartdns custom settings"
 msgstr "smartdns 自定义设置，具体配置参数参考指导"
 

package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua

@@ -70,7 +70,7 @@ end
 ---- Support DualStack ip selection
 o = s:taboption("settings", Flag, "dualstack_ip_selection", translate("Dual-stack IP Selection"), translate("Enable IP selection between IPV4 and IPV6"))
 o.rmempty     = false
-o.default     = o.disabled
+o.default     = o.enabled
 o.cfgvalue    = function(...)
     return Flag.cfgvalue(...) or "0"
 end
@@ -87,7 +87,7 @@ end
 o = s:taboption("settings", Flag, "serve_expired", translate("Serve expired"), 
 	translate("Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish."))
 o.rmempty     = false
-o.default     = o.disabled
+o.default     = o.enabled
 o.cfgvalue    = function(...)
     return Flag.cfgvalue(...) or "0"
 end
@@ -112,15 +112,19 @@ o.rempty      = true
 ---- rr-ttl-min
 o = s:taboption("settings", Value, "rr_ttl_min", translate("Domain TTL Min"), translate("Minimum TTL for all domain result."))
 o.rempty      = true
-o.placeholder = "300"
+o.placeholder = "600"
-o.default     = 300
+o.default     = 600
 o.optional    = true
 
----- second dns server
 ---- rr-ttl-max
 o = s:taboption("settings", Value, "rr_ttl_max", translate("Domain TTL Max"), translate("Maximum TTL for all domain result."))
 o.rempty      = true
 
+---- rr-ttl-reply-max
+o = s:taboption("settings", Value, "rr_ttl_reply_max", translate("Domain TTL Max"), translate("Maximum Reply TTL for all domain result."))
+o.rempty      = true
+
+---- second dns server
 ---- Eanble
 o = s:taboption("seconddns", Flag, "seconddns_enabled", translate("Enable"), translate("Enable or disable second DNS server."))
 o.default     = o.disabled

package/luci/files/luci/i18n/smartdns.zh-cn.po

@@ -110,13 +110,13 @@ msgid "Cache Size"
 msgstr "缓存大小"
 
 msgid "DNS domain result cache size"
-msgstr "缓存DNS的结果，缓存大小，配置零则不缓存"
+msgstr "缓存DNS的结果，缓存大小，配置零则不缓存（单位：条）"
 
 msgid "Domain TTL"
 msgstr "域名TTL"
 
 msgid "TTL for all domain result."
-msgstr "设置所有域名的TTL值"
+msgstr "设置所有域名的TTL值（单位：秒，下同）"
 
 msgid "Domain TTL Min"
 msgstr "域名TTL最小值"
@@ -130,6 +130,9 @@ msgstr "域名TTL最大值"
 msgid "Maximum TTL for all domain result."
 msgstr "设置所有域名的TTL最大值"
 
+msgid "Maximum Reply TTL for all domain result."
+msgstr "设置返回给客户端的TTL最大值"
+
 msgid "smartdns custom settings"
 msgstr "smartdns 自定义设置，具体配置参数参考指导"
 

package/luci/files/root/usr/share/luci/menu.d/luci-app-smartdns.json

@@ -6,6 +6,7 @@
 			"path": "smartdns/smartdns"
 		},
 		"depends": {
+			"acl": [ "luci-app-smartdns" ],
 			"uci": { "smartdns": true }
 		}
 	}

package/luci/files/root/www/luci-static/resources/view/smartdns/smartdns.js

@@ -188,7 +188,7 @@ return L.view.extend({
 		o = s.taboption("settings", form.Flag, "dualstack_ip_selection", _("Dual-stack IP Selection"),
 			_("Enable IP selection between IPV4 and IPV6"));
 		o.rmempty = false;
-		o.default = o.disabled;
+		o.default = o.enabled;
 
 		// Domain prefetch load ;
 		o = s.taboption("settings", form.Flag, "prefetch_domain", _("Domain prefetch"),
@@ -200,7 +200,7 @@ return L.view.extend({
 		o = s.taboption("settings", form.Flag, "serve_expired", _("Serve expired"),
 			_("Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish."));
 		o.rmempty = false;
-		o.default = o.disabled;
+		o.default = o.enabled;
 
 		// Redirect;
 		o = s.taboption("settings", form.ListValue, "redirect", _("Redirect"), _("SmartDNS redirect mode"));
@@ -223,16 +223,21 @@ return L.view.extend({
 		o = s.taboption("settings", form.Value, "rr_ttl_min", _("Domain TTL Min"),
 			_("Minimum TTL for all domain result."));
 		o.rempty = true;
-		o.placeholder = "300";
+		o.placeholder = "600";
-		o.default = 300;
+		o.default = 600;
 		o.optional = true;
 
-		// second dns server;
 		// rr-ttl-max;
 		o = s.taboption("settings", form.Value, "rr_ttl_max", _("Domain TTL Max"),
 		_("Maximum TTL for all domain result."));
 		o.rempty = true;
 
+		// rr-ttl-reply-max;
+		o = s.taboption("settings", form.Value, "rr_ttl_reply_max", _("Domain Reply TTL Max"),
+		_("Maximum Reply TTL for all domain result."));
+		o.rempty = true;
+		
+		// second dns server;
 		// Eanble;
 		o = s.taboption("seconddns", form.Flag, "seconddns_enabled", _("Enable"),
 			_("Enable or disable second DNS server."));

package/openwrt/files/etc/init.d/smartdns

@@ -311,6 +311,9 @@ load_service()
 	config_get rr_ttl_max "$section" "rr_ttl_max" ""
 	[ -z "$rr_ttl_max" ] || conf_append "rr-ttl-max" "$rr_ttl_max"
 
+	config_get rr_ttl_reply_max "$section" "rr_ttl_reply_max" ""
+	[ -z "$rr_ttl_reply_max" ] || conf_append "rr-ttl-reply-max" "$rr_ttl_reply_max"
+
 	config_get log_size "$section" "log_size" "64K"
 	[ -z "$log_size" ] || conf_append "log-size" "$log_size"
 

package/openwrt/make.sh

@@ -74,7 +74,7 @@ build()
 	cd $ROOT
 
 	tar zcf $ROOT/data.tar.gz -C root --owner=0 --group=0 .
-	tar zcf $OUTPUTDIR/smartdns.$VER.$FILEARCH.ipk --owner=0 --group=0 control.tar.gz data.tar.gz debian-binary
+	tar zcf $OUTPUTDIR/smartdns.$VER.$FILEARCH.ipk --owner=0 --group=0 ./control.tar.gz ./data.tar.gz ./debian-binary
 	rm -fr $ROOT/
 }
 

package/optware/S50smartdns

@@ -332,10 +332,29 @@ case "$1" in
 		return 0
 	fi
 
+	kill -15 "$pid" 2>/dev/null
+	SLEEP=`which usleep`
+	SLEEPTIME=200000
+	if [ -z "$SLEEP" ]; then
+		SLEEP="sleep"
+		SLEEPTIME=0.2
+	fi
+	N=30
+	while [ $N -gt 0 ]
+	do
+		pid="$(cat "$SMARTDNS_PID" | head -n 1 2>/dev/null)"
+		if [ -z "$pid" ]; then
+			return 0
+		fi
+
 		if [ ! -d "/proc/$pid" ]; then
 			return 0;
 		fi
 
+		$SLEEP $SLEEPTIME 2>/dev/null
+		N=$((N-1))
+	done
+
 	kill -9 "$pid" 2>/dev/null
 	;;
 	restart)

package/redhat/smartdns.spec

@@ -0,0 +1,66 @@
+Name:           smartdns
+Version:        1.2020.09.08
+Release:        2235%{?dist}
+Summary:        smartdns
+
+License:        GPL 3.0
+URL:            https://github.com/pymumu/smartdns
+Source0:        %{name}-%{version}.tar.gz
+
+BuildRequires:  glibc
+BuildRequires:  centos-release >= 7
+BuildRequires:  openssl-devel
+Requires:       glibc
+Requires:       openssl
+Requires:       systemd
+
+%description
+A local DNS server to obtain the fastest website IP for the best Internet experience.
+
+%prep
+%setup -q
+
+%build
+cd src
+make %{?_smp_mflags}
+
+%install
+rm -rf $RPM_BUILD_ROOT
+
+%{__install} -D -m 755 src/smartdns $RPM_BUILD_ROOT%{_sbindir}/smartdns
+%{__install} -D -m 644 etc/smartdns/smartdns.conf $RPM_BUILD_ROOT%{_sysconfdir}/smartdns/smartdns.conf
+%{__install} -D -m 644 systemd/smartdns.service.in $RPM_BUILD_ROOT%{_unitdir}/smartdns.service
+
+
+cat > $RPM_BUILD_ROOT%{_unitdir}/smartdns.service <<EOF
+[Unit]
+Description=smartdns
+ConditionFileIsExecutable=/usr/sbin/smartdns
+After=syslog.target network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/sbin/smartdns -c /etc/smartdns/smartdns.conf -f
+PIDFile=/run/smartdns.pid
+Restart=on-failure
+KillMode=process
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+
+%files
+%defattr(-,root,root,-)
+%{_sbindir}/smartdns
+%config(noreplace) %{_sysconfdir}/smartdns/smartdns.conf
+%{_unitdir}/smartdns.service
+
+%post
+%systemd_post %{name}.service
+
+%preun
+%systemd_preun %{name}.service
+
+%postun
+%systemd_postun_with_restart %{name}.service

src/.gitignore

@@ -0,0 +1,5 @@
+.vscode
+.o
+.DS_Store
+.swp.
+smartdns

src/Makefile

@@ -20,7 +20,7 @@ OBJS=smartdns.o fast_ping.o dns_client.o dns_server.o dns.o util.o tlog.o dns_co
 
 # cflags
 ifndef CFLAGS
-CFLAGS =-O2 -g -Wall -Wstrict-prototypes -fno-omit-frame-pointer -Wstrict-aliasing 
+CFLAGS =-O2 -g -Wall -Wstrict-prototypes -fno-omit-frame-pointer -Wstrict-aliasing -funwind-tables
 endif
 override CFLAGS +=-Iinclude
 override CFLAGS += -DBASE_FILE_NAME=\"$(notdir $<)\"
@@ -35,7 +35,7 @@ override CXXFLAGS +=-Iinclude
 ifeq ($(STATIC), yes)
 override LDFLAGS += -lssl -lcrypto -Wl,--whole-archive -lpthread -Wl,--no-whole-archive -ldl -static
 else
-override LDFLAGS += -lssl -lcrypto -lpthread 
+override LDFLAGS += -lssl -lcrypto -lpthread -ldl
 endif
 
 .PHONY: all clean

src/dns.h

@@ -68,6 +68,7 @@ typedef enum dns_type {
 
 typedef enum dns_opt_code {
 	DNS_OPT_T_ECS = 8, // OPT ECS
+	DNS_OPT_T_COOKIE = 10, //OPT Cookie
 	DNS_OPT_T_TCP_KEEPALIVE = 11,
 	DNS_OPT_T_ALL = 255
 } dns_opt_code_t;
@@ -112,11 +113,15 @@ struct dns_head {
 	unsigned short nrcount; /* number of addititional resource entries */
 } __attribute__((packed, aligned(2)));
 
-struct dns_rrs {
+#define DNS_PACKET_DICT_SIZE 16
-	unsigned short next;
+struct dns_packet_dict_item {
-	unsigned short len;
+	unsigned pos;
-	dns_type_t type;
+	unsigned int hash;
-	unsigned char data[0];
+};
+
+struct dns_packet_dict {
+	short dict_count;
+	struct dns_packet_dict_item names[DNS_PACKET_DICT_SIZE];
 };
 
 /* packet haed */
@@ -129,21 +134,24 @@ struct dns_packet {
 	unsigned short optcount;
 	unsigned short optional;
 	unsigned short payloadsize;
+	struct dns_packet_dict namedict;
 	int size;
 	int len;
 	unsigned char data[0];
 };
 
-/* RRS encode/decode context */
+struct dns_rrs {
-struct dns_data_context {
+	struct dns_packet *packet;
-	unsigned char *data;
+	unsigned short next;
-	unsigned char *ptr;
+	unsigned short len;
-	unsigned int maxsize;
+	dns_type_t type;
+	unsigned char data[0];
 };
 
 /* packet encode/decode context */
 struct dns_context {
 	struct dns_packet *packet;
+	struct dns_packet_dict *namedict;
 	unsigned char *data;
 	unsigned int maxsize;
 	unsigned char *ptr;
@@ -169,6 +177,13 @@ struct dns_opt_ecs {
 	unsigned char source_prefix;
 	unsigned char scope_prefix;
 	unsigned char addr[DNS_RR_AAAA_LEN];
+} __attribute__((packed));;
+
+/* OPT COOLIE */
+struct dns_opt_cookie {
+	char server_cookie_len;
+	unsigned char client_cookie[8];
+	unsigned char server_cookie[32];
 };
 
 /* OPT */
@@ -226,4 +241,12 @@ int dns_encode(unsigned char *data, int size, struct dns_packet *packet);
 
 int dns_packet_init(struct dns_packet *packet, int size, struct dns_head *head);
 
+struct dns_update_param {
+	int id;
+	int ip_ttl;
+	int cname_ttl;
+};
+
+int dns_packet_update(unsigned char *data, int size, struct dns_update_param *param);
+
 #endif

src/dns_cache.c

@@ -19,7 +19,11 @@
 #include "dns_cache.h"
 #include "stringutil.h"
 #include "tlog.h"
+#include <errno.h>
+#include <fcntl.h>
 #include <pthread.h>
+#include <string.h>
+#include <sys/types.h>
 
 #define DNS_CACHE_MAX_HITNUM 5000
 #define DNS_CACHE_HITNUM_STEP 2
@@ -65,7 +69,7 @@ static __attribute__((unused)) struct dns_cache *_dns_cache_last(void)
 	return list_last_entry(&dns_cache_head.cache_list, struct dns_cache, list);
 }
 
-static struct dns_cache *_dns_cache_first(void)
+static struct dns_cache *_dns_inactive_cache_first(void)
 {
 	struct dns_cache *dns_cache = NULL;
 
@@ -82,6 +86,7 @@ static void _dns_cache_delete(struct dns_cache *dns_cache)
 	hash_del(&dns_cache->node);
 	list_del_init(&dns_cache->list);
 	atomic_dec(&dns_cache_head.num);
+	dns_cache_data_free(dns_cache->cache_data);
 	free(dns_cache);
 }
 
@@ -118,10 +123,130 @@ static void _dns_cache_move_inactive(struct dns_cache *dns_cache)
 	list_add_tail(&dns_cache->list, &dns_cache_head.inactive_list);
 }
 
-int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
+enum CACHE_TYPE dns_cache_data_type(struct dns_cache_data *cache_data)
-					  int addr_len, int speed)
+{
+	return cache_data->head.cache_type;
+}
+
+uint32_t dns_cache_get_cache_flag(struct dns_cache_data *cache_data)
+{
+	return cache_data->head.cache_flag;
+}
+
+void dns_cache_data_free(struct dns_cache_data *data)
+{
+	if (data == NULL) {
+		return;
+	}
+
+	free(data);
+}
+
+struct dns_cache_data *dns_cache_new_data(void)
+{
+	struct dns_cache_addr *cache_addr = malloc(sizeof(struct dns_cache_addr));
+	memset(cache_addr, 0, sizeof(struct dns_cache_addr));
+	if (cache_addr == NULL) {
+		return NULL;
+	}
+
+	cache_addr->head.cache_type = CACHE_TYPE_NONE;
+	cache_addr->head.size = sizeof(struct dns_cache_addr) - sizeof(struct dns_cache_data_head);
+
+	return (struct dns_cache_data *)cache_addr;
+}
+
+void dns_cache_set_data_soa(struct dns_cache_data *dns_cache, int32_t cache_flag, char *cname, int cname_ttl)
+{
+	if (dns_cache == NULL) {
+		goto errout;
+	}
+
+	dns_cache->head.is_soa = 1;
+	if (dns_cache->head.cache_type == CACHE_TYPE_PACKET) {
+		return;
+	}
+
+	struct dns_cache_addr *cache_addr = (struct dns_cache_addr *)dns_cache;
+	if (cache_addr == NULL) {
+		goto errout;
+	}
+
+	memset(cache_addr->addr_data.addr, 0, sizeof(cache_addr->addr_data.addr));
+
+	if (cname) {
+		safe_strncpy(cache_addr->addr_data.cname, cname, DNS_MAX_CNAME_LEN);
+		cache_addr->addr_data.cname_ttl = cname_ttl;
+	}
+
+	cache_addr->head.cache_flag = cache_flag;
+	cache_addr->addr_data.soa = 1;
+	cache_addr->head.cache_type = CACHE_TYPE_ADDR;
+	cache_addr->head.size = sizeof(struct dns_cache_addr) - sizeof(struct dns_cache_data_head);
+errout:
+	return;
+}
+
+void dns_cache_set_data_addr(struct dns_cache_data *dns_cache, uint32_t cache_flag, char *cname, int cname_ttl,
+							 unsigned char *addr, int addr_len)
+{
+	if (dns_cache == NULL) {
+		goto errout;
+	}
+
+	struct dns_cache_addr *cache_addr = (struct dns_cache_addr *)dns_cache;
+	if (cache_addr == NULL) {
+		goto errout;
+	}
+
+	if (addr_len == DNS_RR_A_LEN) {
+		memcpy(cache_addr->addr_data.addr, addr, DNS_RR_A_LEN);
+	} else if (addr_len != DNS_RR_AAAA_LEN) {
+		memcpy(cache_addr->addr_data.addr, addr, DNS_RR_AAAA_LEN);
+	} else {
+		goto errout;
+	}
+
+	if (cname) {
+		safe_strncpy(cache_addr->addr_data.cname, cname, DNS_MAX_CNAME_LEN);
+		cache_addr->addr_data.cname_ttl = cname_ttl;
+	}
+
+	cache_addr->head.cache_flag = cache_flag;
+	cache_addr->head.cache_type = CACHE_TYPE_ADDR;
+	cache_addr->head.size = sizeof(struct dns_cache_addr) - sizeof(struct dns_cache_data_head);
+errout:
+	return;
+}
+
+struct dns_cache_data *dns_cache_new_data_packet(uint32_t cache_flag, void *packet, size_t packet_len)
+{
+	struct dns_cache_packet *cache_packet = NULL;
+	size_t data_size = 0;
+	if (packet == NULL || packet_len <= 0) {
+		return NULL;
+	}
+
+	data_size = sizeof(*cache_packet) + packet_len;
+	cache_packet = malloc(data_size);
+	if (cache_packet == NULL) {
+		return NULL;
+	}
+
+	memcpy(cache_packet->data, packet, packet_len);
+	memset(&cache_packet->head, 0, sizeof(cache_packet->head));
+
+	cache_packet->head.cache_flag = cache_flag;
+	cache_packet->head.cache_type = CACHE_TYPE_PACKET;
+	cache_packet->head.size = packet_len;
+
+	return (struct dns_cache_data *)cache_packet;
+}
+
+int dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data)
 {
 	struct dns_cache *dns_cache = NULL;
+	struct dns_cache_data *old_cache_data = NULL;
 
 	if (dns_cache_head.size <= 0) {
 		return 0;
@@ -130,7 +255,7 @@ int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_typ
 	/* lookup existing cache */
 	dns_cache = dns_cache_lookup(domain, qtype);
 	if (dns_cache == NULL) {
-		return dns_cache_insert(domain, cname, cname_ttl, ttl, qtype, addr, addr_len, speed);
+		return dns_cache_insert(domain, ttl, qtype, speed, cache_data);
 	}
 
 	if (ttl < DNS_CACHE_TTL_MIN) {
@@ -139,58 +264,30 @@ int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_typ
 
 	/* update cache data */
 	pthread_mutex_lock(&dns_cache_head.lock);
-	dns_cache->ttl = ttl;
-	dns_cache->qtype = qtype;
-	dns_cache->ttl = ttl;
 	dns_cache->del_pending = 0;
-	dns_cache->speed = speed;
+	dns_cache->info.ttl = ttl;
-	time(&dns_cache->insert_time);
+	dns_cache->info.qtype = qtype;
-	if (qtype == DNS_T_A) {
+	dns_cache->info.ttl = ttl;
-		if (addr_len != DNS_RR_A_LEN) {
+	dns_cache->info.speed = speed;
-			goto errout_unlock;
+	time(&dns_cache->info.insert_time);
-		}
+	old_cache_data = dns_cache->cache_data;
-		memcpy(dns_cache->addr, addr, DNS_RR_A_LEN);
+	dns_cache->cache_data = cache_data;
-	} else if (qtype == DNS_T_AAAA) {
-		if (addr_len != DNS_RR_AAAA_LEN) {
-			goto errout_unlock;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_AAAA_LEN);
-	} else {
-		goto errout_unlock;
-	}
-
-	if (cname) {
-		safe_strncpy(dns_cache->cname, cname, DNS_MAX_CNAME_LEN);
-		dns_cache->cname_ttl = cname_ttl;
-	}
-
 	list_del_init(&dns_cache->list);
 	list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
 	pthread_mutex_unlock(&dns_cache_head.lock);
 
+	dns_cache_data_free(old_cache_data);
 	dns_cache_release(dns_cache);
 	return 0;
-errout_unlock:
-	pthread_mutex_unlock(&dns_cache_head.lock);
-	// errout:
-	if (dns_cache) {
-		dns_cache_release(dns_cache);
-	}
-	return -1;
 }
 
-int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
+int _dns_cache_insert(struct dns_cache_info *info, struct dns_cache_data *cache_data, struct list_head *head)
-					 int addr_len, int speed)
 {
 	uint32_t key = 0;
 	struct dns_cache *dns_cache = NULL;
 
-	if (dns_cache_head.size <= 0) {
-		return 0;
-	}
-
 	/* if cache already exists, free */
-	dns_cache = dns_cache_lookup(domain, qtype);
+	dns_cache = dns_cache_lookup(info->domain, info->qtype);
 	if (dns_cache) {
 		dns_cache_delete(dns_cache);
 		dns_cache_release(dns_cache);
@@ -202,50 +299,22 @@ int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type
 		goto errout;
 	}
 
-	if (ttl < DNS_CACHE_TTL_MIN) {
+	memset(dns_cache, 0, sizeof(*dns_cache));
-		ttl = DNS_CACHE_TTL_MIN;
+	key = hash_string(info->domain);
-	}
+	key = jhash(&info->qtype, sizeof(info->qtype), key);
-
-	key = hash_string(domain);
-	key = jhash(&qtype, sizeof(qtype), key);
-	safe_strncpy(dns_cache->domain, domain, DNS_MAX_CNAME_LEN);
-	dns_cache->cname[0] = 0;
-	dns_cache->qtype = qtype;
-	dns_cache->ttl = ttl;
-	atomic_set(&dns_cache->hitnum, 3);
-	dns_cache->hitnum_update_add = DNS_CACHE_HITNUM_STEP;
-	dns_cache->del_pending = 0;
-	dns_cache->speed = speed;
 	atomic_set(&dns_cache->ref, 1);
-	time(&dns_cache->insert_time);
+	memcpy(&dns_cache->info, info, sizeof(*info));
-	if (qtype == DNS_T_A) {
+	dns_cache->del_pending = 0;
-		if (addr_len != DNS_RR_A_LEN) {
+	dns_cache->cache_data = cache_data;
-			goto errout;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_A_LEN);
-	} else if (qtype == DNS_T_AAAA) {
-		if (addr_len != DNS_RR_AAAA_LEN) {
-			goto errout;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_AAAA_LEN);
-	} else {
-		goto errout;
-	}
-
-	if (cname) {
-		safe_strncpy(dns_cache->cname, cname, DNS_MAX_CNAME_LEN);
-		dns_cache->cname_ttl = cname_ttl;
-	}
-
 	pthread_mutex_lock(&dns_cache_head.lock);
 	hash_add(dns_cache_head.cache_hash, &dns_cache->node, key);
-	list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
+	list_add_tail(&dns_cache->list, head);
 	INIT_LIST_HEAD(&dns_cache->check_list);
 
 	/* Release extra cache, remove oldest cache record */
 	if (atomic_inc_return(&dns_cache_head.num) > dns_cache_head.size) {
 		struct dns_cache *del_cache;
-		del_cache = _dns_cache_first();
+		del_cache = _dns_inactive_cache_first();
 		if (del_cache) {
 			_dns_cache_remove(del_cache);
 		}
@@ -261,6 +330,34 @@ errout:
 	return -1;
 }
 
+int dns_cache_insert(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data)
+{
+	struct dns_cache_info info;
+
+	if (cache_data == NULL || domain == NULL) {
+		return -1;
+	}
+
+	if (dns_cache_head.size <= 0) {
+		dns_cache_data_free(cache_data);
+		return 0;
+	}
+
+	if (ttl < DNS_CACHE_TTL_MIN) {
+		ttl = DNS_CACHE_TTL_MIN;
+	}
+
+	info.hitnum = 3;
+	safe_strncpy(info.domain, domain, DNS_MAX_CNAME_LEN);
+	info.qtype = qtype;
+	info.ttl = ttl;
+	info.hitnum_update_add = DNS_CACHE_HITNUM_STEP;
+	info.speed = speed;
+	time(&info.insert_time);
+
+	return _dns_cache_insert(&info, cache_data, &dns_cache_head.cache_list);
+}
+
 struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 {
 	uint32_t key = 0;
@@ -280,11 +377,11 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 	pthread_mutex_lock(&dns_cache_head.lock);
 	hash_for_each_possible(dns_cache_head.cache_hash, dns_cache, node, key)
 	{
-		if (dns_cache->qtype != qtype) {
+		if (dns_cache->info.qtype != qtype) {
 			continue;
 		}
 
-		if (strncmp(domain, dns_cache->domain, DNS_MAX_CNAME_LEN) != 0) {
+		if (strncmp(domain, dns_cache->info.domain, DNS_MAX_CNAME_LEN) != 0) {
 			continue;
 		}
 
@@ -294,7 +391,7 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 
 	if (dns_cache_ret) {
 		/* Return NULL if the cache times out */
-		if (dns_cache_head.enable_inactive == 0 && (now - dns_cache_ret->insert_time > dns_cache_ret->ttl)) {
+		if (dns_cache_head.enable_inactive == 0 && (now - dns_cache_ret->info.insert_time > dns_cache_ret->info.ttl)) {
 			_dns_cache_remove(dns_cache_ret);
 			dns_cache_ret = NULL;
 		} else {
@@ -313,7 +410,7 @@ int dns_cache_get_ttl(struct dns_cache *dns_cache)
 	int ttl = 0;
 	time(&now);
 
-	ttl = dns_cache->insert_time + dns_cache->ttl - now;
+	ttl = dns_cache->info.insert_time + dns_cache->info.ttl - now;
 	if (ttl < 0) {
 		return 0;
 	}
@@ -321,6 +418,53 @@ int dns_cache_get_ttl(struct dns_cache *dns_cache)
 	return ttl;
 }
 
+int dns_cache_get_cname_ttl(struct dns_cache *dns_cache) 
+{
+	time_t now;
+	int ttl = 0;
+	time(&now);
+
+	struct dns_cache_addr *cache_addr = (struct dns_cache_addr *)dns_cache_get_data(dns_cache);
+
+	if (cache_addr->head.cache_type != CACHE_TYPE_ADDR) {
+		return 0;
+	}
+
+	ttl = dns_cache->info.insert_time + cache_addr->addr_data.cname_ttl - now;
+	if (ttl < 0) {
+		return 0;
+	}
+
+	int addr_ttl = dns_cache_get_ttl(dns_cache);
+	if (ttl < addr_ttl && ttl < 0) {
+		return addr_ttl;
+	}
+
+	if (ttl < 0) {
+		return 0;
+	}
+
+	return ttl;	
+}
+
+int dns_cache_is_soa(struct dns_cache *dns_cache) 
+{
+	if (dns_cache == NULL) {
+		return 0;
+	}
+
+	if (dns_cache->cache_data->head.is_soa) {
+		return 1;
+	}
+
+	return 0;
+}
+
+struct dns_cache_data *dns_cache_get_data(struct dns_cache *dns_cache)
+{
+	return dns_cache->cache_data;
+}
+
 void dns_cache_delete(struct dns_cache *dns_cache)
 {
 	pthread_mutex_lock(&dns_cache_head.lock);
@@ -330,15 +474,14 @@ void dns_cache_delete(struct dns_cache *dns_cache)
 
 int dns_cache_hitnum_dec_get(struct dns_cache *dns_cache)
 {
-	int hitnum = 0;
 	pthread_mutex_lock(&dns_cache_head.lock);
-	hitnum = atomic_dec_return(&dns_cache->hitnum);
+	dns_cache->info.hitnum--;
-	if (dns_cache->hitnum_update_add > DNS_CACHE_HITNUM_STEP) {
+	if (dns_cache->info.hitnum_update_add > DNS_CACHE_HITNUM_STEP) {
-		dns_cache->hitnum_update_add--;
+		dns_cache->info.hitnum_update_add--;
 	}
 	pthread_mutex_unlock(&dns_cache_head.lock);
 
-	return hitnum;
+	return dns_cache->info.hitnum;
 }
 
 void dns_cache_update(struct dns_cache *dns_cache)
@@ -347,13 +490,13 @@ void dns_cache_update(struct dns_cache *dns_cache)
 	if (!list_empty(&dns_cache->list)) {
 		list_del_init(&dns_cache->list);
 		list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
-		atomic_add(dns_cache->hitnum_update_add, &dns_cache->hitnum);
+		dns_cache->info.hitnum += dns_cache->info.hitnum_update_add;
-		if (atomic_read(&dns_cache->hitnum) > DNS_CACHE_MAX_HITNUM) {
+		if (dns_cache->info.hitnum > DNS_CACHE_MAX_HITNUM) {
-			atomic_set(&dns_cache->hitnum, DNS_CACHE_MAX_HITNUM);
+			dns_cache->info.hitnum = DNS_CACHE_MAX_HITNUM;
 		}
 
-		if (dns_cache->hitnum_update_add < DNS_CACHE_HITNUM_STEP_MAX) {
+		if (dns_cache->info.hitnum_update_add < DNS_CACHE_HITNUM_STEP_MAX) {
-			dns_cache->hitnum_update_add++;
+			dns_cache->info.hitnum_update_add++;
 		}
 	}
 	pthread_mutex_unlock(&dns_cache_head.lock);
@@ -367,7 +510,7 @@ void _dns_cache_remove_expired_ttl(time_t *now)
 
 	list_for_each_entry_safe(dns_cache, tmp, &dns_cache_head.inactive_list, list)
 	{
-		ttl = dns_cache->insert_time + dns_cache->ttl - *now;
+		ttl = dns_cache->info.insert_time + dns_cache->info.ttl - *now;
 		if (ttl > 0) {
 			continue;
 		}
@@ -396,7 +539,7 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre)
 	pthread_mutex_lock(&dns_cache_head.lock);
 	list_for_each_entry_safe(dns_cache, tmp, &dns_cache_head.cache_list, list)
 	{
-		ttl = dns_cache->insert_time + dns_cache->ttl - now;
+		ttl = dns_cache->info.insert_time + dns_cache->info.ttl - now;
 		if (ttl > 0 && ttl < ttl_pre) {
 			/* If the TTL time is in the pre-timeout range, call callback function */
 			if (callback && dns_cache->del_pending == 0) {
@@ -408,7 +551,7 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre)
 		}
 
 		if (ttl < 0) {
-			if (dns_cache_head.enable_inactive) {
+			if (dns_cache_head.enable_inactive && (dns_cache_is_soa(dns_cache) == 0)) {
 				_dns_cache_move_inactive(dns_cache);
 			} else {
 				_dns_cache_remove(dns_cache);
@@ -432,6 +575,216 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre)
 	}
 }
 
+static int _dns_cache_read_record(int fd, uint32_t cache_number)
+{
+
+	int i = 0;
+	int ret = 0;
+	struct dns_cache_record cache_record;
+	struct dns_cache_data_head data_head;
+	struct dns_cache_data *cache_data = NULL;
+	struct list_head *head = NULL;
+
+	for (i = 0; i < cache_number; i++) {
+		ret = read(fd, &cache_record, sizeof(cache_record));
+		if (ret != sizeof(cache_record)) {
+			tlog(TLOG_ERROR, "read cache failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (cache_record.magic != MAGIC_CACHE_DATA) {
+			tlog(TLOG_ERROR, "magic is invalid.");
+			goto errout;
+		}
+
+		if (cache_record.type == CACHE_RECORD_TYPE_ACTIVE) {
+			head = &dns_cache_head.cache_list;
+		} else {
+			head = &dns_cache_head.inactive_list;
+		}
+
+		ret = read(fd, &data_head, sizeof(data_head));
+		if (ret != sizeof(data_head)) {
+			tlog(TLOG_ERROR, "read data head failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (data_head.size > 1024 * 8) {
+			tlog(TLOG_ERROR, "data may invalid, skip load cache.");
+			goto errout;
+		}
+
+		cache_data = malloc(data_head.size + sizeof(data_head));
+		if (cache_data == NULL) {
+			tlog(TLOG_ERROR, "malloc cache data failed %s", strerror(errno));
+			goto errout;
+		}
+
+		memcpy(&cache_data->head, &data_head, sizeof(data_head));
+		ret = read(fd, cache_data->data, data_head.size);
+		if (ret != data_head.size) {
+			tlog(TLOG_ERROR, "read cache data failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (_dns_cache_insert(&cache_record.info, cache_data, head) != 0) {
+			tlog(TLOG_ERROR, "insert cache data failed.");
+			cache_data = NULL;
+			goto errout;
+		}
+
+		cache_data = NULL;
+	}
+
+	return 0;
+errout:
+	if (cache_data) {
+		free(cache_data);
+	}
+	return -1;
+}
+
+int dns_cache_load(const char *file)
+{
+	int fd = -1;
+	int ret = 0;
+	fd = open(file, O_RDONLY);
+	if (fd < 0) {
+		return 0;
+	}
+
+	struct dns_cache_file cache_file;
+	ret = read(fd, &cache_file, sizeof(cache_file));
+	if (ret != sizeof(cache_file)) {
+		tlog(TLOG_ERROR, "read cache head failed.");
+		goto errout;
+	}
+
+	if (cache_file.magic != MAGIC_NUMBER) {
+		tlog(TLOG_ERROR, "cache file is invalid.");
+		goto errout;
+	}
+
+	if (strncmp(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN) != 0) {
+		tlog(TLOG_WARN, "cache version is different, skip load cache.");
+		goto errout;
+	}
+
+	if (_dns_cache_read_record(fd, cache_file.cache_number) != 0) {
+		goto errout;
+	}
+
+	close(fd);
+	return 0;
+errout:
+	if (fd > 0) {
+		close(fd);
+	}
+
+	return -1;
+}
+
+static int _dns_cache_write_record(int fd, uint32_t *cache_number, enum CACHE_RECORD_TYPE type, struct list_head *head)
+{
+	struct dns_cache *dns_cache = NULL;
+	struct dns_cache *tmp = NULL;
+	struct dns_cache_record cache_record;
+
+	pthread_mutex_lock(&dns_cache_head.lock);
+	list_for_each_entry_safe_reverse(dns_cache, tmp, head, list)
+	{
+		cache_record.magic = MAGIC_CACHE_DATA;
+		cache_record.type = type;
+		memcpy(&cache_record.info, &dns_cache->info, sizeof(struct dns_cache_info));
+		int ret = write(fd, &cache_record, sizeof(cache_record));
+		if (ret != sizeof(cache_record)) {
+			tlog(TLOG_ERROR, "write cache failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		struct dns_cache_data *cache_data = dns_cache->cache_data;
+		ret = write(fd, cache_data, sizeof(*cache_data) + cache_data->head.size);
+		if (ret != sizeof(*cache_data) + cache_data->head.size) {
+			tlog(TLOG_ERROR, "write cache data failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		(*cache_number)++;
+	}
+
+	pthread_mutex_unlock(&dns_cache_head.lock);
+	return 0;
+
+errout:
+	pthread_mutex_unlock(&dns_cache_head.lock);
+	return -1;
+}
+
+static int _dns_cache_write_records(int fd, uint32_t *cache_number)
+{
+
+	if (_dns_cache_write_record(fd, cache_number, CACHE_RECORD_TYPE_ACTIVE, &dns_cache_head.cache_list) != 0) {
+		return -1;
+	}
+
+	if (_dns_cache_write_record(fd, cache_number, CACHE_RECORD_TYPE_INACTIVE, &dns_cache_head.inactive_list) != 0) {
+		return -1;
+	}
+
+	return 0;
+}
+
+int dns_cache_save(const char *file)
+{
+	int fd = -1;
+	uint32_t cache_number = 0;
+	tlog(TLOG_DEBUG, "write cache file %s", file);
+
+	fd = open(file, O_TRUNC | O_CREAT | O_WRONLY, 0640);
+	if (fd < 0) {
+		tlog(TLOG_ERROR, "create file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	struct dns_cache_file cache_file;
+	memset(&cache_file, 0, sizeof(cache_file));
+	cache_file.magic = MAGIC_NUMBER;
+	safe_strncpy(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN);
+	cache_file.cache_number = 0;
+
+	if (lseek(fd, sizeof(cache_file), SEEK_SET) < 0) {
+		tlog(TLOG_ERROR, "seek file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	if (_dns_cache_write_records(fd, &cache_number) != 0) {
+		tlog(TLOG_ERROR, "write record to file %s failed.", file);
+		goto errout;
+	}
+
+	if (lseek(fd, 0, SEEK_SET) < 0) {
+		tlog(TLOG_ERROR, "seek file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	cache_file.cache_number = cache_number;
+	if (write(fd, &cache_file, sizeof(cache_file)) != sizeof(cache_file)) {
+		tlog(TLOG_ERROR, "write file head %s failed, %s, %d", file, strerror(errno), fd);
+		goto errout;
+	}
+
+	tlog(TLOG_DEBUG, "wrote total %d records.", cache_number);
+
+	close(fd);
+	return 0;
+errout:
+	if (fd > 0) {
+		close(fd);
+	}
+
+	return -1;
+}
+
 void dns_cache_destroy(void)
 {
 	struct dns_cache *dns_cache = NULL;

src/dns_cache.h

@@ -32,36 +32,99 @@ extern "C" {
 #endif
 
 #define DNS_CACHE_TTL_MIN 30
+#define DNS_CACHE_VERSION_LEN 32
+#define MAGIC_NUMBER 0x6548634163536e44
+#define MAGIC_CACHE_DATA 0x44615461
 
-struct dns_cache {
+enum CACHE_TYPE {
-	struct hlist_node node;
+	CACHE_TYPE_NONE,
-	struct list_head list;
+	CACHE_TYPE_ADDR,
-	struct list_head check_list;
+	CACHE_TYPE_PACKET,
-	atomic_t ref;
+};
-	char domain[DNS_MAX_CNAME_LEN];
+
-	char cname[DNS_MAX_CNAME_LEN];
+enum CACHE_RECORD_TYPE {
+	CACHE_RECORD_TYPE_ACTIVE,
+	CACHE_RECORD_TYPE_INACTIVE,
+};
+
+struct dns_cache_data_head {
+	uint32_t cache_flag;
+	enum CACHE_TYPE cache_type;
+	int is_soa;
+	size_t size;
+};
+
+struct dns_cache_data {
+	struct dns_cache_data_head head;
+	unsigned char data[0];
+};
+
+struct dns_cache_addr {
+	struct dns_cache_data_head head;
+	struct dns_cache_addr_data {
 		unsigned int cname_ttl;
-	unsigned int ttl;
+		char soa;
-	int speed;
+		char cname[DNS_MAX_CNAME_LEN];
-	atomic_t hitnum;
-	int hitnum_update_add;
-	int del_pending;
-	time_t insert_time;
-	dns_type_t qtype;
 		union {
 			unsigned char ipv4_addr[DNS_RR_A_LEN];
 			unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
 			unsigned char addr[0];
 		};
+	} addr_data;
 };
 
+struct dns_cache_packet {
+	struct dns_cache_data_head head;
+	unsigned char data[0];
+};
+
+struct dns_cache_info {
+	char domain[DNS_MAX_CNAME_LEN];
+	int ttl;
+	int hitnum;
+	int speed;
+	int hitnum_update_add;
+	time_t insert_time;
+	dns_type_t qtype;
+};
+
+struct dns_cache_record {
+	uint32_t magic;
+	enum CACHE_RECORD_TYPE type;
+	struct dns_cache_info info;
+};
+
+struct dns_cache {
+	struct hlist_node node;
+	struct list_head list;
+	struct list_head check_list;
+
+	atomic_t ref;
+	int del_pending;
+
+	struct dns_cache_info info;
+	struct dns_cache_data *cache_data;
+};
+
+struct dns_cache_file {
+	uint64_t magic;
+	char version[DNS_CACHE_VERSION_LEN];
+	uint32_t cache_number;
+};
+
+enum CACHE_TYPE dns_cache_data_type(struct dns_cache_data *cache_data);
+
+uint32_t dns_cache_get_cache_flag(struct dns_cache_data *cache_data);
+
+void dns_cache_data_free(struct dns_cache_data *data);
+
+struct dns_cache_data *dns_cache_new_data_packet(uint32_t cache_flag, void *packet, size_t packet_len);
+
 int dns_cache_init(int size, int enable_inactive, int inactive_list_expired);
 
-int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
+int dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data);
-					  int addr_len, int speed);
 
-int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
+int dns_cache_insert(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data);
-					 int addr_len, int speed);
 
 struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype);
 
@@ -81,8 +144,25 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre);
 
 int dns_cache_get_ttl(struct dns_cache *dns_cache);
 
+int dns_cache_get_cname_ttl(struct dns_cache *dns_cache);
+
+int dns_cache_is_soa(struct dns_cache *dns_cache);
+
+struct dns_cache_data *dns_cache_new_data(void);
+
+struct dns_cache_data *dns_cache_get_data(struct dns_cache *dns_cache);
+
+void dns_cache_set_data_addr(struct dns_cache_data *dns_cache, uint32_t cache_flag, char *cname, int cname_ttl,
+							 unsigned char *addr, int addr_len);
+
+void dns_cache_set_data_soa(struct dns_cache_data *dns_cache, int32_t cache_flag, char *cname, int cname_ttl);
+
 void dns_cache_destroy(void);
 
+int dns_cache_load(const char *file);
+
+int dns_cache_save(const char *file);
+
 #ifdef __cpluscplus
 }
 #endif

src/dns_client.c

@@ -58,7 +58,7 @@
 #define DNS_TCP_IDLE_TIMEOUT (60 * 10)
 #define DNS_TCP_CONNECT_TIMEOUT (5)
 #define DNS_QUERY_TIMEOUT (500)
-#define DNS_QUERY_RETRY (6)
+#define DNS_QUERY_RETRY (4)
 #define DNS_PENDING_SERVER_RETRY 40
 #define SOCKET_PRIORITY (6)
 #define SOCKET_IP_TOS (IPTOS_LOWDELAY | IPTOS_RELIABILITY)
@@ -105,8 +105,10 @@ struct dns_server_info {
 	int ttl;
 	int ttl_range;
 	SSL *ssl;
+	int ssl_write_len;
 	SSL_CTX *ssl_ctx;
 	SSL_SESSION *ssl_session;
+	pthread_mutex_t lock;
 	char skip_check_cert;
 	dns_server_status status;
 
@@ -115,6 +117,7 @@ struct dns_server_info {
 
 	time_t last_send;
 	time_t last_recv;
+	int prohibit;
 
 	/* server addr info */
 	unsigned short ai_family;
@@ -182,6 +185,9 @@ struct dns_client {
 	struct list_head dns_server_list;
 	struct dns_server_group *default_group;
 
+	SSL_CTX *ssl_ctx;
+	int ssl_verify_skip;
+
 	/* query list */
 	pthread_mutex_t dns_request_lock;
 	struct list_head dns_request_list;
@@ -248,6 +254,96 @@ static LIST_HEAD(pending_servers);
 static pthread_mutex_t pending_server_mutex = PTHREAD_MUTEX_INITIALIZER;
 static int dns_client_has_bootstrap_dns = 0;
 
+int _ssl_read(struct dns_server_info *server, void *buff, int num)
+{
+	int ret = 0;
+	if (server == NULL || buff == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_read(server->ssl, buff, num);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_write(struct dns_server_info *server, const void *buff, int num)
+{
+	int ret = 0;
+	if (server == NULL || buff == NULL || server->ssl == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_write(server->ssl, buff, num);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_shutdown(struct dns_server_info *server)
+{
+	int ret = 0;
+	if (server == NULL || server->ssl == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_shutdown(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_get_error(struct dns_server_info *server, int ret)
+{
+	int err = 0;
+	if (server == NULL || server->ssl == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	err = SSL_get_error(server->ssl, ret);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+int _ssl_do_handshake(struct dns_server_info *server)
+{
+	int err = 0;
+	if (server == NULL || server->ssl == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	err = SSL_do_handshake(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+int _ssl_session_reused(struct dns_server_info *server)
+{
+	int err = 0;
+	if (server == NULL || server->ssl == NULL) {
+		return SSL_ERROR_SYSCALL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	err = SSL_session_reused(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+SSL_SESSION *_ssl_get1_session(struct dns_server_info *server)
+{
+	SSL_SESSION *ret = 0;
+	if (server == NULL || server->ssl == NULL) {
+		return NULL;
+	}
+
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_get1_session(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
 const char *_dns_server_get_type_string(dns_server_type_t type)
 {
 	const char *type_str = "";
@@ -342,6 +438,10 @@ static struct dns_server_info *_dns_client_get_server(char *server_ip, int port,
 	struct dns_server_info *server_info, *tmp;
 	struct dns_server_info *server_info_return = NULL;
 
+	if (server_ip == NULL) {
+		return NULL;
+	}
+
 	pthread_mutex_lock(&client.server_list_lock);
 	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
 	{
@@ -444,6 +544,10 @@ static int _dns_client_add_to_pending_group(char *group_name, char *server_ip, i
 	struct dns_server_pending *pending = NULL;
 	struct dns_server_pending_group *group = NULL;
 
+	if (group_name == NULL || server_ip == NULL) {
+		goto errout;
+	}
+
 	pthread_mutex_lock(&pending_server_mutex);
 	list_for_each_entry_safe(item, tmp, &pending_servers, list)
 	{
@@ -485,6 +589,10 @@ static int _dns_client_add_to_group_pending(char *group_name, char *server_ip, i
 {
 	struct dns_server_info *server_info = NULL;
 
+	if (group_name == NULL || server_ip == NULL) {
+		return -1;
+	}
+
 	server_info = _dns_client_get_server(server_ip, port, server_type);
 	if (server_info == NULL) {
 		if (ispending == 0) {
@@ -565,6 +673,10 @@ int dns_client_add_group(char *group_name)
 	unsigned long key;
 	struct dns_server_group *group = NULL;
 
+	if (group_name == NULL) {
+		return -1;
+	}
+
 	if (_dns_client_get_group(group_name) != NULL) {
 		tlog(TLOG_ERROR, "add group %s failed, group already exists", group_name);
 		return -1;
@@ -596,6 +708,10 @@ static int _dns_client_remove_group(struct dns_server_group *group)
 	struct dns_server_group_member *group_member;
 	struct dns_server_group_member *tmp;
 
+	if (group == NULL) {
+		return 0;
+	}
+
 	list_for_each_entry_safe(group_member, tmp, &group->head, list)
 	{
 		_dns_client_remove_member(group_member);
@@ -613,6 +729,10 @@ int dns_client_remove_group(char *group_name)
 	struct dns_server_group *group = NULL;
 	struct hlist_node *tmp = NULL;
 
+	if (group_name == NULL) {
+		return -1;
+	}
+
 	key = hash_string(group_name);
 	hash_for_each_possible_safe(client.group, group, tmp, node, key)
 	{
@@ -721,6 +841,10 @@ static int _dns_client_set_trusted_cert(SSL_CTX *ssl_ctx)
 	char *capath = NULL;
 	int cert_path_set = 0;
 
+	if (ssl_ctx == NULL) {
+		return -1;
+	}
+
 	if (dns_conf_ca_file[0]) {
 		cafile = dns_conf_ca_file;
 	}
@@ -731,15 +855,19 @@ static int _dns_client_set_trusted_cert(SSL_CTX *ssl_ctx)
 
 	if (cafile == NULL && capath == NULL) {
 		if (SSL_CTX_set_default_verify_paths(ssl_ctx)) {
+			cert_path_set = 1;
+		}
+
+		const STACK_OF(X509_NAME) *cas = SSL_CTX_get_client_CA_list(ssl_ctx);
+		if (cas && sk_X509_NAME_num(cas) == 0) {
 			cafile = "/etc/ssl/certs/ca-certificates.crt";
 			capath = "/etc/ssl/certs";
-		} else {
+			cert_path_set = 0;
-			cert_path_set = 1;
 		}
 	}
 
 	if (cert_path_set == 0) {
-		if (!SSL_CTX_load_verify_locations(ssl_ctx, cafile, capath)) {
+		if (SSL_CTX_load_verify_locations(ssl_ctx, cafile, capath) == 0) {
 			tlog(TLOG_WARN, "load certificate from %s:%s failed.", cafile, capath);
 			return -1;
 		}
@@ -748,6 +876,47 @@ static int _dns_client_set_trusted_cert(SSL_CTX *ssl_ctx)
 	return 0;
 }
 
+SSL_CTX *_ssl_ctx_get(void)
+{
+	pthread_mutex_lock(&client.server_list_lock);
+	SSL_CTX *ssl_ctx = client.ssl_ctx;
+	if (ssl_ctx) {
+		pthread_mutex_unlock(&client.server_list_lock);
+		return ssl_ctx;
+	}
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
+	ssl_ctx = SSL_CTX_new(TLS_client_method());
+#else
+	ssl_ctx = SSL_CTX_new(SSLv23_client_method());
+#endif
+
+	if (ssl_ctx == NULL) {
+		tlog(TLOG_ERROR, "init ssl failed.");
+		goto errout;
+	}
+
+	SSL_CTX_set_options(ssl_ctx, SSL_OP_ALL | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
+	SSL_CTX_set_session_cache_mode(ssl_ctx, SSL_SESS_CACHE_CLIENT);
+	SSL_CTX_sess_set_cache_size(ssl_ctx, DNS_MAX_SERVERS);
+	if (_dns_client_set_trusted_cert(ssl_ctx) != 0) {
+		SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_NONE, NULL);
+		client.ssl_verify_skip = 1;
+	}
+
+	client.ssl_ctx = ssl_ctx;
+	pthread_mutex_unlock(&client.server_list_lock);
+	return client.ssl_ctx;
+errout:
+	
+	pthread_mutex_unlock(&client.server_list_lock);
+	if (ssl_ctx) {
+		SSL_CTX_free(ssl_ctx);
+	}
+
+	return NULL;
+}
+
 /* add dns server information */
 static int _dns_client_server_add(char *server_ip, char *server_host, int port, dns_server_type_t server_type,
 								  struct client_dns_server_flags *flags)
@@ -836,6 +1005,8 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 	server_info->ttl = ttl;
 	server_info->ttl_range = 0;
 	server_info->skip_check_cert = skip_check_cert;
+	server_info->prohibit = 0;
+	pthread_mutex_init(&server_info->lock, NULL);
 	memcpy(&server_info->flags, flags, sizeof(server_info->flags));
 
 	/* exclude this server from default group */
@@ -848,23 +1019,14 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 
 	/* if server type is TLS, create ssl context */
 	if (server_type == DNS_SERVER_TLS || server_type == DNS_SERVER_HTTPS) {
-#if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
+		server_info->ssl_ctx = _ssl_ctx_get();
-		server_info->ssl_ctx = SSL_CTX_new(TLS_client_method());
-#else
-		server_info->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
-#endif
-
 		if (server_info->ssl_ctx == NULL) {
 			tlog(TLOG_ERROR, "init ssl failed.");
 			goto errout;
 		}
 
-		SSL_CTX_set_options(server_info->ssl_ctx, SSL_OP_ALL | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
+		if (client.ssl_verify_skip) {
-		SSL_CTX_set_session_cache_mode(server_info->ssl_ctx, SSL_SESS_CACHE_CLIENT);
-		if (_dns_client_set_trusted_cert(server_info->ssl_ctx) != 0) {
-			tlog(TLOG_WARN, "disable check certificate for %s.", server_info->ip);
 			server_info->skip_check_cert = 1;
-			SSL_CTX_set_verify(server_info->ssl_ctx, SSL_VERIFY_NONE, NULL);
 		}
 	}
 
@@ -909,11 +1071,7 @@ errout:
 			fast_ping_stop(server_info->ping_host);
 		}
 
-		if (server_info->ssl_ctx) {
+		pthread_mutex_destroy(&server_info->lock);
-			SSL_CTX_free(server_info->ssl_ctx);
-			server_info->ssl_ctx = NULL;
-		}
-
 		free(server_info);
 	}
 
@@ -932,9 +1090,12 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)
 
 	if (server_info->ssl) {
 		/* Shutdown ssl */
-		SSL_shutdown(server_info->ssl);
+		if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
+			_ssl_shutdown(server_info);
+		}
 		SSL_free(server_info->ssl);
 		server_info->ssl = NULL;
+		server_info->ssl_write_len = -1;
 	}
 
 	/* remove fd from epoll */
@@ -949,6 +1110,36 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)
 	tlog(TLOG_DEBUG, "server %s closed.", server_info->ip);
 }
 
+static void _dns_client_shutdown_socket(struct dns_server_info *server_info)
+{
+	if (server_info->fd <= 0) {
+		return;
+	}
+
+	switch (server_info->type) {
+	case DNS_SERVER_UDP:
+		return;
+		break;
+	case DNS_SERVER_TCP:
+		if (server_info->fd > 0) {
+			shutdown(server_info->fd, SHUT_RDWR);
+		}
+		break;
+	case DNS_SERVER_TLS:
+	case DNS_SERVER_HTTPS:
+		if (server_info->ssl) {
+			/* Shutdown ssl */
+			if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
+				_ssl_shutdown(server_info);
+			}
+			shutdown(server_info->fd, SHUT_RDWR);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
 static void _dns_client_server_close(struct dns_server_info *server_info)
 {
 	/* stop ping task */
@@ -965,11 +1156,8 @@ static void _dns_client_server_close(struct dns_server_info *server_info)
 		server_info->ssl_session = NULL;
 	}
 
-	if (server_info->ssl_ctx) {
-		SSL_CTX_free(server_info->ssl_ctx);
 	server_info->ssl_ctx = NULL;
 }
-}
 
 /* remove all servers information */
 static void _dns_client_server_remove_all(void)
@@ -980,6 +1168,7 @@ static void _dns_client_server_remove_all(void)
 	{
 		list_del(&server_info->list);
 		_dns_client_server_close(server_info);
+		pthread_mutex_destroy(&server_info->lock);
 		free(server_info);
 	}
 	pthread_mutex_unlock(&client.server_list_lock);
@@ -1433,7 +1622,7 @@ static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *
 	}
 
 	_dns_client_query_release(query);
-	return ret;
+	return 0;
 }
 
 static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
@@ -1524,6 +1713,9 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 		}
 	}
 
+	server_info->fd = fd;
+	server_info->status = DNS_SERVER_STATUS_CONNECTING;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN | EPOLLOUT;
 	event.data.ptr = server_info;
@@ -1532,17 +1724,19 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 		return -1;
 	}
 
-	server_info->fd = fd;
-	server_info->status = DNS_SERVER_STATUS_CONNECTING;
-
 	tlog(TLOG_DEBUG, "tcp server %s connecting.\n", server_info->ip);
 
 	return 0;
 errout:
+	if (server_info->fd > 0) {
+		server_info->fd = -1;
+	}
+
+	server_info->status = DNS_SERVER_STATUS_INIT;
+
 	if (fd > 0) {
 		close(fd);
 	}
-
 	return -1;
 }
 
@@ -1556,19 +1750,19 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 	const int ip_tos = SOCKET_IP_TOS;
 
 	if (server_info->ssl_ctx == NULL) {
-		tlog(TLOG_ERROR, "create ssl ctx failed.");
+		tlog(TLOG_ERROR, "create ssl ctx failed, %s", server_info->ip);
 		goto errout;
 	}
 
 	ssl = SSL_new(server_info->ssl_ctx);
 	if (ssl == NULL) {
-		tlog(TLOG_ERROR, "new ssl failed.");
+		tlog(TLOG_ERROR, "new ssl failed, %s", server_info->ip);
 		goto errout;
 	}
 
 	fd = socket(server_info->ai_family, SOCK_STREAM, 0);
 	if (fd < 0) {
-		tlog(TLOG_ERROR, "create socket failed.");
+		tlog(TLOG_ERROR, "create socket failed, %s", strerror(errno));
 		goto errout;
 	}
 
@@ -1617,6 +1811,11 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 		SSL_set_tlsext_host_name(ssl, hostname);
 	}
 
+	server_info->fd = fd;
+	server_info->ssl = ssl;
+	server_info->ssl_write_len = -1;
+	server_info->status = DNS_SERVER_STATUS_CONNECTING;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN | EPOLLOUT;
 	event.data.ptr = server_info;
@@ -1625,14 +1824,20 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 		goto errout;
 	}
 
-	server_info->fd = fd;
-	server_info->ssl = ssl;
-	server_info->status = DNS_SERVER_STATUS_CONNECTING;
-
 	tlog(TLOG_DEBUG, "tls server %s connecting.\n", server_info->ip);
 
 	return 0;
 errout:
+	if (server_info->fd > 0) {
+		server_info->fd = -1;
+	}
+
+	if (server_info->ssl) {
+		server_info->ssl = NULL;
+	}
+
+	server_info->status = DNS_SERVER_STATUS_INIT;
+
 	if (fd > 0) {
 		close(fd);
 	}
@@ -1731,28 +1936,28 @@ static int _dns_client_process_udp(struct dns_server_info *server_info, struct e
 	return 0;
 }
 
-static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
+static int _dns_client_socket_ssl_send(struct dns_server_info *server, const void *buf, int num)
 {
 	int ret = 0;
 	int ssl_ret = 0;
 	unsigned long ssl_err = 0;
 
-	if (ssl == NULL) {
+	if (server->ssl == NULL) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	ret = SSL_write(ssl, buf, num);
+	ret = _ssl_write(server, buf, num);
 	if (ret > 0) {
 		return ret;
 	}
 
-	ssl_ret = SSL_get_error(ssl, ret);
+	ssl_ret = _ssl_get_error(server, ret);
 	switch (ssl_ret) {
 	case SSL_ERROR_NONE:
-	case SSL_ERROR_ZERO_RETURN:
 		return 0;
 		break;
+	case SSL_ERROR_ZERO_RETURN:
 	case SSL_ERROR_WANT_READ:
 		errno = EAGAIN;
 		ret = -1;
@@ -1765,7 +1970,8 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 		ssl_err = ERR_get_error();
 		int ssl_reason = ERR_GET_REASON(ssl_err);
 		if (ssl_reason == SSL_R_UNINITIALIZED || ssl_reason == SSL_R_PROTOCOL_IS_SHUTDOWN ||
-			ssl_reason == SSL_R_BAD_LENGTH || ssl_reason == SSL_R_SHUTDOWN_WHILE_IN_INIT) {
+			ssl_reason == SSL_R_BAD_LENGTH || ssl_reason == SSL_R_SHUTDOWN_WHILE_IN_INIT ||
+			ssl_reason == SSL_R_BAD_WRITE_RETRY) {
 			errno = EAGAIN;
 			return -1;
 		}
@@ -1786,23 +1992,23 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 	return ret;
 }
 
-static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
+static int _dns_client_socket_ssl_recv(struct dns_server_info *server, void *buf, int num)
 {
 	int ret = 0;
 	int ssl_ret = 0;
 	unsigned long ssl_err = 0;
 
-	if (ssl == NULL) {
+	if (server->ssl == NULL) {
 		errno = EFAULT;
 		return -1;
 	}
 
-	ret = SSL_read(ssl, buf, num);
+	ret = _ssl_read(server, buf, num);
 	if (ret >= 0) {
 		return ret;
 	}
 
-	ssl_ret = SSL_get_error(ssl, ret);
+	ssl_ret = _ssl_get_error(server, ret);
 	switch (ssl_ret) {
 	case SSL_ERROR_NONE:
 	case SSL_ERROR_ZERO_RETURN:
@@ -1828,11 +2034,15 @@ static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
 			return 0;
 		}
 
-		tlog(TLOG_ERROR, "SSL read fail error no: %s(%ld)\n", ERR_reason_error_string(ssl_err), ssl_err);
+		tlog(TLOG_ERROR, "SSL read fail error no: %s(%lx)\n", ERR_reason_error_string(ssl_err), ssl_err);
 		errno = EFAULT;
 		ret = -1;
 		break;
 	case SSL_ERROR_SYSCALL:
+		if (errno == 0) {
+			return 0;
+		}
+
 		if (errno != ECONNRESET) {
 			tlog(TLOG_INFO, "SSL syscall failed, %s ", strerror(errno));
 		}
@@ -1854,7 +2064,18 @@ static int _dns_client_socket_send(struct dns_server_info *server_info)
 	} else if (server_info->type == DNS_SERVER_TCP) {
 		return send(server_info->fd, server_info->send_buff.data, server_info->send_buff.len, MSG_NOSIGNAL);
 	} else if (server_info->type == DNS_SERVER_TLS || server_info->type == DNS_SERVER_HTTPS) {
-		return _dns_client_socket_ssl_send(server_info->ssl, server_info->send_buff.data, server_info->send_buff.len);
+		int write_len = server_info->send_buff.len;
+		if (server_info->ssl_write_len > 0) {
+			write_len = server_info->ssl_write_len;
+			server_info->ssl_write_len = -1;
+		}
+		int ret = _dns_client_socket_ssl_send(server_info, server_info->send_buff.data, write_len);
+		if (ret != 0) {
+			if (errno == EAGAIN) {
+				server_info->ssl_write_len = write_len;
+			}
+		}
+		return ret;
 	} else {
 		return -1;
 	}
@@ -1868,7 +2089,7 @@ static int _dns_client_socket_recv(struct dns_server_info *server_info)
 		return recv(server_info->fd, server_info->recv_buff.data + server_info->recv_buff.len,
 					DNS_TCP_BUFFER - server_info->recv_buff.len, 0);
 	} else if (server_info->type == DNS_SERVER_TLS || server_info->type == DNS_SERVER_HTTPS) {
-		return _dns_client_socket_ssl_recv(server_info->ssl, server_info->recv_buff.data + server_info->recv_buff.len,
+		return _dns_client_socket_ssl_recv(server_info, server_info->recv_buff.data + server_info->recv_buff.len,
 										   DNS_TCP_BUFFER - server_info->recv_buff.len);
 	} else {
 		return -1;
@@ -1933,6 +2154,7 @@ static int _dns_client_process_tcp_buff(struct dns_server_info *server_info)
 		}
 
 		tlog(TLOG_DEBUG, "recv tcp packet from %s, len = %d", server_info->ip, len);
+		time(&server_info->last_recv);
 		/* process result */
 		if (_dns_client_recv(server_info, inpacket_data, dns_packet_len, &server_info->addr, server_info->ai_addrlen) !=
 			0) {
@@ -1986,6 +2208,11 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 				goto errout;
 			}
 
+			if (errno == ETIMEDOUT) {
+				tlog(TLOG_INFO, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
+				goto errout;
+			}
+
 			tlog(TLOG_ERROR, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
 			goto errout;
 		}
@@ -2006,7 +2233,6 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 			return ret;
 		}
 
-		time(&server_info->last_recv);
 		server_info->recv_buff.len += len;
 		if (server_info->recv_buff.len <= 2) {
 			/* wait and recv */
@@ -2115,7 +2341,8 @@ static int _dns_client_tls_matchName(const char *host, const char *pattern, int
 	return match;
 }
 
-static int _dns_client_tls_get_cert_CN(X509 *cert, char *cn, int max_cn_len) {
+static int _dns_client_tls_get_cert_CN(X509 *cert, char *cn, int max_cn_len)
+{
 	X509_NAME *cert_name = NULL;
 
 	cert_name = X509_get_subject_name(cert);
@@ -2153,8 +2380,10 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
 		return -1;
 	}
 
+	pthread_mutex_lock(&server_info->lock);
 	cert = SSL_get_peer_certificate(server_info->ssl);
 	if (cert == NULL) {
+		pthread_mutex_unlock(&server_info->lock);
 		tlog(TLOG_ERROR, "get peer certificate failed.");
 		return -1;
 	}
@@ -2162,13 +2391,15 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
 	if (server_info->skip_check_cert == 0) {
 		long res = SSL_get_verify_result(server_info->ssl);
 		if (res != X509_V_OK) {
+			pthread_mutex_unlock(&server_info->lock);
 			peer_CN[0] = '\0';
 			_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN));
-			tlog(TLOG_WARN, "peer server %s certificate verify failed", server_info->ip);
+			tlog(TLOG_WARN, "peer server %s certificate verify failed, ret = %ld", server_info->ip, res);
 			tlog(TLOG_WARN, "peer CN: %s", peer_CN);
 			goto errout;
 		}
 	}
+	pthread_mutex_unlock(&server_info->lock);
 
 	if (_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN)) != 0) {
 		tlog(TLOG_ERROR, "get cert CN failed.");
@@ -2268,12 +2499,12 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 
 	if (server_info->status == DNS_SERVER_STATUS_CONNECTING) {
 		/* do SSL hand shake */
-		ret = SSL_do_handshake(server_info->ssl);
+		ret = _ssl_do_handshake(server_info);
 		if (ret == 0) {
 			goto errout;
 		} else if (ret < 0) {
 			memset(&fd_event, 0, sizeof(fd_event));
-			ssl_ret = SSL_get_error(server_info->ssl, ret);
+			ssl_ret = _ssl_get_error(server_info, ret);
 			if (ssl_ret == SSL_ERROR_WANT_READ) {
 				fd_event.events = EPOLLIN;
 			} else if (ssl_ret == SSL_ERROR_WANT_WRITE) {
@@ -2302,7 +2533,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 
 		tlog(TLOG_DEBUG, "tls server %s connected.\n", server_info->ip);
 		/* Was the stored session reused? */
-		if (SSL_session_reused(server_info->ssl)) {
+		if (_ssl_session_reused(server_info)) {
 			tlog(TLOG_DEBUG, "reused session");
 		} else {
 			tlog(TLOG_DEBUG, "new session");
@@ -2320,7 +2551,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 			}
 
 			/* save ssl session for next request */
-			server_info->ssl_session = SSL_get1_session(server_info->ssl);
+			server_info->ssl_session = _ssl_get1_session(server_info);
 			pthread_mutex_unlock(&client.server_list_lock);
 		}
 
@@ -2433,7 +2664,7 @@ static int _dns_client_send_tcp(struct dns_server_info *server_info, void *packe
 			/* save data to buffer, and retry when EPOLLOUT is available */
 			return _dns_client_send_data_to_buffer(server_info, inpacket, len);
 		} else if (errno == EPIPE) {
-			shutdown(server_info->fd, SHUT_RDWR);
+			_dns_client_shutdown_socket(server_info);
 		}
 		return -1;
 	} else if (send_len < len) {
@@ -2471,13 +2702,13 @@ static int _dns_client_send_tls(struct dns_server_info *server_info, void *packe
 		return -1;
 	}
 
-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, len);
+	send_len = _dns_client_socket_ssl_send(server_info, inpacket, len);
 	if (send_len <= 0) {
 		if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
 			/* save data to buffer, and retry when EPOLLOUT is available */
 			return _dns_client_send_data_to_buffer(server_info, inpacket, len);
 		} else if (server_info->ssl && errno != ENOMEM) {
-			SSL_set_shutdown(server_info->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
+			_dns_client_shutdown_socket(server_info);
 		}
 		return -1;
 	} else if (send_len < len) {
@@ -2522,13 +2753,13 @@ static int _dns_client_send_https(struct dns_server_info *server_info, void *pac
 		return -1;
 	}
 
-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, http_len);
+	send_len = _dns_client_socket_ssl_send(server_info, inpacket, http_len);
 	if (send_len <= 0) {
 		if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
 			/* save data to buffer, and retry when EPOLLOUT is available */
 			return _dns_client_send_data_to_buffer(server_info, inpacket, http_len);
 		} else if (server_info->ssl && errno != ENOMEM) {
-			SSL_set_shutdown(server_info->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
+			_dns_client_shutdown_socket(server_info);
 		}
 		return -1;
 	} else if (send_len < http_len) {
@@ -2547,15 +2778,27 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 	int ret = 0;
 	int send_err = 0;
 	int i = 0;
+	int total_server = 0;
 
 	query->send_tick = get_tick_count();
 
 	/* send query to all dns servers */
 	for (i = 0; i < 2; i++) {
+		total_server = 0;
 		pthread_mutex_lock(&client.server_list_lock);
 		list_for_each_entry_safe(group_member, tmp, &query->server_group->head, list)
 		{
 			server_info = group_member->server;
+			if (server_info->prohibit) {
+				time_t now;
+				time(&now);
+				if ((now - 60 < server_info->last_send) && (now - 5 > server_info->last_recv)) {
+					continue;
+				}
+				server_info->prohibit = 0;
+			}
+			total_server++;
+			tlog(TLOG_DEBUG, "send query to server %s", server_info->ip);
 			if (server_info->fd <= 0) {
 				ret = _dns_client_create_socket(server_info);
 				if (ret != 0) {
@@ -2596,21 +2839,20 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 					tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
 						 server_info->type);
 					_dns_client_close_socket(server_info);
-				} else if (send_err != ENOMEM) {
+					atomic_dec(&query->dns_request_sent);
-					tlog(TLOG_ERROR, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
+					continue;
-						 server_info->type);
+				}
-				} else {
+
 				tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
 					 server_info->type);
 				time_t now;
 				time(&now);
-					if (now - 5 > server_info->last_recv) {
+				if (now - 5 > server_info->last_recv || send_err != ENOMEM) {
-						server_info->recv_buff.len = 0;
+					server_info->prohibit = 1;
-						server_info->send_buff.len = 0;
+					tlog(TLOG_INFO, "server %s not alive, prohibit", server_info->ip);
-						tlog(TLOG_DEBUG, "server %s not response, retry.", server_info->ip);
+					_dns_client_shutdown_socket(server_info);
-						_dns_client_close_socket(server_info);
-					}
 				}
+
 				atomic_dec(&query->dns_request_sent);
 				continue;
 			}
@@ -2624,7 +2866,7 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 	}
 
 	if (atomic_read(&query->dns_request_sent) <= 0) {
-		tlog(TLOG_ERROR, "Send query to upstream server failed.");
+		tlog(TLOG_ERROR, "Send query to upstream server failed, total server number %d", total_server);
 		return -1;
 	}
 
@@ -2710,6 +2952,10 @@ int dns_client_query(char *domain, int qtype, dns_client_callback callback, void
 	int ret = 0;
 	uint32_t key = 0;
 
+	if (domain == NULL) {
+		goto errout;
+	}
+
 	query = malloc(sizeof(*query));
 	if (query == NULL) {
 		goto errout;
@@ -2867,7 +3113,7 @@ static void _dns_client_add_pending_servers(void)
 		if (pending->query_v4 == 0) {
 			pending->query_v4 = 1;
 			_dns_client_server_pending_get(pending);
-			if (dns_server_query(pending->host, DNS_T_A, _dns_client_pending_server_resolve, pending) != 0) {
+			if (dns_server_query(pending->host, DNS_T_A, 0, _dns_client_pending_server_resolve, pending) != 0) {
 				_dns_client_server_pending_release_lck(pending);
 			}
 		}
@@ -2875,14 +3121,13 @@ static void _dns_client_add_pending_servers(void)
 		if (pending->query_v6 == 0) {
 			pending->query_v6 = 1;
 			_dns_client_server_pending_get(pending);
-			if (dns_server_query(pending->host, DNS_T_AAAA, _dns_client_pending_server_resolve, pending) != 0) {
+			if (dns_server_query(pending->host, DNS_T_AAAA, 0, _dns_client_pending_server_resolve, pending) != 0) {
 				_dns_client_server_pending_release_lck(pending);
 			}
 		}
 
 		/* if both A, AAAA has query result, select fastest IP address */
 		if (pending->has_v4 && pending->has_v6) {
-
 			if (pending->ping_time_v4 <= pending->ping_time_v6 && pending->ipv4[0]) {
 				dnsserver_ip = pending->ipv4;
 			} else {
@@ -2905,6 +3150,7 @@ static void _dns_client_add_pending_servers(void)
 			if (add_success == 0) {
 				tlog(TLOG_WARN, "add pending DNS server %s failed.", pending->host);
 			}
+			list_del_init(&pending->list);
 			_dns_client_server_pending_release_lck(pending);
 		} else {
 			tlog(TLOG_DEBUG, "add pending DNS server %s failed, retry %d...", pending->host, pending->retry_cnt);
@@ -3027,6 +3273,34 @@ static void *_dns_client_work(void *arg)
 
 int dns_client_set_ecs(char *ip, int subnet)
 {
+	struct sockaddr_storage addr;
+	socklen_t addr_len = sizeof(addr);
+	getaddr_by_host(ip, (struct sockaddr *)&addr, &addr_len);
+
+	switch (addr.ss_family) {
+	case AF_INET: {
+		struct sockaddr_in *addr_in;
+		addr_in = (struct sockaddr_in *)&addr;
+		memcpy(&client.ecs_ipv4.ipv4_addr, &addr_in->sin_addr.s_addr, 4);
+		client.ecs_ipv4.bitlen = subnet;
+		client.ecs_ipv4.enable = 1;
+	} break;
+	case AF_INET6: {
+		struct sockaddr_in6 *addr_in6;
+		addr_in6 = (struct sockaddr_in6 *)&addr;
+		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
+			memcpy(&client.ecs_ipv4.ipv4_addr, addr_in6->sin6_addr.s6_addr + 12, 4);
+			client.ecs_ipv4.bitlen = subnet;
+			client.ecs_ipv4.enable = 1;
+		} else {
+			memcpy(&client.ecs_ipv6.ipv6_addr, addr_in6->sin6_addr.s6_addr, 16);
+			client.ecs_ipv6.bitlen = subnet;
+			client.ecs_ipv6.enable = 1;
+		}
+	} break;
+	default:
+		return -1;
+	}
 	return 0;
 }
 
@@ -3107,4 +3381,8 @@ void dns_client_exit(void)
 
 	pthread_mutex_destroy(&client.server_list_lock);
 	pthread_mutex_destroy(&client.domain_map_lock);
+	if (client.ssl_ctx) {
+		SSL_CTX_free(client.ssl_ctx);
+		client.ssl_ctx = NULL;
+	}
 }

src/dns_conf.c

@@ -37,6 +37,8 @@ struct dns_ipset_table {
 };
 static struct dns_ipset_table dns_ipset_table;
 
+struct dns_qtype_soa_table dns_qtype_soa_table;
+
 /* dns groups */
 struct dns_group_table dns_group_table;
 
@@ -48,8 +50,9 @@ int dns_conf_tcp_idle_time = 120;
 /* cache */
 int dns_conf_cachesize = DEFAULT_DNS_CACHE_SIZE;
 int dns_conf_prefetch = 0;
-int dns_conf_serve_expired = 0;
+int dns_conf_serve_expired = 1;
 int dns_conf_serve_expired_ttl = 0;
+int dns_conf_serve_expired_reply_ttl = 5;
 
 /* upstream servers */
 struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
@@ -72,6 +75,9 @@ int dns_conf_log_num = 8;
 char dns_conf_ca_file[DNS_MAX_PATH];
 char dns_conf_ca_path[DNS_MAX_PATH];
 
+char dns_conf_cache_file[DNS_MAX_PATH];
+int dns_conf_cache_persist = 2;
+
 /* auditing */
 int dns_conf_audit_enable = 0;
 int dns_conf_audit_log_SOA;
@@ -84,12 +90,13 @@ art_tree dns_conf_domain_rule;
 struct dns_conf_address_rule dns_conf_address_rule;
 
 /* dual-stack selection */
-int dns_conf_dualstack_ip_selection;
+int dns_conf_dualstack_ip_selection = 1;
-int dns_conf_dualstack_ip_selection_threshold = 30;
+int dns_conf_dualstack_ip_selection_threshold = 15;
 
 /* TTL */
 int dns_conf_rr_ttl;
-int dns_conf_rr_ttl_min;
+int dns_conf_rr_ttl_reply_max;
+int dns_conf_rr_ttl_min = 600;
 int dns_conf_rr_ttl_max;
 int dns_conf_force_AAAA_SOA;
 
@@ -107,6 +114,10 @@ static int _get_domain(char *value, char *domain, int max_dmain_size, char **ptr
 	char *end = NULL;
 	int len = 0;
 
+	if (value == NULL || domain == NULL) {
+		goto errout;
+	}
+
 	/* first field */
 	begin = strstr(value, "/");
 	if (begin == NULL) {
@@ -474,7 +485,7 @@ errout:
 	return -1;
 }
 
-static int _config_domain_rule_flag_set(char *domain, unsigned int flag)
+static int _config_domain_rule_flag_set(char *domain, unsigned int flag, unsigned int is_clear)
 {
 	struct dns_domain_rule *domain_rule = NULL;
 	struct dns_domain_rule *old_domain_rule = NULL;
@@ -508,12 +519,18 @@ static int _config_domain_rule_flag_set(char *domain, unsigned int flag)
 	/* add new rule to domain */
 	if (domain_rule->rules[DOMAIN_RULE_FLAGS] == NULL) {
 		rule_flags = malloc(sizeof(*rule_flags));
+		memset(rule_flags, 0, sizeof(*rule_flags));
 		rule_flags->flags = 0;
 		domain_rule->rules[DOMAIN_RULE_FLAGS] = rule_flags;
 	}
 
 	rule_flags = domain_rule->rules[DOMAIN_RULE_FLAGS];
+	if (is_clear == false) {
 		rule_flags->flags |= flag;
+	} else {
+		rule_flags->flags &= ~flag;
+	}
+	rule_flags->is_flag_set |= flag;
 
 	/* update domain rule */
 	if (add_domain_rule) {
@@ -581,11 +598,40 @@ static int _conf_domain_rule_ipset(char *domain, const char *ipsetname)
 {
 	struct dns_ipset_rule *ipset_rule = NULL;
 	const char *ipset = NULL;
+	char *copied_name = NULL;
+	enum domain_rule type;
+	int ignore_flag;
+
+	copied_name = strdup(ipsetname);
+
+	if (copied_name == NULL) {
+		goto errout;
+	}
+
+	for (char *tok = strtok(copied_name, ","); tok; tok = strtok(NULL, ",")) {
+		if (tok[0] == '#') {
+			if (strncmp(tok, "#6:", 3u) == 0) {
+				type = DOMAIN_RULE_IPSET_IPV6;
+				ignore_flag = DOMAIN_FLAG_IPSET_IPV6_IGN;
+			} else if (strncmp(tok, "#4:", 3u) == 0) {
+				type = DOMAIN_RULE_IPSET_IPV4;
+				ignore_flag = DOMAIN_FLAG_IPSET_IPV4_IGN;
+			} else {
+				goto errout;
+			}
+			tok += 3;
+		} else {
+			type = DOMAIN_RULE_IPSET;
+			ignore_flag = DOMAIN_FLAG_IPSET_IGN;
+		}
+
+		if (strncmp(tok, "-", 1) == 0) {
+			_config_domain_rule_flag_set(domain, ignore_flag, 0);
+			continue;
+		}
 
-	/* Process domain option */
-	if (strncmp(ipsetname, "-", sizeof("-")) != 0) {
 		/* new ipset domain */
-		ipset = _dns_conf_get_ipset(ipsetname);
+		ipset = _dns_conf_get_ipset(tok);
 		if (ipset == NULL) {
 			goto errout;
 		}
@@ -596,26 +642,26 @@ static int _conf_domain_rule_ipset(char *domain, const char *ipsetname)
 		}
 
 		ipset_rule->ipsetname = ipset;
-	} else {
+
-		/* ignore this domain */
+		if (_config_domain_rule_add(domain, type, ipset_rule) != 0) {
-		if (_config_domain_rule_flag_set(domain, DOMAIN_FLAG_IPSET_IGNORE) != 0) {
 			goto errout;
 		}
-
-		return 0;
 	}
 
-	if (_config_domain_rule_add(domain, DOMAIN_RULE_IPSET, ipset_rule) != 0) {
+	goto clear;
-		goto errout;
-	}
 
-	return 0;
 errout:
+	tlog(TLOG_ERROR, "add ipset %s failed", ipsetname);
+
 	if (ipset_rule) {
 		free(ipset_rule);
 	}
 
-	tlog(TLOG_ERROR, "add ipset %s failed", ipsetname);
+clear:
+	if (copied_name) {
+		free(copied_name);
+	}
+
 	return 0;
 }
 
@@ -662,7 +708,7 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 		}
 
 		/* add SOA rule */
-		if (_config_domain_rule_flag_set(domain, flag) != 0) {
+		if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
 			goto errout;
 		}
 
@@ -679,7 +725,7 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 		}
 
 		/* ignore rule */
-		if (_config_domain_rule_flag_set(domain, flag) != 0) {
+		if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
 			goto errout;
 		}
 
@@ -1000,7 +1046,7 @@ static int _conf_domain_rule_nameserver(char *domain, const char *group_name)
 		nameserver_rule->group_name = group;
 	} else {
 		/* ignore this domain */
-		if (_config_domain_rule_flag_set(domain, DOMAIN_FLAG_NAMESERVER_IGNORE) != 0) {
+		if (_config_domain_rule_flag_set(domain, DOMAIN_FLAG_NAMESERVER_IGNORE, 0) != 0) {
 			goto errout;
 		}
 
@@ -1021,6 +1067,26 @@ errout:
 	return 0;
 }
 
+static int _conf_domain_rule_dualstack_selection(char *domain, const char *yesno)
+{
+	if (strncmp(yesno, "yes", sizeof("yes")) == 0 || strncmp(yesno, "Yes", sizeof("Yes")) == 0) {
+		if (_config_domain_rule_flag_set(domain, DOMAIN_FLAG_DUALSTACK_SELECT, 0) != 0) {
+			goto errout;
+		}
+	} else {
+		/* ignore this domain */
+		if (_config_domain_rule_flag_set(domain, DOMAIN_FLAG_DUALSTACK_SELECT, 1) != 0) {
+			goto errout;
+		}
+	}
+
+	return 0;
+
+errout:
+	tlog(TLOG_ERROR, "set dualstack for %s failed. ", domain);
+	return 1;
+}
+
 static int _config_nameserver(void *data, int argc, char *argv[])
 {
 	char domain[DNS_MAX_CONF_CNAME_LEN];
@@ -1108,6 +1174,44 @@ static int _config_iplist_rule(char *subnet, enum address_rule rule)
 	return 0;
 }
 
+static int _config_qtype_soa(void *data, int argc, char *argv[])
+{
+	struct dns_qtype_soa_list *soa_list;
+	int i = 0;
+
+	if (argc <= 1) {
+		return -1;
+	}
+
+	for (i = 1; i < argc; i++) {
+		soa_list = malloc(sizeof(*soa_list));
+		if (soa_list == NULL) {
+			tlog(TLOG_ERROR, "cannot malloc memory");
+			return -1;
+		}
+
+		memset(soa_list, 0, sizeof(*soa_list));
+		soa_list->qtypeid = atol(argv[i]);
+		uint32_t key = hash_32_generic(soa_list->qtypeid, 32);
+		hash_add(dns_qtype_soa_table.qtype, &soa_list->node, key);
+	}
+
+	return 0;
+}
+
+static void _config_qtype_soa_table_destroy(void)
+{
+	struct dns_qtype_soa_list *soa_list = NULL;
+	struct hlist_node *tmp = NULL;
+	int i;
+
+	hash_for_each_safe(dns_qtype_soa_table.qtype, i, tmp, soa_list, node)
+	{
+		hlist_del_init(&soa_list->node);
+		free(soa_list);
+	}
+}
+
 static int _config_blacklist_ip(void *data, int argc, char *argv[])
 {
 	if (argc <= 1) {
@@ -1153,7 +1257,7 @@ static int _conf_edns_client_subnet(void *data, int argc, char *argv[])
 	struct sockaddr_storage addr;
 	socklen_t addr_len = sizeof(addr);
 
-	if (argc <= 1 || data == NULL) {
+	if (argc <= 1) {
 		return -1;
 	}
 
@@ -1231,6 +1335,7 @@ static int _conf_domain_rules(void *data, int argc, char *argv[])
 		{"address", required_argument, NULL, 'a'},
 		{"ipset", required_argument, NULL, 'p'},
 		{"nameserver", required_argument, NULL, 'n'},
+		{"dualstack-ip-selection", required_argument, NULL, 'd'},
 		{NULL, no_argument, NULL, 0}
 	};
 	/* clang-format on */
@@ -1247,7 +1352,7 @@ static int _conf_domain_rules(void *data, int argc, char *argv[])
 	/* process extra options */
 	optind = 1;
 	while (1) {
-		opt = getopt_long_only(argc, argv, "", long_options, NULL);
+		opt = getopt_long_only(argc, argv, "c:a:p:n:d:", long_options, NULL);
 		if (opt == -1) {
 			break;
 		}
@@ -1305,6 +1410,15 @@ static int _conf_domain_rules(void *data, int argc, char *argv[])
 
 			break;
 		}
+		case 'd': {
+			const char *yesno = optarg;
+			if (_conf_domain_rule_dualstack_selection(domain, yesno) != 0) {
+				tlog(TLOG_ERROR, "set dualstack selection rule failed.");
+				goto errout;
+			}
+
+			break;
+		}
 		default:
 			break;
 		}
@@ -1354,9 +1468,12 @@ static struct config_item _config_item[] = {
 	CONF_CUSTOM("speed-check-mode", _config_speed_check_mode, NULL),
 	CONF_INT("tcp-idle-time", &dns_conf_tcp_idle_time, 0, 3600),
 	CONF_INT("cache-size", &dns_conf_cachesize, 0, CONF_INT_MAX),
+	CONF_STRING("cache-file", (char *)&dns_conf_cache_file, DNS_MAX_PATH),
+	CONF_YESNO("cache-persist", &dns_conf_cache_persist),
 	CONF_YESNO("prefetch-domain", &dns_conf_prefetch),
 	CONF_YESNO("serve-expired", &dns_conf_serve_expired),
 	CONF_INT("serve-expired-ttl", &dns_conf_serve_expired_ttl, 0, CONF_INT_MAX),
+	CONF_INT("serve-expired-reply-ttl", &dns_conf_serve_expired_reply_ttl, 0, CONF_INT_MAX),
 	CONF_YESNO("dualstack-ip-selection", &dns_conf_dualstack_ip_selection),
 	CONF_INT("dualstack-ip-selection-threshold", &dns_conf_dualstack_ip_selection_threshold, 0, 1000),
 	CONF_CUSTOM("log-level", _config_log_level, NULL),
@@ -1371,7 +1488,9 @@ static struct config_item _config_item[] = {
 	CONF_INT("rr-ttl", &dns_conf_rr_ttl, 0, CONF_INT_MAX),
 	CONF_INT("rr-ttl-min", &dns_conf_rr_ttl_min, 0, CONF_INT_MAX),
 	CONF_INT("rr-ttl-max", &dns_conf_rr_ttl_max, 0, CONF_INT_MAX),
+	CONF_INT("rr-ttl-reply-max", &dns_conf_rr_ttl_reply_max, 0, CONF_INT_MAX),
 	CONF_YESNO("force-AAAA-SOA", &dns_conf_force_AAAA_SOA),
+	CONF_CUSTOM("force-qtype-SOA", _config_qtype_soa, NULL),
 	CONF_CUSTOM("blacklist-ip", _config_blacklist_ip, NULL),
 	CONF_CUSTOM("whitelist-ip", _conf_whitelist_ip, NULL),
 	CONF_CUSTOM("bogus-nxdomain", _conf_bogus_nxdomain, NULL),
@@ -1408,9 +1527,15 @@ int config_addtional_file(void *data, int argc, char *argv[])
 	if (conf_file[0] != '/') {
 		safe_strncpy(file_path_dir, conf_get_conf_file(), DNS_MAX_PATH);
 		dirname(file_path_dir);
+		if (strncmp(file_path_dir, conf_get_conf_file(), sizeof(file_path_dir)) == 0) {
+			if (snprintf(file_path, DNS_MAX_PATH, "%s", conf_file) < 0) {
+				return -1;
+			}
+		} else {
 			if (snprintf(file_path, DNS_MAX_PATH, "%s/%s", file_path_dir, conf_file) < 0) {
 				return -1;
 			}
+		}
 	} else {
 		safe_strncpy(file_path, conf_file, DNS_MAX_PATH);
 	}
@@ -1436,6 +1561,7 @@ static int _dns_server_load_conf_init(void)
 	art_tree_init(&dns_conf_domain_rule);
 
 	hash_init(dns_ipset_table.ipset);
+	hash_init(dns_qtype_soa_table.qtype);
 	hash_init(dns_group_table.group);
 
 	return 0;
@@ -1448,6 +1574,7 @@ void dns_server_load_exit(void)
 	Destroy_Radix(dns_conf_address_rule.ipv6, _config_address_destroy, NULL);
 	_config_ipset_table_destroy();
 	_config_group_table_destroy();
+	_config_qtype_soa_table_destroy();
 }
 
 static int _dns_conf_speed_check_mode_verify(void)

src/dns_conf.h

@@ -49,12 +49,15 @@ extern "C" {
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
 #define SMARTDNS_LOG_FILE "/var/log/smartdns.log"
 #define SMARTDNS_AUDIT_FILE "/var/log/smartdns-audit.log"
+#define SMARTDNS_CACHE_FILE "/tmp/smartdns.cache"
 
 enum domain_rule {
 	DOMAIN_RULE_FLAGS = 0,
 	DOMAIN_RULE_ADDRESS_IPV4,
 	DOMAIN_RULE_ADDRESS_IPV6,
 	DOMAIN_RULE_IPSET,
+	DOMAIN_RULE_IPSET_IPV4,
+	DOMAIN_RULE_IPSET_IPV6,
 	DOMAIN_RULE_NAMESERVER,
 	DOMAIN_RULE_CHECKSPEED,
 	DOMAIN_RULE_MAX,
@@ -77,8 +80,11 @@ typedef enum {
 #define DOMAIN_FLAG_ADDR_IGN (1 << 3)
 #define DOMAIN_FLAG_ADDR_IPV4_IGN (1 << 4)
 #define DOMAIN_FLAG_ADDR_IPV6_IGN (1 << 5)
-#define DOMAIN_FLAG_IPSET_IGNORE (1 << 6)
+#define DOMAIN_FLAG_IPSET_IGN (1 << 6)
-#define DOMAIN_FLAG_NAMESERVER_IGNORE (1 << 7)
+#define DOMAIN_FLAG_IPSET_IPV4_IGN (1 << 7)
+#define DOMAIN_FLAG_IPSET_IPV6_IGN (1 << 8)
+#define DOMAIN_FLAG_NAMESERVER_IGNORE (1 << 9)
+#define DOMAIN_FLAG_DUALSTACK_SELECT (1 << 10)
 
 #define SERVER_FLAG_EXCLUDE_DEFAULT (1 << 0)
 
@@ -94,6 +100,7 @@ typedef enum {
 
 struct dns_rule_flags {
 	unsigned int flags;
+	unsigned int is_flag_set;
 };
 
 struct dns_address_IPV4 {
@@ -196,6 +203,16 @@ struct dns_bind_ip {
 	const char *group;
 };
 
+struct dns_qtype_soa_list {
+	struct hlist_node node;
+	uint32_t qtypeid;
+};
+
+struct dns_qtype_soa_table {
+	DECLARE_HASHTABLE(qtype, 8);
+};
+extern struct dns_qtype_soa_table dns_qtype_soa_table;
+
 extern struct dns_bind_ip dns_conf_bind_ip[DNS_MAX_BIND_IP];
 extern int dns_conf_bind_ip_num;
 
@@ -204,6 +221,7 @@ extern int dns_conf_cachesize;
 extern int dns_conf_prefetch;
 extern int dns_conf_serve_expired;
 extern int dns_conf_serve_expired_ttl;
+extern int dns_conf_serve_expired_reply_ttl;
 extern struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
 extern int dns_conf_server_num;
 
@@ -215,6 +233,9 @@ extern int dns_conf_log_num;
 extern char dns_conf_ca_file[DNS_MAX_PATH];
 extern char dns_conf_ca_path[DNS_MAX_PATH];
 
+extern char dns_conf_cache_file[DNS_MAX_PATH];
+extern int dns_conf_cache_persist;
+
 extern struct dns_domain_check_order dns_conf_check_order;
 
 extern struct dns_server_groups dns_conf_server_groups[DNS_NAX_GROUP_NUMBER];
@@ -234,6 +255,7 @@ extern int dns_conf_dualstack_ip_selection;
 extern int dns_conf_dualstack_ip_selection_threshold;
 
 extern int dns_conf_rr_ttl;
+extern int dns_conf_rr_ttl_reply_max;
 extern int dns_conf_rr_ttl_min;
 extern int dns_conf_rr_ttl_max;
 extern int dns_conf_force_AAAA_SOA;

src/dns_server.h

@@ -20,6 +20,7 @@
 #define _SMART_DNS_SERVER_H
 
 #include "dns.h"
+#include <stdint.h>
 
 #ifdef __cpluscplus
 extern "C" {
@@ -40,7 +41,7 @@ typedef int (*dns_result_callback)(char *domain, dns_rtcode_t rtcode, dns_type_t
 								   unsigned int ping_time, void *user_ptr);
 
 /* query domain */
-int dns_server_query(char *domain, int qtype, dns_result_callback callback, void *user_ptr);
+int dns_server_query(char *domain, int qtype, uint32_t server_flags, dns_result_callback callback, void *user_ptr);
 
 #ifdef __cpluscplus
 }

src/fast_ping.c

@@ -365,7 +365,12 @@ static void _fast_ping_close_host_sock(struct ping_host_struct *ping_host)
 
 static void _fast_ping_host_put(struct ping_host_struct *ping_host)
 {
-	if (!atomic_dec_and_test(&ping_host->ref)) {
+	int ref_cnt = atomic_dec_and_test(&ping_host->ref);
+	if (!ref_cnt) {
+		if (ref_cnt < 0) {
+			tlog(TLOG_ERROR, "invalid refcount of ping_host %s", ping_host->host);
+			abort();
+		}
 		return;
 	}
 
@@ -1081,15 +1086,19 @@ struct ping_host_struct *fast_ping_start(PING_TYPE type, const char *host, int c
 	pthread_mutex_unlock(&ping.map_lock);
 
 	_fast_ping_host_get(ping_host);
+	_fast_ping_host_get(ping_host);
+	// for ping race condition, get reference count twice
 	if (_fast_ping_sendping(ping_host) != 0) {
 		goto errout_remove;
 	}
 
 	ping_host->run = 1;
 	freeaddrinfo(gai);
+	_fast_ping_host_put(ping_host);
 	return ping_host;
 errout_remove:
 	fast_ping_stop(ping_host);
+	_fast_ping_host_put(ping_host);
 	ping_host = NULL;
 errout:
 	if (gai) {

src/smartdns.c

@@ -363,7 +363,7 @@ static void _sig_error_exit(int signo, siginfo_t *siginfo, void *ct)
 		 "%s %s)\n",
 		 signo, siginfo->si_code, siginfo->si_errno, siginfo->si_pid, getpid(), PC, (unsigned long)siginfo->si_addr,
 		 __DATE__, __TIME__, arch);
-
+	print_stack();
 	sleep(1);
 	_exit(0);
 }
@@ -439,6 +439,7 @@ int main(int argc, char *argv[])
 		goto errout;
 	}
 
+	signal(SIGPIPE, SIG_IGN);
 	if (dns_server_load_conf(config_file) != 0) {
 		fprintf(stderr, "load config failed.\n");
 		goto errout;
@@ -451,7 +452,7 @@ int main(int argc, char *argv[])
 	}
 
 	signal(SIGINT, _sig_exit);
-	signal(SIGPIPE, SIG_IGN);
+	signal(SIGTERM, _sig_exit);
 	atexit(_smartdns_exit);
 
 	return _smartdns_run();

src/tlog.c

@@ -1,6 +1,6 @@
 /*
  * tinylog
- * Copyright (C) 2018-2019 Nick Peng <pymumu@gmail.com>
+ * Copyright (C) 2018-2020 Nick Peng <pymumu@gmail.com>
  * https://github.com/pymumu/tinylog
  */
 #ifndef _GNU_SOURCE
@@ -10,6 +10,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <libgen.h>
 #include <limits.h>
 #include <pthread.h>
 #include <stdarg.h>
@@ -21,7 +22,6 @@
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <libgen.h>
 #include <unistd.h>
 
 #ifndef likely
@@ -40,6 +40,8 @@
 #define TLOG_BUFF_LEN (PATH_MAX + TLOG_LOG_NAME_LEN * 3)
 #define TLOG_SUFFIX_GZ ".gz"
 #define TLOG_SUFFIX_LOG ""
+#define TLOG_MAX_LINE_SIZE_SET (1024 * 8)
+#define TLOG_MIN_LINE_SIZE_SET (128)
 
 #define TLOG_SEGMENT_MAGIC 0xFF446154
 
@@ -57,6 +59,9 @@ struct tlog_log {
     char logdir[PATH_MAX];
     char logname[TLOG_LOG_NAME_LEN];
     char suffix[TLOG_LOG_NAME_LEN];
+    char pending_logfile[PATH_MAX];
+    int rename_pending;
+    int fail;
     int logsize;
     int logcount;
     int block;
@@ -66,12 +71,15 @@ struct tlog_log {
     int multi_log;
     int logscreen;
     int segment_log;
+    unsigned int max_line_size;
 
     tlog_output_func output_func;
     void *private_data;
 
     time_t last_try;
     time_t last_waitpid;
+    mode_t file_perm;
+    mode_t archive_perm;
 
     int waiters;
     int is_exit;
@@ -283,11 +291,37 @@ static int _tlog_gettime(struct tlog_time *cur_time)
     return 0;
 }
 
+void tlog_set_maxline_size(struct tlog_log *log, int size)
+{
+    if (log == NULL) {
+        return;
+    }
+
+    if (size < TLOG_MIN_LINE_SIZE_SET) {
+        size = TLOG_MIN_LINE_SIZE_SET;
+    } else if (size > TLOG_MAX_LINE_SIZE_SET) {
+        size = TLOG_MAX_LINE_SIZE_SET;
+    }
+
+    log->max_line_size = size;
+}
+
+void tlog_set_permission(struct tlog_log *log, unsigned int file, unsigned int archive)
+{
+    log->file_perm = file;
+    log->archive_perm = archive;
+}
+
 int tlog_localtime(struct tlog_time *tm)
 {
     return _tlog_gettime(tm);
 }
 
+tlog_log *tlog_get_root(void)
+{
+    return tlog.root;
+}
+
 void tlog_set_private(tlog_log *log, void *private_data)
 {
     if (log == NULL) {
@@ -438,7 +472,7 @@ static int _tlog_need_drop(struct tlog_log *log)
     }
 
     /* if free buffer length is less than min line length */
-    if (maxlen < TLOG_MAX_LINE_LEN) {
+    if (maxlen < log->max_line_size) {
         log->dropped++;
         ret = 0;
     }
@@ -450,14 +484,14 @@ static int _tlog_vprintf(struct tlog_log *log, vprint_callback print_callback, v
 {
     int len;
     int maxlen = 0;
-    char buff[TLOG_MAX_LINE_LEN];
-
     struct tlog_segment_head *segment_head = NULL;
 
     if (log == NULL || format == NULL) {
         return -1;
     }
 
+    char buff[log->max_line_size];
+
     if (log->buff == NULL) {
         return -1;
     }
@@ -469,7 +503,7 @@ static int _tlog_vprintf(struct tlog_log *log, vprint_callback print_callback, v
     len = print_callback(buff, sizeof(buff), userptr, format, ap);
     if (len <= 0) {
         return -1;
-    } else if (len >= TLOG_MAX_LINE_LEN) {
+    } else if (len >= log->max_line_size) {
         strncpy(buff, "[LOG TOO LONG, DISCARD]\n", sizeof(buff));
         buff[sizeof(buff) - 1] = '\0';
         len = strnlen(buff, sizeof(buff));
@@ -490,7 +524,7 @@ static int _tlog_vprintf(struct tlog_log *log, vprint_callback print_callback, v
         }
 
         /* if free buffer length is less than min line length */
-        if (maxlen < TLOG_MAX_LINE_LEN) {
+        if (maxlen < log->max_line_size) {
             if (log->end != log->start) {
                 tlog.notify_log = log;
                 pthread_cond_signal(&tlog.cond);
@@ -516,7 +550,7 @@ static int _tlog_vprintf(struct tlog_log *log, vprint_callback print_callback, v
 
             pthread_mutex_lock(&tlog.lock);
         }
-    } while (maxlen < TLOG_MAX_LINE_LEN);
+    } while (maxlen < log->max_line_size);
 
     if (log->segment_log) {
         segment_head = (struct tlog_segment_head *)(log->buff + log->end);
@@ -532,7 +566,7 @@ static int _tlog_vprintf(struct tlog_log *log, vprint_callback print_callback, v
     }
 
     /* if remain buffer is not enough for a line, move end to start of buffer. */
-    if (log->end > log->buffsize - TLOG_MAX_LINE_LEN) {
+    if (log->end > log->buffsize - log->max_line_size) {
         log->ext_end = log->end;
         log->end = 0;
     }
@@ -658,6 +692,8 @@ static int _tlog_rename_logfile(struct tlog_log *log, const char *log_file)
         return -1;
     }
 
+    chmod(archive_file, log->archive_perm);
+
     return 0;
 }
 
@@ -1023,15 +1059,40 @@ static int _tlog_archive_log(struct tlog_log *log)
     }
 }
 
+void _tlog_get_log_name_dir(struct tlog_log *log)
+{
+    char log_file[PATH_MAX];
+    if (log->fd > 0) {
+        close(log->fd);
+        log->fd = -1;
+    }
+
+    pthread_mutex_lock(&tlog.lock);
+    strncpy(log_file, log->pending_logfile, sizeof(log_file) - 1);
+    log_file[sizeof(log_file) - 1] = '\0';
+    strncpy(log->logdir, dirname(log_file), sizeof(log->logdir));
+    log->logdir[sizeof(log->logdir) - 1] = '\0';
+    strncpy(log_file, log->pending_logfile, PATH_MAX);
+    log_file[sizeof(log_file) - 1] = '\0';
+    strncpy(log->logname, basename(log_file), sizeof(log->logname));
+    log->logname[sizeof(log->logname) - 1] = '\0';
+    pthread_mutex_unlock(&tlog.lock);
+}
+
 static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)
 {
     int len;
     int unused __attribute__((unused));
 
-    if (bufflen <= 0) {
+    if (bufflen <= 0 || log->fail) {
         return 0;
     }
 
+    if (log->rename_pending) {
+        _tlog_get_log_name_dir(log);
+        log->rename_pending = 0;
+    }
+
     /* output log to screen */
     if (log->logscreen) {
         unused = write(STDOUT_FILENO, buff, bufflen);
@@ -1072,7 +1133,7 @@ static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)
         }
         snprintf(logfile, sizeof(logfile), "%s/%s", log->logdir, log->logname);
         log->filesize = 0;
-        log->fd = open(logfile, O_APPEND | O_CREAT | O_WRONLY | O_CLOEXEC, 0640);
+        log->fd = open(logfile, O_APPEND | O_CREAT | O_WRONLY | O_CLOEXEC, log->file_perm);
         if (log->fd < 0) {
             if (print_errmsg == 0) {
                 return -1;
@@ -1131,7 +1192,6 @@ static int _tlog_any_has_data_locked(void)
     return 0;
 }
 
-
 static int _tlog_any_has_data(void)
 {
     int ret = 0;
@@ -1263,7 +1323,6 @@ static void _tlog_wakeup_waiters(struct tlog_log *log)
     pthread_mutex_unlock(&log->lock);
 }
 
-
 static void _tlog_write_one_segment_log(struct tlog_log *log, char *buff, int bufflen)
 {
     struct tlog_segment_head *segment_head = NULL;
@@ -1336,6 +1395,35 @@ static int _tlog_root_write_log(struct tlog_log *log, const char *buff, int buff
     return tlog.output_func(&empty_info.info, buff, bufflen, tlog_get_private(log));
 }
 
+static void tlog_wait_zip_fini(void)
+{
+    tlog_log *next;
+    if (tlog.root == NULL) {
+        return;
+    }
+
+    int wait_zip = 1;
+    int time_out = 0;
+    while (wait_zip) {
+        wait_zip = 0;
+        time_out++;
+        next = tlog.log;
+        while (next) {
+            if (next->zip_pid > 0 && wait_zip == 0) {
+                wait_zip = 1;
+                usleep(1000);
+            }
+
+            if (kill(next->zip_pid, 0) != 0 || time_out >= 5000) {
+                next->zip_pid = -1;
+            }
+            next = next->next;
+        }
+    }
+
+    return;
+}
+
 static void *_tlog_work(void *arg)
 {
     int log_len = 0;
@@ -1349,6 +1437,9 @@ static void *_tlog_work(void *arg)
 
     unused = arg;
 
+    // for child process
+    tlog_wait_zip_fini();
+
     while (1) {
         log_len = 0;
         log_extlen = 0;
@@ -1377,7 +1468,7 @@ static void *_tlog_work(void *arg)
             log = _tlog_wait_log_locked(log);
             if (log == NULL) {
                 pthread_mutex_unlock(&tlog.lock);
-                if (errno != ETIMEDOUT) {
+                if (errno != ETIMEDOUT && tlog.run) {
                     sleep(1);
                 }
                 continue;
@@ -1518,10 +1609,14 @@ tlog_level tlog_getlevel(void)
     return tlog_set_level;
 }
 
+void tlog_set_logfile(const char *logfile)
+{
+    tlog_rename_logfile(tlog.root, logfile);
+}
+
 tlog_log *tlog_open(const char *logfile, int maxlogsize, int maxlogcount, int buffsize, unsigned int flag)
 {
     struct tlog_log *log = NULL;
-    char log_file[PATH_MAX];
 
     if (tlog.run == 0) {
         fprintf(stderr, "tlog is not initialized.");
@@ -1546,22 +1641,19 @@ tlog_log *tlog_open(const char *logfile, int maxlogsize, int maxlogcount, int bu
     log->filesize = 0;
     log->zip_pid = -1;
     log->is_exit = 0;
+    log->fail = 0;
     log->waiters = 0;
     log->block = ((flag & TLOG_NONBLOCK) == 0) ? 1 : 0;
     log->nocompress = ((flag & TLOG_NOCOMPRESS) == 0) ? 0 : 1;
     log->logscreen = ((flag & TLOG_SCREEN) == 0) ? 0 : 1;
     log->multi_log = ((flag & TLOG_MULTI_WRITE) == 0) ? 0 : 1;
     log->segment_log = ((flag & TLOG_SEGMENT) == 0) ? 0 : 1;
+    log->max_line_size = TLOG_MAX_LINE_LEN;
     log->output_func = _tlog_write;
+    log->file_perm = S_IRUSR | S_IWUSR | S_IRGRP;
+    log->archive_perm = S_IRUSR | S_IRGRP;
 
-    strncpy(log_file, logfile, sizeof(log_file) - 1);
+    tlog_rename_logfile(log, logfile);
-    log_file[sizeof(log_file) - 1] = '\0';
-    strncpy(log->logdir, dirname(log_file), sizeof(log->logdir));
-    log->logdir[sizeof(log->logdir) - 1] = '\0';
-    strncpy(log_file, logfile, PATH_MAX);
-    log_file[sizeof(log_file) - 1] = '\0';
-    strncpy(log->logname, basename(log_file), sizeof(log->logname));
-    log->logname[sizeof(log->logname) - 1] = '\0';
     if (log->nocompress) {
         strncpy(log->suffix, TLOG_SUFFIX_LOG, sizeof(log->suffix));
     } else {
@@ -1605,6 +1697,74 @@ void tlog_close(tlog_log *log)
     log->is_exit = 1;
 }
 
+void tlog_rename_logfile(struct tlog_log *log, const char *logfile)
+{
+    pthread_mutex_lock(&tlog.lock);
+    strncpy(log->pending_logfile, logfile, sizeof(log->pending_logfile) - 1);
+    pthread_mutex_unlock(&tlog.lock);
+    log->rename_pending = 1;
+}
+
+static void tlog_fork_prepare(void)
+{
+    if (tlog.root == NULL) {
+        return;
+    }
+
+    pthread_mutex_lock(&tlog.lock);
+    tlog_log *next;
+    next = tlog.log;
+    while (next) {
+        next->multi_log = 1;
+        next = next->next;
+    }
+}
+
+static void tlog_fork_parent(void)
+{
+    if (tlog.root == NULL) {
+        return;
+    }
+
+    pthread_mutex_unlock(&tlog.lock);
+}
+
+static void tlog_fork_child(void)
+{
+    pthread_attr_t attr;
+    tlog_log *next;
+    if (tlog.root == NULL) {
+        return;
+    }
+
+    next = tlog.log;
+    while (next) {
+        next->start = 0;
+        next->end = 0;
+        next->ext_end = 0;
+        next->dropped = 0;
+        next->filesize = 0;
+        next = next->next;
+    }
+
+    pthread_attr_init(&attr);
+    int ret = pthread_create(&tlog.tid, &attr, _tlog_work, NULL);
+    if (ret != 0) {
+        fprintf(stderr, "create tlog work thread failed, %s\n", strerror(errno));
+        goto errout;
+    }
+
+    goto out;
+errout:
+    next = tlog.log;
+    while (next) {
+        next->fail = 1;
+        next = next->next;
+    }
+out:
+    pthread_mutex_unlock(&tlog.lock);
+}
+
 int tlog_init(const char *logfile, int maxlogsize, int maxlogcount, int buffsize, unsigned int flag)
 {
     pthread_attr_t attr;
@@ -1616,7 +1776,7 @@ int tlog_init(const char *logfile, int maxlogsize, int maxlogcount, int buffsize
         return -1;
     }
 
-    if (buffsize > 0 && buffsize < TLOG_MAX_LINE_LEN * 2) {
+    if (buffsize > 0 && buffsize < TLOG_MAX_LINE_SIZE_SET * 2) {
         fprintf(stderr, "buffer size is invalid.\n");
         return -1;
     }
@@ -1645,6 +1805,9 @@ int tlog_init(const char *logfile, int maxlogsize, int maxlogcount, int buffsize
     }
 
     tlog.root = log;
+    if (flag & TLOG_SUPPORT_FORK) {
+        pthread_atfork(&tlog_fork_prepare, &tlog_fork_parent, &tlog_fork_child);
+    }
     return 0;
 errout:
     if (tlog.tid > 0) {

src/tlog.h

@@ -1,19 +1,20 @@
 /*
  * tinylog
- * Copyright (C) 2018-2019 Ruilin Peng (Nick) <pymumu@gmail.com>
+ * Copyright (C) 2018-2021 Ruilin Peng (Nick) <pymumu@gmail.com>
  * https://github.com/pymumu/tinylog
  */
 
 #ifndef TLOG_H
 #define TLOG_H
 #include <stdarg.h>
+#include <sys/stat.h>
 
 #ifdef __cplusplus
-#include <string>
+#include <functional>
+#include <iostream>
 #include <memory>
 #include <sstream>
-#include <iostream>
+#include <string>
-#include <functional>
 extern "C" {
 #endif /*__cplusplus */
 
@@ -60,6 +61,9 @@ struct tlog_time {
 /* enable log to screen */
 #define TLOG_SCREEN (1 << 4)
 
+/* enable suppport fork process */
+#define TLOG_SUPPORT_FORK (1 << 5)
+
 struct tlog_loginfo {
     tlog_level level;
     const char *file;
@@ -74,7 +78,9 @@ level: Current log Levels
 format: Log formats
 */
 #ifndef BASE_FILE_NAME
-#define BASE_FILE_NAME __FILE__
+#define BASE_FILE_NAME                                                     \
+  (__builtin_strrchr(__FILE__, '/') ? __builtin_strrchr(__FILE__, '/') + 1 \
+                                    : __FILE__)
 #endif
 #define tlog(level, format, ...) tlog_ext(level, BASE_FILE_NAME, __LINE__, __func__, NULL, format, ##__VA_ARGS__)
 
@@ -91,6 +97,9 @@ extern int tlog_setlevel(tlog_level level);
 /* get log level */
 extern tlog_level tlog_getlevel(void);
 
+/* set log file */
+extern void tlog_set_logfile(const char *logfile);
+
 /* enalbe log to screen */
 extern void tlog_setlogscreen(int enable);
 
@@ -132,6 +141,10 @@ extern int tlog_reg_log_output_func(tlog_log_output_func output, void *private_d
 
 struct tlog_log;
 typedef struct tlog_log tlog_log;
+
+/* get root log handler */
+extern tlog_log *tlog_get_root(void);
+
 /*
 Function: open a new log stream, handler should close by tlog_close
 logfile: log file.
@@ -149,6 +162,9 @@ extern int tlog_write(struct tlog_log *log, const char *buff, int bufflen);
 /* close log stream */
 extern void tlog_close(tlog_log *log);
 
+/* change log file */
+extern void tlog_rename_logfile(struct tlog_log *log, const char *logfile);
+
 /*
 Function: Print log to log stream
 log: log stream
@@ -180,47 +196,78 @@ extern void *tlog_get_private(tlog_log *log);
 /* get local time */
 extern int tlog_localtime(struct tlog_time *tm);
 
+/* set max line size */
+extern void tlog_set_maxline_size(struct tlog_log *log, int size);
+
+/*
+Function: set log file and archive permission
+log: log stream
+file: log file permission, default is 640
+archive: archive file permission, default is 440
+*/
+
+extern void tlog_set_permission(struct  tlog_log *log, mode_t file, mode_t archive);
+
 #ifdef __cplusplus
 class Tlog {
-    using Stream = std::ostringstream;
-    using Buffer = std::unique_ptr<Stream, std::function<void(Stream*)>>;
 public:
-    Tlog(){}
+    Tlog(tlog_level level, const char *file, int line, const char *func, void *userptr)
-    ~Tlog(){}
+    {
-
+        level_ = level;
-    static Tlog &Instance() {
+        file_ = file;
-        static Tlog logger;
+        line_ = line;
-        return logger;
+        func_ = func;
+        userptr_ = userptr;
     }
 
-    Buffer LogStream(tlog_level level, const char *file, int line, const char *func, void *userptr) {
+    ~Tlog()
-        return Buffer(new Stream, [=](Stream *st) {
+    {
-            tlog_ext(level, file, line, func, userptr, "%s", st->str().c_str());
+        tlog_ext(level_, file_, line_, func_, userptr_, "%s", msg_.str().c_str());
-        });
     }
+
+    std::ostream &Stream()
+    {
+        return msg_;
+    }
+
+private:
+    tlog_level level_;
+    const char *file_;
+    int line_;
+    const char *func_;
+    void *userptr_;
+    std::ostringstream msg_;
 };
 
 class TlogOut {
-    using Stream = std::ostringstream;
-    using Buffer = std::unique_ptr<Stream, std::function<void(Stream*)>>;
 public:
-    TlogOut(){}
+    TlogOut(tlog_log *log)
-    ~TlogOut(){}
+    {
-
+        log_ = log;
-    static TlogOut &Instance() {
-        static TlogOut logger;
-        return logger;
     }
 
-    Buffer Out(tlog_log *log) {
+    ~TlogOut()
-        return Buffer(new Stream, [=](Stream *st) {
+    {
-            tlog_printf(log, "%s", st->str().c_str());
+        if (log_ == nullptr) {
-        });
+            return;
         }
+
+        tlog_printf(log_, "%s", msg_.str().c_str());
+    }
+
+    std::ostream &Stream()
+    {
+        return msg_;
+    }
+
+private:
+    tlog_log *log_;
+    std::ostringstream msg_;
 };
 
-#define Tlog_logger (Tlog::Instance())
+#define Tlog_stream(level)        \
-#define Tlog_stream(level) if (tlog_getlevel() <= level) *Tlog_logger.LogStream(level, BASE_FILE_NAME, __LINE__, __func__, NULL) 
+    if (tlog_getlevel() <= level) \
+    Tlog(level, BASE_FILE_NAME, __LINE__, __func__, NULL).Stream()
 #define tlog_debug Tlog_stream(TLOG_DEBUG)
 #define tlog_info Tlog_stream(TLOG_INFO)
 #define tlog_notice Tlog_stream(TLOG_NOTICE)
@@ -228,8 +275,7 @@ public:
 #define tlog_error Tlog_stream(TLOG_ERROR)
 #define tlog_fatal Tlog_stream(TLOG_FATAL)
 
-#define Tlog_out_logger (TlogOut::Instance())
+#define tlog_out(stream) TlogOut(stream).Stream()
-#define tlog_out(stream)  (*Tlog_out_logger.Out(stream))
 
 } /*__cplusplus */
 #else

src/util.c

@@ -21,11 +21,14 @@
 #endif
 #include "util.h"
 #include "dns_conf.h"
+#include "tlog.h"
 #include <arpa/inet.h>
+#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <linux/capability.h>
+#include <linux/limits.h>
 #include <linux/netlink.h>
 #include <netinet/tcp.h>
 #include <openssl/crypto.h>
@@ -35,9 +38,11 @@
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
+#include <sys/statvfs.h>
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
+#include <unwind.h>
 
 #define TMP_BUFF_LEN_32 32
 
@@ -513,6 +518,7 @@ static int _ipset_operate(const char *ipsetname, const unsigned char addr[], int
 	ssize_t rc;
 	int af = 0;
 	static const struct sockaddr_nl snl = {.nl_family = AF_NETLINK};
+	uint32_t expire;
 
 	if (addr_len != IPV4_ADDR_LEN && addr_len != IPV6_ADDR_LEN) {
 		errno = EINVAL;
@@ -567,8 +573,8 @@ static int _ipset_operate(const char *ipsetname, const unsigned char addr[], int
 	nested[1]->len = (void *)buffer + NETLINK_ALIGN(netlink_head->nlmsg_len) - (void *)nested[1];
 
 	if (timeout > 0 && _ipset_support_timeout(ipsetname) == 0) {
-		timeout = htonl(timeout);
+		expire = htonl(timeout);
-		_ipset_add_attr(netlink_head, IPSET_ATTR_TIMEOUT | NLA_F_NET_BYTEORDER, sizeof(timeout), &timeout);
+		_ipset_add_attr(netlink_head, IPSET_ATTR_TIMEOUT | NLA_F_NET_BYTEORDER, sizeof(expire), &expire);
 	}
 
 	nested[0]->len = (void *)buffer + NETLINK_ALIGN(netlink_head->nlmsg_len) - (void *)nested[0];
@@ -603,15 +609,22 @@ int ipset_del(const char *ipsetname, const unsigned char addr[], int addr_len)
 
 unsigned char *SSL_SHA256(const unsigned char *d, size_t n, unsigned char *md)
 {
-	SHA256_CTX c;
 	static unsigned char m[SHA256_DIGEST_LENGTH];
 
 	if (md == NULL)
 		md = m;
-	SHA256_Init(&c);
+
-	SHA256_Update(&c, d, n);
+	EVP_MD_CTX* ctx = EVP_MD_CTX_create();
-	SHA256_Final(md, &c);
+	if (ctx == NULL) {
-	OPENSSL_cleanse(&c, sizeof(c));
+		return NULL;
+	}
+
+	EVP_MD_CTX_init(ctx);
+	EVP_DigestInit_ex(ctx, EVP_sha256(), NULL);
+	EVP_DigestUpdate(ctx, d, n);
+	EVP_DigestFinal_ex(ctx, m, NULL);
+	EVP_MD_CTX_destroy(ctx);
+
 	return (md);
 }
 
@@ -732,7 +745,11 @@ void SSL_CRYPTO_thread_setup(void)
 		pthread_mutex_init(&(lock_cs[i]), NULL);
 	}
 
+#if OPENSSL_API_COMPAT < 0x10000000
 	CRYPTO_set_id_callback(_pthreads_thread_id);
+#else
+	CRYPTO_THREADID_set_callback(_pthreads_thread_id);
+#endif
 	CRYPTO_set_locking_callback(_pthreads_locking_callback);
 }
 
@@ -935,7 +952,7 @@ void get_compiled_time(struct tm *tm)
 	int hour, min, sec;
 	static const char *month_names = "JanFebMarAprMayJunJulAugSepOctNovDec";
 
-	sscanf(__DATE__, "%5s %d %d", s_month, &day, &year);
+	sscanf(__DATE__, "%4s %d %d", s_month, &day, &year);
 	month = (strstr(month_names, s_month) - month_names) / 3;
 	sscanf(__TIME__, "%d:%d:%d", &hour, &min, &sec);
 	tm->tm_year = year - 1900;
@@ -995,3 +1012,64 @@ int set_sock_lingertime(int fd, int time)
 
 	return 0;
 }
+
+uint64_t get_free_space(const char *path)
+{
+	uint64_t size = 0;
+	struct statvfs buf;
+	if (statvfs(path, &buf) != 0) {
+		return 0;
+	}
+
+	size = (uint64_t)buf.f_frsize * buf.f_bavail;
+
+	return size;
+}
+
+struct backtrace_state {
+	void **current;
+	void **end;
+};
+
+static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context *context, void *arg)
+{
+	struct backtrace_state *state = (struct backtrace_state *)(arg);
+	uintptr_t pc = _Unwind_GetIP(context);
+	if (pc) {
+		if (state->current == state->end) {
+			return _URC_END_OF_STACK;
+		} else {
+			*state->current++ = (void *)(pc);
+		}
+	}
+	return _URC_NO_REASON;
+}
+
+void print_stack(void)
+{
+	const size_t max_buffer = 30;
+	void *buffer[max_buffer];
+	int idx = 0;
+
+	struct backtrace_state state = {buffer, buffer + max_buffer};
+	_Unwind_Backtrace(unwind_callback, &state);
+	int frame_num = state.current - buffer;
+	if (frame_num == 0) {
+		return;
+	}
+	
+	tlog(TLOG_FATAL, "Stack:");
+	for (idx = 0; idx < frame_num; ++idx) {
+		const void *addr = buffer[idx];
+		const char *symbol = "";
+
+		Dl_info info;
+		memset(&info, 0, sizeof(info));
+		if (dladdr(addr, &info) && info.dli_sname) {
+			symbol = info.dli_sname;
+		}
+
+		void *offset = (void *)((char *)(addr) - (char *)(info.dli_fbase));
+		tlog(TLOG_FATAL, "#%.2d: %p %s from %s+%p", idx + 1, addr, symbol, info.dli_fname, offset);
+	}
+}

src/util.h

@@ -106,6 +106,10 @@ int set_sock_keepalive(int fd, int keepidle, int keepinterval, int keepcnt);
 
 int set_sock_lingertime(int fd, int time);
 
+uint64_t get_free_space(const char *path);
+
+void print_stack(void);
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus */

systemd/smartdns.service.in

@@ -1,5 +1,5 @@
 [Unit]
-Description=smart dns server
+Description=SmartDNS Server
 After=network.target 
 StartLimitBurst=0
 StartLimitIntervalSec=60
@@ -12,6 +12,7 @@ ExecStart=@SBINDIR@/smartdns -p @RUNSTATEDIR@/smartdns.pid $SMART_DNS_OPTS
 KillMode=process
 Restart=always
 RestartSec=2
+TimeoutStopSec=5
 
 [Install]
 WantedBy=multi-user.target