第14天：第一阶段总结与综合实战

# day14_network_inspector.py
# 功能：综合网络配置检测工具

import socket
import struct
import subprocess
import platform
import sys
from typing import Dict, List, Tuple

class NetworkInspector:
    """
    网络配置检测工具

    功能：
        1. 获取本机网络配置
        2. 测试网络连通性
        3. DNS解析测试
        4. 生成诊断报告
    """

    def __init__(self):
        self.system = platform.system()
        self.report = []

    def add_to_report(self, section: str, content: str):
        """添加内容到报告"""
        self.report.append(f"\n{'='*60}")
        self.report.append(f" {section}")
        self.report.append('='*60)
        self.report.append(content)

    def get_local_ip(self) -> str:
        """
        获取本机IP地址

        返回值：
            本机IP地址字符串

        工作原理：
            创建UDP socket连接到外部地址（不实际发送数据）
            从socket获取本机使用的IP地址
        """
        try:
            # 创建UDP socket
            s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            # 连接到外部地址（Google DNS）
            s.connect(("8.8.8.8", 80))
            # 获取socket使用的本地IP
            local_ip = s.getsockname()[0]
            s.close()
            return local_ip
        except Exception as e:
            return f"获取失败: {e}"

    def get_hostname(self) -> str:
        """获取主机名"""
        return socket.gethostname()

    def get_network_interfaces(self) -> Dict[str, str]:
        """
        获取网络接口信息

        返回值：
            包含接口信息的字典
        """
        interfaces = {}
        try:
            # 获取主机名对应的所有IP地址
            hostname = socket.gethostname()
            local_ips = socket.gethostbyname_ex(hostname)[2]

            interfaces['主机名'] = hostname
            interfaces['本机IP'] = self.get_local_ip()
            interfaces['所有IP'] = ', '.join(local_ips)

        except Exception as e:
            interfaces['错误'] = str(e)

        return interfaces

    def test_connectivity(self, host: str = "8.8.8.8", port: int = 53) -> Tuple[bool, str]:
        """
        测试网络连通性

        参数：
            host: 目标主机
            port: 目标端口

        返回值：
            (是否连通, 详细信息)
        """
        try:
            # 尝试建立TCP连接
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.settimeout(3)
            start_time = socket.time.time()
            result = sock.connect_ex((host, port))
            end_time = socket.time.time()
            sock.close()

            if result == 0:
                latency = (end_time - start_time) * 1000  # 转换为毫秒
                return True, f"✅ 连接成功 ({host}:{port}) - 延迟: {latency:.2f}ms"
            else:
                return False, f"❌ 连接失败 ({host}:{port})"
        except Exception as e:
            return False, f"❌ 连接异常: {e}"

    def test_dns(self, domain: str = "www.baidu.com") -> Tuple[bool, str]:
        """
        测试DNS解析

        参数：
            domain: 要解析的域名

        返回值：
            (是否成功, 详细信息)
        """
        try:
            start_time = socket.time.time()
            ip = socket.gethostbyname(domain)
            end_time = socket.time.time()

            query_time = (end_time - start_time) * 1000
            return True, f"✅ DNS解析成功\n   {domain} → {ip}\n   查询时间: {query_time:.2f}ms"
        except socket.gaierror as e:
            return False, f"❌ DNS解析失败: {e}"
        except Exception as e:
            return False, f"❌ DNS查询异常: {e}"

    def get_default_gateway(self) -> str:
        """
        获取默认网关

        返回值：
            默认网关IP地址
        """
        try:
            if self.system == "Windows":
                result = subprocess.run(
                    ['ipconfig'],
                    capture_output=True,
                    text=True
                )
                output = result.stdout
                for line in output.split('\n'):
                    if '默认网关' in line or 'Default Gateway' in line:
                        parts = line.split(':')
                        if len(parts) > 1:
                            gateway = parts[1].strip()
                            if gateway and gateway != '':
                                return gateway
            else:
                # Linux/Mac
                result = subprocess.run(
                    ['ip', 'route'],
                    capture_output=True,
                    text=True
                )
                output = result.stdout
                for line in output.split('\n'):
                    if 'default' in line:
                        parts = line.split()
                        if len(parts) > 2:
                            return parts[2]

            return "未找到"
        except Exception as e:
            return f"获取失败: {e}"

    def run_full_inspection(self):
        """
        运行完整的网络检测

        工作流程：
            1. 获取本机网络配置
            2. 测试本地连通性
            3. 测试外网连通性
            4. 测试DNS解析
            5. 生成诊断报告
        """
        print("\n" + "="*60)
        print(" 网络配置检测工具 - Network Inspector")
        print("="*60)

        # 1. 本机配置
        print("\n[1/5] 正在获取本机网络配置...")
        interfaces = self.get_network_interfaces()
        gateway = self.get_default_gateway()

        config_info = []
        config_info.append(f"主机名:    {interfaces.get('主机名', '未知')}")
        config_info.append(f"本机IP:    {interfaces.get('本机IP', '未知')}")
        config_info.append(f"默认网关:  {gateway}")
        config_info.append(f"操作系统:  {self.system}")

        self.add_to_report("本机网络配置", '\n'.join(config_info))
        for line in config_info:
            print(f"  {line}")

        # 2. 测试网关连通性
        print("\n[2/5] 正在测试网关连通性...")
        if gateway != "未找到" and gateway != "获取失败":
            success, msg = self.test_connectivity(gateway, 80)
            self.add_to_report("网关连通性测试", msg)
            print(f"  {msg}")
        else:
            msg = "❌ 无法获取网关，跳过测试"
            self.add_to_report("网关连通性测试", msg)
            print(f"  {msg}")

        # 3. 测试外网连通性
        print("\n[3/5] 正在测试外网连通性...")
        test_hosts = [
            ("8.8.8.8", 53, "Google DNS"),
            ("114.114.114.114", 53, "114 DNS"),
            ("1.1.1.1", 53, "Cloudflare DNS")
        ]

        connectivity_results = []
        for host, port, name in test_hosts:
            success, msg = self.test_connectivity(host, port)
            connectivity_results.append(f"{name}: {msg}")
            print(f"  {msg}")

        self.add_to_report("外网连通性测试", '\n'.join(connectivity_results))

        # 4. 测试DNS
        print("\n[4/5] 正在测试DNS解析...")
        test_domains = [
            "www.baidu.com",
            "www.google.com",
            "www.github.com"
        ]

        dns_results = []
        for domain in test_domains:
            success, msg = self.test_dns(domain)
            dns_results.append(msg)
            print(f"  {msg}")

        self.add_to_report("DNS解析测试", '\n'.join(dns_results))

        # 5. 生成诊断建议
        print("\n[5/5] 正在生成诊断报告...")
        diagnosis = self.generate_diagnosis()
        self.add_to_report("诊断建议", diagnosis)

    def generate_diagnosis(self) -> str:
        """
        生成诊断建议

        返回值：
            诊断建议字符串
        """
        suggestions = []

        # 检查报告中的问题
        report_text = '\n'.join(self.report)

        if '连接失败' in report_text or '连接异常' in report_text:
            suggestions.append("⚠️  检测到网络连接问题：")
            suggestions.append("   1. 检查网线或WiFi连接")
            suggestions.append("   2. 检查防火墙设置")
            suggestions.append("   3. 尝试重启路由器")

        if 'DNS解析失败' in report_text:
            suggestions.append("\n⚠️  检测到DNS解析问题：")
            suggestions.append("   1. 检查DNS服务器配置")
            suggestions.append("   2. 尝试使用公共DNS (8.8.8.8)")
            suggestions.append("   3. 清除DNS缓存")

        if not suggestions:
            suggestions.append("✅ 网络状态良好，未发现明显问题")

        return '\n'.join(suggestions)

    def print_report(self):
        """打印完整报告"""
        print("\n\n" + "="*60)
        print(" 完整诊断报告")
        print("="*60)

        for section in self.report:
            print(section)

        print("\n" + "="*60)
        print(" 报告结束")
        print("="*60 + "\n")

    def save_report(self, filename: str = "network_report.txt"):
        """
        保存报告到文件

        参数：
            filename: 保存的文件名
        """
        try:
            with open(filename, 'w', encoding='utf-8') as f:
                f.write("网络配置检测报告\n")
                f.write(f"生成时间: {socket.time.ctime()}\n")
                f.write('\n'.join(self.report))
            print(f"\n✅ 报告已保存到: {filename}")
        except Exception as e:
            print(f"\n❌ 保存报告失败: {e}")


def main():
    """主程序"""
    print("""
    ╔══════════════════════════════════════════════════════════╗
    ║       网络配置检测工具 v1.0                               ║
    ║       Network Configuration Inspector                    ║
    ╚══════════════════════════════════════════════════════════╝
    """)

    inspector = NetworkInspector()

    try:
        # 运行完整检测
        inspector.run_full_inspection()

        # 打印报告
        inspector.print_report()

        # 保存报告
        save_option = input("\n是否保存报告到文件？(y/n): ").strip().lower()
        if save_option == 'y':
            filename = input("请输入文件名 (默认: network_report.txt): ").strip()
            if not filename:
                filename = "network_report.txt"
            inspector.save_report(filename)

    except KeyboardInterrupt:
        print("\n\n用户中断程序")
        sys.exit(0)
    except Exception as e:
        print(f"\n❌ 程序异常: {e}")
        sys.exit(1)


if __name__ == "__main__":
    main()

# 运行程序
python code/day14/day14_network_inspector.py

输出示例：
╔══════════════════════════════════════════════════════════╗
║       网络配置检测工具 v1.0                               ║
║       Network Configuration Inspector                    ║
╚══════════════════════════════════════════════════════════╝

============================================================
 网络配置检测工具 - Network Inspector
============================================================

[1/5] 正在获取本机网络配置...
  主机名:    DESKTOP-ABC123
  本机IP:    192.168.1.100
  默认网关:  192.168.1.1
  操作系统:  Windows

[2/5] 正在测试网关连通性...
  ✅ 连接成功 (192.168.1.1:80) - 延迟: 1.23ms

[3/5] 正在测试外网连通性...
  ✅ 连接成功 (8.8.8.8:53) - 延迟: 15.67ms
  ✅ 连接成功 (114.114.114.114:53) - 延迟: 12.34ms
  ✅ 连接成功 (1.1.1.1:53) - 延迟: 18.90ms

[4/5] 正在测试DNS解析...
  ✅ DNS解析成功
     www.baidu.com → 39.156.66.10
     查询时间: 45.67ms
  ✅ DNS解析成功
     www.google.com → 172.217.160.68
     查询时间: 23.45ms
  ✅ DNS解析成功
     www.github.com → 20.205.243.166
     查询时间: 34.56ms

[5/5] 正在生成诊断报告...

ipconfig /all              # 查看详细网络配置
ipconfig /release          # 释放DHCP分配的IP
ipconfig /renew            # 重新获取IP
ipconfig /flushdns         # 清除DNS缓存
ipconfig /displaydns       # 显示DNS缓存

ping <IP>                  # 测试连通性
ping -t <IP>              # 持续ping
tracert <域名>             # 追踪路由
nslookup <域名>            # DNS查询
arp -a                     # 查看ARP缓存
netstat -an               # 查看网络连接
route print               # 查看路由表

ip addr show              # 查看网络配置
ip route show             # 查看路由表
ifconfig                  # 查看网络接口（旧）

ping <IP>                 # 测试连通性
ping -c 4 <IP>           # ping 4次
traceroute <域名>         # 追踪路由
dig <域名>                # DNS查询（详细）
nslookup <域名>           # DNS查询（简单）

arp -a                    # 查看ARP缓存
netstat -an              # 查看网络连接
ss -tulpn                # 查看监听端口

sudo dhclient -r         # 释放IP
sudo dhclient            # 获取IP
sudo systemd-resolve --flush-caches  # 清除DNS缓存