基于Nginx 反向代理获取真实IP的问题详解

  server {    listen  9461; # 监听端口号    server_name localhost 192.168.88.22; # 访问地址    location / {     root 项目路径; # 例如：E:/Publish/xxx/;     index index.html;          # 此处用于处理 Vue、Angular、React 使用H5 的 History时 重写的问题     if (!-e $request_filename) {      rewrite ^(.*) /index.html last;      break;     }    }        # 代理服务端接口    location /api {     proxy_pass http://localhost:9460/api;# 代理接口地址     # Host配置以及域名传递     proxy_set_header Host $host;     proxy_set_header X-Real-IP $remote_addr;     proxy_set_header REMOTE-HOST $remote_addr;     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;    }   }

  #region Ip(客户端IP地址)  /// <summary>  /// 客户端IP地址  /// </summary>  public static string Ip  {   get   {    var result = string.Empty;    if (HttpContext.Current != null)    {     result = GetWebClientIp();    }    if (string.IsNullOrWhiteSpace(result))    {     result = GetLanIp();    }    return result;   }  }  /// <summary>  /// 获取Web客户端的IP  /// </summary>  /// <returns></returns>  private static string GetWebClientIp()  {   var ip = GetWebProxyRealIp() ?? GetWebRemoteIp();   foreach (var hostAddress in Dns.GetHostAddresses(ip))   {    if (hostAddress.AddressFamily == AddressFamily.InterNetwork)    {     return hostAddress.ToString();    }   }   return string.Empty;  }  /// <summary>  /// 获取Web远程IP  /// </summary>  /// <returns></returns>  private static string GetWebRemoteIp()  {   try   {    return HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] ??      HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"] ?? "";   }   catch (Exception e)   {    return string.Empty;   }  }  /// <summary>  /// 获取Web代理真实IP  /// </summary>  /// <returns></returns>  private static string GetWebProxyRealIp()  {   var request = HttpContext.Current.Request;   string ip = request.Headers.Get("x-forwarded-for");   if (string.IsNullOrEmpty(ip) || string.Equals("unknown", ip, StringComparison.OrdinalIgnoreCase))   {    ip = request.Headers.Get("Proxy-Client-IP");   }   if (string.IsNullOrEmpty(ip) || string.Equals("unknown", ip, StringComparison.OrdinalIgnoreCase))   {    ip = request.Headers.Get("WL-Proxy-Client-IP");   }   if (string.IsNullOrEmpty(ip) || string.Equals("unknown", ip, StringComparison.OrdinalIgnoreCase))   {    ip = request.UserHostAddress;   }   if (string.IsNullOrEmpty(ip))   {    return string.Empty;   }   // 可能存在如下格式：X-Forwarded-For: client, proxy1, proxy2   if (ip.Contains(", "))   {    // 如果存在多个反向代理，获得的IP是一个用逗号分隔的IP集合，取第一个    // X-Forwarded-For: client 第一个    string[] ips = ip.Split(new string[1] {", "}, StringSplitOptions.RemoveEmptyEntries);    var i = 0;    for (i = 0; i < ips.Length; i++)    {     if (ips[i] != "")     {      // 判断是否为内网IP      if (false == IsInnerIp(ips[i]))      {       IPAddress realIp;       if (IPAddress.TryParse(ips[i], out realIp) && ips[i].Split('.').Length == 4)       {        //合法IP        return ips[i];       }       return "";      }     }    }    ip = ips[0];// 默认获取第一个IP地址   }   return ip;  }  /// <summary>  /// 判断IP地址是否为内网IP地址  /// </summary>  /// <param name="ip">IP地址</param>  /// <returns></returns>  private static bool IsInnerIp(string ip)  {   bool isInnerIp = false;   ulong ipNum = Ip2Ulong(ip);   /**    * 私有IP    * A类：10.0.0.0-10.255.255.255    * B类：172.16.0.0-172.31.255.255    * C类：192.168.0.0-192.168.255.255    * 当然，还有127这个网段是环回地址    */   ulong aBegin = Ip2Ulong("10.0.0.0");   ulong aEnd = Ip2Ulong("10.255.255.255");   ulong bBegin = Ip2Ulong("172.16.0.0");   ulong bEnd = Ip2Ulong("10.31.255.255");   ulong cBegin = Ip2Ulong("192.168.0.0");   ulong cEnd = Ip2Ulong("192.168.255.255");   isInnerIp = IsInner(ipNum, aBegin, aEnd) || IsInner(ipNum, bBegin, bEnd) || IsInner(ipNum, cBegin, cEnd) ||      ip.Equals("127.0.0.1");   return isInnerIp;  }  /// <summary>  /// 将IP地址转换为Long型数字  /// </summary>  /// <param name="ip">IP地址</param>  /// <returns></returns>  private static ulong Ip2Ulong(string ip)  {   byte[] bytes = IPAddress.Parse(ip).GetAddressBytes();   ulong ret = 0;   foreach (var b in bytes)   {    ret <<= 8;    ret |= b;   }   return ret;  }  /// <summary>  /// 判断用户IP地址转换为Long型后是否在内网IP地址所在范围  /// </summary>  /// <param name="userIp">用户IP</param>  /// <param name="begin">开始范围</param>  /// <param name="end">结束范围</param>  /// <returns></returns>  private static bool IsInner(ulong userIp, ulong begin, ulong end)  {   return (userIp >= begin) && (userIp <= end);  }  /// <summary>  /// 获取局域网IP  /// </summary>  /// <returns></returns>  private static string GetLanIp()  {   foreach (var hostAddress in Dns.GetHostAddresses(Dns.GetHostName()))   {    if (hostAddress.AddressFamily == AddressFamily.InterNetwork)    {     return hostAddress.ToString();    }   }   return string.Empty;  }  #endregion