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