背景介绍
H5支付要求商户在统一下单接口中上传用户真实ip地址“spbill_create_ip”，为保证微信端获取的用户ip地址与商户端获取的一致，提供了以下获取用户ip的指引，希望对大家有所帮助。
没有代理的情况
在商户的前端接入层没有做代理的情况下获取ip的方式比较简单，直接获取'REMOTE_ADDR '即可。
1function get_client_ip(){
2 $cip = "unknown";
3 if ($_SERVER['REMOTE_ADDR']){
4 $cip = $_SERVER['REMOTE_ADDR']
5 }elseif (getenv("REMOTE_ADDR")){
6 $cip = getenv("REMOTE_ADDR");
7 }
8 return $ip
9} 有代理的情况
在有代理的情况下，因为要代替客户端去访问服务器，所以，当请求包经过反向代理后，在代理服务器这里这个IP数据包的IP包头做了修改，最终后端WEB服务器得到的数据包的头部源IP地址是代理服务器的IP地址。这样一来，后端服务器的程序就无法获取用户的真实ip。
1proxy_set_header Host $host;
2proxy_set_header X-Real-IP $remote_addr;
3proxy_set_header X-Real-Port $remote_port;
4proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
1vi /usr/local/apache/conf/httpd.conf
2Include conf/extra/httpd-remoteip.conf
3vi /usr/local/apache/conf/extra/httpd-remoteip.conf
4LoadModule remoteip_module modules/mod_remoteip.so
5RemoteIPHeader X-Forwarded-For
6RemoteIPinternalProxy 127.0.0.1
1string GetClientIp(CgiInput* poInput) {
2 string client_ip = "";
3 string strClientIPList;
4 GetHttpHeader("X-Forwarded-For", strClientIPList);
5
6 if (strClientIPList.empty()){
7 GetHttpHeader("X-Real-IP", strClientIPList);}
8
9 if (!strClientIPList.empty()){
10 size_t iPos = strClientIPList.find( "," );
11 if( iPos != std::string::npos ){
12 client_ip = strClientIPList.substr( iPos );}
13 else{
14 client_ip = strClientIPList;
15 }
16 }
17
18 if (client_ip.empty()){
19 GetHttpHeader("PROXY_FORWARDED_FOR", strClientIPList);
20 // 需进行兼容
21 if(strClientIPList.empty()){
22 client_ip = getRemoteAddr();
23 }else{
24 size_t iPos = strClientIPList.find( "," );
25 if( iPos != std::string::npos ) {
26 client_ip = strClientIPList.substr( iPos );
27 }
28 else{
29 client_ip = strClientIPList;
30 }
31 }
32}
33
34 if(!MMPayCommFunc::IsIp(client_ip))
35 client_ip = getRemoteAddr();
36 return client_ip;
37}
