iptables 端口转发的一个问题[已解决]

客户要求通过WAN口访问web界面，且自定义端口，在本站论坛的各位高人悉心指导下终于得到解决

     iptables -t nat -I PREROUTING -i eth1 -p tcp -m tcp --dport 8080 -j REDIRECT --to-ports 80

转换eth1(WAN口)的8080端口访问到80端口

但在默认配置编译出来的内核，无法执行 REDIRECT 这个模块

iptable 命令有些模块是默认关闭的，要在内核配置里开启才可以用
（Realtek SDK）
linux_menuconfig - Networking support -Networking options-Network packet filtering framework (Netfilter)  --->此处有许多targget match ...可以添加

以下是iptables执行的代码片段，以便日后查阅

int Port=0, wan_port1 = 0, wan_port2 = 0;
    apmib_get( MIB_WEB_WAN_ACCESS_ENABLED, (void *)&intVal);
    apmib_get( MIB_WAN_WEB_PORT1, (void *)&wan_port1);
    apmib_get( MIB_WAN_WEB_PORT2, (void *)&wan_port2);
    Port = (wan_port1<<8)^wan_port2;
    if(intVal==1){
        //printf("\n%s_%d__oldport:%d,port:%d\n",__FILE__,__LINE__,old_port,intVal1);
        char portStr[10];
        RunSystemCmd(NULL_FILE, Iptables, ADD, INPUT, _protocol, _tcp, dport, "80:80", in, pInterface, _dest, WanIpAddr, jump, ACCEPT, NULL_STR);
        if(old_port!=0){//删除之前的两条旧规则以免冲突
            sprintf(portStr,"%d",old_port);
            RunSystemCmd(NULL_FILE, Iptables, _table, nat_table, DEL, PREROUTING, in, pInterface, _protocol, _tcp,    dport, portStr, jump, REDIRECT, "--to-ports", "80", NULL_STR);
            RunSystemCmd(NULL_FILE, Iptables, _table, nat_table, DEL, PREROUTING, in, pInterface, _protocol, _tcp,    dport, "80", jump, REDIRECT, "--to-ports", portStr, NULL_STR);

        }

        if(intVal1!=80){// add by Zuo 20130524 ,转换wan口访问web端口号
            sprintf(portStr,"%d",Port);
            RunSystemCmd(NULL_FILE, Iptables, _table, nat_table, INSERT, PREROUTING, in, pInterface, _protocol, _tcp,    dport, portStr, jump, REDIRECT, "--to-ports", "80", NULL_STR);
            RunSystemCmd(NULL_FILE, Iptables, _table, nat_table, INSERT, PREROUTING, in, pInterface, _protocol, _tcp,    dport, "80", jump, REDIRECT, "--to-ports", portStr, NULL_STR);
            old_port=Port;//每次转换端口都记录下端口号，为了下次更改端口号之后删除之前的转换规则

        }

    }else{
        RunSystemCmd(NULL_FILE, Iptables, ADD, INPUT, _protocol, _tcp, dport, "80:80", in, pInterface, _dest, WanIpAddr, jump, DROP, NULL_STR);
    }

特别感谢版主  的耐心。
以此记方便后查者