// 验证IP的正则

var ip_reg = /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;

// 验证子网掩码的正则

var mask_reg = /^(254|252|248|240|224|192|128|0)\.0\.0\.0|255\.(254|252|248|240|224|192|128|0)\.0\.0|255\.255\.(254|252|248|240|224|192|128|0)\.0|255\.255\.255\.(254|252|248|240|224|192|128|0)$/;

/**
*　　把IP地址转换成二进制格式
*　　@param string   ip    待转换的IP的地址
*/

function ip_to_binary(ip)

{

    if (ip_reg.test(ip)) {

        var ip_str = "",

            ip_arr = ip.split(".");

        for (var i = 0; i < 4; i++) {

            curr_num = ip_arr[i];

            number_bin = parseInt(curr_num);

            number_bin = number_bin.toString(2);

            count = 8 - number_bin.length;

            for (var j = 0; j < count; j++) {

                number_bin = "0" + number_bin;

            }

            ip_str += number_bin;

        }

        return ip_str;

    }

    return '';

}

/**
*　　把二进制格式转换成IP地址
*　　@param string   binary    待转换的二进制　　
*/

function binary_to_ip(binary)

{

    if (binary.length == 32) {

        a = parseInt(binary.substr(0, 8), 2);

        b = parseInt(binary.substr(8, 8), 2);

        c = parseInt(binary.substr(16, 8), 2);

        d = parseInt(binary.slice(-8), 2);

        return a + '.' + b + '.' + c + '.' + d;

    }

    return '';

}

/**
*　　根据子网掩码和网关计算网络地址和广播地址
*　　@param  string    mask    子网掩码
*　　@param  string    gateway 网关
*/

function get_network_broadcast_addr(mask, gateway)

{

    network_broadcast = [];

    network_addr = "";

    mask_arr = mask.split(".");

    ip_arr = ip.split(".");

    // 计算IP的网络地址 与(&)运算

    for (var i = 0; i < 4; i++) {

        number1 = parseInt(mask_arr[i]);

        number2 = parseInt(ip_arr[i]);

        network_addr += number1 & number2;

        if( i < 3 ){

            network_addr += ".";

        }

    }

    network_broadcast.push(network_addr);

    // 计算广播地址

    // 子掩码后面有几个0，就去掉IP地址后几位再补1

    mask_binary = ip_to_binary(mask);

    gateway_binary = ip_to_binary(ip);

    mask_zero = mask_binary.split(0).length - 1;

    one_number = new Array(mask_zero + 1).join('1'); // IP地址后位补1

    gateway_hou_wei_bu_yi = gateway_binary.slice(0, -mask_zero) + one_number;

    network_broadcast.push(binary_to_ip(gateway_hou_wei_bu_yi));

    return network_broadcast;

}

//  全排列组合算法（两两递归组合）

function doExchange(doubleArrays)

{

    var len = doubleArrays.length;

    if(len >= 2){

        var len1 = doubleArrays[0].length;

        var len2 = doubleArrays[1].length;

        var newlen = len1 * len2;

        var temp = new Array(newlen);

        var index = 0;

        for(var i = 0; i < len1; i++){

            for(var j = 0; j < len2; j++){

                temp[index] = doubleArrays[0][i] + '.' + doubleArrays[1][j];

                index++;

            }

        }

        var newArray = new Array(len - 1);

        for(var i = 2; i < len; i++){

            newArray[i - 1] = doubleArrays[i];

        }

        newArray[0] = temp;

        return doExchange(newArray);

    } else{

        return doubleArrays[0];

    }

}

/**
*　　获取由网络地址和广播址组成的所有IP组合
*　　@param  string    network_addr    网络地址
*　　@param  string    broadcast_addr  广播地址
*　　@param  string    gateway         网关
*/

function return_ip(network_addr, broadcast_addr, gateway)

{

    range = [];

    start = network_addr.split(".");

    end = broadcast.split(".");

    // range格式为[[192], [168], [0,1,2...254], [0,1,2...254]]

    for (var i = 0; i < 4; i++) {

        if (start[i] == end[i]) {

            range[i] = [start[i]];

        } else {

            min = Math.min(start[i], end[i]);

            max = Math.max(start[i], end[i]);

            temp = [];
　　　　　　　 if (i == 3) min = 199; // 从200起计

            for (var j = min; j <= max; j++) {

                temp.push(j);

            }

            range[i] = temp;

        }

    }

    ip_list = doExchange(range);

    ip_list.shift(); // 去掉网络地址

    ip_list.pop(); // 去掉广播地址

    gateway_index = -1;

    // 去掉网关

    for (var k = 0; k < ip_list.length; k++) {

        if (ip_list[k] == gateway) {

            gateway_index = k;

            break;

        }

    }

    if (gateway_index > -1) {

        ip_list.splice(gateway_index, 1);

    }

    return ip_list;

}