[网络协议]前端使用js来获取ip起始和结束地址

为了下次找的方便，写个文章记录下
ip起始地址

function getLowAddr (ip, netMask) {
  let lowAddr = '';
  const ipArray = [];
  const netMaskArray = [];
  // I参数不正确
  if (ip.split('.').length !== 4 || netMask === '') {
    return '';
  }
  for (let i = 0; i < 4; i += 1) {
    ipArray[i] = Number(ip.split('.')[i]);
    netMaskArray[i] = netMask.split('.')[i];
    if (
      Number(ipArray[i]) > 255 ||
      Number(ipArray[i]) < 0 ||
      (Number(netMaskArray[i]) > 255 && Number(netMaskArray[i]) < 0)
    ) {
      return '';
    }
    ipArray[i] = Number(ipArray[i]) & Number(netMaskArray[i]);
  }
  // 构造最小地址
  for (let i = 0; i < 4; i += 1) {
    if (i === 3) {
      ipArray[i] = Number(ipArray[i]) + 1;
    }
    if (lowAddr === '') {
      lowAddr += ipArray[i];
    } else {
      lowAddr += `.${ipArray[i]}`;
    }
  }
  return lowAddr;
}

ip结束地址

 function getHighAddr (ip, netMask) {
  let lowAddr = getLowAddr(ip, netMask);
    let hostNumber = getHostNumber(netMask);
    if ('' === lowAddr || hostNumber === 0) {
      return '';
    }

    let lowAddrArray = [];
    for (let i = 0; i < 4; i += 1) {
      lowAddrArray[i] = Number(lowAddr.split('.')[i]);
      if (i === 3) {
        lowAddrArray[i] = Number(lowAddrArray[i]) - 1;
      }
    }
    lowAddrArray[3] = lowAddrArray[3] + Number(hostNumber - 1);
    //alert(lowAddrArray[3]);
    if (lowAddrArray[3] > 255) {
      let k = parseInt(String(lowAddrArray[3] / 256), 10);
      //alert(k);
      lowAddrArray[3] = lowAddrArray[3] % 256;
      //alert(lowAddrArray[3]);
      lowAddrArray[2] = Number(lowAddrArray[2]) + Number(k);
      //alert(lowAddrArray[2]);
      if (lowAddrArray[2] > 255) {
        k = parseInt(String(lowAddrArray[2] / 256), 10);
        lowAddrArray[2] = lowAddrArray[2] % 256;
        lowAddrArray[1] = Number(lowAddrArray[1]) + Number(k);
        if (lowAddrArray[1] > 255) {
          k = parseInt(String(lowAddrArray[1] / 256), 10);
          lowAddrArray[1] = lowAddrArray[1] % 256;
          lowAddrArray[0] = Number(lowAddrArray[0]) + Number(k);
        }
      }
    }

    let highAddr = '';
    for (let i = 0; i < 4; i += 1) {
      if (i === 3) {
        lowAddrArray[i] -= 1;
      }
      if ('' === highAddr) {
        highAddr = String(lowAddrArray[i]);
      } else {
        highAddr += '.' + lowAddrArray[i];
      }
    }

    return highAddr;
}

获取主机数

/**
 * 获取主机数
 *
 * @param netMask
 * @returns {Number}
 */
function getHostNumber(netMask) {
  let hostNumber = 0;
  const netMaskArray = [];
  for (let i = 0; i < 4; i += 1) {
    netMaskArray[i] = netMask.split('.')[i];
    if (Number(netMaskArray[i]) < 255) {
      hostNumber = 256 ** (3 - i) * (256 - Number(netMaskArray[i]));
      break;
    }
  }

  return hostNumber;
}

转换掩码的格式

function getNetMask(inetMask) {
  let netMask = '';
  if (inetMask > 32) {
    return netMask;
  }
  // 子网掩码为1占了几个字节
  const num1 = parseInt(`${inetMask / 8}`, 2);
  // 子网掩码的补位位数
  let num2 = inetMask % 8;
  const array = [];
  for (let i = 0; i < num1; i += 1) {
    array[i] = 255;
  }
  for (let i = num1; i < 4; i += 1) {
    array[i] = 0;
  }
  for (let i = 0; i < num2; num2 -= 1) {
    array[num1] += 2 ** (8 - num2);
  }
  netMask = `${array[0]}.${array[1]}.${array[2]}.${array[3]}`;

  return netMask;
}

将ip转换成数字比较大小

function ipToNumber(ip) {
  var numbers = ip.split('.');
    return (
      parseInt(numbers[0], 10) * 256 * 256 * 256 +
      parseInt(numbers[1], 10) * 256 * 256 +
      parseInt(numbers[2], 10) * 256 +
      parseInt(numbers[3], 10)
    );
}