js logical judgment for ip address, subnet mask, gateway_javascript skills

Because I need to do js verification of static address configuration, I searched a lot of information and found that the Internet is all about the validity check of ip and mask. There is no logical judgment of ip, submask and gateway. I wrote the code myself for those who need it. refer to.

Popular knowledge about gateway addresses:

First point: Perform the AND operation of 1 and 1 to get 1, 1 and 0 are 0, and 0 and 0 are 0. First expand the ip and subnet mask
10.70.64.223 00001010 .01000110.01000000.11011111
255.255.255.0 111111111.11111111.11111111.00000000
The network segment is 00001010 .01000110.01000000.00000000
Then converted to decimal it is: 10.70.64.0

Second point: The AND operation of the IP address and the subnet mask and the AND operation of the gateway address and the subnet mask should be the same. , that is, the host numbers are consistent.
Here, I first use js to separate ip, mask, and gateway according to ‘.’ and then combine them to make a judgment.

The third point: Bitwise AND operation of js

result = [integer 1] & [integer 1]
& performs a bitwise AND operation on each bit of two 32-bit expressions. If both bits are 1, the result is 1. Otherwise, the result is 0.

Sharejs logical judgment on ip address, subnet mask, gatewayDetailed code

function checkIP(ip) 
{ 
 obj=ip;
 var exp=/^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/; 
 var reg = obj.match(exp); 
 if(reg==null) 
 { 
  return false;//不合法
 } 
 else 
 { 
  return true; //合法
 } 
}
 
function checkMask(mask) 
{ 
 obj=mask; 
 var exp=/^(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)$/; 
 var reg = obj.match(exp); 
 if(reg==null) 
 { 
   return false; //"非法"
 } 
  else 
 { 
   return true; //"合法"
 } 
} 
 var static_ip= document.getElementById('static_ip').value;
  var static_mask= document.getElementById('static_mask').value; 
  var static_gw= document.getElementById('static_gw').value;

  
  if (static_ip=='')
  {
   // $("#static_ip_error").css("display","block");
   document.getElementById('static_ip').focus();
   return false;
  }else if(!checkIP(static_ip))
  {
   //$("#static_ip_error").css("display","none");
   document.getElementById('static_ip').focus();
   return false;    
  }
   
  if(static_mask=='')
  { 
   //$("#static_mask_error").css("display","block");
   document.getElementById('static_mask').focus();
   return false;  
  }else if(!checkMask(static_mask))
  {
   //$("#static_mask_error").css("display","none"); 
   document.getElementById('static_mask').focus();
   return false;  
  }  
  
  if(static_gw=='')
  { 
   //$("#static_gw_error").css("display","block");
   document.getElementById('static_gw').focus();
   return false;  
  }else if(!checkIP(static_gw))
  {
   //$("#static_gw_error").css("display","none");
   document.getElementById('static_gw').focus();
   return false;    
  } 
 

 if(static_ip == static_mask || static_mask == static_gw || static_mask == static_gw)
 {
  alert('地址输入错误！');
  return false; //3个地址不能相同
 }
 
 var static_ip_arr = new Array;
 var static_mask_arr = new Array;
 var static_gw_arr = new Array;
  
 static_ip_arr = static_ip.split(".");
 static_mask_arr = static_mask.split(".");
 static_gw_arr = static_gw.split(".");

 var res0 = parseInt(lan_ip_arr[0]) & parseInt(static_mask_arr[0]);
 var res1 = parseInt(lan_ip_arr[1]) & parseInt(static_mask_arr[1]);
 var res2 = parseInt(lan_ip_arr[2]) & parseInt(static_mask_arr[2]);
 var res3 = parseInt(lan_ip_arr[3]) & parseInt(static_mask_arr[3]);
 
 var res0_gw = parseInt(static_gw_arr[0]) & parseInt(static_mask_arr[0]);
 var res1_gw = parseInt(static_gw_arr[1]) & parseInt(static_mask_arr[1]);
 var res2_gw = parseInt(static_gw_arr[2]) & parseInt(static_mask_arr[2]);
 var res3_gw = parseInt(static_gw_arr[3]) & parseInt(static_mask_arr[3]);
 
 if(res0==res0_gw && res1==res1_gw && res2==res2_gw && res3==res3_gw)
 {
  
 }else{
  alert('IP地址与子网掩码、网关地址不匹配！');
  return false;
 }

JS verification code for legality of IP and subnet mask sharing:

function checkIP(ip) 
{ 
  obj=ip;
  var exp=/^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/; 
  var reg = obj.match(exp); 
  if(reg==null) 
  { 
    return false;//不合法
  } 
  else 
  { 
    return true; //合法
  } 
}
 
function checkMask(mask) 
{ 
  obj=mask; 
  var exp=/^(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)$/; 
  var reg = obj.match(exp); 
  if(reg==null) 
  { 
     return false; //"非法"
  } 
   else 
  { 
     return true; //"合法"
  } 
}

The above is the entire content of this article, I hope it will be helpful to everyone’s study.