SQL Script - Check if a IP has been black listed

Question

Hi, I am studing SQL, and I would like your advice, to see if my code is written properly, or better way to do it. This script create:

• a table to store IPs address that are Black Listed
• a sproc to allow spitting an IP address in 4 octet

• a SPROC that allow to check if a IP is Black Listed or not Please let me know! thanks!

  -- Black Listed Table
  CREATE TABLE UtlBlacklistedIPs 
          ( 
              octet1 TINYINT, 
              octet2 TINYINT, 
              octet3 TINYINT, 
              octet4 TINYINT 
          );
  

1 SPROC

    -- Convert an IP address in 4 octet for db storing
  CREATE PROCEDURE dbo.storeIPoctetsv1 
   @ip CHAR(15) 
  AS 
  BEGIN 
   SET NOCOUNT ON 
   INSERT UtlBlacklistedIPs(octet1, octet2, octet3, octet4) 
    SELECT 
     CONVERT(TINYINT, PARSENAME(@ip, 4)), 
     CONVERT(TINYINT, PARSENAME(@ip, 3)), 
     CONVERT(TINYINT, PARSENAME(@ip, 2)), 
     CONVERT(TINYINT, PARSENAME(@ip, 1)) 
  END

2 SPROC

-- SPROC check if an IP address has been black listed
CREATE PROCEDURE dbo.sprocCheckIp
     @ip CHAR(15)
    AS
    BEGIN
     SET NOCOUNT ON
     DECLARE
     @octet1 tinyint,
     @octet2 tinyint,
     @octet3 tinyint,
     @octet4 tinyint;

     SET @octet1 = CONVERT(tinyint, PARSENAME(@ip, 4)); 
     SET @octet2 = CONVERT(tinyint, PARSENAME(@ip, 3));
     SET @octet3 = CONVERT(tinyint, PARSENAME(@ip, 2));
     SET @octet4 = CONVERT(tinyint, PARSENAME(@ip, 1));

     IF EXISTS ( 
      SELECT octet1, octet2, octet3, octet4
      FROM UtlBlacklistedIPs
      WHERE
      octet1 =@octet1
      AND octet2 =@octet2
      AND octet3 =@octet3
      AND octet4 =@octet4
      )
       BEGIN
        PRINT 'Ip: '+@ip+' is black listed'
       END

      ELSE
       BEGIN     
        PRINT 'Ip: '+@ip+' is NOT black listed'
       END     
    END

Some values

    -- Insert dummy values
DECLARE @i INT 
SET @i = 0 
WHILE @i < 2000 
BEGIN 

    EXEC dbo.storeIPoctetsv1 @ip = '204.71.34.21' 
    EXEC dbo.storeIPoctetsv1 @ip = '12.38.145.32' 
    EXEC dbo.storeIPoctetsv1 @ip = '127.0.0.1' 

    SET @i = @i + 1 
END

Use the SPROC

    -- Use SPROc
    EXEC dbo.sprocCheckIp '125.254.125.111' -- NOT black listed Ip
    EXEC dbo.sprocCheckIp '204.71.34.21' -- black listed Ip

Answer 1

I assume you're going to use this outside of the database, presumably in .NET? In that case, I'd re-structure like this:

• SProc to store black-listed IP, with four octets as input
• SProc to check any IP, with four octets as input and 0 or 1 as output (using RETURN, not PRINT)
• Do the splitting of IP addresses in .NET instead. SQL Server has very poor string handling, so you're far better off writing a class Ip with a static method int[] ToOctets(string ip) that handles this for you. You'll use it as such: var octs = Ip.ToOctets("213.82.158.93")
• When you check if an IP is black-listed or not, you call ExecuteScalar (or whatever the method to get a scalar value from a stored procedure might be called with the connector you prefer) to get the result.

Answer 2

I agree with Thomas, but do have a question: why are you storing the IP in 4 separate columns? If the whole point of the exercise is to track "black-listed IP addresses", then when would you ever need to examine just a piece of the IP address -- wouldn't you always be looking at the entire thing? So splitting/re-combining octets seems unnecessary. It causes you to write a lot of extra T-SQL too.