HMailServer: block autobanned ip addresses permanently

Many people seem to try logging into my HMailserver, without success. The attempts are eventually blocked by the servers autoban functionality, but it's really annoying to see so many red autobanned ip-ranges showing up in my ip-configuration screen (moreover, it's slowing that screen down), so in case of many login-attempts I wanted to block such an ip-range for a longer period, say 30 days.

Because the blocked ipranges are stored in a MySQL database, this can be done using a MySQL-server scheduled event:

use [your hmaildatabase];
delimiter |

CREATE EVENT Block_Email_Hackers
ON SCHEDULE EVERY 3 HOUR STARTS '[startdate]'
COMMENT 'Block e-mailserver blocked ip-ranges for 30 days (runs every 3 hours)'
DO
BEGIN
 -- block the first range of a list of ipranges for 30 days
 update hm_securityranges
  set rangeexpirestime = date_add(now(), interval 30 day)
     ,rangepriorityid = 500
     ,rangename = CONCAT('BLOCK: ', INET_NTOA(rangelowerip1), ' dd: ', now())
  where rangeid > 0
    and rangeid in (
   select distinct rangeid from (
    select rangeid, rangelowerip1, max(rangeexpirestime) as maxexp
   from hm_securityranges r
     where rangename like 'auto-ban%'
    group by rangelowerip1
   ) as ranges
  );
  -- remove all other ranges for the blocked ip addresses from the db
 delete from hm_securityranges where rangename like 'auto-ban%' and rangeexpires = 1;
END |
DELIMITER ;

Note: it may be possible that you block a genuine user of your mail server (who for example forget his password).

A simple css only tooltip using a data-attribute

There are many ways to create tooltips, and in the past I've created and used a relatively complex ECMAScript framework for it. But with css3, at least for simple and small tooltips, this framework becomes obsolete.

Here's a cookbook for creating a simple tooltip. I'll be using a data attribute for the element, and use css to format it.

First, let's create an element containing the data-tooltip attribute. To be able to use a transition effect for the tooltip, the trick is to hide the element using opacity, a negative z-index and an absolute position

<div data-tooltip="This is the tooltip text, to be shown on hover">Lorem ipsum etc.</div>

Next step: create css for the :before pseudo class. Note: you could also use the :after pseudo class, but that has consequences for positioning the tooltip. Just fiddle around with the css presented here.

[data-tooltip]:before {
    /* use the attribute value for the content */
    content: attr(data-tooltip);
    /* hide the pseudo element, next three lines are mandatory */
    opacity: 0;
    /* get it out of the way if not hovered */
    top: -1000em;
    position: absolute;
    /* format the pseudo-element, this is examplary */
    font-size: 0.8em;
    padding: 0.1em 0.3em;
    max-width: 400px;
    border: 1px solid #888;
    background: white;
    margin-top: 1.5em;
    white-space: pre;
    text-align: left;
    border-radius: 5px;
    box-shadow: 1px 1px 4px #888;
}

And the last step: create css for the :hover pseudo class

[data-tooltip]:hover:before {
    /* show the pseudo element, following two lines are mandatory */
    top: auto;
    z-index: 2;
    /* a 'fade in' effect, the element fades in after a delay of 0.3 seconds */
    transition: opacity 0.4s 0.3s ease-in;
}

That's all. It should look like this.

The technique is used here (hover the numbers).

Simplicity please

Sometimes programmers choose programmer solutions, which really can be too complex.

So I think this ...

function stringRepeat(str, num) {
    num = Number(num);
    var result = '';
    while (true) {
        if (num & 1) { // (1)
            result += str;
        }
        num >>>= 1; // (2)
        if (num <= 0) break;
        str += str;
    }
    return result;
}

[Found @ ②ality – JavaScript and more]

... (though nifty and nice code) can be replaced by:

function stringRepeat(str, num) {
    return Array( (num || 1) + 1 ).join(str);
}

Where num || 1 ensures that the initial string is always returned, even if num is not passed in the method call.

Replace all diacritics in strings using a Regular Expression

To replace all diacritics (aka 'extended characters') by their HtmlEncoded counterpart in strings use:

[SomeString]
  .replace(
           /[\u0080-\u024F]/g,
           function(a) {return '&#'+a.charCodeAt(0)+';';}
  );

For example:

"Diëlectrische Coëfficiënten".replace(/[\u0080-\u024F]/g, function(a) {return '&#'+a.charCodeAt(0)+';';});
//    returns
//=> "Diëlectrische Coëfficiënten"

How to check a string value to contain a set of predefined characters with a regular expression in javascript

This struck me only now: if you want to check some string to contain a set of predefined characters using a regular expression for that set, in javascript you just need to compare the length of the matching result to the length of the input string. Like this:

var str = 'this string can contain nothing else but digits, spaces,'+
          'commas and alphabetic characters';
alert(String(str.match(/[a-z\,\.\s0-9]/ig).length === str.length));
//returns true

The set [a-z\,\.\s0-9] contains spaces, letters (case insensitive), digits, dots and comma's. Matching the set to a string that only contains characters from the set should deliver a resulting array with exactly the length of the input string. And yes, it does.

Why didn't I think of that before? Well ehr....