Re: [PATCH] Fix for Bug #12050: Adding fixed leases with one 'add' click

[Michael Tremer <michael.tremer@ipfire.org>]

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Hi,

> On 17 Apr 2019, at 22:49, Bernhard Bitsch <Bernhard.Bitsch(a)gmx.de> wrote:
> 
> Hi,
> some explanations from the author:
> 
>> Gesendet: Mittwoch, 17. April 2019 um 11:31 Uhr
>> Von: "Michael Tremer" <michael.tremer(a)ipfire.org>
>> An: "Matthias Fischer" <matthias.fischer(a)ipfire.org>
>> Cc: development(a)lists.ipfire.org, BeBiMa <bbitsch(a)ipfire.org>
>> Betreff: Re: [PATCH] Fix for Bug #12050: Adding fixed leases with one 'add' click
>> 
>> Hi,
>> 
>> Thanks Matthias for helping out here. However, I do not get the patch.
>> 
>> There is no explanation about what it is meant to do. The intention already is that the lease is added in the first place.
>> 
> 
> The intention for the patch is to include new leases at the end with all fields defined by the admin.
> Up to now a new lease was added after an additional edit.

Those comments *must* be in the code. Nobody goes through thousands of emails on a mailing list to find out what is actually intended in the code.

> 
>>> On 16 Apr 2019, at 17:41, Matthias Fischer <matthias.fischer(a)ipfire.org> wrote:
>>> 
>>> Signed-off-by: BeBiMa <bbitsch(a)ipfire.org>
>>> Reviewed-by: Matthias Fischer <matthias.fischer(a)ipfire.org>
>>> ---
>>> html/cgi-bin/dhcp.cgi | 12 ++++++++++++
>>> 1 file changed, 12 insertions(+)
>>> 
>>> diff --git a/html/cgi-bin/dhcp.cgi b/html/cgi-bin/dhcp.cgi
>>> index 675d80012..ba5b54f84 100644
>>> --- a/html/cgi-bin/dhcp.cgi
>>> +++ b/html/cgi-bin/dhcp.cgi
>>> @@ -412,12 +412,16 @@ if ($dhcpsettings{'ACTION'} eq $Lang::tr{'add'}.'2') {
>>>    }
>>> 
>>>    my $key = 0;
>>> +    my $szc =  scalar(@current2);
>>>    CHECK:foreach my $line (@current2) {
>>>        my @temp = split(/\,/,$line);
>>>        if($dhcpsettings{'KEY2'} ne $key) {
>>> 	    # same MAC is OK on different subnets. This test is not complete because
>>> 	    # if ip are not inside a known subnet, I don't warn.
>>> 	    # Also it may be needed to put duplicate fixed lease in their right subnet definition..
>>> +	    if ((lc($dhcpsettings{'FIX_MAC'}) eq lc($temp[0])) &&(lc($dhcpsettings{'FIX_ADDR'}) eq lc($temp[1]))) {
>>> +	        last CHECK;
>>> +       }
>> 
>> Why is this needed?
> 
> Check for existing lease. If <MAC,IP> is defined already we don't need to loop further.
> 
>> 
>>> 	    foreach my $itf (@ITFs) {
>>> 		my $scoped = &General::IpInSubnet($dhcpsettings{'FIX_ADDR'},
>>> 						  $netsettings{"${itf}_NETADDRESS"},
>>> @@ -442,11 +446,19 @@ if ($dhcpsettings{'ACTION'} eq $Lang::tr{'add'}.'2') {
>>> 	$dhcpsettings{'FIX_FILENAME'} = &Header::cleanhtml($dhcpsettings{'FIX_FILENAME'});
>>> 	$dhcpsettings{'FIX_ROOTPATH'} = &Header::cleanhtml($dhcpsettings{'FIX_ROOTPATH'});
>>> 	if ($dhcpsettings{'KEY2'} eq '') { #add or edit ?
>> 
>> This block here is not indented correctly.
>> 
>> I understand that the code is already very messy, but we should not make it worse either.
>> 
> How should indention be done? By spaces, tabs? How many colums define an indent?

In the patch it looks like you wrapped the block into another if condition. So it has to be indented to make that obvious.

> The original file (and many ohters!) have an mixture of tab/space. Should we patch that step by step ( tab=4 ) to increase readability.

This is not about tabs or spaces.

> No problem. But this will produce a great number of patches. I made these modifications local, but generated the diff with "different spacing isn't a difference" option.

Please just use “git diff”. It has a variety of settings that are just right.

> This generated a short diff without real corrections only.
> 
>>> +	    if($key == $szc) { #add
>>> +	        @current2[$key] = "$dhcpsettings{'FIX_MAC'},$dhcpsettings{'FIX_ADDR'},$dhcpsettings{'FIX_ENABLED'},$dhcpsettings{'FIX_NEXTADDR'},$dhcpsettings{'FIX_FILENAME'},$dhcpsettings{'FIX_ROOTPATH'},$dhcpsettings{'FIX_REMARK'}\n";
>>> +	        # sort newly added/modified entry
>>> +	        &sortcurrent2;
>> 
>> Are you sure we can sort here?
>> 
>> See: https://git.ipfire.org/?p=ipfire-2.x.git;a=commitdiff;h=31672dc8bdb223ebf425ff96be64318f2d68e0d7
>> 
> 
> Yes! Why not?

Because of the commit I referred to.

> 
>>> +	        &General::log($Lang::tr{'fixed ip lease added'});
>>> +	        $dhcpsettings{'KEY2'} = '';
>>> +        } else { #edit
>>> 	    unshift (@current2, "$dhcpsettings{'FIX_MAC'},$dhcpsettings{'FIX_ADDR'},$dhcpsettings{'FIX_ENABLED'},$dhcpsettings{'FIX_NEXTADDR'},$dhcpsettings{'FIX_FILENAME'},$dhcpsettings{'FIX_ROOTPATH'},$dhcpsettings{'FIX_REMARK'}\n");
>>> 	    &General::log($Lang::tr{'fixed ip lease added'});
>>> 
>>> 	    # Enter edit mode
>>> 	    $dhcpsettings{'KEY2'} = 0;
>>> +	    }
>>> 	} else {
>>> 	    @current2[$dhcpsettings{'KEY2'}] = "$dhcpsettings{'FIX_MAC'},$dhcpsettings{'FIX_ADDR'},$dhcpsettings{'FIX_ENABLED'},$dhcpsettings{'FIX_NEXTADDR'},$dhcpsettings{'FIX_FILENAME'},$dhcpsettings{'FIX_ROOTPATH'},$dhcpsettings{'FIX_REMARK'}\n";
>>> 	    $dhcpsettings{'KEY2'} = '';       # End edit mode
>>> --
>>> 2.18.0
>>> 
>> 
>> -Michael
>> 
>> 
> 
> Again, my intention was a quick resolution for the behaviour mentioned in the forum post, which initiated my code review of dhcpi.cgi

Okay, I will try to explain this one last time - not just only for you, but generally:

I am not interested in quick and dirty solutions. That is how you break things. I am interested in well-documented, peer-reviewed and tested code. We are creating some piece of high-quality software - or aim to do so at least - and there is no space for quick and dirty.

Please figure out how to set up a local Git repository, how to set up a branch, how to commit things and what rules there are to follow. Then find out on how to submit a patchset to the mailing list - after it has been tested. It is all in the link that I sent you.

This is not a competition about who can submit patches the fastest.

> I found a couple of behaviours of this page, which are not obvious or straight forward ( adding dynamic leases to  static leases, for example, maybe this is invoked now by my modification).

What are those? Why are we not talking about those first and then come up with fixes? The whole DHCP page is a mess. I am not sure if it can even be fixed or of things won’t just become worse.

> I am  reviewing this piece of code at the moment and plan to suggest some modifications/corrections with formally legal patches. I hope this is ok for the core devs.

As I said, please follow the process. It is there for a reason. This is not to make things difficult. In fact it makes things a lot easier in the long term.

-Michael

> 
> Regards,
> Bernhard