[Samba] Samba 4 + Squidguardian

Tue Oct 20 11:39:51 UTC 2015

On 20/10/15 11:43, mathias dufresne wrote:
> 2015-10-20 11:10 GMT+02:00 Rowland Penny <rowlandpenny241155 at gmail.com>:
>
>> On 20/10/15 09:05, mathias dufresne wrote:
>>
>>> 2015-10-19 18:08 GMT+02:00 Rowland Penny <rowlandpenny241155 at gmail.com
>>> <mailto:rowlandpenny241155 at gmail.com>>:
>>>
>>>
>>>      On 19/10/15 16:46, mathias dufresne wrote:
>>>
>>>          AD from Samba or Microsoft is mainly a database for storing
>>>          users (and
>>>          associated stuffs). It comes also with stuffs (protocols) to
>>>          connect and
>>>          retrieve information.
>>>
>>>          How the client uses these information is, as always, a choice
>>>          from that
>>>          specific client.
>>>
>>>          Your AD client is your Squid/Squidguard(ian) server. Its job
>>>          as AD client
>>>          is to get some users information from AD to build system
>>>          users. I insist on
>>>          the fact system users are forged. Purely.
>>>
>>>          What is responsible of that forging process? What you declared in
>>>          /etc/nsswitch.conf.
>>>          Generally it is winbind, sssd or nlscd.
>>>
>>>          Each one of these tools comes with its own set of option,
>>>          tweak and
>>>          configuration files to define how to forge users from local
>>>          system point of
>>>          view.
>>>
>>>          Each one except for Winbind which forge users as it decide to,
>>>          no matter
>>>          the desires of local system admin. At least this is how I
>>>          understood
>>>          winbind behaviour (which has no configuration file for what I
>>>          know).
>>>
>>>
>>>      Well, apart from idmap.ldb on a DC and the idmap_config lines in
>>>      smb.conf on a domain member, there are no configuration files. :-D
>>>
>>>
>>> idmap.ldb -> TDB database version 6, little-endian hash size 10000 bytes
>>> idmap_config lines in smb.conf -> how would you set them to configure
>>> Winbind to not add domain to user?
>>>
>> Well, I will give you this one, on DC you cannot, but on a domain member
>> you can: winbind use default domain = yes
>> However, it is not recommended to use the DC as a fileserver
>
> OK for that option I didn't knew which is effectively to remove domain part
> of user name.
> Not OK with your remark regarding file server: why changing the way system
> users are created means to share files?

I never mentioned how users are created in relation to how to share 
files, you seem to be wanting to use the DC to server files, I was just 
pointing out that this is not recommended.

>
>>
>> To use gidNumber rather than 100 which seems to reflect "primaryGroupID:
>>> 513",
>>>
>> Give the users unique uidNumbers and Domain Users a gidNumber
>
> What gidNumber is given to system user? Is it gidNumber attribute content
> or something else?
> What I mean is simple: if I configure gidNumber for all my users, don't you
> think I do that for my system users have this gidNumber in use rather gid
> set to 100?
> Are you telling me I'm stupid to want users with different GID? Isn't it a
> common UNIX practice? Are you telling me all others admins doing that are
> also stupid?

Well in the context of AD *YES*, in AD, every users primary group is 
'Domain Users' and there is no concept of a private group. You control 
access by using NTFS ACLs, either by setting these from windows or with 
'setfacl'. To change a users primary group, you will need to change the 
users PrimaryGidNumber attribute to contain the RID of the new group, it 
is possible but has to be done in a certain way. I would not suggest 
doing this, windows expects every user to be a member of 'Domain Users'.

>
>
>>
>> to set up home directory to unixHomeDirectory or to homeDirectory rather
>>> than /home/<short domain name>/ sAMAccountName?
>>>
>> template homedir = /home/%U
>
> False. Here you gave me an option to force one kind of home directory for
> all users. This is not what I was asking. Can't you imagine that some users
> could need some other home directory? What if some applicative user is
> named "toto" and this user needs to have a home directory set to
> /home/toto_applicative_folder?

No, you never asked that, you just said it couldn't be done and I also 
said using the DC as a fileserver is not recommended, on a domain 
member, the 'unixHomeDirectory' attribute is available and winbind will 
use it.

> Should I modify this user .bashrc or .profile to force an export of HOME
> variable? Is it a nice way to proceed when using the right tool I can set
> this different home directory directly in AD?

No, just use Samba in AD mode as recommended.

>
>
>>
>> Is it possible to use CN or userPrincipalName rather SAMAccountName when
>>> building the system user?
>>>
>> No, you have lost me again, what do you mean by 'building the system user'
>
> OK, here we going further.
> AD is a database. When we want to use users from AD into Linux or UNIX
> systems, we retrieve some information from AD (Login, UID, GID, Gecos, Home
> directory, Shell) and we use these information to generate lines looking
> like lines from /etc/passwd. This process is the fact of building system
> user.

Ah, you mean extracting the users info from AD like this:

rowland at debnet:~$ getent passwd rowland
rowland:*:10000:10000::/home/rowland:/bin/bash

This is on a domain member (in fact it is on the netbook, I am typing 
this on)

> Using the very same AD and changing what attribute is used to fill some
> field of these user lines will result in different user.
>
> Example:
> uid:x:uidNumber:gidNumber:gecos:homeDirectory:loginShell
> or
> sAMAccountName:x:uidNumber:gidNumber:displayName:unixHomeDirectory:loginShell
>
> These are two ways to use AD content to generate system users. Different
> users.
>
> I'm not telling one way is better than the other, I'm telling AD can be
> used in several ways. And using winbind is minimizing this number of ways
> as it is lacking configuration options.

No, you are confusing the ways that info can be extracted from AD with 
what the OS actually needs, winbind can and will supply this info, but 
only fully on a domain member.

>
>>
>>
>>> So it is not configurable.
>>>
>> Yes it is, fully on a domain member, partially on a DC
>
> Show me. Stop telling it is possible without example as it has no value.
> I gave two different user lines, show me how with winbind I can obtain both.

You are using nlscd and as such to tell it to extract certain info, some 
of this info is not really required, but I have added the 'gecos' 
attribute to my AD object and now get this:

rowland at debnet:~$ getent passwd rowland
rowland:*:10000:10000:Rowland Penny:/home/rowland:/bin/bash

So, I get the username, the users UID, their primary GID, gecos, Unix 
home directory and what shell the user will use, all obtained from AD, 
what else does the OS need?

>
>
>>
>>
>>>
>>>          Perhaps you are using winbind, in that case winbind is
>>>          responsible to add
>>>          domain and backslashes when forging your users.
>>>
>>>          I don't know at all nlscd but some are using it on that
>>>          mailing list. So I
>>>          expect it does its job too.
>>>
>>>          I tried SSSD for the company I'm working these days and it
>>>          comes with lot
>>>          of configuration options. I expect it can force addition of AD
>>>          domain to
>>>          username but it is not the default behaviour.
>>>
>>>          On some DC where it uses winbind to forge users:
>>>
>>>
>>>      No, sorry, I cannot understand what you mean by forge, in English
>>>      this word is used for creating your own banknotes or a thing used
>>>      by a blacksmith.
>>>
>>>
>>> In fact a blacksmith forges items using blacksmith tools. He creates
>>> these items. These items can be something else than his own tools. In fact
>>> if a blacksmith was only able to craft its own tools and nothing else for
>>> other peoples, this kind of job would have quickly disappeared...
>>>
>> So what you meant was 'create a user', please don't try to get creative
>> with the English language, just say what you mean.
>> As for forge and a blacksmith, the word can mean the place a blacksmith
>> works, the 'action' of the blacksmith doing something i.e. a blacksmith
>> forges horseshoes (technical note: no, this actually done by a farrier)
>> (further note: blacksmiths have virtually disappeared)
>> Have we played enough with *my* language yet?
>
> In fact what I meant was "using some tool to retrieve some information from
> AD to create a system user using these information". I just thought forging
> was clear enough, my bad.

Very bad, forging has nothing to with retrieving, extracting, pulling, 
obtaining (I could go on) info from AD.

>
>
>>
>>
>>> Anyway you get the point, forging, crafting, building, assembling
>>> elements to obtain something else, they are same concept.
>>>
>> Same basic concept, but they all mean totally different things.
>
> Perhaps, I'm not English native. In my own language, French, all these
> words have a similar background described by "assembling elements to obtain
> something else". Which is what winbind and consort are doing. Assembling
> elements from AD.

They do not really mean that in English.

>
>>
>>
>>>
>>>      If you add a Uidnumber to user a user in AD, then it should show
>>>      on a DC, even if you are not using winbind.
>>>
>>>
>>> Here you should have meant "if you are using winbind" which is true for
>>> UID and wrong for GID which is not reflecting gidNumber configured into AD.
>>>
>> Ah, that is because you think that giving a user a gidNumber, this becomes
>> the users main GID, it doesn't. The users primary gid number is obtained
>> from what is set in the aptly named 'PrimaryGidNumber' attribute, AD
>> obtains this and then uses whatever gidNumber that groups object contains.
>
> False. In system point of view user primary group is the one declared in
> user line (the equivalent of line from /etc/passwd) and this can be changed
> using "sg" command for example.
>
> And what attribute is used to generate that line is a choice. Samba team
> has chosen to use 'PrimaryGidNumber' attribute,

Yes, but what else would you use for a users primary group number (the 
clue is in the attribute name)

> well, that's their choice

Yes and it was a good choice with relevance to AD and as I said it 
really doesn't need to be changed, you just need to use windows 
permissions instead of Unix permissions.

> and it is most certainly relevant in certain conditions. Not all. And
> that's so obvious other tools used to generate system users from AD have
> this configurable.
>

This is because they are trying to force AD to work with Unix, instead 
of Unix working with windows.

>>
>>
>> Should I speak again about home dir ? Shell ? Gecos ? login attribute ?...
>>
>> No, because I have already dealt with that.
>
> I still don't see where you dealt with that : )

Well I did :-)

>
>
>>
>>
>>> SSSD grant sys admin possibility to chose all that, forging users as
>>> sysadmin wants to (which is most generally what his bosses asked to him).
>>> Winbind can't.
>>> And here the question is "how can the user have username using <username>
>>> syntax rather than <domainname>\<username>. Is it possible to remove domain
>>> part from username when using winbind? With the idmap_config lines perhaps
>>> ? :p
>>>
>> Anything that sssd can do, winbind can do, but, as I have admitted, only
>> fully on a domain member.
>
> Wrong. Very wrong. One thing to push us a bit outside of the current
> subject: SSSD can connect on several domains and several LDAP trees which
> are not domains at same time. Can winbind do that? Just for fun : )

You can get winbind to know about different domains, but why would you 
bother, do it the windows way, have one domain and use 'sites'.

Rowland

>
> I know you were speaking about generating user lines from one and only one
> AD domain. Once more: show me how to generate different user lines for the
> same user into the same AD, without changing anything into that AD. Then
> I'll start to accept winbind is configurable. Until now, for me it is not.
>
>
>>
>>
>>> And more: how system is configured to retrieve users from AD! AD seems
>>> well configured: it works. The question is about how to obtain system users
>>> according to what this user needs and not according to what winbind thinks
>>> it is the right way.
>>>
>> As I said, winbind will do what sssd does, in fact winbind is that good,
>> the later versions of sssd implements a lot of the winbind code.
>
> I never say winbind is not well coded, useless or anything like that. I say
> winbind is not as configurable as SSSD which makes SSSD more suitable for
> some needs.
>
> And once again, show me how to generate different user lines with winbind
> when using the AD DB, just changing what attribute is used for parts of
> these lines (gecos, username, home dir, all of them).
>
>
>>
>> Rowland
>>
>>
>> --
>> To unsubscribe from this list go to the following URL and read the
>> instructions:  https://lists.samba.org/mailman/options/samba
>>