Re: Make coretutils work better with SELinux.

[Daniel J Walsh]

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On 11/01/2012 11:47 AM, Pádraig Brady wrote:
> On 11/01/2012 01:20 PM, Daniel J Walsh wrote:
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>> 
>> On 10/31/2012 08:54 PM, Pádraig Brady wrote:
>>> On 10/30/2012 02:43 PM, Daniel J Walsh wrote:
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>>>> For some reason I could not get git to take more then a one line 
>>>> comment. This is the comment I was trying to add.
>>>> 
>>>> 
>>>> build: Change -Z opt w/out arg label target with default label
>>>> 
>>>> The -Z without argument will ask SELinux what the default label of
>>>> the i dest object should be and then attempt to change it.
>>>> 
>>>> The -Z with an optional context will create all targets with the
>>>> optional label. This is still supported for backwards compatability.
>>>> 
>>>> The mv command does not support the optional argument.
>>>> 
>>>> 
>>>> BTW, it looks like coreutils has removed -ZCONTEXT from cp, if I had
>>>> my druthers, I would make all commands just use -Z and not allow the 
>>>> optional arg.  Then -Z would just set the default label.  I would
>>>> bet that no one in history has executed a command like:
>>>> 
>>>> mkdir -Zunconfined_u:object_r:httpd_user_content_t:s0 ~/myweb
>>> 
>>> Thanks for the update.
>>> 
>>> Short options with optional args are very problematic. It would mean
>>> `cp -aZ` was OK while `cp -Za` was not etc. Also in Red Hat distros,
>>> `cp -Z` requires an arg, so changing that would mean that older scripts
>>> that used `cp -Z blah...` would break with newer cp, as a space is not
>>> allowed for optional args.
>>> 
>>> For that reason I would keep -Z and --context as is, but deprecate them
>>> for the commands that set a context, and add a new --new-context option
>>> that could take the optional arg:
>>> 
>>> In that way, -Z can continue to be used as it is commonly with
>>> commands like `ls` etc. to _read_ the context. Whereas the currently
>>> rare form of {mkdir,cp,install} -Z context:to_write can be deprecated
>>> in favor of:
>>> 
>>> --new-context[=CONTEXT] set security context to CONTEXT, or set context
>>> to the system default for the destination.
>>> 
>>> I'm mildly in favor of introducing --new-context, over just making 
>>> --context take an optional arg (so that it's obvious a new context is
>>> being set, rather than one being copied), but I'm strongly against
>>> making -Z take an optional arg.
>>> 
>>> cheers, Pádraig.
>> 
>> If I made the -Z option not take an optional arg but default to "setting
>> the default context, on the commands that create new content", are you ok
>> with that?
>> 
>> Then make --context or --new-context always take an arg?
> 
> That would be preferable, but the main worry I'd have with that, is install
> scripts and packages etc. in Red Hat land doing: `install -Z
> context:to_write ...`
> 
> I don't think we could break compatibility with that now?
> 
> thanks, Pádraig.

I would be shocked if we were.  I have never seen anything like that in 10 
years.

Most people would have no idea how to do it.
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