Naive Qs about selinux modules

[Johnson, Richard]

Daniel J Walsh wrote: 
Johnson, Richard wrote:
>> Q:  Can any SELinux directive be put into a policy smodule, or are
there
>> restrictions?
>> 
>>  
>> 
>> For example: suppose I wanted to:
>> 
>>   allow snmpd_t apmd_t:process ptrace; 
>>   allow snmpd_t auditd_t:process ptrace;
>>   allow snmpd_t automount_t:process ptrace;
>>  [ ...and so on ]
>> 
>> so that snmpd could access mib .1.3.6.1.2.1.6. (advisability
>> notwithstanding) Could these directives be put into a policy module
even
>> though the base policy already has an snmpd i/f?
>> 
>Yes although  watch out for name conflicts,  IE Don't name your module
>the same as an existing module or you will replace it.
>
>BTW the interface
>domain_read_all_domains_state(snmpd_t)
>
>Is probably what you want.
>> 
>> Q.  Can a module define new booleans?  If so are they persistent if
the
>> module is unloaded and reloaded?
>> 
>Yes and the booleans will be removed if you unload the policy.
>
>> For example; an snmpd policy module with an snmpd_can_ptrace boolean.
>> Are there namespace conventions?
> 
>Well we would prefer all booleans to be named with the name of the
>module.  Although there are a lot of booleans that do not follow that
>standard.  I would love to have aliasing for booleans so we could
rename
>them.
>> 
>> Q. What happens if the base policy (or another policy modules) is
>> updated with overlapping statements. 
>  
>They are additive.
>> 
>> Am I correct in believing that the set of allows is the union of the
>> base allows + all module allows?
>  
>Yes

Thanks.  And thanks for the hint about domain_read_all_domains_state().