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Re: Vnode scope implementation


> Am 21.08.2009 um 12:19 schrieb YAMAMOTO Takashi:
>> hi,
>>> Hey,
>>> Sorry for the delay, I was a bit busy.
>>> I don't see any reason to hold with implementing the vnode scope just
>>> because we can't control operations on a remote host. Therefore, I'll
>>> give it a few more days (just in case) before moving forward.
>> what will you do for nfs etc, by "moving forward"?
>> do nothing and give up mandating the use of vnode scope?
> I think it's quite clear that in the case of networked file systems it  
> is always the serving machine that has "the last word" on security  
> decisions and restrictions.  So while a nfs client could tighten  
> restrictions, it can not loosen them.  I think this is a fact we have  
> to live with.

sure.  i'm asking how will we live with the fact.


>> YAMAMOTO Takashi
>>> Thanks,
>>> -e.
>>> Elad Efrat wrote:
>>>> On Tue, Aug 4, 2009 at 2:07 AM, YAMAMOTO 
>>>> Takashi< 
>>>> > wrote:
>>>>>> but IIUC it can prevent what the
>>>>>> remote file-system would allow
>>>>> sometimes it can, but in general it can't.
>>>>> 1. a client sends a request to a server.
>>>>> 2. the server decided to allow the operation, and actually  
>>>>> process it,
>>>>> and return the result to the client.
>>>>> ie. you don't have a chance to pass "fs_decision" to kauth.
>>>> Ugh, the above was an obvious typo on my part. I agree, we don't  
>>>> have
>>>> a chance to pass fs_decision to kauth(9) because the remote server
>>>> will already perform the operation.
>>>>>> Should we enforce that
>>>>>> limitation on all file-systems, or make remote file-systems an
>>>>>> exception? Veriexec sets a precedent of the latter, which I think
>>>>>> makes sense. Do you have something else in mind?
>>>>> i'm not sure if "remote file-systems or not" is a good  
>>>>> classification
>>>>> method.
>>>> How else would you classify it? and you still don't answer the
>>>> question of whether you have a solution that will not be considered
>>>> "broken". ;)
>>>> Thanks,
>>>> -e.

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