From: Chris McGee <newton688@gmail.com>
To: 9fans <9fans@9fans.net>
Subject: Re: [9fans] fd and /srv filesystem
Date: Wed, 4 Oct 2023 19:42:50 -0400 [thread overview]
Message-ID: <6F39A2EA-0896-4B39-AF15-250E60D65125@gmail.com> (raw)
In-Reply-To: <F00F7DE00644F83935EB0DD8FC72BEDE@eigenstate.org>
Thanks all for the explanations. I think I understand better now.
Chris
> On Oct 4, 2023, at 12:06 PM, ori@eigenstate.org wrote:
>
> Quoth Chris McGee <newton688@gmail.com>:
>> Hi All,
>>
>> I was thinking about file descriptors in the context of Plan 9. On Unix an
>> fd is generally only usable by the current process, and child ones through
>> a fork with some special incantation if one wants to communicate one over a
>> domain socket. This is possibly for security reasons, avoiding other users'
>> processes from trying to guess the fd of a critical file.
>>
>> It's common practice in Plan 9 to post an fd (sometimes via a pipe) from
>> one process to the /srv filesystem so that others can discover it and open
>> a comms channel. Does the kernel transform the fd into something when
>> posted to /srv so that it can be consumed by any other process in the
>> system?
>>
>> Thanks,
>> Chris
>>
>
> it's all just Chans in the kernel; devsrv just provides
> a way of giving an open chan a name in the namespace.
>
------------------------------------------
9fans: 9fans
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prev parent reply other threads:[~2023-10-04 23:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-04 10:29 Chris McGee
2023-10-04 12:20 ` hiro
2023-10-04 12:25 ` hiro
2023-10-04 16:06 ` ori
2023-10-04 23:42 ` Chris McGee [this message]
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