[GSoC] Capsicum application adaptation and core libraries

Ilya Bakulin webmaster at kibab.com
Thu Apr 7 20:11:00 UTC 2011

 On 07.04.2011 13:31, Robert N. M. Watson wrote:
> On 7 Apr 2011, at 10:13, Ilya Bakulin wrote:
>> some time ago I've read a paper about Capsicum (it was published at Google
>> reseach papers page). I think that this is an interesting technology, and
>> adopting it for use in FreeBSD base system is worth an effort. Also I see
>> this idea as GSoC suggested idea on Ideas page [1].
>> So I'd like to take this as a possible GSoC project for this summer. As
>> the task description seems to be very broad, I'd like to be more specific
>> about what is to be done during the summer.
>> As core Capsicum libraries will appear in FreeBSD 9 anyway, I think it's
>> possible to take several applications from the base system and modify them
>> to use Capsicum sandboxes. For example, the FreeBSD syslog daemon might be
>> an interesting application to adapt to compartmentalisation model. Exact
>> list of applications that will be adapted is to be discussed. Primary
>> focus should be, however on "sbin" and "usr.sbin" world parts.
>> Do you think that this work may be useful?
> Hi Ilya:
> I think this sort of project would be great for Google Summer of Code. A results-oriented effort, which starts with a specific set of system services or components, and works back into their dependencies (such as critical libraries, missing Capsicum features, etc) sounds like a good way to go about it. A key question throughout, needs to be "what is protected from whom" -- each use of compartmentalisation comes with performance cost and code complexity, and selecting the most valuable applications will be a central part of the work.
> Critical system services, such as syslogd, etc, sound like good places to begin, as well as nailing down use of Capsicum in dhclient, sshd, etc, which we've experimented with but haven't yet merged into FreeBSD. It would also be interesting to apply Capsicum to pipeline components such as gzcat, grep, sed, nroff (and in the future, and perhaps a better match, mandoc), so that when components operate on streams and don't require additional inputs and outputs, they operate entirely in sandboxes.
> As will become clear once you dig in, there are some missing things needed to really round out the Capsicum API. The web page refers largely to "services" for sandboxes -- as capability mode forbids creating new network connections, potential services to sandboxes include passing in pre-connected sockets, files/subtrees based on policy, etc, that might be expressed somehow: by the application writer during sandbox setup, or be dynamic in response to changing situations.
> Another interesting direction to run in might be to start pushing Capsicum support into higher level applications that desperately need it: PDF rendering, for example! There's a lot of interesting work to be done here. However, the remaining proposal period is pretty short -- I'd encourage you to put together as concrete a proposal as possible -- necessarily somewhat open-ended, but lay out in moderate detail how you'd spend the first month: specific policy and security goals, concrete tasks, elements to change, and what you think the challenges are, etc.
> Robert
> !DSPAM:4d9d84a210433086818784!

Hi Robert,
thank you for your comments. I've posted a project proposal to GSoC
website [1]. I've tried to take your suggestions into account. If there
are any questions, I'll be happy to answer them.
[1] http://socghop.appspot.com/gsoc/proposal/review/google/gsoc2011/kibab/1

Ilya Bakulin

More information about the freebsd-hackers mailing list