[Sugar-devel] [ASLO] Release Read ETexts-19

[James Simmons]

Sascha,

I was looking at the code for Leer Pen Drive and thinking how I could
improve on it, and in the process I ended up looking at
git.sugarlabs.org at the code for Journal.  Apparently that is not the
most recent code, but I was a bit surprised that Journal inherits from
Activity.  That wouldn't be too surprising except that the Journal
Activity can write to a USB or thumb drive.  I couldn't figure out how
or even where it was doing it, but it does seem that you could write
an Activity that does everything the Journal does, from writing to
mounted media to unmounting it.

How is that possible?  My guess: like everything else I don't fully
understand about Sugar, it has something to do with DBus.

If anyone could point me to something that might help my understanding
I'd appreciate it.

James Simmons


On Wed, Mar 17, 2010 at 6:13 AM, Sascha Silbe
<sascha-ml-ui-sugar-devel at silbe.org> wrote:
> On Tue, Mar 16, 2010 at 07:55:59PM -0500, James Simmons wrote:
>
>> It would be nice if one of the things Activities were allowed to write
>> to was external drives mounted on /media.
>
> The only thing that might prevent that is Rainbow, which isn't installed by
> default on any system running > 0.82 that I know of (and in 0.82-using OLPC
> builds it's supposed to allow access to /media [1]). So while you cannot
> depend on it, it will work fine in most cases in the near future.
>
>> That would enable anyone to put together a Journal-like Activity and yet
>> would probably not do too much harm securitywise.
>
> I have to disagree, access to /media/* is equally sensitive as access to the
> data store. It's even so similar that we might use the same set of
> permissions for both.
>
> FTR: Rainbow currently doesn't do anything special for /media. Sugar (or
> probably the Gnome parts it's based on) mounts FAT filesystems in /media
> with dmask=0077, thereby denying access to anyone but the primary user. In
> combination this means access to /media/* is denied to activities running on
> recent Sugar and Rainbow.