I _think_ I don't need to gate other socket calls; you can't do anything
without bind() and connect(). And they should be good places to dump
more precise details later about the kind of server or client connection
being attempted.
In the process we now also have a mechanism for Teliva to overlay errors
while apps run. Might make sense to make that available to apps as well.
But I'm starting to realize that any app access to the Teliva areas of
the screen is fraught with risk.
Our sandboxing model is a blunt caricature, just two booleans. But let's
see how far this gets us.
Still doesn't persist, and definitely has no effect.
Current plan:
- two booleans to gate file and network access, respectively
- false shows as green, true shows as orange
- if _both_ booleans are true, then both show as red to indicate that
there are no protections.
It looks like attron doesn't actually enable colors near 256, even
though https://linux.die.net/man/3/attron suggests it does.
> COLOR_PAIR values can only be OR'd with attributes if the pair
> number is less than 256.
Put stuff people messing with Teliva apps are likely to need above the C
interface.
The state of documentation for Teliva app creators is still quite poor.
All they really have to go on is the example apps.
This isn't necessarily for sandboxing, but they don't really work right
now in the presence of ncurses, and it seems better to not include
broken stuff. Maybe we can get them to coexist with ncurses down the
road.
I'd originally thought of allowing policies to be influenced by
arbitrary code. But that may be overkill:
- it's probably not a good idea to allow policies to read/write from file system
- it's even less a good idea to allow policies to access the network
- particularly since it's difficult (error-prone) to distinguish GET/POST in arbitrary protocols
- once you allow file system and network, you're pretty close to owned
So let's first focus on the simplest policy, the one that is easiest to
secure. We'll add capabilities to policies as we gain confidence we can
secure them.
I want to support cursor movement across wrapped lines, and the old
implementation doesn't seem on the right track for that.
Interesting that this required me to add the new symmetric test.
I should have documented that I'd never actually seen that code path
trigger before. Here's a minimal test that did it just now:
function test_foo()
return a+1
end
E2: [string "test_foo"]:2: attempt to perform arithmetic on global 'a' (a nil value)
A simple missing variable doesn't do it since it just evaluates to nil.
Without this commit, the above test was silently continuing to the main
app after failing tests.
