Now that sessions with non-local identities can exist, the host/local
identity should be empowered to forcefully log off any session it hosts.
Additionally, we augment the logout logic with redirect functionality:
it now respects the "redirect" query parameter in the same way the login
page does. Still defaults to redirecting to the login page.
We previously had no mechanism for giving error responses, if a client
submitted an invalid request into a channel. Guest access makes this
important, because guests cannot interact with remote ships. Attempting
to do so will cause a gall crash.
Here, we add error handling logic to channel request processing. We
catch the invalid cases described above and invalidate the entire batch
of channel requests if they occur. We make sure to drop the moves and
revert the state we changed, and give a 400 to the client that
informally describes the problem(s).
aka "the open eyre" aka "universal basic identity"
Urbit already supports presence on the clearnet, but fails to expose any
of its interactive affordances to unauthenticated users. Here, we
improve this situation by granting "guest identity" @ps to every
unauthenticated HTTP request, and extending the channels functionality
to them.
Sessions no longer represent only the local identity. Instead, each
session has either the local identity, or a fake guest identity
associated with it.
Every request that does not provide a session key/cookie gets assigned
a fresh one with a guest identity on the spot. As a result, every
single request has an identity associated with it.
The identity of a request gets propagated into userspace, if the request
ends up there.
For normal HTTP requests, this means the src.bowl gets set to that
identity for both the watch and poke of the request. For backwards
compatibility, the authenticated flag on the request noun gets set at
normal: only true if the request came from the local identity.
For channel requests, this means the src.bowl gets set to that identity
for any pokes and watches it sends, and it can only send those to agents
running on the local ship.
The scry endpoint remains unchanged in its behavior: only available to
the local identity.
Notable implementation detail changes in this diff include:
- Factored all gall interactions out into +deal-as.
- Sessions no longer represent exclusively the local identity. This
matters a lot to +give-session-tokens, %code-changed, and logout
handling.
- Session management got factored out into explicit +start-session and
+close-session arms.
Previously, if an incoming request caused a crash, we would just drop it
on the floor. We should at least have the decency to serve the client a
quick 500 and let them get on with their day.
We make sure not to touch state here. The connection is guaranteed-fresh
because of the task's semantics, and we're handling it in-line in one go.
Notably we only give a simple "crud!" for the body, instead of the full
error trace. We don't know whether the request is authenticated or not
(and who knows if checking was the cause of the crash!), and the crud
might leak sensitive details about the ship it occurred on. For the
owner, the trace still gets printed into the terminal.
=case was added as an argument to read-s to support %cs subs
it was accidentally removed as an argument during a merge,
breaking %cs subs by causing it to always crash in a
comparison between case and [%da now], because case resolved
to the mold rather than a value. this commit restores
intended functionality.
