WebSocket always defers the decision to the server, because it didn't
have to deal with legacy compatibility... but the same-origin policy is
still a reasonable default.
Origin checks do not protect against a directly connecting attacker --
they can lie about their host, but can also lie about their origin.
Origin checks protect against a connection from 3rd-party controlled
script in a context where a victim browser's cookies will be passed
along. And if an attacker has breached that protection, they've already
compromised the HTTP session, so treating the WebSocket connection in
the same way seems reasonable.
In case this logic proves incorrect (or anyone just wants to be more
paranoid), we retain a config option to disable it.
IO#close and IO#read across threads don't get along so well:
After T1 enters #read and releases the GVL, T2 can call #close on the
IO, thereby both closing the fd and freeing the buffer while T1 is using
them.
Before this patch, if you were to make a file edit in your Rails
application and you tried to load up the page, it would hang
indefinitely. The issue is that Active Record is trying to cleanup after
itself and clear all active connection, but Action Cable is still
holding onto a connection from the pool. To resolve this, we are now
shutting down the pubsub adapter before classes are reloaded, to avoid
this altogether (connection is being returned to the pool).
Credits to @skateman for discovering this bug. :)
Mostly, this is just to avoid EventMachine. But there's also an argument
to be made that we're better off using a different protocol library for
our test suite than the one we use to implement the server.
When the `allow_same_origin_as_host` is set to `true`, the request
forgery protection permits `HTTP_ORIGIN` values starting with the
corresponding `proto://` prefix followed by `HTTP_HOST`. This way
it is not required to specify the list of allowed URLs.
Fixes#23757.
Before this commit, even if `reject` was called in the `subscribe`
method for an Action Cable channel, all actions on that channel could
still be invoked. This calls a `return` if a rejected connection tries
to invoke any actions on the channel.
Inserted spaces in the name of Rails components.
Since I was on it, also used PostgreSQL instead of Postgres
because albeit Postgres is an accepted alias, PostgreSQL is
the official name and the actual name of the adapter.
See
https://wiki.postgresql.org/wiki/ProjectName
with regard to PostgreSQL vs Postgres.
