Introduce `Clock.call_when_running(...)` to wrap startup code in a
logcontext, ensuring we can identify which server generated the logs.
Background:
> Ideally, nothing from the Synapse homeserver would be logged against the `sentinel`
> logcontext as we want to know which server the logs came from. In practice, this is not
> always the case yet especially outside of request handling.
>
> Global things outside of Synapse (e.g. Twisted reactor code) should run in the
> `sentinel` logcontext. It's only when it calls into application code that a logcontext
> gets activated. This means the reactor should be started in the `sentinel` logcontext,
> and any time an awaitable yields control back to the reactor, it should reset the
> logcontext to be the `sentinel` logcontext. This is important to avoid leaking the
> current logcontext to the reactor (which would then get picked up and associated with
> the next thing the reactor does).
>
> *-- `docs/log_contexts.md`
Also adds a lint to prefer `Clock.call_when_running(...)` over
`reactor.callWhenRunning(...)`
Part of https://github.com/element-hq/synapse/issues/18905
This PR makes a few radical changes to media. This now stores the SHA256
hash of each file stored in the database (excluding thumbnails, more on
that later). If a set of media is quarantined, any additional uploads of
the same file contents or any other files with the same hash will be
quarantined at the same time.
Currently this does NOT:
- De-duplicate media, although a future extension could be to do that.
- Run any background jobs to identify the hashes of older files. This
could also be a future extension, though the value of doing so is
limited to combat the abuse of recent media.
- Hash thumbnails. It's assumed that thumbnails are parented to some
form of media, so you'd likely be wanting to quarantine the media and
the thumbnail at the same time.
When a module rejects a piece of media we end up trying to close the
same logging context twice.
Instead of fixing the existing code we refactor to use an async context
manager, which is easier to write correctly.
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
This converts the media servlet URLs in the same way as
(most) of the rest of Synapse. This will give more flexibility
in the versions each endpoint exists under.
The stubs have some issues so this has some generous cast
and ignores in it, but it is better than not having stubs.
Note that confusing that Element is a function which creates
_Element instances (and similarly for Comment).
There are two situations which were previously not properly checked:
1. If the requested URL was replaced with an oEmbed URL, then the
oEmbed URL was not checked against url_preview_url_blacklist.
2. Follow-up URLs (either via autodiscovery of oEmbed or to pre-cache
images) were not checked against url_preview_url_blacklist.
This stops media (and thumbnails) from being accessed from the
listed domains. It does not delete any already locally cached media,
but will prevent accessing it.
Note that admin APIs are unaffected by this change.
* Removes the `v1` directory from `test.rest.media.v1`.
* Moves the non-REST code from `synapse.rest.media.v1` to `synapse.media`.
* Flatten the `v1` directory from `synapse.rest.media`, but leave compatiblity
with 3rd party media repositories and spam checkers.
Previously if an autodiscovered oEmbed request failed (e.g. the
oEmbed endpoint is down or does not exist) then the entire URL
preview would fail. Instead we now return everything we can, even
if this additional request fails.
* Fix MediaStorage type hint
* Typecheck tests.rest.media.v1.test_media_storage
* Changelog
* Remove assert and make the comment succinct
* Fix syntax for olddeps
It doesn't seem valid that HTML entities should appear in
the title field of oEmbed responses, but a popular WordPress
plug-in seems to do it.
There should not be harm in unescaping these.
Attempt to parse any valid information from an oEmbed response
(instead of bailing at the first unexpected data). This should allow
for more partial oEmbed data to be returned, resulting in better /
more URL previews, even if those URL previews are only partial.
Fix https://github.com/matrix-org/synapse/issues/13016
## New error code and status
### Before
Previously, we returned a `404` for `/thumbnail` which isn't even in the spec.
```json
{
"errcode": "M_NOT_FOUND",
"error": "Not found [b'hs1', b'tefQeZhmVxoiBfuFQUKRzJxc']"
}
```
### After
What does the spec say?
> 400: The request does not make sense to the server, or the server cannot thumbnail the content. For example, the client requested non-integer dimensions or asked for negatively-sized images.
>
> *-- https://spec.matrix.org/v1.1/client-server-api/#get_matrixmediav3thumbnailservernamemediaid*
Now with this PR, we respond with a `400` when we don't have thumbnails to serve and we explain why we might not have any thumbnails.
```json
{
"errcode": "M_UNKNOWN",
"error": "Cannot find any thumbnails for the requested media ([b'example.com', b'12345']). This might mean the media is not a supported_media_format=(image/jpeg, image/jpg, image/webp, image/gif, image/png) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)",
}
```
> Cannot find any thumbnails for the requested media ([b'example.com', b'12345']). This might mean the media is not a supported_media_format=(image/jpeg, image/jpg, image/webp, image/gif, image/png) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)
---
We still respond with a 404 in many other places. But we can iterate on those later and maybe keep some in some specific places after spec updates/clarification: https://github.com/matrix-org/matrix-spec/issues/1122
We can also iterate on the bugs where Synapse doesn't thumbnail when it should in other issues/PRs.
* Make _iterate_over_text easier to read by using simple data structures
* Prefer a set of tags to ignore
In my tests, it's 4x faster to check for containment in a set of this size
* Add a stack size limit to _iterate_over_text
* Continue accepting the case where there is no body element
* Use an early return instead for None
Co-authored-by: Richard van der Hoff <richard@matrix.org>
Pull out `twitter:` meta tags when generating a preview and
use it to augment any `og:` meta tags.
Prefers Open Graph information over Twitter card information.
This implements an allow list for content types for which Synapse will attempt URL preview. If a URL resolves to a resource with a content type which isn't in the list, the download will terminate immediately.
This makes sense given that Synapse would never successfully generate a URL preview for such files in the first place, and helps prevent issues with streaming media servers, such as #8302.
Signed-off-by: Denis Kasak dkasak@termina.org.uk
* Splits the logic for parsing HTML from the resource handling code.
* Fix a circular import in the oEmbed code (which uses the HTML parsing code).
* Renames some of the HTML parsing methods to:
* Make it clear which methods are "internal" to the module.
* Clarify what the methods do.
* add code to handle missing content-type header and a test to verify that it works
* add handling for missing content-type in the /upload endpoint as well
* slightly refactor test code to put private method in approriate place
* handle possible null value for content-type when pulling from the local db
* add changelog
* refactor test and add code to handle missing content-type in cached remote media
* requested changes
* Update changelog.d/11200.bugfix
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
