Commit Graph

13100 Commits

Author SHA1 Message Date
Erik Johnston
e550ab17ad
Increase default join burst ratelimiting (#9674)
It's legitimate behaviour to try and join a bunch of rooms at once.
2021-03-23 14:52:20 +00:00
Jonathan de Jong
0caf2a338e
Fix federation stall on concurrent access errors (#9639) 2021-03-23 13:52:30 +00:00
Richard van der Hoff
4ecba9bd5c
Federation API for Space summary (#9652)
Builds on the work done in #9643 to add a federation API for space summaries.

There's a bit of refactoring of the existing client-server code first, to avoid too much duplication.
2021-03-23 11:51:12 +00:00
Patrick Cloke
b7748d3c00
Import HomeServer from the proper module. (#9665) 2021-03-23 07:12:48 -04:00
Andrew Morgan
5b268997bd
Allow providing credentials to HTTPS_PROXY (#9657)
Addresses https://github.com/matrix-org/synapse-dinsic/issues/70

This PR causes `ProxyAgent` to attempt to extract credentials from an `HTTPS_PROXY` env var. If credentials are found, a `Proxy-Authorization` header ([details](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Proxy-Authorization)) is sent to the proxy server to authenticate against it. The headers are *not* passed to the remote server.

Also added some type hints.
2021-03-22 17:20:47 +00:00
Ankit Dobhal
d66f9070cd
Fixed code misc. quality issues (#9649)
- Merge 'isinstance' calls.
- Remove unnecessary dict call outside of comprehension.
- Use 'sys.exit()' calls.
2021-03-22 11:18:13 -04:00
Erik Johnston
d600d4506b Merge branch 'master' into develop 2021-03-22 13:36:36 +00:00
Erik Johnston
e2904f720d 1.30.0 2021-03-22 13:15:55 +00:00
Brendan Abolivier
b6ed4f55ac
Incorporate review 2021-03-19 18:19:50 +01:00
Brendan Abolivier
592d6305fd
Merge branch 'develop' into babolivier/msc3026 2021-03-19 16:12:40 +01:00
Brendan Abolivier
0b56481caa
Fix lint 2021-03-19 16:11:08 +01:00
Richard van der Hoff
066068f034 fix mypy 2021-03-19 12:20:11 +00:00
Patrick Cloke
9b0e3009fa Fix type-hints from bad merge. 2021-03-18 14:40:56 -04:00
Richard van der Hoff
004234f03a
Initial spaces summary API (#9643)
This is very bare-bones for now: federation will come soon, while pagination is descoped for now but will come later.
2021-03-18 18:24:16 +00:00
Brendan Abolivier
066c703729
Move support for MSC3026 behind an experimental flag 2021-03-18 18:37:19 +01:00
Dirk Klimpel
8dd2ea65a9
Consistently check whether a password may be set for a user. (#9636) 2021-03-18 12:54:08 -04:00
Erik Johnston
dd71eb0f8a
Make federation catchup send last event from any server. (#9640)
Currently federation catchup will send the last *local* event that we
failed to send to the remote. This can cause issues for large rooms
where lots of servers have sent events while the remote server was down,
as when it comes back up again it'll be flooded with events from various
points in the DAG.

Instead, let's make it so that all the servers send the most recent
events, even if its not theirs. The remote should deduplicate the
events, so there shouldn't be much overhead in doing this.
Alternatively, the servers could only send local events if they were
also extremities and hope that the other server will send the event
over, but that is a bit risky.
2021-03-18 15:52:26 +00:00
Brendan Abolivier
405aeb0b2c
Implement MSC3026: busy presence state 2021-03-18 16:34:47 +01:00
Andrew Morgan
7b06f85c0e
Ensure we use a copy of the event content dict before modifying it in serialize_event (#9585)
This bug was discovered by DINUM. We were modifying `serialized_event["content"]`, which - if you've got `USE_FROZEN_DICTS` turned on or are [using a third party rules module](17cd48fe51/synapse/events/third_party_rules.py (L73-L76)) - will raise a 500 if you try to a edit a reply to a message.

`serialized_event["content"]` could be set to the edit event's content, instead of a copy of it, which is bad as we attempt to modify it. Instead, we also end up modifying the original event's content. DINUM uses a third party rules module, which meant the event's content got frozen and thus an exception was raised.

To be clear, the problem is not that the event's content was frozen. In fact doing so helped us uncover the fact we weren't copying event content correctly.
2021-03-17 16:51:55 +00:00
Patrick Cloke
cc324d53fe
Fix up types for the typing handler. (#9638)
By splitting this to two separate methods the callers know
what methods they can expect on the handler.
2021-03-17 11:30:21 -04:00
Hubert Chathi
73dbce5523
only save remote cross-signing keys if they're different from the current ones (#9634)
Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
2021-03-17 11:04:57 -04:00
Erik Johnston
ad721fc559
Fix bad naming of storage function (#9637)
We had two functions named `get_forward_extremities_for_room` and
`get_forward_extremeties_for_room` that took different paramters. We
rename one of them to avoid confusion.
2021-03-17 13:20:08 +00:00
Richard van der Hoff
567f88f835
Prep work for removing outlier from internal_metadata (#9411)
* Populate `internal_metadata.outlier` based on `events` table

Rather than relying on `outlier` being in the `internal_metadata` column,
populate it based on the `events.outlier` column.

* Move `outlier` out of InternalMetadata._dict

Ultimately, this will allow us to stop writing it to the database. For now, we
have to grandfather it back in so as to maintain compatibility with older
versions of Synapse.
2021-03-17 12:33:18 +00:00
Patrick Cloke
b449af0379
Add type hints to the room member handler. (#9631) 2021-03-17 07:14:39 -04:00
Jonathan de Jong
27d2820c33
Enable flake8-bugbear, but disable most checks. (#9499)
* Adds B00 to ignored checks.
* Fixes remaining issues.
2021-03-16 14:19:27 -04:00
Hubbe
dd5e5dc1d6
Add SSO attribute requirements for OIDC providers (#9609)
Allows limiting who can login using OIDC via the claims
made from the IdP.
2021-03-16 11:46:07 -04:00
Dirk Klimpel
8000cf1315
Return m.change_password.enabled=false if local database is disabled (#9588)
Instead of if the user does not have a password hash. This allows a SSO
user to add a password to their account, but only if the local password
database is configured.
2021-03-16 11:44:25 -04:00
Andrew Morgan
d315e96443 1.30.0rc1 2021-03-16 13:45:46 +00:00
Andrew Morgan
847ecdd8fa
Pass SSO IdP information to spam checker's registration function (#9626)
Fixes https://github.com/matrix-org/synapse/issues/9572

When a SSO user logs in for the first time, we create a local Matrix user for them. This goes through the register_user flow, which ends up triggering the spam checker. Spam checker modules don't currently have any way to differentiate between a user trying to sign up initially, versus an SSO user (whom has presumably already been approved elsewhere) trying to log in for the first time.

This PR passes `auth_provider_id` as an argument to the `check_registration_for_spam` function. This argument will contain an ID of an SSO provider (`"saml"`, `"cas"`, etc.) if one was used, else `None`.
2021-03-16 12:41:41 +00:00
Patrick Cloke
1383508f29
Handle an empty cookie as an invalid macaroon. (#9620)
* Handle an empty cookie as an invalid macaroon.

* Newsfragment
2021-03-16 11:29:35 +00:00
Richard van der Hoff
dd69110d95
Add support for stable MSC2858 API (#9617)
The stable format uses different brand identifiers, so we need to support two
identifiers for each IdP.
2021-03-16 11:21:26 +00:00
Richard van der Hoff
5b5bc188cf
Clean up config settings for stats (#9604)
... and complain if people try to turn it off.
2021-03-16 10:57:54 +00:00
Andrew Morgan
1b0eaed21f
Prevent bundling aggregations for state events (#9619)
There's no need to do aggregation bundling for state events. Doing so can cause performance issues.
2021-03-16 10:27:51 +00:00
Richard van der Hoff
1c8a2541da
Fix Internal Server Error on GET /saml2/authn_response (#9623)
* Fix Internal Server Error on `GET /saml2/authn_response`

Seems to have been introduced in #8765 (Synapse 1.24.0)

* Fix newsfile
2021-03-16 10:20:20 +00:00
Patrick Cloke
d29b71aa50
Fix remaining mypy issues due to Twisted upgrade. (#9608) 2021-03-15 11:14:39 -04:00
Erik Johnston
026503fa3b
Don't go into federation catch up mode so easily (#9561)
Federation catch up mode is very inefficient if the number of events
that the remote server has missed is small, since handling gaps can be
very expensive, c.f. #9492.

Instead of going into catch up mode whenever we see an error, we instead
do so only if we've backed off from trying the remote for more than an
hour (the assumption being that in such a case it is more than a
transient failure).
2021-03-15 14:42:40 +00:00
Richard van der Hoff
af2248f8bf
Optimise missing prev_event handling (#9601)
Background: When we receive incoming federation traffic, and notice that we are missing prev_events from 
the incoming traffic, first we do a `/get_missing_events` request, and then if we still have missing prev_events,
we set up new backwards-extremities. To do that, we need to make a `/state_ids` request to ask the remote
server for the state at those prev_events, and then we may need to then ask the remote server for any events
in that state which we don't already have, as well as the auth events for those missing state events, so that we
can auth them.

This PR attempts to optimise the processing of that state request. The `state_ids` API returns a list of the state
events, as well as a list of all the auth events for *all* of those state events. The optimisation comes from the
observation that we are currently loading all of those auth events into memory at the start of the operation, but
we almost certainly aren't going to need *all* of the auth events. Rather, we can check that we have them, and
leave the actual load into memory for later. (Ideally the federation API would tell us which auth events we're
actually going to need, but it doesn't.)

The effect of this is to reduce the number of events that I need to load for an event in Matrix HQ from about
60000 to about 22000, which means it can stay in my in-memory cache, whereas previously the sheer number
of events meant that all 60K events had to be loaded from db for each request, due to the amount of cache
churn. (NB I've already tripled the size of the cache from its default of 10K).

Unfortunately I've ended up basically C&Ping `_get_state_for_room` and `_get_events_from_store_or_dest` into
a new method, because `_get_state_for_room` is also called during backfill, which expects the auth events to be
returned, so the same tricks don't work. That said, I don't really know why that codepath is completely different
(ultimately we're doing the same thing in setting up a new backwards extremity) so I've left a TODO suggesting
that we clean it up.
2021-03-15 13:51:02 +00:00
Patrick Cloke
55da8df078
Fix additional type hints from Twisted 21.2.0. (#9591) 2021-03-12 11:37:57 -05:00
Richard van der Hoff
1e67bff833
Reject concurrent transactions (#9597)
If more transactions arrive from an origin while we're still processing the
first one, reject them.

Hopefully a quick fix to https://github.com/matrix-org/synapse/issues/9489
2021-03-12 15:14:55 +00:00
Richard van der Hoff
2b328d7e02
Improve logging when processing incoming transactions (#9596)
Put the room id in the logcontext, to make it easier to understand what's going on.
2021-03-12 15:08:03 +00:00
Richard van der Hoff
464e5da7b2
Add logging for redis connection setup (#9590) 2021-03-11 18:35:09 +00:00
Patrick Cloke
e55bd0e110
Add tests for blacklisting reactor/agent. (#9563) 2021-03-11 09:15:22 -05:00
Dirk Klimpel
70d1b6abff
Re-Activating account when local passwords are disabled (#9587)
Fixes: #8393
2021-03-11 13:52:32 +00:00
Richard van der Hoff
a7a3790066
Convert Requester to attrs (#9586)
... because namedtuples suck

Fix up a couple of other annotations to keep mypy happy.
2021-03-10 18:15:56 +00:00
Richard van der Hoff
1107214a1d
Fix the auth provider on the logins metric (#9573)
We either need to pass the auth provider over the replication api, or make sure
we report the auth provider on the worker that received the request. I've gone
with the latter.
2021-03-10 18:15:03 +00:00
Patrick Cloke
2a99cc6524
Use the chain cover index in get_auth_chain_ids. (#9576)
This uses a simplified version of get_chain_cover_difference to calculate
auth chain of events.
2021-03-10 09:57:59 -05:00
Patrick Cloke
918f6ed827
Fix a bug in the background task for purging chain cover. (#9583) 2021-03-10 08:55:52 -05:00
Patrick Cloke
dc51d8ffaf
Add a background task to purge unused chain IDs. (#9542)
This is a companion change to apply the fix in #9498 /
922788c604 to previously
purged rooms.
2021-03-09 11:22:25 -05:00
Richard van der Hoff
eaada74075
JWT OIDC secrets for Sign in with Apple (#9549)
Apple had to be special. They want a client secret which is generated from an EC key.

Fixes #9220. Also fixes #9212 while I'm here.
2021-03-09 15:03:37 +00:00
Erik Johnston
9cd18cc588
Retry 5xx errors in federation client (#9567)
Fixes #8915
2021-03-09 13:15:12 +00:00
Patrick Cloke
7fdc6cefb3
Fix additional type hints. (#9543)
Type hint fixes due to Twisted 21.2.0 adding type hints.
2021-03-09 07:41:32 -05:00
Patrick Cloke
075c16b410
Handle image transparency better when thumbnailing. (#9473)
Properly uses RGBA mode for 1- and 8-bit images with transparency
(instead of RBG mode).
2021-03-09 07:37:09 -05:00
Jonathan de Jong
9898470e7d
Add logging to ObservableDeferred callbacks (#9523) 2021-03-09 11:09:31 +00:00
Matthew Hodgson
0764d0c6e5 quick config comment tweak to clarify allow_profile_lookup_over_federation 2021-03-08 21:52:04 +00:00
Jonathan de Jong
d6196efafc
Add ResponseCache tests. (#9458) 2021-03-08 14:00:07 -05:00
Dirk Klimpel
7076eee4b9
Add type hints to purge room and server notice admin API. (#9520) 2021-03-08 10:34:38 -05:00
Erik Johnston
b988b07bb0 Merge branch 'master' into develop 2021-03-08 14:06:35 +00:00
Erik Johnston
15c788e22d 1.29.0 2021-03-08 13:52:13 +00:00
Patrick Cloke
58114f8a17
Create a SynapseReactor type which incorporates the necessary reactor interfaces. (#9528)
This helps fix some type hints when running with Twisted 21.2.0.
2021-03-08 08:25:43 -05:00
Richard van der Hoff
8a4b3738f3
Replace last_*_pdu_age metrics with timestamps (#9540)
Following the advice at
https://prometheus.io/docs/practices/instrumentation/#timestamps-not-time-since,
it's preferable to export unix timestamps, not ages.

There doesn't seem to be any particular naming convention for timestamp
metrics.
2021-03-04 16:40:18 +00:00
Richard van der Hoff
df425c2c63
Prometheus metrics for logins and registrations (#9511)
Add prom metrics for number of users successfully registering and logging in, by SSO provider.
2021-03-04 16:39:27 +00:00
Richard van der Hoff
7eb6e39a8f
Record the SSO Auth Provider in the login token (#9510)
This great big stack of commits is a a whole load of hoop-jumping to make it easier to store additional values in login tokens, and then to actually store the SSO Identity Provider in the login token. (Making use of that data will follow in a subsequent PR.)
2021-03-04 14:44:22 +00:00
Erik Johnston
3f49d80dcf 1.29.0rc1 2021-03-04 10:12:53 +00:00
Patrick Cloke
33a02f0f52
Fix additional type hints from Twisted upgrade. (#9518) 2021-03-03 15:47:38 -05:00
Richard van der Hoff
4db07f9aef
Set X-Forwarded-Proto header when frontend-proxy proxies a request (#9539)
Should fix some remaining warnings
2021-03-03 18:49:08 +00:00
Erik Johnston
a4fa044c00
Fix 'rejected_events_metadata' background update (#9537)
Turns out matrix.org has an event that has duplicate auth events (which really isn't supposed to happen, but here we are). This caused the background update to fail due to `UniqueViolation`.
2021-03-03 16:04:24 +00:00
Patrick Cloke
922788c604
Purge chain cover tables when purging events. (#9498) 2021-03-03 11:04:08 -05:00
Dirk Klimpel
d790d0d314
Add type hints to user admin API. (#9521) 2021-03-03 08:09:39 -05:00
Patrick Cloke
0c330423bc
Bump the mypy and mypy-zope versions. (#9529) 2021-03-03 07:19:19 -05:00
Erik Johnston
16f9f93eb7
Make deleting stale pushers a background update (#9536) 2021-03-03 12:08:16 +00:00
Aaron Raimist
0279e0e086
Prevent presence background jobs from running when presence is disabled (#9530)
Prevent presence background jobs from running when presence is disabled

Signed-off-by: Aaron Raimist <aaron@raim.ist>
2021-03-03 10:21:46 +00:00
Patrick Cloke
aee10768d8 Revert "Fix #8518 (sync requests being cached wrongly on timeout) (#9358)"
This reverts commit f5c93fc993.

This is being backed out due to a regression (#9507) and additional
review feedback being provided.
2021-03-02 09:43:34 -05:00
Erik Johnston
7f5d753d06
Re-run rejected metadata background update. (#9503)
It landed in schema version 58 after 59 had been created, causing some
servers to not run it. The main effect of was that not all rooms had
their chain cover calculated correctly. After the BG updates complete
the chain covers will get fixed when a new state event in the affected
rooms is received.
2021-03-02 14:31:23 +00:00
Erik Johnston
16108c579d
Fix SQL delta file taking a long time to run (#9516)
Fixes #9504
2021-03-02 14:05:01 +00:00
Dirk Klimpel
f00c4e7af0
Add type hints to device and event report admin API (#9519) 2021-03-02 09:31:12 +00:00
Patrick Cloke
ad8589d392
Fix a bug when a room alias is given to the admin join endpoint (#9506) 2021-03-01 13:59:01 -05:00
Patrick Cloke
16ec8c3272
(Hopefully) stop leaking file descriptors in media repo. (#9497)
By consuming the response if the headers imply that the
content is too large.
2021-03-01 12:45:00 -05:00
Patrick Cloke
a0bc9d387e
Use the proper Request in type hints. (#9515)
This also pins the Twisted version in the mypy job for CI until
proper type hints are fixed throughout Synapse.
2021-03-01 12:23:46 -05:00
Jonathan de Jong
e12077a78a
Allow bytecode again (#9502)
In #75, bytecode was disabled (from a bit of FUD back in `python<2.4` days, according to dev chat), I think it's safe enough to enable it again.

Added in `__pycache__/` and `.pyc`/`.pyd` to `.gitignore`, to extra-insure compiled files don't get committed.

`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
2021-02-26 18:30:54 +00:00
Tim Leung
ddb240293a
Add support for no_proxy and case insensitive env variables (#9372)
### Changes proposed in this PR

- Add support for the `no_proxy` and `NO_PROXY` environment variables
  - Internally rely on urllib's [`proxy_bypass_environment`](bdb941be42/Lib/urllib/request.py (L2519))
- Extract env variables using urllib's `getproxies`/[`getproxies_environment`](bdb941be42/Lib/urllib/request.py (L2488)) which supports lowercase + uppercase, preferring lowercase, except for `HTTP_PROXY` in a CGI environment

This does contain behaviour changes for consumers so making sure these are called out:
- `no_proxy`/`NO_PROXY` is now respected
- lowercase `https_proxy` is now allowed and taken over `HTTPS_PROXY`

Related to #9306 which also uses `ProxyAgent`

Signed-off-by: Timothy Leung tim95@hotmail.co.uk
2021-02-26 17:37:57 +00:00
Richard van der Hoff
15090de850
SSO: redirect to public URL before setting cookies (#9436)
... otherwise, we don't get the cookie back.
2021-02-26 14:02:06 +00:00
Erik Johnston
2566dc57ce
Test that we require validated email for email pushers (#9496) 2021-02-25 15:35:14 +00:00
Erik Johnston
1e62d9ee8c
Ensure pushers are deleted for deactivated accounts (#9285) 2021-02-25 13:56:55 +00:00
Erik Johnston
1efdcc3e87 Merge branch 'master' into develop 2021-02-25 10:53:31 +00:00
Erik Johnston
b5c4fe1971 1.28.0 2021-02-25 10:22:07 +00:00
Richard van der Hoff
d8e95e5452
Add support for X-Forwarded-Proto (#9472)
rewrite XForwardedForRequest to set `isSecure()` based on
`X-Forwarded-Proto`. Also implement `getClientAddress()` while we're here.
2021-02-24 18:11:33 +00:00
Erik Johnston
7cc571510b
Add SQL delta for deleting stale pushers (#9479) 2021-02-24 17:21:10 +00:00
Jonathan de Jong
f5c93fc993
Fix #8518 (sync requests being cached wrongly on timeout) (#9358)
This fixes #8518 by adding a conditional check on `SyncResult` in a function when `prev_stream_token == current_stream_token`, as a sanity check. In `CachedResponse.set.<remove>()`, the result is immediately popped from the cache if the conditional function returns "false".

This prevents the caching of a timed-out `SyncResult` (that has `next_key` as the stream key that produced that `SyncResult`). The cache is prevented from returning a `SyncResult` that makes the client request the same stream key over and over again, effectively making it stuck in a loop of requesting and getting a response immediately for as long as the cache keeps those values.

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>
2021-02-24 13:57:00 +00:00
Erik Johnston
2927921942
Clean up ShardedWorkerHandlingConfig (#9466)
* Split ShardedWorkerHandlingConfig

This is so that we have a type level understanding of when it is safe to
call `get_instance(..)` (as opposed to `should_handle(..)`).

* Remove special cases in ShardedWorkerHandlingConfig.

`ShardedWorkerHandlingConfig` tried to handle the various different ways
it was possible to configure federation senders and pushers. This led to
special cases that weren't hit during testing.

To fix this the handling of the different cases is moved from there and
`generic_worker` into the worker config class. This allows us to have
the logic in one place and allows the rest of the code to ignore the
different cases.
2021-02-24 13:23:18 +00:00
Erik Johnston
0b5c967813
Refactor to ensure we call check_consistency (#9470)
The idea here is to stop people forgetting to call `check_consistency`. Folks can still just pass in `None` to the new args in `build_sequence_generator`, but hopefully they won't.
2021-02-24 10:13:53 +00:00
Patrick Cloke
7292b7c0eb
Add back the deprecated SAML endpoint. (#9474) 2021-02-23 12:57:37 -05:00
Richard van der Hoff
713145d3de
Add a comment about systemd-python. (#9464)
This confused me for a while.
2021-02-23 13:42:36 +00:00
Patrick Cloke
65a9eb8994
Include newly added sequences in the port DB script. (#9449)
And ensure the consistency of `event_auth_chain_id`.
2021-02-23 07:33:24 -05:00
Erik Johnston
66f4949e7f
Fix deleting pushers when using sharded pushers. (#9465) 2021-02-22 21:14:42 +00:00
Richard van der Hoff
1b2d6d55c5
Remove vestiges of uploads_path config (#9462)
`uploads_path` was a thing that was never used; most of it was removed in #6628
but a few vestiges remained.
2021-02-22 19:54:49 +00:00
Dirk Klimpel
71c9f8de6d
Add an order_by field to list users' media admin API. (#8978) 2021-02-22 14:38:51 -05:00
Andrew Morgan
0a363f9ca4
Remove cache for get_shared_rooms_for_users (#9416)
This PR remove the cache for the `get_shared_rooms_for_users` storage method (the db method driving the experimental "what rooms do I share with this user?" feature: [MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)). Currently subsequent requests to the endpoint will return the same result, even if your shared rooms with that user have changed.

The cache was added in https://github.com/matrix-org/synapse/pull/7785, but we forgot to ensure it was invalidated appropriately.

Upon attempting to invalidate it, I found that the cache had to be entirely invalidated whenever a user (remote or local) joined or left a room. This didn't make for a very useful cache, especially for a function that may or may not be called very often. Thus, I've opted to remove it instead of invalidating it.
2021-02-22 16:52:45 +00:00
Andrew Morgan
e22b71810e
Clean up the user directory sample config section (#9385)
The user directory sample config section was a little messy, and didn't adhere to our [recommended config format guidelines](https://github.com/matrix-org/synapse/blob/develop/docs/code_style.md#configuration-file-format).

This PR cleans that up a bit.
2021-02-22 11:44:31 +00:00
Patrick Cloke
fc8b3d8809
Ratelimit cross-user key sharing requests. (#8957) 2021-02-19 13:20:34 -05:00
Erik Johnston
179c0953ff
Regenerate exact thumbnails if missing (#9438) 2021-02-19 17:09:57 +00:00