From 15e87d5b9cad85c9926bea7905d2db44820d4752 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Sat, 2 Mar 2024 19:14:34 -0500 Subject: [PATCH] MSC4010: Push rules and account data (#4010) * Clarify how m.push_rules works with account_data. * Typo fix. * Fix typo. Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> * Add info on MSC3391. * Clarify potential issues. * Clarify returned value * Fix typo. Co-authored-by: David Vo * Add information on Conduit. Co-authored-by: Alexey Rusakov * More consistent wording. --------- Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Co-authored-by: David Vo Co-authored-by: Alexey Rusakov --- proposals/4010-push-rules-and-account-data.md | 80 +++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 proposals/4010-push-rules-and-account-data.md diff --git a/proposals/4010-push-rules-and-account-data.md b/proposals/4010-push-rules-and-account-data.md new file mode 100644 index 00000000..cd59b575 --- /dev/null +++ b/proposals/4010-push-rules-and-account-data.md @@ -0,0 +1,80 @@ +# MSC4010: Push rules and account data + +Push rules have a [bespoke API](https://spec.matrix.org/v1.6/client-server-api/#push-rules-api) +which clients use to retrieve, add, modify, and remove push rules. Any modifications +made using this API are sent to all clients via a `m.push_rules` event in the +`account_data` section in the +[the next `/sync` response](https://spec.matrix.org/v1.6/client-server-api/#push-rules-events). + +The client-server API does not have any special behavior around using the +[account data APIs](https://spec.matrix.org/v1.6/client-server-api/#client-behaviour-17) +with the `m.push_rules` type leading to different behavior on different homeservers: + +* Synapse will accept the data and shadow the real push rules in `/sync`, but + *won't use the data when evaluating push rules*. +* Dendrite will return an HTTP 403 if you attempt to set `m.push_rules` via + `/account_data`. +* Conduit has no protections for special account data. It will accept `m.push_rules` via + `/account_data` *and* use those when evaluating push rules. + +The [fully read marker](https://spec.matrix.org/v1.6/client-server-api/#fully-read-markers) +operates in a similar way and +[servers must reject updating `m.fully_read` via `/account_data`](https://spec.matrix.org/v1.6/client-server-api/#server-behaviour-10). + +Note that when attempting to set `m.fully_read` via `/account_data` the following +behavior is observed: + +* Synapse will reject it with a 405 error (only for room account data). +* Dendrite will reject it with an HTTP 403 error. + +## Proposal + +To make push rules data consistent with fully read markers, the following +clarifications are offered: + +* The `m.push_rules` account data type becomes protected and cannot be set using + the `/account_data` API, similarly to `m.fully_read`. +* "Rejected" means to use the 405 error response as + [documented](https://spec.matrix.org/v1.6/client-server-api/#put_matrixclientv3useruseridaccount_datatype): + + > This `type` of account data is controlled by the server; it cannot be modified + > by clients. Errcode: `M_BAD_JSON`. +* `m.push_rules` and `m.fully_read` should be rejected for both global and room + account data. +* Reading `m.push_rules` and `m.fully_read` should be allowed (although note that + currently `m.push_rules` only makes sense for global account data and `m.fully_read` + only makes sense for room account data). The format should match what is currently + [returned via `/sync`](https://spec.matrix.org/v1.6/client-server-api/#push-rules-events). + +The above rules shall also apply when deleting account data if [MSC3391](https://github.com/matrix-org/matrix-spec-proposals/pull/3391) +is merged before this MSC. + +## Potential issues + +It is possible that a client is currently storing data in the `m.push_rules` +(or global `m.fully_read`) account data. After this change it could no longer +be updated, deleted, or retrieved. It seems unlikely that the data stored here +is done purposefully (and is likely the result of undefined behavior that this +MSC is attempting to fix). + +## Alternatives + +An alternative would be to remove the current push rules API and have clients +store all push rules in bulk. This would be subject to race conditions between +clients. + +A slight variation of the above would be to *additionally* define the `/account_data/m.push_rules` +endpoint as bulk modifying the push rules data. This could be seen as an alternative +to [MSC3934](https://github.com/matrix-org/matrix-spec-proposals/pull/3934). + +## Security considerations + +None foreseen. + +## Unstable prefix + +This is mostly clarifications and does not add any event types or new endpoints. + +## Dependencies + +N/A