5 Commits (b2ced97ac460110f9a1bf4088b27e0d5eba4f086)

Author	SHA1	Message	Date
mmsqe	f3314bb6df	rpc: add limit for batch request items and response size (#26681) ... This PR adds server-side limits for JSON-RPC batch requests. Before this change, batches were limited only by processing time. The server would pick calls from the batch and answer them until the response timeout occurred, then stop processing the remaining batch items. Here, we are adding two additional limits which can be configured: - the 'item limit': batches can have at most N items - the 'response size limit': batches can contain at most X response bytes These limits are optional in package rpc. In Geth, we set a default limit of 1000 items and 25MB response size. When a batch goes over the limit, an error response is returned to the client. However, doing this correctly isn't always possible. In JSON-RPC, only method calls with a valid `id` can be responded to. Since batches may also contain non-call messages or notifications, the best effort thing we can do to report an error with the batch itself is reporting the limit violation as an error for the first method call in the batch. If a batch is too large, but contains only notifications and responses, the error will be reported with a null `id`. The RPC client was also changed so it can deal with errors resulting from too large batches. An older client connected to the server code in this PR could get stuck until the request timeout occurred when the batch is too large. **Upgrading to a version of the RPC client containing this change is strongly recommended to avoid timeout issues.** For some weird reason, when writing the original client implementation, @fjl worked off of the assumption that responses could be distributed across batches arbitrarily. So for a batch request containing requests `[A B C]`, the server could respond with `[A B C]` but also with `[A B] [C]` or even `[A] [B] [C]` and it wouldn't make a difference to the client. So in the implementation of BatchCallContext, the client waited for all requests in the batch individually. If the server didn't respond to some of the requests in the batch, the client would eventually just time out (if a context was used). With the addition of batch limits into the server, we anticipate that people will hit this kind of error way more often. To handle this properly, the client now waits for a single response batch and expects it to contain all responses to the requests. --------- Co-authored-by: Felix Lange <fjl@twurst.com> Co-authored-by: Martin Holst Swende <martin@swende.se>	1 year ago
Nicholas	610cf02c4a	rpc: improve error codes for internal server errors (#25678) ... This changes the error code returned by the RPC server in certain situations: - handler panic: code -32603 - result marshaling error: code -32603 - attempt to subscribe via HTTP: code -32001 In all of the above cases, the server previously returned the default error code -32000. Co-authored-by: Nicholas Zhao <nicholas.zhao@gmail.com> Co-authored-by: Felix Lange <fjl@twurst.com>	2 years ago
Seungbae Yu	38e002f464	rpc: check that "version" is "2.0" in request objects (#25570) ... The JSON-RPC spec requires the "version" field to be exactly "2.0", so we should verify that. This change is not backwards-compatible with sloppy client implementations, but I decided to go ahead with it anyway because the failure will be caught via the returned error.	2 years ago
Felix Lange	5883afb3ef	rpc: fix issue with null JSON-RPC messages (#21497)	4 years ago
Felix Lange	245f3146c2	rpc: implement full bi-directional communication (#18471) ... New APIs added: client.RegisterName(namespace, service) // makes service available to server client.Notify(ctx, method, args...) // sends a notification ClientFromContext(ctx) // to get a client in handler method This is essentially a rewrite of the server-side code. JSON-RPC processing code is now the same on both server and client side. Many minor issues were fixed in the process and there is a new test suite for JSON-RPC spec compliance (and non-compliance in some cases). List of behavior changes: - Method handlers are now called with a per-request context instead of a per-connection context. The context is canceled right after the method returns. - Subscription error channels are always closed when the connection ends. There is no need to also wait on the Notifier's Closed channel to detect whether the subscription has ended. - Client now omits "params" instead of sending "params": null when there are no arguments to a call. The previous behavior was not compliant with the spec. The server still accepts "params": null. - Floating point numbers are allowed as "id". The spec doesn't allow them, but we handle request "id" as json.RawMessage and guarantee that the same number will be sent back. - Logging is improved significantly. There is now a message at DEBUG level for each RPC call served.	6 years ago