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>
Here we add special handling for sending an error response when the write timeout of the
HTTP server is just about to expire. This is surprisingly difficult to get right, since is
must be ensured that all output is fully flushed in time, which needs support from
multiple levels of the RPC handler stack:
The timeout response can't use chunked transfer-encoding because there is no way to write
the final terminating chunk. net/http writes it when the topmost handler returns, but the
timeout will already be over by the time that happens. We decided to disable chunked
encoding by setting content-length explicitly.
Gzip compression must also be disabled for timeout responses because we don't know the
true content-length before compressing all output, i.e. compression would reintroduce
chunked transfer-encoding.
rpc: fix connection tracking in Server
When upgrading to mapset/v2 with generics, the set element type used in
rpc.Server had to be changed to *ServerCodec because ServerCodec is not
'comparable'. While the distinction is technically correct, we know all
possible ServerCodec types, and all of them are comparable. So just use
a map instead.
* rpc, node: refactor request validation and add jwt validation
* node, rpc: fix error message, ignore engine api in RegisterAPIs
* node: make authenticated port configurable
* eth/catalyst: enable unauthenticated version of engine api
* node: rework obtainjwtsecret (backport later)
* cmd/geth: added auth port flag
* node: happy lint, happy life
* node: refactor authenticated api
Modifies the authentication mechanism to use default values
* node: trim spaces and newline away from secret
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
This replaces the sketchy and undocumented string context keys for HTTP requests
with a defined interface. Using string keys with context is discouraged because
they may clash with keys created by other packages.
We added these keys to make connection metadata available in the signer, so this
change also updates signer/core to use the new PeerInfo API.
* rpc: improve codec abstraction
rpc.ServerCodec is an opaque interface. There was only one way to get a
codec using existing APIs: rpc.NewJSONCodec. This change exports
newCodec (as NewFuncCodec) and NewJSONCodec (as NewCodec). It also makes
all codec methods non-public to avoid showing internals in godoc.
While here, remove codec options in tests because they are not
supported anymore.
* p2p/simulations: use github.com/gorilla/websocket
This package was the last remaining user of golang.org/x/net/websocket.
Migrating to the new library wasn't straightforward because it is no
longer possible to treat WebSocket connections as a net.Conn.
* vendor: delete golang.org/x/net/websocket
* rpc: fix godoc comments and run gofmt
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.
* p2p/discover, p2p/discv5: add marshaling methods to Node
* p2p/netutil: make Netlist decodable from TOML
* common/math: encode nil HexOrDecimal256 as 0x0
* cmd/geth: add --config file flag
* cmd/geth: add missing license header
* eth: prettify Config again, fix tests
* eth: use gasprice.Config instead of duplicating its fields
* eth/gasprice: hide nil default from dumpconfig output
* cmd/geth: hide genesis block in dumpconfig output
* node: make tests compile
* console: fix tests
* cmd/geth: make TOML keys look exactly like Go struct fields
* p2p: use discovery by default
This makes the zero Config slightly more useful. It also fixes package
node tests because Node detects reuse of the datadir through the
NodeDatabase.
* cmd/geth: make ethstats URL settable through config file
* cmd/faucet: fix configuration
* cmd/geth: dedup attach tests
* eth: add comment for DefaultConfig
* eth: pass downloader.SyncMode in Config
This removes the FastSync, LightSync flags in favour of a more
general SyncMode flag.
* cmd/utils: remove jitvm flags
* cmd/utils: make mutually exclusive flag error prettier
It now reads:
Fatal: flags --dev, --testnet can't be used at the same time
* p2p: fix typo
* node: add DefaultConfig, use it for geth
* mobile: add missing NoDiscovery option
* cmd/utils: drop MakeNode
This exposed a couple of places that needed to be updated to use
node.DefaultConfig.
* node: fix typo
* eth: make fast sync the default mode
* cmd/utils: remove IPCApiFlag (unused)
* node: remove default IPC path
Set it in the frontends instead.
* cmd/geth: add --syncmode
* cmd/utils: make --ipcdisable and --ipcpath mutually exclusive
* cmd/utils: don't enable WS, HTTP when setting addr
* cmd/utils: fix --identity
There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.
This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.
If a batch request contained an invalid method, the server would reply
with a non-batch error response. Fix this by tracking an error for each
batch element.
The server delayed closing of connections for 3s when stopping. This was
supposed to allow for slow handlers, but it didn't really work. When
geth quits, it will just exit immediately after quitting the server.
Removing the timer makes testing easier because all connections will be
closed after Stop returns.
Context keys must have a unique type in order to prevent
any unintented clashes. The code used int(1) as key.
Fix it by implementing the pattern recommended by package context.
