This fixes a rare issue where the client subscription forwarding loop
would attempt send on the subscription's channel after Unsubscribe has
returned, leading to a panic if the subscription channel was already
closed by the user. Example:
sub, _ := client.Subscribe(..., channel, ...)
sub.Unsubscribe()
close(channel)
The race occurred because Unsubscribe called quitWithServer to tell the
forwarding loop to stop sending on sub.channel, but did not wait for the
loop to actually come down. This is fixed by adding an additional channel
to track the shutdown, on which Unsubscribe now waits.
Fixes#22322
* rpc: remove 'exported or builtin' restriction for parameters
There is no technial reason for this restriction because package reflect
can create values of any type. Requiring parameters and return values to
be exported causes a lot of noise in package exports.
* rpc: fix staticcheck warnings
* rpc: implement websockets with github.com/gorilla/websocket
This change makes package rpc use the github.com/gorilla/websocket
package for WebSockets instead of golang.org/x/net/websocket. The new
library is more robust and supports all WebSocket features including
continuation frames.
There are new tests for two issues with the previously-used library:
- TestWebsocketClientPing checks handling of Ping frames.
- TestWebsocketLargeCall checks whether the request size limit is
applied correctly.
* rpc: raise HTTP/WebSocket request size limit to 5MB
* rpc: remove default origin for client connections
The client used to put the local hostname into the Origin header because
the server wanted an origin to accept the connection, but that's silly:
Origin is for browsers/websites. The nobody would whitelist a particular
hostname.
Now that the server doesn't need Origin anymore, don't bother setting
one for clients. Users who need an origin can use DialWebsocket to
create a client with arbitrary origin if needed.
* vendor: put golang.org/x/net/websocket back
* rpc: don't set Origin header for empty (default) origin
* rpc: add HTTP status code to handshake error
This makes it easier to debug failing connections.
* ethstats: use github.com/gorilla/websocket
* rpc: fix lint
