404 not found for WS connection on windows server

[Gdocal]

Hi, I can't do any RPC request to my node via WS. On an attempt to connect to it I got an error 404 not found. This issue occurs with the latest geth v1.9.20 on dedicated Server. At home, I have version 1.9.18 and it works fine with my code. I tried to connect to it locally and from home- the same issue. Node works fine via HTTP connection. I tried to change the port to other value, it didn't help.

My file of configuration:

[Node]
DataDir = "C:\\Eth Nodes\\Geth"
IPCPath = "geth.ipc"
HTTPHost = "0.0.0.0"
HTTPPort = 8081
HTTPVirtualHosts = ["localhost"]
HTTPModules = ["web3", "eth", "net", "db", "txpool", "admin"]
WSHost = "0.0.0.0"
WSOrigins = ["*"]
WSPort = 10000
WSModules = ["web3", "eth", "net", "db", "txpool", "admin"]
GraphQLVirtualHosts = ["localhost"]

System information

Geth version: v1.9.20
OS & Version: Windows Server 2019 Standart

Expected behaviour

ws connection should work

Actual behaviour

ws connection crashed with 404 error

UPD1:
I use c# library Nethereum, version 3.8.0 to communicate with geth

UPD2:
I think the issue is Connection header

Nethereum request looks like:

GET http://127.0.0.1:8888/ HTTP/1.1
Connection: Upgrade,Keep-Alive
Upgrade: websocket
Sec-WebSocket-Key: K+ysZX+D3PT+zeo6zzE4ig==
Sec-WebSocket-Version: 13
Host: 127.0.0.1:8888

go-ethereum/node/rpcstack.go

Line 316 in c0c0161

strings.ToLower(r.Header.Get("Connection")) == "upgrade"

here code expects only one value

Nethereum can't modify the Connection header.

[Gdocal]

the line should be replaced to
strings.Contains(strings.ToLower(r.Header.Get("Connection")), "upgrade")
fixed issue for me

[adamschmideg]

@Gdocal would you open a PR for this? So it will fix it for others, too ;)

[BisonAl]

This is happening for me as well - though on linux.

Connecting to websocket worked with no issues on 1.9.13, but since upgrading tn 1.9.20 I'm also getting 404's back on requests like geth attach.

No nevermind actually, fell victim to #21441 - hadn't realized the websocket path was changed, there were no mentions in the release note :/