Websocket client and server configuration issue

[FrozenK 0]

Hello,

I'm trying to configure the most simple websocket client (with TSslWebSocketCli) and server (with TSslHttpAppSrv) in order to get them communicate with each other locally.
Worth noting that I'm a beginner in the internet communication protocol world, this is why I'm trying to get the minimum working and then I will build from that.
I'm using the ICS 9.0 C++ package, I believe I have a configuration problem more than a C++ problem.

For the client part, I configured the following (no TLS for now) :

client->SocketFamily = sfAnyIPv4;
client->DebugLevel = DebugHdr;
client->CertVerMethod = CertVerNone;
client->SslCliSecurity = sslCliSecDefault;
client->URL = "ws://127.0.0.1/";
client->WSPingSecs = 10;

event handlers to get something printed in the terminal :

client->OnHttpRestProg = HttpRestProg;
client->OnWSFrameRcvd = FrameRcvd;
client->OnWSConnected = Connected;
client->OnWSDisconnected = Disconnected;

For the server part, based on the Delphi samples OverbyteIcsBasicWebServer1.pas and OverbyteIcsSslMultiWebServ.pas, I configured :

server->AuthRealm = "ics";
server->SocketErrs = wsErrFriendly;
server->ExclusiveAddr = true;
server->SessionTimeout = 300;
server->MaxSessions = 100;
server->OnDisplay = Display;
server->SslEnable = false;
server->SslCliCertMethod = sslCliCertNone;
server->SslCertAutoOrder = false;
server->CertExpireDays = 30;
server->OcspSrvStapling = false;
server->AddGetAllowedPath("/", afBeginBy, "WEB-APP");

server->OnClientConnect = ClientConnect;

I added an host :

server->IcsHosts->Clear();
TIcsHost *host = new TIcsHost(server->IcsHosts);
host->HostEnabled = true;
host->HostNames->Text = "localhost";    
host->HostTag = "WEB-APP";                
host->Descr = "WebApp Server";
host->BindIpAddr = "127.0.0.1";
host->BindNonPort = 80;
host->BindSslPort = 0;                     
host->WebDefDoc = "index.html";             
host->WebDocDir = dir + "data"; 

When the client is connecting (TSslWebSocketCli.WSConnect), OnClientConnect is triggered server side, then :

THttpWSSrvConn *conn = (THttpWSSrvConn *)Client;
conn->WSessionCookie = "OverbyteIcsWebAppServer" + server->Port;
conn->OnWSLogEvent = ClientLogEvent;
conn->OnWSHandshake = ClientHandShake;
conn->OnWSDisconnected = ClientDisconnected;
conn->OnWSFrameRcvd = ClientFrameRcvd;
conn->OnWSFrameSent = ClientFrameSent;
conn->OnWSReady = ClientReady;
conn->OnWSPingTimer = ClientPingTimer;
conn->OnBgException = ClientBgException;

Then the server handle the request (these are called : THttpConnection::ProcessRequest(), ::ProcessGet(), ::ProcessGetHeadDel(), ::SendDocument()...) and returns an "HTTP/1.1 200 OK" response to the client. From TSslWebSocketCli.WSConnect I get "WebSocket: Failed to Connect:" but the LastResponse string is empty. It looks like the server treats my websocket upgrade request as a "classic" request, so it returns an "HTTP/1.1 200 OK" response instead of the expected "HTTP/1.1 101 Switching Protocols". To make sure my client part was ok, I quickly tried it on a node.js websocket server, no problem, I get the "101 Switching Protocols" response and the websocket connection is established.

If I do not use TSslWebSocketCli.WSConnect but do a "manual" GET with an upgrade request header and on server side add an url handler (TUrlHandlerIndexHtml) and send a response header through AnswerStream, the connection is established. But if I send frames from the client, OnWSFrameRcvd is not triggred server side (as expected I believe since server has no clue I handled the upgrade "myself").

Hopefully this post makes sense, in short, I don't understand why my upgrade request on url: "ws://127.0.0.1/" fails on the ICS server, any help would be appreciated.

Thanks in advance.

Edited December 20, 2024 by FrozenK

[Angus Robertson 590]

I'd first make the general comment that it is always best to develop and test the two parts of client/server applications separately, against known working versions. 

 

In this case, with the ICS OverbyteIcsSslMultiWebServ and OverbyteIcsHttpRestTst samples.  Don't know if C++ allows you to build them, but the wiki site allows you to download prebuilt executable files.

 

Your settings are missing a websocket path or page, just ws://127.0.0.1/ so you are assuming the web server default HTML page is actually a Websocket request, this was never testing with the ICS web server, perhaps my fault for not expecting anyone to try that.  Since you set default page to index.html, I assume that is the websocket URL you are checking for, but you don;t show any of that code.

 

I find it best to use a virtual path /websocket/ to clarify that such requests from HTML.

 

Angus

 

[FrozenK 0]

Thanks a lot for your help Angus. After I modified the path and also specified "THttpWSSrvConn" as the "server->ClientClass" (whichi I missed), it is now working fine.
Happy Holiday season.