Hi, thanks for bringing this to my attention, i've commited my latest diff.
/Benno Daniel Lamando(d...@danopia.net) on 2019.02.28 21:09:35 -0800: > Hi all, > > I noticed that relayd doesn't support Websocket connections. > When a Websocket request is forwarded through relayd, > the handshake completes ok, but the backend never > receives further packets sent from the client. > > I found several messages in the openbsd-misc archive > mentioning websockets not working with relayd: > - https://marc.info/?l=openbsd-misc&m=152510591921674 > - https://marc.info/?l=openbsd-misc&m=152558941423236 > - https://marc.info/?l=openbsd-misc&m=153997265632162 > > After examining conversations and the relayd source I've traced > this to the fact that Websockets negotiate using the GET method. > relayd does not currently forward any request body upstream > after forwarding a GET message from the client: > > case HTTP_METHOD_GET: > cre->toread = 0; > > I found that relayd already supports bidirectional client<->server > communication when the HTTP CONNECT method is sent by > the client. Websockets are signalled slightly differently. > The client includes a 'Connection: Upgrade' header, and > the server returns an HTTP 101 response body. > There are also other websocket-specific headers but they > do not concern us as a proxy server. > > The Websocket handshake is completed by the server sending: > HTTP/1.1 101 Switching Protocols > According to RFC 2616's section on HTTP 101: > The server will switch protocols to those defined by the response's > Upgrade header field immediately after the empty line which > terminates the 101 response. > > I've attached a small patch for relayd which re-enables > client->server forwarding when an HTTP 101 is passed down. > Applying this patch over OpenBSD 6.5-beta allows relayd to > pass bidirectional websocket data, fixing my chat app :) > > PS: I???ve also tested relayd by relaying the example server from here: > https://www.websocket.org/echo.html > If you try that, note that the server is strict about the `Connection??? > request header being preserved. Otherwise it will 400. > > > Index: relay_http.c > =================================================================== > RCS file: /cvs/src/usr.sbin/relayd/relay_http.c,v > retrieving revision 1.71 > diff -u -p -r1.71 relay_http.c > --- relay_http.c 6 Aug 2018 17:31:31 -0000 1.71 > +++ relay_http.c 1 Mar 2019 04:52:26 -0000 > @@ -276,6 +276,13 @@ relay_read_http(struct bufferevent *bev, > DPRINTF("http_version %s http_rescode %s " > "http_resmesg %s", desc->http_version, > desc->http_rescode, desc->http_resmesg); > + > + /* HTTP 101 Switching Protocols */ > + if (desc->http_status == 101) { > + cre->dst->toread = TOREAD_UNLIMITED; > + cre->dst->bev->readcb = relay_read; > + } > + > goto lookup; > } else if (cre->line == 1 && cre->dir == RELAY_DIR_REQUEST) { > if ((desc->http_method = relay_httpmethod_byname(key)) >
