If cloudflared was unable to register the UDP session with the
edge, the socket would be left open to be eventually closed by the
OS, or garbage collected by the runtime. Considering that either of
these closes happened significantly after some delay, it was causing
cloudflared to hold open file descriptors longer than usual if continuously
unable to register sessions.
## Summary
To prevent bad eyeballs and severs to be able to exhaust the quic
control flows we are adding the possibility of having a timeout
for a write operation to be acknowledged. This will prevent hanging
connections from exhausting the quic control flows, creating a DDoS.
In the streambased origin proxy flow (example ssh over access), there is
a chance when we do not flush on http.ResponseWriter writes. This PR
guarantees that the response writer passed to proxy stream has a flusher
embedded after writes. This means we write much more often back to the
ResponseWriter and are not waiting. Note, this is only something we do
when proxyHTTP-ing to a StreamBasedOriginProxy because we do not want to
have situations where we are not sending information that is needed by
the other side (eyeball).
I deliberately kept this as an unregistertimeout because that was the
intent. In the future we could change this to a UDPConnConfig if we want
to pass multiple values here.
The idea of this PR is simply to add a configurable unregister UDP
timeout.
The lucas-clemente/quic-go package moved namespaces and our branch
went stale, this new fork provides support for the new quic-go repo
and applies the max datagram frame size change.
Until the max datagram frame size support gets upstreamed into quic-go,
this can be used to unblock go 1.20 support as the old
lucas-clemente/quic-go will not get go 1.20 support.
Going forward, the only protocols supported will be QUIC and HTTP2,
defaulting to QUIC for "auto". Selecting h2mux protocol will be forcibly
upgraded to http2 internally.
This changes fixes a bug where cloudflared was not propagating errors
when proxying the body of an HTTP request.
In a situation where we already sent HTTP status code, the eyeball would
see the request as sucessfully when in fact it wasn't.
To solve this, we need to guarantee that we produce HTTP RST_STREAM
frames.
This change was applied to both http2 and quic transports.
This PR changes protocol initialization of the other N connections to be
the same as the one we know the initial tunnel connected with. This is
so we homogenize connections and not lead to some connections being
QUIC-able and the others not.
There's also an improvement to the connection registered log so we know
what protocol every individual connection connected with from the
cloudflared side.
Remove send and return methods from Funnel interface. Users of Funnel can provide their own send and return methods without wrapper to comply with the interface.
Move packet router to ingress package to avoid circular dependency
A funnel is an abstraction for 1 source to many destinations.
As part of this refactoring, shared logic between Darwin and Linux are moved into icmp_posix
In a previous commit, we fixed a bug where the client roundtrip code
could close the request body, which in fact would be the quic.Stream,
thus closing the write-side.
The way that was fixed, prevented the client roundtrip code from closing
also read-side (the body).
This fixes that, by allowing close to only close the read side, which
will guarantee that any subsquent will fail with an error or EOF it
occurred before the close.
cloudflared falls back aggressively to HTTP/2 protocol if a connection
attempt with QUIC failed. This was done to ensure that machines with UDP
egress disabled did not stop clients from connecting to the cloudlfare
edge. This PR improves on that experience by having cloudflared remember
if a QUIC connection was successful which implies UDP egress works. In
this case, cloudflared does not fallback to HTTP/2 and keeps trying to
connect to the edge with QUIC.
Devin Carr
João "Pisco" Fernandes
Chung-Ting
João Oliveirinha
Sudarsan Reddy
iBug
Bas Westerbaan
Nuno Diegues