When a registration response from cloudflared gets lost on it's way back to the edge, the edge service will retry and send another registration request. Since cloudflared already has bound the local UDP socket for the provided request id, we want to re-send the registration response.
There are three types of retries that the edge will send:
1. A retry from the same QUIC connection index; cloudflared will just respond back with a registration response and reset the idle timer for the session.
2. A retry from a different QUIC connection index; cloudflared will need to migrate the current session connection to this new QUIC connection and reset the idle timer for the session.
3. A retry to a different cloudflared connector; cloudflared will eventually time the session out since no further packets will arrive to the session at the original connector.
Closes TUN-8709
The current supervisor serves the quic connection by performing all of the following in one method:
1. Dial QUIC edge connection
2. Initialize datagram muxer for UDP sessions and ICMP
3. Wrap all together in a single struct to serve the process loops
In an effort to better support modularity, each of these steps were broken out into their own separate methods that the supervisor will compose together to create the TunnelConnection and run its `Serve` method.
This also provides us with the capability to better interchange the functionality supported by the datagram session manager in the future with a new mechanism.
Closes TUN-8661
For macOS, we want to set the DF bit for the UDP packets used by the QUIC
connection; to achieve this, you need to explicitly set the network
to either "udp4" or "udp6". When determining which network type to pick
we need to use the edge IP address chosen to align with what the local
IP family interface we will use. This means we want cloudflared to bind
to local interfaces for a random port, so we provide a zero IP and 0 port
number (ex. 0.0.0.0:0). However, instead of providing the zero IP, we
can leave the value as nil and let the kernel decide which interface and
pick a random port as defined by the target edge IP family.
This was previously broken for IPv6-only edge connectivity on macOS and
all other operating systems should be unaffected because the network type
was left as default "udp" which will rely on the provided local or remote
IP for selection.
Closes TUN-8688
Some more legacy h2mux code to be cleaned up and moved out of the way.
The h2mux.Header used in the serialization for http2 proxied headers is moved to connection module. Additionally, the booleanfuse structure is also moved to supervisor as it is also needed. Both of these structures could be evaluated later for removal/updates, however, the intent of the proposed changes here is to remove the dependencies on the h2mux code and removal.
Approved-by: Chung-Ting Huang <chungting@cloudflare.com>
Approved-by: Luis Neto <lneto@cloudflare.com>
Approved-by: Gonçalo Garcia <ggarcia@cloudflare.com>
MR: https://gitlab.cfdata.org/cloudflare/tun/cloudflared/-/merge_requests/1576
Whenever cloudflared receives a SIGTERM or SIGINT it goes into graceful shutdown mode, which unregisters the connection and closes the control stream. Unregistering makes it so we no longer receive any new requests and makes the edge close the connection, allowing in-flight requests to finish (within a 3 minute period).
This was working fine for http2 connections, but the quic proxy was cancelling the context as soon as the controls stream ended, forcing the process to stop immediately.
This commit changes the behavior so that we wait the full grace period before cancelling the request
Revert "TUN-8621: Fix cloudflared version in change notes."
Revert "PPIP-2310: Update quick tunnel disclaimer"
Revert "TUN-8621: Prevent QUIC connection from closing before grace period after unregistering"
Revert "TUN-8484: Print response when QuickTunnel can't be unmarshalled"
Revert "TUN-8592: Use metadata from the edge to determine if request body is empty for QUIC transport"
Whenever cloudflared receives a SIGTERM or SIGINT it goes into graceful shutdown mode, which unregisters the connection and closes the control stream. Unregistering makes it so we no longer receive any new requests and makes the edge close the connection, allowing in-flight requests to finish (within a 3 minute period).
This was working fine for http2 connections, but the quic proxy was cancelling the context as soon as the controls stream ended, forcing the process to stop immediately.
This commit changes the behavior so that we wait the full grace period before cancelling the request
Since legacy tunnels have been removed for a while now, we can remove
many of the capnp rpc interfaces that are no longer leveraged by the
legacy tunnel registration and authentication mechanisms.
A clock structure was used to help support unit testing timetravel
but it is a globally shared object and is likely unsafe to share
across tests. Reordering of the tests seemed to have intermittent
failures for the TestWaitForBackoffFallback specifically on windows
builds.
Adjusting this to be a shim inside the BackoffHandler struct should
resolve shared object overrides in unit testing.
Additionally, added the reset retries functionality to be inline with
the ResetNow function of the BackoffHandler to align better with
expected functionality of the method.
Removes unused reconnectCredentialManager.
Combines the tunnelrpc and quic/schema capnp files into the same module.
To help reduce future issues with capnp id generation, capnpids are
provided in the capnp files from the existing capnp struct ids generated
in the go files.
Reduces the overall interface of the Capnp methods to the rest of
the code by providing an interface that will handle the quic protocol
selection.
Introduces a new `rpc-timeout` config that will allow all of the
SessionManager and ConfigurationManager RPC requests to have a timeout.
The timeout for these values is set to 5 seconds as non of these operations
for the managers should take a long time to complete.
Removed the RPC-specific logger as it never provided good debugging value
as the RPC method names were not visible in the logs.
## 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.
This commit implements the option to disable PTMU discovery for QUIC
connections.
QUIC finds the PMTU during startup by increasing Ping packet frames
until Ping responses are not received anymore, and it seems to stick
with that PMTU forever.
This is no problem if the PTMU doesn't change over time, but if it does
it may case packet drops.
We add this hidden flag for debugging purposes in such situations as a
quick way to validate if problems that are being seen can be solved by
reducing the packet size to the edge.
Note however, that this option may impact UDP proxying since we expect
being able to send UDP packets of 1280 bytes over QUIC.
So, this option should not be used when tunnel is being used for UDP
proxying.
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 PR does two things:
It changes how we fallback to a lower protocol: The current state
is to try connecting with a protocol. If it fails, fall back to a
lower protocol. And try connecting with that and so on. With this PR,
if we fail to connect with a protocol, we will try to connect to other
edge addresses first. Only if we fail to connect to those will we
fall back to a lower protocol.
It fixes a behaviour where if we fail to connect to an edge addr,
we keep re-trying the same address over and over again.
This PR now switches between edge addresses on subsequent connecton attempts.
Note that through these switches, it still respects the backoff time.
(We are connecting to a different edge, but this helps to not bombard an edge
address with connect requests if a particular edge addresses stops working).
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
printing `seconds` is superfluous since time.Duration already adds the `s` suffix
Invalid log message would be
```
Retrying connection in up to 1s seconds
```
Co-authored-by: João Oliveirinha <joliveirinha@cloudflare.com>
Previously allowing the reconnect signal forcibly close the connection
caused a race condition on which error was returned by the errgroup
in the tunnel connection. Allowing the signal to return and provide
a context cancel to the connection provides a safer shutdown of the
tunnel for this test-only scenario.
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
GoncaloGarcia
chungthuang
João "Pisco" Fernandes
João Oliveirinha
Sudarsan Reddy
iBug
Robin Brämer
Bas Westerbaan
Nuno Diegues