The tests were using a broker URL of "test.broker" (i.e., a schema-less,
host-less, relative path), and running assertions on the value of
b.url.Path. This is strange, especially in tests regarding domain
fronting, where we care about b.url.Host, not b.url.Path. This commit
changes the broker URL to "http://test.broker" and changes tests to
check b.url.Host. I also added an additional assertion for an empty
b.Host in the non-domain-fronted case.
So the assignment of proxies is based on the load. The number of clients
is ronded down to 8. Existing proxies that doesn't report the number
of clients will be distributed equaly to new proxies until they get 8
clients, that is okish as the existing proxies do have a maximum
capacity of 10.
Fixes#40048
We used a WaitGroup to prevent a call to Peers.End from melting
snowflakes while a new one is being collected. However, calls to
WaitGroup.Add are in a race with WaitGroup.Wait. To fix this, we use a
Mutex instead.
The race condition occurs because concurrent goroutines are intermixing
reads and writes of `WebRTCPeer.closed`.
Spotted when integrating Snowflake inside OONI in
https://github.com/ooni/probe-cli/pull/373.
The race condition occurs because concurrent goroutines are
intermixing reads and writes of `WebRTCPeer.lastReceive`.
Spotted when integrating Snowflake inside OONI in
https://github.com/ooni/probe-cli/pull/373.
This fixes a stats collection bug where we were converting client
addresses between a string and net.Addr using the clientAddr function
multiple times, resulting in an empty string for all addresses.
In VSCode, the staticcheck tool emits this warning:
> should call wg.Add(1) before starting the goroutine to
> avoid a race (SA2000)go-staticcheck
To avoid this warning, just move wg.Add outside.
Send the client poll request and response in a json-encoded format in
the HTTP request body rather than sending the data in HTTP headers. This
will pave the way for using domain-fronting alternatives for the
Snowflake rendezvous.
Make a stack of cleanup functions to run (as with defer), but clear the
stack before returning if no error occurs.
Uselessly pushing the stream.Close() cleanup just before clearing the
stack is an intentional safeguard, for in case additional operations are
added before the return in the future.
Fixes#40042.
Follow up to 160ae2d
Analysis by @dcf,
> I don't think the sync.Once around logMetrics is necessary anymore.
Its original purpose was to inhibit logging on later file handles of
metrics.log, if there were more than one opened. See 171c55a9 and #29734
(comment 2593039) "Making a singleton *Metrics variable causes problems
with how Convey does tests. It shouldn't be called more than once, but
for now I'm using sync.Once on the logging at least so it's explicit."
Commit ba4fe1a7 changed it so that metrics.log is opened in main, used
to create a *log.Logger, and that same instance of *log.Logger is passed
to both NewMetrics and NewBrokerContext. It's safe to share the same
*log.Logger across multiple BrokerContext.
Doesn't seem like it needs to exist outside of the metrics struct.
Also, the call to logMetrics is moved to the constructor. A metrics
instance is only created when a BrokerContext is created, which only
happens at startup. The sync of only doing that once is left for
documentation purposes, since it doesn't hurt, but also seems redundant.
Introduce a waitgroup and done channel to ensure that both the read and
write gorouting for turbotunnel connections terminate when the
connection is closed.
The default prometheus registry exports data that may be useful for
side-channel attacks. This removes all of the default metrics and makes
sure we are only reporting snowflake metrics from the broker.
This change adds a prometheus exporter for our existing snowflake broker
metrics. Current values for the metrics can be fetched by sending a GET
request to /prometheus.
Snowflake copies data between the OR connection and the KCP stream,
meaning that in most cases the copy loops will only terminate once the
OR connection times out. In this case the OR connection is already
closed and so calls to CloseRead and CloseWrite will generate errors.
