Return an error if the connection was already closed. On the first
close, return an error if any of the calls inside Close() returned an
error in this order:
- smux.Stream.Close()
- pconn.Close()
- smux.Session.Close()
This commmit changes the command-line and Bridge line arguments to take
a comma-separated list of front domains. The change is backwards
compatible with old Bridge and ClientTransportPlugin lines. At
rendezvous time, a front domain will be randomly chosen from the list.
A follow-up wants to pass in a new property from the ClientConfig but it
would be an API breaking change to NewBrokerChannel.
However, it's unclear why NewBrokerChannel is exported at all. No other
package in the repo depends on it and the known users of the library
probably wouldn't be construct them.
While this patch was being reviewed, a new constructor was added,
NewBrokerChannelWithUTLSSettings, with effectively the same issue.
Both of those exported ones are deleted here.
This should increase the maximum amount of inflight data and hopefully
the performance of Snowflake, especially for clients geographically
distant from proxies and the server.
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.
Run the snowflake collection ReconnectTimeout timer in parallel to the
negotiation with the broker. This way, if the broker takes a long time
to respond the client doesn't have to wait the full timeout to respond.
Each SOCKS connection has its own set of snowflakes and broker poll
loop. Since the session manager was tied to a single set of snowflakes,
this resulted in a bug where RedialPacketConn would sometimes try to
pull snowflakes from a previously melted pool. The fix is to maintain
separate smux sessions for each SOCKS connection, tied to its own
snowflake pool.
This fixes a race condition in which snowflakes.End() is called while
snowflakes.Collect() is in progress resulting in a write to a closed
channel. We now wait for all in-progress collections to finish and add
an extra check before proceeding with a collection.
Bug #21314: maintains a separate snowflake connect loop per SOCKS
connection. This way, if Tor decides to stop using Snowflake, Snowflake
will stop using the client's network.
