We now first exchange a very minimal header, consisting of just the
name of the protocol ("weave") and the min and max version (encoded as
a byte each) we support. This leaves all other details of the
protocol, including the contents of of the handshake, open.
Peers agree to communicate using the maximum mutually supported
version. We record this in the LocalConnection, though atm nothing is
making use of that information.
We set a shorter than normal deadline (10s instead of 60s) for the
header exchange, so we detect version mismatches, garbage, or
non-responsive remotes quickly.
We reset the protocol version to '1' since this is a fresh start; old
weaves will not be able to parse the header.
Closes#871.
Instead of erroring when we receive gossip for an unknown channel, we
create a GossipChannel on the fly, with a SurrogateGossiper singleton
as the gossiper.
The SurrogateGossiper ignores unicasts and relays broadcasts and
gossip.
and take extra locks to avoid race conditions.
Also removed the sendPendingGossip() from mockChannelConnection.SendProtocolMsg(),
because waiting in flush now creates a deadlock. Tests will have to
call sendPendingGossip() explicitly if they need it.
This is how fragmentation tests used to happen:
A: conn.stackFrag = false
A->B: StartFragmentationTest
B->A: send large non-DF UDP packet
A->B: FragmentationReceived
B: conn.stackFrag = true
conn.stackFrag = true means "UDP packets sent to the other peer get
correctly fragmented and re-assembled".
Note how A clears its own stackFrag flag, but the test establishes
whether fragmentation works for B->A, and ends up setting stackFrag on
B. Not only is this weird, it also means that if A previously had
stackFrag=true, it will now start fragmenting packets until B
initiates a fragmentation test.
The new sequence is:
A: conn.stackFrag = false
A->B: send large non-DF UDP packet
B->A: FragmentationReceived
A: conn.stackFrag = true
Closes#746.
The main purpose of this is to set an upper bound on the rate at which
an attacker might execute a brute force attack on the weave password.
No need to get clever or precise here.
Closes#837.
David Wragg