In order to be able to properly restart switch several times we should
have the sequential process of channel link stop. In other words if we
stopped the switch we should be sure that all channel links have been
stopped too. Addition of the goroutine during the force close was added
because of the deadlock:
Trace:
1. link:force_close_notification
2. link:wipe_channel
3. peer:switch_remove_link
4. switch:stop_link
5. link:wait <-- deadlock
This commit modifies the errors that we return within the
handleLocalDispatch method. Rather than returning a regular error, or
simply the matching error code in some instances, we now _always_
return an instance of ForwardingError. This will allow the router to
make more intelligent decisions w.r.t routing HTLC’s as with this
information it will now be able to differentiate errors that occur
within the switch (before sending out the HTLC), from errors that occur
within the HTLC route itself.
This commit adds a new field to the switch’s Config, namely the public
key of the backing lightning node. This field will soon be used to
return more detailed errors messages back to the ChannelRouter itself.
This commit renames the Deobfuscator interface to ErrorDecrypter and
the Obfuscator interface to ErrorEncrypter. With this rename, the
purpose of these two interfaces are a bit clearer.
Additionally, DecryptError (which was formerly Deobfuscate) now
directly returns an ForwardingError type instead of the
lnwire.FailureMessage.
This commit modifies the error we return to the end user in the case of
an insufficient link capacity error when handling a local payment
dispatch. Previously we would return a
lnwire.CodeTemporaryChannelFailure, however, this isn’t necessary as
this is a local payment attempt and we don’t give up any sensitive
information by returning the best available bandwidth, and what we need
to complete the payment.
This commit fixes a bug related to swallowing an error that should go
to the switch in the case of an insufficient balance error when
attempting to add a new HTLC to the channel state machine. In this
case, an error would never be returned back to the client/switch, and
the internal processing within the channelLink would loop forever,
attempting to add an HTLC that can’t be added due to insufficient
balance to state machine itself.
We fix this issue by only treating the lnwallet.ErrMaxHTLCNumber as the
only error that prompts adding an HTLC to the overflow queue rather
than sending the error directly back to the switch.
This commit adds a new method to the HtlcSwitch:
UpdateForwardingPolicies. With this method callers are now able to
modify the forwarding policies of all, or some currently active links.
We also make a slight modification to the way that forwarding policy
updates are handled within the links themselves to ensure that we don’t
override with a zero value for any of the fields.
This commit modifies how the htlcswitch handles close requests.
Previously it could be the case that a new channel was added, but at
the same time a channel was requested to be closed. This would result
in a circular waiting dependency: the peer contacts the switch, who
tries to contact the peer.
We eliminate this possibility by ensuring that the switch handles all
close requests asynchronously. With this, the switch won't block
indefinitely in the scenario described above.
In previous commits we have intoduced the onion errors. Some of this
errors include lnwire.ChannelUpdate message. In order to change
topology accordingly to the received error, from nodes where failure
have occured, we have to propogate the update to the router subsystem.
Within the network, it's important that when an HTLC forwarding failure
occurs, the recipient is notified in a timely manner in order to ensure
that errors are graceful and not unknown. For that reason with
accordance to BOLT №4 onion failure obfuscation have been added.
This commit fixes a regression introduce in the prior commit which
added full verification of the per-hop payloads to the ChannelLink
interface. When this was initially implemented, the added checks
weren’t guarded on the existence of debughtlc’s. As a result,
debughtlc’s would be rejected as they don’t match the expected invoice
value.
This commit fixes that issue by only checking the hop payload if debug
HTLC mode isn’t on.
This commit fixes some issues in the display of the stats logger which
resulted in: stats being printed even though no forwarding activity
took place, and underflow of integers resulting in weird outputs when
forwarding.
This commit also adds some additional comments and renames the main
forwarding goroutine to its former name.
This commit gives the start for making the htlc manager and htlc switch
testable. The testability of htlc switch have been achieved by mocking
all external subsystems. The concrete list of updates:
1. create standalone package for htlc switch.
2. add "ChannelLink" interface, which represent the previous htlc link.
3. add "Peer" interface, which represent the remote node inside our
subsystem.
4. add htlc switch config to htlc switch susbystem, which stores the
handlers which are not elongs to any of the above interfaces.
With this commit we are able test htlc switch even without having
the concrete implementation of Peer, ChannelLink structures, they will
be added later.
