This commit adds a check during router's startup and fails the inflight
HTLCs if they are routing using channels unknown to us. The channels are
unknown because they are already closed, usually long time ago.
We shift the duty of determining the policies to the backward pass as
the forward pass will only be responsible for finding the corrected
receiver amount.
Note that this is not a pure refactor as demonstrated in the test, as
the forward pass doesn't select new policies anymore, which is less
flexible and doesn't lead to the highest possible receiver amount. This
is however neccessary as we otherwise won't be able to compute
forwarding amounts involving inbound fees and this edge case is unlikely
to occur, because we search for a min amount for a route that was most
likely constructed for a larger amount.
If multiple blinded paths are provided, they will each have a different
pub key for the destination node. This makes using our existing
pathfinding logic tricky since it depends on having a single destination
node (characterised by a single pub key). We want to re-use this logic.
So what we do is swap out the pub keys of the destinaion hop with a
pseudo target pub key. This will then be used during pathfinding. Later
on once a path is found, we will swap the real destination keys back in
so that onion creation can be done.
We split up the functionality in getRouteUnifiers into checking that all
edges exist via getEdgeUnifiers and then add a backward pass that will
be responsible for determining the sender amount.
We remove the node pub key from the error string, as in route building
this is duplicate info, which can be determined from the input keys,
further it's not available in the backward pass anymore.
We refactor the BuildRoute test to use the require library and add a
test case for a max HTLC violation on the last hop.
Add a `FindBlindedPaths` method to the `ChannelRouter` which will use
the new `findBlindedPaths` function to get a set of candidate blinded
path routes. It then uses mission control to select the best of these
paths.
Note that as of this commit, the MC data we get from these queries won't
mean much since we wont have data about a channel in the direction
towards us. But we do this now in preparation for a future PR which will
start writing mission control success pairs for successful receives from
blinded route paths.
This commit is a large refactor that moves over various responsibilities
from the ChannelRouter to the graph.Builder. These include all graph
related tasks such as:
- graph pruning
- validation of new network updates & persisting new updates
- notifying topology update clients of any changes.
This is a large commit but:
- many of the files are purely moved from `routing` to `graph`
- the business logic put in the graph Builder is copied exactly as is
from the ChannelRouter with one exception:
- The ChannelRouter just needs to be able to call the Builder's
`ApplyChannelUpdate` method. So this is now exported and provided to
the ChannelRouter as a config option.
- The trickiest part was just moving over the test code since quite a
bit had to be duplicated.
In preparation for adding a clean Graph DB interface, we create a
version of FetchLightningNode that doesnt allow a caller to provide in a
transaction.
In this commit, we completely remove the Router's dependence on a Graph
source that requires a `kvdb.RTx`. In so doing, we are more prepared for
a future where the Graph source is backed by different DB structure such
as pure SQL.
The two areas affected here are: the ChannelRouter's graph access that
it uses for pathfinding. And the SessionSource's graph access that it
uses for payments.
The ChannelRouter gets given a Graph and the SessionSource is given a
GraphSessionFactory which it can use to create a new session. Behind the
scenes, this will acquire a kvdb.RTx that will be used for calls to the
Graph's `ForEachNodeChannel` method.
In the previous commit the AdditionalEdge interface was introduced
with both of its implementations `BlindedEdge` and `PrivateEdge`.
In both cases where we append a route either by a blinded route
section or private route hints we now use these new types. In
addition the `PayloadSizeFunc` type is introduced in the
`unifiedEdge` struct. This is necessary to have the payload size
function at hand when searching for a route hence not overshooting
the max sphinx package size of 1300 bytes.
This commit makes sure a testing payment is created via
`createDummyLightningPayment` to ensure the payment hash is unique to
avoid collision of the same payment hash being used in uint tests. Since
the tests are running in parallel and accessing db, if two difference
tests are using the same payment hash, no clean test state can be
guaranteed.
The old payment lifecycle is removed due to it's not "unit" -
maintaining these tests probably takes as much work as the actual
methods being tested, if not more so. Moreover, the usage of the old
mockers in current payment lifecycle test is removed as it re-implements
other interfaces and sometimes implements it uniquely just for the
tests. This is bad as, not only we need to work on the actual interface
implementations and test them , but also re-implement them again in the
test without testing them!
This commit adds a new interface method `TerminalInfo` and changes its
implementation to return an `*HTLCAttempt` so it includes the route for
a successful payment. Method `GetFailureReason` is now removed as its
returned value can be found in the above method.
This commit adds a new struct, `stateStep`, to decide the workflow
inside `resumePayment`.
It also refactors `collectResultAsync` introducing a new channel
`resultCollected`. This channel is used to signal the payment
lifecycle that an HTLC attempt result is ready to be processed.
This commit removes the method `launchShard` and splits its original
functionality into two steps - first create the attempt, second send the
attempt. This enables us to have finer control over "which error is
returned from which system and how to handle it".
Finally, The LightningNode object is removed from ChannelEdgePolicy.
This is a step towards letting ChannelEdgePolicy reflect exactly the
schema that is on disk.
This is also nice because the `Node` object is not necessarily always
required when the ChannelEdgePolicy is loaded from the DB, so now it
only get's loaded when needed.
In preparation for the next commit which will remove the
`*LightningNode` from the `ChannelEdgePolicy` struct,
`FetchLightningNode` is modified to take in an optional transaction so
that it can be utilised in places where a transaction exists.
Add the option to include a blinded route in a route request (exclusive
to including hop hints, because it's incongruous to include both), and
express the route as a chain of hop hints.
Using a chain of hints over a single hint to represent the whole path
allows us to re-use our route construction to fill in a lot of the
path on our behalf.
This commit introduces a single struct to hold all of the parameters
that are passed to FindRoute. This cleans up an already overloaded
function signature and prepares us for handling requests with blinded
routes where we need to perform some additional processing on our
para (such as extracting the target node from the blinded path).
This commit turns `MPPayment` into an interface inside `routing`. Having
this interface gives us the benefit to write more granular unit tests
inside payment lifecycle. As seen from the modified unit tests, several
hacky ways of testing the `SendPayment` method is now replaced by a mock
over `MPPayment`.
In this commit, we update the Sig type to support ECDSA and schnorr
signatures. We need to do this as the HTLC signatures will become
schnorr sigs for taproot channels. The current spec draft opts to
overload this field since both the sigs are actually 64 bytes in length.
The only consideration with this move is that callers need to "coerce" a
sig to the proper type if they need schnorr signatures.
We make the capacity factor configurable via an lnd.conf routerrpc
apriori parameter. The capacity factor trades off increased success
probability with a reduced set of channel candidates, which may lead to
increased fees. To let users choose whether the factor is active or not,
we add a config setting where a capacity fraction of 1.0 disables the
factor. We limit the capacity fraction to values between 0.75 and 1.0.
Lower values may discard too many channels.
We use a more general `Estimator` interface for probability estimation
in missioncontrol.
The estimator is created outside of `NewMissionControl`, passed in as a
`MissionControlConfig` field, to facilitate usage of externally supplied
estimators.
* we rename the current probability estimator to be the "apriori"
probability estimator to distinguish from a different implementation
later
* the AprioriEstimator is exported to later be able to type switch
* getLocalPairProbability -> LocalPairProbabiltiy (later part of an
exported interface)
* getPairProbability -> getPairProbabiltiy (later part of an exported
interface)
This commit renames the method `GetPaymentResult` to be
`GetAttemptResult` to avoid potential confusion and to address the
one-to-many relationship between a payment and its attempts.
Add ignore condition to additional edges that connect to self. These
edges are already known and avoiding these hints protect the payment
from malformed channel ids which could lead to infinite loop.
Fixes lightningnetwork#6169.
Co-authored-by: lsunsi <lsunsi@pm.me>
yyforyongyu