Make various sender side adjustments so that a sender is able to send an
MP payment to a single blinded path without actually including an MPP
record in the payment.
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 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 preparation for structs outside of the `routing` package implementing
this interface, export `routingGraph` and rename it to `Graph` so as to
avoid stuttering.
In this commit, we further reduce the routingGraph interface and this
time we make it more node-agnostic so that it can be backed by any graph
and not one with a concept of "sourceNode".
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 updates route construction to backfill the fields
required for payment to blinded paths and set amount to forward
and expiry fields to zero for intermediate hops (as is instructed
in the route blinding specification).
We could attempt to do this in the first pass, but that loop
relies on fields like amount to forward and expiry to calculate
each hop backwards, so we keep it simple (stupid) and post
processes the blinded portion, since it's computationally cheap
and more readable.
This commit was previously split into the following parts to ease
review:
- 2d746f68: replace imports
- 4008f0fd: use ecdsa.Signature
- 849e33d1: remove btcec.S256()
- b8f6ebbd: use v2 library correctly
- fa80bca9: bump go modules
This commit partially reverts bf27d05a.
To avoid creating multiple database transactions during a single path
finding operation, we create an explicit transaction when the cached
graph is instantiated.
We cache the source node to avoid needing to look that up for every path
finding session.
The database transaction will be nil in case of the in-memory graph.
This commit adds payment session to shardHandler to enable private edge
policies being updated in shardHandler. The relevant interface and mock
are updated. From now on, upon seeing a ChannelUpdate message,
shardHandler will first try to find the target policy in additionalEdges
and update it. If nothing found, it will then check the database for
edge policy to update.
This commit adds the method UpdateAdditionalEdge in PaymentSession,
which allows the addtional channel edge policy to be updated from a
ChannelUpdate message. Another method, GetAdditionalEdgePolicy is added
to allow querying additional edge policies.
With this patch, we'll fail out earlier in the cycle in case of
some wonky parameters, and not leave zombie payments in the router
which currently are not cleaned up.
Since we want to support AMP payment using a different unique payment
identifier (AMP payments don't go to one specific hash), we change the
nomenclature to be Identifier instead of PaymentHash.
In this commit, we thread through the necessary state to allow users to
set a max shard amount. If this value is set, then this'll effectively
serve as a ceiling for all our split attempts. If we need to split,
we'll first try to use `paymentAmt/2`, if that's bigger than
`MaxShardAmt, then we'll use the latter instead.
Ideally in the future we have a dynamic way to automatically set both
the `MaxShardAmt` as well as `MaxParts` for users. Until then exposing
these two new fields will allow us to experiment with setting them
automatically using the RPC interface, and also give users a bit more
control over how we attempt to route payments, akin to coin control for
on-chain payments.
Fixes#4730
This commit reverts cb4cd49dc8 to bring
back the insufficient local balance failure.
Distinguishing betweeen this failure and a regular "no route" failure
prevents meaningless htlcs from being sent out.
Modifies the payment session to launch additional pathfinding attempts
for lower amounts. If a single shot payment isn't possible, the goal is
to try to complete the payment using multiple htlcs. In previous
commits, the payment lifecycle has been prepared to deal with
partial-amount routes returned from the payment session. It will query
for additional shards if needed.
Additionally a new rpc payment parameter is added that controls the
maximum number of shards that will be used for the payment.
With mpp it isn't possible anymore for findPath to determine that there
isn't enough local bandwidth. The full payment amount isn't known at
that point.
In a follow-up, this payment outcome can be reintroduced on a higher
level (payment lifecycle).
We whitelist a set of "expected" errors that can be returned from
RequestRoute, by converting them into a new type noRouteError. For any
other error returned by RequestRoute, we'll now exit immediately.
active shards
In preparation for doing pathfinding for routes sending a value less
than the total payment amount, we let the payment session take the max
amount to send and the fee limit as arguments to RequestRoute.
This commit moves supplying of the information in the LightningPayment
to the initialization of the paymentSession, away from every call to
RequestRoute.
Instead the paymentSession will store this information internally, as it
doesn't change between payment attempts.
This is done to rid the RequestRoute call of the LightingPayment
argument, as for SendToRoute calls, it is not needed to supply the next
route.
