This commit fixes the heuristic we use for identifying the party
that broadcast a Simple Taproot Channel commitment transaction.
Prior to this change we checked if the last script element was an
OP_DROP. However, both the local and remote commitment outputs
have an OP_DROP at the end.
The new approach checks the resolver's SignDescriptor and compares
that key to the keys in the channel's local ChannelConfig. If the
key is the delay key, we know that it is our commitment transaction.
This commit fixes an issue where we did not properly detect and
therefore record the coop close transaction if it used the newer
RBF coop close v2 scheme. This only affects coop closes of
taproot channels today.
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.
This is preparation for an upcoming commit that will move over various
responsibilities from the ChannelRouter to the graph Builder. So that
that commit can be a pure code-move commit, the template for the new
sub-system is added up front here.
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 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".
Only include the final hop's cltv delta in the total timelock
calculation if the route does not include a blinded path. This is
because in a blinded path, the final hops final cltv delta will be
included in the blinded path's accumlated cltv delta value.
With this commit, we remove the responsibility of remembering not to set
the `finalHop.cltvDelta` from the caller of `newRoute`. The relevant
test is updated accordingly.
This commit adds a blinded_paths field to the PayReq proto message. A
new helper called `CreateRPCBlindedPayments` is then added to convert
the zpay32 type to the existing `lnrpc.BlindedPaymentPath` type and add
this to the `PayReq` in the `DecodePayReq` rpc method.
When we start creating blinded paths to ourselves, we will want to be
able to pad the data for each hop so that the `encrypted_recipient_data`
for each hop is the same. We add a `PadBy` method that allows a caller
to add a certain number of bytes to the padding field. Note that adding
n bytes won't always mean that the encoded payload will increase by size
n since there will be overhead for the type and lenght fields for the new
TLV field. This will also be the case when the number of bytes added
results in a BigSize bucket jump for TLV length field. The
responsibility of ensuring that the final payloads are the same size is
left to the caller who may need to call PadBy iteratively to achieve the
goal. I decided to leave this to the caller since doing this at the
actual TLV level will be quite intrusive & I think it is uneccessary to
touch that code for this unique use case.
Add the PathID (tlv type 6) field to BlindedRouteData. This will be used
for the final hop of a blinded route. A new constructor is also added
for BlindedRouteData which can specifically be used for the final hop.
For the final hop in a blinded route, the SCID and RelayInfo fields will
_not_ be set. So these fields need to be converted to optional records.
The existing BlindedRouteData constructor is also renamed to
`NewNonFinalBlindedRouteData` in preparation for a
`NewFinalBlindedRouteData` constructor which will be used to construct
the blinded data for the final hop which will contain a much smaller set
of data. The SCID and RelayInfo parameters of the constructor are left
as non-pointers in order to force the caller to set them in the case
that the constructor is called for non-final nodes. The other option
would be to create a single constructor where all parameters are
optional but I think this makes it easier for the caller to make a
mistake.
Later on in this series, we will need to know during path finding if an
edge we are traversing was derived from a blinded payment path. In
preparation for that, we add a BlindedPayment member to the
`unifiedEdge` struct.
The reason we will need this later on is because: In the case where we
receive multiple blinded paths from the receipient, we will first swap
out the final hop node of each path with a single unified target node so
that path finding can work as normal. Once we have selected a route
though, we will want to know which path an edge belongs to so that we
can swap the correct destination node back in.
Add a constructor for unified edge. In upcoming commits, we will add a
new member to unifiedEdge and a constructor forces us to not forget to
populate a required member.
Expand the AdditionalEdges interface with a BlindedPayment method. In
upcoming commits, we will want to know if an AdditionalEdge was derived
from a blinded payment or not and we will also need some information
from the blinded payment it was derived from. So we expand the interface
here to avoid needing to do type casts later on. The new method may
return nil if the edge was not derived from a blinded payment.
