In this commit, we update the hop hint selection to account for the fact
that with MPP, a single payment may consume multiple channels. As is, if
a user only has two 0.5 BTC channels, and tries to make a 1 BTC channel,
then the current logic won't include any hop hints.
To solve this, we first add all the channels which in isolation can
carry the payment in question. We then do another pass that accumulates
channels until either we reach our hop-hint limit, or the total
bandwidth that we've accumulate is greater than 2x the payment amount.
This commit clamps all user-chosen CLTVs in LND to be at least 18, which
is the new conservative value used in the sepc. This minimum is applied
uniformly to forwarding CLTV deltas (via channel updates) as well as
final CLTV deltas for new invoices.
Previously it wasn't possible to store a preimage in the invoice
database and signal that a payment should not be settled right away. The
only way to hold a payment was to insert the magic UnknownPreimage value
in the invoice database. This commit introduces a distinct flag to
signal that an invoice is a hold invoice and thereby allows the preimage
to be present in the database already.
Preparation for (key send) hodl invoices for which we already know the
preimage.
In this commit, we move to clamp down somewhat on the max invoice size
after the limit was removed as part of the mpp changes. In #4210, it was
reported that a value of -1, would underflow and end up as 18 million
BTC, which would trip checks w.r.t the max expressible value in mSAT.
In this commit, we clamp things down to 100k BTC, which should be more
than enough for anybody.
Fixes#4210.
In this commit, we remove the restriction surrounding the largest
invoices that we'll allow a user to create. After #3967 has landed,
users will be able to send in _aggregate_ a payment larger than the
current max HTLC size limit in the network. As a result, we can just
treat that value as the system's MTU, and allow users to request
payments it multiples of that MTU value.
A follow up to this PR at a later time will also allow wumbo _channels_.
However, that requires us to tweak the way we scale CSV values, as post
wumbo, there is no true channel size limit, only the
_local_ limit of a given node. We also need to implement a way for nodes
to signal to other nodes their accepted max channel size.
This commit modifies Lighting.AddInvoice and InvoicesRPC.AddHoldInvoice
to include the node's supported feature bits on the invoice. For now
this only includes the optional TLV Onion Payload bit.
This commit restructures an invoice's ContractTerms to better encompass
the restrictions placed on settling. For instance, the final ctlv delta
and invoice expiry are moved from the main invoice body (where
additional metadata is stored). Additionally, it moves the State field
outside of the terms since it is rather metadata about the invoice
instead of any terms offered to the sender in the payment request.
This commit adds a set of htlcs to the Invoice struct and
serializes/deserializes this set to/from disk. It is a preparation for
accurate invoice accounting across restarts of lnd.
A migration is added for the invoice htlcs.
In addition to these changes, separate final cltv delta and expiry
invoice fields are created and populated. Previously it was required
to decode this from the stored payment request. The reason to create
a combined commit is to prevent multiple migrations.
