It's possible for our peer to publish a commitment tx that has already
updated our balance for an htlc before we've completed removing it from
our commitment tx (aka before we've updated our balance). This used to
crash, now we just update our balance (and the channel balance logs!)
and keep going.
If they've removed anything from our balance, we'll end up counting it
as chain_fees below. Not ideal but fine... probably.
This moves the notification for our coin spends from when it's
successfully submited to the mempool to when they're confirmed in a
block.
We also add an 'informational' notice tagged as `spend_track` which
can be used to track which transaction a wallet output was spent in.
Previously we were annotating every movement with the blockheight of
lightningd at notification time. Which is lossy in terms of info, and
won't be helpful for reorg reconciliation. Here we switch over to
logging chain moves iff they've been confirmed.
Next PR will fix this up for withdrawals, which are currently tagged
with a blockheight of zero, since we log on successful send.
On node start we replay onchaind's transactions from the database/from
our loaded htlc table. To keep things tidy, we shouldn't notify the
ledger about these, so we wrap pretty much everything in a flag that
tells us whether or not this is a replay.
There's a very small corner case where dust transactions will get missed
if the node crashes after the htlc has been added to the database but
before we've successfully notified onchaind about it.
Notably, most of the obtrusive updates to onchaind wrappings are due to
the fact that we record dust (ignored outputs) before we receive
confirmation of its confirmation.
Mostly we update existing tests to account for channel balances. In a
few places, new tests were needed as there wasn't an existing pathway
that tested the chain-fees for a few penalty cases
We record htlcs when they're fulfilled as 'withdrawals' that are
onchain. This should make use of the payment_hash that we stashed.
Additionally, if an htlc spend comes through that's not ours, it's
probably them resolving our attempted cheat; we should allow it to
proceed without bombing, and just do our accounting as necessary. It'll
all come out in the wash.
For cheats, we do a little bit of weird accounting. First we 'update'
our on-ledger balance to be the entirety of the channel's balance. Then,
as outputs get resolved, we record the fees and outputs as withdrawals
from this amount.
It's possible that they might successfully 'cheat', in which case we
record those as 'penalty' but debits (not credits).
Ignored outputs don't end up in the same 'resolved' pathway as other
tracked outputs do, so we mark them as moved when proposed/broadcast
instead of when resolved (since they'll never flow through as resolved)
These are incoming from onchaind, so the result of any transactions
we've created or outputs we own as a result of a channel closure. These
go into the 'wallet' account.
onchaind is the only daemon that emits coin events, and those are all
onchain (ha!), so the only 'wire' facility we need for coin moves are
for the 'chain' type.
Transactions that we 'get' from bitciond don't have the input values
available on the transaction; for these cases we'll sum up the inputs
amounts using a different data source than the transaction's
`input_amounts`. So we need to expose it here.
HTLCs trigger a coin movement only when their final form (state) is
reached. This prevents us from needing to concern ourselves with
retries, as well as being the absolutely most correct in terms of
answering the question 'when has the money irrevocably changed hands'.
All coin movements should pass this bar, for ultimate accounting
correctness
Adds a new plugin notification for getting information about coin
movements. Also includes two 'helper' notification methods that can be
called from within lightningd. Separated from the 'common' set because
the lightningd struct is required to finalize the blockheight etc
Changelog-Added: Plugins: new notification type 'coin_movement'
The current plan for coin movements involves tagging
origination/destination htlc's with a separate tag from 'routed' htlcs
(which pass through our node). In order to do this, we need a persistent flag on
incoming htlcs as to whether or not we are the final destination.
secp256k1 Python library is not maintained anymore and coincurve was
already used in the `wire` module.
Changelog-None
Signed-off-by: Michal Rostecki <mrostecki@mailfence.com>
1. Use status_debug() instead of status_unusual() for when we can't make a
penalty tx (this happens easily the time if we fund a channel).
2. Use status_failed() (which exits) instead of status_broken() (which doesn't!)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
lisa neigut
Michal Rostecki
Rusty Russell
Christian Decker