It appears the local signatures which are specified in the channel
transaction-generation tests were never checked directly (though
they were checked as a part of the overall fully-signed-transaction
tests).
Check them explicitly so that they can be updated for static remote
key.
Features for a given context are duplicated throughout the features
module. Use a macro for defining a Context and the applicable features
such that features only need to be defined for a Context in one place.
The Context provides bitmasks for selecting known and unknown feature
flags.
BOLT 1 and BOLT 9 refer to features as "known" if a peer understands
them. They also use the term "supported" to mean either optional or
required.
Update the features module to use similar terminology.
- Define contexts in terms of required and optional features rather than
just supported features
- Define known features as those that are optional or required
- Rename supported() constructor to known()
For completeness, clear_optional_bit for each feature is now called
clear_bits and clears both optional and required bits.
Instead of adding signatures to LocalCommitmentTransactions, we
instead leave them unsigned and use them to construct signed
Transactions when we want them. This cleans up the guts of
LocalCommitmentTransaction enough that we can, and do, expose its
state to the world, allowing external signers to have a basic
awareness of what they're signing.
1107ab06c3 introduced an API to have a
ChannelKeys implementer sign HTLC transactions by calling into the
LocalCommitmentTransaction object, which would then store the tx.
This API was incredibly awkward, both because it required an
external signer trust our own internal interfaces, but also because
it didn't allow for any inspection of what was about to be signed.
Further, it signed the HTLC transactions one-by-one in a somewhat
inefficient way, and there isn't a clear way to resolve this (as
the which-HTLC parameter has to refer to something in between the
HTLC's arbitrary index, and its index in the commitment tx, which
has "holes" for the non-HTLC outputs and skips some HTLCs).
We replace it with a new function in ChannelKeys which allows us
to sign all HTLCs in a given commitment transaction (which allows
for a bit more effeciency on the signers' part, as well as
sidesteps the which-HTLC issue). This may also simplify the signer
implementation as we will always want to sign all HTLCs spending a
given commitment transaction at once anyway.
We also de-mut the LocalCommitmentTransaction passed to the
ChanKeys, instead opting to make LocalCommitmentTransaction const
and avoid storing any new HTLC-related data in it.
This cleans up sign_local_commitment somewhat by returning a
Result<Signaure, ()> over the local commitment transaction instead
of modifying the struct which was passed in.
This is the first step in making LocalCommitmentTransaction a
completely pub struct, using it just to communicate enough
information to the user to allow them to construct a signaure
instead of having it contain a bunch of logic.
This should make it much easier to implement a custom ChannelKeys
by disconnecting the local commitment transaction signing from our
own datastructures.
We want to avoid a third-party channel closure, where a random node
by sending us a payment expiring at current height, would trigger our
onchain logic to close the channel due to a near-expiration.
Since we now are always initialised with an initial local commitment
transaction available now, we might as well take advantage of it and
stop using an Option<> where we don't need to.
Previously, we created the initial ChannelMonitor on outbound
channels when we generated the funding_created message. This was
somewhat unnecessary as, at that time, we hadn't yet received
clearance to broadcast our initial funding transaction, and thus
there should never be any use for a ChannelMonitor. It also
complicated ChannelMonitor a bit as, at this point, we didn't have
an initial local commitment transaction.
By moving the creation of the initial ChannelMonitor to when we
receive our counterparty's funding_signed, we can ensure that any
ChannelMonitor will always have both a latest remote commitment tx
and a latest local commitment tx for broadcast.
This also fixes a strange API where we would close a channel
unceremoniously on peer-disconnection if we hadn't yet received the
funding_signed, but we'd already have a ChannelMonitor for that
channel. While it isn't strictly a bug (some potential DoS issues
aside), it is strange that these two definitions of a channel being
open were not in sync.
1107ab06c3 introduced some additional
metadata, including per-HTLC data in LocalCommitmentTransaction. To
keep diff reasonable it did so in ChannelMonitor after the
LocalCommitmentTransaction had been constructed and passed over the
wall, but there's little reason to do so - we should just be
constructing them with the data from the start, filled in by Channel.
This cleans up some internal interfaces a bit, slightly reduces
some data duplication and moves us one step forward to exposing
the guts of LocalCommitmentTransaction publicly in a sensible way.
The ChanKeys is created with knowledge of the Channel's value and
funding redeemscript up-front, so we should not be providing it
when making signing requests.
HTLC Transaction can't be bumped without sighash changes
so their gneeration is one-time for nwo. We move them in
OnchainTxHandler for simplifying ChannelMonitor and to prepare
storage of keys material behind one external signer interface.
Some tests break due to change in transaction broadcaster order.
Number of transactions may vary because of temporary anti-duplicata
tweak can't dissociate between 2- broadcast from different
origins (ChannelMonitor, ChannelManager) and 2-broadcast from same
component.
Extend external signer interface to sign HTLC transactions on its
behalf without seckey passing. This move will allow us to remove
key access access from ChannelMonitor hot memory in further work.
HTLC transactions should stay half-signed by remote until
we need to broadcast them for timing-out/claiming HTLCs onchain.
Extend external signer interface to sign local commitment transactions
on its behalf without seckey passing. This move will allow us to remove
key access from ChannelMonitor hot memory in further work.
Local commitment transaction should stay half-signed by remote until
we need to broadcast for a channel force-close or a HTLC to timeout onchain.
Add an unsafe test-only version of sign_local_commitment to fulfill our
test_framework needs.
If we call get_update_fulfill_htlc (in this case via
ChannelManager::claim_funds_internal ->
Channel::get_update_fulfill_htlc_and_commit) and it finds that we
already have a holding-cell pending HTLC claim, it will return no
monitor update but leave latest_monitor_update_id incremented.
If we later go and add a new monitor update we'll panic as the
updates appear to have been applied out-of-order.
Enforce a minimum htlc_minimum_msat of 1.
Instead of computing dynamically htlc_minimum_msat based on feerate,
relies on user-provided configuration value. This let user compute
an economical-driven channel parameter according to network dynamics.
Failing this requirement at sending means a strict receiver would
fail our channel while processing a HTLC routed from a third-party.
Fix by enforcing check on both sender and receiver side.
This was the way DataLossProtect was originally written, however it
didn't match other implementations at the time during testing. It
turns out, other implementations didn't agree with each other
anyway (depending on the exact timeline), so the spec was clarified
somewhat in https://github.com/lightningnetwork/lightning-rfc/pull/550
. This updates us to be in line with the new guidance and appears
to solve out-of-sync issues in testing.
Fixes issue #493 and should resolve some issues where other nodes
(incorrectly) reject channel_update/node_announcement messages
which have a serial number that is not a relatively recent
timestamp.
This is a cheap way to fix an error in Router serialization
roundtrip due to us calling read_to_end during the read of
channel/node announcement/updates. During normal message reading,
we only have limited bytes to read (specifically the message buffer)
so this is fine, however when we read them inside Router, we have
more data from other fields of the Router available as well. Thus,
we end up reading the entire rest of the Router into one message
field, and failing to deserialize.
Because such fields are always stored in Option<>s, we can simply
use a LengthLimitingStream in the Option<> serialization format and
make only the correct number of bytes available.
By using a variable-length integer for the new field, we avoid
wasting space compared to the existing serialization format.
This makes Readable symmetric with Writeable and makes sense -
something which is Readable should be Readable for any stream which
implements std::io::Read, not only for a stream type it decides on.
This solves some lifetime-compatibility issues in trying to read()
from a LengthLimitingReader in arbitrary Readable impls.
This removes the somewhat-easy-to-misuse Clone from ChannelMonitors,
opening us up to being able to track Events in ChannelMonitors with
less risk of misuse.
Sadly it doesn't remove the Clone requirement for ChannelKeys,
though gets us much closer - we now just need to request a second
copy once when we go to create the ChannelMonitors.
This is a rather huge diff, almost entirely due to removing the
type parameter from ChannelError which was added in
c20e930b31 due to holding the
ChannelKeys in ChannelMonitors.
This prepares for only creating the ChannelMonitor on funding by
removing any channel_monitor calls from Channel open/accept-time to
funding-signed time.
This is a rather big step towards using the new ChannelMonitorUpdate
flow, using it in the various commitment signing and commitment
update message processing functions in Channel. Becase they all
often call each other, they all have to be updated as a group,
resulting in the somewhat large diff in this commit.
In order to keep the update_ids strictly increasing by one for
ease of use on the user end, we have to play some games with the
latest_monitor_update_id field, though its generally still pretty
readable, and the pattern of "get an update_id at the start, and
use the one we got at the start when returning, irrespective of
what other calls into the Channel during that time did" is
relatively straightforward.
This is the first of several steps to update ChannelMonitor updates
to use the new ChannelMonitorUpdate objects, demonstrating how the
new flow works in Channel.
This is the first step in migrating ChannelMonitor updating logic
to use incremental Update objects instead of copying the
ChannelMonitors themselves and insert_combine()ing them.
This adds most of the scaffolding and updates relevant comments to
refer to the new architecture, without changing how any actual
updates occur.
Currently Channel relies on its own internal channel_monitor copy
to keep track of funding_txo information, which is both a bit
awkward and not ideal if we want to get rid of the ChannelMonitor
copy in Channel.
Instead, just duplicate it (its small) and keep it directly in
Channel, allowing us to remove the (super awkward)
ChannelMonitor::unset_funding_txo().
In the process of removing a local ChannelMonitor in each Channel,
we need to track our counterpartys' commitment secrets so that we
can check them locally instead of calling our channel monitor to
do that work for us.
Previously, when attempting to write out a channel with some
RemoteAnnounced pending inbound HTLCs, we'd write out the count
without them, but write out some of their fields. We should drop
them as intended as they will need to be reannounced upon
reconnection.
This was found while attempting to simply reproduce a different
bug by adding tests for ChannelManager serialization rount-trip at
the end of each functional_test (in Node::drop). That test is
included here to prevent some classes of similar bugs in the future.
We previously tracked funding transaction confirmation by marking
funding_tx_confirmations to 1 when we see it in a block and
incrementing each block thereafter if its non-0. To avoid
double-incrementing the first confirmation, we did the increment
(and funding_locked check) after doing the first-confirmation
checks. Thus, we'd never hit the funding_locked case during the
first confirmation.
To address this, we simply swap the order of the checks, though
bumping the funding_tx_confirmations increment up to the top.
Reported-by: Igor Cota <igor@codexapertus.com>
