Outputs to watch are tracked by ChannelMonitor as of
73dce207dd. Instead of determining new
outputs to watch independently using ChainWatchedUtil, do so by
comparing against outputs already tracked. Thus, ChainWatchedUtil and
WatchEvent are no longer needed.
WatchEventProvider served as a means for replacing ChainWatchInterface.
However, it requires users to explicitly fetch WatchEvents, even if not
interested in them. Replace WatchEventProvider by chain::Filter, which
is an optional member of ChainMonitor. If set, interesting transactions
and output spends are registered such that blocks containing them can be
retrieved from a chain source in an efficient manner.
This is useful when the chain source is not a full node. For Electrum,
it allows for pre-filtered blocks. For BIP157/158, it serves as a means
to match against compact filters.
BlockNotifier was removed in the previous commit, thus ChainListener is
no longer needed. Instead, anything needing chain events should be
notified directly.
BlockNotifier is a convenience for handing blocks to listeners. However,
it requires that each listener conforms to the ChainListener interface.
Additionally, there are only two listeners, ChannelManager and
ChainMonitor, the latter of which may not be used when monitoring
channels remotely. Remove BlockNotifier since it doesn't provide much
value and constrains each listener to a specific interface.
Rename ManyChannelMonitor to chain::Watch and move to chain/mod.rs,
where chain-related interfaces live. Update the documentation for
clarity and to conform to rustdoc formatting.
ChainWatchInterface was intended as an interface for watching rather
than accessing the chain. Remove get_chain_utxo and add chain::Access
trait for this behavior. Wrap it with an Option in NetGraphMsgHandler in
order to simplify the error interface.
SimpleManyChannelMonitor is parameterized by ChainWatchInterface to
signal what transactions and outputs to watch for on chain. The
interface has grown to cover chain access (via get_chain_utxo) and block
block filtering (via filter_block and reentered), which has added
complexity for implementations and user (see ChainWatchInterfaceUtil).
Pull the watch functionality out as a first step to eliminating
ChainWatchInterface entirely.
Use a simple ChainListner implementation rather than large test objects
for testing BlockNotifier.
Remove unregister_single_listener_ref_test since it is redundant with
unregister_single_listener_test.
Remove unnecessary clone() calls.
ChainListeners should be independent of each other, but in practice this
is not the case because ChainWatchInterface introduces a dependency
between them. Push ChainWatchInterface down into the ChainListener
implementations where needed. Update ChainListener's block_connected
method to take a slice of the form &[(usize, &Transaction)] where each
transaction is paired with its position within the block.
In anticipation for removing support for users calling
block_connected multiple times for the same block to include all
relevant transactions in the next PR, this commit stops testing
such cases. Specifically, users who filter blocks for relevant
transactions before calling block_connected will need to filter by
including any transactions which spend a previously-matched
transaction in the same block (and we now do so in our own
filtering logic, which is also used in our testing).
We'd previously largely not turned on derive(Debug) on any of our
structs, but not for good reason. Especially for Events objects,
Debug can be a very useful for users to quickly print what they
received from us without having to write out a large match.
Comment meaning of holder/counterparty
Diverse chan_utils cleanups
Cleanups post-cbindings merge
Fix misusage of holder_selected_contest_delay instead of counterparty
_selected_contest_delay in HolderCommitmentTransaction
Fix old payment_point comment
A TxCreationKeys set represents the key which will be embedded in output
scripts of a party's commitment tx state. Among them there is a always
a key belonging to counter-party, the HTLC pubkey. To dissociate
strongly, prefix keys with broadcaster/countersignatory.
A revocation keypair is attributed to the broadcaster as it's used
to punish a fraudulent broadcast while minding that such keypair
derivation method will be always used by countersignatory as it's
its task to enforce punishement thanks to the release secret.
To avoid reviewers confusion, rename counterparty_to_self_delay
to counteparty_selected_contest_delay, i.e the justice delay announced
by a channel counterparty restraining our transactions, and to_self_delay
to locally_selected_contest_delay, i.e the justice delay announced by us
restraining counterparty's transactions
We deviate from wider nomenclature by prefixing local data with a
locally_ extension due to the leak of this value in transactions/scripts
builder, where the confusion may happen.
Rename further AcceptChannelData to the new nomenclature.
Variables should be named according to the script semantic which is
an invariant with regards to generating a local or remote commitment
transaction.
I.e a broadcaster_htlc_key will always guard a HTLC to the party able
to broadcast the computed transactions whereas countersignatory_htlc_key
will guard HTLC to a countersignatory of the commitment transaction.
Lightning OutPoints only have 16 bits to express the output index
instead of Bitcoin's 32 bits, implying that some outputs are
possibly not expressible as lightning OutPoints. However, such
OutPoints can never be hit within the lightning protocol, and must
be on-chain spam sent by a third party wishing to donate us money.
Still, in order to do so, the third party would need to fill nearly
an entire block with garbage, so this case should be relatively
safe.
A new comment in channelmonitor explains the reasoning a bit
further.
Instead of using the explicit type which is being returned, refer
to them as Self::AssociatedType, to make clear to the bindings what
type of thing is being returned.
Due to a desire to be able to override temporary channel IDs and
onion keys, KeysInterface had two separate fetch-random-32-bytes
interfaces - an onion-key specific version which fetched 2 random
32 byte strings and a temporary-channel-id specific version.
It turns out, we never actually need to override both at once (as
creating a new channel and sending an outbound payment are always
separate top-level calls), so there's no reason to add two
functions to the interface when both really do the same thing.
This changes the LICENSE file and adds license headers to most files
to relicense under dual Apache-2.0 and MIT. This is helpful in that
we retain the patent grant issued under Apache-2.0-licensed work,
avoiding some sticky patent issues, while still allowing users who
are more comfortable with the simpler MIT license to use that.
See https://github.com/rust-bitcoin/rust-lightning/issues/659 for
relicensing statements from code authors.
Allows calling of InMemoryChannelKeys methods.
The wrapping makes it obvious to signer implementers that the pre-derived keys are a local cache and should not be trusted in a validating signer.
The commitment secret is sensitive - it can be used by an attacker to
steal funds if the node also signs the same transaction. Therefore,
only release the secret from ChannelKeys when we are revoking a
transaction.
We use them largely as indexes into a Vec<Transaction> so there's
little reason for them to be u32s. Instead, use them as usize
everywhere.
We also take this opportunity to add range checks before
short_channel_id calculation, as we could otherwise end up with a
bogus short_channel_id due to an output index out of range.
Instead of making the filter_block fn in the ChainWatchInterface
trait return both a list of indexes of transaction positions within
the block and references to the transactions themselves, return
only the list of indexes and then build the reference list at the
callsite.
While this may be slightly less effecient from a memory locality
perspective, it shouldn't be materially different.
This should make it more practical to generate bindings for
filter_block as it no longer needs to reference Rust Transaction
objects that are contained in a Rust Block object (which we'd
otherwise just pass over the FFI in fully-serialized form).
In general, we don't need an explicit lifetime when doing something
like:
fn get_thing(&self) -> &Thing { &self.thing }.
This also makes it easier to reason about what's going on in the
bindings generation.
As we drop the requirement that all ChannelKeys expose the private
keys used, we should have a way to access the private keys in use
when using InMemoryChannelKeys.
Instead of blindly signing provided witnessScript, signer must derive
channel keys corresponding to the provided per-commitment-point and
regenerate templated witnessScript to ensure its syntax correctness.
