There is a possible race condition when both the latest block hash and
height are needed. Combine these in one struct and place them behind a
single lock.
Instead of relying on the user to ensure the funding transaction is
correct (and panicing when it is confirmed), we should check it is
correct when it is generated. By taking the full funding transaciton
from the user on generation, we can also handle broadcasting for
them instead of doing so via an event.
When we force-close a channel, for whatever reason, it is nice to
send an error message to our peer. This allows them to closes the
channel on their end instead of trying to send through it and
failing. Further, it may induce them to broadcast their commitment
transaction, possibly getting that confirmed and saving us on fees.
This commit adds a few more cases where we should have been sending
error messages but weren't. It also includes an almost-global
replace in tests of the second argument in
`check_closed_broadcast!()` from false to true (indicating an error
message is expected). There are only a few exceptions, notably
those where the closure is the result of our counterparty having
sent *us* an error message.
chain::Filter::register_output may return an in-block dependent
transaction that spends the output. Test the scenario where the txdata
given to ChainMonitor::block_connected includes a commitment transaction
whose HTLC output is spent in the same block but not included in txdata.
Instead, it is returned by chain::Filter::register_output when given the
commitment transaction's HTLC output. This is a common scenario for
Electrum clients, which provided filtered txdata.
Many functional tests rely on being able to call block_connected
arbitrarily, jumping back in time to confirm a transaction at a
specific height. Instead, this takes us one step towards having a
well-formed blockchain in the functional tests.
We also take this opportunity to reduce the number of blocks
connected during tests, requiring a number of constant tweaks in
various functional tests.
Co-authored-by: Valentine Wallace <vwallace@protonmail.com>
Co-authored-by: Matt Corallo <git@bluematt.me>
Sadly the connected-in-order tests have to be skipped in our normal
test suite as many tests violate it. Luckily we can still enforce
it in the tests which run in other crates.
Co-authored-by: Matt Corallo <git@bluematt.me>
Co-authored-by: Jeffrey Czyz <jkczyz@gmail.com>
We currently only use it to override the graph-specific features
returned in the route, though we should also use it to enable or
disable MPP.
Note that tests which relied on MPP behavior have had all of their
get_route calls upgraded to provide the MPP flag.
When ChannelMonitors are persisted, they need to store the most recent
block hash seen. However, for newly created channels the default block
hash is used. If persisted before a block is connected, the funding
output may be missed when syncing after a restart. Instead, initialize
ChannelManager with a "birthday" hash so it can be used later when
creating channels.
The instructions for `ChannelManagerReadArgs` indicate that you need
to connect blocks on a newly-deserialized `ChannelManager` in a
separate pass from the newly-deserialized `ChannelMontiors` as the
`ChannelManager` assumes the ability to update the monitors during
block [dis]connected events, saying that users need to:
```
4) Reconnect blocks on your ChannelMonitors
5) Move the ChannelMonitors into your local chain::Watch.
6) Disconnect/connect blocks on the ChannelManager.
```
This is fine for `ChannelManager`'s purpose, but is very awkward
for users. Notably, our new `lightning-block-sync` implemented
on-load reconnection in the most obvious (and performant) way -
connecting the blocks all at once, violating the
`ChannelManagerReadArgs` API.
Luckily, the events in question really don't need to be processed
with the same urgency as most channel monitor updates. The only two
monitor updates which can occur in block_[dis]connected is either
a) in block_connected, we identify a now-confirmed commitment
transaction, closing one of our channels, or
b) in block_disconnected, the funding transaction is reorganized
out of the chain, making our channel no longer funded.
In the case of (a), sending a monitor update which broadcasts a
conflicting holder commitment transaction is far from
time-critical, though we should still ensure we do it. In the case
of (b), we should try to broadcast our holder commitment transaction
when we can, but within a few minutes is fine on the scale of
block mining anyway.
Note that in both cases cannot simply move the logic to
ChannelMonitor::block[dis]_connected, as this could result in us
broadcasting a commitment transaction from ChannelMonitor, then
revoking the now-broadcasted state, and only then receiving the
block_[dis]connected event in the ChannelManager.
Thus, we move both events into an internal invent queue and process
them in timer_chan_freshness_every_min().
If the ChannelManager never receives any blocks, it'll return a default blockhash
on deserialization. It's preferable for this to be an Option instead.
Now that ChannelMonitor uses an internal Mutex to support interior
mutability, ChainMonitor can use a RwLock to manage its ChannelMonitor
map. This allows parallelization of update_channel operations since an
exclusive lock only needs to be held when adding to the map in
watch_channel.
* Implemented protocol.
* Made feature optional.
* Verify that the default value is true.
* Verify that on shutdown,
if Channel.supports_shutdown_anysegwit is enabled,
the script can be a witness program.
* Added a test that verifies that a scriptpubkey
for an unreleased segwit version is handled successfully.
* Added a test that verifies that
if node has op_shutdown_anysegwit disabled,
a scriptpubkey with an unreleased segwit version on shutdown
throws an error.
* Added peer InitFeatures to handle_shutdown
* Check if shutdown script is valid when given upfront.
* Added a test to verify that an invalid test results in error.
* Added a test to check that if a segwit script with version 0 is provided,
the updated anysegwit check detects it and returns unsupported.
* An empty script is only allowed when sent as upfront shutdown script,
so make sure that check is only done for accept/open_channel situations.
* Instead of reimplementing a variant of is_witness_script,
just call it and verify that the witness version is not 0.
The `ChannelKeys` object really isn't about keys at all anymore,
its all about signing. At the same time, we rename the type aliases
used in traits from both `ChanKeySigner` and `Keys` to just
`Signer` (or, in contexts where Channel isnt clear, `ChanSigner`).
This drops any direct calls to a generic `ChannelKeys::read()` and
replaces it with the new `KeysInterface::read_chan_signer()`. Still,
under the hood all of our own `KeysInterface::read_chan_signer()`
implementations simply call out to a `Readable::read()` implemention.
There's no reason to have ChannelMonitor::write_for_disk instead of
just using the Writeable trait anymore. Previously, it was used to
differentiate with `write_for_watchtower`, but support for
watchtower-mode ChannelMonitors was never completed and the partial
bits were removed long ago.
This has the nice benefit of hitting the custom Writeable codepaths
in C bindings instead of trying to hit trait-generics paths.
This changes adds the genesis block hash as a BlockHash to the
NetworkGraph struct. Making the NetworkGraph aware allows the message
handler to validate the chain_hash for received messages. This change
also adds the hash value to the Writeable and Readable methods.
The full_stack_target managed to find a bug where, if we receive
a funding_created message which has a channel_id identical to an
existing channel, we'll end up
(a) having the monitor update for the new channel fail (due to
duplicate outpoint),
(b) creating a monitor update for the new channel as we
force-close it,
(c) panicing due to the force-close monitor update is applied to
the original channel and is considered out-of-order.
Obviously we shouldn't be creating a force-close monitor update for
a channel which can never appear on chain, so we do that here and
add a test which previously failed and checks a few
duplicate-channel-id cases.
If a persister returns a temporary failure, the channel monitor should be able
to be put on ice and then revived later. If a persister returns a permanent
failure, the channel should be force closed.
Intended to be a cross-platform implementation of the
channelmonitor::Persist trait.
This adds a new lightning-persister crate, that uses the
newly exposed lightning crate's test utilities.
Notably, this crate is pretty small right now. However, due to
future plans to add more data persistence (e.g. persisting the
ChannelManager, etc) and a desire to avoid pulling in filesystem
usage into the core lightning package, it is best for it to be
separated out.
Note: Windows necessitates the use of OpenOptions with the `write`
permission enabled to `sync_all` on a newly opened channel's
data file.
- The ChainMonitor should:
Whenever a new channel is added or updated, these updates
should be conveyed to the persister and persisted to disk.
Even if the update errors while it's being applied, the
updated monitor still needs to be persisted.
This also pays a fee on the transactions we generate in response to
SpendableOutputDescriptors in tests.
This fixes the known issues in #630, though we should test for
standardness in other ways as well.
Previously, we had a concept of "rescaning" blocks when we detected
a need to monitor for a new set of outputs in future blocks while
connecting a block. In such cases, we'd need to possibly learn about
these new spends later in the *same block*, requiring clients who
filter blocks to get a newly-filtered copy of the same block. While
redoing the chain access API, it became increasingly clear this was
an overly complicated API feature, and it seems likely most clients
will not use it anyway.
Further, any client who *does* filter blocks can simply update their
filtering algorithm to include any descendants of matched
transactions in the filter results, avoiding the need for rescan
support entirely.
Thus, it was decided that we'd move forward without rescan support
in #649, however to avoid significant further changes in the
already-large 649, we decided to fully remove support in a
follow-up.
Here, we remove the API features that existed for rescan and fix
the few tests to not rely on it.
After this commit, we now only ever have one possible version of
block connection transactions, making it possible to be
significantly more confident in our test coverage actually
capturing all realistic scenarios.
Given the chain::Watch interface is defined in terms of ChannelMonitor
and ChannelMonitorUpdateErr, move channelmonitor.rs from the ln module
to the chain module.
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.
ManyChannelMonitor was renamed chain::Watch in the previous commit. Use
a more concise name for an implementation that monitors the chain for
channel activity. Future work will parameterize the struct to allow for
different varieties of persistence. Thus, users usually will be able to
use ChainMonitor directly rather than implementing a chain::Watch that
wraps it.
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.
