Matt Corallo [Sat, 4 Mar 2023 01:16:57 +0000 (01:16 +0000)]
Make `fuzz_threaded_connections` more robust
In `fuzz_threaded_connections`, if one thread is being run while
another is starved, and the running thread manages to call
`timer_tick_ocurred` twice after the starved thread constructs the
inbound connection but before it delivers the first bytes, we'll
receive an immediate error and `unwrap` it, causing failure.
The fix is trivial, simply remove the unwrap and return if we're
already disconnected when we do the initial read.
While we're here, we also reduce the frequency of the
`timer_tick_ocurred` calls to give us a chance to occasionally
deliver some additional messages.
Jeffrey Czyz [Fri, 6 Jan 2023 04:00:31 +0000 (22:00 -0600)]
Guard against division by zero in scorer
Since a node may announce that the htlc_maximum_msat of a channel is
zero, adding one to the denominator in the bucket formulas will prevent
the panic from ever happening. While the routing algorithm may never
select such a channel to score, this precaution may still be useful in
case the algorithm changes or if the scorer is used with a different
routing algorithm.
Matt Corallo [Fri, 3 Mar 2023 20:03:57 +0000 (20:03 +0000)]
Expose the node secret key in `{Phantom,}KeysManager`
When we removed the private keys from the signing interface we
forgot to re-add them in the public interface of our own
implementations, which users may need.
Matt Corallo [Fri, 3 Mar 2023 05:14:04 +0000 (05:14 +0000)]
Do not auto-select the lightning `std` feature from tx-sync crate
We have some downstream folks who are using LDK in wasm compiled
via the normal rust wasm path. To ensure nothing breaks they want
to use `no-std` on the lightning crate, disabling time calls as
those panic. However, the HTTP logic in
`lightning-transaction-sync` gets automatically stubbed out by the
HTTP client crates when targeting wasm via `wasm_bindgen`, so it
works fine despite the std restrictions.
In order to make both work, `lightning-transaction-sync` can remain
`std`, but needs to not automatically enable the `std` flag on the
`lightning` crate, ie by setting `default-features = false`. We do
so here.
Matt Corallo [Fri, 3 Mar 2023 01:24:24 +0000 (01:24 +0000)]
Pass `FailureCode` to `fail_htlc_backwards` by ownership
`FaliureCode` is a trivial enum with no body, so we shouldn't be
passing it by reference. Its sufficiently strange that the Java
bindings aren't happy with it, which is fine, we should just fix it
here.
Matt Corallo [Wed, 22 Feb 2023 02:40:59 +0000 (02:40 +0000)]
Track claimed outbound HTLCs in ChannelMonitors
When we receive an update_fulfill_htlc message, we immediately try
to "claim" the HTLC against the HTLCSource. If there is one, this
works great, we immediately generate a `ChannelMonitorUpdate` for
the corresponding inbound HTLC and persist that before we ever get
to processing our counterparty's `commitment_signed` and persisting
the corresponding `ChannelMonitorUpdate`.
However, if there isn't one (and this is the first successful HTLC
for a payment we sent), we immediately generate a `PaymentSent`
event and queue it up for the user. Then, a millisecond later, we
receive the `commitment_signed` from our peer, removing the HTLC
from the latest local commitment transaction as a side-effect of
the `ChannelMonitorUpdate` applied.
If the user has processed the `PaymentSent` event by that point,
great, we're done. However, if they have not, and we crash prior to
persisting the `ChannelManager`, on startup we get confused about
the state of the payment. We'll force-close the channel for being
stale, and see an HTLC which was removed and is no longer present
in the latest commitment transaction (which we're broadcasting).
Because we claim corresponding inbound HTLCs before updating a
`ChannelMonitor`, we assume such HTLCs have failed - attempting to
fail after having claimed should be a noop. However, in the
sent-payment case we now generate a `PaymentFailed` event for the
user, allowing an HTLC to complete without giving the user a
preimage.
Here we address this issue by storing the payment preimages for
claimed outbound HTLCs in the `ChannelMonitor`, in addition to the
existing inbound HTLC preimages already stored there. This allows
us to fix the specific issue described by checking for a preimage
and switching the type of event generated in response. In addition,
it reduces the risk of future confusion by ensuring we don't fail
HTLCs which were claimed but not fully committed to before a crash.
It does not, however, full fix the issue here - because the
preimages are removed after the HTLC has been fully removed from
available commitment transactions if we are substantially delayed
in persisting the `ChannelManager` from the time we receive the
`update_fulfill_htlc` until after a full commitment signed dance
completes we may still hit this issue. The full fix for this issue
is to delay the persistence of the `ChannelMonitorUpdate` until
after the `PaymentSent` event has been processed. This avoids the
issue entirely, ensuring we process the event before updating the
`ChannelMonitor`, the same as we ensure the upstream HTLC has been
claimed before updating the `ChannelMonitor` for forwarded
payments.
The full solution will be implemented in a later work, however this
change still makes sense at that point as well - if we were to
delay the initial `commitment_signed` `ChannelMonitorUpdate` util
after the `PaymentSent` event has been processed (which likely
requires a database update on the users' end), we'd hold our
`commitment_signed` + `revoke_and_ack` response for two DB writes
(i.e. `fsync()` calls), making our commitment transaction
processing a full `fsync` slower. By making this change first, we
can instead delay the `ChannelMonitorUpdate` from the
counterparty's final `revoke_and_ack` message until the event has
been processed, giving us a full network roundtrip to do so and
avoiding delaying our response as long as an `fsync` is faster than
a network roundtrip.
Jeffrey Czyz [Thu, 5 Jan 2023 17:50:24 +0000 (11:50 -0600)]
Fix scorer panic when available capacity is zero
ProbabilisticScorer takes a ChannelUsage when computing a penalty for a
channel. The formula for calculating the liquidity penalty reduces the
maximum capacity by the amount of in-flight HTLCs (available capacity)
and adds one to prevent division by zero.
However, since the available capacity is passed to
DirectedChannelLiquidity as the capacity, other penalty formulas may use
the available (i.e., reduced) capacity inadvertently. In practice, this
has two ramifications for the historical liquidity penalty computation:
1. The bucket formula doesn't have a consistent denominator for a given
channel.
2. The bucket formula may divide by zero when the in-flight HTLC amount
equals or exceeds the effective capacity.
Fixing this involves only using the available capacity when appropriate.
Matt Corallo [Tue, 28 Feb 2023 21:38:29 +0000 (21:38 +0000)]
Improve `PeerHandler` debug_assertions and checks
This removes two panics from `PeerHandler` which can trivially be
`debug_assert!(false); return Err;`s, and adds another
`debug_assertion` on internal state consistency during disconnect.
Matt Corallo [Thu, 2 Mar 2023 07:50:16 +0000 (07:50 +0000)]
Make waking after a future completes propagates to the next future
In our `wakers`, if we first `notify` a future, which is then
`poll`ed complete, and then `notify` the same waker again before a
new future is fetched, that new future will be marked as
non-complete initially and wait for a third `notify`.
The fix is luckily rather trivial, when we `notify` a future, if it
is completed immediately, simply wipe the future state so that we
look at the pending-notify flag when we generate the next future.
Matt Corallo [Tue, 28 Feb 2023 19:42:31 +0000 (19:42 +0000)]
Mark `IndexedMap` types as `(C-not exported)`
While we could try to expose the type explicitly, we already have
alternative accessors for bindings, and mapping `Hash`, `Ord` and
the other requirements for `IndexedMap` would be a good chunk of
additional work.
Matt Corallo [Tue, 28 Feb 2023 21:28:13 +0000 (21:28 +0000)]
Remove peers from the `node_id_to_descriptor` even without init
When a peer has finished the noise handshake, but has not yet
completed the lightning `Init`-based handshake, they will be
present in the `node_id_to_descriptor` set, even though
`Peer::handshake_complete()` returns false. Thus, when we go to
disconnect such a peer, we must ensure that we remove it from the
descriptor set as well.
Failing to do so caused an `Inconsistent peers set state!` panic in
the C bindings network handler.
John Cantrell [Tue, 28 Feb 2023 16:39:29 +0000 (11:39 -0500)]
Surface bitcoind rpc error code
Users of the RpcClient had no way to access the error code
returned by bitcoind's rpc. We embed a new RpcError struct
as the inner error for the returned io::Error. Users can access
both the code and the message using this inner struct.
Matt Corallo [Thu, 23 Feb 2023 19:06:21 +0000 (19:06 +0000)]
Do not fail to apply RGS updates for removed channels
If we receive a Rapid Gossip Sync update for channels where we are
missing the existing channel data, we should ignore the missing
channel. This can happen in a number of cases, whether because we
received updated channel information via an onion error from an
HTLC failure or because we've partially synced the graph from a
peer over the standard lightning P2P protocol.
Matt Corallo [Sun, 26 Feb 2023 20:22:28 +0000 (20:22 +0000)]
Make sure individual mutexes are constructed on different lines
Our lockdep logic (on Windows) identifies a mutex based on which
line it was constructed on. Thus, if we have two mutexes
constructed on the same line it will generate false positives.
Matt Corallo [Wed, 22 Feb 2023 22:54:38 +0000 (22:54 +0000)]
Disallow taking two instances of the same mutex at the same time
Taking two instances of the same mutex may be totally fine, but it
requires a total lockorder that we cannot (trivially) check. Thus,
its generally unsafe to do if we can avoid it.
To discourage doing this, here we default to panicing on such locks
in our lockorder tests, with a separate lock function added that is
clearly labeled "unsafe" to allow doing so when we can guarantee a
total lockorder.
This requires adapting a number of sites to the new API, including
fixing a bug this turned up in `ChannelMonitor`'s `PartialEq` where
no lockorder was guaranteed.
Matt Corallo [Thu, 2 Feb 2023 22:38:54 +0000 (22:38 +0000)]
Refuse recursive read locks in lockorder testing
Our existing lockorder tests assume that a read lock on a thread
that is already holding the same read lock is totally fine. This
isn't at all true. The `std` `RwLock` behavior is
platform-dependent - on most platforms readers can starve writers
as readers will never block for a pending writer. However, on
platforms where this is not the case, one thread trying to take a
write lock may deadlock with another thread that both already has,
and is attempting to take again, a read lock.
Worse, our in-tree `FairRwLock` exhibits this behavior explicitly
on all platforms to avoid the starvation issue.
Thus, we shouldn't have any special handling for allowing recursive
read locks, so we simply remove it here.
Matt Corallo [Wed, 22 Feb 2023 22:10:46 +0000 (22:10 +0000)]
Don't `per_peer_state` read locks recursively in monitor updating
When handling a `ChannelMonitor` update via the new
`handle_new_monitor_update` macro, we always call the macro with
the `per_peer_state` read lock held and have the macro drop the
per-peer state lock. Then, when handling the resulting updates, we
may take the `per_peer_state` read lock again in another function.
In a coming commit, recursive read locks will be disallowed, so we
have to drop the `per_peer_state` read lock before calling
additional functions in `handle_new_monitor_update`, which we do
here.
Matt Corallo [Fri, 3 Feb 2023 00:46:50 +0000 (00:46 +0000)]
Expect callers to hold read locks before `channel_monitor_updated`
Our existing lockorder tests assume that a read lock on a thread
that is already holding the same read lock is totally fine. This
isn't at all true. The `std` `RwLock` behavior is
platform-dependent - on most platforms readers can starve writers
as readers will never block for a pending writer. However, on
platforms where this is not the case, one thread trying to take a
write lock may deadlock with another thread that both already has,
and is attempting to take again, a read lock.
Worse, our in-tree `FairRwLock` exhibits this behavior explicitly
on all platforms to avoid the starvation issue.
Sadly, a user ended up hitting this deadlock in production in the
form of a call to `get_and_clear_pending_msg_events` which holds
the `ChannelManager::total_consistency_lock` before calling
`process_pending_monitor_events` and eventually
`channel_monitor_updated`, which tries to take the same read lock
again.
Luckily, the fix is trivial, simply remove the redundand read lock
in `channel_monitor_updated`.
Matt Corallo [Fri, 3 Feb 2023 00:33:27 +0000 (00:33 +0000)]
Hold the `total_consistency_lock` while in `outbound_payment` fns
We previously avoided holding the `total_consistency_lock` while
doing crypto operations to build onions. However, now that we've
abstracted out the outbound payment logic into a utility module,
ensuring the state is consistent at all times is now abstracted
away from code authors and reviewers, making it likely to break.
Further, because we now call `send_payment_along_path` both with,
and without, the `total_consistency_lock`, and because recursive
read locks may deadlock, it would now be quite difficult to figure
out which paths through `outbound_payment` need the lock and which
don't.
While it may slow writes somewhat, it's not really worth trying to
figure out this mess, instead we just hold the
`total_consistency_lock` before going into `outbound_payment`
functions.
Matt Corallo [Mon, 6 Feb 2023 22:12:09 +0000 (22:12 +0000)]
Remove the `final_cltv_expiry_delta` in `RouteParameters` entirely
fbc08477e8dcdd8f3f2ada8ca77388b6185febe2 purported to "move" the
`final_cltv_expiry_delta` field to `PaymentParamters` from
`RouteParameters`. However, for naive backwards-compatibility
reasons it left the existing on in place and only added a new,
redundant field in `PaymentParameters`.
It turns out there's really no reason for this - if we take a more
critical eye towards backwards compatibility we can figure out the
correct value in every `PaymentParameters` while deserializing.
We do this here - making `PaymentParameters` a `ReadableArgs`
taking a "default" `cltv_expiry_delta` when it goes to read. This
allows existing `RouteParameters` objects to pass the read
`final_cltv_expiry_delta` field in to be used if the new field
wasn't present.
Matt Corallo [Mon, 6 Feb 2023 21:56:39 +0000 (21:56 +0000)]
Support `ReadableArgs` types across in the TLV struct serialization
This adds `required` support for trait-wrapped reading (e.g. for
objects read via `ReadableArgs`) as well as support for the
trait-wrapped reading syntax across the TLV struct/enum
serialization macros.
Matt Corallo [Mon, 6 Feb 2023 21:43:10 +0000 (21:43 +0000)]
Require a non-0 number of non-empty paths when deserializing routes
When we read a `Route` (or a list of `RouteHop`s), we should never
have zero paths or zero `RouteHop`s in a path. As such, its fine to
simply reject these at deserialization-time. Technically this could
lead to something which we can generate not round-trip'ing
serialization, but that seems okay here.
Matt Corallo [Mon, 27 Feb 2023 17:32:07 +0000 (17:32 +0000)]
Move `lightning-transaction-sync` out of the main workspace
Because `lightning-transaction-sync` does not have an MSRV (and
because its dev-dependencies are huge), we can't build it by
default when devs run `cargo test`, so it is moved out of the
top-level workspace.
Fix upgradable_required fields to actually be required in lower level macros
When using lower level macros such as read_tlv_stream, upgradable_required
fields have been treated as regular options. This is incorrect, they should
either be upgradable_options or treated as required fields.
This field was previous useful in manual retries for users to know when all
paths of a payment have failed and it is safe to retry. Now that we support
automatic retries in ChannelManager and no longer support manual retries, the
field is no longer useful.
For backwards compat, we now always write false for this field. If we didn't do
this, previous versions would default this field's value to true, which can be
problematic because some clients have relied on the field to indicate when a
full payment retry is safe.
Jeffrey Czyz [Thu, 16 Feb 2023 02:17:18 +0000 (20:17 -0600)]
Fix amount overflow in Invoice building
An overflow can occur when multiplying the offer amount by the requested
quantity when no amount is given in the request. Return an error instead
of overflowing.
Jeffrey Czyz [Wed, 15 Feb 2023 22:43:41 +0000 (16:43 -0600)]
Fix amount overflow in Offer parsing and building
An overflow can occur when multiplying the offer amount by the requested
quantity when checking if the given amount is enough. Return an error
instead of overflowing.
Jeffrey Czyz [Thu, 9 Feb 2023 17:09:23 +0000 (11:09 -0600)]
Fuzz test for bech32 decoding
Fuzz testing bech32 decoding along with deserializing the underlying
message can result in overly exhaustive searches. Instead, the message
deserializations are now fuzzed separately. Add fuzzing for bech32
decoding.
Jeffrey Czyz [Thu, 9 Feb 2023 16:59:11 +0000 (10:59 -0600)]
Expose Bech32Encode trait for fuzzing
In order to fuzz test Bech32Encode parsing independent of the underlying
message deserialization, the trait needs to be exposed. Conditionally
expose it only for fuzzing.
Jeffrey Czyz [Fri, 20 Jan 2023 22:30:45 +0000 (16:30 -0600)]
Fuzz test for parsing Invoice
An invoice is serialized as a TLV stream and encoded as bytes. Add a
fuzz test that parses the TLV stream and deserializes the underlying
Invoice. Then compare the original bytes with those obtained by
re-serializing the Invoice.
Jeffrey Czyz [Fri, 20 Jan 2023 19:34:34 +0000 (13:34 -0600)]
Fuzz test for parsing InvoiceRequest
An invoice request is serialized as a TLV stream and encoded as bytes.
Add a fuzz test that parses the TLV stream and deserializes the
underlying InvoiceRequest. Then compare the original bytes with those
obtained by re-serializing the InvoiceRequest.
Matt Corallo [Thu, 9 Feb 2023 19:20:22 +0000 (19:20 +0000)]
Remove genesis block hash from public API
Forcing users to pass a genesis block hash has ended up being
error-prone largely due to byte-swapping questions for bindings
users. Further, our API is currently inconsistent - in
`ChannelManager` we take a `Bitcoin::Network` but in `NetworkGraph`
we take the genesis block hash.
Luckily `NetworkGraph` is the only remaining place where we require
users pass the genesis block hash, so swapping it for a `Network`
is a simple change.
Prior to this, we returned PaymentSendFailure from auto retry send payment
methods. This implied that we might return a PartialFailure from them, which
has never been the case. So it makes sense to rework the errors to be a better
fit for the methods.
We're taking error handling in a totally different direction now to make it
more asynchronous, see send_payment_internal for more information.
Matt Corallo [Sun, 19 Feb 2023 00:13:51 +0000 (00:13 +0000)]
Don't generate a `ChannelMonitorUpdate` for closed chans on shutdown
The `Channel::get_shutdown` docs are very clear - if the channel
jumps to `Shutdown` as a result of not being funded when we go to
initiate shutdown we should not generate a `ChannelMonitorUpdate`
as there's no need to bother with the shutdown script - we're
force-closing anyway.
However, this wasn't actually implemented, potentially causing a
spurious monitor update for no reason.
Matt Corallo [Sat, 3 Dec 2022 03:15:04 +0000 (03:15 +0000)]
Use the new monitor persistence flow for `funding_created` handling
Building on the previous commits, this finishes our transition to
doing all message-sending in the monitor update completion
pipeline, unifying our immediate- and async- `ChannelMonitor`
update and persistence flows.
Matt Corallo [Mon, 6 Feb 2023 23:03:38 +0000 (23:03 +0000)]
Use new monitor persistence flow in funding_signed handling
In the previous commit, we moved all our `ChannelMonitorUpdate`
pipelines to use a new async path via the
`handle_new_monitor_update` macro. This avoids having two message
sending pathways and simply sends messages in the "monitor update
completed" flow, which is shared between sync and async monitor
updates.
Here we reuse the new macro for handling `funding_signed` messages
when doing an initial `ChannelMonitor` persistence. This provides
a similar benefit, simplifying the code a trivial amount, but
importantly allows us to fully remove the original
`handle_monitor_update_res` macro.
Matt Corallo [Wed, 11 Jan 2023 21:37:57 +0000 (21:37 +0000)]
Always process `ChannelMonitorUpdate`s asynchronously
We currently have two codepaths on most channel update functions -
most methods return a set of messages to send a peer iff the
`ChannelMonitorUpdate` succeeds, but if it does not we push the
messages back into the `Channel` and then pull them back out when
the `ChannelMonitorUpdate` completes and send them then. This adds
a substantial amount of complexity in very critical codepaths.
Instead, here we swap all our channel update codepaths to
immediately set the channel-update-required flag and only return a
`ChannelMonitorUpdate` to the `ChannelManager`. Internally in the
`Channel` we store a queue of `ChannelMonitorUpdate`s, which will
become critical in future work to surface pending
`ChannelMonitorUpdate`s to users at startup so they can complete.
This leaves some redundant work in `Channel` to be cleaned up
later. Specifically, we still generate the messages which we will
now ignore and regenerate later.
This commit updates the `ChannelMonitorUpdate` pipeline across all
the places we generate them.
Matt Corallo [Sat, 3 Dec 2022 05:38:24 +0000 (05:38 +0000)]
Move TODO from `handle_monitor_update_res` into `Channel`
The TODO mentioned in `handle_monitor_update_res` about how we
might forget about HTLCs in case of permanent monitor update
failure still applies in spite of all our changes. If a channel is
drop'd in general, monitor-pending updates may be lost if the
monitor update failed to persist.
This was always the case, and is ultimately the general form of the
the specific TODO, so we simply leave comments there
Matt Corallo [Fri, 27 Jan 2023 06:14:18 +0000 (06:14 +0000)]
Handle `MonitorUpdateCompletionAction`s after monitor update sync
In a previous PR, we added a `MonitorUpdateCompletionAction` enum
which described actions to take after a `ChannelMonitorUpdate`
persistence completes. At the time, it was only used to execute
actions in-line, however in the next commit we'll start (correctly)
leaving the existing actions until after monitor updates complete.
Matt Corallo [Thu, 26 Jan 2023 04:47:25 +0000 (04:47 +0000)]
Limit the number of pending un-funded inbound channel
Because we store some (not large, but not zero) state per-peer,
it's useful to limit the number of peers we have connected, at
least with some buffer.
Much more importantly, each channel has a relatively large cost,
especially around the `ChannelMonitor`s we have to build for each.
Thus, here, we limit the number of channels per-peer which aren't
(yet) on-chain, as well as limit the number of (inbound) peers
which don't have a (funded-on-chain) channel.