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 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().
This is important for a number of reasons:
* Firstly, I hit this trying to implement rescan in the demo
bitcoinrpc client - if individual ChannelMonitors are out of
sync with each other, we cannot add them all into a
ManyChannelMonitor together and then rescan, but need to rescan
them individually without having to do a bunch of manual work.
Of the three return values in ChannelMonitor::block_connected,
only the HTLCsource stuff that is moved here makes no sense to
be exposed to the user.
* Secondly, the logic currently in ManyChannelMonitor cannot be
reproduced by the user! HTLCSource is deliberately an opaque
type but we use its data to decide which things to keep when
inserting into the HashMap. This would prevent a user from
properly implementing a replacement ManyChannelMonitor, which is
unacceptable.
* Finally, by moving the tracking into ChannelMonitor, we can
serialize them out, which prevents us from forgetting them when
loading from disk, though there are still other races which need
to be handled to make this fully safe (see TODOs in
ChannelManager).
This is safe as no two entries can have the same HTLCSource across
different channels (or, if they did, it would be a rather serious
bug), though note that, IIRC, when this code was added, the
HTLCSource field in the values was not present.
We also take this opportunity to rename the fetch function to match
our other event interfaces, makaing it clear that by calling the
function the set of HTLCUpdates will also be cleared.
Previously, if we have a live ChannelManager (that has seen blocks)
and we open a new Channel, if we serialize that ChannelManager
before a new block comes in, we'll fail to deserialize it. This is
the result of an overly-ambigious last_block_connected check which
would see 0s for the new channel but the previous block for the
ChannelManager as a whole.
We add a new test which catches this error as well as hopefully
getting some test coverage for other similar issues in the future.
This implements the new TLV variable-length encoding for onion hop
data, opting to send it if the RouteHop's node_features indicates
support. It also uses the new process_inline method in ChaCha20 to
optimize a few things (though it grows a new TODO for a
probably-important optimization).
This prepares for variable-length per-hop-data by wrapping the full
hop_data field in a decrypting stream, with a few minor
optimizations and redundant allocations to boot.
Its a bit awkward to have an hmac field covering the struct that
its in, and there is little difference in removing it, so just pull
it out and use a [u8; 32] where we care about the hmac.
Previously OnionHopData contained a OnionRealm0HopData field however
instead of bumping the realm number, it has been replaced with a
length, used to indicte the length of a TLV-formatted object.
Because a TLV-formatted hop data can contain the same information as
a realm-0 hop data, we flatten the field and simply keep track of
what format it was in.
Additional changes:
* Update fuzz crate to match ChannelManager's new API
* Update lightning-net-tokio library to match ChannelManager's new ChannelMonitor Deref API
* Update tests to match ChannelManager's new ChannelMonitor Deref API
This exposes the latest Init-context features in the ChannelDetails
passed to the Router during route calculation, which combines those
with the Node-context features tracked from node_announcements to
provide the latest Node-context features in RouteHop structs.
Fields are also added for Channel-context features, though those are
only partially used since no such features are defined today anyway.
These will be useful when determining whether to use new
TLV-formatted onion hop datas when generating onions for peers.
Since we want to keep track of the Init-context features for every
peer we have channels with, we have to keep them for as long as the
peer is connected (since we may open a channel with them at any
point).
We go ahead and take this opportunity to create a new per-peer-state
struct which has two levels of mutexes which is appropriate for
moving channel storage to.
Since we can't process messages from a given peer in parallel, the
inner lock is a regular mutex, but the outer lock is RW so that we
can process for different peers at the same time with an outer read
lock.
Accessing a struct through an std::syn::MutexGuard using implicit
dereferencing can confuse the borrow checker. This situation arises when
obtaining mutable references to more than one field of the struct, which
is normally allowed.
https://doc.rust-lang.org/nomicon/borrow-splitting.html
However, when using implicit dereferencing, a mutable reference to the
the entire struct is taken. Thus, attempting to access another field in
this manner will lead to a compilation error.
https://doc.rust-lang.org/error-index.html#E0499
A simple way to avoid this is to first obtain a mutable reference to the
struct using explicit dereferencing.
This merges local and global features into one struct, which is
parameterized by where it appers. The parameterization restricts
which queries can be made and which features can be set, in line
with the latest BOLT 9.
Closes#427.
Simplify interfaces between ChannelMessageHandler and PeerManager,
by switching all ChannelMessageHandler errors to HandleError sent
internally instead of being return. With further refactors in Router
and PeerChannelEncryptor, errors management on the PeerManager-side
won't be splitted between try_potential_handleerror and HandleError
processing.
Inside ChannelManager, we now log MsgHandleErrInternal and send
ErrorAction to PeerManager.
On a high-level, it should allow client using API to be more flexible
by polling events instead of waiting function call returns.
We also update handle_error macro to take channel_state_lock from
caller which should avoid some deadlock potential for some edges
cases.
Filter out IgnoreError in handle_error macro, update test in
consequence.
We now have current-local-tx broadcast ability in channel monitors
directly (for ChannelManager deserialization), so we can just use
that instead of always having the Channel store signed ready-to-go
copies of the latest local commitment transaction.
This is further kinda nice since ChannelMonitor is live and can, eg
broadcast HTLC-Success transactions immediately as they will be
generated at broadcast time instead of in advance.
Finally, this lets us clean up a tiny bit in Channel.
Instead of having in-memory access to the list of private keys
associated with a channel, we should have a generic API which
allows us to request signing, allowing the user to store private
keys any way they like.
The first step is the (rather mechanical) process of templating
the entire tree of ChannelManager -> Channel impls by the
key-providing type. In a later commit we should expose only public
keys where possible.
Latency/peer disconnection may trigger us to mark as disabled
some of our channels. After some time, if channels are still
disabled we need to broadcast ChannelUpdate to inform other network
peers about the uselessness of these channels.
Because filter_block takes a and returns a list of s , we must add a lifetime to the ChainWatchInterface, which bubbles up in a lot of places. These places include adding a lifetime to the Node struct, which causes a lot of rearranging tests so that variables don't go out of scope before the Node that owns them does.
Adding this struct will allow us to remove the circular reference
between ChainListeners and the ChainWatchInterface, because it
separates out the responsibility of notifying listeners about new
blocks from the responsibility of storing and retrieving watched
transactions.
This includes the purpose of this PR, which is to remove the circular reference created by ChainListeners self-adding themselves to their ChainWatchInterface's `listeners` field.
