feature-bit channels
This allows opening zero-conf chan-type, scid-alias chan-type, and
scid-alias feature-bit channels. scid-alias chan-type channels are
required to be private. Two paths are available for opening a zero-conf
channel:
* explicit chan-type negotiation
* LDK carve-out where chan-types are not used, LND is on the
receiving end, and a ChannelAcceptor is used to enable zero-conf
When a zero-conf channel is negotiated, the funding manager:
* sends a FundingLocked with an alias
* waits for a FundingLocked from the remote peer
* calls addToRouterGraph to persist the channel using our alias in
the graph. The peer's alias is used to send them a ChannelUpdate.
* wait for six confirmations. If public, the alias edge in the
graph is deleted and replaced (not atomically) with the confirmed
edge. Our policy is also read-and-replaced, but the counterparty's
policy won't exist until they send it to us.
When a scid-alias-feature channel is negotiated, the funding manager:
* sends a FundingLocked with an alias:
* calls addToRouterGraph, sends ChannelUpdate with the confirmed SCID
since it exists.
* when six confirmations occurs, the edge is deleted and re-inserted
since the peer may have sent us an alias ChannelUpdate that we are
storing in the graph.
Since it is possible for a user to toggle the scid-alias-feature-bit
to on while channels exist in the funding manager, care has been taken
to ensure that an alias is ALWAYS sent in the funding_locked message
if this happens.
This allows the router to determine what is and isn't an alias from
lnd's definition of an alias. Any ChannelAnnouncement that has an
alias ShortChannelID field is not verified on-chain. To prevent a
DoS vector from existing, the gossiper ensures that only the local
lnd node can send its ChannelAnnouncements to the router with an
alias ShortChannelID.
This commit was previously split into the following parts to ease
review:
- 2d746f68: replace imports
- 4008f0fd: use ecdsa.Signature
- 849e33d1: remove btcec.S256()
- b8f6ebbd: use v2 library correctly
- fa80bca9: bump go modules
To further separate the channel graph from the channel state, we
refactor the AddrsForNode method to use the graphs's public methods
instead of directly accessing any buckets. This makes sure that we can
have the channel state cached with just its buckets while not using a
kvdb level cache for the graph.
At the same time we refactor the graph's test to also be less dependent
upon the channel state DB.
Fixes an issue where an out of order block error occurs in the router. When this occurs, the change uses the chain notifier to catch up on missed blocks and uses those blocks to fully update the routing graph with closed channels. Fixes#4710, #5132
Adds an optional tx parameter to ForAllOutgoingChannels and FetchChannel
so that data can be queried within the context of an existing database
transaction.
In this commit, we fix a regression introduced by a recent bug fix in
this area. Before this change, we'd inspect the error returned by
`processSendError`, and then fail the payment from the PoV of mission
control using the returned error.
A recent refactoring removed `processSendError` and combined the logic
with `tryApplyChannelUpdate` in order to introduce a new
`handleSendError` method that consolidates the logic within the
`shardHandler`. Along the way, the behavior of the prior check was
replicated in the form of a new internal `failPayment` closure. However,
the new function closure ends up returning a `channeldb.FailureReason`
instance, which is actually an `error`.
In the wild, when `SendToRoute` fails due to an error at the
destination, then this new logic caused the `handleSendErorr` method to
fail with an error, returning an unstructured error back to the caller,
instead of the usual payment failure details.
We fix this by no longer checking the `handleSendErorr` for an error as
normal. The `handleSendErorr` function as is will always return an error
of type `*channeldb.FailureReason`, therefore we don't need to treat it
as a normal error. Instead, we check for the type of error returned, and
update the control tower state accordingly.
With this commit, the test added in the prior commit now passes.
Fixes#5477.
This commit moves the handleSendError method from ChannelRouter to
shardHandler. In doing so, shardHandler can now apply updates to the
in-memory paymentSession if they are found in the error message.
It seems #5246 introduced a subtle bug that lead to the error "out of
order block: expecting height=1, got height=XXX" some times during
startup. Apparently it can happen that during pruning of the graph tip
some blocks can come in before we start our chain view and the new block
subscription. By querying the chain backend for the best height before
syncing with the graph we ensure that we never miss a block.
The router subsystem has its own goroutine that receives chain updates
and then does its (quite time consuming) work on each new block. To make
it possible to find out what block the router currently is synced to, we
export its internal best height through a new method.
In this commit we add a new error for when we fail to validate the
funding transaction (invalid script, etc) and mark it as a zombie like
the other failed validation cases.
In this commit, we start to add any channels that fail the normal chain
validation to the zombie index. With this change, we'll ensure that we
won't continue to re-process the same set of spent channels over and
over again.
Fixes#5191.
This ensures the waiting receiving channel always receives an error to
prevent a deadlock when processing a network update that fails due to
the validation barrier.
On commit d5aedbcbd9:
1000 @ 0x43a285 0x44a38f 0xc42e86 0xc80fda 0xc8682d 0xc976c9 0x46fce1
github.com/lightningnetwork/lnd/routing.(*ChannelRouter).AddNode+0x245 github.com/lightningnetwork/lnd/routing/router.go:2218
github.com/lightningnetwork/lnd/discovery.(*AuthenticatedGossiper).addNode+0x3b9 github.com/lightningnetwork/lnd/discovery/gossiper.go:1510
github.com/lightningnetwork/lnd/discovery.(*AuthenticatedGossiper).processNetworkAnnouncement+0x574c github.com/lightningnetwork/lnd/discovery/gossiper.go:1554
github.com/lightningnetwork/lnd/discovery.(*AuthenticatedGossiper).networkHandler.func1+0x24github.com/lightningnetwork/lnd/discovery/gossiper.go:1043
Since we want to support AMP payment using a different unique payment
identifier (AMP payments don't go to one specific hash), we change the
nomenclature to be Identifier instead of PaymentHash.
We'll let the payment's lifecycle register each shard it's sending with
the ShardTracker, canceling failed shards. This will be the foundation
for correct AMP derivation for each shard we'll send.
To distinguish the attempt's unique ID from the overall payment
identifier, we name it attemptID everywhere, and note that the
paymentHash argument won't be the actual payment hash for AMP payments.
In this commit, we add strict zombie pruning as a config level param.
This allow us to add the option for those that want a tighter graph, and
not change the default composition of the channel graph for most users
over night.
In addition, we expand the test case slightly by testing that the self
node won't be pruned, but also that if there's a node with only a single
known stale edge, then both variants will prune that edge.
Since zombie pruning can be very slow on some devices (e.g. mobile) it
would stall lnd startup. Since it is not essential for pruning to be
finished for lnd to be functional, we instead delay the initial prune by
30 seconds.
Note that we could also wait for the graphPruneInterval to tick, but
since this is by default 2 hours, it is unlikely that a mobile app will
ever be open that long.
