In order to facilitate persistence during the funding process, added
the isPending flag to channels so that when the daemon restarts, we can
properly re-initialize the chain notifier and update the state of
channels that were going through the funding process.
In this commit the initial implementation of revocation hash
generation 'elkrem' was replaced with 'shachain' Rusty Russel
implementation which currently enshrined in the spec. This alghoritm has
the same asymptotic characteristics but has more complex scheme
to determine wish hash we can drop and what needs to be stored
in order to be able to achive full compression.
This commit removes the String() method from the FeatureVector as it
can produce confusing output when revving a feature vector and not
knowing the strip mapping ahead of time.
Introduce TimelockShift which is used to make sure the commitment
transaction is spendable by setting the locktime with it so that
it is larger than 500,000,000, thus interpreting it as Unix epoch
timestamp and not a block height. It is also smaller than the current
timestamp which has bit (1 << 30) set, so there is no risk of having
the commitment transaction be rejected. This way we can safely use
the lower 24 bits of the locktime field for part of the obscured
commitment transaction number.
Add tests to assert maximum state can be used. Also test
that more than one input in the commitment transaction
will fail and that having state number larger than
maxStateHint will fail.
Fix SetStateNumHint and GetStateNumHint to properly
set and get the stateNumHints using the lower 24 bits
of the locktime of the commitment transaction as the
lower 24 bits of the obfuscated state number and the
lower 24 bits of the sequence field as the higher 24
bits.
github.com/lightningnetwork/lnd master ✗
0m ◒
▶ golint
htlcswitch.go:292:4: should replace numUpdates += 1 with numUpdates++
htlcswitch.go:554:6: var onionId should be onionID
htlcswitch.go:629:7: var onionId should be onionID
lnd_test.go:133:1: context.Context should be the first parameter of a
function
lnd_test.go:177:1: context.Context should be the first parameter of a
function
networktest.go:84:2: struct field nodeId should be nodeID
peer.go:1704:16: should omit 2nd value from range; this loop is
equivalent to `for invoice := range ...`
rpcserver.go:57:6: func newRpcServer should be newRPCServer
github.com/lightningnetwork/lnd master ✗
9m ⚑ ◒ ⍉
▶ go vet
features.go:12: github.com/lightningnetwork/lnd/lnwire.Feature
composite literal uses unkeyed fields
fundingmanager.go:380: no formatting directive in Errorf call
exit status 1
This commit fixes a race condition in the notifyBlockEpochs detected by
the race condition detector. Previously the notifyBlockEpochs function
could cause a race condition when a new caller was either cancelling an
existing notification intent or creating a new one.
We fix this issue by making the call to notifyBlockEpochs synchronous
rather than asynchronous. An alternative would be to add a mutex
guarding the map state. The channel itself is buffered with a good
margin, so there shouldn’t be a huge impact.
This commit fixes a bug in the wallet’s internal reservation manager
that prevented it from cleaning up the resources used by a reservation
after it was finished running through the workflow.
We fix this issue by ensuring the reservations context is deleted from
the funding limbo.
It is the callers responsibility to properly .Cancel() a reservation in
the case of an error during the funding workflow.
Previously, during the channel funding process, peers sent wire
messages using peer.queueMsg. By switching to server.sendToPeer, the
fundingManager is more resilient to network connection issues or system
restarts during the funding process. With server.sendToPeer, if a peer
gets disconnected, the daemon can attempt to reconnect and continue the
process using the peer’s public key ID.
This commit adds a feature bit for the recently implemented state
machine as defined within the specification. With this commit, older
non-upgraded lnd nodes will fail a bit more gracefully when connecting
to updated nodes.
In this commit we modify the testSingleHopInvoice test to ensure that
we obtain the proper preimage from the SendPayment RPC upon successful
payment completion.
This commit creates a distint type for the opaque failure reason within
the UpdateFailHTLC message. This new type is needed as this is the only
variable length byte slice within the protocol and therefore requires a
length prefix in order to serialize/deserialize properly.
This commit fixes a bug that was introduced when we moved to using
64-bit integers for storing the revocation log state. When we made this
change, we forgot to increase the size of the buffer which stores the
key for the particular channel state from 40 to 44 bytes to account for
the 4 additional bytes in the new 64-bit integer.
This bug has been fixed by properly sizing the key buffer. We’ve also
added an additional test to ensure that we retrieve the proper state
after multiple state updates.
This commit adds an additional case of the closeObserver that will
properly handle the case of a channel being closed by a de-sync’d
commitment transaction from the PoV of the local node. In the case of a
minor 1-state divergence, the commitment transaction broadcast by the
remote node will be 1 state ahead of the commitment transaction we have
locally. This should be seen as a regular unilateral close as they
remote peer didn’t violate the channel contract in any way.
We address this case by changing the `==` to a `>=`.
This commit addresses an edge case which has been discovered by testers
of lnd of testnet. When/if channels get out of sync the unilateral
channel closure of a remote node may go undetected, which causes the
local node to lose their ability to purge the now closed channel from
their database state.
With this commit, if we try to force close a channel but detect it as
double-spent due to a prior commitment transaction being broadcast,
then we simply forget the channel as it has already been closed.
This commit modifies a peer’s htlcManager goroutine in order to
properly implement the new state machine defined by the specification.
The major change to this new state machine is that we can no longer
have a limited number of unrevoked commitment states. As a result, we
no longer need to track how many outsanding changes we have, and only
need to track if we have a pending change or not. This simplifies the
logic a bit.
Additionally, when receive a new signature we FIRST send an
RevokeAndAck, THEN we if we need to send a signature in response or
not. This is the major change to the state machine from the PoV of the
htlcManager. Previously, the order was flipped.
This commit updates the set of channel state machine tests to properly
compile and execute with the latest set of changes to the state
machine.
Most of the changes within this commit are just renaming and field
changes as a result of the new wire messages.
The more substantial change is due to the change in semantics of the
new state machine w.r.t what has and has not been ACK’d when a new
state transition is implemented. In the case of a concurrent update
(both sides add to the log before a state transition), both sides need
to trigger a state update in order to ensure their updates have been
included.
This commit updates the internal channel state machine to the one as
described within the spec and currently implemented within the rest of
the other Lightning implementations.
At a high level the following modifications have been made:
* When signing we no loner include the index of the remote party’s
log
that our signature covers. Instead we include ALL of our current
updates, but only the updates of the remote party that we’ve
ACK’d.
* A pending change is considered ACK’d once a revocation message
has been received, locking in the changes in the remote party’s
commitment transaction.
* When sending a new commitment, we remember the index of our
log at that point so we can mark that portion of the log as ACK’d
once we receive a revocation message from the remote party.
* When receiving a new commitment signature, we include ALL of
the remote party’s changes that we’ve received but only our set
of changes that’ve been ACK’d by the remote party.
* Implicitly a revocation message now also implicitly serves to ACK
all the changes that were included in the CommitSig message
received before it.
The resulting change is a rather minor diff. However, with this state
machine it’s important to note that the order to sig/revoke messages
has been swapped. A proper exchange now looks like the following:
* Alice -> Add, Add, Add
* Alice -> Sig
* Revoke <- Bob
* Sig <- Bob
* Alice -> Revoke
One other thing that’s worth noting is that with this state machine,
since what’s included in an update is implicit, both side may need to
at times send a new commitment update in the case of a concurrent state
transition initiated by both sides.
Finally, all counters/indexes have been made 64-bit integers in order
to properly match the spec.
This commit adds a new struct to the channel state machine: updateLog.
updateLog encapsulates the update log linked list itself, a series of
new counters we’ll need in order to switch to the spec’s state machine
and also the index into the log itself. This new struct serves to
simplify much of the logic surrounding the update log and also
elminates a bit of code duplication within the current state machine.
This commit only adds the new struct. The rest of the state machine
will be updated in a later commit to use the new log and its new
counters.
This commit fixes a bug in the LightingChannel commitment state machine
which could occasionally result in the total number of satoshis sent or
received being counted twice if a redundant state transition were
initiated.
To fix this bug, we now only increment the number of satoshi
sent/recv’d iff it’s the first time the HTLC has been processed.
This commit ensures that when a channel’s closeObserver is signaled to
exit before a channel closure has been detected, then the resources
dedicated to the pending spend notification can be freed up.
This commit minifies the BtcdNotifier concrete implementation of the
ChainNotifier interface to allow callers to optionally cancel an
outstanding block epoch or spend notificaiton intent.
To do this efficiently, we now give each notification intent a unique
ID based on if it’s an epoch intent or a spend intent. We then use this
ID to reference back to the original un-dispatched notification intent
when the caller wishes to cancel the intent.
When iterating with the ChainNotifier, it currently isn’t possible to
cancel a non-dispatched yet active notificaiton intent. As a result,
this can be rather wasteful in many parts of lnd which my repeatedly
create a new spend notification depending on if/when a peer is
connected or not.
In order to fix this, we add a new `Cancel func()` field to both the
`BlockEpochEvent` and `SpendEvent` structs. This new closure attribute
allows the caller to cancel the yet-to-be-dispathed event, allowing the
ChainNotifier to free up resources.
