Commit Graph

258 Commits

Author SHA1 Message Date
Andrey Samokhvalov
1b4e723a5d htlcswicth+channel: switch to store onion blobs in payment descriptor
After addition of the retransmission logic in the channel link, we
should make the onion blobs persistant, the proper way to do this is
include the onion blobs in the payment descriptor rather than storing
them in the distinct struct in the channel link.
2017-11-09 16:38:57 -08:00
Andrey Samokhvalov
d70ffe93e4 htlcswitch+channel: add channel states synchronization
In this commit BOLT№2 retranmission logic for the channel link have
been added. Now if channel link have been initialised with the
'SyncState' field than it will send the lnwire.ChannelReestablish
message and will be waiting for receiving the same message from remote
side. Exchange of this message allow both sides understand which
updates they should exchange with each other in order sync their
states.
2017-11-09 16:38:57 -08:00
Jim Posen
a13ad0a339 multi: Fix various typos. 2017-10-25 13:20:54 -07:00
Jim Posen
2b58a39d30 lnwallet: Simplify updateLog struct by removing redundant pointers.
The updateLog struct contains pointers that refer to the state of the
commitment chains. Instead, query the commitments directly.
2017-10-25 13:11:46 -07:00
Olaoluwa Osuntokun
3b94e5df4d
lnwallet: introduce distinct HTLC counter+index on top of updateLog
In this commit, we fix an existing derivation from the commitment state
machine as defined within the specification. Before this commit, we
only kept a single counter which both HTLC adds and fails/settles would
share. This was valid in the prior pre-spec iteration of the state
machine. However in the current draft of the spec, only a distinct
counter for HTLCs are used throughout.

This would cause an incompatibility, as if we mixed adds and settles
during an exchange, then our counter values would differ with other
implementations. To remedy this, we now introduce a distinct HTLC
counter and index within the updateLog.

Each Add will increment both the log counter, and the HTLC counter.
Each Settle/Fail will only increment the log counter. Inbound
Settle/Fails will index into the HTLC index as to target the proper
HTLC. The PaymentDescriptor type has been extended with an additional
field (HltcIndex) which itself tracks the index of an incoming/outgoing
HTLC.
2017-10-22 18:36:57 -07:00
Jim Posen
7c1ae8bda3 lnwallet: Split tx generation code out of fetchCommitmentView.
This moves the commitment transaction generation code out of
fetchCommitmentView into createCommitmentTx. Aside from being a pretty
clean logical split, this allows the transaction generation code to be
unit tested more effectively.
2017-10-19 22:23:14 -07:00
Jim Posen
bd497438af lnwallet: Pass around key ring instead of individual keys.
The signatures of some functions/methods in lnwallet are simplified by
passing in a commitmentKeyRing argument instead of multiple keys.
2017-10-19 22:23:14 -07:00
Jim Posen
3151a3a596 lnwallet: Refactor commitment key generation code.
Create struct holding all commitment keys to clean up code and avoid
deriving keys multiple times.
2017-10-19 22:23:14 -07:00
Laura Cressman
156772d04a channeldb: use binary.Read/Write with bools in channel.go
Use binary.Read/Write in functions to serialize and deserialize
channel close summary and HTLC boolean data, as well as in
methods to put and fetch channel funding info. Remove lnd
implementations of readBool and writeBool as they are no
longer needed. Also fix a few minor typos.
2017-10-02 23:13:47 -07:00
flaurida
e106cfdef1 lnwallet: replace sort.Sort with sort.Slice in channel.go
Use sort.Slice in SignNextCommitment function in lnwallet/channel.go,
as part of the move to use new language features. Remove
sortableSignBatch type wrapper for slice of signJobs since it is
no longer needed to sort jobs according to their output indices.
Also fix a few minor typos in channel.go and sigpool.go.
2017-10-02 23:13:47 -07:00
Johan T. Halseth
6b3844ea66
lnwallet: add getter for channelState.RemoteNextCommitment 2017-10-02 13:29:32 +02:00
Olaoluwa Osuntokun
30d5b90626
lnwallet: properly derive key tweaks in newHtlcResolution
This commit fixes an existing bug where we attempted to re-use the same
commitTweak value when creating an HTLC resolution. Instead, we now
create the commit tweak value factoring the key that is to be used for
signing.
2017-09-29 20:27:19 -07:00
Olaoluwa Osuntokun
dc764c992c
lnwallet: fix bug in extractHtlcResolutions, ensure slice is contiguous
This commit fixes an existing bug within extractHtlcResolutions. The
prior code would use an index to assign the returned
OutgoingHtlcResolutions into a single slice. However, this is invalid
as there are two cases where an HTLC might be skipped: if it’s an
incoming HTLC, or if the HLTC itself is dust from the PoV of the
commitment chain.

To fix this, we now instead use append to add items to the slice. This
ensure that we don’t have any “empty” items in between fully populated
items.
2017-09-29 14:32:22 -07:00
Olaoluwa Osuntokun
2141b481ef
lnwallet: properly set the pkScript within an HTLC resolution 2017-09-29 14:28:19 -07:00
Olaoluwa Osuntokun
0086e6e427
lnwallet: in extractHtlcResolutions use csvDelay gated on commitment ownership
This commit fixes a bug wherein we would use the incorrect csvDelay
when crafting HTLC resolutions after a unilateral channel closure.
Previously, we would always use the csvDelay of the local party, as in
the force close case that’s the correct value. However, a unilateral
channel closure instead requires the _remote_ delay.
2017-09-26 19:06:55 -07:00
Olaoluwa Osuntokun
21782374c9
lnwallet: properly use delayKey for htlc-timeout tx in newHtlcResolution
This commit fixes an existing bug when crafting the HTLC resolution in
the face of a commitment broadcast. Previously, we we’re using the
localKey which is incorrect, as directly below we properly use the
delayKey when crafting the secondLevelHtlcScript to sign.
2017-09-26 18:31:22 -07:00
Olaoluwa Osuntokun
8a682d9ec3
lnwallet: add a MaturityDelay field to UnilateralCloseSummary
This commit adds a new field: MaturityDelay, to the
UnilateralCloseSummary struct. This new field will be required, in an
upcoming update as it’s needed in order to properly sweep the
second-level HTLC outputs after MaturityDelay blocks has passed since
confirmation.
2017-09-26 18:00:24 -07:00
Olaoluwa Osuntokun
34604f6214
lnwallet: properly use the p2wkh script in SignDesc for retributions
This commit fixes a minor bug (that doesn’t affect anything atm) when
crafting the SignDesc for sweeping breached outputs. Previously, we
would take the p2wkh script and then p2wsh-ify that, placing that into
the SignDesc. This is incorrect as the p2wkh script is “injected” into
the sighash when signing, and thus doesn’t need another encoding layer.
2017-09-26 17:57:29 -07:00
Olaoluwa Osuntokun
1d487ea78b Merge pull request #341 from cfromknecht/breach-filter-commit-dust
Breach Arbiter Ignore Dust Commitment Outputs
2017-09-26 17:10:12 -07:00
Conner Fromknecht
223f77d135
lnwallet/channel: filter commitment outputs if dust 2017-09-25 18:57:03 -07:00
Olaoluwa Osuntokun
21d151d2ce
lnwallet: ensure the goroutines of all channels are stopped after test execution 2017-09-24 20:20:15 -07:00
Olaoluwa Osuntokun
9164cc218a
lnwallet: modify ReceiveFailHTLC to return value of HTLC failed 2017-09-24 20:17:53 -07:00
Olaoluwa Osuntokun
f576a74bf6
lnwallet: modify SettleHTLC to return value of HTLC settled
This commit adds an additional return value to SettleHTLC in order to
make way for an upcoming change to modify the way bandwidth status from
the link to the switch is reported.
2017-09-24 20:17:14 -07:00
Olaoluwa Osuntokun
815826caac
lnwallet: remove public LocalAvailableBalance method from channel
This commit removes the current active LocalAvailableBalance method
from the channel state machine itself. We still maintain the internal
availableLocalBalance method locally as this is used to ensure that we
don’t add an HTLC which puts our available balance below zero.
2017-09-24 20:13:04 -07:00
Conner Fromknecht
faf1d40bd0
lnwallet/channel: adds directionality htlc retributions
This commit also adds an incoming flag to
        HtlcRetribution struct to allow the breach arbiter to
        generate the appropriate witness based on the htlc's
        directionality.

        It also ensures that the size of the htlc retribution
        slice is now determined by the size of the number of
        htlcs present in the revoked snapshot, which fixes a
        minor bug that could lead to nil pointer deferences.
2017-09-19 19:18:20 -07:00
Olaoluwa Osuntokun
a52d405998
lnwallet: ensure HTLC values are properly converted to SAT in commit tx
This commit fixes a bug within the HTLC construction and commitment
transaction construction that would result in HTLC _values_ within the
commitment transaction being off by a factor of 1000. This was due to
the fact that we failed to convert the amount of an HTLC, in mSAT, to
SAT before placing it as an output within the commitment transaction.
When attempt to locate the output index of a particular half, we use
the unconverted amount, meaning it was unnoticed.

This commit adds a new assertion within the TestSimpleAddSettleWorkflow
test to ensure that the HTLC is found within the commitment transaction
with the proper value in satoshi.
2017-08-30 15:34:18 -07:00
Olaoluwa Osuntokun
6e54aba7ac
lnwallet: convert channel state machine accounting to milli-satoshi 2017-08-22 00:52:50 -07:00
Johan T. Halseth
b9516b7cdd
lnwallet: make CreateCloseProposal take absolute fee instead of fee rate 2017-08-11 12:09:39 +02:00
Olaoluwa Osuntokun
43b736225b
multi: add new method to generate fresh node announcments 2017-08-04 18:32:33 -07:00
Olaoluwa Osuntokun
db793991ac
lnwallet: don't add trimmed HTLC value to initiator commitment fees
This commit fixes a lingering bug in the way the internal channel state
machine handled fee calculation. Previously, we would count the dust
HTLC’s that were trimmed towards the fee that the initiator paid. This
is invalid as otherwise, the initiator would always benefit from dust
HTLC’s. Instead, we now simply “donate” the dust HTLC’s to the miner in
the commitment transaction. This change puts us in compliance with
BOLT-0003.
2017-07-31 20:41:23 -07:00
Olaoluwa Osuntokun
5ece7fec2d
lnwallet: add a String() method to updateType 2017-07-31 20:37:51 -07:00
Olaoluwa Osuntokun
747e0f57d1
multi: fix linter errors 2017-07-30 18:22:45 -07:00
Olaoluwa Osuntokun
899fa1ea3e
lnwallet: properly populate the signDesc within UnilateralCloseSummary
This commit modifies the closeObserver code to populate the signDesc in
the case we have a non-trimmed balance. Additionally, we now also add a
*wire.OutPoint field to the struct in order to allow receivers of the
message to construct a witness that can spend the newly created output
to their wallet.
2017-07-30 17:52:18 -07:00
Olaoluwa Osuntokun
8a23de5303
lnwallet: consult current state instead of revocation log during unilateral closure 2017-07-30 17:52:14 -07:00
Olaoluwa Osuntokun
8121bc77ce
lnwallet: add delivery scripts as a param to CreateCloseProposal+ CompleteCooperativeClose
This commit modifies the methods that transition the state of the
channel into an active closing state. With the new commitment design,
the delivery scripts are no longer pre-committed to the initial funding
messages. Instead, the scripts are sent at the instant that either side
decides to shutdown within the Shutdown message.
2017-07-30 17:51:05 -07:00
Olaoluwa Osuntokun
40e9120c04
lnwallet: populate HTLC resolutions after observing a unilateral channel close 2017-07-30 17:51:02 -07:00
Olaoluwa Osuntokun
01aa4eb2ae
lnwallet: populate HTLC resolutions within the ForceCloseSummary 2017-07-30 17:50:59 -07:00
Olaoluwa Osuntokun
83e0116d7e
lnwallet: extend the UnilateralCloseSummary to include HTLC resolutions
This commit adds a new companion struct: OutgoingHtlcResolution to the
commitment state machine. The purpose of this struct is the provide the
caller with the information necessary to sweep all outgoing HTLC’s in
the case of a broadcast up-to-date commitment transaction.

The HTLC resolutions allow a caller to sweep an outgoing HTLC into
their wallet after the absolute timeout of the HTLc has passed. This is
a two step process, with the first portion consisting of broadcasting
the HTLC timeout transaction itself, and the second portion consisting
of claiming the HTLC itself after a CSV delay.
2017-07-30 17:50:55 -07:00
Olaoluwa Osuntokun
a4c07d061e
lnwallet: the BreachRetribution struct is now aware of HTLC outputs
This commit adds awareness of active HTLC outputs to the
BreachRetribution struct. Previously, in the case of a breach, the
struct was only populated with enough information to sweep the two
commitment outputs. With this commit, the struct now has enough
information to sweep _all_ outputs within the commitment transaction.
2017-07-30 17:50:51 -07:00
Olaoluwa Osuntokun
5a78f80ffe
lnwallet: update restoreStateLogs to be aware of new commitment scheme 2017-07-30 17:50:47 -07:00
Olaoluwa Osuntokun
b9da43a2b8
lnwallet: update fetchCommitmentView due to new commitment design
This commit updates the central fetchCommitmentView method to manage
and derive the necessary easy required to create new commitments due to
the new state machine design within the specification. Each state now
requires us to derive a number of keys for each commitment state:
localDelay, remoteDelay, localKey, remoteKey, the commitment point, and
finally the revocation key itself.
2017-07-30 17:50:43 -07:00
Olaoluwa Osuntokun
3a052d2874
lnwallet: when creating new states, dispatch HTLC signing to sigPool 2017-07-30 17:50:40 -07:00
Olaoluwa Osuntokun
f569b80a80
lnwallet: when verifying new states, dispatch HTLC sig validation to sigPool 2017-07-30 17:50:37 -07:00
Olaoluwa Osuntokun
cd8672f824
lnwallet: update CreateCommitTx due to new key derivation 2017-07-30 17:50:34 -07:00
Olaoluwa Osuntokun
e314b83559
lnwallet: update HTLC script generation to account for new covenant HTLC's
This commit updates the set of functions tasked with generating HTLC’s
scripts for new commitments to now adhere to the new commitment
transaction design. With this change, the process of claiming an HTLC
now requires a second-level HTLC transaction, which solves a prior
issues due to the tight coupling of the timeout and delay clauses when
claiming an HTLC.
2017-07-30 17:50:31 -07:00
Olaoluwa Osuntokun
8b9a58cb15
lnwallet: add a sigPool instances to the state machine struct 2017-07-30 17:50:27 -07:00
Olaoluwa Osuntokun
4c9bd9dc54
lnwallet: when handling possible channel breach, only log if contract breach 2017-07-30 17:50:24 -07:00
Olaoluwa Osuntokun
e56258917e
lnwallet: introduce populateHtlcIndexes for tracking HTLC indexes in commitments
This commit adds a new method to the commitment struct:
populateHtlcIndexes.  populateHtlcIndexes modifies the set of HTLC's
locked-into the target view to have full indexing information
populated. This information is required as we need to keep track of the
indexes of each HTLC in order to properly write the current state to
disk, and also to locate the PaymentDescriptor corresponding to HTLC
outputs in the commitment transaction.

We also modify toChannelDelta to take not of these new changes, and
access the appropriate index directly.
2017-07-30 17:50:21 -07:00
Olaoluwa Osuntokun
549688d793
lnwallet: remove isDustLocal and isDustRemote, replace w/ htlcIsDust
This commit modifies the way we account for dust HTLC’s within the
commitment state machine when creating and validating new states.
Previously, an HTLC was dust if the amount of the HTLC was below the
dustLimit of the commitment chain. Now, with the HTLC covenant
transaction, the value of the HTLC also needs to cover the required fee
of the HTLC covenant transaction at the specified fee rate of the
commitment chain.

As a result, we now determine if an HTLC is dust or not, only at the
commitment site, using the new htlcIsDust function.
2017-07-30 17:50:16 -07:00
Olaoluwa Osuntokun
91165d98bb
lnwallet: eliminate the InitialRevocationWindow within the state machine
This commit modifies the current core channel state machine in order to
may a step towards BOLT-0002 and BOLT-0003 compliance. In this change,
we abandon the prior revocation window, in favor of a fixed revocation
window of size two. The revocation window will be filled at the start
of the lifetime of the channel, and never extended from there until the
channel has been fully closed.

We now maintain two variables, the current un-revoked commitment point,
and the next commitment point to use when creating a new state. The
next commitment point must initially be inserted into the channel state
with the InitNextRevocation method.

A major difference between the prior revocation key handling is that
the remote party now instead sends us the _commitment point_ in
isolation, which we then use locally (with our revocation base point)
to create the next full revocation key for _their_ commitment
transaction.
2017-07-30 17:50:13 -07:00
Olaoluwa Osuntokun
c7df82ab68
lnwallet: update the LightningChannel API usage for recent channels changes
This commit updates much of the state interaction within the
LightningChannel structure to account for the recent changes within the
chanenldb involving the OpenChannel struct, namely the introduction of
ChannelConfig and ChannelConstraints.
2017-07-30 17:50:10 -07:00
Olaoluwa Osuntokun
14832d8c09
lnwallet+lnwire: minor grammatical fixes after UpdateFee merge 2017-07-14 17:10:42 -07:00
Johan T. Halseth
ebe05f6568 lnwallet: add update_fee message support.
This commit adds the possibility for the initiator of a
channel to send the update_fee message, as specified
in BOLT#2. After the message is sent and both parties
have committed to the updated fee, all new commitment
messages in the channel will use the specified fee.
2017-07-14 16:39:15 -07:00
bryanvu
5068541044 lnwallet: apply dust HTLC amounts to fees
If an HTLC’s value is below a node’s dust limit, the amount for that
HTLC should be applied to to the fee used for the channel’s commitment
transaction.
2017-07-06 18:05:43 -07:00
Olaoluwa Osuntokun
5dd7b157a0
lnwallet: fix race condition when forwarding by creating new pubkey
This commit fixes a race condition that would at times occur in the
htlcswitch.TestChannelLinkBidirectionalOneHopPayments test case. A race
condition would occur in the goroutine running ReceiveNewCommitment
compared with the grouting that would obtain the snapshot in order to
make a forwarding decision.

We fix this by creating a new public key for each new commitment
transaction such that we complete avoid the read/write race condition.
2017-06-19 17:43:57 +02:00
Olaoluwa Osuntokun
6937a42f2d
lnwallet: add new ShortChanID method to LightningChannel 2017-06-16 23:25:13 +02:00
Olaoluwa Osuntokun
2e05051176
lnwallet: clarify comment within commitment state sanity function 2017-06-08 22:25:06 -07:00
Olaoluwa Osuntokun
9676d476c9
lnwallet: fix race condition in channel state machine, use single mutex
This commit fixes a race condition that was discovered as a result of
the new htlcswitch package. The StateSnapshot method and all of the
other methods which mutate the state of the channel state machine were
using distinct mutexes. The fix is trivial: all methods accessing the
internal channel state variable now use the same mutex.
2017-06-08 22:24:20 -07:00
Olaoluwa Osuntokun
54f849a62e
lnwallet: use the FundingBroadcastHeight as height hint for spend ntfns 2017-06-05 19:17:13 -07:00
Andrey Samokhvalov
f774e3d9bf lnwallet: add missed addition of RHash
add rhash to the payment descriptor when receiving the settle htlc in
order to be able to pass it during settle htlc packet generation and
later find the user pending payment by rhash without additional hashing.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
0e51b1d22d channeldb: add available balance function
In this commit we made state machine to be responsible for returning
proper available balance - amount of satoshi which we able to use at
current moment. This will help us in constrction channel link
abstraction.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
fde27716d1 channeldb: add restriction to to use only half of the capacity locally
In this commit severe bug have been fixed which allows the state of the
nodes to be desychnorinesed in the moments of high htlc flow. We limit
the number of the htlc which we can add to commitment transaction
to half of the available capcity. This change fixes the bug when
commimtment transaction on the verge of being full, in this case race
condition might occures and remote htlc will be rejected, but at the
same time they will be added on remote side, the same situiation will
happen with htlc we have added, which cause the commitment transactions
to be different.
2017-05-31 11:06:08 -07:00
bryanvu
408be356fb lnwallet: update channel close to use fee estimation interface
This commit switches the channel close workflow to use the lnwallet fee
estimation interface rather than the hardcoded proposedFee.
2017-05-23 14:31:20 -07:00
bryanvu
514760f529 peer: handling for channel shutdown messages
This commit changes the cooperative channel close workflow to comply
with the latest spec. This adds steps to handle and send shutdown
messages as well as moving responsibility for sending the channel close
message from the initiator to the responder.
2017-05-23 14:31:20 -07:00
Olaoluwa Osuntokun
e689ef61dd
lnwallet: when calc'ing fee for commitment tx, use current fee-per-kw
This commit modifies the fee calculation logic when creating or
accepting a new commitment transaction to use the set FeePerKw within
the channel rather then re-query the estimator each time. The prior
behavior was benign as we currently use a static fee estimator, but the
dynamic setting this could’ve caused a state divergence.
2017-05-16 19:05:18 -07:00
Olaoluwa Osuntokun
82f591dbab
lnwallet: add TODO to properly roll dust outputs into initiator's paid fee 2017-05-16 19:02:52 -07:00
bryanvu
4ac7cc719f lnwallet: replace hard-coded fees and adjust tests accordingly
This commit replaces the hard-coded 5000 satoshi fees with calls to the
FeeEstimator interface. This should provide a way to cleanly plug in
additional fee calculation algorithms in the future. This change
affected quite a few tests. When possible, the tests were changed to
assert amounts sent rather than balances so that fees wouldn't need to
be taken into account. There were several tests for which this wasn't
possible, so calls to the static fee calculator were made.
2017-05-15 20:26:11 -07:00
bryanvu
abe2e502d5 lnwallet: add FeeEstimator interface, StaticFeeEstimator implementation
This commit adds the FeeEstimator interface, which can be used for
future fee calculation implementations. Currently, there is only the
StaticFeeEstimator implementation, which returns the same fee rate for
any transaction.
2017-05-15 20:26:11 -07:00
bryanvu
320bed7e6b lnwallet: add CommitFee field to OpenChannel
In order to cleanly handle shutdowns and restarts during state machine operation, the fee for the current
commitment transaction must be persisted. This allows the fee to be
reapplied when the current state is reloaded.
2017-05-15 20:26:11 -07:00
Olaoluwa Osuntokun
80598dff11
lnwallet: in closeObserver if commitment is is ours, exit early 2017-05-15 18:21:02 -07:00
Olaoluwa Osuntokun
d2585ae6e5
lnwallet: add new struct UnilateralCloseSummary to provide complete channel close details 2017-05-15 18:20:59 -07:00
Olaoluwa Osuntokun
34959e4648
peer+lnwallet: update API usage to recent channeldb changes 2017-05-14 19:23:57 -07:00
Olaoluwa Osuntokun
1b4862d815
lnwallet: use new ChainNotifier API, typo fixes 2017-05-11 15:21:05 -07:00
Olaoluwa Osuntokun
521c76d65a
lnwallet: add distinct channel to send close details over
This commit modifies the actions of the closeObserver goroutine to
utilize a _new_ channel to send channel close details over. The
original close signal channel is still used to notify observers that a
channel _has_ been closed, but this new channel will provide a single
observer with details w.r.t _how_ a channel was closed.
2017-05-04 17:39:24 -07:00
Olaoluwa Osuntokun
5e48cf1273
lnwallet: upon force close detection populate close summary 2017-05-04 17:39:22 -07:00
Olaoluwa Osuntokun
be583306ab
lnwallet: include the origin chanPoint in the ForceCloseSummary
This commit adds an additional field to the ForceCloseSummary that
allows observers of the channel that sends this struct to track _which_
channel the force close came from.
2017-05-04 17:39:20 -07:00
Olaoluwa Osuntokun
77ae9f560e
lnwallet: update DeleteState method to latest DB API change 2017-05-04 17:39:17 -07:00
Olaoluwa Osuntokun
c06894a2e6
lnwire: replace ChannelPoint with ChannelID, use new PendingChanID 2017-04-16 15:22:27 -07:00
Olaoluwa Osuntokun
17d6835861
lnwallet: removed unused sync.RWMutex in PaymentDescriptor 2017-04-11 22:08:25 -07:00
Olaoluwa Osuntokun
31acace692
lnwallet: convert PendingUpdates to FullySynced
This commit improves the channel state machine by converting the
objective PendingUpdates method to a subjective FullySynced method
which is to be used in place of PendingUpdates. The new FullySynced
method is fully encompassing and replaces any upper state required by
the state machine which wraps this one.

The new FullySynced method is identical to PendingUpdates aside from
the fact that: it now also factors in the log message index of the
remote commitment chain, and also introduces a concept of an “owed
commitment”. A commitment chain owes a commitment if the height of the
local commitment chain is higher than that of the remote chain.
2017-04-11 22:02:33 -07:00
Olaoluwa Osuntokun
4cd277c8da
lnwallet: eliminate usage of LightningChannel.theirPrevPkScript
This commit removes the theirPrevPkScript field from the
LightningChannel struct all together. It’s no longer needed as the more
fundamental mutation bug has been fixed within the channel state
machine.
2017-04-11 22:02:30 -07:00
Olaoluwa Osuntokun
a3fd738491
lnwallet: fix HTLC mutation bug in commitment chain
This commit fixes a class of bug that can arise in the channel state
machine when a very high throughput workflow is attempted. Since the
PaymentDescriptor’s within a commitment pointed directly into the log,
any changes to a payment descriptor would also be reflected in all
other ones. Due to this mutation possibility, at times, the
locateOutputIndex method would fail since the HTLC’s pkScript was
modified, causing the channel to fail.

We fix this class of bug by simply ensure that once an HTLC has been
associated with a particular commitment, then it becomes immutable.
2017-04-11 22:02:26 -07:00
Olaoluwa Osuntokun
eca3a10064
lnwallet: reorder PaymentDescriptor attributes to reduce padding 2017-04-11 22:02:23 -07:00
Olaoluwa Osuntokun
d6c863e2d1
lnwallet: initialize the height of both commitment chains independently
This commit fixes a slight oversight in the current state machine which
assumes that both commitment chains are always at the same height. In a
future where we move back to allowing nodes to pipeline commitment
updates, this will not always be the case.
2017-03-24 16:26:03 -07:00
Olaoluwa Osuntokun
a8671c485f
lnwallet: properly observe dust limits during cooperative chan closure
This commit fixes a lingering TODO within the wallet portion of the
codebase by properly adhering to the set dust limits when closing a
channel. With this new commit if a party’s current settled balance is
below their current dust-limit, then it will be omitted from the
commitment transaction.

The prior test that asserted negative outputs are rejected has been
removed as they’ll now be avoided by ensuring we omit dust outputs from
the commitment transaction.
2017-03-24 16:20:12 -07:00
Olaoluwa Osuntokun
2dd1c0de3d
lnwallet: adhere to project code-style in restoreStateLogs
This commit does some minor shuffling around and also adds some
additional comments to the restoreStateLogs method within the channel
state machine. After the latest merge in this area, the code has
diverged slightly from what’s considered typical within the rest of the
codebase.
2017-03-24 16:15:19 -07:00
Olaoluwa Osuntokun
c241892104
lnwallet: use full struct initialization for outputs in CreateCommitmentTx 2017-03-24 16:13:36 -07:00
Christopher Jämthagen
d958ea005f lnwallet: check for correct value in HTLC outputs in commitment transaction
It is possible that that there are multiple HTLCs with different values,
but the same public key script. As such, a check against the value should
be performed when looking for HTLC outputs in a commitment transaction.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
17d29ba62e lnwallet: properly restore public key scripts for HTLCs
Create a new helper method called genHtlcScript which will
generate the public key scripts for a supplied HTLC. This functionality
from addHTLC is removed, and addHTLC will instead call this new
method.

In restoreStateLogs we will regenerate the public key scripts for the
HTLCs with genHtlcScript and restore the proper values.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
78e102f08d lnwallet: fix settled/cancelled HTLCs remote pkScripts + cleanup
When an HTLC is either cancelled or settled we must properly set the
pkScript for the HTLC on the remote commitment, such that we can
generate a valid ChannelDelta.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
2222df21f3 lnwallet: fix dust limit checks and toChannelDelta() handling of dust 2017-03-21 21:21:46 -07:00
Christopher Jämthagen
05a90df67a lnwallet: return error from toChannelDelta() if htlc output is not found 2017-03-21 21:21:46 -07:00
Christopher Jämthagen
9083007ece lnwallet: fix bug that retrieves incorrect pkScript in toChannelDelta()
Description of bug:
When calling ReceiveNewCommitment() we will progress through methods
fetchCommitmentView and addHTLC which will add HTLC outputs to the
commitment transaction in the local commitment chain and save the
pkScript to the relevant PaymentDescriptor which resides in the
corresponding updateLog. Finally the local commitment will be added
to the local commitment chain.

When the same user next calls SignNextCommitment we will again
progress through fetchCommitmentView and addHTLC. In addHTLC we will
now overwrite the pkScripts in the PaymentDescriptors with the
pkScript from the context of the remote commitment. When we later
call RevokeCurrentCommitment and proceed into toChannelDelta, we
will not be able to find the correct pkScript in the PaymentDescriptor
to match it against the outputs in the commitment transaction.
This will lead to the nested function locateOutputIndex returning
incorrect values.

Fixing the bug:
We introduce three new fields in PaymentDescriptor:
* ourPkScript
* theirPkScript
* theirPrevPkScript

ourPkScript will include the pkScript for the HTLC from the context
of the local commitment.

theirPkScript will take the value of the latest pkScript for the HTLC
from the context of the remote commitment.

theirPrevPkScript will take the second-latest pkScript for the HTLC
from the context of the remote commitment. This is the value we use
in toChannelDelta when we save a revoked commitment from our peer.

The appropriate value of these fields are set in the addHTLC method.

Additionally we pass a boolean value to toChannelDelta so we know
whether we are operating on a local or remote commitment and grab
the correct pkScript in locateUpdateIndex.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
4d03f60e40 lnwallet: handle duplicate payment hashes in toChannelDelta() 2017-03-21 21:21:46 -07:00
Thomas Preindl
a1bb36730a lnd: fix typos in comments 2017-03-16 12:39:40 -07:00
Olaoluwa Osuntokun
f217093c00
multi: replace usage of fastsha256 with crypto/sha256
This commit removes all instances of the fastsha256 library and
replaces it with the sha256 library in the standard library. This
change should see a number of performance improvements as the standard
library has highly optimized assembly instructions with use vectorized
instructions as the platform supports.
2017-03-15 18:56:41 -07:00
Andrey Samokhvalov
ee2379775c lnd: fix golint warning which requires to add additional comments 2017-03-13 16:30:23 -07:00
Christopher Jämthagen
a6a503bf28 lnwallet: ForceCloseSummary should check if to-local output exists
If the value of the to-local output is below the dust limit, the
ForceCloseSummary should not include a sign descriptor for this output.

We also find the proper to-self output by looking for the expected public
key script and not assume that no HTLC outputs exist.
2017-03-09 15:32:31 -08:00
Christopher Jämthagen
52b56b8cf2 lnwallet+test: no dust outputs in commitment transaction + tests
Currently non-HTLC outputs will be accepted in the commitment
transaction as long as it is non-zero. We change this by not allowing
outputs with a value lower than the dust limit. The value of such
an output will go towards transaction fees.
2017-03-09 15:32:31 -08:00
Olaoluwa Osuntokun
fc54c5d8d8
lnwallet: perform sanity check on cooperative closure transacitons
This commit fixes a class of bug that currently exists within the
cooperative closure methods for the channel state machine. As an
example, due to the current hard coded fees, if one of the outputs
generated within the generated closure transaction has a negative
output, then the initiating node would gladly forward this to the
remote node. The remote node would then reject the closure as the
transaction is invalid. However, the act of completing the closure
would cause the remote node’s state machine to shift into a “closed”
state. As a result, any further closure attempts by the first node
(force or regular) would go unnoticed by the remote node.

We fix this issue by ensuring the transaction is “sane” before
initiating of completing a cooperative channel closure.

At test case has been added exercising the particular erroneous case
reported by “moli” on IRC.
2017-02-27 21:00:25 -06:00