Commit Graph

183 Commits

Author SHA1 Message Date
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
Olaoluwa Osuntokun
8283ff2da6
lnwallet: during cooperative closure don't shift status until end
This commit avoids a class of bug wherein the state of the channel
would be marked as closing enough though an error occurred somewhere in
the function. The bug was due to the fact that the channel `status` was
shifted before any actual logic within the function(s) were executed.

We fix this bug by _only_ shifting the channel status once the function
has completed without any error.
2017-02-27 20:52:30 -06:00
Olaoluwa Osuntokun
f0c13c5a15
lnwallet: expose a NextRevocationKey method in channel state machine
This commit adds a new method to the channel’s state machine:
NextRevocationKey. This method is being added in preparation for the
upcoming change to switch to the commitment transaction format outlined
in the spec. When this comes to pass, the ExtendRevocationWindow method
will be removed, as it will no longer be needed.

The NextRevocationKey method will be needed as to conform to the spec,
we’ll need to send the next revocation key within the `fundingLocked`
message.
2017-02-24 16:31:48 -08:00
Olaoluwa Osuntokun
9adc5f6484
lnwallet+channeldb: update callers to shachain API changes 2017-02-24 16:31:45 -08:00
Andrey Samokhvalov
f86557c3e4 channeldb+lnwallet: replace elkrem with shachain
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.
2017-02-22 16:49:29 -08:00
Christopher Jämthagen
873211c02f Use 48-bit commitment transaction numbers
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.
2017-02-22 15:46:59 -08:00
Olaoluwa Osuntokun
75787b3e4d
lnwallet: use spew when logging logging retribution 2017-02-21 01:43:39 -08:00
Olaoluwa Osuntokun
f2e077c10c
lnwallet: account for de-sync'd channels within closeObserver
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 `>=`.
2017-02-21 01:43:27 -08:00
Olaoluwa Osuntokun
0e0e207802
lnwallet: update state machine to the version within the spec
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.
2017-02-21 01:43:15 -08:00
Olaoluwa Osuntokun
6cf905088c
lnwallet: create new updateLog abstraction within channel state machine
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.
2017-02-21 01:43:13 -08:00
Olaoluwa Osuntokun
39f0300995
lnwallet: add godoc comments to a channel's updateTypes 2017-02-21 01:43:10 -08:00
Olaoluwa Osuntokun
a9416300e5
lnwallet: ensure that total satoshi sent/received aren't counted twice
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.
2017-02-21 01:43:07 -08:00
Olaoluwa Osuntokun
fb9bf054cc
lnwallet: cancel the spend notification when a channel's closeObserver exits
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.
2017-02-21 01:43:04 -08:00
Christopher Jämthagen
a2403d9c07 lnwallet: optimize PaymentDescriptor lookup on HTLC state transitions
rHashMap is used to store the PaymentDescriptor belonging to a received
HTLC's revocation hash. This improves the efficiency of looking up
PaymentDescriptors from their RHash whenever we want to settle or cancel
that HTLC.
2017-02-08 18:22:01 -08:00
Olaoluwa Osuntokun
62bcd59db4
lnwallet: add ability to cancel the channel's closeObserver
This commit adds the ability to cancel a channel’s internal
closeObserver goroutine by adding a new public facing Stop method.

Additionally, we now make passing a ChainNotifier interface completely
optional. If the ChainNotifier isn’t passed in as a constructor, then
the closeObserver goroutine will never be launched. This new feature
lets the caller ensure that only a single closeObsever for any given
channels exists.
2017-02-02 17:11:03 -08:00
Olaoluwa Osuntokun
f4b403679b
lnwallet: remove BlockChainIO as a dependency to LightningChannel
This commit removes the BlockChainIO interface as a dependency to the
LightningChannel struct as the interface is no longer used within the
operation of the LightningChannel.
2017-02-02 17:05:40 -08:00
Trevin Hofmann
40c7bac3aa multi: fix a variety of typos throughout the repo 2017-01-17 17:02:56 -08:00
Olaoluwa Osuntokun
55f89be10f
lnwallet+lnd: ensure curve parameters are set to avoid panics
This commit fixes a bug introduced by the past attempt to Make Logging
Great Again. Since we unset the curve parameters when reading/writing
the messages, if we have a lingering reference that’s active elsewhere
in the daemon, then we’ll modify that reference. To fix this, we now
explicitly set the Curve parameters in two areas.

A similar commit has been pushed to lightning-onion.
2017-01-14 19:44:37 -08:00
Olaoluwa Osuntokun
ae72475612
lnwallet: create channel close summary when commitment broadcast detected
This commit modifies the closeObserver goroutine to ensure that a close
summary has been inserted into the database before signalling any
observers that a unilateral channel closure was detected. This fixes a
slight bug where a peer would force close a channel, but we wouldn’t
properly detect that and clean up the channel state if had a failed
cooperative channel closure.
2017-01-14 18:01:28 -08:00
Olaoluwa Osuntokun
c451258fd2
lnwallet: properly detect initiator cooperative close in closeObserver
This commit modifies the logic of the closeObserver slightly to not
incorrectly mark the broadcast of the commitment transaction triggered
by a cooperative channel closure as an unprompted broadcast.
2017-01-12 18:30:07 -08:00
Olaoluwa Osuntokun
c9dbaa1403
lnwallet: include r-hash of canceled htlc in log entry for cancel
This commit modifies the logic around adding cancel entries to the
update log for the commitment state machine slightly by also including
the r-hash of the HTLC that’s been cancelled in the entry for the
cancellation. With this change, we can accurately track which HTLC is
being cancelled within outer sub-systems.
2017-01-07 21:22:01 -08:00
Olaoluwa Osuntokun
9bb5a45f89
lnwallet: the canceller of an HTLC targets by payment hash not index
This commit alters the new HTLC cancellation logic to instead allow the
canceller of an HTLC to cancel the HTLC by the payment hash rather than
the index of the HTLC.
2017-01-07 21:20:57 -08:00
Olaoluwa Osuntokun
fd0c0574e6
lnwallet: add send/recv of HTLC cancellations to state machine
This commit adds the ability to send/recv HTLC cancellation to the
commitment state machine. Previously this feature had been
unimplemented within the state machine, with only adds/settles working.

With this change, there’s now now no concept of “timing” out HTLC’s,
only the cancellation of HTLC’s which may be triggered for various
reasons.
2017-01-07 21:20:51 -08:00
Olaoluwa Osuntokun
5affed38fc
multi: update btcsuite API's to latest upstream changes
This commit makes a large number of minor changes concerning API usage
within the deamon to match the latest version on the upstream btcsuite
libraries.

The major changes are the switch from wire.ShaHash to chainhash.Hash,
and that wire.NewMsgTx() now takes a paramter indicating the version of
the transaction to be created.
2017-01-05 13:56:34 -08:00
Olaoluwa Osuntokun
0585ed93be
lnwallet: use in-memory height within channel's closeObserver
This commit partially rectifies a quick hack that was previously thrown
in to address an issue discovered due to possible state inconsistencies
between an active channel object and the daemon’s breachAbrbiter.

A prior commit has modified the interaction between the peer and the
breachArbiter to eliminate the state in consistency. Therefore, we no
longer need to access the database to ensure that we’re observing the
latest channel state in order to correctly make a decision about
whether a broadcast commitment transaction is a breach or not.
2016-12-27 16:45:10 -08:00
Olaoluwa Osuntokun
4790ce96a8
lnwallet: public expose funding keys in channel state machine
This commit modifies the attributes of the LightningChannel struct to
publicly expose the funding keys used within the channel for the local
and remote party. Exposing these keys publicly will allow callers to
use the keys involved to generate authenticated channel advertisements
for the routing layer.
2016-12-27 16:43:34 -08:00
Andrey Samokhvalov
d01f1b5ff4 fundingmanager+lnwallet: add HTLC dust limit logic 2016-12-13 11:01:57 -08:00
Andrey Samokhvalov
5a82240c6a lnwire+lnwallet+fundingmanager: general improvements 2016-12-13 11:01:57 -08:00
Olaoluwa Osuntokun
e0c09a016b
lnwallet: use stored initiator bool to properly construct close tx
This commit modifies the channel closing logic to remove the hard coded
bools indicating which side is attempting the closure. With the recent
changes, the initiator must always pay the channel closure fees.

This information is recently stored on disk, therefore we can use the
boolean to ensure that the closure transaction is created properly no
matter who initiates the close.

This fixes a bug.
2016-12-07 22:39:33 -08:00
Olaoluwa Osuntokun
494fcec874
breacharbiter: introduce new sub-system to watch for breaches
This commit introduces a new sub-system into the daemon whose job it is
to vigilantly watch for any potential channel breaches throughout the
up-time of the daemon. The logic which was moved from the utxoNursery
in a prior commit now resides within the breachArbiter.

Upon start-up the breachArbiter will query the database for all active
channels, launching a goroutine for each channel in order to be able to
take action if a channel breach is detected. The breachArbiter is also
responsible for notifying the htlcSwitch about channel breaches in
order to black-list the breached linked during any multi-hop forwarding
decisions.
2016-11-28 19:44:09 -08:00
Andrey Samokhvalov
da3028e10c lnwallet: add HTLC count validation 2016-11-23 20:02:29 -06:00
Andrey Samokhvalov
391d5cd401 lnwallet: add commitment transaction estimation 2016-11-23 20:02:29 -06:00
Andrey Samokhvalov
5b9e4ae61e general: fix typos, rename variables, add comments 2016-11-23 20:02:29 -06:00
bryanvu
faf9daddf6 lnwallet: calculate channel's total satoshis sent and received
When HTLCs are settled, the channel’s TotalSatoshisSent and
TotalSatoshisReceived fields are updated.
2016-11-22 14:57:03 -06:00
Olaoluwa Osuntokun
cc63db0aee
lnwallet: add detection+handling of contract breaches in channel
This commit adds detection of contract breaches within the commitment
state-machine for a channel. A contract breach is defined as the event
wherein a channel counter-party broadcasts a previously revoked
commitment transaction. Such an event immediately closes a channel as
the funds are now in a state of dispute.

Once a breach is detected, a snapshot of the breached state is
retrieved from the database’s revocation log. This snapshot is then
used to generate the revocation leaf used within this particular state
along with all the other information ncessary to sweep ALL active funds
within the channel. This information is encapsulated within the
BreachRetribution struct which is sent over a new channel dedicated to
sending/receiving BreachRetributions.
2016-11-21 00:54:45 -06:00
Olaoluwa Osuntokun
188811cf05
lnwallet: populate the output index of an HTLC in ChannelDeltas
This commit modifies the logic within the state machine to properly
populate the new field of `OutputIndex` which the HTLC stored within a
channel delta.

With this change, in the future we’ll be able to quickly locate a
particular HTLC output in the scenario that the commitment transaction
has been broadcast on-chain and we need to sweep it. Allocating a few
extra bytes on-disk saves us from the guess-and-check logic+code
required otherwise.
2016-11-20 23:54:24 -06:00
Olaoluwa Osuntokun
2d884618aa
lnwallet: ensure all channel state machine methods are thread-safe
This commit adds some necessary locking to ensure that all updates to
the internal state of the commitment state machine are fully serial and
thread-safe. This change is required to ensure future actions w.r.t
taking action once a revoked commitment transaction has been broadcast
are not carried out while the channel’s state is being updated.
2016-11-20 23:33:27 -06:00
Olaoluwa Osuntokun
74122a0901
lnwallet: encode obfuscated state hints in the commitment tx
This commit modifies the channel state machine slightly to encode the
current state number using 30-bits of the sequence number within the
commitment transaction’s only input.

Such a modification reduces up the processing time required to punish
the counter party for breaching the contract established within the
channel by broadcasting an older revoked state.

This fixes #58 with a minor modification to what was originally
suggested.
2016-11-16 12:49:44 -08:00
Olaoluwa Osuntokun
4113260f9f
lnwallet: minor comment correction 2016-11-10 17:38:59 -08:00
Olaoluwa Osuntokun
e1d9d9c8d2
lnwallet: update to adhere to new channeldb API change
This commit modifies the lnwallet code and related tests in order to
adhere to the recent field-name change to channeldb.OpenChannel.
Instead of having the field ‘TheirLNID’ which is the sha256 of the
node’s public key, we now instead use the public key directly in all
contexts.
2016-10-25 16:41:22 -07:00
Andrey Samokhvalov
14c6770b76 general: fix typos 2016-10-22 01:48:05 +03:00
andrew.shvv
e515710a7d multi: use witnessScript everywhere instead of redeemScript
This commit consists of a mass variable renaming to call the pkScript being executed for segwit outputs the `witnessScript` instead of `redeemScript`. The latter naming convention is generally considered to be reserved for the context of BIP 16 execution. With segwit to be deployed soon, we should be using the correct terminology uniformly through the codebase. 

In addition some minor typos throughout the codebase has been fixed.
2016-10-15 16:02:09 -07:00
Olaoluwa Osuntokun
9d5b0885d4
lnwallet/channel: add r-preimages to the PaymentDescriptor for settles 2016-09-21 19:49:07 -07:00
Olaoluwa Osuntokun
d0353b2864
lnwallet: add ability to trigger a force closure within channel state machine
This commit introduces the concept of a manually initiated “force”
closer within the channel state machine. A force closure is a closure
initiated by a  local subsystem which broadcasts the current commitment
state directly on-chain rather than attempting to cooperatively
negotiate a closure with the remote party.

A force closure returns a ForceCloseSummary which includes all the
details required for claiming all rightfully owned outputs within the
broadcast commitment transaction.

Additionally two new publicly exported channels are introduced, one
which is closed due a locally initiated force closure, and the other
which is closed once we detect that the remote party has executed a
unilateral closure by broadcasting their version of the commitment
transaction.
2016-09-12 19:07:35 -07:00
Olaoluwa Osuntokun
affd7793b3
lnwallet: add htlc persistence, state log restoration to channel state machine
This commit adds full persistence logic of the current lowest
un-revoked height within each commitment chain. The newly added
channeldb methods for record state transitions within both commitment
chains are now utilized. This un-settled HTLC state is now read upon
initialization, with the proper log entries inserted into the state
update log which reflect the garbage collected log right before the
restart.

A new set of tests have been added to exercise a few edge cases around
HTLC persistence to ensure the in-memory log is properly restored based
on the on-disk snapshot.
2016-09-12 19:07:04 -07:00
Olaoluwa Osuntokun
671098325d
lnwallet: refactor all wallet/channel interaction to use the WalletController.
This commit performs a major refactor of the current wallet,
reservation, and channel code in order to call into a WalletController
implementation rather than directly into btcwallet.

The current set of wallets tests have been modified in order to test
against *all* registered WalletController implementations rather than
only btcwallet. As a result, all future WalletControllers primary need
to ensure that their implementation passes the current set of tests
(which will be expanded into the future), providing an easy path of
integration assurance.

Rather than directly holding the private keys throughout funding and
channel creation, the burden of securing keys has been shifted to the
specified WalletController and Signer interfaces. All signing is done
via the Signer interface rather than directly, increasing flexibility
dramatically.

During channel funding, rather than creating a txscript.Engine to
verify commitment signatures, regular ECDSA sig verification is now
used instead. This is faster and more efficient.

Finally certain fields/methods within ChannelReservation and
LightningChannel have been exposed publicly in order to restrict the
amount of modifications the prior tests needed to undergo in order to
support testing directly agains the WalletController interface.
2016-09-08 12:25:54 -07:00
Olaoluwa Osuntokun
8bbd010f74
lnwallet: use the ChainNotifier interface throughout instead of BtcdNotifier
This commit refactors the code within lnwallet interacting with the
ChainNotifier to accept, and call against the implementation rather
than a single concrete implementation.

LightningWallet no longer creates it’s own BtcdNotifier implementation
doing construction, now instead accepting a pre-started `ChainNotifier`
interface.  All imports have been updated to reflect the new naming
scheme.
2016-09-01 19:13:19 -07:00
Olaoluwa Osuntokun
4104a9bcde
lnwallet: never create zero-value outputs within the commitment transaction 2016-07-27 12:15:50 -07:00
Olaoluwa Osuntokun
c0614c0478
lnwallet: add basic tests for cooperative channel closure
This commit adds a basic test for cooperative channel closure. The
current test ensures correctness of the cooperative closure procedure
initiated by either the channel initiator, or the channel responder.
2016-07-27 11:32:35 -07:00
Olaoluwa Osuntokun
e01dd7f18d
lnwallet: properly make channelState an enum by using iota 2016-07-27 11:29:49 -07:00
Olaoluwa Osuntokun
8a56fbf196
lnwallet: switch name of package logger to avoid module collision 2016-07-27 11:29:07 -07:00
Olaoluwa Osuntokun
2bb65a3fb8
lnwallet: add PendingUpdates method to channel state machine
This commit adds a new method, “PendingUpdates” to the channel state
machine which is intended to be a source to give callers a hint as to
when an additional commitment signature should be sent independent of
any request/response book keeping.
2016-07-21 16:52:18 -07:00
Olaoluwa Osuntokun
4063171918
lnwallet: partition state update logs within channel state machine
This commit patrons the state update logs properly within the channel
state machine. This change fixes a number of bugs caused by treating a
central log as two logically distinct logs. Rather than having a bit
indicating if the entry is incoming/outgoing, an entry is added to a
remote or local log depending on which modification method is used.

As a result the code is much easier to follow due to separation of
concerts.

Finally, when attempting to sign a new update with an exhausted
renovation window a distinct error is returned in order to allow higher
level callers to properly back-off and handle the protocol event.
2016-07-21 16:50:38 -07:00
Olaoluwa Osuntokun
b60270f3f7
lnwallet: include htlcs to settle in returned set of htlc's to forward
This commit fixes a slight bug in the channel state machine’s code
executed when processing a revocation messages. With this commit after
processing a revocation, log entries which we should forward to the
downstream or upstream peer for settling/adding HTLC’s are now properly
returned.

The testa have also been updated to ensure to correct htlc’s are
returned “for forwarding”.
2016-07-16 18:12:49 -07:00
Olaoluwa Osuntokun
2c303a1879
lnwallet: AddHTLC now returns log index of created log entry 2016-07-16 18:02:09 -07:00
Olaoluwa Osuntokun
7dea354711
lnwallet: properly handle HTLC settles in channel state-machine
We no longer track HTLC’s by their r-hash within the log into the
index, as we may have multiple HTLC’s that can be redeemed by the same
pre-image. Instead we now use a separate index which is keyed by a
log-index.

Additionally, the SettleHTLC method now also returns the index of the
HTLC being settled which allows the remote party to quickly locate the
HTLC within their log.

This commit also introduces a few trace/debug log messages which will
likely be pruned in the near future
2016-07-12 17:35:57 -07:00
Olaoluwa Osuntokun
06f062e678
lnwallet: sync revocation state after receiving a revocation 2016-07-12 17:32:42 -07:00
Olaoluwa Osuntokun
14d669dfd1
lnwallet: decrease initial revocation window to 4 2016-07-12 17:31:01 -07:00
Olaoluwa Osuntokun
94c242073a
lnwallet: finish initial draft of LightningChannel state machine
This commit finishes the initial draft of the commitment state machine.
A full re-write of the prior protocol which combines aspects of the
former ‘lnstate’ package has replaced the prior un-finished
stop-and-wait protocol.

This new protocol is designed to operate in an asynchronous environment
and to facilitate non-blocking batched and pipelined updates to the
committed channel states. The protocol is also de-synchronized meaning
that either side can propose new commitment states independent of the
actions of the other party.

The state machine implemented is very similar to that of c-lightning,
however we allow multiple unrevoked commentates in order to minimize
blocking, and also to reduce latency across several hops in a
bi-directional setting.

The current implementation consists of 3 main data structures: a
commitment chain which consist of unrevoked commitment transactions
(one for each side), and a (mostly) append-only log of HTLC updates
shared between both sides. New commitments proposed index into the log
denoting which updates they include, this allows both parties to
progress chains independent of one another. Revoked commitments, reduce
the length of the chain by one, and free up space within the revocation
window.

At this point only basic tests are in place for the state machine,
however more extensive testing infrastructure along with formal proofs
using PlusCall are planned.
2016-07-05 17:02:03 -07:00
Olaoluwa Osuntokun
1b490c52ed
lnwallet: createCommitTx now a revocation key 2016-06-30 12:12:19 -07:00
Olaoluwa Osuntokun
e22734f9cf
lnwallet: update HTLC+commitment scripts
This commit updates the previous HTLC and commitment scripts to their
current latest evolution.

The HTLC scripts have been optimized for space savings, the
functionality itself has remained relatively unchanged. A trade off was
made to add additional bytes into the sigScript in order to avoid
extraneous CHECKSIG’s. The rationale is that an extra 1-2 bytes in the
sigScript to guide execution, are worthwhile since they’re in the
witness, and witness data may be pruned in the near future.

The primary change is within the commitment transaction itself. Instead
of using revocation hashes, we now use signature based revocation. This
saves space in the Script, and optimizes away an extra hashing
operation. Elkrem/shachain is still used but, we now use the pre-images
to homomorphically derive a public key which the other party will be
able to sign with, once we disclose the pre-image itself.

Finally, we have switched to using SHA-256 everywhere uniformly for
both revocation hashes, and payment hashes. The rationale is that the
output of ripemd160 is too small for modern security margins, and that
other coins/chains are more likely to have SHA-256 implemented, than
ripemd160.

A set of tests has also been included which contain (mostly) exhaustive
tests of all possible redemption paths for both commitment and HTLC.
2016-06-27 11:35:32 -07:00
Olaoluwa Osuntokun
ac8736ff99
lnwallet: convert commitment no-delay output to p2wsh 2016-06-27 11:21:13 -07:00
Olaoluwa Osuntokun
05fb9b5a6d
lnwallet: payment and revocation hashes are now 32 bytes
This unifies some inconstancies across the code-base with hashes being
32 vs 20 bytes. All hashes, whether payment or revocation are now
uniformly 32 bytes everywhere. As a result, only OP_SHA256 will be used
within commitment and HTLC scripts. The rationale for using sha256
instead of hash160 for the HTLC payment pre-image is that alternative
chains are more likely to have sha256 implemented, rather than
ripemd160.

A forthcoming commit will update the current commitment, and HTLC
scripts.
2016-06-26 23:04:14 -07:00
Olaoluwa Osuntokun
77a006f03b
lnwallet: ChannelPoint() now returns a pointer to outpoint 2016-06-22 22:15:13 -07:00
Olaoluwa Osuntokun
e17bdf08ea
lnwallet: expose db channel deletion+snapshotting 2016-06-22 22:12:37 -07:00
Olaoluwa Osuntokun
45236fa092
lnwallet: implement cooperative closure for LightningChannel
A cooperative closure of a LightningChannel proceeds in two steps.
First, the party who wishes to close the channel sends a signature for
the closing transaction. Next, the responder reconstructs the closing
transaction identically as the initiator did using a canonical
input/output ordering, and the currently settled balance within the
channel. At this point, the responder then broadcasts the closure
transaction. It is the responsibility of the initiator to watch for
this transaction broadcast within the network to clean up any resources
they committed to the active channel.
2016-06-21 13:13:22 -07:00
Olaoluwa Osuntokun
27e6839060
lnwallet: publicly export constructor for LightningChannel 2016-06-21 13:13:18 -07:00
Olaoluwa Osuntokun
507520cda9
lnwallet: move channelState from channeldb to channel.go 2016-06-21 13:13:14 -07:00
Olaoluwa Osuntokun
fcff17c336
multi: change all imports to roasbeef's forks
This commit will allow the general public to build lnd without jumping
through hoops setting up their local git branches nicely with all of
our forks.
2016-05-15 17:22:37 +03:00
Olaoluwa Osuntokun
eeb2887fe9
lnwallet: segwit-ify all scripts and signing utils 2016-05-03 20:06:39 -07:00
Olaoluwa Osuntokun
1e35018e89 lnwallet: fix compile errors against btcd's segwit branch 2016-04-12 21:37:08 -07:00
Olaoluwa Osuntokun
4b16763f4d lnwallet: update channel.go to new OpenChannel fields
Simply to compile, channel.go will be replaced with lnstate soon
enough.
2016-03-24 00:00:59 -07:00
Tadge Dryja
0d3639435f can sync with segnet in hard mode
lots of changes but they seem to work
2016-02-15 22:13:17 -08:00
Olaoluwa Osuntokun
ab16933575 lnwallet: commit tx should have final sequence num 2016-02-05 20:24:32 -08:00
Olaoluwa Osuntokun
81a4887d11 lnwallet: move lockTimeToSequence to script_utils.go 2016-02-05 20:24:17 -08:00
Olaoluwa Osuntokun
fa05ee9a22 lnwallet: move pubKey comparison for funding output spend into spendMultiSig func
* This change makes the spendMultiSig function testable independent of
the reservation workflow.
2016-02-05 12:33:22 -08:00