This commit adds LinkErrors with failure details to htlcs which fail on
our incoming link. This change is made with the intention of notifying
detailed htlc failure reasons in sendHTLCError. The FailureDetail
interface is implemented on FailureResolutionResults so that they can
directly be used to enrich LinkErrors. sendHtlcError is updated to
take a LinkError in preparation for the addition of a htlcnotifier
which will notify the detail of the error.
This commit adds a linkError field to track the value of failures
which occur at our node. This field is set when local payments or
multi hop htlcs fail in the switch or on our outgoing link. This
addition is required for the addition of a htlc notifier which will
notify these failures in handleDownstreamPacket.
The passing of link error to failAddPacket removes the need for an
additional error field, because the link error's failure detail will
contain any additional metadata. In the places where the failure detail
does not cover all the metadata that was previously supplied by addr
err, the error is logged before calling failAddPacket so that this
change does not reduce the amount of information we log.
Add a FailureDetail interface which allows us have different kinds of
failures for link errors. This interface will be used to cover failures
that occur when on invoice payment, because the errors have already
been enumerated in the invoices package.
Rename FailureDetail in a separate commit so that a FailureDetail
interface can be introduced in the following commit.
OutgoingFailureOnionDecode is renamed to OutgoingFailureDecodeError
to specifically indicate that we could not decode the wire
failure that our payment experienced.
This commit repalces the htlcResolution struct with an interface.
This interface is implemeted by failure, settle and accept resolution
structs. Only settles and fails are exported because the existing
code that handles htlc resolutions uses a nil resolution to indicate
that a htlc was accepted. The accept resolution is used internally
to report on the resolution result of the accepted htlc, but a nil
resolution is surfaced. Further refactoring of all the functions
that call NotifyExitHopHtlc to handle a htlc accept case (rather than
having a nil check) is required.
Add a CheckCircularForward function which detects packets which are
forwards over the same incoming and outgoing link, and errors if the
node is configured to disallow forwards of this nature. This check is
added to increase the cost of a liquidity lockup attack, because it
increases the length of the route required to lock up an individual
node's bandwidth. Since nodes are currently limited to 20 hops,
increasing the length of the route needed to lock up capital increases
the number of malicious payments an attacker will have to route, which
increases the capital requirement of the attack overall.
Update the ChannelLink interface to specifically
return the LinkError struct. This error implements
the ClearTextError interface, so will be picked
up as a routing realted error by the router.
With LinkErrors implemented, the switch now
returns a LinkError for all failures on our
incoming/outgoing link and ForwardingError when
the failure occurs down the line.
Update the type check used for checking local payment
failures to check on the ClearTextError interface rather
than on the ForwardingError type. This change prepares
for splitting payment errors up into Link and Forwarding
errors.
This change introduces a LinkError implementation
of the ClearTextError interface. This error is intended
to represent failures which occur on our incoming and
outgoing link when sending, receiving and forwarding
htlcs. Paired with ForwardingError, which is represents
failures that did not occur at our node, this error
covers all non-opaque errors that the switch experiences.
This commit adds a ClearTextError interface
which is implemented by non-opaque errors that
we know the underlying wire failure message for.
This interface is implemented by ForwardingErrors,
because we can fully decrypt the onion blob to
obtain the underlying failure reason. This interface
will also be implemented by errors which originate
at our node in following commits, because we know
the failure reason when we fail the htlc.
The lnwire interface is un-embedded in the
ForwardingError struct in favour of implementing
this interface. This change is made to protect
against accidental passing of a ForwardingError
to the wire, where the embedded FailureMessage
interface will present as wire failure but
will not serialize properly.
Add a constructor for the creation of forwarding errors.
A special constructor is added for the case where we have
an unknown wire failure, and must set a nil failure message.
We abstract away how keys are generated for the different channel types
types (currently tweak(less)).
Intention is that more of the logic that is unique for each commitment
type lives in commitment.go, making the channel state machine oblivious
to the keys and outputs being created on the commitment tx for a given
channel state.
This commit adds a getResolutionFailure function
which returns an appropriate wire failure based
on the outcome of a htlc resolution. It also updates
the MissionControlStore test to ensure that lnd
can handle failures which occur due to mpp timeout.
This commit moves handling of invoice not found
errors into NotifyExitHopHtlc and exposes a
resolution result to the calling functions. The
intention of this change is to make calling
functions as naive of the invoice registry's
mechanics as possible.
When NotifyExitHopHtlc is called and an invoice
is not found, calling functions can take action
based on the HtlcResolution's InvoiceNotFound
outcome rather than having to add a special error
check on every call to handle the error.
This commit adds the resolution result obtained
while updating an invoice in the registry to
htlcResolution. The field can be used by calling
functions to determine the outcome of the
update and act appropriately.
This commit renames HodlEvent to HtlcResolution
to better reflect the fact that the struct is
only used for htlc settles and cancels, and that
it is not specifically used for hodl invoices.
This commit adds InvoiceExpryWatcher which is a separate class that
receives new invoices (and existing ones upon restart) from InvoiceRegistry
and actively watches their expiry. When an invoice is expired
InvoiceExpiryWatcher will call into InvoiceRegistry to cancel the
invoice and by that notify all subscribers about the state change.
This commit is adapted from @Bluetegu's original
pull request #1462.
This commit reads an optional address to pay funds out to
from a user iniitiated close channel address. If the channel
already has a shutdown script set, the request will fail if
an address is provided. Otherwise, the cooperative close will
pay out to the address provided.
This commit restructures an invoice's ContractTerms to better encompass
the restrictions placed on settling. For instance, the final ctlv delta
and invoice expiry are moved from the main invoice body (where
additional metadata is stored). Additionally, it moves the State field
outside of the terms since it is rather metadata about the invoice
instead of any terms offered to the sender in the payment request.
Tlv is used more widely in lnd than just for the onion payload. This
commit isolated the protocol-specific odd/even logic, so that tlv can be
used freely elsewhere. An example of this use is db serialization.
With the introduction of additional payload fields for mpp, it becomes
a necessity to have their values available in the on-chain resolution
flow. The incoming contest resolver notifies the invoice registry of the
arrival of a payment and needs to supply all parameters for the registry
to validate the htlc.
Replace logCommitTick as a way to deal with revocation window exhaustion
by retrying to update the commit tx when the remote revocation is
received.
The rationale is that the revocation window always opens up because of a
revoke message that is received from the other party. It is therefore
not necessary to set a timer for this. The reception of the revoke
message is the trigger to send a new commit sig if necessary.
Instead of tracking local updates in a separate link variable, query
this state from the channel itself.
This commit also fixes the issue where the commit tx was not updated
anymore after a failed first attempt because the revocation window was
closed. Also those pending updates will be taken into account when the
remote party revokes.
Previously the channel method FullySynced was used to decide whether to
send a new commit sig message. However, it could happen that FullySynced
was false, but that we didn't owe a commitment signature. Instead we
were waiting on the other party to send us a signature. If that
happened, we'd send out an empty commit sig. This commit modifies the
condition that triggers a new commit sig and fixes this deviation from
the spec.
