These race conditions originate from the mock database storing and
returning pointers, rather than returning a copy.
Observed on Travis:
WARNING: DATA RACE
Read at 0x00c0003222b8 by goroutine 149:
github.com/lightningnetwork/lnd/watchtower/wtclient.(*sessionQueue).drainBackups()
/home/runner/work/lnd/lnd/watchtower/wtclient/session_queue.go:288 +0xed
github.com/lightningnetwork/lnd/watchtower/wtclient.(*sessionQueue).sessionManager()
/home/runner/work/lnd/lnd/watchtower/wtclient/session_queue.go:281 +0x450
Previous write at 0x00c0003222b8 by goroutine 93:
github.com/lightningnetwork/lnd/watchtower/wtclient.getClientSessions()
/home/runner/work/lnd/lnd/watchtower/wtclient/client.go:365 +0x24f
github.com/lightningnetwork/lnd/watchtower/wtclient.(*TowerClient).handleNewTower()
/home/runner/work/lnd/lnd/watchtower/wtclient/client.go:1063 +0x23e
github.com/lightningnetwork/lnd/watchtower/wtclient.(*TowerClient).backupDispatcher()
/home/runner/work/lnd/lnd/watchtower/wtclient/client.go:784 +0x10b9
This commit introduces a new test case that asserts all of the witness
size constants currently in the codebase. We also reintroduce the
AcceptedHtlcSuccessWitnessSize and OfferedHtlcTimeoutWitnessSize
constants that were recently removed for the sake of completeness.
In asserting the witnes sizes, there were three uncovered discrepancies:
* OfferedHtlcSuccessWitnessSize overestimated by about 30% because it
included an extra signature in the calculation.
* ToLocalPenaltyWitnessSize was underestimated by one byte, because it
was missing the length byte for the OP_TRUE. This has implications
the watchtower protocol since the client and server are assumed to
share the same weight estimates used for signing. This commit keeps
the current behavior, with the intention of rolling out negotiation
for which weight estimate to use for a given session.
* AcceptedHtlcScriptSize was underestimated by one byte because it was
missing a length byte for the value 32 pushed on the stack when
asserting the preimage's length. This affects all AcceptedHtlc*
witness sizes.
This commit lets the watchtower automatically create hidden services
by giving it a pointer to a TorController. The server was also slightly
refactored so that it was not the sole owner of the TorController.
In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.
In this commit, we update the tower+link logic to tag a commitment as
the new (tweakless) format if it applies. In order to do this, the
BackupTask method has gained an additional parameter to indicate the
type of commitment that we're attempting to upload. This new tweakless
bool is then threaded through all the way to back up task creation to
ensure that we make the proper input.Input.
Finally, we've added a new test case for each existing test case to test
each case w/ and w/o the tweakless modifier.
With the introduction of the WatchtowerClient RPC subserver, the lnd
configuration flag to specify private watchtowers for the client is no
longer needed and can lead to confusion upon users. Therefore, we remove
the flag completely, and only rely on the watchtower client being active
through a new --wtclient.active flag.
We do this as a convenience for WatchtowerClient users so that they do
not need to re-add towers upon restarts. We ensure not to re-add towers
that have been previously removed by determining whether it has any
lingering active sessions.
In this commit, we extend the wtclient.Client interface with the
following methods:
* AddTower
* RemoveTower
* RegisteredTowers
* LookupTower
* Stats
Care has been taken to ensure that any in-memory state updates are
_only_ performed after a successful database update.
These methods are currently unused, but they serve as a dependency for
the upcoming WatchtowerClient RPC subserver.
These operations are currently unused, but will be integrated into the
TowerClient at a later point as future preparation for the
WatchtowerClient RPC subserver, which will allow users to add, remove,
and list the watchtowers currntly in use.
This currently takes O(N) time as there does not exist an index of
active client sessions for each watchtower within the client's database.
This index is likely to be added in the future.
This commit specifies two bbolt options when opening the underlying
channel and watchtower databases so that there is reduced heap
pressure in case the bbolt database has a lot of free pages in the
B+ tree.
Modifies the bbolt and mock tower databases to only accept blobs that
are the expected size of the session's blob type. This prevents resource
exhaustion attacks where a client may provide disproportionately large
encrypted blob, even though all supported blob types are of fixed-size.
