Before publishing the close tx to the network and commit to the
StateCommitmentBroadcasted state, we mark the commitment as broadcasted
and store it to the db. This ensures it will get re-published on startup
if we go down.
Instead of marking the channel Borked in cases where we want to force
close it, we immediately let the peer fail the link. The channel state
will instead be updated by the channel arbitrator, which will transition
to StateBroadcastCommit, marking the channel borked, then marking the
commitment tx broadcasted right before publishing the force close tx. We
do this to avoid the case where we would mark it Borked, but go down
before being able to publish the closing tx.
Storing the force close tx ensures it will be re-published on startup.
Instead of marking the database state when processing the channel
reestablishment message, we wait for the result of this processing to
arrive in the link, and mark it accordingly in the database here.
We do this move the logic determining whether we should force close the
channel or not, and what state to mark it in the DB, to the same place,
as these need to be consistent.
This commit converts the ErrCommitSyncLocalDataLoss error into a struct,
that also holds the received last unrevoked commit point from the remote
party.
TestChainArbitratorRepulishCommitment testst that the chain arbitrator
will republish closing transactions for channels marked
CommitementBroadcast in the database at startup.
When loading active channels for a connected peer, we gather channel
sync messages for all borked channels, and send them to the peer. This
should help a peer realize that the state is irreconcible, as we have
already realized.
Checks that we get ErrDoubleSpend as expected when publishing a
conflicting mempool transaction with the same fee as the existing one,
and that we can publish a replacement with a higher fee successfully.
error
Since btcwallet will return typed errors now, we can simplify the
matching logic in order to return ErrDoubleSpend.
In case a transaction cannot be published since it did not satisfy the
requirements for a valid replacement, return ErrDoubleSpend to indicate
it was not propagated.
This commit checks that the size of the bech32 encoded invoice is not
greater than 7092 bytes, which is the maximum number of bytes that can
fit into a QR code. This mitigates a potential DoS vector where an attacker
could craft a very large bech32 invoice string containing an absurd amount
of route and/or hop hints. If sent to an application that processes
payment requests, this would allocate a burdensome amount of memory
due to the public key parsing for each route/hop hint.
For a 1.7MB payment request, this yielded about 38MB in allocations
from just parsing public keys:
```
45.51MB 7.31% 92.07% 45.51MB 7.31% math/big.nat.make
25.50MB 4.09% 96.16% 25.50MB 4.09% github.com/lightningnetwork/lnd/zpay32.bech32VerifyChecksum
1MB 0.16% 96.32% 39.50MB 6.34% github.com/lightningnetwork/lnd/zpay32.parseRouteHint
1MB 0.16% 96.48% 33.50MB 5.38% github.com/btcsuite/btcd/btcec.decompressPoint
0.50MB 0.08% 96.56% 7.50MB 1.20% crypto/elliptic.(*CurveParams).doubleJacobian
0.50MB 0.08% 96.64% 38MB 6.10% github.com/btcsuite/btcd/btcec.ParsePubKey
0 0% 96.64% 12MB 1.93% crypto/ecdsa.Verify
0 0% 96.64% 8MB 1.28% crypto/elliptic.(*CurveParams).ScalarBaseMult
0 0% 96.64% 12MB 1.93% crypto/elliptic.(*CurveParams).ScalarMult
```
With this change, memory usage will be far lower as decoding will exit
early with an error if the invoice is too large.
In this commit, we update the router and link to support users
updating the max HTLC policy for their channels. By updating these internal
systems before updating the RPC server and lncli, we protect users from
being shown an option that doesn't actually work.
The policy update logic that resided part in the gossiper and
part in the rpc server is extracted into its own object.
This prepares for additional validation logic to be added for policy
updates that would otherwise make the gossiper heavier.
It is also a small first step towards separation of our own channel data
from the rest of the graph.
As a preparation for making the gossiper less responsible for validating
and supplementing local channel policy updates, this commits moves the
on-the-fly max htlc migration up the call tree. The plan for a follow up
commit is to move it out of the gossiper completely for local channel
updates, so that we don't need to return a list of final applied policies
anymore.
Since the ErrorCodes are not part of the spec, they cannot be read by
other implementations.
Instead of only sending the error code we therefore send the complete
error message. This will have the same effect at the client, as it will
just get the full error instead of the code indicating which error it
is. It will also be compatible with other impls.
Note that the GRPC error codes will change, since we don't set them
anymore.
