This commit introduces the chanacceptor package which is used
to determine, by a set of heuristics, which open channel messages
to accept and reject. Currently, two acceptors are implemented
via the ChannelAcceptor interface: ChainedAcceptor and RPCAcceptor.
The RPCAcceptor allows the RPC client to respond to the open channel
request, and the ChainedAcceptor allows a conjunction of acceptors
to be used.
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 fixes a potential issue within the fundingmanager, where
failing to write the channel opening state could cause the channel being
marked open in the DB, but the opening state not being set. On startup
this would cause the channel state machine to not be able to resume.
We fix this by saving the channel opening state _first_. This works
because saving the opening state is idempotent, and in case a channel is
found pending at startup, it will re-register for confirmation
notifications and re-do the process.
Since the advanceFundingState now can handle pending channels, we'll
call it for both pending and non-pending channels, just making sure that
we re-initialize the channel barriers and re-publish the funding tx fro
pending channels.
This commit makes advanceFundingState check whether a channel is still
pending before checking the channel opening state. This lets us call it
directly, without checking whether a channel has confirmed first.
This commit makes the waitForFundingTimeout method synchronous, and
return ErrConfirmationTimeout in case the timeout is reached.
We also simplify the internals by using waitForTimout defined earlier.
This commit defines a new method waitForTimeout, that will be used to
listen for channels timing out. It handles a subset of what is already
handled by waitForFundingWithTimeout, but we want to break that one up
in smaller parts, and waitForTimeout is the first of these.
Since waitForFundingConfirmation is always called in a goroutine, we
make this explicit by requireing the caller to always increment the
waitgroup before calling it.
Similarly to what we did in the previous commit, we move the
responsibility of marking the channel open by calling
handleFundingConfirmation out from waitForFundingWithTimeout to the
caller.
This commit moves the handling of a funding confirmation out of
waitForFundingConfirmation, and instead let the caller handle marking
the channel opened.
This commit moves the opening logic found within
waitForFundingConfirmation into a new method handleFundingConfirmation.
This will make it easier to later break up waitForFundingConfirmation,
and avoid code duplication.
This commit removes the handleFundingConfirmation method, and instead
hands the newly confirmed channel of to advanceFundingState, which will
take the channel through the rest of the channel opening flow.
Since the advanceFundingSigned now can resume a channel from any state,
we resue the logic in handleFundingSigned instead of manually executing
each step of the funding flow.
This commit make the advanceFundingStateMethod synchronous. It will now
query the database for a channel's opening state, and call the method
stateStep until the channel has finished the opening procedure.
This commit extracts the funding state check we do at startup into a new
method advanceFundingState. In later commits we will modify this method
to work for all funding state machine flows, not only on restart.
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.
