Previously, if we were offline when a funding transaction was
locked in, and then we came back online, calling
`best_block_updated` once followed by `transactions_confirmed`,
we'd not generate a funding_locked until the next
`best_block_updated`.
We address this by re-calling `best_block_updated` in
`transactions_confirmed`, similar to how `ChannelMonitor` works.
This creates an SCID alias for all of our outbound channels, which
we send to our counterparties as a part of the `funding_locked`
message and then recognize in any HTLC forwarding instructions.
Note that we generate an SCID alias for all channels, including
already open ones, even though we currently have no way of
communicating to our peers the SCID alias for already-open
channels.
Its very confusing to have multiple fields that do the same thing,
one of which isn't even used for its stated purpose anymore after
the previous few commits.
There are currently two issues with
`bolt2_open_channel_sending_node_checks_part1` which counteract
each other and hide that the test isn't testing what it should be.
First of all, the final `create_channel` call actually fails
because we try to open a channel with ourselves, instead of
panicing as the test is supposed to check for.
However, when we fix the create_channel call to panic, when we
drop `nodes[1]` after `create_channel` panics, we fail the
no-pending-messages test as it as an expeted `accept_channel` in
its outbound buffer. This causes a double-panic.
Previously, these two offset each other - instead of panicing in
`create_channel` we'd panic in the Node drop checks.
This fixes both by fetching the `accept_channel` before we go into
the panic'ing `create_channel` call (who's arguments were
corrected).
Prior to cryptographic payment secrets, when we process a received
payment in `process_pending_htlc_fowards` we'd remove its entry
from the `pending_inbound_payments` map and give the user a
`PaymentReceived` event.
Thereafter, if a second HTLC came in with the same payment hash, it
would find no entry in the `pending_inbound_payments` map and be
immediately failed in `process_pending_htlc_forwards`.
Thus, each HTLC will either result in a `PaymentReceived` event or
be failed, with no possibility for both.
As of 8464875555, we no longer
materially have a pending-inbound-payments map, and thus
more-than-happily accept a second payment with the same payment
hash even if we just failed a previous one for having mis-matched
payment data.
This can cause an issue if the two HTLCs are received back-to-back,
with the first being accepted as valid, generating a
`PaymentReceived` event. Then, when the second comes in we'll hit
the "total value {} ran over expected value" condition and fail
*all* pending HTLCs with the same payment hash. At this point,
we'll have a pending failure for both HTLCs, as well as a
`PaymentReceived` event for the user.
Thereafter, if the user attempts to fail the HTLC in response to
the `PaymentReceived`, they'll get a debug panic at channel.rs:1657
'Tried to fail an HTLC that was already failed'.
The solution is to avoid bulk-failing all pending HTLCs for a
payment. This feels like the right thing to do anyway - if a sender
accidentally sends an extra HTLC after a payment has ben fully
paid, we shouldn't fail the entire payment.
Found by the `chanmon_consistency` fuzz test.
Add functional tests for manually responding to inbound channel requests.
Responding to inbound channel requests are required when the
`manually_accept_inbound_channels` config flag is set to true.
The tests cover the following cases:
* Accepting an inbound channel request
* Rejecting an inbound channel request
* FundingCreated message sent by the counterparty before accepting the
inbound channel request
* Attempting to accept an inbound channel request twice
* Attempting to accept an unkown inbound channel
Given the balance is reported as "total balance if we went to chain
ignoring fees", it seems reasonable to include claimed HTLCs - if
we went to chain we'd get those funds, less on-chain fees. Further,
if we do not include them, its possible to have pending outbound
holding-cell HTLCs underflow the balance calculation, causing a
panic in debug mode, and bogus values in release.
This resolves a subtraction underflow bug found by the
`chanmon_consistency` fuzz target.
The spec actually requires we never send `announcement_signatures`
(and, thus, `channel_announcement`s) until after six confirmations.
However, we would happily have sent them prior to that as long as
we exchange `funding_locked` messages with our countarparty. Thanks
to re-broadcasting this issue is largely harmless, however it could
have some negative interactions with less-robust peers. Much more
importantly, this represents an important step towards supporting
0-conf channels, where `funding_locked` messages may be exchanged
before we even have an SCID to construct the messages with.
Because there is no ACK mechanism for `announcement_signatures` we
rely on existing channel updates to stop rebroadcasting them - if
we sent a `commitment_signed` after an `announcement_signatures`
and later receive a `revoke_and_ack`, we know our counterparty also
received our `announcement_signatures`. This may resolve some rare
edge-cases where we send a `funding_locked` which our counterparty
receives, but lose connection before the `announcement_signatures`
(usually the very next message) arrives.
Sadly, because the set of places where an `announcement_signatures`
may now be generated more closely mirrors where `funding_locked`
messages may be generated, but they are now separate, there is a
substantial amount of code motion providing relevant parameters
about current block information and ensuring we can return new
`announcement_signatures` messages.
While its generally harmless to do so (the messages will simply be
dropped in `PeerManager`) there is a potential race condition where
the FundingLocked message enters the outbound message queue, then
the peer reconnects, and then the FundingLocked message is
delivered prior to the normal ChannelReestablish flow.
We also take this opportunity to rewrite
`test_funding_peer_disconnect` to be explicit instead of using
`reconnect_peers`. This allows it to check each message being sent
carefully, whereas `reconnect_peers` is rather lazy and accepts
that sometimes signatures will be exchanged, and sometimes not.
and replace payment_secret with encrypted metadata
See docs on `inbound_payment::verify` for details
Also add min_value checks to all create_inbound_payment* methods
When a payment fails, a payer needs to know when they can consider
a payment as fully-failed, and when only some of the HTLCs in the
payment have failed. This isn't possible with the current event
scheme, as discovered recently and as described in the previous
commit.
This adds a new event which describes when a payment is fully and
irrevocably failed, generating it only after the payment has
expired or been marked as expired with
`ChannelManager::mark_retries_exceeded` *and* all HTLCs for it
have failed. With this, a payer can more simply deduce when a
payment has failed and use that to remove payment state or
finalize a payment failure.
A peer providing a channel_reserve_satoshis of 0 (or less than our
dust limit) is insecure, but only for them. Because some LSPs do it
with some level of trust of the clients (for a substantial UX
improvement), we explicitly allow it. Because its unlikely to
happen often in normal testing, we test it explicitly here.
We update the `Channel::update_time_counter` field (which is copied
into `ChannelUpdate::timestamp`) only when the channel is
initialized or closes, and when a new block is connected. However,
if a peer disconnects or reconnects, we may wish to generate
`ChannelUpdate` updates in between new blocks. In such a case, we
need to make sure the `timestamp` field is newer than any previous
updates' `timestamp` fields, which we do here by simply
incrementing it when the channel status is changed.
As a side effect of this we have to update
`test_background_processor` to ensure it eventually succeeds even
if the serialization of the `ChannelManager` changes after the test
begins.
A single PaymentSent event is generated when a payment is fulfilled.
This is occurs when the preimage is revealed on the first claimed HTLC.
For subsequent HTLCs, the event is not generated.
In order to score channels involved with a successful payments, the
scorer must be notified of each successful path involved in the payment.
Add a PaymentPathSuccessful event for this purpose. Generate it whenever
a part is removed from a pending outbound payment. This avoids duplicate
events when reconnecting to a peer.
Previously, we would reject inbound channels if the funder wasn't
able to meet our channel reserve on their first commitment
transaction only if they also failed to push enough to us for us
to not meet their initial channel reserve as well.
There's not a lot of reason to care about us meeting their reserve,
however - its largely expected that they may not push enough to us
in the initial open to meet it, and its not actually our problem if
they don't.
Further, we used our own fee, instead of the channel's actual fee,
to calculate fee affordability of the initial commitment
transaction.
We resolve both issues here, rewriting the combined affordability
check conditionals in inbound channel open handling and adding a
fee affordability check for outbound channels as well.
The prior code may have allowed a counterparty to start the channel
with "no punishment" states - violating the reason for the reserve
threshold.
Instead of magic hard-coded constants, its better for tests to
derive the values used so that they change if constants are changed
and so that it is easier to re-derive constants in the future as
needed.
In upcoming commits, we'll be making the payment secret and payment hash/preimage
derivable from info about the payment + a node secret. This means we don't
need to store any info about incoming payments and can eventually get rid of the
channelmanager::pending_inbound_payments map.
