No more copies!
I tried changing the cstate->side[].htlcs to htlc_map rather than a
simple pointer array, but we rely on those array indices heavily for
permutation mapping, and it turned into a major rewrite (especially
for the steal case).
Eventually, we're going to want to reconstruct the commit info for
older commit txs rather than keeping all the permutation and
per-commit-info HTLC information in memory, so we can do the work
then.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the logical place for it to belong: with the HTLC. For the manually-created
HTLCs, we create a simple one-hop route.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We've been stuffing these into sha256s, but they're actually nonces.
Create a new structure for that for clarity.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
And make the add/fail/fulfill arg a pointer to a union htlc_staging
directly, removing struct htlc_progress.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There's no real reason to avoid commands for the next commit; this has
the benefit that we can remove the infrastructure to queue commands.
The only exceptions are the commit command and the opening phase.
We still only allow one commit at a time, but that's mainly run off a
timer which can try again later. For the JSONRPC API used for
testing, we can simply fail the commit if one is in progress.
For opening we add an explicit peer_open_complete() call in place of
using the command infrastructure.
Commands are now outside the state machine altogether: we simply have
it return the new state instead of the command status. The JSONRPC
functions can also now run commands directly.
This removes the idea of "peercond" as well: you can simply examine
the states to determine whether an input is valid. There are
fine-grained helpers for this now, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We already removed the on-chain states, now we remove the "clearing" state
(which wasn't fully implemented anyway).
This turns into two smaller state machines: one for clearing, which
still allows HTLCs to be failed and fulfilled, and one for mutual
close negotiation which only allows close_signature messages.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We watch the anchor output, and separate it into different cases.
This is simpler with segwit (txids are known before sigs), but we also
had missed the case of our own commit transaction spend.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There's no reason to, it's a simple p2wpkh to our key.
We still spend the "to-us" from our commit tx, since it could be
theoretically be stolen by the revocation value, and it's a complex
p2wsh which a normal wallet won't have the information to spend.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Turns out that we want to pass information about the commit info, the
HTLC number and (sometimes) the R value, so create a struct for that.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We always set *matches to false (outside the branch, oops). We also
distinguish the case where we ack from the case where they acked,
which removes a FIXME and makes it work.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We now keep a list of commitment transaction states for "us" and
"them", as well as a "struct channel_state" for staged changes.
We manipulate these structures as we send out packets, receive
packets, or receive acknowledgement of packets. In particular, we
update the other nodes' staging_cstate as we send out our requests,
and update our own staging_cstate are we receive acks. When we
receive a request, we update both (as we immediately send out our
ack).
The RPC output is changed; rather than expose the complexity, we
expose our last committed state: what would happen if we have to drop
to the blockchain now.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rather than creating packets then queueing them, call out to functions
which do both. This moves us towards doing more work in those functions
where we send out a request, which is sometimes clearer.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We don't actually implement closing when we have HTLCs (we should
allow it, as that's what the clearing phase is for), since soon we'll
rewrite HTLC to match the async HTLC protocol of BOLT #2.
Note that this folds the close paths, using a simple check if we have
a close transaction. That's a slight state layer violation, but
reduces code duplication.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If something goes wrong after we've broadcast the anchor tx, we need to use
the commit tx to spend it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We have to sign the commit at this stage, so easiest if peer isn't const
so we can sign it in-place.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This tell us to disarm the INPUT_CLOSE_COMPLETE_TIMEOUT: either we hit
an error and are going to unilateral close, or we received their signature
successfully.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Actually generating the anchor transaction in my implementation
requires interaction with bitcoind, which we want to be async. So add
a callback and a new state to wait for it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We use both union fields idata->btc and idata->htlc, which is clearly
wrong. Have peer_tx_revealed_r_value return the HTLC it's talking
about.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This lets us eliminate struct state_effect altogether (the next patch
removes the now-unused arguments).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We only have one htlc in flight at a time, but sometimes it changes:
particularly when we are lowpriority and a highpriority request comes
in. Handle this using a set of callbacks for htlc handling.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a unilateral close occurs, we have to watch on-chain ("live")
HTLCs. If the other side spends their HTLC output, we need to grab
the rvalue. If it times out, we need to spend it back to ourselves.
If we get an R value, we need to spend our own HTLC output back to
ourselves.
Because there are multiple HTLCs, this doesn't fit very neatly into a
state machine. We divide into "have htlcs" and "don't have htlcs",
and use a INPUT_NO_MORE_HTLCS once all htlcs are resolved to transition.
Our test harness now tracks individual HTLCs, so we refined some
inputs (in particular, it won't try to complete/timeout an HTLC before
we have any).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell