We track whether each change is affordable as we go;
test_channel_drainage got us so close that the difference mattered; we
hit an assert when we tried to commit the tx and realized we couldn't
afford it.
We should not be trying to add an HTLC if it will result in the funder
being unable to afford it on either the local *or remote* commitments.
Note the test still "fails" because it refuses to send the final
payment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Subtracting both arbitrarily reduces our capacity, even for ourselves
since the routing logic uses this maximum.
I also changed 'advertise' to 'advertize', since we use american
spelling.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
@pm47 gave a great bug report showing c-lightning sending the same
UPDATE_FEE over and over, with the final surprise result being that we
blamed the peer for sending us multiple empty commits!
The spam is caused by us checking "are we at the desired feerate?" but
then if we can't afford the desired feerate, setting the feerate we
can afford, even though it's a duplicate. Doing the feerate cap before
we test if it's what we have already eliminates this.
But the empty commits was harder to find: it's caused by a heuristic in
channel_rcvd_revoke_and_ack:
```
/* For funder, ack also means time to apply new feerate locally. */
if (channel->funder == LOCAL &&
(channel->view[LOCAL].feerate_per_kw
!= channel->view[REMOTE].feerate_per_kw)) {
status_trace("Applying feerate %u to LOCAL (was %u)",
channel->view[REMOTE].feerate_per_kw,
channel->view[LOCAL].feerate_per_kw);
channel->view[LOCAL].feerate_per_kw
= channel->view[REMOTE].feerate_per_kw;
channel->changes_pending[LOCAL] = true;
}
```
We assume we never send duplicates, so we detect an otherwise-empty
change using the difference in feerates. If we don't set this flag,
we will get upset if we receive a commitment_signed since we consider
there to be no changes to commit.
This is actually hard to test: the previous commit adds a test which
spams update_fee and doesn't trigger this bug, because both sides
use the same "there's nothing outstanding" logic.
Fixes: #2701
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Keeping the uintmap ordering all the broadcastable messages is expensive:
130MB for the million-channels project. But now we delete obsolete entries
from the store, we can have the per-peer daemons simply read that sequentially
and stream the gossip itself.
This is the most primitive version, where all gossip is streamed;
successive patches will bring back proper handling of timestamp filtering
and initial_routing_sync.
We add a gossip_state field to track what's happening with our gossip
streaming: it's initialized in gossipd, and currently always set, but
once we handle timestamps the per-peer daemon may do it when the first
filter is sent.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Encapsulating the peer state was a win for lightningd; not surprisingly,
it's even more of a win for the other daemons, especially as we want
to add a little gossip information.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We ask gossipd for the channel_update for the outgoing channel; any other
messages it sends us get queued for later processing.
But this is overzealous: we can shunt those msgs to the peer while
we're waiting. This fixes a nasty case where we have to handle
WIRE_GOSSIPD_NEW_STORE_FD messages by queuing the fd for later.
This then means that WIRE_GOSSIPD_NEW_STORE_FD can be handled
internally inside handle_gossip_msg(), since it's always dealt with
the same, simplifying all callers.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1. Add remote_ann_node_sigs and remote_bitcoin_sigs fields in channel_init message;
2. Master add announcement signatures into channel_init message, and send this message to Channeld.
Channeld will initial the channel with this signatures when it reenables the channel.
Channeld sends announcement signatures to Master by this message.
When Channeld receive a new channel announcement msg, (After channel locking)it will sends announcement signatures to Master by this message.
Instead of reading the store ourselves, we can just send them an
offset. This saves gossipd a lot of work, putting it where it belongs
(in the daemon responsible for the specific peer).
MCP bench results:
store_load_msec:28509-31001(29206.6+/-9.4e+02)
vsz_kb:580004-580016(580006+/-4.8)
store_rewrite_sec:11.640000-12.730000(11.908+/-0.41)
listnodes_sec:1.790000-1.880000(1.83+/-0.032)
listchannels_sec:21.180000-21.950000(21.476+/-0.27)
routing_sec:2.210000-11.160000(7.126+/-3.1)
peer_write_all_sec:36.270000-41.200000(38.168+/-1.9)
Signficant savings in streaming gossip:
-peer_write_all_sec:48.160000-51.480000(49.608+/-1.1)
+peer_write_all_sec:35.780000-37.980000(36.43+/-0.81)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The spec says not to send a commitment_signed without any changes, but LND
does this. To understand why, you have to understand how LND works. I
haven't read the code, but I'm pretty sure it works like this:
1. lnd slows down to do garbage collection, because it's in Go.
2. When an alert timer goes off, noticing it's not making process, it
sends a twitter message to @roasbeef.
3. @roasbeef sshs into the user's machine and binary patches lnd to send
a commitment_signed message.
4. Unfortunately he works so fast that various laws of causality are broken,
meaning sometimes the commitment_signed is sent before any of thes
other things happen.
I'm fairly sure that this will stop as @roasbeef ages, or lnd introduces
some kind of causality enforcement fix.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Don't turn them to/from pubkeys implicitly. This means nodeids in the store
don't get converted, but bitcoin keys still do.
MCP results from 5 runs, min-max(mean +/- stddev):
store_load_msec:33934-35251(34531.4+/-5e+02)
vsz_kb:2637488
store_rewrite_sec:34.720000-35.130000(34.94+/-0.14)
listnodes_sec:1.020000-1.290000(1.146+/-0.086)
listchannels_sec:51.110000-58.240000(54.826+/-2.5)
routing_sec:30.000000-33.320000(30.726+/-1.3)
peer_write_all_sec:50.370000-52.970000(51.646+/-1.1)
MCP notable changes from previous patch (>1 stddev):
-store_load_msec:46184-47474(46673.4+/-4.5e+02)
+store_load_msec:33934-35251(34531.4+/-5e+02)
-vsz_kb:2638880
+vsz_kb:2637488
-store_rewrite_sec:46.750000-48.280000(47.512+/-0.51)
+store_rewrite_sec:34.720000-35.130000(34.94+/-0.14)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I tried to just do gossipd, but it was uncontainable, so this ended up being
a complete sweep.
We didn't get much space saving in gossipd, even though we should save
24 bytes per node.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The `wally_tx_input`s do not keep track of their input value, which means we
need to track them ourselves if we try to sign these transactions at a later
point in time.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
1. Rename channel_funding_locked to channel_funding_depth in
channeld/channel_wire.csv.
2. Add minimum_depth in struct channel in common/initial_channel.h and
change corresponding init function: new_initial_channel().
3. Add confirmation_needed in struct peer in channeld/channeld.c.
4. Rename channel_tell_funding_locked to channel_tell_depth.
5. Call channel_tell_depth even if depth < minimum, and still call
lockin_complete in channel_tell_depth, iff depth > minimum_depth.
6. channeld ignore the channel_funding_depth unless its >
minimum_depth(except to update billboard, and set
peer->confirmation_needed = minimum_depth - depth).
Basically we tell it that every field ending in '_msat' is a struct
amount_msat, and 'satoshis' is an amount_sat. The exceptions are
channel_update's fee_base_msat which is a u32, and
final_incorrect_htlc_amount's incoming_htlc_amt which is also a
'struct amount_msat'.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
As a side-effect of using amount_msat in gossipd/routing.c, we explicitly
handle overflows and don't need to pre-prune ridiculous-fee channels.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LND seems to do this occasionally, though fixed in new versions. Workaround
in the meantime.
I tested this by hacking our code to send it prematurely, and this worked.
Fixes: #2219
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This solves (or at least reduces probability of) a deadlock in channeld
when there is lot of gossip traffic, see issue #2286. That issue is
almost identical to #1943 (deadlock in openingd) and so is the fix.
Spurious errors were occuring around checking the provided
current commitment point from the peer on reconnect when
option_data_loss_protect is enabled. The problem was that
we were using an inaccurate measure to screen for which
commitment point to compare the peer's provided one to.
This fixes the problem with screening, plus makes our
data_loss test a teensy bit more robust.
Christian and I both unwittingly used it in form:
*tal_arr_expand(&x) = tal(x, ...)
Since '=' isn't a sequence point, the compiler can (and does!) cache
the value of x, handing it to tal *after* tal_arr_expand() moves it
due to tal_resize().
The new version is somewhat less convenient to use, but doesn't have
this problem, since the assignment is always evaluated after the
resize.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is based on Christian's change, but removes all trace of the old codes.
I've proposed another spec change which removes this code altogether:
https://github.com/lightningnetwork/lightning-rfc/pull/544
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Reported-by: Rusty Russell <@rustyrussell>
This is mainly just copying over the copy-editing from the
lightning-rfc repository.
[ Split to just perform changes prior to the UNKNOWN_PAYMENT_HASH change --RR ]
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Reported-by: Rusty Russell <@rustyrussell>
Fortunately, we can calculate the sha256 ourselves, so the
outgoing channeld doesn't need to tell us.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When the next node tells us the onion is malformed, we now actually
report the failcode to lightningd (rather than generating an invalid
error as we do now).
We could generate the onion at this point, but except we don't know
the shared secret; we'd have to plumb that through from the incoming
channeld's HTLC.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This covers all the cases where an onion can be malformed; this means
we know in advance that it's bad. That allows us to distinguish two
cases: where lightningd rejects the onion as bad, and where the next
peer rejects the next onion as bad. Both of those (will) set failcode
to one of the BADONION values.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's more natural than using a zero-secret when something goes wrong.
Also note that the HSM will actually kill the connection if the ECDH
fails, which is fortunately statistically unlikely.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We have an incompatibility with lnd it seems: I've lost channels on
reconnect with 'sync error'. Since I never got this code to be reliable,
disable it for next release since I suspect it's our fault :(
And reenable the check which didn't work, for others to untangle.
I couldn't get option_data_loss_protect to be reliable, and I disabled
the check. This was a mistake, I should have either spent even more
time trying to get to the bottom of this (especially, writing test
vectors for the spec and testing against other implementations).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is prep work for when we sign htlc txs with
SIGHASH_SINGLE|SIGHASH_ANYONECANPAY.
We still deal with raw signatures for the htlc txs at the moment, since
we send them like that across the wire, and changing that was simply too
painful (for the moment?).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We only use them for re-transmitting the last commitment tx,
and the HSM signs them sync so it's straight-line code.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>