This is probably worth preventing.
1. Our depth estimate would be inaccurate possibly leading to us
timing out too early.
2. If we're not up-to-date our onchain funds are unknown.
3. We wouldn't be able to send or receive HTLCs until we're synced anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
`close` takes two optional arguments: `force` and `timeout`.
`timeout` doesn't timeout the close (there's no way to do that), just
the JSON call. `force` (default `false`) if set, means we unilaterally
close at the timeout, instead of just failing.
Timing out JSON calls is generally deprecated: that's the job of the
client. And the semantics of this are confusing, even to me! A
better API is a timeout which, if non-zero, is the time at which we
give up and unilaterally close.
The transition code is awkward, but we'll manage for the three
releases until we can remove it.
The new defaults are to unilaterally close after 48 hours.
Fixes: #2791
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The helpme plugin is more comprensive, but this at least connects to a
few random nodes, and doesn't require python libraries in path or anything.
I selected the nodes from helpme.py, eliminating ones I couldn't reach.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Note that we move adding the plugin to the plugins list to the end, otherwise
the hook from logging can examine the (uninitialized) plugin.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is easy since we did the option parsing cleanup, but it has the
effect that plugins are launched from the lightning-dir. Now
we have dynamic plugins, this means startup and post-startup plugins
experience the same environment.
This is absolutely a desirable thing: they can just drop files in
their cwd rather than having to move (including, I might note, core
files!).
We also highlight the change in various places (and a drive-up update
of PLUGINS.md which says you have to use --plugin).
The next patch adds a backwards compatibility wedge for old users of
relative plugin paths.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The reason lnd was sending sync error was that we were taking more than
30 seconds to send the channel_reestablish after connect. That's
understandable on my test node under valgrind, but shouldn't happen normally.
However, it seems it has at least once,
(see https://github.com/ElementsProject/lightning/issues/2847)
: space out startup so it's less likely to happen.
Suggested-by: @cfromknecht
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
updates the bolt version to 6639cef095a2ecc7b8f0c48c6e7f2f906fbfbc58.
this requires us to use the new bolt parser at generate-bolt.py
and updates to all of the type specifications (ie. from u8 -> byte)
Due to API instability we are disabling the RPC method for this release, but
will re-enable it after the release again.
Signed-off-by: Christian Decker <@cdecker>
This is a painpoint with testing, that there's a noticable delay between
"Shutting down" from lightning-cli and being able to restart lightningd.
This fixes that by creating a canned response for this case, which is
simply written out immediately before exit. At this point, the pidfile
has been deleted, the sockets have been closed, and the database
has been closed.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The next commit breaks it: `if b' }\n' not in buff:` is always true since
we're about to clean up our JSON so there won't be a space. I could have
hacked the space in our JSON, but 6 months is long enough anyway.
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>
This allows you to prepare a tx, then release or discard it later.
Shares almost all the code with json_withdraw (which is now technically
superfluous).
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.
Unfortuntely we get spurious uninitialized variable warnings with
anything but -O3 or no optimization, so set default CWARNFLAGS
appropriately.
MCP bench results without optimization:
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)
MCP bench with -Og: 22% speedup vs no optimization
store_load_msec:21963-23645(22841+/-6.6e+02)
vsz_kb:579916
store_rewrite_sec:10.080000-10.960000(10.456+/-0.3)
listnodes_sec:1.280000-1.390000(1.338+/-0.047)
listchannels_sec:14.770000-16.080000(15.518+/-0.46)
routing_sec:0.990000-6.660000(3.958+/-2.2)
peer_write_all_sec:29.950000-32.950000(31.138+/-1)
MCP bench with -O2: 31% speedup vs no optimization
store_load_msec:20713-22088(21505.6+/-4.8e+02)
vsz_kb:579928
store_rewrite_sec:9.570000-11.200000(10.192+/-0.54)
listnodes_sec:0.960000-1.090000(1.028+/-0.045)
listchannels_sec:10.400000-11.770000(11.012+/-0.48)
routing_sec:0.300000-3.140000(1.978+/-1.1)
peer_write_all_sec:28.980000-30.310000(29.572+/-0.44)
MCP bench with -O3 -flto: 36% speedup vs no optimization
store_load_msec:19616-20191(19862.6+/-1.9e+02)
vsz_kb:578452
store_rewrite_sec:8.980000-9.960000(9.55+/-0.32)
listnodes_sec:0.920000-1.910000(1.18+/-0.38)
listchannels_sec:8.960000-9.450000(9.206+/-0.16)
routing_sec:0.730000-1.850000(1.438+/-0.42)
peer_write_all_sec:28.090000-29.410000(28.772+/-0.42)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Without this, the connect command hangs in one of my branches. This logic
is from the old days when gossipd handled connections, and we wanted
to make sure it didn't hang up on this client due to the error.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
68fe5eacde introduced a skip in the iteration
of the available funds, which means utxos[i] may be off the end of utxos.
Reported-and-debugged-by: @nitramiz
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>
This also allows plugins to do "hold invoices" a-la LND, useful for
just-in-time inventory handling.
We're careful to handle the invoice getting paid behind our backs, and
the incoming HTLC going away.
Once @cdecker's sphinx rework is in, we can also hand the raw payload
to the invoice_payment_hook, for special effects.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For online services, shorter may be fine, but for casual use I'm usually
in a different timezone than the payer, so needs to be at least 1 day.
Certainly 1 hr is short if they have to open a channel.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The user can explicitly create such things (within [] or ") as we paste
those cases literally, but not for the simple cases.
Fixes: #2550
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Travis caught an error where this happened: when closingd reconnects it
was sending the reestablish message without the option_dataloss_protect
fields. That causes the peer to fail the channel!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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).
We set the version BIP32_VER_TEST_PRIVATE for testnet/regtest
BIP32 privkey generation with libwally-core, and set
BIP32_VER_MAIN_PRIVATE for mainnet.
For litecoin, we also set it like bitcoin else.
lightning_connectd(19780): STATUS_FAIL_INTERNAL_ERROR: Failed to bind on 2 socket: Address family not supported by protocol
"Untested code is buggy code"
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
And fix trivial typo in MAKING-RELEASES.md, and date retreival in
build-release.sh and repro-build.sh (real git tags start with v!)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
New name is less confusing, and most people should be transitioning to
listpays rather than this anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is to future-proof against multi-part-payments: the low-level commands
will start returning multiple results once we have that, so prepare
transition plan now.
Closes: #2372
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the same deprecation, but one level up. For the moment, we
still support invoices with a `h` field (where description will be
necessary) but that will be removed once this option is removed.
Note that I just changed pylightning without backwards compatibility,
since the field was unlikely to be used, but we could do something
more complex here?
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This field was used by `pay` to hold the bolt11 description if the bolt11
string used `h` to hash the description (which nobody ever did). If the
`h` field wasn't present, it could contain anything, as it wasn't checked.
It's really useful to have a label for payments (eg. '1 Cuban'), but adding
yet-another option would be painful, so we simply rename 'description'
to 'label' except inside the db.
This means we need to do some tricky parameter parsing to handle array
and keyword JSON arguments, but only until we remove the old name.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Without this, there's no proof of payment, since it is the signed invoice
that make the receipt valid.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I tried to fundchannel 0.01btc, and of course it wanted 8 decimals exactly.
If I can't get this right, it's probably a bad idea.
I still don't allow whole number of btc though, since that's probably a mistake
and you're not supposed to put that much in c-lightning yet :)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In particular this matches the case of `their_unilateral/to_us` outputs, which
were missing their addresses so far.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Little point having users handle the postfixes manually, this
translates them, and also allows Millisatoshi to be used wherever an
'int' would be previously.
There are also helpers to create the formatting in a way c-lightning's
JSONRPC will accept.
All standard arithmetic operations with integers work.
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>
We need to still accept it when parsing the database, but this flag
should allow upgrade testing for devs building on top
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Also one less headache for reproducible builds. But unlike
libsodium, this only seems common in Ubuntu.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Up until now, riskfactor was useless due to implementation bugs, and
also the default setting is wrong (too low to have an effect on
reasonable payment scenarios).
Let's simplify the definition (by assuming that P(failure) of a node
is 1), to make it a simple percentage. I examined the current network
fees to see what would work, and under this definition, a default of
10 seems reasonable (equivalent to 1000 under the old definition).
It is *this* change which finally fixes our test case! The riskfactor
is now 40msat (1500000 * 14 * 10 / 5259600 = 39.9), comparable with
worst-case fuzz is 50msat (1001 * 0.05 = 50).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We were only comparing by total msatoshis.
Note, this *still* isn't sufficient to fix our indirect problem, as
our risk values are all 1 (the minimum):
lightning_gossipd(25480): 2 hop solution: 1501990 + 2
lightning_gossipd(25480): 3 hop solution: 1501971 + 3
...
lightning_gossipd(25480): => chose 3 hop solution
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the direct cause of the failure of the original
test_pay_direct test and it makes sense: invoice routehints may not be
necessary, so try without them *first* rather than last.
We didn't mention the use of routehints in CHANGELOG at all yet, so
do that now.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Don't do this:
(gdb) bt
#0 0x00007f37ae667c40 in ?? () from /lib/x86_64-linux-gnu/libz.so.1
#1 0x00007f37ae668b38 in ?? () from /lib/x86_64-linux-gnu/libz.so.1
#2 0x00007f37ae669907 in deflate () from /lib/x86_64-linux-gnu/libz.so.1
#3 0x00007f37ae674c65 in compress2 () from /lib/x86_64-linux-gnu/libz.so.1
#4 0x000000000040cfe3 in zencode_scids (ctx=0xc1f118, scids=0x2599bc49 "\a\325{", len=176320) at gossipd/gossipd.c:218
#5 0x000000000040d0b3 in encode_short_channel_ids_end (encoded=0x7fff8f98d9f0, max_bytes=65490) at gossipd/gossipd.c:236
#6 0x000000000040dd28 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290511, number_of_blocks=8) at gossipd/gossipd.c:576
#7 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290511, number_of_blocks=16) at gossipd/gossipd.c:595
#8 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290495, number_of_blocks=32) at gossipd/gossipd.c:596
#9 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290495, number_of_blocks=64) at gossipd/gossipd.c:595
#10 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=128) at gossipd/gossipd.c:596
#11 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=256) at gossipd/gossipd.c:595
#12 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=512) at gossipd/gossipd.c:595
#13 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=1024) at gossipd/gossipd.c:595
#14 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=2047) at gossipd/gossipd.c:596
#15 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=4095) at gossipd/gossipd.c:595
#16 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=8191) at gossipd/gossipd.c:595
#17 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=16382) at gossipd/gossipd.c:595
#18 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=32764) at gossipd/gossipd.c:595
#19 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=65528) at gossipd/gossipd.c:595
#20 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=131056) at gossipd/gossipd.c:595
#21 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=262112) at gossipd/gossipd.c:595
#22 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=524225) at gossipd/gossipd.c:595
#23 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=1048450) at gossipd/gossipd.c:595
#24 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=2096900) at gossipd/gossipd.c:595
#25 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=4193801) at gossipd/gossipd.c:595
#26 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=8387603) at gossipd/gossipd.c:595
#27 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=16775207) at gossipd/gossipd.c:595
#28 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=33550414) at gossipd/gossipd.c:596
#29 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=67100829) at gossipd/gossipd.c:595
#30 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=134201659) at gossipd/gossipd.c:595
#31 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=268403318) at gossipd/gossipd.c:595
#32 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=536806636) at gossipd/gossipd.c:595
#33 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=1073613273) at gossipd/gossipd.c:595
#34 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=2147226547) at gossipd/gossipd.c:595
#35 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=4294453094) at gossipd/gossipd.c:595
#36 0x000000000040df26 in handle_query_channel_range (peer=0x3868fc8, msg=0x37e0678 "\001\ao\342\214\n\266\361\263r\301\246\242F\256c\367O\223\036\203e\341Z\b\234h\326\031") at gossipd/gossipd.c:625
The cause was that converting a block number to an scid truncates it
at 24 bits. When we look through the index from (truncated number) to
(real end number) we get every channel, which is too large to encode,
so we iterate again.
This fixes both that problem, and also the issue that we'd end up
dividing into many empty sections until we get to the highest block
number. Instead, we just tack the empty blocks on to then end of the
final query.
(My initial version requested 0xFFFFFFFE blocks, but the dev code
which records what blocks were returned can't make a bitmap that big
on 32 bit).
Reported-by: George Vaccaro
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
seed isn't very useful at this level: I've left it in routing.c
because it might be useful for detailed testing. Pretty sure it's unused,
so I simply removed it.
The fuzzpercent is documented to default at 5%, but actually was 75%.
Fix that too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Since we are planning to release a bug fix release, and the plugin
subsystem is not yet complete, it is better to make plugin support
opt-in while we continue testing.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
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>
Funder can't spend the fee it needs to pay for the commitment transaction:
we were not converting to millisatoshis, however!
This breaks our routeboost test, which no longer has sufficient funds
to make payment.
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>
We inadvertently broke the compatibility between the python library
and the binary when switching to \n\n-delimiters. This reintroduces
the old inefficient parsing, and dynamically upgrades to the faster
version if it detects the \n\n-delimiter.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
The check command allows us to check the parameters of a command
without running it. Example:
lightning-cli check invoice 234 foo desc
We do this by removing the "command_to_check" parameter and then using the
remaining parameters as-is.
I chose the parameter name "command_to_check" instead of just "command" because
it must be unique to all other parameter names for all other commands. Why?
Because it may be ambiguous in the case of a json object, where the parameters are
not necessary ordered. We don't know which one is the command to check and
which one is a parameter.
Signed-off-by: Mark Beckwith <wythe@intrig.com>
We now keep multiple commands for a json_connection, and an array of
json_streams.
When a command wants to write something, we allocate a new json_stream
at the end of the array.
We always output from the first available json_stream; once that
command has finished, we free that and move to the next. Once all are
done, we wake the reader.
This means we won't read a new command if output is still pending, but
as most commands don't start writing until they're ready to write
everything, we still get command parallelism.
In particular, you can now 'waitinvoice' and 'delinvoice' and it will
work even though the 'waitinvoice' blocks.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We need to keep the remaining buffer, and we need to try to parse it
before we read the next. I first tried keeping it in the object, but
its lifetime is that of the *socket*, which we actually reopen for
every command.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
