The idea is that gossipd can give us the cupdate we need for an error, and
we wire things up so that we ask for it (async) just before we send the
error to the subdaemon.
I tried many other things, but they were all too high-risk.
1. We need to ask gossipd every time, since it produces these lazily
(in particular, it doesn't actually generate an offline update unless
the channel is used).
2. We can't do async calls in random places, since we'll end up with
an HTLC in limbo. What if another path tries to fail it at the same time?
3. This allows us to use a temporary_node_failure error, and upgrade it
when gossipd replies. This doesn't change any existing assumptions.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a common thing to do, so create a macro.
Unfortunately, it still needs the type arg, because the paramter may
be const, and the return cannot be, and C doesn't have a general
"(-const)" cast.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This completes the conversion; any in-flight HTLC failures get turned into temporary_node_failures.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
At the moment, we store e.g. WIRE_TEMPORARY_CHANNEL_FAILURE, and then
lightningd has a large demux function which turns that into the correct
error message.
Such an enum demuxer is an anti-pattern.
Instead, store the message directly for output HTLCs; channeld now
sends us an error message rather than an error code.
For input HTLCs we will still need the failure code if the onion was
bad (since we need to prompt channeld to send a completely different
message than normal), though we can (and will!) eliminate its use in
non-BADONION failure cases.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We're going to change our internal structure next, so this is preparation.
We populate existing errors with temporary node failures, for simplicity.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of making it ourselves, lightningd does it. Now we only have
two cases of failed htlcs: completely malformed (BADONION), and with
an already-wrapped onion reply to send.
This makes channeld's job much simpler.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I hadn't realized that lightningd asks gossipd every time we forward
a payment. But I'm going to abuse it here to get the latest channel_update,
otherwise (as lightningd takes over error message generation) lightningd
needs to do an async request at various painful points.
So have gossipd tell us the lastest update (stripped so compatible with
the strange in-onion-error format).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Turn it into temporary node failure: this only happens if we restart
with a failed htlc in, but it's clearer and more robust to handle it
generically.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Added in d901304120, this column is null in old dbs like mine:
2020-02-15T00:08:41.444Z **BROKEN** database: Accessing a null column 12 in query SELECT id, channel_htlc_id, msatoshi, cltv_expiry, hstate, payment_hash, payment_key, routing_onion, failuremsg, malformed_onion, origin_htlc, shared_secret, received_time FROM channel_htlcs WHERE direction= ? AND channel_id= ? AND hstate != ?
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the peer is not connected, or other error which means we don't
actually create an outgoing HTLC, we don't record the
short_channel_id. This is unhelpful!
Pass the scid down to the wallet code, and explicitly hand the
scid and amount down to the notification code rather than handing it
the htlc_out (which it doesn't need).
Changelog-Changed: JSON API: `listforwards` now shows `out_channel` even if we couldn't forward.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This sets the nLockTime to the tip (and accordingly each input's nSequence to
0xfffffffe) for withdrawal transactions.
Even if the anti fee-sniping argument might not be valid until some time yet,
this makes our regular wallet transactions far less distinguishable from
bitcoind's ones since it now defaults to using native Segwit transactions
(like us). Moreover other wallets are likely to implement this (if they
haven't already).
Changelog-Added: wallet: withdrawal transactions now sets nlocktime to the current tip.
Before this patch we used `int` for error codes. The problem with
`int` is that we try to pass it to/from wire and the size of `int` is
not defined by the standard. So a sender with 4-byte `int` would write
4 bytes to the wire and a receiver with 2-byte `int` (for example) would
read just 2 bytes from the wire.
To resolve this:
* Introduce an error code type with a known size:
`typedef s32 errcode_t`.
* Change all error code macros to constants of type `errcode_t`.
Constants also play better with gdb - it would visualize the name of
the constant instead of the numeric value.
* Change all functions that take error codes to take the new type
`errcode_t` instead of `int`.
* Introduce towire / fromwire functions to send / receive the newly added
type `errcode_t` and use it instead of `towire_int()`.
In addition:
* Remove the now unneeded `towire_int()`.
* Replace a hardcoded error code `-2` with a new constant
`INVOICE_EXPIRED_DURING_WAIT` (903).
Changelog-Changed: The waitinvoice command would now return error code 903 to designate that the invoice expired during wait, instead of the previous -2
This command injects a custom message into the encrypted transport stream to
the peer, allowing users to build custom protocols on top of c-lightning
without requiring any changes to c-lightning itself.
Generally I prefer structures over u8, since the size is enforced at
runtime; and in several places we were doing conversions as the code
using Sphinx does treat struct secret as type of the secret.
Note that passing an array is the same as passing the address, so
changing from 'u8 secret[32]' to 'struct secret secret' means various
'secret' parameters change to '&secret'. Technically, '&secret' also
would have worked before, since '&' is a noop on array, but that's
always seemed a bit weird.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes it clear we're dealing with a message which is a wrapped error
reply (needing unwrap_onionreply), not an already-wrapped one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I really want a type which means "I am a wrapped onion reply" as separate
from "I am a normal wire msg". Currently both user u8 *, and I got very
confused trying to figure out where each one was an unwrapped error msg,
or where it still needed (un)wrapping.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
`wallet_payment_store` would free the `wallet_payment` instance which would
then cause us to reload it from the DB. Instead of doing the store->free->load
dance we now tell `wallet_payment_store` whether it should take ownership and
leave it alone if not.
Passing the payment around instead of referencing it through payment_hash and
partid is a nice side-effect.
The optimistic lock prevents multiple instances of c-lightning making
concurrent modifications to the database. That would be unsafe as it messes up
the state in the DB. The optimistic lock is implemented by checking whether a
gated update on the previous value of the `data_version` actually results in
an update. If that's not the case the DB has been changed under our feet.
The lock provides linearizability of DB modifications: if a database is
changed under the feet of a running process that process will `abort()`, which
from a global point of view is as if it had crashed right after the last
successful commit. Any process that also changed the DB must've started
between the last successful commit and the unsuccessful one since otherwise
its counters would not have matched (which would also have aborted that
transaction). So this reduces all the possible timelines to an equivalent
where the first process died, and the second process recovered from the DB.
This is not that interesting for `sqlite3` where we are also protected via the
PID file, but when running on multiple hosts against the same DB, e.g., with
`postgres`, this protection becomes important.
Changelog-Added: DB: Optimistic logging prevents instances from running concurrently against the same database, providing linear consistency to changes.
This increments the `data_version` upon committing dirty transactions, reads
the last data_version upon startup, and tracks the number in memory in
parallel to the DB (see next commit for rationale).
Changelog-Changed: JSON-RPC: Added a `data_version` field to the `db_write` hook which returns a numeric transaction counter.
This is the final step: we pass the complete fee_states to and from
channeld.
Changelog-Fixed: "Bad commitment signature" closing channels when we sent back-to-back update_fee messages across multiple reconnects.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The upgrade here is a bit tricky: we map the two values into the
feerate_state. This is trivial if they're both the same, but if
they're different we don't know exactly what state they're in (this
being the source of the bug!).
So, we assume that the have received the update and not acked it,
as that would be the normal case.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The invoice_try_pay code now takes a set, rather than a single htlc, but
it's basically the same thing.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a transient field, so rework things so we don't leave it in
struct htlc_out. Instead, load htlc_in first and connect htlc_out to
them as we go.
This also changes one place where we use it instead of the am_origin
flag.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is in preparation for partial payments. For existing payments,
partid is 0 (to match the corresponding payment).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is in preparation for partial payments. For existing payments,
partid is 0 (arbitrarity) and total_msat is msatoshi.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now "raw_payload" is always the complete string (including realm or length
bytes at the front).
This has several effects:
1. We can receive an decrypt an onion which is grossly malformed.
2. We can still hand this to the htlc_accepted hook.
3. We then fail it unless the htlc_accepted accepts it manually.
4. The createonion API now takes the raw payload, and does not know
anything about "style".
The only caveat is that the sphinx code needs to know the payload
length: we have a call for that, which simply tells it to copy the
entire onion (and treat us as the final node) if it's invalid.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we can't decode the onion, because the onion got corrupted or we used
`sendonion` without specifying the `shared_secrets` used, the best we can do
is tell the caller instead.
This means that c-lightning can now internally decrypt an eventual error
message, and not force the caller to implement the decryption. The main
difficulty was that we now have a new state (channels and nodes not specified,
while shared_secrets are specified) which needed to be handled.
We are breaking with a couple of assumptions, namely that we have the
`path_secrets` to decode the error onion. If this happens we just want it to
error out.
