mirrors/core-lightning
1
0
Fork 0
mirror of https://github.com/ElementsProject/lightning.git synced 2025-02-22 14:42:40 +01:00
Code Issues Projects Releases Wiki Activity

df, channeld: cleanup how psbt signalling works

Browse source 
We used to send our tx_sigs before we got to channeld existing. We
changed how this worked so that multifundchannel could live, but failed
to clean up the logic of what "having a psbt around" means wrt channeld
and messaging our peer.

The general idea is that we want to send `tx_signatures` to our peer on
reconnect until they've sent us `funding_locked`.

Note that it's an error to
  - send `funding_locked` without having sent `tx_signatures`
  - send `tx_signatures` after sending `funding_locked`

We use the 'finalized' state of the peer's inputs/outputs to help signal
where we are in receiving their sigs -- but this doesn't work at all for
opens where the peer doesn't contribute inputs at all.

This isn't really a huge deal, but it does mean that if we receive a
peer's `tx_sigs` more than once (will happen for a reconnect before
`funding_locked`), then we'll issue a notification about receiving their
sigs multiple times. /shrug
This commit is contained in:
niftynei 2020-10-14 20:24:08 -05:00 • committed by Rusty Russell
parent d535a27104
commit 1b3a9be416
1 changed files with 48 additions and 18 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

66
channeld/channeld.c
View file

@ -518,6 +518,20 @@ static void announce_channel(struct peer *peer)
send_channel_update(peer, 0);
}
#if EXPERIMENTAL_FEATURES
static enum tx_role our_tx_role(const struct peer *peer)
{
return peer->channel->opener == LOCAL ?
TX_INITIATOR : TX_ACCEPTER;
}
#endif
static enum tx_role their_tx_role(const struct peer *peer)
{
return peer->channel->opener == LOCAL ?
TX_ACCEPTER : TX_INITIATOR;
}
static void channel_announcement_negotiate(struct peer *peer)
{
/* Don't do any announcement work if we're shutting down */
@ -598,6 +612,13 @@ static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
if (peer->shutdown_sent[LOCAL])
return;
if (peer->psbt && !psbt_side_finalized(peer->psbt,
their_tx_role(peer)))
peer_failed(peer->pps,
&peer->channel_id,
"Rcvd `funding_locked` from peer but "
"have not received `tx_signatures`");
peer->old_remote_per_commit = peer->remote_per_commit;
if (!fromwire_funding_locked(msg, &chanid,
&peer->remote_per_commit))
@ -614,6 +635,7 @@ static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
&peer->channel_id));
peer->funding_locked[REMOTE] = true;
peer->psbt = tal_free(peer->psbt);
wire_sync_write(MASTER_FD,
take(towire_channeld_got_funding_locked(NULL,
&peer->remote_per_commit)));
@ -2043,8 +2065,7 @@ static void handle_tx_sigs(struct peer *peer, const u8 *msg)
const struct witness_stack **ws;
size_t j = 0;
enum tx_role role = peer->channel->opener == REMOTE
? TX_INITIATOR : TX_ACCEPTER;
enum tx_role their_role = their_tx_role(peer);
if (!fromwire_tx_signatures(tmpctx, msg, &cid, &txid,
cast_const3(
@ -2080,6 +2101,15 @@ static void handle_tx_sigs(struct peer *peer, const u8 *msg)
return;
}
/* This check only works if they've got inputs we need sigs for.
* In the case where they send duplicate tx_sigs but have no
* sigs, we'll end up re-notifying */
if (tal_count(ws) && psbt_side_finalized(peer->psbt, their_role)) {
status_info("Got duplicate WIRE_TX_SIGNATURES, "
"already have their sigs. Ignoring");
return;
}
/* We put the PSBT + sigs all together */
for (size_t i = 0; i < peer->psbt->num_inputs; i++) {
struct wally_psbt_input *in =
@ -2094,7 +2124,7 @@ static void handle_tx_sigs(struct peer *peer, const u8 *msg)
peer->psbt));
return;
}
if (in_serial % 2 != role)
if (in_serial % 2 != their_role)
continue;
if (j == tal_count(ws))
@ -2111,8 +2141,6 @@ static void handle_tx_sigs(struct peer *peer, const u8 *msg)
* as soon as we've got our sigs */
wire_sync_write(MASTER_FD,
take(towire_channeld_funding_sigs(NULL, peer->psbt)));
peer->psbt = tal_free(peer->psbt);
}
#endif /* EXPERIMENTAL_FEATURES */
@ -2773,9 +2801,8 @@ static void peer_reconnect(struct peer *peer,
#if EXPERIMENTAL_FEATURES
/* Send our tx_sigs again */
enum tx_role role = peer->channel->opener == LOCAL
? TX_INITIATOR : TX_ACCEPTER;
if (peer->psbt && psbt_side_finalized(peer->psbt, role)
if (peer->psbt && psbt_side_finalized(peer->psbt,
our_tx_role(peer))
&& !peer->funding_locked[REMOTE])
sync_crypto_write(peer->pps,
take(psbt_to_tx_sigs_msg(NULL, peer->channel,
@ -2973,13 +3000,6 @@ static void handle_funding_depth(struct peer *peer, const u8 *msg)
&depth))
master_badmsg(WIRE_CHANNELD_FUNDING_DEPTH, msg);
/* We were waiting for them to send us their
* `tx_signatures`, but they never did. As a
* result we'll still have the psbt */
if (peer->psbt) {
return;
}
/* Too late, we're shutting down! */
if (peer->shutdown_sent[LOCAL])
return;
@ -2988,6 +3008,18 @@ static void handle_funding_depth(struct peer *peer, const u8 *msg)
peer->depth_togo = peer->channel->minimum_depth - depth;
} else {
/* We were waiting for them to send us their
* `tx_signatures`, but they never did. As a
* result we'll still have the psbt */
if (peer->psbt && !psbt_side_finalized(peer->psbt,
their_tx_role(peer))) {
peer_failed(peer->pps, &peer->channel_id,
"Funding tx reached funding depth %d "
"but we haven't received peer's "
"tx_signatures",
depth);
}
peer->depth_togo = 0;
assert(scid);
@ -3571,11 +3603,9 @@ static void init_channel(struct peer *peer)
sync_crypto_write(peer->pps, take(fwd_msg));
#if EXPERIMENTAL_FEATURES
enum tx_role role;
role = opener == LOCAL ? TX_INITIATOR : TX_ACCEPTER;
/* peer_reconnect does this if needed */
if (!reconnected && peer->psbt &&
psbt_side_finalized(peer->psbt, role))
psbt_side_finalized(peer->psbt, our_tx_role(peer)))
sync_crypto_write(peer->pps,
take(psbt_to_tx_sigs_msg(NULL, peer->channel,
peer->psbt)));