splice: Pass is_locked between channeld and ld

To support resuming `splice_locked` across channel reconnect, we need to pass inflight `is_locked` between lightningd and channeld.

This implements that interface between channeld and lightningd so each inflight should have up to date `is_locked` values between restarts.

Author: ddustin

channeld/channeld.c

@@ -3361,7 +3361,8 @@ static void resume_splice_negotiation(struct peer *peer,
 
 		msg = towire_channeld_update_inflight(NULL, current_psbt,
 						      their_commit->tx,
-						      &their_commit->commit_signature);
+						      &their_commit->commit_signature,
+						      inflight->is_locked);
 		wire_sync_write(MASTER_FD, take(msg));
 	}
 
@@ -3431,7 +3432,8 @@ static void resume_splice_negotiation(struct peer *peer,
 			    inflight->force_sign_first)
 		&& send_signature) {
 		msg = towire_channeld_update_inflight(NULL, current_psbt,
-						      NULL, NULL);
+						      NULL, NULL,
+						      inflight->is_locked);
 		wire_sync_write(MASTER_FD, take(msg));
 
 		msg = towire_channeld_splice_sending_sigs(tmpctx, &final_txid);
@@ -3600,7 +3602,8 @@ static void resume_splice_negotiation(struct peer *peer,
 	if (recv_signature) {
 		/* We let core validate our peer's signatures are correct. */
 		msg = towire_channeld_update_inflight(NULL, current_psbt, NULL,
-						      NULL);
+						      NULL,
+						      inflight->is_locked);
 		wire_sync_write(MASTER_FD, take(msg));
 	}
 
@@ -3831,6 +3834,7 @@ static void splice_accepter(struct peer *peer, const u8 *inmsg)
 	new_inflight->last_tx = NULL;
 	new_inflight->i_am_initiator = false;
 	new_inflight->force_sign_first = peer->splicing->force_sign_first;
+	new_inflight->is_locked = false;
 
 	current_push_val = relative_splice_balance_fundee(peer, our_role,ictx->current_psbt,
 					  outpoint.n, splice_funding_index);
@@ -4055,6 +4059,7 @@ static void splice_initiator_user_finalized(struct peer *peer)
 	new_inflight->last_tx = NULL;
 	new_inflight->i_am_initiator = true;
 	new_inflight->force_sign_first = peer->splicing->force_sign_first;
+	new_inflight->is_locked = false;
 
 	/* Switch over to using inflight psbt. This allows us to be reentrant.
 	 * On restart we *will* have inflight psbt but we will not have any
@@ -4085,7 +4090,8 @@ static void splice_initiator_user_finalized(struct peer *peer)
 
 	outmsg = towire_channeld_update_inflight(NULL, new_inflight->psbt,
 						 their_commit->tx,
-						 &their_commit->commit_signature);
+						 &their_commit->commit_signature,
+						 new_inflight->is_locked);
 	wire_sync_write(MASTER_FD, take(outmsg));
 
 	sign_first = do_i_sign_first(peer, new_inflight->psbt, our_role,
@@ -4244,7 +4250,8 @@ static void splice_initiator_user_signed(struct peer *peer, const u8 *inmsg)
 	 * restart and reestablish later. */
 	outmsg = towire_channeld_update_inflight(NULL, inflight->psbt,
 						 inflight->last_tx,
-						 &inflight->last_sig);
+						 &inflight->last_sig,
+						 inflight->is_locked);
 
 	wire_sync_write(MASTER_FD, take(outmsg));
 
@@ -5597,6 +5604,20 @@ static void handle_funding_depth(struct peer *peer, const u8 *msg)
 
 			peer->splice_state->locked_txid = txid;
 
+			for (size_t i = 0; i < tal_count(peer->splice_state->inflights); i++) {
+				struct inflight *inflight = peer->splice_state->inflights[i];
+				if (bitcoin_txid_eq(&inflight->outpoint.txid,
+						    &txid)) {
+					inflight->is_locked = true;
+					msg = towire_channeld_update_inflight(NULL,
+									      inflight->psbt,
+									      NULL,
+									      NULL,
+									      inflight->is_locked);
+					wire_sync_write(MASTER_FD, take(msg));
+				}
+			}
+
 			peer_write(peer->pps, take(msg));
 
 			peer->splice_state->locked_ready[LOCAL] = true;
@@ -6068,6 +6089,7 @@ static void init_channel(struct peer *peer)
 	struct penalty_base *pbases;
 	bool reestablish_only;
 	struct channel_type *channel_type;
+	bool found_locked_inflight;
 
 	assert(!(fcntl(MASTER_FD, F_GETFL) & O_NONBLOCK));
 

channeld/channeld_wire.csv

@@ -273,6 +273,7 @@ msgtype,channeld_update_inflight,7219
 msgdata,channeld_update_inflight,psbt,wally_psbt,
 msgdata,channeld_update_inflight,last_tx,?bitcoin_tx,
 msgdata,channeld_update_inflight,last_sig,?bitcoin_signature,
+msgdata,channeld_update_inflight,is_locked,bool,
 
 # channeld->master: A funding error has occured
 msgtype,channeld_splice_funding_error,7220

lightningd/channel_control.c

@@ -886,9 +886,10 @@ static void handle_update_inflight(struct lightningd *ld,
 	struct bitcoin_txid txid;
 	struct bitcoin_tx *last_tx;
 	struct bitcoin_signature *last_sig;
+	bool is_locked;
 
 	if (!fromwire_channeld_update_inflight(tmpctx, msg, &psbt, &last_tx,
-					       &last_sig)) {
+					       &last_sig, &is_locked)) {
 		channel_internal_error(channel,
 				       "bad channel_add_inflight %s",
 				       tal_hex(channel, msg));
@@ -916,6 +917,8 @@ static void handle_update_inflight(struct lightningd *ld,
 	if (last_sig)
 		inflight->last_sig = *last_sig;
 
+	inflight->is_locked = is_locked;
+
 	tal_wally_start();
 	if (wally_psbt_combine(inflight->funding_psbt, psbt) != WALLY_OK) {
 		channel_internal_error(channel,
@@ -1812,6 +1815,7 @@ bool peer_start_channeld(struct channel *channel,
 		infcopy->last_sig = inflight->last_sig;
 		infcopy->i_am_initiator = inflight->i_am_initiator;
 		infcopy->force_sign_first = inflight->force_sign_first;
+		infcopy->is_locked = inflight->is_locked;
 
 		tal_wally_start();
 		wally_psbt_clone_alloc(inflight->funding_psbt, 0, &infcopy->psbt);