dual-fund: add require_confirmed_inputs to RBF flows

We now require peers to reaffirm their preference for
`require_confirmed_inputs` when executing an RBF.

Requested-By: @t-bast

lightningd/dual_open_control.c

@@ -543,6 +543,13 @@ static void rbf_channel_hook_cb(struct rbf_channel_payload *payload STEALS)
 		return subd_send_msg(dualopend, take(msg));
 	}
 
+	/* Update the remote's require confirmed preferences */
+	if (payload->req_confirmed_ins_remote != channel->req_confirmed_ins[REMOTE]) {
+		channel->req_confirmed_ins[REMOTE] =
+			payload->req_confirmed_ins_remote;
+		wallet_channel_save(dualopend->ld->wallet, channel);
+	}
+
 	/* Update channel with new open attempt. */
 	channel->open_attempt = new_channel_open_attempt(channel);
 	msg = towire_dualopend_got_rbf_offer_reply(NULL,
@@ -2002,7 +2009,8 @@ static void rbf_got_offer(struct subd *dualopend, const u8 *msg)
 					      &payload->our_last_funding,
 					      &payload->funding_feerate_per_kw,
 					      &payload->locktime,
-					      &payload->requested_lease_amt)) {
+					      &payload->requested_lease_amt,
+					      &payload->req_confirmed_ins_remote)) {
 		channel_internal_error(channel,
 				       "Bad WIRE_DUALOPEND_GOT_RBF_OFFER: %s",
 				       tal_hex(msg, msg));
@@ -2027,8 +2035,6 @@ static void rbf_got_offer(struct subd *dualopend, const u8 *msg)
 	payload->peer_id = channel->peer->id;
 	payload->feerate_our_max = feerate_max(dualopend->ld, NULL);
 	payload->feerate_our_min = feerate_min(dualopend->ld, NULL);
-	payload->req_confirmed_ins_remote =
-		channel->req_confirmed_ins[REMOTE];
 
 	payload->psbt = NULL;
 
@@ -3243,6 +3249,25 @@ done:
 	tal_free(pv);
 }
 
+static void handle_update_require_confirmed(struct subd *dualopend,
+					    const u8 *msg)
+{
+	bool require_confirmed;
+	struct channel *channel = dualopend->channel;
+
+	if (!fromwire_dualopend_update_require_confirmed(msg, &require_confirmed)) {
+		channel_internal_error(dualopend->channel,
+				       "Bad DUALOPEND_UPDATE_REQUIRE_CONFIRMED: %s",
+				       tal_hex(msg, msg));
+		return;
+	}
+
+	if (channel->req_confirmed_ins[REMOTE] != require_confirmed) {
+		channel->req_confirmed_ins[REMOTE] = require_confirmed;
+		wallet_channel_save(dualopend->ld->wallet, channel);
+	}
+}
+
 static void handle_validate_inputs(struct subd *dualopend,
 				   const u8 *msg)
 {
@@ -3632,6 +3657,9 @@ static unsigned int dual_opend_msg(struct subd *dualopend,
 		case WIRE_DUALOPEND_VALIDATE_INPUTS:
 			handle_validate_inputs(dualopend, msg);
 			return 0;
+		case WIRE_DUALOPEND_UPDATE_REQUIRE_CONFIRMED:
+			handle_update_require_confirmed(dualopend, msg);
+			return 0;
 		/* Messages we send */
 		case WIRE_DUALOPEND_INIT:
 		case WIRE_DUALOPEND_REINIT:

openingd/dualopend.c

@@ -3564,6 +3564,14 @@ static void rbf_local_start(struct state *state, u8 *msg)
 	*init_rbf_tlvs->funding_output_contribution
 	       = (s64)tx_state->opener_funding.satoshis; /* Raw: wire conversion */
 
+
+	/* We repeat whatever we used on initial open for requiring confirmed
+	 * inputs */
+	if (state->require_confirmed_inputs[LOCAL])
+		init_rbf_tlvs->require_confirmed_inputs =
+			tal(init_rbf_tlvs, struct tlv_tx_init_rbf_tlvs_require_confirmed_inputs);
+
+
 	msg = towire_tx_init_rbf(tmpctx, &state->channel_id,
 				 tx_state->tx_locktime,
 				 tx_state->feerate_per_kw_funding,
@@ -3601,6 +3609,14 @@ static void rbf_local_start(struct state *state, u8 *msg)
 	} else
 		tx_state->accepter_funding = state->tx_state->accepter_funding;
 
+	/* Set the require_confirmed_inputs to whatever they set here */
+	if (ack_rbf_tlvs)
+		state->require_confirmed_inputs[REMOTE] =
+			ack_rbf_tlvs->require_confirmed_inputs != NULL;
+	else
+		/* They have to re-affirm to keep it! */
+		state->require_confirmed_inputs[REMOTE] = false;
+
 	/* Check that total funding doesn't overflow */
 	if (!amount_sat_add(&total, tx_state->opener_funding,
 			    tx_state->accepter_funding)) {
@@ -3672,6 +3688,11 @@ static void rbf_local_start(struct state *state, u8 *msg)
 	tal_free(state->tx_state);
 	state->tx_state = tal_steal(state, tx_state);
 
+	/* Notify lightningd about require_confirmed state */
+	msg = towire_dualopend_update_require_confirmed(NULL,
+		state->require_confirmed_inputs[REMOTE]);
+	wire_sync_write(REQ_FD, take(msg));
+
 	/* We merge with RBF's we've initiated now */
 	rbf_wrap_up(state, tx_state, total);
 	tal_free(rbf_ctx);
@@ -3735,6 +3756,14 @@ static void rbf_remote_start(struct state *state, const u8 *rbf_msg)
 		/* Otherwise we use the last known funding amount */
 		tx_state->opener_funding = state->tx_state->opener_funding;
 
+	/* Set the require_confirmed_inputs to whatever they set here */
+	if (init_rbf_tlvs)
+		state->require_confirmed_inputs[REMOTE] =
+			init_rbf_tlvs->require_confirmed_inputs != NULL;
+	else
+		/* They have to re-affirm to keep it! */
+		state->require_confirmed_inputs[REMOTE] = false;
+
 	/* Copy over the channel config info -- everything except
 	 * the reserve will be the same */
 	tx_state->localconf = state->tx_state->localconf;
@@ -3757,7 +3786,8 @@ static void rbf_remote_start(struct state *state, const u8 *rbf_msg)
 					     state->tx_state->accepter_funding,
 					     tx_state->feerate_per_kw_funding,
 					     tx_state->tx_locktime,
-					     state->requested_lease);
+					     state->requested_lease,
+					     state->require_confirmed_inputs[REMOTE]);
 
 	wire_sync_write(REQ_FD, take(msg));
 	msg = wire_sync_read(tmpctx, REQ_FD);
@@ -3833,6 +3863,11 @@ static void rbf_remote_start(struct state *state, const u8 *rbf_msg)
 	*ack_rbf_tlvs->funding_output_contribution
 	       = (s64)tx_state->accepter_funding.satoshis; /* Raw: wire conversion */
 
+	/* We keep whatever we initially set at open for RBFs */
+	if (state->require_confirmed_inputs[LOCAL])
+		ack_rbf_tlvs->require_confirmed_inputs =
+			tal(ack_rbf_tlvs, struct tlv_tx_ack_rbf_tlvs_require_confirmed_inputs);
+
 	msg = towire_tx_ack_rbf(tmpctx, &state->channel_id, ack_rbf_tlvs);
 	peer_write(state->pps, msg);
 	peer_billboard(false, "channel rbf: ack sent, waiting for reply");
@@ -4177,6 +4212,7 @@ static u8 *handle_master_in(struct state *state)
 	case WIRE_DUALOPEND_DRY_RUN:
 	case WIRE_DUALOPEND_VALIDATE_LEASE:
 	case WIRE_DUALOPEND_VALIDATE_INPUTS:
+	case WIRE_DUALOPEND_UPDATE_REQUIRE_CONFIRMED:
 		break;
 	}
 	status_failed(STATUS_FAIL_MASTER_IO,

openingd/dualopend_wire.csv

@@ -118,12 +118,17 @@ msgdata,dualopend_got_rbf_offer,our_last_funding,amount_sat,
 msgdata,dualopend_got_rbf_offer,funding_feerate_per_kw,u32,
 msgdata,dualopend_got_rbf_offer,locktime,u32,
 msgdata,dualopend_got_rbf_offer,requested_lease,?amount_sat,
+msgdata,dualopend_got_rbf_offer,require_confirmed_inputs,bool,
 
 # master->dualopend: reply back with our funding info/contribs
 msgtype,dualopend_got_rbf_offer_reply,7505
 msgdata,dualopend_got_rbf_offer_reply,our_funding,amount_sat,
 msgdata,dualopend_got_rbf_offer_reply,psbt,wally_psbt,
 
+# dualopend->master: update to require_confirmed_inputs preference
+msgtype,dualopend_update_require_confirmed,7511
+msgdata,dualopend_update_require_confirmed,require_confirmed_inputs,bool,
+
 # dualopend->master: is this a valid RBF candidate transaction?
 msgtype,dualopend_rbf_validate,7506
 msgdata,dualopend_rbf_validate,proposed_funding_psbt,wally_psbt,

tests/fuzz/fuzz-wire-tx_ack_rbf.c

@@ -31,10 +31,14 @@ static bool equal(const struct tx_ack_rbf *x, const struct tx_ack_rbf *y)
 		return false;
 
 	assert(x->tlvs && y->tlvs);
-	return memeq(x->tlvs->funding_output_contribution,
+	if (!memeq(x->tlvs->funding_output_contribution,
 		   tal_bytelen(x->tlvs->funding_output_contribution),
 		   y->tlvs->funding_output_contribution,
-		     tal_bytelen(y->tlvs->funding_output_contribution));
+		   tal_bytelen(y->tlvs->funding_output_contribution)))
+		return false;
+
+	return !!x->tlvs->require_confirmed_inputs ==
+	       !!y->tlvs->require_confirmed_inputs;
 }
 
 void run(const u8 *data, size_t size)

tests/fuzz/fuzz-wire-tx_init_rbf.c

@@ -36,10 +36,14 @@ static bool equal(const struct tx_init_rbf *x, const struct tx_init_rbf *y)
 		return false;
 
 	assert(x->tlvs && y->tlvs);
-	return memeq(x->tlvs->funding_output_contribution,
+	if (!memeq(x->tlvs->funding_output_contribution,
 		     tal_bytelen(x->tlvs->funding_output_contribution),
 		     y->tlvs->funding_output_contribution,
-		     tal_bytelen(y->tlvs->funding_output_contribution));
+		     tal_bytelen(y->tlvs->funding_output_contribution)))
+		return false;
+
+	return !!x->tlvs->require_confirmed_inputs ==
+	       !!y->tlvs->require_confirmed_inputs;
 }
 
 void run(const u8 *data, size_t size)

wallet/wallet.c

@@ -2286,9 +2286,10 @@ void wallet_channel_save(struct wallet *w, struct channel *chan)
 					"  remote_feerate_ppm=?," // 48
 					"  remote_cltv_expiry_delta=?," // 49
 					"  remote_htlc_minimum_msat=?," // 50
-					"  remote_htlc_maximum_msat=?,"
-					"  last_stable_connection=?"
-					" WHERE id=?"));
+					"  remote_htlc_maximum_msat=?," // 51
+					"  last_stable_connection=?" // 52
+					"  require_confirm_inputs_remote=?" // 53
+					" WHERE id=?")); // 54
 	db_bind_u64(stmt, chan->their_shachain.id);
 	if (chan->scid)
 		db_bind_short_channel_id(stmt, chan->scid);
@@ -2385,6 +2386,8 @@ void wallet_channel_save(struct wallet *w, struct channel *chan)
 		db_bind_null(stmt);
 	}
 	db_bind_u64(stmt, chan->last_stable_connection);
+
+	db_bind_int(stmt, chan->req_confirmed_ins[REMOTE]);
 	db_bind_u64(stmt, chan->dbid);
 	db_exec_prepared_v2(take(stmt));
 

wire/extracted_peer_03_dual-funding.patch

@@ -1,6 +1,6 @@
 --- wire/peer_wire.csv.raw	2023-09-11 13:32:30.677617251 +0930
 +++ wire/peer_wire.csv.openchannel2	2023-09-11 13:31:47.906308397 +0930
-@@ -37,6 +37,51 @@
+@@ -37,6 +37,53 @@
  tlvdata,n2,tlv1,amount_msat,tu64,
  tlvtype,n2,tlv2,11
  tlvdata,n2,tlv2,cltv_expiry,tu32,
@@ -40,11 +40,13 @@
 +msgdata,tx_init_rbf,tlvs,tx_init_rbf_tlvs,
 +tlvtype,tx_init_rbf_tlvs,funding_output_contribution,0
 +tlvdata,tx_init_rbf_tlvs,funding_output_contribution,satoshis,s64,
++tlvtype,tx_init_rbf_tlvs,require_confirmed_inputs,2
 +msgtype,tx_ack_rbf,73
 +msgdata,tx_ack_rbf,channel_id,channel_id,
 +msgdata,tx_ack_rbf,tlvs,tx_ack_rbf_tlvs,
 +tlvtype,tx_ack_rbf_tlvs,funding_output_contribution,0
 +tlvdata,tx_ack_rbf_tlvs,funding_output_contribution,satoshis,s64,
++tlvtype,tx_ack_rbf_tlvs,require_confirmed_inputs,2
 +msgtype,tx_abort,74
 +msgdata,tx_abort,channel_id,channel_id,
 +msgdata,tx_abort,len,u16,

wire/peer_wire.csv

@@ -76,11 +76,13 @@ msgdata,tx_init_rbf,feerate,u32,
 msgdata,tx_init_rbf,tlvs,tx_init_rbf_tlvs,
 tlvtype,tx_init_rbf_tlvs,funding_output_contribution,0
 tlvdata,tx_init_rbf_tlvs,funding_output_contribution,satoshis,s64,
+tlvtype,tx_init_rbf_tlvs,require_confirmed_inputs,2
 msgtype,tx_ack_rbf,73
 msgdata,tx_ack_rbf,channel_id,channel_id,
 msgdata,tx_ack_rbf,tlvs,tx_ack_rbf_tlvs,
 tlvtype,tx_ack_rbf_tlvs,funding_output_contribution,0
 tlvdata,tx_ack_rbf_tlvs,funding_output_contribution,satoshis,s64,
+tlvtype,tx_ack_rbf_tlvs,require_confirmed_inputs,2
 msgtype,tx_abort,74
 msgdata,tx_abort,channel_id,channel_id,
 msgdata,tx_abort,len,u16,