df: wire up using adaptive locktime for dual-funding

Author: niftynei

common/funding_tx.c

@@ -222,6 +222,7 @@ static void add_outputs(struct bitcoin_tx *tx, struct output_info **outputs,
 
 struct bitcoin_tx *dual_funding_funding_tx(const tal_t *ctx,
 					   const struct chainparams *chainparams,
+					   u32 tx_locktime,
 				           u16 *outnum,
 					   u32 feerate_kw_funding,
 				           struct amount_sat *opener_funding,
@@ -362,7 +363,7 @@ struct bitcoin_tx *dual_funding_funding_tx(const tal_t *ctx,
 		assert(output_count > 0);
 	}
 
-	tx = bitcoin_tx(ctx, chainparams, input_count, output_count, 0);
+	tx = bitcoin_tx(ctx, chainparams, input_count, output_count, tx_locktime);
 
 	/* Add the funding output */
 	wscript = bitcoin_redeem_2of2(tx, local_fundingkey, remote_fundingkey);

common/funding_tx.h

@@ -72,6 +72,7 @@ struct bitcoin_tx *funding_tx(const tal_t *ctx,
  * funding_tx: create a P2WSH funding transaction for a channel.
  * @ctx: context to tal from.
  * @chainparams: (in) the params for the resulting transaction.
+ * @locktime: (in) blockheight to use for the tx locktime
  * @outnum: (out) txout which is the funding output.
  * @feerate_kw_funding: (in) feerate for the funding transaction
  * @opener_funding: (in/out) funding amount contributed by opener
@@ -88,6 +89,7 @@ struct bitcoin_tx *funding_tx(const tal_t *ctx,
  */
 struct bitcoin_tx *dual_funding_funding_tx(const tal_t *ctx,
 	                                   const struct chainparams *chainparams,
+					   u32 tx_locktime,
 				           u16 *outnum,
 					   u32 feerate_kw_funding,
 				           struct amount_sat *opener_funding,

common/test/run-funding_tx_dual.c

@@ -818,6 +818,7 @@ int main(void)
 
 		/* Note that dust_limit is set to 546, via chainparams */
 		funding = dual_funding_funding_tx(tmpctx, chainparams,
+						  0, /* examples all have locktime at 0 */
 						  &outnum, test.feerate,
 						  &test.opener_funding,
 						  test.accepter_funding,

hsmd/hsm_wire.csv

@@ -67,6 +67,7 @@ msgtype,hsm_dual_funding_sigs,40
 msgdata,hsm_dual_funding_sigs,num_utxos,u16,
 msgdata,hsm_dual_funding_sigs,our_utxos,utxo,num_utxos
 msgdata,hsm_dual_funding_sigs,feerate_kw_funding,u32,
+msgdata,hsm_dual_funding_sigs,tx_locktime,u32,
 msgdata,hsm_dual_funding_sigs,opener_funding,amount_sat,
 msgdata,hsm_dual_funding_sigs,accepter_funding,amount_sat,
 msgdata,hsm_dual_funding_sigs,num_opener_inputs,u16,

hsmd/hsmd.c

@@ -1648,7 +1648,7 @@ static struct io_plan *handle_sign_dual_funding_tx(struct io_conn *conn,
 {
 	size_t i = 0, j;
 	struct bitcoin_tx *tx;
-	u32 feerate_kw_funding, offset;
+	u32 feerate_kw_funding, offset, tx_locktime;
 	struct pubkey local_pubkey, remote_pubkey;
 	struct amount_sat opener_funding, accepter_funding;
 	struct input_info **opener_inputs, **accepter_inputs;
@@ -1662,6 +1662,7 @@ static struct io_plan *handle_sign_dual_funding_tx(struct io_conn *conn,
 					    msg_in,
 					    &our_utxos,
 					    &feerate_kw_funding,
+					    &tx_locktime,
 					    &opener_funding,
 					    &accepter_funding,
 					    &opener_inputs,
@@ -1683,6 +1684,7 @@ static struct io_plan *handle_sign_dual_funding_tx(struct io_conn *conn,
 
 	tx = dual_funding_funding_tx(tmpctx,
 				     c->chainparams,
+				     tx_locktime,
 				     NULL,
 				     feerate_kw_funding,
 				     &opener_funding,

lightningd/Makefile

@@ -102,6 +102,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/plugin.c			\
 	lightningd/plugin_control.c		\
 	lightningd/plugin_hook.c		\
+	lightningd/tx_locktime.c		\
 	lightningd/subd.c			\
 	lightningd/watch.c
 

lightningd/opening_control.c

@@ -35,6 +35,7 @@
 #include <lightningd/options.h>
 #include <lightningd/plugin_hook.h>
 #include <lightningd/subd.h>
+#include <lightningd/tx_locktime.h>
 #include <openingd/channel_establishment.h>
 #include <openingd/gen_opening_wire.h>
 #include <wire/gen_common_wire.h>
@@ -1887,6 +1888,7 @@ static struct command_result *json_fund_channel_start(struct command *cmd,
 	struct channel *channel;
 	bool *announce_channel;
 	u32 *feerate_per_kw;
+	u32 locktime;
 
 	u8 *msg = NULL;
 	struct amount_sat *amount;
@@ -1976,6 +1978,11 @@ static struct command_result *json_fund_channel_start(struct command *cmd,
 			type_to_string(fc, struct node_id, id));
 	}
 
+	/* BOLT-b746cacbde53ea6170ec43ee3eff46fbb4139bfd #2
+	 * `locktime` is the locktime for the funding transaction.
+	 */
+	locktime = locktime_for_new_tx(cmd->ld->topology);
+
 	peer->uncommitted_channel->fc = tal_steal(peer->uncommitted_channel, fc);
 	fc->uc = peer->uncommitted_channel;
 
@@ -1992,6 +1999,7 @@ static struct command_result *json_fund_channel_start(struct command *cmd,
 
 	msg = towire_opening_funder_start(NULL,
 					  *amount,
+					  locktime,
 					  fc->push,
 					  fc->our_upfront_shutdown_script,
 					  *feerate_per_kw,

openingd/opening_wire.csv

@@ -87,6 +87,7 @@ msgdata,opening_funder_reply,shutdown_scriptpubkey,u8,shutdown_len
 # master->openingd: start channel establishment for a funding tx
 msgtype,opening_funder_start,6002
 msgdata,opening_funder_start,funding_satoshis,amount_sat,
+msgdata,opening_funder_start,tx_locktime,u32,
 msgdata,opening_funder_start,push_msat,amount_msat,
 msgdata,opening_funder_start,len_upfront,u16,
 msgdata,opening_funder_start,upfront_shutdown_script,u8,len_upfront

openingd/openingd.c

@@ -127,6 +127,9 @@ struct state {
 	struct amount_sat accepter_funding;
 	u32 feerate_per_kw_funding;
 
+	/* Locktime for funding transaction */
+	u32 locktime;
+
 	/* List of queued add input/output/completes.
 	 * These get queued up while we're in transition
 	 * between fundchannel_start and fundchannel_complete
@@ -636,7 +639,7 @@ static u8 *funder_channel_start(struct state *state, u8 channel_flags)
 		state->feerate_per_kw_funding = state->feerate_per_kw;
 		msg = towire_open_channel2(NULL,
 					   &chainparams->genesis_blockhash,
-					   0, /* FIXME: use real locktime */
+					   state->locktime,
 					   NULL, /* FIXME: use real podleh2 */
 					   state->feerate_per_kw_funding,
 					   state->opener_funding,
@@ -1477,6 +1480,7 @@ static u8 *funder_finalize_channel_setup2(struct state *state,
 
 	/* Build the funding transaction */
 	funding_tx = dual_funding_funding_tx(state, chainparams,
+					     state->locktime,
 					     &state->funding_txout,
 					     state->feerate_per_kw_funding,
 					     &state->opener_funding,
@@ -2125,13 +2129,12 @@ static u8 *fundee_channel2(struct state *state, const u8 *open_channel2_msg)
 	const u8 *wscript;
 	u8 channel_flags;
 	u8 *msg;
-	u32 locktime;
 	struct sha256 podle_h2;
 
 	struct tlv_opening_tlvs *tlv = tlv_opening_tlvs_new(tmpctx);
 	if (!fromwire_open_channel2(open_channel2_msg,
 				    &chain_hash,
-				    &locktime,
+				    &state->locktime,
 				    &podle_h2,
 				    &state->feerate_per_kw_funding,
 				    &state->opener_funding,
@@ -2275,6 +2278,7 @@ static u8 *fundee_channel2(struct state *state, const u8 *open_channel2_msg)
 
 	/* Build the funding tx */
 	funding_tx = dual_funding_funding_tx(state, chainparams,
+					     state->locktime,
 					     &state->funding_txout,
 					     state->feerate_per_kw_funding,
 					     &state->opener_funding,
@@ -2418,6 +2422,7 @@ static u8 *fundee_channel2(struct state *state, const u8 *open_channel2_msg)
 	msg = towire_hsm_dual_funding_sigs(tmpctx,
 					   cast_const2(const struct utxo **, utxos),
 					   state->feerate_per_kw_funding,
+					   state->locktime,
 					   state->opener_funding,
 					   state->accepter_funding,
 					   cast_const2(const struct input_info **, their_inputs),
@@ -2975,6 +2980,7 @@ static u8 *handle_master_in(struct state *state)
 	case WIRE_OPENING_FUNDER_START:
 		if (!fromwire_opening_funder_start(tmpctx, msg,
 						   &state->opener_funding,
+						   &state->locktime,
 						   &state->push_msat,
 						   &state->upfront_shutdown_script[LOCAL],
 						   &state->feerate_per_kw,