splicing: Add channel state AWAITING_SPLICE

Update gossip routiens and various other hecks on the channel state to consider AWAITING_SPLICE to be routable and treated similar to CHANNELD_NORMAL.

Small updates to psbt interface

Changelog-None

bitcoin/psbt.c

@@ -95,7 +95,7 @@ bool psbt_is_finalized(const struct wally_psbt *psbt)
 }
 
 struct wally_psbt_input *psbt_add_input(struct wally_psbt *psbt,
-					struct wally_tx_input *input,
+					const struct wally_tx_input *input,
 				       	size_t insert_at)
 {
 	const u32 flags = WALLY_PSBT_FLAG_NON_FINAL; /* Skip script/witness */

bitcoin/psbt.h

@@ -108,7 +108,7 @@ struct wally_tx *psbt_final_tx(const tal_t *ctx, const struct wally_psbt *psbt);
 u8 *psbt_make_key(const tal_t *ctx, u8 key_subtype, const u8 *key_data);
 
 struct wally_psbt_input *psbt_add_input(struct wally_psbt *psbt,
-					struct wally_tx_input *input,
+					const struct wally_tx_input *input,
 					size_t insert_at);
 
 /* One stop shop for adding an input + metadata to a PSBT */

common/jsonrpc_errors.h

@@ -65,6 +65,13 @@ enum jsonrpc_errcode {
 	FUNDING_STATE_INVALID = 312,
 	FUND_CANNOT_AFFORD_WITH_EMERGENCY = 313,
 
+	/* Splice errors */
+	SPLICE_BROADCAST_FAIL = 350,
+	SPLICE_WRONG_OWNER = 351,
+	SPLICE_UNKNOWN_CHANNEL = 352,
+	SPLICE_INVALID_CHANNEL_STATE = 353,
+	SPLICE_NOT_SUPPORTED = 354,
+
 	/* `connect` errors */
 	CONNECT_NO_KNOWN_ADDRESS = 400,
 	CONNECT_ALL_ADDRESSES_FAILED = 401,

common/psbt_internal.c

@@ -116,7 +116,8 @@ void psbt_finalize_input(const tal_t *ctx,
 const struct witness **
 psbt_to_witnesses(const tal_t *ctx,
 		  const struct wally_psbt *psbt,
-		  enum tx_role side_to_stack)
+		  enum tx_role side_to_stack,
+		  int input_index_to_ignore)
 {
 	u64 serial_id;
 	const struct witness **witnesses =
@@ -128,6 +129,9 @@ psbt_to_witnesses(const tal_t *ctx,
 			/* FIXME: throw an error ? */
 			return tal_free(witnesses);
 
+		if (input_index_to_ignore == i)
+			continue;
+
 		/* BOLT-f53ca2301232db780843e894f55d95d512f297f9 #2:
 		 * - if is the *initiator*:
 		 *   - MUST send even `serial_id`s

common/psbt_internal.h

@@ -27,11 +27,13 @@ void psbt_finalize_input(const tal_t *ctx,
  * @ctx - allocation context
  * @psbt - PSBT to copy sigs from
  * @side_to_stack - which side to stack witnesses of
+ * @input_index_to_ignore - which input to not include. Pass -1 to include all.
  */
 const struct witness **
 psbt_to_witnesses(const tal_t *ctx,
 		  const struct wally_psbt *psbt,
-		  enum tx_role side_to_stack);
+		  enum tx_role side_to_stack,
+                  int input_index_to_ignore);
 
 /* psbt_input_weight - Calculate the tx weight for input index `in` */
 size_t psbt_input_weight(struct wally_psbt *psbt,

gossipd/routing.c

@@ -505,7 +505,7 @@ static void remove_chan_from_node(struct routing_state *rstate,
 
 	/* Last channel?  Simply delete node (and associated announce) */
 	if (num_chans == 0) {
-		if(node->rgraph.index != node->bcast.index)
+		if (node->rgraph.index != node->bcast.index)
 			gossip_store_delete(rstate->gs,
 					    &node->rgraph,
 					    WIRE_NODE_ANNOUNCEMENT);
@@ -522,7 +522,7 @@ static void remove_chan_from_node(struct routing_state *rstate,
 
 	/* Removed only public channel?  Remove node announcement. */
 	if (!node_has_broadcastable_channels(node)) {
-		if(node->rgraph.index != node->bcast.index)
+		if (node->rgraph.index != node->bcast.index)
 			gossip_store_delete(rstate->gs,
 					    &node->rgraph,
 					    WIRE_NODE_ANNOUNCEMENT);

lightningd/channel.c

@@ -152,8 +152,11 @@ new_inflight(struct channel *channel,
 	inflight->funding_psbt = tal_steal(inflight, psbt);
 
 	/* Make a 'clone' of this tx */
-	last_tx_psbt_clone = clone_psbt(inflight, last_tx->psbt);
-	inflight->last_tx = bitcoin_tx_with_psbt(inflight, last_tx_psbt_clone);
+	inflight->last_tx = NULL;
+	if (last_tx) {
+		last_tx_psbt_clone = clone_psbt(inflight, last_tx->psbt);
+		inflight->last_tx = bitcoin_tx_with_psbt(inflight, last_tx_psbt_clone);
+	}
 	inflight->last_sig = last_sig;
 	inflight->tx_broadcast = false;
 
@@ -580,6 +583,18 @@ const char *channel_state_str(enum channel_state state)
 	return "unknown";
 }
 
+bool channel_state_normalish(const struct channel *channel)
+{
+	return channel->state == CHANNELD_NORMAL
+		|| channel->state == CHANNELD_AWAITING_SPLICE;
+}
+
+bool channel_state_awaitish(const struct channel *channel)
+{
+	return channel->state == CHANNELD_AWAITING_LOCKIN
+		|| channel->state == CHANNELD_AWAITING_SPLICE;
+}
+
 struct channel *peer_any_active_channel(struct peer *peer, bool *others)
 {
 	struct channel *channel, *ret = NULL;
@@ -793,7 +808,8 @@ void channel_set_state(struct channel *channel,
 	struct timeabs timestamp;
 
 	/* set closer, if known */
-	if (state > CHANNELD_NORMAL && channel->closer == NUM_SIDES) {
+	if (!(state == CHANNELD_AWAITING_SPLICE)
+	    && state > CHANNELD_NORMAL && channel->closer == NUM_SIDES) {
 		if (reason == REASON_LOCAL)   channel->closer = LOCAL;
 		if (reason == REASON_USER)    channel->closer = LOCAL;
 		if (reason == REASON_REMOTE)  channel->closer = REMOTE;

lightningd/channel.h

@@ -384,6 +384,12 @@ void delete_channel(struct channel *channel STEALS);
 const char *channel_state_name(const struct channel *channel);
 const char *channel_state_str(enum channel_state state);
 
+/* Is the channel in NORMAL or AWAITING_SPLICE state? */
+bool channel_state_normalish(const struct channel *channel);
+
+/* Is the channel in AWAITING_*? */
+bool channel_state_awaitish(const struct channel *channel);
+
 void channel_set_owner(struct channel *channel, struct subd *owner);
 
 /* Channel has failed, but can try again. */
@@ -454,12 +460,12 @@ void channel_set_last_tx(struct channel *channel,
 
 static inline bool channel_can_add_htlc(const struct channel *channel)
 {
-	return channel->state == CHANNELD_NORMAL;
+	return channel_state_normalish(channel);
 }
 
 static inline bool channel_fees_can_change(const struct channel *channel)
 {
-	return channel->state == CHANNELD_NORMAL
+	return channel_state_normalish(channel)
 		|| channel->state == CHANNELD_SHUTTING_DOWN;
 }
 

lightningd/channel_control.c

@@ -888,7 +888,8 @@ bool channel_tell_depth(struct lightningd *ld,
 				    txid, depth);
 		return true;
 	} else if (channel->state != CHANNELD_AWAITING_LOCKIN
-	    && channel->state != CHANNELD_NORMAL) {
+	    && channel->state != CHANNELD_NORMAL
+	    && channel->state != CHANNELD_AWAITING_SPLICE) {
 		/* If not awaiting lockin/announce, it doesn't
 		 * care any more */
 		log_debug(channel->log,
@@ -1187,7 +1188,7 @@ static struct command_result *json_dev_feerate(struct command *cmd,
 		return command_fail(cmd, LIGHTNINGD, "Peer not connected");
 
 	channel = peer_any_active_channel(peer, &more_than_one);
-	if (!channel || !channel->owner || channel->state != CHANNELD_NORMAL)
+	if (!channel || !channel->owner || !channel_state_normalish(channel))
 		return command_fail(cmd, LIGHTNINGD, "Peer bad state");
 	/* This is a dev command: fix the api if you need this! */
 	if (more_than_one)
@@ -1247,7 +1248,7 @@ static struct command_result *json_dev_quiesce(struct command *cmd,
 
 	/* FIXME: If this becomes a real API, check for OPT_QUIESCE! */
 	channel = peer_any_active_channel(peer, &more_than_one);
-	if (!channel || !channel->owner || channel->state != CHANNELD_NORMAL)
+	if (!channel || !channel->owner || !channel_state_normalish(channel))
 		return command_fail(cmd, LIGHTNINGD, "Peer bad state");
 	/* This is a dev command: fix the api if you need this! */
 	if (more_than_one)

lightningd/channel_state.h

@@ -40,8 +40,11 @@ enum channel_state {
 
 	/* Dual-funded channel, waiting for lock-in */
 	DUALOPEND_AWAITING_LOCKIN,
+
+	/* Channel has started splice and is awaiting lock-in */
+	CHANNELD_AWAITING_SPLICE,
 };
-#define CHANNEL_STATE_MAX DUALOPEND_AWAITING_LOCKIN
+#define CHANNEL_STATE_MAX CHANNELD_AWAITING_SPLICE
 
 /* These are in the database, so don't renumber them! */
 enum state_change {

lightningd/closing_control.c

@@ -836,6 +836,7 @@ static struct command_result *json_close(struct command *cmd,
 	 * waiting) */
 	switch (channel->state) {
 		case CHANNELD_NORMAL:
+		case CHANNELD_AWAITING_SPLICE:
 		case CHANNELD_AWAITING_LOCKIN:
 		case DUALOPEND_AWAITING_LOCKIN:
 			channel_set_state(channel,

lightningd/peer_control.c

@@ -1170,6 +1170,7 @@ static void connect_activate_subd(struct lightningd *ld, struct channel *channel
 
 	case CHANNELD_AWAITING_LOCKIN:
 	case CHANNELD_NORMAL:
+	case CHANNELD_AWAITING_SPLICE:
 	case CHANNELD_SHUTTING_DOWN:
 	case CLOSINGD_SIGEXCHANGE:
 		assert(!channel->owner);
@@ -1827,10 +1828,13 @@ static enum watch_result funding_depth_cb(struct lightningd *ld,
 	tal_free(txidstr);
 
 	bool min_depth_reached = depth >= channel->minimum_depth;
+	bool min_depth_no_scid = min_depth_reached && !channel->scid;
+	bool some_depth_has_scid = depth && channel->scid;
 
 	/* Reorg can change scid, so always update/save scid when possible (depth=0
 	 * means the stale block with our funding tx was removed) */
-	if ((min_depth_reached && !channel->scid) || (depth && channel->scid)) {
+	if (channel->state != CHANNELD_AWAITING_SPLICE
+	    && (min_depth_no_scid || some_depth_has_scid)) {
 		struct txlocator *loc;
 		struct channel_inflight *inf;
 
@@ -2632,6 +2636,7 @@ static struct command_result *param_channel_or_all(struct command *cmd,
 		*channels = tal_arr(cmd, struct channel *, 0);
 		list_for_each(&peer->channels, channel, list) {
 			if (channel->state != CHANNELD_NORMAL
+			    && channel->state != CHANNELD_AWAITING_SPLICE
 			    && channel->state != CHANNELD_AWAITING_LOCKIN
 			    && channel->state != DUALOPEND_AWAITING_LOCKIN)
 				continue;

lightningd/peer_htlcs.c

@@ -582,7 +582,7 @@ static void htlc_offer_timeout(struct htlc_out *out)
 	assert(out->hstate == SENT_ADD_HTLC);
 
 	/* If owner died, we should already be taken care of. */
-	if (!channel->owner || channel->state != CHANNELD_NORMAL)
+	if (!channel->owner || !channel_state_normalish(channel))
 		return;
 
 	log_unusual(channel->owner->log,

openingd/dualopend.c

@@ -993,7 +993,7 @@ static u8 *psbt_to_tx_sigs_msg(const tal_t *ctx,
 			       const struct wally_psbt *psbt)
 {
 	const struct witness **ws =
-		psbt_to_witnesses(tmpctx, psbt, state->our_role);
+		psbt_to_witnesses(tmpctx, psbt, state->our_role, -1);
 
 	return towire_tx_signatures(ctx, &state->channel_id,
 				    &state->tx_state->funding.txid,

plugins/libplugin-pay.c

@@ -3291,7 +3291,8 @@ static struct command_result *direct_pay_listpeerchannels(struct command *cmd,
 		if (!chan->connected)
 			continue;
 
-		if (!streq(chan->state, "CHANNELD_NORMAL"))
+		if (!streq(chan->state, "CHANNELD_NORMAL")
+			&& !streq(chan->state, "CHANNELD_AWAITING_SPLICE"))
 			continue;
 
 		/* Must have either a local alias for zeroconf

plugins/test/run-route-overlong.c

@@ -255,8 +255,12 @@ static void update_connection(int store_fd,
 			      bool disable)
 {
 	secp256k1_ecdsa_signature dummy_sig;
+	u8 flags = node_id_idx(from, to);
 	u8 *msg;
 
+	if (disable)
+		flags |= ROUTING_FLAGS_DISABLED;
+
 	/* So valgrind doesn't complain */
 	memset(&dummy_sig, 0, sizeof(dummy_sig));
 
@@ -265,8 +269,7 @@ static void update_connection(int store_fd,
 				    &chainparams->genesis_blockhash,
 				    scid, 0,
 				    ROUTING_OPT_HTLC_MAX_MSAT,
-				    node_id_idx(from, to)
-				    + (disable ? ROUTING_FLAGS_DISABLED : 0),
+				    flags,
 				    delay,
 				    min,
 				    base_fee,

plugins/topology.c

@@ -317,7 +317,10 @@ static struct node_map *local_connected(const tal_t *ctx,
 		/* Must also have a channel in CHANNELD_NORMAL */
 		normal_chan = json_tok_streq(buf,
 				   json_get_member(buf, channel, "state"),
-					     "CHANNELD_NORMAL");
+					     "CHANNELD_NORMAL")
+			   || json_tok_streq(buf,
+				   json_get_member(buf, channel, "state"),
+					     "CHANNELD_AWAITING_SPLICE");
 
 		if (normal_chan)
 			node_map_add(connected,