spec: update to latest dual-funding wire changes

the witnesses are maddeningly weird now (you concat everything together)

we also changed some things to be s64's (it's a teeny tiny change)

channeld/channeld.c

@@ -2091,7 +2091,7 @@ static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
 
 static void handle_unexpected_tx_sigs(struct peer *peer, const u8 *msg)
 {
-	const struct witness_stack **ws;
+	const struct witness **witnesses;
 	struct channel_id cid;
 	struct bitcoin_txid txid;
 
@@ -2099,7 +2099,7 @@ static void handle_unexpected_tx_sigs(struct peer *peer, const u8 *msg)
 	 * This happens when they've/we've exchanged channel_ready,
 	 * but they did not receive our channel_ready. */
 	if (!fromwire_tx_signatures(tmpctx, msg, &cid, &txid,
-				    cast_const3(struct witness_stack ***, &ws)))
+				    cast_const3(struct witness ***, &witnesses)))
 		peer_failed_warn(peer->pps, &peer->channel_id,
 			    "Bad tx_signatures %s",
 			    tal_hex(msg, msg));

common/psbt_internal.c

@@ -1,33 +1,97 @@
 #include "config.h"
+#include <assert.h>
+#include <bitcoin/psbt.h>
 #include <bitcoin/script.h>
+#include <bitcoin/varint.h>
 #include <common/psbt_internal.h>
 #include <common/psbt_open.h>
 #include <wire/peer_wire.h>
 
+
+static bool next_size(const u8 **cursor, size_t *max, size_t *size)
+{
+	size_t len;
+	varint_t varint;
+
+	if (*max < 1)
+		return false;
+
+	len = varint_get(*cursor, *max, &varint);
+
+	if (len < 1)
+		return false;
+
+	if (*max < len) {
+		*max = 0;
+		return false;
+	}
+
+	*cursor += len;
+	*max -= len;
+	*size = varint;
+	return true;
+}
+
+static u8 *next_script(const tal_t *ctx, const u8 **cursor, size_t *max)
+{
+	const u8 *p;
+	size_t size;
+	u8 *ret;
+
+	if (!next_size(cursor, max, &size))
+		return NULL;
+
+	if (*max < size) {
+		*max = 0;
+		return NULL;
+	}
+
+	p = *cursor;
+	*max -= size;
+	*cursor += size;
+
+	ret = tal_arr(ctx, u8, size);
+	memcpy(ret, p, size);
+	return ret;
+}
+
 static void
 psbt_input_set_final_witness_stack(const tal_t *ctx,
 				   struct wally_psbt_input *in,
-				   const struct witness_element **elements)
+				   const struct witness *witness)
 {
+	u8 *script, *sctx;
+	const u8 *data = witness->witness_data;
+	size_t size, max = tal_count(data);
+	bool ok;
+
 	wally_tx_witness_stack_free(in->final_witness);
 
-	tal_wally_start();
-	wally_tx_witness_stack_init_alloc(tal_count(elements),
-					  &in->final_witness);
+	/* FIXME: return an error?? */
+	if (!next_size(&data, &max, &size))
+		return;
+
+	tal_wally_start();
+	sctx = tal(NULL, u8);
+
+	wally_tx_witness_stack_init_alloc(size, &in->final_witness);
+
+	while ((script = next_script(sctx, &data, &max)) && script != NULL) {
+		ok = (wally_tx_witness_stack_add(in->final_witness,
+					   script, tal_count(script)) == WALLY_OK);
+		assert(ok);
+	}
 
-	for (size_t i = 0; i < tal_count(elements); i++)
-		wally_tx_witness_stack_add(in->final_witness,
-					   elements[i]->witness_data,
-					   tal_bytelen(elements[i]->witness_data));
 	tal_wally_end(ctx);
+	tal_free(sctx);
 }
 
 void psbt_finalize_input(const tal_t *ctx,
 			 struct wally_psbt_input *in,
-			 const struct witness_element **elements)
+			 const struct witness *witness)
 {
 	const struct wally_map_item *redeem_script;
-	psbt_input_set_final_witness_stack(ctx, in, elements);
+	psbt_input_set_final_witness_stack(ctx, in, witness);
 
 	/* There's this horrible edgecase where we set the final_witnesses
 	 * directly onto the PSBT, but the input is a P2SH-wrapped input
@@ -49,22 +113,20 @@ void psbt_finalize_input(const tal_t *ctx,
 	}
 }
 
-const struct witness_stack **
-psbt_to_witness_stacks(const tal_t *ctx,
-		       const struct wally_psbt *psbt,
-		       enum tx_role side_to_stack)
+const struct witness **
+psbt_to_witnesses(const tal_t *ctx,
+		  const struct wally_psbt *psbt,
+		  enum tx_role side_to_stack)
 {
-	size_t stack_index;
 	u64 serial_id;
-	const struct witness_stack **stacks
-		= tal_arr(ctx, const struct witness_stack *, psbt->num_inputs);
+	const struct witness **witnesses =
+		tal_arr(ctx, const struct witness *, 0);
 
-	stack_index = 0;
 	for (size_t i = 0; i < psbt->num_inputs; i++) {
 		if (!psbt_get_serial_id(&psbt->inputs[i].unknowns,
 					&serial_id))
 			/* FIXME: throw an error ? */
-			return NULL;
+			return tal_free(witnesses);
 
 		/* BOLT-f53ca2301232db780843e894f55d95d512f297f9 #2:
 		 * - if is the *initiator*:
@@ -73,32 +135,29 @@ psbt_to_witness_stacks(const tal_t *ctx,
 		if (serial_id % 2 == side_to_stack) {
 			struct wally_tx_witness_stack *wtx_s =
 				psbt->inputs[i].final_witness;
-			struct witness_stack *stack =
-				tal(stacks, struct witness_stack);
-			/* Convert the wally_tx_witness_stack to
-			 * a witness_stack entry */
-			stack->witness_elements =
-				tal_arr(stack, struct witness_element *,
-					wtx_s->num_items);
-			for (size_t j = 0; j < tal_count(stack->witness_elements); j++) {
-				stack->witness_elements[j] = tal(stack,
-								struct witness_element);
-				stack->witness_elements[j]->witness_data =
-					tal_dup_arr(stack, u8,
-						    wtx_s->items[j].witness,
-						    wtx_s->items[j].witness_len,
-						    0);
 
+			/* BOLT-e299850cb5ebd8bd9c55763bbc498fcdf94a9567 #2:
+			 *
+			 * The `witness_data` is encoded as per bitcoin's
+			 * wire protocol (a CompactSize number of elements,
+			 * with each element a CompactSize length and that
+			 * many bytes following.  Each `witness_data` field
+			 * contains all of the witness elements for a single input,
+			 * including the leading counter of elements.
+			 */
+			struct witness *wit = tal(witnesses, struct witness);
+			wit->witness_data = tal_arr(wit, u8, 0);
+			add_varint(&wit->witness_data, wtx_s->num_items);
+			for (size_t j = 0; j < wtx_s->num_items; j++) {
+				add_varint(&wit->witness_data, wtx_s->items[j].witness_len);
+				tal_expand(&wit->witness_data, wtx_s->items[j].witness,
+					   wtx_s->items[j].witness_len);
 			}
 
-			stacks[stack_index++] = stack;
+			tal_arr_expand(&witnesses, wit);
 		}
 
 	}
 
-	if (stack_index == 0)
-		return tal_free(stacks);
-
-	tal_resize(&stacks, stack_index);
-	return stacks;
+	return witnesses;
 }

common/psbt_internal.h

@@ -7,7 +7,7 @@
 
 struct wally_psbt;
 struct wally_psbt_input;
-struct witness_element;
+struct witness;
 
 /* psbt_finalize_input - Finalize an input with a given witness stack
  *
@@ -15,21 +15,22 @@ struct witness_element;
  * the redeem_script, if any.
  * @ctx - the context to allocate onto
  * @in - input to set final_witness for
- * @witness_element - elements to add to witness stack
+ * @witness - witness data to add to witness stack
  */
 void psbt_finalize_input(const tal_t *ctx,
 			 struct wally_psbt_input *in,
-			 const struct witness_element **elements);
-/* psbt_to_witness_stacks - Take all sigs on a PSBT and copy to a
- * 			    witness_stack
+			 const struct witness *witness);
+
+/* psbt_to_witness_stacks - Take a side's sigs from a PSBT and copy to a
+ * 			    wire witness
  *
  * @ctx - allocation context
  * @psbt - PSBT to copy sigs from
- * @opener - which side initiated this tx
+ * @side_to_stack - which side to stack witnesses of
  */
-const struct witness_stack **
-psbt_to_witness_stacks(const tal_t *ctx,
-		       const struct wally_psbt *psbt,
-		       enum tx_role side_to_stack);
+const struct witness **
+psbt_to_witnesses(const tal_t *ctx,
+		  const struct wally_psbt *psbt,
+		  enum tx_role side_to_stack);
 
 #endif /* LIGHTNING_COMMON_PSBT_INTERNAL_H */

openingd/dualopend.c

@@ -1021,9 +1021,8 @@ static u8 *psbt_to_tx_sigs_msg(const tal_t *ctx,
 			       struct state *state,
 			       const struct wally_psbt *psbt)
 {
-	const struct witness_stack **ws =
-		psbt_to_witness_stacks(tmpctx, psbt,
-				       state->our_role);
+	const struct witness **ws =
+		psbt_to_witnesses(tmpctx, psbt, state->our_role);
 
 	return towire_tx_signatures(ctx, &state->channel_id,
 				    &state->tx_state->funding.txid,
@@ -1034,16 +1033,15 @@ static void handle_tx_sigs(struct state *state, const u8 *msg)
 {
 	struct channel_id cid;
 	struct bitcoin_txid txid;
-	const struct witness_stack **ws;
-	size_t j = 0;
+	const struct witness **witnesses;
 	struct tx_state *tx_state = state->tx_state;
 	enum tx_role their_role = state->our_role == TX_INITIATOR ?
 		TX_ACCEPTER : TX_INITIATOR;
 
 	if (!fromwire_tx_signatures(tmpctx, msg, &cid, &txid,
 				    cast_const3(
-					 struct witness_stack ***,
-					 &ws)))
+					 struct witness ***,
+					 &witnesses)))
 		open_err_fatal(state, "Bad tx_signatures %s",
 			       tal_hex(msg, msg));
 
@@ -1085,11 +1083,10 @@ static void handle_tx_sigs(struct state *state, const u8 *msg)
 					     &tx_state->funding.txid));
 
 	/* We put the PSBT + sigs all together */
-	for (size_t i = 0; i < tx_state->psbt->num_inputs; i++) {
+	for (size_t i = 0, j = 0; i < tx_state->psbt->num_inputs; i++) {
 		struct wally_psbt_input *in =
 			&tx_state->psbt->inputs[i];
 		u64 in_serial;
-		const struct witness_element **elem;
 
 		if (!psbt_get_serial_id(&in->unknowns, &in_serial)) {
 			status_broken("PSBT input %zu missing serial_id %s",
@@ -1101,13 +1098,12 @@ static void handle_tx_sigs(struct state *state, const u8 *msg)
 		if (in_serial % 2 != their_role)
 			continue;
 
-		if (j == tal_count(ws))
-			open_err_warn(state, "Mismatch witness stack count %s",
+		if (j == tal_count(witnesses))
+			open_err_warn(state, "Mismatched witness stack count %s",
 				      tal_hex(msg, msg));
 
-		elem = cast_const2(const struct witness_element **,
-				   ws[j++]->witness_elements);
-		psbt_finalize_input(tx_state->psbt, in, elem);
+		psbt_finalize_input(tx_state->psbt, in, witnesses[j]);
+		j++;
 	}
 
 	tx_state->remote_funding_sigs_rcvd = true;
@@ -3526,9 +3522,9 @@ static void rbf_local_start(struct state *state, u8 *msg)
 	tx_state->tx_locktime = locktime;
 	/* For now, we always just echo/send the funding amount */
 	init_rbf_tlvs->funding_output_contribution
-		= tal(init_rbf_tlvs, u64);
+		= tal(init_rbf_tlvs, s64);
 	*init_rbf_tlvs->funding_output_contribution
-	       = tx_state->opener_funding.satoshis; /* Raw: wire conversion */
+	       = (s64)tx_state->opener_funding.satoshis; /* Raw: wire conversion */
 
 	msg = towire_tx_init_rbf(tmpctx, &state->channel_id,
 				 tx_state->tx_locktime,
@@ -3795,9 +3791,9 @@ static void rbf_remote_start(struct state *state, const u8 *rbf_msg)
 
 	/* We always send the funding amount */
 	ack_rbf_tlvs->funding_output_contribution
-		= tal(ack_rbf_tlvs, u64);
+		= tal(ack_rbf_tlvs, s64);
 	*ack_rbf_tlvs->funding_output_contribution
-	       = tx_state->accepter_funding.satoshis; /* Raw: wire conversion */
+	       = (s64)tx_state->accepter_funding.satoshis; /* Raw: wire conversion */
 
 	msg = towire_tx_ack_rbf(tmpctx, &state->channel_id, ack_rbf_tlvs);
 	peer_write(state->pps, msg);

wire/extracted_peer_11_openchannelv2_updates.patch

@@ -0,0 +1,43 @@
+--- wire/peer_wire.csv	2023-06-29 14:36:10.986268579 -0500
++++ -	2023-06-29 14:37:45.737004393 -0500
+@@ -62,25 +62,22 @@
+ msgdata,tx_signatures,channel_id,channel_id,
+ msgdata,tx_signatures,txid,sha256,
+ msgdata,tx_signatures,num_witnesses,u16,
+-msgdata,tx_signatures,witnesses,witness_stack,num_witnesses
+-subtype,witness_stack
+-subtypedata,witness_stack,num_witness_elements,u16,
+-subtypedata,witness_stack,witness_elements,witness_element,num_witness_elements
+-subtype,witness_element
+-subtypedata,witness_element,len,u16,
+-subtypedata,witness_element,witness_data,byte,len
++msgdata,tx_signatures,witnesses,witness,num_witnesses
++subtype,witness
++subtypedata,witness,len,u16,
++subtypedata,witness,witness_data,byte,len
+ msgtype,tx_init_rbf,72
+ msgdata,tx_init_rbf,channel_id,channel_id,
+ msgdata,tx_init_rbf,locktime,u32,
+ 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,tu64,
++tlvdata,tx_init_rbf_tlvs,funding_output_contribution,satoshis,s64,
+ 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,tu64,
++tlvdata,tx_ack_rbf_tlvs,funding_output_contribution,satoshis,s64,
+ msgtype,tx_abort,74
+ msgdata,tx_abort,channel_id,channel_id,
+ msgdata,tx_abort,len,u16,
+@@ -257,6 +235,8 @@
+ msgdata,channel_reestablish,your_last_per_commitment_secret,byte,32
+ msgdata,channel_reestablish,my_current_per_commitment_point,point,
+ msgdata,channel_reestablish,tlvs,channel_reestablish_tlvs,
++tlvtype,channel_reestablish_tlvs,next_funding,0
++tlvdata,channel_reestablish_tlvs,next_funding,next_funding_txid,sha256,
+ tlvtype,channel_reestablish_tlvs,next_to_send,1
+ tlvdata,channel_reestablish_tlvs,next_to_send,commitment_number,tu64,
+ tlvtype,channel_reestablish_tlvs,desired_channel_type,3

wire/peer_wire.csv

@@ -62,25 +62,22 @@ msgtype,tx_signatures,71
 msgdata,tx_signatures,channel_id,channel_id,
 msgdata,tx_signatures,txid,sha256,
 msgdata,tx_signatures,num_witnesses,u16,
-msgdata,tx_signatures,witnesses,witness_stack,num_witnesses
-subtype,witness_stack
-subtypedata,witness_stack,num_witness_elements,u16,
-subtypedata,witness_stack,witness_elements,witness_element,num_witness_elements
-subtype,witness_element
-subtypedata,witness_element,len,u16,
-subtypedata,witness_element,witness_data,byte,len
+msgdata,tx_signatures,witnesses,witness,num_witnesses
+subtype,witness
+subtypedata,witness,len,u16,
+subtypedata,witness,witness_data,byte,len
 msgtype,tx_init_rbf,72
 msgdata,tx_init_rbf,channel_id,channel_id,
 msgdata,tx_init_rbf,locktime,u32,
 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,tu64,
+tlvdata,tx_init_rbf_tlvs,funding_output_contribution,satoshis,s64,
 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,tu64,
+tlvdata,tx_ack_rbf_tlvs,funding_output_contribution,satoshis,s64,
 msgtype,tx_abort,74
 msgdata,tx_abort,channel_id,channel_id,
 msgdata,tx_abort,len,u16,
@@ -267,6 +264,8 @@ msgdata,channel_reestablish,next_revocation_number,u64,
 msgdata,channel_reestablish,your_last_per_commitment_secret,byte,32
 msgdata,channel_reestablish,my_current_per_commitment_point,point,
 msgdata,channel_reestablish,tlvs,channel_reestablish_tlvs,
+tlvtype,channel_reestablish_tlvs,next_funding,0
+tlvdata,channel_reestablish_tlvs,next_funding,next_funding_txid,sha256,
 tlvtype,channel_reestablish_tlvs,next_to_send,1
 tlvdata,channel_reestablish_tlvs,next_to_send,commitment_number,tu64,
 tlvtype,channel_reestablish_tlvs,desired_channel_type,3