dualopen: use separate wire for passing updated PSBTs back to dualopend

Rusty pointed out that having an empty channel_id is suboptimal; adding
another call is probably the right idea rather than re-using an existing
one.

Suggested-By: @rustyrussell

lightningd/dual_open_control.c

@@ -500,8 +500,7 @@ openchannel2_changed_hook_cb(struct openchannel2_psbt_payload *payload STEALS)
 			    payload);
 
 	subd_send_msg(dualopend,
-		      take(towire_dual_open_psbt_changed(NULL,
-							 &payload->rcvd->cid,
+		      take(towire_dual_open_psbt_updated(NULL,
 							 payload->psbt)));
 }
 
@@ -1086,7 +1085,6 @@ static struct command_result *json_open_channel_update(struct command *cmd,
 	struct node_id *id;
 	struct peer *peer;
 	struct channel *channel;
-	struct channel_id chan_id_unused;
 	u8 *msg;
 
 	if (!param(cmd, buffer, params,
@@ -1123,8 +1121,7 @@ static struct command_result *json_open_channel_update(struct command *cmd,
 
 	peer->uncommitted_channel->fc->cmd = cmd;
 
-	memset(&chan_id_unused, 0, sizeof(chan_id_unused));
-	msg = towire_dual_open_psbt_changed(NULL, &chan_id_unused, psbt);
+	msg = towire_dual_open_psbt_updated(NULL, psbt);
 	subd_send_msg(peer->uncommitted_channel->open_daemon, take(msg));
 	return command_still_pending(cmd);
 }
@@ -1327,6 +1324,7 @@ static unsigned int dual_opend_msg(struct subd *dualopend,
 		case WIRE_DUAL_OPEN_OPENER_INIT:
 		case WIRE_DUAL_OPEN_GOT_OFFER_REPLY:
 		case WIRE_DUAL_OPEN_FAIL:
+		case WIRE_DUAL_OPEN_PSBT_UPDATED:
 		case WIRE_DUAL_OPEN_DEV_MEMLEAK:
 			break;
 	}

openingd/dualopend.c

@@ -376,7 +376,6 @@ fetch_psbt_changes(struct state *state, const struct wally_psbt *psbt)
 {
 	u8 *msg;
 	char *err;
-	struct channel_id unused;
 	struct wally_psbt *updated_psbt;
 
 	/* Go ask lightningd what other changes we've got */
@@ -387,7 +386,7 @@ fetch_psbt_changes(struct state *state, const struct wally_psbt *psbt)
 
 	if (fromwire_dual_open_fail(msg, msg, &err))
 		status_failed(STATUS_FAIL_MASTER_IO, "%s", err);
-	else if (fromwire_dual_open_psbt_changed(state, msg, &unused, &updated_psbt)) {
+	else if (fromwire_dual_open_psbt_updated(state, msg, &updated_psbt)) {
 		/* Does our PSBT meet requirements? */
 		if (!check_balances(state, updated_psbt,
 				    state->our_role == TX_INITIATOR,
@@ -1706,6 +1705,7 @@ static u8 *handle_master_in(struct state *state)
 	case WIRE_DUAL_OPEN_GOT_OFFER_REPLY:
 	case WIRE_DUAL_OPEN_COMMIT_RCVD:
 	case WIRE_DUAL_OPEN_PSBT_CHANGED:
+	case WIRE_DUAL_OPEN_PSBT_UPDATED:
 		break;
 	}
 

openingd/dualopend_wire.csv

@@ -84,11 +84,14 @@ msgdata,dual_open_commit_rcvd,remote_shutdown_len,u16,
 msgdata,dual_open_commit_rcvd,remote_shutdown_scriptpubkey,u8,remote_shutdown_len
 
 # dualopend->master: peer updated the psbt
-# master->dualopend: response from hook when asking for next moves
 msgtype,dual_open_psbt_changed,7107
 msgdata,dual_open_psbt_changed,channel_id,channel_id,
 msgdata,dual_open_psbt_changed,psbt,wally_psbt,
 
+# master->dualopend: we updated the psbt
+msgtype,dual_open_psbt_updated,7108
+msgdata,dual_open_psbt_updated,psbt,wally_psbt,
+
 # master->dualopend: fail this channel open
 msgtype,dual_open_fail,7003
 msgdata,dual_open_fail,reason,wirestring,

openingd/dualopend_wiregen.c

@@ -25,6 +25,7 @@ const char *dualopend_wire_name(int e)
 	case WIRE_DUAL_OPEN_GOT_OFFER_REPLY: return "WIRE_DUAL_OPEN_GOT_OFFER_REPLY";
 	case WIRE_DUAL_OPEN_COMMIT_RCVD: return "WIRE_DUAL_OPEN_COMMIT_RCVD";
 	case WIRE_DUAL_OPEN_PSBT_CHANGED: return "WIRE_DUAL_OPEN_PSBT_CHANGED";
+	case WIRE_DUAL_OPEN_PSBT_UPDATED: return "WIRE_DUAL_OPEN_PSBT_UPDATED";
 	case WIRE_DUAL_OPEN_FAIL: return "WIRE_DUAL_OPEN_FAIL";
 	case WIRE_DUAL_OPEN_FAILED: return "WIRE_DUAL_OPEN_FAILED";
 	case WIRE_DUAL_OPEN_OPENER_INIT: return "WIRE_DUAL_OPEN_OPENER_INIT";
@@ -44,6 +45,7 @@ bool dualopend_wire_is_defined(u16 type)
 	case WIRE_DUAL_OPEN_GOT_OFFER_REPLY:;
 	case WIRE_DUAL_OPEN_COMMIT_RCVD:;
 	case WIRE_DUAL_OPEN_PSBT_CHANGED:;
+	case WIRE_DUAL_OPEN_PSBT_UPDATED:;
 	case WIRE_DUAL_OPEN_FAIL:;
 	case WIRE_DUAL_OPEN_FAILED:;
 	case WIRE_DUAL_OPEN_OPENER_INIT:;
@@ -308,7 +310,6 @@ bool fromwire_dual_open_commit_rcvd(const tal_t *ctx, const void *p, struct chan
 
 /* WIRE: DUAL_OPEN_PSBT_CHANGED */
 /* dualopend->master: peer updated the psbt */
-/* master->dualopend: response from hook when asking for next moves */
 u8 *towire_dual_open_psbt_changed(const tal_t *ctx, const struct channel_id *channel_id, const struct wally_psbt *psbt)
 {
 	u8 *p = tal_arr(ctx, u8, 0);
@@ -331,6 +332,28 @@ bool fromwire_dual_open_psbt_changed(const tal_t *ctx, const void *p, struct cha
 	return cursor != NULL;
 }
 
+/* WIRE: DUAL_OPEN_PSBT_UPDATED */
+/* master->dualopend: we updated the psbt */
+u8 *towire_dual_open_psbt_updated(const tal_t *ctx, const struct wally_psbt *psbt)
+{
+	u8 *p = tal_arr(ctx, u8, 0);
+
+	towire_u16(&p, WIRE_DUAL_OPEN_PSBT_UPDATED);
+	towire_wally_psbt(&p, psbt);
+
+	return memcheck(p, tal_count(p));
+}
+bool fromwire_dual_open_psbt_updated(const tal_t *ctx, const void *p, struct wally_psbt **psbt)
+{
+	const u8 *cursor = p;
+	size_t plen = tal_count(p);
+
+	if (fromwire_u16(&cursor, &plen) != WIRE_DUAL_OPEN_PSBT_UPDATED)
+		return false;
+ 	*psbt = fromwire_wally_psbt(ctx, &cursor, &plen);
+	return cursor != NULL;
+}
+
 /* WIRE: DUAL_OPEN_FAIL */
 /* master->dualopend: fail this channel open */
 u8 *towire_dual_open_fail(const tal_t *ctx, const wirestring *reason)
@@ -454,4 +477,4 @@ bool fromwire_dual_open_dev_memleak_reply(const void *p, bool *leak)
  	*leak = fromwire_bool(&cursor, &plen);
 	return cursor != NULL;
 }
-// SHA256STAMP:4d357681ca9bea1ad36f3fe4d3482a0a12f808dfe20b71f0b9bee78beed0950e
+// SHA256STAMP:37f122e865f6e2432cffb5ae82c77ca2f8a3714baed0c9724a92541092f3aa54

openingd/dualopend_wiregen.h

@@ -27,8 +27,9 @@ enum dualopend_wire {
         /*                     get some signatures for the funding_tx. */
         WIRE_DUAL_OPEN_COMMIT_RCVD = 7007,
         /*  dualopend->master: peer updated the psbt */
-        /*  master->dualopend: response from hook when asking for next moves */
         WIRE_DUAL_OPEN_PSBT_CHANGED = 7107,
+        /*  master->dualopend: we updated the psbt */
+        WIRE_DUAL_OPEN_PSBT_UPDATED = 7108,
         /*  master->dualopend: fail this channel open */
         WIRE_DUAL_OPEN_FAIL = 7003,
         /*  dualopend->master: we failed to negotiate channel */
@@ -74,10 +75,14 @@ bool fromwire_dual_open_commit_rcvd(const tal_t *ctx, const void *p, struct chan
 
 /* WIRE: DUAL_OPEN_PSBT_CHANGED */
 /*  dualopend->master: peer updated the psbt */
-/*  master->dualopend: response from hook when asking for next moves */
 u8 *towire_dual_open_psbt_changed(const tal_t *ctx, const struct channel_id *channel_id, const struct wally_psbt *psbt);
 bool fromwire_dual_open_psbt_changed(const tal_t *ctx, const void *p, struct channel_id *channel_id, struct wally_psbt **psbt);
 
+/* WIRE: DUAL_OPEN_PSBT_UPDATED */
+/*  master->dualopend: we updated the psbt */
+u8 *towire_dual_open_psbt_updated(const tal_t *ctx, const struct wally_psbt *psbt);
+bool fromwire_dual_open_psbt_updated(const tal_t *ctx, const void *p, struct wally_psbt **psbt);
+
 /* WIRE: DUAL_OPEN_FAIL */
 /*  master->dualopend: fail this channel open */
 u8 *towire_dual_open_fail(const tal_t *ctx, const wirestring *reason);
@@ -104,4 +109,4 @@ bool fromwire_dual_open_dev_memleak_reply(const void *p, bool *leak);
 
 
 #endif /* LIGHTNING_OPENINGD_DUALOPEND_WIREGEN_H */
-// SHA256STAMP:4d357681ca9bea1ad36f3fe4d3482a0a12f808dfe20b71f0b9bee78beed0950e
+// SHA256STAMP:37f122e865f6e2432cffb5ae82c77ca2f8a3714baed0c9724a92541092f3aa54