open_command: keep them local to channel

Since this all stays in dualopend/dual_open_control, we can hold
onto the openchannel_signed command to wait for a response here locally.
Previously we were splitting across the channeld/openingd boundary.

lightningd/channel.c

@@ -206,6 +206,7 @@ struct channel *new_channel(struct peer *peer, u64 dbid,
 	channel->dbid = dbid;
 	channel->error = NULL;
 	channel->htlc_timeout = NULL;
+	channel->openchannel_signed_cmd = NULL;
 	if (their_shachain)
 		channel->their_shachain = *their_shachain;
 	else {

lightningd/channel.h

@@ -157,6 +157,9 @@ struct channel {
 
 	/* Last known state_change cause */
 	enum state_change state_change_cause;
+
+	/* Outstanding command for this channel, v2 only */
+	struct command *openchannel_signed_cmd;
 };
 
 struct channel *new_channel(struct peer *peer, u64 dbid,

lightningd/dual_open_control.c

@@ -1051,23 +1051,22 @@ static void sendfunding_done(struct bitcoind *bitcoind UNUSED,
 	const struct wally_tx *wtx = cs->wtx;
 	struct json_stream *response;
 	struct bitcoin_txid txid;
-	struct open_command *oc;
 	struct amount_sat unused;
 	int num_utxos;
+	struct command *cmd = channel->openchannel_signed_cmd;
+	channel->openchannel_signed_cmd = NULL;
 
-	oc = find_open_command(ld, channel);
-	if (!oc && channel->opener == LOCAL) {
+	if (!cmd && channel->opener == LOCAL)
 		log_broken(channel->log,
 			   "No outstanding command for channel %s,"
 			   " funding sent was success? %d",
 			   type_to_string(tmpctx, struct channel_id,
 					  &channel->cid),
 			   success);
-	}
 
 	if (!success) {
-		if (oc)
-			was_pending(command_fail(oc->cmd,
+		if (cmd)
+			was_pending(command_fail(cmd,
 						 FUNDING_BROADCAST_FAIL,
 						 "Error broadcasting funding "
 						 "tx: %s. Unsent tx discarded "
@@ -1090,24 +1089,24 @@ static void sendfunding_done(struct bitcoind *bitcoind UNUSED,
 	num_utxos = wallet_extract_owned_outputs(ld->wallet,
 						 wtx, NULL,
 						 &unused);
-	if (num_utxos) {
+	if (num_utxos)
 		wallet_transaction_add(ld->wallet, wtx, 0, 0);
-	}
 
-	if (oc) {
-		response = json_stream_success(oc->cmd);
+	if (cmd) {
+		response = json_stream_success(cmd);
 		wally_txid(wtx, &txid);
 		json_add_hex_talarr(response, "tx", linearize_wtx(tmpctx, wtx));
 		json_add_txid(response, "txid", &txid);
 		json_add_string(response, "channel_id",
 				type_to_string(tmpctx, struct channel_id,
 					       &channel->cid));
-		was_pending(command_success(oc->cmd, response));
+		was_pending(command_success(cmd, response));
 	}
 
 	tal_free(cs);
 }
 
+
 static void send_funding_tx(struct channel *channel,
 			    const struct wally_tx *wtx TAKES)
 {
@@ -1211,6 +1210,10 @@ json_openchannel_signed(struct command *cmd,
 		return command_fail(cmd, LIGHTNINGD,
 				    "Already have a finalized PSBT for "
 				    "this channel");
+	if (channel->openchannel_signed_cmd)
+		return command_fail(cmd, LIGHTNINGD,
+				    "Already sent sigs, waiting for"
+				    " peer's");
 
 	/* Verify that the psbt's txid matches that of the
 	 * funding txid for this channel */
@@ -1247,9 +1250,6 @@ json_openchannel_signed(struct command *cmd,
 	wallet_channel_save(cmd->ld->wallet, channel);
 	channel_watch_funding(cmd->ld, channel);
 
-	/* Return when the transaction is broadcast */
-	register_open_command(cmd->ld, cmd, channel);
-
 	/* Send our tx_sigs to the peer */
 	subd_send_msg(channel->owner,
 		      take(towire_dualopend_send_tx_sigs(NULL, channel->psbt)));
@@ -1260,6 +1260,7 @@ json_openchannel_signed(struct command *cmd,
 			send_funding_tx(channel, take(wtx));
 	}
 
+	channel->openchannel_signed_cmd = tal_steal(channel, cmd);
 	return command_still_pending(cmd);
 }
 

lightningd/lightningd.c

@@ -196,7 +196,6 @@ static struct lightningd *new_lightningd(const tal_t *ctx)
 	list_head_init(&ld->waitsendpay_commands);
 	list_head_init(&ld->sendpay_commands);
 	list_head_init(&ld->close_commands);
-	list_head_init(&ld->open_commands);
 	list_head_init(&ld->ping_commands);
 	list_head_init(&ld->waitblockheight_commands);
 

lightningd/lightningd.h

@@ -179,8 +179,6 @@ struct lightningd {
 	struct list_head sendpay_commands;
 	/* Outstanding close commands. */
 	struct list_head close_commands;
-	/* Outstanding openchannel_signed commands. */
-	struct list_head open_commands;
 	/* Outstanding ping commands. */
 	struct list_head ping_commands;
 

lightningd/peer_control.c

@@ -323,68 +323,6 @@ register_close_command(struct lightningd *ld,
 			     &close_command_timeout, cc);
 }
 
-/* Destroy the open command structure in reaction to the
- * channel being destroyed. */
-static void
-destroy_open_command_on_channel_destroy(struct channel *_ UNUSED,
-					struct open_command *oc)
-{
-	/* The oc has the command as parent, so resolving the
-	 * command destroys the oc and triggers destroy_open_command.
-	 * Clear the oc->channel first so that we will not try to
-	 * remove a destructor. */
-	oc->channel = NULL;
-	was_pending(command_fail(oc->cmd, LIGHTNINGD,
-				 "Channel forgotten before open concluded."));
-}
-
-/* Destroy the open command structure. */
-static void
-destroy_open_command(struct open_command *oc)
-{
-	list_del(&oc->list);
-	/* If destroy_close_command_on_channel_destroy was
-	 * triggered beforehand, it will have cleared
-	 * the channel field, preventing us from removing it
-	 * from an already-destroyed channel. */
-	if (!oc->channel)
-		return;
-	tal_del_destructor2(oc->channel,
-			    &destroy_open_command_on_channel_destroy,
-			    oc);
-}
-
-struct open_command *find_open_command(struct lightningd *ld,
-				       const struct channel *channel)
-{
-	struct open_command *oc, *n;
-
-	list_for_each_safe (&ld->open_commands, oc, n, list) {
-		if (oc->channel != channel)
-			continue;
-		return oc;
-	}
-
-	return NULL;
-}
-
-void register_open_command(struct lightningd *ld,
-			   struct command *cmd,
-			   struct channel *channel)
-{
-	struct open_command *oc;
-	assert(channel);
-
-	oc = tal(cmd, struct open_command);
-	list_add_tail(&ld->open_commands, &oc->list);
-	oc->cmd = cmd;
-	oc->channel = channel;
-	tal_add_destructor(oc, &destroy_open_command);
-	tal_add_destructor2(channel,
-			    &destroy_open_command_on_channel_destroy,
-			    oc);
-}
-
 static bool invalid_last_tx(const struct bitcoin_tx *tx)
 {
 	/* This problem goes back further, but was discovered just before the

lightningd/peer_control.h

@@ -52,15 +52,6 @@ struct peer {
 #endif
 };
 
-struct open_command {
-	/* Inside struct lightningd open_commands. */
-	struct list_node list;
-	/* Command structure. This is the parent of the open command. */
-	struct command *cmd;
-	/* Channel being opened. */
-	struct channel *channel;
-};
-
 struct peer *find_peer_by_dbid(struct lightningd *ld, u64 dbid);
 
 struct peer *new_peer(struct lightningd *ld, u64 dbid,
@@ -99,16 +90,6 @@ void channel_watch_funding(struct lightningd *ld, struct channel *channel);
 
 struct amount_msat channel_amount_receivable(const struct channel *channel);
 
-/* Find the open command that was registered for this channel */
-struct open_command *find_open_command(struct lightningd *ld,
-				       const struct channel *channel);
-
-/* Save an `openchannel_signed` command */
-void register_open_command(struct lightningd *ld,
-			   struct command *cmd,
-			   struct channel *channel);
-
-
 /* Pull peers, channels and HTLCs from db, and wire them up.
  * Returns any HTLCs we have to resubmit via htlcs_resubmit. */
 struct htlc_in_map *load_channels_from_wallet(struct lightningd *ld);