subd: keep track of 'channel's type

Back in the days before dual-funding, the `channel` struct on subd was
only every one type per daemon (either struct channel or struct
uncommitted_channel)

The RBF requirement on dualopend means that dualopend's channel,
however, can now be two different things -- either channel or
uncommitted_channel.

To track the difference/disambiguate, we now track the channel type on a
flag on the subd. It gets updated when we swap out the channel.

lightningd/channel_control.c

@@ -462,7 +462,8 @@ void peer_start_channeld(struct channel *channel,
 
 	channel_set_owner(channel,
 			  new_channel_subd(ld,
-					   "lightning_channeld", channel,
+					   "lightning_channeld",
+					   channel, CHANNEL,
 					   &channel->peer->id,
 					   channel->log, true,
 					   channeld_wire_name,

lightningd/closing_control.c

@@ -194,7 +194,7 @@ void peer_start_closingd(struct channel *channel,
 	channel_set_owner(channel,
 			  new_channel_subd(ld,
 					   "lightning_closingd",
-					   channel, &channel->peer->id,
+					   channel, CHANNEL, &channel->peer->id,
 					   channel->log, true,
 					   closingd_wire_name, closing_msg,
 					   channel_errmsg,

lightningd/dual_open_control.c

@@ -816,7 +816,7 @@ static void accepter_commit_received(struct subd *dualopend,
 					payload->rcvd->channel->dbid,
 					pbase);
 
-	subd_swap_channel(uc->open_daemon, payload->rcvd->channel,
+	subd_swap_channel(uc->open_daemon, payload->rcvd->channel, CHANNEL,
 			  channel_errmsg, channel_set_billboard);
 	payload->rcvd->channel->owner = dualopend;
 	/* We don't have a command, so set to NULL here */
@@ -936,7 +936,7 @@ static void opener_commit_received(struct subd *dualopend,
 
 	was_pending(command_success(uc->fc->cmd, response));
 
-	subd_swap_channel(uc->open_daemon, channel,
+	subd_swap_channel(uc->open_daemon, channel, CHANNEL,
 			  channel_errmsg, channel_set_billboard);
 	channel->owner = dualopend;
 	goto cleanup;
@@ -1708,7 +1708,8 @@ void peer_start_dualopend(struct peer *peer,
 
 	uc->open_daemon = new_channel_subd(peer->ld,
 					   "lightning_dualopend",
-					   uc, &peer->id, uc->log,
+					   uc, UNCOMMITTED, &peer->id,
+					   uc->log,
 					   true, dualopend_wire_name,
 					   dual_opend_msg,
 					   opend_channel_errmsg,

lightningd/onchain_control.c

@@ -588,7 +588,8 @@ enum watch_result onchaind_funding_spent(struct channel *channel,
 
 	channel_set_owner(channel, new_channel_subd(ld,
 						    "lightning_onchaind",
-						    channel, &channel->peer->id,
+						    channel, CHANNEL,
+						    &channel->peer->id,
 						    channel->log, false,
 						    onchaind_wire_name,
 						    onchain_msg,

lightningd/opening_control.c

@@ -893,7 +893,7 @@ void peer_start_openingd(struct peer *peer,
 
 	uc->open_daemon = new_channel_subd(peer->ld,
 					"lightning_openingd",
-					uc, &peer->id, uc->log,
+					uc, UNCOMMITTED, &peer->id, uc->log,
 					true, openingd_wire_name,
 					openingd_msg,
 					opend_channel_errmsg,

lightningd/subd.c

@@ -606,6 +606,7 @@ static struct io_plan *msg_setup(struct io_conn *conn, struct subd *sd)
 static struct subd *new_subd(struct lightningd *ld,
 			     const char *name,
 			     void *channel,
+			     enum channel_type ctype,
 			     const struct node_id *node_id,
 			     struct log *base_log,
 			     bool talks_to_peer,
@@ -678,6 +679,7 @@ static struct subd *new_subd(struct lightningd *ld,
 	tal_add_destructor(sd, destroy_subd);
 	list_head_init(&sd->reqs);
 	sd->channel = channel;
+	sd->ctype = ctype;
 	if (node_id)
 		sd->node_id = tal_dup(sd, struct node_id, node_id);
 	else
@@ -706,7 +708,8 @@ struct subd *new_global_subd(struct lightningd *ld,
 	struct subd *sd;
 
 	va_start(ap, msgcb);
-	sd = new_subd(ld, name, NULL, NULL, NULL, false, msgname, msgcb, NULL, NULL, &ap);
+	sd = new_subd(ld, name, NULL, NONE, NULL, NULL, false,
+		      msgname, msgcb, NULL, NULL, &ap);
 	va_end(ap);
 
 	sd->must_not_exit = true;
@@ -716,6 +719,7 @@ struct subd *new_global_subd(struct lightningd *ld,
 struct subd *new_channel_subd_(struct lightningd *ld,
 			       const char *name,
 			       void *channel,
+			       enum channel_type ctype,
 			       const struct node_id *node_id,
 			       struct log *base_log,
 			       bool talks_to_peer,
@@ -736,8 +740,8 @@ struct subd *new_channel_subd_(struct lightningd *ld,
 	struct subd *sd;
 
 	va_start(ap, billboardcb);
-	sd = new_subd(ld, name, channel, node_id, base_log, talks_to_peer,
-		      msgname, msgcb, errcb, billboardcb, &ap);
+	sd = new_subd(ld, name, channel, ctype, node_id, base_log,
+		      talks_to_peer, msgname, msgcb, errcb, billboardcb, &ap);
 	va_end(ap);
 	return sd;
 }
@@ -823,16 +827,18 @@ void subd_release_channel(struct subd *owner, void *channel)
 }
 
 void subd_swap_channel_(struct subd *daemon, void *channel,
-		       void (*errcb)(void *channel,
-				     struct per_peer_state *pps,
-				     const struct channel_id *channel_id,
-				     const char *desc,
-				     bool soft_error,
-				     const u8 *err_for_them),
+			enum channel_type ctype,
+			void (*errcb)(void *channel,
+				      struct per_peer_state *pps,
+				      const struct channel_id *channel_id,
+				      const char *desc,
+				      bool soft_error,
+				      const u8 *err_for_them),
 			void (*billboardcb)(void *channel, bool perm,
 					    const char *happenings))
 {
 	daemon->channel = channel;
+	daemon->ctype = ctype;
 	daemon->errcb = errcb;
 	daemon->billboardcb = billboardcb;
 }

lightningd/subd.h

@@ -18,6 +18,12 @@ struct per_peer_state;
 /* And reply failures are requests + 200 */
 #define SUBD_REPLYFAIL_OFFSET 200
 
+enum channel_type {
+	UNCOMMITTED,
+	CHANNEL,
+	NONE,
+};
+
 /* One of our subds. */
 struct subd {
 	/* Name, like John, or "lightning_hsmd" */
@@ -31,6 +37,7 @@ struct subd {
 
 	/* If we are associated with a single channel, this points to it. */
 	void *channel;
+	enum channel_type ctype;
 
 	/* For logging */
 	struct log *log;
@@ -98,6 +105,7 @@ struct subd *new_global_subd(struct lightningd *ld,
  * @ld: global state
  * @name: basename of daemon
  * @channel: channel to associate.
+ * @ctype: type of @channel struct.
  * @node_id: node_id of peer, for logging.
  * @base_log: log to use (actually makes a copy so it has name in prefix)
  * @msgname: function to get name from messages
@@ -114,6 +122,7 @@ struct subd *new_global_subd(struct lightningd *ld,
 struct subd *new_channel_subd_(struct lightningd *ld,
 			       const char *name,
 			       void *channel,
+			       enum channel_type ctype,
 			       const struct node_id *node_id,
 			       struct log *base_log,
 			       bool talks_to_peer,
@@ -130,10 +139,11 @@ struct subd *new_channel_subd_(struct lightningd *ld,
 						   const char *happenings),
 			       ...);
 
-#define new_channel_subd(ld, name, channel, node_id, log, talks_to_peer, \
-			 msgname, msgcb, errcb, billboardcb, ...)	\
-	new_channel_subd_((ld), (name), (channel), (node_id), (log),	\
-			  (talks_to_peer),				\
+#define new_channel_subd(ld, name, channel, ctype, node_id, log, 	\
+			 talks_to_peer, msgname, msgcb, errcb, 		\
+			 billboardcb, ...)				\
+	new_channel_subd_((ld), (name), (channel), (ctype), (node_id), 	\
+			  (log), (talks_to_peer),			\
 			  (msgname), (msgcb),				\
 			  typesafe_cb_postargs(void, void *, (errcb),	\
 					       (channel),		\
@@ -146,8 +156,8 @@ struct subd *new_channel_subd_(struct lightningd *ld,
 			  __VA_ARGS__)
 
 /* subd_swap_channel - Swap the daemon's channel out */
-#define subd_swap_channel(subd, channel, errcb, billboardcb)		\
-	subd_swap_channel_((subd), (channel),				\
+#define subd_swap_channel(subd, channel, ctype, errcb, billboardcb)	\
+	subd_swap_channel_((subd), (channel), (ctype),			\
 			   typesafe_cb_postargs(void, void *,		\
 						(errcb),		\
 						(channel),		\
@@ -160,6 +170,7 @@ struct subd *new_channel_subd_(struct lightningd *ld,
 						const char *))
 
 void subd_swap_channel_(struct subd *daemon, void *channel,
+			enum channel_type ctype,
 			void (*errcb)(void *channel,
 				      struct per_peer_state *pps,
 				      const struct channel_id *channel_id,