packets: remember callbacks for acks on queued packets.

Not used yet.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/packets.c

@@ -72,7 +72,9 @@ static void queue_raw_pkt(struct peer *peer, Pkt *pkt)
 {
 	size_t n = tal_count(peer->outpkt);
 	tal_resize(&peer->outpkt, n+1);
-	peer->outpkt[n] = pkt;
+	peer->outpkt[n].pkt = pkt;
+	peer->outpkt[n].ack_cb = NULL;
+	peer->outpkt[n].ack_arg = NULL;
 
 	/* In case it was waiting for output. */
 	io_wake(peer);

daemon/peer.c

@@ -136,7 +136,7 @@ static void state_single(struct peer *peer,
 	}
 
 	if (tal_count(peer->outpkt) > old_outpkts) {
-		Pkt *outpkt = peer->outpkt[old_outpkts];
+		Pkt *outpkt = peer->outpkt[old_outpkts].pkt;
 		log_add(peer->log, " (out %s)", input_name(outpkt->pkt_case));
 	}
 	if (broadcast) {
@@ -224,7 +224,7 @@ static void state_event(struct peer *peer,
 
 static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
 {
-	Pkt *out;
+	struct out_pkt out;
 	size_t n = tal_count(peer->outpkt);
 
 	if (n == 0) {
@@ -237,7 +237,8 @@ static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
 	out = peer->outpkt[0];
 	memmove(peer->outpkt, peer->outpkt + 1, (sizeof(*peer->outpkt)*(n-1)));
 	tal_resize(&peer->outpkt, n-1);
-	return peer_write_packet(conn, peer, out, NULL, NULL, pkt_out);
+	return peer_write_packet(conn, peer, out.pkt, out.ack_cb, out.ack_arg,
+				 pkt_out);
 }
 
 static struct io_plan *pkt_in(struct io_conn *conn, struct peer *peer)
@@ -341,7 +342,7 @@ static struct peer *new_peer(struct lightningd_state *dstate,
 	peer->io_data = NULL;
 	peer->secrets = NULL;
 	list_head_init(&peer->watches);
-	peer->outpkt = tal_arr(peer, Pkt *, 0);
+	peer->outpkt = tal_arr(peer, struct out_pkt, 0);
 	peer->curr_cmd.cmd = INPUT_NONE;
 	list_head_init(&peer->pending_cmd);
 	peer->current_htlc = NULL;

daemon/peer.h

@@ -73,6 +73,12 @@ struct htlc_progress {
 	struct bitcoin_signature their_sig;
 };
 
+struct out_pkt {
+	Pkt *pkt;
+	void (*ack_cb)(struct peer *peer, void *arg);
+	void *ack_arg;
+};
+
 struct peer {
 	/* dstate->peers list */
 	struct list_node list;
@@ -112,7 +118,7 @@ struct peer {
 	Pkt *inpkt;
 
 	/* Queue of output packets. */
-	Pkt **outpkt;
+	struct out_pkt *outpkt;
 
 	/* Anchor tx output */
 	struct {