Channeld: Add new wire type:channel_got_announcement

Channeld sends announcement signatures to Master by this message.
When Channeld receive a new channel announcement msg, (After channel locking)it will sends announcement signatures to Master by this message.

channeld/channel_wire.csv

@@ -185,3 +185,8 @@ channel_fail_fallen_behind,,remote_per_commitment_point,struct pubkey
 channel_specific_feerates,1029
 channel_specific_feerates,,feerate_base,u32
 channel_specific_feerates,,feerate_ppm,u32
+
+# When we receive announcement_signatures for channel announce
+channel_got_announcement,1017
+channel_got_announcement,,remote_ann_node_sig,secp256k1_ecdsa_signature
+channel_got_announcement,,remote_ann_bitcoin_sig,secp256k1_ecdsa_signature

channeld/channeld.c

@@ -451,8 +451,6 @@ static void announce_channel(struct peer *peer)
 {
 	u8 *cannounce;
 
-	check_short_ids_match(peer);
-
 	cannounce = create_channel_announcement(tmpctx, peer);
 
 	wire_sync_write(GOSSIP_FD, cannounce);
@@ -493,15 +491,29 @@ static void channel_announcement_negotiate(struct peer *peer)
 	 *      has been sent and received AND the funding transaction has at least six confirmations.
  	 */
 	if (peer->announce_depth_reached && !peer->have_sigs[LOCAL]) {
+		/* When we reenable the channel, we will also send the announcement to remote peer, and
+		 * receive the remote announcement reply. But we will rebuild the channel with announcement
+		 * from the DB directly, other than waiting for the remote announcement reply.
+		 */
 		send_announcement_signatures(peer);
 		peer->have_sigs[LOCAL] = true;
 		billboard_update(peer);
 	}
 
 	/* If we've completed the signature exchange, we can send a real
 	 * announcement, otherwise we send a temporary one */
-	if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
+	if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE]) {
+		check_short_ids_match(peer);
+
+		/* After making sure short_channel_ids match, we can send remote
+		 * announcement to MASTER. */
+		wire_sync_write(MASTER_FD,
+			        take(towire_channel_got_announcement(NULL,
+			        &peer->announcement_node_sigs[REMOTE],
+			        &peer->announcement_bitcoin_sigs[REMOTE])));
+
 		announce_channel(peer);
+	}
 }
 
 static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
@@ -2778,6 +2790,7 @@ static void req_in(struct peer *peer, const u8 *msg)
 	case WIRE_CHANNEL_GOT_COMMITSIG_REPLY:
 	case WIRE_CHANNEL_GOT_REVOKE_REPLY:
 	case WIRE_CHANNEL_GOT_FUNDING_LOCKED:
+	case WIRE_CHANNEL_GOT_ANNOUNCEMENT:
 	case WIRE_CHANNEL_GOT_SHUTDOWN:
 	case WIRE_CHANNEL_SHUTDOWN_COMPLETE:
 	case WIRE_CHANNEL_DEV_REENABLE_COMMIT_REPLY:

lightningd/channel_control.c

@@ -117,6 +117,31 @@ static void peer_got_funding_locked(struct channel *channel, const u8 *msg)
 		lockin_complete(channel);
 }
 
+static void peer_got_announcement(struct channel *channel, const u8 *msg)
+{
+	secp256k1_ecdsa_signature remote_ann_node_sig;
+	secp256k1_ecdsa_signature remote_ann_bitcoin_sig;
+
+	if(!(channel->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL)) {
+		channel_internal_error(channel,
+				       "No ANNOUNCE flag, no announcemnt signatures! %s",
+				       tal_hex(tmpctx, msg));
+	}
+
+	if (!fromwire_channel_got_announcement(msg,
+					       &remote_ann_node_sig,
+					       &remote_ann_bitcoin_sig)) {
+		channel_internal_error(channel,
+				       "bad channel_got_funding_locked %s",
+				       tal_hex(tmpctx, msg));
+		return;
+	}
+
+	wallet_announcement_save(channel->peer->ld->wallet, channel->dbid,
+				 &remote_ann_node_sig,
+				 &remote_ann_bitcoin_sig);
+}
+
 static void peer_got_shutdown(struct channel *channel, const u8 *msg)
 {
 	u8 *scriptpubkey;
@@ -219,6 +244,9 @@ static unsigned channel_msg(struct subd *sd, const u8 *msg, const int *fds)
 	case WIRE_CHANNEL_GOT_FUNDING_LOCKED:
 		peer_got_funding_locked(sd->channel, msg);
 		break;
+	case WIRE_CHANNEL_GOT_ANNOUNCEMENT:
+		peer_got_announcement(sd->channel, msg);
+		break;
 	case WIRE_CHANNEL_GOT_SHUTDOWN:
 		peer_got_shutdown(sd->channel, msg);
 		break;