Function send_manual_ping

connectd/multiplex.c:1748–1809

Lightningd says to send a ping */

/* Lightningd says to send a ping */
void send_manual_ping(struct daemon *daemon, const u8 *msg)
{
	u8 *ping;
	struct node_id id;
	u64 reqid;
	u16 len, num_pong_bytes;
	struct peer *peer;

	if (!fromwire_connectd_ping(msg, &reqid, &id, &num_pong_bytes, &len))
		master_badmsg(WIRE_CONNECTD_PING, msg);

	peer = peer_htable_get(daemon->peers, &id);
	if (!peer) {
		daemon_conn_send(daemon->master,
				 take(towire_connectd_ping_done(NULL, reqid,
								false, 0)));
		return;
	}

	/* We're not supposed to send another ping until previous replied */
	if (peer->expecting_pong != PONG_UNEXPECTED) {
		daemon_conn_send(daemon->master,
				 take(towire_connectd_ping_done(NULL, reqid,
								false, 0)));
		return;
	}

	/* It should never ask for an oversize ping. */
	ping = make_ping(NULL, num_pong_bytes, len);
	if (tal_count(ping) > 65535)
		status_failed(STATUS_FAIL_MASTER_IO, "Oversize ping");

	peer->ping_start = time_mono();
	inject_peer_msg(peer, take(ping));

	status_debug("sending ping expecting %sresponse",
		     num_pong_bytes >= 65532 ? "no " : "");

	/* BOLT #1:
	 *
	 * A node receiving a `ping` message:
	 *  - if `num_pong_bytes` is less than 65532:
	 *    - MUST respond by sending a `pong` message, with `byteslen` equal
	 *      to `num_pong_bytes`.
	 *  - otherwise (`num_pong_bytes` is **not** less than 65532):
	 *    - MUST ignore the `ping`.
	 */
	if (num_pong_bytes >= 65532) {
		daemon_conn_send(daemon->master,
				 take(towire_connectd_ping_done(NULL, reqid,
								 true, 0)));
		return;
	}

	/* We'll respond to lightningd once the pong comes in */
	peer->expecting_pong = PONG_EXPECTED_COMMAND;
	peer->ping_reqid = reqid;