Fix: prioritize control socket communication in relayd

[lttng-tools.git] / src / common / sessiond-comm / relayd.h

/*
 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
 *                      Julien Desfossez <julien.desfossez@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef _RELAYD_COMM
#define _RELAYD_COMM

#define _GNU_SOURCE

#include <limits.h>
#include <stdint.h>

#include <lttng/lttng.h>
#include <common/defaults.h>

#define RELAYD_VERSION_COMM_MAJOR             2
#define RELAYD_VERSION_COMM_MINOR             1

/*
 * lttng-relayd communication header.
 */
struct lttcomm_relayd_hdr {
	/* Circuit ID not used for now so always ignored */
	uint64_t circuit_id;
	uint64_t data_size;		/* data size following this header */
	uint32_t cmd;			/* enum lttcomm_relayd_command */
	uint32_t cmd_version;	/* command version */
} LTTNG_PACKED;

/*
 * lttng-relayd data header.
 */
struct lttcomm_relayd_data_hdr {
	/* Circuit ID not used for now so always ignored */
	uint64_t circuit_id;
	uint64_t stream_id;     /* Stream ID known by the relayd */
	uint64_t net_seq_num;   /* Network sequence number, per stream. */
	uint32_t data_size;     /* data size following this header */
	uint32_t padding_size;  /* Size of 0 padding the data */
} LTTNG_PACKED;

/*
 * Reply from a create session command.
 */
struct lttcomm_relayd_status_session {
	uint64_t session_id;
	uint32_t ret_code;
} LTTNG_PACKED;

/*
 * Used to add a stream on the relay daemon.
 */
struct lttcomm_relayd_add_stream {
	char channel_name[DEFAULT_STREAM_NAME_LEN];
	char pathname[PATH_MAX];
} LTTNG_PACKED;

/*
 * Answer from an add stream command.
 */
struct lttcomm_relayd_status_stream {
	uint64_t handle;
	uint32_t ret_code;
} LTTNG_PACKED;

/*
 * Used to return command code for command not needing special data.
 */
struct lttcomm_relayd_generic_reply {
	uint32_t ret_code;
} LTTNG_PACKED;

/*
 * Used to update synchronization information.
 */
struct lttcomm_relayd_update_sync_info {
	/* TODO: fill the structure. Feature not implemented yet */
} LTTNG_PACKED;

/*
 * Version command.
 */
struct lttcomm_relayd_version {
	uint32_t major;
	uint32_t minor;
} LTTNG_PACKED;

/*
 * Metadata payload used when metadata command is sent.
 */
struct lttcomm_relayd_metadata_payload {
	uint64_t stream_id;
	uint32_t padding_size;
	char payload[];
} LTTNG_PACKED;

/*
 * Used to indicate that a specific stream id can now be closed.
 */
struct lttcomm_relayd_close_stream {
	uint64_t stream_id;
	uint64_t last_net_seq_num;	/* sequence number of last packet */
} LTTNG_PACKED;

/*
 * Used to test if for a given stream id the data is pending on the relayd side
 * for reading.
 */
struct lttcomm_relayd_data_pending {
	uint64_t stream_id;
	uint64_t last_net_seq_num; /* Sequence number of the last packet */
} LTTNG_PACKED;

struct lttcomm_relayd_begin_data_pending {
	uint64_t session_id;
} LTTNG_PACKED;

struct lttcomm_relayd_end_data_pending {
	uint64_t session_id;
} LTTNG_PACKED;

#endif	/* _RELAYD_COMM */