SoW-2019-0002: Dynamic Snapshot

[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl-helper.h

/*
 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#ifndef LTTNG_CTL_HELPER_H
#define LTTNG_CTL_HELPER_H

#include <stdio.h>

#include <common/sessiond-comm/sessiond-comm.h>
#include <lttng/lttng.h>

/*
 * NOTE: Every symbol in this helper header MUST be set to hidden so not to
 * polute the library name space. Use LTTNG_HIDDEN macro before declaring the
 * function in the C file.
 */

/* Copy helper functions. */
void lttng_ctl_copy_string(char *dst, const char *src, size_t len);
void lttng_ctl_copy_lttng_domain(struct lttng_domain *dst,
		struct lttng_domain *src);

/*
 * Sends the lttcomm message to the session daemon and fills buf if the
 * returned data is not NULL.
 *
 * Return the size of the received data on success or else a negative lttng
 * error code. If buf is NULL, 0 is returned on success.
 */
int lttng_ctl_ask_sessiond_fds_varlen(struct lttcomm_session_msg *lsm,
		const int *fds, size_t nb_fd,
		const void *vardata, size_t vardata_len,
		void **user_payload_buf, void **user_cmd_header_buf,
		size_t *user_cmd_header_len);

/*
 * Calls lttng_ctl_ask_sessiond_fds_varlen() with no expected command header.
 */
static inline
int lttng_ctl_ask_sessiond_varlen_no_cmd_header(struct lttcomm_session_msg *lsm,
		void *vardata, size_t vardata_len, void **user_payload_buf)
{
	return lttng_ctl_ask_sessiond_fds_varlen(lsm, NULL, 0, vardata,
		vardata_len, user_payload_buf, NULL, NULL);
}

/*
 * Calls lttng_ctl_ask_sessiond_fds_varlen() with fds and no expected command header.
 */
static inline
int lttng_ctl_ask_sessiond_fds_no_cmd_header(struct lttcomm_session_msg *lsm,
		const int *fds, size_t nb_fd, void **buf)
{
	return lttng_ctl_ask_sessiond_fds_varlen(lsm, fds, nb_fd, NULL,
		0, NULL, NULL, NULL);
}

/*
 * Calls lttng_ctl_ask_sessiond_fds_varlen() with fds with no expected command
 * header and with varlen data.
 */
static inline int lttng_ctl_ask_sessiond_fds_varlen_no_cmd_header(
		struct lttcomm_session_msg *lsm,
		const int *fds,
		size_t nb_fd,
		void *vardata,
		size_t vardata_len,
		void **user_payload_buf)
{
	return lttng_ctl_ask_sessiond_fds_varlen(lsm, fds, nb_fd, vardata,
			vardata_len, user_payload_buf, NULL, NULL);
}

/*
 * Use this if no variable length data needs to be sent.
 */
static inline
int lttng_ctl_ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
{
	return lttng_ctl_ask_sessiond_varlen_no_cmd_header(lsm, NULL, 0, buf);
}

int lttng_check_tracing_group(void);

int connect_sessiond(void);

#endif /* LTTNG_CTL_HELPER_H */