[lttng-tools.git] / src / common / relayd / relayd.c

/*
 * Copyright (C) 2012 - David Goulet <dgoulet@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.
 */

#define _LGPL_SOURCE
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <inttypes.h>

#include <common/common.h>
#include <common/defaults.h>
#include <common/compat/endian.h>
#include <common/compat/string.h>
#include <common/sessiond-comm/relayd.h>
#include <common/index/ctf-index.h>
#include <common/trace-chunk.h>
#include <common/string-utils/format.h>

#include "relayd.h"

static
bool relayd_supports_chunks(const struct lttcomm_relayd_sock *sock)
{
        if (sock->major > 2) {
                return true;
        } else if (sock->major == 2 && sock->minor >= 11) {
                return true;
        }
        return false;
}

static
bool relayd_supports_get_configuration(const struct lttcomm_relayd_sock *sock)
{
        if (sock->major > 2) {
                return true;
        } else if (sock->major == 2 && sock->minor >= 12) {
                return true;
        }
        return false;
}

/*
 * Send command. Fill up the header and append the data.
 */
static int send_command(struct lttcomm_relayd_sock *rsock,
                enum lttcomm_relayd_command cmd, const void *data, size_t size,
                int flags)
{
        int ret;
        struct lttcomm_relayd_hdr header;
        char *buf;
        uint64_t buf_size = sizeof(header);

        if (rsock->sock.fd < 0) {
                return -ECONNRESET;
        }

        if (data) {
                buf_size += size;
        }

        buf = zmalloc(buf_size);
        if (buf == NULL) {
                PERROR("zmalloc relayd send command buf");
                ret = -1;
                goto alloc_error;
        }

        memset(&header, 0, sizeof(header));
        header.cmd = htobe32(cmd);
        header.data_size = htobe64(size);

        /* Zeroed for now since not used. */
        header.cmd_version = 0;
        header.circuit_id = 0;

        /* Prepare buffer to send. */
        memcpy(buf, &header, sizeof(header));
        if (data) {
                memcpy(buf + sizeof(header), data, size);
        }

        DBG3("Relayd sending command %d of size %" PRIu64, (int) cmd, buf_size);
        ret = rsock->sock.ops->sendmsg(&rsock->sock, buf, buf_size, flags);
        if (ret < 0) {
                PERROR("Failed to send command %d of size %" PRIu64,
                                (int) cmd, buf_size);
                ret = -errno;
                goto error;
        }
error:
        free(buf);
alloc_error:
        return ret;
}

/*
 * Receive reply data on socket. This MUST be call after send_command or else
 * could result in unexpected behavior(s).
 */
static int recv_reply(struct lttcomm_relayd_sock *rsock, void *data, size_t size)
{
        int ret;

        if (rsock->sock.fd < 0) {
                return -ECONNRESET;
        }

        DBG3("Relayd waiting for reply of size %zu", size);

        ret = rsock->sock.ops->recvmsg(&rsock->sock, data, size, 0);
        if (ret <= 0 || ret != size) {
                if (ret == 0) {
                        /* Orderly shutdown. */
                        DBG("Socket %d has performed an orderly shutdown", rsock->sock.fd);
                } else {
                        DBG("Receiving reply failed on sock %d for size %zu with ret %d",
                                        rsock->sock.fd, size, ret);
                }
                /* Always return -1 here and the caller can use errno. */
                ret = -1;
                goto error;
        }

error:
        return ret;
}

/*
 * Starting from 2.11, RELAYD_CREATE_SESSION payload (session_name,
 * hostname, and base_path) have no length restriction on the sender side.
 * Length for both payloads is stored in the msg struct. A new dynamic size
 * payload size is introduced.
 */
static int relayd_create_session_2_11(struct lttcomm_relayd_sock *rsock,
                const char *session_name, const char *hostname,
                const char *base_path, int session_live_timer,
                unsigned int snapshot, uint64_t sessiond_session_id,
                const lttng_uuid sessiond_uuid, const uint64_t *current_chunk_id,
                time_t creation_time, bool session_name_contains_creation_time,
                struct lttcomm_relayd_create_session_reply_2_11 *reply,
                char *output_path)
{
        int ret;
        struct lttcomm_relayd_create_session_2_11 *msg = NULL;
        size_t session_name_len;
        size_t hostname_len;
        size_t base_path_len;
        size_t msg_length;
        char *dst;

        if (!base_path) {
                base_path = "";
        }
        /* The three names are sent with a '\0' delimiter between them. */
        session_name_len = strlen(session_name) + 1;
        hostname_len = strlen(hostname) + 1;
        base_path_len = strlen(base_path) + 1;

        msg_length = sizeof(*msg) + session_name_len + hostname_len + base_path_len;
        msg = zmalloc(msg_length);
        if (!msg) {
                PERROR("zmalloc create_session_2_11 command message");
                ret = -1;
                goto error;
        }

        assert(session_name_len <= UINT32_MAX);
        msg->session_name_len = htobe32(session_name_len);

        assert(hostname_len <= UINT32_MAX);
        msg->hostname_len = htobe32(hostname_len);

        assert(base_path_len <= UINT32_MAX);
        msg->base_path_len = htobe32(base_path_len);

        dst = msg->names;
        if (lttng_strncpy(dst, session_name, session_name_len)) {
                ret = -1;
                goto error;
        }
        dst += session_name_len;
        if (lttng_strncpy(dst, hostname, hostname_len)) {
                ret = -1;
                goto error;
        }
        dst += hostname_len;
        if (lttng_strncpy(dst, base_path, base_path_len)) {
                ret = -1;
                goto error;
        }

        msg->live_timer = htobe32(session_live_timer);
        msg->snapshot = !!snapshot;

        lttng_uuid_copy(msg->sessiond_uuid, sessiond_uuid);
        msg->session_id = htobe64(sessiond_session_id);
        msg->session_name_contains_creation_time = session_name_contains_creation_time;
        if (current_chunk_id) {
                LTTNG_OPTIONAL_SET(&msg->current_chunk_id,
                                htobe64(*current_chunk_id));
        }

        msg->creation_time = htobe64((uint64_t) creation_time);

        /* Send command */
        ret = send_command(rsock, RELAYD_CREATE_SESSION, msg, msg_length, 0);
        if (ret < 0) {
                goto error;
        }
        /* Receive response */
        ret = recv_reply(rsock, reply, sizeof(*reply));
        if (ret < 0) {
                goto error;
        }
        reply->generic.session_id = be64toh(reply->generic.session_id);
        reply->generic.ret_code = be32toh(reply->generic.ret_code);
        reply->output_path_length = be32toh(reply->output_path_length);
        if (reply->output_path_length >= LTTNG_PATH_MAX) {
                ERR("Invalid session output path length in reply (%" PRIu32 " bytes) exceeds maximal allowed length (%d bytes)",
                                reply->output_path_length, LTTNG_PATH_MAX);
                ret = -1;
                goto error;
        }
        ret = recv_reply(rsock, output_path, reply->output_path_length);
        if (ret < 0) {
                goto error;
        }
error:
        free(msg);
        return ret;
}
/*
 * From 2.4 to 2.10, RELAYD_CREATE_SESSION takes additional parameters to
 * support the live reading capability.
 */
static int relayd_create_session_2_4(struct lttcomm_relayd_sock *rsock,
                const char *session_name, const char *hostname,
                int session_live_timer, unsigned int snapshot,
                struct lttcomm_relayd_status_session *reply)
{
        int ret;
        struct lttcomm_relayd_create_session_2_4 msg;

        if (lttng_strncpy(msg.session_name, session_name,
                        sizeof(msg.session_name))) {
                ret = -1;
                goto error;
        }
        if (lttng_strncpy(msg.hostname, hostname, sizeof(msg.hostname))) {
                ret = -1;
                goto error;
        }
        msg.live_timer = htobe32(session_live_timer);
        msg.snapshot = htobe32(snapshot);

        /* Send command */
        ret = send_command(rsock, RELAYD_CREATE_SESSION, &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, reply, sizeof(*reply));
        if (ret < 0) {
                goto error;
        }
        reply->session_id = be64toh(reply->session_id);
        reply->ret_code = be32toh(reply->ret_code);
error:
        return ret;
}

/*
 * RELAYD_CREATE_SESSION from 2.1 to 2.3.
 */
static int relayd_create_session_2_1(struct lttcomm_relayd_sock *rsock,
                struct lttcomm_relayd_status_session *reply)
{
        int ret;

        /* Send command */
        ret = send_command(rsock, RELAYD_CREATE_SESSION, NULL, 0, 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, reply, sizeof(*reply));
        if (ret < 0) {
                goto error;
        }
        reply->session_id = be64toh(reply->session_id);
        reply->ret_code = be32toh(reply->ret_code);
error:
        return ret;
}

/*
 * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
 * set session_id of the relayd if we have a successful reply from the relayd.
 *
 * On success, return 0 else a negative value which is either an errno error or
 * a lttng error code from the relayd.
 */
int relayd_create_session(struct lttcomm_relayd_sock *rsock,
                uint64_t *relayd_session_id,
                const char *session_name, const char *hostname,
                const char *base_path, int session_live_timer,
                unsigned int snapshot, uint64_t sessiond_session_id,
                const lttng_uuid sessiond_uuid,
                const uint64_t *current_chunk_id,
                time_t creation_time, bool session_name_contains_creation_time,
                char *output_path)
{
        int ret;
        struct lttcomm_relayd_create_session_reply_2_11 reply = {};

        assert(rsock);
        assert(relayd_session_id);

        DBG("Relayd create session");

        if (rsock->minor < 4) {
                /* From 2.1 to 2.3 */
                ret = relayd_create_session_2_1(rsock, &reply.generic);
        } else if (rsock->minor >= 4 && rsock->minor < 11) {
                /* From 2.4 to 2.10 */
                ret = relayd_create_session_2_4(rsock, session_name,
                                hostname, session_live_timer, snapshot,
                                &reply.generic);
        } else {
                /* From 2.11 to ... */
                ret = relayd_create_session_2_11(rsock, session_name,
                                hostname, base_path, session_live_timer, snapshot,
                                sessiond_session_id, sessiond_uuid,
                                current_chunk_id, creation_time,
                                session_name_contains_creation_time,
                                &reply, output_path);
        }

        if (ret < 0) {
                goto error;
        }

        /* Return session id or negative ret code. */
        if (reply.generic.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd create session replied error %d",
                        reply.generic.ret_code);
                goto error;
        } else {
                ret = 0;
                *relayd_session_id = reply.generic.session_id;
        }

        DBG("Relayd session created with id %" PRIu64, reply.generic.session_id);

error:
        return ret;
}

static int relayd_add_stream_2_1(struct lttcomm_relayd_sock *rsock,
                const char *channel_name, const char *pathname)
{
        int ret;
        struct lttcomm_relayd_add_stream msg;

        memset(&msg, 0, sizeof(msg));
        if (lttng_strncpy(msg.channel_name, channel_name,
                                sizeof(msg.channel_name))) {
                ret = -1;
                goto error;
        }

        if (lttng_strncpy(msg.pathname, pathname,
                                sizeof(msg.pathname))) {
                ret = -1;
                goto error;
        }

        /* Send command */
        ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
        if (ret < 0) {
                ret = -1;
                goto error;
        }
        ret = 0;
error:
        return ret;
}

static int relayd_add_stream_2_2(struct lttcomm_relayd_sock *rsock,
                const char *channel_name, const char *pathname,
                uint64_t tracefile_size, uint64_t tracefile_count)
{
        int ret;
        struct lttcomm_relayd_add_stream_2_2 msg;

        memset(&msg, 0, sizeof(msg));
        /* Compat with relayd 2.2 to 2.10 */
        if (lttng_strncpy(msg.channel_name, channel_name,
                                sizeof(msg.channel_name))) {
                ret = -1;
                goto error;
        }
        if (lttng_strncpy(msg.pathname, pathname,
                                sizeof(msg.pathname))) {
                ret = -1;
                goto error;
        }
        msg.tracefile_size = htobe64(tracefile_size);
        msg.tracefile_count = htobe64(tracefile_count);

        /* Send command */
        ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }
        ret = 0;
error:
        return ret;
}

static int relayd_add_stream_2_11(struct lttcomm_relayd_sock *rsock,
                const char *channel_name, const char *pathname,
                uint64_t tracefile_size, uint64_t tracefile_count,
                uint64_t trace_archive_id)
{
        int ret;
        struct lttcomm_relayd_add_stream_2_11 *msg = NULL;
        size_t channel_name_len;
        size_t pathname_len;
        size_t msg_length;

        /* The two names are sent with a '\0' delimiter between them. */
        channel_name_len = strlen(channel_name) + 1;
        pathname_len = strlen(pathname) + 1;

        msg_length = sizeof(*msg) + channel_name_len + pathname_len;
        msg = zmalloc(msg_length);
        if (!msg) {
                PERROR("zmalloc add_stream_2_11 command message");
                ret = -1;
                goto error;
        }

        assert(channel_name_len <= UINT32_MAX);
        msg->channel_name_len = htobe32(channel_name_len);

        assert(pathname_len <= UINT32_MAX);
        msg->pathname_len = htobe32(pathname_len);

        if (lttng_strncpy(msg->names, channel_name, channel_name_len)) {
                ret = -1;
                goto error;
        }
        if (lttng_strncpy(msg->names + channel_name_len, pathname, pathname_len)) {
                ret = -1;
                goto error;
        }

        msg->tracefile_size = htobe64(tracefile_size);
        msg->tracefile_count = htobe64(tracefile_count);
        msg->trace_chunk_id = htobe64(trace_archive_id);

        /* Send command */
        ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) msg, msg_length, 0);
        if (ret < 0) {
                goto error;
        }
        ret = 0;
error:
        free(msg);
        return ret;
}

/*
 * Add stream on the relayd and assign stream handle to the stream_id argument.
 *
 * Chunks are not supported by relayd prior to 2.11, but are used to
 * internally between session daemon and consumer daemon to keep track
 * of the channel and stream output path.
 *
 * On success return 0 else return ret_code negative value.
 */
int relayd_add_stream(struct lttcomm_relayd_sock *rsock, const char *channel_name,
                const char *domain_name, const char *_pathname, uint64_t *stream_id,
                uint64_t tracefile_size, uint64_t tracefile_count,
                struct lttng_trace_chunk *trace_chunk)
{
        int ret;
        struct lttcomm_relayd_status_stream reply;
        char pathname[RELAYD_COMM_LTTNG_PATH_MAX];
        char *separator;

        /* Code flow error. Safety net. */
        assert(rsock);
        assert(channel_name);
        assert(domain_name);
        assert(_pathname);
        assert(trace_chunk);

        DBG("Relayd adding stream for channel name %s", channel_name);

        if (_pathname[0] == '\0') {
                separator = "";
        } else {
                separator = "/";
        }
        ret = snprintf(pathname, RELAYD_COMM_LTTNG_PATH_MAX, "%s%s%s",
                        domain_name, separator, _pathname);
        if (ret <= 0 || ret >= RELAYD_COMM_LTTNG_PATH_MAX) {
                ERR("stream path too long.");
                ret = -1;
                goto error;
        }

        /* Compat with relayd 2.1 */
        if (rsock->minor == 1) {
                /* For 2.1 */
                ret = relayd_add_stream_2_1(rsock, channel_name, pathname);
        
        } else if (rsock->minor > 1 && rsock->minor < 11) {
                /* From 2.2 to 2.10 */
                ret = relayd_add_stream_2_2(rsock, channel_name, pathname,
                                tracefile_size, tracefile_count);
        } else {
                enum lttng_trace_chunk_status chunk_status;
                uint64_t chunk_id;

                chunk_status = lttng_trace_chunk_get_id(trace_chunk,
                                &chunk_id);
                assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);

                /* From 2.11 to ...*/
                ret = relayd_add_stream_2_11(rsock, channel_name, pathname,
                                tracefile_size, tracefile_count,
                                chunk_id);
        }

        if (ret) {
                ret = -1;
                goto error;
        }

        /* Waiting for reply */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        /* Back to host bytes order. */
        reply.handle = be64toh(reply.handle);
        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd add stream replied error %d", reply.ret_code);
        } else {
                /* Success */
                ret = 0;
                *stream_id = reply.handle;
        }

        DBG("Relayd stream added successfully with handle %" PRIu64,
                        reply.handle);

error:
        return ret;
}

/*
 * Inform the relay that all the streams for the current channel has been sent.
 *
 * On success return 0 else return ret_code negative value.
 */
int relayd_streams_sent(struct lttcomm_relayd_sock *rsock)
{
        int ret;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd sending streams sent.");

        /* This feature was introduced in 2.4, ignore it for earlier versions. */
        if (rsock->minor < 4) {
                ret = 0;
                goto end;
        }

        /* Send command */
        ret = send_command(rsock, RELAYD_STREAMS_SENT, NULL, 0, 0);
        if (ret < 0) {
                goto error;
        }

        /* Waiting for reply */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        /* Back to host bytes order. */
        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd streams sent replied error %d", reply.ret_code);
                goto error;
        } else {
                /* Success */
                ret = 0;
        }

        DBG("Relayd streams sent success");

error:
end:
        return ret;
}

/*
 * Check version numbers on the relayd.
 * If major versions are compatible, we assign minor_to_use to the
 * minor version of the procotol we are going to use for this session.
 *
 * Return 0 if the two daemons are compatible, LTTNG_ERR_RELAYD_VERSION_FAIL
 * otherwise, or a negative value on network errors.
 */
int relayd_version_check(struct lttcomm_relayd_sock *rsock)
{
        int ret;
        struct lttcomm_relayd_version msg;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd version check for major.minor %u.%u", rsock->major,
                        rsock->minor);

        memset(&msg, 0, sizeof(msg));
        /* Prepare network byte order before transmission. */
        msg.major = htobe32(rsock->major);
        msg.minor = htobe32(rsock->minor);

        /* Send command */
        ret = send_command(rsock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &msg, sizeof(msg));
        if (ret < 0) {
                goto error;
        }

        /* Set back to host bytes order */
        msg.major = be32toh(msg.major);
        msg.minor = be32toh(msg.minor);

        /*
         * Only validate the major version. If the other side is higher,
         * communication is not possible. Only major version equal can talk to each
         * other. If the minor version differs, the lowest version is used by both
         * sides.
         */
        if (msg.major != rsock->major) {
                /* Not compatible */
                ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
                DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
                                msg.major, rsock->major);
                goto error;
        }

        /*
         * If the relayd's minor version is higher, it will adapt to our version so
         * we can continue to use the latest relayd communication data structure.
         * If the received minor version is higher, the relayd should adapt to us.
         */
        if (rsock->minor > msg.minor) {
                rsock->minor = msg.minor;
        }

        /* Version number compatible */
        DBG2("Relayd version is compatible, using protocol version %u.%u",
                        rsock->major, rsock->minor);
        ret = 0;

error:
        return ret;
}

/*
 * Add stream on the relayd and assign stream handle to the stream_id argument.
 *
 * On success return 0 else return ret_code negative value.
 */
int relayd_send_metadata(struct lttcomm_relayd_sock *rsock, size_t len)
{
        int ret;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd sending metadata of size %zu", len);

        /* Send command */
        ret = send_command(rsock, RELAYD_SEND_METADATA, NULL, len, 0);
        if (ret < 0) {
                goto error;
        }

        DBG2("Relayd metadata added successfully");

        /*
         * After that call, the metadata data MUST be sent to the relayd so the
         * receive size on the other end matches the len of the metadata packet
         * header. This is why we don't wait for a reply here.
         */

error:
        return ret;
}

/*
 * Connect to relay daemon with an allocated lttcomm_relayd_sock.
 */
int relayd_connect(struct lttcomm_relayd_sock *rsock)
{
        /* Code flow error. Safety net. */
        assert(rsock);

        if (!rsock->sock.ops) {
                /*
                 * Attempting a connect on a non-initialized socket.
                 */
                return -ECONNRESET;
        }

        DBG3("Relayd connect ...");

        return rsock->sock.ops->connect(&rsock->sock);
}

/*
 * Close relayd socket with an allocated lttcomm_relayd_sock.
 *
 * If no socket operations are found, simply return 0 meaning that everything
 * is fine. Without operations, the socket can not possibly be opened or used.
 * This is possible if the socket was allocated but not created. However, the
 * caller could simply use it to store a valid file descriptor for instance
 * passed over a Unix socket and call this to cleanup but still without a valid
 * ops pointer.
 *
 * Return the close returned value. On error, a negative value is usually
 * returned back from close(2).
 */
int relayd_close(struct lttcomm_relayd_sock *rsock)
{
        int ret;

        /* Code flow error. Safety net. */
        assert(rsock);

        /* An invalid fd is fine, return success. */
        if (rsock->sock.fd < 0) {
                ret = 0;
                goto end;
        }

        DBG3("Relayd closing socket %d", rsock->sock.fd);

        if (rsock->sock.ops) {
                ret = rsock->sock.ops->close(&rsock->sock);
        } else {
                /* Default call if no specific ops found. */
                ret = close(rsock->sock.fd);
                if (ret < 0) {
                        PERROR("relayd_close default close");
                }
        }
        rsock->sock.fd = -1;

end:
        return ret;
}

/*
 * Send data header structure to the relayd.
 */
int relayd_send_data_hdr(struct lttcomm_relayd_sock *rsock,
                struct lttcomm_relayd_data_hdr *hdr, size_t size)
{
        int ret;

        /* Code flow error. Safety net. */
        assert(rsock);
        assert(hdr);

        if (rsock->sock.fd < 0) {
                return -ECONNRESET;
        }

        DBG3("Relayd sending data header of size %zu", size);

        /* Again, safety net */
        if (size == 0) {
                size = sizeof(struct lttcomm_relayd_data_hdr);
        }

        /* Only send data header. */
        ret = rsock->sock.ops->sendmsg(&rsock->sock, hdr, size, 0);
        if (ret < 0) {
                ret = -errno;
                goto error;
        }

        /*
         * The data MUST be sent right after that command for the receive on the
         * other end to match the size in the header.
         */

error:
        return ret;
}

/*
 * Send close stream command to the relayd.
 */
int relayd_send_close_stream(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
                uint64_t last_net_seq_num)
{
        int ret;
        struct lttcomm_relayd_close_stream msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd closing stream id %" PRIu64, stream_id);

        memset(&msg, 0, sizeof(msg));
        msg.stream_id = htobe64(stream_id);
        msg.last_net_seq_num = htobe64(last_net_seq_num);

        /* Send command */
        ret = send_command(rsock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd close stream replied error %d", reply.ret_code);
        } else {
                /* Success */
                ret = 0;
        }

        DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);

error:
        return ret;
}

/*
 * Check for data availability for a given stream id.
 *
 * Return 0 if NOT pending, 1 if so and a negative value on error.
 */
int relayd_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
                uint64_t last_net_seq_num)
{
        int ret;
        struct lttcomm_relayd_data_pending msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd data pending for stream id %" PRIu64, stream_id);

        memset(&msg, 0, sizeof(msg));
        msg.stream_id = htobe64(stream_id);
        msg.last_net_seq_num = htobe64(last_net_seq_num);

        /* Send command */
        ret = send_command(rsock, RELAYD_DATA_PENDING, (void *) &msg,
                        sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code >= LTTNG_OK) {
                ERR("Relayd data pending replied error %d", reply.ret_code);
        }

        /* At this point, the ret code is either 1 or 0 */
        ret = reply.ret_code;

        DBG("Relayd data is %s pending for stream id %" PRIu64,
                        ret == 1 ? "" : "NOT", stream_id);

error:
        return ret;
}

/*
 * Check on the relayd side for a quiescent state on the control socket.
 */
int relayd_quiescent_control(struct lttcomm_relayd_sock *rsock,
                uint64_t metadata_stream_id)
{
        int ret;
        struct lttcomm_relayd_quiescent_control msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd checking quiescent control state");

        memset(&msg, 0, sizeof(msg));
        msg.stream_id = htobe64(metadata_stream_id);

        /* Send command */
        ret = send_command(rsock, RELAYD_QUIESCENT_CONTROL, &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd quiescent control replied error %d", reply.ret_code);
                goto error;
        }

        /* Control socket is quiescent */
        return 0;

error:
        return ret;
}

/*
 * Begin a data pending command for a specific session id.
 */
int relayd_begin_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id)
{
        int ret;
        struct lttcomm_relayd_begin_data_pending msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd begin data pending");

        memset(&msg, 0, sizeof(msg));
        msg.session_id = htobe64(id);

        /* Send command */
        ret = send_command(rsock, RELAYD_BEGIN_DATA_PENDING, &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd begin data pending replied error %d", reply.ret_code);
                goto error;
        }

        return 0;

error:
        return ret;
}

/*
 * End a data pending command for a specific session id.
 *
 * Return 0 on success and set is_data_inflight to 0 if no data is being
 * streamed or 1 if it is the case.
 */
int relayd_end_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id,
                unsigned int *is_data_inflight)
{
        int ret, recv_ret;
        struct lttcomm_relayd_end_data_pending msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        DBG("Relayd end data pending");

        memset(&msg, 0, sizeof(msg));
        msg.session_id = htobe64(id);

        /* Send command */
        ret = send_command(rsock, RELAYD_END_DATA_PENDING, &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        recv_ret = be32toh(reply.ret_code);
        if (recv_ret < 0) {
                ret = recv_ret;
                goto error;
        }

        *is_data_inflight = recv_ret;

        DBG("Relayd end data pending is data inflight: %d", recv_ret);

        return 0;

error:
        return ret;
}

/*
 * Send index to the relayd.
 */
int relayd_send_index(struct lttcomm_relayd_sock *rsock,
                struct ctf_packet_index *index, uint64_t relay_stream_id,
                uint64_t net_seq_num)
{
        int ret;
        struct lttcomm_relayd_index msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        if (rsock->minor < 4) {
                DBG("Not sending indexes before protocol 2.4");
                ret = 0;
                goto error;
        }

        DBG("Relayd sending index for stream ID %" PRIu64, relay_stream_id);

        memset(&msg, 0, sizeof(msg));
        msg.relay_stream_id = htobe64(relay_stream_id);
        msg.net_seq_num = htobe64(net_seq_num);

        /* The index is already in big endian. */
        msg.packet_size = index->packet_size;
        msg.content_size = index->content_size;
        msg.timestamp_begin = index->timestamp_begin;
        msg.timestamp_end = index->timestamp_end;
        msg.events_discarded = index->events_discarded;
        msg.stream_id = index->stream_id;

        if (rsock->minor >= 8) {
                msg.stream_instance_id = index->stream_instance_id;
                msg.packet_seq_num = index->packet_seq_num;
        }

        /* Send command */
        ret = send_command(rsock, RELAYD_SEND_INDEX, &msg,
                lttcomm_relayd_index_len(lttng_to_index_major(rsock->major,
                                                                rsock->minor),
                                lttng_to_index_minor(rsock->major, rsock->minor)),
                                0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd send index replied error %d", reply.ret_code);
        } else {
                /* Success */
                ret = 0;
        }

error:
        return ret;
}

/*
 * Ask the relay to reset the metadata trace file (regeneration).
 */
int relayd_reset_metadata(struct lttcomm_relayd_sock *rsock,
                uint64_t stream_id, uint64_t version)
{
        int ret;
        struct lttcomm_relayd_reset_metadata msg;
        struct lttcomm_relayd_generic_reply reply;

        /* Code flow error. Safety net. */
        assert(rsock);

        /* Should have been prevented by the sessiond. */
        if (rsock->minor < 8) {
                ERR("Metadata regeneration unsupported before 2.8");
                ret = -1;
                goto error;
        }

        DBG("Relayd reset metadata stream id %" PRIu64, stream_id);

        memset(&msg, 0, sizeof(msg));
        msg.stream_id = htobe64(stream_id);
        msg.version = htobe64(version);

        /* Send command */
        ret = send_command(rsock, RELAYD_RESET_METADATA, (void *) &msg, sizeof(msg), 0);
        if (ret < 0) {
                goto error;
        }

        /* Receive response */
        ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
        if (ret < 0) {
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);

        /* Return session id or negative ret code. */
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd reset metadata replied error %d", reply.ret_code);
        } else {
                /* Success */
                ret = 0;
        }

        DBG("Relayd reset metadata stream id %" PRIu64 " successfully", stream_id);

error:
        return ret;
}

int relayd_rotate_streams(struct lttcomm_relayd_sock *sock,
                unsigned int stream_count, const uint64_t *new_chunk_id,
                const struct relayd_stream_rotation_position *positions)
{
        int ret;
        unsigned int i;
        struct lttng_dynamic_buffer payload;
        struct lttcomm_relayd_generic_reply reply = {};
        const struct lttcomm_relayd_rotate_streams msg = {
                .stream_count = htobe32((uint32_t) stream_count),
                .new_chunk_id = (typeof(msg.new_chunk_id)) {
                        .is_set = !!new_chunk_id,
                        .value = htobe64(new_chunk_id ? *new_chunk_id : 0),
                },
        };
        char new_chunk_id_buf[MAX_INT_DEC_LEN(*new_chunk_id)] = {};
        const char *new_chunk_id_str;

        if (!relayd_supports_chunks(sock)) {
                DBG("Refusing to rotate remote streams: relayd does not support chunks");
                return 0;
        }

        lttng_dynamic_buffer_init(&payload);

        /* Code flow error. Safety net. */
        assert(sock);

        if (new_chunk_id) {
                ret = snprintf(new_chunk_id_buf, sizeof(new_chunk_id_buf),
                                "%" PRIu64, *new_chunk_id);
                if (ret == -1 || ret >= sizeof(new_chunk_id_buf)) {
                        new_chunk_id_str = "formatting error";
                } else {
                        new_chunk_id_str = new_chunk_id_buf;
                }
        } else {
                new_chunk_id_str = "none";
        }

        DBG("Preparing \"rotate streams\" command payload: new_chunk_id = %s, stream_count = %u",
                        new_chunk_id_str, stream_count);

        ret = lttng_dynamic_buffer_append(&payload, &msg, sizeof(msg));
        if (ret) {
                ERR("Failed to allocate \"rotate streams\" command payload");
                goto error;
        }

        for (i = 0; i < stream_count; i++) {
                const struct relayd_stream_rotation_position *position =
                                &positions[i];
                const struct lttcomm_relayd_stream_rotation_position comm_position = {
                        .stream_id = htobe64(position->stream_id),
                        .rotate_at_seq_num = htobe64(
                                        position->rotate_at_seq_num),
                };

                DBG("Rotate stream %" PRIu64 "at sequence number %" PRIu64,
                                position->stream_id,
                                position->rotate_at_seq_num);
                ret = lttng_dynamic_buffer_append(&payload, &comm_position,
                                sizeof(comm_position));
                if (ret) {
                        ERR("Failed to allocate \"rotate streams\" command payload");
                        goto error;
                }
        }

        /* Send command. */
        ret = send_command(sock, RELAYD_ROTATE_STREAMS, payload.data,
                        payload.size, 0);
        if (ret < 0) {
                ERR("Failed to send \"rotate stream\" command");
                goto error;
        }

        /* Receive response. */
        ret = recv_reply(sock, &reply, sizeof(reply));
        if (ret < 0) {
                ERR("Failed to receive \"rotate streams\" command reply");
                goto error;
        }

        reply.ret_code = be32toh(reply.ret_code);
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd rotate streams replied error %d", reply.ret_code);
        } else {
                /* Success. */
                ret = 0;
                DBG("Relayd rotated streams successfully");
        }

error:
        lttng_dynamic_buffer_reset(&payload);
        return ret;
}

int relayd_create_trace_chunk(struct lttcomm_relayd_sock *sock,
                struct lttng_trace_chunk *chunk)
{
        int ret = 0;
        enum lttng_trace_chunk_status status;
        struct lttcomm_relayd_create_trace_chunk msg = {};
        struct lttcomm_relayd_generic_reply reply = {};
        struct lttng_dynamic_buffer payload;
        uint64_t chunk_id;
        time_t creation_timestamp;
        const char *chunk_name;
        size_t chunk_name_length;
        bool overridden_name;

        lttng_dynamic_buffer_init(&payload);

        if (!relayd_supports_chunks(sock)) {
                DBG("Refusing to create remote trace chunk: relayd does not support chunks");
                goto end;
        }

        status = lttng_trace_chunk_get_id(chunk, &chunk_id);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                ret = -1;
                goto end;
        }

        status = lttng_trace_chunk_get_creation_timestamp(
                        chunk, &creation_timestamp);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                ret = -1;
                goto end;
        }

        status = lttng_trace_chunk_get_name(
                        chunk, &chunk_name, &overridden_name);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK &&
                        status != LTTNG_TRACE_CHUNK_STATUS_NONE) {
                ret = -1;
                goto end;
        }

        chunk_name_length = overridden_name ? (strlen(chunk_name) + 1) : 0;
        msg = (typeof(msg)){
                .chunk_id = htobe64(chunk_id),
                .creation_timestamp = htobe64((uint64_t) creation_timestamp),
                .override_name_length = htobe32((uint32_t) chunk_name_length),
        };

        ret = lttng_dynamic_buffer_append(&payload, &msg, sizeof(msg));
        if (ret) {
                goto end;
        }
        if (chunk_name_length) {
                ret = lttng_dynamic_buffer_append(
                                &payload, chunk_name, chunk_name_length);
                if (ret) {
                        goto end;
                }
        }

        ret = send_command(sock, RELAYD_CREATE_TRACE_CHUNK, payload.data,
                        payload.size, 0);
        if (ret < 0) {
                ERR("Failed to send trace chunk creation command to relay daemon");
                goto end;
        }

        ret = recv_reply(sock, &reply, sizeof(reply));
        if (ret < 0) {
                ERR("Failed to receive relay daemon trace chunk creation command reply");
                goto end;
        }

        reply.ret_code = be32toh(reply.ret_code);
        if (reply.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd trace chunk create replied error %d",
                                reply.ret_code);
        } else {
                ret = 0;
                DBG("Relayd successfully created trace chunk: chunk_id = %" PRIu64,
                                chunk_id);
        }

end:
        lttng_dynamic_buffer_reset(&payload);
        return ret;
}

int relayd_close_trace_chunk(struct lttcomm_relayd_sock *sock,
                struct lttng_trace_chunk *chunk,
                char *path)
{
        int ret = 0;
        enum lttng_trace_chunk_status status;
        struct lttcomm_relayd_close_trace_chunk msg = {};
        struct lttcomm_relayd_close_trace_chunk_reply reply = {};
        uint64_t chunk_id;
        time_t close_timestamp;
        LTTNG_OPTIONAL(enum lttng_trace_chunk_command_type) close_command = {};

        if (!relayd_supports_chunks(sock)) {
                DBG("Refusing to close remote trace chunk: relayd does not support chunks");
                goto end;
        }

        status = lttng_trace_chunk_get_id(chunk, &chunk_id);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                ERR("Failed to get trace chunk id");
                ret = -1;
                goto end;
        }

        status = lttng_trace_chunk_get_close_timestamp(chunk, &close_timestamp);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                ERR("Failed to get trace chunk close timestamp");
                ret = -1;
                goto end;
        }

        status = lttng_trace_chunk_get_close_command(chunk,
                        &close_command.value);
        switch (status) {
        case LTTNG_TRACE_CHUNK_STATUS_OK:
                close_command.is_set = 1;
                break;
        case LTTNG_TRACE_CHUNK_STATUS_NONE:
                break;
        default:
                ERR("Failed to get trace chunk close command");
                ret = -1;
                goto end;
        }

        msg = (typeof(msg)){
                .chunk_id = htobe64(chunk_id),
                .close_timestamp = htobe64((uint64_t) close_timestamp),
                .close_command = {
                        .value = htobe32((uint32_t) close_command.value),
                        .is_set = close_command.is_set,
                },
        };

        ret = send_command(sock, RELAYD_CLOSE_TRACE_CHUNK, &msg, sizeof(msg),
                        0);
        if (ret < 0) {
                ERR("Failed to send trace chunk close command to relay daemon");
                goto end;
        }

        ret = recv_reply(sock, &reply, sizeof(reply));
        if (ret < 0) {
                ERR("Failed to receive relay daemon trace chunk close command reply");
                goto end;
        }

        reply.path_length = be32toh(reply.path_length);
        if (reply.path_length >= LTTNG_PATH_MAX) {
                ERR("Chunk path too long");
                ret = -1;
                goto end;
        }

        ret = recv_reply(sock, path, reply.path_length);
        if (ret < 0) {
                ERR("Failed to receive relay daemon trace chunk close command reply");
                goto end;
        }
        if (path[reply.path_length - 1] != '\0') {
                ERR("Invalid trace chunk path returned by relay daemon (not null-terminated)");
                ret = -1;
                goto end;
        }

        reply.generic.ret_code = be32toh(reply.generic.ret_code);
        if (reply.generic.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd trace chunk close replied error %d",
                                reply.generic.ret_code);
        } else {
                ret = 0;
                DBG("Relayd successfully closed trace chunk: chunk_id = %" PRIu64,
                                chunk_id);
        }
end:
        return ret;
}

int relayd_trace_chunk_exists(struct lttcomm_relayd_sock *sock,
                uint64_t chunk_id, bool *chunk_exists)
{
        int ret = 0;
        struct lttcomm_relayd_trace_chunk_exists msg = {};
        struct lttcomm_relayd_trace_chunk_exists_reply reply = {};

        if (!relayd_supports_chunks(sock)) {
                DBG("Refusing to check for trace chunk existence: relayd does not support chunks");
                /* The chunk will never exist */
                *chunk_exists = false;
                goto end;
        }

        msg = (typeof(msg)){
                        .chunk_id = htobe64(chunk_id),
        };

        ret = send_command(sock, RELAYD_TRACE_CHUNK_EXISTS, &msg, sizeof(msg),
                        0);
        if (ret < 0) {
                ERR("Failed to send trace chunk exists command to relay daemon");
                goto end;
        }

        ret = recv_reply(sock, &reply, sizeof(reply));
        if (ret < 0) {
                ERR("Failed to receive relay daemon trace chunk close command reply");
                goto end;
        }

        reply.generic.ret_code = be32toh(reply.generic.ret_code);
        if (reply.generic.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd trace chunk close replied error %d",
                                reply.generic.ret_code);
        } else {
                ret = 0;
                DBG("Relayd successfully checked trace chunk existence: chunk_id = %" PRIu64
                                ", exists = %s", chunk_id,
                                reply.trace_chunk_exists ? "true" : "false");
                *chunk_exists = !!reply.trace_chunk_exists;
        }
end:
        return ret;
}

int relayd_get_configuration(struct lttcomm_relayd_sock *sock,
                uint64_t query_flags,
                uint64_t *result_flags)
{
        int ret = 0;
        struct lttcomm_relayd_get_configuration msg = (typeof(msg)) {
                .query_flags = htobe64(query_flags),
        };
        struct lttcomm_relayd_get_configuration_reply reply = {};

        if (!relayd_supports_get_configuration(sock)) {
                DBG("Refusing to get relayd configuration (unsupported by relayd)");
                if (query_flags) {
                        ret = -1;
                        goto end;
                }
                *result_flags = 0;
                goto end;
        }

        ret = send_command(sock, RELAYD_GET_CONFIGURATION, &msg, sizeof(msg),
                        0);
        if (ret < 0) {
                ERR("Failed to send get configuration command to relay daemon");
                goto end;
        }

        ret = recv_reply(sock, &reply, sizeof(reply));
        if (ret < 0) {
                ERR("Failed to receive relay daemon get configuration command reply");
                goto end;
        }

        reply.generic.ret_code = be32toh(reply.generic.ret_code);
        if (reply.generic.ret_code != LTTNG_OK) {
                ret = -1;
                ERR("Relayd get configuration replied error %d",
                                reply.generic.ret_code);
        } else {
                reply.relayd_configuration_flags =
                        be64toh(reply.relayd_configuration_flags);
                ret = 0;
                DBG("Relayd successfully got configuration: query_flags = %" PRIu64
                                ", results_flags = %" PRIu64, query_flags,
                                reply.relayd_configuration_flags);
                *result_flags = reply.relayd_configuration_flags;
        }
end:
        return ret;
}