X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fclient.c;h=d83bee8e66441c8f6b9ddb08f8821ef83a468191;hp=ae027d5e0d35a1b7bddb4b391d6feeb12aceb27a;hb=bae46a81520110e52c5af423ce712b9099fe23dd;hpb=55c9e7cac24318259d4f2549c97f7577b7b52db4

diff --git a/src/bin/lttng-sessiond/client.c b/src/bin/lttng-sessiond/client.c
index ae027d5e0..d83bee8e6 100644
--- a/src/bin/lttng-sessiond/client.c
+++ b/src/bin/lttng-sessiond/client.c
@@ -1,33 +1,37 @@
 /*
- * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
- *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *               2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@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.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * 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.
  */
 
-#include <stddef.h>
-#include <pthread.h>
-#include <signal.h>
-#include <sys/stat.h>
+#include "common/buffer-view.h"
+#include "common/compat/socket.h"
+#include "common/dynamic-buffer.h"
+#include "common/dynamic-array.h"
+#include "common/payload.h"
+#include "common/payload-view.h"
+#include "common/fd-handle.h"
+#include "common/sessiond-comm/sessiond-comm.h"
+#include "common/payload.h"
+#include "common/payload-view.h"
+#include "lttng/lttng-error.h"
+#include "lttng/tracker.h"
 #include <common/compat/getenv.h>
+#include <common/tracker.h>
 #include <common/unix.h>
 #include <common/utils.h>
-#include <lttng/userspace-probe-internal.h>
 #include <lttng/event-internal.h>
-#include <lttng/session-internal.h>
 #include <lttng/session-descriptor-internal.h>
+#include <lttng/session-internal.h>
+#include <lttng/userspace-probe-internal.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stddef.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #include "client.h"
 #include "lttng-sessiond.h"
@@ -39,6 +43,7 @@
 #include "utils.h"
 #include "manage-consumer.h"
 #include "clear.h"
+#include "agent-thread.h"
 
 static bool is_root;
 
@@ -81,42 +86,99 @@ static int setup_lttng_msg(struct command_ctx *cmd_ctx,
 {
 	int ret = 0;
 	const size_t header_len = sizeof(struct lttcomm_lttng_msg);
-	const size_t cmd_header_offset = header_len;
-	const size_t payload_offset = cmd_header_offset + cmd_header_len;
 	const size_t total_msg_size = header_len + cmd_header_len + payload_len;
-
-	free(cmd_ctx->llm);
-	cmd_ctx->llm = zmalloc(total_msg_size);
-
-	if (cmd_ctx->llm == NULL) {
-		PERROR("zmalloc");
-		ret = -ENOMEM;
+	const struct lttcomm_lttng_msg llm = {
+		.cmd_type = cmd_ctx->lsm.cmd_type,
+		.pid = cmd_ctx->lsm.domain.attr.pid,
+		.cmd_header_size = cmd_header_len,
+		.data_size = payload_len,
+	};
+
+	ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
+	if (ret) {
 		goto end;
 	}
 
-	/* Copy common data */
-	cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
-	cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
-	cmd_ctx->llm->cmd_header_size = cmd_header_len;
-	cmd_ctx->llm->data_size = payload_len;
+	lttng_dynamic_pointer_array_clear(&cmd_ctx->reply_payload._fd_handles);
+
 	cmd_ctx->lttng_msg_size = total_msg_size;
 
-	/* Copy command header */
+	/* Append reply header. */
+	ret = lttng_dynamic_buffer_append(
+			&cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
+	if (ret) {
+		goto end;
+	}
+
+	/* Append command header. */
 	if (cmd_header_len) {
-		memcpy(((uint8_t *) cmd_ctx->llm) + cmd_header_offset, cmd_header_buf,
-			cmd_header_len);
+		ret = lttng_dynamic_buffer_append(
+				&cmd_ctx->reply_payload.buffer, cmd_header_buf,
+				cmd_header_len);
+		if (ret) {
+			goto end;
+		}
 	}
 
-	/* Copy payload */
+	/* Append payload. */
 	if (payload_len) {
-		memcpy(((uint8_t *) cmd_ctx->llm) + payload_offset, payload_buf,
-			payload_len);
+		ret = lttng_dynamic_buffer_append(
+				&cmd_ctx->reply_payload.buffer, payload_buf,
+				payload_len);
+		if (ret) {
+			goto end;
+		}
 	}
 
 end:
 	return ret;
 }
 
+static int setup_empty_lttng_msg(struct command_ctx *cmd_ctx)
+{
+	int ret;
+	const struct lttcomm_lttng_msg llm = {};
+
+	ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
+	if (ret) {
+		goto end;
+	}
+
+	/* Append place-holder reply header. */
+	ret = lttng_dynamic_buffer_append(
+			&cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
+	if (ret) {
+		goto end;
+	}
+
+	cmd_ctx->lttng_msg_size = sizeof(llm);
+end:
+	return ret;
+}
+
+static void update_lttng_msg(struct command_ctx *cmd_ctx, size_t cmd_header_len,
+		size_t payload_len)
+{
+	const size_t header_len = sizeof(struct lttcomm_lttng_msg);
+	const size_t total_msg_size = header_len + cmd_header_len + payload_len;
+	const struct lttcomm_lttng_msg llm = {
+		.cmd_type = cmd_ctx->lsm.cmd_type,
+		.pid = cmd_ctx->lsm.domain.attr.pid,
+		.cmd_header_size = cmd_header_len,
+		.data_size = payload_len,
+	};
+	struct lttcomm_lttng_msg *p_llm;
+
+	assert(cmd_ctx->reply_payload.buffer.size >= sizeof(llm));
+
+	p_llm = (typeof(p_llm)) cmd_ctx->reply_payload.buffer.data;
+
+	/* Update existing header. */
+	memcpy(p_llm, &llm, sizeof(llm));
+
+	cmd_ctx->lttng_msg_size = total_msg_size;
+}
+
 /*
  * Start the thread_manage_consumer. This must be done after a lttng-consumerd
  * exec or it will fail.
@@ -146,7 +208,7 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 		/*
 		 * Exec consumerd.
 		 */
-		if (config.verbose_consumer) {
+		if (the_config.verbose_consumer) {
 			verbosity = "--verbose";
 		} else if (lttng_opt_quiet) {
 			verbosity = "--quiet";
@@ -162,36 +224,38 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 			 * fallback on the 32-bit one,
 			 */
 			DBG3("Looking for a kernel consumer at these locations:");
-			DBG3("	1) %s", config.consumerd64_bin_path.value ? : "NULL");
+			DBG3("	1) %s", the_config.consumerd64_bin_path.value ? : "NULL");
 			DBG3("	2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
-			DBG3("	3) %s", config.consumerd32_bin_path.value ? : "NULL");
-			if (stat(config.consumerd64_bin_path.value, &st) == 0) {
+			DBG3("	3) %s", the_config.consumerd32_bin_path.value ? : "NULL");
+			if (stat(the_config.consumerd64_bin_path.value, &st) == 0) {
 				DBG3("Found location #1");
-				consumer_to_use = config.consumerd64_bin_path.value;
+				consumer_to_use = the_config.consumerd64_bin_path.value;
 			} else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
 				DBG3("Found location #2");
 				consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
-			} else if (config.consumerd32_bin_path.value &&
-					stat(config.consumerd32_bin_path.value, &st) == 0) {
+			} else if (the_config.consumerd32_bin_path.value &&
+					stat(the_config.consumerd32_bin_path.value, &st) == 0) {
 				DBG3("Found location #3");
-				consumer_to_use = config.consumerd32_bin_path.value;
+				consumer_to_use = the_config.consumerd32_bin_path.value;
 			} else {
 				DBG("Could not find any valid consumerd executable");
 				ret = -EINVAL;
 				goto error;
 			}
 			DBG("Using kernel consumer at: %s",  consumer_to_use);
-			(void) execl(consumer_to_use,
-				"lttng-consumerd", verbosity, "-k",
-				"--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-				"--consumerd-err-sock", consumer_data->err_unix_sock_path,
-				"--group", config.tracing_group_name.value,
-				NULL);
+			(void) execl(consumer_to_use, "lttng-consumerd",
+					verbosity, "-k", "--consumerd-cmd-sock",
+					consumer_data->cmd_unix_sock_path,
+					"--consumerd-err-sock",
+					consumer_data->err_unix_sock_path,
+					"--group",
+					the_config.tracing_group_name.value,
+					NULL);
 			break;
 		case LTTNG_CONSUMER64_UST:
 		{
-			if (config.consumerd64_lib_dir.value) {
-				char *tmp;
+			if (the_config.consumerd64_lib_dir.value) {
+				const char *tmp;
 				size_t tmplen;
 				char *tmpnew;
 
@@ -199,13 +263,13 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 				if (!tmp) {
 					tmp = "";
 				}
-				tmplen = strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
+				tmplen = strlen(the_config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
 				tmpnew = zmalloc(tmplen + 1 /* \0 */);
 				if (!tmpnew) {
 					ret = -ENOMEM;
 					goto error;
 				}
-				strcat(tmpnew, config.consumerd64_lib_dir.value);
+				strcat(tmpnew, the_config.consumerd64_lib_dir.value);
 				if (tmp[0] != '\0') {
 					strcat(tmpnew, ":");
 					strcat(tmpnew, tmp);
@@ -217,18 +281,23 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 					goto error;
 				}
 			}
-			DBG("Using 64-bit UST consumer at: %s",  config.consumerd64_bin_path.value);
-			(void) execl(config.consumerd64_bin_path.value, "lttng-consumerd", verbosity, "-u",
-					"--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-					"--consumerd-err-sock", consumer_data->err_unix_sock_path,
-					"--group", config.tracing_group_name.value,
+			DBG("Using 64-bit UST consumer at: %s",
+					the_config.consumerd64_bin_path.value);
+			(void) execl(the_config.consumerd64_bin_path.value,
+					"lttng-consumerd", verbosity, "-u",
+					"--consumerd-cmd-sock",
+					consumer_data->cmd_unix_sock_path,
+					"--consumerd-err-sock",
+					consumer_data->err_unix_sock_path,
+					"--group",
+					the_config.tracing_group_name.value,
 					NULL);
 			break;
 		}
 		case LTTNG_CONSUMER32_UST:
 		{
-			if (config.consumerd32_lib_dir.value) {
-				char *tmp;
+			if (the_config.consumerd32_lib_dir.value) {
+				const char *tmp;
 				size_t tmplen;
 				char *tmpnew;
 
@@ -236,13 +305,13 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 				if (!tmp) {
 					tmp = "";
 				}
-				tmplen = strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
+				tmplen = strlen(the_config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
 				tmpnew = zmalloc(tmplen + 1 /* \0 */);
 				if (!tmpnew) {
 					ret = -ENOMEM;
 					goto error;
 				}
-				strcat(tmpnew, config.consumerd32_lib_dir.value);
+				strcat(tmpnew, the_config.consumerd32_lib_dir.value);
 				if (tmp[0] != '\0') {
 					strcat(tmpnew, ":");
 					strcat(tmpnew, tmp);
@@ -254,11 +323,16 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 					goto error;
 				}
 			}
-			DBG("Using 32-bit UST consumer at: %s",  config.consumerd32_bin_path.value);
-			(void) execl(config.consumerd32_bin_path.value, "lttng-consumerd", verbosity, "-u",
-					"--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-					"--consumerd-err-sock", consumer_data->err_unix_sock_path,
-					"--group", config.tracing_group_name.value,
+			DBG("Using 32-bit UST consumer at: %s",
+					the_config.consumerd32_bin_path.value);
+			(void) execl(the_config.consumerd32_bin_path.value,
+					"lttng-consumerd", verbosity, "-u",
+					"--consumerd-cmd-sock",
+					consumer_data->cmd_unix_sock_path,
+					"--consumerd-err-sock",
+					consumer_data->err_unix_sock_path,
+					"--group",
+					the_config.tracing_group_name.value,
 					NULL);
 			break;
 		}
@@ -499,6 +573,7 @@ static int create_kernel_session(struct ltt_session *session)
 	session->kernel_session->gid = session->gid;
 	session->kernel_session->output_traces = session->output_traces;
 	session->kernel_session->snapshot_mode = session->snapshot_mode;
+	session->kernel_session->is_live_session = session->live_timer != 0;
 
 	return LTTNG_OK;
 
@@ -518,15 +593,14 @@ static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
 	struct ltt_session *session;
 	const struct ltt_session_list *session_list = session_get_list();
 
-	DBG("Counting number of available session for UID %d GID %d",
-			uid, gid);
+	DBG("Counting number of available session for UID %d", uid);
 	cds_list_for_each_entry(session, &session_list->head, list) {
 		if (!session_get(session)) {
 			continue;
 		}
 		session_lock(session);
 		/* Only count the sessions the user can control. */
-		if (session_access_ok(session, uid, gid) &&
+		if (session_access_ok(session, uid) &&
 				!session->destroyed) {
 			i++;
 		}
@@ -539,19 +613,19 @@ static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
 static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
 		int *sock_error, struct lttng_event *event)
 {
-	int fd, ret;
+	int fd = -1, ret;
 	struct lttng_userspace_probe_location *probe_location;
-	const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
-	struct lttng_dynamic_buffer probe_location_buffer;
-	struct lttng_buffer_view buffer_view;
+	struct lttng_payload probe_location_payload;
+	struct fd_handle *handle = NULL;
 
 	/*
-	 * Create a buffer to store the serialized version of the probe
+	 * Create a payload to store the serialized version of the probe
 	 * location.
 	 */
-	lttng_dynamic_buffer_init(&probe_location_buffer);
-	ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
-			cmd_ctx->lsm->u.enable.userspace_probe_location_len);
+	lttng_payload_init(&probe_location_payload);
+
+	ret = lttng_dynamic_buffer_set_size(&probe_location_payload.buffer,
+			cmd_ctx->lsm.u.enable.userspace_probe_location_len);
 	if (ret) {
 		ret = LTTNG_ERR_NOMEM;
 		goto error;
@@ -560,27 +634,11 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
 	/*
 	 * Receive the probe location.
 	 */
-	ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
-			probe_location_buffer.size);
+	ret = lttcomm_recv_unix_sock(sock, probe_location_payload.buffer.data,
+			probe_location_payload.buffer.size);
 	if (ret <= 0) {
 		DBG("Nothing recv() from client var len data... continuing");
 		*sock_error = 1;
-		lttng_dynamic_buffer_reset(&probe_location_buffer);
-		ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-		goto error;
-	}
-
-	buffer_view = lttng_buffer_view_from_dynamic_buffer(
-			&probe_location_buffer, 0, probe_location_buffer.size);
-
-	/*
-	 * Extract the probe location from the serialized version.
-	 */
-	ret = lttng_userspace_probe_location_create_from_buffer(
-				&buffer_view, &probe_location);
-	if (ret < 0) {
-		WARN("Failed to create a userspace probe location from the received buffer");
-		lttng_dynamic_buffer_reset( &probe_location_buffer);
 		ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 		goto error;
 	}
@@ -597,35 +655,35 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
 		goto error;
 	}
 
-	/*
-	 * Set the file descriptor received from the client through the unix
-	 * socket in the probe location.
-	 */
-	lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
-	if (!lookup) {
-		ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+	handle = fd_handle_create(fd);
+	if (!handle) {
+		ret = LTTNG_ERR_NOMEM;
 		goto error;
 	}
 
-	/*
-	 * From the kernel tracer's perspective, all userspace probe event types
-	 * are all the same: a file and an offset.
-	 */
-	switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
-	case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
-		ret = lttng_userspace_probe_location_function_set_binary_fd(
-				probe_location, fd);
-		break;
-	case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
-		ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
-				probe_location, fd);
-		break;
-	default:
-		ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+	/* Transferred to the handle. */
+	fd = -1;
+
+	ret = lttng_payload_push_fd_handle(&probe_location_payload, handle);
+	if (ret) {
+		ERR("Failed to add userspace probe file descriptor to payload");
+		ret = LTTNG_ERR_NOMEM;
 		goto error;
 	}
 
-	if (ret) {
+	fd_handle_put(handle);
+	handle = NULL;
+
+	{
+		struct lttng_payload_view view = lttng_payload_view_from_payload(
+			&probe_location_payload, 0, -1);
+
+		/* Extract the probe location from the serialized version. */
+		ret = lttng_userspace_probe_location_create_from_payload(
+				&view, &probe_location);
+	}
+	if (ret < 0) {
+		WARN("Failed to create a userspace probe location from the received buffer");
 		ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 		goto error;
 	}
@@ -637,11 +695,91 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
 		goto error;
 	}
 
-	lttng_dynamic_buffer_reset(&probe_location_buffer);
 error:
+	if (fd >= 0) {
+		if (close(fd)) {
+			PERROR("Failed to close userspace probe location binary fd");
+		}
+	}
+
+	fd_handle_put(handle);
+	lttng_payload_reset(&probe_location_payload);
 	return ret;
 }
 
+static enum lttng_error_code receive_lttng_trigger(struct command_ctx *cmd_ctx,
+		int sock,
+		int *sock_error,
+		struct lttng_trigger **_trigger)
+{
+	int ret;
+	size_t trigger_len;
+	ssize_t sock_recv_len;
+	enum lttng_error_code ret_code;
+	struct lttng_payload trigger_payload;
+	struct lttng_trigger *trigger = NULL;
+
+	lttng_payload_init(&trigger_payload);
+	trigger_len = (size_t) cmd_ctx->lsm.u.trigger.length;
+	ret = lttng_dynamic_buffer_set_size(
+			&trigger_payload.buffer, trigger_len);
+	if (ret) {
+		ret_code = LTTNG_ERR_NOMEM;
+		goto end;
+	}
+
+	sock_recv_len = lttcomm_recv_unix_sock(
+			sock, trigger_payload.buffer.data, trigger_len);
+	if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
+		ERR("Failed to receive trigger in command payload");
+		*sock_error = 1;
+		ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+		goto end;
+	}
+
+	/* Receive fds, if any. */
+	if (cmd_ctx->lsm.fd_count > 0) {
+		sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
+				sock, cmd_ctx->lsm.fd_count, &trigger_payload);
+		if (sock_recv_len > 0 &&
+				sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
+			ERR("Failed to receive all file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
+					cmd_ctx->lsm.fd_count, (int) ret);
+			ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+			*sock_error = 1;
+			goto end;
+		} else if (sock_recv_len <= 0) {
+			ERR("Failed to receive file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
+					cmd_ctx->lsm.fd_count, (int) ret);
+			ret_code = LTTNG_ERR_FATAL;
+			*sock_error = 1;
+			goto end;
+		}
+	}
+
+	/* Deserialize trigger. */
+	{
+		struct lttng_payload_view view =
+				lttng_payload_view_from_payload(
+						&trigger_payload, 0, -1);
+
+		if (lttng_trigger_create_from_payload(&view, &trigger) !=
+				trigger_len) {
+			ERR("Invalid trigger received as part of command payload");
+			ret_code = LTTNG_ERR_INVALID_TRIGGER;
+			lttng_trigger_put(trigger);
+			goto end;
+		}
+	}
+
+	*_trigger = trigger;
+	ret_code = LTTNG_OK;
+
+end:
+	lttng_payload_reset(&trigger_payload);
+	return ret_code;
+}
+
 /*
  * Version of setup_lttng_msg() without command header.
  */
@@ -651,24 +789,6 @@ static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
 	return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
 }
 
-/*
- * Free memory of a command context structure.
- */
-static void clean_command_ctx(struct command_ctx **cmd_ctx)
-{
-	DBG("Clean command context structure");
-	if (*cmd_ctx) {
-		if ((*cmd_ctx)->llm) {
-			free((*cmd_ctx)->llm);
-		}
-		if ((*cmd_ctx)->lsm) {
-			free((*cmd_ctx)->lsm);
-		}
-		free(*cmd_ctx);
-		*cmd_ctx = NULL;
-	}
-}
-
 /*
  * Check if the current kernel tracer supports the session rotation feature.
  * Return 1 if it does, 0 otherwise.
@@ -677,7 +797,8 @@ static int check_rotate_compatible(void)
 {
 	int ret = 1;
 
-	if (kernel_tracer_version.major != 2 || kernel_tracer_version.minor < 11) {
+	if (the_kernel_tracer_version.major != 2 ||
+			the_kernel_tracer_version.minor < 11) {
 		DBG("Kernel tracer version is not compatible with the rotation feature");
 		ret = 0;
 	}
@@ -690,14 +811,32 @@ static int check_rotate_compatible(void)
  *
  * Return lttcomm error code.
  */
-static int send_unix_sock(int sock, void *buf, size_t len)
+static int send_unix_sock(int sock, struct lttng_payload_view *view)
 {
+	int ret;
+	const int fd_count = lttng_payload_view_get_fd_handle_count(view);
+
 	/* Check valid length */
-	if (len == 0) {
-		return -1;
+	if (view->buffer.size == 0) {
+		ret = -1;
+		goto end;
 	}
 
-	return lttcomm_send_unix_sock(sock, buf, len);
+	ret = lttcomm_send_unix_sock(
+			sock, view->buffer.data, view->buffer.size);
+	if (ret < 0) {
+		goto end;
+	}
+
+	if (fd_count > 0) {
+		ret = lttcomm_send_payload_view_fds_unix_sock(sock, view);
+		if (ret < 0) {
+			goto end;
+		}
+	}
+
+end:
+	return ret;
 }
 
 /*
@@ -717,16 +856,19 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 		int *sock_error)
 {
 	int ret = LTTNG_OK;
-	int need_tracing_session = 1;
-	int need_domain;
+	bool need_tracing_session = true;
+	bool need_domain;
+	bool need_consumerd;
 
-	DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
+	DBG("Processing client command '%s\' (%d)",
+		lttcomm_sessiond_command_str(cmd_ctx->lsm.cmd_type),
+		cmd_ctx->lsm.cmd_type);
 
 	assert(!rcu_read_ongoing());
 
 	*sock_error = 0;
 
-	switch (cmd_ctx->lsm->cmd_type) {
+	switch (cmd_ctx->lsm.cmd_type) {
 	case LTTNG_CREATE_SESSION_EXT:
 	case LTTNG_DESTROY_SESSION:
 	case LTTNG_LIST_SESSIONS:
@@ -742,21 +884,31 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	case LTTNG_SET_SESSION_SHM_PATH:
 	case LTTNG_REGENERATE_METADATA:
 	case LTTNG_REGENERATE_STATEDUMP:
-	case LTTNG_REGISTER_TRIGGER:
-	case LTTNG_UNREGISTER_TRIGGER:
 	case LTTNG_ROTATE_SESSION:
 	case LTTNG_ROTATION_GET_INFO:
 	case LTTNG_ROTATION_SET_SCHEDULE:
 	case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
 	case LTTNG_CLEAR_SESSION:
-		need_domain = 0;
+	case LTTNG_LIST_TRIGGERS:
+		need_domain = false;
 		break;
 	default:
-		need_domain = 1;
+		need_domain = true;
 	}
 
-	if (config.no_kernel && need_domain
-			&& cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
+	/* Needs a functioning consumerd? */
+	switch (cmd_ctx->lsm.cmd_type) {
+	case LTTNG_REGISTER_TRIGGER:
+	case LTTNG_UNREGISTER_TRIGGER:
+		need_consumerd = false;
+		break;
+	default:
+		need_consumerd = true;
+		break;
+	}
+
+	if (the_config.no_kernel && need_domain &&
+			cmd_ctx->lsm.domain.type == LTTNG_DOMAIN_KERNEL) {
 		if (!is_root) {
 			ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
 		} else {
@@ -766,14 +918,14 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	}
 
 	/* Deny register consumer if we already have a spawned consumer. */
-	if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
-		pthread_mutex_lock(&kconsumer_data.pid_mutex);
-		if (kconsumer_data.pid > 0) {
+	if (cmd_ctx->lsm.cmd_type == LTTNG_REGISTER_CONSUMER) {
+		pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
+		if (the_kconsumer_data.pid > 0) {
 			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
-			pthread_mutex_unlock(&kconsumer_data.pid_mutex);
+			pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
 			goto error;
 		}
-		pthread_mutex_unlock(&kconsumer_data.pid_mutex);
+		pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
 	}
 
 	/*
@@ -781,7 +933,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	 * this here so we don't have to make the call for no payload at each
 	 * command.
 	 */
-	switch(cmd_ctx->lsm->cmd_type) {
+	switch(cmd_ctx->lsm.cmd_type) {
 	case LTTNG_LIST_SESSIONS:
 	case LTTNG_LIST_TRACEPOINTS:
 	case LTTNG_LIST_TRACEPOINT_FIELDS:
@@ -789,11 +941,14 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	case LTTNG_LIST_CHANNELS:
 	case LTTNG_LIST_EVENTS:
 	case LTTNG_LIST_SYSCALLS:
-	case LTTNG_LIST_TRACKER_IDS:
+	case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
+	case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
+	case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
 	case LTTNG_DATA_PENDING:
 	case LTTNG_ROTATE_SESSION:
 	case LTTNG_ROTATION_GET_INFO:
-	case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
+	case LTTNG_REGISTER_TRIGGER:
+	case LTTNG_LIST_TRIGGERS:
 		break;
 	default:
 		/* Setup lttng message with no payload */
@@ -805,7 +960,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	}
 
 	/* Commands that DO NOT need a session. */
-	switch (cmd_ctx->lsm->cmd_type) {
+	switch (cmd_ctx->lsm.cmd_type) {
 	case LTTNG_CREATE_SESSION_EXT:
 	case LTTNG_LIST_SESSIONS:
 	case LTTNG_LIST_TRACEPOINTS:
@@ -814,17 +969,18 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	case LTTNG_SAVE_SESSION:
 	case LTTNG_REGISTER_TRIGGER:
 	case LTTNG_UNREGISTER_TRIGGER:
-		need_tracing_session = 0;
+	case LTTNG_LIST_TRIGGERS:
+		need_tracing_session = false;
 		break;
 	default:
-		DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
+		DBG("Getting session %s by name", cmd_ctx->lsm.session.name);
 		/*
 		 * We keep the session list lock across _all_ commands
 		 * for now, because the per-session lock does not
 		 * handle teardown properly.
 		 */
 		session_lock_list();
-		cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
+		cmd_ctx->session = session_find_by_name(cmd_ctx->lsm.session.name);
 		if (cmd_ctx->session == NULL) {
 			ret = LTTNG_ERR_SESS_NOT_FOUND;
 			goto error;
@@ -841,10 +997,10 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	 * handled, process that right before so we save some round trip in useless
 	 * code path.
 	 */
-	switch (cmd_ctx->lsm->cmd_type) {
+	switch (cmd_ctx->lsm.cmd_type) {
 	case LTTNG_DISABLE_CHANNEL:
 	case LTTNG_DISABLE_EVENT:
-		switch (cmd_ctx->lsm->domain.type) {
+		switch (cmd_ctx->lsm.domain.type) {
 		case LTTNG_DOMAIN_KERNEL:
 			if (!cmd_ctx->session->kernel_session) {
 				ret = LTTNG_ERR_NO_CHANNEL;
@@ -875,7 +1031,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	/*
 	 * Check domain type for specific "pre-action".
 	 */
-	switch (cmd_ctx->lsm->domain.type) {
+	switch (cmd_ctx->lsm.domain.type) {
 	case LTTNG_DOMAIN_KERNEL:
 		if (!is_root) {
 			ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
@@ -892,7 +1048,8 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 		}
 
 		/* Consumer is in an ERROR state. Report back to client */
-		if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
+		if (need_consumerd && uatomic_read(&the_kernel_consumerd_state) ==
+						CONSUMER_ERROR) {
 			ret = LTTNG_ERR_NO_KERNCONSUMERD;
 			goto error;
 		}
@@ -908,25 +1065,25 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 			}
 
 			/* Start the kernel consumer daemon */
-			pthread_mutex_lock(&kconsumer_data.pid_mutex);
-			if (kconsumer_data.pid == 0 &&
-					cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-				pthread_mutex_unlock(&kconsumer_data.pid_mutex);
-				ret = start_consumerd(&kconsumer_data);
+			pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
+			if (the_kconsumer_data.pid == 0 &&
+					cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
+				pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
+				ret = start_consumerd(&the_kconsumer_data);
 				if (ret < 0) {
 					ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 					goto error;
 				}
-				uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
+				uatomic_set(&the_kernel_consumerd_state, CONSUMER_STARTED);
 			} else {
-				pthread_mutex_unlock(&kconsumer_data.pid_mutex);
+				pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
 			}
 
 			/*
 			 * The consumer was just spawned so we need to add the socket to
 			 * the consumer output of the session if exist.
 			 */
-			ret = consumer_create_socket(&kconsumer_data,
+			ret = consumer_create_socket(&the_kconsumer_data,
 					cmd_ctx->session->kernel_session->consumer);
 			if (ret < 0) {
 				goto error;
@@ -937,14 +1094,22 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 	case LTTNG_DOMAIN_JUL:
 	case LTTNG_DOMAIN_LOG4J:
 	case LTTNG_DOMAIN_PYTHON:
+		if (!agent_tracing_is_enabled()) {
+			ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
+			goto error;
+		}
+		/* Fallthrough */
 	case LTTNG_DOMAIN_UST:
 	{
 		if (!ust_app_supported()) {
 			ret = LTTNG_ERR_NO_UST;
 			goto error;
 		}
+
 		/* Consumer is in an ERROR state. Report back to client */
-		if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
+		if (need_consumerd &&
+				uatomic_read(&the_ust_consumerd_state) ==
+						CONSUMER_ERROR) {
 			ret = LTTNG_ERR_NO_USTCONSUMERD;
 			goto error;
 		}
@@ -953,7 +1118,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 			/* Create UST session if none exist. */
 			if (cmd_ctx->session->ust_session == NULL) {
 				ret = create_ust_session(cmd_ctx->session,
-						ALIGNED_CONST_PTR(cmd_ctx->lsm->domain));
+						ALIGNED_CONST_PTR(cmd_ctx->lsm.domain));
 				if (ret != LTTNG_OK) {
 					goto error;
 				}
@@ -961,58 +1126,58 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 
 			/* Start the UST consumer daemons */
 			/* 64-bit */
-			pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
-			if (config.consumerd64_bin_path.value &&
-					ustconsumer64_data.pid == 0 &&
-					cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-				pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
-				ret = start_consumerd(&ustconsumer64_data);
+			pthread_mutex_lock(&the_ustconsumer64_data.pid_mutex);
+			if (the_config.consumerd64_bin_path.value &&
+					the_ustconsumer64_data.pid == 0 &&
+					cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
+				pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
+				ret = start_consumerd(&the_ustconsumer64_data);
 				if (ret < 0) {
 					ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
-					uatomic_set(&ust_consumerd64_fd, -EINVAL);
+					uatomic_set(&the_ust_consumerd64_fd, -EINVAL);
 					goto error;
 				}
 
-				uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
-				uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
+				uatomic_set(&the_ust_consumerd64_fd, the_ustconsumer64_data.cmd_sock);
+				uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
 			} else {
-				pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
+				pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
 			}
 
 			/*
 			 * Setup socket for consumer 64 bit. No need for atomic access
 			 * since it was set above and can ONLY be set in this thread.
 			 */
-			ret = consumer_create_socket(&ustconsumer64_data,
+			ret = consumer_create_socket(&the_ustconsumer64_data,
 					cmd_ctx->session->ust_session->consumer);
 			if (ret < 0) {
 				goto error;
 			}
 
 			/* 32-bit */
-			pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
-			if (config.consumerd32_bin_path.value &&
-					ustconsumer32_data.pid == 0 &&
-					cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-				pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
-				ret = start_consumerd(&ustconsumer32_data);
+			pthread_mutex_lock(&the_ustconsumer32_data.pid_mutex);
+			if (the_config.consumerd32_bin_path.value &&
+					the_ustconsumer32_data.pid == 0 &&
+					cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
+				pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
+				ret = start_consumerd(&the_ustconsumer32_data);
 				if (ret < 0) {
 					ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
-					uatomic_set(&ust_consumerd32_fd, -EINVAL);
+					uatomic_set(&the_ust_consumerd32_fd, -EINVAL);
 					goto error;
 				}
 
-				uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
-				uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
+				uatomic_set(&the_ust_consumerd32_fd, the_ustconsumer32_data.cmd_sock);
+				uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
 			} else {
-				pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
+				pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
 			}
 
 			/*
 			 * Setup socket for consumer 32 bit. No need for atomic access
 			 * since it was set above and can ONLY be set in this thread.
 			 */
-			ret = consumer_create_socket(&ustconsumer32_data,
+			ret = consumer_create_socket(&the_ustconsumer32_data,
 					cmd_ctx->session->ust_session->consumer);
 			if (ret < 0) {
 				goto error;
@@ -1026,22 +1191,22 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
 skip_domain:
 
 	/* Validate consumer daemon state when start/stop trace command */
-	if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
-			cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
-		switch (cmd_ctx->lsm->domain.type) {
+	if (cmd_ctx->lsm.cmd_type == LTTNG_START_TRACE ||
+			cmd_ctx->lsm.cmd_type == LTTNG_STOP_TRACE) {
+		switch (cmd_ctx->lsm.domain.type) {
 		case LTTNG_DOMAIN_NONE:
 			break;
 		case LTTNG_DOMAIN_JUL:
 		case LTTNG_DOMAIN_LOG4J:
 		case LTTNG_DOMAIN_PYTHON:
 		case LTTNG_DOMAIN_UST:
-			if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
+			if (uatomic_read(&the_ust_consumerd_state) != CONSUMER_STARTED) {
 				ret = LTTNG_ERR_NO_USTCONSUMERD;
 				goto error;
 			}
 			break;
 		case LTTNG_DOMAIN_KERNEL:
-			if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
+			if (uatomic_read(&the_kernel_consumerd_state) != CONSUMER_STARTED) {
 				ret = LTTNG_ERR_NO_KERNCONSUMERD;
 				goto error;
 			}
@@ -1053,13 +1218,12 @@ skip_domain:
 	}
 
 	/*
-	 * Check that the UID or GID match that of the tracing session.
+	 * Check that the UID matches that of the tracing session.
 	 * The root user can interact with all sessions.
 	 */
 	if (need_tracing_session) {
 		if (!session_access_ok(cmd_ctx->session,
-				LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
-				LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds)) ||
+				LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds)) ||
 				cmd_ctx->session->destroyed) {
 			ret = LTTNG_ERR_EPERM;
 			goto error;
@@ -1082,20 +1246,20 @@ skip_domain:
 	}
 
 	/* Process by command type */
-	switch (cmd_ctx->lsm->cmd_type) {
+	switch (cmd_ctx->lsm.cmd_type) {
 	case LTTNG_ADD_CONTEXT:
 	{
 		/*
 		 * An LTTNG_ADD_CONTEXT command might have a supplementary
 		 * payload if the context being added is an application context.
 		 */
-		if (cmd_ctx->lsm->u.context.ctx.ctx ==
+		if (cmd_ctx->lsm.u.context.ctx.ctx ==
 				LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
 			char *provider_name = NULL, *context_name = NULL;
 			size_t provider_name_len =
-					cmd_ctx->lsm->u.context.provider_name_len;
+					cmd_ctx->lsm.u.context.provider_name_len;
 			size_t context_name_len =
-					cmd_ctx->lsm->u.context.context_name_len;
+					cmd_ctx->lsm.u.context.context_name_len;
 
 			if (provider_name_len == 0 || context_name_len == 0) {
 				/*
@@ -1111,7 +1275,7 @@ skip_domain:
 				ret = -LTTNG_ERR_NOMEM;
 				goto error;
 			}
-			cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name =
+			cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name =
 					provider_name;
 
 			context_name = zmalloc(context_name_len + 1);
@@ -1119,7 +1283,7 @@ skip_domain:
 				ret = -LTTNG_ERR_NOMEM;
 				goto error_add_context;
 			}
-			cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name =
+			cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name =
 					context_name;
 
 			ret = lttcomm_recv_unix_sock(*sock, provider_name,
@@ -1140,16 +1304,16 @@ skip_domain:
 		 * names.
 		 */
 		ret = cmd_add_context(cmd_ctx->session,
-				cmd_ctx->lsm->domain.type,
-				cmd_ctx->lsm->u.context.channel_name,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.context.ctx),
-				kernel_poll_pipe[1]);
+				cmd_ctx->lsm.domain.type,
+				cmd_ctx->lsm.u.context.channel_name,
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.context.ctx),
+				the_kernel_poll_pipe[1]);
 
-		cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name = NULL;
-		cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name = NULL;
+		cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name = NULL;
+		cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name = NULL;
 error_add_context:
-		free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name);
-		free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name);
+		free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name);
+		free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name);
 		if (ret < 0) {
 			goto error;
 		}
@@ -1157,8 +1321,8 @@ error_add_context:
 	}
 	case LTTNG_DISABLE_CHANNEL:
 	{
-		ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-				cmd_ctx->lsm->u.disable.channel_name);
+		ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm.domain.type,
+				cmd_ctx->lsm.u.disable.channel_name);
 		break;
 	}
 	case LTTNG_DISABLE_EVENT:
@@ -1173,8 +1337,8 @@ error_add_context:
 		 * the filter payload and encounter an error because the session
 		 * daemon closes the socket without ever handling this data.
 		 */
-		size_t count = cmd_ctx->lsm->u.disable.expression_len +
-			cmd_ctx->lsm->u.disable.bytecode_len;
+		size_t count = cmd_ctx->lsm.u.disable.expression_len +
+			cmd_ctx->lsm.u.disable.bytecode_len;
 
 		if (count) {
 			char data[LTTNG_FILTER_MAX_LEN];
@@ -1190,127 +1354,229 @@ error_add_context:
 				count -= (size_t) ret;
 			}
 		}
-		ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-				cmd_ctx->lsm->u.disable.channel_name,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.disable.event));
+		ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm.domain.type,
+				cmd_ctx->lsm.u.disable.channel_name,
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.disable.event));
 		break;
 	}
 	case LTTNG_ENABLE_CHANNEL:
 	{
-		cmd_ctx->lsm->u.channel.chan.attr.extended.ptr =
-				(struct lttng_channel_extended *) &cmd_ctx->lsm->u.channel.extended;
+		cmd_ctx->lsm.u.channel.chan.attr.extended.ptr =
+				(struct lttng_channel_extended *) &cmd_ctx->lsm.u.channel.extended;
 		ret = cmd_enable_channel(cmd_ctx->session,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.channel.chan),
-				kernel_poll_pipe[1]);
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.domain),
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.channel.chan),
+				the_kernel_poll_pipe[1]);
 		break;
 	}
-	case LTTNG_TRACK_ID:
+	case LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
+	case LTTNG_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
 	{
-		struct lttng_tracker_id id;
+		struct lttng_dynamic_buffer payload;
+		struct lttng_buffer_view payload_view;
+		const bool add_value =
+				cmd_ctx->lsm.cmd_type ==
+				LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
+		const size_t name_len =
+				cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value
+						.name_len;
+		const enum lttng_domain_type domain_type =
+				(enum lttng_domain_type)
+						cmd_ctx->lsm.domain.type;
+		const enum lttng_process_attr process_attr =
+				(enum lttng_process_attr) cmd_ctx->lsm.u
+						.process_attr_tracker_add_remove_include_value
+						.process_attr;
+		const enum lttng_process_attr_value_type value_type =
+				(enum lttng_process_attr_value_type) cmd_ctx
+						->lsm.u
+						.process_attr_tracker_add_remove_include_value
+						.value_type;
+		struct process_attr_value *value;
+		enum lttng_error_code ret_code;
+		long login_name_max;
+
+		login_name_max = sysconf(_SC_LOGIN_NAME_MAX);
+		if (login_name_max < 0) {
+			PERROR("Failed to get _SC_LOGIN_NAME_MAX system configuration");
+			ret = LTTNG_ERR_INVALID;
+			goto error;
+		}
 
-		memset(&id, 0, sizeof(id));
-		id.type = cmd_ctx->lsm->u.id_tracker.id_type;
-		switch (id.type) {
-		case LTTNG_ID_ALL:
-			break;
-		case LTTNG_ID_VALUE:
-			id.value = cmd_ctx->lsm->u.id_tracker.u.value;
-			break;
-		case LTTNG_ID_STRING:
-		{
-			const size_t var_len = cmd_ctx->lsm->u.id_tracker.u.var_len;
+		/* Receive remaining variable length payload if applicable. */
+		if (name_len > login_name_max) {
+			/*
+			 * POSIX mandates user and group names that are at least
+			 * 8 characters long. Note that although shadow-utils
+			 * (useradd, groupaadd, etc.) use 32 chars as their
+			 * limit (from bits/utmp.h, UT_NAMESIZE),
+			 * LOGIN_NAME_MAX is defined to 256.
+			 */
+			ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %ld",
+					add_value ? "addition" : "removal",
+					name_len, login_name_max);
+			ret = LTTNG_ERR_INVALID;
+			goto error;
+		}
 
-			id.string = zmalloc(var_len);
-			if (!id.string) {
+		lttng_dynamic_buffer_init(&payload);
+		if (name_len != 0) {
+			/*
+			 * Receive variable payload for user/group name
+			 * arguments.
+			 */
+			ret = lttng_dynamic_buffer_set_size(&payload, name_len);
+			if (ret) {
+				ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
+						add_value ? "add" : "remove");
 				ret = LTTNG_ERR_NOMEM;
-				goto error;
+				goto error_add_remove_tracker_value;
 			}
-			DBG("Receiving var len tracker id string from client");
-			ret = lttcomm_recv_unix_sock(*sock, id.string, var_len);
+
+			ret = lttcomm_recv_unix_sock(
+					*sock, payload.data, name_len);
 			if (ret <= 0) {
-				DBG("Nothing received");
+				ERR("Failed to receive payload of %s process attribute tracker value argument",
+						add_value ? "add" : "remove");
 				*sock_error = 1;
-				free(id.string);
-				ret = LTTNG_ERR_INVALID;
-				goto error;
+				ret = LTTNG_ERR_INVALID_PROTOCOL;
+				goto error_add_remove_tracker_value;
 			}
-			if (strnlen(id.string, var_len) != var_len - 1) {
-				DBG("String received as tracker ID is not NULL-terminated");
-				free(id.string);
-				ret = LTTNG_ERR_INVALID;
-				goto error;
-			}
-			break;
 		}
-		default:
-			ret = LTTNG_ERR_INVALID;
-			goto error;
+
+		payload_view = lttng_buffer_view_from_dynamic_buffer(
+				&payload, 0, name_len);
+		if (name_len > 0 && !lttng_buffer_view_is_valid(&payload_view)) {
+			ret = LTTNG_ERR_INVALID_PROTOCOL;
+			goto error_add_remove_tracker_value;
+		}
+
+		/*
+		 * Validate the value type and domains are legal for the process
+		 * attribute tracker that is specified and convert the value to
+		 * add/remove to the internal sessiond representation.
+		 */
+		ret_code = process_attr_value_from_comm(domain_type,
+				process_attr, value_type,
+				&cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value
+						 .integral_value,
+				&payload_view, &value);
+		if (ret_code != LTTNG_OK) {
+			ret = ret_code;
+			goto error_add_remove_tracker_value;
+		}
+
+		if (add_value) {
+			ret = cmd_process_attr_tracker_inclusion_set_add_value(
+					cmd_ctx->session, domain_type,
+					process_attr, value);
+		} else {
+			ret = cmd_process_attr_tracker_inclusion_set_remove_value(
+					cmd_ctx->session, domain_type,
+					process_attr, value);
 		}
-		ret = cmd_track_id(cmd_ctx->session,
-				cmd_ctx->lsm->u.id_tracker.tracker_type,
-				cmd_ctx->lsm->domain.type, &id);
-		free(id.string);
+		process_attr_value_destroy(value);
+	error_add_remove_tracker_value:
+		lttng_dynamic_buffer_reset(&payload);
 		break;
 	}
-	case LTTNG_UNTRACK_ID:
+	case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
 	{
-		struct lttng_tracker_id id;
-
-		memset(&id, 0, sizeof(id));
-		id.type = cmd_ctx->lsm->u.id_tracker.id_type;
-		switch (id.type) {
-		case LTTNG_ID_ALL:
-			break;
-		case LTTNG_ID_VALUE:
-			id.value = cmd_ctx->lsm->u.id_tracker.u.value;
-			break;
-		case LTTNG_ID_STRING:
-		{
-			const size_t var_len = cmd_ctx->lsm->u.id_tracker.u.var_len;
+		enum lttng_tracking_policy tracking_policy;
+		const enum lttng_domain_type domain_type =
+				(enum lttng_domain_type)
+						cmd_ctx->lsm.domain.type;
+		const enum lttng_process_attr process_attr =
+				(enum lttng_process_attr) cmd_ctx->lsm.u
+						.process_attr_tracker_get_tracking_policy
+						.process_attr;
+
+		ret = cmd_process_attr_tracker_get_tracking_policy(
+				cmd_ctx->session, domain_type, process_attr,
+				&tracking_policy);
+		if (ret != LTTNG_OK) {
+			goto error;
+		}
 
-			id.string = zmalloc(var_len);
-			if (!id.string) {
-				ret = LTTNG_ERR_NOMEM;
-				goto error;
-			}
-			DBG("Receiving var len tracker id string from client");
-			ret = lttcomm_recv_unix_sock(*sock, id.string, var_len);
-			if (ret <= 0) {
-				DBG("Nothing received");
-				*sock_error = 1;
-				free(id.string);
-				ret = LTTNG_ERR_INVALID;
-				goto error;
-			}
-			if (strnlen(id.string, var_len) != var_len - 1) {
-				DBG("String received as tracker ID is not NULL-terminated");
-				free(id.string);
-				ret = LTTNG_ERR_INVALID;
-				goto error;
-			}
-			break;
+		ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
+				&(uint32_t){tracking_policy}, sizeof(uint32_t));
+		if (ret < 0) {
+			ret = LTTNG_ERR_NOMEM;
+			goto error;
 		}
-		default:
-			ret = LTTNG_ERR_INVALID;
+		ret = LTTNG_OK;
+		break;
+	}
+	case LTTNG_PROCESS_ATTR_TRACKER_SET_POLICY:
+	{
+		const enum lttng_tracking_policy tracking_policy =
+				(enum lttng_tracking_policy) cmd_ctx->lsm.u
+						.process_attr_tracker_set_tracking_policy
+						.tracking_policy;
+		const enum lttng_domain_type domain_type =
+				(enum lttng_domain_type)
+						cmd_ctx->lsm.domain.type;
+		const enum lttng_process_attr process_attr =
+				(enum lttng_process_attr) cmd_ctx->lsm.u
+						.process_attr_tracker_set_tracking_policy
+						.process_attr;
+
+		ret = cmd_process_attr_tracker_set_tracking_policy(
+				cmd_ctx->session, domain_type, process_attr,
+				tracking_policy);
+		if (ret != LTTNG_OK) {
 			goto error;
 		}
-		ret = cmd_untrack_id(cmd_ctx->session,
-				cmd_ctx->lsm->u.id_tracker.tracker_type,
-				cmd_ctx->lsm->domain.type, &id);
-		free(id.string);
+		break;
+	}
+	case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
+	{
+		struct lttng_process_attr_values *values;
+		struct lttng_dynamic_buffer reply;
+		const enum lttng_domain_type domain_type =
+				(enum lttng_domain_type)
+						cmd_ctx->lsm.domain.type;
+		const enum lttng_process_attr process_attr =
+				(enum lttng_process_attr) cmd_ctx->lsm.u
+						.process_attr_tracker_get_inclusion_set
+						.process_attr;
+
+		ret = cmd_process_attr_tracker_get_inclusion_set(
+				cmd_ctx->session, domain_type, process_attr,
+				&values);
+		if (ret != LTTNG_OK) {
+			goto error;
+		}
+
+		lttng_dynamic_buffer_init(&reply);
+		ret = lttng_process_attr_values_serialize(values, &reply);
+		if (ret < 0) {
+			goto error_tracker_get_inclusion_set;
+		}
+
+		ret = setup_lttng_msg_no_cmd_header(
+				cmd_ctx, reply.data, reply.size);
+		if (ret < 0) {
+			ret = LTTNG_ERR_NOMEM;
+			goto error_tracker_get_inclusion_set;
+		}
+		ret = LTTNG_OK;
+
+	error_tracker_get_inclusion_set:
+		lttng_process_attr_values_destroy(values);
+		lttng_dynamic_buffer_reset(&reply);
 		break;
 	}
 	case LTTNG_ENABLE_EVENT:
 	{
 		struct lttng_event *ev = NULL;
 		struct lttng_event_exclusion *exclusion = NULL;
-		struct lttng_filter_bytecode *bytecode = NULL;
+		struct lttng_bytecode *bytecode = NULL;
 		char *filter_expression = NULL;
 
 		/* Handle exclusion events and receive it from the client. */
-		if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
-			size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
+		if (cmd_ctx->lsm.u.enable.exclusion_count > 0) {
+			size_t count = cmd_ctx->lsm.u.enable.exclusion_count;
 
 			exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
 					(count * LTTNG_SYMBOL_NAME_LEN));
@@ -1333,9 +1599,9 @@ error_add_context:
 		}
 
 		/* Get filter expression from client. */
-		if (cmd_ctx->lsm->u.enable.expression_len > 0) {
+		if (cmd_ctx->lsm.u.enable.expression_len > 0) {
 			size_t expression_len =
-				cmd_ctx->lsm->u.enable.expression_len;
+				cmd_ctx->lsm.u.enable.expression_len;
 
 			if (expression_len > LTTNG_FILTER_MAX_LEN) {
 				ret = LTTNG_ERR_FILTER_INVAL;
@@ -1365,8 +1631,8 @@ error_add_context:
 		}
 
 		/* Handle filter and get bytecode from client. */
-		if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
-			size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
+		if (cmd_ctx->lsm.u.enable.bytecode_len > 0) {
+			size_t bytecode_len = cmd_ctx->lsm.u.enable.bytecode_len;
 
 			if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
 				ret = LTTNG_ERR_FILTER_INVAL;
@@ -1405,10 +1671,10 @@ error_add_context:
 			}
 		}
 
-		ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm->u.enable.event));
+		ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm.u.enable.event));
 		if (!ev) {
 			DBG("Failed to copy event: %s",
-					cmd_ctx->lsm->u.enable.event.name);
+					cmd_ctx->lsm.u.enable.event.name);
 			free(filter_expression);
 			free(bytecode);
 			free(exclusion);
@@ -1417,7 +1683,7 @@ error_add_context:
 		}
 
 
-		if (cmd_ctx->lsm->u.enable.userspace_probe_location_len > 0) {
+		if (cmd_ctx->lsm.u.enable.userspace_probe_location_len > 0) {
 			/* Expect a userspace probe description. */
 			ret = receive_userspace_probe(cmd_ctx, *sock, sock_error, ev);
 			if (ret) {
@@ -1430,11 +1696,11 @@ error_add_context:
 		}
 
 		ret = cmd_enable_event(cmd_ctx->session,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
-				cmd_ctx->lsm->u.enable.channel_name,
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.domain),
+				cmd_ctx->lsm.u.enable.channel_name,
 				ev,
 				filter_expression, bytecode, exclusion,
-				kernel_poll_pipe[1]);
+				the_kernel_poll_pipe[1]);
 		lttng_event_destroy(ev);
 		break;
 	}
@@ -1444,7 +1710,7 @@ error_add_context:
 		ssize_t nb_events;
 
 		session_lock_list();
-		nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
+		nb_events = cmd_list_tracepoints(cmd_ctx->lsm.domain.type, &events);
 		session_unlock_list();
 		if (nb_events < 0) {
 			/* Return value is a negative lttng_error_code. */
@@ -1473,7 +1739,7 @@ error_add_context:
 		ssize_t nb_fields;
 
 		session_lock_list();
-		nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm->domain.type,
+		nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm.domain.type,
 				&fields);
 		session_unlock_list();
 		if (nb_fields < 0) {
@@ -1524,78 +1790,12 @@ error_add_context:
 		ret = LTTNG_OK;
 		break;
 	}
-	case LTTNG_LIST_TRACKER_IDS:
-	{
-		struct lttcomm_tracker_command_header cmd_header;
-		struct lttng_tracker_id *ids = NULL;
-		ssize_t nr_ids, i;
-		struct lttng_dynamic_buffer buf;
-
-		nr_ids = cmd_list_tracker_ids(
-				cmd_ctx->lsm->u.id_tracker.tracker_type,
-				cmd_ctx->session, cmd_ctx->lsm->domain.type,
-				&ids);
-		if (nr_ids < 0) {
-			/* Return value is a negative lttng_error_code. */
-			ret = -nr_ids;
-			goto error;
-		}
-
-		lttng_dynamic_buffer_init(&buf);
-		for (i = 0; i < nr_ids; i++) {
-			struct lttng_tracker_id *id = &ids[i];
-			struct lttcomm_tracker_id_header id_hdr;
-			size_t var_data_len = 0;
-
-			memset(&id_hdr, 0, sizeof(id_hdr));
-			id_hdr.type = id->type;
-			switch (id->type) {
-			case LTTNG_ID_ALL:
-				break;
-			case LTTNG_ID_VALUE:
-				id_hdr.u.value = id->value;
-				break;
-			case LTTNG_ID_STRING:
-				id_hdr.u.var_data_len = var_data_len =
-						strlen(id->string) + 1;
-				break;
-			default:
-				ret = LTTNG_ERR_INVALID;
-				goto error;
-			}
-			ret = lttng_dynamic_buffer_append(
-					&buf, &id_hdr, sizeof(id_hdr));
-			if (ret) {
-				ret = LTTNG_ERR_NOMEM;
-				goto error;
-			}
-			ret = lttng_dynamic_buffer_append(
-					&buf, id->string, var_data_len);
-			if (ret) {
-				ret = LTTNG_ERR_NOMEM;
-				goto error;
-			}
-			free(id->string);
-		}
-
-		cmd_header.nb_tracker_id = nr_ids;
-		ret = setup_lttng_msg(cmd_ctx, buf.data, buf.size, &cmd_header,
-				sizeof(cmd_header));
-		free(ids);
-		lttng_dynamic_buffer_reset(&buf);
-		if (ret < 0) {
-			goto setup_error;
-		}
-
-		ret = LTTNG_OK;
-		break;
-	}
 	case LTTNG_SET_CONSUMER_URI:
 	{
 		size_t nb_uri, len;
 		struct lttng_uri *uris;
 
-		nb_uri = cmd_ctx->lsm->u.uri.size;
+		nb_uri = cmd_ctx->lsm.u.uri.size;
 		len = nb_uri * sizeof(struct lttng_uri);
 
 		if (nb_uri == 0) {
@@ -1656,8 +1856,7 @@ error_add_context:
 	case LTTNG_DESTROY_SESSION:
 	{
 		ret = cmd_destroy_session(cmd_ctx->session,
-				notification_thread_handle,
-				sock);
+				the_notification_thread_handle, sock);
 		break;
 	}
 	case LTTNG_LIST_DOMAINS:
@@ -1688,7 +1887,7 @@ error_add_context:
 		ssize_t payload_size;
 		struct lttng_channel *channels = NULL;
 
-		payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
+		payload_size = cmd_list_channels(cmd_ctx->lsm.domain.type,
 				cmd_ctx->session, &channels);
 		if (payload_size < 0) {
 			/* Return value is a negative lttng_error_code. */
@@ -1709,32 +1908,34 @@ error_add_context:
 	}
 	case LTTNG_LIST_EVENTS:
 	{
-		ssize_t nb_event;
-		struct lttng_event *events = NULL;
-		struct lttcomm_event_command_header cmd_header;
-		size_t total_size;
-
-		memset(&cmd_header, 0, sizeof(cmd_header));
-		/* Extended infos are included at the end of events */
-		nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
-			cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
-			&events, &total_size);
-
-		if (nb_event < 0) {
-			/* Return value is a negative lttng_error_code. */
-			ret = -nb_event;
-			goto error;
+		ssize_t list_ret;
+		struct lttcomm_event_command_header cmd_header = {};
+		size_t original_payload_size;
+		size_t payload_size;
+
+		ret = setup_empty_lttng_msg(cmd_ctx);
+		if (ret) {
+			ret = LTTNG_ERR_NOMEM;
+			goto setup_error;
 		}
 
-		cmd_header.nb_events = nb_event;
-		ret = setup_lttng_msg(cmd_ctx, events, total_size,
-			&cmd_header, sizeof(cmd_header));
-		free(events);
+		original_payload_size = cmd_ctx->reply_payload.buffer.size;
 
-		if (ret < 0) {
-			goto setup_error;
+		/* Extended infos are included at the end of the payload. */
+		list_ret = cmd_list_events(cmd_ctx->lsm.domain.type,
+				cmd_ctx->session,
+				cmd_ctx->lsm.u.list.channel_name,
+				&cmd_ctx->reply_payload);
+		if (list_ret < 0) {
+			/* Return value is a negative lttng_error_code. */
+			ret = -list_ret;
+			goto error;
 		}
 
+		payload_size = cmd_ctx->reply_payload.buffer.size -
+				sizeof(cmd_header) - original_payload_size;
+		update_lttng_msg(cmd_ctx, sizeof(cmd_header), payload_size);
+
 		ret = LTTNG_OK;
 		break;
 	}
@@ -1779,17 +1980,17 @@ error_add_context:
 	{
 		struct consumer_data *cdata;
 
-		switch (cmd_ctx->lsm->domain.type) {
+		switch (cmd_ctx->lsm.domain.type) {
 		case LTTNG_DOMAIN_KERNEL:
-			cdata = &kconsumer_data;
+			cdata = &the_kconsumer_data;
 			break;
 		default:
 			ret = LTTNG_ERR_UND;
 			goto error;
 		}
 
-		ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-				cmd_ctx->lsm->u.reg.path, cdata);
+		ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm.domain.type,
+				cmd_ctx->lsm.u.reg.path, cdata);
 		break;
 	}
 	case LTTNG_DATA_PENDING:
@@ -1840,7 +2041,7 @@ error_add_context:
 		struct lttcomm_lttng_output_id reply;
 
 		ret = cmd_snapshot_add_output(cmd_ctx->session,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output),
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_output.output),
 				&snapshot_id);
 		if (ret != LTTNG_OK) {
 			goto error;
@@ -1860,7 +2061,7 @@ error_add_context:
 	case LTTNG_SNAPSHOT_DEL_OUTPUT:
 	{
 		ret = cmd_snapshot_del_output(cmd_ctx->session,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output));
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_output.output));
 		break;
 	}
 	case LTTNG_SNAPSHOT_LIST_OUTPUT:
@@ -1889,8 +2090,8 @@ error_add_context:
 	case LTTNG_SNAPSHOT_RECORD:
 	{
 		ret = cmd_snapshot_record(cmd_ctx->session,
-				ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_record.output),
-				cmd_ctx->lsm->u.snapshot_record.wait);
+				ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_record.output),
+				cmd_ctx->lsm.u.snapshot_record.wait);
 		break;
 	}
 	case LTTNG_CREATE_SESSION_EXT:
@@ -1926,14 +2127,14 @@ error_add_context:
 	}
 	case LTTNG_SAVE_SESSION:
 	{
-		ret = cmd_save_sessions(&cmd_ctx->lsm->u.save_session.attr,
+		ret = cmd_save_sessions(&cmd_ctx->lsm.u.save_session.attr,
 			&cmd_ctx->creds);
 		break;
 	}
 	case LTTNG_SET_SESSION_SHM_PATH:
 	{
 		ret = cmd_set_session_shm_path(cmd_ctx->session,
-				cmd_ctx->lsm->u.set_shm_path.shm_path);
+				cmd_ctx->lsm.u.set_shm_path.shm_path);
 		break;
 	}
 	case LTTNG_REGENERATE_METADATA:
@@ -1948,14 +2149,71 @@ error_add_context:
 	}
 	case LTTNG_REGISTER_TRIGGER:
 	{
-		ret = cmd_register_trigger(cmd_ctx, *sock,
-				notification_thread_handle);
+		struct lttng_trigger *payload_trigger;
+		struct lttng_trigger *return_trigger;
+		size_t original_reply_payload_size;
+		size_t reply_payload_size;
+		const struct lttng_credentials cmd_creds = {
+			.uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
+			.gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
+		};
+
+		ret = setup_empty_lttng_msg(cmd_ctx);
+		if (ret) {
+			ret = LTTNG_ERR_NOMEM;
+			goto setup_error;
+		}
+
+		ret = receive_lttng_trigger(
+				cmd_ctx, *sock, sock_error, &payload_trigger);
+		if (ret != LTTNG_OK) {
+			goto error;
+		}
+
+		original_reply_payload_size = cmd_ctx->reply_payload.buffer.size;
+
+		ret = cmd_register_trigger(&cmd_creds, payload_trigger,
+				the_notification_thread_handle,
+				&return_trigger);
+		if (ret != LTTNG_OK) {
+			lttng_trigger_put(payload_trigger);
+			goto error;
+		}
+
+		ret = lttng_trigger_serialize(return_trigger, &cmd_ctx->reply_payload);
+		lttng_trigger_put(payload_trigger);
+		lttng_trigger_put(return_trigger);
+		if (ret) {
+			ERR("Failed to serialize trigger in reply to \"register trigger\" command");
+			ret = LTTNG_ERR_NOMEM;
+			goto error;
+		}
+
+		reply_payload_size = cmd_ctx->reply_payload.buffer.size -
+			original_reply_payload_size;
+
+		update_lttng_msg(cmd_ctx, 0, reply_payload_size);
+
+		ret = LTTNG_OK;
 		break;
 	}
 	case LTTNG_UNREGISTER_TRIGGER:
 	{
-		ret = cmd_unregister_trigger(cmd_ctx, *sock,
-				notification_thread_handle);
+		struct lttng_trigger *payload_trigger;
+		const struct lttng_credentials cmd_creds = {
+			.uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
+			.gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
+		};
+
+		ret = receive_lttng_trigger(
+				cmd_ctx, *sock, sock_error, &payload_trigger);
+		if (ret != LTTNG_OK) {
+			goto error;
+		}
+
+		ret = cmd_unregister_trigger(&cmd_creds, payload_trigger,
+				the_notification_thread_handle);
+		lttng_trigger_put(payload_trigger);
 		break;
 	}
 	case LTTNG_ROTATE_SESSION:
@@ -1995,7 +2253,7 @@ error_add_context:
 
 		memset(&get_info_return, 0, sizeof(get_info_return));
 		ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
-				cmd_ctx->lsm->u.get_rotation_info.rotation_id);
+				cmd_ctx->lsm.u.get_rotation_info.rotation_id);
 		if (ret < 0) {
 			ret = -ret;
 			goto error;
@@ -2023,15 +2281,13 @@ error_add_context:
 			goto error;
 		}
 
-		set_schedule = cmd_ctx->lsm->u.rotation_set_schedule.set == 1;
-		schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm->u.rotation_set_schedule.type;
-		value = cmd_ctx->lsm->u.rotation_set_schedule.value;
+		set_schedule = cmd_ctx->lsm.u.rotation_set_schedule.set == 1;
+		schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm.u.rotation_set_schedule.type;
+		value = cmd_ctx->lsm.u.rotation_set_schedule.value;
 
-		ret = cmd_rotation_set_schedule(cmd_ctx->session,
-				set_schedule,
-				schedule_type,
-				value,
-				notification_thread_handle);
+		ret = cmd_rotation_set_schedule(cmd_ctx->session, set_schedule,
+				schedule_type, value,
+				the_notification_thread_handle);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -2062,20 +2318,58 @@ error_add_context:
 		ret = cmd_clear_session(cmd_ctx->session, sock);
 		break;
 	}
+	case LTTNG_LIST_TRIGGERS:
+	{
+		struct lttng_triggers *return_triggers = NULL;
+		size_t original_payload_size;
+		size_t payload_size;
+
+		ret = setup_empty_lttng_msg(cmd_ctx);
+		if (ret) {
+			ret = LTTNG_ERR_NOMEM;
+			goto setup_error;
+		}
+
+		original_payload_size = cmd_ctx->reply_payload.buffer.size;
+
+		ret = cmd_list_triggers(cmd_ctx, the_notification_thread_handle,
+				&return_triggers);
+		if (ret != LTTNG_OK) {
+			goto error;
+		}
+
+		assert(return_triggers);
+		ret = lttng_triggers_serialize(
+				return_triggers, &cmd_ctx->reply_payload);
+		lttng_triggers_destroy(return_triggers);
+		if (ret) {
+			ERR("Failed to serialize triggers in reply to `list triggers` command");
+			ret = LTTNG_ERR_NOMEM;
+			goto error;
+		}
+
+		payload_size = cmd_ctx->reply_payload.buffer.size -
+			original_payload_size;
+
+		update_lttng_msg(cmd_ctx, 0, payload_size);
+
+		ret = LTTNG_OK;
+		break;
+	}
 	default:
 		ret = LTTNG_ERR_UND;
 		break;
 	}
 
 error:
-	if (cmd_ctx->llm == NULL) {
-		DBG("Missing llm structure. Allocating one.");
+	if (cmd_ctx->reply_payload.buffer.size == 0) {
+		DBG("Missing llm header, creating one.");
 		if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
 			goto setup_error;
 		}
 	}
 	/* Set return code */
-	cmd_ctx->llm->ret_code = ret;
+	((struct lttcomm_lttng_msg *) (cmd_ctx->reply_payload.buffer.data))->ret_code = ret;
 setup_error:
 	if (cmd_ctx->session) {
 		session_unlock(cmd_ctx->session);
@@ -2096,9 +2390,11 @@ static int create_client_sock(void)
 	const mode_t old_umask = umask(0);
 
 	/* Create client tool unix socket */
-	client_sock = lttcomm_create_unix_sock(config.client_unix_sock_path.value);
+	client_sock = lttcomm_create_unix_sock(
+			the_config.client_unix_sock_path.value);
 	if (client_sock < 0) {
-		ERR("Create unix sock failed: %s", config.client_unix_sock_path.value);
+		ERR("Create unix sock failed: %s",
+				the_config.client_unix_sock_path.value);
 		ret = -1;
 		goto end;
 	}
@@ -2112,10 +2408,11 @@ static int create_client_sock(void)
 	}
 
 	/* File permission MUST be 660 */
-	ret = chmod(config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+	ret = chmod(the_config.client_unix_sock_path.value,
+			S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 	if (ret < 0) {
 		ERR("Set file permissions failed: %s",
-				config.client_unix_sock_path.value);
+				the_config.client_unix_sock_path.value);
 		PERROR("chmod");
 		(void) lttcomm_close_unix_sock(client_sock);
 		ret = -1;
@@ -2149,21 +2446,23 @@ static void *thread_manage_clients(void *data)
 	int sock = -1, ret, i, pollfd, err = -1;
 	int sock_error;
 	uint32_t revents, nb_fd;
-	struct command_ctx *cmd_ctx = NULL;
 	struct lttng_poll_event events;
 	const int client_sock = thread_state.client_sock;
 	struct lttng_pipe *quit_pipe = data;
 	const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
+	struct command_ctx cmd_ctx = {};
 
 	DBG("[thread] Manage client started");
 
+	lttng_payload_init(&cmd_ctx.reply_payload);
+
 	is_root = (getuid() == 0);
 
 	pthread_cleanup_push(thread_init_cleanup, NULL);
 
 	rcu_register_thread();
 
-	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
+	health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
 
 	health_code_update();
 
@@ -2194,7 +2493,7 @@ static void *thread_manage_clients(void *data)
 	}
 
 	/* Set state as running. */
-        set_thread_status(true);
+	set_thread_status(true);
 	pthread_cleanup_pop(0);
 
 	/* This testpoint is after we signal readiness to the parent. */
@@ -2211,6 +2510,14 @@ static void *thread_manage_clients(void *data)
 	while (1) {
 		const struct cmd_completion_handler *cmd_completion_handler;
 
+		cmd_ctx.creds = (lttng_sock_cred) {
+			.uid = UINT32_MAX,
+			.gid = UINT32_MAX,
+		};
+		cmd_ctx.session = NULL;
+		lttng_payload_clear(&cmd_ctx.reply_payload);
+		cmd_ctx.lttng_msg_size = 0;
+
 		DBG("Accepting client command ...");
 
 		/* Inifinite blocking call, waiting for transmission */
@@ -2274,23 +2581,6 @@ static void *thread_manage_clients(void *data)
 			goto error;
 		}
 
-		/* Allocate context command to process the client request */
-		cmd_ctx = zmalloc(sizeof(struct command_ctx));
-		if (cmd_ctx == NULL) {
-			PERROR("zmalloc cmd_ctx");
-			goto error;
-		}
-
-		/* Allocate data buffer for reception */
-		cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
-		if (cmd_ctx->lsm == NULL) {
-			PERROR("zmalloc cmd_ctx->lsm");
-			goto error;
-		}
-
-		cmd_ctx->llm = NULL;
-		cmd_ctx->session = NULL;
-
 		health_code_update();
 
 		/*
@@ -2299,16 +2589,15 @@ static void *thread_manage_clients(void *data)
 		 * the client.
 		 */
 		DBG("Receiving data from client ...");
-		ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
-				sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
-		if (ret <= 0) {
-			DBG("Nothing recv() from client... continuing");
+		ret = lttcomm_recv_creds_unix_sock(sock, &cmd_ctx.lsm,
+				sizeof(struct lttcomm_session_msg), &cmd_ctx.creds);
+		if (ret != sizeof(struct lttcomm_session_msg)) {
+			DBG("Incomplete recv() from client... continuing");
 			ret = close(sock);
 			if (ret) {
 				PERROR("close");
 			}
 			sock = -1;
-			clean_command_ctx(&cmd_ctx);
 			continue;
 		}
 
@@ -2324,7 +2613,7 @@ static void *thread_manage_clients(void *data)
 		 * informations for the client. The command context struct contains
 		 * everything this function may needs.
 		 */
-		ret = process_client_msg(cmd_ctx, &sock, &sock_error);
+		ret = process_client_msg(&cmd_ctx, &sock, &sock_error);
 		rcu_thread_offline();
 		if (ret < 0) {
 			if (sock >= 0) {
@@ -2332,8 +2621,8 @@ static void *thread_manage_clients(void *data)
 				if (ret) {
 					PERROR("close");
 				}
-                        }
-                        sock = -1;
+			}
+			sock = -1;
 			/*
 			 * TODO: Inform client somehow of the fatal error. At
 			 * this point, ret < 0 means that a zmalloc failed
@@ -2341,10 +2630,17 @@ static void *thread_manage_clients(void *data)
 			 * command, unless a socket error has been
 			 * detected.
 			 */
-			clean_command_ctx(&cmd_ctx);
 			continue;
 		}
 
+		if (ret < LTTNG_OK || ret >= LTTNG_ERR_NR) {
+			WARN("Command returned an invalid status code, returning unknown error: "
+					"command type = %s (%d), ret = %d",
+					lttcomm_sessiond_command_str(cmd_ctx.lsm.cmd_type),
+					cmd_ctx.lsm.cmd_type, ret);
+			ret = LTTNG_ERR_UNK;
+		}
+
 		cmd_completion_handler = cmd_pop_completion_handler();
 		if (cmd_completion_handler) {
 			enum lttng_error_code completion_code;
@@ -2352,7 +2648,6 @@ static void *thread_manage_clients(void *data)
 			completion_code = cmd_completion_handler->run(
 					cmd_completion_handler->data);
 			if (completion_code != LTTNG_OK) {
-				clean_command_ctx(&cmd_ctx);
 				continue;
 			}
 		}
@@ -2360,12 +2655,23 @@ static void *thread_manage_clients(void *data)
 		health_code_update();
 
 		if (sock >= 0) {
+			struct lttng_payload_view view =
+					lttng_payload_view_from_payload(
+							&cmd_ctx.reply_payload,
+							0, -1);
+			struct lttcomm_lttng_msg *llm = (typeof(
+					llm)) cmd_ctx.reply_payload.buffer.data;
+
+			assert(cmd_ctx.reply_payload.buffer.size >= sizeof(*llm));
+			assert(cmd_ctx.lttng_msg_size == cmd_ctx.reply_payload.buffer.size);
+
+			llm->fd_count = lttng_payload_view_get_fd_handle_count(&view);
+
 			DBG("Sending response (size: %d, retcode: %s (%d))",
-					cmd_ctx->lttng_msg_size,
-					lttng_strerror(-cmd_ctx->llm->ret_code),
-					cmd_ctx->llm->ret_code);
-			ret = send_unix_sock(sock, cmd_ctx->llm,
-					cmd_ctx->lttng_msg_size);
+					cmd_ctx.lttng_msg_size,
+					lttng_strerror(-llm->ret_code),
+					llm->ret_code);
+			ret = send_unix_sock(sock, &view);
 			if (ret < 0) {
 				ERR("Failed to send data back to client");
 			}
@@ -2375,10 +2681,8 @@ static void *thread_manage_clients(void *data)
 			if (ret) {
 				PERROR("close");
 			}
-                }
-                sock = -1;
-
-		clean_command_ctx(&cmd_ctx);
+		}
+		sock = -1;
 
 		health_code_update();
 	}
@@ -2393,11 +2697,10 @@ error:
 	}
 
 	lttng_poll_clean(&events);
-	clean_command_ctx(&cmd_ctx);
 
 error_listen:
 error_create_poll:
-	unlink(config.client_unix_sock_path.value);
+	unlink(the_config.client_unix_sock_path.value);
 	ret = close(client_sock);
 	if (ret) {
 		PERROR("close");
@@ -2408,10 +2711,10 @@ error_create_poll:
 		ERR("Health error occurred in %s", __func__);
 	}
 
-	health_unregister(health_sessiond);
+	health_unregister(the_health_sessiond);
 
 	DBG("Client thread dying");
-
+	lttng_payload_reset(&cmd_ctx.reply_payload);
 	rcu_unregister_thread();
 	return NULL;
 }