X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fenable_channels.c;h=22331cec2b2ead8d032ede422df7f581df4f7c38;hp=e27fe88cecff1a826e62e849539bdaa4187a8a93;hb=c1e4642cd27bd5b70c0eca1011d9e452bd24f018;hpb=679b4943c3b0f451e7f4fbcd804dd8a7a679e253

diff --git a/src/bin/lttng/commands/enable_channels.c b/src/bin/lttng/commands/enable_channels.c
index e27fe88ce..22331cec2 100644
--- a/src/bin/lttng/commands/enable_channels.c
+++ b/src/bin/lttng/commands/enable_channels.c
@@ -1,22 +1,21 @@
 /*
  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; only version 2
- * of the License.
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ * 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 _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <popt.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -25,18 +24,37 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <inttypes.h>
+#include <assert.h>
+#include <ctype.h>
+
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/utils.h>
+#include <common/mi-lttng.h>
 
 #include "../command.h"
+#include "../utils.h"
+
 
+static struct lttng_channel chan_opts;
 static char *opt_channels;
 static int opt_kernel;
 static char *opt_session_name;
 static int opt_userspace;
-static struct lttng_channel chan;
-#if 0
-/* Not implemented yet */
-static char *opt_cmd_name;
-static pid_t opt_pid;
+static char *opt_output;
+static int opt_buffer_uid;
+static int opt_buffer_pid;
+static int opt_buffer_global;
+static struct {
+	bool set;
+	uint32_t interval;
+} opt_monitor_timer;
+
+static struct mi_writer *writer;
+
+#ifdef LTTNG_EMBED_HELP
+static const char help_msg[] =
+#include <lttng-enable-channel.1.h>
+;
 #endif
 
 enum {
@@ -46,75 +64,42 @@ enum {
 	OPT_SUBBUF_SIZE,
 	OPT_NUM_SUBBUF,
 	OPT_SWITCH_TIMER,
+	OPT_MONITOR_TIMER,
 	OPT_READ_TIMER,
 	OPT_USERSPACE,
 	OPT_LIST_OPTIONS,
+	OPT_TRACEFILE_SIZE,
+	OPT_TRACEFILE_COUNT,
 };
 
 static struct lttng_handle *handle;
 
+const char *output_mmap = "mmap";
+const char *output_splice = "splice";
+
 static struct poptOption long_options[] = {
 	/* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
 	{"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
 	{"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
 	{"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
-#if 0
-	/* Not implemented yet */
-	{"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
-	{"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
-#else
 	{"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
-#endif
 	{"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
 	{"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
-	{"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
+	{"subbuf-size",    0,   POPT_ARG_STRING, 0, OPT_SUBBUF_SIZE, 0, 0},
 	{"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
 	{"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
+	{"monitor-timer",  0,   POPT_ARG_INT, 0, OPT_MONITOR_TIMER, 0, 0},
 	{"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
 	{"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
+	{"output",         0,   POPT_ARG_STRING, &opt_output, 0, 0, 0},
+	{"buffers-uid",    0,	POPT_ARG_VAL, &opt_buffer_uid, 1, 0, 0},
+	{"buffers-pid",    0,	POPT_ARG_VAL, &opt_buffer_pid, 1, 0, 0},
+	{"buffers-global", 0,	POPT_ARG_VAL, &opt_buffer_global, 1, 0, 0},
+	{"tracefile-size", 'C',   POPT_ARG_INT, 0, OPT_TRACEFILE_SIZE, 0, 0},
+	{"tracefile-count", 'W',   POPT_ARG_INT, 0, OPT_TRACEFILE_COUNT, 0, 0},
 	{0, 0, 0, 0, 0, 0, 0}
 };
 
-/*
- * usage
- */
-static void usage(FILE *ofp)
-{
-	fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "  -h, --help               Show this help\n");
-	fprintf(ofp, "      --list-options       Simple listing of options\n");
-	fprintf(ofp, "  -s, --session            Apply on session name\n");
-	fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
-#if 0
-	fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
-	fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
-	fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
-	fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
-#else
-	fprintf(ofp, "  -u, --userspace          Apply for the user-space tracer\n");
-#endif
-	fprintf(ofp, "\n");
-	fprintf(ofp, "Channel options:\n");
-	fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
-		DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
-	fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
-		DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
-	fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
-	fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
-		DEFAULT_CHANNEL_SUBBUF_SIZE,
-		DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
-	fprintf(ofp, "      --num-subbuf         Number of subbufers\n");
-	fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
-		DEFAULT_CHANNEL_SUBBUF_NUM,
-		DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
-	fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: %u)\n",
-		DEFAULT_CHANNEL_SWITCH_TIMER);
-	fprintf(ofp, "      --read-timer         Read timer interval in usec (default: %u)\n",
-		DEFAULT_CHANNEL_READ_TIMER);
-	fprintf(ofp, "\n");
-}
-
 /*
  * Set default attributes depending on those already defined from the command
  * line.
@@ -123,26 +108,34 @@ static void set_default_attr(struct lttng_domain *dom)
 {
 	struct lttng_channel_attr default_attr;
 
+	memset(&default_attr, 0, sizeof(default_attr));
+
 	/* Set attributes */
 	lttng_channel_set_default_attr(dom, &default_attr);
 
-	if (chan.attr.overwrite == -1) {
-		chan.attr.overwrite = default_attr.overwrite;
+	if (chan_opts.attr.overwrite == -1) {
+		chan_opts.attr.overwrite = default_attr.overwrite;
+	}
+	if (chan_opts.attr.subbuf_size == -1) {
+		chan_opts.attr.subbuf_size = default_attr.subbuf_size;
 	}
-	if (chan.attr.subbuf_size == -1) {
-		chan.attr.subbuf_size = default_attr.subbuf_size;
+	if (chan_opts.attr.num_subbuf == -1) {
+		chan_opts.attr.num_subbuf = default_attr.num_subbuf;
 	}
-	if (chan.attr.num_subbuf == -1) {
-		chan.attr.num_subbuf = default_attr.num_subbuf;
+	if (chan_opts.attr.switch_timer_interval == -1) {
+		chan_opts.attr.switch_timer_interval = default_attr.switch_timer_interval;
 	}
-	if (chan.attr.switch_timer_interval == -1) {
-		chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
+	if (chan_opts.attr.read_timer_interval == -1) {
+		chan_opts.attr.read_timer_interval = default_attr.read_timer_interval;
 	}
-	if (chan.attr.read_timer_interval == -1) {
-		chan.attr.read_timer_interval = default_attr.read_timer_interval;
+	if ((int) chan_opts.attr.output == -1) {
+		chan_opts.attr.output = default_attr.output;
 	}
-	if (chan.attr.output == -1) {
-		chan.attr.output = default_attr.output;
+	if (chan_opts.attr.tracefile_count == -1) {
+		chan_opts.attr.tracefile_count = default_attr.tracefile_count;
+	}
+	if (chan_opts.attr.tracefile_size == -1) {
+		chan_opts.attr.tracefile_size = default_attr.tracefile_size;
 	}
 }
 
@@ -151,52 +144,211 @@ static void set_default_attr(struct lttng_domain *dom)
  */
 static int enable_channel(char *session_name)
 {
-	int ret = CMD_SUCCESS;
+	struct lttng_channel *channel = NULL;
+	int ret = CMD_SUCCESS, warn = 0, error = 0, success = 0;
 	char *channel_name;
 	struct lttng_domain dom;
 
+	memset(&dom, 0, sizeof(dom));
+
 	/* Create lttng domain */
 	if (opt_kernel) {
 		dom.type = LTTNG_DOMAIN_KERNEL;
+		dom.buf_type = LTTNG_BUFFER_GLOBAL;
+		if (opt_buffer_uid || opt_buffer_pid) {
+			ERR("Buffer type not supported for domain -k");
+			ret = CMD_ERROR;
+			goto error;
+		}
 	} else if (opt_userspace) {
 		dom.type = LTTNG_DOMAIN_UST;
+		if (opt_buffer_pid) {
+			dom.buf_type = LTTNG_BUFFER_PER_PID;
+		} else {
+			if (opt_buffer_global) {
+				ERR("Buffer type not supported for domain -u");
+				ret = CMD_ERROR;
+				goto error;
+			}
+			dom.buf_type = LTTNG_BUFFER_PER_UID;
+		}
 	} else {
-		ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
-		ret = CMD_UNDEFINED;
-		goto error;
+		/* Checked by the caller. */
+		assert(0);
 	}
 
 	set_default_attr(&dom);
 
+	if (chan_opts.attr.tracefile_size == 0 && chan_opts.attr.tracefile_count) {
+		ERR("Missing option --tracefile-size. "
+				"A file count without a size won't do anything.");
+		ret = CMD_ERROR;
+		goto error;
+	}
+
+	if ((chan_opts.attr.tracefile_size > 0) &&
+			(chan_opts.attr.tracefile_size < chan_opts.attr.subbuf_size)) {
+		WARN("Tracefile size rounded up from (%" PRIu64 ") to subbuffer size (%" PRIu64 ")",
+				chan_opts.attr.tracefile_size, chan_opts.attr.subbuf_size);
+		chan_opts.attr.tracefile_size = chan_opts.attr.subbuf_size;
+	}
+
+	/* Setting channel output */
+	if (opt_output) {
+		if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
+			chan_opts.attr.output = LTTNG_EVENT_MMAP;
+		} else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
+			chan_opts.attr.output = LTTNG_EVENT_SPLICE;
+		} else {
+			ERR("Unknown output type %s. Possible values are: %s, %s\n",
+					opt_output, output_mmap, output_splice);
+			ret = CMD_ERROR;
+			goto error;
+		}
+	}
+
 	handle = lttng_create_handle(session_name, &dom);
 	if (handle == NULL) {
 		ret = -1;
 		goto error;
 	}
 
+	/* Mi open channels element */
+	if (lttng_opt_mi) {
+		assert(writer);
+		ret = mi_lttng_channels_open(writer);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto error;
+		}
+	}
+
 	/* Strip channel list (format: chan1,chan2,...) */
 	channel_name = strtok(opt_channels, ",");
 	while (channel_name != NULL) {
-		/* Copy channel name and normalize it */
-		strncpy(chan.name, channel_name, NAME_MAX);
-		chan.name[NAME_MAX - 1] = '\0';
+		void *extended_ptr;
+
+		/* Validate channel name's length */
+		if (strlen(channel_name) >= NAME_MAX) {
+			ERR("Channel name is too long (max. %zu characters)",
+					sizeof(chan_opts.name) - 1);
+			error = 1;
+			goto skip_enable;
+		}
+
+		/*
+		 * A dynamically-allocated channel is used in order to allow
+		 * the configuration of extended attributes (post-2.9).
+		 */
+		channel = lttng_channel_create(&dom);
+		if (!channel) {
+			ERR("Unable to create channel object");
+			error = 1;
+			goto error;
+		}
+
+		/* Copy channel name */
+		strcpy(channel->name, channel_name);
+		channel->enabled = 1;
+		extended_ptr = channel->attr.extended.ptr;
+		memcpy(&channel->attr, &chan_opts.attr, sizeof(chan_opts.attr));
+		channel->attr.extended.ptr = extended_ptr;
+		if (opt_monitor_timer.set) {
+			ret = lttng_channel_set_monitor_timer_interval(channel,
+					opt_monitor_timer.interval);
+			if (ret) {
+				ERR("Failed to set the channel's monitor timer interval");
+				error = 1;
+				goto error;
+			}
+		}
 
 		DBG("Enabling channel %s", channel_name);
 
-		ret = lttng_enable_channel(handle, &chan);
+		ret = lttng_enable_channel(handle, channel);
 		if (ret < 0) {
-			goto error;
+			success = 0;
+			switch (-ret) {
+			case LTTNG_ERR_KERN_CHAN_EXIST:
+			case LTTNG_ERR_UST_CHAN_EXIST:
+			case LTTNG_ERR_CHAN_EXIST:
+				WARN("Channel %s: %s (session %s)", channel_name,
+						lttng_strerror(ret), session_name);
+				warn = 1;
+				break;
+			case LTTNG_ERR_INVALID_CHANNEL_NAME:
+				ERR("Invalid channel name: \"%s\". "
+				    "Channel names may not start with '.', and "
+				    "may not contain '/'.", channel_name);
+				error = 1;
+				break;
+			default:
+				ERR("Channel %s: %s (session %s)", channel_name,
+						lttng_strerror(ret), session_name);
+				error = 1;
+				break;
+			}
 		} else {
 			MSG("%s channel %s enabled for session %s",
-					opt_kernel ? "Kernel" : "UST", channel_name,
-					session_name);
+					get_domain_str(dom.type), channel_name, session_name);
+			success = 1;
 		}
 
-		/* Next event */
+skip_enable:
+		if (lttng_opt_mi) {
+			/* Mi print the channel element and leave it open */
+			ret = mi_lttng_channel(writer, channel, 1);
+			if (ret) {
+				ret = CMD_ERROR;
+				goto error;
+			}
+
+			/* Individual Success ? */
+			ret = mi_lttng_writer_write_element_bool(writer,
+					mi_lttng_element_command_success, success);
+			if (ret) {
+				ret = CMD_ERROR;
+				goto error;
+			}
+
+			/* Close channel element */
+			ret = mi_lttng_writer_close_element(writer);
+			if (ret) {
+				ret = CMD_ERROR;
+				goto error;
+			}
+		}
+
+		/* Next channel */
 		channel_name = strtok(NULL, ",");
+		lttng_channel_destroy(channel);
+		channel = NULL;
 	}
 
+	if (lttng_opt_mi) {
+		/* Close channels element */
+		ret = mi_lttng_writer_close_element(writer);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto error;
+		}
+	}
+
+	ret = CMD_SUCCESS;
+
 error:
+	if (channel) {
+		lttng_channel_destroy(channel);
+	}
+	/* If more important error happen bypass the warning */
+	if (!ret && warn) {
+		ret = CMD_WARNING;
+	}
+	/* If more important error happen bypass the warning */
+	if (!ret && error) {
+		ret = CMD_ERROR;
+	}
+
 	lttng_destroy_handle(handle);
 
 	return ret;
@@ -211,7 +363,8 @@ static void init_channel_config(void)
 	 * Put -1 everywhere so we can identify those set by the command line and
 	 * those needed to be set by the default values.
 	 */
-	memset(&chan.attr, -1, sizeof(chan.attr));
+	memset(&chan_opts.attr, -1, sizeof(chan_opts.attr));
+	chan_opts.attr.extended.ptr = NULL;
 }
 
 /*
@@ -219,9 +372,10 @@ static void init_channel_config(void)
  */
 int cmd_enable_channels(int argc, const char **argv)
 {
-	int opt, ret;
+	int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 	static poptContext pc;
 	char *session_name = NULL;
+	char *opt_arg = NULL;
 
 	init_channel_config();
 
@@ -231,67 +385,286 @@ int cmd_enable_channels(int argc, const char **argv)
 	while ((opt = poptGetNextOpt(pc)) != -1) {
 		switch (opt) {
 		case OPT_HELP:
-			usage(stderr);
-			ret = CMD_SUCCESS;
+			SHOW_HELP();
 			goto end;
 		case OPT_DISCARD:
-			chan.attr.overwrite = 0;
+			chan_opts.attr.overwrite = 0;
 			DBG("Channel set to discard");
 			break;
 		case OPT_OVERWRITE:
-			chan.attr.overwrite = 1;
+			chan_opts.attr.overwrite = 1;
 			DBG("Channel set to overwrite");
 			break;
 		case OPT_SUBBUF_SIZE:
-			chan.attr.subbuf_size = atol(poptGetOptArg(pc));
-			DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
+		{
+			uint64_t rounded_size;
+			int order;
+
+			/* Parse the size */
+			opt_arg = poptGetOptArg(pc);
+			if (utils_parse_size_suffix(opt_arg, &chan_opts.attr.subbuf_size) < 0 || !chan_opts.attr.subbuf_size) {
+				ERR("Wrong value in --subbuf-size parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+
+			order = get_count_order_u64(chan_opts.attr.subbuf_size);
+			assert(order >= 0);
+			rounded_size = 1ULL << order;
+			if (rounded_size < chan_opts.attr.subbuf_size) {
+				ERR("The subbuf size (%" PRIu64 ") is rounded and overflows!",
+						chan_opts.attr.subbuf_size);
+				ret = CMD_ERROR;
+				goto end;
+			}
+
+			if (rounded_size != chan_opts.attr.subbuf_size) {
+				WARN("The subbuf size (%" PRIu64 ") is rounded to the next power of 2 (%" PRIu64 ")",
+						chan_opts.attr.subbuf_size, rounded_size);
+				chan_opts.attr.subbuf_size = rounded_size;
+			}
+
+			/* Should now be power of 2 */
+			assert(!((chan_opts.attr.subbuf_size - 1) & chan_opts.attr.subbuf_size));
+
+			DBG("Channel subbuf size set to %" PRIu64, chan_opts.attr.subbuf_size);
 			break;
+		}
 		case OPT_NUM_SUBBUF:
-			chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
-			DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
+		{
+			uint64_t rounded_size;
+			int order;
+
+			errno = 0;
+			opt_arg = poptGetOptArg(pc);
+			chan_opts.attr.num_subbuf = strtoull(opt_arg, NULL, 0);
+			if (errno != 0 || !chan_opts.attr.num_subbuf || !isdigit(opt_arg[0])) {
+				ERR("Wrong value in --num-subbuf parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+
+			order = get_count_order_u64(chan_opts.attr.num_subbuf);
+			assert(order >= 0);
+			rounded_size = 1ULL << order;
+			if (rounded_size < chan_opts.attr.num_subbuf) {
+				ERR("The number of subbuffers (%" PRIu64 ") is rounded and overflows!",
+						chan_opts.attr.num_subbuf);
+				ret = CMD_ERROR;
+				goto end;
+			}
+
+			if (rounded_size != chan_opts.attr.num_subbuf) {
+				WARN("The number of subbuffers (%" PRIu64 ") is rounded to the next power of 2 (%" PRIu64 ")",
+						chan_opts.attr.num_subbuf, rounded_size);
+				chan_opts.attr.num_subbuf = rounded_size;
+			}
+
+			/* Should now be power of 2 */
+			assert(!((chan_opts.attr.num_subbuf - 1) & chan_opts.attr.num_subbuf));
+
+			DBG("Channel subbuf num set to %" PRIu64, chan_opts.attr.num_subbuf);
 			break;
+		}
 		case OPT_SWITCH_TIMER:
-			chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
-			DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
+		{
+			unsigned long v;
+
+			errno = 0;
+			opt_arg = poptGetOptArg(pc);
+			v = strtoul(opt_arg, NULL, 0);
+			if (errno != 0 || !isdigit(opt_arg[0])) {
+				ERR("Wrong value in --switch-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			if (v != (uint32_t) v) {
+				ERR("32-bit overflow in --switch-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			chan_opts.attr.switch_timer_interval = (uint32_t) v;
+			DBG("Channel switch timer interval set to %d", chan_opts.attr.switch_timer_interval);
 			break;
+		}
 		case OPT_READ_TIMER:
-			chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
-			DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
+		{
+			unsigned long v;
+
+			errno = 0;
+			opt_arg = poptGetOptArg(pc);
+			v = strtoul(opt_arg, NULL, 0);
+			if (errno != 0 || !isdigit(opt_arg[0])) {
+				ERR("Wrong value in --read-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			if (v != (uint32_t) v) {
+				ERR("32-bit overflow in --read-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			chan_opts.attr.read_timer_interval = (uint32_t) v;
+			DBG("Channel read timer interval set to %d", chan_opts.attr.read_timer_interval);
 			break;
+		}
+		case OPT_MONITOR_TIMER:
+		{
+			unsigned long v;
+
+			errno = 0;
+			opt_arg = poptGetOptArg(pc);
+			v = strtoul(opt_arg, NULL, 0);
+			if (errno != 0 || !isdigit(opt_arg[0])) {
+				ERR("Wrong value in --monitor-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			if (v != (uint32_t) v) {
+				ERR("32-bit overflow in --monitor-timer parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			opt_monitor_timer.interval = (uint32_t) v;
+			opt_monitor_timer.set = true;
+			DBG("Channel monitor timer interval set to %d", opt_monitor_timer.interval);
+			break;
+		}
 		case OPT_USERSPACE:
 			opt_userspace = 1;
 			break;
+		case OPT_TRACEFILE_SIZE:
+			opt_arg = poptGetOptArg(pc);
+			if (utils_parse_size_suffix(opt_arg, &chan_opts.attr.tracefile_size) < 0) {
+				ERR("Wrong value in --tracefile-size parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			DBG("Maximum tracefile size set to %" PRIu64,
+					chan_opts.attr.tracefile_size);
+			break;
+		case OPT_TRACEFILE_COUNT:
+		{
+			unsigned long v;
+
+			errno = 0;
+			opt_arg = poptGetOptArg(pc);
+			v = strtoul(opt_arg, NULL, 0);
+			if (errno != 0 || !isdigit(opt_arg[0])) {
+				ERR("Wrong value in --tracefile-count parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			if (v != (uint32_t) v) {
+				ERR("32-bit overflow in --tracefile-count parameter: %s", opt_arg);
+				ret = CMD_ERROR;
+				goto end;
+			}
+			chan_opts.attr.tracefile_count = (uint32_t) v;
+			DBG("Maximum tracefile count set to %" PRIu64,
+					chan_opts.attr.tracefile_count);
+			break;
+		}
 		case OPT_LIST_OPTIONS:
 			list_cmd_options(stdout, long_options);
-			ret = CMD_SUCCESS;
 			goto end;
 		default:
-			usage(stderr);
 			ret = CMD_UNDEFINED;
 			goto end;
 		}
 	}
 
+	ret = print_missing_or_multiple_domains(opt_kernel + opt_userspace);
+	if (ret) {
+		ret = CMD_ERROR;
+		goto end;
+	}
+
+	/* Mi check */
+	if (lttng_opt_mi) {
+		writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
+		if (!writer) {
+			ret = -LTTNG_ERR_NOMEM;
+			goto end;
+		}
+
+		/* Open command element */
+		ret = mi_lttng_writer_command_open(writer,
+				mi_lttng_element_command_enable_channels);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+
+		/* Open output element */
+		ret = mi_lttng_writer_open_element(writer,
+				mi_lttng_element_command_output);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+	}
+
 	opt_channels = (char*) poptGetArg(pc);
 	if (opt_channels == NULL) {
 		ERR("Missing channel name.\n");
-		usage(stderr);
-		ret = CMD_SUCCESS;
-		goto end;
+		ret = CMD_ERROR;
+		success = 0;
+		goto mi_closing;
 	}
 
 	if (!opt_session_name) {
 		session_name = get_session_name();
 		if (session_name == NULL) {
-			ret = -1;
-			goto end;
+			command_ret = CMD_ERROR;
+			success = 0;
+			goto mi_closing;
 		}
 	} else {
 		session_name = opt_session_name;
 	}
 
-	ret = enable_channel(session_name);
+	command_ret = enable_channel(session_name);
+	if (command_ret) {
+		success = 0;
+	}
+
+mi_closing:
+	/* Mi closing */
+	if (lttng_opt_mi) {
+		/* Close  output element */
+		ret = mi_lttng_writer_close_element(writer);
+		if (ret) {
+			goto end;
+		}
+
+		/* Success ? */
+		ret = mi_lttng_writer_write_element_bool(writer,
+				mi_lttng_element_command_success, success);
+		if (ret) {
+			goto end;
+		}
+
+		/* Command element close */
+		ret = mi_lttng_writer_command_close(writer);
+		if (ret) {
+			goto end;
+		}
+	}
 
 end:
+	/* Mi clean-up */
+	if (writer && mi_lttng_writer_destroy(writer)) {
+		/* Preserve original error code */
+		ret = ret ? ret : LTTNG_ERR_MI_IO_FAIL;
+	}
+
+	if (!opt_session_name && session_name) {
+		free(session_name);
+	}
+
+	/* Overwrite ret if an error occurred when enable_channel */
+	ret = command_ret ? command_ret : ret;
+	poptFreeContext(pc);
 	return ret;
 }