[lttng-tools.git] / src / bin / lttng / commands / view.c

/*
 * Copyright (C) 2011 - 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 _GNU_SOURCE
#define _LGPL_SOURCE
#include <popt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "../command.h"
#include <config.h>

static char *opt_session_name;
static char *opt_viewer;
static char *opt_trace_path;
static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
//static const char *lttv_gui_bin = CONFIG_LTTV_GUI_BIN;

enum {
	OPT_HELP = 1,
	OPT_LIST_OPTIONS,
};

static struct poptOption long_options[] = {
	/* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
	{"help",        'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
	{"list-options", 0,  POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
	{"viewer",      'e', POPT_ARG_STRING, &opt_viewer, 0, 0, 0},
	{"trace-path",  't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0}
};

/*
 * This is needed for each viewer since we are using execvp().
 */
static const char *babeltrace_opts[] = { "babeltrace" };
//static const char *lttv_gui_opts[] = { "lttv-gui", "-t", };

/*
 * Type is also use as the index in the viewers array. So please, make sure
 * your enum value is in the right order in the array below.
 */
enum viewer_type {
	VIEWER_BABELTRACE    = 0,
	VIEWER_LTTV_GUI      = 1,
	VIEWER_USER_DEFINED  = 2,
};

/*
 * NOTE: "lttv" is a shell command and it's not working for exec() family
 * functions so we might think of removing this wrapper or using bash.
 */
static struct viewers {
	const char *exec_name;
	enum viewer_type type;
} viewers[] = {
	{ "babeltrace", VIEWER_BABELTRACE },
	{ "lttv-gui", VIEWER_LTTV_GUI },
	{ NULL, VIEWER_USER_DEFINED },
};

/* Is the session we are trying to view is in live mode. */
static int session_live_mode;

/*
 * usage
 */
static void usage(FILE *ofp)
{
	fprintf(ofp, "usage: lttng view [SESSION_NAME] [OPTIONS]\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "By default, the babeltrace viewer will be used for text viewing\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Where SESSION_NAME is an optional session name. If not specified, lttng will\n");
	fprintf(ofp, "get it from the configuration file (.lttngrc).\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Options:\n");
	fprintf(ofp, "  -h, --help               Show this help\n");
	fprintf(ofp, "      --list-options       Simple listing of options\n");
	fprintf(ofp, "  -t, --trace-path PATH    Trace directory path for the viewer\n");
	fprintf(ofp, "  -e, --viewer CMD         Specify viewer and/or options to use\n");
	fprintf(ofp, "                           This will completely override the default viewers so\n");
	fprintf(ofp, "                           please make sure to specify the full command. The trace\n");
	fprintf(ofp, "                           directory path of the session will be appended at the end\n");
	fprintf(ofp, "                           to the arguments\n");
	fprintf(ofp, "\n");
}

static struct viewers *parse_options(void)
{
	if (opt_viewer == NULL) {
		/* Default is babeltrace */
		return &(viewers[VIEWER_BABELTRACE]);
	}

#if 0
	if (strstr(opt_viewer, viewers[VIEWER_LTTV_GUI].exec_name) == 0) {
		return &(viewers[VIEWER_LTTV_GUI]);
	}
#endif

	/*
	 * This means that if -e, --viewers is used, we just override everything
	 * with it. For supported viewers like lttv, we could simply detect if "-t"
	 * is passed and if not, add the trace directory to it.
	 */
	return &(viewers[VIEWER_USER_DEFINED]);
}

/*
 * Alloc an array of string pointer from a simple string having all options
 * seperated by spaces. Also adds the trace path to the arguments.
 *
 * The returning pointer is ready to be passed to execvp().
 */
static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
{
	int i = 0, ignore_space = 0;
	unsigned int num_opts = 1;
	char **argv, *token = opts;

	/* Count number of arguments. */
	do {
		if (*token == ' ') {
			/* Use to ignore consecutive spaces */
			if (!ignore_space) {
				num_opts++;
			}
			ignore_space = 1;
		} else {
			ignore_space = 0;
		}
		token++;
	} while (*token != '\0');

	/* Add two here for the NULL terminating element and trace path */
	argv = zmalloc(sizeof(char *) * (num_opts + 2));
	if (argv == NULL) {
		goto error;
	}

	token = strtok(opts, " ");
	while (token != NULL) {
		argv[i] = strdup(token);
		if (argv[i] == NULL) {
			goto error;
		}
		token = strtok(NULL, " ");
		i++;
	}

	argv[num_opts] = (char *) trace_path;
	argv[num_opts + 1] = NULL;

	return argv;

error:
	if (argv) {
		for (i = 0; i < num_opts + 2; i++) {
			free(argv[i]);
		}
		free(argv);
	}

	return NULL;
}

/*
 * Alloc an array of string pointer from an array of strings. It also adds
 * the trace path to the argv.
 *
 * The returning pointer is ready to be passed to execvp().
 */
static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
		const char *trace_path)
{
	char **argv;
	size_t size, mem_len;


	/* Add one for the NULL terminating element. */
	mem_len = opts_len + 1;
	if (session_live_mode) {
		/* Add 3 option for the live mode being "-i lttng-live URL". */
		mem_len += 3;
	} else {
		/* Add option for the trace path. */
		mem_len += 1;
	}

	size = sizeof(char *) * mem_len;

	/* Add two here for the trace_path and the NULL terminating element. */
	argv = zmalloc(size);
	if (argv == NULL) {
		goto error;
	}

	memcpy(argv, opts, size);

	if (session_live_mode) {
		argv[opts_len] = "-i";
		argv[opts_len + 1] = "lttng-live";
		argv[opts_len + 2] = (char *) trace_path;
		argv[opts_len + 3] = NULL;
	} else {
		argv[opts_len] = (char *) trace_path;
		argv[opts_len + 1] = NULL;
	}

error:
	return argv;
}

/*
 * Spawn viewer with the trace directory path.
 */
static int spawn_viewer(const char *trace_path)
{
	int ret = 0;
	struct stat status;
	const char *viewer_bin = NULL;
	struct viewers *viewer;
	char **argv = NULL;

	/* Check for --viewer options */
	viewer = parse_options();
	if (viewer == NULL) {
		ret = CMD_ERROR;
		goto error;
	}

	switch (viewer->type) {
	case VIEWER_BABELTRACE:
		if (stat(babeltrace_bin, &status) == 0) {
			viewer_bin = babeltrace_bin;
		} else {
			viewer_bin = viewer->exec_name;
		}
		argv = alloc_argv_from_local_opts(babeltrace_opts,
				ARRAY_SIZE(babeltrace_opts), trace_path);
		break;
	case VIEWER_USER_DEFINED:
		argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
		if (argv) {
			viewer_bin = argv[0];
		}
		break;
	default:
		viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
		argv = alloc_argv_from_local_opts(babeltrace_opts,
				ARRAY_SIZE(babeltrace_opts), trace_path);
		break;
	}

	if (argv == NULL || !viewer_bin) {
		ret = CMD_FATAL;
		goto error;
	}

	DBG("Using %s viewer", viewer_bin);

	ret = execvp(viewer_bin, argv);
	if (ret) {
		if (errno == ENOENT) {
			ERR("%s not found on the system", viewer_bin);
		} else {
			PERROR("exec: %s", viewer_bin);
		}
		free(argv);
		ret = CMD_FATAL;
		goto error;
	}

error:
	return ret;
}

/*
 * Build the live path we need for the lttng live view.
 */
static char *build_live_path(char *session_name)
{
	int ret;
	char *path = NULL;
	char hostname[HOST_NAME_MAX];

	ret = gethostname(hostname, sizeof(hostname));
	if (ret < 0) {
		PERROR("gethostname");
		goto error;
	}

	ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
			session_name);
	if (ret < 0) {
		PERROR("asprintf live path");
		goto error;
	}

error:
	return path;
}

/*
 * Exec viewer if found and use session name path.
 */
static int view_trace(void)
{
	int ret;
	char *session_name, *trace_path = NULL;
	struct lttng_session *sessions = NULL;

	/*
	 * Safety net. If lttng is suid at some point for *any* useless reasons,
	 * this prevent any bad execution of binaries.
	 */
	if (getuid() != 0) {
		if (getuid() != geteuid()) {
			ERR("UID does not match effective UID.");
			ret = CMD_ERROR;
			goto error;
		} else if (getgid() != getegid()) {
			ERR("GID does not match effective GID.");
			ret = CMD_ERROR;
			goto error;
		}
	}

	/* User define trace path override the session name */
	if (opt_trace_path) {
		session_name = NULL;
	} else if(opt_session_name == NULL) {
		session_name = get_session_name();
		if (session_name == NULL) {
			ret = CMD_ERROR;
			goto error;
		}
	} else {
		session_name = opt_session_name;
	}

	DBG("Viewing trace for session %s", session_name);

	if (session_name) {
		int i, count, found = 0;

		/* Getting all sessions */
		count = lttng_list_sessions(&sessions);
		if (count < 0) {
			ERR("Unable to list sessions. Session name %s not found.",
					session_name);
			MSG("Is there a session daemon running?");
			ret = CMD_ERROR;
			goto free_error;
		}

		/* Find our session listed by the session daemon */
		for (i = 0; i < count; i++) {
			if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
				found = 1;
				break;
			}
		}

		if (!found) {
			MSG("Session name %s not found", session_name);
			ret = CMD_ERROR;
			goto free_sessions;
		}

		session_live_mode = sessions[i].live_timer_interval;

		DBG("Session live mode set to %d", session_live_mode);

		if (sessions[i].enabled && !session_live_mode) {
			WARN("Session %s is running. Please stop it before reading it.",
					session_name);
			ret = CMD_ERROR;
			goto free_sessions;
		}

		/* If the timer interval is set we are in live mode. */
		if (session_live_mode) {
			trace_path = build_live_path(session_name);
			if (!trace_path) {
				ret = CMD_ERROR;
				goto free_sessions;
			}
		} else {
			/* Get file system session path. */
			trace_path = sessions[i].path;
		}
	} else {
		trace_path = opt_trace_path;
	}

	MSG("Trace directory: %s\n", trace_path);

	ret = spawn_viewer(trace_path);
	if (ret < 0) {
		/* Don't set ret so lttng can interpret the sessiond error. */
		goto free_sessions;
	}

free_sessions:
	if (session_live_mode) {
		free(trace_path);
	}
	free(sessions);
free_error:
	if (opt_session_name == NULL) {
		free(session_name);
	}
error:
	return ret;
}

/*
 * The 'view <options>' first level command
 */
int cmd_view(int argc, const char **argv)
{
	int opt, ret = CMD_SUCCESS;
	static poptContext pc;

	pc = poptGetContext(NULL, argc, argv, long_options, 0);
	poptReadDefaultConfig(pc, 0);

	if (lttng_opt_mi) {
		WARN("mi does not apply to view command");
	}

	while ((opt = poptGetNextOpt(pc)) != -1) {
		switch (opt) {
		case OPT_HELP:
			usage(stdout);
			goto end;
		case OPT_LIST_OPTIONS:
			list_cmd_options(stdout, long_options);
			goto end;
		default:
			usage(stderr);
			ret = CMD_UNDEFINED;
			goto end;
		}
	}

	opt_session_name = (char*) poptGetArg(pc);

	ret = view_trace();

end:
	poptFreeContext(pc);
	return ret;
}
Commit	Line	Data
0c95f5b2 DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
	3	*
d14d33bf AM	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
0c95f5b2	7	*
d14d33bf AM	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
0c95f5b2	12	*
d14d33bf AM	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
0c95f5b2 DG	16	*/
	17
	18	#define _GNU_SOURCE
6c1c0768	19	#define _LGPL_SOURCE
0c95f5b2 DG	20	#include <popt.h>
	21	#include <stdio.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <sys/stat.h>
	25	#include <sys/types.h>
	26	#include <unistd.h>
	27
	28	#include "../command.h"
	29	#include <config.h>
	30
	31	static char *opt_session_name;
	32	static char *opt_viewer;
f1f887c0	33	static char *opt_trace_path;
0c95f5b2 DG	34	static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
	35	//static const char *lttv_gui_bin = CONFIG_LTTV_GUI_BIN;
	36
	37	enum {
	38	OPT_HELP = 1,
	39	OPT_LIST_OPTIONS,
	40	};
	41
	42	static struct poptOption long_options[] = {
	43	/* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
	44	{"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
	45	{"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
	46	{"viewer", 'e', POPT_ARG_STRING, &opt_viewer, 0, 0, 0},
f1f887c0	47	{"trace-path", 't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
0c95f5b2 DG	48	{0, 0, 0, 0, 0, 0, 0}
	49	};
	50
	51	/*
	52	* This is needed for each viewer since we are using execvp().
	53	*/
36ef520f	54	static const char *babeltrace_opts[] = { "babeltrace" };
0c95f5b2 DG	55	//static const char *lttv_gui_opts[] = { "lttv-gui", "-t", };
	56
	57	/*
	58	* Type is also use as the index in the viewers array. So please, make sure
	59	* your enum value is in the right order in the array below.
	60	*/
	61	enum viewer_type {
	62	VIEWER_BABELTRACE = 0,
	63	VIEWER_LTTV_GUI = 1,
	64	VIEWER_USER_DEFINED = 2,
	65	};
	66
	67	/*
	68	* NOTE: "lttv" is a shell command and it's not working for exec() family
	69	* functions so we might think of removing this wrapper or using bash.
	70	*/
	71	static struct viewers {
	72	const char *exec_name;
	73	enum viewer_type type;
	74	} viewers[] = {
	75	{ "babeltrace", VIEWER_BABELTRACE },
	76	{ "lttv-gui", VIEWER_LTTV_GUI },
	77	{ NULL, VIEWER_USER_DEFINED },
	78	};
	79
8960e9cd DG	80	/* Is the session we are trying to view is in live mode. */
	81	static int session_live_mode;
	82
0c95f5b2 DG	83	/*
	84	* usage
	85	*/
	86	static void usage(FILE *ofp)
	87	{
	88	fprintf(ofp, "usage: lttng view [SESSION_NAME] [OPTIONS]\n");
	89	fprintf(ofp, "\n");
	90	fprintf(ofp, "By default, the babeltrace viewer will be used for text viewing\n");
	91	fprintf(ofp, "\n");
	92	fprintf(ofp, "Where SESSION_NAME is an optional session name. If not specified, lttng will\n");
	93	fprintf(ofp, "get it from the configuration file (.lttngrc).\n");
	94	fprintf(ofp, "\n");
32a6298d	95	fprintf(ofp, "Options:\n");
0c95f5b2 DG	96	fprintf(ofp, " -h, --help Show this help\n");
0c95f5b2 DG	97	fprintf(ofp, " --list-options Simple listing of options\n");
f1f887c0	98	fprintf(ofp, " -t, --trace-path PATH Trace directory path for the viewer\n");
0c95f5b2 DG	99	fprintf(ofp, " -e, --viewer CMD Specify viewer and/or options to use\n");
0c95f5b2 DG	100	fprintf(ofp, " This will completely override the default viewers so\n");
f1f887c0 DG	101	fprintf(ofp, " please make sure to specify the full command. The trace\n");
	102	fprintf(ofp, " directory path of the session will be appended at the end\n");
	103	fprintf(ofp, " to the arguments\n");
0c95f5b2 DG	104	fprintf(ofp, "\n");
	105	}
	106
	107	static struct viewers *parse_options(void)
	108	{
	109	if (opt_viewer == NULL) {
	110	/* Default is babeltrace */
	111	return &(viewers[VIEWER_BABELTRACE]);
	112	}
	113
	114	#if 0
	115	if (strstr(opt_viewer, viewers[VIEWER_LTTV_GUI].exec_name) == 0) {
	116	return &(viewers[VIEWER_LTTV_GUI]);
	117	}
	118	#endif
	119
	120	/*
	121	* This means that if -e, --viewers is used, we just override everything
	122	* with it. For supported viewers like lttv, we could simply detect if "-t"
	123	* is passed and if not, add the trace directory to it.
	124	*/
	125	return &(viewers[VIEWER_USER_DEFINED]);
	126	}
	127
	128	/*
	129	* Alloc an array of string pointer from a simple string having all options
	130	* seperated by spaces. Also adds the trace path to the arguments.
	131	*
	132	* The returning pointer is ready to be passed to execvp().
	133	*/
	134	static char *alloc_argv_from_user_opts(char opts, const char *trace_path)
	135	{
	136	int i = 0, ignore_space = 0;
	137	unsigned int num_opts = 1;
	138	char *argv, token = opts;
	139
	140	/* Count number of arguments. */
	141	do {
	142	if (*token == ' ') {
	143	/* Use to ignore consecutive spaces */
	144	if (!ignore_space) {
	145	num_opts++;
	146	}
	147	ignore_space = 1;
	148	} else {
	149	ignore_space = 0;
	150	}
	151	token++;
	152	} while (*token != '\0');
	153
	154	/* Add two here for the NULL terminating element and trace path */
1025878e	155	argv = zmalloc(sizeof(char ) (num_opts + 2));
0c95f5b2 DG	156	if (argv == NULL) {
	157	goto error;
	158	}
	159
	160	token = strtok(opts, " ");
	161	while (token != NULL) {
	162	argv[i] = strdup(token);
44721eb2 MD	163	if (argv[i] == NULL) {
	164	goto error;
	165	}
0c95f5b2 DG	166	token = strtok(NULL, " ");
	167	i++;
	168	}
	169
	170	argv[num_opts] = (char *) trace_path;
	171	argv[num_opts + 1] = NULL;
	172
	173	return argv;
	174
	175	error:
879ba548 JG	176	if (argv) {
	177	for (i = 0; i < num_opts + 2; i++) {
	178	free(argv[i]);
	179	}
	180	free(argv);
	181	}
	182
0c95f5b2 DG	183	return NULL;
	184	}
	185
	186	/*
	187	* Alloc an array of string pointer from an array of strings. It also adds
	188	* the trace path to the argv.
	189	*
	190	* The returning pointer is ready to be passed to execvp().
	191	*/
	192	static char alloc_argv_from_local_opts(const char opts, size_t opts_len,
	193	const char *trace_path)
	194	{
	195	char **argv;
8960e9cd DG	196	size_t size, mem_len;
	197
	198
	199	/* Add one for the NULL terminating element. */
	200	mem_len = opts_len + 1;
	201	if (session_live_mode) {
	202	/* Add 3 option for the live mode being "-i lttng-live URL". */
	203	mem_len += 3;
	204	} else {
	205	/* Add option for the trace path. */
	206	mem_len += 1;
	207	}
0c95f5b2	208
8960e9cd	209	size = sizeof(char ) mem_len;
0c95f5b2 DG	210
0c95f5b2 DG	211	/* Add two here for the trace_path and the NULL terminating element. */
1025878e	212	argv = zmalloc(size);
0c95f5b2 DG	213	if (argv == NULL) {
	214	goto error;
	215	}
	216
	217	memcpy(argv, opts, size);
	218
8960e9cd DG	219	if (session_live_mode) {
	220	argv[opts_len] = "-i";
	221	argv[opts_len + 1] = "lttng-live";
	222	argv[opts_len + 2] = (char *) trace_path;
	223	argv[opts_len + 3] = NULL;
	224	} else {
	225	argv[opts_len] = (char *) trace_path;
	226	argv[opts_len + 1] = NULL;
	227	}
0c95f5b2 DG	228
	229	error:
	230	return argv;
	231	}
	232
	233	/*
	234	* Spawn viewer with the trace directory path.
	235	*/
	236	static int spawn_viewer(const char *trace_path)
	237	{
	238	int ret = 0;
0c95f5b2 DG	239	struct stat status;
	240	const char *viewer_bin = NULL;
	241	struct viewers *viewer;
	242	char **argv = NULL;
	243
	244	/* Check for --viewer options */
	245	viewer = parse_options();
	246	if (viewer == NULL) {
	247	ret = CMD_ERROR;
	248	goto error;
	249	}
	250
85a68078 DG	251	switch (viewer->type) {
	252	case VIEWER_BABELTRACE:
	253	if (stat(babeltrace_bin, &status) == 0) {
	254	viewer_bin = babeltrace_bin;
	255	} else {
	256	viewer_bin = viewer->exec_name;
	257	}
	258	argv = alloc_argv_from_local_opts(babeltrace_opts,
	259	ARRAY_SIZE(babeltrace_opts), trace_path);
	260	break;
85a68078 DG	261	case VIEWER_USER_DEFINED:
	262	argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
	263	if (argv) {
	264	viewer_bin = argv[0];
0c95f5b2	265	}
85a68078 DG	266	break;
	267	default:
	268	viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
	269	argv = alloc_argv_from_local_opts(babeltrace_opts,
	270	ARRAY_SIZE(babeltrace_opts), trace_path);
	271	break;
	272	}
0c95f5b2	273
57138fbd	274	if (argv == NULL \|\| !viewer_bin) {
85a68078 DG	275	ret = CMD_FATAL;
	276	goto error;
	277	}
0c95f5b2	278
85a68078	279	DBG("Using %s viewer", viewer_bin);
0c95f5b2	280
85a68078 DG	281	ret = execvp(viewer_bin, argv);
85a68078 DG	282	if (ret) {
0c687325 JD	283	if (errno == ENOENT) {
	284	ERR("%s not found on the system", viewer_bin);
	285	} else {
	286	PERROR("exec: %s", viewer_bin);
	287	}
85a68078	288	free(argv);
0c95f5b2	289	ret = CMD_FATAL;
85a68078	290	goto error;
0c95f5b2 DG	291	}
	292
	293	error:
	294	return ret;
	295	}
	296
8960e9cd DG	297	/*
	298	* Build the live path we need for the lttng live view.
	299	*/
	300	static char build_live_path(char session_name)
	301	{
	302	int ret;
	303	char *path = NULL;
	304	char hostname[HOST_NAME_MAX];
	305
	306	ret = gethostname(hostname, sizeof(hostname));
	307	if (ret < 0) {
6f04ed72	308	PERROR("gethostname");
8960e9cd DG	309	goto error;
	310	}
	311
	312	ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
	313	session_name);
	314	if (ret < 0) {
6f04ed72	315	PERROR("asprintf live path");
8960e9cd DG	316	goto error;
	317	}
	318
	319	error:
	320	return path;
	321	}
	322
0c95f5b2 DG	323	/*
	324	* Exec viewer if found and use session name path.
	325	*/
	326	static int view_trace(void)
	327	{
c617c0c6	328	int ret;
8960e9cd	329	char session_name, trace_path = NULL;
0c95f5b2 DG	330	struct lttng_session *sessions = NULL;
	331
	332	/*
	333	* Safety net. If lttng is suid at some point for any useless reasons,
f1f887c0	334	* this prevent any bad execution of binaries.
0c95f5b2 DG	335	*/
	336	if (getuid() != 0) {
	337	if (getuid() != geteuid()) {
	338	ERR("UID does not match effective UID.");
6e9261f4	339	ret = CMD_ERROR;
0c95f5b2 DG	340	goto error;
	341	} else if (getgid() != getegid()) {
	342	ERR("GID does not match effective GID.");
6e9261f4	343	ret = CMD_ERROR;
0c95f5b2 DG	344	goto error;
	345	}
	346	}
	347
f1f887c0 DG	348	/* User define trace path override the session name */
	349	if (opt_trace_path) {
	350	session_name = NULL;
	351	} else if(opt_session_name == NULL) {
0c95f5b2 DG	352	session_name = get_session_name();
	353	if (session_name == NULL) {
	354	ret = CMD_ERROR;
	355	goto error;
	356	}
	357	} else {
	358	session_name = opt_session_name;
	359	}
	360
	361	DBG("Viewing trace for session %s", session_name);
	362
f1f887c0	363	if (session_name) {
c617c0c6 MD	364	int i, count, found = 0;
c617c0c6 MD	365
f1f887c0 DG	366	/* Getting all sessions */
	367	count = lttng_list_sessions(&sessions);
	368	if (count < 0) {
	369	ERR("Unable to list sessions. Session name %s not found.",
	370	session_name);
	371	MSG("Is there a session daemon running?");
	372	ret = CMD_ERROR;
	373	goto free_error;
	374	}
0c95f5b2	375
f1f887c0 DG	376	/* Find our session listed by the session daemon */
	377	for (i = 0; i < count; i++) {
	378	if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
	379	found = 1;
	380	break;
	381	}
0c95f5b2	382	}
0c95f5b2	383
f1f887c0 DG	384	if (!found) {
	385	MSG("Session name %s not found", session_name);
	386	ret = CMD_ERROR;
	387	goto free_sessions;
	388	}
	389
8960e9cd DG	390	session_live_mode = sessions[i].live_timer_interval;
	391
	392	DBG("Session live mode set to %d", session_live_mode);
3822545d	393
8960e9cd	394	if (sessions[i].enabled && !session_live_mode) {
3822545d DG	395	WARN("Session %s is running. Please stop it before reading it.",
	396	session_name);
	397	ret = CMD_ERROR;
	398	goto free_sessions;
	399	}
8960e9cd DG	400
	401	/* If the timer interval is set we are in live mode. */
	402	if (session_live_mode) {
	403	trace_path = build_live_path(session_name);
	404	if (!trace_path) {
	405	ret = CMD_ERROR;
	406	goto free_sessions;
	407	}
	408	} else {
	409	/* Get file system session path. */
	410	trace_path = sessions[i].path;
	411	}
f1f887c0 DG	412	} else {
f1f887c0 DG	413	trace_path = opt_trace_path;
0c95f5b2 DG	414	}
0c95f5b2 DG	415
f1f887c0	416	MSG("Trace directory: %s\n", trace_path);
0c95f5b2	417
f1f887c0	418	ret = spawn_viewer(trace_path);
0c95f5b2 DG	419	if (ret < 0) {
	420	/* Don't set ret so lttng can interpret the sessiond error. */
	421	goto free_sessions;
	422	}
	423
0c95f5b2	424	free_sessions:
8960e9cd DG	425	if (session_live_mode) {
	426	free(trace_path);
	427	}
0e428499	428	free(sessions);
0c95f5b2 DG	429	free_error:
	430	if (opt_session_name == NULL) {
	431	free(session_name);
	432	}
	433	error:
	434	return ret;
	435	}
	436
	437	/*
	438	* The 'view <options>' first level command
	439	*/
	440	int cmd_view(int argc, const char **argv)
	441	{
	442	int opt, ret = CMD_SUCCESS;
	443	static poptContext pc;
	444
	445	pc = poptGetContext(NULL, argc, argv, long_options, 0);
	446	poptReadDefaultConfig(pc, 0);
	447
c7e35b03 JR	448	if (lttng_opt_mi) {
	449	WARN("mi does not apply to view command");
	450	}
	451
0c95f5b2 DG	452	while ((opt = poptGetNextOpt(pc)) != -1) {
	453	switch (opt) {
	454	case OPT_HELP:
	455	usage(stdout);
	456	goto end;
	457	case OPT_LIST_OPTIONS:
	458	list_cmd_options(stdout, long_options);
	459	goto end;
	460	default:
	461	usage(stderr);
	462	ret = CMD_UNDEFINED;
	463	goto end;
	464	}
	465	}
	466
	467	opt_session_name = (char*) poptGetArg(pc);
	468
	469	ret = view_trace();
	470
	471	end:
	472	poptFreeContext(pc);
	473	return ret;
	474	}