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

/*
 * 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, 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
#include <getopt.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <config.h>
#include <ctype.h>

#include <lttng/lttng.h>
#include <common/error.h>

#include "command.h"

/* Variables */
static char *progname;
static int opt_no_sessiond;
static char *opt_sessiond_path;
static pid_t sessiond_pid;
static volatile int recv_child_signal;

char *opt_relayd_path;

enum {
	OPT_RELAYD_PATH,
	OPT_SESSION_PATH,
	OPT_DUMP_OPTIONS,
	OPT_DUMP_COMMANDS,
};

/* Getopt options. No first level command. */
static struct option long_options[] = {
	{"version",          0, NULL, 'V'},
	{"help",             0, NULL, 'h'},
	{"group",            1, NULL, 'g'},
	{"verbose",          0, NULL, 'v'},
	{"quiet",            0, NULL, 'q'},
	{"no-sessiond",      0, NULL, 'n'},
	{"sessiond-path",    1, NULL, OPT_SESSION_PATH},
	{"relayd-path",      1, NULL, OPT_RELAYD_PATH},
	{"list-options",     0, NULL, OPT_DUMP_OPTIONS},
	{"list-commands",    0, NULL, OPT_DUMP_COMMANDS},
	{NULL, 0, NULL, 0}
};

/* First level command */
static struct cmd_struct commands[] =  {
	{ "list", cmd_list},
	{ "create", cmd_create},
	{ "destroy", cmd_destroy},
	{ "start", cmd_start},
	{ "stop", cmd_stop},
	{ "enable-event", cmd_enable_events},
	{ "disable-event", cmd_disable_events},
	{ "enable-channel", cmd_enable_channels},
	{ "disable-channel", cmd_disable_channels},
	{ "add-context", cmd_add_context},
	{ "set-session", cmd_set_session},
	{ "version", cmd_version},
	{ "calibrate", cmd_calibrate},
	{ "view", cmd_view},
	{ "snapshot", cmd_snapshot},
	{ "save", cmd_save},
	{ "load", cmd_load},
	{ "enable-consumer", cmd_enable_consumer}, /* OBSOLETE */
	{ "disable-consumer", cmd_disable_consumer}, /* OBSOLETE */
	{ NULL, NULL}	/* Array closure */
};

static void usage(FILE *ofp)
{
	fprintf(ofp, "LTTng Trace Control " FULL_VERSION" - " VERSION_NAME"\n\n");
	fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND> [<ARGS>]\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Options:\n");
	fprintf(ofp, "  -V, --version              Show version\n");
	fprintf(ofp, "  -h, --help                 Show this help\n");
	fprintf(ofp, "      --list-options         Simple listing of lttng options\n");
	fprintf(ofp, "      --list-commands        Simple listing of lttng commands\n");
	fprintf(ofp, "  -v, --verbose              Increase verbosity\n");
	fprintf(ofp, "  -q, --quiet                Quiet mode\n");
	fprintf(ofp, "  -g, --group NAME           Unix tracing group name. (default: tracing)\n");
	fprintf(ofp, "  -n, --no-sessiond          Don't spawn a session daemon\n");
	fprintf(ofp, "      --sessiond-path PATH   Session daemon full path\n");
	fprintf(ofp, "      --relayd-path PATH     Relayd daemon full path\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Commands:\n");
	fprintf(ofp, "    add-context       Add context to event and/or channel\n");
	fprintf(ofp, "    calibrate         Quantify LTTng overhead\n");
	fprintf(ofp, "    create            Create tracing session\n");
	fprintf(ofp, "    destroy           Tear down tracing session\n");
	fprintf(ofp, "    enable-channel    Enable tracing channel\n");
	fprintf(ofp, "    enable-event      Enable tracing event\n");
	fprintf(ofp, "    disable-channel   Disable tracing channel\n");
	fprintf(ofp, "    disable-event     Disable tracing event\n");
	fprintf(ofp, "    list              List possible tracing options\n");
	fprintf(ofp, "    set-session       Set current session name\n");
	fprintf(ofp, "    snapshot          Snapshot buffers of current session name\n");
	fprintf(ofp, "    start             Start tracing\n");
	fprintf(ofp, "    stop              Stop tracing\n");
	fprintf(ofp, "    version           Show version information\n");
	fprintf(ofp, "    view              Start trace viewer\n");
	fprintf(ofp, "    save              Save session configuration\n");
	fprintf(ofp, "    load              Load session configuration\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Each command also has its own -h, --help option.\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "Please see the lttng(1) man page for full documentation.\n");
	fprintf(ofp, "See http://lttng.org for updates, bug reports and news.\n");
}

static void version(FILE *ofp)
{
	fprintf(ofp, "%s (LTTng Trace Control) " FULL_VERSION" - " VERSION_NAME"\n",
			progname);
}

/*
 *  list_options
 *
 *  List options line by line. This is mostly for bash auto completion and to
 *  avoid difficult parsing.
 */
static void list_options(FILE *ofp)
{
	int i = 0;
	struct option *option = NULL;

	option = &long_options[i];
	while (option->name != NULL) {
		fprintf(ofp, "--%s\n", option->name);

		if (isprint(option->val)) {
			fprintf(ofp, "-%c\n", option->val);
		}

		i++;
		option = &long_options[i];
	}
}

/*
 * clean_exit
 */
static void clean_exit(int code)
{
	DBG("Clean exit");
	exit(code);
}

/*
 *  sighandler
 *
 *  Signal handler for the daemon
 */
static void sighandler(int sig)
{
	int status;

	switch (sig) {
		case SIGTERM:
			DBG("SIGTERM caught");
			clean_exit(EXIT_FAILURE);
			break;
		case SIGCHLD:
			DBG("SIGCHLD caught");
			waitpid(sessiond_pid, &status, 0);
			recv_child_signal = 1;
			/* Indicate that the session daemon died */
			sessiond_pid = 0;
			ERR("Session daemon died (exit status %d)", WEXITSTATUS(status));
			break;
		case SIGUSR1:
			/* Notify is done */
			recv_child_signal = 1;
			DBG("SIGUSR1 caught");
			break;
		default:
			DBG("Unknown signal %d caught", sig);
			break;
	}

	return;
}

/*
 *  set_signal_handler
 *
 *  Setup signal handler for SIGCHLD and SIGTERM.
 */
static int set_signal_handler(void)
{
	int ret = 0;
	struct sigaction sa;
	sigset_t sigset;

	if ((ret = sigemptyset(&sigset)) < 0) {
		perror("sigemptyset");
		goto end;
	}

	sa.sa_handler = sighandler;
	sa.sa_mask = sigset;
	sa.sa_flags = 0;
	if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
		perror("sigaction");
		goto end;
	}

	if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
		perror("sigaction");
		goto end;
	}

	if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
		perror("sigaction");
		goto end;
	}

end:
	return ret;
}

/*
 *  handle_command
 *
 *  Handle the full argv list of a first level command. Will find the command
 *  in the global commands array and call the function callback associated.
 *
 *  If command not found, return -1
 *  else, return function command error code.
 */
static int handle_command(int argc, char **argv)
{
	int i = 0, ret;
	struct cmd_struct *cmd;

	if (*argv == NULL) {
		ret = CMD_SUCCESS;
		goto end;
	}

	cmd = &commands[i];
	while (cmd->func != NULL) {
		/* Find command */
		if (strcmp(argv[0], cmd->name) == 0) {
			ret = cmd->func(argc, (const char**) argv);
			goto end;
		}
		i++;
		cmd = &commands[i];
	}

	/* Command not found */
	ret = CMD_UNDEFINED;

end:
	return ret;
}

/*
 *  spawn_sessiond
 *
 *  Spawn a session daemon by forking and execv.
 */
static int spawn_sessiond(char *pathname)
{
	int ret = 0;
	pid_t pid;

	MSG("Spawning a session daemon");
	recv_child_signal = 0;
	pid = fork();
	if (pid == 0) {
		/*
		 * Spawn session daemon and tell
		 * it to signal us when ready.
		 */
		execlp(pathname, "lttng-sessiond", "--sig-parent", "--quiet", NULL);
		/* execlp only returns if error happened */
		if (errno == ENOENT) {
			ERR("No session daemon found. Use --sessiond-path.");
		} else {
			perror("execlp");
		}
		kill(getppid(), SIGTERM);	/* wake parent */
		exit(EXIT_FAILURE);
	} else if (pid > 0) {
		sessiond_pid = pid;
		/*
		 * Wait for lttng-sessiond to start. We need to use a flag to check if
		 * the signal has been sent to us, because the child can be scheduled
		 * before the parent, and thus send the signal before this check. In
		 * the signal handler, we set the recv_child_signal flag, so anytime we
		 * check it after the fork is fine. Note that sleep() is interrupted
		 * before the 1 second delay as soon as the signal is received, so it
		 * will not cause visible delay for the user.
		 */
		while (!recv_child_signal) {
			sleep(1);
		}
		/*
		 * The signal handler will nullify sessiond_pid on SIGCHLD
		 */
		if (!sessiond_pid) {
			exit(EXIT_FAILURE);
		}
		goto end;
	} else {
		perror("fork");
		ret = -1;
		goto end;
	}

end:
	return ret;
}

/*
 *  check_sessiond
 *
 *  Check if the session daemon is available using
 *  the liblttngctl API for the check. If not, try to
 *  spawn a daemon.
 */
static int check_sessiond(void)
{
	int ret;
	char *pathname = NULL;

	ret = lttng_session_daemon_alive();
	if (ret == 0) {	/* not alive */
		/* Try command line option path */
		pathname = opt_sessiond_path;

		/* Try LTTNG_SESSIOND_PATH env variable */
		if (pathname == NULL) {
			pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
		}

		/* Try with configured path */
		if (pathname == NULL) {
			if (CONFIG_SESSIOND_BIN[0] != '\0') {
				pathname = CONFIG_SESSIOND_BIN;
			}
		}

		/* Let's rock and roll while trying the default path */
		if (pathname == NULL) {
			pathname = INSTALL_BIN_PATH "/lttng-sessiond";
		}

		DBG("Session daemon at: %s", pathname);

		/* Check existence and permissions */
		ret = access(pathname, F_OK | X_OK);
		if (ret < 0) {
			ERR("No such file or access denied: %s", pathname);
			goto end;
		}

		ret = spawn_sessiond(pathname);
		if (ret < 0) {
			ERR("Problem occurred when starting %s", pathname);
		}
	}
end:
	return ret;
}

/*
 * Check args for specific options that *must* not trigger a session daemon
 * execution.
 *
 * Return 1 if match else 0.
 */
static int check_args_no_sessiond(int argc, char **argv)
{
	int i;

	for (i = 0; i < argc; i++) {
		if ((strncmp(argv[i], "-h", sizeof("-h")) == 0) ||
				strncmp(argv[i], "--h", sizeof("--h")) == 0 ||
				strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0 ||
				strncmp(argv[i], "--list-commands", sizeof("--list-commands")) == 0 ||
				strncmp(argv[i], "version", sizeof("version")) == 0 ||
				strncmp(argv[i], "view", sizeof("view")) == 0) {
			return 1;
		}
	}

	return 0;
}

/*
 * Parse command line arguments.
 *
 * Return 0 if OK, else -1
 */
static int parse_args(int argc, char **argv)
{
	int opt, ret;

	if (argc < 2) {
		usage(stderr);
		clean_exit(EXIT_FAILURE);
	}

	while ((opt = getopt_long(argc, argv, "+Vhnvqg:", long_options, NULL)) != -1) {
		switch (opt) {
		case 'V':
			version(stdout);
			ret = 0;
			goto end;
		case 'h':
			usage(stdout);
			ret = 0;
			goto end;
		case 'v':
			/* There is only 3 possible level of verbosity. (-vvv) */
			if (lttng_opt_verbose < 3) {
				lttng_opt_verbose += 1;
			}
			break;
		case 'q':
			lttng_opt_quiet = 1;
			break;
		case 'g':
			lttng_set_tracing_group(optarg);
			break;
		case 'n':
			opt_no_sessiond = 1;
			break;
		case OPT_SESSION_PATH:
			opt_sessiond_path = strdup(optarg);
			break;
		case OPT_RELAYD_PATH:
			opt_relayd_path = strdup(optarg);
			break;
		case OPT_DUMP_OPTIONS:
			list_options(stdout);
			ret = 0;
			goto end;
		case OPT_DUMP_COMMANDS:
			list_commands(commands, stdout);
			ret = 0;
			goto end;
		default:
			usage(stderr);
			ret = 1;
			goto error;
		}
	}

	/* If both options are specified, quiet wins */
	if (lttng_opt_verbose && lttng_opt_quiet) {
		lttng_opt_verbose = 0;
	}

	/* Spawn session daemon if needed */
	if (opt_no_sessiond == 0 && check_args_no_sessiond(argc, argv) == 0 &&
			(check_sessiond() < 0)) {
		ret = 1;
		goto error;
	}

	/* No leftovers, print usage and quit */
	if ((argc - optind) == 0) {
		usage(stderr);
		ret = 1;
		goto error;
	}

	/* 
	 * Handle leftovers which is a first level command with the trailing
	 * options.
	 */
	ret = handle_command(argc - optind, argv + optind);
	switch (ret) {
	case CMD_WARNING:
		WARN("Some command(s) went wrong");
		break;
	case CMD_ERROR:
		ERR("Command error");
		break;
	case CMD_UNDEFINED:
		ERR("Undefined command");
		break;
	case CMD_FATAL:
		ERR("Fatal error");
		break;
	case CMD_UNSUPPORTED:
		ERR("Unsupported command");
		break;
	case -1:
		usage(stderr);
		ret = 1;
		break;
	case 0:
		break;
	default:
		if (ret < 0) {
			ret = -ret;
		}
		break;
	}

end:
error:
	return ret;
}


/*
 *  main
 */
int main(int argc, char *argv[])
{
	int ret;
	char *user;

	progname = argv[0] ? argv[0] : "lttng";

	/* For Mathieu Desnoyers a.k.a. Dr. Tracing */
	user = getenv("USER");
	if (user != NULL && ((strncmp(progname, "drtrace", 7) == 0 ||
				strncmp("compudj", user, 7) == 0))) {
		MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
	}
	/* Thanks Mathieu */

	ret = set_signal_handler();
	if (ret < 0) {
		clean_exit(ret);
	}

	ret = parse_args(argc, argv);
	if (ret != 0) {
		clean_exit(ret);
	}

	return 0;
}
Commit	Line	Data
826d496d MD	1	/*
826d496d MD	2	* Copyright (c) 2011 David Goulet <david.goulet@polymtl.ca>
fac6795d DG	3	*
fac6795d DG	4	* This program is free software; you can redistribute it and/or modify
d14d33bf AM	5	* it under the terms of the GNU General Public License, version 2 only,
d14d33bf AM	6	* as published by the Free Software Foundation.
fac6795d DG	7	*
	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.
	12	*
	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.
fac6795d DG	16	*/
	17
	18	#define _GNU_SOURCE
fac6795d	19	#include <getopt.h>
f3ed775e	20	#include <signal.h>
fac6795d DG	21	#include <stdio.h>
	22	#include <stdlib.h>
	23	#include <string.h>
8db8d1dc DG	24	#include <sys/types.h>
8db8d1dc DG	25	#include <sys/wait.h>
fac6795d	26	#include <unistd.h>
3bd1e081	27	#include <config.h>
730389d9	28	#include <ctype.h>
fac6795d	29
5b97ec60	30	#include <lttng/lttng.h>
db758600	31	#include <common/error.h>
fac6795d	32
c399183f	33	#include "command.h"
fac6795d DG	34
	35	/* Variables */
	36	static char *progname;
f3ed775e DG	37	static int opt_no_sessiond;
f3ed775e DG	38	static char *opt_sessiond_path;
8db8d1dc	39	static pid_t sessiond_pid;
5a532b68	40	static volatile int recv_child_signal;
f3ed775e	41
8960e9cd DG	42	char *opt_relayd_path;
8960e9cd DG	43
f3ed775e	44	enum {
8960e9cd	45	OPT_RELAYD_PATH,
f3ed775e	46	OPT_SESSION_PATH,
865abf65 SM	47	OPT_DUMP_OPTIONS,
865abf65 SM	48	OPT_DUMP_COMMANDS,
f3ed775e DG	49	};
	50
	51	/* Getopt options. No first level command. */
	52	static struct option long_options[] = {
70318c38	53	{"version", 0, NULL, 'V'},
f3ed775e DG	54	{"help", 0, NULL, 'h'},
	55	{"group", 1, NULL, 'g'},
	56	{"verbose", 0, NULL, 'v'},
	57	{"quiet", 0, NULL, 'q'},
8490ae7b	58	{"no-sessiond", 0, NULL, 'n'},
f3ed775e	59	{"sessiond-path", 1, NULL, OPT_SESSION_PATH},
8960e9cd	60	{"relayd-path", 1, NULL, OPT_RELAYD_PATH},
865abf65 SM	61	{"list-options", 0, NULL, OPT_DUMP_OPTIONS},
865abf65 SM	62	{"list-commands", 0, NULL, OPT_DUMP_COMMANDS},
f3ed775e DG	63	{NULL, 0, NULL, 0}
	64	};
	65
	66	/* First level command */
	67	static struct cmd_struct commands[] = {
	68	{ "list", cmd_list},
	69	{ "create", cmd_create},
	70	{ "destroy", cmd_destroy},
f3ed775e DG	71	{ "start", cmd_start},
	72	{ "stop", cmd_stop},
	73	{ "enable-event", cmd_enable_events},
e953ef25	74	{ "disable-event", cmd_disable_events},
d36b8583	75	{ "enable-channel", cmd_enable_channels},
26cc6b4e	76	{ "disable-channel", cmd_disable_channels},
d65106b1	77	{ "add-context", cmd_add_context},
3087ef18	78	{ "set-session", cmd_set_session},
eb9cb8b7	79	{ "version", cmd_version},
d0254c7c	80	{ "calibrate", cmd_calibrate},
0c95f5b2	81	{ "view", cmd_view},
57f272ed	82	{ "snapshot", cmd_snapshot},
c864d6d7	83	{ "save", cmd_save},
8c42d845	84	{ "load", cmd_load},
9c6bda17 DG	85	{ "enable-consumer", cmd_enable_consumer}, /* OBSOLETE */
9c6bda17 DG	86	{ "disable-consumer", cmd_disable_consumer}, /* OBSOLETE */
f3ed775e DG	87	{ NULL, NULL} /* Array closure */
	88	};
	89
	90	static void usage(FILE *ofp)
8c0faa1d	91	{
88564da0	92	fprintf(ofp, "LTTng Trace Control " FULL_VERSION" - " VERSION_NAME"\n\n");
32a6298d	93	fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND> [<ARGS>]\n");
f3ed775e DG	94	fprintf(ofp, "\n");
f3ed775e DG	95	fprintf(ofp, "Options:\n");
70318c38	96	fprintf(ofp, " -V, --version Show version\n");
99bab54f TD	97	fprintf(ofp, " -h, --help Show this help\n");
	98	fprintf(ofp, " --list-options Simple listing of lttng options\n");
	99	fprintf(ofp, " --list-commands Simple listing of lttng commands\n");
	100	fprintf(ofp, " -v, --verbose Increase verbosity\n");
	101	fprintf(ofp, " -q, --quiet Quiet mode\n");
	102	fprintf(ofp, " -g, --group NAME Unix tracing group name. (default: tracing)\n");
	103	fprintf(ofp, " -n, --no-sessiond Don't spawn a session daemon\n");
	104	fprintf(ofp, " --sessiond-path PATH Session daemon full path\n");
8960e9cd	105	fprintf(ofp, " --relayd-path PATH Relayd daemon full path\n");
f3ed775e DG	106	fprintf(ofp, "\n");
f3ed775e DG	107	fprintf(ofp, "Commands:\n");
00e2e675 DG	108	fprintf(ofp, " add-context Add context to event and/or channel\n");
	109	fprintf(ofp, " calibrate Quantify LTTng overhead\n");
	110	fprintf(ofp, " create Create tracing session\n");
	111	fprintf(ofp, " destroy Tear down tracing session\n");
	112	fprintf(ofp, " enable-channel Enable tracing channel\n");
	113	fprintf(ofp, " enable-event Enable tracing event\n");
	114	fprintf(ofp, " disable-channel Disable tracing channel\n");
	115	fprintf(ofp, " disable-event Disable tracing event\n");
00e2e675 DG	116	fprintf(ofp, " list List possible tracing options\n");
00e2e675 DG	117	fprintf(ofp, " set-session Set current session name\n");
57f272ed	118	fprintf(ofp, " snapshot Snapshot buffers of current session name\n");
00e2e675 DG	119	fprintf(ofp, " start Start tracing\n");
	120	fprintf(ofp, " stop Stop tracing\n");
	121	fprintf(ofp, " version Show version information\n");
	122	fprintf(ofp, " view Start trace viewer\n");
c864d6d7	123	fprintf(ofp, " save Save session configuration\n");
8c42d845	124	fprintf(ofp, " load Load session configuration\n");
f3ed775e	125	fprintf(ofp, "\n");
99bab54f TD	126	fprintf(ofp, "Each command also has its own -h, --help option.\n");
99bab54f TD	127	fprintf(ofp, "\n");
f3ed775e DG	128	fprintf(ofp, "Please see the lttng(1) man page for full documentation.\n");
f3ed775e DG	129	fprintf(ofp, "See http://lttng.org for updates, bug reports and news.\n");
8c0faa1d DG	130	}
8c0faa1d DG	131
70318c38 SS	132	static void version(FILE *ofp)
70318c38 SS	133	{
88564da0	134	fprintf(ofp, "%s (LTTng Trace Control) " FULL_VERSION" - " VERSION_NAME"\n",
70318c38 SS	135	progname);
	136	}
	137
865abf65 SM	138	/*
	139	* list_options
	140	*
	141	* List options line by line. This is mostly for bash auto completion and to
	142	* avoid difficult parsing.
	143	*/
	144	static void list_options(FILE *ofp)
	145	{
	146	int i = 0;
	147	struct option *option = NULL;
	148
	149	option = &long_options[i];
	150	while (option->name != NULL) {
	151	fprintf(ofp, "--%s\n", option->name);
	152
	153	if (isprint(option->val)) {
	154	fprintf(ofp, "-%c\n", option->val);
	155	}
	156
	157	i++;
	158	option = &long_options[i];
	159	}
	160	}
	161
7442b2ba	162	/*
f3ed775e	163	* clean_exit
96243366	164	*/
f3ed775e	165	static void clean_exit(int code)
96243366	166	{
f3ed775e DG	167	DBG("Clean exit");
f3ed775e DG	168	exit(code);
894be886	169	}
96243366	170
894be886	171	/*
f3ed775e	172	* sighandler
2ef84c95	173	*
f3ed775e	174	* Signal handler for the daemon
2ef84c95	175	*/
f3ed775e	176	static void sighandler(int sig)
2ef84c95	177	{
8db8d1dc DG	178	int status;
8db8d1dc DG	179
f3ed775e DG	180	switch (sig) {
f3ed775e DG	181	case SIGTERM:
99bab54f	182	DBG("SIGTERM caught");
f3ed775e DG	183	clean_exit(EXIT_FAILURE);
	184	break;
	185	case SIGCHLD:
99bab54f	186	DBG("SIGCHLD caught");
8db8d1dc	187	waitpid(sessiond_pid, &status, 0);
5a532b68	188	recv_child_signal = 1;
8db8d1dc DG	189	/* Indicate that the session daemon died */
	190	sessiond_pid = 0;
	191	ERR("Session daemon died (exit status %d)", WEXITSTATUS(status));
	192	break;
	193	case SIGUSR1:
	194	/* Notify is done */
5a532b68	195	recv_child_signal = 1;
99bab54f	196	DBG("SIGUSR1 caught");
f3ed775e DG	197	break;
f3ed775e DG	198	default:
99bab54f	199	DBG("Unknown signal %d caught", sig);
f3ed775e	200	break;
2ef84c95 DG	201	}
2ef84c95 DG	202
f3ed775e	203	return;
2ef84c95 DG	204	}
	205
	206	/*
f3ed775e	207	* set_signal_handler
894be886	208	*
f3ed775e	209	* Setup signal handler for SIGCHLD and SIGTERM.
894be886	210	*/
f3ed775e	211	static int set_signal_handler(void)
894be886	212	{
f3ed775e DG	213	int ret = 0;
	214	struct sigaction sa;
	215	sigset_t sigset;
33a2b854	216
f3ed775e DG	217	if ((ret = sigemptyset(&sigset)) < 0) {
f3ed775e DG	218	perror("sigemptyset");
33a2b854 DG	219	goto end;
	220	}
	221
f3ed775e DG	222	sa.sa_handler = sighandler;
	223	sa.sa_mask = sigset;
	224	sa.sa_flags = 0;
8db8d1dc	225	if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
f3ed775e	226	perror("sigaction");
96243366 DG	227	goto end;
	228	}
	229
f3ed775e DG	230	if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
	231	perror("sigaction");
	232	goto end;
894be886 DG	233	}
894be886 DG	234
8db8d1dc DG	235	if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
	236	perror("sigaction");
	237	goto end;
	238	}
	239
96243366	240	end:
57167058 DG	241	return ret;
	242	}
	243
fac6795d	244	/*
f3ed775e	245	* handle_command
fac6795d	246	*
f3ed775e DG	247	* Handle the full argv list of a first level command. Will find the command
f3ed775e DG	248	* in the global commands array and call the function callback associated.
1c9f7941	249	*
f3ed775e DG	250	* If command not found, return -1
f3ed775e DG	251	* else, return function command error code.
1c9f7941	252	*/
f3ed775e	253	static int handle_command(int argc, char **argv)
1c9f7941	254	{
f3ed775e DG	255	int i = 0, ret;
f3ed775e DG	256	struct cmd_struct *cmd;
1c9f7941	257
f3ed775e DG	258	if (*argv == NULL) {
f3ed775e DG	259	ret = CMD_SUCCESS;
47b74d63	260	goto end;
1c9f7941 DG	261	}
1c9f7941 DG	262
f3ed775e DG	263	cmd = &commands[i];
	264	while (cmd->func != NULL) {
	265	/* Find command */
	266	if (strcmp(argv[0], cmd->name) == 0) {
	267	ret = cmd->func(argc, (const char**) argv);
f3ed775e	268	goto end;
894be886	269	}
f3ed775e DG	270	i++;
f3ed775e DG	271	cmd = &commands[i];
894be886 DG	272	}
894be886 DG	273
f3ed775e	274	/* Command not found */
4ce78777	275	ret = CMD_UNDEFINED;
894be886 DG	276
894be886 DG	277	end:
f3ed775e	278	return ret;
8548ff30 DG	279	}
8548ff30 DG	280
5b8719f5 DG	281	/*
	282	* spawn_sessiond
	283	*
	284	* Spawn a session daemon by forking and execv.
	285	*/
	286	static int spawn_sessiond(char *pathname)
	287	{
	288	int ret = 0;
	289	pid_t pid;
	290
f3ed775e	291	MSG("Spawning a session daemon");
5a532b68	292	recv_child_signal = 0;
5b8719f5 DG	293	pid = fork();
5b8719f5 DG	294	if (pid == 0) {
5e16da05 MD	295	/*
5e16da05 MD	296	* Spawn session daemon and tell
5b8719f5 DG	297	* it to signal us when ready.
5b8719f5 DG	298	*/
32258573	299	execlp(pathname, "lttng-sessiond", "--sig-parent", "--quiet", NULL);
5e16da05 MD	300	/* execlp only returns if error happened */
	301	if (errno == ENOENT) {
	302	ERR("No session daemon found. Use --sessiond-path.");
	303	} else {
	304	perror("execlp");
5b8719f5	305	}
5a532b68	306	kill(getppid(), SIGTERM); /* wake parent */
5e16da05	307	exit(EXIT_FAILURE);
5b8719f5	308	} else if (pid > 0) {
8db8d1dc	309	sessiond_pid = pid;
5a532b68	310	/*
af87c45a DG	311	* Wait for lttng-sessiond to start. We need to use a flag to check if
	312	* the signal has been sent to us, because the child can be scheduled
	313	* before the parent, and thus send the signal before this check. In
	314	* the signal handler, we set the recv_child_signal flag, so anytime we
	315	* check it after the fork is fine. Note that sleep() is interrupted
	316	* before the 1 second delay as soon as the signal is received, so it
	317	* will not cause visible delay for the user.
5a532b68 MD	318	*/
	319	while (!recv_child_signal) {
	320	sleep(1);
	321	}
af87c45a DG	322	/*
	323	* The signal handler will nullify sessiond_pid on SIGCHLD
	324	*/
8db8d1dc DG	325	if (!sessiond_pid) {
	326	exit(EXIT_FAILURE);
	327	}
5b8719f5 DG	328	goto end;
	329	} else {
	330	perror("fork");
	331	ret = -1;
	332	goto end;
	333	}
	334
	335	end:
	336	return ret;
	337	}
	338
fac6795d	339	/*
f3ed775e	340	* check_sessiond
fac6795d DG	341	*
fac6795d DG	342	* Check if the session daemon is available using
5b8719f5 DG	343	* the liblttngctl API for the check. If not, try to
5b8719f5 DG	344	* spawn a daemon.
fac6795d	345	*/
f3ed775e	346	static int check_sessiond(void)
fac6795d DG	347	{
fac6795d DG	348	int ret;
b8ec3da8	349	char *pathname = NULL;
fac6795d	350
947308c4 DG	351	ret = lttng_session_daemon_alive();
947308c4 DG	352	if (ret == 0) { /* not alive */
5b8719f5	353	/* Try command line option path */
b8ec3da8 SM	354	pathname = opt_sessiond_path;
	355
	356	/* Try LTTNG_SESSIOND_PATH env variable */
	357	if (pathname == NULL) {
bbccc3d2	358	pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
5b8719f5 DG	359	}
5b8719f5 DG	360
b8ec3da8	361	/* Try with configured path */
5b8719f5	362	if (pathname == NULL) {
b8ec3da8 SM	363	if (CONFIG_SESSIOND_BIN[0] != '\0') {
b8ec3da8 SM	364	pathname = CONFIG_SESSIOND_BIN;
5b8719f5	365	}
b8ec3da8 SM	366	}
	367
	368	/* Let's rock and roll while trying the default path */
	369	if (pathname == NULL) {
	370	pathname = INSTALL_BIN_PATH "/lttng-sessiond";
	371	}
	372
	373	DBG("Session daemon at: %s", pathname);
	374
	375	/* Check existence and permissions */
	376	ret = access(pathname, F_OK \| X_OK);
	377	if (ret < 0) {
	378	ERR("No such file or access denied: %s", pathname);
	379	goto end;
5b8719f5 DG	380	}
	381
	382	ret = spawn_sessiond(pathname);
5b8719f5	383	if (ret < 0) {
3183dbb0	384	ERR("Problem occurred when starting %s", pathname);
5b8719f5	385	}
c2a79a67	386	}
5b8719f5	387	end:
fac6795d DG	388	return ret;
	389	}
	390
bcfa8a05	391	/*
679b4943 SM	392	* Check args for specific options that must not trigger a session daemon
	393	* execution.
	394	*
	395	* Return 1 if match else 0.
bcfa8a05	396	*/
679b4943	397	static int check_args_no_sessiond(int argc, char **argv)
bcfa8a05 DG	398	{
	399	int i;
	400
	401	for (i = 0; i < argc; i++) {
ba2926ef MD	402	if ((strncmp(argv[i], "-h", sizeof("-h")) == 0) \|\|
ba2926ef MD	403	strncmp(argv[i], "--h", sizeof("--h")) == 0 \|\|
3183dbb0	404	strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0 \|\|
4747a49b	405	strncmp(argv[i], "--list-commands", sizeof("--list-commands")) == 0 \|\|
0c95f5b2 DG	406	strncmp(argv[i], "version", sizeof("version")) == 0 \|\|
0c95f5b2 DG	407	strncmp(argv[i], "view", sizeof("view")) == 0) {
bcfa8a05 DG	408	return 1;
	409	}
	410	}
	411
	412	return 0;
	413	}
	414
5b8719f5	415	/*
3183dbb0	416	* Parse command line arguments.
5b8719f5	417	*
3183dbb0	418	* Return 0 if OK, else -1
5b8719f5	419	*/
f3ed775e	420	static int parse_args(int argc, char **argv)
5b8719f5	421	{
f3ed775e	422	int opt, ret;
5b8719f5	423
f3ed775e DG	424	if (argc < 2) {
	425	usage(stderr);
	426	clean_exit(EXIT_FAILURE);
5b8719f5 DG	427	}
5b8719f5 DG	428
70318c38	429	while ((opt = getopt_long(argc, argv, "+Vhnvqg:", long_options, NULL)) != -1) {
f3ed775e	430	switch (opt) {
70318c38 SS	431	case 'V':
	432	version(stdout);
	433	ret = 0;
	434	goto end;
f3ed775e	435	case 'h':
3183dbb0	436	usage(stdout);
ae856491	437	ret = 0;
3183dbb0	438	goto end;
f3ed775e	439	case 'v':
849e5b7b DG	440	/* There is only 3 possible level of verbosity. (-vvv) */
	441	if (lttng_opt_verbose < 3) {
	442	lttng_opt_verbose += 1;
	443	}
f3ed775e DG	444	break;
f3ed775e DG	445	case 'q':
97e19046	446	lttng_opt_quiet = 1;
f3ed775e DG	447	break;
	448	case 'g':
	449	lttng_set_tracing_group(optarg);
	450	break;
8490ae7b	451	case 'n':
f3ed775e DG	452	opt_no_sessiond = 1;
	453	break;
	454	case OPT_SESSION_PATH:
	455	opt_sessiond_path = strdup(optarg);
	456	break;
8960e9cd DG	457	case OPT_RELAYD_PATH:
	458	opt_relayd_path = strdup(optarg);
	459	break;
865abf65 SM	460	case OPT_DUMP_OPTIONS:
	461	list_options(stdout);
	462	ret = 0;
3183dbb0	463	goto end;
865abf65	464	case OPT_DUMP_COMMANDS:
3c9bd23c	465	list_commands(commands, stdout);
865abf65	466	ret = 0;
3183dbb0	467	goto end;
f3ed775e DG	468	default:
f3ed775e DG	469	usage(stderr);
ae856491	470	ret = 1;
f3ed775e DG	471	goto error;
f3ed775e DG	472	}
5b8719f5	473	}
fac6795d	474
f3ed775e	475	/* If both options are specified, quiet wins */
97e19046 DG	476	if (lttng_opt_verbose && lttng_opt_quiet) {
97e19046 DG	477	lttng_opt_verbose = 0;
5b8719f5 DG	478	}
5b8719f5 DG	479
f3ed775e	480	/* Spawn session daemon if needed */
679b4943	481	if (opt_no_sessiond == 0 && check_args_no_sessiond(argc, argv) == 0 &&
bcfa8a05	482	(check_sessiond() < 0)) {
8005f29a	483	ret = 1;
f3ed775e	484	goto error;
5b8719f5 DG	485	}
5b8719f5 DG	486
f3ed775e DG	487	/* No leftovers, print usage and quit */
	488	if ((argc - optind) == 0) {
	489	usage(stderr);
8005f29a	490	ret = 1;
f3ed775e DG	491	goto error;
f3ed775e DG	492	}
7442b2ba	493
f3ed775e DG	494	/*
	495	* Handle leftovers which is a first level command with the trailing
	496	* options.
	497	*/
	498	ret = handle_command(argc - optind, argv + optind);
ae856491 DG	499	switch (ret) {
	500	case CMD_WARNING:
	501	WARN("Some command(s) went wrong");
	502	break;
	503	case CMD_ERROR:
	504	ERR("Command error");
	505	break;
	506	case CMD_UNDEFINED:
	507	ERR("Undefined command");
	508	break;
	509	case CMD_FATAL:
	510	ERR("Fatal error");
	511	break;
4ce78777 DG	512	case CMD_UNSUPPORTED:
	513	ERR("Unsupported command");
	514	break;
ae856491 DG	515	case -1:
	516	usage(stderr);
	517	ret = 1;
	518	break;
	519	case 0:
	520	break;
	521	default:
42224349 DG	522	if (ret < 0) {
	523	ret = -ret;
	524	}
ae856491	525	break;
96243366 DG	526	}
96243366 DG	527
3183dbb0	528	end:
f3ed775e	529	error:
ae856491	530	return ret;
fac6795d DG	531	}
fac6795d DG	532
f3ed775e	533
fac6795d	534	/*
5b8719f5	535	* main
fac6795d DG	536	*/
	537	int main(int argc, char *argv[])
	538	{
	539	int ret;
cbbb813a	540	char *user;
fac6795d DG	541
	542	progname = argv[0] ? argv[0] : "lttng";
	543
99bab54f	544	/* For Mathieu Desnoyers a.k.a. Dr. Tracing */
cbbb813a DG	545	user = getenv("USER");
	546	if (user != NULL && ((strncmp(progname, "drtrace", 7) == 0 \|\|
	547	strncmp("compudj", user, 7) == 0))) {
4666e71c	548	MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
fac6795d	549	}
cbbb813a	550	/* Thanks Mathieu */
fac6795d	551
5b8719f5 DG	552	ret = set_signal_handler();
5b8719f5 DG	553	if (ret < 0) {
87378cf5	554	clean_exit(ret);
5b8719f5 DG	555	}
5b8719f5 DG	556
f3ed775e	557	ret = parse_args(argc, argv);
ae856491 DG	558	if (ret != 0) {
ae856491 DG	559	clean_exit(ret);
1fff1faa	560	}
87378cf5	561
fac6795d DG	562	return 0;
fac6795d DG	563	}