lttng: Implement lttng clear session command
[lttng-tools.git] / src / bin / lttng / lttng.c
index e6ca9cfd9877485339188fbbbf1626f0a8d21ae7..36a4fbed99e1b5234e986b3a7c10aa85ef00d54e 100644 (file)
@@ -15,7 +15,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <getopt.h>
 #include <signal.h>
 #include <stdio.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 <common/compat/getenv.h>
+#include <common/utils.h>
 
 #include "command.h"
+#include "version.h"
+
+static const char *help_msg =
+#ifdef LTTNG_EMBED_HELP
+#include <lttng.1.h>
+#else
+NULL
+#endif
+;
 
 /* 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;
+int opt_no_sessiond;
+char *opt_sessiond_path;
+
+char *opt_relayd_path;
 
 enum {
+       OPT_RELAYD_PATH,
        OPT_SESSION_PATH,
        OPT_DUMP_OPTIONS,
        OPT_DUMP_COMMANDS,
@@ -47,12 +58,15 @@ enum {
 
 /* 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'},
+       {"mi",               1, NULL, 'm'},
        {"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}
@@ -60,62 +74,60 @@ static struct option long_options[] = {
 
 /* First level command */
 static struct cmd_struct commands[] =  {
-       { "list", cmd_list},
+       { "add-context", cmd_add_context},
        { "create", cmd_create},
+       { "clear", cmd_clear},
        { "destroy", cmd_destroy},
-       { "start", cmd_start},
-       { "stop", cmd_stop},
-       { "enable-event", cmd_enable_events},
+       { "disable-channel", cmd_disable_channels},
        { "disable-event", cmd_disable_events},
        { "enable-channel", cmd_enable_channels},
-       { "disable-channel", cmd_disable_channels},
-       { "add-context", cmd_add_context},
+       { "enable-event", cmd_enable_events},
+       { "help", NULL},
+       { "list", cmd_list},
+       { "load", cmd_load},
+       { "metadata", cmd_metadata},
+       { "regenerate", cmd_regenerate},
+       { "rotate", cmd_rotate},
+       { "enable-rotation", cmd_enable_rotation},
+       { "disable-rotation", cmd_disable_rotation},
+       { "save", cmd_save},
        { "set-session", cmd_set_session},
+       { "snapshot", cmd_snapshot},
+       { "start", cmd_start},
+       { "status", cmd_status},
+       { "stop", cmd_stop},
+       { "track", cmd_track},
+       { "untrack", cmd_untrack},
        { "version", cmd_version},
-       { "calibrate", cmd_calibrate},
        { "view", cmd_view},
-       { "enable-consumer", cmd_enable_consumer},
-       { "disable-consumer", cmd_disable_consumer},
        { NULL, NULL}   /* Array closure */
 };
 
-static void usage(FILE *ofp)
+static void version(FILE *ofp)
 {
-       fprintf(ofp, "LTTng Trace Control " VERSION" - " VERSION_NAME"\n\n");
-       fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND> [<ARGS>]\n");
-       fprintf(ofp, "\n");
-       fprintf(ofp, "Options:\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, "\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, "    enable-consumer   Enable local or streaming consumer\n");
-       fprintf(ofp, "    disable-consumer  Disable consumer\n");
-       fprintf(ofp, "    list              List possible tracing options\n");
-       fprintf(ofp, "    set-session       Set 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, "\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");
+       fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s%s\n",
+                       progname,
+                       GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
+                       EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
+}
+
+/*
+ * Find the MI output type enum from a string. This function is for the support
+ * of machine interface output.
+ */
+static int mi_output_type(const char *output_type)
+{
+       int ret = 0;
+
+       if (!strncasecmp("xml", output_type, 3)) {
+               ret = LTTNG_MI_XML;
+       } else {
+               /* Invalid output format */
+               ERR("MI output format not supported");
+               ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
+       }
+
+       return ret;
 }
 
 /*
@@ -142,25 +154,6 @@ static void list_options(FILE *ofp)
        }
 }
 
-/*
- *  list_commands
- *
- *  List commands line by line. This is mostly for bash auto completion and to
- *  avoid difficult parsing.
- */
-static void list_commands(FILE *ofp)
-{
-       int i = 0;
-       struct cmd_struct *cmd = NULL;
-
-       cmd = &commands[i];
-       while (cmd->name != NULL) {
-               fprintf(ofp, "%s\n", cmd->name);
-               i++;
-               cmd = &commands[i];
-       }
-}
-
 /*
  * clean_exit
  */
@@ -177,26 +170,11 @@ static void clean_exit(int code)
  */
 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;
@@ -217,25 +195,16 @@ static int set_signal_handler(void)
        sigset_t sigset;
 
        if ((ret = sigemptyset(&sigset)) < 0) {
-               perror("sigemptyset");
+               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");
+               PERROR("sigaction");
                goto end;
        }
 
@@ -262,8 +231,14 @@ static int handle_command(int argc, char **argv)
                goto end;
        }
 
+       /* Special case for help command which needs the commands array */
+       if (strcmp(argv[0], "help") == 0) {
+               ret = cmd_help(argc, (const char**) argv, commands);
+               goto end;
+       }
+
        cmd = &commands[i];
-       while (cmd->func != NULL) {
+       while (cmd->name != NULL) {
                /* Find command */
                if (strcmp(argv[0], cmd->name) == 0) {
                        ret = cmd->func(argc, (const char**) argv);
@@ -274,141 +249,81 @@ static int handle_command(int argc, char **argv)
        }
 
        /* Command not found */
-       ret = -1;
+       ret = CMD_UNDEFINED;
 
 end:
        return ret;
 }
 
-/*
- *  spawn_sessiond
- *
- *  Spawn a session daemon by forking and execv.
- */
-static int spawn_sessiond(char *pathname)
+static bool command_exists(const char *command)
 {
-       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, *alloc_pathname = NULL;
-
-       ret = lttng_session_daemon_alive();
-       if (ret == 0) { /* not alive */
-               /* Try command line option path */
-               if (opt_sessiond_path != NULL) {
-                       ret = access(opt_sessiond_path, F_OK | X_OK);
-                       if (ret < 0) {
-                               ERR("No such file or access denied: %s", opt_sessiond_path);
-                               goto end;
-                       }
-                       pathname = opt_sessiond_path;
-               } else {
-                       /* Try LTTNG_SESSIOND_PATH env variable */
-                       pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
-               }
-
-               /* Let's rock and roll */
-               if (pathname == NULL) {
-                       ret = asprintf(&alloc_pathname, INSTALL_BIN_PATH "/lttng-sessiond");
-                       if (ret < 0) {
-                               perror("asprintf spawn sessiond");
-                               goto end;
-                       }
-                       pathname = alloc_pathname;
-               }
+       const struct cmd_struct *cmd = commands;
+       bool exists = false;
 
-               ret = spawn_sessiond(pathname);
-               free(alloc_pathname);
-               if (ret < 0) {
-                       ERR("Problem occurred when starting %s", pathname);
+       while (cmd->name != NULL) {
+               if (!strcmp(command, cmd->name)) {
+                       exists = true;
                        goto end;
                }
+               cmd++;
        }
 
 end:
-       return ret;
+       return exists;
 }
 
-/*
- * 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)
+static void show_basic_help(void)
 {
-       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;
+       puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
+       puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
+       puts("");
+       puts("Available commands:");
+       puts("");
+       puts("Tracing sessions:");
+       puts("  create            " CONFIG_CMD_DESCR_CREATE);
+       puts("  clear             " CONFIG_CMD_DESCR_CLEAR);
+       puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
+       puts("  load              " CONFIG_CMD_DESCR_LOAD);
+       puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
+       puts("  save              " CONFIG_CMD_DESCR_SAVE);
+       puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
+       puts("");
+       puts("Channels:");
+       puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
+       puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
+       puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
+       puts("");
+       puts("Event rules:");
+       puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
+       puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
+       puts("");
+       puts("Status:");
+       puts("  list              " CONFIG_CMD_DESCR_LIST);
+       puts("  status            " CONFIG_CMD_DESCR_STATUS);
+       puts("");
+       puts("Control:");
+       puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
+       puts("  start             " CONFIG_CMD_DESCR_START);
+       puts("  stop              " CONFIG_CMD_DESCR_STOP);
+       puts("");
+       puts("Tracing session rotation:");
+       puts("  disable-rotation  " CONFIG_CMD_DESCR_DISABLE_ROTATION);
+       puts("  enable-rotation   " CONFIG_CMD_DESCR_ENABLE_ROTATION);
+       puts("  rotate            " CONFIG_CMD_DESCR_ROTATE);
+       puts("");
+       puts("Resource tracking:");
+       puts("  track             " CONFIG_CMD_DESCR_TRACK);
+       puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
+       puts("");
+       puts("Miscellaneous:");
+       puts("  help              " CONFIG_CMD_DESCR_HELP);
+       puts("  version           " CONFIG_CMD_DESCR_VERSION);
+       puts("  view              " CONFIG_CMD_DESCR_VIEW);
+       puts("");
+       puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
+       puts("command COMMAND.");
+       puts("");
+       puts("See `man lttng` for more help with the lttng command.");
 }
 
 /*
@@ -420,23 +335,45 @@ static int parse_args(int argc, char **argv)
 {
        int opt, ret;
 
+       if (lttng_is_setuid_setgid()) {
+               ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
+               clean_exit(EXIT_FAILURE);
+       }
+
        if (argc < 2) {
-               usage(stderr);
+               show_basic_help();
                clean_exit(EXIT_FAILURE);
        }
 
-       while ((opt = getopt_long(argc, argv, "+hnvqg:", long_options, NULL)) != -1) {
+       while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
                switch (opt) {
-               case 'h':
-                       usage(stdout);
+               case 'V':
+                       version(stdout);
                        ret = 0;
                        goto end;
+               case 'h':
+                       ret = utils_show_help(1, "lttng", help_msg);
+                       if (ret) {
+                               ERR("Cannot show --help for `lttng`");
+                               perror("exec");
+                       }
+                       goto end;
                case 'v':
-                       lttng_opt_verbose += 1;
+                       /* 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 'm':
+                       lttng_opt_mi = mi_output_type(optarg);
+                       if (lttng_opt_mi < 0) {
+                               ret = lttng_opt_mi;
+                               goto error;
+                       }
+                       break;
                case 'g':
                        lttng_set_tracing_group(optarg);
                        break;
@@ -444,18 +381,30 @@ static int parse_args(int argc, char **argv)
                        opt_no_sessiond = 1;
                        break;
                case OPT_SESSION_PATH:
+                       free(opt_sessiond_path);
                        opt_sessiond_path = strdup(optarg);
+                       if (!opt_sessiond_path) {
+                               ret = -1;
+                               goto error;
+                       }
+                       break;
+               case OPT_RELAYD_PATH:
+                       free(opt_relayd_path);
+                       opt_relayd_path = strdup(optarg);
+                       if (!opt_relayd_path) {
+                               ret = -1;
+                               goto error;
+                       }
                        break;
                case OPT_DUMP_OPTIONS:
                        list_options(stdout);
                        ret = 0;
                        goto end;
                case OPT_DUMP_COMMANDS:
-                       list_commands(stdout);
+                       list_commands(commands, stdout);
                        ret = 0;
                        goto end;
                default:
-                       usage(stderr);
                        ret = 1;
                        goto error;
                }
@@ -466,40 +415,34 @@ static int parse_args(int argc, char **argv)
                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 */
+       /* No leftovers, 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");
+               if (!command_exists(*(argv + optind))) {
+                       MSG("lttng: %s is not an lttng command. See 'lttng --help'.",
+                                       *(argv + optind));
+               } else {
+                       ERR("Unrecognized argument used with \'%s\' command",
+                                       *(argv + optind));
+               }
                break;
        case CMD_FATAL:
-               ERR("Fatal error");
+       case CMD_UNSUPPORTED:
                break;
        case -1:
-               usage(stderr);
                ret = 1;
                break;
        case 0:
@@ -523,18 +466,9 @@ error:
 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);
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