Add channel output method selection
[lttng-tools.git] / lttng / lttng.c
index 8a0d58faeaa8ac7ec7299a7a633d9ada73e8e513..d32f563dd1ea6cab7deaa82520f01da41a982721 100644 (file)
  */
 
 #define _GNU_SOURCE
-#include <errno.h>
-#include <fcntl.h>
 #include <getopt.h>
-#include <grp.h>
-#include <limits.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
 #include <unistd.h>
 
-#include <lttng/liblttngctl.h>
+#include <lttng/lttng.h>
 
-#include "lttng.h"
+#include "cmd.h"
+#include "conf.h"
 #include "lttngerr.h"
 
 /* Variables */
 static char *progname;
 
-/* Prototypes */
-static int process_client_opt(void);
-static int process_opt_list_apps(void);
-static int process_opt_list_sessions(void);
-static int process_opt_list_traces(void);
-static int process_opt_create_session(void);
-static void sighandler(int sig);
-static int set_signal_handler(void);
-static int validate_options(void);
-static char *get_cmdline_by_pid(pid_t pid);
-
-/*
- *  start_client
- *
- *  Process client request from the command line
- *  options. Every tracing action is done by the
- *  liblttngctl API.
- */
-static int process_client_opt(void)
+int opt_quiet;
+int opt_verbose;
+static int opt_no_sessiond;
+static char *opt_sessiond_path;
+
+enum {
+       OPT_NO_SESSIOND,
+       OPT_SESSION_PATH,
+};
+
+/* Getopt options. No first level command. */
+static struct option long_options[] = {
+       {"help",             0, NULL, 'h'},
+       {"group",            1, NULL, 'g'},
+       {"verbose",          0, NULL, 'v'},
+       {"quiet",            0, NULL, 'q'},
+       {"no-sessiond",      0, NULL, OPT_NO_SESSIOND},
+       {"sessiond-path",    1, NULL, OPT_SESSION_PATH},
+       {NULL, 0, NULL, 0}
+};
+
+/* First level command */
+static struct cmd_struct commands[] =  {
+       { "list", cmd_list},
+       { "create", cmd_create},
+       { "destroy", cmd_destroy},
+       { "add-channel", cmd_add_channel},
+       { "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},
+       { NULL, NULL}   /* Array closure */
+};
+
+static void usage(FILE *ofp)
 {
-       int ret;
-       uuid_t uuid;
-
-       /* Connect to the session daemon */
-       ret = lttng_connect_sessiond();
-       if (ret < 0) {
-               goto end;
-       }
-
-       if (opt_list_apps) {
-               ret = process_opt_list_apps();
-               if (ret < 0) {
-                       goto end;
-               }
-       }
-
-       if (opt_list_session) {
-               ret = process_opt_list_sessions();
-               if (ret < 0) {
-                       goto end;
-               }
-       }
-
-       if (opt_list_traces) {
-               ret = process_opt_list_traces();
-               if (ret < 0) {
-                       goto end;
-               }
-       }
-
-       if (opt_create_session != NULL) {
-               ret = process_opt_create_session();
-               if (ret < 0) {
-                       goto end;
-               }
-       }
-
-       if (opt_destroy_session != NULL) {
-               uuid_parse(opt_destroy_session, uuid);
-               ret = lttng_destroy_session(&uuid);
-               if (ret < 0) {
-                       goto end;
-               }
-       }
-
-       if (opt_session_uuid != NULL) {
-               DBG("Set session uuid to %s", opt_session_uuid);
-               lttng_set_current_session_uuid(opt_session_uuid);
-       }
-
-       if (opt_create_trace) {
-               DBG("Create trace for pid %d", opt_create_trace);
-               ret = lttng_ust_create_trace(opt_create_trace);
-               if (ret < 0) {
-                       goto end;
-               }
-               MSG("Trace created successfully!\nUse --start PID to start tracing.");
-       }
-
-       if (opt_start_trace) {
-               DBG("Start trace for pid %d", opt_start_trace);
-               ret = lttng_ust_start_trace(opt_start_trace);
-               if (ret < 0) {
-                       goto end;
-               }
-               MSG("Trace started successfully!");
-       }
-
-       if (opt_stop_trace) {
-               DBG("Stop trace for pid %d", opt_stop_trace);
-               ret = lttng_ust_stop_trace(opt_stop_trace);
-               if (ret < 0) {
-                       goto end;
-               }
-               MSG("Trace stopped successfully!");
-       }
-
-       return 0;
-
-end:
-       ERR("%s", lttng_get_readable_code(ret));
-       return ret;
+       fprintf(ofp, "LTTng Trace Control " VERSION"\n\n");
+       fprintf(ofp, "usage: lttng [options] <command>\n");
+       fprintf(ofp, "\n");
+       fprintf(ofp, "Options:\n");
+       fprintf(ofp, "  -h, --help             Show this help\n");
+       fprintf(ofp, "  -g, --group NAME       Unix tracing group name. (default: tracing)\n");
+       fprintf(ofp, "  -v, --verbose          Verbose mode\n");
+       fprintf(ofp, "  -q, --quiet            Quiet mode\n");
+       fprintf(ofp, "      --no-sessiond      Don't spawn a session daemon\n");
+       fprintf(ofp, "      --sessiond-path    Session daemon full path\n");
+       fprintf(ofp, "\n");
+       fprintf(ofp, "Commands:\n");
+       fprintf(ofp, "    add-channel     Add channel to tracer\n");
+       fprintf(ofp, "    add-context     Add context to event or/and channel\n");
+       fprintf(ofp, "    create          Create tracing session\n");
+       fprintf(ofp, "    destroy         Teardown 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, "    start           Start tracing\n");
+       fprintf(ofp, "    stop            Stop tracing\n");
+       fprintf(ofp, "    version         Show version information\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");
 }
 
 /*
- *  process_opt_list_traces
- *
- *  Get list of all traces for a specific session uuid.
+ * clean_exit
  */
-static int process_opt_list_traces(void)
+static void clean_exit(int code)
 {
-       int ret, i;
-       uuid_t uuid;
-       struct lttng_trace *traces;
-
-       uuid_parse(opt_session_uuid, uuid);
-       ret = lttng_list_traces(&uuid, &traces);
-       if (ret < 0) {
-               goto error;
-       }
-
-       MSG("Userspace traces:");
-       for (i = 0; i < ret; i++) {
-               if (traces[i].type == USERSPACE) {
-                       MSG("\t%d) %s (pid: %d): %s",
-                                       i, traces[i].name, traces[i].pid,
-                                       get_cmdline_by_pid(traces[i].pid));
-               } else {
-                       break;
-               }
-       }
-
-       MSG("Kernel traces:");
-       for (;i < ret; i++) {
-               if (traces[i].type == KERNEL) {
-                       MSG("\t%d) %s", i, traces[i].name);
-               }
-       }
-
-       free(traces);
-
-error:
-       return ret;
+       DBG("Clean exit");
+       exit(code);
 }
 
 /*
- *  process_opt_create_session
+ *  sighandler
  *
- *  Create a new session using the name pass
- *  to the command line.
+ *  Signal handler for the daemon
  */
-static int process_opt_create_session(void)
+static void sighandler(int sig)
 {
-       int ret;
-       uuid_t session_id;
-       char str_uuid[37];
-
-       ret = lttng_create_session(opt_create_session, &session_id);
-       if (ret < 0) {
-               goto error;
+       switch (sig) {
+               case SIGTERM:
+                       DBG("SIGTERM catched");
+                       clean_exit(EXIT_FAILURE);
+                       break;
+               case SIGCHLD:
+                       /* Notify is done */
+                       DBG("SIGCHLD catched");
+                       break;
+               default:
+                       DBG("Unknown signal %d catched", sig);
+                       break;
        }
 
-       uuid_unparse(session_id, str_uuid);
-
-       MSG("Session created:");
-       MSG("    %s (%s)", opt_create_session, str_uuid);
-
-error:
-       return ret;
+       return;
 }
 
 /*
- *  process_opt_list_sessions
+ *  set_signal_handler
  *
- *  Get the list of available sessions from
- *  the session daemon and print it to user.
+ *  Setup signal handler for SIGCHLD and SIGTERM.
  */
-static int process_opt_list_sessions(void)
+static int set_signal_handler(void)
 {
-       int ret, count, i;
-       struct lttng_session *sess;
-
-       count = lttng_list_sessions(&sess);
-       if (count < 0) {
-               ret = count;
-               goto error;
-       }
+       int ret = 0;
+       struct sigaction sa;
+       sigset_t sigset;
 
-       MSG("Available sessions [Name (uuid)]:");
-       for (i = 0; i < count; i++) {
-               MSG("\tName: %s (uuid: %s)", sess[i].name, sess[i].uuid);
+       if ((ret = sigemptyset(&sigset)) < 0) {
+               perror("sigemptyset");
+               goto end;
        }
 
-       free(sess);
-       MSG("\nTo select a session, use --session UUID.");
-
-       return 0;
-
-error:
-       return ret;
-}
-
-/*
- *  process_opt_list_apps
- *
- *  Get the UST traceable pid list and print
- *  them to the user.
- */
-static int process_opt_list_apps(void)
-{
-       int i, ret, count;
-       pid_t *pids;
-       char *cmdline;
-
-       count = lttng_ust_list_apps(&pids);
-       if (count < 0) {
-               ret = count;
-               goto error;
+       sa.sa_handler = sighandler;
+       sa.sa_mask = sigset;
+       sa.sa_flags = 0;
+       if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
+               perror("sigaction");
+               goto end;
        }
 
-       MSG("LTTng UST traceable application [name (pid)]:");
-       for (i=0; i < count; i++) {
-               cmdline = get_cmdline_by_pid(pids[i]);
-               if (cmdline == NULL) {
-                       MSG("\t(not running) (%d)", pids[i]);
-                       continue;
-               }
-               MSG("\t%s (%d)", cmdline, pids[i]);
-               free(cmdline);
+       if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
+               perror("sigaction");
+               goto end;
        }
 
-       /* Allocated by lttng_ust_list_apps() */
-       free(pids);
-
-       return 0;
-
-error:
+end:
        return ret;
 }
 
 /*
- *  get_cmdline_by_pid
+ *  handle_command
  *
- *  Get command line from /proc for a specific pid.
+ *  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.
  *
- *  On success, return an allocated string pointer pointing to
- *  the proc cmdline.
- *  On error, return NULL.
+ *  If command not found, return -1
+ *  else, return function command error code.
  */
-static char *get_cmdline_by_pid(pid_t pid)
+static int handle_command(int argc, char **argv)
 {
-       int ret;
-       FILE *fp;
-       char *cmdline = NULL;
-       char path[24];  /* Can't go bigger than /proc/65535/cmdline */
+       int i = 0, ret;
+       struct cmd_struct *cmd;
 
-       snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
-       fp = fopen(path, "r");
-       if (fp == NULL) {
+       if (*argv == NULL) {
+               ret = CMD_SUCCESS;
                goto end;
        }
 
-       /* Caller must free() *cmdline */
-       cmdline = malloc(PATH_MAX);
-       ret = fread(cmdline, 1, PATH_MAX, fp);
-       fclose(fp);
-
-end:
-       return cmdline;
-}
-
-/*
- *  validate_options
- *
- *  Make sure that all options passed to the command line
- *  are compatible with each others.
- *
- *  On error, return -1
- *  On success, return 0
- */
-static int validate_options(void)
-{
-       if ((opt_session_uuid == NULL) &&
-                       (opt_create_trace || opt_start_trace || opt_list_traces)) {
-               ERR("You need to specify a session UUID.\nPlease use --session UUID to do so.");
-               goto error;
+       cmd = &commands[i];
+       while (cmd->func != NULL) {
+               /* Find command */
+               if (strcmp(argv[0], cmd->name) == 0) {
+                       ret = cmd->func(argc, (const char**) argv);
+                       switch (ret) {
+                       case CMD_ERROR:
+                               ERR("Command error");
+                               break;
+                       case CMD_NOT_IMPLEMENTED:
+                               ERR("Options not implemented");
+                               break;
+                       case CMD_UNDEFINED:
+                               ERR("Undefined command");
+                               break;
+                       case CMD_FATAL:
+                               ERR("Fatal error");
+                               break;
+                       }
+                       goto end;
+               }
+               i++;
+               cmd = &commands[i];
        }
 
-       return 0;
+       /* Command not found */
+       ret = -1;
 
-error:
-       return -1;
+end:
+       return ret;
 }
 
 /*
@@ -342,23 +228,22 @@ static int spawn_sessiond(char *pathname)
        int ret = 0;
        pid_t pid;
 
-       MSG("Spawning session daemon");
+       MSG("Spawning session daemon");
        pid = fork();
        if (pid == 0) {
-               /* Spawn session daemon and tell
+               /*
+                * Spawn session daemon and tell
                 * it to signal us when ready.
                 */
-               ret = execlp(pathname, "ltt-sessiond", "--sig-parent", "--quiet", NULL);
-               if (ret < 0) {
-                       if (errno == ENOENT) {
-                               ERR("No session daemon found. Use --sessiond-path.");
-                       } else {
-                               perror("execlp");
-                       }
-                       kill(getppid(), SIGTERM);
-                       exit(EXIT_FAILURE);
+               execlp(pathname, "ltt-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");
                }
-               exit(EXIT_SUCCESS);
+               kill(getppid(), SIGTERM);       /* unpause parent */
+               exit(EXIT_FAILURE);
        } else if (pid > 0) {
                /* Wait for ltt-sessiond to start */
                pause();
@@ -374,19 +259,19 @@ end:
 }
 
 /*
- *  check_ltt_sessiond
+ *  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_ltt_sessiond(void)
+static int check_sessiond(void)
 {
        int ret;
-       char *pathname = NULL;
+       char *pathname = NULL, *alloc_pathname = NULL;
 
-       ret = lttng_check_session_daemon();
-       if (ret < 0) {
+       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);
@@ -398,24 +283,19 @@ static int check_ltt_sessiond(void)
                } else {
                        /* Try LTTNG_SESSIOND_PATH env variable */
                        pathname = getenv(LTTNG_SESSIOND_PATH_ENV);
-                       if (pathname != NULL) {
-                               /* strdup here in order to make the free()
-                                * not fail later on.
-                                */
-                               pathname = strdup(pathname);
-                       }
                }
 
                /* Let's rock and roll */
                if (pathname == NULL) {
-                       ret = asprintf(&pathname, "ltt-sessiond");
+                       ret = asprintf(&alloc_pathname, "ltt-sessiond");
                        if (ret < 0) {
                                goto end;
                        }
+                       pathname = alloc_pathname;
                }
 
                ret = spawn_sessiond(pathname);
-               free(pathname);
+               free(alloc_pathname);
                if (ret < 0) {
                        ERR("Problem occurs when starting %s", pathname);
                        goto end;
@@ -427,73 +307,83 @@ end:
 }
 
 /*
- *  set_signal_handler
+ *  parse_args
  *
- *  Setup signal handler for SIGCHLD and SIGTERM.
+ *  Parse command line arguments.
+ *  Return 0 if OK, else -1
  */
-static int set_signal_handler(void)
+static int parse_args(int argc, char **argv)
 {
-       int ret = 0;
-       struct sigaction sa;
-       sigset_t sigset;
+       int opt, ret;
 
-       if ((ret = sigemptyset(&sigset)) < 0) {
-               perror("sigemptyset");
-               goto end;
+       if (argc < 2) {
+               usage(stderr);
+               clean_exit(EXIT_FAILURE);
        }
 
-       sa.sa_handler = sighandler;
-       sa.sa_mask = sigset;
-       sa.sa_flags = 0;
-       if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
-               perror("sigaction");
-               goto end;
+       while ((opt = getopt_long(argc, argv, "+hvqg:", long_options, NULL)) != -1) {
+               switch (opt) {
+               case 'h':
+                       usage(stderr);
+                       goto error;
+               case 'v':
+                       opt_verbose = 1;
+                       break;
+               case 'q':
+                       opt_quiet = 1;
+                       break;
+               case 'g':
+                       lttng_set_tracing_group(optarg);
+                       break;
+               case OPT_NO_SESSIOND:
+                       opt_no_sessiond = 1;
+                       break;
+               case OPT_SESSION_PATH:
+                       opt_sessiond_path = strdup(optarg);
+                       break;
+               default:
+                       usage(stderr);
+                       goto error;
+               }
        }
 
-       if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
-               perror("sigaction");
-               goto end;
+       /* If both options are specified, quiet wins */
+       if (opt_verbose && opt_quiet) {
+               opt_verbose = 0;
        }
 
-end:
-       return ret;
-}
+       /* Spawn session daemon if needed */
+       if (opt_no_sessiond == 0 && (check_sessiond() < 0)) {
+               goto error;
+       }
 
-/*
- *  sighandler
- *
- *  Signal handler for the daemon
- */
-static void sighandler(int sig)
-{
-       switch (sig) {
-               case SIGTERM:
-                       DBG("SIGTERM catched");
-                       clean_exit(EXIT_FAILURE);
-                       break;
-               case SIGCHLD:
-                       /* Notify is done */
-                       DBG("SIGCHLD catched");
-                       break;
-               default:
-                       DBG("Unknown signal %d catched", sig);
-                       break;
+       /* No leftovers, print usage and quit */
+       if ((argc - optind) == 0) {
+               usage(stderr);
+               goto error;
        }
 
-       return;
-}
-/*
- * clean_exit
- */
-void clean_exit(int code)
-{
-       DBG("Clean exit");
-       if (lttng_disconnect_sessiond() < 0) {
-               ERR("Session daemon disconnect failed.");
+       /* 
+        * Handle leftovers which is a first level command with the trailing
+        * options.
+        */
+       ret = handle_command(argc - optind, argv + optind);
+       if (ret < 0) {
+               if (ret == -1) {
+                       usage(stderr);
+                       goto error;
+               } else {
+                       ERR("%s", lttng_get_readable_code(ret));
+               }
        }
-       exit(code);
+
+       return ret;
+
+error:
+       return -1;
 }
 
+
 /*
  *  main
  */
@@ -508,48 +398,13 @@ int main(int argc, char *argv[])
                MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0);
        }
 
-       ret = parse_args(argc, (const char **) argv);
-       if (ret < 0) {
-               clean_exit(EXIT_FAILURE);
-       }
-
-       ret = validate_options();
-       if (ret < 0) {
-               return EXIT_FAILURE;
-       }
-
        ret = set_signal_handler();
        if (ret < 0) {
                clean_exit(ret);
        }
 
-       if (opt_tracing_group != NULL) {
-               DBG("Set tracing group to '%s'", opt_tracing_group);
-               lttng_set_tracing_group(opt_tracing_group);
-       }
-
-       /* If ask for kernel tracing, need root perms */
-       if (opt_trace_kernel) {
-               DBG("Kernel tracing activated");
-               if (getuid() != 0) {
-                       ERR("%s must be setuid root", progname);
-                       clean_exit(-EPERM);
-               }
-       }
-
-       /* Check if the lttng session daemon is running.
-        * If no, a daemon will be spawned.
-        */
-       if (opt_no_sessiond == 0 && (check_ltt_sessiond() < 0)) {
-               clean_exit(EXIT_FAILURE);
-       }
-
-       ret = process_client_opt();
-       if (ret < 0) {
-               clean_exit(ret);
-       }
-
-       clean_exit(0);
+       ret = parse_args(argc, argv);
+       clean_exit(ret);
 
        return 0;
 }
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