src/bin/lttng/commands/view.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
   3  *
   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.
   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.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #define _LGPL_SOURCE
  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;
  33 static char *opt_trace_path;
  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},
  47         {"trace-path",  't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
  48         {0, 0, 0, 0, 0, 0, 0}
  49 };
  50
  51 /*
  52  * This is needed for each viewer since we are using execvp().
  53  */
  54 static const char *babeltrace_opts[] = { "babeltrace" };
  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
  80 /* Is the session we are trying to view is in live mode. */
  81 static int session_live_mode;
  82
  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");
  95         fprintf(ofp, "Options:\n");
  96         fprintf(ofp, "  -h, --help               Show this help\n");
  97         fprintf(ofp, "      --list-options       Simple listing of options\n");
  98         fprintf(ofp, "  -t, --trace-path PATH    Trace directory path for the viewer\n");
  99         fprintf(ofp, "  -e, --viewer CMD         Specify viewer and/or options to use\n");
 100         fprintf(ofp, "                           This will completely override the default viewers so\n");
 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");
 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 */
 155         argv = zmalloc(sizeof(char *) * (num_opts + 2));
 156         if (argv == NULL) {
 157                 goto error;
 158         }
 159
 160         token = strtok(opts, " ");
 161         while (token != NULL) {
 162                 argv[i] = strdup(token);
 163                 if (argv[i] == NULL) {
 164                         goto error;
 165                 }
 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:
 176         if (argv) {
 177                 for (i = 0; i < num_opts + 2; i++) {
 178                         free(argv[i]);
 179                 }
 180                 free(argv);
 181         }
 182
 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;
 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         }
 208
 209         size = sizeof(char *) * mem_len;
 210
 211         /* Add two here for the trace_path and the NULL terminating element. */
 212         argv = zmalloc(size);
 213         if (argv == NULL) {
 214                 goto error;
 215         }
 216
 217         memcpy(argv, opts, size);
 218
 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         }
 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;
 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
 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;
 261 #if 0
 262         case VIEWER_LTTV_GUI:
 263                 if (stat(lttv_gui_bin, &status) == 0) {
 264                         viewer_bin = lttv_gui_bin;
 265                 } else {
 266                         viewer_bin = viewer->exec_name;
 267                 }
 268                 argv = alloc_argv_from_local_opts(lttv_gui_opts,
 269                                 ARRAY_SIZE(lttv_gui_opts), trace_path);
 270                 break;
 271 #endif
 272         case VIEWER_USER_DEFINED:
 273                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 274                 if (argv) {
 275                         viewer_bin = argv[0];
 276                 }
 277                 break;
 278         default:
 279                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 280                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 281                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 282                 break;
 283         }
 284
 285         if (argv == NULL) {
 286                 ret = CMD_FATAL;
 287                 goto error;
 288         }
 289
 290         DBG("Using %s viewer", viewer_bin);
 291
 292         ret = execvp(viewer_bin, argv);
 293         if (ret) {
 294                 if (errno == ENOENT) {
 295                         ERR("%s not found on the system", viewer_bin);
 296                 } else {
 297                         PERROR("exec: %s", viewer_bin);
 298                 }
 299                 free(argv);
 300                 ret = CMD_FATAL;
 301                 goto error;
 302         }
 303
 304 error:
 305         return ret;
 306 }
 307
 308 /*
 309  * Build the live path we need for the lttng live view.
 310  */
 311 static char *build_live_path(char *session_name)
 312 {
 313         int ret;
 314         char *path = NULL;
 315         char hostname[HOST_NAME_MAX];
 316
 317         ret = gethostname(hostname, sizeof(hostname));
 318         if (ret < 0) {
 319                 perror("gethostname");
 320                 goto error;
 321         }
 322
 323         ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
 324                         session_name);
 325         if (ret < 0) {
 326                 perror("asprintf live path");
 327                 goto error;
 328         }
 329
 330 error:
 331         return path;
 332 }
 333
 334 /*
 335  * Exec viewer if found and use session name path.
 336  */
 337 static int view_trace(void)
 338 {
 339         int ret;
 340         char *session_name, *trace_path = NULL;
 341         struct lttng_session *sessions = NULL;
 342
 343         /*
 344          * Safety net. If lttng is suid at some point for *any* useless reasons,
 345          * this prevent any bad execution of binaries.
 346          */
 347         if (getuid() != 0) {
 348                 if (getuid() != geteuid()) {
 349                         ERR("UID does not match effective UID.");
 350                         ret = CMD_ERROR;
 351                         goto error;
 352                 } else if (getgid() != getegid()) {
 353                         ERR("GID does not match effective GID.");
 354                         ret = CMD_ERROR;
 355                         goto error;
 356                 }
 357         }
 358
 359         /* User define trace path override the session name */
 360         if (opt_trace_path) {
 361                 session_name = NULL;
 362         } else if(opt_session_name == NULL) {
 363                 session_name = get_session_name();
 364                 if (session_name == NULL) {
 365                         ret = CMD_ERROR;
 366                         goto error;
 367                 }
 368         } else {
 369                 session_name = opt_session_name;
 370         }
 371
 372         DBG("Viewing trace for session %s", session_name);
 373
 374         if (session_name) {
 375                 int i, count, found = 0;
 376
 377                 /* Getting all sessions */
 378                 count = lttng_list_sessions(&sessions);
 379                 if (count < 0) {
 380                         ERR("Unable to list sessions. Session name %s not found.",
 381                                         session_name);
 382                         MSG("Is there a session daemon running?");
 383                         ret = CMD_ERROR;
 384                         goto free_error;
 385                 }
 386
 387                 /* Find our session listed by the session daemon */
 388                 for (i = 0; i < count; i++) {
 389                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 390                                 found = 1;
 391                                 break;
 392                         }
 393                 }
 394
 395                 if (!found) {
 396                         MSG("Session name %s not found", session_name);
 397                         ret = CMD_ERROR;
 398                         goto free_sessions;
 399                 }
 400
 401                 session_live_mode = sessions[i].live_timer_interval;
 402
 403                 DBG("Session live mode set to %d", session_live_mode);
 404
 405                 if (sessions[i].enabled && !session_live_mode) {
 406                         WARN("Session %s is running. Please stop it before reading it.",
 407                                         session_name);
 408                         ret = CMD_ERROR;
 409                         goto free_sessions;
 410                 }
 411
 412                 /* If the timer interval is set we are in live mode. */
 413                 if (session_live_mode) {
 414                         trace_path = build_live_path(session_name);
 415                         if (!trace_path) {
 416                                 ret = CMD_ERROR;
 417                                 goto free_sessions;
 418                         }
 419                 } else {
 420                         /* Get file system session path. */
 421                         trace_path = sessions[i].path;
 422                 }
 423         } else {
 424                 trace_path = opt_trace_path;
 425         }
 426
 427         MSG("Trace directory: %s\n", trace_path);
 428
 429         ret = spawn_viewer(trace_path);
 430         if (ret < 0) {
 431                 /* Don't set ret so lttng can interpret the sessiond error. */
 432                 goto free_sessions;
 433         }
 434
 435 free_sessions:
 436         if (session_live_mode) {
 437                 free(trace_path);
 438         }
 439         free(sessions);
 440 free_error:
 441         if (opt_session_name == NULL) {
 442                 free(session_name);
 443         }
 444 error:
 445         return ret;
 446 }
 447
 448 /*
 449  * The 'view <options>' first level command
 450  */
 451 int cmd_view(int argc, const char **argv)
 452 {
 453         int opt, ret = CMD_SUCCESS;
 454         static poptContext pc;
 455
 456         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 457         poptReadDefaultConfig(pc, 0);
 458
 459         if (lttng_opt_mi) {
 460                 WARN("mi does not apply to view command");
 461         }
 462
 463         while ((opt = poptGetNextOpt(pc)) != -1) {
 464                 switch (opt) {
 465                 case OPT_HELP:
 466                         usage(stdout);
 467                         goto end;
 468                 case OPT_LIST_OPTIONS:
 469                         list_cmd_options(stdout, long_options);
 470                         goto end;
 471                 default:
 472                         usage(stderr);
 473                         ret = CMD_UNDEFINED;
 474                         goto end;
 475                 }
 476         }
 477
 478         opt_session_name = (char*) poptGetArg(pc);
 479
 480         ret = view_trace();
 481
 482 end:
 483         poptFreeContext(pc);
 484         return ret;
 485 }