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 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26
  27 #include "../command.h"
  28 #include <config.h>
  29
  30 static char *opt_session_name;
  31 static char *opt_viewer;
  32 static char *opt_trace_path;
  33 static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
  34 //static const char *lttv_gui_bin = CONFIG_LTTV_GUI_BIN;
  35
  36 enum {
  37         OPT_HELP = 1,
  38         OPT_LIST_OPTIONS,
  39 };
  40
  41 static struct poptOption long_options[] = {
  42         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  43         {"help",        'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  44         {"list-options", 0,  POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  45         {"viewer",      'e', POPT_ARG_STRING, &opt_viewer, 0, 0, 0},
  46         {"trace-path",  't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
  47         {0, 0, 0, 0, 0, 0, 0}
  48 };
  49
  50 /*
  51  * This is needed for each viewer since we are using execvp().
  52  */
  53 static const char *babeltrace_opts[] = { "babeltrace" };
  54 //static const char *lttv_gui_opts[] = { "lttv-gui", "-t", };
  55
  56 /*
  57  * Type is also use as the index in the viewers array. So please, make sure
  58  * your enum value is in the right order in the array below.
  59  */
  60 enum viewer_type {
  61         VIEWER_BABELTRACE    = 0,
  62         VIEWER_LTTV_GUI      = 1,
  63         VIEWER_USER_DEFINED  = 2,
  64 };
  65
  66 /*
  67  * NOTE: "lttv" is a shell command and it's not working for exec() family
  68  * functions so we might think of removing this wrapper or using bash.
  69  */
  70 static struct viewers {
  71         const char *exec_name;
  72         enum viewer_type type;
  73 } viewers[] = {
  74         { "babeltrace", VIEWER_BABELTRACE },
  75         { "lttv-gui", VIEWER_LTTV_GUI },
  76         { NULL, VIEWER_USER_DEFINED },
  77 };
  78
  79 /* Is the session we are trying to view is in live mode. */
  80 static int session_live_mode;
  81
  82 /*
  83  * usage
  84  */
  85 static void usage(FILE *ofp)
  86 {
  87         fprintf(ofp, "usage: lttng view [SESSION_NAME] [OPTIONS]\n");
  88         fprintf(ofp, "\n");
  89         fprintf(ofp, "By default, the babeltrace viewer will be used for text viewing\n");
  90         fprintf(ofp, "\n");
  91         fprintf(ofp, "Where SESSION_NAME is an optional session name. If not specified, lttng will\n");
  92         fprintf(ofp, "get it from the configuration file (.lttngrc).\n");
  93         fprintf(ofp, "\n");
  94         fprintf(ofp, "Options:\n");
  95         fprintf(ofp, "  -h, --help               Show this help\n");
  96         fprintf(ofp, "      --list-options       Simple listing of options\n");
  97         fprintf(ofp, "  -t, --trace-path PATH    Trace directory path for the viewer\n");
  98         fprintf(ofp, "  -e, --viewer CMD         Specify viewer and/or options to use\n");
  99         fprintf(ofp, "                           This will completely override the default viewers so\n");
 100         fprintf(ofp, "                           please make sure to specify the full command. The trace\n");
 101         fprintf(ofp, "                           directory path of the session will be appended at the end\n");
 102         fprintf(ofp, "                           to the arguments\n");
 103         fprintf(ofp, "\n");
 104 }
 105
 106 static struct viewers *parse_options(void)
 107 {
 108         if (opt_viewer == NULL) {
 109                 /* Default is babeltrace */
 110                 return &(viewers[VIEWER_BABELTRACE]);
 111         }
 112
 113 #if 0
 114         if (strstr(opt_viewer, viewers[VIEWER_LTTV_GUI].exec_name) == 0) {
 115                 return &(viewers[VIEWER_LTTV_GUI]);
 116         }
 117 #endif
 118
 119         /*
 120          * This means that if -e, --viewers is used, we just override everything
 121          * with it. For supported viewers like lttv, we could simply detect if "-t"
 122          * is passed and if not, add the trace directory to it.
 123          */
 124         return &(viewers[VIEWER_USER_DEFINED]);
 125 }
 126
 127 /*
 128  * Alloc an array of string pointer from a simple string having all options
 129  * seperated by spaces. Also adds the trace path to the arguments.
 130  *
 131  * The returning pointer is ready to be passed to execvp().
 132  */
 133 static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
 134 {
 135         int i = 0, ignore_space = 0;
 136         unsigned int num_opts = 1;
 137         char **argv, *token = opts;
 138
 139         /* Count number of arguments. */
 140         do {
 141                 if (*token == ' ') {
 142                         /* Use to ignore consecutive spaces */
 143                         if (!ignore_space) {
 144                                 num_opts++;
 145                         }
 146                         ignore_space = 1;
 147                 } else {
 148                         ignore_space = 0;
 149                 }
 150                 token++;
 151         } while (*token != '\0');
 152
 153         /* Add two here for the NULL terminating element and trace path */
 154         argv = zmalloc(sizeof(char *) * (num_opts + 2));
 155         if (argv == NULL) {
 156                 goto error;
 157         }
 158
 159         token = strtok(opts, " ");
 160         while (token != NULL) {
 161                 argv[i] = strdup(token);
 162                 if (argv[i] == NULL) {
 163                         goto error;
 164                 }
 165                 token = strtok(NULL, " ");
 166                 i++;
 167         }
 168
 169         argv[num_opts] = (char *) trace_path;
 170         argv[num_opts + 1] = NULL;
 171
 172         return argv;
 173
 174 error:
 175         if (argv) {
 176                 for (i = 0; i < num_opts + 2; i++) {
 177                         free(argv[i]);
 178                 }
 179                 free(argv);
 180         }
 181
 182         return NULL;
 183 }
 184
 185 /*
 186  * Alloc an array of string pointer from an array of strings. It also adds
 187  * the trace path to the argv.
 188  *
 189  * The returning pointer is ready to be passed to execvp().
 190  */
 191 static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
 192                 const char *trace_path)
 193 {
 194         char **argv;
 195         size_t size, mem_len;
 196
 197
 198         /* Add one for the NULL terminating element. */
 199         mem_len = opts_len + 1;
 200         if (session_live_mode) {
 201                 /* Add 3 option for the live mode being "-i lttng-live URL". */
 202                 mem_len += 3;
 203         } else {
 204                 /* Add option for the trace path. */
 205                 mem_len += 1;
 206         }
 207
 208         size = sizeof(char *) * mem_len;
 209
 210         /* Add two here for the trace_path and the NULL terminating element. */
 211         argv = zmalloc(size);
 212         if (argv == NULL) {
 213                 goto error;
 214         }
 215
 216         memcpy(argv, opts, size);
 217
 218         if (session_live_mode) {
 219                 argv[opts_len] = "-i";
 220                 argv[opts_len + 1] = "lttng-live";
 221                 argv[opts_len + 2] = (char *) trace_path;
 222                 argv[opts_len + 3] = NULL;
 223         } else {
 224                 argv[opts_len] = (char *) trace_path;
 225                 argv[opts_len + 1] = NULL;
 226         }
 227
 228 error:
 229         return argv;
 230 }
 231
 232 /*
 233  * Spawn viewer with the trace directory path.
 234  */
 235 static int spawn_viewer(const char *trace_path)
 236 {
 237         int ret = 0;
 238         struct stat status;
 239         const char *viewer_bin = NULL;
 240         struct viewers *viewer;
 241         char **argv = NULL;
 242
 243         /* Check for --viewer options */
 244         viewer = parse_options();
 245         if (viewer == NULL) {
 246                 ret = CMD_ERROR;
 247                 goto error;
 248         }
 249
 250         switch (viewer->type) {
 251         case VIEWER_BABELTRACE:
 252                 if (stat(babeltrace_bin, &status) == 0) {
 253                         viewer_bin = babeltrace_bin;
 254                 } else {
 255                         viewer_bin = viewer->exec_name;
 256                 }
 257                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 258                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 259                 break;
 260 #if 0
 261         case VIEWER_LTTV_GUI:
 262                 if (stat(lttv_gui_bin, &status) == 0) {
 263                         viewer_bin = lttv_gui_bin;
 264                 } else {
 265                         viewer_bin = viewer->exec_name;
 266                 }
 267                 argv = alloc_argv_from_local_opts(lttv_gui_opts,
 268                                 ARRAY_SIZE(lttv_gui_opts), trace_path);
 269                 break;
 270 #endif
 271         case VIEWER_USER_DEFINED:
 272                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 273                 if (argv) {
 274                         viewer_bin = argv[0];
 275                 }
 276                 break;
 277         default:
 278                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 279                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 280                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 281                 break;
 282         }
 283
 284         if (argv == NULL || !viewer_bin) {
 285                 ret = CMD_FATAL;
 286                 goto error;
 287         }
 288
 289         DBG("Using %s viewer", viewer_bin);
 290
 291         ret = execvp(viewer_bin, argv);
 292         if (ret) {
 293                 if (errno == ENOENT) {
 294                         ERR("%s not found on the system", viewer_bin);
 295                 } else {
 296                         PERROR("exec: %s", viewer_bin);
 297                 }
 298                 free(argv);
 299                 ret = CMD_FATAL;
 300                 goto error;
 301         }
 302
 303 error:
 304         return ret;
 305 }
 306
 307 /*
 308  * Build the live path we need for the lttng live view.
 309  */
 310 static char *build_live_path(char *session_name)
 311 {
 312         int ret;
 313         char *path = NULL;
 314         char hostname[HOST_NAME_MAX];
 315
 316         ret = gethostname(hostname, sizeof(hostname));
 317         if (ret < 0) {
 318                 perror("gethostname");
 319                 goto error;
 320         }
 321
 322         ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
 323                         session_name);
 324         if (ret < 0) {
 325                 perror("asprintf live path");
 326                 goto error;
 327         }
 328
 329 error:
 330         return path;
 331 }
 332
 333 /*
 334  * Exec viewer if found and use session name path.
 335  */
 336 static int view_trace(void)
 337 {
 338         int ret;
 339         char *session_name, *trace_path = NULL;
 340         struct lttng_session *sessions = NULL;
 341
 342         /*
 343          * Safety net. If lttng is suid at some point for *any* useless reasons,
 344          * this prevent any bad execution of binaries.
 345          */
 346         if (getuid() != 0) {
 347                 if (getuid() != geteuid()) {
 348                         ERR("UID does not match effective UID.");
 349                         ret = CMD_ERROR;
 350                         goto error;
 351                 } else if (getgid() != getegid()) {
 352                         ERR("GID does not match effective GID.");
 353                         ret = CMD_ERROR;
 354                         goto error;
 355                 }
 356         }
 357
 358         /* User define trace path override the session name */
 359         if (opt_trace_path) {
 360                 session_name = NULL;
 361         } else if(opt_session_name == NULL) {
 362                 session_name = get_session_name();
 363                 if (session_name == NULL) {
 364                         ret = CMD_ERROR;
 365                         goto error;
 366                 }
 367         } else {
 368                 session_name = opt_session_name;
 369         }
 370
 371         DBG("Viewing trace for session %s", session_name);
 372
 373         if (session_name) {
 374                 int i, count, found = 0;
 375
 376                 /* Getting all sessions */
 377                 count = lttng_list_sessions(&sessions);
 378                 if (count < 0) {
 379                         ERR("Unable to list sessions. Session name %s not found.",
 380                                         session_name);
 381                         MSG("Is there a session daemon running?");
 382                         ret = CMD_ERROR;
 383                         goto free_error;
 384                 }
 385
 386                 /* Find our session listed by the session daemon */
 387                 for (i = 0; i < count; i++) {
 388                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 389                                 found = 1;
 390                                 break;
 391                         }
 392                 }
 393
 394                 if (!found) {
 395                         MSG("Session name %s not found", session_name);
 396                         ret = CMD_ERROR;
 397                         goto free_sessions;
 398                 }
 399
 400                 session_live_mode = sessions[i].live_timer_interval;
 401
 402                 DBG("Session live mode set to %d", session_live_mode);
 403
 404                 if (sessions[i].enabled && !session_live_mode) {
 405                         WARN("Session %s is running. Please stop it before reading it.",
 406                                         session_name);
 407                         ret = CMD_ERROR;
 408                         goto free_sessions;
 409                 }
 410
 411                 /* If the timer interval is set we are in live mode. */
 412                 if (session_live_mode) {
 413                         trace_path = build_live_path(session_name);
 414                         if (!trace_path) {
 415                                 ret = CMD_ERROR;
 416                                 goto free_sessions;
 417                         }
 418                 } else {
 419                         /* Get file system session path. */
 420                         trace_path = sessions[i].path;
 421                 }
 422         } else {
 423                 trace_path = opt_trace_path;
 424         }
 425
 426         MSG("Trace directory: %s\n", trace_path);
 427
 428         ret = spawn_viewer(trace_path);
 429         if (ret < 0) {
 430                 /* Don't set ret so lttng can interpret the sessiond error. */
 431                 goto free_sessions;
 432         }
 433
 434 free_sessions:
 435         if (session_live_mode) {
 436                 free(trace_path);
 437         }
 438         free(sessions);
 439 free_error:
 440         if (opt_session_name == NULL) {
 441                 free(session_name);
 442         }
 443 error:
 444         return ret;
 445 }
 446
 447 /*
 448  * The 'view <options>' first level command
 449  */
 450 int cmd_view(int argc, const char **argv)
 451 {
 452         int opt, ret = CMD_SUCCESS;
 453         static poptContext pc;
 454
 455         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 456         poptReadDefaultConfig(pc, 0);
 457
 458         if (lttng_opt_mi) {
 459                 WARN("mi does not apply to view command");
 460         }
 461
 462         while ((opt = poptGetNextOpt(pc)) != -1) {
 463                 switch (opt) {
 464                 case OPT_HELP:
 465                         usage(stdout);
 466                         goto end;
 467                 case OPT_LIST_OPTIONS:
 468                         list_cmd_options(stdout, long_options);
 469                         goto end;
 470                 default:
 471                         usage(stderr);
 472                         ret = CMD_UNDEFINED;
 473                         goto end;
 474                 }
 475         }
 476
 477         opt_session_name = (char*) poptGetArg(pc);
 478
 479         ret = view_trace();
 480
 481 end:
 482         poptFreeContext(pc);
 483         return ret;
 484 }