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         case VIEWER_USER_DEFINED:
 262                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 263                 if (argv) {
 264                         viewer_bin = argv[0];
 265                 }
 266                 break;
 267         default:
 268                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 269                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 270                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 271                 break;
 272         }
 273
 274         if (argv == NULL || !viewer_bin) {
 275                 ret = CMD_FATAL;
 276                 goto error;
 277         }
 278
 279         DBG("Using %s viewer", viewer_bin);
 280
 281         ret = execvp(viewer_bin, argv);
 282         if (ret) {
 283                 if (errno == ENOENT) {
 284                         ERR("%s not found on the system", viewer_bin);
 285                 } else {
 286                         PERROR("exec: %s", viewer_bin);
 287                 }
 288                 free(argv);
 289                 ret = CMD_FATAL;
 290                 goto error;
 291         }
 292
 293 error:
 294         return ret;
 295 }
 296
 297 /*
 298  * Build the live path we need for the lttng live view.
 299  */
 300 static char *build_live_path(char *session_name)
 301 {
 302         int ret;
 303         char *path = NULL;
 304         char hostname[HOST_NAME_MAX];
 305
 306         ret = gethostname(hostname, sizeof(hostname));
 307         if (ret < 0) {
 308                 PERROR("gethostname");
 309                 goto error;
 310         }
 311
 312         ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
 313                         session_name);
 314         if (ret < 0) {
 315                 PERROR("asprintf live path");
 316                 goto error;
 317         }
 318
 319 error:
 320         return path;
 321 }
 322
 323 /*
 324  * Exec viewer if found and use session name path.
 325  */
 326 static int view_trace(void)
 327 {
 328         int ret;
 329         char *session_name, *trace_path = NULL;
 330         struct lttng_session *sessions = NULL;
 331
 332         /*
 333          * Safety net. If lttng is suid at some point for *any* useless reasons,
 334          * this prevent any bad execution of binaries.
 335          */
 336         if (getuid() != 0) {
 337                 if (getuid() != geteuid()) {
 338                         ERR("UID does not match effective UID.");
 339                         ret = CMD_ERROR;
 340                         goto error;
 341                 } else if (getgid() != getegid()) {
 342                         ERR("GID does not match effective GID.");
 343                         ret = CMD_ERROR;
 344                         goto error;
 345                 }
 346         }
 347
 348         /* User define trace path override the session name */
 349         if (opt_trace_path) {
 350                 session_name = NULL;
 351         } else if(opt_session_name == NULL) {
 352                 session_name = get_session_name();
 353                 if (session_name == NULL) {
 354                         ret = CMD_ERROR;
 355                         goto error;
 356                 }
 357         } else {
 358                 session_name = opt_session_name;
 359         }
 360
 361         DBG("Viewing trace for session %s", session_name);
 362
 363         if (session_name) {
 364                 int i, count, found = 0;
 365
 366                 /* Getting all sessions */
 367                 count = lttng_list_sessions(&sessions);
 368                 if (count < 0) {
 369                         ERR("Unable to list sessions. Session name %s not found.",
 370                                         session_name);
 371                         MSG("Is there a session daemon running?");
 372                         ret = CMD_ERROR;
 373                         goto free_error;
 374                 }
 375
 376                 /* Find our session listed by the session daemon */
 377                 for (i = 0; i < count; i++) {
 378                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 379                                 found = 1;
 380                                 break;
 381                         }
 382                 }
 383
 384                 if (!found) {
 385                         MSG("Session name %s not found", session_name);
 386                         ret = CMD_ERROR;
 387                         goto free_sessions;
 388                 }
 389
 390                 session_live_mode = sessions[i].live_timer_interval;
 391
 392                 DBG("Session live mode set to %d", session_live_mode);
 393
 394                 if (sessions[i].enabled && !session_live_mode) {
 395                         WARN("Session %s is running. Please stop it before reading it.",
 396                                         session_name);
 397                         ret = CMD_ERROR;
 398                         goto free_sessions;
 399                 }
 400
 401                 /* If the timer interval is set we are in live mode. */
 402                 if (session_live_mode) {
 403                         trace_path = build_live_path(session_name);
 404                         if (!trace_path) {
 405                                 ret = CMD_ERROR;
 406                                 goto free_sessions;
 407                         }
 408                 } else {
 409                         /* Get file system session path. */
 410                         trace_path = sessions[i].path;
 411                 }
 412         } else {
 413                 trace_path = opt_trace_path;
 414         }
 415
 416         MSG("Trace directory: %s\n", trace_path);
 417
 418         ret = spawn_viewer(trace_path);
 419         if (ret < 0) {
 420                 /* Don't set ret so lttng can interpret the sessiond error. */
 421                 goto free_sessions;
 422         }
 423
 424 free_sessions:
 425         if (session_live_mode) {
 426                 free(trace_path);
 427         }
 428         free(sessions);
 429 free_error:
 430         if (opt_session_name == NULL) {
 431                 free(session_name);
 432         }
 433 error:
 434         return ret;
 435 }
 436
 437 /*
 438  * The 'view <options>' first level command
 439  */
 440 int cmd_view(int argc, const char **argv)
 441 {
 442         int opt, ret = CMD_SUCCESS;
 443         static poptContext pc;
 444
 445         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 446         poptReadDefaultConfig(pc, 0);
 447
 448         if (lttng_opt_mi) {
 449                 WARN("mi does not apply to view command");
 450         }
 451
 452         while ((opt = poptGetNextOpt(pc)) != -1) {
 453                 switch (opt) {
 454                 case OPT_HELP:
 455                         usage(stdout);
 456                         goto end;
 457                 case OPT_LIST_OPTIONS:
 458                         list_cmd_options(stdout, long_options);
 459                         goto end;
 460                 default:
 461                         usage(stderr);
 462                         ret = CMD_UNDEFINED;
 463                         goto end;
 464                 }
 465         }
 466
 467         opt_session_name = (char*) poptGetArg(pc);
 468
 469         ret = view_trace();
 470
 471 end:
 472         poptFreeContext(pc);
 473         return ret;
 474 }