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         return NULL;
 177 }
 178
 179 /*
 180  * Alloc an array of string pointer from an array of strings. It also adds
 181  * the trace path to the argv.
 182  *
 183  * The returning pointer is ready to be passed to execvp().
 184  */
 185 static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
 186                 const char *trace_path)
 187 {
 188         char **argv;
 189         size_t size, mem_len;
 190
 191
 192         /* Add one for the NULL terminating element. */
 193         mem_len = opts_len + 1;
 194         if (session_live_mode) {
 195                 /* Add 3 option for the live mode being "-i lttng-live URL". */
 196                 mem_len += 3;
 197         } else {
 198                 /* Add option for the trace path. */
 199                 mem_len += 1;
 200         }
 201
 202         size = sizeof(char *) * mem_len;
 203
 204         /* Add two here for the trace_path and the NULL terminating element. */
 205         argv = zmalloc(size);
 206         if (argv == NULL) {
 207                 goto error;
 208         }
 209
 210         memcpy(argv, opts, size);
 211
 212         if (session_live_mode) {
 213                 argv[opts_len] = "-i";
 214                 argv[opts_len + 1] = "lttng-live";
 215                 argv[opts_len + 2] = (char *) trace_path;
 216                 argv[opts_len + 3] = NULL;
 217         } else {
 218                 argv[opts_len] = (char *) trace_path;
 219                 argv[opts_len + 1] = NULL;
 220         }
 221
 222 error:
 223         return argv;
 224 }
 225
 226 /*
 227  * Spawn viewer with the trace directory path.
 228  */
 229 static int spawn_viewer(const char *trace_path)
 230 {
 231         int ret = 0;
 232         struct stat status;
 233         const char *viewer_bin = NULL;
 234         struct viewers *viewer;
 235         char **argv = NULL;
 236
 237         /* Check for --viewer options */
 238         viewer = parse_options();
 239         if (viewer == NULL) {
 240                 ret = CMD_ERROR;
 241                 goto error;
 242         }
 243
 244         switch (viewer->type) {
 245         case VIEWER_BABELTRACE:
 246                 if (stat(babeltrace_bin, &status) == 0) {
 247                         viewer_bin = babeltrace_bin;
 248                 } else {
 249                         viewer_bin = viewer->exec_name;
 250                 }
 251                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 252                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 253                 break;
 254 #if 0
 255         case VIEWER_LTTV_GUI:
 256                 if (stat(lttv_gui_bin, &status) == 0) {
 257                         viewer_bin = lttv_gui_bin;
 258                 } else {
 259                         viewer_bin = viewer->exec_name;
 260                 }
 261                 argv = alloc_argv_from_local_opts(lttv_gui_opts,
 262                                 ARRAY_SIZE(lttv_gui_opts), trace_path);
 263                 break;
 264 #endif
 265         case VIEWER_USER_DEFINED:
 266                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 267                 if (argv) {
 268                         viewer_bin = argv[0];
 269                 }
 270                 break;
 271         default:
 272                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 273                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 274                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 275                 break;
 276         }
 277
 278         if (argv == NULL) {
 279                 ret = CMD_FATAL;
 280                 goto error;
 281         }
 282
 283         DBG("Using %s viewer", viewer_bin);
 284
 285         ret = execvp(viewer_bin, argv);
 286         if (ret) {
 287                 if (errno == ENOENT) {
 288                         ERR("%s not found on the system", viewer_bin);
 289                 } else {
 290                         PERROR("exec: %s", viewer_bin);
 291                 }
 292                 free(argv);
 293                 ret = CMD_FATAL;
 294                 goto error;
 295         }
 296
 297 error:
 298         return ret;
 299 }
 300
 301 /*
 302  * Build the live path we need for the lttng live view.
 303  */
 304 static char *build_live_path(char *session_name)
 305 {
 306         int ret;
 307         char *path = NULL;
 308         char hostname[HOST_NAME_MAX];
 309
 310         ret = gethostname(hostname, sizeof(hostname));
 311         if (ret < 0) {
 312                 perror("gethostname");
 313                 goto error;
 314         }
 315
 316         ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
 317                         session_name);
 318         if (ret < 0) {
 319                 perror("asprintf live path");
 320                 goto error;
 321         }
 322
 323 error:
 324         return path;
 325 }
 326
 327 /*
 328  * Exec viewer if found and use session name path.
 329  */
 330 static int view_trace(void)
 331 {
 332         int ret;
 333         char *session_name, *trace_path = NULL;
 334         struct lttng_session *sessions = NULL;
 335
 336         /*
 337          * Safety net. If lttng is suid at some point for *any* useless reasons,
 338          * this prevent any bad execution of binaries.
 339          */
 340         if (getuid() != 0) {
 341                 if (getuid() != geteuid()) {
 342                         ERR("UID does not match effective UID.");
 343                         ret = CMD_ERROR;
 344                         goto error;
 345                 } else if (getgid() != getegid()) {
 346                         ERR("GID does not match effective GID.");
 347                         ret = CMD_ERROR;
 348                         goto error;
 349                 }
 350         }
 351
 352         /* User define trace path override the session name */
 353         if (opt_trace_path) {
 354                 session_name = NULL;
 355         } else if(opt_session_name == NULL) {
 356                 session_name = get_session_name();
 357                 if (session_name == NULL) {
 358                         ret = CMD_ERROR;
 359                         goto error;
 360                 }
 361         } else {
 362                 session_name = opt_session_name;
 363         }
 364
 365         DBG("Viewing trace for session %s", session_name);
 366
 367         if (session_name) {
 368                 int i, count, found = 0;
 369
 370                 /* Getting all sessions */
 371                 count = lttng_list_sessions(&sessions);
 372                 if (count < 0) {
 373                         ERR("Unable to list sessions. Session name %s not found.",
 374                                         session_name);
 375                         MSG("Is there a session daemon running?");
 376                         ret = CMD_ERROR;
 377                         goto free_error;
 378                 }
 379
 380                 /* Find our session listed by the session daemon */
 381                 for (i = 0; i < count; i++) {
 382                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 383                                 found = 1;
 384                                 break;
 385                         }
 386                 }
 387
 388                 if (!found) {
 389                         MSG("Session name %s not found", session_name);
 390                         ret = CMD_ERROR;
 391                         goto free_sessions;
 392                 }
 393
 394                 session_live_mode = sessions[i].live_timer_interval;
 395
 396                 DBG("Session live mode set to %d", session_live_mode);
 397
 398                 if (sessions[i].enabled && !session_live_mode) {
 399                         WARN("Session %s is running. Please stop it before reading it.",
 400                                         session_name);
 401                         ret = CMD_ERROR;
 402                         goto free_sessions;
 403                 }
 404
 405                 /* If the timer interval is set we are in live mode. */
 406                 if (session_live_mode) {
 407                         trace_path = build_live_path(session_name);
 408                         if (!trace_path) {
 409                                 ret = CMD_ERROR;
 410                                 goto free_sessions;
 411                         }
 412                 } else {
 413                         /* Get file system session path. */
 414                         trace_path = sessions[i].path;
 415                 }
 416         } else {
 417                 trace_path = opt_trace_path;
 418         }
 419
 420         MSG("Trace directory: %s\n", trace_path);
 421
 422         ret = spawn_viewer(trace_path);
 423         if (ret < 0) {
 424                 /* Don't set ret so lttng can interpret the sessiond error. */
 425                 goto free_sessions;
 426         }
 427
 428 free_sessions:
 429         if (session_live_mode) {
 430                 free(trace_path);
 431         }
 432         free(sessions);
 433 free_error:
 434         if (opt_session_name == NULL) {
 435                 free(session_name);
 436         }
 437 error:
 438         return ret;
 439 }
 440
 441 /*
 442  * The 'view <options>' first level command
 443  */
 444 int cmd_view(int argc, const char **argv)
 445 {
 446         int opt, ret = CMD_SUCCESS;
 447         static poptContext pc;
 448
 449         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 450         poptReadDefaultConfig(pc, 0);
 451
 452         if (lttng_opt_mi) {
 453                 WARN("mi does not apply to view command");
 454         }
 455
 456         while ((opt = poptGetNextOpt(pc)) != -1) {
 457                 switch (opt) {
 458                 case OPT_HELP:
 459                         usage(stdout);
 460                         goto end;
 461                 case OPT_LIST_OPTIONS:
 462                         list_cmd_options(stdout, long_options);
 463                         goto end;
 464                 default:
 465                         usage(stderr);
 466                         ret = CMD_UNDEFINED;
 467                         goto end;
 468                 }
 469         }
 470
 471         opt_session_name = (char*) poptGetArg(pc);
 472
 473         ret = view_trace();
 474
 475 end:
 476         poptFreeContext(pc);
 477         return ret;
 478 }