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