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         return NULL;
 176 }
 177
 178 /*
 179  * Alloc an array of string pointer from an array of strings. It also adds
 180  * the trace path to the argv.
 181  *
 182  * The returning pointer is ready to be passed to execvp().
 183  */
 184 static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
 185                 const char *trace_path)
 186 {
 187         char **argv;
 188         size_t size, mem_len;
 189
 190
 191         /* Add one for the NULL terminating element. */
 192         mem_len = opts_len + 1;
 193         if (session_live_mode) {
 194                 /* Add 3 option for the live mode being "-i lttng-live URL". */
 195                 mem_len += 3;
 196         } else {
 197                 /* Add option for the trace path. */
 198                 mem_len += 1;
 199         }
 200
 201         size = sizeof(char *) * mem_len;
 202
 203         /* Add two here for the trace_path and the NULL terminating element. */
 204         argv = zmalloc(size);
 205         if (argv == NULL) {
 206                 goto error;
 207         }
 208
 209         memcpy(argv, opts, size);
 210
 211         if (session_live_mode) {
 212                 argv[opts_len] = "-i";
 213                 argv[opts_len + 1] = "lttng-live";
 214                 argv[opts_len + 2] = (char *) trace_path;
 215                 argv[opts_len + 3] = NULL;
 216         } else {
 217                 argv[opts_len] = (char *) trace_path;
 218                 argv[opts_len + 1] = NULL;
 219         }
 220
 221 error:
 222         return argv;
 223 }
 224
 225 /*
 226  * Spawn viewer with the trace directory path.
 227  */
 228 static int spawn_viewer(const char *trace_path)
 229 {
 230         int ret = 0;
 231         struct stat status;
 232         const char *viewer_bin = NULL;
 233         struct viewers *viewer;
 234         char **argv = NULL;
 235
 236         /* Check for --viewer options */
 237         viewer = parse_options();
 238         if (viewer == NULL) {
 239                 ret = CMD_ERROR;
 240                 goto error;
 241         }
 242
 243         switch (viewer->type) {
 244         case VIEWER_BABELTRACE:
 245                 if (stat(babeltrace_bin, &status) == 0) {
 246                         viewer_bin = babeltrace_bin;
 247                 } else {
 248                         viewer_bin = viewer->exec_name;
 249                 }
 250                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 251                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 252                 break;
 253 #if 0
 254         case VIEWER_LTTV_GUI:
 255                 if (stat(lttv_gui_bin, &status) == 0) {
 256                         viewer_bin = lttv_gui_bin;
 257                 } else {
 258                         viewer_bin = viewer->exec_name;
 259                 }
 260                 argv = alloc_argv_from_local_opts(lttv_gui_opts,
 261                                 ARRAY_SIZE(lttv_gui_opts), trace_path);
 262                 break;
 263 #endif
 264         case VIEWER_USER_DEFINED:
 265                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 266                 if (argv) {
 267                         viewer_bin = argv[0];
 268                 }
 269                 break;
 270         default:
 271                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 272                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 273                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 274                 break;
 275         }
 276
 277         if (argv == NULL) {
 278                 ret = CMD_FATAL;
 279                 goto error;
 280         }
 281
 282         DBG("Using %s viewer", viewer_bin);
 283
 284         ret = execvp(viewer_bin, argv);
 285         if (ret) {
 286                 if (errno == ENOENT) {
 287                         ERR("%s not found on the system", viewer_bin);
 288                 } else {
 289                         PERROR("exec: %s", viewer_bin);
 290                 }
 291                 free(argv);
 292                 ret = CMD_FATAL;
 293                 goto error;
 294         }
 295
 296 error:
 297         return ret;
 298 }
 299
 300 /*
 301  * Build the live path we need for the lttng live view.
 302  */
 303 static char *build_live_path(char *session_name)
 304 {
 305         int ret;
 306         char *path = NULL;
 307         char hostname[HOST_NAME_MAX];
 308
 309         ret = gethostname(hostname, sizeof(hostname));
 310         if (ret < 0) {
 311                 perror("gethostname");
 312                 goto error;
 313         }
 314
 315         ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
 316                         session_name);
 317         if (ret < 0) {
 318                 perror("asprintf live path");
 319                 goto error;
 320         }
 321
 322 error:
 323         return path;
 324 }
 325
 326 /*
 327  * Exec viewer if found and use session name path.
 328  */
 329 static int view_trace(void)
 330 {
 331         int ret;
 332         char *session_name, *trace_path = NULL;
 333         struct lttng_session *sessions = NULL;
 334
 335         /*
 336          * Safety net. If lttng is suid at some point for *any* useless reasons,
 337          * this prevent any bad execution of binaries.
 338          */
 339         if (getuid() != 0) {
 340                 if (getuid() != geteuid()) {
 341                         ERR("UID does not match effective UID.");
 342                         ret = CMD_ERROR;
 343                         goto error;
 344                 } else if (getgid() != getegid()) {
 345                         ERR("GID does not match effective GID.");
 346                         ret = CMD_ERROR;
 347                         goto error;
 348                 }
 349         }
 350
 351         /* User define trace path override the session name */
 352         if (opt_trace_path) {
 353                 session_name = NULL;
 354         } else if(opt_session_name == NULL) {
 355                 session_name = get_session_name();
 356                 if (session_name == NULL) {
 357                         ret = CMD_ERROR;
 358                         goto error;
 359                 }
 360         } else {
 361                 session_name = opt_session_name;
 362         }
 363
 364         DBG("Viewing trace for session %s", session_name);
 365
 366         if (session_name) {
 367                 int i, count, found = 0;
 368
 369                 /* Getting all sessions */
 370                 count = lttng_list_sessions(&sessions);
 371                 if (count < 0) {
 372                         ERR("Unable to list sessions. Session name %s not found.",
 373                                         session_name);
 374                         MSG("Is there a session daemon running?");
 375                         ret = CMD_ERROR;
 376                         goto free_error;
 377                 }
 378
 379                 /* Find our session listed by the session daemon */
 380                 for (i = 0; i < count; i++) {
 381                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 382                                 found = 1;
 383                                 break;
 384                         }
 385                 }
 386
 387                 if (!found) {
 388                         MSG("Session name %s not found", session_name);
 389                         ret = CMD_ERROR;
 390                         goto free_sessions;
 391                 }
 392
 393                 session_live_mode = sessions[i].live_timer_interval;
 394
 395                 DBG("Session live mode set to %d", session_live_mode);
 396
 397                 if (sessions[i].enabled && !session_live_mode) {
 398                         WARN("Session %s is running. Please stop it before reading it.",
 399                                         session_name);
 400                         ret = CMD_ERROR;
 401                         goto free_sessions;
 402                 }
 403
 404                 /* If the timer interval is set we are in live mode. */
 405                 if (session_live_mode) {
 406                         trace_path = build_live_path(session_name);
 407                         if (!trace_path) {
 408                                 ret = CMD_ERROR;
 409                                 goto free_sessions;
 410                         }
 411                 } else {
 412                         /* Get file system session path. */
 413                         trace_path = sessions[i].path;
 414                 }
 415         } else {
 416                 trace_path = opt_trace_path;
 417         }
 418
 419         MSG("Trace directory: %s\n", trace_path);
 420
 421         ret = spawn_viewer(trace_path);
 422         if (ret < 0) {
 423                 /* Don't set ret so lttng can interpret the sessiond error. */
 424                 goto free_sessions;
 425         }
 426
 427 free_sessions:
 428         if (session_live_mode) {
 429                 free(trace_path);
 430         }
 431         free(sessions);
 432 free_error:
 433         if (opt_session_name == NULL) {
 434                 free(session_name);
 435         }
 436 error:
 437         return ret;
 438 }
 439
 440 /*
 441  * The 'view <options>' first level command
 442  */
 443 int cmd_view(int argc, const char **argv)
 444 {
 445         int opt, ret = CMD_SUCCESS;
 446         static poptContext pc;
 447
 448         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 449         poptReadDefaultConfig(pc, 0);
 450
 451         while ((opt = poptGetNextOpt(pc)) != -1) {
 452                 switch (opt) {
 453                 case OPT_HELP:
 454                         usage(stdout);
 455                         goto end;
 456                 case OPT_LIST_OPTIONS:
 457                         list_cmd_options(stdout, long_options);
 458                         goto end;
 459                 default:
 460                         usage(stderr);
 461                         ret = CMD_UNDEFINED;
 462                         goto end;
 463                 }
 464         }
 465
 466         opt_session_name = (char*) poptGetArg(pc);
 467
 468         ret = view_trace();
 469
 470 end:
 471         poptFreeContext(pc);
 472         return ret;
 473 }