src/bin/lttng/commands/track-untrack.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #define _LGPL_SOURCE
  21 #include <ctype.h>
  22 #include <popt.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <unistd.h>
  29 #include <assert.h>
  30
  31 #include <urcu/list.h>
  32
  33 #include <common/mi-lttng.h>
  34
  35 #include "../command.h"
  36
  37 enum cmd_type {
  38         CMD_TRACK,
  39         CMD_UNTRACK,
  40 };
  41
  42 static char *opt_session_name;
  43 static int opt_kernel;
  44 static int opt_userspace;
  45 static int opt_all;
  46 static char *opt_pid_string;
  47 static int opt_pid;
  48
  49 enum {
  50         OPT_HELP = 1,
  51         OPT_LIST_OPTIONS,
  52         OPT_SESSION,
  53         OPT_PID,
  54 };
  55
  56 static struct poptOption long_options[] = {
  57         /* { longName, shortName, argInfo, argPtr, value, descrip, argDesc, } */
  58         { "help",               'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0, },
  59         { "session",            's', POPT_ARG_STRING, &opt_session_name, OPT_SESSION, 0, 0, },
  60         { "kernel",             'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0, },
  61         { "userspace",          'u', POPT_ARG_VAL, &opt_userspace, 1, 0, 0, },
  62         { "pid",                'p', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_pid_string, OPT_PID, 0, 0, },
  63         { "all",                'a', POPT_ARG_VAL, &opt_all, 1, 0, 0, },
  64         { "list-options",       0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, 0, 0, },
  65         { 0, 0, 0, 0, 0, 0, 0, },
  66 };
  67
  68 /*
  69  * usage
  70  */
  71 static void usage(FILE *ofp, const char *cmd_str)
  72 {
  73         fprintf(ofp, "usage: lttng %s [-k|-u] [OPTIONS]\n", cmd_str);
  74         fprintf(ofp, "\n");
  75         fprintf(ofp, "If no session is given (-s), the context is added to\n");
  76         fprintf(ofp, "the current sesssion. Exactly one domain (-k or -u)\n");
  77         fprintf(ofp, "must be specified.\n");
  78         fprintf(ofp, "\n");
  79         fprintf(ofp, "Options:\n");
  80         fprintf(ofp, "  -h, --help               Show this help.\n");
  81         fprintf(ofp, "      --list-options       Simple listing of options.\n");
  82         fprintf(ofp, "  -s, --session NAME       Apply to session name.\n");
  83         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer.\n");
  84         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer.\n");
  85         fprintf(ofp, "  -p, --pid [PID]          Process ID tracker. Leave PID empty when used with --all.\n");
  86         fprintf(ofp, "  -a, --all                All PIDs (use with --pid).\n");
  87         fprintf(ofp, "\n");
  88 }
  89
  90 static
  91 int parse_pid_string(const char *_pid_string,
  92                 int all, int **_pid_list, int *nr_pids)
  93 {
  94         const char *one_pid_str;
  95         char *iter;
  96         int retval = CMD_SUCCESS;
  97         int count = 0;
  98         int *pid_list = NULL;
  99         char *pid_string = NULL;
 100         char *endptr;
 101
 102         if (all && _pid_string) {
 103                 ERR("An empty PID string is expected with --all");
 104                 retval = CMD_ERROR;
 105                 goto error;
 106         }
 107         if (!all && !_pid_string) {
 108                 ERR("Please specify --all with an empty PID string");
 109                 retval = CMD_ERROR;
 110                 goto error;
 111         }
 112         if (all) {
 113                 pid_list = zmalloc(sizeof(*_pid_list));
 114                 if (!pid_list) {
 115                         ERR("Out of memory");
 116                         retval = CMD_ERROR;
 117                         goto error;
 118                 }
 119                 /* Empty PID string means all PIDs */
 120                 count = 1;
 121                 pid_list[0] = -1;
 122                 goto assign;
 123         }
 124
 125         pid_string = strdup(_pid_string);
 126         if (!pid_string) {
 127                 ERR("Out of memory");
 128                 retval = CMD_ERROR;
 129                 goto error;
 130         }
 131
 132         /* Count */
 133         one_pid_str = strtok_r(pid_string, ",", &iter);
 134         while (one_pid_str != NULL) {
 135                 unsigned long v;
 136
 137                 errno = 0;
 138                 v = strtoul(one_pid_str, &endptr, 10);
 139                 if ((v == 0 && errno == EINVAL)
 140                                 || (v == ULONG_MAX && errno == ERANGE)
 141                                 || (*one_pid_str != '\0' && *endptr != '\0')){
 142                         ERR("Error parsing PID %s", one_pid_str);
 143                         retval = CMD_ERROR;
 144                         goto error;
 145                 }
 146
 147                 if ((long) v > INT_MAX || (int) v < 0) {
 148                         ERR("Invalid PID value %ld", (long) v);
 149                         retval = CMD_ERROR;
 150                         goto error;
 151                 }
 152                 count++;
 153
 154                 /* For next loop */
 155                 one_pid_str = strtok_r(NULL, ",", &iter);
 156         }
 157
 158         free(pid_string);
 159         /* Identity of delimiter has been lost in first pass. */
 160         pid_string = strdup(_pid_string);
 161         if (!pid_string) {
 162                 ERR("Out of memory");
 163                 retval = CMD_ERROR;
 164                 goto error;
 165         }
 166
 167         /* Allocate */
 168         pid_list = zmalloc(count * sizeof(*pid_list));
 169         if (!pid_list) {
 170                 ERR("Out of memory");
 171                 retval = CMD_ERROR;
 172                 goto error;
 173         }
 174
 175         /* Copy */
 176         count = 0;
 177         one_pid_str = strtok_r(pid_string, ",", &iter);
 178         while (one_pid_str != NULL) {
 179                 unsigned long v;
 180
 181                 v = strtoul(one_pid_str, NULL, 10);
 182                 pid_list[count++] = (int) v;
 183
 184                 /* For next loop */
 185                 one_pid_str = strtok_r(NULL, ",", &iter);
 186         }
 187
 188 assign:
 189         *nr_pids = count;
 190         *_pid_list = pid_list;
 191         goto end;       /* SUCCESS */
 192
 193         /* ERROR */
 194 error:
 195         free(pid_list);
 196 end:
 197         free(pid_string);
 198         return retval;
 199 }
 200
 201 static
 202 enum cmd_error_code track_untrack_pid(enum cmd_type cmd_type, const char *cmd_str,
 203                 const char *session_name, const char *pid_string,
 204                 int all, struct mi_writer *writer)
 205 {
 206         int ret, success = 1 , i;
 207         enum cmd_error_code retval = CMD_SUCCESS;
 208         int *pid_list = NULL;
 209         int nr_pids;
 210         struct lttng_domain dom;
 211         struct lttng_handle *handle = NULL;
 212         int (*cmd_func)(struct lttng_handle *handle, int pid);
 213
 214         switch (cmd_type) {
 215         case CMD_TRACK:
 216                 cmd_func = lttng_track_pid;
 217                 break;
 218         case CMD_UNTRACK:
 219                 cmd_func = lttng_untrack_pid;
 220                 break;
 221         default:
 222                 ERR("Unknown command");
 223                 retval = CMD_ERROR;
 224                 goto end;
 225         }
 226
 227         memset(&dom, 0, sizeof(dom));
 228         if (opt_kernel) {
 229                 dom.type = LTTNG_DOMAIN_KERNEL;
 230         } else if (opt_userspace) {
 231                 dom.type = LTTNG_DOMAIN_UST;
 232         } else {
 233                 /* Checked by the caller. */
 234                 assert(0);
 235         }
 236
 237         ret = parse_pid_string(pid_string, all, &pid_list, &nr_pids);
 238         if (ret != CMD_SUCCESS) {
 239                 ERR("Error parsing PID string");
 240                 usage(stderr, cmd_str);
 241                 retval = CMD_ERROR;
 242                 goto end;
 243         }
 244
 245         handle = lttng_create_handle(session_name, &dom);
 246         if (handle == NULL) {
 247                 retval = CMD_ERROR;
 248                 goto end;
 249         }
 250
 251         if (writer) {
 252                 /* Open process element */
 253                 ret = mi_lttng_targets_open(writer);
 254                 if (ret) {
 255                         retval = CMD_ERROR;
 256                         goto end;
 257                 }
 258         }
 259
 260         for (i = 0; i < nr_pids; i++) {
 261                 DBG("%s PID %d", cmd_str, pid_list[i]);
 262                 ret = cmd_func(handle, pid_list[i]);
 263                 if (ret) {
 264                         switch (-ret) {
 265                         case LTTNG_ERR_PID_TRACKED:
 266                                 WARN("PID %i already tracked in session %s",
 267                                                 pid_list[i], session_name);
 268                                 success = 1;
 269                                 retval = CMD_SUCCESS;
 270                                 break;
 271                         case LTTNG_ERR_PID_NOT_TRACKED:
 272                                 WARN("PID %i not tracked in session %s",
 273                                                 pid_list[i], session_name);
 274                                 success = 1;
 275                                 retval = CMD_SUCCESS;
 276                                 break;
 277                         default:
 278                                 ERR("%s", lttng_strerror(ret));
 279                                 success = 0;
 280                                 retval = CMD_ERROR;
 281                                 break;
 282                         }
 283                 } else {
 284                         MSG("PID %i %sed in session %s",
 285                                         pid_list[i], cmd_str, session_name);
 286                         success = 1;
 287                 }
 288
 289                 /* Mi */
 290                 if (writer) {
 291                         ret = mi_lttng_pid_target(writer, pid_list[i], 1);
 292                         if (ret) {
 293                                 retval = CMD_ERROR;
 294                                 goto end;
 295                         }
 296
 297                         ret = mi_lttng_writer_write_element_bool(writer,
 298                                         mi_lttng_element_success, success);
 299                         if (ret) {
 300                                 retval = CMD_ERROR;
 301                                 goto end;
 302                         }
 303
 304                         ret = mi_lttng_writer_close_element(writer);
 305                         if (ret) {
 306                                 retval = CMD_ERROR;
 307                                 goto end;
 308                         }
 309                 }
 310         }
 311
 312         if (writer) {
 313                 /* Close targets element */
 314                 ret = mi_lttng_writer_close_element(writer);
 315                 if (ret) {
 316                         retval = CMD_ERROR;
 317                         goto end;
 318                 }
 319         }
 320
 321 end:
 322         if (handle) {
 323                 lttng_destroy_handle(handle);
 324         }
 325         free(pid_list);
 326         return retval;
 327 }
 328
 329 static
 330 const char *get_mi_element_command(enum cmd_type cmd_type)
 331 {
 332         switch (cmd_type) {
 333         case CMD_TRACK:
 334                 return mi_lttng_element_command_track;
 335         case CMD_UNTRACK:
 336                 return mi_lttng_element_command_untrack;
 337         default:
 338                 return NULL;
 339         }
 340 }
 341
 342 /*
 343  * Add/remove tracker to/from session.
 344  */
 345 static
 346 int cmd_track_untrack(enum cmd_type cmd_type, const char *cmd_str,
 347                 int argc, const char **argv)
 348 {
 349         int opt, ret = 0;
 350         enum cmd_error_code command_ret = CMD_SUCCESS;
 351         int success = 1;
 352         static poptContext pc;
 353         char *session_name = NULL;
 354         struct mi_writer *writer = NULL;
 355
 356         if (argc < 1) {
 357                 usage(stderr, cmd_str);
 358                 command_ret = CMD_ERROR;
 359                 goto end;
 360         }
 361
 362         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 363         poptReadDefaultConfig(pc, 0);
 364
 365         while ((opt = poptGetNextOpt(pc)) != -1) {
 366                 switch (opt) {
 367                 case OPT_HELP:
 368                         usage(stdout, cmd_str);
 369                         goto end;
 370                 case OPT_LIST_OPTIONS:
 371                         list_cmd_options(stdout, long_options);
 372                         goto end;
 373                 case OPT_SESSION:
 374                 case OPT_PID:
 375                         opt_pid = 1;
 376                         break;
 377                 default:
 378                         usage(stderr, cmd_str);
 379                         command_ret = CMD_UNDEFINED;
 380                         goto end;
 381                 }
 382         }
 383
 384         ret = print_missing_or_multiple_domains(opt_kernel + opt_userspace);
 385         if (ret) {
 386                 ret = CMD_ERROR;
 387                 goto end;
 388         }
 389
 390         if (!opt_session_name) {
 391                 session_name = get_session_name();
 392                 if (session_name == NULL) {
 393                         command_ret = CMD_ERROR;
 394                         goto end;
 395                 }
 396         } else {
 397                 session_name = opt_session_name;
 398         }
 399
 400         /* Currently only PID tracker is supported */
 401         if (!opt_pid) {
 402                 ERR("Please specify at least one tracker with its expected arguments");
 403                 usage(stderr, cmd_str);
 404                 command_ret = CMD_ERROR;
 405                 goto end;
 406         }
 407
 408         /* Mi check */
 409         if (lttng_opt_mi) {
 410                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 411                 if (!writer) {
 412                         command_ret = CMD_ERROR;
 413                         goto end;
 414                 }
 415         }
 416
 417         if (writer) {
 418                 /* Open command element */
 419                 ret = mi_lttng_writer_command_open(writer,
 420                                 get_mi_element_command(cmd_type));
 421                 if (ret) {
 422                         command_ret = CMD_ERROR;
 423                         goto end;
 424                 }
 425
 426                 /* Open output element */
 427                 ret = mi_lttng_writer_open_element(writer,
 428                                 mi_lttng_element_command_output);
 429                 if (ret) {
 430                         command_ret = CMD_ERROR;
 431                         goto end;
 432                 }
 433         }
 434
 435         command_ret = track_untrack_pid(cmd_type,
 436                         cmd_str, session_name, opt_pid_string,
 437                         opt_all, writer);
 438         if (command_ret != CMD_SUCCESS) {
 439                 success = 0;
 440         }
 441
 442         /* Mi closing */
 443         if (writer) {
 444                 /* Close  output element */
 445                 ret = mi_lttng_writer_close_element(writer);
 446                 if (ret) {
 447                         command_ret = CMD_ERROR;
 448                         goto end;
 449                 }
 450
 451                 /* Success ? */
 452                 ret = mi_lttng_writer_write_element_bool(writer,
 453                                 mi_lttng_element_command_success, success);
 454                 if (ret) {
 455                         command_ret = CMD_ERROR;
 456                         goto end;
 457                 }
 458
 459                 /* Command element close */
 460                 ret = mi_lttng_writer_command_close(writer);
 461                 if (ret) {
 462                         command_ret = CMD_ERROR;
 463                         goto end;
 464                 }
 465         }
 466
 467 end:
 468         if (!opt_session_name) {
 469                 free(session_name);
 470         }
 471
 472         /* Mi clean-up */
 473         if (writer && mi_lttng_writer_destroy(writer)) {
 474                 /* Preserve original error code */
 475                 command_ret = CMD_ERROR;
 476         }
 477
 478         poptFreeContext(pc);
 479         return (int) command_ret;
 480 }
 481
 482 int cmd_track(int argc, const char **argv)
 483 {
 484         return cmd_track_untrack(CMD_TRACK, "track", argc, argv);
 485 }
 486
 487 int cmd_untrack(int argc, const char **argv)
 488 {
 489         return cmd_track_untrack(CMD_UNTRACK, "untrack", argc, argv);
 490 }