src/bin/lttng/commands/destroy.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   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 #include <common/mi-lttng.h>
  30 #include <common/sessiond-comm/sessiond-comm.h>
  31 #include <common/utils.h>
  32
  33 static char *opt_session_name;
  34 static int opt_destroy_all;
  35 static int opt_no_wait;
  36
  37 /* Mi writer */
  38 static struct mi_writer *writer;
  39
  40 enum {
  41         OPT_HELP = 1,
  42         OPT_LIST_OPTIONS,
  43 };
  44
  45 static struct poptOption long_options[] = {
  46         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  47         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  48         {"all",       'a', POPT_ARG_VAL, &opt_destroy_all, 1, 0, 0},
  49         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  50         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  51         {0, 0, 0, 0, 0, 0, 0}
  52 };
  53
  54 /*
  55  * usage
  56  */
  57 static void usage(FILE *ofp)
  58 {
  59         fprintf(ofp, "usage: lttng destroy [NAME] [OPTIONS]\n");
  60         fprintf(ofp, "\n");
  61         fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
  62         fprintf(ofp, "get it from the configuration directory (.lttng).\n");
  63         fprintf(ofp, "\n");
  64         fprintf(ofp, "Options:\n");
  65         fprintf(ofp, "  -h, --help           Show this help\n");
  66         fprintf(ofp, "  -a, --all            Destroy all sessions\n");
  67         fprintf(ofp, "      --list-options   Simple listing of options\n");
  68         fprintf(ofp, "  -n, --no-wait        Don't wait for data availability\n");
  69         fprintf(ofp, "\n");
  70 }
  71
  72 /*
  73  * destroy_session
  74  *
  75  * Unregister the provided session to the session daemon. On success, removes
  76  * the default configuration.
  77  */
  78 static int destroy_session(struct lttng_session *session)
  79 {
  80         int ret;
  81         char *session_name = NULL;
  82
  83         ret = lttng_stop_tracing_no_wait(session->name);
  84         if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
  85                 ERR("%s", lttng_strerror(ret));
  86         }
  87         if (!opt_no_wait) {
  88                 _MSG("Waiting for data availability");
  89                 fflush(stdout);
  90                 do {
  91                         ret = lttng_data_pending(session->name);
  92                         if (ret < 0) {
  93                                 /* Return the data available call error. */
  94                                 goto error;
  95                         }
  96
  97                         /*
  98                          * Data sleep time before retrying (in usec). Don't sleep if the call
  99                          * returned value indicates availability.
 100                          */
 101                         if (ret) {
 102                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
 103                                 _MSG(".");
 104                                 fflush(stdout);
 105                         }
 106                 } while (ret != 0);
 107                 MSG("");
 108         }
 109
 110         ret = lttng_destroy_session_no_wait(session->name);
 111         if (ret < 0) {
 112                 goto error;
 113         }
 114
 115         MSG("Session %s destroyed", session->name);
 116
 117         session_name = get_session_name_quiet();
 118         if (session_name && !strncmp(session->name, session_name, NAME_MAX)) {
 119                 config_destroy_default();
 120         }
 121
 122         if (lttng_opt_mi) {
 123                 ret = mi_lttng_session(writer, session, 0);
 124                 if (ret) {
 125                         ret = CMD_ERROR;
 126                         goto error;
 127                 }
 128         }
 129
 130         ret = CMD_SUCCESS;
 131 error:
 132         free(session_name);
 133         return ret;
 134 }
 135
 136 /*
 137  * destroy_all_sessions
 138  *
 139  * Call destroy_sessions for each registered sessions
 140  */
 141 static int destroy_all_sessions(struct lttng_session *sessions, int count)
 142 {
 143         int i, ret = CMD_SUCCESS;
 144
 145         if (count == 0) {
 146                 MSG("No session found, nothing to do.");
 147         } else if (count < 0) {
 148                 ERR("%s", lttng_strerror(ret));
 149                 goto error;
 150         }
 151
 152         for (i = 0; i < count; i++) {
 153                 ret = destroy_session(&sessions[i]);
 154                 if (ret < 0) {
 155                         goto error;
 156                 }
 157         }
 158 error:
 159         return ret;
 160 }
 161
 162 /*
 163  * The 'destroy <options>' first level command
 164  */
 165 int cmd_destroy(int argc, const char **argv)
 166 {
 167         int opt;
 168         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 169         static poptContext pc;
 170         char *session_name = NULL;
 171
 172         struct lttng_session *sessions;
 173         int count;
 174         int found;
 175
 176         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 177         poptReadDefaultConfig(pc, 0);
 178
 179         while ((opt = poptGetNextOpt(pc)) != -1) {
 180                 switch (opt) {
 181                 case OPT_HELP:
 182                         usage(stdout);
 183                         break;
 184                 case OPT_LIST_OPTIONS:
 185                         list_cmd_options(stdout, long_options);
 186                         break;
 187                 default:
 188                         usage(stderr);
 189                         ret = CMD_UNDEFINED;
 190                         break;
 191                 }
 192                 goto end;
 193         }
 194
 195         /* Mi preparation */
 196         if (lttng_opt_mi) {
 197                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 198                 if (!writer) {
 199                         ret = -LTTNG_ERR_NOMEM;
 200                         goto end;
 201                 }
 202
 203                 /* Open command element */
 204                 ret = mi_lttng_writer_command_open(writer,
 205                                 mi_lttng_element_command_destroy);
 206                 if (ret) {
 207                         ret = CMD_ERROR;
 208                         goto end;
 209                 }
 210
 211                 /* Open output element */
 212                 ret = mi_lttng_writer_open_element(writer,
 213                                 mi_lttng_element_command_output);
 214                 if (ret) {
 215                         ret = CMD_ERROR;
 216                         goto end;
 217                 }
 218
 219                 /* For validation and semantic purpose we open a sessions element */
 220                 ret = mi_lttng_sessions_open(writer);
 221                 if (ret) {
 222                         ret = CMD_ERROR;
 223                         goto end;
 224                 }
 225         }
 226
 227         /* Recuperate all sessions for further operation */
 228         count = lttng_list_sessions(&sessions);
 229         if (count < 0) {
 230                 command_ret = count;
 231                 success = 0;
 232                 goto mi_closing;
 233         }
 234
 235         /* Ignore session name in case all sessions are to be destroyed */
 236         if (opt_destroy_all) {
 237                 command_ret = destroy_all_sessions(sessions, count);
 238                 if (command_ret) {
 239                         success = 0;
 240                 }
 241         } else {
 242                 opt_session_name = (char *) poptGetArg(pc);
 243
 244                 if (!opt_session_name) {
 245                         /* No session name specified, lookup default */
 246                         session_name = get_session_name();
 247                         if (session_name == NULL) {
 248                                 command_ret = CMD_ERROR;
 249                                 success = 0;
 250                                 goto mi_closing;
 251                         }
 252                 } else {
 253                         session_name = opt_session_name;
 254                 }
 255
 256                 /* Find the corresponding lttng_session struct */
 257                 found = 0;
 258                 for (i = 0; i < count; i++) {
 259                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 260                                 found = 1;
 261                                 command_ret = destroy_session(&sessions[i]);
 262                                 if (command_ret) {
 263                                         success = 0;
 264                                 }
 265
 266                         }
 267                 }
 268
 269                 if (!found) {
 270                         ERR("Session name %s not found", session_name);
 271                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 272                         success = 0;
 273                         goto mi_closing;
 274                 }
 275         }
 276
 277 mi_closing:
 278         /* Mi closing */
 279         if (lttng_opt_mi) {
 280                 /* Close sessions and output element element */
 281                 ret = mi_lttng_close_multi_element(writer, 2);
 282                 if (ret) {
 283                         ret = CMD_ERROR;
 284                         goto end;
 285                 }
 286
 287                 /* Success ? */
 288                 ret = mi_lttng_writer_write_element_bool(writer,
 289                                 mi_lttng_element_command_success, success);
 290                 if (ret) {
 291                         ret = CMD_ERROR;
 292                         goto end;
 293                 }
 294
 295                 /* Command element close */
 296                 ret = mi_lttng_writer_command_close(writer);
 297                 if (ret) {
 298                         ret = CMD_ERROR;
 299                         goto end;
 300                 }
 301         }
 302 end:
 303         /* Mi clean-up */
 304         if (writer && mi_lttng_writer_destroy(writer)) {
 305                 /* Preserve original error code */
 306                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 307         }
 308
 309         if (opt_session_name == NULL) {
 310                 free(session_name);
 311         }
 312
 313         /* Overwrite ret if an error occurred during destroy_session/all */
 314         ret = command_ret ? command_ret : ret;
 315
 316         poptFreeContext(pc);
 317         return ret;
 318 }