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