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