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 #define _LGPL_SOURCE
  20 #include <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27
  28 #include "../command.h"
  29
  30 #include <common/mi-lttng.h>
  31 #include <common/sessiond-comm/sessiond-comm.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
  79         ret = lttng_destroy_session(session->name);
  80         if (ret < 0) {
  81                 switch (-ret) {
  82                 case LTTNG_ERR_SESS_NOT_FOUND:
  83                         WARN("Session name %s not found", session->name);
  84                         break;
  85                 default:
  86                         ERR("%s", lttng_strerror(ret));
  87                         break;
  88                 }
  89                 goto error;
  90         }
  91
  92         MSG("Session %s destroyed", session->name);
  93         config_destroy_default();
  94
  95         if (lttng_opt_mi) {
  96                 ret = mi_lttng_session(writer, session, 0);
  97                 if (ret) {
  98                         ret = CMD_ERROR;
  99                         goto error;
 100                 }
 101         }
 102
 103         ret = CMD_SUCCESS;
 104 error:
 105         return ret;
 106 }
 107
 108 /*
 109  * destroy_all_sessions
 110  *
 111  * Call destroy_sessions for each registered sessions
 112  */
 113 static int destroy_all_sessions(struct lttng_session *sessions, int count)
 114 {
 115         int i, ret = CMD_SUCCESS;
 116
 117         if (count == 0) {
 118                 MSG("No session found, nothing to do.");
 119         } else if (count < 0) {
 120                 ERR("%s", lttng_strerror(ret));
 121                 goto error;
 122         }
 123
 124         for (i = 0; i < count; i++) {
 125                 ret = destroy_session(&sessions[i]);
 126                 if (ret < 0) {
 127                         goto error;
 128                 }
 129         }
 130 error:
 131         return ret;
 132 }
 133
 134 /*
 135  * The 'destroy <options>' first level command
 136  */
 137 int cmd_destroy(int argc, const char **argv)
 138 {
 139         int opt;
 140         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 141         static poptContext pc;
 142         char *session_name = NULL;
 143
 144         struct lttng_session *sessions;
 145         int count;
 146         int found;
 147
 148         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 149         poptReadDefaultConfig(pc, 0);
 150
 151         while ((opt = poptGetNextOpt(pc)) != -1) {
 152                 switch (opt) {
 153                 case OPT_HELP:
 154                         usage(stdout);
 155                         break;
 156                 case OPT_LIST_OPTIONS:
 157                         list_cmd_options(stdout, long_options);
 158                         break;
 159                 default:
 160                         usage(stderr);
 161                         ret = CMD_UNDEFINED;
 162                         break;
 163                 }
 164                 goto end;
 165         }
 166
 167         /* Mi preparation */
 168         if (lttng_opt_mi) {
 169                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 170                 if (!writer) {
 171                         ret = -LTTNG_ERR_NOMEM;
 172                         goto end;
 173                 }
 174
 175                 /* Open command element */
 176                 ret = mi_lttng_writer_command_open(writer,
 177                                 mi_lttng_element_command_destroy);
 178                 if (ret) {
 179                         ret = CMD_ERROR;
 180                         goto end;
 181                 }
 182
 183                 /* Open output element */
 184                 ret = mi_lttng_writer_open_element(writer,
 185                                 mi_lttng_element_command_output);
 186                 if (ret) {
 187                         ret = CMD_ERROR;
 188                         goto end;
 189                 }
 190
 191                 /* For validation and semantic purpose we open a sessions element */
 192                 ret = mi_lttng_sessions_open(writer);
 193                 if (ret) {
 194                         ret = CMD_ERROR;
 195                         goto end;
 196                 }
 197         }
 198
 199         /* Recuperate all sessions for further operation */
 200         count = lttng_list_sessions(&sessions);
 201         if (count < 0) {
 202                 command_ret = count;
 203                 success = 0;
 204                 goto mi_closing;
 205         }
 206
 207         /* Ignore session name in case all sessions are to be destroyed */
 208         if (opt_destroy_all) {
 209                 command_ret = destroy_all_sessions(sessions, count);
 210                 if (command_ret) {
 211                         success = 0;
 212                 }
 213         } else {
 214                 opt_session_name = (char *) poptGetArg(pc);
 215
 216                 if (opt_session_name == NULL) {
 217                         /* No session name specified, lookup default */
 218                         session_name = get_session_name();
 219                         if (session_name == NULL) {
 220                                 command_ret = CMD_ERROR;
 221                                 success = 0;
 222                                 goto mi_closing;
 223                         }
 224                 } else {
 225                         session_name = opt_session_name;
 226                 }
 227
 228                 /* Find the corresponding lttng_session struct */
 229                 found = 0;
 230                 for (i = 0; i < count; i++) {
 231                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 232                                 found = 1;
 233                                 command_ret = destroy_session(&sessions[i]);
 234                                 if (command_ret) {
 235                                         success = 0;
 236                                 }
 237
 238                         }
 239                 }
 240
 241                 if (!found) {
 242                         ERR("Session name %s not found", session_name);
 243                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 244                         success = 0;
 245                         goto mi_closing;
 246                 }
 247         }
 248
 249 mi_closing:
 250         /* Mi closing */
 251         if (lttng_opt_mi) {
 252                 /* Close sessions and output element element */
 253                 ret = mi_lttng_close_multi_element(writer, 2);
 254                 if (ret) {
 255                         ret = CMD_ERROR;
 256                         goto end;
 257                 }
 258
 259                 /* Success ? */
 260                 ret = mi_lttng_writer_write_element_bool(writer,
 261                                 mi_lttng_element_command_success, success);
 262                 if (ret) {
 263                         ret = CMD_ERROR;
 264                         goto end;
 265                 }
 266
 267                 /* Command element close */
 268                 ret = mi_lttng_writer_command_close(writer);
 269                 if (ret) {
 270                         ret = CMD_ERROR;
 271                         goto end;
 272                 }
 273         }
 274 end:
 275         /* Mi clean-up */
 276         if (writer && mi_lttng_writer_destroy(writer)) {
 277                 /* Preserve original error code */
 278                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 279         }
 280
 281         if (opt_session_name == NULL) {
 282                 free(session_name);
 283         }
 284
 285         /* Overwrite ret if an error occurred during destroy_session/all */
 286         ret = command_ret ? command_ret : ret;
 287
 288         poptFreeContext(pc);
 289         return ret;
 290 }