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