src/bin/lttng/commands/clear.c

   1 /*
   2  * Copyright (C) 2019 - Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com>
   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 #include <stdbool.h>
  27 #include <lttng/clear.h>
  28 #include <lttng/clear-handle.h>
  29
  30 #include "../command.h"
  31
  32 #include <common/mi-lttng.h>
  33 #include <common/sessiond-comm/sessiond-comm.h>
  34 #include <common/utils.h>
  35
  36 static int opt_clear_all;
  37
  38 #ifdef LTTNG_EMBED_HELP
  39 static const char help_msg[] =
  40 #include <lttng-clear.1.h>
  41 ;
  42 #endif
  43
  44 /* Mi writer */
  45 static struct mi_writer *writer;
  46
  47 enum {
  48         OPT_HELP = 1,
  49         OPT_LIST_OPTIONS,
  50 };
  51
  52 static struct poptOption long_options[] = {
  53         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  54         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  55         {"all",       'a', POPT_ARG_VAL, &opt_clear_all, 1, 0, 0},
  56         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  57         {0, 0, 0, 0, 0, 0, 0}
  58 };
  59
  60 /*
  61  * clear session
  62  */
  63 static int clear_session(struct lttng_session *session)
  64 {
  65         enum lttng_clear_handle_status status =
  66                         LTTNG_CLEAR_HANDLE_STATUS_OK;
  67         struct lttng_clear_handle *handle = NULL;
  68         enum lttng_error_code ret_code;
  69         bool printed_wait_msg = false;
  70         char *session_name = NULL;
  71         int ret;
  72
  73         ret = lttng_clear_session(session->name, &handle);
  74         if (ret < 0) {
  75                 ERR("%s", lttng_strerror(ret));
  76                 goto error;
  77         }
  78
  79         do {
  80                 status = lttng_clear_handle_wait_for_completion(handle,
  81                                 DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US / USEC_PER_MSEC);
  82                 switch (status) {
  83                 case LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT:
  84                         if (!printed_wait_msg) {
  85                                 _MSG("Waiting for clear of session \"%s\"",
  86                                                 session->name);
  87                                 printed_wait_msg = true;
  88                         }
  89                         _MSG(".");
  90                         fflush(stdout);
  91                         break;
  92                 case LTTNG_CLEAR_HANDLE_STATUS_COMPLETED:
  93                         break;
  94                 default:
  95                         ERR("Failed to wait for the completion of clear for session \"%s\"",
  96                                         session->name);
  97                         ret = -1;
  98                         goto error;
  99                 }
 100         } while (status == LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT);
 101
 102         status = lttng_clear_handle_get_result(handle, &ret_code);
 103         if (status != LTTNG_CLEAR_HANDLE_STATUS_OK) {
 104                 ERR("Failed to get the result of session clear");
 105                 ret = -1;
 106                 goto error;
 107         }
 108         if (ret_code != LTTNG_OK) {
 109                 ret = -ret_code;
 110                 goto error;
 111         }
 112
 113         MSG("%sSession \"%s\" cleared", printed_wait_msg ? "\n" : "",
 114                         session->name);
 115         printed_wait_msg = false;
 116
 117         if (lttng_opt_mi) {
 118                 ret = mi_lttng_session(writer, session, 0);
 119                 if (ret) {
 120                         ret = CMD_ERROR;
 121                         goto error;
 122                 }
 123         }
 124
 125         ret = CMD_SUCCESS;
 126 error:
 127         if (printed_wait_msg) {
 128                 MSG("");
 129         }
 130         lttng_clear_handle_destroy(handle);
 131         free(session_name);
 132         return ret;
 133 }
 134
 135 /*
 136  * clear all sessions
 137  *
 138  * Call clear_session for each registered sessions
 139  */
 140 static int clear_all_sessions(struct lttng_session *sessions, int count)
 141 {
 142         int i, ret = CMD_SUCCESS;
 143
 144         if (count == 0) {
 145                 MSG("No session found, nothing to do.");
 146         } else if (count < 0) {
 147                 ERR("%s", lttng_strerror(ret));
 148                 goto error;
 149         }
 150
 151         for (i = 0; i < count; i++) {
 152                 ret = clear_session(&sessions[i]);
 153                 if (ret < 0) {
 154                         goto error;
 155                 }
 156         }
 157 error:
 158         return ret;
 159 }
 160
 161 /*
 162  * The 'clear <options>' first level command
 163  */
 164 int cmd_clear(int argc, const char **argv)
 165 {
 166         int opt;
 167         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 168         static poptContext pc;
 169         char *session_name = NULL;
 170         const char *leftover = NULL;
 171
 172         struct lttng_session *sessions = NULL;
 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                         SHOW_HELP();
 183                         break;
 184                 case OPT_LIST_OPTIONS:
 185                         list_cmd_options(stdout, long_options);
 186                         break;
 187                 default:
 188                         ret = CMD_UNDEFINED;
 189                         break;
 190                 }
 191                 goto end;
 192         }
 193
 194         /* Mi preparation */
 195         if (lttng_opt_mi) {
 196                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 197                 if (!writer) {
 198                         ret = -LTTNG_ERR_NOMEM;
 199                         goto end;
 200                 }
 201
 202                 /* Open command element */
 203                 ret = mi_lttng_writer_command_open(writer,
 204                                 mi_lttng_element_command_clear);
 205                 if (ret) {
 206                         ret = CMD_ERROR;
 207                         goto end;
 208                 }
 209
 210                 /* Open output element */
 211                 ret = mi_lttng_writer_open_element(writer,
 212                                 mi_lttng_element_command_output);
 213                 if (ret) {
 214                         ret = CMD_ERROR;
 215                         goto end;
 216                 }
 217
 218                 /* For validation and semantic purpose we open a sessions element */
 219                 ret = mi_lttng_sessions_open(writer);
 220                 if (ret) {
 221                         ret = CMD_ERROR;
 222                         goto end;
 223                 }
 224         }
 225
 226         if (!opt_clear_all) {
 227                 /*
 228                  * popt expects us to free this even if it returns a const char *.
 229                  * See https://www.mail-archive.com/popt-devel@rpm5.org/msg00193.html
 230                  * Force cast to char * allowing later freeing if necessary.
 231                  */
 232                 session_name = (char *) poptGetArg(pc);
 233
 234                 if (!session_name) {
 235                         /* No session name specified, lookup default */
 236                         session_name = get_session_name();
 237                         if (session_name == NULL) {
 238                                 command_ret = CMD_ERROR;
 239                                 success = 0;
 240                                 goto mi_closing;
 241                         }
 242                 }
 243         } else {
 244                 session_name = NULL;
 245         }
 246
 247         leftover = poptGetArg(pc);
 248         if (leftover) {
 249                 ERR("Unknown argument: %s", leftover);
 250                 ret = CMD_ERROR;
 251                 success = 0;
 252                 goto mi_closing;
 253         }
 254
 255         /* Recuperate all sessions for further operation */
 256         count = lttng_list_sessions(&sessions);
 257         if (count < 0) {
 258                 ERR("%s", lttng_strerror(count));
 259                 command_ret = CMD_ERROR;
 260                 success = 0;
 261                 goto mi_closing;
 262         }
 263
 264         /* Ignore session name in case all sessions are to be cleaned */
 265         if (opt_clear_all) {
 266                 command_ret = clear_all_sessions(sessions, count);
 267                 if (command_ret) {
 268                         ERR("%s", lttng_strerror(command_ret));
 269                         success = 0;
 270                 }
 271         } else {
 272                 /* Find the corresponding lttng_session struct */
 273                 found = 0;
 274                 for (i = 0; i < count; i++) {
 275                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 276                                 found = 1;
 277                                 command_ret = clear_session(&sessions[i]);
 278                                 if (command_ret) {
 279                                         ERR("%s", lttng_strerror(command_ret));
 280                                         success = 0;
 281                                 }
 282                         }
 283                 }
 284
 285                 if (!found) {
 286                         ERR("Session name %s not found", session_name);
 287                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 288                         success = 0;
 289                         goto mi_closing;
 290                 }
 291         }
 292
 293 mi_closing:
 294         /* Mi closing */
 295         if (lttng_opt_mi) {
 296                 /* Close sessions and output element element */
 297                 ret = mi_lttng_close_multi_element(writer, 2);
 298                 if (ret) {
 299                         ret = CMD_ERROR;
 300                         goto end;
 301                 }
 302
 303                 /* Success ? */
 304                 ret = mi_lttng_writer_write_element_bool(writer,
 305                                 mi_lttng_element_command_success, success);
 306                 if (ret) {
 307                         ret = CMD_ERROR;
 308                         goto end;
 309                 }
 310
 311                 /* Command element close */
 312                 ret = mi_lttng_writer_command_close(writer);
 313                 if (ret) {
 314                         ret = CMD_ERROR;
 315                         goto end;
 316                 }
 317         }
 318 end:
 319         /* Mi clean-up */
 320         if (writer && mi_lttng_writer_destroy(writer)) {
 321                 /* Preserve original error code */
 322                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 323         }
 324
 325         free(sessions);
 326         free(session_name);
 327
 328         /* Overwrite ret if an error occurred during clear_session/all */
 329         ret = command_ret ? command_ret : ret;
 330
 331         poptFreeContext(pc);
 332         return ret;
 333 }