src/bin/lttng/commands/clear.c

   1 /*
   2  * Copyright (C) 2019 Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include <popt.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/stat.h>
  14 #include <sys/types.h>
  15 #include <unistd.h>
  16 #include <stdbool.h>
  17 #include <lttng/clear.h>
  18 #include <lttng/clear-handle.h>
  19
  20 #include "../command.h"
  21
  22 #include <common/mi-lttng.h>
  23 #include <common/sessiond-comm/sessiond-comm.h>
  24 #include <common/utils.h>
  25
  26 static int opt_clear_all;
  27
  28 #ifdef LTTNG_EMBED_HELP
  29 static const char help_msg[] =
  30 #include <lttng-clear.1.h>
  31 ;
  32 #endif
  33
  34 /* Mi writer */
  35 static struct mi_writer *writer;
  36
  37 enum {
  38         OPT_HELP = 1,
  39         OPT_LIST_OPTIONS,
  40 };
  41
  42 static struct poptOption long_options[] = {
  43         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  44         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  45         {"all",       'a', POPT_ARG_VAL, &opt_clear_all, 1, 0, 0},
  46         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  47         {0, 0, 0, 0, 0, 0, 0}
  48 };
  49
  50 /*
  51  * clear session
  52  */
  53 static int clear_session(struct lttng_session *session)
  54 {
  55         enum lttng_clear_handle_status status =
  56                         LTTNG_CLEAR_HANDLE_STATUS_OK;
  57         struct lttng_clear_handle *handle = NULL;
  58         enum lttng_error_code ret_code;
  59         bool printed_wait_msg = false;
  60         char *session_name = NULL;
  61         int ret;
  62
  63         ret = lttng_clear_session(session->name, &handle);
  64         if (ret < 0) {
  65                 ERR("%s", lttng_strerror(ret));
  66                 goto error;
  67         }
  68
  69         do {
  70                 status = lttng_clear_handle_wait_for_completion(handle,
  71                                 DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US / USEC_PER_MSEC);
  72                 switch (status) {
  73                 case LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT:
  74                         if (!printed_wait_msg) {
  75                                 _MSG("Waiting for clear of session \"%s\"",
  76                                                 session->name);
  77                                 printed_wait_msg = true;
  78                         }
  79                         _MSG(".");
  80                         fflush(stdout);
  81                         break;
  82                 case LTTNG_CLEAR_HANDLE_STATUS_COMPLETED:
  83                         break;
  84                 default:
  85                         ERR("Failed to wait for the completion of clear for session \"%s\"",
  86                                         session->name);
  87                         ret = -1;
  88                         goto error;
  89                 }
  90         } while (status == LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT);
  91
  92         status = lttng_clear_handle_get_result(handle, &ret_code);
  93         if (status != LTTNG_CLEAR_HANDLE_STATUS_OK) {
  94                 ERR("Failed to get the result of session clear");
  95                 ret = -1;
  96                 goto error;
  97         }
  98         if (ret_code != LTTNG_OK) {
  99                 ret = -ret_code;
 100                 goto error;
 101         }
 102
 103         MSG("%sSession \"%s\" cleared", printed_wait_msg ? "\n" : "",
 104                         session->name);
 105         printed_wait_msg = false;
 106
 107         if (lttng_opt_mi) {
 108                 ret = mi_lttng_session(writer, session, 0);
 109                 if (ret) {
 110                         ret = CMD_ERROR;
 111                         goto error;
 112                 }
 113         }
 114
 115         ret = CMD_SUCCESS;
 116 error:
 117         if (printed_wait_msg) {
 118                 MSG("");
 119         }
 120         lttng_clear_handle_destroy(handle);
 121         free(session_name);
 122         return ret;
 123 }
 124
 125 /*
 126  * clear all sessions
 127  *
 128  * Call clear_session for each registered sessions
 129  */
 130 static int clear_all_sessions(struct lttng_session *sessions, int count)
 131 {
 132         int i, ret = CMD_SUCCESS;
 133
 134         if (count == 0) {
 135                 MSG("No session found, nothing to do.");
 136         } else if (count < 0) {
 137                 ERR("%s", lttng_strerror(ret));
 138                 goto error;
 139         }
 140
 141         for (i = 0; i < count; i++) {
 142                 ret = clear_session(&sessions[i]);
 143                 if (ret < 0) {
 144                         goto error;
 145                 }
 146         }
 147 error:
 148         return ret;
 149 }
 150
 151 /*
 152  * The 'clear <options>' first level command
 153  */
 154 int cmd_clear(int argc, const char **argv)
 155 {
 156         int opt;
 157         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 158         static poptContext pc;
 159         char *session_name = NULL;
 160         const char *leftover = NULL;
 161         bool free_session_name = false;
 162         struct lttng_session *sessions = NULL;
 163         int count;
 164         int found;
 165
 166         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 167         poptReadDefaultConfig(pc, 0);
 168
 169         while ((opt = poptGetNextOpt(pc)) != -1) {
 170                 switch (opt) {
 171                 case OPT_HELP:
 172                         SHOW_HELP();
 173                         break;
 174                 case OPT_LIST_OPTIONS:
 175                         list_cmd_options(stdout, long_options);
 176                         break;
 177                 default:
 178                         ret = CMD_UNDEFINED;
 179                         break;
 180                 }
 181                 goto end;
 182         }
 183
 184         /* Mi preparation */
 185         if (lttng_opt_mi) {
 186                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 187                 if (!writer) {
 188                         ret = -LTTNG_ERR_NOMEM;
 189                         goto end;
 190                 }
 191
 192                 /* Open command element */
 193                 ret = mi_lttng_writer_command_open(writer,
 194                                 mi_lttng_element_command_clear);
 195                 if (ret) {
 196                         ret = CMD_ERROR;
 197                         goto end;
 198                 }
 199
 200                 /* Open output element */
 201                 ret = mi_lttng_writer_open_element(writer,
 202                                 mi_lttng_element_command_output);
 203                 if (ret) {
 204                         ret = CMD_ERROR;
 205                         goto end;
 206                 }
 207
 208                 /* For validation and semantic purpose we open a sessions element */
 209                 ret = mi_lttng_sessions_open(writer);
 210                 if (ret) {
 211                         ret = CMD_ERROR;
 212                         goto end;
 213                 }
 214         }
 215
 216         if (!opt_clear_all) {
 217                 session_name = (char *) poptGetArg(pc);
 218                 if (!session_name) {
 219                         /* No session name specified, lookup default */
 220                         session_name = get_session_name();
 221                         if (session_name == NULL) {
 222                                 command_ret = CMD_ERROR;
 223                                 success = 0;
 224                                 goto mi_closing;
 225                         }
 226                         free_session_name = true;
 227                 }
 228         } else {
 229                 session_name = NULL;
 230         }
 231
 232         leftover = poptGetArg(pc);
 233         if (leftover) {
 234                 ERR("Unknown argument: %s", leftover);
 235                 ret = CMD_ERROR;
 236                 success = 0;
 237                 goto mi_closing;
 238         }
 239
 240         /* Recuperate all sessions for further operation */
 241         count = lttng_list_sessions(&sessions);
 242         if (count < 0) {
 243                 ERR("%s", lttng_strerror(count));
 244                 command_ret = CMD_ERROR;
 245                 success = 0;
 246                 goto mi_closing;
 247         }
 248
 249         /* Ignore session name in case all sessions are to be cleaned */
 250         if (opt_clear_all) {
 251                 command_ret = clear_all_sessions(sessions, count);
 252                 if (command_ret) {
 253                         ERR("%s", lttng_strerror(command_ret));
 254                         success = 0;
 255                 }
 256         } else {
 257                 /* Find the corresponding lttng_session struct */
 258                 found = 0;
 259                 for (i = 0; i < count; i++) {
 260                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 261                                 found = 1;
 262                                 command_ret = clear_session(&sessions[i]);
 263                                 if (command_ret) {
 264                                         ERR("%s", lttng_strerror(command_ret));
 265                                         success = 0;
 266                                 }
 267                         }
 268                 }
 269
 270                 if (!found) {
 271                         ERR("Session name %s not found", session_name);
 272                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 273                         success = 0;
 274                         goto mi_closing;
 275                 }
 276         }
 277
 278 mi_closing:
 279         /* Mi closing */
 280         if (lttng_opt_mi) {
 281                 /* Close sessions and output element element */
 282                 ret = mi_lttng_close_multi_element(writer, 2);
 283                 if (ret) {
 284                         ret = CMD_ERROR;
 285                         goto end;
 286                 }
 287
 288                 /* Success ? */
 289                 ret = mi_lttng_writer_write_element_bool(writer,
 290                                 mi_lttng_element_command_success, success);
 291                 if (ret) {
 292                         ret = CMD_ERROR;
 293                         goto end;
 294                 }
 295
 296                 /* Command element close */
 297                 ret = mi_lttng_writer_command_close(writer);
 298                 if (ret) {
 299                         ret = CMD_ERROR;
 300                         goto end;
 301                 }
 302         }
 303 end:
 304         /* Mi clean-up */
 305         if (writer && mi_lttng_writer_destroy(writer)) {
 306                 /* Preserve original error code */
 307                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 308         }
 309
 310         free(sessions);
 311         if (free_session_name) {
 312                 free(session_name);
 313         }
 314
 315         /* Overwrite ret if an error occurred during clear_session/all */
 316         ret = command_ret ? command_ret : ret;
 317
 318         poptFreeContext(pc);
 319         return ret;
 320 }