src/bin/lttng/commands/clear.cpp

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