src/bin/lttng/commands/metadata.cpp

   1 /*
   2  * Copyright (C) 2015 Julien Desfossez <jdesfossez@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "../command.hpp"
  10
  11 #include <common/mi-lttng.hpp>
  12
  13 #include <ctype.h>
  14 #include <popt.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19
  20 static char *opt_session_name;
  21 static char *session_name = nullptr;
  22
  23 static int metadata_regenerate(int argc, const char **argv);
  24
  25 #ifdef LTTNG_EMBED_HELP
  26 static const char help_msg[] =
  27 #include <lttng-metadata.1.h>
  28         ;
  29 #endif
  30
  31 enum {
  32         OPT_HELP = 1,
  33         OPT_LIST_OPTIONS,
  34         OPT_LIST_COMMANDS,
  35 };
  36
  37 static struct mi_writer *writer;
  38
  39 static struct poptOption long_options[] = {
  40         /* { longName, shortName, argInfo, argPtr, value, descrip, argDesc, } */
  41         {
  42                 "help",
  43                 'h',
  44                 POPT_ARG_NONE,
  45                 nullptr,
  46                 OPT_HELP,
  47                 nullptr,
  48                 nullptr,
  49         },
  50         { "session", 's', POPT_ARG_STRING, &opt_session_name, 0, nullptr, nullptr },
  51         {
  52                 "list-options",
  53                 0,
  54                 POPT_ARG_NONE,
  55                 nullptr,
  56                 OPT_LIST_OPTIONS,
  57                 nullptr,
  58                 nullptr,
  59         },
  60         { "list-commands", 0, POPT_ARG_NONE, nullptr, OPT_LIST_COMMANDS, nullptr, nullptr },
  61         {
  62                 nullptr,
  63                 0,
  64                 0,
  65                 nullptr,
  66                 0,
  67                 nullptr,
  68                 nullptr,
  69         },
  70 };
  71
  72 static struct cmd_struct actions[] = {
  73         { "regenerate", metadata_regenerate }, { nullptr, nullptr } /* Array closure */
  74 };
  75
  76 /*
  77  * Count and return the number of arguments in argv.
  78  */
  79 static int count_arguments(const char **argv)
  80 {
  81         int i = 0;
  82
  83         LTTNG_ASSERT(argv);
  84
  85         while (argv[i] != nullptr) {
  86                 i++;
  87         }
  88
  89         return i;
  90 }
  91
  92 static int metadata_regenerate(int argc, const char **argv __attribute__((unused)))
  93 {
  94         int ret;
  95
  96         if (argc > 1) {
  97                 ret = CMD_UNDEFINED;
  98                 goto end;
  99         }
 100         ret = lttng_regenerate_metadata(session_name);
 101         if (ret == 0) {
 102                 MSG("Metadata successfully regenerated for session %s", session_name);
 103         } else {
 104                 ERR("%s", lttng_strerror(ret));
 105         }
 106
 107 end:
 108         return ret;
 109 }
 110
 111 static int handle_command(const char **argv)
 112 {
 113         struct cmd_struct *cmd;
 114         int ret = CMD_SUCCESS, i = 0, argc, command_ret = CMD_SUCCESS;
 115
 116         if (argv == nullptr) {
 117                 ERR("No action specified for metadata command.");
 118                 ret = CMD_ERROR;
 119                 goto end;
 120         }
 121
 122         argc = count_arguments(argv);
 123         LTTNG_ASSERT(argc >= 1);
 124
 125         cmd = &actions[i];
 126         while (cmd->func != nullptr) {
 127                 /* Find command */
 128                 if (strcmp(argv[0], cmd->name) == 0) {
 129                         if (lttng_opt_mi) {
 130                                 /* Action element */
 131                                 ret = mi_lttng_writer_open_element(
 132                                         writer, mi_lttng_element_command_metadata_action);
 133                                 if (ret) {
 134                                         ret = CMD_ERROR;
 135                                         goto end;
 136                                 }
 137
 138                                 /* Name of the action */
 139                                 ret = mi_lttng_writer_write_element_string(
 140                                         writer, config_element_name, argv[0]);
 141                                 if (ret) {
 142                                         ret = CMD_ERROR;
 143                                         goto end;
 144                                 }
 145                         }
 146                         command_ret = cmd->func(argc, argv);
 147                         if (lttng_opt_mi) {
 148                                 /* Close output and action element */
 149                                 ret = mi_lttng_writer_close_element(writer);
 150                                 if (ret) {
 151                                         ret = CMD_ERROR;
 152                                         goto end;
 153                                 }
 154                         }
 155                         goto end;
 156                 }
 157
 158                 cmd = &actions[i++];
 159         }
 160
 161         ret = CMD_UNDEFINED;
 162
 163 end:
 164         /* Overwrite ret if an error occurred in cmd->func() */
 165         ret = command_ret ? command_ret : ret;
 166         return ret;
 167 }
 168
 169 /*
 170  * Metadata command handling.
 171  */
 172 int cmd_metadata(int argc, const char **argv)
 173 {
 174         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 175         static poptContext pc;
 176
 177         if (argc < 1) {
 178                 SHOW_HELP();
 179                 ret = CMD_ERROR;
 180                 goto end;
 181         }
 182
 183         pc = poptGetContext(nullptr, argc, argv, long_options, 0);
 184         poptReadDefaultConfig(pc, 0);
 185
 186         if (lttng_opt_mi) {
 187                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 188                 if (!writer) {
 189                         ret = -LTTNG_ERR_NOMEM;
 190                         goto end;
 191                 }
 192                 /* Open command element */
 193                 ret = mi_lttng_writer_command_open(writer, mi_lttng_element_command_metadata);
 194                 if (ret) {
 195                         ret = CMD_ERROR;
 196                         goto end;
 197                 }
 198
 199                 /* Open output element */
 200                 ret = mi_lttng_writer_open_element(writer, mi_lttng_element_command_output);
 201                 if (ret) {
 202                         ret = CMD_ERROR;
 203                         goto end;
 204                 }
 205         }
 206
 207         while ((opt = poptGetNextOpt(pc)) != -1) {
 208                 switch (opt) {
 209                 case OPT_HELP:
 210                         SHOW_HELP();
 211                         goto end;
 212                 case OPT_LIST_OPTIONS:
 213                         list_cmd_options(stdout, long_options);
 214                         goto end;
 215                 case OPT_LIST_COMMANDS:
 216                         list_commands(actions, stdout);
 217                         goto end;
 218                 default:
 219                         SHOW_HELP();
 220                         ret = CMD_UNDEFINED;
 221                         goto end;
 222                 }
 223         }
 224
 225         if (!opt_session_name) {
 226                 session_name = get_session_name();
 227                 if (session_name == nullptr) {
 228                         ret = CMD_ERROR;
 229                         goto end;
 230                 }
 231         } else {
 232                 session_name = opt_session_name;
 233         }
 234
 235         command_ret = handle_command(poptGetArgs(pc));
 236         if (command_ret) {
 237                 success = 0;
 238         }
 239
 240         if (lttng_opt_mi) {
 241                 /* Close output element */
 242                 ret = mi_lttng_writer_close_element(writer);
 243                 if (ret) {
 244                         ret = CMD_ERROR;
 245                         goto end;
 246                 }
 247
 248                 /* Success ? */
 249                 ret = mi_lttng_writer_write_element_bool(
 250                         writer, mi_lttng_element_command_success, success);
 251                 if (ret) {
 252                         ret = CMD_ERROR;
 253                         goto end;
 254                 }
 255
 256                 /* Command element close */
 257                 ret = mi_lttng_writer_command_close(writer);
 258                 if (ret) {
 259                         ret = CMD_ERROR;
 260                         goto end;
 261                 }
 262         }
 263
 264 end:
 265         /* Mi clean-up */
 266         if (writer && mi_lttng_writer_destroy(writer)) {
 267                 /* Preserve original error code */
 268                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 269         }
 270
 271         if (!opt_session_name) {
 272                 free(session_name);
 273         }
 274
 275         /* Overwrite ret if an error occurred during handle_command() */
 276         ret = command_ret ? command_ret : ret;
 277
 278         poptFreeContext(pc);
 279         return ret;
 280 }